Luman recruiting factor is involved in stromal cell proliferation during decidualization in mice

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.

Carnitine palmitoyltransferase 1A is essential for decidualization in mice

Decidualization accompanies with extensive stromal cell proliferation and differentiation, is a crucial step in early pregnancy. Aberrant decidualization is linked to infertility and miscarriage but the mechanisms remain unclear. Carnitine palmitoyltransferase 1A (CPT1A) is an enzyme catalyzing key steps in the fatty acid beta-oxidation pathway. The objective of this study was to investigate the role of CPT1A in decidualization during early pregnancy. An increased expression of CPT1A was found both in Days 6 and 7 as compared with in Days 1, 4 and 5. Further examination showed that on days 5-7 of pregnancy, the protein level of CPT1A was strongly up-regulated at implantation sites compared with inter-implantation sites, the location of CPT1A protein was distributed in the decidual zone. Upon further exploration, CPT1A expression was significantly increased in response to artificially induced decidualization both in vivo and in vitro. After down-regulating CPT1A expression by CPT1A-small interfering RNA (siCPT1A) in primary mouse endometrial stromal cells, expressions of decidualization markers and cell proliferation markers were decreased. After siCPT1A was transfected into the mouse uterus, decidualization impaired and then led to the loss of the implanted embryos. Thus, CPT1A is important for decidualization in mice and it may regulate the stromal cell proliferation progress. It is worth noting that the expression of CPT1A protein of human decidua was significantly decreased in spontaneous abortion groups compared to normal pregnancy groups. Collectively, CPT1A is essential for endometrium of early pregnant mice and humans.

A missense variant in CREBRF is associated with taller stature in Samoans

OBJECTIVES

Studies have demonstrated that rs373863828, a missense variant in CREBRF, is associated with a number of anthropometric traits including body mass index (BMI), obesity, percent body fat, hip circumference, and abdominal circumference. Given the biological relationship between height and adiposity, we hypothesized that the effect of this variant on BMI might be due in part to an association of this variant with height.

METHODS

We tested the hypothesis that minor allele of rs373863828 is associated with height in a Samoan population in two adult cohorts and in a separate cohort of children (age 5-18 years old) using linear mixed modeling.

RESULTS

We found evidence of a strong relationship between rs373863828 and greater mean height in Samoan adults (0.77 cm greater average height for each copy of the minor allele) with the same direction of effect in Samoan children.

CONCLUSIONS

These results suggest that the missense variant rs373863828 in CREBRF, first identified through an association with larger BMI, may be related to an underlying biological mechanism affecting overall body size including stature.

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.