成纤维细胞生长因子在软骨发育过程中的基因芯片分析及相关研究

目的 检测并分析促分裂原活化蛋白激酶(MAPK)信号通路中成纤维细胞生长因子(FGF)在软骨发育过程中的基因表达规律;通过细胞培养观察FGF基因对骨髓基质干细胞(BMSCs)生长特性的影响. 方法用基因芯片技术建立妊娠胎鼠肢芽软骨发育过程的基因表达谱,分析MAPK信号通路中碱性成纤维细胞生长因子(brGF)在软骨发育过程中的基因表达规律.构建bFGF质粒并转染至培养的BMSCs中,用MTT法、免疫组织化学、HE染色、RT-PCR及酶联免疫吸附法检测bFGF基因转染BMSCs的效果及产物表达. 结果 MAPK信号通路中的FGF在软骨发育过程中的软骨形成关键期表达显著上调,并启动MAPK信号通路,促进软骨形成.bFGF基因转染的BMSCs生长活力较强,可以保持2周以上;HE染色显示细胞增殖旺盛,胞核深染;RT-PCR表明有bFGF的基因表达;酶联免疫吸附法检测bFGF表达量高. 结论 FGF能够启动MAPK信号通路从而促进软骨彤成.bFGF质粒转染BMSCs后可促进BMSCs的增殖,细胞有向软骨细胞分化趋势.     

番茄红素对D-半乳糖诱导衰老大鼠椎间盘的影响

目的 观察D-半乳糖诱导衰老大鼠模型椎间盘等的变化及番茄红素对其影响.方法 将30只SD大鼠随机分成对照组、模型组和干预组.模型组和干预组每天颈部皮下注射D-半乳糖,对照组用等量生理盐水替代,干预组每天用番茄红素灌胃.各组每周称体重,12周后处死并取椎间盘及血清观测.结果 与对照组相比,模型组椎间盘明显退变,干预组椎间盘轻微退变;模型组体重减轻(P<0.05)、抗氧化水平下降明显(P<0.05.P<0.01).而干预组较模型组体重及抗氧化水平有所升高(P<0.05·P<0.01).结论 D-半乳糖在诱导大鼠衰老的过程中可诱发椎间盘退变.而番茄红素可延缓椎间盘退变的进展.     

Wilson病病理性脾切除对体液免疫功能的影响

目的探讨肝豆状核变性(肝豆)门脉高压症患者行脾切除术后对机体体液免疫功能的影响。方法回顾分析26例肝豆门脉高压症患者术前1周和行脾切除脾术后3周机体体液免疫功能(IgG、IgA、IgM、C3、C4)的变化。结果肝豆肝硬化门脉高压症患者,脾切除脾术后3周IgA、C3、C4较术前显著升高(P<0.01～0.001),而IgG、IgM无明显变化(P>0.05)。结论肝豆门脉高压症淤血肿大的脾脏对体液免疫功能有抑制作用,脾切除后获得改善。     

股骨头坏死的关节软骨病变研究进展

股骨头坏死治疗方式的选择,应充分考虑到关节软骨的状况。软骨、软骨下皮质骨及软骨下小梁骨在结构和功能上被看成是一个功能单元体。软骨下小梁骨坏死,既改变了关节软骨的载荷传导与分布途径,使相邻的软骨下皮质骨与软骨易于遭受机械性损伤,也破坏了软骨下区的微循环,影响软骨营养的获得及代谢产物的排出,使相邻的软骨下皮质骨与软骨易于遭受代谢性损伤。股骨头骨坏死的临床研究和实验研究显示,股骨头坏死的骨缺损对覆盖其上的邻近关节软骨的结构和代谢有损害作用。     

Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson–dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.     

Dermatan sulfate in the synovial fluid of patients with knee osteoarthritis

Biochemical factors play an important role in osteoarthritis (OA) pathogenesis. The purpose of this study is to clarify whether the dermatan sulfate (DS) levels in the synovial fluid of patients with knee OA are related to residual cartilage. Synovial fluid was obtained from 51 OA patients. Knee radiographs were evaluated with the Kellgren–Lawrence (K/L) grading scale. The levels of the following disaccharides were measured by high-performance liquid chromatography (HPLC): DS (DSΔDi4S), chondroitin 6-sulfate (CSΔDi6S), and chondroitin 4-sulfate (CSΔDi4S). The concentration of cartilage oligomeric matrix protein (COMP) was measured by a sandwich ELISA. The levels of DSΔDi4S in Grades 0 and I OA were significantly higher than levels in Grade II (P = 0.0458), Grade III (P < 0.0001) and Grade IV (P < 0.0001), and we found strong relationships between the levels of DSΔDi4S and those of CSΔDi6S (P < 0.0001, r = 0.705), CSΔDi4S (P < 0.0001, r = 0.750), and COMP (P < 0.0001, r = 0.699). We conclude that the presence of DSΔDi4S reflects proteoglycan metabolism in the residual articular cartilage of OA patients. This suggests that metabolism of the small leucine-rich repeat proteoglycans decorin and biglycan, which contain chains of DSΔDi4S, is similar to that of aggrecan.     

Presence of alpha-globin mRNA and migration of bone marrow cells after sciatic nerve injury suggests their participation in the degeneration/regeneration process

We have previously reported that in the distal stump of ligated sciatic nerves, there is a change in the distribution of myelin basic protein (MBP) and P0 protein immunoreactivities. These results agreed with the studies of myelin isolated from the distal stump of animals submitted to ligation of the sciatic nerve, showing a gradual increase in a 14 kDa band with an electrophoretic mobility similar to that of an MBP isoform, among other changes. This band, which was resolved into two bands of 14 and 15 kDa using a 16% gel, was found to contain a mixture of MBP fragments and peptides with great homology with alpha- and beta-globins. In agreement with these results, we have demonstrated that the mRNA of alpha-globin is present in the proximal and distal stumps of the ligated nerve. It is also detected at very low levels in Schwann cells isolated from normal nerves. These results could be due to the presence of alpha- and/or beta-globin arising from immature cells of the erythroid series. Also, they could be present in macrophages, which spontaneously migrate to the injured nerve to promote the degradation of myelin proteins. Cells isolated from normal adult rat bone marrow which were injected intraortically were found to migrate to the injured area. These cells could contribute to the remyelination of the damaged area participating in the removal of myelin debris, through their transdifferentiation into Schwann cells or through their fusion with preexisting Schwann cells in the distal stump of the injured sciatic nerve.     

Analysis of cerebellar Purkinje cells using EAAT4 glutamate transporter promoter reporter in mice generated via bacterial artificial chromosome-mediated transgenesis

The EAAT4 glutamate transporter helps regulate excitatory neurotransmission and prevents glutamate-mediated excitotoxicity in the cerebellum. Immunohistochemistry and in situ hybridization have previously defined a cerebellar cell population expressing this protein. These methods, however, are not well suited for evaluating the dynamic regulation of the transporter and its gene-especially in living tissues. To better study EAAT4 expression and regulation, we generated bacterial artificial chromosome (BAC) promoter eGFP reporter transgenic mice. Histological analysis of the transgenic mice revealed that the EAAT4 promoter is active predominantly in Purkinje cells, but can also be modestly detected in other neurons early postnatally. EAAT4 promoter activity was not present in non-neuronal cells. Cerebellar organotypic slice cultures prepared from BAC transgenic mice provided a unique reagent to study transporter and Purkinje cell expression and regulation in living tissue. The correlation of promoter activity to protein expression makes the EAAT4 BAC promoter reporter a valuable tool to study regulation of EAAT4 expression.     

The complex aetiology of frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) is now a widely recognised form of dementia. This heterogeneous disease has been of particular interest to geneticists due to its high rate of heritability with up to 40% of patients reporting a family history of the disease in at least one extra family member. There have been several chromosome loci linked to this disorder and three genes have already been identified. Remarkably, it has been recently demonstrated that 2 of these are only 1.7 Mb from one another on chromosome 17q21, these being tau and progranulin. The identification of these genes has contributed greatly to our understanding of the differing neuropathologies associated with FTLD. Furthermore, the discovery that TDP-43 is a component of the neuronal inclusions seen in the most common neuropathological subtype has also helped expand the biochemical pathways that are the focus of much FTLD research. Nevertheless, other genes causing FTLD remain to be identified and their biology elucidated before we have a complete understanding of the complex aetiology of this disease.     

Analysis of connexin subunits required for the survival of vestibular hair cells

Mutations in connexin (Cx) genes are responsible for a large proportion of human inherited prelingual deafness cases. The most commonly found human Cx mutations are either Cx26 or Cx30 deletions. Histological observations made in the organ of Corti of homozygous Cx26 and Cx30 gene knockout mice show that cochlear hair cells degenerate after the onset of hearing. However, it is unclear whether vestibular hair cells undergo similar degeneration in connexin knockout mice. To address this question, we first examined expression patterns of Cx26 and Cx30 in the saccule, utricle, and ampulla by immunolabeling. In wild-type mice, Cx26 and Cx30 immunoreactivity was found extensively in vestibular supporting cells and connective tissue cells, and the two Cxs were co-localized in most gap junction (GJ) plaques. Targeted deletion of the Cx30 gene, which caused little change in Cx26 expression pattern, resulted in a significant and age-related loss of vestibular hair cells only in the saccule. dUTP nick end labeling (TUNEL) staining also revealed on-going apoptosis specifically in saccular hair cells of Cx30(-/-) mice. These results indicated that hair cell survival in the utricle and ampulae does not require Cx30. Importantly, over-expressing the Cx26 gene from a modified bacterial artificial chromosome in the Cx30(-/-) background rescued the saccular hair cells. These results suggest that it is the reduction in the total amount of GJs rather than the specific loss of Cx30 that underlies saccular hair cell death in Cx30(-/-) mice. Hybrid GJs co-assembled from Cx26 and Cx30 were not essential for the survival of saccular hair cells.