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: 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 globuleepidermal growth factor-factor 8 (MFG-E8) could attenuate renal fibrosis by inhibiting the RhoA/ROCK pathway. Methods: We investigated whether BMSC-EVs have anti-fibrotic 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 an increased level of MDA and 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.

Therapeutic Role of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Female Reproductive Diseases

“…Oxidative stress is a phenomenon resulted from accumulation of ROS, which impairs the function and structures of cells and tissues ( 136 , 149 ). BMSC-EVs could protect cells from toxic effects of peroxide via reducing malondialdehyde (MDA) and increasing superoxide dismutase 1 (SOD1) and catalase expression ( 151 ). Moreover, MSC-EVs were likely to have a mitochondrial (MIT)-protective effect.…”

“…Moreover, MSC-EVs were likely to have a mitochondrial (MIT)-protective effect. The compromised mitochondrial membrane potential (MMP) or ATP level was rescued, and ROS level was reduced significantly after MSC-EVs treatment ( 151 , 152 ). For this reason, studies about the mechanism of MSC-EVs in ameliorating POI, should not only focus on the effect of anti-apoptosis of GCs under lower levels of ROS, but also further explore the influence of MSC-EVs on MIT dysfunction of GCs or oocytes.…”

Mesenchymal Stem Cell-Derived Extracellular Vesicles to the Rescue of Renal Injury

“…The anti-inflammatory effects of EVs can be attributed to their paracrine delivery of immunomodulatory molecules or expression of surface proteins that minimises infiltration of immune cells, such as macrophages, T cells, and NK cells [ 134 ]. BM-MSC-exosomes downregulated pro-inflammatory cytokines (IL-6, IL-1β, IFN-γ, TNF-α) and stimulated anti-inflammatory cytokines (IL-10) in rodents with IRI [ 113 ], unilateral ureteral obstruction (UUO) [ 135 ], or gentamicin- [ 98 ] or cisplatin-induced AKI [ 107 , 108 , 136 ]. Additionally, umbilical-MSC-exosomes upregulated miR-146b, leading to reduced IRAK1 expression and NF-κB transcriptional activity in TECs in mice with sepsis-associated AKI [ 137 ].…”

“…Milk fat globule-epidermal growth factor-factor 8 (MFG-E8) is a glycoprotein that inhibits the RhoA/ROCK signalling pathway. BM-MSC-EVs delivered MFG-E8 to rats with UUO and reduced inflammation, macrophage infiltration, mitochondrial damage, apoptosis, oxidative stress, and the EMT within two weeks [ 135 ].…”

Stem cells in the treatment of renal fibrosis: a review of preclinical and clinical studies of renal fibrosis pathogenesis

“…Milk globule epidermal growth factor 8 (MFG-E8) is a secretory multifunctional glycoprotein that usually exists in human milk globules. Shi et al [ 113 ] showed that BM-MSC-EVs could decrease renal fibrosis by producing MFG-E8, which suppressed the RhoA/ROCK pathway. Ninichuk et al [ 114 ] injected BM-MSCs via the tail vein in COL4A3-deficient mice (Alport disease model) and showed that BM-MSCs could decrease BUN and Scr and inhibit glomerulosclerosis and renal fibrosis, but EVGF and BMP7 were not changed.…”