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.

Macrophage­derived exosomal miRNA­155 promotes tubular injury in ischemia­induced acute kidney injury.

Tubule injury is a characteristic pathological feature of acute kidney injury (AKI) and determines the prognosis of kidney disease. However, the exact mechanism of tubule injury remains largely unclear. In the present study, the exact mechanism of tubule injury was investigated. Bilateral renal ischemia/reperfusion (I/R) injury (I/RI) was induced in mice and exosome secretion inhibitor GW4869 and miRNA­155 inhibitor were used. In addition, the exosomal microRNA (miR)­155­mediated cross­talk between macrophage and tubular cells was also investigated. It was determined that tubular injury was observed in an I/R­induced AKI model, which was closely associated with macrophage infiltration. Interestingly, blocking exosome production using GW4869 ameliorated tubular injury in I/R­induced AKI. Mechanistically, once released, activated macrophage­derived exosomal miR­155 was internalized by tubular cells, resulting in increased tubule injury through targeting of suppressor of cytokine signaling­1 (SOCS­1), a negative regulator of NF­κB signaling. In addition, a dual­luciferase reporter assay confirmed that SOCS­1 was the direct target of miR­155 in tubular cells. Notably, injection of these miR­155­enriched exosomes into renal parenchyma resulted in increased tubule injury in vivo. Thus, the present study demonstrated that exosomal miR­155 mediated the communication between activated macrophages and injured tubules, leading to progression of AKI, which not only provide novel insights into the pathophysiology of AKI but also offer a new therapeutic strategy for kidney diseases.

A PLA2R-IgG4 Antibody-Based Predictive Model for Assessing Risk Stratification of Idiopathic Membranous Nephropathy.

Background: Known as an autoimmune glomerular disease, idiopathic membranous nephropathy (IMN) is considered to be associated with phospholipase A2 receptor (PLA2R) in terms of the main pathogenesis. The quantitative detection of serum PLA2R-IgG and PLA2R-IgG4 antibodies by time-resolved fluoroimmunoassay (TRFIA) was determined, and the value of them, both in the clinical prediction of risk stratification in IMN, was observed in this study. Methods: 95 patients with IMN proved by renal biopsy were enrolled, who had tested positive for serum PLA2R antibodies by ELISA, and the quantitative detection of serum PLA2R-IgG and PLA2R-IgG4 antibodies was achieved by TRFIA. All the patients were divided into low-, medium-, and high-risk groups, respectively, which were set as dependent variables, according to proteinuria and renal function. Random forest (RF) was used to estimate the value of serum PLA2R-IgG and PLA2R-IgG4 in predicting the risk stratification of progression in IMN. Results: Out-of-bag estimates of variable importance in RF were employed to evaluate the impact of each input variable on the final classification accuracy. The variable of albumin, PLA2R-IgG, and PLA2R-IgG4 had high values (>0.3) of 0.3156, 0.3981, and 0.7682, respectively, which meant that these three were more important for the risk stratification of progression in IMN. In order to further assess the contribution of PLA2R-IgG and PLA2R-IgG4 to the model, we built four different models and found that PLA2R-IgG4 played an important role in improving the predictive ability of the model. Conclusions: In this study, we established a random forest model to evaluate the value of serum PLA2R-IgG4 antibodies in predicting risk stratification of IMN. Compared with PLA2R-IgG, PLA2R-IgG4 is a more efficient biomarker in predicting the risk of progression in IMN.

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.

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.

The protective effect and mechanism of lentinan on acute kidney injury in septic rats.

BACKGROUND: This study aimed to investigate the protective effect and mechanism of lentinan (LNT) on acute kidney injury (AKI) in septic rats. METHODS: A total 72 male SD rats were randomly divided into 6 groups with 12 rats in each group. Except for the sham group, all groups, including the burn sepsis group (BS group), the positive drug control group (dexamethasone, 5 mg/kg, PC group), the LNT low-concentration group (LNT-L group) (50 mg/kg), the LNT medium-concentration group (LNT-M group) (100 mg/kg), and the LNT high-concentration group (LNT-H group) (200 mg/kg), were intraperitoneally injected with the same amount of normal saline 30 min before injury. The levels of serum interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor alpha (TNF-α); the indexes of blood urea nitrogen (BUN) and creatinine (Cr); and the protein expression levels of inducible nitric oxide synthase (iNOS), intercellular adhesion molecule 1 (ICAM-1), and nuclear factor-κB (NF-κB) in renal tissue were detected 24 hours after the model was established. RESULTS: Compared with the sham group, the BUN and Cr of the other groups were significantly higher, while those of the LNT group with different concentrations were significantly lower than those of the BS group (P<0.05). Compared with the sham group, the protein expression levels of NF-κB, iNOS, and ICAM-1 along with the levels of pro-inflammatory factors TNF-α and IL-6 in serum were significantly increased, while the levels of anti-inflammatory factors IL-4 and IL-10 were obviously lower in the BS group. Compared with the BS group, the protein expression levels of NF-κB, iNOS, and ICAM-1 along with the levels of pro-inflammatory factors TNF-α and IL-6 in serum were significantly decreased, while the levels of anti-inflammatory factors IL-4 and IL-10 were obviously increased in the LNT group with different concentrations.. CONCLUSIONS: LNT has a certain protective effect on AKI in septic rats, and its mechanism may involve inhibiting the activation of NF-κB, which suppresses the expression of proinflammatory factors in turn, thus promoting the release of anti-inflammatory factors.

BAFF is involved in the pathogenesis of IgA nephropathy by activating the TRAF6/NF­κB signaling pathway in glomerular mesangial cells.

The aim of the present study was to investigate the involvement of B cell­activating factor (BAFF) in the pathogenesis of IgA nephropathy by activating the tumor necrosis factor receptor­associated factor 6 (TRAF6)/NF­κB signaling pathway in glomerular mesangial cells. For the clinical analysis, blood, urine and kidney tissue samples were collected from 58 patients diagnosed with primary IgA nephropathy by renal biopsy. For the in vitro study, glomerular mesangial cells were divided into five groups: Control (con)­short hairpin RNA (shRNA) (control group); con­shRNA + BAFF (20 ng/ml); con­shRNA + BAFF + BAFF­RFc chimera protein (500 µg/ml); TRAF6­shRNA; and TRAF6­shRNA + BAFF (20 ng/ml). For the in vivo experiments, 60 Sprague­Dawley rats were randomly divided into four groups: Con­small interfering RNA (siRNA) (control group); con­siRNA + IgA (IgA nephropathy group), BAFF­RFc chimera protein (2 µg/ml) + IgA, and TRAF6­siRNA (0.2 µM) + IgA. Reverse transcription­quantitative PCR was performed to evaluate the mRNA expression levels of TRAF6, connective tissue growth factor (CTGF), fibronectin (FN) and NF­κBP65. Western blot analysis was used to detect the protein expression levels of TRAF6, FN, CTGF and phosphorylated­NF­κBP65 in glomerular mesangial cells and kidney tissues. The results revealed that plasma BAFF levels were positively correlated with the severity of pathological damage in patients with IgA nephropathy. In vitro, BAFF induced the mRNA and protein expression of TRAF6, CTGF, FN and NF­κBP65 in glomerular mesangial cells. After the BAFF­RFc chimera protein was added to inhibit the binding of BAFF and BAFF­receptor (­R), this effect was reduced. In vivo, inhibition of the effects of BAFF via injection with the BAFF­R Fc chimera protein reduced kidney damage in rats suffering from IgA nephropathy. The effect on the expression of signaling pathway­associated proteins was also alleviated. In conclusion, BAFF enhanced the expression of fibroblast factors in the kidneys by activating the TRAF6/NF­κB signaling pathway.

Serum uric acid is an independent predictor of renal outcomes in patients with idiopathic membranous nephropathy.

PURPOSE: Accumulating evidence suggests that a relationship exists between serum uric acid (UA) and the progression of chronic kidney disease (CKD), but information regarding idiopathic membranous nephropathy (IMN) is limited. METHODS: Patients with renal biopsy-confirmed diagnosis of IMN between 2009 and 2017 were identified. The demographic and clinical data recorded at the time of renal biopsy were considered the baseline values. The included cases were separated into three groups based on tertiles of the baseline serum UA level, and the relationship between serum UA and poor renal outcome was investigated by receiver operating characteristic (ROC) and time-event analyses. The primary endpoint was poor renal outcome, which was defined as a decrease in the estimated glomerular filtration rate to 50% of the baseline level or progression to end-stage renal disease during the follow-up. RESULTS: Of 989 cases, 572 eligible patients were included. During a median of 18 months of follow-up, 45 (7.9%) patients progressed to the primary endpoint. Both baseline serum UA and time-averaged UA levels could be used for discrimination of renal outcomes, but the difference was not significant (p value = 0.6). Our Cox regression analysis further demonstrated that baseline serum UA was an independent predictor of poor renal outcome in IMN patients, and subgroup analysis revealed a gender difference in the predictive effect of serum UA. CONCLUSIONS: Our study demonstrated that baseline serum UA was an independent predictor of poor renal outcome in patients with IMN, and a gender difference in the predictive effect was observed in our cohort.

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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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.

c­Maf inducing protein inhibits cofilin­1 activity and alters podocyte cytoskeleton organization.

The glomerular visceral epithelial cells, also termed podocytes, are key in maintaining the normal renal filtration barrier. Although it has been demonstrated that stimulation of c­Maf inducing protein (CMIP) expression is involved in podocyte damage, the molecular events during this process remain unclear. In the current study, CMIP­induced proximal signaling was investigated by focusing on its effect on cofilin­1 activity in puromycin aminonucleoside (PA)­damaged podocytes. An obvious elevation of CMIP expression and phosphorylated (p) cofilin­1 levels was detected in cultured podocytes treated with PA and in glomeruli isolated from PA­induced nephropathy rats. Stable knockdown of CMIP prevented upregulation of p­cofilin­1 and reorganization of actin cytoskeleton in PA­treated podocytes. The activity of the Src family kinase Fyn was reduced, whereas small GTPase Ras homolog gene family, member A (RhoA) activity was increased in PA­treated podocytes. Stimulation of CMIP expression inhibited Fyn activation and decreased the expression level of p­p190RhoGAP, a negative regulator of RhoA activity. The level of p­LIM domain kinase 1 (LIMK1), a downstream effector of RhoA, increased significantly in PA­treated podocytes. Notably, the applications of RhoA inhibitor or knockdown of LIMK prevented increase of the p­cofilin­1 level in PA­treated podocytes. Thus, the current data provided evidence that the CMIP/Fyn/RhoA/cofilin­1 signaling pathway may be associated with actin disorganization and podocyte foot process spreading following podocyte injury.

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.

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.

Serum levels of three angiogenic factors in systemic lupus erythematosus and their clinical significance.

Our research investigates the serum levels of three angiogenic factors in the AF family, namely, placenta growth factor (PlGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF), in 54 patients with SLE (SLE group) and 28 healthy controls (normal control) through ELISA measurement. And their interrelationships were also systematically analyzed. The SLE patients were then divided into active SLE group and inactive SLE group according to the SLEDAI score. The results show that serum levels of PlGF, bFGF, and VEGF in all SLE group and active SLE group were higher than those in normal controls. Serum levels of PlGF and bFGF in inactive SLE group were higher than those in normal controls. The level of PlGF was positively correlated with VEGF in SLE patients and positive correlation is also shown in bFGF with VEGF. The levels of PlGF and VEGF in SLE patients were positively correlated with both ESR and SLEDAI score. Thus a tentative conclusion can be drawn that the serum levels of the angiogenic factors, for example, PlGF, bFGF, and VEGF, may be relevant in the pathogenesis of SLE, and the concentrations of PlGF and VEGF seem to be the markers of SLE activity.

Simvastatin increases ADAMTS13 expression in podocytes.

INTRODUCTION: ADAMTS13 is a specific von Willebrand factor-cleaving protease. Severe deficiency of ADAMTS13 is the main cause of thrombotic thrombocytopenic purpura. ADAMTS13 is mainly synthesized and released from hepatic stellate cells and endothelial cells, but is also expressed in other cells, including kidney podocytes. Simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has a beneficial effect on atherosclerosis and also has anti-inflammatory and antithrombotic properties. A recent study indicates that ADAMTS13 reduces inflammatory plaque formation during early atherosclerosis in mice. In our study, we investigated the effects of simvastatin on inflammatory cytokines-induced ADAMTS13 expression in podocytes. MATERIALS AND METHODS: A conditionally immortalized mouse podocyte cell line was utilized to study the expression of ADAMTS13 in podocytes. The influence of TNF-α, IL-4, IL-6 and simvastatin on ADAMTS13 was investigated. ADAMTS13 mRNA levels in podocytes were measured by using real-time PCR and protein levels were detected by Western blotting. RESULTS: Simvastatin significantly up-regulated the expression levels of ADAMTS13 mRNA and protein in podocytes. IL-6 decreased ADAMTS13 expression, and TNF-α had no significant effects on ADAMTS13 expression in podocytes. IL-4 reduced ADAMTS13 mRNA expression but not its protein level. Simvastatin was able also reversed the inhibitory effect of IL-6. CONCLUSIONS: We demonstrate that simvastatin increases the expression of ADAMTS13 in a dose-dependent manner in podocytes, which likely contributes to the antithrombotic property of statin. Different inflammatory cytokines have different effects on the levels of ADAMTS13 mRNA expression and protein within podocytes.

Von Willebrand factor, ADAMTS13 activity, TNF-α and their relationships in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) often exhibit associated endothelial dysfunction and inflammation. Systemic inflammation may contribute to the endothelial dysfunction and accelerated thrombosis observed in CKD patients. In this study, we assessed the relationships among endothelial dysfunction, a disintegrin-like and metalloprotease with thrombospondin type 1 repeats 13 (ADAMTS13) activity and levels of inflammatory cytokines in CKD patients. CKD patients were classified into three groups: The chronic glomerulonephritis group (CGN; n=31), the idiopathic nephritic syndrome group (NS; n=32) and the lupus nephritis group (LN; n=41). We measured the plasma levels of tumor necrosis factor-α (TNF-α), von Willebrand factor (VWF) antigen (VWF:Ag) and ADAMTS13 activity using an ELISA-based method in CKD patients (n=104) and normal controls (n=32). The ratio of the VWF:Ag levels to ADAMTS13 activity was calculated. The VWF:Ag levels were significantly higher and the ADAMTS13 activities were significantly lower in the disease groups compared to the controls (P<0.01). ADAMTS13 activity was lower in the NS group compared to the CGN and LN groups (P<0.05). The TNF-α levels were higher in the CKD group compared to the control group (P<0.01). TNF-α was positively correlated with the VWF:Ag levels (r=0.242, P=0.013) and negatively correlated with the glomerular filtration rate (GFR) (r=-0.193, P=0.049). ADAMTS13 activity was negatively correlated with the cholesterol levels in CKD patients (r=-0.2, P= 0.042). TNF-α levels in CKD were positively correlated with the VWF:Ag levels and negatively correlated with GFR, which indicates that inflammation may be a major cause of endothelial dysfunction and an index of renal function. The VWF:Ag levels increased and ADAMTS13 activity decreased in CKD patients, which indicates that CKD leads to a prothrombotic state.

Synthesis and DNA cleavage activity of 2-hydrazinyl-1,4,5,6-tetrahydropyrimidine containing hydroxy group.

2-Hydrazinyl-1,4,5,6-tetrahydropyrimidin-5-ol dihydrochloride 2, as well as 2-hydrazinyl-4,5-dihydro-1H-imidazole dihydrochloride 1, was synthesized as metal-free DNA cleaving agent. Agarose gel electrophoresis was used to assess the plasmid pUC 19 DNA cleavage activities in the presence of 1 and 2. DNA cleavage efficiency of 2 exhibits remarkable increases compared with its corresponding non-hydroxy compound 1. Kinetic data of DNA cleavage promoted by 2 fit to the Michaelis-Menten-type equation with k(max) of 0.0378+/-0.0013 h(-1) giving 10(6)-fold rate acceleration over uncatalyzed DNA. The acceleration is driven by the spatial proximity of the nucleophilic hydroxy group and the electrophilic activation for the phosphodiester by the ammonium and/or guanidinium groups. In vitro cytotoxic activities toward Hela cells and human leukemia HL-60 cells were also examined, and 2 exhibits stronger cytotoxic activities than 1.