ROS-Induced GATA4 and GATA6 Downregulation Inhibits StAR Expression in LPS-Treated Porcine Granulosa-Lutein Cells

Atractylenolide-I Alleviates Hyperglycemia-Induced Heart Developmental Malformations through Direct and Indirect Modulation of the STAT3 Pathway

BACKGROUND

Gestational diabetes could elevate the risk of congenital heart defects (CHD) in infants, and effective preventive and therapeutic medications are currently lacking. Atractylenolide-I (AT-I) is the active ingredient of Atractylodes Macrocephala Koidz (known as Baizhu in China), which is a traditional pregnancy-supporting Chinese herb.

PURPOSE

In this study, we investigated the protective effect of AT-I on the development of CHD in embryos exposed to high glucose (HG).

STUDY DESIGN AND METHODS

First, systematic review search results revealed associations between gestational diabetes mellitus (GDM) and cardiovascular malformations. Subsequently, a second systematic review indicated that heart malformations were consistently associated with oxidative stress and cell apoptosis. We assessed the cytotoxic impacts of Atractylenolide compounds (AT-I, AT-II, and AT-III) on H9c2 cells and chick embryos, determining an optimal concentration of AT-I for further investigation. Second, immunofluorescence, western blot, Polymerase Chain Reaction (PCR), and flow cytometry were utilized to delve into the mechanisms through which AT-I mitigates oxidative stress and apoptosis in cardiac cells. Molecular docking was employed to investigate whether AT-I exerts cardioprotective effects via the STAT3 pathway. Then, we developed a streptozotocin-induced diabetes mellitus (PGDM) mouse model to evaluate AT-I's protective efficacy in mammals. Finally, we explored how AT-I protects hyperglycemia-induced abnormal fetal heart development through microbiota analysis and untargeted metabolomics analysis.

RESULTS

The study showed the protective effect of AT-I on embryonic development using a chick embryo model which rescued the increase in the reactive oxygen species (ROS) and decrease in cell survival induced by HG. We also provided evidence suggesting that AT-I might directly interact with STAT3, inhibiting its phosphorylation. Further, in the PGDM mouse model, we observed that AT-I not only partially alleviated PGDM-related blood glucose issues and complications but also mitigated hyperglycemia-induced abnormal fetal heart development in pregnant mice. This effect is hypothesized to be mediated through alterations in gut microbiota composition. We proposed that dysregulation in microbiota metabolism could influence the downstream STAT3 signaling pathway via EGFR, consequently impacting cardiac development and formation.

CONCLUSIONS

This study marks the first documented instance of AT-I's effectiveness in reducing the risk of early cardiac developmental anomalies in fetuses affected by gestational diabetes. AT-I achieves this by inhibiting the STAT3 pathway activated by ROS during gestational diabetes, significantly reducing the risk of fetal cardiac abnormalities. Notably, AT-I also indirectly safeguards normal fetal cardiac development by influencing the maternal gut microbiota and suppressing the EGFR/STAT3 pathway.

miR-21/SMAD2 Is Involved in the Decrease in Progesterone Synthesis Caused by Lipopolysaccharide Exposure in Follicular Granulosa Cells of Laying Goose

Lipopolysaccharide (LPS) is one of the important pathogenic substances of E. coli and Salmonella, which causes injury to the reproductive system. Ovarian dysfunction due to Gram-negative bacterial infections is a major cause of reduced reproductive performance in geese. However, the specific molecular mechanisms of LPS-induced impairment of sex steroid hormone synthesis have not been determined. The regulatory mechanism of miRNA has been proposed in many physiological and pathogenic mechanisms. Therefore, the role of miRNA in breeding geese exposed to LPS during the peak laying period was investigated. In this study, twenty Yangzhou geese at peak laying period were injected with LPS for 0 h, 24 h, and 36 h. The follicular granulosa layer was taken for RNA-seq and analyzed for differentially expressed miRNAs. It was observed that LPS changed the appearance of hierarchical follicles. miRNA sequencing analysis was applied, and miR-21 and SMAD2 (SMAD family member 2) were selected from 51 differentially expressed miRNAs through bioinformatics prediction. The results showed that miR-21 down-regulated SMAD2 expression and progesterone (P4) production in LPS-treated goose granulosa cells (GCs). It also determined that overexpression of miR-21 or silence of SMAD2 suppressed the sex steroid biosynthesis pathway by decreasing STAR and CYP11A1 expression. Down-regulation of miR-21 exacerbates the LPS-induced decline in P4 synthesis and vice versa. The findings indicated that miR-21 was involved in LPS regulation of P4 synthesis in goose granulosa cells by down-regulating SMAD2. This study provides theoretical support for the prevention of LPS-induced ovarian dysfunction in geese.

The role of miR-10a-5p in LPS-induced inhibition of progesterone synthesis in goose granulosa cells by down-regulating CYP11A1

The poultry ovary is a preferred target for E. coli and Salmonella infection of tissues, and lipopolysaccharide (LPS) is a critical molecule in infecting the organism and interfering with cell function, invading the ovaries through the cloaca and interfering with progesterone (P4) secretion by follicular granulosa cells (GCs), seriously affecting the health of breeding geese. miRNAs are small, non-coding RNAs with a variety of important regulatory roles. To investigate the mechanism of miR-10a-5p mediated LPS inhibition of progesterone synthesis in goose granulosa cells, Yangzhou geese at peak laying period were selected as experimental animals to verify the expression levels of genes and transcription factors related to progesterone synthesis. In this study, bioinformatic predictions identified miR-10a-5p target gene CYP11A1, and genes and transcription factors related to the sex steroid hormone secretion pathway were screened. We detected that LPS inhibited CYP11A1 expression while increasing miR-10a-5p expression in vivo. Progesterone decreased significantly in goose granulosa cells treatment with 1 μg/mL LPS for 24 h, while progesterone-related genes and regulatory factors were also suppressed. We also determined that the downregulation of miR-10a-5p led to CYP11A1 expression. Overexpression of miR-10a-5p suppressed LPS-induced CYP11A1 expression, resulting in decreased progesterone secretion. Our findings indicated that miR-10a-5p was up-regulated by LPS and inhibited progesterone synthesis by down-regulating CYP11A1. This study provides insight into the molecular mechanisms regulating geese reproduction and ovulation.

GATA4: Regulation of expression and functions in goat granulosa cells

GATA4 plays a pivotal role in the reproductive processes of mammals. However, the research on GATA4 in goat ovary is limited. This study aimed to study the expression and function of GATA4 in goat ovary. Utilizing real-time PCR and western blot analysis, we studied the expression and regulatory mechanisms of GATA4 in goat ovary and granulosa cells (GCs). We found that GATA4 was expressed in all follicle types in the goat ovary, with significantly higher levels in GCs of larger follicles (>3 mm) compared to those in smaller follicles (<3 mm). Additionally, we demonstrated that human chorionic gonadotrophin (hCG) induced GATA4 mRNA expression via the activation of PKA, MEK, p38 MAPK, PKC, and PI3K pathways in vitro. Our study also showed that hCG suppressed the levels of miR-200b and miR-429, which in turn directly target GATA4, thereby modulating the basal and hCG-induced expression of GATA4. Functionally, we examined the effect of siRNA-mediated GATA4 knockdown on cell proliferation and hormone secretion in goat GCs. Our results revealed that knockdown of GATA4, miR-200b, and miR-429 suppressed cell proliferation. Moreover, knockdown of GATA4 decreased estradiol and progesterone production by inhibiting the promoter activities of CYP11A1, CYP19A1, HSD3B, and StAR. Collectively, our findings suggest a critical involvement of GATA4 in regulating goat GC survival and steroidogenesis.

Interleukin-22 promotes proliferation and reverses LPS-induced apoptosis and steroidogenesis attenuation in human ovarian granulosa cells: implications for polycystic ovary syndrome pathogenesis

OBJECTIVE

Interleukin 22 (IL-22) plays a role in inflammatory diseases. However, whether IL-22 affects the function of ovarian granulosa cells (GCs) and its relationship with Polycystic Ovary Syndrome (PCOS)remains unclear.

METHODS

We investigated the level of IL-22 in human follicular fluid using ELISA. The expression and localization of the IL-22 receptor 1 (IL-22R1) in GCs were investigated by RT-PCR and immunofluorescence staining, respectively. The proliferation of KGN cells (human GCs line) was assessed by CCK-8 assay and EdU assay after treatment with recombinant human IL-22 (rhIL-22) and lipopolysaccharide (LPS). Apoptosis was assessed using flow cytometry. Apoptotic proteins and steroidogenic genes were detected by western blotting.

RESULTS

ELISA's results showed that compared with the control group, PCOS patients showed lower expression of IL-22 in follicular fluid. Immunofluorescence showed that IL-22R1 is expressed and localized in human granulosa cell membranes. IL-22 promoted cell proliferation and reversed LPS-induced inhibition of cell proliferation. IL-22 alone did not affect apoptotic or steroidogenic protein expression, however, it reversed LPS-induced apoptosis via downregulation of Bcl-2, upregulation of Bax and cleaved caspase-3, and restoration of LPS-downregulated StAR, CYP11A1, and CYP19A1 expression. Western blotting confirmed that IL-22 activated the JAK2/STAT3 signaling.

CONCLUSION

IL-22 promotes cell proliferation, inhibits apoptosis, and regulates KGN cell steroidogenesis confronted with LPS, and decreased IL-22 may be involved in the development of PCOS.

Dual role of NR4A1 in porcine ovarian granulosa cell differentiation and granulosa-lutein cell regression in vitro

This study aimed to investigate the role of NR4A1 in forskolin (FSK)-induced granulosa cell (GC) differentiation and PGF_2α-induced granulosa-lutein cell (GLC) regression. For experiment 1, primary porcine GCs were pre-cultured for 6 d before induced-differentiation by FSK with or without siNR4A1, and changes in GC proliferation, lipid droplets (LDs), and P₄ level were detected. For experiment 2, the GLC model was established by FSK as in experiment 1, and then PGF_2α was utilized to induce GLC regression with or without siNR4A1, changes in P₄ secretion, apoptosis proteins, and associated signaling pathway members were detected. Results showed that in experiment 1, FSK up-regulated NR4A1 expression during GC differentiation and decreased GC proliferation activity, which was reversed by siNR4A1. siNR4A1 inhibited the FSK-induced decreases in Cyclin B1/D1 and CDK1/2 mRNA abundances, and increases in P21/P27 mRNA abundances, and FSK-induced LD accumulation. FSK up-regulated P₄ secretion and StAR, CYP11A1 and HSD3B expression, decreased CYP19A1 expression, which were reversed by siNR4A1 except for StAR expression. In experiment 2, PGF_2α induced NR4A1 expression and reduced GLC viability, which were reversed by siNR4A1. Compared with PGF_2α group, the levels of P₄ secretion and StAR expression were higher in PGF_2α+siNR4A1 group, while CYP11A1 and HSD3B expressions held at low levels. siNR4A1 inhibited PGF_2α-induced expression of apoptosis proteins (caspase3, Bax, Fas, TNFa), ATF3, and phosphorylated MAPKs (ERK1/2, P38, JNK). In summary, NR4A1 is involved in regulating porcine GC differentiation and GLC regression as well as the changes in cell proliferation, apoptosis, steroidogenesis, and MAPK pathways, which provide a theoretical basis for further understanding of the mechanism of porcine luteal formation and regression.

Tumor-Derived Oxidative Stress Triggers Ovarian Follicle Loss in Breast Cancer

Breast cancer is a common indication for ovarian cryopreservation. However, whether the grafting ovarian tissue meets functional requirements, as well as the need for additional interventions, remains unclear. The current study demonstrates abnormal serum hormones in breast cancer in humans and breast cancer cell line-derived tumor-bearing mice, and for the first time shows tumor-induced loss of primordial and growing follicles and the number of follicles being lost to either growth or atresia. A gene signature of tumor-bearing mice demonstrates the disturbed regulatory network of steroidogenesis, which links to mitochondria dysfunction in oocytes and granulosa cells via the phosphatidylinositol 3-kinase signaling pathway. Notably, increased reactive oxygen species are identified in serum and ovarian tissues in tumor-bearing mice. Furthermore, supplementation with vitamin C promotes follicular quiescence, repairing tumor-induced follicle loss via inactivation of the phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway, indicating that antioxidants should be a potential fertility therapy to achieve more numbers of healthy follicles ready for ovarian cryopreservation.

Transforming growth factor-β1 disrupts angiogenesis during the follicular-luteal transition through the Smad-serpin family E member 1 (SERPINE1)/serpin family B member 5 (SERPINB5) signalling pathway in the cow

Intense angiogenesis is critical for the development of the corpus luteum and is tightly regulated by numerous factors. However, the exact role transforming growth factor-β1 (TGFB1) plays during this follicular-luteal transition remains unclear. This study hypothesised that TGFB1, acting through TGFB receptor 1 (TGFBR1) and Smad2/3 signalling, would suppress angiogenesis during the follicular-luteal transition. Using a serum-free luteinising follicular angiogenesis culture system, TGFB1 (1 and 10ngmL-1 ) markedly disrupted the formation of capillary-like structures, reducing the endothelial cell network area and the number of branch points (P <0.001 compared with control). Furthermore, TGFB1 activated canonical Smad signalling and inhibited endothelial nitric oxide synthase (NOS3 ) mRNA expression, but upregulated latent TGFB-binding protein and TGFBR1 , serpin family E member 1 (SERPINE1 ) and serpin family B member 5 (SERPINB5 ) mRNA expression. SB431542, a TGFBR1 inhibitor, reversed the TGFB1-induced upregulation of SERPINE1 and SERPINB5 . In addition, TGFB1 reduced progesterone synthesis by decreasing the expression of steroidogenic acute regulatory protein (STAR ), cytochrome P450 family 11 subfamily A member 1 (CYP11A1 ) and 3β-hydroxysteroid dehydrogenase (HSD3B1 ) expression. These results show that TGFB1 regulates NOS3 , SERPINE1 and SERPINB5 expression via TGFBR1 and Smad2/3 signalling and this could be the mechanism by which TGFB1 suppresses endothelial networks. Thereby, TGFB1 may provide critical homeostatic control of angiogenesis during the follicular-luteal transition. The findings of this study reveal the molecular mechanisms underlying the actions of TGFB1 in early luteinisation, which may lead to novel therapeutic strategies to reverse luteal inadequacy.

TNFα-Erk1/2 signaling pathway-regulated SerpinE1 and SerpinB2 are involved in lipopolysaccharide-induced porcine granulosa cell proliferation

Lipopolysaccharide (LPS) is an inhibitory factor that causes hormonal imbalance and subsequently affects ovarian function and fertility in mammals. Previous studies have shown that the exposure of granulosa cells (GC) to LPS leads to steroidogenesis dysfunction. However, the effects of LPS on the viability of GC remain largely unclear. In the present study, we aimed to address this question and unveil the underlying molecular mechanisms using cultured porcine GC. Results showed that GC proliferation and tumor necrosis factor α (TNFα) secretion were significantly increased after exposure to LPS, and these effects were completely reversed by blocking the TNFα sheddase, ADAM17. Moreover, GC proliferation induced by LPS was mimicked by treatment with recombinant TNFα. In addition, SerpinE1 and SerpinB2 expression levels increased in GC after treatment with LPS or recombinant TNFα, whereas blocking the Erk1/2 pathway completely abolished these effects and also inhibited GC proliferation. Further, consistent with the effects of blocking the Erk1/2 pathway, cell proliferation was completely inhibited by knocking down SerpinE1 or SerpinB2 in the presence of LPS or recombinant TNFα. Mitochondrial membrane potential (MMP) polarization in GC was increased by LPS or recombinant TNFα treatment, and these changes were completely negated by Erk1/2 inhibition, but not by SerpinE1 or SerpinB2 knockdown. Taken together, these results suggested that the TNFα-mediated upregulation of SerpinE1 and SerpinB2, through activation of the Erk1/2 pathway plays a crucial role in LPS-stimulated GC proliferation, and the increase in GC MMP may synergistically influence this process.

Integrated Analysis of miRNA-mRNA Interaction Network in Porcine Granulosa Cells Undergoing Oxidative Stress

Oxidative stress (OS), a common intracellular phenomenon induced by excess reactive oxygen species (ROS) generation, has been shown to be associated with mammalian ovarian follicular development blockage and granulosa cell (GC) impairment. However, the mechanism involved in these effects remains unknown, and the effect of OS on the transcriptome profiles in porcine GCs has not been fully characterized. In this study, we found that hydrogen peroxide-mediated oxidative stress induced porcine GC apoptosis and impaired cell viability. Moreover, RNA-seq analysis showed that oxidative stress induced dramatic changes in gene expression in porcine GCs. A total of 2025 differentially expressed genes (DEGs) were identified, including 1940 DEmRNAs and 55 DEmiRNAs. Functional annotation showed that the DEGs were mainly associated with cell states and function regulation. In addition, multiple hub genes (FOXO1, SOD2, BMP2, DICER1, BCL2L11, FZD4, ssc-miR-424, and ssc-miR-27b) were identified by constructing protein-protein interaction and DEmiRNA-DEmRNA regulatory networks. Furthermore, a gene-pathway-function coregulatory network was established and demonstrated that these hub genes were enriched in FoxO, TGF-β, Wnt, PIK3-Akt, MAPK, and cAMP signaling pathways, which play important roles in regulating cell apoptosis, cell proliferation, stress responses, and hormone secretion. The current research provides a comprehensive perspective of the effects of oxidative stress on porcine GCs and also identifies potential therapeutic targets for oxidative stress-induced female infertility.