THE EXPRESSION AND LOCALIZATION OF LRF IN THE FEMALE REPRODUCTIVE TRACT OF CYCLING MICE THROUGHOUT THE ESTROUS CYCLE

CREBRF regulates apoptosis and estradiol via ISG15/ISGylation in pig granulosa cells

Granulosa cells play a crucial role in the reproductive processes of female animals, as their proliferation, apoptosis, and hormonal secretion are vital for follicular development and ovulation. Although the role and mechanisms of CREBRF in the reproductive system have been partly reported, its functions in ovarian granulosa cells have not been fully explored. In this study, the results indicated that the expression of CREBRF in the ovaries at 30 days after birth was significantly higher than that during puberty and sexual maturity. Studies on the function of CREBRF found that CREBRF could enhance the synthesis of estradiol and had no effect on progesterone synthesis in pig granulosa cells. At the same time, CREBRF could suppress apoptosis through the Bax/caspase3/caspase9 pathway and modulation of ISG15/ISGylation in pig granulosa cells. During this process, the expression of many genes changed in granulosa cells. Several genes (CMPK2, MX1, MX2, ZBP1, PML, CHAC1, and BAX) which were promoted apoptosis, were upregulated after CREBRF knockdown with siRNA. ISG15-protein conjugation genes (HERC5, UBA7, UBE2L6, ISG15) were also were upregulated. On the contrary, the expression of anti-apoptotic (RFK, SNAP23) genes decreased. In conclusion, CREBRF could enhance the synthesis of estradiol and acted as anti-apoptosis role in pig granulosa cells. This discovery can provide novel insights for further elucidating the molecular mechanisms of granulosa cells in the ovary and potentially identifies CREBRF as a molecular target for improving fertility.

Ano1 regulates embryo transport by modulating intracellular calcium levels in oviduct smooth muscle

Oviductal smooth muscle exhibits spontaneous rhythmic contraction (SRC) and controls the passage of the ova at the exact time, but its mechanistic regulation remains to be determined. In this study, female mice with Ano1SMKO (smooth muscle-specific deletion of Ano1) had reduced fertility. Deficiency of Ano1 in mice resulted in impaired oviductal SRC function and reduced calcium signaling in individual smooth muscle cells in the oviduct. The Ano1 antagonist T16Ainh-A01 dose-dependently inhibited SRCs and [Ca2+]i in the oviducts of humans and mice. A similar inhibitory effect of SRCs and [Ca2+]i was observed after treatment with nifedipine. In our study, ANO1 acted primarily as an activator or amplifier in [Ca2+]i and contraction of tubal smooth muscle cells. We found that tubal SRC was markedly attenuated in patients with ectopic pregnancy. Then, our study was designed to determine whether chloride channel Ano1-mediated smooth muscle motility is associated with tubal SRC. Our findings reveal a new mechanism for the regulation of tubal motility that may be associated with abnormal pregnancies such as ectopic pregnancies.

CREB3 regulatory factor -mTOR-autophagy regulates goat endometrial function during early pregnancy

In domestic ruminants, a receptive endometrium is crucial for successful pregnancy. Although many essential molecular modulators and pathways have been identified during early pregnancy, the precise mechanisms regulating goat endometrial function remains largely unknown. Here, we describe a novel regulator during early pregnancy, whereby hormones increased CREB3 regulatory factor (CREBRF) expression and act as a potential activator of autophagy in endometrial epithelial cells (EECs) via the mTOR pathway. Our results showed that knockdown of CREBRF via shCREBRF hampered EECs proliferation by S-phase cell cycle arrest and significantly inhibited endometrial function. We also reported that CREBRF-mTOR-autophagy pathway plays a vital role in regulating endometrial function, with a blockade of the mTOR by rapamycin demonstrating the regulatory function on prostaglandin (PGs) secretion and cell attachment in EECs. Moreover, chloroquine pretreatment also proved the above conclusion. Collectively, our findings provide new insight into the molecular mechanisms of goat endometrial function and indicate that the CREBRF-mTOR-autophagy pathway plays a central role in PGs secretion and cell attachment.

COPS5 negatively regulates goat endometrial function via the ERN1 and mTOR-autophagy pathways during early pregnancy

In ruminant, adequate endometrial function is a major factor affecting implantation and economic efficiency. However, the precise mechanisms regulating goat endometrial function during the peri-implantation period of pregnancy are still unclear. Here, we investigated the functional role and signal transduction of the fifth component of the constitutive photomorphogenic-9 signalosome (COPS5) in the regulation of endometrial function in endometrial epithelial cells (EECs). Our results showed that hormones decreased COPS5 expression, and COPS5-mediated regulation of endometrial function. We also found that knockdown of COPS5 hindered EECs proliferation by the G1-phase cell cycle arrest. Hormones affected the activity of COPS5 through hormones receptors, while feedback from the expression of COPS5 regulated the transcription of the receptor. Moreover, knockdown of endoplasmic reticulum (ER) to nucleus signaling 1 (ERN1) via si-ERN1 partly inhibited endometrial function in shCOPS5 EECs. In addition, blocking the mTOR pathway by rapamycin promoted endometrial function in si-ERN1-transfected shCOPS5 EECs. Overall, these results suggest that COPS5 negatively regulates goat endometrial function via the ERN1 and mTOR-autophagy pathways and provide new insights into the mechanistic pathways of COPS5 during female reproductive development.

Hormone regulates endometrial function via cooperation of endoplasmic reticulum stress and mTOR-autophagy

In ruminant, the receptive endometrium and the elongation of the hatched blastocyst are required to complete the process of implantation. However, the mechanisms regulating goat endometrial function during the peri-implantation period of pregnancy are still unclear. In this study, EECs were treated with progesterone, estradiol, and interferon-tau (IFNT). We have found that endoplasmic reticulum (ER) stress was activated under hormones treatment. To identify the cellular mechanism of regulation of endometrial function, we investigated the effect of ER stress activator thapsigargin (TG) and inhibitor 4 phenyl butyric acid (4-PBA) on EECs. We found that TG, which activated the three branches of UPR, increased the expression of genes associated with promoting conceptus elongation and cellular attachment, significantly up-regulated the spheroid attachment rate and PGE₂ /PGF_2α ratio. 4-PBA pre-treatment inhibited UPR and inhibited promoting conceptus elongation and cellular attachment related genes, but the spheroid attachment rate and PGE₂ /PGF_2α ratio were not changed significantly. Moreover, knockdown of ATF6 via shATF6 promoted the conceptus elongation related genes, but increased the dissolution of the corpus luteum. Besides, blocking ATF6 attenuated autophagy by activating mammalian target of rapamycin (mTOR) pathway. Moreover, rapamycin (mTOR inhibitor) pre-treatment inhibited the expression of promoting conceptus elongation and increased PGE₂ /PGF_2α ratio. Taken together, our study indicated that physiological level of ER stress may contribute to early pregnancy success, and ATF6 signaling pathway cooperated with autophagy to regulate endometrial function by modulating mTOR pathway.

Herp depletion arrests the S phase of the cell cycle and increases estradiol synthesis in mouse granulosa cells

The endoplasmic reticulum (ER) stress response has been implicated in the development, atresia and luteinization of ovarian follicles. However, there have been few reports concerning the role of Herp, an ER stress-induced protein, in follicular development. The present study aims to detect the distribution and cyclic variations of Herp during the estrous cycle and to reveal the roles of Herp in regulating the cell cycle, apoptosis and steroid hormone biosynthesis in mouse granulosa cells. In this study, immunohistochemistry staining showed that Herp expression was primarily in the granulosa cells and oocytes. Furthermore, we constructed recombinant lentiviral vectors for Herp short hairpin interfering RNA (shRNA) expression; immunofluorescence staining, real-time quantitative PCR (RT-qPCR) and western blot analysis revealed that Herp was successfully knocked down. Flow cytometry showed that knockdown of Herp arrested granulosa cells at the S phase of the cell cycle. More importantly, ELISA analysis revealed that Herp knockdown significantly upregulated the concentration of estradiol (E2) in the culture supernatants. RT-qPCR was performed to determine the regulatory mechanism of Herp knockdown in the cell cycle, and in steroid synthesis, RT-qPCR analysis revealed that Herp knockdown upregulated the mRNA expression of steroidogenic enzymes (Cyp19a1) and downregulated metabolic enzymes (Cyp1b1) and cell cycle factors (cyclin A1, cyclin B1 and cyclin D2). These results suggest that Herp may regulate the cell cycle and hormone secretions in mouse granulosa cells. The present study helps to elucidate the physiological functions of Herp as they relate to reproduction.

The Increased Expression of Connexin and VEGF in Mouse Ovarian Tissue Vitrification by Follicle Stimulating Hormone

Ovarian follicular damages were caused by cryoinjury during the process of ovarian vitrification and ischemia/reperfusion during the process of ovarian transplantation. And appropriate FSH plays an important role in antiapoptosis during ovarian follicle development. Therefore, in this study, 0.3 IU/mL FSH was administered into medium during mouse ovarian cryopreservation by vitrification to ascertain the function of FSH on ovarian vitrification and avascular transplantation. The results suggested that the expressions of Cx37, Cx43, apoptotic molecular caspase-3, and angiogenesis molecular VEGF were confirmed using immunohistochemistry, western blotting, and real-time PCR, and the results suggested that the treatment with FSH remarkably increased the number of morphologically normal follicles in vitrified/warmed ovaries by upregulating the expression of Cx37, Cx43, VEGF, and VEGF receptor 2, but downregulating the expression of caspase-3. In addition, the vitrified/warmed ovaries were transplanted, and the related fertility was analyzed, and the results suggested that the fertility, neoangiogenesis, and follicle reserve were remarkably increased in the FSH administrated group. Taken together, administration of 0.3 IU/mL FSH during ovarian cryopreservation by vitrification can maintain ovarian survival during ovarian vitrification and increases the blood supply with avascular transplantation via upregulation of Cx43, Cx37, and VEGF/VEGFR2, as well as through its antiapoptotic effects.

The spatiotemporal expression and localization implicates a potential role for SerpinB11 in the process of mouse spermatogenesis and apoptosis

In this study, the spatiotemporal expression of SerpinB11 in the mouse testis from postnatal 1-60 d was checked, the SerpinB11 protein strongly localized in the intermediate spermatogonia, B-type spermatogonium, preleptotene spermatocyte, leptonema spermatocyte, zygotene spermatocyte, but weakly localized in the pachytene spermatocyte, diplotene spermatocyte, sphere sperm, and the apoptotic sperm was positive stained of SerpinB11 protein, the localization of cell cycle marker CDK4 and meiosis marker SCP3 were investigated, and the SCP3 and SerpinB11 colocalized in the intermediate spermatogonia, B-type spermatogonium, preleptotene spermatocyte. Taken together, these results suggested that SerpinB11 might involved in spermatogenesis and apoptosis.

Reference gene selection for real-time quantitative PCR analysis on ovarian cryopreservation by vitrification in mice

PURPOSE

To ensure the correct interpretation of the results of quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) from ovarian tissue cryopreserved by vitrification, it is critical to normalize expression levels to a reference gene with stable messenger RNA (mRNA) expression in the vitrified/warmed ovarian tissue. The aim of this work was to identify suitable reference genes for qRT-PCR analysis during ovarian cryopreservation by vitrification.

METHODS

GeNorm, NormFinder, comparative Delta-CT, and BestKeeper were used to analyze the expression and stability of the 14 reference genes GAPDH, ABL1, ACTB, CDKN1A, GPER, GUSB, HPRT1, HSP90AB1, IPO8, PPIA, RPL4, RPL30, TBP, and UPAR.

RESULTS

Our results indicated that ACTB and RPL4 were relatively stable reference genes in vitrified/warmed ovaries.