In vitro research on vitiligo: strategies, principles, methodological options and common pitfalls.

Understanding the cellular and molecular mechanisms leading to melanocyte loss in vitiligo is a mandatory step in improving the overall management of vitiligo patients. Until now, the study of vitiligo was characterised by a fragmented approach, and it is very hard to share and compare the data obtained by the different teams. The scenario mirrors the pathogenic puzzle, but it delays a true productive focus on the disease. The in vitro research is based on different models, ranging from monolayer cell culture of epidermal and dermal cells or 3D reconstructed skin to histological data, gene expression, computer simulation profile. For each model, several different (biochemical, phenotypic, immunological) aspects have been considered, increasing the mass of data difficult to be merged. Our purpose was to provide a practical synopsis of consolidated and advanced possibilities in the study of vitiligo, showing how data have been poorly shared until now. Following a short overview of the background of the disease, the approaches, ranging from basic cell biology to molecular and 'omics' studies, are summarised. New fluorescent probes and techniques open new possibilities for functional studies. Next, intracellular and superficial markers of the melanocytes, the main involved cells, are listed. Moving the focus from the epidermal level to the systemic and subcellular ones, this review aims to propose innovative multidisciplinary options for the vitiligo understanding. This paper focuses on the major practical and theoretical questions to be solved. It may be the basis for a more coordinated and productive approach to the biological question.