Exosomes Secreted from Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Accelerate Skin Cell Proliferation

Abstract

Induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) serve as a unique source for cell therapy. We investigated whether exosomes from iMSCs promote the proliferation of human keratinocytes (HaCaT) and human dermal fibroblasts (HDFs). iPSCs were established from human Wharton’s jelly MSCs and were allowed to differentiate into iMSCs. Exosomes were collected from the culture supernatant of MSCs (MSC-exo) and iMSCs (iMSC-exo), and their characteristics were investigated. Both exosome types possessed basic characteristics of exosomes and were taken up by skin cells in vitro and in vivo. A significant increase in HaCaT proliferation was observed with iMSC-exo, although both exosomes increased the viability and cell cycle progression in HaCaT and HDFs. No significant difference was observed in the closure of wound scratch and the expression of reparative genes between cells treated with the two exosome types. Both exosomes enhanced the secretion of collagen in HaCaT and HDFs; however, an increase in fibronectin level was observed only in HaCaT, and this effect was better with iMSC-exo treatment. Only iMSC-exo increased the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2. Our results indicate that iMSC-exo promote the proliferation of skin cells by stimulating ERK1/2 and highlight the application of iMSCs for producing exosomes.

Utilization of Human Induced Pluripotent Stem Cells for Cardiac Repair

“…For instance, exosomes secreted by CDCs were found to promote the proliferation of cardiomyocyte in mouse MI hearts (Ibrahim et al, 2014). Similarly, exosomes derived by iMSCs promoted the proliferation of human fibroblasts in vitro in a dose-dependent manner while iMSCs-derived exosomes enhanced the viability and cell cycle progression in human keratinocytes and human dermal fibroblasts (Kim et al, 2018). Ye et al (2019) in one of their studies treated bovine aortic endothelial cells with 100 µg/ml of hiPSC-CM-derived exosomes and found a significant increase in cell proliferation when compared to control (no exosomes).…”

“…Furthermore, exosomes released by iPSC-derived MSCs alleviate hepatic ischemia reperfusion injury (I/R) possibly by decreasing oxidative stress, reducing inflammatory responses and inhibiting apoptosis. In addition, exosomes secreted by iPSC-derived MSCs promote the growth, proliferation, and migration of human dermal fibroblast by stimulating ERK1/2 (Kim et al, 2018). A recent study reported that after 7 weeks of peri-infarct injections, the best preservation of left ventricle function was found in the exosome (released by iPSC-derived cardiovascular progenitors) injected hearts compared to those injected with iPSC-CMs, iPSC-derived cardiovascular progenitors or PBS.…”

Enhanced Wound Healing- and Inflammasome-Associated Gene Expression in TNFAIP3-Interacting Protein 1- (TNIP1-) Deficient HaCaT Keratinocytes Parallels Reduced Reepithelialization

“…HaCaT keratinocytes, a spontaneously immortalized, nontumorigenic line [18], were cultured as previously described [13]. The HaCaT keratinocyte line has been extensively used to model human keratinocyte inflammatory pathway signaling, cytokine production, and reepithelialization [19][20][21][22][23][24][25][26]. TNIP1-targeting siRNA or nontargeting negative control siRNA was used to transfect HaCaT keratinocytes (triplicate wells plated as follows: 6well, 480,000 cells/well; 12-well, 160,000 cells/well; 24-well, 80,000 cells/well) 24 hr postplating.…”

“…SABiosciences PCR Array software was used to , maintained for 24 hr in standard media, and then switched to serum-free media for another 24 hr during which time they reached confluence. A "wound" was created in HaCaT monolayers [25,26] by dragging the point of a sterile yellow micropipette tip across the well center. Immediately after performing the scratch, cells were washed twice with PBS before addition (time 0) of serum-free media with poly (I:C) at 1 μg/mL or nuclease-free H 2 O as vehicle control for 24 hr.…”

“…To test TNIP1 impact during reepithelialization, we used an in vitro wound model [25,26] with confluent HaCaT keratinocytes under conditions of normal (nontargeting siRNA) or deficient TNIP1 (TNIP1 siRNA) protein levels (Figures 3(a) and 3(b)). Cells with reduced TNIP1 protein under vehicle conditions had scratch area recovery similar to those with normal levels of TNIP1 protein.…”