Evaluation of the epigenetic mechanism by DNA methylation and GLUT4 expression in skeletal muscle tissue of adult rats, prole of rats with periodontal disease

Author(s)

Maria Sara de Lima Coutinho Mattera

• Document type: Doctoral Thesis
• Press: Araçatuba. 2019-08-05.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2019-08-01
• Advisor: Doris Hissako Matsushita

Abstract

It is well establishedthat the fetal environment is linked to maternal health, and abnormal stimuli or aggressions during intrauterine life can result in changes in the physiology and metabolism of offspring, increasing the risk of disease in adult life, this phenomenon is known as fetal programming. Changes in DNA methylation and gene expression are considered molecular mechanisms responsible for this programming. Previous studies have demonstrated that maternal periodontaldisease (PD) promotes insulin resistance, increased plasma concentrations of cytokines, reduced GLUT4 content and its plasma membrane translocation index in its adult offspring. And cytokines, such as TNF-α, have been linked to reduced GLUT4 expressionthrough the activation of nuclear transcription factor kappa B (NF-κB). In addition, this cytokine can stimulate some serine kinases including IκB kinase (IKK), c-Jun amino-terminal kinase (JNK) and extracellular signal–regulated kinases (ERKs)that are involved in insulin resistance. These findings evidenced the need for further studies to verify the mechanisms involved in these changes. Therefore, the objectives of the present study were to evaluate in adult rats, offspring of rats with PD: 1) birth weight and during the75 days of age;2) glycemia and insulinemia; 3) GLUT4 and IRS1mRNA expression in skeletal muscle gastrocnemius (MG); 4) the degree of DNA methylation in the promoter region of the GLUT4 gene in MG; 5) phosphorylation of JNK, IKKα/β, ERK 1/2, NF-κBp65 andNF-κBp50 proteins and their total contents in MG; 6) TNF-α content in MG. Female Wistar rats were distributed into a control group and anexperimental periodontal disease group, in which the disease is induced by ligation with silk thread around the 1st molar. Seven days after ligature placement, animals from both groups mated and daily vaginal smears were taken to verify the presence of sperm. Pregnant rats were kept in individual cages. The body weights of the offspring were measured once weekly from birth until 75 days of age. When male offspring of these rats completed 75 days, the experiments were performed: 1) glycemia and insulinemia; 2) GLUT4 and IRS1mRNA expression in skeletal muscle gastrocnemius (MG); 3) the degree of DNA methylation in the promoter region of the GLUT4 gene in MG; 4) phosphorylation of JNK, IKKα/β, ERK 1/2, NF-κBp65 and NF-κBp50 proteins and their total contents in MG; 5) TNF-α content in MG. The results demonstrated that maternal periodontal disease promotes in its adult offspring low birth weight (LBW), insulin resistance, increased TNF-α content in MG, increased IKKα/β, ERK 1/2, NF-κBp65 (phosphorylationstatusand content) and NF-κBp50 phosphorylation status in the MG, decrease in gene expression of GLUT4 and increase in IRS1gene expression; but does not promote in this progeny change in the degree of DNA methylation in the promoter region of the GLUT4 gene, and JNK phosphorylationstatusin MG.Therefore, this study is of fundamental importance for the understanding of some of the mechanisms involved in the relationship between maternal periodontal disease and insulin resistance in adult offspring. In addition, it shows that ideal maternal oral health can help prevent future illnesses in adult offspring. (AU)

• FAPESP's process: 15/12018-7 - EVALUATION EPIGENETIC MECHANISM BY DNA METHYLATION AND EXPRESSION OF GLUT4 AND IRS-1 IN SKELETAL MUSCLE TISSUE OF ADULT RATS, OFFSPRING OF RATS WITH PERIODONTAL DISEASE
• Grantee: Maria Sara de Lima Coutinho Mattera
• Support Opportunities: Scholarships in Brazil - Doctorate