Nitrogen-containing bisphosphonate induces enhancement of OPG expression and inhibition of RANKL expression via inhibition of farnesyl pyrophosphate synthase to inhibit the osteogenic differentiation and calcification in vascular smooth muscle cells.

BACKGROUND: Nitrogen-containing bisphosphonate(N-BP)had been found to inhibit the osteogenic differentiation and calcification in vascular smooth muscle cells (VSMCs), but the mechanism is not clear. We intend to verify that N-BP induces enhancement of OPG expression and inhibition of RANKL expression via inhibition of farnesyl pyrophosphate synthase(FPPS) to inhibit the osteogenic differentiation and calcification in VSMCs. METHODS: ß-glycerophosphate (ß-GP) was used to induce the osteogenic differentiation and calcification in VSMCs. VSMCs were treated with N-BP or pretreated with downstream products of farnesyl pyrophosphate synthase(FPPS) in mevalonate pathway, such as farnesol (FOH) or geranylgeraniol (GGOH). Alizarin red S staining and determination of calcium content were used to detect calcium deposition.Western Blotting were used to detect expressions of proteins(OPG and RANKL ) and osteogenic marker proteins (Runx2 and OPN). RESULTS: ß-GP induced the osteogenic differentiation and calcification in VSMCs, increased RANKL protein expression and had no significant effect on OPG protein expression. With the treatment of N-BP, the expression of OPG protein was increased and expression of RANKL protein was decreased in VSMCs undergoing osteogenic differentiation and calcification. In addition, N-BP reduced the osteogenic marker proteins (Runx2 and OPN) expression and calcium deposition in VSMCs undergoing osteogenic differentiation and calcification. These effects of N-BP on the osteogenic differentiation and calcification in VSMCs were concentration-dependent, which could be reversed by the downstream products of FPPS, such as FOH or GGOH. CONCLUSION: N-BP increases OPG expression and decreases RANKL expression via inhibition of FPPS to inhibit the osteogenic differentiation and calcification in VSMCs.

Astragaloside IV relieves passive heymann nephritis and podocyte injury by suppressing the TRAF6/NF-κb axis.

The pathogenesis of membranous nephropathy (MN) involves podocyte injury that is attributed to inflammatory responses induced by local immune deposits. Astragaloside IV (AS-IV) is known for its robust anti-inflammatory properties. Here, we investigated the effects of AS-IV on passive Heymann nephritis (PHN) rats and TNF-α-induced podocytes to determine the underlying molecular mechanisms of MN. Serum biochemical parameters, 24-h urine protein excretion and renal histopathology were evaluated in PHN and control rats. The expression of tumor necrosis factor receptor associated factor 6 (TRAF6), the phosphorylation of nuclear factor kappa B (p-NF-κB), the expression of associated proinflammatory cytokines (TNF-α, IL-6 and IL-1ß) and the ubiquitination of TRAF6 were measured in PHN rats and TNF-α-induced podocytes. We detected a marked increase in mRNA expression of TNF-α, IL-6 and IL-1ß and in the protein abundance of p-NF-κB and TRAF6 within the renal tissues of PHN rats and TNF-α-induced podocytes. Conversely, there was a reduction in the K48-linked ubiquitination of TRAF6. Additionally, AS-IV was effective in ameliorating serum creatinine, proteinuria, and renal histopathology in PHN rats. This effect was concomitant with the suppression of NF-κB pathway activation and decreased expression of TNF-α, IL-6, IL-1ß and TRAF6. AS-IV decreased TRAF6 levels by promoting K48-linked ubiquitin conjugation to TRAF6, which triggered ubiquitin-mediated degradation. In summary, AS-IV averted renal impairment in PHN rats and TNF-α-induced podocytes, likely by modulating the inflammatory response through the TRAF6/NF-κB axis. Targeting TRAF6 holds therapeutic promise for managing MN.

Effects of dexmedetomidine administration on outcomes in critically ill patients with acute kidney injury: A propensity score-matching analysis.

PURPOSE: To evaluate the effects of dexmedetomidine (DEX) on outcomes of critically ill patients with acute kidney injury (AKI). MATERIALS AND METHODS: Data were extracted from the Medical Information Mart for Intensive Care III database (MIMIC III). Propensity score matching (PSM) analysis (1 : 3), Cox proportional hazards model, linear regression and logistic regression model were used to assess the effect of DEX on clinical outcomes. RESULTS: After PSM, 324 pairs of patients were matched between the patients with DEX administration and those without. DEX administration was associated with decreased in-hospital mortality (hazard ratio (HR) 0.287; 95% CI 0.151 - 0.542; p < 0.001) and 90-day mortality (HR 0.344; 95% CI 0.221 - 0.534; p < 0.001), and it was also associated with reduced length of stay (LOS) in ICU (4.54 (3.13,7.72) vs. 5.24 (3.15,10.91), p < 0.001) and LOS in hospital (11.63 (8.02,16.79) vs 12.09 (7.83,20.44), p = 0.002). Subgroup analysis showed that the above associations existed only in the mild and moderate AKI subgroups, but not in the severe AKI subgroup. Nevertheless, DEX administration was not associated with recovery of renal function (HR 1.199; 95% CI 0.851 - 1.688; p = 0.300). CONCLUSION: DEX administration improved outcomes in critically ill patients with mild and moderate AKI and could be a good choice of sedation.

Impact of klotho on the expression of SRGAP2a in podocytes in diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is the major cause of kidney failure, and glomerular podocytes play critical roles in the pathogenesis of DN by maintaining the glomerular structure and filtration barrier. Klotho and Slit-Robo GTP activating protein 2a (SRGAP2a) have been indicated to play protective roles in reducing kidney injury, but whether there is an internal relationship between these two factors is unclear. METHODS: In this study, we cultured differentiated rat podocytes in vitro and measured the SRGAP2a expressions by immunofluorescence staining, quantitative real-time PCR (qRT-PCR) and western blotting, after siRNA-mediated transforming growth factor ß1 (TGF-ß1) silencing, TGF-ß1 overexpression and in the presence of a reactive oxygen species (ROS) inhibitor. And we detected the expressions of SRGAP2a, small mother against decapentaplegic (Smad)2/3, phosphorylated-Smad2/3 (p-Smad2/3), Smad7, and NAD(P)H oxidase 4 (NOX4), ROS levels and podocyte cytoskeletal remodelling under high glucose (HG) and exogenous klotho conditions. In addition, we performed haematoxylin-eosin (HE) staining and immunohistochemistry with diabetic rat models to confirm the in vitro results. RESULTS: The results indicated that SRGAP2a expression was significantly upregulated under siRNA-mediated TGF-ß1 silencing conditions or after adding a ROS inhibitor, but significantly downregulated with TGF-ß1 overexpression, in the presence of HG. The supplementation of exogenous klotho under HG conditions significantly increased the SRGAP2a expression, remodelled the actin cytoskeleton and altered the expressions of Smad2/3, p-Smad2/3, Smad7 and NOX4 and reduced the ROS generation in podocytes. Moreover, klotho administration protected kidney injury in DN rats. CONCLUSIONS: This study indicated that klotho may modulate the expression of SRGAP2a by regulating the ROS and TGF-ß1 signalling pathways and provided theoretical support for klotho protein as a novel therapeutic strategy for treating DN patients.

Relationship of complement activation pathway to clinical and pathological characteristics and renal outcome in patients with lupus nephritis.

BACKGROUND: Involvement of the complement system in the pathogenesis of lupus nephritis (LN) is well accepted, but its exact role remains unclear. The aim of this study was to investigate the relationship of complement activation pathway to clinical and pathological characteristics and renal outcome in patients with LN. MATERIAL AND METHODS: Patients with LN were divided into two groups: those in whom the complement system was mainly activated through the classical pathway (low serum C3 and C4 levels; CP group); and those in whom the complement system was solely activated through the alternative pathway (low serum C3 with normal C4 levels; AP group). Clinical and pathological data and renal outcomes were compared between the two groups. RESULTS: A total of 102 LN patients were enrolled in this study, 63 patients (61.8%) in the CP group and 39 patients (38.2%) in the AP group. LN patients in the CP group had significantly higher SLEDAI (p < 0.001), more anti-dsDNA (p = 0.001), higher renal activity index (p < 0.001), and more class IV LN (p = 0.008) than LN patients in the AP group. Mean length of follow-up was 50.6 ± 26.4 months. Renal outcome in the form of progression of kidney disease was significantly poorer in the CP group in the AP group (p = 0.037). CONCLUSION: Our findings suggest that evaluation of the complement activation pattern may be useful for evaluating disease activity and predicting the prognosis of LN.

Extracellular vesicle-derived AEBP1 mRNA as a novel candidate biomarker for diabetic kidney disease.

BACKGROUND: A novel and improved methodology is still required for the diagnosis of diabetic kidney disease (DKD). The aim of the present study was to identify novel biomarkers using extracellular vesicle (EV)-derived mRNA based on kidney tissue microarray data. METHODS: Candidate genes were identified by intersecting the differentially expressed genes (DEGs) and eGFR-correlated genes using the GEO datasets GSE30528 and GSE96804, followed by clinical parameter correlation and diagnostic efficacy assessment. RESULTS: Fifteen intersecting genes, including 8 positively correlated genes, B3GALT2, CDH10, MIR3916, NELL1, OCLM, PRKAR2B, TREM1 and USP46, and 7 negatively correlated genes, AEBP1, CDH6, HSD17B2, LUM, MS4A4A, PTN and RASSF9, were confirmed. The expression level assessment results revealed significantly increased levels of AEBP1 in DKD-derived EVs compared to those in T2DM and control EVs. Correlation analysis revealed that AEBP1 levels were positively correlated with Cr, 24-h urine protein and serum CYC and negatively correlated with eGFR and LDL, and good diagnostic efficacy for DKD was also found using AEBP1 levels to differentiate DKD patients from T2DM patients or controls. CONCLUSIONS: Our results confirmed that the AEBP1 level from plasma EVs could differentiate DKD patients from T2DM patients and control subjects and was a good indication of the function of multiple critical clinical parameters. The AEBP1 level of EVs may serve as a novel and efficacious biomarker for DKD diagnosis.

Association of antiphospholipid antibodies with clinical activity and renal pathological activity in patients with lupus nephritis.

OBJECTIVES: This study aimed to investigate the association of antiphospholipid antibodies (aPL) with clinical activity and renal pathological activity in patients with lupus nephritis (LN). METHODS: Levels of anticardiolipin () antibodies, anti-ß2-glycoprotein I (anti-ß2-GPI) antibodies and lupus anticoagulant (LAC) were measured, and other clinical and pathological data were also obtained during the same period before renal biopsy. RESULTS: A total of 83 patients with LN were included in this study, 40 patients (48.2%) in the s positive group and 43 patients in the aPL negative group. LN patients with positive aPL had significantly higher SLEDAI (p = 0.012), more hematuria (p = 0.043), lower serum C3 (p = 0.003) and C4 (p = 0.014), and a higher pathological activity index (p = 0.012), more micro-thrombosis (p = 0.046) and more C3 deposits (p = 0.038) in the glomerulus than patients with negative aPL The level of IgG- was significantly correlated with SLEDAI and serum level of C3 (r = 0.44, p < 0.001; r = -0.39, p = 0.003, respectively). The level of IgM- was significantly correlated with SLEDAI, and serum levels of C3 and C4 (r = 0.27, p = 0.014; r = -0.22, p = 0.041; r = -0.23, p = 0.035, respectively). CONCLUSIONS: Our work suggests that aPL, especially, are correlated with both clinical activity and renal pathological activity in patients with LN.

Predictors of renal outcomes in crescentic and mixed class of ANCA-associated glomerulonephritis.

BACKGROUND: The aim of this study was to investigate the predictors of renal outcomes in crescentic and mixed class of ANCA-associated glomerulonephritis. MATERIALS AND METHODS: We systematically reviewed the medical records of patients with ANCA-associated glomerulonephritis admitted to our hospital from December 2008 to December 2018, and found 30 patients with crescentic and 40 patients with mixed ANCA-associated glomerulonephritis. RESULTS: End-stage renal disease developed in 33.3 and 25% patients over a median follow-up of 45.1 and 46.7 months in the crescentic and mixed group, respectively. There was no significant difference in renal survival rates between the two histological subgroups (log-rank p = 0.558). In the Cox regression model, old age, lower estimated glomerular filtration rate (eGFR), lower normal glomeruli ratio, and a higher tubular atrophy and interstitial fibrosis ratio were significantly associated end-stage renal disease (p < 0.05 for all). Among our patients, 17.1% were at low risk, 57.1% were at medium risk, and 25.7% were at high risk according to antineutrophil cytoplasmic antibody renal risk score and end-stage renal disease developed in 8.3, 40, and 66.7%, respectively (p = 0.024). CONCLUSION: These findings indicated that the renal risk score was a better prognostic tool than Berden's classification in a cohort with crescentic and mixed histologic categories.

The effects of pre-dialysis blood pressure targets on prognosis and health-related quality of life in haemodialysis patients.

OBJECTIVE: The aim of the study is to investigate the effects of pre-dialysis blood pressure targets on health-related quality of life and prognosis and to determine the optimal target for pre-dialysis blood pressure in haemodialysis patients. METHODS: A total of 58 haemodialysis patients undergoing dialysis for more than 3 months were enrolled in the study from 1 January 2018 to 31 December 2018. The subjects were divided into two groups according to their pre-dialysis blood pressure: a standard target group (pre-dialysis systolic blood pressure of 110-140 mm Hg) and a relaxed target group (pre-dialysis systolic blood pressure of 155-165 mm Hg). The Quality Metrics SF-36 survey instrument was used to assess health-related quality of life in the study participants. In addition, general clinical data and biochemical indicators including heart rate, respiration rate, blood pressure and ultrafiltration volume and rate during dialysis were observed and recorded. Patients were followed-up for 12 months, and prognostic data were recorded. Death was regarded as the endpoint. RESULTS: Scores on the SF-36 in the standard target group were significantly higher than those in the relaxed target group, with the exception of the role-emotional (RE) and mental health (MH) dimensions. At the end of the study, the number of mortality events in the relaxed target group was higher than in the standard target group. There were no other significant differences between the two groups. CONCLUSION: The scores from the health-related quality of life survey were higher in standard target group, but no differences in mortality risk between the two groups were observed.

Association between serum elastin-derived peptides and abdominal aortic calcification in peritoneal dialysis patients: a cross-sectional study.

BACKGROUND: Peritoneal dialysis (PD) patients experience accelerated arterial aging, which is characterized by elastin degradation. Elastin-derived peptides (EDPs) are direct products of elastin fragmentation. This study tried to explore the association between serum EDPs and abdominal aortic calcification (AAC) in PD patients. METHODS: Serum levels of EDPs were analyzed in 126 eligible PD patients and 30 controls. PD patients were grouped according to the annularity of AAC evaluated by an abdominal computed tomography (CT) scan. Serum EDPs were analyzed in relation to the presence of AAC or severe AAC in PD patients by logistic regression analysis. RESULTS: Serum EDPs in PD patients were significantly higher than age-matched controls. In 126 PD patients, higher EDPs was associated with greater risk of present AAC (OR = 1.056, 95%CI 1.010-1.103) and severe AAC (OR = 1.062, 95%CI 1.004-1.123). A combination of EDPs substantially improved the accuracy of diagnostic performance for AAC and severe AAC. CONCLUSIONS: EDPs can predict the presence and extent of AAC in PD patients, indicating its possible role to recognize PD patients at risk for AAC and severe AAC.

Serum urate goal attainment and associated factors in Chinese gout patients.

We conducted a cross-sectional study with 350 gout patients to investigate serum urate acid (sUA) goal attainment (sUA < 360 µmol/L) and associated factors in Chinese gout patients in the Affiliated Hospital of Nantong University from August 2015 to September 2017. Descriptive statistics, health assessment questionnaire, global visual analog scale for general health and Gout Knowledge Questionnaire were calculated comparing patients at sUA goal or not at sUA goal. Univariate analysis and logistic regression models were applied to analyze data. The proportion of urate-lowering therapy (ULT) use was 61.2% (211/350). The mean ± standard deviation sUA of the participants was 475.07 ± 121.53 µmol/L. Only 17.4% of gout patients attain the serum urate goal, which also means 289(82.6%) patients cannot keep their sUA below the target of 360 µmol/L. The factors associated with sUA goal attainment including age, education level and ULT use. Among these, age, waist hip ratio, ULT, family history of cardiovascular disease was the predictor of sUA goal attainment. In conclusion, more than 80% of gout patients did not achieve sUA goal. Younger and fatter patients were more difficult to control the serum urate level.

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.

Prevention of contrast-induced nephropathy with prostaglandin E1 in patients undergoing percutaneous coronary procedures: A meta-analysis of 24 randomized controlled trials
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BACKGROUND: Contrast-induced nephropathy (CIN) is the third most common cause of acute kidney injury in hospitalized patients. There have been many conflicting results across trials that have evaluated the prophylactic efficacy of prostaglandin E1 (PGE1) for prevention of CIN in patients undergoing percutaneous coronary procedures. PGE1 may have renal-protective effects due to its pleiotropic properties. The aim of this study was to evaluate the efficacy of PGE1 in preventing CIN. MATERIALS AND METHODS: We searched PubMed, Embase, Cochrane Library, Chinese Biomedical Literature, China National Knowledge Infrastructure, VIP Information/Chinese Scientific Journals, and WANFANG databases for randomized controlled trials (RCTs) comparing the preventive effects of PGE1 versus controls (conventional hydration, no PGE1, or placebo) on CIN in patients undergoing percutaneous coronary procedures from January 1999 to June 2016. Study characteristics and outcome data were abstracted by two independent reviewers; the risk of bias was also assessed by two reviewers. RESULTS: 24 RCTs involving 3,915 patients were included. Compared with controls, PGE1 reduced the risk of CIN (risk ratio: 0.40, 95% confidence interval (CI): 0.33, 0.48; p < 0.01). Serum creatinine levels in the PGE1 groups were significantly lower than in the control groups at 24, 48, and 72 hours after operation (mean difference (MD): -10.06, 95% CI: -16.94, -3.19; MD: -15.47, 95% CI: -21.75, -9.18; and MD: -11.15, 95% CI: -14.40, -7.91, respectively). Cystatin C was significantly lower for the PGE1 group than the control groups at 24, 48, and 72 hours after operation (MD: -0.24, 95% CI: -0.40, -0.07; MD: -0.34, 95% CI: -0.53, -0.14; and MD: -0.32, 95% CI: -0.49, -0.15, respectively). CONCLUSION: PGE1 may play an important role in reducing the incidence of CIN in patients undergoing percutaneous coronary procedures.
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Oleanolic acid attenuates TGF-ß1-induced epithelial-mesenchymal transition in NRK-52E cells.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) plays an important role in the progression of renal interstitial fibrosis, which finally leads to renal failure. Oleanolic acid (OA), an activator of NF-E2-related factor 2 (Nrf2), is reported to attenuate renal fibrosis in mice with unilateral ureteral obstruction. However, the role of OA in the regulation of EMT and the underlying mechanisms remain to be investigated. This study aimed to evaluate the effects of OA on EMT of renal proximal tubular epithelial cell line (NRK-52E) induced by TGF-ß1, and to elucidate its underlying mechanism. METHODS: Cells were incubated with TGF-ß1 in the presence or absence of OA. The epithelial marker E-cadherin, the mesenchymal markers, α-smooth muscle actin (α-SMA), fibronectin, Nrf2, klotho, the signal transducer (p-Smad2/3), EMT initiator (Snail), and ILK were assayed by western blotting. RESULTS: Our results showed that the NRK-52E cells incubated with TGF-ß1 induced EMT with transition to the spindle-like morphology, down-regulated the expression of E-cadherin but up-regulated the expression of α-SMA and fibronectin. However, the treatment with OA reversed all EMT markers in a dose-dependent manner. OA also restored the expression of Nrf2 and klotho, decreased the phosphorylation of Smad2/3, ILK, and Snail in cells which was initiated by TGF-ß1. CONCLUSION: OA can attenuate TGF-ß1 mediate EMT in renal tubular epithelial cells and may be a promising therapeutic agent in the treatment of renal fibrosis.

Increased C4 and decreased C3 levels are associated with a poor prognosis in patients with immunoglobulin A nephropathy: a retrospective study.

BACKGROUND: An association between serum complement levels and poor renal prognosis in patients with immunoglobulin A nephropathy (IgAN) remains controversial. METHODS: We conducted a retrospective study examining the relationship between serum complement levels and prognosis in patients with IgAN. Between 2009 and 2013, patients with biopsy-confirmed IgAN were identified from the Second Affiliated Hospital of Wenzhou Medical College, China, and various parameters were documented during follow-up until 2015. The definition of the primary endpoint was a decrease of estimated glomerular filtration rate (eGFR) more than 30% from their baseline levels. RESULTS: A total of 403 patients (55.3% female, average 33.7 months of follow-up) were identified and enrolled, with the primary endpoint occurring in 39 (9.8%) patients. Among the patients selected, 202 (50.1%) received corticosteroid treatment alone or in combination with another immunosuppressant (GS group), while others did not receive immunosuppressive treatment (non-GS group). The incidence of the primary endpoint was slightly lower in the GS group compared to the non-GS group (7.0% versus 12.6%, p = 0.06). Multivariate Cox proportional-hazard regression analyses, adjusting for age, systolic and diastolic blood pressure, 24-h urine protein, and immunosuppressive therapy, showed that serum complement 4 (C4) levels (hazard ratio [HR] 2.4, 95% confidence interval [CI] 1.6-3.8, p < 0.001) and serum complement 3 (C3) levels (HR 0.6, 95% CI 0.2-0.6, p < 0.001) were significantly associated with a poor prognosis among patients with IgAN. CONCLUSIONS: We demonstrated that an increase in serum C4, as well as a decrease in C3, was an important outcome determinant for patients with IgAN. Testing serum C3 and C4 levels might assist in predicting renal outcomes among these patients.

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.

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.

Staurosporine Induces Platelet Apoptosis Through p38 Mitogen-Activated Protein Kinase Signaling Pathway.

BACKGROUND: Staurosporine (STS), a microbial alkaloid and potent PKC inhibitor, has become one of the most promising anti-cancer drugs. STS effectively induces apoptosis in many nucleated cells; however, it is still unclear whether STS induces apoptosis in enucleated platelets. METHODS: Apoptotic events in platelets treated with STS were assessed by flow cytometry or western blotting. RESULTS: STS induced depolarization of mitochondrial inner transmembrane potential (ΔΨm), up-regulation of Bax and Bak, phosphatidylserine (PS) exposure, release of mitochondrial cytochrome c, and activation of caspase-8 and caspase-9 in human platelets. Furthermore, STS stimulation induced phosphorylation of p38 mitogen-activated protein kinase (MAPK). Inhibition of p38 MAPK activation significantly reduced ΔΨm depolarization and PS exposure in platelets stimulated with STS. CONCLUSIONS: These data indicate that STS induces platelet apoptosis via the p38 MAPK signaling pathway. These findings suggest that platelet apoptosis-related hemorrhage should be noticed in STS and its derivatives in clinical tests.

Enhanced platelet apoptosis in chronic uremic patients.

BACKGROUND: There is a paucity of research on platelet apoptosis and its contribution to platelet dysfunction in uremic patients. The present study sought to analyze platelets apoptosis in uremic patients who underwent different dialysis modalities. METHODS: Sixteen chronic uremic patients (5 on hemodialysis, 6 on peritoneal dialysis and 5 on non-dialysis) and 16 controls were studied. Platelet-rich plasma was detected for apoptotic events including depolarization of mitochondrial inner membrane potential (ΔΨm), phosphatidylserine (PS) exposure, activation of caspases-3 and Bcl-2 family proteins variations by Flow Cytometry or by Western-Blot. Washed normal platelets were incubated with normal or uremic platelet poor plasma and then were detected apoptotic events. Platelets function was assessed by ristocetin induced aggregative function test. RESULTS: Compared to controls, uremic platelets demonstrated greater apoptosis for the ΔΨm depolarization (43.48 ± 9.58 vs. 52.76 ± 15.36, p = 0.005) as well as PS exposure (1.36 ± 0.51 vs. 0.99 ± 0.27, p < 0.001). There was no significant difference among different treatment groups (for the ΔΨm depolarization f = 0.16, p = 0.85; for the PS exposure f = 1.06, p = 0.36). Western Blot analyses showed caspase-3 activation and pro-apoptotic Bcl-2 family proteins expression. Platelets exposed to uremic plasma exhibited distinct apoptosis phenomena. Ristocetin induced platelet aggregation was markedly diminished in uremic patients and treated platelets. CONCLUSIONS: These findings indicate that platelets are incurred apoptosis in uremia patients. Uremic plasma accelerates apoptosis of normal platelets, resulting in a dysfunctional pattern of platelets in uremia. Uremic platelets apoptosis has no relationship with dialysis modality.