Autor(es)

Bosch, Rosemary Viola ; Alvarez-Flores, Miryam Paola ; Maria, Durvanei Augusto ; Chudzinski-Tavassi, Ana Marisa

• Tipo de documento: Artigo Científico
• Fonte: BIOMEDICINE & PHARMACOTHERAPY; v. 82, p. 537-546, AUG 2016.
• Citações Web of Science: 5

Resumo

Fibroblasts are the main cellular component of connective tissues and play important roles in health and disease through the production of collagen, fibronectin and growth factors. Under certain conditions, such as wound healing, fibroblasts intensify their metabolic demand, while the restriction of nutrients affect matrix composition, cell metabolism and behavior. In lepidopterans, wound healing is regulated by ecdysteroid hormones, which upregulate multifunctional proteins such as hemolin. However, the role of hemolin in cell proliferation and wound healing is not clear. rLosac is a recombinant hemolin from the caterpillar Lonomia obliqua whose proliferative and cytoprotective effects on endothelial cells have been described. Here, we show that rLosac induces a marked cell survival effect on fibroblast submitted to serum deprivation, which is observable as early as 24 h, as demonstrated through the MTT assay, as well as an increase in migration of human dermal fibroblasts (HDF). No effects on cell proliferation or cell cycle distribution of fibroblasts in normal conditions were observed, suggesting that rLosac induces an effect in stressful conditions such serum deprivation but not when nutrient are sufficient. By flow cytometry, rLosac caused an apparent dose-dependent increase in cells in the S phase of the cell cycle and a significant reduction of cells with fragmented DNA. Furthermore, treatment with rLosac results in a significant decrease in the production of reactive oxygen species and in the loss of mitochondrial membrane potential, indicating that a reduction in oxidative stress is involved in rLosac-mediated cytoprotection. Our results also show an up-regulation of Bcl-2 and a down-regulation of Bax protein levels, inhibition of cytochrome c release and a reduction in caspase-3 levels, all considered critical factors for apoptosis. Moreover, rLosac treatment reduces the morphological changes induced by prolonged serum deprivation including the emergence of apoptotic bodies, nucleus fragmentation, cytoplasmic vacuolization and loss of extracellular matrix organization. The wound scratch test assay revealed that rLosac could enhance wound healing in vitro. Altogether, these findings suggest that rLosac strongly induces cellular protection in conditions of stress by serum deprivation preventing damage and loss of mitochondrial function by inhibiting apoptosis. This finding opens a new perspective to further understand the role of hemolin proteins during cellular processes such as wound healing and development. (C) 2016 Elsevier Masson SAS. All rights reserved. (AU)

• Processo FAPESP: 13/07467-1 - CeTICS - Centro de Toxinas, Imuno-Resposta e Sinalização Celular
• Beneficiário: Hugo Aguirre Armelin
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 15/50040-4 - Rational approach for searching molecular targets involved in inflammatory events and cell survival
• Beneficiário: Ana Marisa Chudzinski-Tavassi
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa Aplicada
• Processo FAPESP: 13/06892-0 - Moléculas multifuncionais da lagarta Lonomia obliqua: planejamento de novas entidades químicas e interrelação com os mecanismos celulares
• Beneficiário: Ana Marisa Chudzinski-Tavassi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/54092-5 - Expressão e caracterização bioquímica do rLosac, um ativador de fator X recombinante das cerdas da lagarta Lanomia obliqua: mecanismos celulares envolvidos na atividade proliferativa e antiapoptótica
• Beneficiário: Ana Marisa Chudzinski-Tavassi
• Modalidade de apoio: Auxílio à Pesquisa - Regular