Genistein ameliorates parathyroid hormone-induced epithelial-to-mesenchymal transition and inhibits expression of connective tissue growth factor in human renal proximal tubular cells.

INTRODUCTION: Genistein, a soybean and soy-based product, has been reported to inhibit the growth of a wide range of cancer cells, but there is no evidence concerning its treatment of chronic kidney disease. The aim was to investigate whether genistein has potential to inhibit parathyroid hormone (PTH)-induced renal interstitial fibrosis. MATERIAL AND METHODS: Using human renal tubular epithelial HK-2 cells, α-smooth muscle actin (α-SMA) was assessed by using immunofluorescence detection. α-Smooth muscle actin, E-cadherin and connective tissue growth factor (CTGF) were measured by Western blot analysis. The promoter activity of the CTGF gene was examined by the luciferase reporter assay. RESULTS: When cells were treated with PTH (0.1 nM) for 48 h, α-SMA protein expression was induced significantly, the protein expression of E-cadherin decreased substantially, and the promoter activity of the CTGF gene as well as its mRNA and protein expression levels increased (p < 0.01). Interestingly, genistein effectively inhibited PTH-induced α-SMA expression, restored E-cadherin expression, decreased mRNA and protein expression of CTGF, and suppressed the promoter activity of CTGF in a dose-dependent manner. CONCLUSIONS: Genistein has the ability to block the biomarker for renal transdifferentiation and epithelial-to-mesenchymal transition, α-SMA, following PTH treatment and inhibit CTGF expression in human renal tubular epithelial cells; these might be important modes of actions that contribute to genistein anti-fibrogenic effects and may have great implications for its potential in clinical treatment of renal interstitial fibrosis.

11ß-Hydroxysteroid dehydrogenase 1 inhibition attenuates collagen-induced arthritis.

11ß-Hydroxysteroid dehydrogenase 1 (11ß-HSD1) plays an important role in inflammation. However, the role of 11ß-HSD1 in rheumatoid arthritis (RA) remains unknown. The purpose of this study was to evaluate the therapeutic effects of a selective 11ß-HSD1 inhibitor BVT-2733 in collagen-induced arthritis (CIA) and its underlying mechanisms. CIA mice were treated with BVT-2733 (100 mg/kg, orally) or vehicle twice daily for 2 weeks. Arthritis score and joint histology were investigated. The levels of pro-inflammatory cytokines as well as anti-type II collagen antibody (anti-CII) were detected by ELISA. Western blot analysis was used to assess the activation of NF-κB and NLRP1 inflammasome in joint tissues and in human RA synovial cells. BVT-2733 treatment attenuated the arthritis severity and anti-CII level in CIA mice. BVT-2733 also decreased the levels of serum TNF-α, IL-1ß, IL-6 and IL-17. BVT-2733 treatment also significantly reduced synovial inflammation and joint destruction. NF-κB activation and NLRP1 inflammasome assembly were also inhibited in arthritic joints and human RA synovial cells. In conclusion, BVT-2733 exhibits an anti-inflammatory effect on CIA. This protective effect is, at least partly, mediated by inhibition of the NF-κB and NLRP1 inflammasome signaling pathways. 11ß-HSD1 inhibition may represent a potential therapeutic target for RA patients.

Parathyroid hormone-mitogen-activated protein kinase axis exerts fibrogenic effect of connective tissue growth factor on human renal proximal tubular cells.

BACKGROUND: Enhanced and prolonged expression of connective tissue growth factor (CTGF) is associated with kidney fibrosis. Parathyroid hormone (PTH) is involved in the genesis of disturbed calcium/phosphate metabolism and ostitis fibrosa in renal failure. PTH activated mitogen-activated protein kinase (MAPK) signaling pathway is present in renal tubular cells. The aim of this study was to identify the mechanism how the signal is transduced to result in extracellular signal-regulated protein kinase (ERK) activation, leading to upregulation of CTGF. METHODS: The levels of CTGF mRNA and protein in human kidney proximal tubular cells (HK-2) treated with PTH in the presence or absence of the MAPK inhibitor PD98059 were analyzed by quantitative real-time polymerase chain reaction (RT-PCR) and immunoblotting assay. The activation of the CTGF promoter in HK-2 cells was determined by the dual-luciferase assay. The effects of the protein kinase A (PKA) activator 8-Br-cAMP and protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) on MAPK phosphorylation, and the effects of the PKA inhibitor H89 and PKC inhibitor calphostin C on MAPK phosphorylation and CTGF expression were detected by immunoblotting assay. RESULTS: PD98059 inhibited the PTH stimulated expression of CTGF, which strongly suggested that the MAPK signaling pathway plays an important role in the PTH-induced CTGF upregulation in renal tubular cells. A PKA activator as well as PKC activators induced MAPK phosphorylation, and both PKA and PKC inhibitors antagonized PTH-induced MAPK phosphorylation and CTGF expression. CONCLUSION: CTGF expression is upregulated by PTH through a PKC/PKA-ERK-dependent pathway.

[Oxidative stress status in patients with various degrees of chronic renal insufficiency].

OBJECTIVE: To observe the changes of lipid peroxidation and antioxidative enzyme activities of chronic renal insufficiency (CRI) and to explore their effects on the pathogenesis of CRI. METHODS: Serum levels of malondialdehyde (MDA), serum glutathione peroxidase (GSH-Px) and serum superoxide dismutase (SOD) in 36 non-dialyzed patients with various degrees and 12 hemodialyzed (HD) were determined with the method of chemistry colorimetry. RESULTS: Thirty-six CRI and 12 HD patients included in the study had higher SOD activities when compared with the controls [(110.30+/-18.60) kNU/L]. They also had lower serum GSH-Px activity than the controls [(120.63+/-27.57) x 10(4)U/L]. Serum MDA levels in the patients were higher than that in the controls [(4.06+/-0.67) micromol/L]. Serum SOD, GSH-Px and MDA concentrations in 36 non-dialyzed patients with various degrees were also correlated with creatinine clearance (r(G)=0.68, P<0.01; r(M)=-0.52, P<0.01; r(S)=-0.44, P<0.05). CONCLUSION: Free radicals, lipid peroxidation and the abnormality in antioxidative system may play an important role in the pathogenesis of CRI and correlated with impaired renal function, and that they can be regarded as important clinical indexes to infect the severity of chronic renal insufficiency.