kn-93 and Reperfusion-Injury

This study aimed to understand the mechanistic role of N-methyl-D-aspartate receptor (NMDAR) in acute fibrogenesis using models of in vivo ureter obstruction and in vitro TGF-β administration.. The expression of NR1 was upregulated in obstructed kidneys, while NR1 knockdown significantly reduced both interstitial volume expansion and the changes in the expression of α-smooth muscle actin, S100A4, fibronectin, COL1A1, Snail, and E-cadherin in acute RF. TGF-β1 treatment increased the elongation phenotype of HK-2 cells and the expression of membrane-located NR1 and phosphorylated CaMKII and extracellular signal-regulated kinase (ERK). MK801 and KN93 reduced CaMKII and ERK phosphorylation levels, while MK801, but not KN93, reduced the membrane NR1 signal. The levels of phosphorylated CaMKII and ERK also increased in kidneys with obstruction but were decreased by NR1 knockdown. The 4-week administration of DXM preserved renal cortex volume in kidneys with moderate ischemic-reperfusion injury.. NMDAR participates in both acute and chronic renal fibrogenesis potentially via CaMKII-induced ERK activation.

Topics: Animals; Benzylamines; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Dextromethorphan; Dizocilpine Maleate; Epithelial-Mesenchymal Transition; Excitatory Amino Acid Antagonists; Fibrosis; Gene Knockdown Techniques; Humans; In Vitro Techniques; Kidney; Kidney Tubules, Proximal; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Protein Kinase Inhibitors; Receptors, N-Methyl-D-Aspartate; Renal Insufficiency, Chronic; Reperfusion Injury; Sulfonamides; Transforming Growth Factor beta; Ureteral Obstruction

BACKGROUND The aim of this study was to explore the potential role of TRPC6 in the pathophysiology of HK-2 cell injury following ischemia reperfusion (I/R). MATERIAL AND METHODS TRPC6 expression was analyzed by immunofluorescence staining. siRNA was transfected to knockout of TRPC6 in HK-2 cells, and in vitro I/R was then induced. Cell apoptosis and necrosis were determined by Annexin V-FITC/PI staining. Necroptosis was determined by necrostatin-1 and expressions of necroptosis-related proteins were evaluated. OAG, SKF96365, or KN-93 was further used to interfere with TRPC6 expression. RESULTS Cytoplasmic TRPC6 expression was demonstrated. I/R induced TRPC6 expression in normal or NC siRNA-transfected cells but not in TRPC6 siRNA-knockout ones. There was a progressive increase in apoptotic and necrotic cells with increasing reoxygenation time in all 3 groups, while necrosis in TRPC6 siRNA-transfected cells was comparatively higher than that of the other 2 groups (p<0.05). Expressions of necroptosis-related proteins were interfered with following I/R and these effects were enhanced by TRPC6 siRNA. Application of OAG, SKF96365, or KN93 further affected necroptosis following I/R. CONCLUSIONS This study described the expression and functional relevance of TRPC6 in the pathophysiology of HK-2 cell following I/R. Our results regarding the ability of TRPC6 to specifically interrupt necroptosis may shed new light on its role in prevention and control of ischemic kidney injury.

Topics: Apoptosis; Benzylamines; Blotting, Western; Cell Line; Cell Shape; Down-Regulation; Epithelial Cells; Fluorescent Antibody Technique; Humans; Imidazoles; Ischemia; Kidney Tubules; Necrosis; Oxygen; Protective Agents; Reperfusion Injury; RNA, Small Interfering; Sulfonamides; TRPC Cation Channels; TRPC6 Cation Channel; Up-Regulation