時差--生理時鐘亂了，可能引發肝癌!

熬夜過度可能引發肝癌!
美國貝勒醫學院研究人員發現，使小鼠突然生理時鐘被打亂一段長期的時間(20小時開燈、4小時關燈；一般為12小時開燈、12小時關燈)，經過30個星期後，小鼠肝臟有過度累積脂肪的現象，而其中有9%的小鼠引發了肝癌。這樣的現象可能與肝臟細胞的bile acids以及 constitutive androstane receptor (CAR) 活化有關。CAR原本是調節肝臟再生的一種受體，會受到bile acid的刺激。此外，若另一個控制bile acid產生在正常範圍的受體FXR被剔除時，即便生理時鐘正常運作的小鼠，仍有30%會引發肝癌。
所以，在怎麼忙，也要好好遵守生理時鐘，不要長時間熬夜過度，免得影響身體健康。

根據最近的科學期刊：

Circadian Homeostasis of Liver Metabolism Suppresses Hepatocarcinogenesis 

Cancer Cell Volume 30, Issue 6, p909–924, 12 December 2016  

Chronic jet lag induces spontaneous hepatocellular carcinoma (HCC) in wild-type mice following a mechanism very similar to that observed in obese humans. The process initiates with non-alcoholic fatty liver disease (NAFLD) that progresses to steatohepatitis and fibrosis before HCC detection. This pathophysiological pathway is driven by jet-lag-induced genome-wide gene deregulation and global liver metabolic dysfunction, with nuclear receptor-controlled cholesterol/bile acid and xenobiotic metabolism among the top deregulated pathways. Ablation of farnesoid X receptor dramatically increases enterohepatic bile acid levels and jet-lag-induced HCC, while loss of constitutive androstane receptor (CAR), a well-known liver tumor promoter that mediates toxic bile acid signaling, inhibits NAFLD-induced hepatocarcinogenesis. Circadian disruption activates CAR by promoting cholestasis, peripheral clock disruption, and sympathetic dysfunction.