Aminopeptidases, prolil oligopeptidase and representative peptides in adipocytes from obese and food deprived rats

• Grant number: 10/01385-5
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2010
• End date: September 30, 2012
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Paulo Flávio Silveira
• Grantee: Paulo Flávio Silveira
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Metabolic disorders, such as obesity and anorexia, change the reserve of energy and functionality of adipocytes. The discovery of insulin-regulated aminopeptidase, which hydrolyses peptides such as oxytocin and vasopressin and binds angiotensin IV, highlights the importance of studying the involvement of peptidases in the endocrine function of adipose tissue. Peptide YY, neuropeptide Y, b-endorphin, growth hormone-releasing hormone, substance P, glucose-dependent insulinotropic polypeptide (or gastric inhibitory polypeptide), enterostatin and particularly the glucagon-like peptide type 1 are susceptible to the hydrolysis by dipeptidyl peptidase IV. Furthermore, the acid, basic, cystyl, leucyl and neutral aminopeptidases, as well as prolyl oligopeptidase act on other peptides that are also relevant for the functions of adipose tissue, e.g. angiotensins, bradykinin, cholecystokinin, encephalins, interleukins, oxytocin, somatostatin and vasopressin. This project will measure the gene expression of acid, basic, cystyl, dipeptidyl peptidase IV, leucyl and neutral aminopeptidases and prolyl oligopeptidase in total adipocytes isolated from periepididymal and/or retroperitoneal fat pads, as well as protein expression and the catalytic activities of these peptidases in total adipocytes and their membrane-bound, low and high microsomal density fractions in order to evaluate (i) which of these peptidases exist in the adipocyte, (ii) if they are or have any relationship with an insulin-regulated type of aminopeptidase and with the situations of obesity and food deprivation, and (iii) if in these situations the translocation of these peptidases can be modified in vitro by angiotensins, bradykinin, oxytocin and vasopressin, comparatively to insulin. The results will contribute to highlight the mechanisms of adipocytes acting in energy balance. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ALPONTI, RAFAELA FADONI; VIANA, LUCIANA GODOY; YAMANOUYE, NORMA; SILVEIRA, PAULO FLAVIO. Insulin-regulated aminopeptidase in adipocyte is Cys-specific and affected by obesity. JOURNAL OF MOLECULAR ENDOCRINOLOGY, v. 55, n. 1, p. 1-8, AUG 2015. (10/01385-5)

ALPONTI, RAFAELA FADONI; SILVEIRA, PAULO FLAVIO. Adipocyte aminopeptidases in obesity and fasting. Molecular and Cellular Endocrinology, v. 415, n. C, p. 24-31, NOV 5 2015. (10/01385-5)

ALPONTI, RAFAELA FADONI; ALVES, PATRICIA LUCIO; SILVEIRA, PAULO FLAVIO. Novel adipocyte aminopeptidases are selectively upregulated by insulin in healthy and obese rats. Journal of Endocrinology, v. 228, n. 2, p. 97-104, FEB 2016. (10/01385-5)