Effects of SPATA6 on proliferation, apoptosis and steroidogenesis of Hu sheep Leydig cells in vitro

Betaine alleviates spermatogenic cells apoptosis of oligoasthenozoospermia rat model by up-regulating methyltransferases and affecting DNA methylation

BACKGROUND

Oligoasthenozoospermia is the most common type of semen abnormality in male infertile patients. Betaine (BET) has been proved to have pharmacological effects on improving semen quality. BET also belongs to endogenous physiological active substances in the testis. However, the physiological function of BET in rat testis and its pharmacological mechanism against oligoasthenozoospermia remain unclear.

PURPOSE

This research aims to prove the therapeutic effect and potential mechanism of BET on oligoasthenozoospermia rat model induced by Tripterygium wilfordii glycosides (TWGs).

METHODS

The oligoasthenozoospermia rat model was established by a continuous gavage of TWGs (60 mg/kg) for 28 days. Negative control group, oligoasthenozoospermia group, positive drug group (levocarnitine, 300 mg/kg), and 200 mg/kg, 400 mg/kg, and 800 mg/kg BET groups were created for exploring the therapeutic effect of BET on the oligoasthenozoospermia rat model. The therapeutic effect was evaluated by HE and TUNEL staining. Immunofluorescence assay of DNMT3A, PIWIL1, PRMT5, SETDB1, BHMT2, and METTL3, methylation capture sequencing, Pi-RNA sequencing, and molecular docking were used to elucidate potential pharmacological mechanisms.

RESULTS

It is proved that BET can significantly restore testicular pathological damage induced by TWGs, which also can significantly reverse the apoptosis of spermatogenic cells. The spermatogenic cell protein expression levels of DNMT3A, PIWIL1, PRMT5, SETDB1, BHMT2, and METTL3 significantly decreased in oligoasthenozoospermia group. 400 mg/kg and 800 mg/kg BET groups can significantly increase expression level of the above-mentioned proteins. Methylation capture sequencing showed that BET can significantly increase the 5mC methylation level of Spata, Spag, and Specc spermatogenesis-related genes. Pi-RNA sequencing proved that the above-mentioned genes produce a large number of Pi-RNA under BET intervention. Pi-RNA can form complexes with PIWI proteins to participate in DNA methylation of target genes. Molecular docking indicated that BET may not directly act as substrate for methyltransferase and instead participates in DNA methylation by promoting the methionine cycle and increasing S-adenosylmethionine synthesis.

CONCLUSION

BET has a significant therapeutic effect on oligoasthenozoospermia rat model induced by TWPs. The mechanism mainly involves that BET can increase the methylation level of Spata, Specc, and Spag target genes through the PIWI/Pi-RNA pathway and up-regulation of methyltransferases (including DNA methyltransferases and histone methyltransferases).

Copy number variants selected during pig domestication inferred from whole genome resequencing

Over extended periods of natural and artificial selection, China has developed numerous exceptional pig breeds. Deciphering the germplasm characteristics of these breeds is crucial for their preservation and utilization. While many studies have employed single nucleotide polymorphism (SNP) analysis to investigate the local pig germplasm characteristics, copy number variation (CNV), another significant type of genetic variation, has been less explored in understanding pig resources. In this study, we examined the CNVs of 18 Wanbei pigs (WBP) using whole genome resequencing data with an average depth of 12.61. We identified a total of 8,783 CNVs (~30.07 Mb, 1.20% of the pig genome) in WBP, including 8,427 deletions and 356 duplications. Utilizing fixation index (Fst), we determined that 164 CNVs were within the top 1% of the Fst value and defined as under selection. Functional enrichment analyses of the genes associated with these selected CNVs revealed genes linked to reproduction (SPATA6, CFAP43, CFTR, BPTF), growth and development (NR6A1, SMYD3, VIPR2), and immunity (PARD3, FYB2). This study enhances our understanding of the genomic characteristics of the Wanbei pig and offers a theoretical foundation for the future breeding of this breed.

Molecular characterization of SPATA6 and association of its SNPs with testicular size in sheep

The testis is an important organ for maintaining fertility in males, and testis size is positively correlated with ejaculate volume, sperm motility, thus fertility. Spermatogenesis-associated 6 (SPATA6) is an evolutionarily conserved testis-specific gene reported in many species. However, the effect of SPATA6 expression levels on testicular development and the effect of single nucleotide polymorphisms (SNPs) on testis and epididymis phenotype in sheep have not been studied. The purpose of the research was to investigate the expression profile of SPATA6 and its effect on testicular development and to confirm the effect of SNPs on the testis and epididymis phenotype. In this study, we detected a 1245bp coding sequence (CDS) of SPATA6 and encoded 414 amino acids. The expression levels of SPATA6 were significantly higher in the testis than in other tissues and gradually increased with testis development. Moreover, the expression level in the large testis was significantly higher than that in the small testis at six months. A total of 11 SNPs were detected in the coding region of SPATA6 by cDNA-pooling sequencing and improved multiplex ligation detection reaction (iMLDR) methods. Correlation analysis showed that SNP2 (c. 3631C > G) significantly affected left epididymis weight (LEW) and right epididymis weight (REW), and SNP10 (c. 937 A > G) significantly affected REW. And the combined genotype of SNP1 (c. 4245 G > A) and SNP2 significantly affected REW. The current study concluded that SPATA6 plays an important role in testicular development and the SNPs significantly associated with the epididymis phenotype can provide molecular markers for the early selection of high-fertility Hu sheep.

Comprehensive analyses of 435 goat transcriptomes provides insight into male reproduction

A systematic analysis of genes related to reproduction is crucial for obtaining a comprehensive understanding of the molecular mechanisms that underlie male reproductive traits in mammals. Here, we utilized 435 goat transcriptome datasets to unveil the testicular tissue-specific genes (TSGs), allele-specific expression (ASE) genes and their uncharacterized transcriptional features related to male goat reproduction. Results showed a total of 1790 TSGs were identified in goat testis, which was the most among all tissues. GO enrichment analyses suggested that testicular TSGs were mainly involved in spermatogenesis, multicellular organism development, spermatid development, and flagellated sperm motility. Subsequently, a total of 95 highly conserved TSGs (HCTSGs), 508 middle conserved TSGs (MCTSGs) and 42 no conserved TSGs (NCTSGs) were identified in goat testis. GO enrichment analyses suggested that the HCTSGs and MCTSGs has a more important association with male reproduction than NCTSGs. Additionally, we identified 644 ASE genes, including 88 tissue-specific ASE (TS-ASE) genes (e.g., FSIP2, TDRD9). GO enrichment analyses indicated that both ASE genes and TS-ASE genes were associated with goat male reproduction. Overall, this study revealed an extensive gene set involved in the regulation of male goat reproduction and their dynamic transcription patterns. Data reported here provide valuable insights for a further improvement of the economic benefits of goats as well as future treatments for male infertility.

LncRNA12097.1 contributes to endometrial cell growth by enhancing YES1 activating β-catenin via sponging miR-145-5p

Despite previous investigations elucidating the regulatory mechanisms of long non-coding RNAs (lncRNAs) in endometrial function and reproductive disorders, the precise pathways through which lncRNAs impact endometrial functions and fertility remain unclear. In this study, we performed an expression profile analysis of lncRNAs in the endometrial tissue of Hu sheep with different prolificacy, identifying 13,707 lncRNAs. We discovered a bidirectional lncRNA, designated lncRNA12097.1, exhibiting significant up-regulation exclusively in the endometrium of Hu sheep with high fecundity. Functional analyses revealed lncRNA12097.1 significantly enhanced proliferation and cell cycle progression in both endometrial epithelial cell (EEC) and stromal cells (ESC), while inhibiting apoptosis in these cell types. Mechanistically, we demonstrated a directly interaction between lncRNA12097.1 and miR-145-5p, with YES proto-oncogene 1 (YES1) being identified as a validated target of miR-145-5p. Interference with lncRNA12097.1 resulted in suppressed cell growth through down-regulation of YES1 expression, which could be rescued by miR-145-5p. Furthermore, lncRNA12097.1 functions as a competitive endogenous RNA (ceRNA) for miR-145-5p in ESCs, sequestering miR-145-5p and preventing its binding to the 3'UTR of YES1 mRNA. This interaction led to increased expression of YES1 and subsequent activation of downstream β-catenin signaling, thereby promoting ESC growth in Hu sheep. These findings provide novel molecular insights into the mechanisms underlying prolificacy in sheep.

Preliminary study of melatonin in the proliferation and apoptosis of Hu sheep dermal papilla cells in vitro

Previous studies have shown that melatonin has a certain regulatory effect on the growth of sheep wool. However, the mechanism of melatonin action remains unknown. In the present study, we aimed to understand the role of exogenous melatonin in the dermal papilla cells of Hu sheep. To confirm the optimal melatonin treatment regimen for Hu sheep dermal papilla cells, we detected the cell viability by exposing them to different concentrations of melatonin and different treatment times. The results showed that cell viability was best when dermal papilla cells were treated with 1000 pg/ml of melatonin for 48 h. According to the results of qPCR, CCK-8, EDU, Western blot, and Flow cytometry analysis, we found that 1000 pg/ml melatonin promoted the proliferation and inhibited the apoptosis of dermal papilla cells compared with the exogenous melatonin blank group (control group). Furthermore, we also found that 1000 pg/ml of melatonin promoted the cell cycle progress of dermal papilla cells according to the results of qPCR and Flow cytometry analysis. Overall, our findings showed that melatonin plays an important role in the dermal papilla cells of Hu sheep.

CREB1 Is Involved in miR-134-5p-Mediated Endometrial Stromal Cell Proliferation, Apoptosis, and Autophagy

The successful establishment of endometrial receptivity is a key factor in ensuring the fertility of ewes and their economic benefits. Hu sheep have attracted attention due to their high fecundity and year-round estrus. In this study, we found that in the luteal phase, the uterine gland density, uterine coefficient, and number of uterine caruncles of high-fertility Hu sheep were higher than those of low-fertility Hu sheep. Thousands of differentially expressed genes were identified in the endometrium of Hu sheep with different fertility potential using RNA sequencing (RNA-Seq). Several genes involved in endometrial receptivity were screened using bioinformatics analysis. The qRT-PCR analysis further revealed the differential expression of cAMP reactive element binding protein-1 (CREB1) in the Hu sheep endometrium during the estrous cycle. Functionally, our results suggested that CREB1 significantly affected the expression level of endometrial receptivity marker genes, promoted cell proliferation by facilitating the transition from the G1 phase to the S phase, and inhibited cell apoptosis and autophagy. Moreover, we observed a negative linear correlation between miR-134-5p and CREB1 in the endometrium. In addition, CREB1 overexpression prevented the negative effect of miR-134-5p on endometrial stromal cell (ESC) growth. Taken together, these data indicated that CREB1 was regulated by miR-134-5p and may promote the establishment of uterine receptivity by regulating the function of ESCs. Moreover, this study provides new theoretical references for identifying candidate genes associated with fertility.

Prolactin inhibitor changes testosterone production, testicular morphology, and related genes expression in cashmere goats

Prolactin has multifaceted roles in lactation, growth, metabolism, osmoregulation, behavior, and the reproduction of animals. This study aimed to investigate the involvement of prolactin in testicular function in cashmere goats. Twenty cashmere goats were randomly assigned to either the control group (CON) or the bromocriptine treatment group (BCR, bromocriptine, prolactin inhibitor). Blood and testis samples collected for analysis after 30 days of treatment. The results indicated that, compared with the CON group, BCR significantly decreased (p < 0.05) the serum concentrations of prolactin, and significantly increased (p < 0.05) the levels of testosterone and luteinizing hormone (LH) on day 30. The serum level of the follicle-stimulating hormone (FSH) was not affected (p > 0.05) by the treatment. The mean seminiferous tubule diameter and spermatogenic epithelium thickness were increased (p < 0.05) in the BCR group. Subsequently, we performed RNA sequencing and bioinformatics analysis to identify the key genes and pathways associated with the regulation of spermatogenesis or testosterone secretion function. A total of 142 differentially expressed genes (DEGs) were identified (91 were upregulated, 51 were downregulated). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the DEGs were mainly involved in the extracellular matrix (ECM), hippo, and steroid hormone biosynthesis, which are related to testicular function. The expression of the genes SULT2B1, CYP3A24, and CYP3A74 in the steroid hormone biosynthesis pathway significantly increased (p < 0.05) in the BCR group, which was validated by qRT-PCR. These results provide a basis for understanding the mechanisms underlying the regulation of testicular function by prolactin in cashmere goats.

Insights into the architecture of human-induced polygenic selection in Duroc pigs

Background

As one of the most utilized commercial composite boar lines, Duroc pigs have been introduced to China and undergone strongly human-induced selection over the past decades. However, the efficiencies and limitations of previous breeding of Chinese Duroc pigs are largely understudied. The objective of this study was to uncover directional polygenic selection in the Duroc pig genome, and investigate points overlooked in the past breeding process.

Results

Here, we utilized the Generation Proxy Selection Mapping (GPSM) on a dataset of 1067 Duroc pigs with 8,766,074 imputed SNPs. GPSM detected a total of 5649 putative SNPs actively under selection in the Chinese Duroc pig population, and the potential functions of the selection regions were mainly related to production, meat and carcass traits. Meanwhile, we observed that the allele frequency of variants related to teat number (NT) relevant traits was also changed, which might be influenced by genes that had pleiotropic effects. First, we identified the direction of selection on NT traits by \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hat{G}$$\end{document}G^, and further pinpointed large-effect genomic regions associated with NT relevant traits by selection signature and GWAS. Combining results of NT relevant traits-specific selection signatures and GWAS, we found three common genome regions, which were overlapped with QTLs related to production, meat and carcass traits besides “teat number” QTLs. This implied that there were some pleiotropic variants underlying NT and economic traits. We further found that rs346331089 has pleiotropic effects on NT and economic traits, e.g., litter size at weaning (LSW), litter weight at weaning (LWW), days to 100 kg (D100), backfat thickness at 100 kg (B100), and loin muscle area at 100 kg (L100) traits.

Conclusions

The selected loci that we identified across methods displayed the past breeding process of Chinese Duroc pigs, and our findings could be used to inform future breeding decision.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00751-x.

PPP2R2A affects embryonic implantation by regulating the proliferation and apoptosis of Hu sheep endometrial stromal cells

Embryonic implantation is a complex reproductive physiological process in mammals. Although several endometrial proteins affecting embryonic implantation have been reported in the past, there are still potential endometrial proteins that have been neglected, and their specific regulatory mechanisms are unclear. This study demonstrated that protein phosphatase 2A regulatory subunit B55α (PPP2R2A) served as a novel regulator in medication of sheep embryonic implantation in vitro. Our results showed that sheep PPP2R2A encoded 447 amino acids and shared 91.74%-92.36% amino acid sequences with its orthologs compared with other species. Meanwhile, PPP2R2A was widely expressed in sheep uterine tissues, and it could regulate the expression levels of key regulators of embryonic implantation in endometrial stromal cells (ESCs). Knockdown of PPP2R2A significantly inhibited cell proliferation by blocking cell cycle transfer G0/G1 into S phase accompanied by downregulation of CDK2, CDK4, CCND1, CCNE1 and upregulation of P21. In contrast to PPP2R2A overexpression, PPP2R2A interference greatly promoted cell apoptosis and the expression of BAX, CASP3, CASP9 and BAX/BCL-2. Taken together, these results suggest that PPP2R2A, as a novel regulatory factor, affects embryonic implantation via regulating the proliferation and apoptosis of Hu sheep ESCs in vitro.

INHBA transfection regulates proliferation, apoptosis and hormone synthesis in sheep granulosa cells

Inhibin subunit beta A (INHBA) participates in the synthesis of inhibin A, activin A and activin AB. Here we investigated the effect and molecular mechanism of INHBA on proliferation, apoptosis and hormone synthesis in sheep granulosa cells (GCs) using in vitro transfection. We first noticed that INHBA expression increased with follicle diameter and was widely distributed in ovarian tissue. The proliferation rate of GCs was significantly increased and decreased with overexpression and silence of INHBA, respectively, compared with the negative controls. INHBA transfection affected GC proliferation and apoptosis, regulating the expression of many cell cycle-related and apoptosis-related genes. INHBA overexpression significantly decreased activin and estradiol secretion while increasing inhibin and progesterone secretion. The expression of follicle-stimulating hormone beta subunit was significantly decreased and increased with INHBA overexpression and knockdown, respectively. Notably, silence of INHBA inhibited the expression of many transforming growth factor beta-related genes. Overall, the functional molecule of INHBA gene may be associated with follicular development via regulating proliferation, apoptosis and folliculogenesis-related hormone secretion of sheep GCs. In addition, our findings may contribute to a better understanding of the law of follicular development and thus improve the reproductive performance of female animals.