The naked mole-rat Heterocephalus glaber is a eusocial mammal exhibiting extreme longevity (37-year lifespan), extraordinary resistance to hypoxia and absence of cardiovascular disease. To identify the mechanisms behind these exceptional traits, metabolomics and RNAseq of cardiac tissue from naked mole-rats was compared to other African mole-rat genera (Cape, Cape dune, Common, Natal, Mahali, Highveld and Damaraland mole-rats) and evolutionarily divergent mammals (Hottentot golden mole and C57/BL6 mouse). We identify metabolic and genetic adaptations unique to naked mole-rats including elevated glycogen, thus enabling glycolytic ATP generation during cardiac ischemia. Elevated normoxic expression of HIF-1α is observed while downstream hypoxia responsive-genes are down-regulated, suggesting adaptation to low oxygen environments. Naked mole-rat hearts show reduced succinate levels during ischemia compared to C57/BL6 mouse and negligible tissue damage following ischemia-reperfusion injury. These evolutionary traits reflect adaptation to a unique hypoxic and eusocial lifestyle that collectively may contribute to their longevity and health span.
Background: The placenta stands at the maternal–fetal interface and is a key organ regulating the intrauterine environment. In pregnancies exposed to obesity, placental function, signaling, and nutrient handling are adversely altered. Pre-conception weight loss is a potential intervention to alter an obesogenic milieu of pregnancy, which we investigated in a mouse model of maternal obesity using diet or administration of the glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide. Methods: Pre-pregnancy weight loss in C57BL/6 high-fat diet (HFD)-fed dams was induced in the pre-pregnancy period by switching diet from HFD to chow diet or administering liraglutide (0.3 mg/kg/day subcutaneously for 4 weeks) whilst continuing HFD. In addition, a group of HFD-fed dams were switched to chow diet post-conception. The metabolomic profile and gene expression within the placenta was compared at day 18–20 of gestation. Results: 1H NMR spectroscopy metabolomic analysis of placenta of HFD mice showed an altered amino acid metabolomic profile, with lower aspartate, glutamate, and glutamine levels compared to the placenta of chow-fed mice (p < 0.05). Meanwhile, gene expression analysis identified both oxidative stress and inflammation in the placentas of HFD-fed dams. Whilst dietary modification alone was sufficient to reduce markers of oxidative stress and inflammation, liraglutide treatment modulated pathological changes, including placental metabolic stress but not inflammation. Conclusions: These findings highlight the importance of dietary or pharmacological interventions in the pre- or immediate post-conception period, with pre-conception offering a critical window to reduce aberrant placental changes induced by obesity.