Maternal obesity increases hypothalamic miR-505-5p expression in mouse offspring leading to altered fatty acid sensing and increased intake of high-fat food

Parental high-fat diet induces upregulation of macrophage receptor with collagenous structure expression and exacerbates colorectal inflammation via the nuclear factor kappa-B pathway in offspring

Parental high-fat diet (HFD) increases offspring's susceptibility to colorectal inflammation, but the underlying mechanism remains unclear. Using mouse models, we compared colorectal inflammation between offspring of HFD-fed and normal diet-fed parents. Histological analysis and immunostaining revealed that offspring of HFD-fed parents exhibited shortened colorectal length, decreased goblet cells, and reduced tight junction protein expression, particularly when maintained on HFD. RNA sequencing of colorectal tissue identified elevated expression of macrophage receptor with collagenous structure (MARCO) in these offspring. Immunofluorescence co-localization staining confirmed increased MARCO-positive macrophages in their colorectal tissue. Notably, switching offspring to normal diet partially alleviated these inflammatory responses, although some manifestations remained. Further investigation showed that high-lipid stimulation increased MARCO expression in macrophages and promoted inflammatory cytokine secretion through nuclear factor kappa-B (NF-κB) pathway activation. In vitro experiments demonstrated that MARCO knockdown inhibited the expression of inflammatory cytokines and prevented tight junction protein destruction in cocultured intestinal cells. Our findings reveal that parental HFD induces MARCO upregulation in offspring's colorectal macrophages and exacerbates colorectal inflammation through the NF-κB pathway, providing new insights into the mechanism by which parental HFD affects offspring's intestinal health.

Diet-Induced Obesity in the Rat Impairs Sphingolipid Metabolism in the Brain and This Metabolic Dysfunction Is Transmitted to the Offspring via Both the Maternal and the Paternal Lineage

Obesity leads to a number of health problems, including learning and memory deficits that can be passed on to the offspring via a developmental programming process. However, the mechanisms involved in the deleterious effects of obesity on cognition remain largely unknown. This study aimed to assess the impact of obesity on the production of sphingolipids (ceramides and sphingomyelins) in the brain and its relationship with the learning deficits displayed by obese individuals. We also sought to determine whether the effects of obesity on brain sphingolipid synthesis could be passed on to the offspring. Learning abilities and brain concentration of sphingolipids in male and female control and obese founder rats (F0) and their offspring (F1) were evaluated, respectively, by the novel object recognition test and by ultra-performance liquid chromatography tandem mass spectrometry. In addition, a global lipidome profiling of the cerebral cortex and hippocampus was performed. Both male and female F0 rats showed impaired learning and increased concentrations of ceramides and sphingomyelins in the hippocampus and frontal cortex compared to their control counterparts. However, the overall lipidome profile of these brain regions did not change with obesity. Remarkably, the alterations in brain sphingolipid synthesis, as well as the cognitive impairment induced by obesity, were also present in adult F1 male rats born to obese mothers or sired by obese fathers and were associated with enhanced expression of mRNAs coding for enzymes involved in the de novo synthesis of ceramides. These results show that the cognitive deficits and impaired sphingolipid metabolism induced by obesity can be transmitted to the offspring through both the maternal and paternal lineages and suggest that an increase in the brain concentration of sphingolipids could play a causal role in the cognitive deficits associated with obesity.

Epigenetic regulation is involved in reversal of obesity

Epigenetic processes play a crucial role in mediating the impact of environmental energetic challenges, from overconsumption to starvation. Over-nutrition of energy-dense foods and sedentary lifestyles contribute to the development of obesity, characterized by excessive fat storage and impaired metabolic signaling, stemming from disrupted brain signaling. Conversely, dieting and physical activity facilitate body weight rebalancing and trigger adaptive neural responses. These adaptations involve the upregulation of neurogenesis, synaptic plasticity and optimized brain function and energy homeostasis, balanced hormone signaling, normal metabolism, and reduced inflammation. The transition of the brain from a maladaptive to an adaptive state is partially guided by epigenetic mechanisms. While epigenetic mechanisms underlying obesity-related brain changes have been described, their role in mediating the reversal of maladaptation/obesity through lifestyle interventions remains less explored. This review focuses on elucidating epigenetic mechanisms involved in hypothalamic adaptations induced by lifestyle interventions. Given that lifestyle interventions are widely prescribed and accessible approaches for weight loss and maintenance, it is our challenge to uncover epigenetic mechanisms moderating these hypothalamic-functional beneficial changes.

The roles of the gut microbiota, metabolites, and epigenetics in the effects of maternal exercise on offspring metabolism

Metabolic diseases, including obesity, dyslipidemia, and type 2 diabetes, have become severe challenges worldwide. The Developmental Origins of Health and Disease (DOHaD) hypothesis suggests that an adverse intrauterine environment can increase the risk of metabolic disorders in offspring. Studies have demonstrated that maternal exercise is an effective intervention for improving the offspring metabolic health. However, the pathways through which exercise works are unclear. It has been reported that the gut microbiota mediates the effect of maternal exercise on offspring metabolism, and epigenetic modifications have also been proposed to be important molecular mechanisms. Microbial metabolites can influence epigenetics by providing substrates for DNA or histone modifications, binding to G-protein-coupled receptors to affect downstream pathways, or regulating the activity of epigenetic modifying enzymes. This review aims to summarize the intergenerational effect of maternal exercise and proposes that gut microbiota-metabolites-epigenetic regulation is an important mechanism by which maternal exercise improves offspring metabolism, which may yield novel targets for the early prevention and intervention of metabolic diseases.

Endurance exercise attenuates Gαq-RNAi induced hereditary obesity and skeletal muscle dysfunction via improving skeletal muscle Srl/MRCC-I pathway in Drosophila

G protein alpha q subunit (Gαq) can binds to the G protein-coupled receptor (GPCR) for signaling and is closely related to lipid metabolism. Endurance exercise is an effective means of combating acquired obesity and its complications, but the mechanisms by which endurance exercise modulates hereditary obesity and its complications are unknown. In this study, we achieved knockdown of Gαq in drosophila adipose tissue and skeletal muscle by constructing the Gαq-UAS-RNAi/Ppl-Gal4 and Gαq-UAS-RNAi/Mef2-GAl4 systems. Drosophila were subjected a three-week endurance exercise intervention, and changes in relevant indicators were detected and observed by RT-PCR, ELISA, oil red staining, immunofluorescence staining, and transmission electron microscopy. The results showed that knockdown of Gαq in both adipose tissue and skeletal muscle induced a significant increase in triglycerides accompanied by a decrease in rapid climbing ability, a decrease in Superoxide Dismutase (SOD) activity level, and a decrease in Mitochondrial respiratory chain complexI (MRCC I) content in Drosophila whole body and skeletal muscle, and down-regulated the expression of the G protein alpha q subunit (Gαq), the skeletal muscle myosin heavy chain expression gene (Mhc), mitochondrial biogenesis gene Spargal(the PGC-1alpha homologue in Drosophila). Endurance exercise significantly improved the triglyceride levels in the whole body and skeletal muscle of drosophila with Gαq knockdown in adipose tissue and skeletal muscle, as well as their ability to climb, increased SOD activity level and MRCCI content level, and up-regulated the expression of Gαq, Mhc, and Spargal(Srl). Thus, the present findings suggest that genetic defects in the Gαq gene in adipose and skeletal muscle tissues induce hereditary obesity and skeletal muscle dysfunction, and that endurance exercise attenuates this hereditary obesity and concomitant skeletal muscle dysfunction in drosophila by improving skeletal muscle fiber contractile proteins, mitochondrial function and function, and antioxidant capacity via mediating the Gαq/Mhc, Gαq/Srl/MRCC-I, and Gαq/SOD pathways.