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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

High-Fat Diet Obesity Associated With Insulin Resistance Increases Cell Proliferation, Estrogen Receptor, and PI3K Proteins in Rat Ventral Prostate

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Author(s):
Ribeiro, Daniele Lisboa [1, 2] ; Pinto, Maria Etelvina [1] ; Rafacho, Alex [3] ; Bosqueiro, Jose Roberto [4] ; Maeda, Samantha Yuri [1] ; Anselmo-Franci, Janete Aparecida [5] ; Taboga, Sebastiao Roberto [1] ; Goes, Rejane Maira [1]
Total Authors: 8
Affiliation:
[1] Univ Estadual Paulista UNESP, Inst Biosci Letters & Exact Sci, Dept Biol, Sao Paulo - Brazil
[2] Univ Fed Uberlandia, Inst Biomed Sci, Sect Histol, BR-38400 Uberlandia, MG - Brazil
[3] Univ Estadual Paulista UNESP, Sch Sci, Dept Phys Educ, Sao Paulo - Brazil
[4] Univ Fed Santa Catarina, Ctr Biol Sci, Dept Physiol Sci, Florianopolis, SC - Brazil
[5] Univ Sao Paulo, Sch Dent, Dept Morphol Stomatol & Physiol, BR-09500900 Sao Paulo - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Journal of Andrology; v. 33, n. 5, p. 854-865, SEP-OCT 2012.
Web of Science Citations: 23
Abstract

In this study, we evaluated the effects of obesity and insulin resistance induced by a high-fat diet on prostate morphophysiology, focusing on cell proliferation, expression of androgen (AR) and estrogen receptors (ER) and proteins of the insulin signaling pathway. Adult male Wistar rats were fed a high-fat diet (20% fat) for 15 weeks, whereas control animals received a balanced diet (4% fat). Both groups were then divided and treated for 2 weeks with 1 mg/kg body weight/day of the aromatase inhibitor letrozole or vehicle only. The ventral prostate was analyzed with immunohistochemical, histopathological, stereological, and Western blotting methods. Obese rats showed insulin resistance, hyperinsulinemia, and reduced plasma testosterone levels. The incidence of prostatic intraepithelial neoplasia (PIN) was 2.7 times higher in obese rats and affected 0.4% of the gland compared with 0.1% PIN areas found in control rats. Obesity doubled cell proliferation in both prostate epithelium and stroma. AR content decreased in the prostate of obese rats and estrogen receptor beta (ER beta) increased in this group. Protein levels of insulin receptor substrate 1 and protein kinase B diminished in the obese group, whereas phosphatidylinositol 3-kinase (PI3K) increased significantly. Most structural changes observed in the prostate of obese rats normalized after letrozole treatment, except for increased stromal cell proliferation and ER beta expression, which might be associated with insulin resistance. This experimental model of obesity and insulin resistance induced by a high-fat diet increases cell proliferation in rat prostate. Such alterations are associated with decreased levels of AR and increased ER beta and PI3K proteins. This change can facilitate the establishment of proliferative lesions in rat prostate. (AU)

FAPESP's process: 08/00542-0 - REPERCUSSIONS OF THE OBESITY IN THE RAT VENTRAL PROSTATE: HISTOLOGICAL CHARACTERIZATION AND ANALYSIS OF THE ESTROGEN ROLE
Grantee:Daniele Lisboa Ribeiro
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 08/05341-2 - REPERCUSSIONS OF THE OBESITY IN THE RAT VENTRAL PROSTATE: HISTOLOGICAL CHARACTERIZATION AND ANALYSIS OF ESTROGEN ROLE
Grantee:Rejane Maira Góes
Support Opportunities: Regular Research Grants