Tubular epithelial-mesenchymal transition (EMT) has been widely accepted as the underlying mechanisms of renal interstitial fibrosis (RIF). The production of reactive oxygen species (ROS) plays a vital role in tubular EMT process. The purpose of this study was to investigate the involved molecular mechanisms in TGF-beta-induced EMT and identify the potential role of glutathione S-transferase alpha 3 (GSTA3) in this process. The iTRAQ screening was performed to identify protein alterations of the rats underwent unilateral-ureteral obstruction (UUO). Protein expression of GSTA3 in patients with obstructive nephropathy and UUO rats was detected by immunohistochemistry. Protein and mRNA expression of GSTA3 in UUO rats and NRK-52E cells were determined by Western blot and RT-PCR. siRNA and overexpression plasmid were transfected specifically to assess the role of GSTA3 in RIF. The generation of ROS was measured by dichlorofluorescein fluorescence analysis. GSTA3 protein and mRNA expression was significantly reduced in UUO rats. Immunohistochemical analysis revealed that GSTA3 expression was reduced in renal cortex in UUO rats and patients with obstructive nephropathy. Treating with TGF-β1 down-regulated GSTA3 expression in NRK-52E cells, which have been found to be correlated with the decreased expression in E-cadherin and megalin and increased expression in α-smooth muscle actin. Furthermore, knocking down GSTA3 in NRK-52 cells led to increased production of ROS and tubular EMT, whereas overexpressing GSTA3 ameliorated ROS production and prevented the occurrence of tubular EMT. GSTA3 plays a protective role against tubular EMT in renal fibrosis, suggesting GSTA3 is a potential therapeutic target for RIF.

Previous studies demonstrated that cGAS pathway is related to the inflammation amplification in a variety of autoimmune diseases. Lysine acetyltransferase family (KATs) can regulate the nuclear transcription or cytoplasmic activation of cGAS through different mechanisms. However, its role and related immunity patterns in systemic lupus erythematosus (SLE) have not been explored. In this study, RNA-seq and scRNA-seq profiling were performed for peripheral blood mononuclear cells (PBMCs) from patients with SLE. R packages were used for bioinformatic analysis. Cell culture, RT-PCR, western blotting, immunofluorescence, immunohistochemistry, and ELISA were used to explore gene expression in vitro or clinical specimens. Plasmid transfection and mass spectrometry were used to detect protein modifications. Eight acetyltransferase and deacetylase family members with significantly differential expression in SLE were found. Among them, KAT2A was abnormally upregulated and positively correlated with disease activity index. Further, KAT2A-cGAS pathway was aberrantly expressed in specific immune cell subsets in SLE. In vitro studies showed KAT2A modulated cGAS through increasing expression and post-translational modification. Our research provides novel insights for accurately positioning specific immune-cell subgroups in which KAT2A-cGAS reaction mainly works and KAT2A regulation patterns.

Purpose: To investigate whether Niban protein plays a role in renal interstitial fibrosis by regulating renal tubular epithelial cell apoptosis and explore the underlying mechanism. Methods: Unilateral ureteral obstruction (UUO) model was performed in C57B/6J mice, and divided into sham operation group and groups of days 3, days 7, and days 14. Niban expression was detected by immunohistochemistry and Western blot. TUNEL assays were used to detected apoptosis. Niban siRNA and overexpression Niban plasmid were transfected in HK-2 cells respectively to explore apoptosis related mechanisms of Niban during angiotensin II (AngII) – and endoplasmic reticulum (ER) stress-induced injury. Results: With the development of obstruction, Niban’s expression decreased gradually while apoptosis increased. Silencing of Niban not only increased the AngII- and ER stress-induced apoptosis, but also promoted the expression of caspase 8, caspase 9, Bip, and Chop. Overexpression of Niban reduced AngII-induced apoptosis and the expression of caspase 8 and caspase 9. Conclusions: Niban protein is involved in apoptosis regulation in HK-2 cells, and most likely via caspase-dependent pathway.

Aim: Apoptosis is one of the most important mechanisms underlying renal interstitial fibrosis. We identified the role of protein Niban in apoptosis of tumour cells. The purpose of this study was to assess the expression of Niban in renal interstitial fibrosis of humans and rats.Methods: Immunohistochemistry was used to detect Niban in patients with obstructive nephropathy. Proteomics and gene array analysis were performed to screen different molecules involved in the pathophysiology of unilateral‐ureteral obstruction rats. We confirmed Niban using immunohistochemistry and Western blot in renal cortex of UUO rats and HK‐2 cells. TUNEL assay and flow cytometry revealed apoptosis of renal tubular cells. siRNA and overexpression plasmid were transfected specifically to study the possible function of Niban.Results: Niban was decreased apparently in renal tubular cells of patients with obstructive nephropathy, compared with controls. Niban decreased in renal cortex of UUO rats and transforming growth factor‐β1 (TGF‐β1)‐stimulated HK‐2 cells. siRNA of Niban increased apoptosis of HK‐2 cells. TGF‐β1 also increased apoptosis of HK‐2 cells. Overexpression of Niban failed to diminish apoptosis of HK‐2 cells induced by TGF‐β1.Conclusions: Niban decreased in renal tubular cells of patients of obstructive nephropathy, UUO rats and TGF‐β1 stimulated HK‐2 cells. Suppressing Niban increases apoptosis in HK‐2 cells. Niban may be associated with apoptosis of HK‐2 cells.