Body temperature-dependent microRNA expression analysis in rats

We made rat models of mild, moderate and severe hypothermia, and performed body temperature-dependent microRNA expression analysis in illiopsoas muscle. Twelve male wistar rats (Pathogen-free 9-week-old) were divided into 4 groups (control, mild, moderate and severe hypothermia), which were belonged 3 rats, and were anesthetized with intraperitoneal. After 30 minutes, they were treated at cold (ambient temperature: 4 °C), and chronologically measured rectal temperature (Ret). Control was euthanized by cervical dislocation at 30 minutes after anesthesia. Mild hypothermia was done by cervical dislocation when the Ret reached 30°C. Similarly, moderate and severe hypothermia also was done when the Ret did 22°C and 12°C, respectively. Total RNA from iliopsoas muscle was extracted using miRNeasy Mini kit (QIAGEN GmbH, Hilden, Germany) according to the manufacturer's instructions. RNA integrity was assessed by on-chip capillary electrophoresis using an Agilent RNA 6000 Nano kit and Agilent 2100 Bioanalyzer (Agilent Technologies, Inc., Santa Clara, CA, USA). Microarray analysis was performed on a total of 12 samples (each group n=3) using Rat_miRNA_V21.0_Microarray.