Effects Of Steroid Hormones And Its Antagonist On The Proliferation Of 3T3-L1 Preadipocytes And Lipid Droplet Formation

For a long time, adipose tissue has been considered the organ of terminal differentiation only for energy supply. However, with the discovery of leptin, TNF-α, adiponectin and resistin etc. some scholars have put forward that adipose tissue is an endocrine organ. In the past ten years, the secretion function of adipose tissue and as endocrine organ the function in many physiological and pathological processes in the body has been attracting much attention. Therefore, as a centre of lipid and energy metabolism hub, lipid drops also more and more get the attention of people. Lipid droplets exist in many tissues and cells, such as adipocytes, liver cells, adrenal cortex, and muscle cells and so on. The lipid droplets in adipocytes and liver cells is an important part in energy storage, the lipid droplets in the adrenal cortex is the materials to supply the synthesis of steroid hormones, and lipid droplets in the macrophages may play a key role in the inflammatory response. This suggests lipid droplets in difference cells hava different function.But several studies by our group found that, goat and mouse cervix during delivery contain fat cells and secrete prostaglandin E2(PGE2), which can affect the cervix mature during delivery and delivery. We also found in the cervix of mouse during delivery that lipid droplets of fat cells become larger and more. The lipid droplets change of cervical fat cells during delivery is associated with the change of hormone level during delivery, at present the reason of lipid droplets change of cervical fat cells during delivery there is no such reports at home and abroad. So the purpose of this study is to verify the affect of reproductive hormones on fat cells proliferation and lipid droplets formation, in order to reveal the source of the fat cells in cervical during delivery and the change of lipid droplets.In this experiment, we put the 3T3-L1 mouse fibroblast as the research object, the 3T3-L1 mouse fibroblast proliferation and differentiation as the main research content. We have 3T3-L1 mouse fibroblasts for subculture, frozen storage and recovery. We put the cells in logarithmic growth phase per well of 4000 to 5000 into 96-well cell culture plate, after 12 hours when the cells attached, add 5 % FBS or without FBS DMEM medium, which adding different molar concentrations(10 nm/L, 20 nm/L, 40 nm/L, 80 nm/L) of progesterone, mifepristone, progesterone+mifepristone, estrogen and dexamethasone and culture the cells 12 hours, 24 hours and 48 hours, and determine under 490 nm photometric by MTT method the affect of progesterone, mifepristone, estrogen and dexamethasone on the 3T3-L1 fibroblast proliferation. The results showed that at 12 hours and 24 hours, 5 % FBS and without FBS with progesterone or mifepristone groups were play a promoting role, and a dose dependent. At 12 hours and 24 hours, 5 % FBS and without FBS with 10 nm/L and 20 nm/L progesterone + mifepristone groups were play a promoting role, and a dose dependent. At 12 hours, 24 hours and 48 hours, 5 % FBS and without FBS with 40 nm/L and 80 nm/L progesterone + mifepristone groups were play a promoting role. At 12 hours and 24 hours, 5 % FBS with estrogen groups had not obvious effect and at 48 hours were play an inhibition role. At 12 hours and 24 hours, without FBS with estrogen groups were play a promoting role, but at 48 hours, converted to inhibition. At 12 hours, 24 hours and 48 hours, 5 % FBS and without FBS with dexamethasone groups were play an inhibition role, and no dose dependent. At the same time, by the comparison between 5 % FBS and without FBS group we found that the hormones in the absence of FBS play a more significant role. These results show that the FBS plays an important role in the process of cell growth. Progesterone, mifepristone promote the growth of 3T3-L1 fibroblasts, make its exit the logarithmic growth phase into recession ahead of time, and in 48 hours showed inhibition; Progesterone and its antagonist mifepristone combined with low dose can promote the growth of 3T3-L1 fibroblasts, high dose inhibit the growth of 3T3-L1 fibroblasts; Estrogen and dexamethasone inhibit the growth of 3T3-L1 fibroblasts.We induce to differentiate the 3T3-L1 fibroblast with the classic cocktail derivation, at the same time add different molar concentration(10 nm/L, 20 nm/L and 40 nm/L, 80 nm/L) of progesterone, mifepristone, progesterone + mifepristone, estrogen and dexamethasone. We observe the 3T3-L1 fibroblasts of differentiation of 2, 4, 6 days with oil red O staining under inverted microscope. The results showed that with the extension of time, the cell count and lipid droplets adding the FBS were more than without FBS group. It showed the FBS is an important nutrition factor in the process of cell growth and differentiation. And compared with the negative 5 % FBS and without FBS group, with the extension of time, progesterone, estrogen and dexamethasone group of lipid droplets quantity increase gradually, promote the 3T3-L1 cell differentiation. Progesterone + mifepristone and mifepristone group has less fat droplets, inhibit the 3T3-L1 cell differentiation.