Laboratory of Wildlife Biology and Medicine, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan.
Laboratory of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido, 060-0818, Japan.
J Comp Physiol B. 2021 Mar;191(2):397-409. doi: 10.1007/s00360-020-01337-7. Epub 2021 Jan 18.
Hibernating bears survive up to 6 months without feeding while yet maintaining metabolic homeostasis. We previously reported expression changes in energy metabolism-related genes in the liver of hibernating Japanese black bears. The present study examined the role of microRNAs in the regulation of hepatic gene expression during hibernation. The quantitative analyses revealed significant increases in the expression of 4 microRNAs (miR-221-3p, miR-222-3p, miR-455-3p, and miR-195a-5p) and decreases of 2 microRNAs (miR-122-5p and miR-7a-1-5p) during hibernation. RNA sequencing and in silico target prediction regarding 3 upregulated microRNAs (miR-221-3p, miR-222-3p and miR-455-3p) found 13 target mRNAs with significantly decreased expression during hibernation. The transfection of microRNA mimics into cells showed that miR-222 and miR-455 reduced solute carrier family 16 member 4 (SLC16A4) and fatty acid synthase (FASN) mRNA expression, respectively. Our results suggest that the increased levels of hepatic miRNA during hibernation (miR-222-3p and miR-455-3p) negatively regulate the expression of targeted genes predicted to be involved in the transport of energy source and de novo fatty acid synthesis, is consistent with a regulatory role of these miRNAs in energy metabolism in hibernating black bears.
冬眠熊在不进食的情况下可存活长达 6 个月,同时仍保持代谢平衡。我们之前报道了冬眠日本黑熊肝脏中与能量代谢相关的基因表达变化。本研究探讨了 microRNAs 在冬眠期间调节肝脏基因表达中的作用。定量分析显示,在冬眠期间,有 4 种 microRNAs(miR-221-3p、miR-222-3p、miR-455-3p 和 miR-195a-5p)的表达显著增加,而 2 种 microRNAs(miR-122-5p 和 miR-7a-1-5p)的表达显著降低。针对 3 种上调的 microRNAs(miR-221-3p、miR-222-3p 和 miR-455-3p)的 RNA 测序和计算机预测目标表明,在冬眠期间有 13 个靶 mRNAs 的表达显著降低。microRNA 模拟物转染细胞后发现,miR-222 和 miR-455 分别降低溶质载体家族 16 成员 4(SLC16A4)和脂肪酸合成酶(FASN)mRNA 的表达。我们的结果表明,冬眠期间肝脏 microRNA(miR-222-3p 和 miR-455-3p)水平升高,负调控预测参与能量物质转运和从头脂肪酸合成的靶基因的表达,这与这些 microRNAs 在冬眠黑熊能量代谢中的调节作用一致。