Tumoricidal effects of unprimed and curcumin-primed adipose-derived stem cells on human hepatoma HepG2 cells under oxidative conditions.

INTRODUCTION: Adipose-derived stem cells (ASCs) have been proven to have tumoricidal effects against hepatic cancer cell lines. However, it appears that exposure to oxidative microenvironment compromises the potential outcome of ASCs in real hepatoma. Herein, we aimed to examine the tumoricidal effects of ASCs under oxidative conditions and to investigate the impact of curcumin priming on ASCs' therapeutic potential. METHODS: We used human hepatoma (HepG2) cells in a coculture system with unprimed or curcumin-primed ASCs (Cur-ASCs) under H2O2-induced oxidative conditions. To investigate HepG2 proliferation and death, MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) and annexin V staining assays were performed. To determine the HepG2 migration and invasion potential, the scratch healing and the transwell invasion assays were performed. To evaluate the expression of apoptosis-protein markers, Western blotting was performed. RESULTS: Cur-ASCs suppressed HepG2 proliferation, migration, and invasion as well as prompted apoptosis more significantly compared to unprimed ASCs under oxidative conditions. Expressional studies also revealed an obvious decline in the BCL-2/BAX ratio in HepG2 cocultured with Cur-ASCs. In addition, we noticed a marked elevation of apoptosis and senescence in unprimed ASCs compared to Cur-ASCs after coculture experiments, which demonstrated that curcumin priming preserved the survival and growth potential of ASCs; hence, Cur-ASCs performed better tumoricidal functions under oxidative conditions. CONCLUSION: Our findings suggest that ASCs have the intrinsic ability to induce cell death in HepG2 cells; however, their functions can be compromised under oxidative conditions. We believe that curcumin priming is an effective approach for improving the therapeutic effectiveness of ASCs in the cancerous microenvironment.

Vitamin E pretreated Wharton's jelly-derived mesenchymal stem cells attenuate CCl4-induced hepatocyte injury in vitro and liver fibrosis in vivo.

Oxidative microenvironment in fibrotic liver alleviates the efficacious outcome of mesenchymal stem cells (MSCs)-based cell therapy. Recent evidence suggests that pharmacological pretreatment is a rational approach to harness the MSCs with higher therapeutic potential. Here, we investigated whether Vitamin E pretreatment can boost the antifibrotic effects of Wharton's jelly-derived MSCs (WJMSCs). We used rat liver-derived hepatocytes injured by CCl4 treatment in co-culture system with Vitamin E pretreated-WJMSCs (Vit E-WJMSCs) to evaluate the hepatoprotective effect of Vit E-WJMSCs. After 24 h of co-culturing, we found that Vit E-WJMSCs rescued injured hepatocytes as hepatocyte injury-associated medium (AST, ALT, and ALP) and mRNA (Cyp2e1, Hif1-α, and Il-1ß) markers reduced to normal levels. Subsequently, CCl4-induced liver fibrosis rat models were employed to examine the antifibrotic potential of Vit E-WJMSCs. After 1 month of cell transplantation, it was revealed that Vit E-WJMSCs transplantation ceased fibrotic progression, as evident by improved hepatic architecture and functions, more significantly in comparison to naïve WJMSCs. In addition, Vit E-WJMSCs transplantation decreased the expressions of fibrosis-associated gene (Tgf-ß1, α-Sma, and Col1α1) markers in the liver parenchyma. Intriguingly, the results of tracing experiments discovered that more WJMSCs engrafted in the Vit E-WJMSCs treated rat livers compared to naïve WJMSCs treated livers. These findings implicate that pretreatment of WJMSCs with Vitamin E improves their tolerance to hostile niche of fibrotic liver; thereby further enhancing their efficacy for hepatic fibrosis.

Serum from CCl4-induced acute rat injury model induces differentiation of ADSCs towards hepatic cells and reduces liver fibrosis.

Cellular therapies hold promise to alleviate liver diseases. This study explored the potential of allogenic serum isolated from rat with acute CCl4 injury to differentiate adipose derived stem cells (ADSCs) towards hepatic lineage. Acute liver injury was induced by CCl4 which caused significant increase in serum levels of VEGF, SDF1α and EGF. ADSCs were preconditioned with 3% serum isolated from normal and acute liver injury models. ADSCs showed enhanced expression of hepatic markers (AFP, albumin, CK8 and CK19). These differentiated ADSCs were transplanted intra-hepatically in CCl4-induced liver fibrosis model. After one month of transplantation, fibrosis and liver functions (alkaline phosphatase, ALAT and bilirubin) showed marked improvement in acute injury group. Elevated expression of hepatic (AFP, albumin, CK 18 and HNF4a) and pro survival markers (PCNA and VEGF) and improvement in liver architecture as deduced from results of alpha smooth muscle actin, Sirius red and Masson's trichome staining was observed.

In vitro differentiated hepatic oval-like cells enhance hepatic regeneration in CCl4 -induced hepatic injury.

Hepatic oval cells are likely to be activated during advanced stage of liver fibrosis to reconstruct damaged hepatic tissue. However, their scarcity, difficulties in isolation, and in vitro expansion hampered their transplantation in fibrotic liver. This study was aimed to investigate the repair potential of in vitro differentiated hepatic oval-like cells in CCl4 -induced liver fibrosis. BMSCs and oval cells were isolated and characterized from C57BL/6 GFP+ mice. BMSCs were differentiated into oval cells by preconditioning with HGF, EGF, SCF, and LIF and analyzed for the oval cells-specific genes. Efficiency of oval cells to reduce hepatocyte injury was studied by determining cell viability, release of LDH, and biochemical tests in a co-culture system. Further, in vivo repair potential of differentiated oval cells was determined in CCl4 -induced fibrotic model by gene expression analysis, biochemical tests, mason trichrome, and Sirius red staining. Differentiated oval cells expressed hepatic oval cells-specific markers AFP, ALB, CK8, CK18, CK19. These differentiated cells when co-cultured with injured hepatocytes showed significant hepato-protection as measured by reduction in apoptosis, LDH release, and improvement in liver functions. Transplantation of differentiated oval cells like cells in fibrotic livers exhibited enhanced homing, reduced liver fibrosis, and improved liver functions by augmenting hepatic microenvironment by improved liver functions. This preconditioning strategy to differentiate BMSCs into oval cell leads to improved survival and homing of transplanted cells. In addition, reduction in fibrosis and functional improvement in mice with CCl4 -induced liver fibrosis was achieved.