Implantation of Adipose-Derived Stem Cells for Tailored Therapy on Liver Fibrosis

Abstract

Mesenchymal stem cells can be obtained from various adult tissues, and have a potency of multi-lineage differentiation. Among them, adipose-derived stem cells (ADSCs) were known as the most appropriate mesenchymal stem cells for therapeutic application because of rapid proliferation in vitro and harmless acquisition from patients. This study was tried to grope the effective hepatic differentiation using human ADSCs and the new cell implantation for cell therapy on liver fibrosis. For hepatic differentiation of ADSCs, collagen type I (Col I) which is major component in liver extracellular matrix (ECM) was conditioned with various concentration on culture plates. Based on these conditions, hepatic induced hADSCs with Activin A, a member of TGF-β superfamily, and various growth factors such as HGF, bFGF, EGF and OSM for 20 days expressed the bipotential hepatic precursor genes(FOXA2, CK7, SOX17 and CK19) on low concentration of Col I, and the hepatic specific genes(HNF4α, ALB) on high concentration by RT-PCR analysis. In immunocytochemistry assay, the results were similar to gene expressions. Also, on high concentration of Col I, bi-nuclear cells which is hepatic progenitor cells were observed more than low. Accordingly, it was assumed that ECM have the influence for cell differentiation into target tissue, and that Col I based scaffold with bipotential hepatic differentiated hADSCs can induce into functional hepatocytes. And, - 2 - considering of implantation of scaffolds was convinced the enhancing of therapeutic effect and the possibility of development for bio-artificial liver. Scaffolds for cells implantation were produced to disk type porous scaffolds with 5% Col I, and wrapped with nanofiber for prevention the leakage of applied cells to outside. After application of bipotential hepatic differentiated hADSCs and nondifferentiated hADSCs into scaffolds, grafts were implanted into SCID mice which had liver fibrosis by intraperitoneal injection with TAA (thioacetamide) for 6 weeks. Implanted scaffolds were maintained without degradation for 30 days after implantation. And it appeared the stricture with around organs such as liver, spleen and pancreas. In implantation of hepatic differentiated hADSCs applied scaffolds, blood serum albumin significantly increased higher than the datum of non-differentiated hADSCs from post-op 10 days. In comparison with intra-splenic injection, blood serum albumin had higher levels in implantation groups of scaffolds. In these results, the developmental possibility of fundamental bio-artificial liver and the endocrine effect via implanted cells were evaluated.