Morphological analysis of intranuclear bFGF

本项目旨在探讨核内bFGF在小脑浦肯野细胞发育、肝细胞再生和成肌细胞再生中的作用。出生后第7天，通过小脑皮质鉴定出具有免疫反应性的浦肯野细胞，它们主要在顶端细胞质和近端树突表达bfgf样免疫反应性。从出生后第14天到出生后第28天，浦肯野细胞的细胞质和细胞核均可见bfgf样免疫反应性。统计分析显示，有核bfgf免疫反应的浦肯野细胞在出生后第21天达到高峰。第42天后，具有核nFGF的浦肯野细胞数量明显减少。利用bFGF进行再生肝细胞免疫印迹实验和ELISA检测显示，在部分肝切除术后48小时，再生肝核亚细胞部分中bFGF的高分子量瞬间增加。光镜下观察肝切除核组织中bFGF和PCNA的免疫反应。电镜显示bfgf样免疫反应性主要发生在核常染色质中，很少发生在再生肝细胞的异染色质或核仁中。这些结果提示高分子量形式的bFGF在肝细胞增殖和有丝分裂中起重要作用。采用免疫印迹法和电镜观察出生后第28天mdx营养不良小鼠咬肌中bfgf样免疫反应的定位。电镜下，在小的再生肌细胞中检测到bFGF的免疫反应性，而具有致密肌丝的成熟肌细胞不表现出bFGF的免疫反应性。研究了阻断bFGF与其受体结合的血小板因子4 （PF4）对成肌细胞培养的影响。bFGF刺激成肌细胞增殖和肌管形成，而PF4抑制bFGF的这些作用。生物特异性相互作用分析（BIA）核心系统显示成肌细胞膜部分含有bfgf结合元件，这些元件被PF4阻断。少

This project was performed to investigate the function of intranuclear bFGF in developing cerebellar Purkinje cell, regenerating hepatocyte and myoblast.1.Development of Purkinje cells with bFGFGOn postnatal day 7, immunoreactive Purkinje cells were identified throught cerebellar cortex, and they expressed bFGF-like immunoreactivity mainly in the apical cytoplasm and proximal dendrites. From postnatal day 14 to postnatal day 28, bFGF-like immunoreactivity was noted throughout the cytoplasm and nuclei of Purkinje cells. Statistical analysis showed that Purkinje cells with nuclear bFGF-immunoreaction peaked on postnatal day 21. After postnsl day 42, Purkinje cells with nuclear nFGF showed a marked decrease in number.2.Regenerating hepatocytes with bFGFImmunoblot experiments and ELISA showed a transient increase in high-moleculae-weight froms of bFGF in the nuclear subcellular fraction of regenerating liver 48h after partial hepatectomy. By light microscopy, bFGF and PCNA immunoreactiviti … More es were detected in the nuclei of hepatectomy. Electron microscopy demonstrated bFGF-like immunoreactivity mainly in the nuclear euchromatin and rarely in the heterochromatin or nucleoli of regenerating hepatocytes. These results suggest an important role of the high-molecular-weight forms of bFGF in hepatocyte proliferation and mitosis.3.Myogenic activity of bFGFThe localization of bFGF-like immunoreactivity in the masseter muscle of dystrophic mdx mice on postnatal day 28 was investigated by immunoblot analysis and electron microscopy. By electron microscopy, bFGF immunoreactivity was detected in small regenerating myocytes, and mature myocytes with densely packed myofilaments did not exhibit bFGF immunoreactivity. The effect or bFGF and platelet factor 4 (PF4), which blocks the binding of bFGF to its receptor, on myoblast culture was investigated. bFGF stimulated myoblast proliferation and myotube formation, but PF4 inhibited these effects of bFGF.The biospecific interaction analysis (BIA) core system showed that the myoblast membrane fraction contains bFGF-binding elements which are blocked by PF4. Less