Análise da expressão de miRNAS e genes-alvo em sangue periférico de equinos quarto de milha antes e após treino.

Abstract

In the world, there are approximately 60 million horses, Brazil is the 4th country with the largest number of horses in heads (≤6 million). Brazilian Agribusiness generates around R$ 7.5 billion annually and the use of horses in sports is the most profitable segment of equinoculture. In chapter I, the objective was to carry out a literature review, seeking to understand the use of the Quarter Horse and its main related activities, as well as to understand the animal physiology related to exercise. For review, 7 base articles and 92 articles for discussion were used. In chapter II, the objective of the research was to investigate the differential expression of microRNAs and participatory target genes in exercise metabolic pathways, and to verify hematological and clinical alterations in QM horses under different physiological conditions. For the experiment, 10 horses (Equus caballus) of the quarter mile breed were used. The animals were submitted to physical efforts with obstacle avoidance and were clinically evaluated before and after exercise. Respiratory Rate, Heart Rate and Rectal Temperature were used as clinical parameters, 19 whole blood parameters were used as hematological parameters (complete blood count), for molecular evaluation the ALDOA and EGFR genes and the miR-133b and miR-1260b microRNAs were selected. . As clinical results, there were statistical differences for FR (<0.0001), FC (<0.0001) and TR (<0.0001), these parameters should be considered as important in the management of animal health, as well as evaluating the physiological performance of horses during training. The 9 hematological parameters that showed significance (p<0.05) before and after exercise were: Erythrocyte; hematocrit; Hemoglobin; Mean Corpuscular Volume; Range of distribution of erythrocytes; Mean Corpuscular Hemoglobin, Neutrophils and Lymphocytes. These parameters are related to aerobic capacity due to increased oxygen transport, making equine health indicators. The expression of genes ALDOA (p<0.0454) and EGFR (p<0.0198) and microsRNAs -133b (p<0.0240), -1260b (p<0.0066) were significant after exercise. The regulation of the ALDOA gene is associated with the metabolism of oxygen for the conversion of energy, the regulation of the EGFR may be more related to the post-training recovery provoked by the inflammatory response responsive to the exercise, due to the great physiological stress and energy expenditure, the miR -133b and -1260b had not yet been reported in the literature associated with modulation of exercise metabolic pathways, despite not regulating the genes of this research, these micros showed to be regulated after exercise, which shows that they regulate other target genes. These biomarkers found can be used as a reference for athletes of the QM race created in the north and northeast of Brazil. The changes observed for some parameters in the variables weight and sex had no clinical relevance (p>0.05). A future biochemical examination may show evidence of other biomarkers.