Study of ultrastructural changes and pattern of growth factors immunohistochemical expression on aging of submandibular, sublingual and lip salivary glands of humans

• Grant number: 13/23417-4
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2014
• End date: November 30, 2016
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Adriana da Costa Neves
• Grantee: Adriana da Costa Neves
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: Marcelo Cavenaghi Pereira da Silva ; Silvia Vanessa Lourenço

Abstract

Xerostomia is a major complaint of many elderly individuals and is considered a major clinical problem in the field of geriatrics. Histological analysis has demonstrated that with increasing age the parenchyma of the salivary glands (mainly the acinar tissue) is gradually replaced by fat and connective tissue and ductal component. Despite the structural changes involve both the parenchymal and stromal tissue, it is unclear how the extent of these structural alterations affect the function of these glands. It is also unclear whether functional changes are due to age-related reductions in efficiency of the glandular cells or in the number of functionally efficient cell. Thus the study of ultrastructural changes that occur in different cell types of salivary glands during the process of human aging, could contribute to the understanding of cell differentiation mechanisms involved in the aging biology of human salivary glands.The salivary glands are natural reservoirs of growth factors. The epidermal growth factor (EGF) and nerve growth factor (NGF) are synthesized and secreted by salivary glands cells, however, the physiological role of these proteins in saliva has not been fully elucidated. Reviewing the literature, we found that morphological localization of growth factors are much more scarce in human salivary glands than in glands of rodents, thus more studies on this subject are needed in order to clarify what portion of the glandular system they are produced. Furthermore, there are no studies which evaluate changes in growth factors expression during the aging process of human salivary glands. Nevertheless, the objective of this study is to evaluate changes in pattern of immunohistochemical expression of growth factors and their receptors FGF - 10, FGFR2, EGF and EGFR, pro - NGF, TrkA and p75 in the submandibular, sublingual and minor labial salivary glands in human aging process. In addition, ultrastructural alterations in glandular different cellular components will also be evaluated during human aging. (AU)