Shunhua Zhang

Follicle development refers to the process in which the follicles in the ovary gradually develop from the primary stage to a mature state, and most primary follicles fail to develop normally, without forming a dense granular cell layer and cell wall, which is identified as atretic follicles. Granulosa cells assist follicle development by producing hormones and providing support, and interference in the interaction between granulosa cells and oocytes may lead to the formation of atretic follicles. Ferroptosis, as a non-apoptotic form of death, is caused by cells accumulating lethal levels of iron-dependent phospholipid peroxides. Healthy follicles ranging from 4 to 5 mm were randomly divided into two groups: a control group (DMSO) and treatment group (10 uM of ferroptosis inducer erastin). Each group was sequenced after three repeated cultures for 24 h. We found that ferroptosis was associated with atretic follicles and that the in vitro treatment of healthy follicles with the ferroptosis inducer erastin produced a phenotype similar to that of atretic follicles. Overall, our study elucidates that tRF-1:30-Gly-GCC-2 is involved in the apoptosis and ferroptosis of GCs. Mechanistically, tRF-1:30-Gly-GCC-2 inhibits granulosa cell proliferation and promotes ferroptosis by inhibiting Mitogen-activated protein kinase 1 (MAPK1). tRF-1:30-Gly-GCC-2 may be a novel molecular target for improving the development of atretic follicles in ovarian dysfunction. In conclusion, our study provides a new perspective on the pathogenesis of granulosa cell dysfunction and follicular atresia.

Currently, there is an increasing amount of evidence indicating that exosomes and the miRNAs they contain are crucial players in various biological processes. However, the role of exosomes and miRNAs in snake venom during the envenomation process remains largely unknown. In this study, fresh venom from Naja atra of different ages (2-month-old, 1-year-old, and 5-year-old) was collected, and exosomes were isolated through ultracentrifugation. The study found that exosomes with inactivated proteins and enzymes can still cause symptoms similar to cobra envenomation, indicating that substances other than proteins and enzymes in exosomes may also play an essential role in cobra envenomation. Furthermore, the expression profiles of isolated exosome miRNAs were analyzed. The study showed that a large number of miRNAs were co-expressed and abundant in cobra venom exosomes (CV-exosomes) of different ages, including miR-2904, which had high expression abundance and specific sequences. The specific miR-2094 derived from CV-exosomes (CV-exo-miR-2904) was overexpressed both in vitro and in vivo. As a result, CV-exo-miR-2904 induced symptoms similar to cobra envenomation in mice and caused liver damage, demonstrating that it plays a crucial role in cobra envenomation. These results reveal that CV-exosomes and the miRNAs they contain play a significant regulatory role in cobra envenomation. Our findings provide new insights for the treatment of cobra bites and the development of snake venom-based medicines.

As a novel non-coding RNA with important functions corresponding to various cellular stresses, the function of tRFs in angiogenesis remains unclear. Firstly, small RNA sequencing was performed on normal and post-muscle injury mouse tibialis anterior muscle to identify and analyse differentially expressed tRF/tiRNA. tRNA GlnCTG-derived fragments (tRF^GlnCTG) were found to be overexpressed in high abundance in the damaged muscle. Subsequent in vitro experiments revealed that the overexpression of tRF^GlnCTG suppressed the vascular endothelial cells’ viability, cell cycle G1/S transition, proliferation, migration, and tube-formation capacity. Similarly, in vivo experiments showed that the tRF^GlnCTG decreased the relative mRNA levels of vascular endothelial cell markers and pro-angiogenic factors and reduced the proportion of CD31-positive cells. Finally, luciferase activity analysis confirmed that the tRF^GlnCTG directly targeted the 3′UTR of Antxr1, leading to a significant reduction in the mRNA expression of the target gene. These results suggest that tRF^GlnCTG is a key regulator of vascular endothelial cell function. The results provide a new idea for further exploration of the molecular mechanisms that regulate angiogenesis.

MicroRNAs are a class of small RNAs that have been extensively studied, which are involved in many biological processes and disease occurrence. The incidence of intrauterine growth restriction is higher in mammals, especially multiparous mammals. In this study, we found that the weight of the longissimus dorsi of intrauterine growth-restricted pigs was significantly lower than that of normal pigs. Then, intrauterine growth-restricted pig longissimus dorsi were used to characterize miRNA expression profiles by RNA sequencing. A total of 333 miRNAs were identified, of which 26 were differentially expressed. Functional enrichment analysis showed that these differentially expressed miRNAs regulate the expression of their target genes (such as PIK3R1, CCND2, AKT3, and MAP3K7), and these target genes play an important role in the proliferation and differentiation of skeletal muscle through signaling pathways such as the PI3K-Akt, MAPK, and FoxO signaling pathways. Furthermore, miRNA-451 was significantly upregulated in IUGR pig skeletal muscle. Overexpression of miR-451 in C2C12 cells significantly promoted the expression of Mb, Myod, Myog, Myh1, and Myh7, suggesting that miR-451 may be involved in the regulation of the myoblastic differentiation of C2C12 cells. Our results reveal the role of miRNA-451 in regulating myogenic differentiation of skeletal muscle in pigs with intrauterine growth restriction.

Spermatogenesis is temperature-dependent, and the increase in testicular temperature seriously affects mammalian spermatogenesis and semen quality. In this study, the testicular heat stress model of mice was made with a 43 °C water bath for 25 min, and the effects of heat stress on semen quality and spermatogenesis-related regulators were analyzed. On the 7th day after heat stress, testis weight shrank to 68.45% and sperm density dropped to 33.20%. High-throughput sequencing analysis showed that 98 microRNAs (miRNAs) and 369 mRNAs were down-regulated, while 77 miRNAs and 1424 mRNAs were up-regulated after heat stress. Through gene ontology (GO) analysis of differentially expressed genes and miRNA–mRNA co-expression networks, it was found that heat stress may be involved in the regulation of testicular atrophy and spermatogenesis disorders by affecting cell meiosis process and cell cycle. In addition, through functional enrichment analysis, co-expression regulatory network, correlation analysis and in vitro experiment, it was found that miR-143-3p may be a representative potential key regulatory factor affecting spermatogenesis under heat stress. In summary, our results enrich the understanding of miRNAs in testicular heat stress and provide a reference for the prevention and treatment of heat-stress-induced spermatogenesis disorders.

Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by hyperandrogenemia with multiple suspended sinus follicles, thickened cortical tissue, and excessive proliferation of ovarian granulosa cells that severely affects the fertility and quality of life of women. The addition of n-3 PUFA to the diet may slightly reduce body weight and greatly alleviate disturbed blood hormone levels in PCOS mice. We treated KGN as a cell model for n-3 PUFA addition and showed that n-3 PUFA inhibited the proliferation of GCs and promoted ferroptosis in ovarian granulosa cells. We used CCK-8, fluorescence quantitative transmission electron microscopy experiments and ferroptosis marker gene detection and other methods. Furthermore, n-3 PUFA was found to promote YAP1 exocytosis by activating Hippo and weakening the cross-talk between YAP1 and Nrf2 by activating the Hippo signaling pathway. In this study, we found that n-3 PUFA inhibited the over proliferation of granulosa cells in ovarian follicles by activating Hippo, promoting YAP1 exocytosis, weakening the cross-talk between YAP1 and Nrf2, and ultimately activating the ferroptosis sensitivity of ovarian granulosa cells. We demonstrate that n-3 PUFA can alleviate the hormonal and estrous cycle disorder with PCOS by inhibiting the YAP1-Nrf2 crosstalk that suppresses over proliferating ovarian granulosa cells and promotes iron death in GCs. These findings reveal the molecular mechanisms by which n-3 PUFA attenuates PCOS and identify YAP1-Nrf2 as a potential therapeutic target for regulation granulosa cells in PCOS.

Noncoding RNAs (ncRNAs) called tsRNAs (tRNA-derived short RNAs) have the ability to regulate gene expression. The information on tsRNAs in fat tissue is, however, limited. By sequencing, identifying, and analyzing tsRNAs using pigs as animal models, this research reports for the first time the characteristics of tsRNAs in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). A total of 474 tsRNAs, 20 and 21 of which were particularly expressed in VAT and SAT, respectively, were found in WAT. According to the analysis of the tsRNA/miRNA/mRNA co-expression network, the tsRNAs with differential expression were primarily engaged in the endocrine and immune systems, which fall under the classification of organic systems, as well as the global and overview maps and lipid metropolis, which fall under the category of metabolism. This research also discovered a connection between the activity of the host tRNA engaged in translation and the production of tsRNAs. This research also discovered that tRF-Gly-GCC-037/tRF-Gly-GCC-042/tRF-Gly-CCC-016 and miR-218a/miR281b may be involved in the regulation of fatty acid metabolism in adipose tissue through SCD based on the tsRNA/miRNA/mRNA/fatty acid network. In conclusion, our findings enrich the understanding of ncRNAs in WAT metabolism and health regulation, as well as reveal the differences between SAT and VAT at the level of tsRNAs.

The sirtuin family, a group of NAD+-dependent class 3 histone deacetylases (HDACs), was extensively studied initially as a group of longevity genes that are activated in caloric restriction and act in concert with nicotinamide adenine dinucleotides to extend the lifespan. Subsequent studies have found that sirtuins are involved in various physiological processes, including cell proliferation, apoptosis, cell cycle progression, and insulin signaling, and they have been extensively studied as cancer genes. In recent years, it has been found that caloric restriction increases ovarian reserves, suggesting that sirtuins may play a regulatory role in reproductive capacity, and interest in the sirtuin family has continued to increase. The purpose of this paper is to summarize the existing studies and analyze the role and mechanism of SIRT1, a member of the sirtuin family, in regulating ovarian function. Research and review on the positive regulation of SIRT1 in ovarian function and its therapeutic effect on PCOS syndrome.

Epigenetic factors, including non-coding RNA regulation, play a vital role in the development of obesity and have been well researched. Transfer RNA-derived small RNA (tsRNA) is a class of non-coding RNA proven to be involved in various aspects of mammalian biology. Here we take pigs as a model for obesity research and use tsRNA-seq to investigate the difference in tsRNA expression in the subcutaneous adipose tissue of obese and lean pigs to elucidate the role of tsRNA in obesity development. A total of 482 tsRNAs were identified in pig adipose tissue, of which 123 were significantly differentially accumulated tsRNAs compared with the control group. The tRF-5c was the main type of these tsRNAs. The largest number of tsRNAs produced was the Gly-carrying tRNA, which produced 81 tsRNAs. Functional enrichment analysis revealed that differential tsRNAs indirectly participated in MAPK, AMPK, insulin resistance, the TNF signaling pathway, adipocytokine signaling pathway, and other signaling pathways by interacting with target genes. These are involved in bioenergetic metabolic regulatory processes, suggesting that tsRNAs may influence these pathways to mediate the regulation of energy metabolism in porcine adipocytes to promote lipid deposition, thus contributing to obesity. Our findings suggest a potential function of tsRNA in regulating obesity development.

This study aimed to identify biomarkers for pork quality evaluation. Firstly, the correlation between indicators of pork quality evaluation was investigated. The pH of pork meat at 45 min post slaughter showed a significant negative correlation with meat color indicators (r: −0.4868–−0.3040). Subsequently, porcine plasma samples were further divided into low pH (pH = 6.16 ± 0.22) or high pH (pH = 6.75 ± 0.08) groups. Plasma metabolites in both sample groups were investigated using untargeted metabolomics. In total, 90 metabolites were recognized as differential metabolites using partial least squares discriminant analysis. Pathway enrichment analysis indicated these differential metabolites were enriched in amino acid metabolism and energy metabolism. Correlation analysis revealed that creatinine, L-carnitine, D-sphingosine, citraconic acid, and other metabolites may constitute novel plasma biomarkers with the pH value of pork meat. The current study provides important insights into plasma biomarkers for predicting pork quality based on pH value.