The Expression Of SDF-1α And Its Receptor CXCR4 On Bone Marrow Mesenchymal Stem Cells In Patients With Chronic Liver Failure

The first section: the expression of SDF-1αin patients with chronic liver failureBackground: Stem cells homing to the injury tissue may be regulated through stromal cell derived factor-1α(SDF-1α) and its receptor CXCR4. However, little is known about SDF-1αprotein expression in Peripheral blood and liver tissue of patients with chronic liver failure. Objectiv: To investigate the expression of SDF-1αin liver tissues and plasma of patients with chronic liver failure. Methods: Peripheral blood was collected from 12 patients with chronic liver failure, 23 patients with hepatitis B and 8 healthy donors. Plasma SDF-1αlevels were determined by enzyme-linked immunosorbent assay (ELISA). Fresh liver tissues were obtained from 12 patients with chronic liver failure and 4 controls receiving liver resection for benign lesions, SDF-1αwas stainzed by immunohistochemistry methods. Results: The level of SDF-1αexpression in plasma of patients with chronic liver failure was lower than that of the patients with hepatitis B and healthy donors (1629.6±115.3 pg/ml vs 2209.5±89.2 pg/ml, P<0.05), there is no statistical difference between those of the healthy donors and patients with hepatitis B (2448.1±721.3 pg/ml vs 2209.5±89.2 pg/ml, P>0.05). The expression of SDF-1αis greatly higher in tissues of patients with chronic liver failure than the normal liver tissues (P<0.05), and SDF-1αwas mainly expressed in biliary epithelial cells of interlobular and septal bile ducts, hepatic oval cells also strongly expressed SDF-1αprotein. Conclusion: In patients with chronic liver failure, increased expression of SDF-1αin the local injured liver environment along with decreased SDF-1αin the Peripheral blood may create a homing gradient, which facilitates the recruitment of stem cells from the bone marrow into the circulation and then into the liver.The second section: the expression of CXCR4 on the surface of human Bone marrow mesenchymal stem cells in liver failure environmentBackground: Bone marrow mesenchymal stem cells (MSCs) are attractive candidates for cell based therapies. The chemokine SDF-1αand its unique receptor CXCR4 play a critical role in mediating the homing of MSCs to injured tissues. However, only a small proportion of MSCs expresses functionally active CXCR4. We hypothesized the possibility that environment of liver failure may up-regulate CXCR4 on the surface of MSCs. Objective:To detect whether environment of liver failure may up-regulate CXCR4 on the surface of MSCs. Methods: MSCs was isolated from healthy donors and cultured with cell culture technique. MSCs were stimulated with plasma from patient with chronic liver failure, plasma from healthy donor ,IL-6, LPS or TNF-alpha for respectively 48 hours. Cell-surface expression of CXCR4 was assessed by flow cytometry. Results: Human MSCs is fusiform shape under light microscope and dull staining in cytoplasm stained by ALP methods. The expression of CXCR4 of MSCs in groups stimulated with plasma from patient with chronic liver failure for 48 hours, IL-6 and LPS is 28.03±0.45%, 14.17±0.47% and 17.07±0.40%, respectively. In culture media, the expression of CXCR4 is 9.20±0.46%, there is statistical difference between three stimulated groups and control group (P<0.05). The expression of CXCR4 on the surface of MSCs stimulated with TNF-alpha and n plasma from healthy donors is 9.17±0.31% and 8.77±0.45%, respectively. It is no statistical difference compared with control group (P>0.05). Conclusion: MSCs from patients with chronic liver failure may demonstrate enhanced expression of CXCR4 on the surface of MSCs, IL-6 and LPS may be important stimulating factors in this procedure.