Expression of Nodal, Cripto, SMAD3, Phosphorylated SMAD3, and SMAD4 in the Proliferative Endometrium of Women With Endometriosis

• Published in: Reproductive sciences (Thousand Oaks, Calif.) Calif.), 2015-05, Vol.22 (5), p.527-533
• Main Authors: Cruz, Cynthia Dela, Del Puerto, Helen L., Rocha, Ana Luiza L., Cavallo, Inês K., Clarizia, Alessandra D., Petraglia, Felice, Reis, Fernando M.
• Format: Article
• Language: English
• Subjects: Adult; Blotting, Western; Case-Control Studies; Cell Proliferation; Embryology; Endometriosis - diagnosis; Endometriosis - genetics; Endometriosis - metabolism; Endometrium - chemistry; Endometrium - pathology; Female; Gene Expression Regulation; GPI-Linked Proteins - analysis; GPI-Linked Proteins - genetics; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins - analysis; Intercellular Signaling Peptides and Proteins - genetics; Medicine & Public Health; Neoplasm Proteins - analysis; Neoplasm Proteins - genetics; Nodal Protein - analysis; Nodal Protein - genetics; Obstetrics/Perinatology/Midwifery; Original; Original Article; Phosphorylation; Real-Time Polymerase Chain Reaction; Reproductive Medicine; RNA, Messenger - analysis; Signal Transduction; Smad3 Protein - analysis; Smad3 Protein - genetics; Smad4 Protein - analysis; Smad4 Protein - genetics; Young Adult
• ISSN: 1933-7191; 1933-7205
• DOI: 10.1177/1933719114549855

Background: Nodal is a growth factor of the transforming growth factor β superfamily that is expressed in high turnover tissues, such as the human endometrium, and in several malignancies. The effects of Nodal are modulated by the coreceptor Cripto and mediated by SMAD proteins. This study evaluated the gene and protein expression of Nodal, Cripto, total and phosphorylated (p) SMAD3, and SMAD4 in the proliferative endometrium of women with and without endometriosis. Method: Total RNA was isolated and complementary DNA synthesized from eutopic endometrium of women with (n = 15) and without (n = 12) endometriosis, followed by quantitative real-time polymerase chain reaction (PCR) to evaluate the gene expression of Nodal, Cripto, SMAD3, and SMAD4. Western blot was used to evaluate the protein levels of Nodal and Cripto, and immunohistochemistry was performed to localize SMAD3, pSMAD3, and SMAD4. Results: Although Nodal expression was unchanged in women with endometriosis, real-time PCR indicated lower gene expression of Cripto (fold change 0.27, P < .05) in the endometriosis group. This difference, however, was not maintained at protein expression level as assessed by Western blot. The immunostaining of total SMAD3 was reduced in the endometriosis group (P < .01), but the localization of pSMAD3 and the nuclear staining of SMAD4 were unchanged. Conclusion: These findings suggest that the Nodal signaling pathway has subtle changes in the endometrium of women with endometriosis, but this imbalance may not cause functional damage as it seems not to affect the nuclear expression of SMAD4.