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Abstract Background Disruptions in intracellular pH (pHi) homeostasis, causing deviations from the physiological range, can damage renal epithelial cells. However, the existence of an adaptive mechanism to restore pHi to normalcy remains unclear. Early research identified H+ as a critical mediator of ischemic preconditioning (IPC), leading to the concept of acidic preconditioning (AP). This concept proposes that short-term, repetitive acidic stimulation can enhance a cell’s capacity to withstand subsequent adverse stress. While AP has demonstrated protective effects in various ischemia-reperfusion (I/R) injury models, its application in kidney injury remains largely unexplored. Methods An AP model was established in human kidney (HK2) cells by treating them with an acidic medium for 12 h, followed by a recovery period with a normal medium for 6 h. To induce hypoxia/reoxygenation (H/R) injury, HK2 cells were subjected to hypoxia for 24 h and reoxygenation for 1 h. In vivo, a mouse model of IPC was established by clamping the bilateral renal pedicles for 15 min, followed by reperfusion for 4 days. Conversely, the I/R model involved clamping the bilateral renal pedicles for 35 min and reperfusion for 24 h. Western blotting was employed to evaluate the expression levels of cleaved caspase 3, cleaved caspase 9, NHE1, KIM1, FAK, and NOX4. A pH-sensitive fluorescent probe was used to measure pHi, while a Hemin/CNF microelectrode monitored kidney tissue pH. Immunofluorescence staining was performed to visualize the localization of NHE1, NOX4, and FAK, along with the actin cytoskeleton structure in HK2 cells. Cell adhesion and scratch assays were conducted to assess cell motility. Results Our findings demonstrated that AP could effectively mitigate H/R injury in HK2 cells. This protective effect and the maintenance of pHi homeostasis by AP involved the upregulation of Na+/H+ exchanger 1 (NHE1) expression and activity. The activity of NHE1 was regulated by dynamic changes in pHi-dependent phosphorylation of Focal Adhesion Kinase (FAK) at Y397. This process was associated with NOX4-mediated reactive oxygen species (ROS) production. Furthermore, AP induced the co-localization of FAK, NOX4, and NHE1 in focal adhesions, promoting cytoskeletal remodeling and enhancing cell adhesion and migration capabilities. Conclusions This study provides compelling evidence that AP maintains pHi homeostasis and promotes cytoskeletal remodeling through FAK/NOX4/NHE1 signaling. This signaling pathway ultimately contributes to alleviated H/R injury in HK2 cells.

Introduction Hypertension and rising serum uric acid (sUA) played a pivotal role in the development of Chronic Kidney Disease (CKD). This study investigates the interactive effect of sUA and hypertension on CKD and identifies the optimal threshold of sUA among individuals with and without hypertension in the Chinese community population.Materials and methods The study included 4180 individuals aged 45–85 years, derived from the China Health and Retirement Longitudinal Study (CHARLS) between 2011 and 2015. Additionally, a hospital-based study enrolled subjects in the Department of Nephrology at Zhongshan Hospital, China from January 1, 2019, to December 31, 2021. The interaction effect analysis were used to assess the impact of sUA and hypertension on CKD. We also compared the distribution of sUA and the CKD risk in community populations, distinguishing between those with and without hypertension. For the hospital-based population, kidney injury was marked by a KIM-1 positive area.Results Our results indicate a higher prevalence of CKD in the community population with hypertension (10.2% vs. 3.9%, p

Abstract Pulmonary fibrosis (PF) is a severe pulmonary disease with limited available therapeutic choices. Recent evidence increasingly points to abnormal lipid metabolism as a critical factor in PF pathogenesis. Our latest research identifies the dysregulation of low-density lipoprotein (LDL) is a new risk factor for PF, contributing to alveolar epithelial and endothelial cell damage, and fibroblast activation. In this study, we first integrative summarize the published literature about lipid metabolite changes found in PF, including phospholipids, glycolipids, steroids, fatty acids, triglycerides, and lipoproteins. We then reanalyze two single-cell RNA-sequencing (scRNA-seq) datasets of PF, and the corresponding lipid metabolomic genes responsible for these lipids’ biosynthesis, catabolism, transport, and modification processes are uncovered. Intriguingly, we found that macrophage is the most active cell type in lipid metabolism, with almost all lipid metabolic genes being altered in macrophages of PF. In type 2 alveolar epithelial cells, lipid metabolic differentially expressed genes (DEGs) are primarily associated with the cytidine diphosphate diacylglycerol pathway, cholesterol metabolism, and triglyceride synthesis. Endothelial cells are partly responsible for sphingomyelin, phosphatidylcholine, and phosphatidylethanolamines reprogramming as their metabolic genes are dysregulated in PF. Fibroblasts may contribute to abnormal cholesterol, phosphatidylcholine, and phosphatidylethanolamine metabolism in PF. Therefore, the reprogrammed lipid profiles in PF may be attributed to the aberrant expression of lipid metabolic genes in different cell types. Taken together, these insights underscore the potential of targeting lipid metabolism in developing innovative therapeutic strategies, potentially leading to extended overall survival in individuals affected by PF.

Abstract Background No uniform consensus has been achieved regarding the ambulation protocol after transfemoral cerebral angiography (TFA). Until now, in most hospitals patients are prescribed 8-12 h strict immobilization along with bed rest in the supine position after TFA in China, which causes great discomfort to patients. Objective To evaluate the effect of an evidence-based early ambulation protocol on the prevention of vascular complications and general discomfort in patients following transfemoral cerebral angiography (TFA). Methods A prospective quasi-experimental study was conducted on 214 patients undergoing TFA with manual compression. Patients in the experimental group were placed supine position for 2 h with a sandbag placed on the wound dressing, followed by a semi-seated position for another 2 h. After this period, patients took 2 h bed rest (move freely) with the sandbag removed, and were allowed to get out of bed 6 h after TFA. Patients in the control group were restricted to an 8 h bed rest in a supine position with the affected leg straight and immobilized. The vascular complications (bleeding, hematoma, ecchymosis) and levels of comfort (low back pain, leg pain, and blood pressure) were evaluated after the procedure. Numeric Rating Scale (NRS) pain scores, systolic blood pressure (SBP); diastolic blood pressure (DBP) were measured hourly for 8 h after TFA. Results There was no significant difference in the two groups with regard to vascular complications including bleeding events (P = 0.621), bleeding volume (P = 0.321), and area of hematoma (P = 0.156). The area of ecchymosis in the experimental group was significantly smaller than the control group (P = 0.031). Compared with the control group, the NRS score for low back pain in the 4th, 5th, 6th, 7th, and 8th hour after TFA were significantly lower (P

Abstract Background Chronic kidney disease (CKD) is a global public health concern. Therefore, to provide timely intervention for non-hospitalized high-risk patients and rationally allocate limited clinical resources is important to mine the key factors when designing a CKD prediction model. Methods This study included data from 1,358 patients with CKD pathologically confirmed during the period from December 2017 to September 2020 at Zhongshan Hospital. A CKD prediction interpretation framework based on machine learning was proposed. From among 100 variables, 17 were selected for the model construction through a recursive feature elimination with logistic regression feature screening. Several machine learning classifiers, including extreme gradient boosting, gaussian-based naive bayes, a neural network, ridge regression, and linear model logistic regression (LR), were trained, and an ensemble model was developed to predict 24-hour urine protein. The detailed relationship between the risk of CKD progression and these predictors was determined using a global interpretation. A patient-specific analysis was conducted using a local interpretation. Results The results showed that LR achieved the best performance, with an area under the curve (AUC) of 0.850 in a single machine learning model. The ensemble model constructed using the voting integration method further improved the AUC to 0.856. The major predictors of moderate-to-severe severity included lower levels of 25-OH-vitamin, albumin, transferrin in males, and higher levels of cystatin C. Conclusions Compared with the clinical single kidney function evaluation indicators (eGFR, Scr), the machine learning model proposed in this study improved the prediction accuracy of CKD progression by 17.6% and 24.6%, respectively, and the AUC was improved by 0.250 and 0.236, respectively. Our framework can achieve a good predictive interpretation and provide effective clinical decision support.

With the rapid development of China's economy and society, the innovation of grassroots social governance has become increasingly important. This paper constructs 35 grassroots social governance innovation samples. Using the TOE theoretical framework and a fuzzy set qualitative comparative analysis (fsQCA), this paper analyzes the joint effects and interactive relationships of multiple factors on grassroots social governance innovation performance from three dimensions: technology, organization, and environment. The research reveals that internal environmental openness is a necessary condition for achieving high innovation performance in grassroots social governance, and proposes four grouping models that affect the performance of grassroots social governance innovation. This paper explores the inner logic of grassroots social governance innovation from a histological perspective, and on this basis proposes an adaptive path to enhance the performance of grassroots social governance innovation.

Background: Burns are a common concern around the world, with the majority of cases happening in low- and middle-income nations. China is the largest developing country. With the unremitting efforts of domestic colleagues, China has taken the lead in the treatment of burn in the world. With the change of times, we have observed some noteworthy changes in the types of patients that have admitted our Burns and Plastic Surgery, the Affiliated Hospital of Yangzhou University. Methods: This retrospective observational study included brought into; all patients reached to our burn unit during 2013–2021. The gathered data were descriptively examined and statistically contrasted with each other year. Results: Of 4407 cases admitted to burn unit during 2013–2021, men constituted 56 % of such cases, with an average age of 47.3 ± 19.3 years. Moreover, among the patients hospitalized, January and February usually admit fewer than other months. Between 2013 and 2021, both the number of patients admitted to burn unit and the expense of their hospitalization rose yearly. The percentage of burn patients admitted to burn ward of our hospital is decreasing, especially during the period of serious Coronavirus disease (COVID-19) epidemic. We also observed that during the COVID-19 pandemic, patients with superficial masses also dropped off a cliff because of government controls. Conclusion: The diseases in the department show the trend of maximizing marginal disciplines, burn surgeons are facing a more complex challenge. Further research addressing the relationship between the change of patient types and economic and social development in burn department will help to foster better pinpoint hospitalization patients need, fine service for hospitalized patients.

The mortality rate associated with acute lung injury (ALI) and its severe form, acute respiratory distress syndrome, is high. Induced pluripotent stem cell (iPSC) therapy is a potential treatment method for ALI, but its therapeutic efficacy is limited in injured lungs. Nitric oxide (NO) has various physiological actions. The current study investigated the effect of iPSCs pretreated with NO donors in paraquat (PQ)-induced ALI mouse model. Male C57BL/6 mice were intraperitoneally injected with PQ, followed by infusion of phosphate-buffered saline, iPSCs, L-arginine pretreated iPSCs, or Nitro-L-arginine methylester (L-NAME) pretreated iPSCs through the tail veins. Histopathological changes, pulmonary microvascular permeability, and inflammatory cytokine levels were analyzed after 3 or 28 d. The effects on iPSC proliferation, migration, and adhesion were evaluated in vitro. More L-arginine-pretreated iPSCs were selectively trafficked into the injured pulmonary tissue of mice with LPS-induced ALI, drastically diminishing the histopathologic changes and inflammatory cytokine levels (IL-1β and IL-6). There was also markedly improved pulmonary microvascular permeability and pulmonary function. The NO inhibitor abolished the protective effects of iPSCs. In addition, the ability of L-arginine to promote the proliferation and migration of iPSCs was decreased by L-NAME pretreatment, suggesting that NO might mediate the therapeutic benefits of iPSC. The improvement of the iPSC physiological changes by the endogenous gaseous molecule NO reduces lung injury severity. L-Arginine represents a pharmacologically important strategy for enhancing the therapeutic potential of iPSCs.

Abstract Background We aimed to explore the association between long-term drinking behavior change patterns with hyperuricemia (HUA) in Chinese community adults. Methods This study was designed as a community-based unbalanced cohort study involving 4127 adults aged between 18 ~ 75 years, derived from the China Health and Nutrition Survey (CHNS) in 1997 and 2009. Drinking behavior change patterns were categorized into: never drinking, change to drinking, quitting drinking, and continued drinking. The alcoholism, type, and frequency of drinking were further categorized. We applied logistic regression models to explore the associations between drinking behavior change patterns and HUA. Results The average age of the participants was 54.6 (± 11.3) years and 47.8% were male. The overall prevalence of HUA was 15.5%. Drinking behavior change patterns of quitting (aOR 1.8; 95% CI 1.1 ~ 2.8) and continued drinking (aOR 2.0; 95% CI 1.3 ~ 3.0) were positively associated with high risks of HUA in the male participants. Early drinking behaviors such as liquor intake (aOR 1.8; 95% CI 1.4 ~ 2.5) and high consumption or frequency showed a positive correlation with HUA. Of note, heavy alcoholism (aOR 2.0; 95% CI 1.4 ~ 2.8) and daily drinking (aOR 2.5; 95% CI 1.7 ~ 3.6) had the highest risks of HUA. Furthermore, in the male participants, the association between early total alcohol intake and HUA was more pronounced at 18 standard drinks intake, with a stable increasing trend. In contrast, no statistical correlation was observed between the drinking behaviors and HUA in the female participants. Conclusions Drinking behavior change patterns of quitting and continued drinking are strongly associated with increased risks of HUA in males. The risks emanated from early drinking behaviors such as liquor drinking, high drinking frequency, and alcohol consumption. Although quitting drinking was associated with lower HUA risks compared to continued drinking, it still presented an undeniable risk for HUA.

Abstract Purpose Genetic testing is widely used in diagnosing genetic hearing loss in patients. Other than providing genetic etiology, the benefits of genetic testing in pediatric patients with hearing loss are less investigated. Methods From 2018–2020, pediatric patients who initially presented isolated hearing loss were enrolled. Comprehensive genetic testing, including GJB2/SLC26A4 multiplex amplicon sequencing, STRC/OTOA copy number variation analysis, and exome sequencing, were hierarchically offered. Clinical follow-up and examinations were performed. Results A total of 80 pediatric patients who initially presented isolated hearing loss were considered as nonsyndromic hearing loss and enrolled in this study. The definitive diagnosis yield was 66% (53/80) and the likely diagnosis yield was 8% (6/80) through comprehensive genetic testing. With the aid of genetic testing and further clinical follow-up and examinations, the clinical diagnoses and medical management were altered in eleven patients (19%, 11/59); five were syndromic hearing loss; six were nonsyndromic hearing loss mimics. Conclusion Syndromic hearing loss and nonsyndromic hearing loss mimics are common in pediatric patients who initially present with isolated hearing loss. The comprehensive genetic testing provides not only a high diagnostic yield but also valuable information for clinicians to uncover subclinical or pre-symptomatic phenotypes, which allows early diagnosis of SHL, and leads to precise genetic counseling and changes the medical management.

Abstract Arterial baroreceptors (BRs) play a vital role in the regulation of the cardiopulmonary system. What is known about how these sensors operate at the subcellular level is limited, however. Until recently, one afferent axon was considered to be connected to a single baroreceptor (one-sensor theory). However, in the lung, a single airway mechanosensory unit is now known to house many sensors (multiple-sensor theory). Here we tested the hypothesis that multiple-sensor theory also operates in BR units, using both morphological and electrophysiological approaches in rabbit aortic arch (in whole mount) labeled with Na+/K+-ATPase, as well as myelin basic protein antibodies, and examined microscopically. Sensory structures presented in compact clusters, similar to bunches of grapes. Sensory terminals, like those in the airways, formed leaf-like or knob-like expansions. That is, a single myelinated axon connected with multiple sensors forming a network. We also recorded single-unit activities from aortic baroreceptors in the depressor nerve in anesthetized rabbits and examined the unit response to a bolus intravenous injection of phenylephrine. Unit activity increased progressively as blood pressure (BP) increased. Five of eleven units abruptly changed their discharge pattern to a lower activity level after BP attained a plateau for a minute or two (when BP was maintained at the high level). These findings clearly show that the high discharge baroreceptor deactivates after over-excitation and unit activity falls to a low discharge sensor. In conclusion, our morphological and physiological data support the hypothesis that multiple-sensory theory can be applied to BR units.

Summary: TWIK-related acid-sensitive K+ channel-2 (TASK-2, encoded by Kcnk5) is essential in cell biological processes, by regulating transmembrane K+ balance. In the present study, we aimed to clarify the role of TASK-2 in renal fibrosis and explore the underlying mechanism. We found that TASK-2 level was elevated in the renal tubular UUO- and UIR-induced renal fibrosis as well as in patients with renal tubulointerstitial fibrosis. Knockout of Kcnk5 or inhibition of TASK-2 in renal tubules attenuated G2/M cell-cycle arrest and alleviated renal fibrosis. Mechanistically, demethylase fat mass and obesity-associated protein (FTO) reduced N6-adenosine methylation (m6A) of Kcnk5 mRNA following renal fibrosis. FTO deficiency attenuated the upregulation of TASK-2 and renal fibrosis. The results demonstrated the crucial role of TASK-2 in renal fibrosis, which is conducive to a better understanding of the pathogenesis of renal fibrosis. TASK-2 may be a potential treatment strategy to alleviate the development of renal fibrosis.

Abstract Podocytes are known to play a determining role in the progression of proteinuric kidney disease. N6-methyladenosine (m6A), as the most abundant chemical modification in eukaryotic mRNA, has been reported to participate in various pathological processes. However, its role in podocyte injury remains unclear. In this study, we observed the elevated m6A RNA levels and the most upregulated METTL14 expression in kidneys of mice with adriamycin (ADR) and diabetic nephropathy. METTL14 was also evidently increased in renal biopsy samples from patients with focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy and in cultured human podocytes with ADR or advanced glycation end product (AGE) treatment in vitro. Functionally, we generated mice with podocyte-specific METTL14 deletion, and identified METTL14 knockout in podocytes improved glomerular function and alleviated podocyte injury, characterized by activation of autophagy and inhibition of apoptosis and inflammation, in mice with ADR nephropathy. Similar to the results in vivo, knockdown of METTL14 facilitated autophagy and alleviated apoptosis and inflammation in podocytes under ADR or AGE condition in vitro. Mechanically, we identified METTL14 knockdown upregulated the level of Sirt1, a well-known protective deacetylase in proteinuric kidney diseases, in podocytes with ADR or AGE treatment. The results of MeRIP-qPCR and dual-luciferase reporter assay indicated METTL14 promoted Sirt1 mRNA m6A modification and degradation in injured podocytes. Our findings suggest METTL14-dependent RNA m6A modification contributes to podocyte injury through posttranscriptional regulation of Sirt1 mRNA, which provide a potential approach for the diagnosis and treatment of podocytopathies.

Abstract Hearing loss is one of the most common birth disorders in humans, with an estimated prevalence of 1–3 in every 1000 newborns. This study investigates the molecular etiology of a hearing loss cohort using a stepwise strategy to effectively diagnose patients and address the challenges posed by the genetic heterogeneity and variable mutation spectrum of hearing loss. In order to target known pathogenic variants, multiplex PCR plus next-generation sequencing was applied in the first step; patients which did not receive a diagnosis from this were further referred for exome sequencing. A total of 92 unrelated patients with nonsyndromic hearing loss were enrolled in the study. In total, 64% (59/92) of the patients were molecularly diagnosed, 44 of them in the first step by multiplex PCR plus sequencing. Exome sequencing resulted in eleven diagnoses (23%, 11/48) and four probable diagnoses (8%, 4/48) among the 48 patients who were not diagnosed in the first step. The rate of secondary findings from exome sequencing in our cohort was 3% (2/58). This research presents a molecular diagnosis spectrum of 92 non-syndromic hearing loss patients and demonstrates the benefits of using a stepwise diagnostic approach in the genetic testing of nonsyndromic hearing loss.

Abstract Treatments for pulmonary fibrosis (PF) are ineffective because its molecular pathogenesis and therapeutic targets are unclear. Here, we show that the expression of low‐density lipoprotein receptor (LDLR) was significantly decreased in alveolar type II (ATII) and fibroblast cells, whereas it was increased in endothelial cells from systemic sclerosis‐related PF (SSc‐PF) patients and idiopathic PF (IPF) patients compared with healthy controls. However, the plasma levels of low‐density lipoprotein (LDL) increased in SSc‐PF and IPF patients. The disrupted LDL–LDLR metabolism was also observed in four mouse PF models. Upon bleomycin (BLM) treatment, Ldlr‐deficient (Ldlr−/−) mice exhibited remarkably higher LDL levels, abundant apoptosis, increased fibroblast‐like endothelial and ATII cells and significantly earlier and more severe fibrotic response compared to wild‐type mice. In vitro experiments revealed that apoptosis and TGF‐β1 production were induced by LDL, while fibroblast‐like cell accumulation and ET‐1 expression were induced by LDLR knockdown. Treatment of fibroblasts with LDL or culture medium derived from LDL‐pretreated endothelial or epithelial cells led to obvious fibrotic responses in vitro. Similar results were observed after LDLR knockdown operation. These results suggest that disturbed LDL–LDLR metabolism contributes in various ways to the malfunction of endothelial and epithelial cells, and fibroblasts during pulmonary fibrogenesis. In addition, pharmacological restoration of LDLR levels by using a combination of atorvastatin and alirocumab inhibited BLM‐induced LDL elevation, apoptosis, fibroblast‐like cell accumulation and mitigated PF in mice. Therefore, LDL–LDLR may serve as an important mediator in PF, and LDLR enhancing strategies may have beneficial effects on PF.

Background: There is limited evidence on the relationship between social isolation and renal outcomes. To address this gap, this study estimated the prospective relationship of social isolation with rapid kidney function decline and the development of chronic kidney disease (CKD) in middle-aged and elderly Chinese with normal kidney function.Methods: We analyzed data from 3,031 participants aged ≥ 45 years with baseline estimated glomerular filtration rates (eGFR) ≥ 60 ml/min/1.73 m2. All data were obtained from the 2011 and 2015 waves of the Chinese Longitudinal Study of Health and Retirement (CHARLS). eGFR was estimated based on a combination of serum creatinine and cystatin C. The primary outcome was rapid decline in renal function, as defined by an eGFR decrease of > 5 ml/min/1.73 m2 per year, while the secondary outcome was the development of CKD, as defined by an eGFR decrease to a level < 60 ml/min/1.73 m2.Results: During the follow-up of 4 years, 258 (8.5%) participants experienced a rapid decline in renal function, while 87 (2.9%) developed CKD. In the fully adjusted model, high social isolation was significantly related to an increased risk of experiencing a rapid decline in renal function (OR 1.805, 95% CI 1.310–2.487) and CKD onset (OR 1.842, 95% CI 1.084–3.129). Among the five components of social isolation, being unmarried, not participating in social activities, and living alone independently predicted declined renal function.Conclusions: Social isolation is significantly associated with the risk of rapid eGFR decline and CKD onset in middle-aged and older adults with normal kidney function in China.

IntroductionThe current study sought to explore the effect of baseline serum uric acid (SUA) on the risk of all-cause mortality among Chinese adults aged 45~75 years and to determine its interaction relationship with diabetes.MethodsThe study was designed as a community-based cohort of 4467 adults aged between 45~75 years included in a 6-years follow-up period from 2009 to 2015 years by the China Health and Nutrition Survey (CHNS). Baseline SUA levels were grouped into quartiles and its association on all-cause mortality was explored using multivariate Cox proportional hazards models. Stratified analyses were performed to explore the associations of SUA quartiles with all-cause mortality among diabetic and non-diabetic individuals.ResultsA total of 141 deaths (5.3 per 1000 person-years) were recorded During a follow-up of 26431 person-years. Out of the 141 deaths, 28 deaths (10.1 per 1000 person-years) were reported in the diabetic groups and 113 deaths (4.8 per 1000 person-years) were recorded in the non-diabetic group. An increased risk of all-cause mortality was observed for participants in the first and fourth quartiles compared with the second SUA quartile, (Q1 SUA: aHR=2.1, 95% CI 1.1~4.1; Q4 SUA: aHR=2.1, 95% CI 1.1~4.0). Stratification of participants by diabetes status showed a U-shaped association for non-diabetic individuals. Whereas, declined eGFR, rather than SUA, was an independent risk factor for all-cause mortality in diabetic individuals (aHR=0.7, 95% CI 0.6~1.0).ConclusionOur study proved that the prognostic role of SUA for predicting all-cause death might be regulated by diabetes. Both low and high SUA levels were associated with increased mortality, supporting a U-shaped association only in non-diabetic individuals. Whereas, renal dysfunction rather than SUA was an independent risk factor for all-cause mortality. Further studies should be conducted to determine the SUA levels at which intervention should be conducted and explore target follow-up strategies to prevent progression leading to poor prognosis.

ABSTRACT Candida albicans is the most common human fungal pathogen, causing diseases ranging from mucosal to systemic infections for both immunocompetent and immunocompromised individuals. Lysine 2-hydroxyisobutyrylation is a highly conserved posttranslational modification found in a wide variety of organisms. In this study, we surveyed the biological impact of 2-hydroxyisobutyrylation on lysine residuals (Khib) in C. albicans. Using an antibody enrichment approach along with the traditional liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, we analyzed the pattern of Khib-modified proteins and sites in one wild-type strain of C. albicans. We identified 1,438 Khib-modified proteins with 6,659 modified sites in this strain, and a more detailed bioinformatics analysis indicated that the Khib-modified proteins are involved in a wide range of cellular functions with diverse subcellular locations. Functional enrichment analysis featured several prominent functional pathways, including ribosome, biosynthesis of antibiotics, biosynthesis of secondary metabolites, biosynthesis of amino acids and carbon metabolism, of which the ribosome pathway is the most affected pathway. Even compared with the reported numbers of lysine acetylation (Kac) and succinylation (Ksuc) sites, the numbers of Khib-modified sites on ribosomal proteins remained the highest for C. albicans. These bioinformatic results suggest that 2-hydroxyisobutyrylation may play an indispensable role in the regulation of the ribosomal biogenesis and protein translation. Findings in this study may provide new insights for studying posttranslational modification (PTM)-associated mechanisms in fungal development and pathogenicity. IMPORTANCE C. albicans is one of the most commonly reported fungal pathogens in mucosal and systemic infections. A better understanding of its growth habits and metabolic processes in the host should help improve defense strategies. The newly discovered protein posttranslational modification (PTM) on histones is one epigenetic mechanism which has been linked to many pathogenic events, including cancers. The types of PTM and their pathogenic roles in C. albicans are still somewhat poorly understood, even though studies of C. albicans based on acetylation inhibitors have shed some light on their function, and it seems that PTMs regulate pathogenic adhesion factors. Here, we quantified and analyzed the occurrence of lysine 2-hydroxyisobutyrylation (Khib) in C. albicans. The Khib-modified proteins are enriched with respect to carbon metabolism, ribosomal biogenesis, and protein translation in C. albicans.

ABSTRACT Candida albicans is an opportunistic pathogen that causes lethal fungal infections in immunocompromised patients. Lysine crotonylation is a newly discovered PTM (posttranslational modification) epigenetic type that may play a critical role in regulating gene expression. In this study, we used an antibody-enrichment approach along with LC-MS/MS to carry out a quantitative crotonylome analysis in C. albicans. We found a total of 5,242 crotonylation sites and 1,584 crotonylated proteins among 9,038 proteins in this organism. Of these crotonylated proteins, a few unique crotonylated motifs are noted such as D and E in positions +1, +2, or +3 or K and R in positions +5 or +6, while A, E, F, G, P, W, and Y are in the −1 position or A, K, and R are found in positions −5, −6, −7, or −8. Functional analysis has shown that a majority of the crotonylated proteins are related to biosynthetic events and carbon metabolism. When combined with previously collected data on acetylation and succinylation, PPI (protein-protein interaction network) analysis reveals that proteins with functions in ribosomal biogenesis, oxidative phosphorylation, nucleus activity, and proteasome formation are heavily modified by these three PTM types. To the best of our knowledge, this is the first crotonylome study carried out in C. albicans and is an important step to a better understanding of the biological and pathogenic impact of PTM in C. albicans. IMPORTANCE C. albicans is a kind of pathogen of fungal infections that is found worldwide. Lysine crotonylation of proteins as a recently discovered PTM (posttranslational modification) may have a critical role in regulating cells. We first carried out large-scale analysis of crotonylated proteome and multiple PTM analysis (acetylation, succinylation, and crotonylation), then drew a diagram to show multiple PTM sites on histones in C. albicans of our study. This study about crotonylome in human pathogenic fungi is a milestone that first and deeply investigates the functional analysis of crotonylated proteins in C. albicans, which marks an important start for further research.

Renal tubule-interstitial fibrosis is related to chronic kidney disease progression and a typical feature of the aging kidney. Epigenetic modifications of fibrosis-prone genes regulate the development of renal fibrosis. As a kind of “epigenetic diet”, soy isoflavone genistein was reported to have renal protective action and epigenetic-modulating effects. However, its renal protection role and underlying mechanisms are yet to be fully clarified. Herein, we showed that genistein exhibits a demonstrable anti-fibrotic effect on kidney in vivo UUO (unilateral ureteral occlusion) model and renal epithelial cells in vitro model. The mechanism is strongly associated with epithelial-to-mesenchymal transition and m6A RNA demethylase ALKBH5. Mouse fibrotic kidneys induced by UUO exhibited adverse expression of renal fibrosis-related proteins and significant increases in the total m6A level. As an eraser, ALKBH5 showed severer suppression in the renal fibrosis process. However, genistein pretreatment restored ALKBH5 loss remarkably and reduced renal fibrosis, abnormal protein, and inflammatory markers. The examination of possible mechanisms revealed that genistein promoted ALKBH5 and maybe induced the level of mRNA m6A methylation in some epithelial-to-mesenchymal transition-related transcription factors. We found snail was the critical regulator and critical for the protective role of genistein. To verify the relationship between ALKBH5 and snail, we generated knockdown and overexpression of ALKBH5 cells in vitro. ALKBH5 knockdown enhanced the mesenchymal phenotype marker α-smooth muscle actin and snail expression. In agreement, overexpression ALKBH5 increased epithelial adhesion molecule E-cadherin and reduced snail expression. In conclusion, genistein increased renal ALKBH5 expression in UUO-induced renal fibrosis and reduced RNA m6A levels and ameliorates renal damages.

Background/Aims: Even though delayed ischemic preconditioning (DIPC) has been reported to produce renal protection, the underlying mechanism remains poorly understood. We reported that a 15-minute renal ischemic preconditioning (IPC) 4 days before subsequent ischemia-reperfusion attenuated renal injury Kidney dendritic cells (DCs) are abundant in the renal tubulointerstitium and, depending on their status, can induce immune activation or tolerance. The aim of the present study was to investigate the role of DCs in IPC of the kidney. Methods: Mouse kidneys were challenged by transient brief episodes of sublethal ischemia followed by subsequent prolonged ischemia. DC abundance and maturation in the spleen and kidney were measured by flow cytometry and immunohistochemical staining. To confirm the function of mature DCs in the renoprotective effect of IPC on renal ischemia-reperfusion injury the A2 adenosine receptor (A2AR) antagonist SCH58261 was administered to stimulate DC maturation prior to assessment of renal functional and histological injury and the inflammatory reaction. Results: Compared with sham-operated animals, preconditioned mice had a reduced injury with less CD11c+ cells, lower levels of the pro-inflammatory cytokine IL-17 and reduced expression of the mature DC marker CCR7. Preconditioned mice also produced more of the anti-inflammatory cytokine IL-10. Both renal cells and splenocytes from these mice had more DCs (CD45+/CD11c+/F4/80-), but fewer of these DCs were mature (CD45+/CD11c+/ F4/80-/MHC-II+/CD80+) compared with those from sham-treated animals, suggesting that the immunomodulatory effect of renal ischemic preconditioning is both local and systemic. Additionally, injection of the A2AR antagonist SCH58261 reversed IPC-induced inhibition of DC maturation and mitigated the protective effect of preconditioning, suggesting that DC maturation contributes to immune cell-mediated ischemic preconditioning. Conclusion: Our results show that DIPC of the kidney provides local and systemic immunosuppression by inhibiting DC maturation and hence mediates a renal protective effect.

Background/Aims: Extracellular ATP performs multiple important functions via activation of P2 receptors on the cell surface. P2Y receptors play critical roles in ATP evoked response in human lung adenocarcinoma cells (A549 cells). Emodin is an anthraquinone derivative originally isolated from Chinese rhubarb, possesses anticancer properties. In this study we examined the inhibiting effects of emodin on proliferation, migration and epithelial-mesenchymal transition (EMT) by suppressing P2Y receptors-dependent Ca2+ increase and nuclear factor-κB (NF-KB) signaling in A549 cells. Methods: A549 cells were pretreated with emodin before stimulation with ATP for the indicated time. Then, intracellular Ca2+ concentration ([Ca2+]i) was measured by Fluo-8/AM staining. Cell proliferation and cell cycle progression were tested by CCK8 assay and flow cytometry In addition, wound healing and western blot were performed to determine cell migration and related protein levels (Bcl-2, Bax, claudin-1, NF-κB). Results: Emodin blunted ATP/UTP-induced increase of [Ca2+]i and cell proliferation concentration-dependently Meanwhile, it decreased ATP-induced cells accumulation in the S phase. Furthermore, emodin altered protein abundance of Bcl-2, Bax and claudin-1 and attenuated EMT caused by ATP. Such ATP-induced cellular reactions were also inhibited by a nonselective P2Y receptors antagonist, suramin, in a similar way to emodin. Besides, emodin could inhibit activation of NF-κB, thus suppressed ATP-induced proliferation, migration and EMT. Conclusion: Our results demonstrated that emodin inhibits ATP-induced proliferation, migration, EMT by suppressing P2Y receptors-mediated [Ca2+]i increase and NF-κB signaling in A549 cells.

The ventrolateral medulla (VLM), including the lateral paragigantocellular nucleus (LPGi) and rostral VLM (RVLM), is commonly considered to be a chemosensitive region. However, the specific mechanism of chemoreception in the VLM remains elusive. Acid-sensing ion channels (ASICs), a family of voltage-independent proton-gated cation channels, can be activated by an external pH decrease to cause Na+ entry and induce neuronal excitability. TWIK-related acid-sensitive potassium channels (TASKs) are members of another group of pH-sensitive channels; in contrast to AISICs, they can be stimulated by pH increases and are inhibited by pH decreases in the physiological range. Our previous study demonstrated that ASICs take part in chemoreception. The aims of this study are to explore whether TASKs participate in the acid sensitivity of neurons in the VLM, thereby cooperating with ASICs. Our research demonstrated that TASKs, including TASK1 and TASK3, are colocalized with ASIC1 in VLM neurons. Blocking TASKs by microinjection of the non-selective TASK antagonist bupivacaine (BUP), specific TASK1 antagonist anandamide (AEA) or specific TASK3 antagonist ruthenium red (RR) into the VLM increased the integrated phrenic nerve discharge (iPND), shortened the inspiratory time (Ti) and enhanced the respiratory drive (iPND/Ti). In addition, microinjection of artificial cerebrospinal fluid (ACSF) at a pH of 7.0 or 6.5 prolonged Ti, increased iPND and enhanced respiratory drive, which were inhibited by the ASIC antagonist amiloride (AMI). By contrast, microinjection of alkaline ACSF decreased iPND and respiratory drive, which were inhibited by AEA. Taken together, our data suggest that TASK1 and TASK3 are coexpressed with ASIC1 in the VLM. Moreover, TASK1 and TASK3 contribute to the central regulation of breathing by coordinating with each other to perceive local pH changes; these results indicate a novel chemosensitive mechanism of the VLM.

Renal tubular injury and innate immune responses induced by hypoxia contribute to acute kidney injury. Accumulating evidence suggests that miR-21 overexpression protects against kidney ischemia injury. Additionally, miR-21 emerges as a key inhibitor in dendritic cell maturation. Thus, we hypothesized that miR-21 protects the kidney from IR injury by suppressing epithelial cell damage and inflammatory reaction. In this study, we investigated effects of miR-21 and its signaling pathways (PTEN/AKT/mTOR/HIF, PDCD4/NFκ-B) on kidney ischemia/reperfusion (IR) injury in vitro and in vivo. The results revealed that IR increased miR-21, HIF1α, and 2α expression in vivo and in vitro. MiR-21 interacted with HIF1α and 2α through the PTEN/AKT/mTOR pathway. Moreover, inhibition of miR-21 activated PDCD4/NFκ-B pathways, which are critical for dendritic cell maturation. Renal IR triggers local inflammation by inducing the dendritic cell maturation and promoting the secretion of IL-12, IL-6, and TNF-α cytokines. Knockdown of miR-21 intensified the effect of IR on tubular epithelial cell apoptosis and dendritic cell maturation. Our results suggested that IR-inducible miR-21 protects epithelial cells from IR injury via a feedback interaction with HIF (PTEN/AKT/mTOR/HIF/miR-21) and by inhibiting maturation of DCs through the PDCD4/NF-κB pathway. These findings highlight new therapeutic opportunities in AKI.

Aim: Cisplatin is an effective chemotherapeutic drug, but the application in clinical is greatly limited by its nephrotoxicity. Necrostatin-1 (Nec-1), an inhibitor of RIP1 kinase, has been reported to inhibit RIP-mediated necroptosis. The aim of this study is to detect the protective effects of Nec-1 on the nephrotoxicity of cisplatin and to investigate its renoprotection mechanism.Methods: 8-week-old male C57BL/6 mice were randomly assigned into four groups: Control, Nec-1, Cisplatin, and Cisplatin+Nec-1. Mice were treated with cisplatin with or without Nec-1 pre-treatment. Renal function, histological changes, necroptosis, and apoptotic markers were investigated. NFκB pathway related proteins, proinflammatory cytokines, oxidative stress markers, renal Klotho, and autophagy-related proteins levels were also examined.Results: Renal function and histological data displayed that the treatment with Nec-1 significantly attenuates cisplatin-induced renal damage. The expression of RIPK1/RIPK3/MLKL were significantly enhanced in cisplatin group as compared to the control group (p < 0.05) and was significantly reduced by pre-treatment of Nec-1 (p < 0.05). The level of stress and apoptosis-related protein, including p-JNK, p-c-Jun, p-p38, Bax/Bcl-2 ratio, and caspase-3 showed the similar trend. Pre-treatment with Nec-1 inhibit NFκB signaling, reduced proinflammatory cytokines and oxidative stress, up-regulated renal Klotho, and autophagy-related proteins levels.Conclusion: Our results suggest that Nec-1 could be a potential therapeutic drug against the cisplatin-induced nephrotoxicity through its anti-necroptosis, anti-apoptotic, anti-inflammatory anti-oxidant and retain Klotho expression and activate autophagy effects in the kidney.

Hypoxia is an important and influential factor in development. The embryonic kidney is exposed to a hypoxic environment throughout its development. The Wnt/β-catenin pathway plays vital roles in the differentiation and self-renewal of metanephrogenic mesenchymal stem cells (MMSCs) from which the kidney is derived. Thus, we hypothesized that hypoxia can regulate the differentiation and pluripotency of MMSCs through the Wnt/β-catenin pathway. To test this hypothesis, MMSCs from rats at embryonic day 18.5 were cultured in normoxic (21% O2) and hypoxic (1% O2) conditions. The effects of hypoxia on differentiation, stemness, proliferation, and apoptosis of cultured MMSCs and on the activity of the Wnt/β-catenin pathway were tested. Our results revealed that the hypoxic condition increased the number of epithelial cells (E-cadherin+ or CK18+) as well the expression of markers of renal tubule epithelia cells (CDH6, Aqp1, and OPN), decreased the number and proliferation of stem cells (SIX-2+ or CITED1+), and induced apoptosis. Additionally, hypoxia reduced the expression of Wnt4 as well as its downstream molecules β-catenin, LEF-1, and Axin2. Activation of the Wnt/β-catenin pathway by LiCl or BIO modified the effects of hypoxia on the differentiation and self-renewal of MMSCs. Thus, we concluded that hypoxia induces the differentiation and inhibits the self-renewal of MMSCs by inhibiting the Wnt/β-catenin pathway. The observations further our understanding of the effects of hypoxia on kidney.

Sensory units of pulmonary slowly adapting receptors (SARs) are more active in large airways than in small airways. However, there is no explanation for this phenomenon. Although sensory structures in large airways resemble those in small airways, they are bigger and more complex. Possibly, a larger receptor provides greater surface area for depolarization, and thus has a lower activating threshold and/or a higher sensitivity to stretch, leading to more nerve electrical activities. Recently, a single sensory unit has been reported to contain multiple receptors. Therefore, sensory units in large airways may contain more SARs, which may contribute to high activities. To test this hypothesis, we used a double staining technique to identify sensory receptor sizes. We labeled the sensory structure with Na+/K+-ATPase antibodies and the myelin sheath with myelin basic protein (MBP) antibodies. A SAR can be defined as the end formation beyond MBP labeling. Thus, we are able to compare sizes of sensory structures and SARs in large (trachea and bronchi) vs small (bronchioles 0.05). However, the sensory structure contains more SARs in large airways than in small airways (9.6±0.6 vs 3.6±0.3; P

Acid-sensing ion channels (ASICs) are present in neurons and may contribute to chemoreception. Among six subunits of ASICs, ASIC1 is mainly expressed in the central nervous system. Recently, multiple sites in the brain including the lateral hypothalamus (LH) have been found to be sensitive to extracellular acidification. Since LH contains orexin neurons and innervates the medulla respiratory center, we hypothesize that ASIC1 is expressed on the orexin neuron and contributes to acid-induced increase in respiratory drive. To test this hypothesis, we used double immunofluorescence to determine whether ASIC1 is expressed on orexin neurons in the LH, and assessed integrated phrenic nerve discharge (iPND) in intact rats in response to acidification of the LH. We found that ASIC1 was co-localized with orexinA in the LH. Microinjection of acidified artificial cerebrospinal fluid increased the amplitude of iPND by 70% (pH 7.4 v.s. pH 6.5:1.05±0.12 v.s. 1.70±0.10, n = 6, P

Ovarian cancer (OC) is the third most common kind of gynecological tumor, in addition to being the most lethal. Transcription factor Dp-1 (TFDP1) functions as a binding partner for E2F transcription factors, and its target genes include those involved in DNA synthesis, cell cycle, and apoptosis. However, the regulatory role of TFDP1 in OC remains incompletely understood. This study aimed to investigate the role and mechanism of TFDP1 in OC. TFDP1 was highly expressed in the ovarian epithelial tissues of OC patients, and the expression of TFDP1 in OC cells was higher than that in normal ovarian epithelial cells. Silencing of TFDP1 inhibited the biological activity of OC cells and hindered cell cycle entry. Zinc finger protein 146 (ZNF146) knockdown induced cell cycle arrest at the G0/G1 phase and tumor growth by blocking TFDP1 transcription, which was overturned by ectopic expression of TFDP1. TFDP1 stimulated DEP domain-containing protein 1B (DEPDC1B) expression through transcriptional activation. DEPDC1B increased the proportion of OC cells in the G2/M phase and potentiated tumor malignant progression in nude mice inhibited by sh-ZNF146. Taken together, these findings demonstrate that ZNF146 participates in TFDP1/DEPDC1B activation and plays a vital role in the cell cycle in OC. [ABSTRACT FROM AUTHOR]

The compression packer rubber is one of the core components of the packer. According to the sealing mechanism of the compression packers rubber, the deformation of rubber between the central tube and casing tube is analyzed in the initial and working stages. The compression rubber is also strained radially against the support ring by means of a controlled tubular expansion process. In this paper, the theoretical model for the deformation analysis is established by the structure and working characteristics of rubber tube. In addition, the nonlinear relationship between the material, geometry and stress in the constrained and stable deformation stages is analyzed by application of pressure methods. The analytical results show the contact pressure and shear stress distribution on the sealing surface of the rubber and the effect of rubber geometry and its material properties on sealing performance in terms of maximum sealing pressure. Then, the criterion of sealing performance evaluation of the rubber is established by the numerical results. This analytical model will provide a theoretical basis and guidance for the structural design of the compression packer rubber and it will be of great significance to improve the sealing performance and reliability of packer rubber. [ABSTRACT FROM AUTHOR]

Vascular endothelial cells may serve crucial roles in the development of acute kidney injury (AKI). microRNA (miR)‑21, which possesses a renal protective function has been found on vascular endothelial cells. The present study aimed to test the hypothesis that miR‑21 may protect vascular endothelial cells against injury, which may contribute to the protective effects of renal delayed ischemic preconditioning (IPC). Preconditioned (15 min ischemia) or Sham mice (not clamped) were subjected to 35 min occlusion of bilateral renal pedicles 4 days following preconditioning or Sham treatment. Human umbilical vein endothelial cells (HUVECs) were treated with cobalt(II) chloride (CoCl2) to establish an in vitro hypoxia model. Locked nucleic acid‑modified anti‑miR‑21 or scrambled control oligonucleotides were transfected into cells or delivered into mice via tail vein injection <1 h prior to IPC. Following 24 h of reperfusion or hypoxia, morphological and functional parameters, apoptosis and miR‑21 and programmed cell death 4 (PDCD4) expression were assessed in vivo and in vitro. Treatment of HUVECs with CoCl2 led to an upregulation of miR‑21 expression, a downregulation of PDCD4 protein expression and attenuation of apoptosis. Inhibition of miR‑21 expression led to increased expression levels of PDCD4 protein and apoptosis in HUVECs. IPC attenuated renal IR injury in mice. The protective effect of IPC appeared to be dependent on upregulated miR‑21 expression. IPC‑induced upregulation of miR‑21 expression also occurred in HUVECs, and IPC also led to reduced PDCD4 expression and vascular permeability in mouse kidneys. The effects of IPC were attenuated by the inhibition of miR‑21; miR‑21 expression attenuated damage in vascular endothelial cells, which may contribute to the protective effects of delayed IPC on renal IR injury. The present study suggested a novel target for the prevention and repair of AKI in the future. [ABSTRACT FROM AUTHOR]

Background: Mounting evidence indicated that the elevated serum uric acid level was associated with an increased risk of acute kidney injury (AKI). Our goal was to systematically evaluate the correlation of serum uric acid (SUA) level and incidence of AKI by longitudinal cohort studies.Methods: We searched electronic databases and the reference lists of relevant articles. 18 cohort studies with 75,200 patients were analyzed in this random-effect meta-analysis. Hyperuricemia was defined as SUA levels greater than 360-420 μmol/L (6-7 mg/dl), which was various according to different studies. Data including serum uric acid, serum creatinine, and incidence of AKI and hospital mortality were summarized using random-effects meta-analysis.Results: The hyperuricemia group significantly exerted a higher risk of AKI compared to the controls (odds ratio OR 2.24, 95% CI 1.76-2.86, p < 0.01). Furthermore, there is less difference of the pooled rate of AKI after cardiac surgery between hyperuricemia and control group (34.3% vs 29.7%, OR 1.24, 95% CI 0.96-1.60, p = 0.10), while the rates after PCI were much higher in hyperuricemia group than that in control group (16.0% vs 5.3%, OR 3.24, 95% CI 1.93-5.45, p < 0.01). In addition, there were significant differences in baseline renal function at admission between hyperuricemia and control groups in most of the included studies. The relationship between hyperuricemia and hospital mortality was not significant. The pooled pre-operative SUA levels were higher in AKI group than that in the non-AKI group.Conclusions: Elevated SUA level showed an increased risk for AKI in patients and measurements of SUA may help identify risks for AKI in these patients. [ABSTRACT FROM AUTHOR]

Background: Remote ischemic preconditioning (RIPC) is a promising approach to preventing acute kidney injury (AKI), but its efficacy is controversial.Methods: A systematic review of 30 randomized controlled trials was conducted to investigate the effects of RIPC on the incidence and outcomes of AKI. Random effects model meta-analyses and meta-regressions were used to generate summary estimates and explore sources of heterogeneity. The primary outcome was incidence of AKI and hospital mortality.Results: The total pooled incidence of AKI in the RIPC group was 11.5 %, significantly less than the 23.3 % incidence in the control group (P = 0.009). Subgroup analyses indicated that RIPC significantly reduced the incidence of AKI in the contrast-induced AKI (CI-AKI) subgroup from 13.5 % to 6.5 % (P = 0.000), but not in the ischemia/reperfusion-induced AKI (IR-AKI) subgroup (from 29.5 % to 24.7 %, P = 0.173). Random effects meta-regression indicated that RIPC tended to strengthen its renoprotective effect (q = 3.95, df = 1, P = 0.047) in these trials with a higher percentage of diabetes mellitus. RIPC had no significant effect on the incidence of stages 1-3 AKI or renal replacement therapy, change in serum creatinine and estimated glomerular filtration rate (eGFR), hospital or 30-day mortality, or length of hospital stay. But RIPC significantly increased the minimum eGFR in the IR-AKI subgroup (P = 0.006) compared with the control group. In addition, the length of ICU stay in the RIPC group was significantly shorter than in the control group (2.6 vs 2.0 days, P = 0.003).Conclusions: We found strong evidence to support the application of RIPC to prevent CI-AKI, but not IR-AKI. [ABSTRACT FROM AUTHOR]