Lei Chen

There was an error in the original publication

Skeletal muscle is a core component of the motor system, responsible for movement, posture maintenance, and energy metabolism. It plays a vital role in physiological stress, injury repair, and metabolic homeostasis. In recent years, with the advancement of epigenetic research, RNA modification has become a hot topic in skeletal muscle biology. This article systematically reviews the progress in the study of RNA modification in regulating the fate of skeletal muscle, focusing on the dynamic regulatory mechanisms and pathophysiological significance of N6-methyladenosine (m⁶A) modification in muscle differentiation, regeneration, and atrophy. It also briefly introduces the existing evidence for 5-methylcytidine (m⁵C), adenosine-to-inosine (A-to-I) editing, and pseudouridine (Ψ) in skeletal muscle. A comprehensive understanding of these mechanisms is crucial for elucidating the physiological regulation of skeletal muscle and the pathogenesis of related diseases and also provides a new direction for the development of intervention strategies.

Background: Rotavirus (RV) infection damages mature intestinal epithelial cells and is a leading cause of severe diarrhea in infants and young animals. However, the host cell death pathways involved in RV infection remain incompletely understood. This study used an RV-infected IPEC-J2 cell model and integrated transcriptomic, proteomic, and functional assays to investigate whether RV infection is associated with ferroptosis and NCOA4-mediated ferritinophagy. Results: High-throughput sequencing and data-independent acquisition (DIA)-based quantitative proteomic analysis showed enrichment of ferroptosis, autophagy, and cell death-related signaling pathways after RV infection. Functional assays showed that RV infection was associated with intracellular Fe ²⁺ accumulation and lipid peroxidation. The ferroptosis inducer (erastin) increased VP6 expression, whereas the ferroptosis inhibitor (Fer-1) attenuated this effect. NCOA4, a ferritinophagy receptor, was upregulated after RV infection. NCOA4 knockdown reduced RV-associated Fe ²⁺ accumulation, ROS production, ferritin degradation-related changes, and VP6 expression, whereas NCOA4 overexpression enhanced these responses. The autophagy inhibitor (3-MA) and the lysosomal blocker (CQ) attenuated RV-associated ferroptosis markers and VP6 expression, consistent with involvement of the autophagy-lysosome pathway in ferritin turnover. Conclusions: These findings support a model in which RV infection promotes ferroptosis-associated changes and VP6 expression through NCOA4-mediated ferritinophagy in IPEC-J2 cells. As this study was performed in vitro and did not directly measure epithelial transport, barrier function, infectious viral yield, or diarrheal outcomes, further in vivo studies are needed to determine the contribution of this pathway to RV pathogenesis.

Background: Ovarian granulosa cells (GCs) play a pivotal role in folliculogenesis, and their dysfunction is central to disorders such as polycystic ovary syndrome (PCOS) and premature ovarian failure (POF). MicroRNAs (miRNAs) have emerged as crucial post-transcriptional regulators of GC homeostasis. Method: This review synthesizes current evidence by systematically analyzing relevant studies, integrating data from in vitro GC models, animal experiments, human cell lines, and clinical samples to elucidate the specific mechanisms by which miRNAs regulate GCs. Results: miRNAs precisely modulate GC proliferation, apoptosis, steroidogenesis, and oxidative stress responses by targeting key signaling pathways (e.g., PI3K/AKT/mTOR, TGF-β/SMAD) and functional genes (e.g., TP53, CYP19A1). Exosomal miRNAs serve as vital mediators of communication within the follicular microenvironment. To date, nearly 200 miRNAs have been associated with PCOS. Conclusions: miRNAs constitute a decisive regulatory network governing GC fate, offering promising therapeutic targets for PCOS and POF. However, significant challenges remain, primarily miRNA pleiotropy and the lack of follicle-specific delivery systems. Future clinical translation requires rigorous validation in human-relevant models.

Background: Testicular development and spermatogenesis are intricate biological processes controlled by a coordinated transcriptional network. However, comprehensive characterization of full-length transcripts and non-coding RNAs (ncRNAs) during porcine testicular sexual maturation remains limited. Methods: This study systematically profiled the transcriptional landscape of pig testes prior to (pre-sexual maturity, PSM) and following (post-sexual maturity, SM) sexual maturity using Oxford Nanopore Technologies (ONT) long-read sequencing. Results: There were 11,060 differentially expressed mRNAs (DEGs), 15,338 differentially expressed transcripts (DETs), 688 differentially expressed lncRNAs (DELs), and 19 differentially expressed circRNAs (DEcircRNAs) between PSM and SM groups among the 9941 mRNAs, 15,339 transcripts, 4136 lncRNAs (58.58% being LincRNAs). These differential RNAs converged on 133 shared GO terms (e.g., spermatogenesis, male gamete generation) and 58 common KEGG pathways (e.g., metabolic pathways, Wnt/MAPK signaling), according to functional enrichment and combined analysis. Core genes (e.g., PRM1, ODF2, GSTM3) demonstrated synergistic expression across gene, transcript, lncRNA-cistarget, and circRNA levels. Furthermore, DELs were associated with steroid biosynthesis and N-glycan biosynthesis, whereas DEcircRNAs, which were mostly upregulated after puberty, were thought to control genes linked to spermatogenesis. Conclusions: This research sheds light on the dynamic transcriptional reprogramming that occurs during the maturation of pig testicles, advances our knowledge of coding and ncRNA regulatory networks in male mammals, and offers useful molecular markers for enhancing pig reproductive efficiency.

Granulosa cell ferroptosis is a critical factor in follicular atresia and premature ovarian insufficiency (POI). As a regulated form of programmed cell death, ferroptosis is gaining significant attention in reproductive medicine research. MicroRNAs (miRNAs) play a crucial role in regulating key aspects of ferroptosis, including the glutathione-GPX4 pathway, glutamate/cystine transport, and iron and lipid metabolism. The present study demonstrates that miR-26a positively modulates ferroptosis by targeting SLC7A11, a member of the solute carrier family. We found that oocytes and granulosa cells are susceptible to the ferroptosis inducer erastin, and employed RNA sequencing to delineate the miRNA expression profiles during erastin-induced damage and ferroptosis. Notably, miR-26a expression was significantly upregulated in erastin-treated oocytes. Importantly, overexpression of miR-26a promoted ferroptosis in granulosa cells, while its knockdown inhibited this process. Ectopic miR-26a expression suppressed SLC7A11, thereby increasing ferroptosis. Our findings indicate that miR-26a influences ferroptosis by inhibiting glutathione synthesis, reducing cellular antioxidant capacity, and suggesting a potential strategy to enhance reproductive potential.

Ferroptosis is a new mode of cell death, which is characterized by inducing the accumulation of lipid peroxides dependent on iron ions and reactive oxygen species. It has been found that ferroptosis can lead to follicle atresia by promoting granulosa cell death and increasing its reactive oxygen species content, but the specific mechanism has not been elucidated. Through transcriptome sequencing, we found that ferroptosis markers and related genes were upregulated in porcine atretic follicles. PTGS2 was found to be differentially expressed between atretic and healthy follicles. By inhibiting NF-κB nuclear translocation, inhibition of the PTGS2 gene expression reduced the degree of ferroptosis in granulosa cells and rescued granulosa cell death and oxidative stress caused by ferroptosis. Therefore, we propose that the NF-κB/PTGS2 axis plays a key role in ferroptosis-induced granulosa cell death, leading to follicular atresia. Melatonin, a neurohormone secreted by the pineal gland of the upper thalamus, is involved in the regulation of various metabolic, immune, reproductive, and other processes. In the ferroptosis treatment group, melatonin treatment alleviated the degree of ferroptosis (downregulation of ferroptosis marker genes and markers) and decreased the expression of PTGS2. In summary, we have demonstrated that melatonin inhibits ferroptosis via the NF-κB/PTGS2 axis in granulosa cells.

Intrauterine growth restriction (IUGR) severely hinders the development of the livestock industry and impacts economic efficiency. MicroRNAs (miRNAs) participate in the epigenetic regulation of animal growth and development. Using IUGR pigs as a model, this study analyzed transcriptomic data from IUGR piglets to investigate the miRNA-mRNA regulatory network in their testes. Compared with NBW pigs, IUGR pigs exhibited reduced testicular volume, decreased weight, and abnormal testicular development. A total of 4945 differentially expressed mRNAs and 53 differentially expressed miRNAs were identified in IUGR testicular tissues, including 1748 downregulated and 3197 upregulated mRNAs, as well as 41 upregulated and 12 downregulated miRNAs. The integrated analysis of differentially expressed genes, miRNA target genes, and the miRNA-mRNA network revealed that IUGR may impair testicular development by disrupting cell cycle progression and apoptotic pathways, thereby hindering normal testicular cell growth. Furthermore, analysis of the miRNA-mRNA network indicated that miRNAs such as ssc-miR-23a, ssc-miR-29c, ssc-miR-193a-3p, and ssc-miR-574-3p could serve as potential marker miRNAs for IUGR testes, while YWHAZ, YWHAB, and PPP2CA may function as core target genes within this regulatory network. In conclusion, this study enhances our understanding of male reproduction in IUGR pigs and provides a theoretical foundation for preventing and treating IUGR-induced male reproductive disorders.

Follicle health determines the number and quality of sows’ ovulation, thereby influencing the litter size and the piglets’ viability. Granulosa cells (GCs) play a crucial role in follicular formation and development, and oxidative stress-induced GC death is a major cause of follicular dysplasia. Previous studies have confirmed that oxidative stress triggers apoptosis in granulosa cells. In this study, we explored how oxidative stress influences apoptosis in porcine ovarian granulosa cells. We find that porcine atretic follicles exhibit significant oxidative stress, accompanied by the activation of the mitogen-activated protein kinase (MAPK) signaling pathway, including the upregulation of key factors such as apoptosis signal-regulating kinase 1 (ASK1). Healthy follicles of 3–5 mm were randomly assigned to the control group, H₂O₂ treatment group, and selonsertib pretreatment group. The porcine ovarian GCs were placed in cell culture medium supplemented with H₂O₂ to assess ROS production, cell proliferation, apoptosis, the expression levels of oxidative stress-related genes, and expression levels of apoptosis-related proteins. In vitro experiments in mouse GCs further confirmed that H₂O₂-induced oxidative stress triggers the upregulation of the MAPK pathway and promotes granulosa cell apoptosis. The results showed that H₂O₂ treatment induced ROS production and apoptosis in porcine GCs and inhibited GC viability. Additionally, selonsertib pretreatment attenuated apoptosis in GCs by inhibiting H₂O₂-induced oxidative stress. In summary, our findings reveal that oxidative stress induced granulosa cell apoptosis via the MAPK signaling pathway, impairing proper follicular development in pigs.

Pork is a major global source of animal protein, and improving both its production efficiency and meat quality is a central goal in modern animal agriculture and food systems. This study investigated post-inflection-point growth patterns in two genetically distinct pig breeds—the lean-type Yorkshire pig (YP) and the fatty-type Qingyu pig (QYP)—with the aim of elucidating breed-specific characteristics that influence pork quality and yield. Comprehensive evaluations of carcass traits, meat quality attributes, nutritional composition, and gene expression profiles were conducted. After the growth inflection point, carcass traits exhibited greater variability than meat quality traits in both breeds, though with distinct patterns. YPs displayed superior muscle development, with the longissimus muscle area (LMA) increasing rapidly before plateauing at ~130 kg, whereas QYPs maintained more gradual but sustained muscle growth. In contrast, intramuscular fat (IMF)—a key determinant of meat flavor and texture—accumulated faster in YPs post inflection but plateaued earlier in QYPs. Correlation and clustering analyses revealed more synchronized regulation of meat quality traits in QYPs, while YPs showed greater trait variability. Gene expression patterns aligned with these phenotypic trends, highlighting distinct regulatory mechanisms for muscle and fat development in each breed. In addition, based on the growth curves, we calculated the peak age at which the growth rate declined in lean-type and fat-type pigs, which was approximately 200 days for YPs and around 270 days for QYPs. This suggests that these ages may represent the optimal slaughter times for the respective breeds, balancing both economic efficiency and meat quality. These findings provide valuable insights for enhancing pork quality through precision management and offer theoretical guidance for developing breed-specific feeding strategies, slaughter timing, and value-added pork production tailored to consumer preferences in the modern food market.