Notch信号通路参与卵巢生殖干细胞的调控及卵巢的衰老进程

卵巢生殖干细胞(ovarian germline stem cells, OGSCs)的发现,打破了生殖医学领域传统的"固定卵泡池"理论。近年来,OGSCs新的研究成果不断涌现,但关于OGSCs体内调控机制的研究仍然较少。Notch通路广泛参与多种成体干细胞不对称分裂的过程,并与细胞衰老密切相关,但其是否参与OGSCs的体内调控机制及卵巢的衰老进程尚不清楚。本研究以原代培养技术提取OGSCs,通过荧光双标染色发现,OGSCs标志基因MVH、Oct4与Notch信号通路相关分子Notch1、Hes1在OGSCs中存在共表达;抑制Notch信号通路活性后,cck-8检测发现,OGSCs的增殖活性呈下降趋势;而以免疫组化、荧光双标、Western印迹法检测性成熟期(2月龄)、不孕和衰老(20月龄)小鼠卵巢皮层中MVH、Oct4、Notch1和Hes1的表达变化,发现2月龄小鼠卵巢皮层中MVH、Oct4、Notch1和Hes1的表达量较高(P<0.05),而不孕和衰老小鼠卵巢皮层中,MVH、Oct4、Notch1和Hes1的表达量均明显下降。上述结果表明,Notch信号通路在小鼠OGSCs中高表达,并可能参与调控OGSCs的增殖机制及卵巢的衰老进程。

The Notch Signaling Pathway is Involved in the Regulation of Ovarian Germline Stem Cells and the Aging Process of Ovaries

The discovery of ovarian germline stem cells (OGSCs) revolutionizes the traditional theory in the field of reproductive. In recent years, many research results of OGSCs have been proposed, but studies on the regulatory mechanisms of OGSCs in vivo are still limited. The Notch signaling pathway is involved in the asymmetric division of many adult stem cells widely, and it is closely related to cellular senescence. However, whether it regulates OGSCs in vivo and the aging process of ovaries is not clear. In this study, OGSCs were extracted by the primary culture technique, and we found that OGSC marker genes MVH,Oct4 and the Notch pathway-related molecules Notch1 and Hes1 co-localized by immunofluorescence staining. After inhibiting the activity of the Notch pathway, the proliferation activity of OGSCs detected by cck-8 was down-regulated. Subsequently, the expressions of MVH, Oct4 and Notch1, Hes1 in the ovarian cortex of mice with sexual maturity (2 months old), infertility and aging (20 months old) were detected by immunohistochemical, immunofluorescence staining and Western blotting. The expression levels of MVH, Oct4, Notch1, and Hes1 in the ovarian cortex of two-month-old mice was higher, while these in infertile mice and 20-month-old mice was significantly decreased. These results indicate that the Notch signaling pathway is highly expressed in mouse OGSCs, and may be involved in the proliferation mechanism of OGSCs and the aging process of ovaries.