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

Dynamic responses during early development of the sea urchin Strongylocentrotus intermedius to CO2-driven ocean acidification: A microRNA-mRNA integrated analysis

To explore the dynamic molecular responses to CO2-driven ocean acidification (OA) during the early developmental stages of sea urchins, gametes of Strongylocentrotus intermedius were fertilized and developed to the four-armed larva stage in either natural seawater (as a control; pHNBS = 7.99 ± 0.01) or acidified conditions (ΔpHNBS = -0.3, -0.4, and - 0.5 units) according to the prediction for ocean pH by the end of this century. Specimens from five developmental stages (fertilization, cleavage, blastula, prism, and four-armed larva) were collected and comparative microRNA (miRNA) and mRNA transcriptome analyses were performed. The results showed that 1) a total of 22,224 differentially expressed genes (DEGs) and 51 differentially expressed miRNAs (DEMs) were identified in the OA-treated groups compared with the control group. 2) The numbers of both DEGs and DEMs were the largest at the blastula stage, indicating dramatic changes in gene expression. 3) Five "miR-1/DEG" modules were identified as potential biomarkers reflecting the response of sea urchins to OA during the early developmental period. 4) The PI3K/Akt signaling pathway was a key pathway involved in the response of S. intermedius to OA in its early developmental stages. This study deepens our understanding of the dynamic molecular regulatory mechanisms underlying sea urchin responses to CO2-driven OA.

Oxidative stress controls lncRNA-mediated sow granulosa cell functions in a FoxO1-dependent manner

BACKGROUND

Oxidative stress (OS) is involved in low female fertility by altering multi-omics such as the transcriptome, miRome, and lncRNome in follicular cells and follicular fluid. However, the mechanism by which OS affects multi-omics dynamics remains largely unknown. Here, we report that OS induces lncRNome dynamics in sow granulosa cells (sGCs), which is partially dependent on the transcription factor activity of its effector, FoxO1.

RESULTS

A total of 2,283 putative FoxO recognition elements (FREs) were identified in the promoters of 394 lncRNAs, accounting for 91.20% (394/432) of the lncRNAs regulated by OS. ChIP and reporter assays showed that the effector FoxO1 mediated OS regulation of lncRNA transcription in a transcription factor activity-dependent manner. In sGCs, OS induces the transcription and function (e.g., apoptosis) of NORSF (non-coding RNA involved in sow fertility), a nuclear lncRNA involved in sGC function via FoxO1. Furthermore, FoxO1 has been identified as a transcriptional activator of NORSF in sGCs that interacts with the FRE motif of its promoter. Meanwhile, OS downregulates the transcription of CYP19A1, which encodes an essential enzyme for estrogen synthesis and 17β-estradiol (E2) release by sGCs via the FoxO1 and NORSF axis. Phenotypically, dysregulation of NORSF transcription caused by 2 novel adjacent transitions in the promoter leads to decreased sow fertility.

CONCLUSION

These results suggest a model of OS-stimulated lncRNome dynamics in sGCs and a new signaling pathway of OS that influences sGC function and sow fertility.

The effects and mechanisms of heat stress on mammalian oocyte and embryo development

The sum of nonspecific physiological responses exhibited by mammals in response to the disruption of thermal balance caused by high-temperature environments is referred to as heat stress (HS). HS affects the normal development of mammalian oocyte and embryos and leads to significant economic losses. Therefore, it is of great importance to gain a deep understanding of the mechanisms underlying the effects of HS on oocyte and embryonic development and to explore strategies for mitigating or preventing its detrimental impacts in the livestock industry. This article provides an overview of the negative effects of HS on mammalian oocyte growth, granulosa cell maturation and function, and embryonic development. It summarizes the mechanisms by which HS affects embryonic development, including generation of reactive oxygen species (ROS), endocrine disruption, the heat shock system, mitochondrial autophagy, and molecular-level alterations. Furthermore, it discusses various measures to ameliorate the effects of HS, such as antioxidant use, enhancement of mitochondrial function, gene editing, cultivating varieties possessing heat-resistant genes, and optimizing the animals'rearing environment. This article serves as a valuable reference for better understanding the relationship between HS and mammalian embryonic development as well as for improving the development of mammalian embryos and economic benefits under HS conditions in livestock production.

MiR-196a-5p hinders vascular smooth muscle cell proliferation and vascular remodeling via repressing BACH1 expression

Hyperproliferation of vascular smooth muscle cells (VSMCs) is a driver of hypertensive vascular remodeling. This study aimed to uncover the mechanism of BTB and CNC homology 1 (BACH1) and microRNAs (miRNAs) in VSMC growth and hypertensive vascular remodeling. With the help of TargetScan, miRWalk, miRDB, and miRTarBase online database, we identified that BACH1 might be targeted by miR-196a-5p, and overexpressed in VSMCs and aortic tissues from spontaneously hypertensive rats (SHRs). Gain- and loss-of-function experiments demonstrated that miR-196a-5p suppressed VSMC proliferation, oxidative stress and hypertensive vascular remodeling. Double luciferase reporter gene assay and functional verification showed that miR-196a-5p cracked down the transcription and translation of BACH1 in both Wistar Kyoto rats (WKYs) and SHRs. Silencing BACH1 mimicked the actions of miR-196a-5p overexpression on attenuating the proliferation and oxidative damage of VSMCs derived from SHRs. Importantly, miR-196a-5p overexpression and BACH1 knockdown cooperatively inhibited VSMC proliferation and oxidative stress in SHRs. Furthermore, miR-196a-5p, if knocked down in SHRs, aggravated hypertension, upregulated BACH1 and promoted VSMC proliferation, all contributing to vascular remodeling. Taken together, targeting miR-196a-5p to downregulate BACH1 may be a promising strategy for retarding VSMC proliferation and hypertensive vascular remodeling.

From stability to reliability: Unveiling the un-biased reference genes in porcine ovarian granulosa cells under different conditions

Selection of optimal reference genes (RGs) is fundamental for functional genomics studies and gene expression analysis, which are two main approaches to identify functional genes and their expression patterns. However, no systematic study has identified the suitable RGs in porcine ovarian granulosa cells (GCs) which are essential for follicle fate and sow fertility. In this study, the expression profiles of 12 widely-used RGs (GAPDH, RPLP0, ACTB, TUBA1B, EIF3K, PPIA, ATP5F1, B2M, HPRT1, UBC, RPS3, and EEF1A1) in porcine GCs during follicular development and under different abiotic stresses were systematically investigated. Expression stability of the candidate RGs were comprehensively accessed by five statistical algorithms including ΔCt, NormFinder, BestKeeper, geNorm, and RefFinder, indicating that RPS3 and PPIA are the optimal RGs during follicular development, EEF1A1 and RPLP0 are most stable under oxidative stress and inflammation, while ATP5F1, B2M, and RPS3 have higher stability under starvation and heat stress. Notably, the most commonly used RGs (ACTB, GAPDH, and TUBA1B) exhibited low stability in GCs. Reliability of stable RGs was verified by RT-qPCR and showed that selection of the stable RGs significantly improved the detection accuracy of qPCR, which confirms once again that the stability of RGs should not be taken for granted. Our findings identified optimal RG sets in porcine GCs under different conditions, which is helpful in future studies to accurately identify the key regulators and their expression patterns during follicular development in sows.

Comparative miRNA expression profile analysis of porcine ovarian follicles: new insights into the initiation mechanism of follicular atresia

Follicular atresia occurs in every stage of ovarian development, which is relevant to female fertility. In the past decade, increasing studies have confirmed that miRNAs, a class of short non-coding RNAs, play an important role in follicular atresia by post-transcription regulation of their target genes. However, the function of miRNAs on follicular atresia initiation is unknown. In the present study, high-throughput small RNA sequencing was performed to analyze differential miRNA expression profiles between healthy (HF) follicles and early atretic (EAF) follicles. A total of 237 conserved miRNA were detected, and the miR-143 is the highest expressed in follicles. Meanwhile, we also found wide sequence variations (isomiRs) in porcine ovarian miRNA, including in 5'un-translation region, core seed sequences and 3'untranslation region. Furthermore, we identified 22 differentially expressed miRNAs in EAF groups compared to HF group, of which 3 miRNAs were upregulated, as well as 19 miRNAs were downregulated, and then the RT-PCR was performed to validate these profiles. The target genes of these differentially expressed miRNAs were predicted by using miRwalk, miRDB, and Targetscan database, respectively. Moreover, the gene ontology and KEGG pathway enrichment established that the regulating functions and signaling pathways of these miRNAs contribute to follicular atresia initiation and cell fate. In conclusion, this study provides new insights into the changes of miRNAs in early atretic follicles to demonstrate their molecular regulation in ovarian follicular atretic initiation.

β-Nicotinamide Mononucleotide Alleviates Hydrogen Peroxide-Induced Cell Cycle Arrest and Death in Ovarian Granulosa Cells

Maintaining normal functions of ovarian granulosa cells (GCs) is essential for oocyte development and maturation. The dysfunction of GCs impairs nutrition supply and estrogen secretion by follicles, thus negatively affecting the breeding capacity of farm animals. Impaired GCs is generally associated with declines in Nicotinamide adenine dinucleotide (NAD+) levels, which triggers un-controlled oxidative stress, and the oxidative stress, thus, attack the subcellular structures and cause cell damage. β-nicotinamide mononucleotide (NMN), a NAD+ precursor, has demonstrated well-known antioxidant properties in several studies. In this study, using two types of ovarian GCs (mouse GCs (mGCs) and human granulosa cell line (KGN)) as cell models, we aimed to investigate the potential effects of NMN on gene expression patterns and antioxidant capacity of both mGCs and KGN that were exposed to hydrogen peroxide (H2O2). As shown in results of the study, mGCs that were exposed to H2O2 significantly altered the gene expression patterns, with 428 differentially expressed genes (DEGs) when compared with those of the control group. Furthermore, adding NMN to H2O2-cultured mGCs displayed 621 DEGs. The functional enrichment analysis revealed that DEGs were mainly enriched in key pathways like cell cycle, senescence, and cell death. Using RT-qPCR, CCK8, and β-galactosidase staining, we found that H2O2 exposure on mGCs obviously reduced cell activity/mRNA expressions of antioxidant genes, inhibited cell proliferation, and induced cellular senescence. Notably, NMN supplementation partially prevented these H2O2-induced abnormalities. Moreover, these similar beneficial effects of NMN on antioxidant capacity were confirmed in the KGN cell models that were exposed to H2O2. Taken together, the present results demonstrate that NMN supplementation protects against H2O2-induced impairments in gene expression pattern, cell cycle arrest, and cell death in ovarian GCs through boosting NAD+ levels and provide potential strategies to ameliorate uncontrolled oxidative stress in ovarian GCs.

Melatonin-Mediated Suppression of mtROS-JNK-FOXO1 Pathway Alleviates Hypoxia-Induced Apoptosis in Porcine Granulosa Cells

Numerous studies have established that the hypoxic conditions within ovarian follicles induce apoptosis in granulosa cells (GCs), a pivotal hallmark of follicular atresia. Melatonin (N-acetyl-5-methoxytryptamine, MT), a versatile antioxidant naturally present in follicular fluid, acts as a safeguard for maintaining GCs' survival during stress exposure. In this study, we unveil an innovative protective mechanism of melatonin against hypoxia-triggered GC apoptosis by selectively inhibiting mitochondrial ROS (mtROS) generation. Specifically, under hypoxic conditions, a gradual accumulation of mitochondrial ROS occurred, consequently activating the JNK-FOXO1 pathway, and driving GCs toward apoptosis. The blocking of JNK or FOXO1 diminished hypoxia-induced GC apoptosis, but this effect was nullified in the presence of GSH, indicating that mtROS instigates apoptosis through the JNK-FOXO1 pathway. Consistent with this, hypoxic GCs treated with melatonin exhibited decreased levels of mtROS, reduced JNK-FOXO1 activation, and mitigated apoptosis. However, the protective capabilities of melatonin were attenuated upon inhibiting its receptor MTNR1B, accompanied by the decreased expression of antioxidant genes. Notably, SOD2, a key mitochondrial antioxidant gene modulated by the melatonin-MTNR1B axis, effectively inhibited the activation of mtROS-JNK-FOXO1 and subsequent apoptosis, whereas SOD2 knockdown abrogated the protective role of melatonin in hypoxic GCs. In conclusion, our study elucidates that melatonin, through MTNR1B activation, fosters SOD2 expression, effectively quelling mtROS-JNK-FOXO1-mediated apoptosis in follicular GCs under hypoxic stress.

Mechanisms of and Potential Medications for Oxidative Stress in Ovarian Granulosa Cells: A Review

Granulosa cells are essential for follicle initiation and development, and their abnormal function or apoptosis is a crucial factor leading to follicular atresia. A state of oxidative stress occurs when the balance between the production of reactive oxygen species and the regulation of the antioxidant system is disturbed. Oxidative stress is one of the most important causes of the abnormal function and apoptosis of granulosa cells. Oxidative stress in granulosa cells causes female reproductive system diseases, such as polycystic ovary syndrome and premature ovarian failure. In recent years, studies have confirmed that the mechanism of oxidative stress in granulosa cells is closely linked to the PI3K-AKT signaling pathway, MAPK signaling pathway, FOXO axis, Nrf2 pathway, NF-κB signaling pathway, and mitophagy. It has been found that drugs such as sulforaphane, Periplaneta americana peptide, and resveratrol can mitigate the functional damage caused by oxidative stress on granulosa cells. This paper reviews some of the mechanisms involved in oxidative stress in granulosa cells and describes the mechanisms underlying the pharmacological treatment of oxidative stress 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.

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.

A Mutation in Endogenous saRNA miR-23a Influences Granulosa Cells Response to Oxidative Stress

Phenotypes are the result of the interaction between the gene and the environment, so the response of individuals with different genotypes to an environment is variable. Here, we reported that a mutation in miR-23a influences granulosa cells (GCs) response to oxidative stress, a common mechanism of environmental factors affecting female reproduction. We showed that nuclear miR-23a is a pro-apoptotic miRNA in porcine GCs through the activation of the transcription and function of NORHA, a long non-coding RNA (lncRNA) induces GC apoptosis and responses to oxidative stress. Mechanistically, miR-23a acts as an endogenous small activating RNA (saRNA) to alter histone modifications of the NORHA promoter through the direct binding to its core promoter. A C > T mutation was identified at −398 nt of the miR-23a core promoter, which created a novel binding site for the transcription factor SMAD4 and recruited the transcription repressor SMAD4 to inhibit miR-23a transcription and function in GCs. Notably, g.−398C > T mutation in the miR-23a promoter reduced GCs response to oxidative stress. In addition, g.−398C > T mutation was significantly associated with sow fertility traits. In short, our findings preliminarily revealed the genetic basis of individual differences in the response to oxidative stress from the perspective of a single mutation and identified miR-23a as a candidate gene for the environmental adaptation to oxidative stress.

Discovery of Differentially Expressed MicroRNAs in Porcine Ovaries With Smaller and Larger Litter Size

The number of live births in a litter is an important reproductive trait, and is one of the main indicators which reflect the production level and economic benefit of a pig farm. The ovary is an important reproductive organ of the sow, and it undergoes a series of biological processes during each estrous cycle. A complex transcriptional network containing coding and non-coding RNAs in the ovary closely regulates the reproductive capability of sows. However, the molecular regulation mechanisms affecting sow litter size are still unclear. We investigated the expression profiles of microRNAs (miRNAs) in porcine ovaries from sows with smaller than average litter sizes (SLS) and those with larger litter sizes (LLS). In total, 411 miRNAs were identified, and of these 17 were significantly down-regulated and 16 miRNAs were up-regulated when comparing sows with LLS and SLS, respectively. We further characterized the role of miR-183 which was one of the most up-regulated miRNAs. CCK-8, EdU incorporation and western blotting assays demonstrated that miR-183 promoted the proliferation of granulosa cells (GCs) in pig ovaries. Moreover, miR-183 inhibited the synthesis of estradiol in GCs and promoted the synthesis of progesterone. These results will help in gaining understanding of the role of miRNAs in regulating porcine litter size.

ALK7 Inhibition Protects Osteoblast Cells Against High Glucoseinduced ROS Production via Nrf2/HO-1 Signaling Pathway

BACKGROUND

Some studies demonstrated that under high-glucose (HG) condition, osteoblasts develop oxidative stress, which will impair their normal functions. The effects of activin receptor-like kinase 7 (ALK7) silencing on HG-induced osteoblasts remained unclear.

OBJECTIVE

The aim of this study was to explore the effect of ALK7 on HG-induced osteoblasts.

METHODS

MC3T3-E1 cells were treated with different concentrations of HG (0, 50, 100, 200 and 300mg/dL), and the cell viability was detected using cell counting kit-8 (CCK-8). HG-treated MC3T3-E1 cells were transfected with siALK7 or ALK7 overexpression plasmid or siNrf2, and then the viability and apoptosis were detected by CCK-8 and flow cytometry. The levels of Reactive Oxygen Species (ROS), collagen I and calcification nodule were determined by oxidative stress kits, Enzyme-linked immunosorbent assay and Alizarin red staining. The expressions of NF-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and osteoblast-associated genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot.

RESULTS

Cell viability was reduced with HG treatment. Silencing ALK7 inhibited the effect of HG on increasing cell apoptosis and ROS production, reduced cell viability, mineralized nodules, and downregulated collagen I and osteoblast-associated genes expression in MC3T3-E1 cells. ALK7 silencing activated the Nrf2/HO-1 signaling pathway by affecting expressions of HO-1 and Nrf2. ALK7 overexpression had the opposite effects. In addition, siNrf2 partially reversed the effects of ALK7 silencing on HG-induced MC3T3-E1 cells.

CONCLUSION

ALK7 silencing protected osteoblasts under HG condition possibly through activating the Nrf2/HO-1 pathway.

MicroRNA Expression Profiling in Porcine Liver, Jejunum and Serum upon Dietary DON Exposure Reveals Candidate Toxicity Biomarkers

Deoxynivalenol (DON), a frequent mycotoxin worldwide, impairs human and animal health. The response of microRNAs, small non-coding RNAs, to DON has been scarcely investigated, but holds remarkable potential for biomarker applications. Hence, we aimed to investigate DON-induced changes in the microRNA expression in porcine liver, jejunum and serum by combining targeted and untargeted analyses. Piglets received uncontaminated feed or feed containing 900 µg/kg and 2500 µg/kg DON for four weeks, followed by a wash-out period. In tissue, only slight changes in microRNA expression were detected, with ssc-miR-10b being downregulated in liver of DON-exposed piglets. In serum, several microRNAs were differentially expressed upon DON exposure, four of which were validated by qPCR (ssc-miR-16, ssc-miR-128, ssc-miR-451, ssc-miR-205). The serum microRNA response to DON increased over time and declined after removal of contaminated diets. Receiver operating curve analyses for individual microRNAs were significant, and a combination of the four microRNAs increased the predictive capacity for DON exposure. Predicted microRNA target genes showed enrichment of several pathways including PIK3-AKT, Wnt/β-catenin, and adherens junctions. This study gives, for the first time, a comprehensive view of the porcine microRNA response to DON, providing a basis for future research on microRNAs as biomarkers for mycotoxins.

The effect of light on follicular development in laying hens

OBJECTIVE

The oxidative stress status and changes of chicken ovary tissue after shading were studied, to determine the mechanism of the effect of shading on follicular development.

METHODS

Twenty healthy laying hens (40 weeks old) with uniform body weight and the same laying rate were randomly divided into two groups (the shading group and normal light group). In the shading group, the cage was covered to reduce the light intensity inside the cage to 0 without affecting ventilation or food intake. The normal lighting group received no additional treatment. After 7 days of shading, oxidative stress related indicators and gene expression were detected.

RESULTS

Analysis of paraffin and ultrathin sections showed that apoptosis of ovarian granulosa cells (GCs) increased significantly after light shading. Enzyme linked immunosorbent assay results revealed that the levels of total antioxidant capacity, malondialdehyde, superoxide dismutase (SOD), glutathione, catalase (CAT), and other substances in the sera, livers, ovaries, and follicular GCs of laying hens increased significantly after shading for 7 days; and reactive oxygen species (ROS) levels in the livers of laying hens also increased significantly. ROS in the serum, ovarian and GCs also increased. After shading for 7 days, the levels of 8-hydroxy-2 deoxyguanosine in the sera and ovarian tissues of laying hens increased significantly. Cell counting kit-8 detection showed that the proliferation activity of GCs in layer follicles decreased after shading for 7 days; the expression level of the anti-apoptotic gene B-cell lymphoma-2 in ovarian tissue and follicular GCs was significantly reduced, and the expression levels of pro-apoptotic caspase 3 (casp3), and SOD, glutathione peroxidase 2 (GPX2), and CAT were all significantly increased.

CONCLUSION

Oxidative stress induced by shading light has a serious inhibitory effect on follicular development during reproduction in laying hens.

miR-31-5p Promotes Oxidative Stress and Vascular Smooth Muscle Cell Migration in Spontaneously Hypertensive Rats via Inhibiting FNDC5 Expression

Oxidative stress and the migration of vascular smooth muscle cells (VSMCs) are important for vascular remodeling in a variety of vascular diseases. miR-31-5p promotes cell migration in colorectal cancer cells but inhibits cell migration in renal cell carcinoma. However, whether miR-31-5p is involved in oxidative stress and VSMC migration remains unknown. This study shows the crucial roles of miR-31-5p in oxidative stress and VSMC migration, as well as underlying mechanisms. Experiments were carried out in primary VSMCs from aortic media of Wistar–Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), as well as the A7r5 cell line. Oxidative stress was assessed by NADPH oxidase (NOX) expression, NOX activity, and reactive oxygen species (ROS) production. Cell migration was evaluated with a Boyden chamber assay and a wound healing assay. The miR-31-5p mimic and inhibitor promoted and attenuated oxidative stress and cell migration in the VSMCs of SHR, respectively. A dual-luciferase reporter assay indicated that miR-31-5p targeted the 3’UTR domain of FNDC5. The miR-31-5p level was raised and FNDC5 expression was reduced in the VSMCs of SHR compared with those of WKY. The miR-31-5p mimic reduced FNDC5 expression in the A7r5 cells and the VSMCs of both WKY and SHR, while the miR-31-5p inhibitor only increased FNDC5 expression in the VSMCs of SHR. Exogenous FNDC5 attenuated not only the oxidative stress and VSMC migration in SHR but also the roles of the miR-31-5p mimic in inducing oxidative stress and VSMC migration. These results indicate that miR-31-5p promotes oxidative stress and VSMC migration in SHR via inhibiting FNDC5 expression. The increased miR-31-5p and reduced FNDC5 in the VSMCs of SHR contribute to enhanced oxidative stress and cell migration.

TRDMT1 participates in the DNA damage repair of granulosa cells in premature ovarian failure

The molecular mechanisms underlying premature ovarian failure, which seriously impacts the physical and psychological health of patients, are not fully understood. Here, we present the role of TRDMT1 in reactive oxygen species-induced granulosa cells death, which is considered an important cause of premature ovarian failure. We found that reactive oxygen species were increased in a H2O2 dose-dependent manner and accompanied by the nuclear shuttling of TRDMT1, increased DNA damage and increased apoptosis of granulosa cells. In addition, reactive oxygen species-induced granulosa cells apoptosis could be prevented by the antioxidant N-acetylcysteine or overexpression of TRDMT1. Furthermore, DNA repair following reactive oxygen species induction was severely impaired/enhanced in TRDMT1 mutants, which exhibited reduced/increased RNA m5C methylation activity. Altogether, our results reveal a novel role of TRDMT1 in the regulation of premature ovarian failure through the repair of reactive oxygen species-triggered DNA damage in granulosa cells and provide an improved understanding of the mechanisms underlying granulosa cells apoptosis, which could potentially be useful for future clinical treatments of premature ovarian failure.

Comprehensive Transcriptome Analysis of mRNA Expression Patterns of Early Embryo Development in Goat under Hypoxic and Normoxic Conditions

Simple Summary

Oxygen plays a vital role in the development of early embryos, no matter whether it is too high or low, it will adversely affect the early embryo development, but the mechanisms involved in these effects are still unclear. RNA-seq was performed to compare 8-cell-stage and blastocyst-stage goat embryos under hypoxic and normoxic conditions, the mRNA expression mechanisms of 8-cell- and blastocyst-stage embryos were systematically analyzed under hypoxic and normoxic conditions. Functional enrichment analysis indicated that these differentially expressed genes (DEGs) were mainly related to biological processes and function regulation. In conclusion, we can infer that oxidative stress regulates early embryo development by affecting the expression of zygotic genes and transcription factors, and those stress genes play a potential role in adaptation to normoxic environments in goat embryos.

Abstract

It has been reported that hypoxic environments were more suitable for the in vitro development of mammalian embryos, but the underlying mechanisms were still unclear. In the present study, RNA-seq was performed to compare 8-cell-stage and blastocyst-stage goat embryos under hypoxic and normoxic conditions; zygotes were checked at 72 and 168 h to 8-cell stage (L8C) and blastocyst stage (LM) in hypoxic conditions and 8-cell stage (H8C) and blastocyst stage (HM) in normoxic conditions. In the H8C and L8C groups, 399 DEGs were identified, including 348 up- and 51 down-regulated DEGs. In the HM and LM groups, 1710 DEGs were identified, including 1516 up- and 194 down-regulated DEGs. The expression levels of zygotic genes, transcription factors, and maternal genes, such as WEE2, GDF9, HSP70.1, BTG4, and UBE2S showed significant changes. Functional enrichment analysis indicated that these DEGs were mainly related to biological processes and function regulation. In addition, combined with the pathway–gene interaction network and protein–protein interaction network, twenty-two of the hub genes were identified and they are mainly involved in energy metabolism, immune stress response, cell cycle, receptor binding, and signal transduction pathways. The present study provides comprehensive insights into the effects of oxidative stress on early embryo development in goats.

Transcriptomic Data Analyses Reveal That Sow Fertility-Related lincRNA NORFA Is Essential for the Normal States and Functions of Granulosa Cells

NORFA, the first lincRNA associated with sow fertility, has been shown to control granulosa cell (GC) functions and follicular atresia. However, the underlying mechanism is not fully understood. In this study, RNA-seq was performed and we noticed that inhibition of NORFA led to dramatic transcriptomic alterations in porcine GCs. A total of 1,272 differentially expressed transcripts were identified, including 1167 DEmRNAs and 105 DEmiRNAs. Furthermore, protein-protein interaction, gene-pathway function, and TF-miRNA-mRNA regulatory networks were established and yielded four regulatory modules with multiple hub genes, such as AR, ATG5, BAK1, CENPE, NR5A1, NFIX, WNT5B, ssc-miR-27b, and ssc-miR-126. Functional assessment showed that these hub DEGs were mainly enriched in TGF-β, PI3K-Akt, FoxO, Wnt, MAPK, and ubiquitin pathways that are essential for GC states (apoptosis and proliferation) and functions (hormone secretion). In vitro, we also found that knockdown of NORFA in porcine GCs significantly induced cell apoptosis, impaired cell viability, and suppressed 17β-estradiol (E2) synthesis. Notably, four candidate genes for sow reproductive traits (INHBA, NCOA1, TGFβ-1, and TGFBR2) were also identified as potential targets of NORFA. These findings present a panoramic view of the transcriptome in NORFA-reduced GCs, highlighting that NORFA, a candidate lincRNA for sow fertility, is crucial for the normal states and functions of GCs.

TGF-β1 controls porcine granulosa cell states: A miRNA-mRNA network view

TGF-β1, an important multi-functional cytokine of the TGF-β signaling pathway, has been reported to be crucial for ovarian granulosa cell (GC) states and female fertility. However, the molecular mechanism underlying TGF-β1 regulation of GC states remains largely unknown. Here, we provide a comprehensive transcriptomic view on TGF-β1 regulation of cell states in porcine GCs. We first confirmed that TGF-β1 can control GC states (apoptosis and proliferation) in pig ovary. RNA-seq showed that 909 differentially expressed genes (DEGs), including 890 DEmRNAs and 19 DEmiRNAs, were identified in TGF-β1-treated porcine GCs. Functional annotation showed that these DEGs were mainly involved in regulating cell states. In addition, multiple hub genes were identified by constructing the protein-protein interaction network, DEmiRNA-DEmRNAs regulatory network, and gene-pathway-function co-expression networks, which were further found to be enriched in FoxO, TGF-β, Wnt, PIK3-Akt, p53 and Ras signaling pathways that play important roles in regulating cell states, cell cycle, proliferation, stress-responses and inflammation. The current research deeply reveals the effects of TGF-β1 on porcine GCs, and also identifies potential therapeutic RNA molecules for inhibiting and rescuing female infertility.