Asunto(s)
Suplementos Dietéticos , Formiatos/uso terapéutico , Defectos del Tubo Neural/genética , Tubo Neural/metabolismo , Aminohidrolasas/genética , Animales , Modelos Animales de Enfermedad , Ácido Fólico/genética , Ácido Fólico/metabolismo , Formiato-Tetrahidrofolato Ligasa/genética , Formiatos/metabolismo , Humanos , Proteínas de Transporte de Membrana/genética , Metilenotetrahidrofolato Deshidrogenasa (NADP)/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Ratones , Complejos Multienzimáticos/genética , Tubo Neural/efectos de los fármacos , Tubo Neural/crecimiento & desarrollo , Tubo Neural/patología , Defectos del Tubo Neural/dietoterapia , Defectos del Tubo Neural/metabolismo , Defectos del Tubo Neural/patologíaRESUMEN
Maternal diabetes-induced birth defects remain a significant health problem. Studying the effect of natural compounds with antioxidant properties and minimal toxicities on diabetic embryopathy may lead to the development of new and safe dietary supplements. Punicalagin is a primary polyphenol found in pomegranate juice, which possesses antioxidant, anti-inflammatory and anti-tumorigenic properties, suggesting a protective effect of punicalagin on diabetic embryopathy. Here, we examined whether punicalagin could reduce high glucose-induced neural tube defects (NTDs), and if this rescue occurs through blockage of cellular stress and caspase activation. Embryonic day 8.5 (E8.5) mouse embryos were cultured for 24 or 36 h with normal (5 mM) glucose or high glucose (16.7 mM), in presence or absence of 10 or 20 µM punicalagin. 10 µM punicalagin slightly reduced NTD formation under high glucose conditions; however, 20 µM punicalagin significantly inhibited high glucose-induced NTD formation. Punicalagin suppressed high glucose-induced lipid peroxidation marker 4-hydroxynonenal, nitrotyrosine-modified proteins, and lipid peroxides. Moreover, punicalagin abrogated endoplasmic reticulum stress by inhibiting phosphorylated protein kinase ribonucleic acid (RNA)-like ER kinase (p-PERK), phosphorylated inositol-requiring protein-1α (p-IRE1α), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), C/EBP-homologous protein (CHOP), binding immunoglobulin protein (BiP) and x-box binding protein 1 (XBP1) mRNA splicing. Additionally, punicalagin suppressed high glucose-induced caspase 3 and caspase 8 cleavage. Punicalagin reduces high glucose-induced NTD formation by blocking cellular stress and caspase activation. These observations suggest punicalagin supplements could mitigate the teratogenic effects of hyperglycemia in the developing embryo, and possibly prevent diabetes-induced NTDs.
Asunto(s)
Antioxidantes/farmacología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Taninos Hidrolizables/farmacología , Defectos del Tubo Neural/prevención & control , Tubo Neural/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Aldehídos/metabolismo , Animales , Caspasas/genética , Caspasas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta a Droga , Embrión de Mamíferos/efectos de los fármacos , Chaperón BiP del Retículo Endoplásmico , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Factor 2 Eucariótico de Iniciación/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Femenino , Regulación de la Expresión Génica , Glucosa , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Tubo Neural/crecimiento & desarrollo , Tubo Neural/metabolismo , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/patología , Fosforilación , Embarazo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Factores de Transcripción del Factor Regulador X , Factor de Transcripción CHOP/genética , Factor de Transcripción CHOP/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína 1 de Unión a la X-Box , eIF-2 Quinasa/genética , eIF-2 Quinasa/metabolismoRESUMEN
The syndrome of hypomagnesemia with secondary hypocalcemia is caused by defective TRPM6. This protein is an ion channel that also contains a kinase in its C-terminus. It is usually diagnosed in childhood and, without treatment with supplemental Mg, affected children suffer from mental retardation, seizures and retarded development. We developed a mouse lacking Trpm6 in order to understand in greater detail the function of this protein. In contrast to our expectations, Trpm6(-/-) mice almost never survived to weaning. Many mice died by embryonic day 12.5. Most that survived to term had neural tube defects consisting of both exencephaly and spina bifida occulta, an unusual combination. Feeding dams a high Mg diet marginally improved offspring survival to weaning. The few Trpm6(-/-) mice that survived were fertile but matings between Trpm6(-/-) mice produced no viable pregnancies. Trpm6(+/-) mice had normal electrolytes except for modestly low plasma [Mg]. In addition, some Trpm6(+/-) mice died prematurely. Absence of Trpm6 produces an apparently different phenotype in mice than in humans. The presence of neural tube defects identifies a previously unsuspected role of Trpm6 in effecting neural tube closure. This genetic defect produces one of very few mouse models of spina bifida occulta. These results point to a critical role of Trpm6 in development and suggest an important role in neural tube closure.