Long non-coding RNA lnc-CCNL1-3:1 promotes granulosa cell apoptosis and suppresses glucose uptake in women with polycystic ovary syndrome

The Role of Ovarian Granulosa Cells Related-ncRNAs in Ovarian Dysfunctions: Mechanism Research and Clinical Exploration

Ovarian dysfunctions, encompassing conditions such as polycystic ovary syndrome (PCOS), premature ovarian failure (POF), premature ovarian insufficiency (POI), and diminished ovarian reserve (DOR), are closely linked to disruptions in follicular development, often tied to granulosa cell (GC) abnormalities. Despite ongoing research, the precise mechanisms underlying these dysfunctions remain elusive. Increasing evidence highlights the pivotal role of non-coding RNAs (ncRNAs) in the pathogenesis of ovarian dysfunctions. As transcripts that do not encode proteins, ncRNAs are capable of regulating gene expression at various levels. They influence GCs by modulating key biological processes including proliferation, apoptosis, autophagy, cell cycle progression, steroidogenesis, mitochondrial function, inflammatory responses, and aging. Disruptions in GC development and function can lead to impaired follicular development, consequently contributing to ovarian dysfunctions. Thus, ncRNAs are likely integral to the regulatory mechanisms underlying these pathologies, exhibiting distinct expression patterns in affected individuals. This review delves into the regulatory roles of ncRNAs in GCs and their implications for ovarian dysfunctions (PCOS, POF, POI, DOR), offering insights into potential biomarkers for ovarian function assessment and novel therapeutic approaches for treating these conditions.

Whispers of the polycystic ovary syndrome theater: Directing role of long noncoding RNAs

Polycystic Ovary Syndrome (PCOS) is a multifaceted endocrine disorder that implicates a spectrum of clinical manifestations, including hormonal imbalance, metabolic dysfunction, and even compromised ovarian granulosa cell (GC) activity. The underlying molecular mechanisms of PCOS remain elusive, presenting a significant barrier to effective diagnosis and treatment. This review delves into the emerging role of long non-coding RNAs (lncRNAs) in the pathophysiology of PCOS, articulating their intricate interactions with mRNAs, microRNAs, and other epigenetic regulators that collectively influence the hormonal and metabolic milieu of PCOS. We examine the dynamic regulatory networks orchestrated by lncRNAs that impact GC function, steroidogenesis, insulin resistance, and inflammatory pathways. By integrating findings from recent studies, we illuminate the potential of lncRNAs as biomarkers for PCOS and highlight their contribution to the disorder, offering a detailed perspective on the lncRNA-mediated modulation of gene expression and pathogenic pathways. Understanding targeted lncRNA interactions with PCOS proposes novel avenues for therapeutic intervention to ameliorate the reproductive and metabolic disturbances characteristic of the syndrome.

ER stress-induced LINC00173 promotes the apoptosis of ovarian granulosa cells by regulating the HRK/PI3K/AKT pathway in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and metabolic abnormality disease that mainly affects women of reproductive age. LINC00173, a novel long noncoding RNA (lncRNA), has emerged as an important factor in the development of PCOS. However, the role of LINC00173 in PCOS development and its specific upstream and downstream mechanisms remain to be further clarified. Here, we found that LINC00173 was significantly upregulated in granulosa cells (GCs) of PCOS patients, and played a crucial role in promoting apoptosis of GCs. Mechanistically, we observed the activation of endoplasmic reticulum (ER) stress in the GCs of PCOS patients, and the ER stress sensor ATF4 could directly induce LINC00173 expression by binding to its promoter. LINC00173 further upregulated the expression of Harakiri (HRK) and subsequently inhibited downstream PI3K/AKT pathway. In conclusions, our study uncovered that ER stress-induced upregulation of LINC00173 leads to increased HRK expression and inhibition of the PI3K/AKT pathway, thereby promoting the progression of PCOS. These findings provide a new therapeutic strategy for the treatment of PCOS.

Gap junctions in polycystic ovary syndrome: Implications for follicular arrest

Gap junctions are specialized intercellular conduits that provide a direct pathway between neighboring cells, which are involved in numerous physiological processes, such as cellular differentiation, cell growth, and metabolic coordination. The effect of gap junctional hemichannels in folliculogenesis is particularly obvious, and the down-regulation of connexins is related to abnormal follicle growth. Polycystic ovary syndrome (PCOS) is a ubiquitous endocrine disorder of the reproductive system, affecting the fertility of adult women due to anovulation. Exciting evidence shows that gap junction is involved in the pathological process related to PCOS and affects the development of follicles in women with PCOS. In this review, we examine the expression of connexins in follicular cells of PCOS and figure out whether such communication could have consequences for PCOS women. While along with results from clinical and related animal studies, we summarize the mechanism of connexins involved in the pathogenesis of PCOS.

Metformin enhances the survival ability of ovarian granulosa cells in polycystic ovary syndrome by promoting LINC00548 to suppress androgen receptor/klotho pathway

BACKGROUND

Metformin (Met) has been reported to play the key role in the pathogenesis of polycystic ovary syndrome (PCOS). However, the precise mechanisms underlying the actions of Met in PCOS remain incompletely understood. This study aimed to confirm the mechanism of Met interacting with a long non-coding RNA LINC00548 in PCOS.

METHODS

Ovarian granulosa cells (OGCs) were incubated 500 nM dihydrotestosterone (DHT) to construct PCOS in vitro model and then were treated 20 μM Met. A series of cell experiments including Cell Counting Kit-8, Terminal uridine nucleotide end labeling, and flow cytometry were performed to confirm the changes of OGC survival ability. Quantitative real-time polymerase chain reaction was conducted to determine the levels of LINC00548, whereas Western blotting was applied to determine the levels of androgen receptor (AR) and klotho.

RESULTS

Met improved the cell viability and suppressed cell apoptosis in DHT-treated OGCs. LINC00548 downregulated in DHT-treated OGCs was upregulated by Met, and its overexpression further enhanced the positive effects of Met on the survival ability of DHT-treated OGCs. In addition, Met could induce the upregulation of LINC00548 to suppress the activation of AR/klotho pathway in DHT-treated OGCs.

CONCLUSION

Overall, this study discovers that Met enhances the survival ability of OGCs in PCOS by elevating LINC00548 expression to suppress AR/klotho pathway.

Puerarin Ameliorated PCOS through Preventing Mitochondrial Dysfunction Dependent on the Maintenance of Intracellular Calcium Homeostasis

Polycystic ovarian syndrome (PCOS) is the major cause of infertility in reproductive women, but no universal drug is feasible. Although puerarin clinically treats cerebrovascular and cardiovascular diseases, its curative effect on PCOS remains elusive. The present study discovered that administration of puerarin restored estrous cycle of PCOS mice and diminished the number of cystic follicles with the concomitant recovery for circulating testosterone, LH and FSH levels, and LH/FSH ratio, indicating the therapeutic role of puerarin in PCOS. KEGG analysis of differential genes between PCOS and control revealed the enrichment in MAPK and calcium signaling pathway. Application of puerarin restricted the phosphorylation of ERK1/2 and JNK, whose activation neutralized the improvement of puerarin on the secretory function and apoptosis of ovarian granulosa cells (GCs). Meanwhile, puerarin alleviated the accumulation of cytosolic Ca2+ through restricting the opening of Ryr and Itpr channels, but this effectiveness was counteracted by the activatory ERK1/2 and JNK. Attenuation of cytosolic Ca2+ counteracted the antagonistic effects of ERK1/2 and JNK activation on puerarin's role in rescuing the calcineurin and Nfatc. Further analysis manifested that Mcu had been authenticated as a direct downstream target of Nfatc to mediate the amelioration of puerarin on mitochondrial Ca2+ uptake. Moreover, puerarin prevented the disorder of ATP content, mitochondrial membrane potential, and mitochondrial permeability transition pore opening through maintaining mitochondrial Ca2+ homeostasis. Collectively, puerarin might ameliorate the symptoms of PCOS mice through preventing mitochondrial dysfunction that is dependent on the maintenance of intracellular Ca2+ homeostasis after inactivation of ERK1/2 and JNK.

The Role of MicroRNA, Long Non-Coding RNA and Circular RNA in the Pathogenesis of Polycystic Ovary Syndrome: A Literature Review

Polycystic ovary syndrome (PCOS) is the most common endocrine-metabolic disease in females of reproductive age, affecting 4-20% of pre-menopausal women worldwide. MicroRNAs (miRNAs) are endogenous, single-stranded, non-coding, regulatory ribonucleic acid molecules found in eukaryotic cells. Abnormal miRNA expression has been associated with several diseases and could possibly explain their underlying pathophysiology. MiRNAs have been extensively studied for their potential diagnostic, prognostic, and therapeutic uses in many diseases, such as type 2 diabetes, obesity, cardiovascular disease, PCOS, and endometriosis. In women with PCOS, miRNAs were found to be abnormally expressed in theca cells, follicular fluid, granulosa cells, peripheral blood leukocytes, serum, and adipose tissue when compared to those without PCOS, making miRNAs a useful potential biomarker for the disease. Key pathways involved in PCOS, such as folliculogenesis, steroidogenesis, and cellular adhesion, are regulated by miRNA. This also highlights their importance as potential prognostic markers. In addition, recent evidence suggests a role for miRNAs in regulating the circadian rhythm (CR). CR is crucial for regulating reproduction through the various functions of the hypothalamic-pituitary-gonadal (HPG) axis and the ovaries. A disordered CR affects reproductive outcomes by inducing insulin resistance, oxidative stress, and systemic inflammation. Moreover, miRNAs were demonstrated to interact with lncRNA and circRNAs, which are thought to play a role in the pathogenesis of PCOS. This review discusses what is currently understood about miRNAs in PCOS, the cellular pathways involved, and their potential role as biomarkers and therapeutic targets.

MiR-134-3p targets HMOX1 to inhibit ferroptosis in granulosa cells of sheep follicles

BACKGROUND

The intricate interplay of gene expression within ovarian granulosa cells (GCs) is not fully understood. This study aimed to investigate the miRNA regulatory mechanisms of ferroptosis during the process of follicle development in lamb GCs.

METHODS

Employing transcriptome sequencing, we compared differentially expressed mRNAs (DE-mRNAs) and miRNAs (DE-miRNAs) in GCs from lambs treated with follicle-stimulating hormone (FL) to untreated controls (CL). We further screened differentially expressed ferroptosis-related genes and identified potential miRNA regulatory factors. The expression patterns of HMOX1 and miRNAs in GCs were validated using qRT‒PCR and Western blotting. Additionally, we investigated the regulatory effect of oar-miR-134-3p on HMOX1 and its function in ferroptosis through cell transfection and erastin treatment.

RESULTS

We identified a total of 4,184 DE-mRNAs and 304 DE-miRNAs. The DE-mRNAs were mainly enriched in ferroptosis, insulin resistance, and the cell cycle. Specifically, we focused on the differential expression of ferroptosis-related genes. Notably, the ferroptosis-related genes HMOX1 and SLC3A2, modulated by DE-miRNAs, were markedly suppressed in FLs. Experimental validation revealed that HMOX1 was significantly downregulated in FL and large follicles, while oar-miR-134-3p was significantly upregulated compared to that in the CLs. HMOX1 expression was regulated by the targeting effect of oar-miR-134-3p. Functional assays further revealed that modulation of oar-miR-134-3p influenced HMOX1 expression and altered cellular responses to ferroptosis induction by erastin.

CONCLUSION

This study suggested that oar-miR-134-3p and HMOX1 may be one of the pathways regulating ferroptosis in GCs. This finding provides new clues to understanding the development and regulatory process of follicles.

Essential Role of Granulosa Cell Glucose and Lipid Metabolism on Oocytes and the Potential Metabolic Imbalance in Polycystic Ovary Syndrome

Granulosa cells are crucial for the establishment and maintenance of bidirectional communication among oocytes. Various intercellular material exchange modes, including paracrine and gap junction, are used between them to achieve the efficient delivery of granulosa cell structural components, energy substrates, and signaling molecules to oocytes. Glucose metabolism and lipid metabolism are two basic energy metabolism pathways in granulosa cells; these are involved in the normal development of oocytes. Pyruvate, produced by granulosa cell glycolysis, is an important energy substrate for oocyte development. Granulosa cells regulate changes in intrafollicular hormone levels through the processing of steroid hormones to control the development process of oocytes. This article reviews the material exchange between oocytes and granulosa cells and expounds the significance of granulosa cells in the development of oocytes through both glucose metabolism and lipid metabolism. In addition, we discuss the effects of glucose and lipid metabolism on oocytes under pathological conditions and explore its relationship to polycystic ovary syndrome (PCOS). A series of changes were found in the endogenous molecules and ncRNAs that are related to glucose and lipid metabolism in granulosa cells under PCOS conditions. These findings provide a new therapeutic target for patients with PCOS; additionally, there is potential for improving the fertility of patients with PCOS and the clinical outcomes of assisted reproduction.

Moringa oleifera leaf supplementation relieves oxidative stress and regulates intestinal flora to ameliorate polycystic ovary syndrome in letrozole-induced rats

This study investigated the effects of supplementation Moringa oleifera leaf (MOL) on relieving oxidative stress, anti-inflammation, changed the relative abundance of multiple intestinal flora and blood biochemical indices during letrozole-induced polycystic ovary syndrome (PCOS). Previous studies have shown that MOL has anti-inflammatory, anti-oxidation, insulin-sensitizing effects. However, whether MOL has beneficial effects on PCOS remains to be elucidated. In the current study, 10-week-old female Sprague-Dawley rats received letrozole to induce PCOS-like rats, and subsequently were treated with a MOL diet. Then, the body weight and estrus cycles were measured regularly in this period. Finally, the ovarian morphology, blood biochemical indices, anti-oxidative, intestinal flora, and anti-inflammation were observed at the end of the experiment. We found that MOL supplementation markedly decreased the body weight, significantly upregulated the expression of Sirt1, FoxO1, PGC-1α, IGF1, and substantially modulated the sex hormone level and improved insulin resistance, which may be associated with the relieves oxidative stress. Moreover, the supplementation of MOL changed the relative abundance of multiple intestinal flora, the relative abundance of Fusobacterium, Prevotella were decreased, and Blautia and Parabacteroides were increased. These results indicate that MOL is potentially a supplementary medication for the management of PCOS.

Integrated bioinformatics analysis elucidates granulosa cell whole-transcriptome landscape of PCOS in China

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common reproductive, neuroendocrine, and metabolic disorder in women of reproductive age that affects up to 5-10% of women of reproductive age. The aetiology of follicle development arrest and critical issues regarding the abnormal follicular development in PCOS remain unclear. The present study aims to systematically evaluate granulosa cell whole-transcriptome sequencing data to gain more insights into the transcriptomic landscape and molecular mechanism of PCOS in China.

METHODS

In the present study, the microarray datasets GSE138518, GSE168404, GSE193123, GSE138572, GSE95728, and GSE145296 were downloaded from the Gene Expression Omnibus (GEO) database. Subsequently, differential expression analysis was performed on the PCOS and control groups, followed by functional interaction prediction analysis to investigate gene-regulatory circuits in PCOS. Finally, hub genes and their associated ncRNAs were validated by qPCR in human-luteinized granulosa (hGL) cells and were correlated with the clinical characteristics of the patients.

RESULTS

A total of 200 differentially expressed mRNAs, 3 differentially expressed miRNAs, 52 differentially expressed lncRNAs, and 66 differentially expressed circRNAs were found in PCOS samples compared with controls. GO and KEGG enrichment analyses indicated that the DEGs were mostly enriched in phospholipid metabolic processes, steroid biosynthesis and inflammation related pathways. In addition, the upregulated miRNA hsa-miR-205-5p was significantly enriched in the ceRNA network, and two hub genes, MVD and PNPLA3, were regulated by hsa-miR-205-5p, which means that hsa-miR-205-5p may play a fundamental role in the pathogenesis of PCOS. We also found that MVD and PNPLA3 were related to metabolic processes and ovarian steroidogenesis, which may be the cause of the follicle development arrest in PCOS patients.

CONCLUSIONS

In summary, we systematically constructed a ceRNA network depicting the interactions between the ncRNAs and the hub genes in PCOS and control subjects and correlated the hub genes with the clinical characteristics of the patients, which provides valuable insights into the granulosa cell whole-transcriptome landscape of PCOS in China.

Evaluation of the p53 pathway in polycystic ovarian syndrome pathogenesis and apoptosis enhancement in human granulosa cells through transcriptome data analysis

The polycystic ovarian syndrome (PCOS) is closely associated with enhanced apoptosis of granulosa cells, which have a vital role in maturation of oocytes. p53 plays a critical role in the regulation of apoptosis and cell cycle arrest, metabolism and insulin resistance. The aim of this study was to investigate the impact of p53 pathway in enhancing apoptosis and abnormal function of granulosa cells. In this study, microarray analysis and RNA sequencing were downloaded from the GEO and used as datasets. Principal Component Analysis (PCA) and online SSizer tool were applied to evaluate the experiment quality control and sample sufficiency, respectively. Bioinformatics' analyses were performed on the selected datasets, and validated by qRT-PCR and western blot analyses. Three datasets out of five ones were chosen for re-analyzing based on the PCA outcomes. 21 deregulated genes were identified via filters including p < 0.05 and |log2FC|≥ 1. Functional enrichment analysis confirmed the relevance of cell cycle regulation and apoptosis as common biological hallmarks in PCOS. Results have shown differentially expressed p53 target genes involved in apoptosis (BAX, FAS, PMAIP1, and CASP8), cell cycle (Cyclins, Cyclin dependent kinases), glucose metabolism and insulin resistance (THBS1), and p53 regulation (MDM2). Subsequently, the relative mRNA expression of FAS, PMAIP1 and MDM2 genes, and protein levels of p53 and MDM2 were confirmed using granulosa cells collected from 20 PCOS women and 18 control individuals by qRT-PCR and western blot, respectively. Results of this study represent the possible role of p53 pathway in pathogenesis of PCOS particularly, through the enhancement of apoptosis in granulosa cells.

SDNOR, a Novel Antioxidative lncRNA, Is Essential for Maintaining the Normal State and Function of Porcine Follicular Granulosa Cells

Increasing evidence shows that lncRNAs, an important kind of endogenous regulator, are involved in the regulation of follicular development and female fertility, but the mechanism remain largely unknown. In this study, we found that SDNOR, a recently identified antiapoptotic lncRNA, is a potential multifunctional regulator in porcine follicular granulosa cells (GCs) through RNA-seq and multi-dimension analyses. SDNOR-mediated regulatory networks were established and identified that SOX9, a transcription factor inhibited by SDNOR, mediates SDNOR's regulation of the transcription of downstream targets. Functional analyses showed that loss of SDNOR significantly impairs GC morphology, inhibits cell proliferation and viability, reduces E2/P4 index, and suppresses the expression of crucial markers, including PCNA, Ki67, CDK2, CYP11A1, CYP19A1, and StAR. Additionally, after the detection of ROS, SOD, GSH-Px, and MDA, we found that SDNOR elevates the resistance of GCs to oxidative stress (OS) and also inhibits OS-induced apoptosis. Notably, GCs with high SDNOR levels are insensitive to oxidative stress, leading to lower apoptosis rates and higher environmental adaptability. In summary, our findings reveal the regulation of porcine GCs in response to oxidative stress from the perspective of lncRNA and demonstrate that SDNOR is an essential antioxidative lncRNA for maintaining the normal state and function of GCs.

Role of CPXM1 in Impaired Glucose Metabolism and Ovarian Dysfunction in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS), a common female endocrinopathy associated with both reproductive and metabolic disorders, has an unclear etiology and unsatisfactory management methods. Carboxypeptidase X, M14 family member 1 (CPXM1) is a protein involved in follicular atresia, insulin production, and adipose tissue production, though its role in PCOS is not fully understood. We used a 60% high-fat diet (HFD) plus dehydroepiandrosterone (DHEA)-induced PCOS mouse model to determine the role of CPXM1 in abnormal glucose metabolism and ovarian dysfunction in PCOS. We found that serum CPXM1 concentrations were higher in PCOS mice and positively correlated with increased levels of serum testosterone and insulin. In both ovarian and adipose tissues of PCOS mice, CPXM1 mRNA and protein levels were significantly increased but GLUT4 levels were significantly decreased. Immunohistochemistry (IHC) staining of the ovary showed increased CPXM1 expression in PCOS. In addition, the protein expression of phosphorylated protein kinase B (p-Akt) was also significantly decreased in PCOS mice. Furthermore, mRNA levels of inflammatory markers such as TNF-α, IL-6, IFN-α, and IFN-γ were increased in ovarian and adipose tissues of PCOS mice. However, IRS-1, IRS-2, and INSR levels were significantly decreased. Our results indicated for the first time that abnormally high expression of CPXM1, increased adiposity, impaired glucose tolerance, and chronic low-grade inflammation may act together in a vicious cycle in the pathophysiology of PCOS. Our research suggests the possibility of CPXM1 as a potential therapeutic target for the treatment of PCOS.

TGF-β1 regulates the lncRNA transcriptome of ovarian granulosa cells in a transcription activity-dependent manner

OBJECTIVES

Transforming growth factor β1 (TGF-β1), an essential cytokine belongs to TGF-β superfamily, is crucial for female fertility. Increasing evidence show that long noncoding RNAs (lncRNAs) influence the state of granulosa cells (GCs). This study aimed to detect the effects of TGF-β1 on the lncRNA transcriptome, and investigate whether lncRNAs mediate the functions of TGF-β1 in GCs.

MATERIAL AND METHODS

RNA-seq and bioinformatics analyses were performed to identify and characterize the differentially expressed lncRNAs (DElncRNAs). The regulatory mechanism of TGF-β1 to lncRNA transcriptome was analyzed by chromatin immunoprecipitation. The effects of lncRNAs on the antiapoptotic and proproliferative functions of TGF-β1 were examined by morphological analysis, fluorescence-activated cell sorting, Cell Counting Kit-8, and Western blot.

RESULTS

A total of 72 DElncRNAs highly sensitive to TGF-β1 were identified with the criteria of |log₂ (fold chage)| ≥ 3 and false discovery rate < 0.05. Functional assessment showed that DElncRNAs were enriched in TGF-β, nuclear factor kappa B, p53, and Hippo pathways which are crucial for the normal state and function of GCs. Importantly, SMAD4 is essential for the regulation of TGF-β1 to lncRNA transcriptome. In vitro studies confirmed that TGF-β1 induced TEX14-IT1 transcription in a SMAD4-dependent manner, and TEX14-IT1 mediated the antiapoptotic and proproliferative effects of TGF-β1 in GCs.

CONCLUSIONS

Our findings demonstrate that TGF-β1 alters lncRNA transcriptome in a SMAD4-dependent manner, and highlight that lncRNAs mediate the functions of TGF-β1 in GCs, which contribute to a better understanding of the epigenetic regulation of female fertility.

The molecular mechanism of miR-96-5p in the pathogenesis and treatment of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), characterized by the androgen excess and arrest of antral follicles, is a common endocrine disorder among women lacking specific diagnostic biomarkers and therapeutic targets. Herein, we studied the molecular mechanism of miR-96-5p in the process of PCOS and its potential applications in PCOS. Clinically, we found that miR-96-5p significantly decreased in serum, follicular fluid and primary human granulosa cells (hGCs) of PCOS patients (n = 70) vs non-PCOS women (n = 60), as well as in the ovaries of 3-types of induced PCOS-like mice. Furthermore, we demonstrated that the elevated circulating miR-96-5p levels were significantly correlated with the PCOS disordered endocrine clinical features, and the area under the curve of receiver operating characteristic was 0.8344, with 75.71% specificity and 80% sensitivity. Mechanically, we identified miR-96-5p as an androgen-regulated miRNA that directly targets the forkhead transcription factor FOXO1. Inhibition of miR-96-5p decreased estrogen synthesis, while decreasing the cell proliferation index of KGN via regulating the expression of FOXO1 and its downstream genes. Inversely, inhibition of FOXO1 abrogated the effect of miR-96-5p on estrogen synthesis and proliferation index. Of note, ovarian intra-bursal injection of miR-96-5p agomir rescued the phenotypes of dehydroepiandrosterone-induced PCOS like mice. In conclusion, our results clarified a vital role of miR-96-5p in the pathogenesis of PCOS and might serve as a novel diagnostic biomarker and therapeutic target for PCOS.

LncGSAR Controls Ovarian Granulosa Cell Steroidogenesis via Sponging MiR-125b to Activate SCAP/SREBP Pathway

Long non-coding RNAs (lncRNAs) have been shown to play important roles in livestock fecundity, and many lncRNAs that affect follicular development and reproductive diseases have been identified in the ovary. However, only a few of them have been functionally annotated and mechanistically validated. In this study, we identified a new lncRNA (lncGSAR) and investigated its effects on the proliferation and steroidogenesis of ovine granulosa cells (GCs). High concentrations of glucose (add 33.6 mM glucose) caused high expression of lncGSAR in GCs by regulating its stability, and lncGSAR overexpression promoted GCs proliferation, estrogen secretion, and inhibited progesterone secretion, whereas interference with lncGASR had the opposite effect. Next, we found that the RNA molecules of lncGSAR act on MiR-125b as competitive endogenous RNA (ceRNA), and SREBP-cleavage-activating protein (SCAP) was verified as a target of MiR-125b. LncGASR overexpression increased the expression of SCAP, SREBP, and steroid hormone-related proteins, which can be attenuated by MiR-125b. Our results demonstrated that lncGSAR can act as a ceRNA to activate SCAP/SREBP signaling by sponging MiR-125b to regulate steroid hormone secretion in GCs. These findings provide new insights into the mechanisms of nutrient-regulated follicle development in ewes.

Long Non-Coding RNA GDAR Regulates Ovine Granulosa Cells Apoptosis by Affecting the Expression of Apoptosis-Related Genes

Short-term dietary supplementation of ewes during the luteal phase can increase fertility, most probably by stimulating glucose uptake by the follicles. However, the molecular mechanism of glucose regulation of follicular development has not yet been clarified, especially the further study of long non-coding RNA (lncRNA) in determining fertility during follicular development. We generated granulosa cell (GC) models of different doses of glucose (0, 2.1, 4.2, 8.4, 16.8 and 33.6 mM), and observed that the highest cell viability was recorded in the 8.4 mM group and the highest apoptosis rates were recorded in the 33.6 mM group. Therefore, a control group (n = 3, 0 mM glucose), a low glucose group (n = 3, add 8.4 mM glucose), and a high glucose group (n = 3, add 33.6 mM glucose) of GCs were created for next whole genomic RNA sequencing. In total, 18,172 novel lncRNAs and 510 annotated lncRNAs were identified in the GCs samples. Gene Ontology indicated that differentially expressed lncRNAs associated with cell apoptosis were highly enriched. Kyoto Encyclopedia of Genes and Genomes enrichment analysis of lncRNA target genes found that the apoptosis pathway and the p53 signaling pathway were both enriched. Furthermore, we focused on the function of a lncGDAR and verified that lncGDAR could influence cell apoptosis in GC development through affecting the mRNA and protein expression of apoptosis-related markers. These results provide the basis for further study of the lncRNA regulation mechanism in nutrition on female fertility.

Novel Hub genes co-expression network mediates dysfunction in a model of polycystic ovary syndrome

BACKGROUND

This study aimed to integrate DNA methylation, miRNA, and mRNA microarray data to construct a gene co-expression network for polycystic ovarian syndrome (PCOS).

METHODS

The weighted gene co-expression network analysis (WGCNA) was conducted to construct a PCOS-related co-expression network by using the GEO public datasets. We performed Gene Ontology and KEGG pathway enrichment analyses for a further exploration of gene function in networks. Finally, the dysfunction module consisting of a co-expression network was mapped to the PCOS patients and tried to provide guidance to the PCOS phenotyping.

RESULTS

Three modules (Midnightbule, Pink, and Red) were identified to be PCOS-related by WGCNA analysis. These module-related genes were enriched in cell response to stimulus, PI3K-Akt signaling pathway, insulin biological process, signaling pathway, and cytokine-cytokine receptor interaction biological processes. The multiple-factor network, including miRNA-lncRNA and DNA methylation-mRNA interaction, was closely associated with PCOS dysfunction.

CONCLUSION

Our study render a novel insight into the mechanisms and might provide candidate biomarkers and therapeutic targets for the classification of PCOS dysfunction.

MiR-383-5p promotes apoptosis of ovarian granulosa cells by targeting CIRP through the PI3K/AKT signaling pathway

PURPOSE

To detect miR-383-5p and cold-inducible RNA binding protein (CIRBP, CIRP) expression in patients with polycystic ovary syndrome (PCOS) and explore the mechanism underlying their effect on apoptosis in ovarian granulosa cells (GCs).

METHODS

GCs were extracted from follicular fluid from 101 patients. MiR-383-5p and CIRP expression were assessed by quantitative real time polymerase chain reaction analysis. Correlation between them was assessed by Spearman correlation analysis. The potential of using miR-383-5p expression for discriminating PCOS and non-PCOS patients was predicted by receiver operating characteristic curve analysis. Proliferation and apoptosis of KGN cells transfected for miR-383-5p overexpression or knockdown was evaluated using cell counting kit-8 assay, flow cytometry, and western blot analysis. CIRP was identified as a direct target of miR-383-5p, and verified by dual-luciferase reporter assay.

RESULTS

The expression level of miR-383-5p was decreased and CIRP mRNA was increased in PCOS patients. The expression of miR-383-5p was correlated negatively with body-mass index, basal luteinizing hormone and testosterone levels, luteinizing hormone/follicle-stimulating hormone ratio, and the number of retrieved and metaphase II oocytes. MiR-383-5p had sufficient potential for prediction of PCOS. There was a negative correlation between the expression of miR-383-5p and CIRP. Overexpression of miR-383-5p enhanced the apoptosis of KGN cells. CIRP reversed the effect of miR-383-5p on promotion of apoptosis. MiR-383-5p mimics could suppress the PI3K/AKT signaling pathway, which was activated by the CIRP overexpressing plasmid.

CONCLUSIONS

MiR-383-5p promoted apoptosis of ovarian GCs through the PI3K/AKT signaling pathway by targeting CIRP.

microRNAs and long non-coding RNAs as biomarkers for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is known as the most common metabolic/endocrine disorder among women of reproductive age. Its complicated causality assessment and diagnostic emphasized the role of non‐coding regulatory RNAs as molecular biomarkers in studying, diagnosing and even as therapeutics of PCOS. This review discusses a comparative summary of research into microRNAs (miRNAs) and long non‐coding RNAs (lncRNAs) that are molecularly or statistically related to PCOS. We categorize the literature in terms of centering on either miRNAs or lncRNAs and discuss the combinatory studies and promising ideas as well. Additionally, we compare the pros and cons of the prominent research methodologies used for each of the abovementioned research themes and discuss how errors can be stopped from propagation by selecting correct methodologies for future research. Finally, it can be concluded that research into miRNAs and lncRNAs has the potential for identifying functional networks of regulation with multiple mRNAs (and hence, functional proteins). This new understanding may eventually afford clinicians to control the molecular course of the pathogenesis better. With further research, RNA (with statistical significance and present in the blood) may be used as biomarkers for the disease, and more possibilities for RNA therapy agents can be identified.

Noncoding RNAs in apoptosis: identification and function

Apoptosis is a vital cellular process that is critical for the maintenance of homeostasis in health and disease. The derailment of apoptotic mechanisms has severe consequences such as abnormal development, cancer, and neurodegenerative diseases. Thus, there exist complex regulatory mechanisms in eukaryotes to preserve the balance between cell growth and cell death. Initially, protein-coding genes were prioritized in the search for such regulatory macromolecules involved in the regulation of apoptosis. However, recent genome annotations and transcriptomics studies have uncovered a plethora of regulatory noncoding RNAs that have the ability to modulate not only apoptosis but also many other biochemical processes in eukaryotes. In this review article, we will cover a brief summary of apoptosis and detection methods followed by an extensive discussion on microRNAs, circular RNAs, and long noncoding RNAs in apoptosis.

GLP-1 Receptor Agonists: Beyond Their Pancreatic Effects

Glucagon like peptide-1 (GLP-1) is an incretin secretory molecule. GLP-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes (T2DM) due to their attributes such as body weight loss, protection of islet β cells, promotion of islet β cell proliferation and minimal side effects. Studies have found that GLP-1R is widely distributed on pancreatic and other tissues and has multiple biological effects, such as reducing neuroinflammation, promoting nerve growth, improving heart function, suppressing appetite, delaying gastric emptying, regulating blood lipid metabolism and reducing fat deposition. Moreover, GLP-1RAs have neuroprotective, anti-infectious, cardiovascular protective, and metabolic regulatory effects, exhibiting good application prospects. Growing attention has been paid to the relationship between GLP-1RAs and tumorigenesis, development and prognosis in patient with T2DM. Here, we reviewed the therapeutic effects and possible mechanisms of action of GLP-1RAs in the nervous, cardiovascular, and endocrine systems and their correlation with metabolism, tumours and other diseases.