Changes in Ucp1, D2 (Dio2) and Glut4 (Slc2a4) mRNA expression in response to short-term cold exposure in the house musk shrew (Suncus murinus).
The house musk shrew (Suncus murinus), or so-called suncus, is a cold-intolerant mammal, but it is unclear why it is susceptible to low temperatures. Cold-intolerance may be the result of lower thermogenic activity in brown adipose tissue (BAT). The early phase of severe cold exposure is a critical period for suncus. Therefore, we exposed suncus to mildly cold temperatures (10-12 degrees C) for 1 to 48 h to increase non-shivering thermogenesis without causing stress and measured changes in the expression of uncoupling protein 1 (Ucp1), type II iodothyronine 5'-deiodinase (Dio2=D2), and glucose transporter 4 (Slc2a4=Glut4) in BAT. These mRNAs play a major role in non-shivering thermogenesis and are mainly regulated by the sympathetic nervous system via direct beta-noradrenergic innervation of BAT. During cold exposure, Ucp1 expression in BAT increased steadily over time, albeit only slightly. Neither D2 nor Glut4 expression in BAT increased immediately; however, they had increased significantly after 24 h and 48 h of cold exposure. These findings suggest that the responsiveness of mRNA regulation is weak and thus may be involved in cold-intolerance in suncus.
Laboratory of Animal Management & Resources, School of Bio-Agricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan.
Daisuke
D
Suzuki
Yoshiharu
Y
Murata
Sen-ichi
S
Oda
D002001:Adipose Tissue, Brown / Q000378:metabolism; D052436:Adipose Tissue, White / Q000378:metabolism; D000818:Animals; D003080:Cold Temperature; D015870:Gene Expression; D051275:Glucose Transporter Type 4 / Q000235:genetics* / Q000378:metabolism; D007453:Iodide Peroxidase / Q000235:genetics* / Q000378:metabolism; D007473:Ion Channels / Q000235:genetics* / Q000378:metabolism; D008297:Male; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis*; D012788:Shrews / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology; D013997:Time Factors; D000071256:Uncoupling Protein 1; D000097564:Iodothyronine Deiodinase Type II
D051275:Glucose Transporter Type 4; D007453:Iodide Peroxidase; D007473:Ion Channels; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D000071256:Uncoupling Protein 1; D000097564:Iodothyronine Deiodinase Type II