Gene expression and localization of 20α-hydroxysteroid dehydrogenase (HSD) in reproductive tissues during early pregnancy of cattle

Functional and morphological maturation of the full-sized and mini-pig corpus luteum by programmed cell death mechanism

Introduction

The formation and function of the corpus luteum (CL) increase the likelihood of pregnancy and efficiently manage implantation. Apoptosis must occur at an appropriate time in the formation of the CL. This also affects its function. However, it is still unclear if the type of apoptosis affects the function.

Material and Methods

We conducted morphological analysis of the CL collected on day 15 between the middle and late oestrous phases of Yorkshire pigs and mini-pigs, and measured the difference in hormone expression and apoptosis using an immunoassay method and messenger RNA level.

Results

The CL cells were more uniform in the Yorkshire pigs than in the mini-pigs, and the composition of the CL was also fuller. The expression of luteinising hormone was higher in the Yorkshire pigs. Apoptosis and the rate of action of matrix metalloproteinases (MMPs) were different between the two pig types. Expression of MMPs was higher in the Yorkshire pigs than in the mini-pigs. However, the expression of caspase 3 and 20alpha-hydroxysteroid dehydrogenase, a progesterone inhibitor, was potentiated in the mini-pigs.

Conclusion

Autophagy throughout the CL was more extensive in the Yorkshire pigs than in the mini-pigs, suggesting that autophagy and cell reorganisation by MMPs were highly correlated. The occurrence of autophagy in the formation and function of the CL may affect the action of hormones and expression of cell reconstitution factors.

Reconstitution of Caruncle Placenta through the 20α-HSD/Casp-3 Apoptotic Pathway during Early Pregnancy in Bovines

Trophoblast cells of endometrium during bovine pregnancy with different characteristics undergo dynamic changes during uterine remodeling, which can be observed as continuous changes, as P4 secreted by the mother is replaced by placental hormones. In this context, the present study analyzed tissues' morphological changes through uterine apoptosis during early pregnancy. In addition, the expression pattern associated with apoptosis genes and 20α-HSD was determined in the endometrium and caruncle tissues. The localization of 20α-HSD, VEGF, Casp3, and mTOR protein was also determined in endometrium and caruncle during early pregnancy. From around 30 days, caruncle trophoblast cells with very high invasiveness expanded the villus section as the gestation period progressed. The surrounding cells detached and reorganized into new cells. In addition, an analysis of the effect of apoptosis on cell reorganization in the caruncle revealed that the expression of 20α-HSD/Casp-3 signals in the villus section gradually increased from 30 to 90 days. However, on the 30th day, glandular epithelial cells occurred sporadically in the trophoblast cell section. Moreover, the apoptosis of trophoblast cells increased at 90 days. Taken together, the results of the present study show that changes in the uterus during early pregnancy promote changes during later pregnancy by inducing the reorganization through the stimulation of 20α-HSD and Casp-3, promoting uterine and caruncle tissues, unlike cell development mediated by hormone signaling.

Regulation of uterine function during estrous cycle, anestrus phase and pregnancy by steroids in red deer (Cervus elaphus L.)

Steroid synthesis and production in ruminant uterus is not obvious, especially in seasonally reproduced. We compared steroid production by investigating enzymes involved in red deer uterine steroid metabolism in reproductive seasons. Blood and uteri (endometrium and myometrium) were collected post mortem from hinds on 4th day (N = 8), 13th day of the cycle (N = 8), anestrus (N = 8) and pregnancy (N = 8). The expression of cytochrome P450 aromatase (P450), 3 -beta-hydroxysteroid dehydrogenase (3β-HSD), 17 -beta-hydroxysteroid dehydrogenase (17β-HSD), aldo-keto reductase family 1 C1 (AKR1C1), estrogen receptor alpha (ERα), and progesterone receptors (PRs), were analyzed using real-time-PCR and Western Blotting. Plasma samples were assayed for 17-beta-estradiol (E2), progesterone (P4), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T4) concentrations by EIA. Hinds at the beginning of the estrous cycle, mainly in endometrium, were characterized by a high mRNA expression of 3β-HSD, AKR1C1, PRs and ERα, contrary to the expression in myometrium during pregnancy (P < 0.05). For P4, E2, and FSH, concentration was the highest during the 13th day of the estrous cycle (P < 0.05). Uterine steroid production and output in hinds as a representative seasonally reproduced ruminant occurred mainly during the estrous cycle and sustained in anestrus.

Expression of matrix metalloproteinases to induce the expression of genes associated with apoptosis during corpus luteum development in bovine

Here we investigated the expressions of apoptosis-associated genes known to induce programed cell death through mRNA expressions of two matrix metalloproteinases (MMPs) that are involved in the degradation of collagen and basal membrane in luteal cells cultured in the treatment media. Our results show that the activity of MMP-2 gelatinase was higher in the CL2 and CL1 of luteal phase, was gradually decreased in the CH2 and CH3 of luteal phase. In particular, the expressions of P4-r and survival-associated genes (IGFr, PI3K, AKT, and mTOR) were strongly induced during CL3 stage, whereas the levels of these genes in corpus luteum (CL) were lower during CL2 and CL1 stages. In the cultured lutein cells analyzed, we found that as MMPs increase, genes related to apoptosis (20α-hydroxy steroid dehydrogenase and caspase-3) also increase. In other words, the results for P4-r and survival-related gene expression patterns in the luteal cells were contrary to the MMPs activation results. These results indicate that active MMPs are differentially expressed to induce the expression of genes associated with programed cell death from the degrading luteal cells. Therefore, our results suggest that the MMPs activation may lead to luteal cell development or death.

Characterization of transgenic mice expressing EGFP under the control of the monkey 20α-hydroxysteroid dehydrogenase promoter

To directly assess the molecular function of the monkey 20α-hydroxysteroid dehydrogenase (20α-HSD) promoter, we generated transgenic mice (tg) expressing enhanced green fluorescent protein (EGFP) under control of this promoter. We demonstrated that prostaglandin F₂α induced 20α-HSD promoter activity in CHO cells in a dose-dependent manner. Furthermore, forskolin treatment markedly reduced 20α-HSD promoter activity, and prolactin exhibited weak inhibitory activity. The transgenic mouse obtained one positive founder male. The transgene was propagated in 10 successive generations without any notable defects to the progeny. EGFP and 20α-HSD in the tg mice were colocalized in the luteal cells of the ovary during late pregnancy. Strong EGFP and 20α-HSD protein signals were also detected in the adult testis. Immunohistochemical analysis revealed high EGFP levels in the seminiferous epithelium, whereas 20α-HSD was expressed in the seminiferous tubules. Our data suggest that the ovaries in monkey and mouse exhibit similar expression patterns of 20α-HSD during pregnancy. However, the expression pattern of EGFP in tg mice testis slightly differed from that of the endogenous 20α-HSD. Further investigation is required to elucidate the functional mechanisms underlying regulation of the monkey 20α-HSD promoter in the tg mice.