Scope: Non-alcoholic fatty liver disease (NAFLD) among adolescents has been related to fructose intake. Additionally, maternal high-fat diet (mHFD) increases the offspring susceptibility to NAFLD at adulthood. Here, it is hypothesized that mHFD may exacerbate the fructose impact in adolescent male rat offspring, by changing the response of contributing mechanisms to liver injury. Methods and results: Female Wistar rats receive standard (mSTD: 9% fat) or high-fat diet (mHFD: 29% fat) prior mating throughout pregnancy and lactation. After weaning, offspring receive standard chow and, from the 25th to 45th day, receive water or fructose-drinking water (15%). At 46 days old, fructose groups show increased adiposity, increased serum and hepatic triglycerides, regardless of maternal diet. Fructose aggravates the hepatic imbalance of redox state already exhibited by mHFD offspring. The hepatic activation of cellular repair pathways by fructose, such as unfolded protein response and macroautophagy, is disrupted only in mHFD offspring. Fructose does not change the liver morphology of mSTD offspring. However, it intensifies the liver injury already present in mHFD offspring.

Graphical AbstractSeptic diaphragm has impaired morphology and increased thickness that seems to be associated, at least in part, with decreased mitochondrial function related to reducing in Pgc1α expression, ATP production, mitochondrial number, and quality in the CLP mice compared with the control group.

Obesity is associated with bioenergetic dysfunction of peripheral muscles; however, little is known regarding the impact of obesity on the diaphragm. We hypothesized that obesity would be associated with diaphragm dysfunction attributable to mitochondrial oxygen consumption and structural and ultrastructural changes. Wistar rat litters were culled to 3 pups to induce early postnatal overfeeding and consequent obesity. Control animals were obtained from unculled litters. From postnatal day 150, diaphragm ultrasonography, computed tomography, high-resolution respirometry, immunohistochemical, biomolecular and ultrastructural histological analyses were performed. The diaphragms of obese animals, compared to those of controls, exhibited presented changes in morphology as increased thickening fraction, diaphragm excursion and diaphragm dome height, as well as increased mitochondrial respiratory capacity coupled to ATP synthesis and maximal respiratory capacity. Fatty acid synthase expression was also higher in obese animals, suggesting a source of energy for the respiratory chain. Myosin heavy chain-IIA was increased, indicating shift from glycolytic toward oxidative muscle fiber profile. Diaphragm tissue also exhibited ultrastructural changes, such as compact, round, and swollen mitochondria with fainter cristae and more lysosomal bodies. Dynamin-1 expression in the diaphragm was reduced in obese rats, suggesting decreased mitochondrial fission. Furthermore, gene expressions of peroxisome gamma proliferator-activated receptor co-activator-1α and superoxide dismutase-2 were lower in obese animals than in controls, which may indicate a predisposition to oxidative injury. In conclusion, in the obesity model used herein, muscle fiber phenotype was altered in a manner likely associated with increased mitochondrial respiratory capability, suggesting respiratory adaptation to increased metabolic demand.

Scope: Perinatal maternal obesity and excessive fructose consumption have been associated with liver metabolic diseases. The study investigates whether moderate maternal high-fat diet affects the liver mitochondria responses to fructose intake in adult offspring. Methods and Results: Wistar female rats have received a standard diet (mSTD) or high-fat diet (mHFD) (9% and 28.6% fat, respectively), before mating until the end of lactation. Male offspring were fed standard diet from weaning to adulthood and received water or fructose-drinking water (15%) from 120 to 150 days old. Fructose induces liver mitochondrial ultrastructural alterations with higher intensity in mHFD offspring, accompanied by reduced autophagy markers. Isolated mitochondria respirometry shows unaltered ATP-coupled oxygen consumption with increased Atp5f1b mRNA only in mHFD offspring. Fructose increases basal respiration and encoding complex I-III mRNA, only in mSTD offspring. Uncoupled respiration is lower in mHFD mitochondria that are unable to exhibit fructose-induced increase Ucp2 mRNA. Fructose decreases antioxidative defense markers, increases unfolded protein response and insulin resistance only in mHFD offspring without fructose-induced hepatic lipid accumulation. Conclusion: Mitochondrial dysfunction and homeostatic disturbances in response to fructose are early events evidencing the higher risk of fructose damage in the liver of adult offspring from dams fed an isocaloric moderate high-fat diet.