Molecular and Cellular Biochemistry 271: 189–196, 2005. c ❣ Springer 2005 Morphological and oxidative alterations on Sertoli cells cytoskeleton due to retinol-induced reactive oxygen species Ramatis Birnfeld de Oliveira, 1 F´ abio Klamt, 1,2 Mauro A. A. Castro, 1,3 Manuela Polydoro, 1 Alfeu Zanotto Filho, 1 Daniel Pens Gelain, 1 Felipe Dal-Pizzol 1,4 and Jos´ e Cl´ audio Fonseca Moreira 1 1 Departamento de Bioqu´ ımica, Centro de Estudos em Estresse Oxidativo, ICBS-Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos 2600 anexo, CEP 90035-003, Porto Alegre, Brasil; 2 Departamento de Biologia, Universidade Luterana do Brasil, Cachoeira do Sul, RS, Brasil; 3 Universidade Luterana do Brasil, Canoas, RS, Brasil; 4 Laborat´ orio de Fisiopatologia Experimental, Universidade do Extremo Sul Catarinense, SC, Brasil Received 5 August 2004; accepted 16 November 2004 Abstract Retinol (vitamin A) is involved in several cellular processes, like cell division, differentiation, transformation and apoptosis. Although it has been shown that retinol is a limitant factor for all these processes, the precise mechanisms by which retinol acts are still unknown. In the present study we hypothesised that alterations in the cytoskeleton of Sertoli cells induced by retinol supplementation could indicate an adaptive maintenance of its functions, since it plays an important role in the transformation process that we observed. Previous results demonstrated that Sertoli cells treated with retinol showed an oxidative imbalance, that leads the cell to two phenotypes: apoptosis or transformation. Our group has identified characteristics of Sertoli cells transformed by retinol which results in normal cell functions modification. In the present study the actin filament fluorescence assay and the deformation coefficient showed a modification in the morphology induced by retinol. We also observed an oxidative alteration in isolated cytoskeleton proteins and did not show alterations when these proteins are analyzed by electrophoreses. Our results showed an increase in mitochondria superoxide production and a decrease in nitric oxide levels. All results were partially or completely reverted by co-treatment of the antioxidant Trolox R  . These findings suggest that the cytoskeleton components suffer individual alterations in different levels and that these alterations generate a global phenotype modification and that these processes are probably ROS dependent. We believe that the results from this study indicate an adaptation of the cytoskeleton to oxidative imbalance since there was not a loss of its function. (Mol Cell Biochem 271: 189–196, 2005) Key words: cytoskeleton, retinol, Sertoli cells, ROS Introduction Retinol (vitamin A) and its metabolites are involved in a num- ber of pathologies [1, 2]. It has been suggested that its effects in several diseases are secondary to their free radical scav- Address for offprints: Ramatis B. de Oliveira, Departamento de Bioqu´ ımica (ICBS-UFRGS) Laborat ´ orio 25, rua Ramiro Barcelos 2600 anexo, CEP 90035-003, Porto Alegre, RS, Brasil (E-mail: ramatusoliveira@yahoo.com.br) enger activity in living systems [3]. However, several authors propose that they are actually pro-oxidants which could lead the cells to carcinogenesis through oxidative damage [4, 5]. It has been demonstrated that the cytoskeleton can be mod- ulated by free radicals [6, 7], and that these phenomena are