RICARDO HSIEH
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Dermatologia, Faculdade de Medicina
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina
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- Immunoexpression of adhesion molecules during human fetal hair development(2020) SILVA, Laura Maria Andrade; HSIEH, Ricardo; LOURENCO, Silvia Vanessa; OTTONI, Veronica; VALENTE, Neusa; FERNANDES, Juliana DumetIntroduction. Hair follicles are produced in a cyclical manner and the machinery involved in the reproduction of these follicles is present since the fetal stage. Although extensive research has been done on the human hair follicle, very little is known about the importance of adhesion molecules in its development. Material and methods. We analyzed here, the immunoexpression of beta-1 integrin, p-cadherin, e-cadherin, and beta-catenin in hair follicles from 26 formalin-fixed and paraffin-embedded skin samples from human embryos and fetus between 12-23 weeks of gestational age. Results. The adhesion molecules beta-1 integrin and e-cadherin/p-cadherin were expressed from 12 weeks and seemed to play a role in regulating epidermis invagination. Beta-catenin immunostaining was negative in all cases; down regulation of this protein may be necessary for fetal hair development and thus facilitating hair follicle down growth. Discussion/Conclusion. Adhesion molecules are essential for hair follicle down growth and proliferation; integrins and cadherins play a major role in this process. More studies are needed to describe hair follicle development.
- Immunostaining study of cytokeratins in human hair follicle development(2020) SILVA, Laura Maria Andrade; HSIEH, Ricardo; LOURENCO, Silvia Vanessa; VALENTE, Neusa Yuriko Sakai; PAIVA, Geise Rezende; FERNANDES, Juliana DumetBackground: The hair follicle is a unique structure, one of the most dynamic structures in mammalians, which can reproduce in every new cycle all the mechanism involved in its fetal development. Although a lot of research has been made about the human hair follicle much less has been discovered about the importance of the cytokeratins (CKs) in its development. Objective: Study the immunohistochemical pattern of epithelial CKs during human hair follicle development. Methods: We performed an immunohistochemical study using fresh post-mortem skin biopsies of human fetuses between 4 and 25 weeks of gestational age to study the expression of cytokeratins (CKs): CK1, CK10, CK13, CK14, CK16 and CK20 during human hair follicle fetal development. Study limitations: Restrospective study with a good number of makers but with a small population. Results/conclusion: We found that, the CKs were expressed in an intermediate time during follicular development. The epithelial CKs (CK1, CK14, CK10, CK13) and the epithelial CKs witha proliferative character such as CK16 were expressed first, as markers of cellular maturation and follicular keratinization. At a later phase, CK20 was expressed in more developed primitive hair follicles as previously discussed in literature. (C) 2020 Sociedade Brasileira de Dermatologia.
- Claudin expression is maintained in mucoepidermoid carcinoma of the salivary gland(2020) ARRUDA, Claudia Fabiana Joca de; COUTINHO-CAMILLO, Claudia Malheiros; MARQUES, Marcia Martins; NAGANO, Cibele Pidorodeski; BOLOGNA, Sheyla Batista; BETTIM, Barbara Beltrame; GERMANO, Janaina Naiara; PINTO, Clovis Antonio Lopes; HSIEH, Ricardo; LOURENCO, Silvia VanessaObjective: The aim of the present study was to investigate the expression of claudin-1,-3,-4,-5 and-7 proteins in mucoepidermoid carcinoma of oral cavity and analyze whether EGF may interfere in the expression of the genes that encode claudins using in vitro models. Material and methods: Using immunohistochemistry, the expression of claudins was searched in 36 histologically graded cases of mucoepidermoid carcinoma. The association of expression of claudins with clinical-pathological parameters was evaluated. An in vitro step investigated the influence of EGF on gene expression of claudins by real time RT-PCR technique. Results: Claudin-1,-3,-4,-5, and-7 were highly expressed in most mucoepidermoid carcinomas. These expres-sions were compared with clinicopathological parameters. High expression of claudin-1 was associated with patients over 40 years-old (p = 0.05) and Caucasians (p = 0.024). In vitro experiments demonstrated a tendency for Claudin gene expression increase after EGF stimulus. Conclusions: The expression of claudins is maintained in mucoepidermoid carcinoma cells and EGF could be related with this expression. Our results point out to a fundamental biological importance to CLDNs in normal and neoplastic tissue. The expression patterns of CLDNs does not yet allow a clinical application, but the biological knowledge will ground evidence to new studies towards possible target-therapies.