Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095-1740, USA.
Cardiac Aging and Redox Signaling Laboratory, Center for Free Radical Biology, Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
Free Radic Biol Med. 2019 Jan;130:592-600. doi: 10.1016/j.freeradbiomed.2018.09.029. Epub 2018 Sep 21.
Intrauterine growth restriction (IUGR) leads to adult obesity, cardiovascular disease, and non-alcoholic fatty liver disease/steatohepatitis. Animal models have shown that combined intrauterine and early postnatal calorie restriction (IPCR) ameliorates these sequelae in adult life. The mechanism by which IPCR protects against adult onset disease is not understood. Autophagy, a lysosomal degradative process, recycles cellular constituents and eliminates damaged organelles, proteins, and oxidants. In this study, we hypothesized that IPCR could regulate autophagy in the liver of male rat offspring. At birth (d1) of male IUGR rat offspring and on day 21 (p21) of life, IPCR male rat offspring had a profound decrease in hepatic autophagy in all three stages of development: initiation, elongation, and maturation. However, upon receiving a normal diet ad-lib throughout adulthood, aged IPCR rats (day 450 of life (p450)), had increased hepatic autophagy, in direct contrast to what was seen in early life. The decreased autophagy at d21 led to the accumulation of ubiquitinated proteins and lipid oxidative products, whereas the increased autophagy in late life had the opposite effect. Oxidized lipids were unchanged at d1 by IUGR treatment indicating that decreased autophagy precedes oxidative stress in early life. When cellular signaling pathways regulating autophagy were examined, the 5' adenosine monophosphate-activated protein kinase pathway (AMPK), and not endoplasmic stress pathways, was found to be altered, suggesting that autophagy is regulated through AMPK signaling pathway in IPCR rats. Taken together, this study reveals that the perinatal nutritional status establishes a nutritionally sensitive memory that enhances hepatic autophagy in late life, a process that perhaps acts as a protective mechanism to limited nutrition.
宫内生长受限(IUGR)会导致成年肥胖、心血管疾病和非酒精性脂肪肝/脂肪性肝炎。动物模型研究表明,宫内和产后早期联合热量限制(IPCR)可改善成年后的这些后遗症。然而,IPCR 保护成年发病的机制尚不清楚。自噬是一种溶酶体降解过程,可回收细胞成分并消除受损的细胞器、蛋白质和氧化剂。在这项研究中,我们假设 IPCR 可以调节雄性大鼠子代肝脏中的自噬。在雄性 IUGR 大鼠子代出生时(d1)和生命第 21 天(p21),IPCR 雄性大鼠子代在发育的所有三个阶段(起始、延伸和成熟)均出现严重的肝自噬减少。然而,当它们在成年后接受自由饮食时,老年 IPCR 大鼠(生命第 450 天(p450))的肝自噬增加,与早期生命中的情况正好相反。d21 时自噬减少导致泛素化蛋白和脂质氧化产物的积累,而晚期生命中自噬增加则产生相反的效果。氧化脂质在 IUGR 处理时在 d1 并未改变,表明早期生命中的氧化应激先于自噬减少。当检查调节自噬的细胞信号通路时,发现 5'腺苷单磷酸激活蛋白激酶通路(AMPK),而不是内质网应激通路,发生改变,这表明自噬是通过 IPCR 大鼠中的 AMPK 信号通路调节的。综上所述,这项研究揭示了围产期营养状况建立了一种营养敏感的记忆,增强了成年后期的肝脏自噬,这一过程可能作为一种保护机制来限制营养。