miR-221-3p regulates apoptosis of ovarian granulosa cells via targeting FOXO1 in older women with diminished ovarian reserve (DOR)

Non-coding RNA-mediated granulosa cell dysfunction during ovarian aging: From mechanisms to potential interventions

As the earliest aging organ in the reproductive system, the ovary has both reproductive and endocrine functions, which are closely related to overall female health. The exact pathogenesis of ovarian aging (OA) remains incompletely understood, with granulosa cells (GCs) dysfunction playing a significant role in this process. Recent advancements in research and biotechnology have highlighted the importance of non-coding RNAs (ncRNAs), including micro RNAs, long non-coding RNAs, and circular RNAs, in regulating the biological functions of GCs through gene expression modulation. This paper provides a comprehensive overview of the role of ncRNAs in various cellular functions such as apoptosis, autophagy, proliferation, and steroid synthesis in GCs, and explores the underlying regulatory mechanisms. Additionally, the therapeutic potential of ncRNAs, particularly those carried by exosomes derived from mesenchymal stem cells, in delaying OA is discussed. Understanding the regulatory mechanisms of ncRNAs in GC function and the current progress in this field is crucial for identifying effective biomarkers and therapeutic targets, ultimately aiding in the early diagnosis, prognostic assessment, and individualized treatment of OA.

miR-361-5p regulates SLC25A24 to maintain mitochondrial function and alleviate granulosa cell dysfunction in diminished ovarian reserve

BACKGROUND

The aim of this study was to investigate the role of miR-361-5p (a tumor suppressor) in regulating granulosa cell function by targeting SLC25A24, a key mitochondrial protein, to uncover potential therapeutic targets for diminished ovarian reserve (DOR).

METHODS

This study included patients undergoing assisted reproductive technology treatment at our hospital. Granulosa cells were isolated from follicular fluid, and KGN cells were used for in vitro experiments. miR-361-5p and SLC25A24 expression levels were manipulated using miRNA mimics and inhibitors, and their effects on cell viability, apoptosis, and mitochondrial function were assessed. Techniques employed included qRT-PCR, Western blot analysis, ELISA, JC-1 staining, and dual-luciferase reporter assays. Key quantitative metrics included changes in mitochondrial DNA (mtDNA), ATP production, and reactive oxygen species (ROS) levels.

RESULTS

miR-361-5p expression was significantly lower in DOR patients' granulosa cells compared to controls (P < 0.01). miR-361-5p inhibition markedly decreased KGN cells viability and increased apoptosis (P < 0.01), while miR-361-5p overexpression had the opposite effects (P < 0.01). SLC25A24 expression was inversely correlated with miR-361-5p levels, and its knockdown reversed the effects of miR-361-5p inhibition. Additionally, miR-361-5p modulation significantly affected mitochondrial function, with its overexpression reducing ROS levels and increasing ATP production (P < 0.01).

CONCLUSION

miR-361-5p plays a pivotal role in maintaining mitochondrial function and reducing KGN cells dysfunction by targeting SLC25A24. These findings offer new insights into the molecular mechanisms of DOR and highlight miR-361-5p as a potential therapeutic target to enhance ovarian reserve and improve fertility outcomes.

miR-192-2 Regulates the Proliferation and Apoptosis of Ovarian Granulosa Cells by Targeting IGFBP2 in Zhedong White Geese

The proliferation and apoptosis of ovarian granulosa cells (GC) is critical for follicular development and ovulation, especially for egg-laying performance in female birds. In geese, follicular atrophy is accompanied by follicular GC apoptosis during brooding stages. MicroRNAs are involved in follicular development, atrophy, ovulation, and degeneration. Our previous high-throughput sequencing study of ovaries from laying and brooding geese revealed that miR-192-2 may be involved in follicle growth and development, as well as follicle cell proliferation and apoptosis in geese. To further investigate the effect of miR-192-2 on GC in geese, we screened the target gene of miR-192-2 (IGFBP2) and constructed a miR-192-2 overexpression and interference vector, synthesized a small interfering RNA for IGFBP2. The results showed that after miR-192-2 overexpression, the mRNA and protein expression of proliferation-related genes (PCNA, CDK2, CCND1, and CCND2) were significantly decreased, the mRNA and protein expression of apoptosis-related genes (Caspase3, Caspase8, and Caspase9) were significantly increased, and the mRNA and protein expression of anti-apoptosis gene Bcl-2 were significantly decreased. While the mRNA and protein expressions of PCNA, CDK2, CCND1, and CCND2 were significantly decreased after the downregulation of IGFBP2 expression, the mRNA and protein expressions of Caspase3, Caspase8, and Caspase9 were significantly increased, and the mRNA and protein expression of Bcl-2 was significantly decreased. In conclusion, miR-192-2 inhibited proliferation and promoted apoptosis of follicular GC by targeting IGFBP2 in Zhedong White geese. Apoptosis of GC leads to follicular atresia, which in turn leads to brooding behavior in female geese. Therefore, it is possible to explore inhibiting the expression of miR-192-2 in production to alter the brooding behavior of Zhedong White Geese, thereby improving egg production and economic returns for producers.

Role of epigenetic regulation in diminished ovarian reserve

Diminished ovarian reserve (DOR) is characterized by a decrease in the number and quality of oocytes, with its incidence increasing annually. Its pathogenesis remains unclear, making it one of the most challenging problems in the field of assisted reproduction. Epigenetic modification, a molecular mechanism affecting genomic activity and expression without altering the DNA sequence, has been widely studied in reproductive medicine and has attracted considerable attention regarding DOR. This review comprehensively examines the various epigenetic regulatory changes in ovarian granulosa cells (OGCs) and oocytes during DOR. DNA methylation plays a crucial role in regulating granulosa cell function, hormone production, and oocyte development, maturation, and senescence. Histone modifications are involved in regulating follicular activation, while non-coding RNAs, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), regulate granulosa cell function and oocyte development. N6-methyladenosine (m6A) modifications are associated with age-related oocyte senescence. Epigenetic clocks based on DNA methylation show potential in predicting ovarian reserve in DOR. Furthermore, it discusses the potential for utilizing epigenetic mechanisms to better diagnose and manage DOR.

MicroRNAs as Biomarkers and Therapeutic Targets in Female Infertility

The study of microRNAs (miRNAs) has emerged in recent decades as a key approach to understanding the pathophysiology of many diseases, exploring their potential role as biomarkers, and testing their use as future treatments. Not only have neurological, cardiovascular diseases, or cancer benefited from this research but also infertility. Female infertility, as a disease, involves alterations at multiple levels, such as ovarian and uterine alterations. This review compiles the latest studies published in humans that link female disorders that affect fertility with altered miRNA profiles. Studies on ovarian alterations, including diminished ovarian reserve (DOR), poor ovarian response to stimulation (POR), premature ovarian insufficiency (POI), and polycystic ovary syndrome (PCOS), are summarized and classified based on the expression and type of sample analyzed. Regarding uterine disorders, this review highlights upregulated and downregulated miRNAs primarily identified as biomarkers for endometriosis, adenomyosis, decreased endometrial receptivity, and implantation failure. However, despite the large number of studies in this field, the same limitations that reduce reproducibility are often observed. Therefore, at the end of this review, the main limitations of this type of study are described, as well as specific precautions or safety measures that should be considered when handling miRNAs.

Seasonal influence on miRNA expression dynamics of extracellular vesicles in equine follicular fluid

BACKGROUND

Ovarian follicular fluid (FF) is a dynamic environment that changes with the seasons, affecting follicle development, ovulation, and oocyte quality. Cells in the follicles release tiny particles called extracellular vesicles (EVs) containing vital regulatory molecules, such as microRNAs (miRNAs). These miRNAs are pivotal in facilitating communication within the follicles through diverse signaling and information transfer forms. EV-coupled miRNA signaling is implicated to be associated with ovarian function, follicle and oocyte growth and response to various environmental insults. Herein, we investigated how seasonal variations directly influence the ovulatory and anovulatory states of ovarian follicles and how are they associated with follicular fluid EV-coupled miRNA dynamics in horses.

RESULTS

Ultrasonographic monitoring and follicular fluid aspiration of preovulatory follicles in horses during the anovulatory (spring: non-breeding) and ovulatory (spring, summer, and fall: breeding) seasons and subsequent EV isolation and miRNA profiling identified significant variation in EV-miRNA cargo content. We identified 97 miRNAs with differential expression among the groups and specific clusters of miRNAs involved in the spring transition (miR-149, -200b, -206, -221, -328, and -615) and peak breeding period (including miR-143, -192, -451, -302b, -100, and let-7c). Bioinformatic analyses showed enrichments in various biological functions, e.g., transcription factor activity, transcription and transcription regulation, nucleic acid binding, sequence-specific DNA binding, p53 signaling, and post-translational modifications. Cluster analyses revealed distinct sets of significantly up- and down-regulated miRNAs associated with spring anovulatory (Cluster 1) and summer ovulation-the peak breeding season (Clusters 4 and 6).

CONCLUSIONS

The findings from the current study shed light on the dynamics of FF-EV-coupled miRNAs in relation to equine ovulatory and anovulatory seasons, and their roles in understanding the mechanisms involved in seasonal shifts and ovulation during the breeding season warrant further investigation.

Effect of moxibustion on expression profile of miRNAs in Tripterygium glycoside-induced decreased ovarian reserve

OBJECTIVE

To explore the possible regulatory mechanism of microRNA (miRNA) in moxibustion treatment for decreased ovarian reserve (DOR).

METHODS

The DOR model was constructed by intragastrical Tripterygium glycoside suspension administration, and moxibustion therapy was simultaneously given. The morphological ovarian changes were observed by hematoxylin and eosin staining. The miRNA expression profile was detected by RNA sequencing, and bioinformatics analysis was performed. Cytoscape software 3.6.1 was used to establish a regulatory network and differentially expressed miRNAs were verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR).

RESULTS

Decreased number of mature follicles, increased atresia follicles, and abnormal granulosa cell morphology were observed in the model group compared with the control group. The moxibustion group demonstrated increased mature follicles, decreased atretic follicles, and significantly decreased abnormal morphology of granulosa cells compared with the model group. Additionally, RNA sequencing results manifested significantly up-regulated miRNA expressions (miR-92b-3p, miR-26-5p_R + 1_1ss10TC, miR-206-3p, miR-9993b-3p_1ss6GA, miR-7857-3p_R-1, miR-219a-2-3p_1ss10GC, miR-3968-p5_1ss10AT, and PC-5p-6478_1795) and down-regulated miR-664-2-5p_R + 1 in the model group, compared with the control group, and the moxibustion group reversed abnormal disorder levels of these miRNAs. Moreover, these differentially expressed miRNAs were mainly involved in the phosphatidylinositol-3-kinase / protein kinase B signaling pathway and nuclear factor erythropoietin-2-related factor 2 / heme oxygenase 1 signaling pathway. Finally, network and RT-qPCR verification revealed miR-9993b-3p_1ss6GA as the most critical miRNA.

CONCLUSION

This experiment proved the effectiveness of moxibustion in improving the ovarian reserve of rats by regulating miRNA expression, especially miR-9993b-3p_1ss6GA.

Mechanism Research of DHEA Treatment Improving Diminished Ovarian Reserve by Attenuating the AMPK-SIRT1 Signaling and Mitophagy

This study aims to investigate the effect and mechanism of dehydroepiandrosterone (DHEA) on diminished ovarian reserve (DOR) by modulating the AMPK-SIRT1 signaling and mitophagy in rats. Three-month-old female Sprague-Dawley (SD) rats were randomized and injected intraperitoneally with sesame oil as the control or deoxyvinylcyclohexene (VCD) to induce DOR. The VCD-injected rats were randomized and injected subcutaneously with vehicle as the model group or with DHEA for 21 days as the DHEA group. After being identified in proestrus, rat blood samples were collected to prepare serum samples, and their ovarian tissues were dissected. Compared with the controls, significantly lower serum estradiol (E2), anti-Müllerian hormone (AMH), and inhibin B (IHNB) and higher follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were detected in the model group (DOR rats). The model group of rats displayed an increase in follicular atresia and a decrease in ovarian volume and the number of growing follicles and corpus luteum, accompanied by increased frequency of oocyte apoptosis and reduced levels of mitochondrial function. Furthermore, significantly higher levels of the AMPK-SIRT1 signaling and mitophagy were observed in the ovaries of rats in the model group. In contrast, treatment with DHEA significantly ameliorated the hormone disorder and morphological changes in the ovaries, reduced the frequency of apoptotic oocytes, and improved mitochondrial function in the ovaries of DOR rats. Mechanistically, DHEA treatment significantly attenuated the AMPK-SIRT1 signaling and mitophagy in the ovaries of DOR rats. DHEA treatment reduced the severity of DOR and enhanced ovarian reserve function by attenuating the AMPK-SIRT1 signaling and mitophagy in the ovaries of rats.

Understanding the Mechanisms of Diminished Ovarian Reserve: Insights from Genetic Variants and Regulatory Factors

Delaying childbearing age has become a trend in modern times, but it has also led to a common challenge in clinical reproductive medicine-diminished ovarian reserve (DOR). Since the mechanism behind DOR is unknown and its clinical features are complex, physicians find it difficult to provide targeted treatment. Many factors affect ovarian reserve function, and existing studies have shown that genetic variants, upstream regulatory genes, and changes in protein expression levels are present in populations with reduced ovarian reserve function. However, existing therapeutic regimens often do not target the genetic profile for more individualized treatment. In this paper, we review the types of genetic variants, mutations, altered expression levels of microRNAs, and other related factors and their effects on the regulation of follicular development, as well as altered DNA methylation. We hope this review will have significant implications for the future treatment of individuals with reduced ovarian reserve.

Forced expression of microRNA-221-3p exerts protective effects against manganese-induced cytotoxicity in human lung epithelial cells

Manganese (Mn)-induced pulmonary toxicity and the underlying molecular mechanisms remain largely enigmatic. Further, in recent years, microRNAs (miRNAs) have emerged as regulators of several pollutants-mediated toxicity. In this context, our study aimed at elucidating whether miRNAs are involved in manganese (II) chloride (MnCl2) (Mn2+)-induced cytotoxicity in lung epithelial cells. Growth inhibition of Mn2+ towards normal human bronchial epithelial (BEAS-2B) and adenocarcinomic human alveolar basal epithelial (A549) cells was analyzed by MTT assay following 24 or 48 h treatment. Reactive oxygen species (ROS) generation, mitochondrial membrane potential (ΔΨm), cell cycle arrest, and apoptosis were evaluated by flow cytometry. RT-qPCR and Western blot were performed to analyze the expression of cyclins, anti-oxidant genes, and miRNAs. We used small RNA sequencing to investigate Mn2+-induced changes in miRNA expression patterns. In both cell lines, Mn2+ treatment inhibited growth in a dose-dependent manner. Further, compared with vehicle-treated cells, Mn2+ (250 μM) treatment induced ROS generation, cell cycle arrest, apoptosis, and decreased ΔΨm as well as altered the expression of cyclins and anti-oxidant genes. Sequencing data revealed that totally 296 miRNAs were differentially expressed in Mn2+-treated cells. Among them, miR-221-3p was one of the topmost down-regulated miRNAs in Mn2+-treated cells. We further confirmed this association in A549 cells. In addition, transient transfection was performed to study gain-of-function experiments. Forced expression of miR-221-3p significantly improved cell viability and reduced Mn2+-induced cell cycle arrest and apoptosis in BEAS-2B cells. In conclusion, miR-221-3p may be the most likely target that accounts for the cytotoxicity of Mn2+-exposed lung epithelial cells.

Network pharmacology and experimental validation on yangjing zhongyu decoction against diminished ovarian reserve

ETHNOPHARMACOLOGICAL RELEVANCE

Diminished ovarian reserve (DOR) was considered a refractory reproductive endocrine condition that negatively affected female reproductivity. Yangjing Zhongyu Decoction (YJZYD) had effects on treating infertility. However, there were few studies on the mechanisms of YJZYD preserving ovarian reserve.

AIM OF THE STUDY

To explore the possible mechanisms of YJZYD against DOR by UPLC-ESI-MS/MS, network pharmacology, and experimental validation.

METHODS

The chemicals of YJZYD were measured by UPLC-ESI-MS/MS. The correlating targets of YJZYD and DOR were identified by the ETCM database, GeneCards database, and PubMed database. The common targets were employed with the DAVID database and visualized with the PPI network. GO and KEGG enrichment analyses were carried out to explore biological progression and pathways. In vivo experiments, energy production was assessed by ATP, and apoptosis rate was analyzed by TUNEL. The serum FSH, AMH, and E2 levels were evaluated by ELISA. Western blotting and immunohistochemistry were used to measure the expression of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, p-Akt, Akt, Bcl-2, and Bax.

RESULTS

132 components in YJZYD were identified by UPLC-ESI-MS/MS. 149 overlapped targets were extracted from YJZYD and DOR, and the top 20 common targets included AKT1 and CYP19A1. ATP binding was involved in GO analysis. In the KEGG enrichment analysis, the metabolic pathway was the top, and the PI3K-Akt signaling pathway was included. In vivo experiments, YJZYD improved ovarian index and histomorphology. After YJZYD treatment, serum FSH, E2, and AMH were well-modulated, and the content of ATP was up-regulated. Besides, the expression of Bax was suppressed in ovarian tissue, while the expressions of SIRT1, PGC1α, NRF1, COX IV, FSHR, CYP19A1, PI3K, Bcl-2, and p-Akt/Akt were enhanced.

CONCLUSION

YJZYD could attenuate reproductive endocrine disturbance and ovarian lesions in vivo by mediating steroidogenesis, energy metabolism, and cell apoptosis. This study uncovered the mechanisms of YJZYD against DOR, providing a theoretical basis for further study.

hsa_circRNA_BECN1 acts as a ceRNA to promote polycystic ovary syndrome progression by sponging the miR-619-5p/Rab5b axis

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease that affects women of reproductive age. It is also a significant cause of infertility. Circular RNAs have been found to have a crucial role in the development and progression of reproductive system diseases. In this study, we focused on circ_BECN1 and aimed to investigate its role and mechanism in PCOS, providing a foundation for early diagnosis and treatment of this condition. Our findings revealed an upregulation of circ_BECN1 expression in the ovarian granulosa cells (GCs) of PCOS patients. Additionally, the silencing of circ_BECN1 resulted in inhibited proliferation and enhanced apoptosis of the human ovarian granulosa-like tumor cell line (KGN), therefore implicating circ_BECN1 in the cell cycle process. Through a dual-luciferase reporting assay, we determined that circ_BECN1 acts as a sponge for miR-619-5p and that Rab5b is the target gene of miR-619-5p. Moreover, the expression of Rab5b was found to be upregulated in the ovarian tissue of PCOS patients. Knocking down circ_BECN1 resulted in decreased Rab5b expression, which was then restored by using a miR-619-5p inhibitor. Additionally, rescue experiments demonstrated that overexpressing Rab5b reversed the effects of circ_BECN1 knockdown on cell proliferation and apoptosis in KGN cells. In summary, our findings indicate that circ_BECN1 is upregulated in PCOS GCs and promotes cell growth and cell cycle progression, and reduces cell apoptosis by modulating the miR-619-5p/Rab5b axis. Therefore, circ_BECN1 may serve as a potential therapeutic target for PCOS treatment.

Rehmannioside D mitigates disease progression in rats with experimental-induced diminished ovarian reserve via Forkhead Box O1/KLOTHO axis

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

Non-Esterified Fatty Acid-Induced Apoptosis in Bovine Granulosa Cells via ROS-Activated PI3K/AKT/FoxO1 Pathway

Non-esterified fatty acid (NEFA), one of negative energy balance (NEB)'s most well-known products, has a significant impact on cows' reproductive potential. Our study used an in vitro model to investigate the deleterious effects of NEFA on bovine granulosa cells (BGCs) and its underlying molecular mechanism. The results showed that high levels of NEFA led to the accumulation of reactive oxygen species (ROS), increased the expression of apoptosis-related factors such as Bcl2-Associated X/B-cell lymphoma-2 (Bax/Bcl-2) and Caspase-3, and down-regulated steroid synthesis-related genes such as sterol regulatory element binding protein 1 (SREBP-1), cytochrome P450c17 (CYP17), and cytochrome P450 aromatase (CYP19), to promote oxidative stress, cell apoptosis, and steroid hormone synthesis disorders in BGCs. In addition, NEFA significantly inhibited phosphatidylinositol 3-kinase (PI3K) and phosphorylated protein kinase B (p-AKT) activity and increased forkhead box O1 (FoxO1) expression. To further explore the role of the PI3K/AKT/FoxO1 signaling pathway in NEFA, we found that pretreatment with AKT-specific activator SC79 (5 mg/mL) for 2 h or transfection with FoxO1 knockdown siRNA in BGCs could alleviate the negative effects of NEFA treatment by decreasing Bax/Bcl-2 ratio and Caspase-3 expression, and upregulating SREBP-1, CYP17, and CYP19 expression. Meanwhile, SC79 significantly inhibited NEFA-induced dephosphorylation and massive nuclear translocation of FoxO1. Taken together, the NEFA induced oxidative stress, apoptosis, and steroid hormone synthesis disorders in BGCs by inhibiting the PI3K/AKT pathway that regulates FoxO1 phosphorylation and nuclear translocation. Our findings help to clarify the molecular mechanisms underlying the negative effects of high levels of NEFA on BGCs.

Effects of acupuncture treatment on microRNAs expression in ovarian tissues from Tripterygium glycoside-induced diminished ovarian reserve rats

Acupuncture is widely used to improve ovarian function. Previously, we demonstrated that acupuncture can improve oxidative stress in rats with tripterygium glycoside tablet suspension (TG)-induced diminished ovarian reserve (DOR). Herein, we aimed to explore the antioxidation mechanism of acupuncture for ameliorating the ovarian reserve in DOR rats. We performed microRNA sequencing and bioinformatics analysis to screen differentially expressed miRNAs (DE miRNAs) in ovarian tissues. In total, 1,172 miRNAs were identified by miRNA sequencing, of which 28 DE miRNAs were detected (including 14 upregulated and 14 downregulated) in ovarian tissues from the acupuncture group when compared with the DOR model rats. Based on functional enrichment analysis, the target genes of DE miRNAs were significantly enriched in GO-biological process (BP) terms associated with biological processes, positive regulation of transcription by RNA polymerase II, signal transduction, regulation of transcription, DNA-templated processes, and oxidation–reduction processes. In the Kyoto Encyclopedia of Genes and Genomes analysis, the main pathways were the MAPK signaling pathway, hepatitis B, proteoglycans in cancer, human cytomegalovirus infection, and the Ras signaling pathway. Finally, reverse transcription-quantitative PCR results confirmed that rno-miR-92b-3p, mdo-miR-26b-5p_R+1_1ss10TC, and bta-miR-7857-3p_R-1 were downregulated in the acupuncture group. The results revealed the impact of acupuncture on miRNA profiling of ovarian tissues from DOR rats, suggesting that rno-miR-92b-3p, mdo-miR-26b-5p_R+1_1ss10TC, and bta-miR-7857-3p_R-1 might provide relevant cues to relieve DOR-mediated oxidative stress.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Expression of pro-apoptotic and anti-apoptotic proteins in granulosa cells of women with diminished ovarian reserve

PURPOSE

To evaluate the expressions of caspase-3 and cytochrome c and heat shock protein 70 (Hsp70) in granulosa cells (GCs) from women with normal ovarian reserve (NOR) and diminished ovarian reserve (DOR) undergoing intracytoplasmic sperm injection (ICSI).

METHODS

GCs were collected from 117 infertile women during oocyte retrieval. Patients were classified into four groups as follows: DOR-COC score of 0, DOR-COC score of I, NOR-COC score of 0, and NOR-COC score of I. The caspase-3, cytochrome c, and Hsp70 analyses were performed immunohistochemically in GCs. The ICSI outcomes were evaluated prospectively.

RESULTS

The clinical pregnancy and live birth rates were higher in DOR-COC score of I (15, 30.6%; 14, 38.9%) and NOR-COC score of I (19, 38.77%; 19, 52.7%) groups, compared with DOR-COC score of 0 (12, 24.4%; 3, 6.1%) and NOR-COC score of 0 (3, 6.1%; 0%) groups (p = 0.0001; 0.00002), respectively. Caspase-3 and cytochrome c expression levels were higher in DOR-COC score of 0 (23, 65.7%; 25, 71.4%) and NOR-COC score of 0 groups (19, 61.3%; 20, 64.5%), compared with DOR-COC score of I (8, 32%; 9, 36%) and NOR-COC score of I groups (7, 26.9%; 8, 30.8%) (p = 0.00297; p = 0.002), respectively. Lower expression levels of Hsp70 were found in DOR-COC score of 0 (11, 31.4%) and NOR-COC score of 0 groups (10, 32.3%), compared with DOR-COC score of I (16, 64%) and NOR-COC score of I groups (20, 76.9%) (p = 0.001), respectively. Hsp70 expression levels were positively correlated with the number of day 3 good-quality embryo and negatively correlated with estradiol levels in the DOR group.

CONCLUSION

Our data suggest that COC score of 0 is associated with increased expression levels of apoptotic proteins, decreased expression levels of anti-apoptotic protein, and poor ICSI clinical outcomes in women with and without DOR.

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18-24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl2) in vitro. Lethal concentration (LC50) values for CdCl2 resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl2, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial-mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

miR-221-3p regulates apoptosis of ovarian granulosa cells via targeting FOXO1 in older women with diminished ovarian reserve (DOR)

In our earlier study, we showed that the expression of microRNA‐221‐3p (miR‐221‐3p) was significantly lower in women of advanced age with diminished ovarian reserve (DOR) compared with young women with normal ovarian reserve (NOR). Therefore, in this study, we aimed to explore how miR‐221‐3p regulates apoptosis of granulosa cells and the pathogenesis of DOR. Bioinformatics prediction and dual‐luciferase reporter assay were conducted to identify the target gene of miR‐221‐3p. miR‐221‐3p expression was manipulated by transfecting KGN cells with miR‐221‐3p mimics, inhibitor, and negative control. Following transfection, apoptosis of granulosa cells was determined by flow cytometry, and the expression of the target gene was measured by quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot analysis (WB). In addition, the expression of the target gene in granulosa cells of DOR patients and NOR patients was measured. miR‐221‐3p were found to directly bind the 3ʹ untranslated region of Forkhead box O1 (FOXO1). Transfection with miR‐221‐3p mimics significantly decreased the apoptosis rate of KGN cells compared with transfection with miR‐221‐3p inhibitors. The expression level of miR‐221‐3p was negatively correlated with the messenger RNA and protein levels of the FOXO1 gene. Besides, FOXO1 expression was upregulated in DOR patients. In conclusion, these results provide evidence that downregulation of miR‐221‐3p expression promotes apoptosis of granulosa cells by upregulating FOXO1 expression, thus serving an important role in DOR pathogenesis.