The global effect of heat on gene expression in cultured bovine mammary epithelial cells

Abstract

Heat stress (HS) in hot climates is a major cause that strongly negatively affects milk yield in dairy cattle, leading to immeasurable economic loss. The heat stress response of bovine mammary epithelial cells (BMECs) is one component of the acute systemic response to HS. Gene networks of BMECs respond to environmental heat loads with both intra-and extracellular signals that coordinate cellular and whole-animal metabolism. Our experimental objective was to characterize the direct effects of heat stress on the cultured bovine mammary epithelial cells by microarray analyses. The data identified 2716 differentially expressed genes in 43,000 transcripts which were changed significantly between heat-stressed and normal bovine mammary epithelial cells (fold change ≥2, P≤0.001). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that these differentially expressed genes are involved in different pathways that regulate cytoskeleton, cell cycle, and stress response processes. Our study provides an overview of gene expression profile and the interaction between gene expression and heat stress, which will lead to further understanding of the potential effects of heat stress on bovine mammary glands.

The effect of heat stress on gene expression, synthesis of steroids, and apoptosis in bovine granulosa cells

“…So, we hypothesized that heat stress may induce the change of gene expression, finally leading to disordered ovarian function. In the present study, using DGE profiling of granulosa cells, we have demonstrated that thermal stress triggers a dramatic and complex program of altered gene expression in GCs similar to some patterns reported in other cell types exposed to thermal stress (Collier et al 2008;Li et al 2015). Some reported that thermal stress can regulate the RNA processing/translation, increase degradation of proteins, disrupt the cytoskeletal components, and alter metabolism process (Collier et al 2006;Sonna et al 2010).…”

“…After 48 h of preculture, when cells attached to the bottom of the wells, the medium was replaced with medium of the same composition. Then cells were cultured at temperatures 38°C (control group) or 40.5°C (heat treatment group) for 2 h, and then the cells were cultured at 38°C for 12 h. Immediately after culture, the cells and culture media were collected for subsequent analyses (Li et al 2015).…”

Proteomic analysis to unravel the effect of heat stress on gene expression and milk synthesis in bovine mammary epithelial cells

“…Mammary tissues were obtained from three healthy Holstein dairy cows at the middle stage of lactation. In vitro cultures of mammary epithelial cells were prepared in accordance with the established methods by Dairy Science Institute of Nanjing Agricultural University (Li et al 2014). The cells were cultured in Dulbecco's modified Eagle's medium (DMEM) containing 4.5 mg/mL glucose and supplemented with 10% fetal bovine serum (Life Technologies, Gaithersburg, MD, USA) and 1% antibiotic-antimycotic solution (Sigma-Aldrich, St. Louis, MO, USA) in a humidified incubator, with 5% CO 2 at 38°C.…”

“…In a previous study, we have found that heat stress could affect the function and gene expression of bovine mammary epithelial cells (BMECs); the response of BMECs to heat stress plays a vital role in regulating mammary function (Li et al . ).…”

“…The alveoli secretion function is also regulated acutely by local autocrine feedback mechanisms that involve milk-borne factors which are sensitive to the frequency and efficiency of milking. In a previous study, we have found that heat stress could affect the function and gene expression of bovine mammary epithelial cells (BMECs); the response of BMECs to heat stress plays a vital role in regulating mammary function (Li et al 2014).…”