Renal Regenerative Potential of Different Extracellular Vesicle Populations Derived from Bone Marrow Mesenchymal Stromal Cells

Abstract

Extracellular vesicles (EVs) derived from human bone marrow mesenchymal stromal cells (MSCs) promote the regeneration of kidneys in different animal models of acute kidney injury (AKI) in a manner comparable with the cells of origin. However, due to the heterogeneity observed in the EVs isolated from MSCs, it is unclear which population is responsible for the proregenerative effects. We therefore evaluated the effect of various EV populations separated by differential ultracentrifugation (10K population enriched with microvesicles and 100K population enriched with exosomes) on AKI recovery. Only the exosomal-enriched population induced an improvement of renal function and morphology comparable with that of the total EV population. Interestingly, the 100K EVs exerted a proproliferative effect on murine tubular epithelial cells, both in vitro and in vivo. Analysis of the molecular content from the different EV populations revealed a distinct profile. The 100K population, for instance, was enriched in specific mRNAs (CCNB1, CDK8, CDC6) reported to influence cell cycle entry and progression; miRNAs involved in regulating proliferative/antiapoptotic pathways and growth factors (hepatocyte growth factor and insulin-like growth factor-1) that could explain the effect of renal tubular cell proliferation. On the other hand, the EV population enriched in microvesicles (10K) was unable to induce renal regeneration and had a molecular profile with lower expression of proproliferative molecules. In conclusion, the different molecular composition of exosome- and microvesicle-enriched populations may explain the regenerative effect of EVs observed in AKI.

Precipitation with polyethylene glycol followed by washing and pelleting by ultracentrifugation enriches extracellular vesicles from tissue culture supernatants in small and large scales

“…As described, sEVs seem to exert most therapeutic functions of MSCs [16,56]. However, in other cell systems larger vesicles have been found to also mediate functional activities [57].…”

Exosomes and microvesicles in normal physiology, pathophysiology, and renal diseases

“…STEC-HUS Shiga toxin-producing Escherichia coli -hemolytic uremic syndrome, aHUS atypical HUS, TTP thrombotic thrombocytopenic purpura, VWF von Willebrand factor, CD62E E-selectin, ICAM-1 intercellular adhesion molecule 1, NDI nephrogenic diabetes insipidus (DI), CDI central DI, ADPKD autosomal dominant polycystic kidney disease, ATG antithymocyte globulin, SLE systemic lupus erythematosus, APS anti-phospholipid syndrome, A adipocytes, I islet cells a Detected extracellular vesicles were not specified as exosomes, microvesicles or apoptotic bodies b Elevated extracellular vesicles and miRNA may serve as biomarkers c The exosomal fraction is responsible for the regenerative effects [146] d Na/H exchanger isoform 3, fetuin-A or activating transcription factor 3 may reflect tubular injury e miRNA profiles correlated with perturbed renal function and renal fibrosis f Indicating complement activation g Correspond to the Birmingham vasculitis activity score h A miRNA profile derived from miRNA containing microvesicles. Protein biomarkers include α1-antitrypsin, aminopeptidase N, vasorin precursor, ceruloplasmin, and podocalyxin…”

Extracellular vesicles and aging

“…For example, EVs derived from marrow or adipose MSCs affect the phenotype and induce healing of many different tissue and cell types, including liver (51), heart (52), pulmonary epithelial cells and kidney (53,54) as well as promote angiogenesis (55,56). Consistent with these regenerative capacities of stem cell EVs, a recent study demonstrated that implantation of healthy hypothalamic stem/progenitor cells into the hypothalamus leads to the slowing of ageing (57).…”