Analysis of circulating-microRNA expression in lactating Holstein cows under summer heat stress

Abstract

Korean peninsular weather is rapidly becoming subtropical due to global warming. In summer 2018, South Korea experienced the highest temperatures since the meteorological observations recorded in 1907. Heat stress has a negative effect on Holstein cows, the most popular breed of dairy cattle in South Korea, which is susceptible to heat. To examine physiological changes in dairy cows under heat stress conditions, we analyzed the profiles circulating microRNAs isolated from whole blood samples collected under heat stress and non-heat stress conditions using small RNA sequencing. We compared the expression profiles in lactating cows under heat stress and non-heat stress conditions to understand the regulation of biological processes in heat-stressed cows. Moreover, we measured several heat stress indicators, such as rectal temperature, milk yield, average daily gain, and progesterone concentration. All these assessments showed that pregnant cows were more susceptible to heat stress than non-pregnant cows. Particularly, progesterone concentrations known to have maternal warming effects were at similar levels in non-pregnant cows but significantly increased in pregnant cows under heat stress conditions. The differentially expressed miRNAs and their putative target genes were analyzed in pregnant cows. Interestingly, we found that differentially expressed miRNAs (bta-miR-146b, bta-miR-20b, bta-miR-29d-3p, bta-miR-1246) specifically targeted progesterone biosynthesis (StAR) and the function of corpus luteum-related genes (CCL11, XCL), suggesting that pregnant cows with elevated progesterone concentrations are more susceptible to heat stress. In addition, we found the differential expression of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) in both pregnant and non-pregnant cows under heat stress conditions. In target gene prediction and gene set enrichment analysis, these miRNAs were found to be associated with the cytoskeleton, cell junction, vasculogenesis, cell proliferation, ATP synthesis, oxidative stress, and immune responses involved in heat response. These miRNAs can be used as potential biomarkers for heat stress.

Comprehensive RNA-Seq Profiling Reveals Temporal and Tissue-Specific Changes in Gene Expression in Sprague–Dawley Rats as Response to Heat Stress Challenges

“…Blood is a good model for medical and physiology research (Cohn, 2015) and is widely used in clinical disease diagnosis because of its advantages of noninvasive collection (Nisenblat et al, 2016;Kiddle et al, 2018). Previous studies have shown that mild/severe heat stress can affect blood physiological, biochemical, and immunological indicators (Bagath et al, 2019;Johnson et al, 2019), as well as the expression of certain genes [e.g., heat shock protein (HSP)] (Garner et al, 2020;Lee et al, 2020). Meanwhile, our previous studies have also proven that blood biomarkers can reflect the degree of acute and short-term heat stress (Dou et al, 2019(Dou et al, , 2020.…”

miRNA Sensing in Livestock: Challenges and Potential Approaches

“…In a study by Lee et. al., [31] blood samples from cows were collected to check the expression of both mRNA and miRNA in different environmental conditions. A total of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) were differentially expressed in both pregnant and non-pregnant cows under heat stress conditions.…”

“…A total of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) were differentially expressed in both pregnant and non-pregnant cows under heat stress conditions. Another study of the effect of heat stress on pregnant cows showed that the miRNAs bta-miR-146b, bta-miR-20b, bta-miR-29d-3p, and bta-miR-1246 that specifically target progesterone biosynthesis (StAR) and the function of corpus luteum-related genes (CCL11, XCL) were differentially expressed [31]. Similarly, a study by Li et al, [32] showed in heat-stressed Holstein cattle, 20 miRNAs had higher levels of expression in their mammary tissues.…”

Análise de parâmetros fisiológicos e perfil de expressão de genes associados ao estresse térmico e eficiência alimentar em bovinos das raças Nelore e Caracu

“…The expression of the HSP90 gene was lower in animals of group 2, which were classified as tolerant to heat stress. Several studies involving breeds raised for milk and meat production have suggested an association of the HSP90 gene with heat tolerance Kim et al, 2020), which has been indicated as a biomarker of heat stress in cattle (Abdelnour et al, 2018;Lee et al, 2020;.…”