Determination of optimized oxygen partial pressure to maximize the liver regenerative potential of the secretome obtained from adipose-derived stem cells

Abstract

BackgroundA hypoxic-preconditioned secretome from stem cells reportedly promotes the functional and regenerative capacity of the liver more effectively than a control secretome. However, the optimum oxygen partial pressure (pO2) in the cell culture system that maximizes the therapeutic potential of the secretome has not yet been determined.MethodsWe first determined the cellular alterations in adipose tissue-derived stem cells (ASCs) cultured under different pO2 (21%, 10%, 5%, and 1%). Subsequently, partially hepatectomized mice were injected with the secretome of ASCs cultured under different pO2, and then sera and liver specimens were obtained for analyses.ResultsOf all AML12 cells cultured under different pO2, the AML12 cells cultured under 1% pO2 showed the highest mRNA expression of proliferation-associated markers (IL-6, HGF, and VEGF). In the cell proliferation assay, the AML12 cells cultured with the secretome of 1% pO2 showed the highest cell proliferation, followed by the cells cultured with the secretome of 21%, 10%, and 5% pO2, in that order. When injected into the partially hepatectomized mice, the 1% pO2 secretome most significantly increased the number of Ki67-positive cells, reduced serum levels of proinflammatory mediators (IL-6 and TNF-α), and reduced serum levels of liver transaminases. In addition, analysis of the liver specimens indicated that injection with the 1% pO2 secretome maximized the expression of the intermediate molecules of the PIP3/Akt and IL-6/STAT3 signaling pathways, all of which are known to promote liver regeneration.ConclusionsThe data of this study suggest that the secretome of ASCs cultured under 1% pO2 has the highest liver reparative and regenerative potential of all the secretomes tested here.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-017-0635-x) contains supplementary material, which is available to authorized users.

The mesenchymal stem cell secretome as an acellular regenerative therapy for liver disease

“…Acceleration of the regenerative response, as well as beneficial effects on reducing hepatic injury or increasing hepatocyte proliferation were enhanced with the use of secretome obtained from ASC that underwent LPS pre-conditioning compared with unstimulated ASC [29, 39, 40]. Similarly, hypoxia pre-conditioning of ASC engendered a secretome product that promoted liver regeneration, with the greatest benefit observed with secretome obtained from MSC exposed to 1% partial pressure of oxygen (pO 2 ) [41]. Hepatocyte proliferation in hypoxia-primed ASC-CM-treated mice was increased following partial hepatectomy and was associated with a reduced suppression of cytokine signaling 3 (SOCS3) expression, enhanced STAT3 signaling and increased HGF, VEGF, and Bcl-XL expression [42].…”

Extracellular Vesicles in the Development of the Non-Alcoholic Fatty Liver Disease: An Update

“…In another hepatic injury study, the EVs from MSC exhibited protective effects on the hepatocytes despite being treated with liver injury stimulant drugs, partly via the upregulation of hepatocyte proliferation [74]. Other studies of EVs from the various origins of MSCs showed similar hepatic protective and regenerative effects, as seen in the bone-marrow-derived MSCs [75][76][77][78][79][80], human umbilical cord-derived MSCs [81][82][83], human liver stem cells [84,85], induced pluripotent stem cell-derived MSCs [86], human embryonic-derived MSCs [64], human menstrual blood-derived MSCs [87], and adipose-derived MSCs [88][89][90][91]. As for the prevention of fibrosis via the suppression of HSCs, a study of EVs from the chorionic plate-derived MSCs showed that these EVs suppressed the activation and proliferation of HSCs due to the presence of miR-125b in the cargo, thus preventing liver fibrosis [92].…”

Antioxidant action of hypoxic conditioned media from adipose-derived stem cells in the hepatic injury of expressing higher reactive oxygen species

“…The cultured ASCs were shown to have characteristics of MSCs; they expressed the MSC marker (CD90) and did not express hematopoietic markers (CD31 and CD34) [910]. We have previously described the processes of ASC or ASC secretome preparation [3410]. In brief, after thawing, ASCs were cultured in MesenPRO RS basal medium (Gibco, Invitrogen, Carlsbad, CA, USA) supplemented with antibiotics (Antibiotic-Antimycotic, Invitrogen).…”

“…Secretome can be induced to the specific purposes by preconditioning processes. Of these, hypoxic preconditioning has been established as one of consistent, reliable and safe ways [23456]. We previously validated the effectiveness of hypoxic conditioned media (HCM) in the mouse model of partial hepatectomy (PH); further, we demonstrated that HCM is more equipped in promoting liver regeneration by highly activating IL-6/STAT3 signaling through decreasing SOCS3 (suppressor of cytokine signaling 3) expression in the liver [34].…”