Western blot and flow cytometry were used to assay the LC3-II expressions. RNAi techniques including shRNA and siRNA were used to investigate the function of MFN1 and FIS1 in HK2 cells cultured in the presence or absence of glucose. Mitochondrial morphology were stained by mitotracker and analyzed by confocal microscopy. TUNEL assay was used to examine the cellular apoptosis in glucose treated wild type and MFN1-depleted HK2 cells. Results: HFHS diet led to vacuolization and thyroidisation of renal tubules, reduced expressions of Mfn1 and Mfn2 and enhanced expressions

of Drp1 and Fis1. Glucose caused mitochondrial fragmentation and apoptosis in HK2 cells. MFN1-depleted cells were more susceptible to glucose-induced mitochondrial fragmentation and cellular apoptosis. SiRNA targeting FIS1 was able to rescue the glucose-induced injuries in MFN1-depleted cells. TEM demonstrated the click here formation of autophagosome in glucose-treated HK2 cells. LC3-II expression was greatly increased in MFN1-depleted cells. Upon silencing FIS1, the increased LC3-II

expression in MFN1-depleted cells was reduced to a comparable level to wild type cells. Conclusion: Our results suggested that glucose drives the mitochondria to fission which eventually leads to mitochondrial fragmentation and cellular apoptosis. Autophagy could be a protective mechanism for glucose-induced injuries in renal tubules. MFN1 also played a protective role in these injuries. Silencing of FIS1, could be a novel strategy to treat DKD. YANG SUNG-SEN1,2, JIANG SI-TSE3, YU I-SHING4, LIN SHU-WHA4, LIN SHIH-HUA1,2 1Division of Nephrology, Department of Medicine, Tri-Service General Hospital,Taipei, learn more Taiwan; 2Graduate Institute of Medical Sciences National Defense Medical Center,Taipei, Taiwan; 3National Laboratory Animal Centre, National mafosfamide Applied Research Laboratories, Taipei, Taiwan;

4Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University,Taipei, Taiwan Introduction: Recently, it was shown that an ubiquitously expressed Cab39 protein could also stimulate Na-(K)-(2)Cl cotransporter [N(K)CC] through activating SPAK/OSR1 kinases mimicking WNK1/4 kinases in vitro study. Methods: We generated and analyzed both the kidney tubule-specific cadherin gene promoter driven flag-tagged mouse Cab39 (KSP-Flag-mCab39) transgenic (Tg) and WNK4 knockout mice. At age of 10–12 weeks fed with normal rodent chaw, phenotype including blood pressure as well as serum and urine electrolytes was measured in WT, Cab39 Tg, Wnk4 knockout and Cab39 TgxWnk4 knockout transgenic mice. The expression of WNK1/4, Cab39, SPAK/OSR1 and N(K)CC was evaluated by western blotting and immunofluorescence stain. Results: Offspring from Cab39 Tg mice with mildly overexpressed abundance of flag-Cab39 (25% ± 6%) were phenotypically normal but a slightly increased p-SPAK/OSR1, p-NKCC2 and p-NCC in the kidneys was found.