Maternal protein restriction and postnatal sugar consumption increases inflammatory response and deregulates metabolic pathways in the liver of male offspring rats with aging

This study investigated the late effects of maternal protein restriction (MPR) and early postnatal sugar consumption on liver health in male Sprague-Dawley rat offspring, focusing on changes observed throughout the aging process. The animals were divided into the following groups: Control (CTR): Male offspring whose dams consumed a normal protein diet (NPD, 17% protein) and water ad libitum during gestation and lactation, and then fed a NPD and water until PND 540; Control + Sugar (CTR + SUG): The same treatment as CTR, but consuming a sugar solution (10% diluted in water) from postnatal day (PND) 21-90, and then fed a NPD and water until PND 540; Gestational and Lactational Low Protein (GLLP): Male offspring whose dams consumed a low-protein diet (LPD, 6% protein) during gestation and lactation and, then fed a NPD and water ad libitum until PND 540; Gestational and Lactational Low Protein + Sugar (GLLP + SUG): male offspring whose dams consumed a LPD during gestation and lactation, and then fed a NPD and a sugar solution (10% diluted in water) ad libitum from PND 21 to 90. On PND 540, the animals were anesthetized, weighed, and euthanized, and their livers were collected for morphological and molecular analyses. The GLLP and GLLP + SUG groups showed lower body weight and lower retroperitoneal fat weight compared to the CTR and CTR + SUG groups. Morphological analysis revealed inflammatory foci in the liver from the CTR + SUG, GLLP, and GLLP + SUG groups, compared to the CTR group. Hepatic activities of CAT, SOD, and GSH-Px were increased in the GLLP + SUG group and decreased in the GLLP group, compared to the CTR group. Immunohistochemistry showed a significant increase in occupied area per foci de hepatocytes positive for GSTpi (placental form) in the CTR + SUG, GLLP, and GLLP + SUG groups, compared to the CTR group. Proteomic analysis of the groups revealed significant changes in hepatic metabolic and inflammatory pathways. In the CTR + SUG group, upregulated pathways associated with non-alcoholic fatty liver disease (NAFLD) and downregulated pathways related to autophagy were observed. In the GLLP and GLLP + SUG groups, there was a significant impact on metabolic pathways, including glucose metabolism, gluconeogenesis, glycogenesis, and cellular stress responses. An upregulation of pathways associated with chemokine- and cytokine-mediated inflammatory processes was also identified, indicating activation of the immune system in the liver during aging. Therefore, MPR, with or without postnatal sugar consumption, resulted in hepatic changes in metabolism and the antioxidant defense in old male offspring.