| As the primary female sex steroid hormones,estrogens plays an important role to promote the development of female genital organs and the appearance of secondary sexual characteristics and maintain it in the normal state.At the same time,it as an important growth,differentiation and functional regulation of factor,which plays an important role in regulating the immune system and thymus.Thymus is the main target organ of estrogen acting on the immune system.It has been reported that estrogen can alter T cell development and induce thymic atrophy and involution,and the destruction of the thymic microenvironment is the main reason for thymus involution.The thymic epithelial cells(TECs)as an important part of making up thymic microenvironment can support T-cell development and maturation.Although some studies have shown that the proliferation,differentiation and function of TECs are intimately linked to their estrogen sensitivity,the specific mechanism of estrogen acting on TECs is not entirely clear.Therefore,there is a great significance on exploring the mechanism of estrogen acting on TECs for studying the thymus involution and atrophy.In this study,mouse thymic epithelial cell line 1(MTEC1)were regarded as our research object to investigate the effect of 17β-Estradiol on the proliferation of MTEC1 and its possible mechanism.In this study,MTEC1 were treated with different concentration(1-50 nmol/L)of 17β-Estradiol for 6 h,12 h and 24 h,the effect of 17β-Estradiol on MTEC1 cell proliferation,cell viability,cell cycle,mRNA expression profile changes and the Nucleus division were detected by using the methods of CCK-8,Edu,flow cytometry,transcriptome sequencing,qRT-PCR and DAPI staining,the results were as follows:(1)17β-Estradiol could signifycantly change cell morphology,decrease cell viability in both a time-and concentration-dependent manner,especially when 50 nmol/L estrogen acts on MTEC1 cells 24 h,the inhibitory effect is obviously.(2)17β-Estradiol could inhibit cell proliferation and induce G2/M phase arrest in MTEC1 as time went by.(3)17β-Estradiol could induce mRNA expression profile changes,which cause the formation of spindle and the process of cell mitosis failure,and the expression changes of cell cycle regulation relevant genes in MTEC1.(4)17β-Estradiol could activate spindle assemble checkpoint by increase the expression of the spindle checkpoint-related genes mRNA levels,which include Bub1 b,Bub1,Mad1l1,Mad2l1,Cdc20,Ttk,Cenpe and Cyclin B1.17β-Estradiol could significantly inhibit the proliferation of MTEC1 cells by arresting MTEC1 in M phase.(5)17β-Estradiol could induce the formation of giant cells with aberrant nuclear morphology,multiple nuclei and/or several micronuclei and may cause mitotic catastrophe.Conclutions: 17β-Estradiol could inhibit MTEC1 cells proliferation by arresting cells in M phase and may cause cell death by causing cell mitotic catastrophe. |
