A new approach in stem cell research—Exosomes: Their mechanism of action via cellular pathways

Abstract

Exosomes are nano-sized vesicles surrounded by a lipid membrane, which tend to be secreted toward extra-cellular environments. Despite being defined as vesicles involved in excretion of molecular wastes by Rose Johnstone in the 1970s, further studies revealed them to be effective in various biological processes such as cancer development, regulation of the immune system, intercellular communication, stem cell biology, and tissue/organ regeneration. Although many studies dealing with the role of exosomes in stem cell differentiation and the use of exosomes isolated from stem cells for the treatment of several diseases have been published, the involved mechanisms remain largely unknown. Further understanding of these mechanisms, which include the involved cellular pathways, may improve the use of exosomes in diagnostic and treatment methods, especially for those involving stem cells. Here, we describe some recent data describing the action mechanism of stem cell-derived exosomes focusing on the implicated cellular pathways, hoping to provide novel information that will be useful for cell biology scientists working in this field.

Transplantation of adipose tissue-derived stem cell-derived exosomes ameliorates erectile function in diabetic rats

“…Further work shows that the mechanism was by secreting a variety of bioactive cytokines, but not differentiating into smooth muscle or endothelial cells. However, ascending evidence indicated that exosomes might be the main components of paracrine factors (Derkus, Emregul, & Emregul, ). Besides, given the major concerns of MSC transplantation in clinical practice, such as cell contamination, cell death and immune rejection, exosome‐based therapy seems to be an alternative treatment strategy (Derkus et al., ).…”

“…However, ascending evidence indicated that exosomes might be the main components of paracrine factors (Derkus, Emregul, & Emregul, ). Besides, given the major concerns of MSC transplantation in clinical practice, such as cell contamination, cell death and immune rejection, exosome‐based therapy seems to be an alternative treatment strategy (Derkus et al., ). Taking advantage of some characteristics of the MSC‐derived exosomes: (i) they are less immunogenic than parental cells because of lower content of membrane‐bound proteins, such as major histocompatibility complex molecules.…”

HLSC-Derived Extracellular Vesicles Attenuate Liver Fibrosis and Inflammation in a Murine Model of Non-alcoholic Steatohepatitis

“…EVs derived from different type of stem/progenitor cells may induce regenerative programs in injured organs/tissues by transcriptional or translational modification in injured target cells. 12,13 To investigate whether HLSC-released EVs (EV-HLSCs) are implicated in the anti-fibrotic effect of HLSCs, we established a model of NASH induced by a methionine-and choline-deprived diet (MCDD) in immunodeficient mice and started a biweekly treatment with EVs after 2 weeks of diet. Mice were sacrificed at week 4; and functional, morphological, and molecular liver alterations were analyzed.…”

Stem cell-derived exosomes: a novel vector for tissue repair and diabetic therapy

“…In many cases, the exosomes secreted from stem cells have been found to mediate this effect. Like their parent cells, exosomes released from pluripotent and multipotent stem cells have been proven to stimulate angiogenesis and cellular regeneration, suppress apoptotic pathways and modulate immunity in chronically damaged tissues both in vivo and in vitro (Derkus et al 2017). Unlike their parent cells, exosomes are not immunoreactive, can pass through biological barriers and pose no risk of maldifferentiation (Kunter et al 2007).…”