10 results on '"Kahng, J."'
Search Results
2. Exercise activates AMPK in mouse and human pancreatic islets to decrease senescence.
- Author
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Carapeto P, Iwasaki K, Hela F, Kahng J, Alves-Wagner AB, Middelbeek RJW, Hirshman MF, Rutter GA, Goodyear LJ, and Aguayo-Mazzucato C
- Subjects
- Humans, Animals, Mice, Male, Female, Insulin Resistance, NF-E2-Related Factor 2 metabolism, Glucagon blood, Glucagon metabolism, Insulin-Secreting Cells metabolism, Enzyme Activation, Signal Transduction, Cellular Senescence, AMP-Activated Protein Kinases metabolism, Physical Conditioning, Animal, Diabetes Mellitus, Type 2 metabolism, Islets of Langerhans metabolism
- Abstract
Beta (β)-cell senescence contributes to type 2 diabetes mellitus (T2DM). While exercise is vital for T2DM management and significantly affects cellular ageing markers, its effect on β-cell senescence remains unexplored. Here, we show that short-term endurance exercise training (treadmill running, 1 h per day for 10 days) in two male and female mouse models of insulin resistance decreases β-cell senescence. In vivo and in vitro experiments revealed that this effect is mediated, at least in part, by training-induced increases in serum glucagon, leading to activation of 5'-AMP-activated protein kinase (AMPK) signalling in β-cells. AMPK activation resulted in the nuclear translocation of NRF2 and decreased expression of senescence markers and effectors. Remarkably, human islets from male and female donors with T2DM treated with serum collected after a 10-week endurance exercise training programme showed a significant decrease in the levels of senescence markers. These findings indicate that exercise training decreases senescence in pancreatic islets, offering promising therapeutic implications for T2DM., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2024
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3. Decreased IGF1R attenuates senescence and improves function in pancreatic β-cells.
- Author
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Iwasaki K, Lalani B, Kahng J, Carapeto P, Sanjines S, Hela F, Abarca C, Tsuji T, Darcy J, Bartke A, Tseng YH, Kulkarni RN, and Aguayo-Mazzucato C
- Subjects
- Animals, Mice, Glucose metabolism, Insulin metabolism, Receptor, IGF Type 1 metabolism, Signal Transduction genetics, Diabetes Mellitus, Type 2 genetics, Diabetes Mellitus, Type 2 metabolism, Insulin-Secreting Cells metabolism
- Abstract
Introduction: The enhanced β-cell senescence that accompanies insulin resistance and aging contributes to cellular dysfunction and loss of transcriptional identity leading to type 2 diabetes (T2D). While senescence is among the 12 recognized hallmarks of aging, its relation to other hallmarks including altered nutrient sensing (insulin/IGF1 pathway) in β-cells is not fully understood. We previously reported that an increased expression of IGF1R in mouse and human β-cells is a marker of older β-cells; however, its contribution to age-related dysfunction and cellular senescence remains to be determined., Methods: In this study, we explored the direct role of IGF1R in β-cell function and senescence using two independent mouse models with decreased IGF1/IGF1R signaling: a) Ames Dwarf mice (Dwarf
+/+ ), which lack growth hormone and therefore have reduced circulating levels of IGF1, and b) inducible β-cell-specific IGF1R knockdown (βIgf1rKD) mice., Results: Compared to Dwarf+/- mice, Dwarf+/+ mice had lower body and pancreas weight, lower circulating IGF1 and insulin levels, and lower IGF1R and p21Cip1 protein expression in β-cells, suggesting the suppression of senescence. Adult βIgf1rKD mice showed improved glucose clearance and glucose-induced insulin secretion, accompanied by decreased p21Cip1 protein expression in β-cells. RNA-Seq of islets isolated from these βIgf1rKD mice revealed the restoration of three signaling pathways known to be downregulated by aging: sulfide oxidation, autophagy, and mTOR signaling. Additionally, deletion of IGF1R in mouse β-cells increased transcription of genes important for maintaining β-cell identity and function, such as Mafa , Nkx6.1 , and Kcnj11 , while decreasing senescence-related genes, such as Cdkn2a , Il1b , and Serpine 1 . Decreased senescence and improved insulin-secretory function of β-cells were also evident when the βIgf1rKD mice were fed a high-fat diet (HFD; 60% kcal from fat, for 5 weeks)., Discussion: These results suggest that IGF1R signaling plays a causal role in aging-induced β-cell dysfunction. Our data also demonstrate a relationship between decreased IGF1R signaling and suppressed cellular senescence in pancreatic β-cells. Future studies can further our understanding of the interaction between senescence and aging, developing interventions that restore β-cell function and identity, therefore preventing the progression to T2D., 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 Iwasaki, Lalani, Kahng, Carapeto, Sanjines, Hela, Abarca, Tsuji, Darcy, Bartke, Tseng, Kulkarni and Aguayo-Mazzucato.)- Published
- 2023
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4. Editorial: Individual differences in second/foreign language speech production: multidisciplinary approaches and new sounds.
- Author
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Sun PP, Yuan B, Yan X, and Kahng J
- Abstract
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.
- Published
- 2023
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5. Development of a Novel Flow Cytometry-Based System for White Blood Cell Differential Counts: 10-color LeukoDiff.
- Author
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Park D, Chang J, Kahng J, Park H, Jo I, Kim Y, and Han K
- Subjects
- Adolescent, Adult, Aged, Automation, Color, Female, Humans, Leukemia, Myeloid, Acute diagnosis, Male, Middle Aged, Young Adult, Flow Cytometry, Leukocyte Count methods, Leukocytes cytology
- Abstract
Background: Flow cytometry (FCM) is commonly used to identify many cell populations. We developed a white blood cell (WBC) differential counting system for detecting abnormal cells using FCM incorporating 10 colors and 11 antibodies in a single tube, called "10-color LeukoDiff," and evaluated its performance., Methods: Ninety-one EDTA-anti-coagulated peripheral blood samples from 76 patients were analyzed using 10-color LeukoDiff. We compared 10 color LeukoDiff results with the results of manual differential count (manual diff). WBCs were classified into 17 cell populations: neutrophils, total lymphocytes, T lymphocytes, B lymphocytes, CD5 and CD19 co-expressing lymphocytes, natural killer cells, total monocytes, 16+ monocytes, eosinophils, immature granulocytes, basophils, myeloblasts, B-blasts, T-blasts, myeloid antigen-positive B-blasts, CD19- plasma cells, and 19+ plasma cells., Results: The correlations between the 10-color LeukoDiff and manual diff results were strong (r>0.9) for mature neutrophils, lymphocytes, eosinophils, immature granulocytes, and blasts and moderate for monocytes and basophils (r=0.86 and 0.74, respectively). There was no discrepancy in blast detection between 10-color LeukoDiff and manual diff results. Furthermore, 10-color LeukoDiff could differentiate the lineage of the blasts and separately count chronic lymphocytic leukemic cells and multiple myeloma cells., Conclusions: The 10-color LeukoDiff provided an accurate and comprehensive WBC differential count. The most important ability of 10-color LeukoDiff is to detect blasts accurately. This system is clinically useful, especially for patients with hematologic diseases, such as acute leukemia, chronic lymphocytic leukemia, and multiple myeloma. Application of this system will improve the development of FCM gating strategy designs., Competing Interests: No potential conflicts of interest relevant to this article were reported., (© The Korean Society for Laboratory Medicine.)
- Published
- 2019
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6. Clinical progress of human papillomavirus genotypes and their persistent infection in subjects with atypical squamous cells of undetermined significance cytology: Statistical and latent Dirichlet allocation analysis.
- Author
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Kim YS, Lee S, Zong N, and Kahng J
- Abstract
The present study aimed to investigate differences in prognosis based on human papillomavirus (HPV) infection, persistent infection and genotype variations for patients exhibiting atypical squamous cells of undetermined significance (ASCUS) in their initial Papanicolaou (PAP) test results. A latent Dirichlet allocation (LDA)-based tool was developed that may offer a facilitated means of communication to be employed during patient-doctor consultations. The present study assessed 491 patients (139 HPV-positive and 352 HPV-negative cases) with a PAP test result of ASCUS with a follow-up period ≥2 years. Patients underwent PAP and HPV DNA chip tests between January 2006 and January 2009. The HPV-positive subjects were followed up with at least 2 instances of PAP and HPV DNA chip tests. The most common genotypes observed were HPV-16 (25.9%, 36/139), HPV-52 (14.4%, 20/139), HPV-58 (13.7%, 19/139), HPV-56 (11.5%, 16/139), HPV-51 (9.4%, 13/139) and HPV-18 (8.6%, 12/139). A total of 33.3% (12/36) patients positive for HPV-16 had cervical intraepithelial neoplasia (CIN)2 or a worse result, which was significantly higher than the prevalence of CIN2 of 1.8% (8/455) in patients negative for HPV-16 (P<0.001), while no significant association was identified for other genotypes in terms of genotype and clinical progress. There was a significant association between clearance and good prognosis (P<0.001). Persistent infection was higher in patients aged ≥51 years (38.7%) than in those aged ≤50 years (20.4%; P=0.036). Progression from persistent infection to CIN2 or worse (19/34, 55.9%) was higher than clearance (0/105, 0.0%; P<0.001). In the LDA analysis, using symmetric Dirichlet priors α=0.1 and β=0.01, and clusters (k)=5 or 10 provided the most meaningful groupings. Statistical and LDA analyses produced consistent results regarding the association between persistent infection of HPV-16, old age and long infection period with a clinical progression of CIN2 or worse. Therefore, LDA results may be presented as explanatory evidence during time-constrained patient-doctor consultations in order to deliver information regarding the patient's status.
- Published
- 2017
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7. Development of a cervical cancer progress prediction tool for human papillomavirus-positive Koreans: A support vector machine-based approach.
- Author
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Kahng J, Kim EH, Kim HG, and Lee W
- Subjects
- Adolescent, Adult, Age Factors, Aged, Biopsy, Child, Female, Genotype, Humans, Middle Aged, Papillomaviridae genetics, Papillomaviridae physiology, Republic of Korea, Sensitivity and Specificity, Uterine Cervical Neoplasms pathology, Vaginal Smears, Young Adult, Asian People, Disease Progression, Support Vector Machine, Uterine Cervical Neoplasms diagnosis, Uterine Cervical Neoplasms virology
- Abstract
Objectives: To develop a Web-based tool to draw attention to patients positive for human papillomavirus (HPV) who have a high risk of progression to cervical cancer, in order to increase compliance with follow-up examinations and facilitate good doctor-patient communication., Methods: Records were retrospectively analysed from women who were positive for HPV on initial testing (before any treatment). Information concerning age, Papanicolaou (PAP) smear result and presence of 15 high-risk HPV genotypes was used in a support vector machine (SVM) model, to identify the patient features that maximally contributed to progression to high-risk cervical lesions., Results: Data from 731 subjects were analysed. The maximum number of correct cancer predictions was seen when four features (PAP, HPV16, HPV52 and HPV35) were used, giving an accuracy of 74.41%. A web-based high-risk cervical lesion prediction application tool was developed using the SVM model results., Conclusions: Use of the web-based prediction tool may help to increase patient compliance with physician advice, and may heighten awareness of the significance of regular follow-up HPV examinations for the prevention of cervical cancer, in Korean women predicted to have heightened risk of the disease., (© The Author(s) 2015.)
- Published
- 2015
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8. The effect of thioctic acid on allodynia in a rat vincristine-induced neuropathy model.
- Author
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Kahng J, Kim TK, Chung EY, Kim YS, and Moon JY
- Subjects
- Animals, Disease Models, Animal, Dose-Response Relationship, Drug, Hyperalgesia chemically induced, Inflammation chemically induced, Neuralgia drug therapy, Pain Measurement, Peripheral Nervous System Diseases drug therapy, Rats, Rats, Sprague-Dawley, Vincristine adverse effects, Anti-Inflammatory Agents therapeutic use, Antioxidants therapeutic use, Hyperalgesia drug therapy, Inflammation drug therapy, Thioctic Acid therapeutic use
- Abstract
Objective: To investigate the antiallodynic effects of thioctic acid in vincristine-induced neuropathy in rats., Methods: Neuropathy was induced in Sprague-Dawley rats via vincristine intraperitoneal injection. After 15 days, rats were investigated for the presence of mechanical and cold allodynia, and those with allodynia received intraperitoneal injection with normal saline or 1, 5, or 10 mg/kg thioctic acid. Mechanical and cold allodynia were assessed before treatment and at 15, 30, 60, 90, 150 and 180 min after treatment., Results: Mechanical and cold allodynia were reduced by thioctic acid injection. The duration of effect increased with thioctic acid dose., Conclusion: Thioctic acid may be an effective treatment for vincristine-induced neuropathy., (© The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)
- Published
- 2015
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9. A novel marker for screening paroxysmal nocturnal hemoglobinuria using routine complete blood count and cell population data.
- Author
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Kahng J, Kim Y, Kim JO, Koh K, Lee JW, and Han K
- Subjects
- Biomarkers metabolism, Blood Cell Count, CD24 Antigen metabolism, CD55 Antigens metabolism, CD59 Antigens metabolism, Erythrocytes cytology, Erythrocytes metabolism, Flow Cytometry, Granulocytes cytology, Granulocytes metabolism, Hemoglobinuria, Paroxysmal metabolism, Humans, Lewis X Antigen metabolism, Sensitivity and Specificity, Hemoglobinuria, Paroxysmal diagnosis
- Abstract
Background: Final diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) may take years demanding a quick diagnosis measure. We used the facts that PNH cells are damaged in acid, and reagents for measuring reticulocytes in Coulter DxH800 (Beckman Coulter, USA) are weakly acidic and hypotonic, to create a new PNH screening marker., Methods: We analyzed 979 complete blood counts (CBC) data from 963 patients including 57 data from 44 PNH patients. Standard criteria for PNH assay for population selection were followed: flow cytometry for CD55 and CD59 on red blood cells (RBCs) to a detection level of 1%; and fluorescent aerolysin, CD24 and CD15 in granulocytes to 0.1%. Twenty-four PNH minor clone-positive samples (minor-PNH+) were taken, in which the clone population was <5% of RBCs and/or granulocytes. Excluding PNH and minor-PNH+ patients, the population was divided into anemia, malignancy, infection, and normal groups. Parameters exhibiting a distinct demarcation between PNH and non-PNH groups were identified, and each parameter cutoff value was sought that includes the maximum [minimum] number of PNH [non-PNH] patients., Results: Cutoff values for 5 selected CBC parameters (MRV, RDWR, MSCV, MN-AL2-NRET, and IRF) were determined. Positive rates were: PNH (86.0%), minor-PNH+ (33.3%), others (5.0%), anemia (13.4%), malignancy (5.3%), infection (3.7%), normal (0.0%); within anemia group, aplastic anemia (40.0%), immune hemolytic anemia (11.1%), iron deficiency anemia (1.6%). Sensitivity (86.0%), specificity (95.0%), PPV (52.1%), and NPV (99.1%) were achieved in PNH screening., Conclusion: A new PNH screening marker is proposed with 95% specificity and 86% sensitivity. The flag identifies PNH patients, reducing time to final diagnosis by flow cytometry.
- Published
- 2015
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10. Flow cytometric white blood cell differential using CytoDiff is excellent for counting blasts.
- Author
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Kahng J, Kim Y, Kim M, Oh EJ, Park YJ, and Han K
- Subjects
- Adult, Female, Humans, Leukocyte Count, Lymphocytes cytology, Male, Neutrophils cytology, Flow Cytometry instrumentation, Leukocytes cytology
- Abstract
Background: The usefulness of the CytoDiff flow cytometric system (Beckman Coulter, USA) has been studied in various conditions, but its performance including rapidity in detecting and counting blasts, the most significant abnormal cells in the peripheral blood, has not been well evaluated. The objective of this study was to evaluate the performance of the CytoDiff differential counting method in challenging samples with blasts., Methods: In total, 815 blood samples were analyzed. Samples flagged as "blasts" or "variant lymphocytes" and showing <10% blasts by manual counts were included. In total, 322 samples showed blasts on manual counts, ranging from 0.5% to 99%. The CytoDiff method was performed by flow cytometry (FC500; Beckman Coulter, USA) with a pre-mixed CytoDiff reagent and analyzing software (CytoDiff CXP 2.0; Beckman Coulter)., Results: The average time required to analyze 20 samples was approximately 60 min for manual counts, and the hands-on time for the CytoDiff method was 15 min. The correlation between the CytoDiff and manual counts was good (r>0.8) for neutrophils and lymphocytes but poor (r<0.8) for other cells. When the cutoff value of the CytoDiff blast count was set at 1%, the sensitivity was 94.4% (95% CI; 91.2-96.6) and specificity was 91.9% (95% CI; 89.0-94.1). The positive predictive value was 88.4% (95% CI; 84.4-91.5) (304/344 cases) and negative predictive value was 96.2% (95% CI; 93.9-97.7) (453/471 cases). The CytoDiff blast counts correlated well to the manual counts (r=0.9223)., Conclusions: The CytoDiff method is a specific, sensitive, and rapid method for counting blasts. A cutoff value of 1% of at least 1 type of blast is recommended for positive CytoDiff blast counts.
- Published
- 2015
- Full Text
- View/download PDF
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