UCHL1 promotes the proliferation of porcine granulosa cells by stabilizing CCNB1

Background The proliferation of porcine ovarian granulosa cells(GCs)is essential to follicular development and the ubiquitin–proteasome system is necessary for maintaining cell cycle homeostasis.Previous studies found that the deubiquitinase ubiquitin carboxyl-terminal hydrolase 1(UCHL1)regulates female reproduction,especially in ovarian development.However,the mechanism by which UCHL1 regulates porcine GC proliferation remains unclear.Results UCHL1 overexpression promoted GC proliferation,and knockdown had the opposite effect.UCHL1 is directly bound to cyclin B1(CCNB1),prolonging the half-life of CCNB1 and inhibiting its degradation,thereby promoting GC proliferation.What's more,a flavonoid compound-isovitexin improved the enzyme activity of UCHL1 and promoted the proliferation of porcine GCs.Conclusions UCHL1 promoted the proliferation of porcine GCs by stabilizing CCNB1,and isovitexin enhanced the enzyme activity of UCHL1.These findings reveal the role of UCHL1 and the potential of isovitexin in regulating proliferation and provide insights into identifying molecular markers and nutrients that affect follicle development.

miR-24-3p promotes proliferation and inhibits apoptosis of porcine granulosa cells by targeting P27

Ovarian follicle development is associated with the physiological functions of granulosa cells(GCs),including proliferation and apoptosis.The level of miR-24-3p in ovarian tissue of high-yielding Yorkshire×Landrace sows was significantly higher than that of low-yielding sows.However,the functions of miR-24-3p on GCs are unclear.In this study,using flow cytometry,5-ethynyl-2′-de-oxyuridine(EdU)staining,and cell count,we showed that miR-24-3p promoted the proliferation of GCs increasing the proportion of cells in the S phase and upregulating the expression of cell cycle genes,moreover,miR-24-3p inhibited GC apoptosis.Mechanistically,on-line prediction,bioinformatics analysis,a luciferase reporter assay,RT-qPCR,and Western blot results showed that the target gene of miR-24-3p in proliferation and apoptosis is cyclin-dependent kinase inhibitor 1B(P27/CDKN1B).Furthermore,the effect of miR-24-3p on GC proliferation and apoptosis was attenuated by P27 overexpression.These findings suggest that miR-24-3p regulates the physiological functions of GCs.

CLOCK inhibits the proliferation of porcine ovarian granulosa cells by targeting ASB9

Background Clock circadian regulator(CLOCK)is a core factor of the mammalian biological clock system in regulat-ing female fertility and ovarian physiology.However,CLOCK’s specific function and molecular mechanism in porcine granulosa cells(GCs)remain unclear.In this study,we focused on CLOCK’s effects on GC proliferation.Results CLOCK significantly inhibited cell proliferation in porcine GCs.CLOCK decreased the expression of cell cycle-related genes,including CCNB1,CCNE1,and CDK4 at the mRNA and protein levels.CDKN1A levels were upregulated by CLOCK.ASB9 is a newly-identified target of CLOCK that inhibits GC proliferation;CLOCK binds to the E-box element in the ASB9 promoter.Conclusions These findings suggest that CLOCK inhibits the proliferation of porcine ovarian GCs by increasing ASB9 level.

Sirtuin 3 regulation:a target to alleviateβ-hydroxybutyric acid-induced mitochondrial dysfunction in bovine granulosa cells

Background During the transition period,the insufficient dry matter intake and a sharply increased in energy consumption to produce large quantities of milk,high yielding cows would enter a negative energy balance(NEB)that causes an increase in ketone bodies(KBs)and decrease in reproduction efficiency.The excess concentrations of circulating KBs,represented byβ-hydroxybutyric acid(BHBA),could lead to oxidative damage,which potentially cause injury to follicular granulosa cells(fGCs)and delayed follicular development.Sirtuin 3(Sirt3)regulates mitochondria reactive oxygen species(mitoROS)homeostasis in a beneficial manner;however,the molecular mechanisms underlying its involvement in the BHBA-induced injury of fGCs is poorly understood.The aim of this study was to explore the protection effects and underlying mechanisms of Sirt3 against BHBA overload-induced damage of fGCs.Results Our findings demonstrated that 2.4 mmol/L of BHBA stress increased the levels of mitoROS in bovine fGCs.Further investigations identified the subsequent mitochondrial dysfunction,including an increased abnormal rate of mitochondrial architecture,mitochondrial permeability transition pore(MPTP)opening,reductions in mitochondrial membrane potential(MMP)and Ca^(2+)release;these dysfunctions then triggered the caspase cascade reaction of apoptosis in fGCs.Notably,the overexpression of Sirt3 prior to treatment enhanced mitochondrial autophagy by increasing the expression levels of Beclin-1,thus preventing BHBA-induced mitochondrial oxidative stress and mitochondrial dysfunction in fGCs.Furthermore,our data suggested that the AMPK-mTOR-Beclin-1 pathway may be involved in the protective mechanism of Sirt3 against cellular injury triggered by BHBA stimulation.Conclusions These findings indicate that Sirt3 protects fGCs from BHBA-triggered injury by enhancing autophagy,attenuating oxidative stress and mitochondrial damage.This study provides new strategies to mitigate the fGCs injury caused by excessive BHBA stress in dairy cows with ketosis.

Effect of Mitochondrial Function of Ovarian Granulosa Cells on In Vitro Fertilization and Embryo Transfer Outcomes in Obese Polycystic Ovary Syndrome Patients

Objective:To investigate the effect of abnormal ovarian granulosa cell metabolism on in vitro fertilization and embryo transfer(IVF-ET)outcomes in obese polycystic ovary syndrome(PCOS)patients.Methods:Patients with PCOS who met the study criteria were screened according to the inclusion criteria.A total of 32 patients with obese PCOS were recruited into the study group,and 39 patients with non-obese PCOS were recruited into the control group.The general data(age,body mass index,and years of infertility),insulin resistance index(HOMA-IR),follicle-stimulating hormone(FSH),luteinizing hormone(LH),granulosa cell mitochondrial function,and IVF-ET outcome of patients in the study group and control group were retrospectively analyzed.Results:The differences in age and years of infertility between the study group and the control group were insignificant(P>0.05),and the body mass index(BMI)of the study group and control group was 30.5±1.24 kg/m2 and 22.3±1.12 kg/m2,respectively,in which the difference was statistically significant(P<0.05);the HOMA-IR of the study group was significantly higher than that of the control group(P<0.05);the reactive oxygen species(ROS)in the study group was significantly higher than that in the control group(P<0.05),and the ATP content in the study group was significantly lower than that in the control group(P<0.05);comparing the FSH and LH levels between the two groups,the difference was not statistically significant(P>0.05);the rate of IVF-ET failure was significantly higher in the study group than in the control group.Conclusion:PCOS is a complex endocrine disorder,and obesity is one of the independent risk factors for the development of PCOS.

Improvement of in vitro Cytoplasmic Maturation of Denuded Porcine Oocytes by Coculture with Follicular Mural Granulosa Cells

[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first polar body extrusion rate, oocyte glutathione （GSH） content, positive rate of brilliant cresyl blue （BCB） staining and development potential of activated oocytes or fertilized oocytes were employed as main indicators to investigate the effects of follicular mural granulosa cell （MGC） coculture on cytoplasmic maturation of cumulus cell-removal oocytes （Denuded Oocyte, DO）. [Result] According to in vitro maturation results, compared with DO group, the first polar body extrusion rate of porcine oocytes in DO＋MGC group was not significantly different, but the nuclear maturation process was improved and was more similar to that in COC （cumulus-oocyte complex） group. Detection of GSH content in mature oocytes showed that there was no significant difference between DO＋ MGC group （optical density of 1 053.67） and COC group （optical density of 1 426.00） or between DO＋MGC group and COC＋GC group （optical density of 1 541.00）, however, GSH content in mature oocytes of DO group （optical density of 724.67） was significantly lower than that of COC group and COC＋GC group （P0.05）. Detection of glucose-6-phosphate dehydrogenase （G6PDH） activity showed that there was no significant difference in BCB positive oocyte rate between DO ＋MGC group （88.26% ） and COC group （92.75%） or between DO＋MGC group and DO group （82.86% ）, however, BCB positive oocyte rate of DO group was significantly lower than that of COC group （P0.05）. Furthermore, the cleavage rate and blastocyst rate of activated mature oocytes derived from DO ＋MGC group （94.98% and 43.67% , respectively） were significantly higher than those from DO group （52.54% and 8.97%, respectively） （P0.05）, and were not significantly different compared with those from COC group （97.11% and 38.30%, respectively）. In addition, the cleavage rate of fertilized oocytes derived from DO＋MGC group （72.65%） showed no significant difference compared with that from DO group （63.59%）, but the blastocyst rate of DO＋MGC group was significantly higher than that of DO group （9.88%） （P0.05）. [Conclusion] MGC coculture can significantly improve the in vitro cytoplasmic maturation quality of denuded porcine oocytes, thereby enhancing the subsequent developmental potential.

Effects of Downregulation of Inhibin α Gene Expression on Apoptosis and Proliferation of Goose Granulosa Cells

Inhibin a is one of the candidate genes that control the ovulation in poultry. To study the genetic effects of inhibin a on apoptosis and proliferation of goose granulosa cells cultured in vitro, two RNA interference （RNAi） expression vectors, psiRNA-INHal and psiRNA-INHα2, were constructed to knock down inhibin α gene expression. After 48 h of transfection, the efficiency of these two RNAi expression vectors was examined by fluorescence microscopy. Meanwhile, inhibin protein expression levels, apoptosis indexes （AI） and proliferation indexes （PI） of granulosa cells were analyzed by flow cytometry. In addition, the supernatants were collected to assay the concentrations of estrogen （E2） and progesterone （P） by radioimmunoassay. The results showed that the expression level of inhibin a in the RNAi group were decreased 30%--40% than those in the control groups （P 〈0.05） and the apoptosis indexes and proliferation indexes in the RNAi groups were significantly higher than those in the control groups （P 〈0.05）. However, the E2 concentrations in the RNAi groups were lower than those in the control groups （P 〈0.05）. These results indicate that inhibin a has antagonistic effect on granulosa cell apoptosis.

MiR-214-3p promotes proliferation and inhibits estradiol synthesis in porcine granulosa cells

Background: Granulosa cells(GCs) proliferation and estradiol synthesis significantly affect follicular development.The miR-214-3p expression in the ovarian tissues of high-yielding sows is higher than that in low-yielding sows,indicating that miR-214-3p may be involved in sow fertility. However, the functions and mechanisms of miR-214-3p on GCs are unclear. This study focuses on miR-214-3p in terms of the effects on GCs proliferation and estradiol synthesis.Results: Our findings revealed that miR-214-3p promotes proliferation and inhibits estradiol synthesis in porcine GCs. MiR-214-3p can increase the percentage of S-phase cells, the number of EdU labeled positive cells, and cell viability. However, E2 concentration was reduced after miR-214-3p agomir treatment. We also found that miR-214-3p up-regulates the expression of cell cycle genes including cell cycle protein B(Cyclin B), cell cycle protein D(Cyclin D), cell cycle protein E(Cyclin E), and cyclin-dependent kinase 4(CDK4) at the transcription and translation levels, but down-regulates the mRNA and protein levels of cytochrome P450 family 11 subfamily A member 1(CYP11A1), cytochrome P450 family 19 subfamily A member 1(CYP19A1), and steroidogenic acute regulatory protein(StAR)(i.e., the key enzymes in estradiol synthesis). On-line prediction, bioinformatics analysis, a luciferase reporter assay, RT-qPCR, and Western blot results showed that the target genes of miR-214-3p in proliferation and estradiol synthesis are Mfn2 and NR5A1, respectively.Conclusions: Our findings suggest that miR-214-3 p plays an important role in the functional regulation of porcine GCs and therefore may be a target gene for regulating follicular development.

Effects of miR-101-3p on goat granulosa cells in vitro and ovarian development in vivo via STC1

Background:MiRNAs act as pivotal post-transcriptional gene mediators in the regulation of diverse biological processes,including proliferation,development and apoptosis.Our previous study has showed that miR-101-3p is differentially expressed in dairy goat ovaries compared single with multiple litters.The objective of this research was to explore the potential function and molecular mechanism of miR-101-3p via its target STC1 in goat ovarian growth and development.Results:cDNA libraries were constructed using goat granulosa cells transfected with miR-101-3p mimics and negative control by RNA-sequencing.In total,142 differentially expressed unigenes(DEGs)were detected between two libraries,including 78 down-regulated and 64 up-regulated genes.GO and KEGG enrichment analysis showed the potential impacts of DEGs on ovarian development.STC1 was singled out from DEGs for further research owing to it regulates reproductive-related processes.In vitro,bioinformatics analysis and 3′-UTR assays confirmed that STC1 was a target of miR-101-3p.ELISA was performed to detect the estrogen(E2)and progesterone(P4)levels.CCK8,EdU and flow cytometry assays were performed to detect the proliferation and apoptosis of granulosa cells.Results showed that miR-101-3p regulated STAR,CYP19A1,CYP11A1 and 3β-HSD steroid hormone synthesis-associated genes by STC1 depletion,thus promoted E2 and P4 secretions.MiR-101-3p also affected the key protein PI3K,PTEN,AKT and mTOR in PI3K-AKT pathway by STC1,thereby suppressing proliferation and promoting apoptosis of granulosa cells.In vivo,the distribution and expression levels of miR-101-3p in mouse ovaries were determined through fluorescence in situ hybridisation(FISH).Immunohistochemistry results showed that STC1 expression was suppressed in mouse ovaries in miR-101-3p-agonist and siRNA-STC1 groups.Small and stunted ovarian fragments,decreased numbers of follicles at diverse stages were observed using Hematoxylin-eosin(HE)staining,thereby showing unusual ovarian development after miR-101-3p overexpression or STC1 depletion.Inhibition of miR-101-3p manifested opposite results.Conclusions:Taken together,our results demonstrated a regulatory mechanism of miR-101-3p via STC1 in goat granulosa cells,and offered the first in vivo example of miR-101-3p and STC1 functions required for ovarian development.

Evaluation of steroidogenic capacity after follicle stimulating hormone stimulation in bovine granulosa cells of Revalor 200~ implanted heifers

Background： Heifers not used as breeding stock are often implanted with steroids to increase growth efficiency thereby altering hormone profiles and potentially changing the environment in which ovarian follicles develop. Because bovine granulosa cell culture is a commonly used technique and often bovine ovaries are collected from abattoirs with no record of implant status, the objective of this study was to determine if the presence of an implant during bovine granulosa cell development impacts follicle stimulating hormone-regulated steroidogenic enzyme expression. Paired ovaries were collected from 16 feedlot heifers subjected to 1 of 3 treatments： non-implanted （n = 5）, Revalor 200 for 28 d （n = 5）, or Revalor 200 for 84 d （n = 6）. Small follicle （1 to 5 mm） granulosa cells were isolated from each pair and incubated with phosphate buffered saline （n = 16） or 100 ng/mL follicle stimulating hormone （n = 16） for 24 h. Results： Granulosa cells of implanted heifers treated with follicle stimulating hormone produced medium concentrations of progesterone similar （P = 0.22） to non-implanted heifers, while medium estradiol concentrations were increased （P 〈 0.10） at 28 and 84 d compared to non-implanted heifers indicating efficacy of treatment. Additionally, real-time PCR analysis in response to follicle stimulating hormone treatment demonstrated a decrease in steroidogenic acute regulatory protein （P = 0.05） mRNA expression in heifers implanted for 84 d and an increase in P450 side chain cleavage mRNA in granulosa cells of heifers implanted for 28 （P 〈 0.10） or 84 d （P 〈 0.05） compared to non-implanted females. However, no difference in expression of 3-beta-hydroxysteroid dehydrogenase （P= 0.57） and aromatase （P = 0.23） were demonstrated in implanted or non-implanted heifers. Conclusions： These results indicate follicles which develop in the presence of high concentrations of androgenic and estrogenic steroids via an implant tend to demonstrate an altered capacity to respond to follicle stimulating hormone stimulation. Thus, efforts should be made to avoid the use of implanted heifers to study steroidogenesis in small follicle granulosa cell culture systems.

Evaluation of heat stress effects on cellular and transcriptional adaptation of bovine granulosa cells

Background:Heat stress is known to affect follicular dynamics,oocyte maturation,and fertilization by impairing steroidogenic ability and viability of bovine granulosa cell(bGCs).The present study explored the physiological and molecular response of bGCs to different heat stress intensities in-vitro.We exposed the primary bGCs to heat stress(HS)at 39℃,40℃ and 41℃ along with control samples(38℃)for 2 h.To evaluate the impact of heat stress on bGCs,several in vitro cellular parameters including cell apoptosis,intracellular reactive oxygen species(ROS)accumulation and HSP70 kinetics were assessed by flow cytometry,florescence microscopy and western blot,respectively.Furthermore,the ELISA was performed to confirm the 17β-estradiol(E2)and progesterone(P4)levels.In addition,the RNA sequencing(RNA-Seq)method was used to get the molecular based response of bGCs to different heat treatments.Results:Our findings revealed that the HS significantly decreased the cell viability,E2 and P4 levels in bGCs,whereas,increased the cellular apoptosis and ROS.Moreover,the RNA-Seq experiments showed that all the treatments(39℃,40℃ and 41℃)significantly regulated many differentially expressed genes(DEGs)i.e.BCL2L1,STAR,CYP11A1,CASP3,SOD2,HSPA13,and MAPK8IP1 and pathways associated with heat stress,apoptosis,steroidogenesis,and oxidative stress.Conclusively,our data demonstrated that the impact of 40°C treatment was comparatively detrimental for cell viability,apoptosis and ROS accumulation.Notably,a similar trend of gene expression was reported by RT-qPCR for RNA-seq data.Conclusions:Our study presented a worthy strategy for the first time to characterize the cellular and transcriptomic adaptation of bGCs to heat stress(39,40 and 41°C)in-vitro.The results infer that these genes and pathways reported in present study could be useful candidates/indicators for heat stress research in dairy cattle.Moreover,the established model of bGCs to heat stress in the current study provides an appropriate platform to understand the mechanism of how heat-stressed bGCs can affect the quality of oocytes and developing embryo.

Follicle-stimulating Hormone(FSH) Induced Internalization of Porcine FSH Receptor in Cultured Porcine Granulosa Cells and Chinese Hamster Ovary Cells Transfected with Recombinant Porcine FSH Receptor cDNA

In order to study the fate of human follicle-stimulating hormone (FSH) when hormone binds to its receptor, a quick biochemical method that can differentiate between the surface-bound and internalized hormone was used to determine the internalization induced by FSH in cultured both porcine granulosa cells and Chinese hamster ovary (CHO) cells expressing recombinant porcine FSH receptor. The results showed that FSH was slowly internalized, and the internalized radioactivity (acid resistant) reached a peak 10-12 h after addition of 125 I-hFSH. It was suggested that FSHR do not get internalized rapidly under physiological circumstances precisely because the appropriate sequences are absent.

p53 and NFκB regulate microRNA-34c expression in porcine ovarian granulosa cells

supported by the National Natural Science Foundation of China （31201771）;the earmarked fund for the China Agriculture Research System （CARS-36）

Expression of Leptin Long-form Receptor mRNA in Luteinized Granulosa Cells of Obese Women with Polycystic Ovary Syndrome

To investigate the expression of mRNA of leptin long-form receptor （OB-Rb） in luteinized granulosa ceils of obese women with polycystic ovary syndrome （PCOS）, and to determine the role of leptin in the physiopathology of PCOS, luteinized granulosa cells were collected from the follicle fluid of 10 obese women who met the diagnostic criteria for PCOS and their BMI was equal to or greater than 25 kg/m^2, and at the same time, granulosa cells were collected from 10 normal women undergoing IVF-ET who served as the control group. Some luteinized granulosa cells were taken from normal women for in-vitro culture, into which human leptin of different concentrations was added （0, 10, 100 and 1000 ng/mL）. After stimulation with leptin for 48 h, RT-PCR was employed for the detection of the expression of OB-RLInRNA in the luteinized granulosa cells. Our results showed that the level of OB-RLmRNA in luteinized granulosa cells of obese PCOS women was higher than those in the control （P〈0.05）. In luteinized granulosa cells cultured in vitro and stimulated by human leptin for 48 h, the level of OB-RLmRNA was higher than those without leptin stimulation （P〈0.01）, and when leptin concentration was at 100 ng/mL, and the level of OB-RLmRNA reached a peak, It is concluded that in obese PCOS women, the level of serum leptin is increased, which promotes the expression of OB-RL in luteinized granulosa cells and increases the sensitivity of the granulosa cells to leptin. Leptin may contribute to anovulation in obese women with PCOS.

Apoptosis and Expression of Protein TRAIL in Granulosa Cells of Rats with Polycystic Ovarian Syndrome

The relationship between apoptosis of granulosa cells and follicle development arrest in polycystic ovarian syndrome (PCOS) rats, and the contribution of tumor necrosis factor related apoptosis inducing ligand (TRAIL) in apoptosis of granulosa cells were explored. By using sodium prasterone sulfate rat PCOS model was induced. The apoptosis of granulosa cells in ovaries of rats was observed by TdT-mediated dUTP-biotin nick end-labeling (TUNEL), and the expression of TRAIL protein and mRNA in granulosa cells was detected by using immunhistochemical staining and reverse transcription polymerase chain reaction (RT-PCR) respectively. The apoptotic rate and the expression of protein TRAIL in granulosa cells were significantly higher in antral follicles from the PCOS rats than in those from the control rats (P<0.01, P<0.05). There was no significant difference in apoptotic rate and the expression of TRAIL protein in granulosa cells of preantral follicles between the PCOS rats and the control rats (P>0.05). No apoptosis and the expression of TRAIL protein in granulosa cells of primordial follicles were found in the two groups. The expression of TRAIL mRNA was significantly stronger in granulosa cells from the PCOS rats than in those from the con- trol rats (P<0.01). It was suggested that the apoptotic rate in granulosa cells was significantly higher in antral follicle from the PCOS rats than in those from the control rats. TRAIL played a role in regu- lating the apoptosis of granulosa cells in PCOS rats.

Effects of Fenvalerate on Steroidogenesis in Cultured Rat Granulosa Cells

Objective This study was designed to examine the in vitro effects of fenvalerate on steroid production and steroidogenic enzymes mRNA expression level in rat granulosa cells. Methods Using primary cultured rat granulosa cells (rGCs) as model, fenvalerate of various concentrations (0, 1, 5, 25, 125, 625 μmol/L) was added to the medium for 24 h. In some cases, optimal concentrations of 22(R)-hydroxycholesterol (25 μmol/L), Follicle stimulating hormone (FSH, 2 mg/L), or 8-Bromo-cAMP (1 mmol/L) were provided. Concentrations of 17β-estradiol(E2) and progesterone (P4) in the medium from the same culture wells were measured by RIA and the steroidogenic enzyme mRNA level was quantified by semi-quantitative RT-PCR. Results Fenvalerate decreased both P4 and E2 production in a dose-dependent manner while it could significantly stimulate rGCs proliferation. This inhibition was stronger in the presence of FSH. Furthermore, it could not be reversed by 22(R)-hydroxycholesterol or 8-Bromo-cAMP. RT-PCR revealed that fenvalerate had no significant effect on 3β-HSD, but could increase the P450scc mRNA level. In addition, 17β-HSD mRNA level was dramatically reduced with the increase of fenvalerate dose after 24 h treatment. Conclusion Fenvalerate inhibits both P4 and E2 production in rGCs. These results support the view that fenvalerate is considered as a kind of endocrine-disrupting chemicals. The mechanism of its disruption may involve the effects on steroidogenesis signaling cascades and/or steroidogenic enzyme’s activity.

Oleic acid reduces steroidogenesis by changing the lipid type stored in lipid droplets of ovarian granulosa cells

Background:Oleic acid is an abundant free fatty acid present in livestock that are in a negative energy-balance state,and it may have detrimental effects on female reproduction and fertility.Oleic acid induces lipid accumulation in bovine granulosa cells,which leads to a foam cell-like morphology and reduced steroidogenesis.However,why oleic acid increases lipid accumulation but decreases steroidogenesis remains unclear.This study focused on oleic acid’s effects on lipid type and steroidogenesis.Results:Oleic acid increased the lipid accumulation in a concentration-dependent manner and mainly increased the triglyceride level and decreased the cholesterol ester level.Oleic acid also led to a decline in estradiol and progesterone production in porcine granulosa cells in vitro.In addition,oleic acid up-regulated the expression of CD36 and diacylglycerol acyltransferase 2,but down-regulated the expression of 3-hydroxy-3-methylglutarylcoenzyme A reductase,scavenger receptor class B member 1 and acetyl-Coenzyme A acetyltransferase 2,as well as steroidogenesis-related genes,including cytochrome P450 family 11 subfamily A member 1,cytochrome P450family 19 subfamily A member 1 and 3 as well as steroidogenic acute regulatory protein at the mRNA and protein levels.An oleic acid-rich diet also enhanced the triglyceride levels and reduced the cholesterol levels in ovarian tissues of female mice,which resulted in lower estradiol levels than in control-fed mice.Compared with the control,decreases in estrus days and the numbers of antral follicles and corpora lutea,as well as an increase in the numbers of the atretic follicles,were found in the oleic acid-fed female mice.Conclusions:Oleic acid changed the lipid type stored in lipid droplets of ovarian granulosa cells,and led to a decrease in steroidogenesis.These results improve our understanding of fertility decline in livestock that are in a negative energy-balance state.

Effect of vitamin D3 on production of progesterone in porcine granulosa cells by regulation of steroidogenic enzymes

1,25-dihydroxyvitamin D3 （VD3）, an active form of Vitamin D, is photosynthesized in the skin of vertebrates in response to solar ultraviolet B radiation （UV-B）. VD3 deficiency can cause health problems such as immune disease, metabolic disease, and bone disorders. It has also been demonstrated that VD3 is involved in reproductive functions. Female sex hormones such as estrogen and progesterone are biosynthesized mainly in ovarian granulosa cells as the ovarian follicle develops. The functions of sex hormones include regulation of the estrus cycle and puberty as well as maintenance of pregnancy in females. In this study, we isolated granulosa cells from porcine ovaries and cultured them for experiments. To examine the effects of VD3 on ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by Real-time PCR and Western blotting assay. Production of progesterone from granulosa cells was also measured by ELISA assay. As a result, transcriptional and translational regulation of progesterone biosynthesis-related genes in granulosa cells was significantly altered by VD3. Furthermore, progesterone concen- trations in porcine granulosa cell-cultured media decreased in response to VD3. These results show that VD3 was a strong regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.

DENND1A desensitizes granulosa cells to FSH by arresting intracellular FSHR transportation

Polycystic ovary syndrome(PCOS)is a complex disorder.Genome-wide association studies(GWAS)have identified several genes associated with this condition,including DENND1A.DENND1A encodes a clathrin-binding protein that functions as a guanine nucleotide exchange factor involved in vesicular transport.However,the specific role of DENND1A in reproductive hormone abnormalities and follicle development disorders in PCOS remain poorly understood.In this study,we investigated DENND1A expression in ovarian granulosa cells(GCs)from PCOS patients and its correlation with hormones.Our results revealed an upregulation of DENND1A expression in GCs from PCOS cases,which was positively correlated with testosterone levels.To further explore the functional implications of DENND1A,we generated a transgenic mouse model overexpressing Dennd1a(TG mice).These TG mice exhibited subfertility,irregular estrous cycles,and increased testosterone production following PMSG stimulation.Additionally,the TG mice displayed diminished responsiveness to FSH,characterized by smaller ovary size,less well-developed follicles,and abnormal expressions of FSH-priming genes.Mechanistically,we found that Dennd1a overexpression disrupted the intracellular trafficking of follicle stimulating hormone receptor(FSHR),promoting its internalization and inhibiting recycling.These findings shed light on the reproductive role of DENND1A and uncover the underlying mechanisms,thereby contributing valuable insights into the pathogenesis of PCOS and providing potential avenues for drug design in PCOS treatment.

Transcriptome Dynamics and Cell Dialogs Between Oocytes and Granulosa Cells in Mouse Follicle Development

The development and maturation of follicles is a sophisticated and multistage process.The dynamic gene expression of oocytes and their surrounding somatic cells and the dialogs between these cells are critical to this process.In this study,we accurately classified the oocyte and follicle development into nine stages and profiled the gene expression of mouse oocytes and their surrounding granulosa cells and cumulus cells.The clustering of the transcriptomes showed the trajectories of two distinct development courses of oocytes and their surrounding somatic cells.Gene expression changes precipitously increased at Type 4 stage and drastically dropped afterward within both oocytes and granulosa cells.Moreover,the number of differentially expressed genes between oocytes and granulosa cells dramatically increased at Type 4 stage,most of which persistently passed on to the later stages.Strikingly,cell communications within and between oocytes and granulosa cells became active from Type 4 stage onward.Cell dialogs connected oocytes and granulosa cells in both unidirectional and bidirectional manners.TGFB2/3,TGFBR2/3,INHBA/B,and ACVR1/1B/2B of TGF-βsignaling pathway functioned in the follicle development.NOTCH signaling pathway regulated the development of granulosa cells.Additionally,many maternally DNA methylation-or H3K27me3-imprinted genes remained active in granulosa cells but silent in oocytes during oogenesis.Collectively,Type 4 stage is the key turning point when significant transcription changes diverge the fate of oocytes and granulosa cells,and the cell dialogs become active to assure follicle development.These findings shed new insights on the transcriptome dynamics and cell dialogs facilitating the development and maturation of oocytes and follicles.