DNA methylation changes of apoptotic genes in organogenesis stage of mice embryos by maternal chlorpyrifos induction

Exosome-derived miR-142-5p from liver stem cells improves the progression of liver fibrosis by regulating macrophage polarization through CTSB

BACKGROUND

This study aims to explore the effect of liver stem cells (LSCs)-derived exosomes and the miR-142a-5p carried by them on the process of fibrosis by regulating macrophages polarization.

METHODS

In this study, CCL₄ was used to establish liver fibrosis model. The morphology and purity of exosomes (EVs) were verified by transmission electron microscopy, western blotting (WB) and nanoparticle tracing analysis (NTA). Real-time quantitative PCR (qRT-PCR), WB and enzyme-linked immunoadsorption (ELISA) were used to detect liver fibrosis markers, macrophage polarization markers and liver injury markers. Histopathological assays were used to verify the liver injury morphology in different groups. The cell co-culture model and liver fibrosis model were constructed to verify the expression of miR-142a-5p and ctsb.

RESULTS

Immunofluorescence of LSCs markers CK-18, epithelial cell adhesion molecule (EpCam), and AFP showed that these markers were up-regulated in LSCs. In addition, we evaluated the ability of LSCs to excrete EVs by labeling LSCs-EVs with PKH67. We found that CCL₄ and EVs were simultaneously treated at 50 and 100 μg doses, and both doses of EVs could reduce the degree of liver fibrosis in mice. We tested markers of M1 or M2 macrophage polarization and found that EVs reduced M1 marker expression and promoted M2 marker expression. Further, ELISA was used to detect the secreted factors related to M1 and M2 in tissue lysates, which also verified the above views. Further analysis showed that the expression of miR-142a-5p increased significantly with the increase of EVs treatment concentration and time. Further, in vitro and in vivo LSCs-EVs regulate macrophage polarization through miR-142a-5p/ctsb pathway and affect the process of liver fibrosis.

CONCLUSION

Our data suggest that EVs-derived miR-142-5p from LSCs improves the progression of liver fibrosis by regulating macrophage polarization through ctsb.

Exposure to chlorpyrifos leads to spindle disorganization and mitochondrial dysfunction of porcine oocytes during in vitro maturation

Chlorpyrifos (CPF), as one of the most extensively applied organophosphorus pesticides (OPs) in agricultural and domestic settings, causes a potential threat to human and animal health. Various reproductive toxicities of CPF have been reported, however, little information is available on whether CPF exposure could exert toxic effects on mammalian oocytes. Herein, the effects of CPF on the meiotic maturation and developmental capability of porcine oocytes were investigated, and the possible toxic mechanisms of CPF were also explored. Porcine cumulus-oocyte complexes (COCs) were treated with 0, 5, 10, or 20 μM CPF for 44 h during in vitro maturation (IVM), and the results showed that the first polar body (PB1) extrusion rate was significantly decreased, and the subsequent developmental competence of the resulting metaphase II (MII) oocytes was also impaired when the concentration of CPF reached 10 μM. In addition, a higher percentage of CPF-exposed oocytes were arrested at the anaphase-telophase I (ATI) stage, accompanied by misaligned chromosomes and aberrant spindles. Furthermore, higher levels of ROS and upregulated antioxidant-related genes (CAT, SOD1, SOD2, GPX) were detected in CPF-treated oocytes. Additionally, CPF treatment led to the depolarization of mitochondrial membrane potential (MMP) and the release of cytochrome c (Cyt c). Simultaneously, the apoptotic rate of the oocytes was significantly increased, and the expression levels of Bax and CASPASE3 were significantly upregulated after CFP exposure. Together, exposure to 10 μM CPF can disrupt the meiotic cycle progression, lead to aberrant spindles and mitochondrial dysfunction, which eventually induce oxidative stress and apoptosis in porcine oocytes.