Preliminary Study Of The Role Of Estrogen And Progesterone In Hematopoietic Activity During Pregnancy

Objective:Studies indicated that hematopoietic activity during pregnancy is significantly enhanced,and pregnancy hormone plays an important role in it.However,the underlying mechanisms have not been fully elucidated.The purpose of this study is to investigate the changes of hematopoietic activity during pregnancy and the role of estrogen and progesterone in it.Methods:Collect peripheral blood from normal full-term pregnant women（n=26）and non-pregnant adult women（n=24）.Isolate the peripheral blood mononuclear cells（PBMCs）and use flow cytometry to detect the ratios of Lin^-CD34⁺hematopoietic stem cells（HSCs）and CD71⁺CD235a⁺erythroid precursor cells（EPCs）to mononuclear cells（MNCs）,the ratio of multipotent progenitors（MPPs）to HSCs and the ratios of common myeloid progenitors（CMPs）,megakaryocyte-erythroid progenitors（MEPs）and granulocyte-macrophage progenitors（GMPs）to MPPs,respectively.Futhermore,isolate CD34⁺HSCs from umbilical cord venous blood（n=36）for in vitro expansion and culture in the presence of estradiol（E2）or progesterone（P4）.Utilize no hormones treatment as the control group.Labeled the cells with carboxyfluorescein diacetate succinimidyl ester（CFSE）,the ratio of CFSE^lowcells to total cells in HSCs and proliferation index（PI）of HSCs was detected by flow cytometry after48 hours and 72 hours of culturing.Moreover,cell counting kit（CCK-8）was used to indirectly detect the cell viabiltiy of HSCs by detecting the optical density（OD）values of HSCs at 450 nm on day 3,5 and 7 of culturing,respectively.Meanwhile,flow cytometry was used to directly detect the number of live cells of HSCs and Lin^-cells and detect the ratios of CMPs,MEPs and GMPs to MPPs,respectively.Results:1.Compared with non-pregnant adult women,the ratio of HSCs to MNCs in the peripheral blood of normal full-term pregnant women was significantly increased（P<0.05）,the ratio of MPPs to HSCs had no significant difference.Besides,the ratio of CMPs to MPPs was significantly decreased（P<0.0001）,while the ratios of MEPs and GMPs to MPPs were significantly increased（P<0.0001,P<0.05）.2.Compared with non-pregnant adult women,the ratio of EPCs to MNCs in the peripheral blood of normal full-term pregnant women was significantly increased（P<0.01）.3.Compared with the non-treatment group,after 48 hours and 72 hours of 50 ng/ml E2 treatment,the ratios of CFSE^lowcells to total cells in HSCs were significantly increased（P<0.05,P<0.01）and the PI of HSCs also significantly increased（P<0.05,P<0.01）,while after 72 hours of 500 ng/ml P4 treatment,the ratio of CFSE^lowcells to total cells in HSCs was significantly increased（P<0.05）and the PI of HSCs also significantly increased（P<0.01）.4.Compared with the non-treatment group,after 5 days and 7 days of 50 ng/ml E2 treatment,the OD values of HSCs at 450 nm were significantly increased（P<0.01,P<0.0001）,while after 7 days of 500 ng/ml P4 treatment,the OD value of HSCs at 450 nm was significantly increased（P<0.01）.5.Compared with the non-treatment group,after 5 days and 7 days of 50 ng/ml E2 treatment,the numbers of live cells of HSCs were significantly increased（P<0.01,P<0.01）and the numbers of live cells of Lin^-cells also significantly increased（P<0.01,P<0.01）,while after 7 days of 500 ng/ml P4 treatment,the number of live cells of HSCs was significantly increased（P<0.05）and the number of live cells of Lin^-cells also significantly increased（P<0.05）.6.Compared with the non-treatment group,after 3,5 and 7 days of 50 ng/ml E2 or 500 ng/ml P4 treatment,there was no significant difference in the ratios of CMPs,MEPs and GMPs to MPPs,respectively.Conclusion:1.Women’s hematopoietic activity is significantly enhanced and significantly differentiated into erythroid cells and myeloid cells during pregnancy.2.Estrogen and progesterone may play important roles in hematopoietic activity during pregnancy,estrogen and progesterone can promote the proliferation of HSCs.