ABSTRACT
Astragaloside IV is the most aboundant and activitve ingredient in Astragalus membranaceus. Many studies have confirmed that astragaloside IV has a renal protective effect on chronic kidney disease. After reviewing the literatures at home and abroad for the past five years, The molecular mechanism of the protective effect of astragaloside IV on kidney was reviewed from the aspects of protection of podocytes, inhibition of renal fibrosis, protection of renal tubular cells, and inhibition of mesangial cell activation. The aim of this study is to analyze the target of astragaloside IV in the treatment of chronic kidney disease, and provide a basis for the application of astragaloside IV in nephropathy.
ABSTRACT
Renal Tubular Cell Apoptosis refers to activation,proliferation,distension,cast formation and cellular apoptosis of the tubular epithelium when the renal tubule undergoes hypoxia,poisoning,inflammatory reaction,plasma protein or amylaceum.This text summarized the researches on the prevention and control of lenal tubular cell apoptosts in renal interstitial fibrosis in the recent years.
ABSTRACT
Objective To explore the role of Na~+/H~+ exchanger 1(NHE1) in injury of human renal tubular cells(HK-2) induced by postasphyxial-serum of neonates.Methods HK-2 was used as the target cell.The attacking concentration of postasphyxial-serum of neonates was 200 mL/L.First,the experiment was designed as control group and asphyxia group,the expression of NHE1 in the HK-2 was detected by immunohisto chemical method in the cells.Second,the experiment group was designed as control group,asphyxia group,and pretreatment with 5-N-Ethyl-N-isopropylamiloride(EIPA) group,then the change of morphology was observed under inverted microscope,and the cell viability was measured by methyl thiazolyl tetrazolium(MTT) method,and the leakage rate of lactate dehydrogenase(LDH) was determined by biochemical methods.Results Compared with blank control group,the expression of NHE1 in the HK-2 was increased signi-ficantly in asphyxia group,the changes of morphology of HK-2 was most serious and obvious,the cell viability decreased,and the leakage rate of LDH increased significantly in asphyxia group.But compared with asphyxia group,the change of morphology of HK-2 was greatly improved,the cell injury was decreased obviously,the leakage rate of LDH was increased and viability was decreased in pretreatment group in a dose 2 ?mol/L.Conclusions The postasphyxial-serum may induce the expression of NHE1,which plays an important role in injury of renal tubular cell induced by postasphyxial-serum in neonates,and inhibiting activity of NHE1 may relieve the injury of renal tubular cells induced by postasphyxial-serum in neonates.
ABSTRACT
BACKGOUND: Renal tubular epithelial cells are primary target for hypoxic injury. Hypoxia induced tubular cell apoptosis has been reported previously and thought to be important mechanism of renal dysfunction in ischemic ARF, but precise signaling mechanisms need to be defined. The aim of this study is to clarify intracellular signaling mechanism mediating apoptosis by hypoxic stimuli in cultured tubular cells. METHODS: HK-2 cells were placed in hypoxic chamber (O2<1%) for 24 hrs in minimal essential medium. DNA fragmentation was detected by Hoechst 33342 stain and FACS. The activation of caspase was measured by fluorometry and activations of p-38, ERK, and JNK were examined by western blot analysis. RESULTS: Hypoxia induced caspase 3 activation and apoptosis at 24 hrs and this was accompanied by increased phosphorylation of p-38, ERK1/2, and JNK. Pretreatment of p-38 inhibitor (SB 203280) and JNK inhibitor (SP600125) did not afftect the activation of caspase 3 and apoptosis but inhibition of ERK1/2 by PD98059 resulted in partial inhibition of caspase 3 and apoptosis induced by hypoxia. CONCLUSION: ERK 1/2 activation can be an upstream signal in hypoxia induced caspase 3 activation and apoptosis in tubular cells.
Subject(s)
Hypoxia , Apoptosis , Blotting, Western , Caspase 3 , DNA Fragmentation , Epithelial Cells , Fluorometry , Negotiating , PhosphorylationABSTRACT
A major limiting factor in the use of cyclosporine A (CsA) is nephrotoxicity, but the mechanisms of nephrotoxicity are not fully understood. In order to elucidate the pathogenesis of CsA tubulotoxicity, we examined mechanisms (DNA synthesis, necrosis and apoptosis) of cellular injury induced by CsA in cultured LLC-PK1 renal tubular cell line. The possible role of Fas antigen in the mediation of CsA-induced cell death and the hypothesis that CsA-mediated injury activates the glucose transporter GLUT1, a stress response gene in renal tubular cells were also investigated. CsA treatment for 24 hours in LLC-PK1 cells showed significantly decreased 3H-thymidine uptake in a dose dependent manner (0.1 microgram/ml to 1 mg/ml), indicating that DNA damage is a sensitive indicator of CsA induced nephrotoxicity. A dose of 10 microgramml CsA caused a significant increase in LDH release (M+/-S.D., 11.0+/-3.0% vs 27.0+/-9.8, p<0.05). On flow cytometric analysis, 9.9 4.2% of control cells appeared in a region of decreased forward light scatter and increased side scatter, respectively. Both indices representing characteristics of apoptotic cell death. Compared to control, treatment with 10 ng/ml of CsA for 24 hours significantly increased the proportion of cells in apoptotic region to 38.9 13.5%. This finding was supported by electrophoretic analysis of the DNA extracted from CsA-treated cells, where a series of bands corresponding to integer multiples of 180 to 200 base pairs was visualized. CsA (0.1 microgram/ml) treatment for 24 hours was seen to cause a significant elevation in the expression of the 45 kD Fas protein by Western blot analysis. In addition, the exposure to CsA was also associated with an increase of GLUT1 protein levels up to 2.2 fold (mean) on Western blot analysis. In conclusion, CsA is directly toxic to tubular cells with inhibiting DNA synthesis and inducing cell death in the form of necrosis or apoptosis. Fas antigen-ligand system and glucose transporter GLUT1 may play roles in mediating CsA induced tubular cytotoxicity.
Subject(s)
Animals , fas Receptor , Apoptosis , Base Pairing , Blotting, Western , Cell Death , Cell Line , Cyclosporine , DNA , DNA Damage , Epithelial Cells , Glucose Transport Proteins, Facilitative , Glucose Transporter Type 1 , LLC-PK1 Cells , Necrosis , Negotiating , SwineABSTRACT
A major limiting factor in the use of cyclosporine A (CsA) is nephrotoxicity, but the mechanisms of nephrotoxicity are not fully understood. In order to elucidate the pathogenesis of CsA tubulotoxicity, we examined mechanisms (DNA synthesis, necrosis and apoptosis) of cellular injury induced by CsA in cultured LLC-PK1 renal tubular cell line. The possible role of Fas antigen in the mediation of CsA-induced cell death and the hypothesis that CsA-mediated injury activates the glucose transporter GLUT1, a stress response gene in renal tubular cells were also investigated. CsA treatment for 24 hours in LLC-PK1 cells showed significantly decreased 3H-thymidine uptake in a dose dependent manner (0.1 microgram/ml to 1 mg/ml), indicating that DNA damage is a sensitive indicator of CsA induced nephrotoxicity. A dose of 10 microgramml CsA caused a significant increase in LDH release (M+/-S.D., 11.0+/-3.0% vs 27.0+/-9.8, p<0.05). On flow cytometric analysis, 9.9 4.2% of control cells appeared in a region of decreased forward light scatter and increased side scatter, respectively. Both indices representing characteristics of apoptotic cell death. Compared to control, treatment with 10 ng/ml of CsA for 24 hours significantly increased the proportion of cells in apoptotic region to 38.9 13.5%. This finding was supported by electrophoretic analysis of the DNA extracted from CsA-treated cells, where a series of bands corresponding to integer multiples of 180 to 200 base pairs was visualized. CsA (0.1 microgram/ml) treatment for 24 hours was seen to cause a significant elevation in the expression of the 45 kD Fas protein by Western blot analysis. In addition, the exposure to CsA was also associated with an increase of GLUT1 protein levels up to 2.2 fold (mean) on Western blot analysis. In conclusion, CsA is directly toxic to tubular cells with inhibiting DNA synthesis and inducing cell death in the form of necrosis or apoptosis. Fas antigen-ligand system and glucose transporter GLUT1 may play roles in mediating CsA induced tubular cytotoxicity.