BioProject

Hibernating American black bears have significantly different clotting parameters than their active summer counterparts, affording them innate protection against venous thromboembolism (VTE) despite prolonged periods of immobility. More...

Hibernating American black bears have significantly different clotting parameters than their active summer counterparts, affording them innate protection against venous thromboembolism (VTE) despite prolonged periods of immobility. Physiologic changes that occur during hibernation are thought to result from differential gene expression, rather than novel genes, and there is increasing evidence miRNAs may play an important role this regulation. We propose that significant differences exist in miRNA expression in the plasma of hibernating black bears compared to their active counter parts (summer), which lead to critical gene regulation responsible for auto-anticoagulation during hibernation. Methods: Blood was collected from 21 American black bears in the Northern Michigan Peninsula in summer 2017 and winter 2018 (11 active, 10 hibernating). Plasma was extracted Results: Fifteen miRNAs were differentially expressed in the plasma of hibernating black bears. Nine miRNAs were significantly downregulated (miR10b-3p, miR-136-3p, miR-181c-5p , miR-200a-3p, miR-200b-5p, miR-200c-3p, miR-320b, miR-320c and miR-320d) and six miRNAs were significantly upregulated (miR-15a-5p, miR-15b-3p, miR-15b-5p, miR-16-5p, miR-92a-3p, miR-150-5p) during hibernation. Twelve miRNAs had no identifiable targets, but miR-200a-3p, miR-200b-5p and miR-200c-3p found to be targets of SERPINC1, the gene responsible for the production of antithrombin (AT). Conclusions: Several miRNAs were differentially expressed in hibernating bears (12). Most importantly miR-200a-3p, miR-200b-5p and miR-200c-3p were all downregulated in hibernation and associated with increased expression of SERPINC1 and production of AT. AT is a powerful anticoagulant and this finding may explain the hibernating black bears ability to achieve auto-anticoagulation and protection from VTE. Overall design: We evaluated if significant differences exist between the expression of miRNAs in the plasma of hibernating black bears compared to their summer active counter parts. Please note that as some bears don't match due to unavailability of the same bears in summer time, differential expression analysis was carried out without pairing them. Less...