Extracellular vesicles produced by bone marrow mesenchymal stem cells attenuate renal fibrosis, in part by inhibiting the RhoA/ROCK pathway, in a UUO rat model

Abstract

Background: Renal interstitial fibrosis is a critical symptom of chronic kidney disease that is associated with high incidence. Extracellular vesicles produced by bone marrow mesenchymal stem cells (BMSC-EVs) can play important roles in the repair of injured tissues. Though numerous studies have reported the effect of EVs on renal fibrosis, the underlying mechanisms remain unclear. We hypothesized that BMSC-EVs containing milk fat globule–epidermal growth factor–factor 8 (MFG-E8) could attenuate renal fibrosis by inhibiting the RhoA/ROCK pathway. Methods: We investigated whether BMSC-EVs have antifibrotic effects in a rat model of renal fibrosis, in which rats were subjected to unilateral ureteral obstruction (UUO), as well as in cultured HK2 cells. Extracellular vesicles from BMSCs were collected and co-cultured with HK2 cells during transforming growth factor-β1 (TGF-β1) treatment. HK2 cells co-cultured with TGF-β1 were also treated with the ROCK inhibitor, Y-27632. Results: Compared with the Sham group, UUO rats displayed fibrotic abnormalities, accompanied by an increased expression of α-smooth muscle actin and Fibronectin and reduced expression of E-cadherin. These molecular and pathological changes suggested increased inflammation in damaged kidneys. Oxidative stress, as evidenced by decreased levels of SOD1 and Catalase, was also observed in UUO kidneys. Additionally, activation of cleaved caspase-3 and PARP1 and increased apoptosis in the proximal tubules confirmed tubular cell apoptosis in the UUO group. All of these phenotypes exhibited by UUO rats were suppressed by treatment with BMSC-EVs. However, the protective effect of BMSC-EVs was completely abolished by the inhibition of MFG-E8. Consistent with the in vivo results, treatment with BMSC-EVs reduced inflammation, oxidative stress, apoptosis, and fibrosis in HK-2 cells stimulated with TGF-β1 in vitro. Interestingly, treatment with Y-27632 protected HK-2 cells against inflammation and fibrosis, although oxidative stress and apoptosis were unchanged. Conclusions: Our results show that BMSC-EVs containing MFG-E8 attenuate renal fibrosis in a rat model of renal fibrosis, partly through RhoA/ROCK pathway inhibition.

Quercetin inhibits the amphiregulin/EGFR signaling‐mediated renal tubular epithelial‐mesenchymal transition and renal fibrosis in obstructive nephropathy

“…The 24 rats were randomly assigned in four groups (6 rats/group): sham group, sham + quercetin group, UUO group, and UUO ± quercetin group. UUO surgery was performed as described previously (Shi, Wang, Zhang, & Jiang, 2020). Briefly, after anesthetizing, the left ureter was exposed via a lateral ventral incision, the mid‐ureter was ligated with two 4–0 silk sutures and cut off from the midpoint of the ligation, and finally the incision was gently closed.…”

Extracellular Vesicles as Theranostic Tools in Kidney Disease

“…In animal models of diabetic nephropathy, these extracellular vesicles blunted albuminuria and relieved inflammation and fibrosis (70). They protected kidney function in some respects better than their parent mesenchymal stem cells (71), attenuated kidney fibrosis in unilateral ureteral obstruction (72), and ameliorated kidney injury in nephropathy (73). However, in rats with kidney transplant rejection, bone marrow mesenchymal stem cell extracellular vesicles did not prolong graft and recipient survival (74).…”

Delayed Supplementation Strategy of Extracellular Vesicles from Adipose-Derived Mesenchymal Stromal Cells with Improved Proregenerative Efficiency in a Fat Transplantation Model

“…They play a vital role in intercellular communication [4]. EVs confer therapeutic effects against myocardial infarction, renal injury, liver injury, and second-degree skin burn wounds either through direct external interactions with target cells or via different mechanisms when internalized (receptor-dependent endocytosis, micropinocytosis, plasma membrane fusion, or phagocytosis) [5][6][7][8][9][10][11][12].…”