Fluroxypyr-1-methylheptyl ester causes apoptosis of bovine mammary gland epithelial cells by regulating PI3K and MAPK signaling pathways and endoplasmic reticulum stress

MicroRNA-2285f regulates milk fat metabolism by targeting MAP2K2 in bovine mammary epithelial cells

In this study, Holstein dairy cows raised in Ningxia were selected as the research object. Mammary epithelial cells (BMECs) were extracted from the milk of eight Holstein cows with significantly different milk fat expression rates and transcribed for sequencing. Bioinformatics analysis was used to analyse the correlation of fat milk percentage, and the critical miR-2285f regulating milk fat was screened out. The target gene binding sites were predicted, and 293T cells and mammary epithelial cells were used as miRNA and target gene models for functional verification in vitro. The tissue difference of miR-2285f Holstein cows was quantitatively analysed by transfecting miR-2285f mimic and inhibitor. Assay (dual luciferase reporter gene assay) and quantitative real-time PCR (quantitative real-time PCR, qRT-PCR), triglyceride (TAG) detection, oil red O detection of lipid droplets, Western Blot assay, Edu and Flow cytometry, The molecular regulatory effects of miR-2285f and target gene MAP2K2 on milk fat metabolism of Holstein dairy cows were studied. The wild-type vector and mutant vector of map2k2-3'utr were constructed, and double luciferase reporting experiments were conducted to verify that MAP2K2 was one of the target genes of miR-2285f. According to qRT-PCR and Western Blot analysis, miR-2285f mainly regulates the expression of MAP2K2 protein in BMECs at the translation level. Bta-miR-2285f can promote cell proliferation and slow cell apoptosis by regulating MAP2K2. Bta-miR-2285f can promote triglyceride (TAG) and lipid droplet accumulation in mammary epithelial cells by targeting MAP2K2. Bta-miR-2285f can regulate protein levels of fat milk marker gene PPARG by targeting MAP2K2. In conclusion, miR-2285f can target the expression of the MAP2K2 gene, promote the proliferation of dairy mammary epithelial cells, inhibit cell apoptosis and regulate the milk fat metabolism in dairy mammary epithelial cells. The results of this study revealed the function of miR-2285f in regulating the differential expression of fat milk in Holstein dairy cows at the cellular level. They provided a theoretical and experimental basis for analysing the regulation network of milk fat synthesis of Holstein dairy cows and the molecular breeding of dairy cows.

Oxyfluorfen induces cell cycle arrest by regulating MAPK, PI3K and autophagy in ruminant immortalized mammary epithelial cells

Oxyfluorfen, a phenoxy phenyl-type herbicide, causes significant damage to ecosystems through chronically effecting invertebrates, fish, and mammals. Considering its adverse effect on ecosystem conservation, it is necessary to investigate its toxic effects on animals. However, the mechanisms of oxyfluorfen toxicity on bovines are not well established. This study investigated the cytotoxic effect of oxyfluorfen on bovine mammary epithelial cells (MAC-T). We conducted several functional experiments to examine the response of MAC-T to oxyfluorfen under various concentrations (0, 1, 2, 5, and 10 ppm). Oxyfluorfen decreased cell viability and increased apoptotic cells by regulating the expression of apoptotic genes and proteins in MAC-T. In addition, oxyfluorfen-treated cells exhibited reduced PCNA expression with a low 3D spheroid formation as compared to that of control cells. Furthermore, oxyfluorfen treatment suppressed cell cycle progression with a decrease in cyclin D1 and cyclin A2 in MAC-T. Next, we performed western blot analysis to verify intercellular signaling changes in oxyfluorfen-treated MAC-T. The phosphor-AKT protein was increased, whereas MAPK signal pathways were decreased. Particularly, the combination of oxyfluorfen with U0126 or SP600125 completely blocked the ERK1/2 and JNK pathways leading to cell viability in MAC-T. Moreover, oxyfluorfen induced inflammatory gene expression and autophagy by increasing phosphorylation of P62 and LC3B in MAC-T. These results demonstrated that oxyfluorfen has cytotoxic effect on MAC-T, implying that the milk production capacity in cows may eventually harm humans.

Fluroxypyr-1-methylheptyl ester induced ROS production and mitochondrial apoptosis through the MAPK signaling cascade in porcine trophectoderm and uterine luminal epithelial cells

FPMH (Fluroxypyr-1-methylheptyl ester) is a synthetic auxin herbicide used in agriculture. The mechanism by which FPMH induces adverse effects in porcine trophectoderm (pTr) and porcine uterine luminal epithelial (pLE) cells, which are involved in porcine implantation, have not been studied yet. Therefore, the present study investigates the toxicological effects of FPMH on pTr and pLE cells. We confirmed that FPMH induced cytotoxic effects on the cells, including apoptosis induction, mitochondrial membrane potential (MMP) depolarization, and ROS production. The phosphorylation of the MAPK pathway (ERK1/2, JNK, and p38) was dysregulated by FPMH administration. In addition, FPMH could suppress cell-cell adhesion and migration abilities of pTr and pLE, which are crucial for implantation. Therefore, exposure to FPMH induced adverse effects in pTr and pLE cells and could result in implantation failure.