Expression and Functional Analysis of the BCL2-Associated Agonist of Cell Death (BAD) Gene in the Sheep Ovary During the Reproductive Cycle

Abstract

Most ewes in China are seasonally polyestrous with normal ovulatory cycles, which is controlled by photoperiod (length of the daily light phase). These ewes are estrous in the short-day season and anestrus in the long-day season and cannot mate during anestrus. Thus seasonal breeding limits both diversification and intensification of production. If sheep can estrus all round year, it can be mated twice per year, which can greatly improve the economic benefits. To change seasonal estrus at the genetic level and cultivating new sheep breeds, it is important to understand the molecular mechanisms of seasonal breeding trait in sheep. The BCL2-associated agonist of cell death (BAD) gene being a regulator of cellular apoptosis was identified by our previous RNA-Seq, which is associated with follicular development in mammalian ovaries. However, the mechanism how BAD can regulate estrus in sheep was poorly understood. In this study, we characterized ovine BAD, including full-length mRNA cloning and protein sequence prediction, as well as BAD expression profile in Small-tailed Han (STH) sheep. The highest expression levels of BAD were observed in sheep hypothalamus, lung, and pituitary, while the lowest expression was in liver. Functional analysis of BAD was performed in primary granulosa cells of sheep. The concentration of P4 was significantly increased after RNAi interference of BAD, while P4 level was shown to be opposite after BAD overexpression in vitro. It has been found that BAD can reduce progesterone levels by promoting ovarian GC apoptosis, which might be involved in regulating the estrus cycle in sheep.

KISS1 Suppresses Apoptosis and Stimulates the Synthesis of E2 in Porcine Ovarian Granulosa Cells

“…In addition, FOXO3 depletion in GCs disrupts the normal ovarian follicular growth in mice [45], and a lower FOXO3 mRNA expression in GCs may lead to infertility in women [46]. BAD can reduce progesterone levels by promoting ovarian GC apoptosis in sheep [47]. Being TSC2-deficient in oocytes results in the depletion of follicles in early adulthood [48].…”

A high-throughput screening approach to discover potential colorectal cancer chemotherapeutics: Repurposing drugs to disrupt 14-3-3 protein-BAD interactions

“…In this study, we utilized a short fragment of murine BAD to construct the BRET sensor rather than the full-length BAD. Previous research has demonstrated that BAD overexpression leads to apoptosis in various cell types [43, 44] , and an advantage of using the BAD-112-136F is its inability to interact with its client BCL-2 proteins due to the lack of BH-3 domain, leading to reduced cytotoxicity [45] . Furthermore, it was not possible to detect BRET when the Rluc8 acceptor and mCitrine donor were fused to 14-3-3ζ and full-length BAD, respectively.…”

Molecular regulation of phenolic compounds on IGF-1 signaling cascade in breast cancer

“…BCL2 is an inducer of cell proliferation and is synthesized in the mitochondria and localized at their membranes through Akt activation, where it influences cell survival by restricting the actions of pro-apoptotic proteins such as BCL2-homologous antagonist/killer (Bak), BCL2-like protein 4 (Bax), and cytochrome c. 73 BAD on the other hand forms a heterodimer with anti-apoptotic protein BCL2 and prevents it from restricting pro-apoptotic proteins. 74 Activation of the PI3K/Akt pathway phosphorylates BAD and restricts its activity. 74 Breast cancers have a high probability of forming metastases, and this is a major factor contributing to the mortality of women suffering from this type of cancer.…”

“…74 Activation of the PI3K/Akt pathway phosphorylates BAD and restricts its activity. 74 Breast cancers have a high probability of forming metastases, and this is a major factor contributing to the mortality of women suffering from this type of cancer. Thus, it is crucial to understand the mechanisms involved in the initiation of metastasis to design therapeutic strategies accordingly.…”