Grazing Affects Exosomal Circulating MicroRNAs in Cattle

Abstract

Circulating microRNAs (c-miRNAs) are associated with physiological adaptation to acute and chronic aerobic exercise in humans. To investigate the potential effect of grazing movement on miRNA circulation in cattle, here we profiled miRNA expression in centrifugally prepared exosomes from the plasma of both grazing and housed Japanese Shorthorn cattle. Microarray analysis of the c-miRNAs resulted in detection of a total of 231 bovine exosomal miRNAs in the plasma, with a constant expression level of let-7g across the duration and cattle groups. Expression of muscle-specific miRNAs such as miR-1, miR-133a, miR-206, miR-208a/b, and miR-499 were undetectable, suggesting the mildness of grazing movement as exercise. According to validation by quantitative RT-PCR, the circulating miR-150 level in the grazing cattle normalized by the endogenous let-7g level was down-regulated after 2 and 4 months of grazing (P < 0.05), and then its levels in housed and grazing cattle equalized when the grazing cattle were returned to a housed situation. Likewise, the levels of miR-19b, miR-148a, miR-221, miR-223, miR-320a, miR-361, and miR-486 were temporarily lowered in the cattle at 1 and/or 2 month of grazing compared to those of the housed cattle (P < 0.05). In contrast, the miR-451 level was up-regulated in the grazing cattle at 2 months of grazing (P = 0.044). The elevation of miR-451 level in the plasma was coincident with that in the biceps femoris muscle of the grazing cattle (P = 0.008), which suggests the secretion or intake of miR-451 between skeletal muscle cells and circulation during grazing. These results revealed that exosomal c-miRNAs in cattle were affected by grazing, suggesting their usefulness as molecular grazing markers and functions in physiological adaptation of grazing cattle associated with endocytosis, focal adhesion, axon guidance, and a variety of intracellular signaling, as predicted by bioinformatic analysis.

Comprehensive analysis of blood cells and plasma identifies tissue-specific miRNAs as potential novel circulating biomarkers in cattle

“…The identification of biomarkers associated with specific production traits and disease conditions in cattle would be of significant agricultural importance. A handful of studies have already linked circulating miRNA profiles with pregnancy and the oestrous cycle [ 19 , 20 ], infection [ 21 , 22 ] and grazing [ 23 ] in cattle, as well as with bacterial disease and feed deprivation in other domestic species [ 24 ]. However, the source and tissue-specificity of circulating miRNA populations in these species have not been determined which, in view of the above, limits the practical significance of those results.…”

Are We Eating Our Way to Prostate Cancer—A Hypothesis Based on the Evolution, Bioaccumulation, and Interspecific Transfer of miR-150

“…With the shift in focus of therapy from treatment to prevention, diet has come under increasing scrutiny, especially with the findings of Spisak et al (2013) that identified the presence of foreign nucleic acid in human plasma [ 73 ]. If plants have minute quantities of potentially carcinogenic miRNAs and cattle are known to take up ingested plant miRNAs [ 74 ], then meat and dairy products in particular are of dietary importance due to the plausible bioaccumulation of the potentially oncogenic miRNAs through human dietary consumption.…”

Plasma exosome profiles from dairy cows with divergent fertility phenotypes

“…Maternal and embryo communication via exosomes may be vital in the recognition and continued development of pregnancy (Burns et al, 2014(Burns et al, , 2016Saadeldin et al, 2015;Burnett and Nowak, 2016;Machtinger et al, 2016). The protein content of exosomes can be used to help elucidate the origin and potential function of exosomes as well as providing clues about the physiological state of an organism (Østergaard et al, 2012;Muroya et al, 2015). Enrichment of immune response and cell signaling ontology terms in protein derived from the blood of cows postpartum suggests that a significant number of exosomes are derived from immune cells or are in- volved in immune function in the dairy cow.…”