Maternal obesity in pregnancy predisposes offspring to insulin resistance and associated cardiovascular disease. Here, we used a well-established sheep model to investigate the effects of maternal obesity on cardiac functions. Multiparous ewes were assigned to a control (CON) diet [100% of National Research Council (NRC) recommendations] or an obesogenic (OB) diet (150% of NRC recommendations) from 60 d before conception to necropsy on d 135 of pregnancy. Fetal blood glucose and insulin were increased (P<0.01, n=8) in OB (35.09+/-2.03 mg/dl and 3.40+/-1.43 microU/ml, respectively) vs. CON ewes (23.80+/-1.38 mg/dl and 0.769+/-0.256 microU/ml). Phosphorylation of AMP-activated protein kinase (AMPK), a cardioprotective signaling pathway, was reduced (P<0.05), while the stress signaling pathway, p38 MAPK, was up-regulated (P<0.05) in OB maternal and fetal hearts. Phosphorylation of c-Jun N-terminal kinase (JNK) and insulin receptor substrate-1 (IRS-1) at Ser-307 were increased (P<0.05) in OB fetal heart associated with lower downstream PI3K-Akt activity (P<0.05), indicating impaired cardiac insulin signaling. Although OB fetal hearts exhibited a normal contractile function vs. CON fetal hearts during basal perfusion, they developed an impaired heart-rate-left-ventricular-developed pressure product in response to high workload stress. Taken together, fetuses of OB mothers demonstrate alterations in cardiac PI3K-Akt, AMPK, and JNK-IRS-1 signaling pathways that would predispose them to insulin resistance and cardiac dysfunction.

Grape seed extract (GSE) is a by-product of the wine industry, with abundant polyphenolic compounds known for their anti-inflammatory and anti-oxidative effects. Using IL10-deficient mice (IL10KO), here we showed that GSE (1% of dry feed weight) ameliorated inflammatory bowel disease (IBD) indices, increased colonic goblet cell numbers and decreased myeloperoxidase levels in the large intestine. Concomitantly, GSE supplementation attenuated inflammation, decreased the expression of pore forming tight junction protein claudin2, and increased levels of Lactobacilli and Bacteroides in the gut microbiota of IL10KO mice. In summary, our study shows that GSE has protective roles on IBD through altering gut inflammation, tight junction protein expression, and gut microbiota composition.

Background and aimsThe impairment of intestinal epithelial barrier is the main etiologic factor of inflammatory bowel disease. The proper intestinal epithelial proliferation and differentiation is crucial for maintaining intestinal integrity. Metformin is a common anti-diabetic drug. The objective is to evaluate the protective effects of metformin on ileal epithelial barrier integrity using interleukin-10 deficient (IL10KO) mice.MethodsWild-type and IL10KO mice were fed with/without metformin for 6 weeks and then ileum was collected for analyses. The mediatory role of AMP-activated protein kinase (AMPK) was further examined by gain and loss of function study in vitro.ResultsCompared to wild-type mice, IL10KO mice had increased proliferation, reduced goblet cell and Paneth cell lineage differentiation in the ileum tissue, which was accompanied with increased crypt expansion. Metformin supplementation mitigated intestinal cell proliferation, restored villus/crypt ratio, increased goblet cell and Paneth cell differentiation and improved barrier function. In addition, metformin supplementation in IL10KO mice suppressed macrophage pro-inflammatory activity as indicated by reduced M1 macrophage abundance and decreased pro-inflammatory cytokine IL-1β, TNF-α and IFN-γ expressions. As a target of metformin, AMPK phosphorylation was enhanced in mice treated with metformin, regardless of mouse genotypes. In correlation, the mRNA level of differentiation regulator including bmp4, bmpr2 and math1 were also increased in IL10KO mice supplemented with metformin, which likely explains the enhanced epithelial differentiation in IL10KO mice with metformin. Consistently, in Caco-2 cells, metformin promoted claudin-3 and E-cadherin assembly and mitigated TNF-α-induced fragmentation of tight junction proteins. Gain and loss of function assay also demonstrated AMPK was correlated with epithelial differentiation and proliferation.ConclusionsMetformin supplementation promotes secretory cell lineage differentiation, suppresses inflammation and improves epithelial barrier function in IL10KO mice likely through activation of AMPK, showing its beneficial effects on gut epithelial.

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