The studies in this thesis describes the barrier defects in Atopic Dermatitis (AD) skin and various techniques to develop AD Human Skin Equivalents (HSEs) which can be used to better... Show more The studies in this thesis describes the barrier defects in Atopic Dermatitis (AD) skin and various techniques to develop AD Human Skin Equivalents (HSEs) which can be used to better understand the role of several factors in the pathogenesis of AD skin. The results described show that Inflammation plays a pivotal role in the development of epidermal and SC features of AD skin and that AD epidermal features can be maintained in vitro when AD skin biopsies are used to generate explant-HSEs. These AD-HSEs can also serve as a tool to screen potential therapeutics for AD and skin barrier repair. However, limitations exist in the complexity and full representation of all possible factors known to influence the development of AD e.g. FLG mutations, other aspects of inflammatory micro-environment, microbe colonization etc. Show less
Danso, M.O.; Drongelen, V. van; Mulder, A.; Gooris, G.S.; Smeden, J. van; El Ghalbzouri, A.; Bouwstra, J.A. 2015
BACKGROUND\nExplant human skin equivalents (Ex-HSEs) can be generated by placing a 4mm skin biopsy onto a dermal equivalent. The keratinocytes migrate from the biopsy onto the dermal equivalent,... Show moreBACKGROUND\nExplant human skin equivalents (Ex-HSEs) can be generated by placing a 4mm skin biopsy onto a dermal equivalent. The keratinocytes migrate from the biopsy onto the dermal equivalent, differentiate and form the epidermis of 1(st) generation Ex-HSEs. This is especially suitable for the expansion of skin material from which only small fragments of skin can be harvested e.g. diseased skin.\nOBJECTIVE\nWe evaluated whether 2(nd) and 3(rd) generation Ex-HSEs can also be generated from a single skin biopsy whilst maintaining the epidermal properties of 1(st) generation Ex-HSEs and native human skin.\nMETHODS\n2(nd) generation Ex-HSEs were produced by placing a biopsy from the 1(st) generation Ex-HSE onto a new dermal equivalent. Likewise, the 3(rd) generation Ex-HSEs were generated from a 2(nd) generation Ex-HSE biopsy.\nRESULTS\nWe show for the first time that Ex-HSEs can be passaged to the 2(nd) and 3(rd) generation and display similar epidermal morphology and expression of differentiation markers as in native human skin and 1(st) generation Ex-HSEs except for involucrin. The 2(nd) and 3(rd) generation Ex-HSEs also show many similarities with 1(st) generation Ex-HSEs in lipid properties e.g. presence of all lipid classes, similar fatty acid chain length distribution and lamellar lipid organization. However, some differences arise in increased level of hexagonal lateral packing and a change in ceramide profiling. The changes in specific lipid classes were also accompanied by changes in the expression of the enzymes responsible for their synthesis.\nCONCLUSION\nThe expansion of skin biopsies to the 2(nd) and 3(rd) generation Ex-HSEs could be a promising method to expand valuable epidermal tissue to analyze morphological and differentiation parameters in the native epidermis. Show less
Danso, M.O.; Drongelen, V. van; Mulder, A.; Gooris, G.; Smeden, J. van; Ghalbzouri, A. el; Bouwstra, J.A. 2015
