基因表达谱揭示淫羊藿总黄酮对皮质酮大鼠肾上腺皮质再生的调控机制

Exploration on Molecular Mechanism of Epimediun Flavonoids in Regulating Adrenocortical Regeneration in Rats with Inhibited Hypothalamic-Pituitary-Adrenal Axis Using Oligonucleotide Microarrays

目的观察淫羊藿总黄酮(epi medium flavonoids,EF)对皮质酮大鼠肾上腺皮质再生的调控作用。方法采用碘化丙啶染色流式细胞术检测细胞周期分布和细胞凋亡率;用末端转移酶介导的X-dUTP缺口末端标记(TUNEL)法原位显示凋亡细胞;用基因芯片技术检测mRNA表达。结果模型组与正常对照组比较,肾上腺细胞G0/G1期阻滞,凋亡率明显升高(P<0·05);EF干预后G0/G1期比例下降,G2/M期比例显著上升(P<0·01),凋亡率下降(P<0·05)。TUNEL法原位细胞凋亡检测显示正常对照组、模型组、治疗组凋亡阳性细胞数分别为(4·67±1·53)、(70·67±9·29)、(18·67±7·64)个(n=3)。皮质酮主要抑制肾上腺的基因表达,其中7个促进细胞周期的基因如V-ras、V-jun均下调。EF治疗后,肾上腺基因表达以上调为主,其中有6个促进细胞周期基因、1个抗凋亡基因,与肾上腺皮质细胞再生密切相关的上游分子IGF-Ⅱ及其受体IGFR,FGF7及其受体FGFR基因,7个参与类固醇生物合成的基因均上调。结论EF通过促进肾上腺皮质细胞增殖、抑制其细胞凋亡、促进类固醇生物合成,从而促进肾上腺皮质再生是EF在激素撤除过程中发挥保护肾上腺皮质功能的机制。

Objective To investigate the regulatory effects of epimedium flavonoids （EF） on adrenocortical regeneration in rats with inhibited hypothalamic-pituitary-adrenal （HPA） axis. Methods Cell distribution in cell cycle and cell apoptotic rate were measured with PI stain and flow-cytometry; apoptosis cells were showed by in situ terminal-deoxynucleotidyl transferase-mediated deoxy-uridine triphosphate-fluorescene nick end labeling assay （TUNEL）, and the genome-wide gene mRNA expression was detected by oligonucleotide microarrays. Results Compared to the normal control, adrenal cells isolated from the HPA axis inhibited model group were arrested in G0/G1 phase, and showed a higher apoptotic rate （P〈0.05）. After treated with EF, cells in G0/G1 phase decreased and those in G2/M phase increased （P 〈 0.01）, and the elevated apoptotic rate reduced significantly （P 〈 0.05）. TUNEL assay showed the number of apoptotic cells per section was 4.67 ± 1.53 in the normal control group, 70.67 ± 9.29 in the model group, and 18.67 ± 7.64 in the EF-treated group respectively （ n = 3）. Gene expressions in adrenal were mostly restrained in the model group, including 7 cytocycle promoting genes, including V-ras,V-jun, etc. , while after treatment with EF, 6 cytocycle promoting genes, 1 anti-apoptotic gene, and genes that closely related with adrenocortical regeneration as IGF- Ⅱ and FGF7 and their recep- tors, as well as 7 steroid biosynthesis participated genes were all up-regulated. Conclusion EF can accelerate adrenocortical cell proliferation, inhibit its apoptosis, and promote steroid biosynthesis so as to enhance adrenocortical regeneration in HPA axis inhibited rats, which may contribute to the beneficial effects of EF in protecting adrenocortical function during glucocorticoid withdrawal.