Rituximab may affect T lymphocyte subsets balance in primary membranous nephropathy.

BACKGROUND: The aim of this study was to investigate the effects and significance of rituximab (RTX) on the levels of T lymphocyte subsets in patients diagnosed with primary membranous nephropathy (PMN). METHODS: A total of 58 PMN patients and 25 healthy donors were chosen as the subjects. Among the PMN patients, 40 individuals received RTX treatment and completed at least 6 months of follow-up. All subjects underwent flow cytometry analysis to determine the peripheral blood lymphocyte subsets. The changes in anti-PLA2R antibody titers and 24-hour urinary protein levels were evaluated by ELISA and Biuret method before and after treatment. RESULTS: (1) The PMN group exhibited a significantly greater percentage of peripheral blood CD3-CD19+ B cells than the healthy group, which is consistent with the findings of previous reports. Additionally, compared with those in the peripheral blood of healthy individuals, the numbers of CD4+ central memory T cells, CD4+ effector memory T cells, CD4+/CD8+, and CD4+CD25+ T cells in the PMN peripheral blood were markedly greater. However, the number of peripheral blood Treg cells was reduced in the PMN group. (2) After 6 months of RTX treatment, PMN patients exhibited significant decreases in anti-PLA2R antibody titers, 24-hour urinary protein levels, and peripheral blood CD3-CD19+ B cells. Importantly, RTX administration decreased CD4+CD25+ T cells and CD4+/CD8+ in the peripheral blood of PMN patients and improved Treg cell levels. (3) RTX treatment induced alterations in the CD4+ T lymphocyte subsets in PMN patients, which did not correlate with B lymphocyte counts or anti-PLA2R antibody titers. CONCLUSIONS: RTX treatment might have a beneficial impact on cellular immunity by effectively restoring the balance of CD4+ T lymphocyte subsets in PMN patients, which is beyond its effects on B cells and antibody production. TRIAL REGISTRATION: The research was registered at the First Affiliated Hospital of Soochow University. REGISTRATION NUMBER: MR-32-23-016211. Registration Date: May 31, 2023.

Clinical study on the correlation between monocyte-related ratios and calcification of the abdominal aorta in peritoneal dialysis patients.

INTRODUCTION: We aimed to investigate the relationship between monocyte/lymphocyte ratio (MLR) and monocyte/high-density lipoprotein ratio (MHR) with abdominal aortic calcification (AAC) in patients on peritoneal dialysis (PD). METHODS: The time-averaged (TA) of relevant indexes and AAC scores (AACs) of 160 eligible patients were measured. RESULTS: Patients divided into the new AAC (n = 57) and the other without (n = 82). High TA-MLR (OR = 110.537, p = 0.018) and long duration of dialysis (OR = 1.045, p < 0.001) were independent risk factors of the new AAC. Patients divided into the no AAC (n = 82), the moderate-to-severe AAC (n = 26), and the mild AAC (n = 52). High TA-MLR (OR = 42.649, p = 0.032), high age at starting PD (OR = 1.055, p < 0.001), and long duration of PD (OR = 1.036, p < 0.001) were independent risk factors of AAC severity. CONCLUSIONS: MLR is an independent risk factor for the occurrence and severity of AAC and its value for the assessment of AAC is better than MHR.

Comparison of the duration of viral RNA shedding and anti-SARS-CoV-2 spike IgG and IgM antibody titers in COVID-19 patients who were vaccinated with inactivated vaccines or not: a retrospective study.

BACKGROUND: At present, the role of inactivated vaccines in viral RNA shedding among Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) breakthrough infections is still unknown. METHODS: We collected data of 147 coronavirus disease 2019 (COVID-19) patients with mild-to-moderate illness who were hospitalized in the Third People's Hospital of Yangzhou from 7 to 20 August 2021 and analyzed the differences in symptoms and laboratory tests among fully vaccinated (FV), partially vaccinated (PV) and unvaccinated (UV) patients. RESULTS: The median duration of viral RNA shedding was shorter in the FV (12 [IQR, 9.5-14] days) and PV (13 [IQR, 9-16.75] days) groups than in the UV group (15 [IQR, 11.75-17.25] days) (adjusted P < 0.001 and adjusted P = 0.23, respectively). The median titers of SARS-CoV-2-specific IgG and IgM were significantly higher in the FV (12.29 S/co [IQR, 2.08-63.59] and 0.3 S/co [IQR, 0.05-2.29], respectively) and PV (0.68 S/co [IQR, 0.14-28.69] and 0.12 S/co [0.03-5.23], respectively) groups than in the UV group (0.06 S/co [IQR, 0.03-0.47] and 0.04 S/co [IQR, 0.02-0.07]) (adjusted P < 0.001 and adjusted P = 0.008, respectively). CONCLUSIONS: Inactivated vaccines may shorten viral RNA shedding in breakthrough infected patients who have mild-to-moderate illness and may improve the ability of the host to generate specific antibodies to infection.

Success of small-dose fractionated sodium thiosulfate in the treatment of calciphylaxis in a peritoneal dialysis patient.

BACKGROUND: Calciphylaxis, or calcific uremic arteriolopathy (CUA), is a rare, fatal disorder of microvascular calcification and thrombosis that typically affects patients with end-stage renal disease (ESRD) receiving long-term dialysis. Fewer reports describe calciphylaxis in peritoneal dialysis patients than hemodialysis patients as per a literature review. To date, there are no clear guidelines for CUA diagnosis and treatment. While sodium thiosulfate (STS) has been increasingly used for treatment in recent years, there have also been reports of severe side effects. There is no uniform standard for its usage and dosage, especially for peritoneal dialysis patients. CASE PRESENTATION: We present a case of a 40-year-old Chinese male patient with ESRD on peritoneal dialysis who developed calciphylaxis with severe painful cutaneous ulcers on the fingers and toes that were managed successfully for 6 months with comprehensive treatment composed mainly of small-dose fractionated sodium thiosulfate. CONCLUSIONS: Our experience suggests that the treatment of calciphylaxis requires timely and multi-angle intervention. Treatment with small-dose fractionated sodium thiosulfate has proven effective and tolerated in this patient.

Quantitative relationship between modern surface pollen and plant community at quadrat scale.

Establishing a precise relationship between modern vegetation and surface pollen is the basis and key to quantitatively reconstruct paleovegetation and paleoclimate based on pollen records. The record of plant community plots has been less considered in the statistical analysis of modern vegetation and surface pollen, which limits the quantitative estimation of its precise relationship. In this study, the quantitative relationships of compositions and quantities between modern surface pollen and plant community were analyzed, based on the Bray-Curtis dissimilarity, through the analysis of 33 surface soil samples and corresponding vegetation plots from forest, meadow steppe, typical steppe and desert steppe on the Northeast China Transect. Results showed that, in a single plot, the relationships between vegetation and pollen in compositions and quantities were different across all families and genera, dominant and common families and genera, and less common and rare families and genera, respectively, due to the differences in pollen dispersal and pollen productivity. There were significant differences among different vegetation types. The compositions of meadow steppe differed greatly, while all families and genera, dominant and common families and genera differed greatly in the quantitative relationship in forest. Less common and rare families and genera differed greatly in the compositions in meadow steppe. The vegetation-pollen relationship of different families and genera was basically the same in terms of composition and quantities. According to the Bray-Curtis dissimilarity, pollen taxa could be divided into three types: over-representative, under-representative and representative types. This dissimilarity index represented both the species composition and quantity relationship between vegetation and pollen both at quadrat scale and at specie level, which could be used as an indicator to quantitatively describe the modern vegetation-pollen relationship.

Upregulation of FABP7 inhibits acute kidney injury-induced TCMK-1 cell apoptosis via activating the PPAR gamma signalling pathway.

Acute kidney injury (AKI) is a frequently seen critical disorder in the clinic. The current research aimed to examine the role of hydroxyacid oxidase 2 (FABP7) in AKI-induced cell apoptosis. A total of 289 overlapping genes were used to perform gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and to construct a protein-protein interaction (PPI) network using the DAVID database and Cytoscape software. The 10 hub genes of the PPI network were screened out using the cytohubba plug-in of Cytoscape software. FABP7 represented both the differentially expressed gene (DEG) from the GSE44925 and GSE62732 datasets and the top hub gene of the PPI network. The results of the PAS assay showed that FABP7 knockout in vivo aggravated lipopolysaccharide (LPS)-induced AKI. Meanwhile, LPS inhibited cell viability and the expression of FABP7, PPARγ, PPARα, PTEN and p27kip1, and increased the TNF-α level, and cleaved caspase-3/-9 expression and the phosphorylation of PTEN in vitro. FABP7 overexpression reversed the effects of LPS on inhibiting cell viability and proliferation, promoting cell apoptosis, increasing the expression of FABP7, PPARγ, PTEN and p27kip1, and reducing cleaved caspase-3/-9 expression and the phosphorylation of PTEN, but had no influence on PPARα expression. The PPARγ signal pathway inhibitors blocked the protective effect of FABP7 overexpression in LPS-treated TCMK-1 cells, while the PPARγ signal pathway activator inhibited the harmful effect of FABP7 inhibition in LPS-treated TCMK-1 cells. In conclusion, FABP7 overexpression inhibited the AKI-induced cell apoptosis and promoted the proliferation through activating the PPARγ signal pathway in vivo and in vitro.

Schisantherin A attenuates sepsis-induced acute kidney injury by suppressing inflammation via regulating the NRF2 pathway.

AIMS: Tubulointerstitial inflammation is recognized as a key determinant of progressive sepsis-induced acute kidney injury (AKI). Schisantherin A (SchA) has been shown to be capable of regulating inflammatory processes. In the present study, we explored the possibility of SchA in preventing lipopolysaccharide (LPS)-induced kidney inflammation and injury. MATERIALS AND METHODS: AKI was induced by a single intraperitoneal injection of LPS in CD1 mice, administration of SchA was used for treatment. The protective effect of SchA on renal function and inflammation were analyzed respectively; the NRK-52E cell line was employed for the in vitro study and relative molecular mechanism was explored. KEY FINDINGS: Administration with SchA markedly attenuated LPS-induced damage on renal function and histopathological changes of the kidney. Additionally, pretreatment with SchA could inhibit the expression of inflammatory factors in the kidneys. In NRK-52E cells, SchA treatment significantly inhibited LPS-induced NF-κB activation and pro-inflammatory cytokine expression. Moreover, SchA could promote NRF2 pathway activation, and further blockade of NRF2 activation reversed the SchA-induced inhibition of NF-κB activation. SIGNIFICANCE: These presented results indicated that SchA may have great potential for protecting against sepsis-induced AKI.

EPA attenuates epithelial-mesenchymal transition and fibrosis through the TGF-ß1/Smad3/ILK pathway in renal tubular epithelial HK-2 cells by up-regulating miR-541.

BACKGROUND: It was reported that eicosapentaenoic acid (EPA) could prevent tubulointerstitial injury in kidney. EPA could also inhibit the epithelial-mesenchymal transition (EMT) of HK-2 cells stimulated by albumin (Alb) in vitro. However, the regulating molecular mechanism of EPA remains to be elucidated. METHODS: An immortalized human proximal tubular cell line (human kidney-2 (HK-2) cells) was used in all experiments. MTT assay was employed to determine the effect of Alb or EPA on the cell viability of HK-2 cells. The miR-541 expression, the mRNA levels of EMT markers E-cadherin, α-smooth muscle actin (α-SMA), and fibrogenesis markers Collagen I and fibronectin (FN) were examined by RT-qPCR assay. The protein levels of E-cadherin, α-SMA and Collagen I, transforming growth factor ß1 (TGF-ß1)/Smad3/integrin-linked kinase (ILK) pathway-related protein TGF-ß1, pSmad2/3, Smad7 and ILK were measured by western blot. Enzyme-linked immunosorbent assay (ELISA) was performed to detect FN expression. The target relationship between miR-541 and TGF-ß1 was confirmed by bioinformatics, luciferase reporter assay and western blot. RESULTS: Low doses of Alb had no effect on the cell viability of HK-2 cells, while EPA repressed the cell viability of HK-2 cells in a concentration-dependent manner. EPA could inhibit EMT and fibrosis and increase the miR-541 expression of HK-2 cells exposed to Alb. Interestingly, introduction of miR-541 effectively abolished the EMT and fibrosis of HK-2 cells stimulated by Alb. Bioinformatics analysis predicted TGF-ß1 as a target gene of miR-541, and subsequent luciferase reporter assay and western blot further supported the prediction. miR-541 counter-regulated TGF-ß1 expression, and inhibited the TGF-ß1/Smad3/ILK pathway. Alb treatment activated the TGF-ß1/Smad3/ILK pathway, while EPA inhibited the activation of the pathway. miR-541 inhibitors reversed the effects of EPA on EMT, fibrosis, and TGF-ß1/Smad3/ILK pathway-related protein expression induced by Alb. CONCLUSION: EPA attenuates EMT and renal fibrosis through the TGF-ß1/Smad3/ILK pathway in renal epithelial cells by targeting miR-541.

Long non-coding RNA MALAT1 interacts with transcription factor Foxo1 to regulate SIRT1 transcription in high glucose-induced HK-2 cells injury.

BACKGROUND: Tubular injury is considered as a crucial pathological feature of diabetic nephropathy. LncRNA MALAT1 is involved in diabetic complications. Hence the role of MALAT1 in high glucose-induced renal tubular epithelial cells (HK-2) injury deserves investigation. METHODS: The diabetic mice model was established with streptozotocin (STZ) injection. The expression of NEAT1, SIRT1, and Foxo1 mRNA and protein was determined with qRT-PCR and western blot, respectively. The serum creatinine and urinary albumin were examined by enzyme linked immunosorbent assay (ELISA). Interaction between MALAT1 and Foxo1 was detected with RIP and RNA pull-down assay, respectively. Dual luciferase reporter assay was used to evaluate the binding between Foxo1 and SIRT1. RESULTS: LncRNA MALAT1 was up-regulated in kidney tissues of diabetic mice and in HK-2 cells treated with high glucose, while the expression of SIRT1 was decreased. Interaction between MALAT1 and Foxo1 was observed in HK-2 cells and the interaction was promoted by high glucose treatment. Foxo1 activated SIRT1 transcription by binding to its promoter, and MALAT1 repressed SIRT1 expression through targeting Foxo1. CONCLUSION: LncRNA MALAT1 interacts with transcription factor Foxo1 to represses SIRT1 transcription in high glucose incubated HK-2 cells, which promotes high glucose-induced HK-2 cells injury.

Sublingual Immunotherapy Decreases Expression of Interleukin-33 in Children with Allergic Rhinitis.

OBJECTIVES: To identify the expression of IL-33 during SLIT (Sublingual immunotherapy) in AR (Allergic rhinitis) children. METHODS: Thirty children received house dust mite (HDM) allergen extract for SLIT and thirty children received placebo in this study. Serum and nasal lavage samples of cases and controls were collected at different time points during SLIT. Interleukin (IL)-33 and other cytokines were estimated in these samples by enzyme-linked immuno sorbent assay (ELISA). Peripheral blood mononuclear cells (PBMC) were prepared and stimulated with rhIL-33 (with or without other stimulators) at different time points during SLIT. RESULTS: The present results showed that both serum and nasal lavage of IL-33 levels decreased significantly after 12 mo treatment and this trend maintained at least until 24 mo. The decreased nasal IL-33 level was positively correlated to local Th2 cytokines and increased IL-10 expression at 2 y post SLIT treatment. In vitro experiments showed that IL-33 promotes IL-4 and IL-5 and inhibits IL-10 expression by peripheral blood mononuclear cells (PBMCs) in AR. CONCLUSIONS: Decreased IL-33 expression during SLIT may contribute to low Th2 response and enhanced Regulatory T cell cytokines expression. Thus, IL-33 maybe an important predictor during SLIT.

Silencing of CXCL12 performs a protective effect on C5b-9-induced injury in podocytes.

PURPOSE: Podocytes, terminal differentiation cell in glomerulu, are crucial to kidney-related diseases such as membranous nephropathy (MN). MN is characterized by podocyte injury and glomerular basement membrane thickening. This paper focused to investigate the expression of chemokine (C-X-C motif) ligand 12 (CXCL12) in MN patients and its possible role in podocyte injury. METHODS: Through the enzyme-linked immunosorbent assay, CXCL12 level in the serum and urine of MN patients was examined. Further, several assays of cell viability, apoptosis, quantitative real-time PCR and western blot were applied to explore the effects of CXCL12 in the model of podocyte injury. RESULTS: We found a significant increase of CXCL12 in serum and urine of MN patients, which indicated that CXCL12 may be involved in the progression of MN. And in vitro C5b-9-induced podocyte injury model, the proliferation of podocytes was inhibited whereas CXCL12/CXCR4 and phosphorylated STAT3 (p-STAT3) were increased. Silencing of CXCL12 remarkably promoted cell proliferation, inhibited cell apoptosis and suppressed CXCL12/CXCR4, p-STAT3 and caspase 3. Consistently, STAT3 inhibitor and berberine (a CXCL12 antagonist) also reduced CXCL12 treatment-induced apoptosis. CONCLUSIONS: All data suggested that silencing of CXCL12 had a protective effect on podocyte injury, which may be through inhibiting CXCL12/STAT3 signaling pathway.

IL-1ß increases urinary corin in patients with primary proteinuric kidney diseases and in 293 cells.

Corin is a serine protease that is important for the regulation of blood pressure and water balance. Corin was initially discovered in the heart, however, it has also been detected in kidney cells, though its function in the kidneys is unclear. To further investigate the function of corin in the kidney, the present study analyzed the levels of corin in urine and blood samples collected from normal individuals and patients with primary proteinuric diseases. The associations between the levels of corin, and the cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) were then assessed. The results demonstrated that corin was detectable in the urine and plasma following an enzyme-linked immunosorbent assay; the level of corin in the urine was associated with the level of urinary ß2-microglobulin (P=0.01), which was indicative of renal tubular injury. When compared with normal individuals, the levels of urinary corin in proteinuric patients were markedly increased (P=0.02), and were also associated with IL-1ß (P=0.03). This correlation between corin and IL-1ß was confirmed in vitro using 293 cells. As the IL-1ß concentrations increased (0, 0.1, 1, 10 ng/ml), an elevation in the level of corin was observed in the culture medium (P<0.01); however, the amount of corin was not markedly altered in the cell lysate (P>0.05). In addition, when TNF-α reached 10 ng/ml, the level of corin in the medium increased significantly when compared with the control group (0 ng/ml; P=0.02), however, no significant difference in corin levels was detected in the cell lysate. The results suggest that the cytokines IL-1ß and TNF-α may increase urinary corin in patients with primary proteinuric kidney diseases. Cytokines may accelerate corin shedding from the cell membrane of renal tubule epithelial cells. These findings indicate that corin may be associated with kidney inflammation and injury.

A Novel Corynebacterium glutamicum l-Glutamate Exporter.

Besides metabolic pathways and regulatory networks, transport systems are also pivotal for cellular metabolism and hyperproduction of biochemicals using microbial cell factories. The identification and characterization of transporters are therefore of great significance for the understanding and engineering of transport reactions. Herein, a novel l-glutamate exporter, MscCG2, which exists extensively in Corynebacterium glutamicum strains but is distinct from the only known l-glutamate exporter, MscCG, was discovered in an industrial l-glutamate-producing C. glutamicum strain. MscCG2 was predicted to possess three transmembrane helices in the N-terminal region and located in the cytoplasmic membrane, which are typical structural characteristics of the mechanosensitive channel of small conductance. MscCG2 has a low amino acid sequence identity (23%) to MscCG and evolved separately from MscCG with four transmembrane helices. Despite the considerable differences between MscCG2 and MscCG in sequence and structure, gene deletion and complementation confirmed that MscCG2 also functioned as an l-glutamate exporter and an osmotic safety valve in C. glutamicum Besides, transcriptional analysis showed that MscCG2 and MscCG genes were transcribed in similar patterns and not induced by l-glutamate-producing conditions. It was also demonstrated that MscCG2-mediated l-glutamate excretion was activated by biotin limitation or penicillin treatment and that constitutive l-glutamate excretion was triggered by a gain-of-function mutation of MscCG2 (A151V). Discovery of MscCG2 will enrich the understanding of bacterial amino acid transport and provide additional targets for exporter engineering.IMPORTANCE The exchange of matter, energy, and information with surroundings is fundamental for cellular metabolism. Therefore, studying transport systems that are essential for these processes is of great significance. Besides, transport systems of bacterial cells are usually related to product excretion as well as product reuptake, making transporter engineering a useful strategy for strain improvement. The significance of our research is in identifying and characterizing a novel l-glutamate exporter from the industrial workhorse Corynebacterium glutamicum, which will enrich the understanding of l-glutamate excretion and provide a new target for studying bacterial amino acid transport and engineering transport reactions.

Laparoscopic versus traditional peritoneal dialysis catheter insertion: a meta analysis.

OBJECTIVE: The objective of this study is to compare the catheter-related complications as well as catheter survival between laparoscopic and traditional surgery in peritoneal dialysis catheter insertion. RESULTS: Five randomized controlled trials and 11 cohort studies were identified. Meta-analysis showed laparoscopic catheter is superior to traditional surgery in terms of controlling catheter migration (OR 0.17, 95% CI 0.08-0.33; p < 0.00001) and catheter survival rate (1-year survival rate: OR 3.05, 95% CI 1.72-5.41, p = 0.0001; 2-year survival rate: OR 2. 07, 95% CI 1.29-3.33, p = 0.0001), but slightly increases the risk of bleeding (OR 2.13, 95% CI 1.07-4.23, p = 0.03). The two groups were not significantly different in other catheter-related complications. As regards the quality of the analysis, only the migration analysis ranked A-level, while the rest fell into Class B or C. The overall research quality was moderate. CONCLUSION: Laparoscopic surgery is superior to traditional surgery on reducing catheter migration and prolonging catheter survival rate according to our analysis.

Alteration of circulatory platelet microparticles and endothelial microparticles in patients with chronic kidney disease.

OBJECTIVE: To compare plasma platelet microparticles (PMPs), P-selectin, endothelial microparticles (EMPs), and von Willebrand factor (vWF) between a normal control group and patients with chronic kidney disease (CKD) and to explore the significance of PMPs and EMPs in CKD. METHODS: Levels of plasma PMPs, P-selectin, EMPs and vWF in 122 CKD patients and 20 normal controls were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Relationships between PMPs, EMPs and blood pressure, creatinine clearance rate, 24-hour urine protein, hemoglobin, and cholesterol were analyzed. RESULTS: (1) Plasma PMPs, P-selectin, EMPs and vWF levels in CKD patients were significantly higher than those of the control group. Plasma PMPs and P-selectin levels for nephrotic syndrome (NS) were significantly higher than for other CKD groups. No significant difference was found between other CKD groups. Plasma EMPs and vWF in NS, lupus nephritis (LN) and hypertensive nephropathy groups were significantly higher than that of diabetic nephropathy (DN) and chronic glomerulonephritis (CGN) groups. (2) Plasma PMPs, P-selectin, EMPs and vWF in stage I-II CKD patients were significantly higher than those of stage III-V CKD patients, no significant difference was found within stage I-II CKD patients or stage III-V CKD patients. (3) PMPs and EMPs were positively correlated with blood pressure and 24-hour urinary protein, but no significant correlation was found with the creatinine clearance rate, hemoglobin or cholesterol. P-selectin and vWF were positively correlated with PMPs and EMPs respectively. CONCLUSION: CKD patients have significant platelet activation and endothelial dysfunction, which was involved in CKD's occurrence and development; high blood pressure and proteinuria are important reasons for platelet activation and endothelial dysfunction in patients with CKD; PMPs and EMPs can be used as new markers for dysfunctional platelet activation and endothelium.

Long non-coding MIAT mediates high glucose-induced renal tubular epithelial injury.

BACKGROUND AND OBJECTIVE: Long non-coding RNAs (lncRNAs) constitute a novel class of non-coding RNAs that take part in occurrence and development of diabetes complication via regulating gene expression. However, litter is known about lncRNAs in the setting of diabetes induced nephropathy. The aim of this study was to examine whether lncRNA-myocardial infarction-associated transcript (MIAT) is involved in diabetes induced renal tubules injury. METHODS: Adult Wister rats were randomly assigned to receive intraperitoneal STZ (65 mg/kg) to induce diabetes. Rats treated with equal volume of citrate buffer were as control. Renal function was evaluated by analysis of serum creatinine and blood urea nitrogen (BUN) every four weeks after STZ administration. Also tubules of all rats were collected for determination of MIAT and Nrf2 level at the corresponding phase. The in vitro high glucose-triggered human renal tubular epithelial cell line (HK-2) was used to explore the mechanism underling MIAT regulated high glucose-induced tubular damage. RESULTS: In diabetic rats, MIAT showed the lower level and its expression is negatively correlated with serum creatinine and BUN. Consistent with diabetic rat, exposed to high glucose, HK-2 cells expressed lower level of MIAT and Nrf2, and also showed reduction in cell viability. By pcDNA-MIAT plasmid transfection, we observed that MIAT overexpression reversed inhibitory action of Nrf2 expression by high glucose. Moreover, the data of RNA pull-down and RIP showed that MIAT controlled Nrf2 cellular through enhancing Nrf2 stability, which was confirmed by CHX and MG132 administration. Inhibitory effect of cell viability by silencing MIAT was also reversed by Nrf2 overexpression. CONCLUSION: In summary, our data suggested that MIAT/Nrf2 served as an important signaling pathway for high glucose induced renal tubular epithelial injury.

High glucose induces renal tubular epithelial injury via Sirt1/NF-kappaB/microR-29/Keap1 signal pathway.

OBJECTIVE: Diabetic nephropathy (DN) is a serious complication that commonly confronted by diabetic patients. A common theory for the pathogenesis of this renal dysfunction in diabetes is cell injury, inflammation as well as oxidative stress. In this content, the detailed molecular mechanism underlying high glucose induced renal tubular epithelial injury was elaborated. METHODS: An in vivo rat model of diabetes by injecting streptozotocin (STZ) and an in vitro high glucose incubated renal tubular epithelial cell (HK-2) model were used. Expression levels of Keap1, nuclear Nrf2 and p65 were determined by western blotting. Level of microR-29 (miR-29) was assessed using quantitative RT-PCR. Combination of p65 and miR-29 promotor was assessed using chromatin immunoprecipitation. Keap1 3'-UTR activity was detected using luciferase reporter gene assay. Cell viability was determined using MTT assay. RESULTS: In diabetic rat, miR-29 was downregulated and its expression is negatively correlated with both of serum creatinine and creatinine clearance. In high glucose incubated HK-2 cell, deacetylases activity of Sirt1 was attenuated that leads to decreased activity of nuclear factor kappa B (NF-κB). NF-κB was demonstrated to regulate miR-29 expression by directly binding to its promotor. The data of luciferase assay showed that miR-29 directly targets to Keap1 mRNA. While high glucose induced down regulation of miR-29 contributed to enhancement of Keap1 expression that finally reduced Nrf2 content by ubiquitinating Nrf2. Additionally, overexpression of miR-29 effectively relieved high glucose-reduced cell viability. CONCLUSION: High glucose induces renal tubular epithelial injury via Sirt1/NF-κB/microR-29/Keap1 signal pathway.

Down-regulation of miR-186 contributes to podocytes apoptosis in membranous nephropathy.

BACKGROUND AND AIM: Podocytes apoptosis is the key process in the development of membranous nephropathy and miR-186 is reported to be related with cell apoptosis. Here we investigated the expression of miR-186 in membranous nephropathy (MGN) patients and the mechanism underlying the podocytes apoptosis. METHODS: Thirty patients with MGN and 30 healthy people were included in this study. The expression of miR-186 was detected in renal tissue and podocyte cells exposed to AngII by real-time PCR. Caspase-3 activity was used to evaluate podocytes apoptosis. TLR4 and P2×7 protein expression was quantified by western blotting. miR-186 inhibitor and miR-186 mimic were transfected into cells to investigate the mechanism underlying miR-186 in podocytes apoptosis. RESULTS: In MGN patients, the level of miR-186 was significantly down-regulated as well as the protein expression of TLR4 and P2×7 was up-regulated in renal tissue. In vitro experiments, TLR4 siRNA increased the expression of miR-186 and miR-186 inhibitor elevated the mRNA and protein expression of P2×7 in podocytes exposed to AngII. In addition, the level of cleaved-caspase-3 was up-regulated by miR-186 inhibitor. The TUNEL-positive cells and caspase-3 activity of podocytes induced by AngII were down-regulated by miR-186 mimic. CONCLUSIONS: We revealed that TLR4 is involved in the regulation of miR-186 expression, and the anti-apoptotic effect of miR-186 on podocytes is correlated with P2×7 regulation.