神经生长因子抑制肝星状细胞增殖的观察

Effects of nerve growth factor on proliferation of hepatic stellate cells

目的观察神经生长因子（NGF）对大鼠肝星状细胞（HSC）增殖的抑制作用，并探讨其作用机制。方法体外培养大鼠肝星状细胞株HSC—T6，将HSC—T6与不同浓度NGF孵育后，用XTT比色法检测NGF对HSC增殖的影响，流式细胞术分析NGF对HSC细胞周期的影响，透射电镜观察经100ng／mlNGF作用24h后HSC形态学变化。结果（100、200、400）ng／ml浓度时NGF对HSC的抑制作用经XTT法测得爿值分别为0．66±0．03、0．69±0．03和0．66±0．03，与对照组（0．73±0．01）比较，差异具有统计学意义垆〈0．05），但无浓度依赖性垆〉0．05）。100、200、400ng／mlNGF作用于HSC24h后，G2期比例分别为14．83％±5．41％、14．73％±2．50％和14．87％±2．060／0，与对照组（7．47％±4．39％）比较，明显增加妒〈0．0S），透射电镜可以见到细胞凋亡的形态学变化。结论NGF可抑制HSC增殖，通过使HSC细胞周期停滞于G2期而抑制HSC增殖可能为其作用机制之一；经NGF作用的大鼠肝星状细胞可出现明显的增殖受抑、细胞凋亡的形态学改变。

Objective To determine the effects of nerve growth factor （NGF） on proliferation of hepatic stellate cells （HSCs） and investigate the related molecular mechanism. Methods After incubating cultured HSCs for 24 h with different concentrations of NGF （100, 200 or 400 ng/mL）, the cell proliferation was observed by XTT colofimetric assay and cell cycle was detected by flow cytometry. Morphological changes in response to a 24 h exposure to 100 ng/mL NGF were observed by transmission electron microscopy. Results NGF significantly inhibited HSC proliferation （P 〈 0.05） in a dose-independent manner. The optical densities of the XTT color±metric assay were 0.66 ± 0.03 for 100 ng/mL NGF, 0.69 ± 0.03 for 200 ng/mL NGF, and 0.66 ± 0.03 for 400 ng/mL NGF, all of which were significantly lower than that of the control group （0.73 ± 0.01; P 〈 0.05）. All concentrations of NGF led to significantly higher numbers of HSCs in the （32 phase （100 ng/mL： 14.83 ± 5.41%, 200 ng/mL： 14.73 ± 2.50%, and 400 ng/mL 14.87 ± 2.06%）, compared to that detected in the control group （7.47 ± 4.39%; P 〈 0.05）. Twenty-four hours of exposure to 100 ng/mL NGF caused morphological changes indicative of apoptosis. Conclusion NGF inhibits the proliferation of HSCs, possibly by arresting the cells in the G2 phase of the cell cycle. NGF-inhibited cells may also undergo apoptosis.