Cytotoxicity and genotoxicity of intravitreal adalimumab administration in rabbit retinal cells / Citotoxicidade e genotoxicidade da administração de adalimumabe intravítreo nas células da retina de coelhos

Purpose: To assess the cytotoxicity and genotoxicity of intravitreal adalimumab treatment in an animal experimental model using cytological and molecular techniques. Methods: Eighteen rabbits were randomly assigned to three groups: control, adalimumab treatment, and placebo. Cytotoxicity on retinal cells was evaluated using flow cytometry assays to determine the level of apoptosis and necrosis. Genotoxicity was evaluated by comet assays to assess DNA damage, and quantitative real-time polymerase chain reaction (qPCR) was used to evaluate expression of apoptosis-inducing caspases (8 and 3). Results: No cytotoxicity or genotoxicity was observed in any of the two treatment groups (adalimumab and placebo) following intravitreal administration compared with the control group. Flow cytometry analysis revealed that more than 90% of the cells were viable, and only a low proportion of retinal cells presented apoptotic (~10%) or necrotic (<1%) activity across all groups. Molecular damage was also low with a maximum of 6.4% DNA degradation observed in the comet assays. In addition, no increase in gene expression of apoptosis-inducing caspases was observed on retinal cells by qPCR in both the adalimumab and placebo groups compared with the control group. Conclusion: The use of adalimumab resulted in no detectable cytotoxicity or genotoxicity on retinal cells for up to 60 days upon administration. These results therefore indicate that adalimumab may be a safe option for intravitreal application to treat ocular inflammatory diseases in which TNF-α is involved. .

Objetivo: Acessar a citotoxicidade e genotoxicidade do tratamento intravítreo de adalimumabe em um modelo experimental animal utilizando técnicas citológicas e moleculares. Métodos: Dezoito coelhos foram aleatoriamente selecionados em três grupos: controle, tratamento intravítreo com adalimumabe e placebo. Os efeitos tóxicos nas células da retina foram avaliados através de ensaios de citometria de fluxo, para a determinação de atividade apoptótica e necrótica. A genotoxidade foi avaliada através de ensaios cometa para determinar danos ao DNA e através de PCR em tempo real para avaliar a expressão genética de caspases (8 e 3) promotoras de apoptose celular. Resultados: Não foram detectadas citotoxicidade e genotoxidade nos dois grupos de tratamento, adalimumabe e placebo, em comparação com o controle. A citometria de fluxo determinou que mais de 90% das células eram viáveis após o tratamento, e uma pequena quantidade de células da retina apresentaram apoptose (~10%) ou necrose (<1%) em todos os grupos. O dano molecular também foi baixo com uma degradação no DNA de no máximo 6,4% detectados nos ensaios cometa. Adicionalmente, não foram observados aumentos na expressão genética das caspases que induzem a apoptose através dos ensaios de PCR em tempo real. Conclusão: O tratamento intravítreo com adalimumabe não promoveu nenhuma citotoxicidade e genotoxicidade detectável em células da retina por até sessenta dias. Estes resultados, portanto, indicam que o adalimumabe pode ser uma opção segura para o tratamento de doenças oculares inflamatórias em que o TNFα está envolvido. .

The ruthenium complex cis-(dichloro)tetrammineruthenium(III) chloride induces apoptosis and damages DNA in murine sarcoma 180 cells.

Ruthenium(III) complexes are increasingly attracting the interest of researchers due to their promising pharmacological properties. Recently, we reported that the cis-(dichloro)tetrammineruthenium(III) chloride compound has cytotoxic effects on murine sarcoma 180 (S-180) cells. In an effort to understand the mechanism responsible for their cytotoxicity, study we investigated the genotoxicity, cell cycle distribution and induction of apoptosis caused by cis- (dichloro)tetrammineruthenium(III) chloride in S-180 tumour cells. cis-(dichloro)tetrammineruthenium(III) chloride treatment induced signifi cant DNA damage in S-180 cells, as detected by the alkaline comet assay. In the cell cycle analysis, cis-(dichloro)tetrammineruthenium(III) chloride caused an increase in the number of cells in G1 phase, accompanied by a decrease in the S and G2 phases after 24 h of treatment. In contrast, the cell cycle distribution of S-180 cells treated with cis-(dichloro)tetrammineruthenium(III) chloride for 48 h showed a concentration-dependent increase in the sub-G1 phase (indicating apoptosis), with a corresponding decrease in cells in the G1, S and G2 phases. In addition, cis-(dichloro)tetrammineruthenium(III) chloride treatment induced apoptosis in a time-dependent manner, as observed by the increased numbers of annexin V-positive cells. Taken together, these fi ndings strongly demonstrate that DNA damage, cell cycle changes and apoptosis may correlate with the cytotoxic effects of cis-(dichloro)tetrammineruthenium( III) chloride on S-180 cells.