Uncoupling protein-3 expression in rodent skeletal muscle is modulated by food intake but not by changes in environmental temperature
Uncoupling protein-3 expression in rodent skeletal muscle is modulated by food intake but not by changes in environmental temperature
复制标题
DOI：
10.1074/jbc.273.1.5
复制
发表时间：
1998-01-02
影响因子：
4.8
通讯作者：
Muzzin, P
中科院分区：
文献类型：
--
作者：
Boss, O;Samec, S;Muzzin, P
解偶联蛋白（UCP）家族的一个新成员UCP3最近被克隆出来，并显示在啮齿动物和人类的骨骼肌中高表达。在本研究中，UCP3在C2C12成肌细胞中过表达，在那里它作为解偶联蛋白。在已知的调节棕色脂肪组织产热的条件下，在啮齿动物肌肉中检测了UCP3 mRNA表达的变化。UCP3的表达在48小时的冷暴露（6℃）下没有变化，而在50%食物限制或禁食1周时，UCP3的表达分别下降了81%或增加了5.6倍。与瘦Zucker大鼠相比，肥胖比罗鱼肌（fa/fa）的UCP3 mRNA水平也降低了36%。禁食诱导的UCP3 mRNA水平的意外升高并未改变体外肌肉基础产热率，但对解耦剂羰基氰化物对三氟甲氧基苯腙的产热能力降低了31%。这种下降可能反映了UCP3潜在的解耦。在热中性暴露的小鼠中，禁食24小时后UCP3 mRNA的表达仍然上调，这些结果表明禁食诱导的UCP3表达的增加与体外肌肉产热能力的维持有关，而不受环境温度的调节。UCP3表达受食物摄入调节的观点对于更好地理解人类肥胖的病理生理具有重要意义。
A new member of the uncoupling protein (UCP) family called UCP3 has recently been cloned and shown to be highly expressed in skeletal muscle of rodents and humans, In the present study, UCP3 was overexpressed in C2C12 myoblasts where it acts as an uncoupling protein, Changes in UCP3 mRNA expression were examined in rodent muscles,under conditions known to modulate thermogenesis in brown adipose tissue, In skeletal muscle, UCP3 expression did not change in response to 48 h of cold exposure (6 degrees C), whereas it was decreased by 81% or increased 5.6-fold by 1 week of 50% food restriction or fasting, respectively. It was also decreased by 36% in soleus muscle of obese (fa/fa) as compared with lean Zucker rats, The unexpected rise of UCP3 mRNA level induced by fasting did not change in vitro muscle basal heat production rate but decreased by 31% the capacity to produce heat in response to the uncoupler carbonyl-cyanide p-trifluoromethoxyphenylhydrazone. This decrease may reflect underlying uncoupling by UCP3. Upregulation of UCP3 mRNA after a 24-h fast was still observed in mice exposed at thermoneutrality, These results show that the increase in UCP3 expression induced by fasting is associated with the maintenance of thermogenesis measured in muscle in vitro and is not modulated by environmental temperature. The notion that UCP3 expression is modulated by food intake is of importance to better understand the pathophysiology of obesity in humans.