Health
Using novel mouse models, Dr Panayotova-Dimitrova’s work has revealed the mechanistic importance of cFLIP in maintaining the health of epidermal skin cells and regulating skin inflammation based on using transgenic animals where the gene of interest is either deleted or expressed in a modified form across all cells. In recent years, research employing transgenic animals has become more refined with the development of a technique for inducing these changes in a cell-specific manner. Gene function analysis can now be carried out at the level of individual cell types, as opposed to being limited to the organism as a whole. This is facilitated by Cre/loxP system-based technology, which Dr Panayotova-Dimitrova and her team have used to create their specialised transgenic mice. Cre-Lox recombination allows for DNA to be modified in target cell types, and for this modification to be consequently triggered by a specific inducer, applied externally. It is this process
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that Dr Panayotova-Dimitrova has used to investigate the function of cFLIP, specifically in keratinocyte skin cells. Prior to Dr Panayotova-Dimitrova’s recent work, virtually nothing was known about the function of cFLIP in the skin in vivo. This was because both conventional mouse models and those lacking cFLIP in the skin from birth have a lethal embryonic phenotype, meaning that further analysis was not possible. Fortunately, by using novel mice models, in which the cFLIP gene could be deleted after the mice had reached adulthood, the researchers were able to circumvent this obstacle. cFLIP’S ROLE IN SKIN CELL DEATH Dr Panayotova-Dimitrova and her team’s
study of transgenic mice which lacked expression of the gene from birth, resulted in embryonic lethality – indicating the crucial role cFLIP plays in tissue development. Where the cFLIP protein was removed in the skin of adults, the skin became severely inflamed, exhibiting blisters, pustules and skin loss. The researchers managed to ascertain that this was associated with caspase activation and apoptotic, not necroptotic, cell death. They also found that the apoptosis of epidermal cells that occurred in the absence of cFLIP, was dependent on autocrine tumour necrosis factor, the production of which is triggered by the loss of cFLIP. This discovery brings with it important insights into human disease. They have found that the same loss of cFLIP is associated with severe drug reactions linked to epidermal apoptosis, such as toxic epidermal necrolysis (TEN). TEN is a severe and often fatal drug hypersensitivity reaction of the skin where excessive cell death occurs. The disease is rare, which has made understanding it more difficult. Although discoveries over the past decade have hinted at details of its pathology, the mechanism behind the reaction within the skin has eluded scientists. To date, there is no efficient treatment for
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