Transplantation of human Wharton's Jelly-derived stem cells alleviates chemically induced liver fibrosis in rats.

There is currently no effective treatment method available for liver fibrosis. We therefore evaluated the use of Wharton's jelly stem cells (WJSCs; the major umbilical cord stem cell population) to treat chemically induced liver fibrosis via intraperitoneal injection of thioacetamide. WJSCs were transplanted into liver-damaged rats via the portal vein and the treatment was evaluated by assessing serum biochemistry and histopathology. Transplanted WJSCs were distributed in the fibrotic area and around blood vessels, and hepatic recovery was accelerated. Serum prothrombin time significantly recovered, and serum albumin also improved at 21 days posttransplantation; collagen accumulation also decreased at 14 days. Thus, human WJSCs promoted recovery after chronic liver damage. Using immunohistochemical analyses, we determined that transplanted WJSCs produce albumin, hepatocyte growth factor (HGF), and metalloproteinase (MMP) after transplantation to chemically injured liver, indicating that WJSC may help to decrease liver collagen and thus may be useful for treating liver fibrosis.

Induction and regulation of differentiation in neural stem cells on ultra-nanocrystalline diamond films.

The interaction of ultra-nanocrystalline diamond (UNCD) with neural stem cells (NSCs) has been studied in order to evaluate its potential as a biomaterial. Hydrogen-terminated UNCD (H-UNCD) films were compared with standard grade polystyrene in terms of their impact on the differentiation of NSCs. When NSCs were cultured on these substrates in medium supplemented with low concentration of serum and without any differentiating factors, H-UNCD films spontaneously induced neuronal differentiation on NSCs. By direct suppression of mitogen-activated protein kinase/extracellular signaling-regulated kinase1/2 (MAPK/Erk1/2) signaling pathway in NSCs using U0126, known to inhibit the activation of Erk1/2, we demonstrated that the enhancement of Erk1/2 pathway is one of the effects of H-UNCD-induced NSCs differentiation. Moreover, functional-blocking antibody directed against integrin beta1 subunit inhibited neuronal differentiation on H-UNCD films. This result demonstrated the involvement of integrin beta1 in H-UNCD-mediated neuronal differentiation. Mechanistic studies revealed the cell adhesion to H-UNCD films associated with focal adhesion kinase (Fak) and initiated MAPK/Erk1/2 signaling. Our study demonstrated that H-UNCD films-mediated NSCs differentiation involves fibronectin-integrin beta1 and Fak-MAPK/Erk signaling pathways in the absence of differentiation factors. These observations raise the potential for the use of UNCD as a biomaterial for central nervous system transplantation and tissue engineering.

Mesenchymal stem cells facilitate recovery from chemically induced liver damage and decrease liver fibrosis.

AIMS: To investigate the feasibility and mechanism of liver damage repair using human bone marrow mesenchymal stem cells (hBMMSCs), we investigated the potential for hBMMSCs in recovery from liver damage, including fibrotic liver repair, using the CCl(4)-induced model for liver damage in the rat. MAIN METHODS: Rats were injected with 0.5 ml/kg CCl(4) to induce liver damage and progressive liver fibrosis. hBMMSCs labeled with GFP were injected into the rats through the portal vein. KEY FINDINGS: After one day of transplantation, GFP-labeled cells were found around the liver lobules, the hepatic blood vessels, and the edge of the liver lobes. Biochemical and histopathological analyses showed significantly increased recovery from liver damage in the transplanted group. In addition, transplanted hBMMSCs express matrix metalloproteinases (MMP), and liver fibrosis was significantly decreased. The degree of fibrosis reduction paralleled the number of hBMMSCs observed in liver sections. SIGNIFICANCE: Our data suggest that hBMMSCs may facilitate recovery from chronic liver damage and may decrease liver fibrosis. Therefore, hBMMSCs are a potential option for treatment of liver cirrhosis.