HRD1-Mediated IGF-1R Ubiquitination Contributes to Renal Protection of Resveratrol in db/db Mice

Abstract

Many studies have provided evidence to demonstrate the beneficial renal effects of resveratrol (RESV) due to its antioxidant character and its capacity for activation of surtuin 1. However, the molecular mechanisms underlying the protective role of RESV against kidney injury are still incompletely understood. The present study used Lepr db/db (db/db) and Lepr db/m (db/m) mice as models to evaluate the effect of RESV on diabetic nephropathy (DN). RESV reduced proteinuria and attenuated the progress of renal fibrosis in db/db mice. Treatment with RESV markedly attenuated the diabetes-induced changes in renal superoxide dismutase copper/zinc, superoxide dismutase manganese, catalase, and malonydialdehyde as well as the renal expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), α-smooth muscle actin (α-SMA), and E-cadherin in db/db mice. The kidney expression of the IGF-1 receptor (IGF-1R) was increased in db/db mice, but the expression of 3-hydroxy-3-methylglutaryl reductase degradation (HRD1), a ubiquitin E3 ligase, was significantly decreased in the DN model. RESV treatment dramatically decreased IGF-1R and increased HRD1 expressions, consistent with data obtained with HKC-8 cells. HRD1 physically interacted with IGF-1R in HKC-8 cells and liquid chromatography and tandem mass spectrometry (LC-MS/MS) data supported the concept that IGF-1R is one of the HRD1 substrates. HRD1 promoted the IGF-1R ubiquitination for degradation in HKC-8 cells, and the down-regulation of HRD1 reversed the protective effects of RESV in HKC-8 cells. In summary, we have demonstrated that RESV reduces proteinuria and attenuates the progression of renal fibrosis in db/db mice. These protective effects of RESV on DN were associated with the up-regulation of HRD1, induced by RESV, and the promotion of IGF-1R ubiquitination and degradation.

HRD1 prevents apoptosis in renal tubular epithelial cells by mediating eIF2α ubiquitylation and degradation

“…2b ) and quantification of HRD1 expression (Fig. 2c ), which is consistent with our previous work 19 . Meanwhile, in the present study, the decreased HRD1 protein in db/db mice was also verified by immunohistochemical staining of kidney tissues of db/db mice as shown in Fig.…”

“…Activation of the PERK-eIF2α-ATF4 pathway confirms that eIF2α plays an important role in ER stress-induced apoptosis. Our previous LC-MS/MS analysis of injured tubular epithelial cells (HKC-8) revealed that eIF2α was a substrate of 3-hydroxy-3-methylglutaryl reductase degradation protein (HRD1), an ERAD-associated E3 ubiquitin ligase 19 . HRD1 physically promotes the degradation of proteins in processes such as renal injury and obesity 19 – 21 .…”

“…Our previous LC-MS/MS analysis of injured tubular epithelial cells (HKC-8) revealed that eIF2α was a substrate of 3-hydroxy-3-methylglutaryl reductase degradation protein (HRD1), an ERAD-associated E3 ubiquitin ligase 19 . HRD1 physically promotes the degradation of proteins in processes such as renal injury and obesity 19 – 21 . Taken together, these findings indicated that eIF2α could undergo ubiquitylation by HRD1, followed by further downregulation through ERAD.…”

Preventative effects of resveratrol and estradiol on streptozotocin-induced diabetes in ovariectomized mice and the related mechanisms

“…Resveratrol, a phytoestrogen, is a naturally occurring phenol compound which is structurally and functionally similar to estrogen [ 31 ]. Recently, data showed that orally administering resveratrol (40 mg/kg/day, a high dose) decreased albuminuria and attenuated the progression of kidney fibrosis in db/db mice [ 32 , 33 ]. In contrast, a paper described that oral resveratrol at 0.5 mg/kg (a low dose) ameliorated DM symptoms and improved insulin resistance in a STZ-induced DM model [ 8 ].…”

Interaction of calcium binding protein S100A16 with myosin-9 promotes cytoskeleton reorganization in renal tubulointerstitial fibrosis

“…Protein digestion, labeling, mass spectrometry data acquisition, and identification were completed in the analysis center of Nanjing Medical University. Briefly, a LTQ-Orbitrap instrument (Thermo Fisher, USA) connected to a Nano ACQUITY UPLC system was used to analyze the labeled the peptide samples, as described previously, as well as the acquired MS/ MS spectra and parameters 19,20 .…”