Epsin1-mediated exosomal sorting of Dll4 modulates the tubular-macrophage crosstalk in diabetic nephropathy.

Tubular epithelial cells (TECs) play critical roles in the development of diabetic nephropathy (DN), and can activate macrophages through the secretion of exosomes. However, the mechanism(s) of TEC-exosomes in macrophage activation under DN remains unknown. By mass spectrometry, 1,644 differentially expressed proteins, especially Dll4, were detected in the urine exosomes of DN patients compared with controls, which was confirmed by western blot assay. Elevated Epsin1 and Dll4/N1ICD expression was observed in kidney tissues in both DN patients and db/db mice and was positively associated with tubulointerstitial damage. Exosomes from high glucose (HG)-treated tubular cells (HK-2) with Epsin1 knockdown (KD) ameliorated macrophage activation, TNF-α, and IL-6 expression, and tubulointerstitial damage in C57BL/6 mice in vivo. In an in vitro study, enriched Dll4 was confirmed in HK-2 cells stimulated with HG, which was captured by THP-1 cells and promoted M1 macrophage activation. In addition, Epsin1 modulated the content of Dll4 in TEC-exosomes stimulated with HG. TEC-exosomes with Epsin1-KD significantly inhibited N1ICD activation and iNOS expression in THP-1 cells compared with incubation with HG alone. These findings suggested that Epsin1 could modulate tubular-macrophage crosstalk in DN by mediating exosomal sorting of Dll4 and Notch1 activation.

Epac activation ameliorates tubulointerstitial inflammation in diabetic nephropathy.

Tubulointerstitial inflammation plays an important role in the progression of diabetic nephropathy (DN), and tubular epithelial cells (TECs) are crucial promoters of the inflammatory cascade. Exchange protein activated by cAMP (Epac) has been shown to suppress the angiotensin II (Ang-II)-induced release of inflammatory cytokines in tubular cells. However, the role of Epac in TEC-mediated tubulointerstitial inflammation in DN remains unknown. We found that administering the Epac agonist 8-pCPT-2'-O-Me-cAMP (8-O-cAMP) to db/db mice inhibited tubulointerstitial inflammation characterized by macrophage infiltration and increased inflammatory cytokine release and consequently alleviated tubulointerstitial fibrosis in the kidney. Furthermore, 8-O-cAMP administration restored CCAAT/enhancer binding protein ß (C/EBP-ß) expression and further upregulated the expression of Suppressor of cytokine signaling 3 (SOCS3), while inhibiting p-STAT3, MCP-1, IL-6, and TNF-α expression in the kidney cortex in db/db mice. And in vitro study showed that macrophage migration and MCP-1 expression induced by high glucose (HG, 30 mM) were notably reduced by 8-O-cAMP in human renal proximal tubule epithelial (HK-2) cells. In addition, 8-O-cAMP treatment restored C/EBP-ß expression in HK-2 cells and promoted C/EBP-ß translocation to the nucleus, where it transcriptionally upregulated SOCS3 expression, subsequently inhibiting STAT3 phosphorylation. Under HG conditions, siRNA-mediated knockdown of C/EBP-ß or SOCS3 in HK-2 cells partially blocked the inhibitory effect of Epac activation on the release of MCP-1. In contrast, SOCS3 overexpression inhibited HG-induced activation of STAT3 and MCP-1 expression in HK-2 cells. These findings indicate that Epac activation via 8-O-cAMP ameliorates tubulointerstitial inflammation in DN through the C/EBP-ß/SOCS3/STAT3 pathway.

Relationships among the Dosage of Erythropoiesis-Stimulating Agents, Erythropoietin Resistance Index, and Mortality in Maintenance Hemodialysis Patients.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) constitute an important treatment option for anemia in hemodialysis (HD) patients. We investigated the relationships among the dosage of ESA, erythropoietin resistance index (ERI) scores, and mortality in Chinese MHD patients. METHODS: This multicenter observational retrospective study included MHD patients from 16 blood purification centers (n = 824) who underwent HD in 2011-2015 and were followed up until December 31, 2016. We collected demographic variables, HD parameters, laboratory values, and ESA dosages. Patients were grouped into quartiles according to ESA dosage to study the effect of ESA dosage on all-cause mortality. The ERI was calculated as follows: ESA (IU/week)/weight (kg)/hemoglobin levels (g/dL). We also compared outcomes among the patients stratified into quartiles according to ERI scores. We used the Cox proportional hazards model to measure the relationships between the ESA dosage, ERI scores, and all-cause mortality. Using propensity score matching, we compared mortality between groups according to ERI scores, classified as either > or ≤12.80. RESULTS: In total, 824 patients were enrolled in the study; 200 (24.3%) all-cause deaths occurred within the observation period. Kaplan-Meier analyses showed that patients administered high dosages of ESAs had significantly worse survival than those administered low dosages of ESAs. A multivariate Cox regression identified that high dosages of ESAs could significantly predict mortality (ESA dosage >10,000.0 IU/week, HR = 1.59, 95% confidence intervals (CIs) (1.04, 2.42), and p = 0.031). Our analysis also indicated a significant increase in the risk of mortality in patients with high ERI scores. Propensity score matching-analyses confirmed that ERI > 12.80 could significantly predict mortality (HR = 1.56, 95% CI [1.11, 2.18], and p = 0.010). CONCLUSIONS: Our data suggested that ESA dosages >10,000.0 IU/week in the first 3 months constitute an independent predictor of all-cause mortality among Chinese MHD patients. A higher degree of resistance to ESA was related to a higher risk of all-cause mortality.

Initiation Condition of Hemodialysis Is Independently Associated with All-Cause Mortality in Maintenance Hemodialysis Patients: A Retrospective Study.

BACKGROUND: Despite the progression of dialysis techniques,  the mortality of hemodialysis (HD) patients is still high in China. Here, a retrospective study was performed to investigate the neglected risk factors of all-cause mortality during maintenance HD (MHD). METHODS: We investigated 117 MHD patients who died between 2011 and 2016 in the Second Xiangya Hospital of Central South University HD center. In order to analyze the risk factors of 48 months all-cause death, the methods of Kaplan-Meier and Cox regression were used. RESULTS: Multivariate analyses of adjusted age and gender showed that MHD patients with estimated glomerular filtration rate <7 or >10 mL/min/1.73 m2 and anemia (hemoglobin <100 g/L) at the initiation of dialysis are independently associated with the higher death risk. Using central venous catheter vascular access, cerebrovascular comorbidities, diabetes, low-flux dialyzer, and dialysis frequency ≤2 times weekly were also the independent risk factors of death within 48 months. CONCLUSIONS: This study indicated that the status of HD initiation is a risk factor of long-term survival in MHD patients, which were usually ignored for lacking of nephrology care prior and could potentially be identified and modified to improve the survival prognosis. Video Journal Club "Cappuccino with Claudio Ronco" at  https://www.karger.com/Journal/ArticleNews/223997?sponsor=52.

A Comparison between Intermittent Peritoneal Dialysis and Automatic Peritoneal Dialysis on Urgent Peritoneal Dialysis.

BACKGROUND: Urgent-start dialysis is a major problem for incident dialysis population. Urgent start on hemodialysis is associated with an increased risk of infectious or mechanical complications, and its mortality is equal to or higher than that of urgent start on peritoneal dialysis (PD). However, compared to patients starting PD in a planned setting, those on urgent-started PD have an increased risk of mechanical complications and lower technique survival. METHODS: In this study, 101 adult incident dialysis patients (≥18 years old) who underwent Tenckhoff catheter implantation were enrolled. All of the patients were grouped according to the urgent PD mode: the intermittent PD (IPD) or automatic PD (APD) group, and patients were followed for 1 year. The paired or independent t test was used to analyze the change of laboratory variables. Pearson chi-square test was applied to compare the short outcome between the 2 groups. RESULTS: When PD was treated for 7 days and 1 month, the APD group has the lower serum potassium and phosphorus levels than the IPD group. The incidence of catheter dysfunction was significantly lower in the APD group. The morbidity of infection associated with PD in the first year was lower in the APD group despite no significant difference existing. The technique survival and patient survival rate have no evident difference between the 2 groups. CONCLUSION: Compared to IPD, urgent start on APD could reduce the risk of mechanical complication, which could be considered a gentle, safe, and feasible alternative to urgent start on IPD.

Use of Ophiocordyceps sinensis (syn. Cordyceps sinensis) combined with angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) versus ACEI/ARB alone in the treatment of diabetic kidney disease: a meta-analysis.

Ophiocordyceps sinensis (O. sinensis; syn. Cordyceps sinensis) has been used in clinical therapy for diabetic kidney disease (DKD) for more than 15 years. O. sinensis is a household name in china and it is available even in supermarket. However, the precise role of O. sinensis has not been fully elucidated with meta-analysis. The aim of this study was to review existing evidence on the effectiveness of O. sinensis for the treatment of DKD. We identified 60 trials involving 4288 participants. Overall, O. sinensis combined with ACEI/ARB had a better effect when compared to ACEI/ARB alone on 24 h UP (MD = -0.23 g/d, 95% CI: - 0.28 to -0.19, p < 0.00001), UAER (MD = -19.71 µg/min, 95% CI: -22.76 to -16.66, p < 0.00001), MAU (MD = -45.09 mg/d, 95% CI: -55.68 to -34.50, p < 0.00001), BUN (MD = -0.70 mmol/L, 95% CI: -1.02 to -0.39, p < 0.0001), SCr (MD = -8.37 µmol/L, 95% CI: -12.41 to -4.32, p < 0.0001), CRP (MD = -1.32 mg/L; 95% CI: -1.78 to -0.86; p < 0.00001), TG (MD = -0.51 mmol/L; 95% CI: -0.69 to -0.34, p < 0.00001), TC (MD = -0.64 mmol/L; 95% CI: -0.91 to -0.37, p < 0.00001), and SBP (MD = -2.01 mmHg; 95% CI: -3.45 to -0.58, p = 0.006). However, no effects were found for DBP, FBG, and HbA1C. This meta-analysis suggested that use of O. sinensis combined with ACEI/ARB may have a more beneficial effect on the proteinuria, inflammatory, dyslipidemia status as compared to ACEI/ARB alone in DKD III-IV stage patients, while there is no evidence that O. sinensis could improve the hyperglycemia status. However, with regard to low-quality and significant heterogeneity of included trials, to further verify the current results from this meta-analysis, long-term and well-designed RCTs with high-quality study are warranted to ascertain the long-term efficacy of O. sinensis.

Significance of serum procalcitonin as biomarker for detection of bacterial peritonitis: a systematic review and meta-analysis.

BACKGROUND: Bacterial peritonitis is serious disease and remains a diagnostic challenge for clinicians. Many studies have highlighted the potential usefulness of procalcitonin (PCT) for identification of bacterial peritonitis, however, the overall diagnostic value of PCT remains unclear. Therefore, we performed a meta-analysis to assess the accuracy of PCT for detection of bacterial peritonitis. METHODS: We performed a systematic searched in MEDLINE, EMBASE, SCOPUS, China Biology Medicine Database (CBM), China National Knowledge Infrastructure Database (CNKI) and Cochrane databases for trials that evaluated the diagnostic role of PCT for bacterial peritonitis. Sensitivity, specificity and other measures of accuracy of PCT were pooled using bivariate random effects models. RESULTS: Eighteen studies involving 1827 patients were included in the present meta-analysis. The pooled sensitivity and specificity of serum PCT for the diagnosis bacterial peritonitis were 0.83 (95% CI: 0.76-0.89) and 0.92 (95% CI: 0.87-0.96), respectively. The positive likelihood ratio was 11.06 (95% CI: 6.31-19.38), negative likelihood ratio was 0.18 (95% CI: 0.12-0.27) and diagnostic odds ratio (DOR) was 61.52 (95% CI: 27.58-137.21). The area under the receiver operating characteristic curve (AUROC) was 0.94. Use of a common PCT cut-off value could improve the DOR to 75.32 and the AUROC to 0.95. Analysis of the seven studies that measured serum C-reactive protein (CRP) indicated that PCT was more accurate than CRP for the diagnosis of bacterial peritonitis. CONCLUSIONS: Our results indicate that PCT determination is a relatively sensitive and specific test for the diagnosis of bacterial peritonitis. However, with regard to methodological limitations and significant heterogeneity, medical decisions should be based on both clinical findings and PCT test results.

Is lead chelation therapy effective for chronic kidney disease? A meta-analysis.

The heavy metal lead (Pb) is a major environmental and occupational hazard. Epidemiological studies have demonstrated a strong association between lead exposure and the presence of chronic kidney injury. Some studies have suggested that chelation therapy with calcium disodium ethylenediaminetetraacetic acid (calcium disodium EDTA) might help decrease the progression of chronic kidney disease among patients with measurable body lead burdens. However, calcium disodium EDTA chelation in lead exposure is controversial due to the potential for adverse effects such as acute tubular necrosis. Therefore, we investigated the available randomized controlled trials assessing the renoprotective effects of calcium disodium EDTA chelation therapy. Our meta-analysis shows that calcium disodium EDTA chelation therapy can effectively delay the progression of chronic kidney disease in patients with measurable body lead burdens reflected by increasing the levels of estimated glomerular filtration rate (eGFR) and creatinine clearance rate (Ccr). There appears to be no conclusive evidence that calcium disodium EDTA can decrease proteinuria.

Effects of vitamin E-coated dialyzer on oxidative stress and inflammation status in hemodialysis patients: a systematic review and meta-analysis.

BACKGROUND: Vitamin E-coated dialyzer may have an effect on oxidative stress and inflammation status in hemodialysis (HD) patients. Therefore, we performed a systematic review to assess the anti-oxidation and anti-inflammatory effects of vitamin E-coated dialyzer in HD patients. METHODS: The randomized controlled trials (RCTs) and quasi-RCTs of vitamin E-coated dialyzer versus conventional dialyzer for HD patients were searched from multiple databases. We screened relevant studies according to predefined inclusion criteria and performed meta-analyses using RevMan 5.1 software. RESULTS: Meta-analysis showed vitamin E-coated dialyzer therapy could significantly decrease the serum thiobarbituric acid reacting substances (TBARS) (SMD, -0.95; 95% CI, -1.28 to -0.61; p < 0.00001), oxLDL (SMD, -0.61; 95% CI, -1.04 to -0.19; p = 0.005), interleukin-6 (IL-6) (SMD, -0.65; 95% CI, -0.97 to -0.32; p < 0.0001) and C-reactive protein (CRP) levels (SMD, -0.46; 95% CI, -0.87 to -0.05; p = 0.03) compared with that of the control group. However, vitamin E-coated dialyzer did not result in increasing the total antioxidant status (TAS) (SMD, 0.23; 95% CI, -0.16 to 0.61; p = 0.25) and the fractional clearance of urea index (Kt/v) levels (MD, -0.07; 95% CI, -0.14 to 0.00; p = 0.06), in addition, there was no significant difference in plasma superoxide dismutase (SOD) level compared with that of the conventional dialyzer & oral vitamin E group (SMD, 0.28; 95% CI, -0.20 to 0.75; p = 0.26). CONCLUSIONS: Vitamin E-coated dialyzer can reduce the oxidative stress and inflammation status reflected by the decreasing of serum TBARS, oxLDL, CRP, and IL-6 levels, and this new dialyzer does not affect the dialysis adequacy.

Functional and structural alterations of peritoneum and secretion of fibrotic cytokines in rats caused by high glucose peritoneal dialysis solutions.

OBJECTIVE: To determine functional and structural alterations of peritoneum and fibrotic cytokines expression in peritoneal dialysis (PD) rats. METHODS: 28 Sprague-Dawley (S-D) rats were randomly divided into four groups and dialyzed with various solutions daily for four weeks: (1) no solution (CON group), (2) 0.9% Saline solution (NS group), (3) 1.5% Dianeal (LG group), (4) 4.25% Dianeal (HG group). Peritoneal equilibration tests, ultrafiltration function and effluent protein quantification were measured. Peritoneum morphology was studied and immunohistochemistry were performed for detection of transforming growth factor ß1 (TGF-ß1), connective tissue growth factor (CTGF), and fibronectin (FN) proteins. Reverse transcriptional-polymerase chain reaction was used to analyze the expression of TGF-ß1, CTGF mRNA. RESULTS: Administration of 4.25% Dianeal caused functional and structural changes of peritoneum, including protein loss through the transport process, decrease of peritoneal solute transport rate and ultrafiltration capacity. The collagen of peritoneum in the HG group was thicker than the other groups. The levels of CTGF, TGF-ß1, and FN proteins were significantly the highest in the HG group, followed by the LG group. The liner correlation analysis showed positive correlations between the levels of CTGF, TGF-ß1, and FN proteins and the collagen thickness. The expression of TGF-ß1 and CTGF mRNA in the HG group were significantly higher than those in the other groups and were indicated positive correlation. CONCLUSION: Using high glucose peritoneal dialysis solutions in rats may not only lead to processing of peritoneal fibrosis, which is promoted by ectopic expression of TGF-ß1, but also increase the expression of CTGF. CTGF is an important fibrotic media of peritoneal fibrosis in PD rats.

[Effects of Shenxiong pill on infarct brain volumes and NF-kappaB expression in SD rats with middle cerebral artery occlusion (MCAO)].

OBJECTIVE: To investigate the effects of Shenxiong Pill on the infarct volume and expression of NF-kappaB in brains of rats with middle cerebral artery occlusion. METHODS: 169 SD rats were randomly divided into five groups: normal group, sham group, model group, cyclophosphamide group and Shenxiong Pill group. MCAO rat models were established by string ligation (for model, cyclophosphamide-treated and Shenxiong-treated groups). Rats in the Shenxiong Pill group was further randomly divided into sub-groups, receiving a range of high dose treatment (5 to 20 times of clinical dosage). Brains of the rats were examined 48 h or 72 h after interventions in a random order. Image processing software was used in the calculation of volume of cerebral infarction. Conventional HE staining was used for observation of brain tissue. Immunohistochemical method was used to determine NF-kappaB expression. RESULTS: Compared with the model group, rats treated with Shenxiong Pill and cyclophosphamide had lower infarct brain volumes (P < 0.05). NF-kappaB positive inflammatory cells were not found in the normal and sham groups. But the MCAO model rats had increased numbers of NF-kappaB positive inflammatory cells and higher integral optical density of NF-kappaB over time. Compared with the model group, lower numbers and expression of NF-kappaB positive inflammatory cells were found in those treated with Shenxiong Pill (P<0. 05). Higher dosage of Shenxiong was associated with lower numbers and expression of NF-gB inflammatory cells (P<0. 05). CONCLUSION: Shenxiong Pill can reduce pathological damage to brains as a result of cerebral ischemia, possibly through inhibiting the expression and activation of NF-kappaB.

Dahuang Zhechong Pill Alleviates Liver Fibrosis Progression by Regulating p38 MAPK/NF-κ B/TGF-ß1 Pathway.

OBJECTIVE: To explore the effect and mechanism of Dahuang Zhechong Pill (DHZCP) on liver fibrosis. METHODS: Liver fibrosis cell model was induced by transforming growth factor-ß (TGF-ß) in hepatic stellate cells (HSC-T6). DHZCP medicated serum (DMS) was prepared in rats. HSC-T6 cells were divided into the control (15% normal blank serum culture), TGF-ß (15% normal blank serum + 5 ng/mL TGF-ß), DHZCP (15% DMS + 5 ng/mL TGF-ß), DHZCP+PDTC [15% DMS + 4 mmol/L ammonium pyrrolidine dithiocarbamate (PDTC)+ 5 ng/mL TGF-ß], and PDTC groups (4 mmol/L PDTC + 5 ng/mL TGF-ß). Cell activity was detected by cell counting kit 8 and levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the cell supernatant were determined by enzyme-linked immunosorbnent assay. Western blot was used to measure the expressions of p38 mitogen-activated protein kinase/nuclear factor kappa B/transforming growth factor-ß1 (p38 MAPK/NF-κ B/TGF-ß1) pathway related proteins, and the localization and expressions of these proteins were observed by immunofluorescence staining. RESULTS: DHZCP improves the viability of cells damaged by TGF-ß and reduces inflammatory cytokines and ALT and AST levels in the supernatant of HSC-T6 cells induced with TGF-ß (P<0.05 or P<0.01). Compared with the TGF-ß group, NF-κ B p65 levels in the DHZCP group were decreased (P<0.05). p38 MAPK and NF-κ B p65 levels in the DHZCP+PDTC were also reduced (P<0.01). Compared with the TGF-ß group, the protein expression of Smad2 showed a downward trend in the DHZCP, DHZCP+PDTC, and PDTC groups (all P<0.01), and the decreasing trend of Samd3 was statistically significant only in DHZCP+PDTC group (P<0.01), whereas Smad7 was increased (P<0.05 or P<0.01). CONCLUSION: DHZCP can inhibit the process of HSC-T6 cell fibrosis by down-regulating the expression of p38 MAPK/NF-κ B/TGF-ß1 pathway.

Outline of occupational chromium poisoning in China.

The present study analyzed the feature of occupational chromium poisoning in China since the 1980s. The collected data were acquired from 18 previous surveys of chromium poisoning in 14 cities of China. The method of risk assessment was applied to calculate the relative risk and 95% CI, p < 0.05 was considered as a significant risk. The results showed that nasal disease was the most common sign of occupational chromium poisoning, and the prevalence rate of nasal disease was 17.83% in total population of 6,998. Further, the risk analysis showed that occupational chromium poisoning led to an increased risk of lung or liver cancer in male workers due to the definite carcinogenicity of hexavalent chromium. Significantly, an increased risk of spontaneous or threatened abortion was also found in female workers. In conclusion, these studies suggest that early detection of impaired reproductive function or impaired lung or liver function in female or male workers is essential for controlling occupational chromium poisoning in China.

[Role of PKCδ on the phosphorylation and mitochondrial translocation of p66Shc in HK-2 cells induced by high glucose].

OBJECTIVE: To observe the effect of PKCδ on the phosphorylation of p66Shc and its mitochondrial translocation in human proximal tubular cells (HK-2) under high glucose (HG). METHODS: HK-2 cells were incubated with different concentrations of D-glucose (5-45 mmol/L) for indicated time (0-48 h). Then the mRNA expressions of PKCδ and p66Shc and the phosphorylation levels of PKCδ (p-PKCδ) and p66Shc (p-p66Shc) were determined by real-time polymerase chain reaction (PCR) and Western blot analysis respectively. In addition, the effect of PKCδ inhibitor on the phosphorylation and mitochondrial translocation of p66Shc in HK-2 cells exposed to HG was also observed. HK-2 cells were divided into 3 groups of 5 mmol/L glucose, 30 mmol/L glucose and 30 mmol/L glucose + 1.0 µmol/L Rottlerin. Cell immunofluorescence and Western blotting were used to observe the phosphorylation and mitochondrial translocation of p66Shc. RESULTS: Both mRNA expression and phosphorylation level of p66shc and PKCδ significantly increased in HK-2 cells after exposure to HG (15, 30, 45 mmol/L). And it was in a concentration- and time-dependent manner as compared with control group (up-regulated 0.9, 1.3 and 1.6-fold in mRNA of PKCδ, 0.4, 1.5 and 2.0-fold in protein of p-PKCδ respectively (all P < 0.05). PKCδ inhibitor Rottlerin dramatically inhibited the phosphorylation and mitochondrial translocation of p66Shc induced by HG in HK-2 cells (down-regulated 3.1 folds in protein of p-p66Shc in mitochondria, P < 0.01). CONCLUSIONS: HG increases the transcription and phosphorylation of PKCδ and p66Shc in HK-2 cells. And PKCδ may modulate the phosphorylation and mitochondrial translocation of p66Shc under HG.

HSP47 regulates ECM accumulation in renal proximal tubular cells induced by TGF-ß1 through ERK1/2 and JNK MAPK pathways.

Heat shock protein (HSP)47 is a collagen-specific molecular chaperone that is essential for the biosynthesis of collagen molecules. It is likely that increased levels of HSP47 contribute to the assembly of procollagen and thereby cause an excessive accumulation of collagens in disease processes associated with fibrosis. Although HSP47 promotes renal fibrosis, the underlying mechanism and associated signaling events have not been clearly delineated. We examined the role of HSP47 in renal fibrosis using a rat unilateral ureteral obstruction model and transforming growth factor (TGF)-ß(1)-treated human proximal tubular epithelial (HK-2) cells. An upregulation of HSP47 in both in vivo and in vitro models was observed, which correlated with the increased synthesis of extracellular matrix (ECM) proteins and expression of tissue-type plasminogen activator inhibitor (PAI)-1. Blockade of HSP47 by short interfering RNA suppressed the expression of ECM proteins and PAI-1. In addition, TGF-ß(1)-induced HSP47 expression in HK-2 cells was attenuated by ERK1/2 and JNK MAPK inhibitors. These data suggest that ERK1/2 and JNK signaling events are involved in modulating the expression of HSP47, the chaperoning effect of which on TGF-ß(1) would ultimately contribute to renal fibrosis by enhancing the synthesis and deposition of ECM proteins.

miRNA589 regulates epithelial-mesenchymal transition in human peritoneal mesothelial cells.

Background. microRNA (miRNA, miR) are thought to interact with multiple mRNAs which are involved in the EMT process. But the role of miRNAs in peritoneal fibrosis has remained unknown. Objective. To determine if miRNA589 regulates the EMT induced by TGFß1 in human peritoneal mesothelial cell line (HMrSV5 cells). Methods. 1. Level of miR589 was detected in both human peritoneal mesothelial cells (HPMCs) isolated from continuous ambulatory peritoneal dialysis (CAPD) patients' effluent and HMrSV5 cells treated with or without TGFß1. 2. HMrSV5 cells were divided into three groups: control group, TGFß1 group, and pre-miR-589+TGFß1 group. The level of miRNA589 was determined by realtime PCR. The expressions of ZO-1, vimentin, and E-cadherin in HPMCs were detected, respectively. Results. Decreased level of miRNA589 was obtained in either HPMCs of long-term CAPD patients or HMrSV5 cells treated with TGFß1. In vitro, TGFß1 led to upregulation of vimentin and downregulation of ZO-1 as well as E-cadherin in HMrSV5 cells, which suggested EMT, was induced. The changes were accompanied with notably decreased level of miRNA589 in HMrSV5 cells treated with TGFß1. Overexpression of miRNA589 by transfection with pre-miRNA589 partially reversed these EMT changes. Conclusion. miRNA589 mediates TGFß1 induced EMT in human peritoneal mesothelial cells.

Norcantharidin, a protective therapeutic agent in renal tubulointerstitial fibrosis.

Progressive renal tubulointerstitial fibrosis is a common final pathway of nearly all forms of chronic kidney disease. Many efforts have been done to arrest or prevent renal tubulointerstitial fibrosis but with little progress. Nowadays, few therapeutic agents are available in clinical use. Norcantharidin (NCTD) is of great benefit in anticancer treatment, by inducing cell apoptosis, inhibiting cell proliferation, in addition, blocking tumor metastasis and angiogenesis in cancer, whereas little attention is given to its relationship with other diseases. Our recent studies demonstrated that NCTD was protective against renal tubulointerstitial fibrosis both in vivo and in vitro. The underlying mechanisms may include modulation of TGF-ß1/Smad signal cascade, inhibition of protein serine/threonine phosphatases (PPP) as well as NF-κB. NCTD may be a promising therapeutic agent for renal tubulointerstitial fibrosis. In the present article, we will review the action of NCTD in renal tubulointerstitial fibrosis and discuss its possible mechanisms.

Evaluation of renal clinicopathological changes in IgA nephropathy by urinary podocytes excretion and podocalyxin expression.

OBJECTIVE: To explore the association of urinary podocyte excretion and renal expression of podocyte-specific marker podocalyxin (PCX) with clinicopathological changes in immunoglobulin A nephropathy (IgAN). METHODS: Morning urine samples from IgAN patients and healthy controls were collected. The expression of glomerular PCX was quantified in 50 IgAN patients diagnosed by renal biopsy. IgAN was classified based on the Lee's Grading system and scored according to the Katafuchi semiquantitative criteria. Morphological evaluation of podocyte was determined by electron microscopy. RESULTS: The amount of urinary podocytes in the IgAN patients was significantly higher than that in the healthy controls (p < 0.01). Pairwise comparison among Lee's grades of IgAN showed that the median of urinary podocytes in Lee's I-II group was lower than that in Lee's III, IV, and V groups (p < 0.05); group III lower than group V (p < 0.05). The positive rate of urinary podocytes was the highest in Lee's IV and V groups (100%), and lowest in Lee's I-II group (55%). Multiple comparison among groups of Lee's grades of IgAN showed that the glomerular PCX expression in Lee's I-II group was higher than that in Lee's III, IV, and V groups (p < 0.05); groups III and IV higher than group V (p < 0.05). The amount of urinary podocytes in IgAN patients was negatively correlated with PCX expression (r = -0.702, p < 0.01), but positively correlated with 24-h urinary protein (r = 0.465, p < 0.01) and glomerular (r = 0.233, p < 0.01) and renal tubular pathological scores (r = 0.307, p < 0.05). The glomerular PCX expression was negatively correlated with 24-h urinary protein (r = -0.367, p < 0.05) and glomerular (r = -0.560, p < 0.05) and tubular pathological scores (r = -0.377, p < 0.05). Electron microscopy showed significant changes in podocytes of IgAN, especially in the foot process. CONCLUSION: The amount of urinary podocyte can reflect the loss of podocytes in renal tissue, which may be a marker of IgAN progression.

Norcantharidin inhibits the expression of extracellular matrix and TGF-ß1 in HK-2 cells induced by high glucose independent of calcineurin signal pathway.

Norcantharidin (NCTD) was shown in our previous studies to attenuate renal tubulointerstitial fibrosis in rat models with diabetic nephropathy (DN). The aim of this study was to determine the effects of NCTD on the expression of extracellular matrix (ECM) and TGF-ß1 in HK-2 cells stimulated by high glucose and on calcineurin (CaN)/NFAT pathway. Whether or not the antifibrotic effect of NCTD on renal interstitium was dependent on its inhibition of CaN pathway was also investigated. Experimental concentrations of NCTD were verified by cytotoxic test and MTT assay. HK-2 cells were transfected with CaN small interference RNA (siRNA). The mRNA and protein expressions of FN, ColIV, TGF-ß1, and CaN in HK-2 cells were detected by real-time PCR and western blot. The CaN/NFAT pathway was examined by indirect immunofluorescence and western blot. Our study revealed that NCTD concentrations over 5 mg/l had overt cytotoxicity on HK-2 cells. Meanwhile, both 2.5 and 5 mg/l NCTD inhibited HK-2 cell proliferation (P < 0.05). NCTD inhibited the upregulation of FN, ColIV, and TGF-ß1 of HK-2 cells stimulated by high glucose (P < 0.05), and also significantly downregulated the expression of CaN mRNA and protein in HK-2 cells (P < 0.05). In addition, not only was the nuclear translocation of NFATc inhibited, but its protein level in the nucleus was also reduced. Following CaN siRNA transfection, CaN mRNA and protein expression were significantly decreased. In contrast, the protein levels of FN, ColIV, and TGF-ß1 increased in HK-2 cells stimulated by high glucose (P < 0.05). However, NCTD treatment downregulated their expression. These results indicated that NCTD could decrease the expression of ECM and TGF-ß1 in HK-2 cells stimulated by high glucose, downregulate CaN expression, and block the CaN/NFAT signaling pathway. However, the effect of NCTD on inhibition of the expression of ECM and TGF-ß1 was not associated with its inhibition of the CaN/NFAT pathway.

Norcantharidin inhibits proliferation and fibronectin expression of HK-2 cells induced by albumin in vitro.

The present study aims to observe the effects of NCTD (norcantharidin) on proliferation and FN (fibronectin) expression in human renal proximal tubular epithelial cell line (HK-2) induced by albumin in vitro. HK-2 cells were divided into control group, albumin group and different concentration of NCTD intervention groups. Proliferation of HK-2 cells was determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide], FN protein in culture media of HK-2 cells was examined by ELISA, and FN mRNA was analysed by RT-PCR (reverse transcription-PCR). We chose less than 5.0 mg/l of NCTD as the experimental concentration for the cytotoxicity test. MTT score was higher in the albumin group than in the control group (P<0.05). As compared with that of the albumin group, MTT score and FN protein concentration decreased, FN mRNA significantly down-regulated in NCTD intervention groups respectively (P<0.05). Our study showed that NCTD could inhibit the albumin-induced cell proliferation and FN expression in HK-2 cells, which might further prove the anti-fibrotic role of NCTD in proteinuria-associated tubulointerstitial damage.