| Mammalian embryonic development is an extremely complex process,and any genetic mutation and environmental factors can lead to abnormal fetal development.It has been shown that abnormal expression of important cardiac development-related genes such as GATA4,NKX2.5,TBX5 and Plagl1 can lead to cardiac developmental arrest.It has also been shown that in cardiac developmental abnormalities,environmental disturbances in the fetus are also important in causing various fetal developmental defects and malformations.For example,maternal diabetes can lead to severe congenital developmental defects such as arrhythmias,atrial septal defects and ventricular hypertrophy in the fetus.Recent studies have shown that mutations in Plakoglobin(γ-Catenin),a homolog of β-Catenin,lead to the development of cardiomyopathy.In our previous study,we found that Plakoglobin correlates with the expression of the cardiac maternally imprinted gene Plagl1 in abnormal heart development due to high glucose.Although no studies have been able to elucidate the role and function of Plakoglobin in heart disease caused by high glucose,we hypothesize that Plakoglobin may be involved in the signaling regulation of cardiac developmental processes under high glucose and most likely plays an important role in it.Therefore,in order to better understand the role of Plakoglobin in embryonic heart development under high glucose conditions,this study focused on the effects of maternal hyperglycemia on mouse fetal heart development,especially on the relationship between histone deacetylase and Plakoglobin expression.A high glucose mouse model was constructed in this study.High glucose female mice were obtained by high glucose and high fat diet induction plus intraperitoneal injection of streptozotocin(STZ),and the high glucose mouse offspring were obtained by combining them with normal male mice in a cage.We morphologically observed the fetuses of hyperglycemic mice at E13.5,E15.5 and E17.5 as well as the fetal heart phenotype,and compared the internal structures of the fetal hearts of hyperglycemic mice with normal controls by HE(Hematoxylin and Eosin,HE)staining technique in paraffin sections.Nkx2.5,Hdac4,Hdac5 and Hdac7 genes were analyzed at the transcriptional level.To verify the expression relationship between Plakoglobin,Plagl1 and the genes of histone deacetylases Hdac4,Hdac5 and Hdac7,we constructed an amniotic chamber injection mouse model.Plakoglobin knockdown mice were obtained by injecting si RNA into the amniotic cavity of E12.5 normal mice.The expression of Plagl1,Nkx2.5,Hdac4,Hdac5 and Hdac7 genes in the hearts of Plakoglobin knockdown mice was analyzed.To exclude the effect of STZ drugs and other factors and to observe more directly the changes of gene expression in the heart under the effect of high glucose,we constructed a mouse primary cardiomyocyte model and validated the expression of Plakoglobin and genes such as Hdac4,Hdac5 and Hdac7 in the conditioned high glucose cardiomyocytes at the cellular level.Phenotypic analysis of fetuses in hyperglycemic mice model showed that maternal hyperglycemia affected fetal head,face and heart development,resulting in heart defects and craniofacial structural abnormalities;analysis of fetal hearts in hyperglycemic mice showed that maternal hyperglycemia caused an elevated fetal heart-to-body ratio,and HE staining results showed that fetal hearts under maternal hyperglycemic conditions showed abnormal features such as ventricular septal defects,severe fibrosis,thin heart The HE staining results showed that the fetal heart showed abnormal features such as ventricular septal defect,severe fibrosis,thin heart wall and loose myocardial tissue arrangement.Fluorescence quantification in real time showed that the expression of Plakoglobin,Plagl1 and Hdac5 were significantly higher and Hdac4 and Hdac7 were significantly lower in the fetal hearts of high glucose mice compared with normal controls.In an amniotic chamber injection mouse model,phenotypic analysis of Plakoglobin knockdown mice showed defective fetal hearts and smaller hearts compared to controls;quantitative results showed that Plakoglobin knockdown resulted in decreased expression of Plagl1 as well as Hdac5 and increased expression of Hdac4 and Hdac7.In the primary cardiomyocyte model,quantitative results showed that the expression of Plakoglobin,Hdac4,Hdac5 and Hdac7 decreased and the expression of Plagl1 increased under high glucose conditions compared with controls.In summary,it is tentatively hypothesized that maternal hyperglycemia may regulate the expression of Plakoglobin and Plagl1 by affecting the expression of Hdac4 and Hdac7,thus causing abnormal fetal heart development in offspring mice.Under maternal hyperglycemia,the expression of Plakoglobin showed an opposite expression trend to that of Hdac4 and Hdac7 and a positive correlation with that of Plagl1,suggesting that Plakoglobin may be regulated by Hdac4 and Hdac7 and play an important role in the abnormal heart development caused by high glucose by regulating the expression of Plagl1.This study focuses on the effects of histone deacetylase and Plakoglobin in maternal hyperglycemia on mouse fetal heart development,providing a basis for enriching the regulatory network of Plakoglobin in the heart and a reference for further understanding the refinement of the pathogenesis of heart disease caused by high glucose. |
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