STUDY OF MECHANISMS INVOLVED IN THE DEVELOPMENT OF INSULIN RESISTANCE IN ADULT RATS, OFFSPRING OF PERIODONTAL DISEASE

• Grant number: 19/04183-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2019
• End date: June 30, 2023
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Doris Hissako Matsushita
• Grantee: Maria Sara de Lima Coutinho Mattera
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Associated scholarship(s): 22/00914-1 - Evaluation of effects of genetically inhibiting or inducing ceramide accumulation in beta cells in mouse models of diabetes (type 1 and type 2) or beta cell regeneration, BE.EP.PD

Abstract

The fetal programming hypothesis suggests that stimuli or aggressions during intrauterine life may result in permanent changes in the physiology and metabolism of offspring, increasing the risk of disease in adult life. Changes in miRNA expression patterns are considered molecular mechanisms responsible for this programming. Previous studies have demonstrated that maternal periodontal disease (PD) promotes insulin resistance, increased plasma concentrations of cytokines, reduced GLUT4 content, plasma membrane, translocation index and expression in adult offspring. In addition, maternal periodontal disease was able to activate inflammatory pathways in the skeletal muscle tissue of adult offspring. This activation was confirmed by increased expression of TNF-alpha, NF-kBp65, NF-kBp50, IKK alpha/beta and ERK1/2. However, there was no change in DNA methylation of the GLUT4 gene and JNK expression in adult offspring. It was possible to infer that one of the reasons for the reduction of the GLUT4 expression in the muscular tissue of adult rats of rats with PD occurred through the activation of inflammatory pathways. These findings evidenced the need for further studies to verify other mechanisms involved, such as miRNAs patterns, in these alterations; and if another tissue, such as adipose tissue, also exhibits these changes in adult offspring. Therefore, the aims of the present study will be to evaluate in adult rats, offspring of rats with periodontal disease: a) glycemia and insulinemia; b) content of glucose transporter protein GLUT4 and TNF-alpha in periepididimal white adipose tissue (pWAT); c) phosphorylation of the proteins JNK, IKK beta, NF-kB p65, NF-kB p50, ERK1 / 2 and their total contents in pWAT; d) tyrosine phosphorylation status of pp185 (IRS-1 / IRS-2) and Akt serine (before and after insulin stimulation) in pWAT; e) analyze of the global expression of miRNAs in gastrocnemius skeletal muscle and pWAT. The rats will be distributed into two groups: 1) with periodontal disease (PED), in which the disease is induced by ligation with silk thread around the 1st molar, 2) control rats (CN). Seven days after ligature placement, the rats of both groups will be placed for mating, verifying daily by vaginal smear, the day of copulation. Pregnant rats will be separated into individual boxes. When male offspring of these rats completed 75 days, will be performing the experiments: a) glycemia (by the glucose oxidase technique) and insulinemia (by the ELISA technique); b) content of the glucose transporter protein GLUT4 and TNF-alpha (by western blotting technique - WB) in qWAT; c) phosphorylation of the proteins JNK, IKK beta, NF-kB p65, NF-kB p50, ERK1 / 2 and their total contents in qWAT (by the WB technique); d) tyrosine phosphorylation status of pp185 (IRS-1 / IRS-2) and Akt serine (before and after the insulin stimulus) in qWAT (by the WB technique); e) analysis of the global expression of miRNAs (by the microarray technique) in gastrocnemius skeletal muscle and pWAT.