A Possible Mechanism for Double-Yolked Eggs in the Early Stage of Egg-Laying in Zhedong White Goose-Function of IGF1 and LHR Signaling.

The cause of double-yolk (DY) egg production in birds is unclear, but it is related to body weight and adiposity. We explored the causes of the high proportion (up to 26%) of DY eggs in the first clutch of Zhedong white geese. We recorded the egg production of Zhedong white geese during the first egg-laying cycle and counted the proportion of DY eggs. We found that 30% of geese had 3 sets of double or triple follicles of the same diameter in the abdomen, which was close to the DY egg rate. In addition, the mRNA expression levels of the steroidogenic acute regulatory protein (StAR) and luteinizing hormone receptor (LHR) genes in granulosa cells were similar within the same set of follicles. Furthermore, the IGF1 concentration in geese that had at least 3 sets of follicles of the same diameter was significantly higher than that in birds with 0-1 set of follicles of the same diameter. Thus, we proposed that, in the first egg-laying stage of geese, high plasma concentrations of IGF1 stimulate the development of pre-hierarchal follicles and cause more than one follicle to be selected at the same time, mature at the same rate under the same gonadotrophin milieu, and ovulate at the same time to produce DY eggs.

Immuno-Neutralization of Follistatin Bioactivity Enhances the Developmental Potential of Ovarian Pre-hierarchical Follicles in Yangzhou Geese.

In order to explore the role of follistatin (FST) in ovarian follicular development and egg production in Yangzhou geese, sixty-four egg laying geese of the same genetic origin were selected and divided into two groups with equal numbers. One group was immunized against the recombinant goose FST protein by intramuscular injection, whereas the control group received bovine serum albumin (BSA) injection. Immunization against FST significantly increased the number of pre-ovulatory follicles. Furthermore, immunization against FST upregulated Lhr, Star, Vldlr, Smad3, and Smad4 mRNA levels in the granulosa layer of pre-hierarchical follicles. The results suggest that FST plays a limiting role in the development of ovarian pre-hierarchical follicles into pre-ovulatory follicles by decreasing follicular sensitivity to activin in geese. The mechanism may be achieved by regulating the SMAD3 signaling pathway, which affects progesterone synthesis and yolk deposition in pre-hierarchical follicles.

Spexin mRNA profile and its response to different photoperiods in Chinese Yangzhou geese (Anas cygnoides).

Spexin (SPX, NPQ), a novel neuropeptide composed of 14 amino acid residues, is evolutionarily conserved among different species. Spexin has been suggested to have pleiotropic functions in mammals. However, reports on spexin in birds are limited. To clarify the role of spexin in goose reproduction, the spexin gene was cloned and analyzed. Analysis of tissue distribution by RT-PCR showed that the expression of spexin and its two receptors was widespread. During the long photoperiod, the expression levels of spexin in the pituitary and hypothalamus and of GALR2/3 in the pituitary decreased, and the GnRH, LHß, and FSHß expression levels increased significantly. This suggests that a long photoperiod regulates reproductive activities by activating the gonadotrope-axis, which is modulated by decreased spexin levels.

CircRNA circ-ATAD1 is downregulated in endometrial cancer and suppresses cell invasion and migration by downregulating miR-10a through methylation.

It has been reported that circ-ATAD1 promotes the development of gastric cancer. This study was carried out to analyze the role of circ-ATAD1 in endometrial cancer (EC). EC and paired non-tumor tissues from EC patients (n = 60) were subjected to the isolation of total RNA and RT-qPCR to analyze the expression of circ-ATAD1 and miR-10a. Correlations between circ-ATAD1 and miR-10a were analyzed by Pearson's correlation coefficient. The effects of circ-ATAD1 overexpression on miR-10a expression and methylation were analyzed by RT-qPCR and methylation-specific PCR (MSP). The roles of circ-ATAD1 and miR-10a in regulating EC cell invasion and migration were analyzed by Transwell assays. We found that circ-ATAD1 was downregulated in EC, while miR-10a was upregulated in EC. An inverse correlation between circ-ATAD1 and miR-10a was observed across EC samples. In EC cells, circ-ATAD1 overexpression decreased miR-10a expression and increased miR-10a gene methylation. Transwell assay analysis showed that circ-ATAD1 overexpression totally reversed the enhancing effects of miR-10a on EC cell invasion and migration. Circ-ATAD1 is downregulated in EC and may suppress EC cell invasion and migration by downregulating miR-10a through methylation.

Upregulation of ITGBL1 predicts poor prognosis and promotes chemoresistance in ovarian cancer.

BACKGROUND: Ovarian cancer remains one of the most lethal malignancies in women and the unfavorable prognosis and frequent recurrence are mainly due to the chemoresistance. However, the main mechanism underlying chemoresistance is still elusive. OBJECTIVE: To determine the role and biological function of ITGBL1 in ovarian cancer chemoresistance. METHODS: Immunohistochemical staining was used to determine the expression of ITGBL1 in ovarian cancer tissues. The association between ITGBL1 expression and clinicopathological features and survival was determined. Functional analysis including cell viability, apoptosis assays were performed after chemo drugs treatment to confirm the role of ITGBL1 in chemoresistance. In vivo tumor growth assay was used to detect the chemosensitivity of tumor cells. Western blot was used to detect the expression of indicated proteins. RESULTS: We noticed that ITGBL1 expression was significantly upregulated in ovarian cancer tissues compared to that in adjacent non-cancer tissues and high expression of ITGBL1 was significantly associated with lymph node invasion and advanced FIGO stage. More importantly, high ITGBL1 was an independent prognostic factor of ovarian cancer. Further experiments demonstrated that ITGBL1 promoted tumor cell resistant to chemo drugs both in vitro and in vivo. Mechanically, we found that ITGBL1 could activate PI3K/Akt signaling and using PI3K/Akt inhibitor could abrogate ITGBL1 induced chemoresistance. CONCLUSIONS: Our findings indicate that upregulation of ITGBL1 has important clinical significance and drives chemoresistance in ovarian cancer. Detection and depletion of ITGBL1 might be the potential approaches for diagnosis and therapy for ovarian cancer patients.