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‑423 sponged by lncRNA NORHA inhibits granulosa cell apoptosis

Background Atresia and degeneration,a follicular developmental fate that reduces female fertility and is triggered by granulosa cell(GC)apoptosis,have been induced by dozens of miRNAs.Here,we report a miRNA,miR-423,that inhibits the initiation of follicular atresia(FA),and early apoptosis of GCs.Results We showed that miR-423 was down-regulated during sow FA,and its levels in follicles were negatively correlated with the GC density and the P4/E2 ratio in the follicular fluid in vivo.The in vitro gain-of-function experiments revealed that miR-423 suppresses cell apoptosis,especially early apoptosis in GCs.Mechanically speaking,the miR-423 targets and interacts with the 3’-UTR of the porcine SMAD7 gene,which encodes an apoptosis-inducing factor in GCs,and represses its expression and pro-apoptotic function.Interestingly,FA and the GC apoptosis-related lncRNA NORHA was demonstrated as a ceRNA of miR-423.Additionally,we showed that a single base deletion/insertion in the miR-423 promoter is significantly associated with the number of stillbirths(NSB)trait of sows.Conclusion These results demonstrate that miR-423 is a small molecule for inhibiting FA initiation and GC early apoptosis,suggesting that treating with miR-423 may be a novel approach for inhibiting FA initiation and improving female fertility.

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.

Smad8 is involvement in follicular development via the regulation of granulosa cell growth and steroidogenesis in mice

Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian reproduction.However,the role of SMAD family member 8(SMAD8,also known as SMAD9),a member of the SMAD family,in mammalian reproduction remains unclear.Methods:We employed RNA interference techniques to knock down Smad8 expression in mouse granulosa cells(GCs)to investigate the effects of Smad8 on GC growth and steroidogenesis.Results:Our findings revealed a significant decrease in the proliferative capacity and a substantial increase in the apoptosis rate of GCs after transfection with Smad8-siRNA for 48 h.Subsequent hormone assays demonstrated a significant decrease in estradiol(E2)levels,whereas progesterone(P4)remained unchanged.Further mechanistic analysis showed that the mRNA expression of proliferating cell nuclear antigen(Pcna),Cyclin D2,cell cycle-dependent kinase 4(Cdk4),B-cell lymphoma-2(Bcl-2),estrogen receptor(Er),luteinizing hormone receptor(Lhr)and cytochrome P450 family 19 subfamily A member 1(Cyp19a1)significantly decreased.Conversely,the mRNA of cysteine aspartate proteinase 3(Caspase 3)significantly increased,wheras Bcl2-associated X(Bax),folliclestimulating hormone receptor(Fshr)and cytochrome P450 family 11 subfamily A member 1(Cyp11a1)remained unchanged compared to the controls.Conclusion:This study indicates that Smad8 knockdown inhibits cell proliferation,promotes apoptosis,reduces Er and Lhr transcription,and decreases E2 production in mouse GCs.These findings suggest that Smad8 may serve as a novel genetic marker for mammalian reproduction.

Adult-Type Granulosa Cell Tumor with Similar Clinical Findings Seen during Ovarian Cystectomy Performed at the Same Time as Laparoscopic Ovarian Drilling for Polycystic Ovarian Syndrome: An Extremely Rare Case

Polycystic ovary syndrome (PCOS) is a major cause of anovulatory infertility. Laparoscopic ovarian drilling (LOD) is a treatment for PCOS that allows the laparoscopic identification of other intra-abdominal lesions and the provision of diagnostic treatment. This study reports a case of PCOS with an ovarian mass in which LOD was aggressively used and a granulosa cell tumor (GCT) was found. A 34-year-old woman with secondary amenorrhea and irregular menstrual cycles presented to the emergency department with abdominal pain of unknown etiology. Imaging studies revealed a 6-cm left ovarian mass with an internal appearance suggestive of a hemorrhage. The patient’s secondary amenorrhea was subsequently diagnosed as PCOS, and LOD was performed to preserve her fertility. Simultaneously, a cystectomy was performed to evaluate the tumor in the left ovary;the diagnosis was adult-type GCT. Although concomitant GCT and PCOS are extremely rare, the two conditions have similar clinical manifestations. In women of reproductive age, the impact of surgery on future fertility should be considered, and the initial surgical technique should be chosen carefully.

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.

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.

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.

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.

Follicle-stimulating hormone is expressed in ovarian follicles of chickens and promotes ovarian granulosa cell proliferation

Follicle-stimulating hormone(FSH),an important hypothalamic-pituitary-gonadal axis(HPG)hormone,is secreted by the pituitary gland.This study confirms that FSH is expressed in chicken follicles at different stages,and positive FSHβ mRNA signals were stronger(P<0.05)in granulosa cells than in oocytes.The 369 bp coding sequence of FSHβ in ovaries is 100%identical to that in the pituitary gland.The experiment in vitro revealed that the ovary possessed FSH secretory capacity.Further,FSHβ mRNA was significantly upregulated(P<0.05)in follicles and significantly higher(P<0.05)than that in the pituitary gland by approximately 2–23 times with the development.The number of granulosa cells decreased significantly(P<0.05)in the cells with siRNA treatment,confirming that the ovarian FSH could promote granulosa cell proliferation.This view was supported by cell cycle analysis and CCND2 and CCNE2 expression.Further research indicated that no difference(P>0.05)was observed between the number of granulosa cells treated with FSHβ siRNA and in exogenous FSH.However,the number of granulosa cells without FSHβ siRNA transfection was significantly higher(P<0.05)for exogenous FSH.This finding suggests that the proliferative effect of exogenous FSH on ovarian granulosa cells depend on endogenous FSH.This study demonstrated that the FSH gene was expressed in chicken follicles and promoted ovarian granulosa cell proliferation,which enriched the theory on HPG axis.

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.

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.

NORHA,a novel follicular atresia-related lncRNA,promotes porcine granulosa cell apoptosis via the miR-183-96-182 cluster and FoxO1 axis

Background:Follicular atresia has been shown to be strongly associated with a low follicle utilization rate and female infertility,which are regulated by many factors such as microRNAs(miRNAs),which constitute a class of noncoding RNAs(ncRNAs).However,little is known about long noncoding RNAs(lncRNAs),which constitute another ncRNA family that regulate follicular atresia.Results:A total of 77 differentially expressed lncRNAs,including 67 upregulated and 10 downregulated lncRNAs,were identified in early atretic follicles compared to healthy follicles by RNA-Sequencing.We characterized a noncoding RNA that was highly expressed in atretic follicles(NORHA).As an intergenic lncRNA,NORHA was one of the upregulated lncRNAs identified in the atretic follicles.To determine NORHA function,RT-PCR,flow cytometry and western blotting were performed,and the results showed that NORHA was involved in follicular atresia by influencing GC apoptosis with or without oxidative stress.To determine the mechanism of action,bioinformatics analysis,luciferase reporter assay and RNA immunoprecipitation assay were performed,and the results showed that NORHA acted as a‘sponge’,that directly bound to the miR-183-96-182 cluster,and thus prevented its targeted inhibition of FoxO1,a major sensor and effector of oxidative stress.Conclusions:We provide a comprehensive perspective of lncRNA regulation of follicular atresia,and demonstrate that NORHA,a novel lncRNA related to follicular atresia,induces GC apoptosis by influencing the activities of the miR-183-96-182 cluster and FoxO1 axis.

Effects of chronic heat stress on granulosa cell apoptosis and follicular atresia in mouse ovary

Background： Heat stress is known to alter follicular dynamics and granulosa cell function and may contribute to the diminished reproductive efficiency commonly observed in mammals during the summer. Although several investigators have studied heat-induced ovarian injury, few reports have focused on the effects of chronic heat stress on ovarian function and the molecular mechanisms through which it induces ovarian injury.Methods： In Exp. 1, 48 female mice were assigned to a control or heat-stressed treatment. After exposure to a constant temperature of 25 ℃ for 7, 14, 21 or 28 d（n = 6） or to 42 ℃ for 3 h per d for 7, 14, 21 or 28 d（n = 6）, the mice were euthanized and their ovaries were analyzed for follicular atresia, granulosa cell apoptosis, changes in the abundance of HSP70 protein and serum concentrations of estradiol. In Exp. 2, the expression of HSP70 and aromatase was quantified in antral follicles cultured in vitro at 37 or 42 ℃ for 24 h. In Exp. 3, granulosa cells from ovaries maintained at 37 or 41 ℃ for 2 h were analyzed for their expression of HSP70, Bim, caspase-3 and cleaved caspase-3.Results： In Exp. 1, body weight and food intake of heat-stressed mice decreased（P 〈 0.05） compared with control mice while the concentration of estradiol in serum was lower（P 〈 0.05） in heat-stressed mice than in control mice. Compared with control mice, the percentage of atretic follicles and the number of antral follicles with severe apoptotic signals were increased（P 〈 0.05） after 21 d of heat-stressed treatment. HSP70 protein was more abundant（P 〈 0.05） in heat-stressed mice than control mice. In Exp. 2, heat stress increased HSP70 and decreased aromatase proteins（P 〈 0.05） in antral follicles. In Exp. 3, TUNEL-positive granulosa cells from heat-stressed ovaries were observed concomitant with a significant increase in HSP70, Bim and cleaved caspase-3 protein.Conclusion： Heat-stress in mice decrease estradiol in serum and aromatase in antral follicles but increased number of atretic follicles and granulosa cell undergoing apoptosis which may explain the decreased fertility commonly observed in heat-stressed animals.

Morphological and Hormonal Identifi cation of Porcine Atretic Follicles and Relationship Analysis of Hormone Receptor Levels During Granulosa Cell Apoptosis In vivo

Recent reports have demonstrated that follicular atresia is initiated or caused by granulosa cell apoptosis followed by theca cell degeneration in mammalian ovaries, but the mechanism of follicular atresia is still to be elucidated. Therefore, our present study was designed to examine our hypothesis that the changes of follicular microenvironment induce the granulosa cell apoptosis during pocrine follicular atresia in vivo. We firstly isolated intact porcine antral follicles and identified them into three groups, healthy follicles （HF）, early atretic follicles （EAF） and progressed atretic follicles （PAF） through morphology and histology. To further confirm their status, we detected hormone levels in follicular fluids and the expression level of apoptosis gene Bax in granulosa cells. The rate of progesterone （P） and estradiol （E2） was increased with the expression of Bax, indicating hormone can be used as a marker of granulosa cell apoptosis or follicular atresia. Finally, we analyzed the expression level of hormone receptor genes in granulosa cells and their relationship with follicular atresia. In PAF, the expression of Progesterone receptor （PGR） was increased significantly while estradiol receptor （ER） had no notable changes, which suggesting the increased-PGR accelerated the effect of P-stimulated granulosa cell apoptosis. The dramatic increasing of androgen receptor （AR） expression in PAF and the obvious increase of tumor necrosis factor-u receptor （TNFR） in EAF indicated that there are different pathways regulating granulosa cell apoptosis during follicular atresia. Together, our results suggested that different pathways of granulosa cell apoptosis was induced by changing the follicular microenvironment during follicular atresia.

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.