Tajima Toshihide, Goda Nobuhito, Fujiki Natsuko, Hishiki Takako, Nishiyama Yasumasa, Senoo-Matsuda Nanami, Shimazu Motohide, Soga Tomoyoshi, Yoshimura Yasunori, Johnson Randall S, Suematsu Makoto
Department of Obstetrics & Gynecology, Keio University, Shinjuku-ku, Tokyo, Japan.
Biochem Biophys Res Commun. 2009 Oct 2;387(4):789-94. doi: 10.1016/j.bbrc.2009.07.115. Epub 2009 Jul 28.
Coordinated recovery of hepatic glucose metabolism is prerequisite for normal liver regeneration. To examine roles of hypoxia inducible factor-1alpha (HIF-1alpha) for hepatic glucose homeostasis during the reparative process, we inactivated the gene in hepatocytes in vivo. Following partial hepatectomy (PH), recovery of residual liver weight was initially retarded in the mutant mice by down-regulation of hepatocyte proliferation, but occurred comparably between the mutant and control mice at 72h after PH. At this time point, the mutant mice showed lowered blood glucose levels with enhanced accumulation of glycogen in the liver. The mutant mice exhibited impairment of hepatic gluconeogenesis as assessed by alanine tolerance test. This appeared to result from reduced expression of PGK-1 and PEPCK since 3-PG, PEP and malate were accumulated to greater extents in the regenerated liver. In conclusion, these findings provide evidence for roles of HIF-1alpha in the regulation of gluconeogenesis under liver regeneration.
肝脏葡萄糖代谢的协调恢复是正常肝脏再生的先决条件。为了研究缺氧诱导因子-1α(HIF-1α)在修复过程中对肝脏葡萄糖稳态的作用,我们在体内使肝细胞中的该基因失活。部分肝切除(PH)后,突变小鼠中残余肝脏重量的恢复最初因肝细胞增殖下调而延迟,但在PH后72小时,突变小鼠和对照小鼠之间的恢复情况相当。此时,突变小鼠的血糖水平降低,肝脏中糖原积累增加。通过丙氨酸耐量试验评估,突变小鼠表现出肝糖异生受损。这似乎是由于PGK-1和PEPCK的表达降低所致,因为3-磷酸甘油、磷酸烯醇丙酮酸和苹果酸在再生肝脏中的积累程度更大。总之,这些发现为HIF-1α在肝脏再生过程中调节糖异生的作用提供了证据。