Comparative treatment efficiency of adipose and bone marrow derived allogenic mesenchymal stem cell transplantation in mouse models of liver fibrosis

Adipose-derived stem cells in the treatment of hepatobiliary diseases and sepsis

Determination of the mesenchymal stem cells is one of the greatest and most exciting achievements that tissue engineering and regenerative medicine have achieved. Adipose-derived mesenchymal stem cells (AD-MSC) are easily isolated and cultured for a long time before losing their stem cell characteristics, which are self-renewal and pluripotency. AD-MSC are mesenchymal stem cells that have pluripotent lineage characteristics. They are easily accessible, and the fraction of stem cells in the adipose tissue lysates is highest among all other sources of mesenchymal stem cells. It is also HLA-DR negative and can be transplanted allogenically without the need for immunosuppression. These advantages have popularized its use in many fields including plastic reconstructive surgery. However, in the field of hepatology and liver transplantation, the progress is slower. AD-MSC have the potential to modulate inflammation, ameliorate ischemia-reperfusion injury, and support liver and biliary tract regeneration. These are very important for the treatment of various hepatobiliary diseases. Furthermore, the anti-inflammatory potential of these cells has paramount importance in the treatment of sepsis. We need alternative therapeutic approaches to treat end-stage liver failure. AD-MSC can provide a means of therapy to bridge to definitive therapeutic alternatives such as liver transplantation. Here we propose to review theoretic applications of AD-MSC in the treatment of hepatobiliary diseases and sepsis.

Alpha lipoic acid priming enhances the hepatoprotective effect of adipose derived stem cells in CCl4 induced hepatic injury in-vitro

Mesenchymal stem cells are known to support hepatic defense against liver fibrosis. However, the fibrosis induced oxidative microenvironment affects the proliferative, regenerative, and angiogenic properties of mesenchymal stem cells. Alpha lipoic acid (ALA) is a strong anti-oxidant which has been shown to ameliorate the adverse effects of fibrosis that otherwise can lead to severe liver problems like cirrhosis and liver failure. Here, we studied the protective role of ALA primed adipose derived stem cells (ADSCs) against carbon tetrachloride (CCl₄₎ induced hepatotoxicity in primary hepatocytes in-vitro. Priming of ADSCs helped to abrogate the damaging effects of fibrosis induced oxidative stress as evidenced by significantly reduced levels of alkaline phosphatase (ALP), Alanine Aminotransferase (ALAT) along with decreased lactate dehydrogenase (LDH) release and improved superoxide dismutase (SOD) activity. ALA and ADSCs synergistically down-regulated the expression of Bax gene, an apoptosis regulator while enhancing cell proliferation by up-regulating the expression of Bcl2l1 gene. This treatment improved the expression of albumin (Alb), cytokeratin-8 (Ck8), and hepatic nuclear factor alpha (Hnf4α). Cytochrome P450 2E1 (Cyp2e1) and Alpha fetoprotein (Afp) were down-regulated to lessen the damage caused by CCl₄ treatment. Furthermore, paracrine release of several growth factors like hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and insulin growth factor (IGF) reinforced the improved response of primary hepatocytes against CCl₄ induced hepatotoxicity in the presence of ALA primed ADSCs. This study suggests that ALA priming may improve the therapeutic potential of ADSCs against chronic liver problems by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant factors heme oxygenase 1 (HO-1) and quinone acceptor oxidoreductase-1 (NQO1).

Mechanisms Underlying Cell Therapy in Liver Fibrosis: An Overview

Fibrosis is a common feature in most pathogenetic processes in the liver, and usually results from a chronic insult that depletes the regenerative capacity of hepatocytes and activates multiple inflammatory pathways, recruiting resident and circulating immune cells, endothelial cells, non-parenchymal hepatic stellate cells, and fibroblasts, which become activated and lead to excessive extracellular matrix accumulation. The ongoing development of liver fibrosis results in a clinically silent and progressive loss of hepatocyte function, demanding the constant need for liver transplantation in clinical practice, and motivating the search for other treatments as the chances of obtaining compatible viable livers become scarcer. Although initially cell therapy has emerged as a plausible alternative to organ transplantation, many factors still challenge the establishment of this technique as a main or even additional therapeutic tool. Herein, the authors discuss the most recent advances and point out the corners and some controversies over several protocols and models that have shown promising results as potential candidates for cell therapy for liver fibrosis, presenting the respective mechanisms proposed for liver regeneration in each case.