温度驯化对布氏田鼠肝脏温敏瞬时受体电位通道蛋白表达的影响

Effect of temperature acclimation on thermosensitive transient receptor potential channels of liver in Brandt’s voles(Lasiopodomys brandtii)

肝脏是哺乳动物基础代谢产热的关键器官。温敏瞬时受体电位通道蛋白(Thermosensitive transient receptor potential channels,Thermo-TRPs)参与了调控肝细胞的生理功能。为了解Thermo-TRPs是否参与肝脏的代谢产热,以成年布氏田鼠(Lasiopodomys brandtii)为研究对象,测定了不同驯化温度下6种Thermo-TRPs在肝脏中的表达,分析其与肝脏产热相关蛋白和信号通路蛋白的关系。结果显示:(1)与高温组相比,低温增加了肝脏解偶联蛋白1(uncoupling protein 1,UCP1)的表达;而与常温组相比,低温降低了肝脏解偶联蛋白3(uncoupling protein 3,UCP3)的表达;(2)6种Thermo-TRPs均在肝脏中表达,与高温组相比,低温显著降低了TRP vanilloid 4(TRPV4)的表达,同时显著增加了腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)的表达;(3)低温显著增加了布氏田鼠血清三碘甲状腺原氨酸(T_(3))水平,提高了T_(3)/T_(4)比值;T_(3)/T_(4)比值与肝脏UCP1和AMPK呈显著正相关,肝脏中UCP1与TRPM2和AMPK呈显著正相关。这些结果表明,肝脏TRPV4和AMPK可能参与了低温环境中代谢产热等生理功能的调节过程。

Liver is a key organ of basal metabolic thermogenesis in mammals.Thermosensitive transient receptor potential channels(Thermo-TRPs)are involved in the regulation of various physiological functions of hepatocytes.In order to understand whether Thermo-TRPs are involved in liver metabolic thermogenesis,we measured the expressions of six types of Thermo-TRPs in liver of adult Brandt’s voles(Lasiopodomys brandtii)acclimated at different temperatures,and assessed the relationship between Thermo-TRPs and liver thermogenesis related proteins and signaling pathway proteins.Results showed that:(1)Compared with the hot(30℃)group,cold(4℃)acclimation increased the expression of uncoupling protein 1(UCP1)in liver but cold acclimation decreased the expression of UCP3 in liver compared with the warm(23℃)group.(2)Six types of Thermo-TRPs were expressed in liver.Compared with the hot group,cold acclimation decreased the expression of TRP vanilloid 4(TRPV4)and increased AMP-activated protein kinase(AMPK)in liver.(3)The level of serum thyroid hormone(T_(3))and the ratio of T_(3)/T_(4)were significantly higher in the cold than other groups.Ratio of T_(3)/T_(4)was positively correlated with UCP1 and AMPK in liver,and UCP1 was positively correlated with TRPM2and AMPK in liver.These results suggest that liver TRPV4 and AMPK may be involved in the regulation of physiological functions such as metabolic thermogenesis under cold conditions.