Post-translational modifications (PTMs) of proteins, as the core mechanism for dynamically regulating follicular development, affect the maintenance of mammalian fertility by precisely coordinating granulosa cell–oocyte interaction, metabolic reprogramming, and epigenetic remodeling. Dysregulation of these modifications directly contributes to major reproductive diseases, including polycystic ovary syndrome (PCOS) and premature ovarian insufficiency (POI). Post-translational modifications regulate follicular development through intricate mechanisms. Thus, this review systematically synthesizes recent advances in PTMs, encompassing traditional ones such as phosphorylation, ubiquitination, and acetylation, alongside emerging modifications including lactylation, SUMOylation, and ISGylation, thereby constructing a more comprehensive PTM landscape of follicular development. Furthermore, this study dissects the molecular interaction networks of these PTMs during follicular activation, maturation, and ovulation, and uncovers the common mechanisms through which PTM dysregulation contributes to pathological conditions, including hyperandrogenism in PCOS and follicular depletion in POI. Finally, this review ultimately provides a theoretical basis for improving livestock reproductive efficiency and precise intervention in clinical ovarian diseases.

Ubiquitous environmental endocrine-disrupting chemicals (EDCs), including bisphenols, phthalates, and heavy metals, pose a severe and persistent threat to mammalian reproductive health worldwide. Oxidative stress acts as the pivotal mediator which drives epigenetic dysregulation in germ cells upon EDC exposure, including aberrant DNA methylation, abnormal histone post-translational modifications and dysregulated non-coding RNA networks. EDC-induced oxidative stress damages endogenous antioxidant defense systems and inactivates key epigenetic regulators, forming a self-reinforcing cycle of redox imbalance and epigenetic dysregulation, which ultimately leads to impaired gametogenesis, reduced fertility, and transgenerational reproductive abnormalities. This review summarizes current evidence indicating that multiple antioxidants, including melatonin, vitamin C, resveratrol, and epigallocatechin gallate, alleviate EDC-induced reproductive toxicity by targeting epigenetic dysregulation. Their protective effects encompass scavenging excessive reactive oxygen species, activating endogenous antioxidant signaling cascades, restoring activity of epigenetic enzymes, and rectifying aberrant histone modification profiles, contributing to the maintenance of epigenetic homeostasis in germ cells. This review clarifies the intrinsic mechanistic link among EDC exposure, oxidative stress, epigenetic dysregulation and reproductive toxicity, which provides a theoretical basis for formulating reproductive health protection strategies against EDC exposure and guides the exploration of clinical epigenetic biomarkers.

Pork serves as a significant meat commodity, with intramuscular fat (IMF) content being a critical determinant of its quality. However, the epigenetic mechanism of porcine IMF deposition is still unclear. This study integrated proteomics and lactylation profiles from the longissimus thoracis (LT) muscles of pigs with extremely high (IMF_H) and extremely low (IMF_L) IMF content to clarify the association between lactylation and porcine fat deposition. Furthermore, an intramuscular preadipocyte induction and differentiation model was conducted to elucidate the changes in lactylation during adipocyte differentiation. Finally, the regulatory role of lactylation in adipocyte differentiation was explored by modulating lactate production during the induction and differentiation of preadipocytes. Proteomic analysis revealed significantly increased expression of key lipid metabolism related proteins (FASN, APOA4, FABP4, ACLY, PLIN1) in IMF_H pig muscle tissues compared with IMF_L tissues, along with substantial activation of lipid metabolism pathways. Lactylation profiling identified 95 differential lysine sites across 56 proteins, with most showing lower lactylation levels in the IMF_H group. The integrative omics analysis revealed differences in lactylation profiles in porcine LT tissues with varying efficiencies of IMF deposition, highlighted PGK1, PKM, and PYGM as central lactylation-modified proteins in porcine fat deposition regulation. Further in vitro study proved that lactate-mediated lactylation inhibited adipogenic differentiation of porcine intramuscular preadipocytes through PPARγ signaling pathway. This study clarified the changes in the lactylation profile in porcine LT tissues with varying efficiencies of IMF deposition, and demonstrated that lactate-mediated lactylation inhibits the PPARγ signaling pathway and the adipogenic differentiation of porcine intramuscular preadipocyte. This study provided a new insight to understanding the epigenetic regulation mechanisms of lipid deposition in pigs.

IMF is a key determinant of meat quality, influencing tenderness, juiciness and flavor, yet the mechanisms underlying its formation remain poorly understood. Previous studies performed whole-genome resequencing and GWAS on pigs with divergent IMF content, identifying MCEE as a candidate gene associated with IMF deposition. Subsequently, gain- and loss-of-function approaches were employed to investigate the role of MCEE in porcine intramuscular preadipocytes. Here, we isolated primary preadipocytes and subjected them to adipogenic induction. The overexpression of MCEE enhanced the proliferation and adipogenic differentiation of porcine intramuscular preadipocytes, whereas its knockdown exerted the opposite effect. Transcriptomic analysis revealed that DEGs were primarily enriched in pathways related to oxidative phosphorylation, mitochondrial dysfunction-associated disorders and others. Subcellular localization prediction indicated mitochondrial targeting of MCEE, and its expression level influenced mitochondrial function, including reactive oxygen species levels, mitochondrial membrane potential and permeability transition pore opening. Collectively, MCEE regulates IMF deposition by modulating mitochondrial function, and these findings provide a potential molecular target for improving meat quality.

Porcine reproductive and respiratory syndrome virus is a major pathogen that causes massive economic losses in the global swine industry. Lysine propionylation and malonylation are metabolism-sensitive post-translational modifications, yet their coordinated regulatory roles during PRRSV pulmonary infection remain unknown. This study combined quantitative proteomics, propionylome and malonylome to characterize host molecular alterations between healthy and PRRSV-infected porcine lung tissues (three piglets per group). Quantitative proteomics identified 1467 significantly downregulated proteins and only 129 upregulated proteins, indicating a profound host protein shutoff during PRRSV pulmonary infection. The two acyl modifications displayed opposite regulatory patterns independent of global protein expression changes: 51 propionylation sites (24 proteins) were upregulated with only 1 downregulated, while 37 malonylation sites (30 proteins) were downregulated and only 5 upregulated. Functional enrichment and PPI network analysis revealed clear functional divergence: hyper-propionylated hub proteins were exclusively enriched in mitochondrial energy metabolism pathways, whereas hypo-malonylated core proteins were mainly involved in lipid metabolism and cell fate regulation. Integrated multi-omics analysis confirmed that protein expression and lysine acylation constitute two coordinated but independent regulatory layers, with histone H4 identified as a candidate target of competitive propionylation/malonylation. This work reports the comprehensive landscape of lysine propionylation and malonylation upon PRRSV infection, reveals a dual-PTM remodeling strategy for viral hijacking of host homeostasis, and provides candidate targets for future functional investigation and antiviral development.