Background Reactive oxygen species (ROS) modulator 1 (ROMO1) is a mitochondrial membrane protein that is essential for the regulation of mitochondrial ROS production and redox sensing. ROMO1 regulates ROS generation within cells and is involved in cellular processes, such as cell proliferation, senescence, and death. Our purpose is to investigates the impact of ROMO1 on the mitochondria during porcine embryogenesis. Results We found that high expression of ROMO1 was associated with porcine preimplantation embryo development, indicating that ROMO1 may contribute to the progression of embryogenesis. Knockdown of ROMO1 disrupted porcine embryo development and blastocyst quality, thereby inducing ROS production and decreasing mitochondrial membrane potential. Knockdown of ROMO1 induced mitochondrial dysfunction by disrupting the balance of OPA1 isoforms to release cytochrome c, reduce ATP, and induce apoptosis. Meanwhile, ROMO1 overexpression showed similar effects as ROMO1 KD on the embryos. Overexpression of ROMO1 rescued the ROMO1 KD-induced defects in embryo development, mitochondrial fragmentation, and apoptosis. Conclusions ROMO1 plays a critical role in embryo development by regulating mitochondrial morphology, function, and apoptosis in pigs.

Increased levels of oxidative stress are major factors that drive the process of post-ovulatory oocyte aging. Epigallocatechin-3-gallate (EGCG), which accounts for up to 50% of the catechins, possesses versatile biological functions, including preventing or treating diabetes, cancer, and heart diseases. The aim of this study was to explore whether EGCG can delay porcine oocyte aging by preventing oxidative stress. Metaphase II (MII) oocytes were cultured for 48 h with different concentrations of EGCG (0–100 μM) in vitro as a post-ovulatory aging model. An optimal concentration of 5 μM EGCG maintained oocyte morphology and developmental competence during aging. The oocytes were randomly divided into five groups: fresh, 24 h control, 24 h EGCG, 48 h control, and 48 h EGCG. The results suggest that EGCG significantly prevents aging-induced oxidative stress, glutathione (GSH) reduction, apoptosis, and autophagy. Moreover, mitochondria DNA copy number was decreased, and the number of active mitochondria and adenosine triphosphate (ATP) levels significantly increased by supplementation with EGCG. Thus, EGCG has a preventive role against aging in porcine post-ovulatory oocytes due to its ability to inhibit oxidative stress and promote mitochondrial biogenesis.

Heat stress (HS) has been known to cause reproductive failure in animals, especially in summer. HS severely affects the developmental potential of oocytes and leads to low fertility rates. Previous studies have reported that HS compromises embryo development in bovine oocytes, and reduces ovarian development in mice, thereby impairing reproductive function in animals. However, the effect of high temperature (HT) on the organelles of porcine oocytes is unknown. In this study, we reported that exposure to HT for 24 h (41°C) significantly decreased meiotic maturation in porcine oocytes (p < 0.05). Further experiments on organelles found that HT induced mitochondrial dysfunction, increased abnormal mitochondrial distribution, and decreased mitochondrial membrane potential (MMP). We also found that HT induced abnormal endoplasmic reticulum (ER) distribution and higher expression of glucose regulatory protein 78 (GRP78), suggesting that HT exposure induces ER stress. Our results also indicated that exposure to HT induced abnormal distribution and dysfunction of the Golgi apparatus, which resulted from a decrease in the expression of the vesicle transporter, Ras-related protein Rab-11A (RAB11A). In addition, we found that HT exposure led to lysosomal damage by increasing the expression of lysosome-associated membrane protein 2 (LAMP2) and microtubule-associated protein 1A/1B-light chain 3 (LC3). In summary, our study revealed that HT exposure disrupts organelle dynamics, which further leads to the failure of meiotic maturation in porcine oocytes.

Background: Activating transcription factor 7 (ATF7) is a member of the ATF/cAMP response element (CRE) B superfamily. ATF2, ATF7, and CRE-BPa are present in vertebrates. Drosophila and fission yeast have only one homologue: dATF2 and Atf1, respectively. Under normal conditions, ATF7 promotes heterochromatin formation by recruiting histone H3K9 di-and tri-methyltransferases. Once the situation changes, all members are phosphorylated by the stress-activated kinase P38 in response to various stressors. However, the role of ATF7 in early porcine embryonic development remains unclear.Results: In this study, we found that ATF7 gradually accumulated in the nucleus and then localized on the pericentric heterochromatin after the late 4-cell stage, while being co-localized with heterochromatin protein 1 (HP1). Knockdown of ATF7 resulted in decreases in the blastocyst rate and blastocyst cell number. ATF7 depletion resulted in downregulation of HP1 and histone 3 lysine 9 dimethylation (H3K9me2) expression. These effects were alleviated when P38 activity was inhibited. High temperatures increased the expression level of pP38, while reducing the quality of porcine embryos, and led to ATF7 phosphorylation. The expression level of H3K9me2 and HP1 was decreased and regulated by P38 activity. Conclusion:Stress-induced ATF7-dependent epigenetic changes play important roles in early porcine embryonic development.

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Rotenone is a commonly used insecticidal chemical in agriculture and it is an inhibitor of mitochondrial complex Ⅰ. Previous studies have found that rotenone induces the production of reactive oxygen species (ROS) by inhibiting electron transport in the mitochondria of somatic and germ cells. However, there is little precise information on the effects of rotenone exposure in porcine oocytes during in vitro maturation, and the mechanisms underlying these effects have not been determined. The Cumulus-oocyte complexes were supplemented with different concentrations of rotenone to elucidate the effects of rotenone exposure on the meiotic maturation of porcine oocytes during in vitro maturation for about 48 hours. First, we found that the maturation rate and expansion of cumulus cells were significantly reduced in the 3 and 5 μM rotenone-treated groups. Subsequently, the concentration of rotenone was determined to be 3 μM. Also, immunofluorescence, western blotting, and image quantification analyses were performed to test the rotenone exposure on the meiotic maturation, total and mitochondrial ROS, mitochondrial function and biogenesis, mitophagy and apoptosis in porcine oocytes. Further experiments showed that rotenone treatment induced mitochondrial dysfunction and failure of mitochondrial biogenesis by repressing the level of SIRT1 during in vitro maturation of porcine oocytes. In addition, rotenone treatment reduced the ratio of active mitochondria to total mitochondria, increased ROS production, and decreased ATP production. The levels of LC3 and active-caspase 3 were significantly increased by rotenone treatment, indicating that mitochondrial dysfunction induced by rotenone increased mitophagy but eventually led to apoptosis. Collectively, these results suggest that rotenone interferes with porcine oocyte maturation by inhibiting mitochondrial function.

Phospholipase C gamma 1 (PLCγ1) plays an oncogenic role in several cancers, alongside its usual physiological roles. Despite studies aimed at identifying the effect of PLCγ1 on tumors, the pathogenic role of PLCγ1 in the tumorigenesis and development of hepatocellular carcinoma (HCC) remains unknown. To investigate the function of PLCγ1 in HCC, we generated hepatocyte-specific PLCγ1 conditional knockout (PLCγ1 f/f ; Alb-Cre) mice and induced HCC with diethylnitrosamine (DEN). Here, we identified that hepatocyte-specific PLCγ1 deletion effectively prevented DEN-induced HCC in mice. PLCγ1 f/f ; Alb-Cre mice showed reduced tumor burden and tumor progression, as well as a decreased incidence of HCC and less marked proliferative and inflammatory responses. We also showed that oncogenic phenotypes such as repressed apoptosis, and promoted proliferation, cell cycle progression and migration, were induced by PLCγ1. In terms of molecular mechanism, PLCγ1 regulated the activation of signal transducer and activator of transcription 3 (STAT3) signaling. Moreover,

Heat stress (HS) is a long-standing hurdle that animals face in the living environment. Alpha-lipoic acid (ALA) is a strong antioxidant synthesized by plants and animals. The present study evaluated the mechanism of ALA action in HS-induced early porcine parthenotes development. Parthenogenetically activated porcine oocytes were divided into three groups: control, high temperature (HT) (42 °C for 10 h), and HT + ALA (with 10 µM ALA). The results show that HT treatment significantly reduced the blastocyst formation rate compared to the control. The addition of ALA partially restored the development and improved the quality of blastocysts. Moreover, supplementation with ALA not only induced lower levels of reactive oxygen species and higher glutathione levels but also markedly reduced the expression of glucose regulatory protein 78. The protein levels of heat shock factor 1 and heat shock protein 40 were higher in the HT + ALA group, which suggests activation of the heat shock response. The addition of ALA reduced the expression of caspase 3 and increased the expression of B-cell lymphoma-extra-large protein. Collectively, this study revealed that ALA supplementation ameliorated HS-induced apoptosis by suppressing oxidative and endoplasmic reticulum stresses via activating the heat shock response, which improved the quality of HS-exposed porcine parthenotes.