Expression of Mitochondria‐Associated Genes (PPARGC1A,NRF‐1,BCL‐2 and BAX) in Follicular Development and Atresia of Goat Ovaries

Abstract

Most follicles undergo atresia during the developmental process. Follicular atresia is predominantly regulated by apoptosis of granulosa cells, but the mechanism underlying apoptosis via the mitochondria-dependent apoptotic pathway is unclear. We aimed to investigate whether the mitochondria-associated genes peroxisome proliferator-activated receptor-gamma, coactivator1-alpha (PPARGC1A), nuclear respiratory factor-1 (NRF-1), B-cell CLL/lymphoma 2 (BCL-2) and BCL2-associated X protein (BAX) played a role in follicular atresia through this pathway. The four mitochondria-associated proteins (PGC-1α, which are encoded by the PPARGC1A gene, NRF-1, BCL-2 and BAX) mainly expressed in granulosa cells. The mRNA and protein levels of PPARGC1A/PGC-1α and NRF-1 in granulosa cells increased with the follicular development. These results showed that these genes may play a role in the regulation of the follicular development. In addition, compared with healthy follicles, the granulosa cell in atretic follicles had a reduced expression of NRF-1, increased BAX expression and increased ratio of BAX to BCL-2 expression. These results suggested that changes of the mitochondria-associated gene expression patterns in granulosa cells may lead to follicular atresia during goat follicle development.

Quercetin alleviated H2O2‐induced apoptosis and steroidogenic impairment in goat luteinized granulosa cells

“…Goat GCs were collected and cultured as described previously. [ 17 ] Briefly, goat ovaries were collected from a local slaughterhouse and promptly transferred to the laboratory within 1 hour in a 0.9% saline solution. Ovaries were rinsed in 70% ethanol for 10 seconds and then washed five times with DPBS.…”

Dual role for the unfolded protein response in the ovary: adaption and apoptosis

“…Death ligand-receptor and mitochondria-mediated apoptotic systems have been shown to be active in GCs of mammalian ovaries (Manabe et al, 2008; Zhang et al, 2015a). However, several signaling molecules involved in these systems (including JNK, Bcl-2, Bax and TRAF) are also present in the UPR and induce apoptosis (Urano et al, 2000).…”

Effects of NRF1 on steroidogenesis and apoptosis in goat luteinized granulosa cells

“…Banerjee and coworkers (2016) also reported that loss of C/EBPδ increased ionizing radiation and mitochondrial dysfunction, which led to antioxidant defense damage and cell apoptosis. In addition, our previous study showed that abnormal expression of NRF1 led to mitochondrial dysfunction (Zhang et al 2015). These results suggest that aberrant expression of NRF1 alters the intracellular redox balance by mitochondrial dysfunction in goat LGCs.…”

“…Downregulation of NRF1 contributes to mitochondrial dysfunction (Wang et al 2006), while overexpression of NRF1 could protect neuronal cells from MPP + -induced mitochondrial dysfunction (Piao et al 2012). Moreover, our previous study has shown that goat GCs have a reduced NRF1 expression in atretic follicles compared with healthy follicles (Zhang et al 2015). Despite these findings, the regulation of NRF1 in GC apoptosis and follicular atresia remains to be elucidated, especially in goat.…”