Sexual dimorphism in activation of placental autophagy in obese women with evidence for fetal programming from a placenta-specific mouse model

The incidence of maternal obesity and its co-morbidities (diabetes, cardiovascular disease) continues to increase at an alarming rate, with major public health implications. In utero exposure to maternal obesity has been associated with development of cardiovascular and metabolic diseases in the offspring as a result of developmental programming. The placenta regulates maternal-fetal metabolism and shows significant changes in its function with maternal obesity. Autophagy is a cell-survival process, which is responsible for the degradation of damaged organelles and misfolded proteins. Here we show an activation of autophagosomal formation and autophagosome-lysosome fusion in placentas of males but not females from overweight (OW) and obese (OB) women vs. normal weight (NW) women. However, total autophagic activity in these placentas appeared to be decreased as it showed an increase in SQSTM1/p62 and a decrease in lysosomal biogenesis. A mouse model with a targeted deletion of the essential autophagy gene Atg7 in placental tissue showed significant placental abnormalities comparable to those seen in human placenta with maternal obesity. These included a decrease in expression of mitochondrial genes and antioxidants, and decreased lysosomal biogenesis. Strikingly, the knockout mice were developmentally programmed as they showed an increased sensitivity to high-fat diet-induced obesity, hyperglycemia, hyperinsulinemia, increased adiposity, and cardiac remodeling. In summary, our results indicate a sexual dimorphism in placental autophagy in response to maternal obesity. We also show that autophagy plays an important role in placental function and that inhibition of placental autophagy programs the offspring to obesity, and to metabolic and cardiovascular diseases.     

Significance of neutrophil microparticles in ischaemia‐reperfusion: Pro‐inflammatory effectors of endothelial senescence and vascular dysfunction

Endothelial senescence is an emerging cause of vascular dysfunction. Because microparticles are effectors of endothelial inflammation and vascular injury after ischaemia‐reperfusion, we examined leucocyte‐derived microparticles of spleen origin as possible contributors. Microparticles were generated from primary rat splenocytes by either lipopolysaccharide or phorbol‐myristate‐acetate/calcium ionophore, under conditions mimicking innate and adaptive immune responses. Incubation of primary porcine coronary endothelial cells with either type of microparticles, but not with those from unstimulated splenocytes, leads to a similar threefold raise in senescence‐associated β‐galactosidase activity within 48 hours, indicating accelerated senescence, to endothelial oxidative stress, and a fivefold and threefold increase in p21 and p16 senescence markers after 24 hours. After 12‐hour incubation, the endothelial‐dependent relaxation of coronary artery rings was reduced by 50%, at distinct optimal microparticle concentration. In vitro, microparticles were pro‐thrombotic by up‐regulating the local angiotensin system, by prompting tissue factor activity and a secondary generation of pro‐coagulant endothelial microparticles. They initiated an early pro‐inflammatory response by inducing phosphorylation of NF‐κB, MAP kinases and Akt after 1 hour, and up‐regulated VCAM‐1 and ICAM‐1 at 24 hours. Accordingly, VCAM‐1 and COX‐2 were also up‐regulated in the coronary artery endothelium and eNOS down‐regulated. Lipopolysaccharide specifically favoured the shedding of neutrophil‐ and monocyte‐derived microparticles. A 80% immuno‐depletion of neutrophil microparticles reduced endothelial senescence by 55%, indicating a key role. Altogether, data suggest that microparticles from activated splenocytes prompt early pro‐inflammatory, pro‐coagulant and pro‐senescent responses in endothelial cells through redox‐sensitive pathways. The control of neutrophil shedding could preserve the endothelium at site of ischaemia‐reperfusion–driven inflammation and delay its dysfunction.     

Association of chemerin with oxidative stress,inflammation and classical adipokines in non‐diabetic obese patients

The prevalence of obesity has been increasing worldwide. Chemerin is a recently discovered adipokine secreted by the enlarged adipose tissue with diverse biological effects that are not well detailed yet. This study aimed to elucidate the potential role of chemerin in oxidative stress and inflammation that are characteristics for excess weight and may eventually lead to insulin resistance and atherosclerotic complications. We also analysed the associations between chemerin and classical adipokines, namely leptin and adiponectin. Therefore, we investigated non‐diabetic obese patients without manifest cardiovascular disease and compared their data to healthy lean individuals. Chemerin correlated positively with markers of oxidative stress and inflammation, while it showed a negative correlation with the measure of antioxidant status, characterized by the HDL‐linked paraoxonase‐1 enzyme. Chemerin also correlated positively with leptin and negatively with adiponectin respectively. In our study population, oxidized low‐density lipoprotein and high‐sensitivity C‐reactive protein were found to be the strongest predictors of chemerin level. We conclude that chemerin may contribute to chronic inflammation and increased oxidative stress in obese individuals, even in the absence of manifest insulin resistance.     

Combined analysis of whole‐exon sequencing and lncRNA sequencing in type 2 diabetes mellitus patients with obesity

This study sought to find more exon mutation sites and lncRNA candidates associated with type 2 diabetes mellitus (T2DM) patients with obesity (O‐T2DM). We used O‐T2DM patients and healthy individuals to detect mutations in their peripheral blood by whole‐exon sequencing. And changes in lncRNA expression caused by mutation sites were studied at the RNA level. Then, we performed GO analysis and KEGG pathway analysis. We found a total of 277 377 mutation sites between O‐T2DM and healthy individuals. Then, we performed a DNA‐RNA joint analysis. Based on the screening of harmful sites, 30 mutant genes shared in O‐T2DM patients were screened. At the RNA level, mutations of 106 differentially expressed genes were displayed. Finally, a consensus mutation site and differential expression consensus gene screening were performed. In the current study, the results revealed significant differences in exon sites in peripheral blood between O‐T2DM and healthy individuals, which may play an important role in the pathogenesis of O‐T2DM by affecting the expression of the corresponding lncRNA. This study provides clues to the molecular mechanisms of metabolic disorders in O‐T2DM patients at the DNA and RNA levels, as well as biomarkers of the risk of these disorders.     

The markers of inflammation and endothelial dysfunction in correlation with glycated haemoglobin are present in type 2 diabetes mellitus patients but not in their relatives

The aim of this study is to test several biomarkers of inflammation, of endothelial dysfunction, glycated haemoglobin, and their reflection in arterial dilatation, in patients with type 2 diabetes mellitus and in their relatives, in order to demonstrate if relatives present markers as a form of precocious indicators of diabetes mellitus. Individuals between 30 and 55 years of age and without clinical arterial disease were divided in three groups: type 2 diabetes mellitus patients without complications (12 men and 18 women); first degree relatives of type 2 diabetes mellitus (14 men and 20 women); and control individuals (9 men and 16 women). Body composition was measured with a bioelectrical impedance analyzer and endothelial function with an eco-Doppler device. We determined glucose, insulin, C-peptide, glycated haemoglobin, fibrinogen, E-selectin, P-selectin, soluble intercellular cell adhesion molecule-1 (ICAM-1), soluble vascular cell adhesion molecule-1 (VCAM-1), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) in plasma. We also studied endothelium independent dilatation and endothelium dependent dilatation. The results: ICAM-1 and VCAM-1 were significantly higher in the diabetic group (237.5+/-43.4 and 692.5+/-168.6 ng/l) than in controls (197.4+/-51.2 and 573.5+/-121.1 ng/l, p=0.011 and 0.013, respectively), but were not higher in the family group (224.5+/-45.2 and 599.8+/-150.4 ng/l). CRP was higher in the diabetic group (3.35+/-3.27 mg/l) than in the other groups (1.28+/-1.29 and 1.61+/-1.54 mg/l, p=0.002) and correlated with glycated haemoglobin. The non-endothelium mediated dilatation was lesser in the diabetic group than in the family group (17.3+/-6.1 vs. 24+/-8, p=0.029) and controls. In conclusion patients with uncomplicated type 2 diabetes, but not their relatives, have biochemical markers of sub-clinical inflammation in relationship with glycated haemoglobin and dysfunction of the endothelial cells markers. In these patients endothelium independent dilatation is more affected than endothelium dependent dilatation.