CircACTR2 in macrophages promotes renal fibrosis by activating macrophage inflammation and epithelial-mesenchymal transition of renal tubular epithelial cells.

The crosstalk between macrophages and tubular epithelial cells (TECs) actively regulates the progression of renal fibrosis. In the present study, we revealed the significance of circular RNA ACTR2 (circACTR2) in regulating macrophage inflammation, epithelial-mesenchymal transition (EMT) of TECs, and the development of renal fibrosis. Our results showed UUO-induced renal fibrosis was associated with increased inflammation and EMT, hypertrophy of contralateral kidney, up-regulations of circACTR2 and NLRP3, and the down-regulation of miR-561. CircACTR2 sufficiently and essentially promoted the activation of NLRP3 inflammasome, pyroptosis, and inflammation in macrophages, and through paracrine effect, stimulated EMT and fibrosis of TECs. Mechanistically, circACTR2 sponged miR-561 and up-regulated NLRP3 expression level to induce the secretion of IL-1ß. In TECs, IL-1ß induced renal fibrosis via up-regulating fascin-1. Knocking down circACTR2 or elevating miR-561 potently alleviated renal fibrosis in vivo. In summary, circACTR2, by sponging miR-561, activated NLRP3 inflammasome, promoted macrophage inflammation, and stimulated macrophage-induced EMT and fibrosis of TECs. Knocking down circACTR2 and overexpressing miR-561 may, thus, benefit the treatment of renal fibrosis.

MiR-200b/c family inhibits renal fibrosis through modulating epithelial-to-mesenchymal transition via targeting fascin-1/CD44 axis.

BACKGROUND: Renal fibrosis is the characteristic of all kinds of chronic kidney diseases (CKDs). Fascin-1 plays an important role in tumor development, but the roles of fascin-1 in renal fibrosis have not been studied. Here, we explored the role of fascin-1 in renal fibrosis and the potential mechanisms. METHODS: Kidney unilateral ureteral obstruction (UUO) mouse model was used as an in vivo model, and proximal tubule epithelial cell lines treated with TGF-ß1 were used as in vitro model of renal fibrosis. Cell transfection was performed to manipulate the expression of miR-200b/c, fascin-1 and CD44. Western blotting, qRT-PCR, immunohistochemistry or immunofluorescence assays were used to measure levels of miR-200b/c, fascin-1, CD44, and fibrosis and EMT-related markers. H&E and Masson stainings were used to examine the degree of injury and fibrosis in kidneys. Dual luciferase assay was used to examine the interaction between miR-200b/c family and fascin-1. RESULTS: Fascin-1 and CD44 levels were both significantly up-regulated while miR-200b/c family was reduced in models of renal fibrosis. Furthermore, overexpression of miR-200b/c family and inhibition of fascin-1 or CD44 ameliorated renal fibrosis through suppressing EMT process. Mechanistically, miR-200b/c family directly and negatively regulated the expression of fascin-1. Overexpression of fascin-1 could reverse the effects of miR-200b/c family on renal fibrosis, and fascin-1 regulated renal fibrosis by activating CD44. CONCLUSION: Our study is the first to show that fascin-1 plays a critical role in renal fibrosis. MiR-200b/c family could inhibit renal fibrosis through modulating EMT process by directly targeting fascin-1/CD44 axis.

Diallyl disulfide effect on the invasion and migration ability of HL-60 cells with a high expression of DJ-1 in the nucleus through the suppression of the Src signaling pathway.

The present study examined the effect of diallyl disulfide (DADS) on the invasion and migration ability of HL-60 cells with a high expression of parkinsonism associated deglycase (DJ-1) in the nucleus (HHDN), and its molecular mechanism. A western blot assay was used to measure the effects of DADS and an Src inhibitor on the expression of DJ-1 and the Src signal pathway in HHDN. The effects of DADS and Src inhibitors on the invasion and migration ability of HHDN was detected using Transwell migration and invasion chamber experiments. The experiments were divided into three groups: A control group (HL-60 cells), an empty vector group and a high expression group (HHDN cells). Western blot assays revealed that the expression of DJ-1 in HHDN was inhibited in a time-dependent manner following treatment with DADS for 24, 48 and 72 h. Following DADS treatment, the expression of phosphorylated Src (p-Src) and phosphorylated Fak (p-Fak) were significantly decreased in all groups compared with the untreated groups, however the expression level of Src, Fak and integrin did not change significantly. Western blot analysis results revealed that following treatment with DADS and Src inhibitor, the expression levels of p-Src and p-Fak significantly decreased in all three groups compared with untreated groups, whereas the expression levels of Src, Fak and integrin did not change significantly. The expression of DJ-1 in HHND was inhibited in time-dependent manner following treatment with DADS and Src inhibitor for 24, 48 and 72 h. Transwell migration and invasion assay results revealed that DADS and Src inhibitors may suppress migration and invasion in leukemic cells, and a combination of the two treatments may result in more efficient suppression. DADS may downregulate DJ-1-mediated invasion and migration in leukemic cells through suppressing the Src-Fak-Integrin signaling pathway, and the Src inhibitor may enhance the antitumor effect of DADS.