Restoring In Vivo-Like Membrane Lipidomics Promotes Exosome Trophic Behavior from Human Placental Mesenchymal Stromal/Stem Cells

Abstract

Human mesenchymal stem cells (hMSCs) are an effective tool in regenerative medicine notably for their intrinsic plentiful paracrine activity rather than differentiating properties. The hMSC secretome includes a wide spectrum of regulatory and trophic factors, encompassing several naked molecules as well as different kinds of extracellular vesicles (EVs). Among EVs, exosomes represent an intriguing population, able to shuttle proteins, transcription factors, and genetic materials, with a relevant role in cell-to-cell communication, modulating biological responses in recipient cells. In this context, the extracellular milieu can greatly impact the paracrine activity of stem cells, modifying their metabolism, and the dynamics of vesicle secretion. In the present study, we investigated the effects elicited on exosome patterning by tailored, ad hoc formulated lipid supplementation (Refeed) in MSCs derived from human fetal membranes (hFM-MSCs). Wound healing experiments revealed that stem cell exposure to exosomes obtained from Refeed-supplemented hFM-MSCs increased their migratory capability, although the amount of exosomes released after Refeed supplementation was lower than that yielded from non-supplemented cells. We found that such a decrease was mainly due to a different rate of exosomal exocytosis rather than to an effect of the lipid supplement on the endocytic pathway. Endoplasmic reticulum homeostasis was modified by supplementation, through the upregulation of PKR-like ER kinase (PERK) and inositol-requiring enzyme 1α (IRE1α). Increased expression of these proteins did not lead to stress-induced, unfolded protein response (UPR)-mediated apoptosis, nor did it affect phosphorylation of p38 kinase, suggesting that PERK and IRE1α overexpression was due to augmented metabolic activities mediated by optimization of a cellular feeding network afforded through lipid supplementation. In summary, these results demonstrate how tailored lipid supplementation can successfully modify the paracrine features in hFM-MSCs, impacting both intracellular vesicle trafficking and secreted exosome number and function.

Paracrine Mechanisms of Mesenchymal Stromal Cells in Angiogenesis

“…Supplementing lipids during the culture of human fetal membrane MSCs has been shown to increase cell proliferation rate, angiogenic differentiation, and immunomodulatory properties [104]. In addition, when these MSCs are exposed to EVs obtained from lipidsupplemented culture, cell migration rates improve as assessed by a wound-healing assay [105]. Depriving MSCs of serum and oxygen also alters its metabolic and lipidomic profile which in turn affects the composition of the released EVs.…”

Microfluidic Tools for Enhanced Characterization of Therapeutic Stem Cells and Prediction of Their Potential Antimicrobial Secretome

“…Accumulated evidence suggests that the therapeutic benefit of MSCs belongs mainly to their paracrine action [75,76], rather than to MSC differentiation after transplantation. Indeed, the current literature supports the notion that MSCs effectively act via their secretome [77] in several clinical conditions [78]. Notably, the expression of indoleamine 2,3-dioxygenase-1 (IDO-1) [79], Human Leukocyte Antigen-G (HLA-G) soluble molecules, interleukin-10 (IL-10), and prostaglandin E2 (PGE2), which are characteristic and efficient immunomodulatory molecules secreted in large amounts by MSCs [13].…”

A Comorbidity Model of Myocardial Ischemia/Reperfusion Injury and Hypercholesterolemia in Rat Cardiac Myocyte Cultures

“…The specific tailored Refeed R composition is shown in Table 1. Similar Refeed compositions for different purposes have been previously developed, as described (Poggi et al, 2015;Chatgilialoglu et al, 2017;Cavallini et al, 2018).…”