Enteric neuropathic changes induced by components of the diet and excess of fluoride

• Grant number: 13/23862-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: June 01, 2014
• End date: December 31, 2014
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Carina Guimarães de Souza Melo
• Supervisor: John Barton Furness
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Institution abroad: University of Melbourne, Australia
• Associated to the scholarship: 11/10233-7 - Evaluation of enteric innervation and proteomic analysis of small intestin of rats exposed to chronic or acute fluoride dose, BP.DR

Abstract

Nutritional factors can induce profound neuroplastic changes in the Enteric Nervous System (ENS). Dietary components, notably high fats, high cholesterol and advanced glycation end-products (AGEs) are associated with important pathologies. Fluoride (F) in the diet has metabolic effects and it may also affect enteric neurons. Consumption of high-fat diets is implicated in the etiology of obesity, and may lead to gastrointestinal symptoms and physiologic adaptations. Altered innervation of the gastrointestinal tract by the ENS has been shown in various animal models of obesity and there is evidence that a high fat diet causes degenerative changes in enteric neurons. Localization of neuropeptides and proteins in the ENS has been valuable in identifying the classes of neurons that contribute to the control of gastrointestinal function. In this project, we will investigate how diet can lead to enteric neuron damage, and possible dietary improvements that can be applied. In order to accomplish this, segments of stomach, ileum, caecum, and colon collected from C57bl6 mice on a normal chow diet, on a high fat, high cholesterol diet or receiving fluoridated water (50 ppm F - NaF in deionized water) will be evaluated. Special immunofluorescence techniques will be performed using double, and where necessary triple labeling with markers of different myenteric and submucosal neuron types, including NOS, ChAT, VIP, Calretinin, Neurofilament Medium, and Somatostatin. All double labeling will be quantified to determine the relative sizes of different populations and the total neuronal population will be identified with anti-Hu staining. Neuropathic changes will be assessed. Likewise, functional neuro-muscular changes will be recorded using ileal and colon segments mounted in organ baths. Added to this, in order to evaluate the effects of AGEs and RAGEs, tissue collected from all the animal groups will be examined with anti-AGEs and anti-RAGE antibodies. (AU)