90 results on '"Guo HC"'
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2. Effects of appropriate low-temperature treatment on the yield and quality of pigmented potato (Solanum tuberosum L.) tubers.
- Author
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Chen BC, Wu XJ, Guo HC, and Xiao JP
- Subjects
- Temperature, Anthocyanins metabolism, Cold Temperature, Photosynthesis, Plant Tubers genetics, Solanum tuberosum metabolism
- Abstract
Temperature is one of the important environmental factors affecting plant growth, yield and quality. Moreover, appropriately low temperature is also beneficial for tuber coloration. The red potato variety Jianchuanhong, whose tuber color is susceptible to temperature, and the purple potato variety Huaxinyangyu, whose tuber color is stable, were used as experimental materials and subjected to 20 °C (control check), 15 °C and 10 °C treatments during the whole growth period. The effects of temperature treatment on the phenotype, the expression levels of structural genes related to anthocyanins and the correlations of each indicator were analyzed. The results showed that treatment at 10 °C significantly inhibited the potato plant height, and the chlorophyll content and photosynthetic parameters in the leaves were reduced, and the enzyme activities of SOD and POD were significantly increased, all indicating that the leaves were damaged. Treatment at 10 °C also affected the tuberization of Huaxinyangyu and reduced the tuberization and coloring of Jianchuanhong, while treatment at 15 °C significantly increased the stem diameter, root-to-shoot ratio, yield and content of secondary metabolites, especially anthocyanins. Similarly, the expression of structural genes were enhanced in two pigmented potatoes under low-temperature treatment conditions. In short, proper low temperature can not only increase yield but also enhance secondary metabolites production. Previous studies have not focused on the effects of appropriate low-temperature treatment during the whole growth period of potato on the changes in metabolites during tuber growth and development, these results can provide a theoretical basis and technical guidance for the selection of pigmented potatoes with better nutritional quality planting environment and the formulation of cultivation measures., (© 2024. The Author(s).)
- Published
- 2024
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3. Structure-guided discovery of aminopeptidase ERAP1 variants capable of processing antigens with novel PC anchor specificities.
- Author
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Pande S and Guo HC
- Subjects
- Humans, Peptides metabolism, Minor Histocompatibility Antigens genetics, Minor Histocompatibility Antigens metabolism, Antigen Presentation, Aminopeptidases genetics, Aminopeptidases chemistry, Aminopeptidases metabolism, Antigens metabolism
- Abstract
Endoplasmic reticulum aminopeptidase 1 (ERAP1) belongs to the oxytocinase subfamily of M1 aminopeptidases (M1APs), which are a diverse family of metalloenzymes involved in a wide range of functions and have been implicated in various chronic and infectious diseases of humans. ERAP1 trims antigenic precursors into correct sizes (8-10 residues long) for Major Histocompatibility Complex (MHC) presentation, by a unique molecular ruler mechanism in which it makes concurrent bindings to substrate N- and C-termini. We have previously determined four crystal structures of ERAP1 C-terminal regulatory domain (termed ERAP1_C domain) in complex with peptide carboxyl (PC)-ends that carry various anchor residues, and identified a specificity subsite for recognizing the PC anchor side chain, denoted as the SC subsite to follow the conventional notations: S1 site for P1, S2 site for P2, and so forth. In this study, we report studies on structure-guided mutational and hydrolysis kinetics, and peptide trimming assays to further examine the functional roles of this SC subsite. Most strikingly, a point mutation V737R results in a change of substrate preference from a hydrophobic to a negatively charged PC anchor residue; the latter is presumed to be a poor substrate for WT ERAP1. These studies validate the crystallographic observations that this SC subsite is directly involved in binding and recognition of the substrate PC anchor and presents a potential target to modulate MHC-restricted immunopeptidomes., (© 2023 The Authors. Immunology published by John Wiley & Sons Ltd.)
- Published
- 2024
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4. Green Vertical-Cavity Surface-Emitting Lasers Based on InGaN Quantum Dots and Short Cavity.
- Author
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Yang T, Chen YH, Wang YC, Ou W, Ying LY, Mei Y, Tian AQ, Liu JP, Guo HC, and Zhang BP
- Abstract
Room temperature low threshold lasing of green GaN-based vertical cavity surface emitting laser (VCSEL) was demonstrated under continuous wave (CW) operation. By using self-formed InGaN quantum dots (QDs) as the active region, the VCSEL emitting at 524.0 nm has a threshold current density of 51.97 A cm
-2 , the lowest ever reported. The QD epitaxial wafer featured with a high IQE of 69.94% and the δ-function-like density of states plays an important role in achieving low threshold current. Besides, a short cavity of the device (~ 4.0 λ) is vital to enhance the spontaneous emission coupling factor to 0.094, increase the gain coefficient factor, and decrease the optical loss. To improve heat dissipation, AlN layer was used as the current confinement layer and electroplated copper plate was used to replace metal bonding. The results provide important guidance to achieving high performance GaN-based VCSELs., (© 2023. Shanghai Jiao Tong University.)- Published
- 2023
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5. In situ detection and mass spectrometry imaging of protein-related metabolites in Bombyx batryticatus before and after frying with wheat bran.
- Author
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Liu P, Wang JM, Guo HC, Zhao MW, Song YX, Guo H, Duan XH, Yan YP, and Zheng YG
- Abstract
Bombyx batryticatus is derived from the dried larva of Bombyx mori Linnaeus infected by Beauveria bassiana (Bals.) Vuillant. Raw Bombyx batryticatus should be stir-fried before oral administration due to its irritation to the gastrointestinal tract. Nevertheless, it is still an arduous task to uncover the intrinsic mechanism of Bombyx batryticatus processing. In this study, we collected two types of Bombyx batryticatus, one being stir-fried and the other serving as a control. Then, an informative approach, which integrated matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) with chemometrics analysis, was established to screen processing-associated markers and reveal in situ spatial distribution patterns of protein-related metabolites. After optimization of experimental conditions, 21 ions were initially detected from Bombyx batryticatus, including amino acids and peptides. In addition, 15 differential markers were screened by orthogonal projection to potential structure discriminant analysis (OPLS-DA), which were localized and visualized in the transverse section of Bombyx batryticatus by MSI. Eventually, it can be demonstrated that the stir-frying process reduces toxicity while potentially boosting specific biological activities of Bombyx batryticatus. In summary, the established strategy could not only clarify the chemical transformation of protein-related metabolites from Bombyx batryticatus before and after frying with wheat bran, but also reveal the significance of Chinese medicine processing technology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Wang, Guo, Zhao, Song, Guo, Duan, Yan and Zheng.)
- Published
- 2023
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6. Proactive personality and critical thinking in Chinese medical students: The moderating effects of psychological safety and academic self-efficacy.
- Author
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Wang YP, Zhao CX, Zhang SE, Li QL, Tian J, Yang ML, Guo HC, Yuan J, Zhou SY, Wang M, and Cao DP
- Abstract
Objectives: This study aimed to identify the relationship among proactive personality, psychological safety, academic self-efficacy and critical thinking, and to further explore whether psychological safety and academic self-efficacy could be a moderator in the association between proactive personality and critical thinking among Chinese medical students., Materials and Methods: The cross-sectional study was carried out from October to December 2020 in China. Totally, 5,920 valid responses were collected at four Chinese medical universities. Critical thinking, proactive personality, psychological safety, academic self-efficacy and demographic factors were assessed through questionnaires. Hierarchical multiple regression was used to identify interrelationship clusters among variables. Simple slope analyses were performed to explore the moderating effects of psychological safety and academic self-efficacy., Results: The mean score of critical thinking among medical students was 3.85 ± 0.61. Proactive personality, psychological safety, and academic self-efficacy were shown to be important factors for critical thinking. Psychological safety and academic self-efficacy moderated the association between proactive personality and critical thinking. A simple slope analysis showed that high psychological safety and academic self-efficacy weakened the impact of proactive personality on critical thinking., Conclusion: Most medical students surveyed in China might have relatively high levels of critical thinking. Psychological safety and academic self-efficacy moderated the association between proactive personality and critical thinking. More interventions related to psychological safety and academic self-efficacy will be helpful to improve critical thinking among Chinese medical students., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Zhao, Zhang, Li, Tian, Yang, Guo, Yuan, Zhou, Wang and Cao.)
- Published
- 2022
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7. MicroRNA-27b-3p down-regulates FGF1 and aggravates pathological cardiac remodelling.
- Author
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Li G, Shao Y, Guo HC, Zhi Y, Qiao B, Ma K, Du J, Lai YQ, and Li Y
- Subjects
- Angiotensin II metabolism, Angiotensin II pharmacology, Animals, Fibrosis, Mice, Mice, Knockout, Myocytes, Cardiac metabolism, Cardiomegaly genetics, Cardiomegaly metabolism, Fibroblast Growth Factor 1 genetics, Fibroblast Growth Factor 1 metabolism, MicroRNAs genetics, MicroRNAs metabolism, Ventricular Remodeling genetics
- Abstract
Aims: The heart undergoes pathological remodelling under increased stress and neuronal imbalance. MicroRNAs (miRNAs) are involved in post-transcriptional regulation of genes in cardiac physiology and pathology. However, the mechanisms underlying miRNA-mediated regulation of pathological cardiac remodelling remain to be studied. This study aimed to explore the function of endogenous microRNA-27b-3p (miR-27b-3p) in pathological cardiac remodelling., Methods and Results: miR-27b-3p expression was elevated in the heart of a transverse aortic constriction (TAC)-induced cardiac hypertrophy mouse model. miR-27b-knockout mice showed significantly attenuated cardiac hypertrophy, fibrosis, and inflammation induced by two independent pathological cardiac hypertrophy models, TAC and Angiotensin II (Ang II) perfusion. Transcriptome sequencing analysis revealed that miR-27b deletion significantly down-regulated TAC-induced cardiac hypertrophy, fibrosis, and inflammatory genes. We identified fibroblast growth factor 1 (FGF1) as a miR-27b-3p target gene in the heart which was up-regulated in miR-27b-null mice. We found that both recombinant FGF1 (rFGF1) and inhibition of miR-27b-3p enhanced mitochondrial oxidative phosphorylation (OXPHOS) and inhibited cardiomyocyte hypertrophy. Importantly, rFGF1 administration inhibited cardiac hypertrophy and fibrosis in TAC- or Ang II-induced models and enhanced OXPHOS by activating PGC1α/β., Conclusions: Our study demonstrated that miR-27b-3p induces pathological cardiac remodelling and suggests that inhibition of endogenous miR-27b-3p or administration of FGF1 might have the potential to suppress cardiac remodelling in a clinical setting., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2022
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8. Mobile Phone Addiction and Academic Procrastination Negatively Impact Academic Achievement Among Chinese Medical Students.
- Author
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Tian J, Zhao JY, Xu JM, Li QL, Sun T, Zhao CX, Gao R, Zhu LY, Guo HC, Yang LB, Cao DP, and Zhang SE
- Abstract
The problem of mobile phone addiction and academic procrastination among medical students has been widely acknowledged. This study aimed to explore the influence of demographic factors on mobile phone addiction, academic procrastination, and academic achievement among medical students. Further, it investigated the association between mobile phone addiction, academic procrastination, and academic achievement. This cross-sectional study was conducted between May and June 2019. A total of 3 511 medical students participated in an online questionnaire survey (effective response rate = 81.7%). Demographic factors, the Scale of Academic Achievement, the short scale of the Mobile Phone Problem Use (MPPUS-10), and the Academic Procrastination Scale-Short (APS-S) were used. Hierarchical multiple regression analysis revealed that the average scores for academic procrastination, mobile phone addiction, and academic achievement were 2.66 ± 0.91, 5.13 ± 1.53, and 4.51 ± 0.71, respectively. Moreover, there were significant differences in gender, grade, leadership experience, and family monthly income across mobile phone addiction, academic procrastination, and academic achievement. Mobile phone addiction was negatively associated with learning dedication, learning performance, and relationship facilitation. Academic procrastination was negatively associated with learning dedication, learning performance, relationship facilitation, and objective achievement. Mobile phone addiction and academic procrastination was revealed as prevalent among Chinese medical students, and negatively influences their academic achievement. It is critical to establish a more efficient learning environment for Chinese medical students to minimize the negative impact of mobile phone addiction and academic procrastination., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tian, Zhao, Xu, Li, Sun, Zhao, Gao, Zhu, Guo, Yang, Cao and Zhang.)
- Published
- 2021
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9. The Association Among Achievement Goal Orientations, Academic Performance, and Academic Well-Being Among Chinese Medical Students: A Cross-Sectional Study.
- Author
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Li QL, Zhao JY, Tian J, Sun T, Zhao CX, Guo HC, Zhu LY, Gao R, Yang LB, Cao DP, and Zhang SE
- Abstract
Learning motivation is a significant factor that ensures quality in medical education, and might affect the academic performance and well-being of medical students. This study aimed to explore the status of achievement goal orientations among medical students in China and to further identify the association among academic performance, academic well-being, and achievement goal orientations. Data were collected through a cross-sectional, anonymous survey conducted with 3,511 respondents (effective response rate = 81.7%), from four medical universities in China, and demographic factors, achievement goal orientations, academic performance, and academic well-being were assessed. The average score of achievement goal orientations of Chinese medical students suggested a difference in demographic factors, including sex, year of study, experience of leadership cadre, and family income. Both mastery and performance-avoidance goals were associated with academic performance, subjective academic stress, subjective learning adaptability, subjective sleep quality, and subjective well-being. Performance-approach goals were related to academic performance, subjective academic stress, and subjective learning adaptability. The achievement goal orientations of the medical students in this study were at a middle level. The findings emphasize the importance of mastery goals for promoting the academic performance and well-being of medical students. More care and attention toward achievement goal orientations can be beneficial for the improvement of the academic performance and well-being among medical students., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Li, Zhao, Tian, Sun, Zhao, Guo, Zhu, Gao, Yang, Cao and Zhang.)
- Published
- 2021
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10. Enhanced recombinant expression and purification of human IRAP for biochemical and crystallography studies.
- Author
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Sui L and Guo HC
- Abstract
Insulin-regulated aminopeptidase (IRAP) in humans is a membrane bound enzyme that has multiple functions. It was first described as a companion protein of the insulin-responsive glucose transporter, Glut4, in specialized vesicles. The protein has subsequently been shown to be identical to the oxytocinase/aminopeptidase or the angiotensin IV (Ang IV) receptor (AT
4 receptor). Some AT4 ligand peptides, such as Ang IV and LVV-hemorphin-7, have been shown to act as IRAP inhibitors that exert memory-enhancing properties. As such IRAP has been a target for developing cognitive enhancers. To facilitate detailed mechanistic studies of IRAP catalysis and inhibition, and to pave the way for biophysical and structural studies of IRAP in complex with peptide inhibitors, we report here an optimized expression and purification system using High Five insect cells. We also report biochemical characterizations of the purified recombinant IRAP with a standard aminopeptidase substrate and an optimized IRAP peptide inhibitor with a Ki of 98 nM., Competing Interests: None., (© 2021 The Authors.)- Published
- 2021
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11. Integrated transcriptomics explored the cancer-promoting genes CDKN3 in esophageal squamous cell cancer.
- Author
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Wang W, Liao K, Guo HC, Zhou S, Yu R, Liu Y, Pan Y, and Pu J
- Subjects
- Adult, Aged, Aged, 80 and over, Biomarkers, Tumor genetics, Biomarkers, Tumor metabolism, Computational Biology, Cyclin-Dependent Kinase Inhibitor Proteins metabolism, Databases, Genetic, Dual-Specificity Phosphatases metabolism, Esophageal Neoplasms pathology, Esophageal Squamous Cell Carcinoma pathology, Esophagus metabolism, Female, Gene Expression Profiling, Humans, Immunohistochemistry, Lymphatic Metastasis genetics, Male, Middle Aged, Neoplasm Staging, Protein Interaction Maps, RNA, Messenger metabolism, Transcriptome, Cyclin-Dependent Kinase Inhibitor Proteins genetics, Dual-Specificity Phosphatases genetics, Esophageal Neoplasms genetics, Esophageal Neoplasms metabolism, Esophageal Squamous Cell Carcinoma genetics, Esophageal Squamous Cell Carcinoma metabolism, Gene Expression
- Abstract
Background and Objectives: Each individual studies is limited to multi-factors and potentially lead to a significant difference of results among them. The present study aim to explore the critical genes related to the development of Esophageal squamous cell carcinoma (ESCC) by integrated transcriptomics and to investigate the clinical significance by experimental validation., Methods: Datasets of protein-coding genes expression which involved in ESCC were downloaded from Gene Expression Omnibus (GEO) database. The "Robustrankaggreg" package in language was used for data integration, and the different expression genes (DEGs) were identified based the cut-off criteria as follows: adjust p-value < 0.05, |fold change (FC)| ≥ 1.5; The protein expression of seed gene in 184 cases of primary ESCC tissues and 50 tumor adjacent normal tissues (at least 5 cm away from the tumor, and defind as the controls) were detected by immunohistochemistry; The relationship between the expression level of seed genes and clinical parameter were analyze. Enumeration data were represented by frequency or percentage (%) and were tested by x
2 test. The P value of less than 0.05 was considered statistically significant., Results: A total of 244 DEGs were identified by comparing gene expression patterns between ESCC patients and the controls based on integrating dataset of GSE77861, GSE77861, GSE100942, GSE26886, GSE17351, GSE38129, GSE33426, GSE20347 and GSE23400; The Cyclin-dependent kinase inhibitor 3 (CDKN3) were identified the top 1 seed gene of top cluster by use of protein-protein Interaction network and plug-in Molecular Complex Detection; The level of CDKN3 mRNA was significantly increased in ESCC patients compared to controls; The positive expression rate of CDKN3 protein in ESCC tissue samples was 32 and 61.4% in control, respectively. The correlations between the expression level of CDKN3 and lymph node metastasis or clinical staging of ESCC patients are statistically significant., Conclusion: Integrated transcriptomics is an efficient approach to system biology. By this procedure, our study improved the understanding of the transcriptome status of ESCC.- Published
- 2021
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12. Multiple Fractures of Cervical Vertebrae Combined with Arcuate Foramen and Vertebral Artery Occlusion: A Case Report and Literature Review.
- Author
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Wang WH, Liu ZY, Guo HC, and Wang H
- Subjects
- Accidental Falls, Cervical Atlas diagnostic imaging, Cervical Vertebrae diagnostic imaging, Fractures, Multiple diagnostic imaging, Humans, Male, Middle Aged, Radiography, Tomography, X-Ray Computed, Traction methods, Vertebral Artery diagnostic imaging, Cervical Atlas abnormalities, Cervical Atlas injuries, Cervical Vertebrae injuries, Fractures, Multiple therapy, Vertebral Artery injuries
- Abstract
Background: The arcuate foramen is a complete or partial bony bridge over the vertebral artery groove of atlas. The mechanism of the arcuate foramen is not clearly understood. Omission of the arcuate foramen sometimes causes lethal iatrogenic injury during spinal surgery., Case Presentation: We describe a patient who was diagnosed with multiple fractures of the cervical vertebrae, arcuate foramen, and right vertebral artery occlusion based on clinical and radiological exams. After conservative treatment, he resumed a normal and productive life., Conclusions: Arcuate foramen is a common variation that causes symptoms such as dizziness, headache, and migraine. If the patient does not develop severe symptoms, conservative treatment can achieve very good results without the necessity to remove the bone bridge. When serious symptoms occur, surgical treatment to resect the bony ridges can relieve the symptoms dramatically., (© 2020 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)
- Published
- 2021
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13. Inhibition of the I Na/K and the activation of peak I Na contribute to the arrhythmogenic effects of aconitine and mesaconitine in guinea pigs.
- Author
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Wang XC, Jia QZ, Yu YL, Wang HD, Guo HC, Ma XD, Liu CT, Chen XY, Miao QF, Guan BC, Su SW, Wei HM, and Wang C
- Subjects
- Aconitine isolation & purification, Aconitum chemistry, Action Potentials drug effects, Animals, Arrhythmias, Cardiac physiopathology, Cardiotoxicity physiopathology, Electrocardiography, Guinea Pigs, Male, Membrane Potentials drug effects, Myocytes, Cardiac drug effects, Myocytes, Cardiac pathology, Patch-Clamp Techniques, Sodium Channels drug effects, Sodium Channels metabolism, Aconitine analogs & derivatives, Aconitine toxicity, Arrhythmias, Cardiac chemically induced, Cardiotoxicity etiology
- Abstract
Aconitine (ACO), a main active ingredient of Aconitum, is well-known for its cardiotoxicity. However, the mechanisms of toxic action of ACO remain unclear. In the current study, we investigated the cardiac effects of ACO and mesaconitine (MACO), a structurally related analog of ACO identified in Aconitum with undocumented cardiotoxicity in guinea pigs. We showed that intravenous administration of ACO or MACO (25 μg/kg) to guinea pigs caused various types of arrhythmias in electrocardiogram (ECG) recording, including ventricular premature beats (VPB), atrioventricular blockade (AVB), ventricular tachycardia (VT), and ventricular fibrillation (VF). MACO displayed more potent arrhythmogenic effect than ACO. We conducted whole-cell patch-clamp recording in isolated guinea pig ventricular myocytes, and observed that treatment with ACO (0.3, 3 μM) or MACO (0.1, 0.3 μM) depolarized the resting membrane potential (RMP) and reduced the action potential amplitude (APA) and durations (APDs) in a concentration-dependent manner. The ACO- and MACO-induced AP remodeling was largely abolished by an I
Na blocker tetrodotoxin (2 μM) and partly abolished by a specific Na+ /K+ pump (NKP) blocker ouabain (0.1 μM). Furthermore, we observed that treatment with ACO or MACO attenuated NKP current (INa/K ) and increased peak INa by accelerating the sodium channel activation with the EC50 of 8.36 ± 1.89 and 1.33 ± 0.16 μM, respectively. Incubation of ventricular myocytes with ACO or MACO concentration-dependently increased intracellular Na+ and Ca2+ concentrations. In conclusion, the current study demonstrates strong arrhythmogenic effects of ACO and MACO resulted from increasing the peak INa via accelerating sodium channel activation and inhibiting the INa/K . These results may help to improve our understanding of cardiotoxic mechanisms of ACO and MACO, and identify potential novel therapeutic targets for Aconitum poisoning.- Published
- 2021
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14. ptsI gene in the phosphotransfer system is a potential target for developing a live attenuated Salmonella vaccine.
- Author
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Zhi Y, Lin SM, Ahn KB, Ji HJ, Guo HC, Ryu S, Seo HS, and Lim S
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- Animals, Colitis immunology, Disease Models, Animal, Down-Regulation immunology, Immunity, Cellular immunology, Immunity, Humoral immunology, Immunization methods, Male, Mice, Mice, Inbred BALB C, Virulence immunology, Bacterial Proteins genetics, Bacterial Proteins immunology, Phosphotransferases genetics, Phosphotransferases immunology, Salmonella Vaccines immunology, Salmonella typhimurium immunology, Vaccines, Attenuated immunology
- Abstract
Salmonella enterica serovar Typhimurium causes invasive non‑typhoidal Salmonella diseases in animals and humans, resulting in a high mortality rate and huge economic losses globally. As the prevalence of antibiotic‑resistant Salmonella has been increasing, vaccination is thought to be the most effective and economical strategy to manage salmonellosis. The present study aimed to investigate whether dysfunction in the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), which is critical for carbon uptake and survival in macrophages, may be adequate to generate Salmonella‑attenuated vaccine strains. A Salmonella strain (KST0555) was generated by deleting the ptsI gene from the PTS and it was revealed that this auxotrophic mutant was unable to efficiently utilize predominant carbon sources during infection (glucose and glycerol), reduced its invasion and replication capacity in macrophages, and significantly (P=0.0065) lowered its virulence in the setting of a mouse colitis model, along with a substantially decreased intestinal colonization and invasiveness compared with its parent strain. The reverse transcription‑quantitative PCR results demonstrated that the virulence genes in Salmonella pathogenicity island-1 (SPI-1) and -2 (SPI-2) and the motility of KST0555 were all downregulated compared with its parent strain. Finally, it was revealed that when mice were immunized orally with live KST0555, Salmonella‑specific humoral and cellular immune responses were effectively elicited, providing protection against Salmonella infection. Thus, the present promising data provides a strong rationale for the advancement of KST0555 as a live Salmonella vaccine candidate and ptsI as a potential target for developing a live attenuated bacterial vaccine strain.
- Published
- 2020
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15. The T99K variant of glycosylasparaginase shows a new structural mechanism of the genetic disease aspartylglucosaminuria.
- Author
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Pande S and Guo HC
- Subjects
- Aspartylglucosaminuria genetics, Aspartylglucosylaminase chemistry, Glycopeptides metabolism, HeLa Cells, Humans, Hydrolysis, Lysosomes chemistry, Lysosomes metabolism, Mutation, Protein Conformation, Tumor Cells, Cultured, Aspartylglucosaminuria enzymology, Aspartylglucosylaminase genetics, Aspartylglucosylaminase metabolism, Genetic Variation
- Abstract
Aspartylglucosaminuria (AGU) is an inherited disease caused by mutations in a lysosomal amidase called aspartylglucosaminidase (AGA) or glycosylasparaginase (GA). This disorder results in an accumulation of glycoasparagines in the lysosomes of virtually all cell types, with severe clinical symptoms affecting the central nervous system, skeletal abnormalities, and connective tissue lesions. GA is synthesized as a single-chain precursor that requires an intramolecular autoprocessing to form a mature amidase. Previously, we showed that a Canadian AGU mutation disrupts this obligatory intramolecular autoprocessing with the enzyme trapped as an inactive precursor. Here, we report biochemical and structural characterization of a model enzyme corresponding to a new American AGU allele, the T99K variant. Unlike other variants with known 3D structures, this T99K model enzyme still has autoprocessing capacity to generate a mature form. However, its amidase activity to digest glycoasparagines remains low, consistent with its association with AGU. We have determined a 1.5-Å-resolution structure of this new AGU model enzyme and built an enzyme-substrate complex to provide a structural basis to analyze the negative effects of the T99K point mutation on K
M and kcat of the amidase. It appears that a "molecular clamp" capable of fixing local disorders at the dimer interface might be able to rescue the deficiency of this new AGU variant., (© 2019 The Protein Society.)- Published
- 2019
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16. Multi-View Laser Point Cloud Global Registration for a Single Object.
- Author
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Wang S, Sun HY, Guo HC, Du L, and Liu TJ
- Abstract
Global registration is an important step in the three-dimensional reconstruction of multi-view laser point clouds for moving objects, but the severe noise, density variation, and overlap ratio between multi-view laser point clouds present significant challenges to global registration. In this paper, a multi-view laser point cloud global registration method based on low-rank sparse decomposition is proposed. Firstly, the spatial distribution features of point clouds were extracted by spatial rasterization to realize loop-closure detection, and the corresponding weight matrix was established according to the similarities of spatial distribution features. The accuracy of adjacent registration transformation was evaluated, and the robustness of low-rank sparse matrix decomposition was enhanced. Then, the objective function that satisfies the global optimization condition was constructed, which prevented the solution space compression generated by the column-orthogonal hypothesis of the matrix. The objective function was solved by the Augmented Lagrange method, and the iterative termination condition was designed according to the prior conditions of single-object global registration. The simulation analysis shows that the proposed method was robust with a wide range of parameters, and the accuracy of loop-closure detection was over 90%. When the pairwise registration error was below 0.1 rad, the proposed method performed better than the three compared methods, and the global registration accuracy was better than 0.05 rad. Finally, the global registration results of real point cloud experiments further proved the validity and stability of the proposed method., Competing Interests: The authors declare no conflict of interest.
- Published
- 2018
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17. Changes and Diurnal Variation of Visual Quality after Orthokeratology in Myopic Children.
- Author
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Guo HC, Jin WQ, Pan AP, Wang QM, Qu J, and Yu AY
- Abstract
Purpose: To assess the changes and the diurnal variation of visual quality after orthokeratology in myopic children., Methods: Forty-four eyes of 22 subjects with a mean age of 10.55 ± 1.53 years (8 to 14 years) were enrolled in this prospective study. Their spherical equivalent ranged from -1.25 to -4.25 diopters (D) and astigmatism was less than 1.00 D. Parameters including corneal curvature, ocular objective scatter index (OSI), the modulation transfer function (MTF), root mean square of ocular and corneal wavefront aberrations, and contrast sensitivity function (CSF) were measured before and at two time points during the same day after 1 month of orthokeratology., Results: After orthokeratology, uncorrected visual acuity (UCVA) and spherical equivalent were significantly improved from baseline ( P < 0.001), and their diurnal variation was not significant ( P =0.083, 0.568). OSI increased from 0.29 ± 0.15 to 0.65 ± 0.31 ( P < 0.001). MTF decreased significantly ( P < 0.01). Corneal curvature and ocular total aberration decreased ( P < 0.001), while the ocular and corneal higher-order aberration increased significantly ( P < 0.01). The CSF under photopic condition decreased at 3 cpd ( P =0.006) and increased at 18 cpd ( P =0.012). The diurnal variation of CSF at 18 cpd under mesopic and high glare conditions and at 12 cpd under photopic condition was significant ( P =0.002, 0.01, 0.017)., Conclusions: Orthokeratology can effectively improve UCVA and high spatial frequency CSF by decreasing the low-order aberrations. However, MTF and CSF at low spatial frequency decreased because of the increase of intraocular scattering and high-order aberrations. Meanwhile, CSF at high spatial frequency fluctuates significantly at two times during the same day after 1 month orthokeratology.
- Published
- 2018
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18. Biochemical and structural insights into an allelic variant causing the lysosomal storage disorder - aspartylglucosaminuria.
- Author
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Pande S, Bizilj W, and Guo HC
- Subjects
- Alleles, Amino Acid Sequence, Amino Acid Substitution genetics, Aspartylglucosaminuria enzymology, Aspartylglucosylaminase metabolism, Crystallography, X-Ray, Finland, Homeostasis genetics, Humans, Lysosomal Storage Diseases genetics, Models, Molecular, Protein Structure, Secondary, Proteolysis, Aspartylglucosaminuria genetics, Aspartylglucosylaminase chemistry, Aspartylglucosylaminase genetics, Point Mutation
- Abstract
Aspartylglucosaminuria (AGU) is a lysosomal storage disorder caused by defects of the hydrolase glycosylasparaginase (GA). Previously, we showed that a Canadian AGU mutation disrupts an obligatory intramolecular autoprocessing with the enzyme trapped as an inactive precursor. Here, we report biochemical and structural characterizations of a model enzyme corresponding to a Finnish AGU allele, the T234I variant. Unlike the Canadian counterpart, the Finnish variant is capable of a slow autoprocessing to generate detectible hydrolyzation activity of the natural substrate of GA. We have determined a 1.6 Å-resolution structure of the Finnish AGU model and built an enzyme-substrate complex to provide a structural basis for analyzing the negative effects of the point mutation on K
M and kcat of the mature enzyme., Enzyme: Glycosylasparaginase or aspartylglucosaminidase, EC3.5.1.26., (© 2018 Federation of European Biochemical Societies.)- Published
- 2018
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19. Ruthenium-catalyzed decarboxylative C-S cross-coupling of carbonothioate: synthesis of allyl(aryl)sulfide.
- Author
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Zheng RH, Guo HC, Chen TT, Huang Q, Huang GB, and Jiang HJ
- Abstract
A novel ruthenium-catalyzed decarboxylative cross-coupling of carbonothioate is disclosed. This method provides straightforward access to the corresponding allyl(aryl)sulfide derivatives in generally good to excellent yields under mild conditions and features a broad substrate scope, wide group tolerance and in particular, no need to use halocarbon precursors., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
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- 2018
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20. Protective effect of berberine on acute cardiomyopathy associated with doxorubicin treatment.
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Xiong C, Wu YZ, Zhang Y, Wu ZX, Chen XY, Jiang P, Guo HC, Xie KR, Wang KX, and Su SW
- Abstract
Doxorubicin (DOX) is a potent and broad-spectrum anthracycline chemotherapeutic agent, but dose-dependent cardiotoxic side effects limit its clinical application. This toxicity is closely associated with the generation of reactive oxygen species (ROS) radical during DOX metabolism. The present study investigated the effects of Berberine (Ber) on DOX-induced acute cardiac injury in a rat model and analysed its mechanism in cardiomyocytes in vitro . Serum creatine kinase (CK), creatine kinase isoenzyme (CK-MB) and malondialdehyde (MDA) levels were significantly increased in the DOX group compared with the control group. This increase was accompanied by cardiac histopathological injury and a decrease in cardiomyocyte superoxide dismutase (SOD) and catalase (CAT). CK, CK-MB and MDA levels decreased and SOD and CAT levels increased in the Ber-treated group compared to the DOX group. Ber ameliorated the DOX-induced increase in cytosolic calcium concentration ([Ca
2+ ]i ), attenuated mitochondrial Ca2+ overload and restored the DOX-induced loss of mitochondrial membrane potential in vitro . These results demonstrated that Ber exhibited protective effects against DOX-induced heart tissue free radical injury, potentially via the inhibition of intracellular Ca2+ elevation and attenuation of mitochondrial dysfunction.- Published
- 2018
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21. Engineering the porosity and acidity of H-Beta zeolite by dealumination for the production of 2-ethylanthraquinone via 2-(4'-ethylbenzoyl)benzoic acid dehydration.
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Liu JX, He N, Liu CY, Wang GR, Xin Q, and Guo HC
- Abstract
Environmentally-friendly zeolites have been used commercially to replace concentrated sulfuric acid and oleum in the alkylation reactions and dehydration of alcohols. However, moderate activity, associated with access and diffusion limitations, low intramolecular dehydration selectivity, associated with unsatisfactory acidity, and unknown reusability have hampered their industrial implementation in the dehydration of bulky 2-(4'-ethylbenzoyl)benzoic acid (E-BBA) to 2-ethylanthraquinone (2-EAQ). Herein, we have discovered that after being treated with mild HNO
3 , nano-sized H-Beta zeolite showed outstanding catalytic activity, selectivity and reusability, compared with a commercial oleum catalyst. A number of techniques, such as XRD, XPS, XRF,29 Si MAS NMR,27 Al MQ MAS NMR, FTIR, NH3 -TPD, argon physisorption and HR-TEM, have been employed to decouple the interdependence between acidity, porosity and catalytic performance. It was found that mild HNO3 treatment could clean out the extra-framework aluminium deposits and selectively extract the aluminium species on the outer surface of Beta zeolites, which strengthened the acidity of the Brønsted acid sites (Si(OH)Al) inside the H-Beta micropores, thus increasing the possibility of intramolecular dehydration of E-BBA. Moreover, this mild HNO3 treatment also dredged the network of intercrystalline mesopores, alleviating the diffusion constraints. Therefore, through the dual adjustment of acidity and porosity, dealuminated H-Beta zeolite has a promising future in the green synthesis of 2-EAQ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2018
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22. Comparison of Clinical Effects between Percutaneous Transluminal Septal Myocardial Ablation and Modified Morrow Septal Myectomy on Patients with Hypertrophic Cardiomyopathy.
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Guo HC, Li JH, Jiang TY, Ren CW, Dai J, Zhou YJ, and Lai YQ
- Subjects
- Adult, Cardiomyopathy, Hypertrophic diagnostic imaging, Catheter Ablation methods, Echocardiography, Female, Heart Septum diagnostic imaging, Humans, Male, Middle Aged, Treatment Outcome, Cardiac Surgical Procedures methods, Cardiomyopathy, Hypertrophic surgery, Heart Septum surgery
- Abstract
Background: Percutaneous transluminal septal myocardial ablation (PTSMA) and modified Morrow septal myectomy (MMSM) are two invasive strategies used to relieve obstruction in patients with hypertrophic cardiomyopathy (HCM). This study aimed to determine the clinical outcome of these two strategies., Methods: From January 2011 to January 2015, 226 patients with HCM were treated, 68 by PTSMA and 158 by MMSM. Both ultrasonic cardiograms and heart functional class were recorded before, after operations and in the follow-up. Categorical variables were compared using Chi-square or Fisher's exact tests. Quantitative variables were compared using the paired samples t-test., Results: Interventricular septal thickness was significantly reduced in both groups (21.27 ± 4.43 mm vs. 18.72 ± 4.13 mm for PTSMA, t = 3.469, P < 0.001, and 21.83 ± 5.03 mm vs. 16.57 ± 3.95 mm for MMSM, t = 10.349, P < 0.001, respectively). The left ventricular outflow tract (LVOT) pressure gradient (PG) significantly decreased after the operations in two groups (70.30 ± 44.79 mmHg vs. 39.78 ± 22.07 mmHg for PTSMA, t = 5.041, P < 0.001, and 74.58 ± 45.52 mmHg vs. 13.95 ± 9.94 mmHg for MMSM, t = 16.357, P < 0.001, respectively). Seven patients (10.29%) in the PTSMA group required a repeat operation in the follow-up. Eight (11.76%) patients were evaluated for New York Heart Association (NYHA) III/IV in the PTSMA group, which was significantly more than the five (3.16%) in the same NYHA classes for the MMSM group at follow-up. Less than 15% of patients in the PTSMA group and none of the patients in the MMSM group complained of chest pain during follow-up., Conclusions: Both strategies can not only relieve LVOT PG but also improve heart function in patients with HCM. However, MMSM might provide a more reliable reduction in gradients compared to PTSMA., Competing Interests: There are no conflicts of interest.
- Published
- 2018
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23. Application of 3D printing in the surgical planning of hypertrophic obstructive cardiomyopathy and physician-patient communication: a preliminary study.
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Guo HC, Wang Y, Dai J, Ren CW, Li JH, and Lai YQ
- Abstract
Background: The aim of this study was to evaluate the effect of 3-dimensional (3D) printing in treatment of hypertrophic obstructive cardiomyopathy (HOCM) and its roles in doctor-patient communication., Methods: 3D-printed models were constructed preoperatively and postoperatively in seven HOCM patients received surgical treatment. Based on multi-slice computed tomography (CT) images, regions of disorder were segmented using the Mimics 19.0 software (Materialise, Leuven, Belgium). After generating an STL-file (StereoLithography file) with patients' data, the 3D printer (Objet350 Connex3, Stratasys Ltd., USA) created a 3D model. The pre- and post-operative 3D-printed models were used to make the surgical plan preoperatively and evaluate the outcome postoperatively. Meanwhile, a questionnaire was designed for patients and their relatives to learn the effectiveness of the 3D-printed prototypes in the preoperative conversations., Results: The heart anatomies were accurately printed with 3D technology. The 3D-printed prototypes were useful for preoperative evaluation, surgical planning, and practice. Preoperative and postoperative echocardiographic evaluation showed left ventricular outflow tract (LVOT) obstruction was adequately relieved (82.71±31.63 to 14.91±6.89 mmHg, P<0.001), the septal thickness was reduced from 21.57±4.65 to 17.42±5.88 mm (P<0.001), and the SAM disappeared completely after the operation. Patients highly appreciated the role of 3D model in preoperative conversations and the communication score was 9.11±0.38 points., Conclusions: A 3D-printed model is a useful tool in individualized planning for myectomies and represent a useful tool for physician-patient communication., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.
- Published
- 2018
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24. Endoscopic Approach to Remove Intra-extracranial Tumors in Various Skull Base Regions: 10-year Experience of a Single Center.
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Zhang QH, Wang ZL, Guo HC, Kong F, Yan B, Li MC, Chen G, Liang JT, Bao YH, and Ling F
- Subjects
- Adolescent, Adult, Aged, Child, Female, Humans, Male, Meningeal Neoplasms pathology, Meningeal Neoplasms surgery, Meningioma pathology, Meningioma surgery, Middle Aged, Neoplasm Recurrence, Local pathology, Neoplasm Recurrence, Local surgery, Retrospective Studies, Skull Base Neoplasms pathology, Young Adult, Neurosurgical Procedures methods, Skull Base pathology, Skull Base surgery, Skull Base Neoplasms surgery
- Abstract
Background: Some problems have been found in the usually adopted combined approach for the removal of intra-extracranial tumors in skull base. Herein, we described a pure endoscopic transnasal or transoral approach (ETA) for the removal of intra-extracranial tumors in various skull base regions., Methods: Retrospectively, clinical data, major surgical complications, pre- and postoperative images, and follow-up information of a series of 85 patients with intra-extracranial tumors in various skull base regions who were treated by surgery via ETA in our skull base center during the past 10 years were reviewed and analyzed., Results: Gross total tumor removal was achieved in 80/85 cases (94.1%) in this study. All 37 cases with tumors in anterior skull base and all 14 cases with tumors in jugular foramen received total tumor removal. Thirteen and three cases with tumors in clivus received total and subtotal tumor removal, respectively. Total and subtotal tumor removal was performed for 16 cases and 2 cases in lateral skull base, respectively. The complications in this study included: cerebrospinal fluid leakage (n = 3), meningitis (n = 3), and new cranial nerve deficits (n = 3; recovered in 3 months after surgery). In the follow-up period of 40-151 months (median: 77 months), seven patients (8.8%) out of the 80 cases of total tumor removal experienced recurrence., Conclusions: Complete resection of intra-extracranial growing tumors in various skull base regions can be achieved via the pure ETA in one stage in selected cases. Surgical procedure for radical removal of tumors is feasible and safe.
- Published
- 2017
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25. Usefulness of intraoperative electromyographic monitoring of oculomotor and abducens nerves during skull base surgery.
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Li ZY, Li MC, Liang JT, Bao YH, Chen G, Guo HC, and Ling F
- Subjects
- Abducens Nerve physiology, Adolescent, Adult, Aged, Brain Neoplasms physiopathology, Brain Neoplasms surgery, Female, Humans, Male, Middle Aged, Neurosurgical Procedures methods, Oculomotor Nerve physiology, Orthopedic Procedures methods, Reproducibility of Results, Young Adult, Abducens Nerve surgery, Electromyography methods, Intraoperative Neurophysiological Monitoring methods, Oculomotor Nerve surgery, Skull Base surgery
- Abstract
Background: Intraoperative neurophysiologic monitoring of the extraocular cranial nerve (EOCN) is not commonly performed because of technical difficulty and risk, reliability of the result and predictability of the postoperative function of the EOCN., Methods: We performed oculomotor nerve (CN III) and abducens nerve (CN VI) intraoperative monitoring in patients with skull base surgery by recording the spontaneous muscle activity (SMA) and compound muscle action potential (CMAP). Two types of needle electrodes of different length were percutaneously inserted into the extraocular muscles with the free-hand technique. We studied the relationships between the SMA and CMAP and postoperative function of CN III and CN VI., Results: A total of 23 patients were included. Nineteen oculomotor nerves and 22 abducens nerves were monitored during surgery, respectively. Neurotonic discharge had a positive predictive value of less than 50% and negative predictive value of more than 80% for postoperative CN III and CN VI dysfunction. The latency of patients with postoperative CN III dysfunction was 2.79 ± 0.13 ms, longer than that with intact CN III function (1.73 ± 0.11 ms). One patient had transient CN VI dysfunction, whose CMAP latency (2.54 ms) was longer than that of intact CN VI function (2.11 ± 0.38 ms). There was no statistically significant difference between patients with paresis and with intact function., Conclusions: The method of intraoperative monitoring of EOCNs described here is safe and useful to record responses of SMA and CMAP. Neurotonic discharge seems to have limited value in predicting the postoperative function of CN III and CN VI. The onset latency of CMAP longer than 2.5 ms after tumor removal is probably relevant to postoperative CN III and CN VI dysfunction. However, a definite quantitative relationship has not been found between the amplitude and stimulation intensity of CMAP and the postoperative outcome of CN III and CN VI.
- Published
- 2017
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26. Surgical Treatment of Arrhythmogenic Right Ventricular Cardiomyopathy with Absent Pulmonary Valve.
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Guo HC, Ren CW, Dai J, and Lai YQ
- Subjects
- Child, Electrocardiography, Humans, Male, Arrhythmogenic Right Ventricular Dysplasia surgery, Pulmonary Valve surgery
- Published
- 2017
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27. Surgical Treatment of Double Outlet Right Ventricle with Absent Pulmonary Valve and Bronchiarctia.
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Guo HC, Ren CW, Dai J, and Lai YQ
- Subjects
- Bronchial Diseases diagnostic imaging, Bronchial Diseases surgery, Double Outlet Right Ventricle diagnostic imaging, Female, Humans, Pulmonary Valve diagnostic imaging, Double Outlet Right Ventricle surgery, Pulmonary Valve surgery
- Published
- 2017
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28. Biological function of Foot-and-mouth disease virus non-structural proteins and non-coding elements.
- Author
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Gao Y, Sun SQ, and Guo HC
- Subjects
- 3' Untranslated Regions, 5' Untranslated Regions, Animals, Foot-and-Mouth Disease Virus genetics, Gene Expression Regulation, Viral, Open Reading Frames, Viral Nonstructural Proteins genetics, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus metabolism, Viral Nonstructural Proteins metabolism
- Abstract
Foot-and-mouth disease virus (FMDV) represses host translation machinery, blocks protein secretion, and cleaves cellular proteins associated with signal transduction and the innate immune response to infection. Non-structural proteins (NSPs) and non-coding elements (NCEs) of FMDV play a critical role in these biological processes. The FMDV virion consists of capsid and nucleic acid. The virus genome is a positive single stranded RNA and encodes a single long open reading frame (ORF) flanked by a long structured 5'-untranslated region (5'-UTR) and a short 3'-UTR. The ORF is translated into a polypeptide chain and processed into four structural proteins (VP1, VP2, VP3, and VP4), 10 NSPs (L(pro), 2A, 2B, 2C, 3A, 3B1-3, 3C(pro), and 3D(pol)), and some cleavage intermediates. In the past decade, an increasing number of studies have begun to focus on the molecular pathogenesis of FMDV NSPs and NCEs. This review collected recent research progress on the biological functions of these NSPs and NCEs on the replication and host cellular regulation of FMDV to understand the molecular mechanism of host-FMDV interactions and provide perspectives for antiviral strategy and development of novel vaccines.
- Published
- 2016
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29. RNAi Reveals Phase-Specific Global Regulators of Human Somatic Cell Reprogramming.
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Toh CX, Chan JW, Chong ZS, Wang HF, Guo HC, Satapathy S, Ma D, Goh GY, Khattar E, Yang L, Tergaonkar V, Chang YT, Collins JJ, Daley GQ, Wee KB, Farran CA, Li H, Lim YP, Bard FA, and Loh YH
- Subjects
- Cells, Cultured, Gene Knockdown Techniques, Genetic Testing, Genome, Human, Humans, Kinetics, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, RNA Splicing genetics, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Small Interfering metabolism, Repressor Proteins metabolism, Serine-Arginine Splicing Factors metabolism, Cellular Reprogramming genetics, RNA Interference
- Abstract
Incomplete knowledge of the mechanisms at work continues to hamper efforts to maximize reprogramming efficiency. Here, we present a systematic genome-wide RNAi screen to determine the global regulators during the early stages of human reprogramming. Our screen identifies functional repressors and effectors that act to impede or promote the reprogramming process. Repressors and effectors form close interacting networks in pathways, including RNA processing, G protein signaling, protein ubiquitination, and chromatin modification. Combinatorial knockdown of five repressors (SMAD3, ZMYM2, SFRS11, SAE1, and ESET) synergistically resulted in ∼85% TRA-1-60-positive cells. Removal of the novel splicing factor SFRS11 during reprogramming is accompanied by rapid acquisition of pluripotency-specific spliced forms. Mechanistically, SFRS11 regulates exon skipping and mutually exclusive splicing of transcripts in genes involved in cell differentiation, mRNA splicing, and chromatin modification. Our study provides insights into the reprogramming process, which comprises comprehensive and multi-layered transcriptional, splicing, and epigenetic machineries., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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30. Identification of cranial nerves around trigeminal schwannomas using diffusion tensor tractography: a technical note and report of 3 cases.
- Author
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Wei PH, Qi ZG, Chen G, Li MC, Liang JT, Guo HC, Bao YH, and Hao Q
- Subjects
- Adult, Cranial Nerve Neoplasms pathology, Female, Humans, Male, Middle Aged, Neurilemmoma pathology, Trigeminal Nerve pathology, Cranial Nerve Neoplasms surgery, Diffusion Tensor Imaging methods, Neurilemmoma surgery, Trigeminal Nerve surgery
- Abstract
Background: There are no large series studies identifying the locations of cranial nerves (CNs) around trigeminal schwannomas (TSs); however, surgically induced cranial neuropathies are commonly observed after surgeries to remove TSs. In this study, we preoperatively identified the location of CNs near TSs using diffusion tensor tractography (DTT)., Methods: An observational study of the DTT results and intraoperative findings was performed. We preoperatively completed tractography from images of patients with TSs who received surgical therapy. The result was later validated during tumorectomy., Results: A total of three consecutive patients were involved in this study. The locations of CNs V-VIII in relation to the tumor was clearly revealed in all cases, except for CN VI in case 3.The predicted fiber tracts were in agreement with intraoperative observations., Conclusions: In this study, preoperative DTT accurately predicted the location of the majority of the nerves of interest. This technique can be applied by surgeons to preoperatively visualize nerve arrangements.
- Published
- 2016
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31. Quantitative Detection of the Foot-And-Mouth Disease Virus Serotype O 146S Antigen for Vaccine Production Using a Double-Antibody Sandwich ELISA and Nonlinear Standard Curves.
- Author
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Feng X, Ma JW, Sun SQ, Guo HC, Yang YM, Jin Y, Zhou GQ, He JJ, Guo JH, Qi SY, Lin M, Cai H, and Liu XT
- Subjects
- Animals, Antigens, Viral immunology, Foot-and-Mouth Disease immunology, Limit of Detection, Vaccines, Inactivated analysis, Vaccines, Inactivated immunology, Viral Vaccines immunology, Antigens, Viral analysis, Enzyme-Linked Immunosorbent Assay methods, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus immunology, Viral Vaccines analysis
- Abstract
The efficacy of an inactivated foot-and-mouth disease (FMD) vaccine is mainly dependent on the integrity of the foot-and-mouth disease virus (FMDV) particles. At present, the standard method to quantify the active component, the 146S antigen, of FMD vaccines is sucrose density gradient (SDG) analysis. However, this method is highly operator dependent and difficult to automate. In contrast, the enzyme-linked immunosorbent assay (ELISA) is a time-saving technique that provides greater simplicity and sensitivity. To establish a valid method to detect and quantify the 146S antigen of a serotype O FMD vaccine, a double-antibody sandwich (DAS) ELISA was compared with an SDG analysis. The DAS ELISA was highly correlated with the SDG method (R2 = 0.9215, P<0.01). In contrast to the SDG method, the DAS ELISA was rapid, robust, repeatable and highly sensitive, with a minimum quantification limit of 0.06 μg/mL. This method can be used to determine the effective antigen yields in inactivated vaccines and thus represents an alternative for assessing the potency of FMD vaccines in vitro. But it still needs to be prospectively validated by analyzing a new vaccine preparation and determining the proper protective dose followed by an in vivo vaccination-challenge study to confirm the ELISA findings.
- Published
- 2016
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32. Choledochojejunostomy with an innovative magnetic compressive anastomosis: How to determine optimal pressure?
- Author
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Xue F, Guo HC, Li JP, Lu JW, Wang HH, Ma F, Liu YX, and Lv Y
- Subjects
- Anastomotic Leak blood, Anastomotic Leak etiology, Animals, Bilirubin blood, Biomarkers blood, Choledochostomy adverse effects, Choledochostomy methods, Cholestasis blood, Disease Models, Animal, Dogs, Equipment Design, Feasibility Studies, Male, Pressure, Suture Techniques, Time Factors, Choledochostomy instrumentation, Cholestasis surgery, Magnetics instrumentation, Magnets adverse effects
- Abstract
Aim: To investigate the optimal magnetic pressure and provide a theoretical basis for choledochojejunostomy magnetic compressive anastomosis (magnamosis)., Methods: Four groups of neodymium-iron-boron magnets with different magnetic pressures of 0.1, 0.2, 0.3 and 0.4 MPa were used to complete the choledochojejunostomy magnamosis. Twenty-six young mongrel dogs were randomly divided into five groups: four groups with different magnetic pressures and 1 group with a hand-suture anastomosis. Serum bilirubin levels were measured in all groups before and 1 wk, 2 wk, 3 wk, 1 mo and 3 mo after surgery. Daily abdominal X-ray fluoroscopy was carried out postoperatively to detect the path and the excretion of the magnet. The animals were euthanized at 1 or 3 mo after the operation, the burst pressure was detected in each anastomosis, and the gross appearance and histology were compared according to the observation., Results: The surgical procedures were all successfully performed in animals. However, animals of group D (magnetic pressure of 0.4 MPa) all experienced complications with bile leakage (4/4), whereas half of animals in group A (magnetic pressure of 0.1 MPa) experienced complications (3/6), 1 animal in the manual group E developed anastomotic stenosis, and animals in group B and group C (magnetic pressure of 0.2 MPa and 0.3 MPa, respectively) all healed well without complications. These results also suggested that the time required to form the stoma was inversely proportional to the magnetic pressure; however, the burst pressure of group A was smaller than those of the other groups at 1 mo (187.5 ± 17.7 vs 290 ± 10/296.7 ± 5.7/287.5 ± 3.5, P < 0.05); the remaining groups did not differ significantly. A histologic examination demonstrated obvious differences between the magnamosis groups and the hand-sewn group., Conclusion: We proved that the optimal range for choledochojejunostomy magnamosis is 0.2 MPa to 0.3 MPa, which will help to improve the clinical application of this technique in the future.
- Published
- 2016
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33. Productive Entry of Foot-and-Mouth Disease Virus via Macropinocytosis Independent of Phosphatidylinositol 3-Kinase.
- Author
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Han SC, Guo HC, Sun SQ, Jin Y, Wei YQ, Feng X, Yao XP, Cao SZ, Xiang Liu D, and Liu XT
- Subjects
- Actins metabolism, Animals, Caveolins metabolism, Cell Line, Cholesterol metabolism, Membrane Lipids metabolism, Receptor Protein-Tyrosine Kinases metabolism, Virus Replication, Foot-and-Mouth Disease Virus physiology, Phosphatidylinositol 3-Kinases metabolism, Pinocytosis, Virus Internalization
- Abstract
Virus entry is an attractive target for therapeutic intervention. Here, using a combination of electron microscopy, immunofluorescence assay, siRNA interference, specific pharmacological inhibitors, and dominant negative mutation, we demonstrated that the entry of foot-and-mouth disease virus (FMDV) triggered a substantial amount of plasma membrane ruffling. We also found that the internalization of FMDV induced a robust increase in fluid-phase uptake, and virions internalized within macropinosomes colocalized with phase uptake marker dextran. During this stage, the Rac1-Pak1 signaling pathway was activated. After specific inhibition on actin, Na(+)/H(+) exchanger, receptor tyrosine kinase, Rac1, Pak1, myosin II, and protein kinase C, the entry and infection of FMDV significantly decreased. However, inhibition of phosphatidylinositol 3-kinase (PI3K) did not reduce FMDV internalization but increased the viral entry and infection to a certain extent, implying that FMDV entry did not require PI3K activity. Results showed that internalization of FMDV exhibited the main hallmarks of macropinocytosis. Moreover, intracellular trafficking of FMDV involves EEA1/Rab5-positive vesicles. The present study demonstrated macropinocytosis as another endocytic pathway apart from the clathrin-mediated pathway. The findings greatly expand our understanding of the molecular mechanisms of FMDV entry into cells, as well as provide potential insights into the entry mechanisms of other picornaviruses.
- Published
- 2016
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34. The application of virus-like particles as vaccines and biological vehicles.
- Author
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Yan D, Wei YQ, Guo HC, and Sun SQ
- Subjects
- Drug Carriers isolation & purification, Vaccines, Virus-Like Particle administration & dosage, Vaccines, Virus-Like Particle isolation & purification, Virosomes isolation & purification, Drug Carriers metabolism, Drug Delivery Systems, Vaccines, Virus-Like Particle immunology, Virosomes metabolism
- Abstract
Virus-like particles (VLPs) can be spontaneously self-assembled by viral structural proteins under appropriate conditions in vitro while excluding the genetic material and potential replication probability. In addition, VLPs possess several features including can be rapidly produced in large quantities through existing expression systems, highly resembling native viruses in terms of conformation and appearance, and displaying repeated cluster of epitopes. Their capsids can be modified via genetic insertion or chemical conjugation which facilitating the multivalent display of a homologous or heterogeneous epitope antigen. Therefore, VLPs are considered as a safe and effective candidate of prophylactic and therapeutic vaccines. VLPs, with a diameter of approximately 20 to 150 nm, also have the characteristics of nanometer materials, such as large surface area, surface-accessible amino acids with reactive moieties (e.g., lysine and glutamic acid residues), inerratic spatial structure, and good biocompatibility. Therefore, assembled VLPs have great potential as a delivery system for specifically carrying a variety of materials. This review summarized recent researches on VLP development as vaccines and biological vehicles, which demonstrated the advantages and potential of VLPs in disease control and prevention and diagnosis. Then, the prospect of VLP biology application in the future is discussed as well.
- Published
- 2015
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35. Tert-butylhydroquinone ameliorates doxorubicin-induced cardiotoxicity by activating Nrf2 and inducing the expression of its target genes.
- Author
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Wang LF, Su SW, Wang L, Zhang GQ, Zhang R, Niu YJ, Guo YS, Li CY, Jiang WB, Liu Y, and Guo HC
- Abstract
Oxidative stress plays an important role in doxorubicin (DOX)-induced cardiotoxicity. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor that orchestrates the antioxidant and cytoprotective responses to oxidative stress. In the present study, we tested whether tert-butylhydroquinone (tBHQ) could protect against DOX-induced cardiotoxicity in vivo and, if so, whether the protection was associated with the up-regulation of the Nrf2 pathway. The results showed that treatment with tBHQ significantly decreased the DOX-induced cardiac injury in wild-type mice. Moreover, tBHQ ameliorated the DOX-induced oxidative stress and apoptosis. Further studies suggested that tBHQ increased the nuclear accumulation of Nrf2 and the Nrf2-regulated gene expression, including heme oxygenase-1 (HO-1) and, Nad(p)h: quinone oxido-reductase-1 (NQO-1) expression. Knocking out Nrf2 in mice abolished the protective effect of tBHQ on the DOX-induced cardiotoxicity. These results indicate that tBHQ has a beneficial effect on DOX-induced cardiotoxicity, and this effect was associated with the enhanced expression of Nrf2 and its downstream antioxidant genes, HO-1 and NQO-1.
- Published
- 2015
36. Systematic identification of factors for provirus silencing in embryonic stem cells.
- Author
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Yang BX, El Farran CA, Guo HC, Yu T, Fang HT, Wang HF, Schlesinger S, Seah YF, Goh GY, Neo SP, Li Y, Lorincz MC, Tergaonkar V, Lim TM, Chen L, Gunaratne J, Collins JJ, Goff SP, Daley GQ, Li H, Bard FA, and Loh YH
- Subjects
- Animals, Chromatin Assembly Factor-1 genetics, Chromatin Assembly Factor-1 metabolism, Embryonal Carcinoma Stem Cells virology, Epigenesis, Genetic, Mice, Small Ubiquitin-Related Modifier Proteins metabolism, Embryonic Stem Cells virology, Endogenous Retroviruses genetics, Proviruses genetics
- Abstract
Embryonic stem cells (ESCs) repress the expression of exogenous proviruses and endogenous retroviruses (ERVs). Here, we systematically dissected the cellular factors involved in provirus repression in embryonic carcinomas (ECs) and ESCs by a genome-wide siRNA screen. Histone chaperones (Chaf1a/b), sumoylation factors (Sumo2/Ube2i/Sae1/Uba2/Senp6), and chromatin modifiers (Trim28/Eset/Atf7ip) are key determinants that establish provirus silencing. RNA-seq analysis uncovered the roles of Chaf1a/b and sumoylation modifiers in the repression of ERVs. ChIP-seq analysis demonstrates direct recruitment of Chaf1a and Sumo2 to ERVs. Chaf1a reinforces transcriptional repression via its interaction with members of the NuRD complex (Kdm1a, Hdac1/2) and Eset, while Sumo2 orchestrates the provirus repressive function of the canonical Zfp809/Trim28/Eset machinery by sumoylation of Trim28. Our study reports a genome-wide atlas of functional nodes that mediate proviral silencing in ESCs and illuminates the comprehensive, interconnected, and multi-layered genetic and epigenetic mechanisms by which ESCs repress retroviruses within the genome., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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37. Quantitative Proteomic Analysis of BHK-21 Cells Infected with Foot-and-Mouth Disease Virus Serotype Asia 1.
- Author
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Guo HC, Jin Y, Han SC, Sun SQ, Wei YQ, Liu XJ, Feng X, Liu DX, and Liu XT
- Subjects
- Animals, Blotting, Western, Cell Line, Chromatography, Liquid, Computational Biology, Down-Regulation, Foot-and-Mouth Disease Virus genetics, Gene Knockdown Techniques, Genes, Viral, Immunoblotting, Isotope Labeling, Mass Spectrometry, Metabolic Networks and Pathways, Proteome metabolism, RNA Interference, RNA, Small Interfering metabolism, Reproducibility of Results, Subcellular Fractions metabolism, Time Factors, Transfection, Up-Regulation, Viral Proteins metabolism, Foot-and-Mouth Disease virology, Foot-and-Mouth Disease Virus physiology, Proteomics methods
- Abstract
Stable isotope labeling with amino acids in cell culture (SILAC) was used to quantitatively study the host cell gene expression profile, in order to achieve an unbiased overview of the protein expression changes in BHK-21 cells infected with FMDV serotype Asia 1. The SILAC-based approach identified overall 2,141 proteins, 153 of which showed significant alteration in the expression level 6 h post FMDV infection (57 up-regulated and 96 down-regulated). Among these proteins, six cellular proteins, including three down-regulated (VPS28, PKR, EVI5) and three up-regulated (LYPLA1, SEC62 and DARs), were selected according to the significance of the changes and/or the relationship with PKR. The expression level and pattern of the selected proteins were validated by immunoblotting and confocal microscopy. Furthermore, the functions of these cellular proteins were assessed by small interfering RNA-mediated depletion, and their functional importance in the replication of FMDV was demonstrated by western blot, reverse transcript PCR (RT-PCR) and 50% Tissue Culture Infective Dose (TCID50). The results suggest that FMDV infection may have effects on the expression of specific cellular proteins to create more favorable conditions for FMDV infection. This study provides novel data that can be utilized to understand the interactions between FMDV and the host cell.
- Published
- 2015
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38. Identification of cranial nerves near large vestibular schwannomas using superselective diffusion tensor tractography: experience with 23 cases.
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Wei PH, Qi ZG, Chen G, Hu P, Li MC, Liang JT, Guo HC, Ling F, and Bao YH
- Subjects
- Adult, Cochlear Nerve physiology, Facial Nerve physiology, Female, Humans, Male, Middle Aged, Neuroma, Acoustic pathology, Trigeminal Nerve physiology, Cochlear Nerve anatomy & histology, Diffusion Tensor Imaging methods, Facial Nerve anatomy & histology, Monitoring, Intraoperative methods, Neuroma, Acoustic surgery, Trigeminal Nerve anatomy & histology
- Abstract
Background: The preservation of the facial nerve (FN) and acoustic function in large vestibular schwannoma (VS) surgery is challenging because of nerve course uncertainties and morphological deviations. Preoperative diffusion tensor tractography (DTT) has been proposed to predict the FN location. This study was conducted to evaluate the effectiveness of this technique for identifying the FN, cochlear nerve (CN) and trigeminal nerve (TN) in large VSs., Methods: The study included 23 consecutive patients with VS of Hannover classification T3b to T4b from November 2013 through May 2014. Diffusion tensor images and anatomical images were acquired. The DTT images of the cranial nerves were extracted before surgery for each patient to determine the relationships of these nerves with the tumor. The results were then validated during the tumorectomy., Results: In 21 (91.30%) patients, the location of the FN on the DTT images agreed with the intraoperative findings, including in 2 patients in whom the FN passed through the interface between the parenchyma and the cystic changes and in 3 patients with a membranoid FN. The CN or fibers of unclear function were observed on DTT images in four patients with functional hearing. One penetrating fiber of unknown function was effectively constructed. The TN was accurately detected on the DTT images for all patients., Conclusions: DTT effectively revealed the location of the FN, including cases in which the FN was membranoid or passed through the interface between an area exhibiting cystic changes and the tumor nodule. Fibers aside from the FN and the TN were revealed by DTT in patients who retained functional hearing. Penetrating fibers were also found using DTT. This technique can be useful during VS resection.
- Published
- 2015
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39. NLRP3 Inflammasome Activation by Viroporins of Animal Viruses.
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Guo HC, Jin Y, Zhi XY, Yan D, and Sun SQ
- Subjects
- Animals, Carrier Proteins genetics, Humans, Inflammasomes genetics, Viral Proteins genetics, Virus Diseases genetics, Virus Diseases virology, Viruses genetics, Carrier Proteins immunology, Inflammasomes immunology, Viral Proteins immunology, Virus Diseases immunology, Viruses immunology
- Abstract
Viroporins are a group of low-molecular-weight proteins containing about 50-120 amino acid residues, which are encoded by animal viruses. Viroporins are involved in several stages of the viral life cycle, including viral gene replication and assembly, as well as viral particle entry and release. Viroporins also play an important role in the regulation of antiviral innate immune responses, especially in inflammasome formation and activation, to ensure the completion of the viral life cycle. By reviewing the research progress made in recent years on the regulation of the NLRP3 inflammasome by viroporins of animal viruses, we aim to understand the importance of viroporins in viral infection and to provide a reference for further research and development of novel antiviral drugs.
- Published
- 2015
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- View/download PDF
40. Viroporin Activity of the Foot-and-Mouth Disease Virus Non-Structural 2B Protein.
- Author
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Ao D, Guo HC, Sun SQ, Sun DH, Fung TS, Wei YQ, Han SC, Yao XP, Cao SZ, Liu DX, and Liu XT
- Subjects
- Amantadine pharmacology, Animals, Calcium metabolism, Cell Line, Cell Membrane Permeability, Cricetinae, Endoplasmic Reticulum virology, Escherichia coli virology, Foot-and-Mouth Disease Virus genetics, Humans, Protein Structure, Tertiary, Virus Release drug effects, Virus Replication physiology, Autophagy genetics, Cell Membrane metabolism, Foot-and-Mouth Disease Virus metabolism, Viral Nonstructural Proteins antagonists & inhibitors, Viral Regulatory and Accessory Proteins antagonists & inhibitors
- Abstract
Viroporins are a family of low-molecular-weight hydrophobic transmembrane proteins that are encoded by various animal viruses. Viroporins form transmembrane pores in host cells via oligomerization, thereby destroying cellular homeostasis and inducing cytopathy for virus replication and virion release. Among the Picornaviridae family of viruses, the 2B protein encoded by enteroviruses is well understood, whereas the viroporin activity of the 2B protein encoded by the foot-and-mouth disease virus (FMDV) has not yet been described. An analysis of the FMDV 2B protein domains by computer-aided programs conducted in this study revealed that this protein may contain two transmembrane regions. Further biochemical, biophysical and functional studies revealed that the protein possesses a number of features typical of a viroporin when it is overexpressed in bacterial and mammalian cells as well as in FMDV-infected cells. The protein was found to be mainly localized in the endoplasmic reticulum (ER), with both the N- and C-terminal domains stretched into the cytosol. It exhibited cytotoxicity in Escherichia coli, which attenuated 2B protein expression. The release of virions from cells infected with FMDV was inhibited by amantadine, a viroporin inhibitor. The 2B protein monomers interacted with each other to form both intracellular and extracellular oligomers. The Ca(2+) concentration in the cells increased, and the integrity of the cytoplasmic membrane was disrupted in cells that expressed the 2B protein. Moreover, the 2B protein induced intense autophagy in host cells. All of the results of this study demonstrate that the FMDV 2B protein has properties that are also found in other viroporins and may be involved in the infection mechanism of FMDV.
- Published
- 2015
- Full Text
- View/download PDF
41. Structural basis of a point mutation that causes the genetic disease aspartylglucosaminuria.
- Author
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Sui L, Lakshminarasimhan D, Pande S, and Guo HC
- Subjects
- Crystallography, X-Ray, Humans, Models, Molecular, Aspartylglucosaminuria genetics, Aspartylglucosylaminase genetics, Point Mutation
- Abstract
Aspartylglucosaminuria (AGU) is a lysosomal storage disease caused by a metabolic disorder of lysosomes to digest Asn-linked glycoproteins. The specific enzyme linked to AGU is a lysosomal hydrolase called glycosylasparaginase. Crystallographic studies revealed that a surface loop blocks the catalytic center of the mature hydrolase. Autoproteolysis is therefore required to remove this P loop and open up the hydrolase center. Nonetheless, AGU mutations result in misprocessing of their precursors and are deficient in hydrolyzing glycoasparagines. To understand the catalytic and structural consequences of AGU mutations, we have characterized two AGU models, one corresponding to a Finnish allele and the other found in a Canadian family. We also report a 2.1 Å resolution structure of the latter AGU model. The current crystallographic study provides a high-resolution structure of an AGU mutant. It reveals substantial conformation changes at the defective autocleavage site of the AGU mutant, which is trapped as an inactive precursor., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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- View/download PDF
42. Topology and biological function of enterovirus non-structural protein 2B as a member of the viroporin family.
- Author
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Ao D, Sun SQ, and Guo HC
- Subjects
- Membrane Proteins metabolism, Molecular Sequence Data, Picornaviridae metabolism, Picornaviridae Infections virology, Sequence Analysis, DNA veterinary, Viral Nonstructural Proteins metabolism, Picornaviridae genetics, Picornaviridae Infections veterinary, Viral Nonstructural Proteins genetics
- Abstract
Viroporins are a group of transmembrane proteins with low molecular weight that are encoded by many animal viruses. Generally, viroporins are composed of 50-120 amino acid residues and possess a minimum of one hydrophobic region that interacts with the lipid bilayer and leads to dispersion. Viroporins are involved in destroying the morphology of host cells and disturbing their biological functions to complete the life cycle of the virus. The 2B proteins encoded by enteroviruses, which belong to the family Picornaviridae, can form transmembrane pores by oligomerization, increase the permeability of plasma membranes, disturb the homeostasis of calcium in cells, induce apoptosis, and cause autophagy; these abilities are shared among viroporins. The present paper introduces the structure and biological characteristics of various 2B proteins encoded by enteroviruses of the family Picornaviridae and may provide a novel idea for developing antiviral drugs.
- Published
- 2014
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- View/download PDF
43. Virus-like particles in picornavirus vaccine development.
- Author
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Dong H, Guo HC, and Sun SQ
- Subjects
- Drug Discovery trends, Humans, Picornaviridae Infections immunology, Drug Discovery methods, Picornaviridae immunology, Picornaviridae Infections prevention & control, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Virus-like particles (VLP), which are similar to natural virus particles but do not contain viral genes, have brought about significant breakthroughs in many research fields because of their unique advantages. The ordered repeating epitopes of VLP can induce immunity responses similar to those prompted by natural viral infection; thus, VLP vaccines are regarded as candidate alternatives to whole-virus vaccines. As picornavirus has serious impacts on human and animal health, the development of efficient and safe vaccines is a key endeavor in preventing virus infections. The characteristics of picornavirus capsid proteins allow the development of VLP vaccines. This paper investigates research scenarios and progress on picornavirus VLP vaccines with the aim of providing a reference for researchers focusing on virology and vaccinology.
- Published
- 2014
- Full Text
- View/download PDF
44. Self-assembly of virus-like particles of canine parvovirus capsid protein expressed from Escherichia coli and application as virus-like particle vaccine.
- Author
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Xu J, Guo HC, Wei YQ, Dong H, Han SC, Ao D, Sun DH, Wang HM, Cao SZ, and Sun SQ
- Subjects
- Animals, Antibodies, Viral blood, Capsid Proteins genetics, Cell Proliferation, Dog Diseases immunology, Dog Diseases virology, Dogs, Escherichia coli genetics, Gene Expression, Injections, Subcutaneous, Lymphocytes immunology, Mice, Parvoviridae Infections immunology, Parvoviridae Infections prevention & control, Parvoviridae Infections virology, Parvovirus, Canine genetics, Recombinant Proteins genetics, Recombinant Proteins metabolism, Vaccination methods, Vaccines, Synthetic administration & dosage, Vaccines, Synthetic genetics, Vaccines, Synthetic immunology, Vaccines, Synthetic isolation & purification, Vaccines, Virus-Like Particle administration & dosage, Vaccines, Virus-Like Particle genetics, Vaccines, Virus-Like Particle isolation & purification, Viral Vaccines administration & dosage, Viral Vaccines genetics, Viral Vaccines isolation & purification, Capsid Proteins metabolism, Dog Diseases prevention & control, Parvoviridae Infections veterinary, Parvovirus, Canine immunology, Protein Multimerization, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Canine parvovirus disease is an acute infectious disease caused by canine parvovirus (CPV). Current commercial vaccines are mainly attenuated and inactivated; as such, problems concerning safety may occur. To resolve this problem, researchers developed virus-like particles (VLPs) as biological nanoparticles resembling natural virions and showing high bio-safety. This property allows the use of VLPs for vaccine development and mechanism studies of viral infections. Tissue-specific drug delivery also employs VLPs as biological nanomaterials. Therefore, VLPs derived from CPV have a great potential in medicine and diagnostics. In this study, small ubiquitin-like modifier (SUMO) fusion motif was utilized to express a whole, naturalVP2 protein of CPV in Escherichia coli. After the cleavage of the fusion motif, the CPV VP2 protein has self-assembled into VLPs. The VLPs had a size and shape that resembled the authentic virus capsid. However, the self-assembly efficiency of VLPs can be affected by different pH levels and ionic strengths. The mice vaccinated subcutaneously with CPV VLPs and CPV-specific immune responses were compared with those immunized with the natural virus. This result showed that VLPs can effectively induce anti-CPV specific antibody and lymphocyte proliferation as a whole virus. This result further suggested that the antigen epitope of CPV was correctly present on VLPs, thereby showing the potential application of a VLP-based CPV vaccine.
- Published
- 2014
- Full Text
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45. Development and characterization of a recombinant infectious bronchitis virus expressing the ectodomain region of S1 gene of H120 strain.
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Wei YQ, Guo HC, Dong H, Wang HM, Xu J, Sun DH, Fang SG, Cai XP, Liu DX, and Sun SQ
- Subjects
- Animals, Chickens, Coronavirus Infections immunology, Infectious bronchitis virus genetics, Poultry Diseases immunology, Viral Vaccines immunology, Infectious bronchitis virus immunology
- Abstract
Infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), is a highly contagious chicken disease, and can lead to serious economic losses in poultry enterprises. The continual introduction of new IBV serotypes requires alternative strategies for the production of timely and safe vaccines against the emergence of variants. Modification of the IBV genome using reverse genetics is one way to generate recombinant IBVs as the candidates of new IBV vaccines. In this study, the recombinant IBV is developed by replacing the ectodomain region of the S1 gene of the IBV Beaudette strain with the corresponding fragment from H120 strain, designated as rBeau-H120(S1e). In Vero cells, the virus proliferates as its parental virus and can cause syncytium formation. The peak titer would reach 10(5.9) 50% (median) tissue culture infective dose/mL at 24 h post-infection. After inoculation of chickens with the recombinant virus, it demonstrated that rBeau-H120(S1e) remained nonpathogenic and was restricted in its replication in vivo. Protection studies showed that vaccination with rBeau-H120 (S1e) at 7-day after hatch provided 80% rate of immune protection against challenge with 10(3) 50% embryos infection dose of the virulent IBV M41 strain. These results indicate that rBeau-H120 (S1e) has the potential to be an alternative vaccine against IBV based on excellent propagation property and immunogenicity. This finding might help in providing further information that replacement of the ectodomain fragment of the IBV Beaudette S1 gene with that from a present field strain is promising for IBV vaccine development.
- Published
- 2014
- Full Text
- View/download PDF
46. Mechanisms of isoform-specific Na/K pump regulation by short- and long-term adrenergic activation in rat ventricular myocytes.
- Author
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Yin J, Guo HC, Yu D, Wang HC, Li JX, and Wang YL
- Subjects
- Adrenergic Agents pharmacology, Animals, Blotting, Western, Cell Membrane metabolism, Cells, Cultured, Cyclic AMP-Dependent Protein Kinases metabolism, Endosomes metabolism, Gene Expression Regulation, Enzymologic drug effects, Isoenzymes genetics, Isoenzymes metabolism, Myocytes, Cardiac metabolism, Protein Kinase C metabolism, Protein Transport drug effects, Rats, Sprague-Dawley, Reverse Transcriptase Polymerase Chain Reaction, Sodium-Potassium-Exchanging ATPase genetics, Time Factors, Isoproterenol pharmacology, Myocytes, Cardiac drug effects, Norepinephrine pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Background: Many stressful conditions, including cardiovascular diseases, induce long-term elevations in circulating catecholamines, thereby leading to changes of the Na/K pump and thus affecting myocardial functions. However, only short-term adrenergic regulation of the Na/K pump has been reported. The present study is the first investigation of long-term adrenergic regulation of the Na/K pump and the potential mechanism., Methods: After acutely isolated Sprague-Dawley rat myocytes were incubated with noradrenaline or isoprenaline for 24 h, Na/K pump high- (IPH) and low-affinity current (IPL), α-isoform mRNA, and α-isoform protein were examined using patch-clamp, RT-PCR, and Western blotting techniques, respectively., Results: After the short-term incubation, isoprenaline reduced the IPL through a PKA-dependent pathway that involves α1-isoform translocation from the membrane to early endosomes, and noradrenaline increased the IPH through a PKC-dependent pathway that involves α2-isoform translocation from late endosomes to the membrane. After long-term incubation, isoprenaline increased the IPL, α1-isoform mRNA, and α1-isoform protein, and noradrenaline reduced the IPH, α2-isoform mRNA, and α1-isoform protein through a PKA-or PKC-dependent pathway, respectively., Conclusions: These results suggest that long-term adrenergic Na/K pump regulation is isoform-specific and negatively feeds back on the short-term response. Furthermore, long-term regulation involves transcription and translation of the respective α-isoform, whereas short-term regulation involves the translocation of the available α-isoform to the plasma membrane., (© 2014 S. Karger AG, Basel.)
- Published
- 2014
- Full Text
- View/download PDF
47. The protective effect of grape seed procyanidin extract against cadmium-induced renal oxidative damage in mice.
- Author
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Chen Q, Zhang R, Li WM, Niu YJ, Guo HC, Liu XH, Hou YC, and Zhao LJ
- Subjects
- Animals, Antioxidants chemistry, Apoptosis drug effects, Biflavonoids chemistry, Blotting, Western, Body Weight drug effects, Cadmium Poisoning pathology, Catechin chemistry, Flow Cytometry, Glutathione Peroxidase metabolism, Immunohistochemistry, Kidney Diseases chemically induced, Kidney Diseases prevention & control, Malondialdehyde metabolism, Mice, Organ Size drug effects, Oxidative Stress drug effects, Proanthocyanidins chemistry, Proto-Oncogene Proteins c-bcl-2 biosynthesis, Seeds chemistry, Superoxide Dismutase metabolism, bcl-2-Associated X Protein biosynthesis, Antioxidants pharmacology, Biflavonoids pharmacology, Cadmium Poisoning prevention & control, Catechin pharmacology, Kidney pathology, Kidney Diseases pathology, Plant Extracts pharmacology, Proanthocyanidins pharmacology, Vitis chemistry
- Abstract
As an important environmental pollutant, cadmium (Cd) can lead to serious renal damage. Grape seed procyanidins extract (GSPE), a biological active component of grape seed, has been shown to possess antioxidative effects. Here, we assessed the protective effect of GSPE on Cd-induced renal damage using animal experiment. After 30 days, the oxidative damage of kidney was evaluated through measurement of superoxide dismutase (SOD), glutathione peroxidation (GSH-Px) and malondialdehyde (MDA). Since, oxidative stress could lead to apoptosis, the renal apoptosis was measured using flow cytometer. Moreover, the expression of apoptosis-related protein Bax and Bcl-2 was analyzed by immunohistochemistry and Western blot. The results showed that Cd led to the decrease of SOD and GSH-Px activities, and the increase of MDA level, induced renal apoptosis. However, the coadministration of GSPE attenuated Cd-induced lipid peroxidation, and antagonized renal apoptosis, probably associated with the expression of Bax and Bcl-2. These data suggested that GSPE has protective effect against renal oxidative damage induced by Cd, which provide a potential natural chemopreventive agent against Cd-poisoning., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
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48. Foot-and-mouth disease virus-like particles produced by a SUMO fusion protein system in Escherichia coli induce potent protective immune responses in guinea pigs, swine and cattle.
- Author
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Guo HC, Sun SQ, Jin Y, Yang SL, Wei YQ, Sun DH, Yin SH, Ma JW, Liu ZX, Guo JH, Luo JX, Yin H, Liu XT, and Liu DX
- Subjects
- Animals, Capsid Proteins immunology, Escherichia coli, Escherichia coli Proteins metabolism, Foot-and-Mouth Disease virology, SUMO-1 Protein metabolism, Vaccines, Virus-Like Particle administration & dosage, Viral Vaccines administration & dosage, Cattle immunology, Foot-and-Mouth Disease immunology, Foot-and-Mouth Disease Virus immunology, Guinea Pigs immunology, Swine immunology, Vaccines, Virus-Like Particle immunology, Viral Vaccines immunology
- Abstract
Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV.
- Published
- 2013
- Full Text
- View/download PDF
49. Immunization of mice by hollow mesoporous silica nanoparticles as carriers of porcine circovirus type 2 ORF2 protein.
- Author
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Guo HC, Feng XM, Sun SQ, Wei YQ, Sun DH, Liu XT, Liu ZX, Luo JX, and Yin H
- Subjects
- Animals, Antibodies, Viral blood, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Cell Proliferation, Interferon-gamma metabolism, Mice, Spleen immunology, Viral Vaccines administration & dosage, Circovirus immunology, Drug Carriers administration & dosage, Nanoparticles administration & dosage, Silicon Dioxide administration & dosage, Vaccination methods, Viral Proteins immunology, Viral Vaccines immunology
- Abstract
Background: Porcine circovirus type 2 (PCV2) is a primary etiological agent of post-weaning multi-systemic wasting syndrome (PMWS), which is a disease of increasing importance to the pig industry worldwide. Hollow mesoporous silica nanoparticles (HMSNs) have gained increasing interest for use in vaccines., Methods: To study the potential of HMSNs for use as a protein delivery system or vaccine carriers. HMSNs were synthesized by a sol-gel/emulsion(oil-in-water/ethanol) method, purified PCV2 GST-ORF2-E protein was loaded into HMSNs, and the resulting HMSN/protein mixture was injected into mice. The uptake and release profiles of protein by HMSNs in vitro were investigated. PCV2 GST-ORF2-E specific antibodies and secretion of IFN-γ were detected by enzyme-linked immunosorbent assays, spleen lymphocyte proliferation was measured by the MTS method, and the percentage of CD4+ and CD8+ were determined by flow cytometry., Results: HMSNs were found to yield better binding capacities and delivery profiles of proteins; the specific immune response induced by PCV2 GST-ORF2-E was maintained for a relatively long period of time after immunization with the HMSN/protein complex., Conclusion: The findings suggest that HMSNs are good protein carriers and have high potential for use in future applications in therapeutic drug delivery.
- Published
- 2012
- Full Text
- View/download PDF
50. Serotonin-mediated modulation of Na+/K+ pump current in rat hippocampal CA1 pyramidal neurons.
- Author
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Zhang LN, Su SW, Guo F, Guo HC, Shi XL, Li WY, Liu X, and Wang YL
- Subjects
- Animals, Animals, Newborn, Biguanides pharmacology, Biophysics, Dose-Response Relationship, Drug, Electric Stimulation, In Vitro Techniques, Neural Inhibition drug effects, Patch-Clamp Techniques, Piperazines pharmacology, Pyramidal Cells physiology, Pyridines pharmacology, Rats, Rats, Sprague-Dawley, Serotonin Antagonists pharmacology, Serotonin Receptor Agonists pharmacology, Sodium Channel Blockers pharmacology, Strophanthidin pharmacology, Tetrodotoxin pharmacology, CA1 Region, Hippocampal cytology, Pyramidal Cells drug effects, Serotonin pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Background: The aim of this study was to investigate whether serotonin (5-hydroxytryptamine, 5-HT) can modulate Na+/K+ pump in rat hippocampal CA1 pyramidal neurons., Results: 5-HT (0.1, 1 mM) showed Na+/K+ pump current (Ip) densities of 0.40 ± 0.04, 0.34 ± 0.03 pA/pF contrast to 0.63 ± 0.04 pA/pF of the control of 0.5 mM strophanthidin (Str), demonstrating 5-HT-induced inhibition of Ip in a dose-dependent manner in hippocampal CA1 pyramidal neurons. The effect was partly attenuated by ondasetron, a 5-HT3 receptor (5-HT3R) antagonist, not by WAY100635, a 5-HT1AR antagonist, while 1-(3-Chlorophenyl) biguanide hydrochloride (m-CPBG), a 5-HT3R specific agonist, mimicked the effect of 5-HT on Ip., Conclusion: 5-HT inhibits neuronal Na+/K+ pump activity via 5-HT3R in rat hippocampal CA1 pyramidal neurons. This discloses novel mechanisms for the function of 5-HT in learning and memory, which may be a useful target to benefit these patients with cognitive disorder.
- Published
- 2012
- Full Text
- View/download PDF
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