Effect of a low-protein diet supplemented with keto-acids on autophagy and inflammation in 5/6 nephrectomized rats.

Ketoacids (KA) are known to preserve muscle mass among patients with chronic kidney disease (CKD) on a low-protein diet (LPD). The present study was to compare the effects of KA supplemented diet therapy in autophagy and inflammation in CKD rats' skeletal muscle. Rats with 5/6 nephrectomy were randomly divided into three groups and fed with either 11 g/kg/day protein [normal-protein diet (NPD)], 3 g/kg/day protein (LPD) or 3 g/kg/day protein which including 5% protein plus 1% KA (LPD + KA) for 24 weeks. Sham-operated rats with NPD intake were used as control. LPD could improve body weight, gastrocnemius muscle mass, as well as gastrocnemius muscle cross-sectional area, with the effect being more obvious in the LPD + KA group. The autophagy marker LC3 (microtubule-associated protein 1 light chain 3), p62, Parkin and PTEN induced putative kinase 1 (PINK1) were significantly attenuate in LPD + KA group than LPD group. LPD + KA group had the lower total mtDNA (mitochondiral DNA) and cytosol mtDNA, NACHT-PYD-containing protein 3 (NALP3) inflammasome than LPD group, but its reactive oxygen species (ROS), caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC) level was higher. Immunoblotting showed IL-1ß (interleukin-1-beta) was lower in LPD and LPD + KA group than the NPD group, but IL-18 showed no significant difference among control and CKD group; toll-like receptor signalling-dependent IL-6 was higher in LPD + KA group than LPD group, but tumor necrosis factor-α (TNF-α) was not significantly changed between LPD + KA and LPD group. Systematic changes of the four cytokines were different from that of the tissue. Although LPD + KA could further ameliorate-activated autophagy than LPD, its effect on the activated inflammation state in CKD was not distinctly. Further study is still required to explore the method of ameliorating inflammation to provide new therapeutic approaches for CKD protein energy wasting (PEW).

Inhibition of the tubular epithelial-to-mesenchymal transition in vivo and in vitro by the Uremic Clearance Granule ().

OBJECTIVE: To investigate the effect of the Uremic Clearance Granule (UCG, ), a Chinese patent medicine, on tubular epithelial-to-mesenchymal transition (EMT) in a unilateral ureteral obstruction (UUO) model in vivo and transforming growth factor (TGF)-ß1 induced EMT of HK-2 cells in vitro. METHODS: In vivo study, 50 Sprague Dawley rats were divided into three groups: a sham operation group (n=10), a UUO group (n=20), and a UUO with UCG treatment group (n=20). The UCG was given at a dose of 4.5 g/kg body weight per day by gavage after surgery. In vitro study, HK-2 cells were cultured in 10% fetal bovine serum (FBS), 10% healthy rat serum, 10% FBS and TGF-ß1 (10 ng/mL), 10% healthy rat serum and TGF-ß1, or 10% rat serum containing the uremic clearance granule and TGF-ß1. The expression of the epithelial marker E-cadherin and the mesenchymal markers vimentin and α-smooth muscle actin (α-SMA) in kidney tissues and HK-2 cells were investigated by Western blot analysis and immunofluorescence staining. RESULTS: The rats of the UUO group showed obvious tubulointerstitial fibrosis, compared with the sham operation group rats. Tubulointerstitial fibrosis score was reduced by 17.5%±1.1% at day 7 and by 20.0%±1.2% at day 14 in the UCG-treated group, compared with the UUO group. The UCG could maintained expression of E-cadherin and suppressed expression of vimentin and α-SMA in kidney tissues of UUO rats at days 7 and 14, as determined by Western blot analysis and immunofluorescence staining. Rat serum containing the UCG partially inhibited TGF-ß1-induced fibroblast phenotype of HK-2 cells and maintained the epithelial morphology of HK-2 cells in vitro. This occurred partially through a reduction of vimentin expression and an increase of E-cadherin expression. CONCLUSION: These results suggest that the UCG prevents tubular EMT and may be a promising agent for treating tubulointerstitial fibrosis.