Potentiation of triamcinolone-induced cleft palate in mice by maternal high dietary fat

Epigenetic implications in maternal diabetes and metabolic syndrome-associated risk of orofacial clefts

Orofacial clefts (OFCs) are one of the most common types of structural birth defects. The etiologies are complicated, involving with genetic, epigenetic, and environmental factors. Studies have found that maternal diabetes and metabolic syndrome are associated with a higher risk of OFCs in offspring. Metabolic syndrome is a clustering of several disease risk factors, including hyperglycemia, dyslipidemia, obesity, and hypertension. Metabolic disease during pregnancy can increase risk of adverse outcomes and significantly influence fetal development, including orofacial formation and fusion. An altered metabolic state may contribute to developmental disorders or congenital defects including OFCs, potentially through epigenetic modulations, such as histone modification, DNA methylation, and noncoding RNA expression to alter activities of critical morphogenetic signaling or related developmental genes. This review summarizes the currently available evidence and underlying mechanisms of how the maternal metabolic syndrome is associated with OFCs in mostly human and some animal studies. It may provide a better understanding of the interactions between intrauterine metabolic status and fetal orofacial development which might be applied toward prevention and treatments of OFCs.

Modeling anterior development in mice: diet as modulator of risk for neural tube defects

Head morphogenesis is a complex process that is controlled by multiple signaling centers. The most common defects of cranial development are craniofacial defects, such as cleft lip and cleft palate, and neural tube defects, such as anencephaly and encephalocoele in humans. More than 400 genes that contribute to proper neural tube closure have been identified in experimental animals, but only very few causative gene mutations have been identified in humans, supporting the notion that environmental influences are critical. The intrauterine environment is influenced by maternal nutrition, and hence, maternal diet can modulate the risk for cranial and neural tube defects. This article reviews recent progress toward a better understanding of nutrients during pregnancy, with particular focus on mouse models for defective neural tube closure. At least four major patterns of nutrient responses are apparent, suggesting that multiple pathways are involved in the response, and likely in the underlying pathogenesis of the defects. Folic acid has been the most widely studied nutrient, and the diverse responses of the mouse models to folic acid supplementation indicate that folic acid is not universally beneficial, but that the effect is dependent on genetic configuration. If this is the case for other nutrients as well, efforts to prevent neural tube defects with nutritional supplementation may need to become more specifically targeted than previously appreciated. Mouse models are indispensable for a better understanding of nutrient-gene interactions in normal pregnancies, as well as in those affected by metabolic diseases, such as diabetes and obesity.

Maternal nutritional status and the risk for orofacial cleft offspring in humans

Periconceptional folate and folic acid intake prevents orofacial clefts (OFC) in the offspring. It has been suggested that other nutrients also play a role. We investigated the preconceptional intake of macronutrients (protein, fat, carbohydrate, fiber, and cholesterol), vitamins (vitamin A, retinol, beta-carotene, ascorbic acid, and alpha-tocopherol), minerals (calcium, phosphorus, iron, magnesium, and zinc) and food groups in mothers of OFC children and controls. At approximately 14 mo after the index pregnancy, 206 mothers of a child with a nonsyndromic OFC and 203 control mothers completed a FFQ on current food intake and a general questionnaire. After exclusion of pregnant and lactating mothers, mothers who reported a change in diet compared with the preconceptional period, and those for whom periconceptional folic acid supplement use was unclear, 182 OFC mothers and 173 control mothers were evaluated. Macronutrient, vitamin, mineral, and food group intakes were compared. After adjustment for energy, quintiles of dietary nutrient intake and odds ratios with 95% CI were calculated. The preconceptional intake of all macronutrients, vitamins, minerals, and food groups with the exception of milk (products), potatoes, pies/cookies were lower in OFC mothers than in controls. The energy-adjusted intakes of vegetable protein, fiber, beta-carotene, ascorbic acid, alpha-tocopherol, iron, and magnesium were significantly lower in cases compared with controls. Increasing intakes of vegetable protein, fiber, ascorbic acid, iron, and magnesium decreased OFC risk. In conclusion, a higher preconceptional intake of nutrients predominantly present in fruits and vegetables reduces the risk of offspring affected by OFC.