Bovine Granulosa Cell Culture

Changes in adiponectin levels of subclinical ketosis cows and their effects on steroid hormone secretion and proliferation in follicular granulosa cells

In dairy cows, the occurrence of subclinical ketosis (SCK) is particularly high during early lactation. Previously, we documented alterations in the abundance of adiponectin (ADPN) in anestrus cows with SCK in comparison to cows in estrus. In the present study, 60 cows were divided into two groups: control (C, n = 30) and SCK (n = 30). Based on cow's estrus situation in two group at 55-60 days postpartum, 15 anestrus SCK cows and estrus cows were designated the SCK-A group and C-E group, respectively. The SCK-A group had downregulated serum and follicular fluid ADPN levels compared with the C-E group. The serum ADPN level was positively correlated with the insulin level and follicle growth rate, and there was a positive correlation between ADPN and glucose in the follicular fluid. Primary culture of dairy cow granulosa cells (GCs) was established to observe the effect of low glucose (Glu) and/or ADPN on GCs cyclins and proteins important for steroid synthesis. The results showed that the addition of 1 µg/mL ADPN alleviated the negative effects of low Glu treatment on the proliferation of GCs and the expression of steroid secretion related protein proteins. Treatment with LY294002 (PI3K inhibitor) four experimental GCs groups: control (0 µg/mL ADPN), 1 µg/mL ADPN, LY294002 inhibitor, and 1 µg/mL ADPN+LY294002. The results showed that ADPN promotes the secretion of steroid hormones by GCs through the PI3K-AKT. In summary, ADPN plays a crucial role in ameliorating postpartum anestrus in dairy cows with SCK.

The Dynamic Transcription Profiles of Proliferating Bovine Ovarian Granulosa When Exposed to Increased Levels of β-Hydroxybutyric Acid

Ketosis is common in high-yield dairy cows. It is a condition that is characterized by the accumulation of serum β-hydroxybutyric acid (BHBA). Both subclinical ketosis and clinical ketosis can compromise the reproductive performance and cause long-lasting negative effects on reproductive efficiency by affecting the proliferation of follicular and granulosa cells. However, the regulatory mechanisms involved in the development of follicular cells and granulosa cells in cows experiencing subclinical ketosis and clinical ketosis remain largely unknown. To investigate the effect of a ketosis-triggered increase in BHBA on bovine follicular granulosa cell development, we detected a significant reduction in the proliferation of granulosa cells (P < 0.05) in the BHBA-1.2 mM and BHBA-2.4 mM groups and a significant increase in the number of granulosa cells in the G1 phase of the cell cycle (P < 0.05). RNA-seq and trend analysis were used to identify differentially expressed genes by comparing three clusters: low-concentration response to 1.2 mM BHBA, high-concentration response to 2.4 mM BHBA, and the similar trend (up or down) response following BHBA concentration increased. GO and KEGG enrichment analyses were performed separately for each cluster. Analysis showed that two novel down-regulated genes (G0S2 and S100A6), which are associated with cell proliferation and cycle progression, were enriched in the low-concentration response to 1.2 mM BHBA. Another differentially expressed gene (PARP), which plays a role in the apoptotic pathway, was enriched in the high-concentration response to 2.4 mM BHBA. We also found that CYP27B1 and CYP17A1, which are associated with Ca2+ homeostasis and estrogen synthesis, were enriched in a similar trend response. In conclusion, we describe the dynamic transcription profiles of granulosa cells under different levels of β-hydroxybutyric stress and report key regulators that may underlie the detrimental effects on the development of follicles and granulosa cells, thus representing potential therapeutic targets to improve fertility in dairy cows with subclinical ketosis or clinical ketosis.

John EJ, Favetta LA. BPA and BPS Affect Connexin 37 in Bovine Cumulus Cells

Bisphenol S (BPS) is used as an alternative plasticizer to Bisphenol A (BPA), despite limited knowledge of potential adverse effects. BPA exhibits endocrine disrupting effects during development. This article focuses on the impact of bisphenols during oocyte maturation. Connexins (Cx) are gap junctional proteins that may be affected by bisphenols, providing insight into their mechanism during development. Cxs 37 and 43 are crucial in facilitating cell communication between cumulus cells and oocytes. Cumulus-oocyte complexes (COCs), denuded oocytes, and cumulus cells were exposed to 0.05 mg/mL BPA or BPS for 24 h. Both compounds had no effect on Cx43. Cumulus cells exhibited a significant increase in Cx37 expression following BPA (p = 0.001) and BPS (p = 0.017) exposure. COCs treated with BPA had increased Cx37 protein expression, whilst BPS showed no effects, suggesting BPA and BPS act through different mechanisms. Experiments conducted in in vitro cultured cumulus cells, obtained by stripping germinal vesicle oocytes, showed significantly increased expression of Cx37 in BPA, but not the BPS, treated group. BPA significantly increased Cx37 protein expression, while BPS did not. Disrupted Cx37 following BPA exposure provides an indication of possible effects of bisphenols on connexins during the early stages of development.

Quercetin alleviated H2 O2 -induced apoptosis and steroidogenic impairment in goat luteinized granulosa cells

Quercetin (Que) is a natural flavonoid in most plants. Luteinized granulosa cell (LGC) culture is necessary for the study of follicle growth/differentiation. In the present study, we analyzed the role of Que in steroid production and apoptosis in hydrogen peroxide (H2 O2 )-treated goat LGCs. The results showed that treatment with H2 O2 induced apoptosis in goat LGCs, and treatment with Que decreased LGC apoptosis induced by H2 O2 (P < .05), accompanied with the different expressions of BAX, BCL-2, Caspase 3, and Cleaved caspase 3. Meanwhile, the messenger RNA expressions of nuclear factor erythroid 2 like 2 (Nrf2) and its downstream genes were upregulated with H2 O2 +Que treatment, accompanied by the increased cellular viability (P < .05). Furthermore, Que alleviated H2 O2 -induced reduction in the secretion of progesterone (P4 ) (P < .05); however, it had no effect on the secretion of estrogen (E2 ). Simultaneously, the expressions of StAR and P450scc were increased when treated with Que +H2 O2 , compared with the group treated with only H2 O2 (P < .05). In conclusion, it is observed that Que could alleviate the H2 O2 -induced apoptosis and steroidogenic impairment in goat LGCs, which might be mediated by the Nrf2 pathway.

Matrix metallopeptidases regulate granulosa cell remodeling through the hormone signaling pathway

Objective:

Granulosa cells (GCs) play a very important role in reproductive physiology due to their effect on developmental and functional changes. However, there are differing views regarding the mechanism by which hormones stimulate GCs. Therefore, our study aims to determine whether GCs, in the absence of initial stimulation (17β-estradiol), select specific types of MMPs that reconstitute cells by stimulation of major hormones [follicle-stimulating hormone (FSH) or/and luteinizing hormone (LH)].

Materials and methods:

Early GCs were extracted from immature follicles of the porcine ovary to analyze the MMPs levels. Using early GCs in pigs, the cell development rate was evaluated by adding 17β-estradiol, FSH, LH, or FSH + LH, respectively, to the DMEM containing 10% FBS. Real-time PCR, zymography, enzyme-linked immunosorbent assay, western blot, and immunofluorescence analysis were also performed to determine the MMPs activation in the GCs.

Results:

Our results confirm that FSH or LH stimulation regulates cell development and intracellular MMPs. In particular, FSH activity kept the MMP-2 and MMP-9 expressions constant in GCs. Conversely, LH activity initially led to rapid increases in the MMP-9 expression, which 96 h later was similar to the MMP-2 expression. Simultaneous utilization of FSH + LH maintained a steady MMP-9 expression and the development of GCs increased. Additionally, when FSH and LH were processed simultaneously, the number of cells increased without changes in cell size, while the cell size changed when LH alone was used.

Conclusion:

Therefore, the results of this study confirm that even without the initial stimulation of GCs, physiological changes occur according to hormonal changes in the environment, and there is variability in the expression of MMPs.

Expression profiling of primary cultured buffalo granulosa cells from different follicular size in comparison with their in vivo counterpart

This study aimed to: (i) characterize cultured granulosa cells (GCs) from different follicle sizes morphologically and molecularly; and (ii) select a suitable model according to follicular size that maintained GC function during culture. Buffalo ovaries were collected from a slaughterhouse and follicles were classified morphologically into: first group ≤ 4 mm, second group 5-8 mm, third group 9-15 mm and fourth group 16-20 mm diameter. GC pellets were divided into two portions. The first portion served as the control fresh pellet, and the secondwas used for 1 week for GC culture. Total RNA was isolated, and qRT-PCR was performed to test for follicle-stimulating hormone receptor (FSHR), cytochrome P450 19 (CYP19), luteinizing hormone/choriogonadotropin receptor (LHCGR), proliferating cell nuclear antigen (PCNA), apoptosis-related cysteine peptidase (CASP3), anti-Müllerian hormone (AMH), and phospholipase A2 group III (PLA2G3) mRNAs. Estradiol (E2) and progesterone (P4) levels in the culture supernatant and in follicular fluids were measured using enzyme-linked immunosorbent assay (ELISA). Basic DMEM-F12 medium maintained the morphological appearance of cultured GCs. The relative abundance of FSHR, CYP19, and LHCGR mRNAs was 0.001 ≤ P ≤ 0.01 and decreased at the end of culture compared with the fresh pellet. There was a fine balance between expression patterns of the proliferation marker gene (PCNA) and the proapoptotic marker gene (CASP3). AMH mRNA was significantly increased (P < 0.001) in cultured GCs from small follicles, while cultured GCs from other three categories (5-8 mm, 9-15 mm and 16-20 mm) showed a clear reduction (P < 0.001). Interestingly, the relative abundance of PLA2G3 mRNA was significantly (P < 0.001) increased in all cultured GCs. E2 and P4 concentrations were significantly (P < 0.001) decreased in all cultured groups. Primary cultured GCs from small follicles could be a good model for better understanding follicular development in Egyptian buffaloes.