大鼠骨髓间充质干细胞成骨分化过程中降钙素基因相关肽受体的表达

[目的]探讨大鼠骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)向成骨细胞分化过程中降钙素基因相关肽(calcitonin gene-related peptide,CGRP)受体的表达变化。[方法]采用全骨髓法体外分离、培养大鼠骨髓间充质干细胞,分为诱导成骨组与未诱导组,在传代培养的不同时期(1、2、3周),采用免疫细胞化学、Western Blot对骨髓间充质干细胞的成骨诱导分化进行鉴定,采用RT-PCR、Western Blot检测各组细胞CGRP受体mRNA、蛋白的表达情况。[结果]RT-PCR结果显示同一时间点诱导组CGRP受体mRNA表达量高于未诱导组,诱导组CGRP受体mRNA表达以时间依赖性的方式不断增高;Western Blot结果显示同一时间点诱导组CGRP受体的蛋白水平高于未诱导组,诱导组CGRP受体蛋白水平以时间依赖性的方式增高。[结论]本实验从mRNA、蛋白水平证实大鼠骨髓间充质干细胞表达CGRP受体,随着成骨诱导的不断进行,CGRP的表达量随之上升。     

RANKL expression is related to the differentiation state of human osteoblasts.

Human osteoblast phenotypes that support osteoclast differentiation and bone formation are not well characterized. Osteoblast differentiation markers were examined in relation to RANKL expression. RANKL expression was induced preferentially in immature cells. These results support an important link between diverse osteoblast functions. Cells of the osteoblast lineage support two apparently distinct functions: bone formation and promotion of osteoclast formation. The aim of this study was to examine the relationship between these phenotypes in human osteoblasts (NHBC), in terms of the pre-osteoblast marker, STRO-1, and the mature osteoblast marker, alkaline phosphatase (AP), and the expression of genes involved in osteoclast formation, RANKL and OPG. The osteotropic stimuli, 1alpha,25(OH)2vitamin D3 (vitD3) and dexamethasone, were found to have profound proliferative and phenotypic effects on NHBCs. VitD3 inhibited NHBC proliferation and increased the percentage of cells expressing STRO-1 over an extended culture period, implying that vitD3 promotes and maintains an immature osteogenic phenotype. Concomitantly, RANKL mRNA expression was upregulated and maintained in NHBC in response to vitD3. Dexamethasone progressively promoted the proliferation of AP-expressing cells, resulting in the overall maturation of the cultures. Dexamethasone had little effect on RANKL mRNA expression and downregulated OPG mRNA expression in a donor-dependent manner. Regression analysis showed that RANKL mRNA expression was associated negatively with the percentage of cells expressing AP (p < 0.01) in vitD3- and dexamethasone-treated NHBCs. In contrast, RANKL mRNA expression was associated positively with the percentage of STRO-1+ cells (p < 0.01). In NHBCs sorted by FACS based on STRO-1 expression (STRO-1bright and STRO-1dim populations), it was found that vitD3 upregulated the expression of RANKL mRNA preferentially in STRO-1bright cells. The results suggest that immature osteoblasts respond to osteotropic factors in a potentially pro-osteoclastogenic manner. Additionally, the dual roles of osteoblasts, in supporting osteoclastogenesis or forming bone, may be performed by the same lineage of cells at different stages of their maturation.     

Natural History of Patients with Recurrent Chronic Hepatitis C Virus and Occult Hepatitis B Co-Infection after Liver Transplantation

It is uncertain whether occult hepatitis B virus co-infection will hasten progressive liver disease in chronic hepatitis C patients after liver transplantation. This study evaluated fibrosis progression and severe fibrosis in 118 consecutive hepatitis B surface antigen-negative patients with virological and histological evidence of recurrent chronic hepatitis C infection co-infected with occult hepatitis B virus after liver transplantation. HBV DNA was detected from serum at the time of recurrent chronic hepatitis C infection by polymerase chain reaction. Each subject underwent a repeat liver biopsy 5 years post-liver transplantation. Occult hepatitis B virus co-infection was present in 41 of the 118 (34.7%) patients. At 5 years post-liver transplantation, 13 of the 41 occult hepatitis B virus co-infected patients compared with 16 of the 77 patients without occult hepatitis B virus co-infection developed fibrosis progression (31.7% vs. 20.8%, respectively, p = 0.39). Eight of 41 the occult hepatitis B virus co-infected patients compared with 13 of the 77 patients without occult hepatitis B virus co-infection had severe fibrosis (19.5% vs. 16.9%, respectively, p = 0.97). In conclusion, occult hepatitis B virus co-infection in patients with recurrent chronic hepatitis C infection was not associated with accelerated fibrosis progression or severe fibrosis after liver transplantation.     

新型钽铌多孔支架材料的细胞生物相容性研究

[目的]研究多孔钽铌(Ta-Nb)材料的细胞相容性。[方法]将兔成骨细胞与多孔钽铌材料共培养,采用CCK-8法检测细胞增殖、扫描电镜观察细胞在材料上的黏附、RT-PCR检测Ⅰ型胶原和骨钙素基因的表达。[结果]CCK-8检测显示实验组多孔钽铌材料上细胞的增殖与空白对照组没有差异性(P﹥0.05);扫描电镜观察到细胞在多孔钽铌的表面和孔隙内大量黏附、增殖和生长,随着共培养时间的增加,材料表面的细胞数量明显增多;RT-PCR显示随着共培养时间的增加,Ⅰ型胶原基因的表达增强(P﹤0.05),骨钙素的表达无明显差异(P﹥0.05)。[结论]多孔钽铌支架材料适于成骨细胞的黏附、生长和分化,具有良好的细胞相容性。     

Hepatitis C-related posttransplant plasma cell proliferative disorder with hepatitis C virus in neoplastic plasma cells: a new posttransplant disease entity?

Plasma cell proliferative disorder (PCPD) developed in two patients with actively replicating hepatitis C virus (HCV) in neoplastic plasma cells after orthotopic liver transplantation for HCV-related end-stage liver disease. PCPD was confined to the transplanted liver and was associated with monoclonal proteins in blood. Bone marrow biopsy did not show any evidence of PCPD. Epstein-Barr virus was not detected by in situ hybridization in either case. In situ hybridization for HCV RNA with sense and antisense probes in liver biopsy specimens showed signals in neoplastic plasma cells as well as in hepatocytes. We suggest that our patients had posttransplant PCPD resulting from HCV. It may represent a new posttransplant disease entity different from previously described posttransplant lymphoproliferative disorder. The findings raise intriguing questions about the role of HCV in PCPDs in patients with chronic HCV infection.