AimsObesity during pregnancy increases risk of cardiovascular disease (CVD) in the offspring and individuals exposed to over-nutrition during fetal life are likely to be exposed to a calorie-rich environment postnatally. Here, we established the consequences of combined exposure to a maternal and post-weaning obesogenic diet on offspring cardiac structure and function using an established mouse model of maternal diet-induced obesity.Methods and resultsThe impact of the maternal and postnatal environment on the offspring metabolic profile, arterial blood pressure, cardiac structure, and function was assessed in 8-week-old C57BL/6 male mice. Measurement of cardiomyocyte cell area, the transcriptional re-activation of cardiac fetal genes as well as genes involved in the regulation of contractile function and matrix remodelling in the adult heart were determined as potential mediators of effects on cardiac function. In the adult offspring: a post-weaning obesogenic diet coupled with exposure to maternal obesity increased serum insulin (P < 0.0001) and leptin levels (P < 0.0001); maternal obesity (P = 0.001) and a post-weaning obesogenic diet (P = 0.002) increased absolute heart weight; maternal obesity (P = 0.01) and offspring obesity (P = 0.01) caused cardiac dysfunction but effects were not additive; cardiac dysfunction resulting from maternal obesity was associated with re-expression of cardiac fetal genes (Myh7: Myh6 ratio; P = 0.0004), however, these genes were not affected by offspring diet; maternal obesity (P = 0.02); and offspring obesity (P = 0.05) caused hypertension and effects were additive.ConclusionsMaternal diet-induced obesity and offspring obesity independently promote cardiac dysfunction and hypertension in adult male progeny. Exposure to maternal obesity alone programmed cardiac dysfunction, associated with hallmarks of pathological left ventricular hypertrophy, including increased cardiomyocyte area, upregulation of fetal genes, and remodelling of cardiac structure. These data highlight that the perinatal period is just as important as adult-onset obesity in predicting CVD risk. Therefore, early developmental periods are key intervention windows to reduce the prevalence of CVD.

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Background: Metformin is commonly used to treat gestational diabetes mellitus. This study investigated the effect of maternal metformin intervention during obese glucose-intolerant pregnancy on the gonadal white adipose tissue (WAT) of 8-week-old male and female mouse offspring. Methods: C57BL/6J female mice were provided with a control (Con) or obesogenic diet (Ob) to induce pre-conception obesity. Half the obese dams were treated orally with 300 mg/kg/d of metformin (Ob-Met) during pregnancy. Gonadal WAT depots from 8-week-old offspring were investigated for adipocyte size, macrophage infiltration and mRNA expression of pro-inflammatory genes using RT-PCR. Results: Gestational metformin attenuated the adiposity in obese dams and increased the gestation length without correcting the offspring in utero growth restriction and catch-up growth caused by maternal obesity. Despite similar body weight, the Ob and Ob-Met offspring of both sexes showed adipocyte hypertrophy in young adulthood. Male Ob-Met offspring had increased WAT depot weight (p < 0.05), exaggerated adipocyte hyperplasia (p < 0.05 vs. Con and Ob offspring), increased macrophage infiltration measured via histology (p < 0.05) and the mRNA expression of F4/80 (p < 0.05). These changes were not observed in female Ob-Met offspring. Conclusions: Maternal metformin intervention during obese pregnancy causes excessive adiposity, adipocyte hyperplasia and WAT inflammation in male offspring, highlighting sex-specific effects of prenatal metformin exposure on offspring WAT.

Aims/hypothesis Metformin is increasingly used to treat gestational diabetes (GDM) and pregnancies complicated by pregestational type 2 diabetes or polycystic ovary syndrome but data regarding long-term offspring outcome are lacking in both human studies and animal models. Using a mouse model, this study investigated the effects of maternal metformin intervention during obese glucose-intolerant pregnancy on adiposity, hepatic steatosis and markers of metabolic health of male and female offspring up to the age of 12 months. Methods C57BL/6J female mice were weaned onto either a control diet (Con) or, to induce pre-conception obesity, an obesogenic diet (Ob). The respective diets were maintained throughout pregnancy and lactation. These obese dams were then randomised to the untreated group or to receive 300 mg/kg oral metformin hydrochloride treatment (Ob-Met) daily during pregnancy. In male and female offspring, body weights and body composition were measured from 1 month until 12 months of age, when serum and tissues were collected for investigation of adipocyte cellularity (histology), adipose tissue inflammation (histology and quantitative RT-PCR), and hepatic steatosis and fibrosis (histochemistry and modified Folch assay). Results At 12 months of age, male Ob and Ob-Met offspring showed increased adiposity, adipocyte hypertrophy, elevated expression of proinflammatory genes, hyperleptinaemia and hepatic lipid accumulation compared with Con offspring. Male Ob-Met offspring failed to show hyperplasia between 8 weeks and 12 months, indicative of restricted adipose tissue expansion, resulting in increased immune cell infiltration and ectopic lipid deposition. Female Ob offspring were relatively protected from these phenotypes but Ob-Met female offspring showed increased adiposity, adipose tissue inflammation, hepatic lipid accumulation, hyperleptinaemia and hyperinsulinaemia compared with Con female offspring. Conclusions/interpretation Maternal metformin treatment of obese dams increased offspring metabolic risk factors in a sex-and age-dependent manner. These observations highlight the importance of following up offspring of both sexes beyond early adulthood after interventions during pregnancy. Our findings illustrate the complexity of balancing short-term benefits to mother and child vs any potential long-term metabolic effects on the offspring when prescribing therapeutic agents that cross the placenta.

Objective and design To determine whether ER stress affects the inhibitory pathways of the human immune system, particularly the immunosuppressive effect of IL-10 on macrophages. Material or subjects In vitro stimulation of human monocyte-derived macrophages. Treatment Cells were stimulated with TLR ligands and IL-10, while ER stress was induced using thapsigargin or tunicamycin. Methods mRNA expression was determined using qPCR, while cytokine protein production was measured using ELISA. Protein expression of receptors and transcription factors was determined using flow cytometry. Student’s t test was used for statistics. Results While under normal conditions IL-10 potently suppresses pro-inflammatory cytokine production by LPS-stimulated macrophages, we demonstrate that ER stress counteracts the immunosuppressive effects of IL-10, leading to increased pro-inflammatory cytokine production. We identified that ER stress directly interferes with IL-10R signaling by reducing STAT3 phosphorylation on Tyr705, which thereby inhibits the expression of SOCS3. Moreover, we show that ER stress also inhibits STAT3 activation induced by other receptors such as IL-6R. Conclusions Combined, these data uncover a new general mechanism by which ER stress promotes inflammation. Considering its potential involvement in the pathogenesis of diseases such as Crohn’s disease and spondyloarthritis, targeting of this mechanism may provide new opportunities to counteract inflammation.

Objective This study investigated the effect of maternal obesity on aged-male offspring liver phenotype and hepatic expression of a programmed miRNA. Methods A mouse model (C57BL/6 J) of maternal diet-induced obesity was used to investigate fasting-serum metabolites, hepatic lipid content, steatosis, and relative mRNA levels (RT-PCR) and protein expression (Western blotting) of key components involved in hepatic and mitochondrial metabolism in 12-month-old offspring. We also measured hepatic lipid peroxidation, mitochondrial content, fibrosis stage, and apoptosis in the offspring. To investigate potential mechanisms leading to the observed phenotype, we also measured the expression of miR-582 (a miRNA previously implicated in liver cirrhosis) in 8-week-old and 12-month-old offspring. Results Body weight and composition was similar between 8-week-old offspring, however, 12-month-old offspring from obese mothers had increased body weight and fat mass (19.5 ± 0.8 g versus 10.4 ± 0.9 g, p < 0.001), as well as elevated serum levels of LDL and leptin and hepatic lipid content (21.4 ± 2.1 g versus 12.9 ± 1.8 g, p < 0.01). This was accompanied by steatosis, increased Bax/Bcl-2 ratio, and overexpression of p-SAPK/JNK, Tgfβ1, Map3k14, and Col1a1 in the liver. Decreased levels of Bcl-2, p-AMPKα, total AMPKα and mitochondrial complexes were also observed. Maternal obesity was associated with increased hepatic miR-582-3p (p < 0.001) and miR-582-5p (p < 0.05). Age was also associated with an increase in both miR-582-3p and miR-582-5p, however, this was more pronounced in the offspring of obese dams, such that differences were greater in 12-month-old animals (−3p: 7.34 ± 1.35 versus 1.39 ± 0.50, p < 0.0001 and −5p: 4.66 ± 1.16 versus 1.63 ± 0.65, p < 0.05). Conclusion Our findings demonstrate that maternal diet-induced obesity has detrimental effects on offspring body composition as well as hepatic phenotype that may be indicative of accelerated-ageing phenotype. These whole-body and cellular phenotypes were associated with age-dependent changes in expression of miRNA-582 that might contribute mechanistically to the development of metabolic disorders in the older progeny.

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Introduction Metformin is the first‐line pharmacological treatment for gestational diabetes in many countries. Although effective at improving maternal glycaemia, metformin readily crosses the placenta and could directly affect the fetus. Indeed, metformin exposure in utero increases postnatal adiposity. However, other long‐term effects on offspring exposed to metformin in utero have not been investigated. Here we explored the impact of maternal metformin treatment during obese, glucose‐intolerant pregnancy on offspring cardiovascular function at one year of age using an established mouse model of maternal diet‐induced obesity. Methods Female C57Bl/6J mice were fed either a standard chow diet [Control dams (Con)] or an obesogenic diet [Obese (Ob) and Obese‐Metformin (Ob‐Met) dams] from weaning up to and including pregnancy and lactation. Ob‐Met dams received a clinically relevant dose of metformin orally from one week prior to mating until day 19 of gestation. All offspring were weaned onto standard chow fed ad libitum at three weeks of age. At one year of age, systolic blood pressure (SBP) was measured by tail cuff plethysmography in the conscious animal and echocardiography was performed under anaesthesia. Post‐mortem, femoral arteries were isolated and vasomotor reactivity tested using in vitro wire myography. Myography dose‐response curves were analysed using mixed effects models, all other data were analysed by One‐Way ANOVA. Post‐hoc multiple comparisons were performed where appropriate. Significance was accepted when P<0.05. Results Relative to controls, female offspring of Ob‐Met dams had increased SBP. However, no differences in SBP were observed in male offspring (Fig.1A). Female offspring of both Ob and Ob‐Met dams had enhanced femoral vasoconstrictor reactivity to K+ (Fig. 1B) but normal cardiac function (Fig. 1C). In contrast, male offspring of both Ob and Ob‐Met dams showed indices of diastolic dysfunction (Fig. 1C) and male offspring of Ob‐Met dams had enhanced femoral vasoconstrictor reactivity to phenylephrine (PE) (Fig.1B). Conclusions Maternal obesity and metformin exposure in utero caused sex‐specific changes in cardiovascular function in 12‐month‐old offspring. In female offspring, exposure to maternal obesity and metformin programmed hypertension with enhanced peripheral vasoconstrictor reactivity. In male offspring, maternal obesity alone programmed echocardiographic indices of left ventricular restrictive filling which were not corrected by metformin treatment, while combined exposure to maternal obesity and metformin also programmed enhanced peripheral vasoconstrictor reactivity. These findings provide novel insight into the long‐term effects of in utero metformin exposure on the cardiovascular health of the next generation in obese pregnancy, and highlight the importance of considering offspring sex in developmental programming studies.