Hidradenitis suppurativa (HS) is a complex inflammatory and debilitating skin disease for which no effective treatment is available currently. This is partly because of the lack of adequate human or animal models to define the pathobiology of the disease. Here, we describe the development of air-liquid (A-L) interface, liquid-submersion (L-S) and bioreactor (Bio) ex vivo skin culture models. All three ex vivo platforms were effective for culturing skin samples up to 14 days. Tissue architecture and integrity remained intact for at least 3 days for healthy skin and 14 days for HS skin. Up to day-3, no significant differences were observed in % early apoptotic cells among all three platforms. However, an increase was observed in late apoptotic/necrotic cells in HS skin at day-3 in A-L and Bio culture. These cultures efficiently support the growth of various cells populations, including keratinocytes and immune cells. Profiling inflammatory gene signatures in HS skin from these ex vivo cultures showed dynamic expression changes at day-3 and day-14. All three culture platforms are necessary to represent the inflammatory gene status of HS skin at day-0, suggesting that not all gene clusters are identically altered in each culture method. Similarly, cytokine/chemokine profiling of the supernatants from vehicle- and drug-treated ex vivo HS cultures again showed better prediction of drug efficacy against HS. Overall, development of these three culture systems collectively provides a powerful tool to uncover the pathobiology of HS progression and screen various drugs against HS.

Hidradenitis suppurativa (HS) is a complex in ammatory and debilitating skin disease for which no effective treatment is available currently. This is partly because of the lack of adequate human or animal models to de ne the pathobiology of the disease. Here, we describe the development of air-liquid (A-L) interface, liquid-submersion (L-S) and bioreactor (Bio) ex vivo skin culture models. All three ex vivo platforms were effective for culturing skin samples up to 14 days. Tissue architecture and integrity remained intact for at least 3 days for healthy skin and 14 days for HS skin. Up to day-3, no signi cant differences were observed in % early apoptotic cells among all three platforms. However, an increase was observed in late apoptotic/necrotic cells in HS skin at day-3 in A-L and Bio culture. These cultures e ciently support the growth of various cells populations, including keratinocytes and immune cells.Pro ling in ammatory gene signatures in HS skin from these ex vivo cultures showed dynamic expression changes at day-3 and day-14. All three culture platforms are necessary to represent the in ammatory gene status of HS skin at day-0, suggesting that not all gene clusters are identically altered in each culture method. Similarly, cytokine/chemokine pro ling of the supernatants from vehicle-and drug-treated ex vivo HS cultures again showed better prediction of drug e cacy against HS. Overall, development of these three culture systems collectively provides a powerful tool to uncover the pathobiology of HS progression and screen various drugs against HS.

Arsenical vesicants cause skin inflammation, blistering, and pain. The lack of appropriate animal models causes difficulty in defining their molecular pathogenesis. Here, Ptch1 +/-/C57BL/6 mice were employed to investigate the pathobiology of the arsenicals lewisite and phenylarsine oxide (PAO). Following lewisite or PAO challenge (24 h), the skin of animals becomes grayish-white, thick, leathery, and wrinkled with increased bi-fold thickness, Draize score, and necrotic patches. In histopathology, infiltrating leukocytes (macrophages and neutrophils), epidermal-dermal separation, edema, apoptotic cells, and disruption of tight and adherens junction proteins can be visualized. PCR arrays and nanoString analyses showed significant increases in cytokines/chemokines and other proinflammatory mediators. As hair follicles (HFs), which provide an immune-privileged environment, may affect immune cell trafficking and consequent inflammatory responses, we compared the pathogenesis of these chemicals in this model to that in Ptch1 +/-/SKH-1 hairless mice. Ptch1 +/-/ SKH-1 mice have rudimentary, whereas Ptch1 +/-/C57BL/6 mice have well-developed HFs. Although no significant differences were observed in qualitative inflammatory responses between the two strains, levels of cytokines/chemokines differed. Importantly, the mechanism of inflammation was identical; both reactive oxygen species induction and consequent activation of unfolded protein response signaling were similar. These data reveal that the acute molecular pathogenesis of arsenicals in these two murine models is similar.

No abstract

Hidradenitis suppurativa (HS) is a complex inflammatory and debilitating skin disease for which no effective treatment is available. This is partly because of the unavailability of suitable human or animal models with which exact pathobiology of the disease can be defined. Here, we describe the development of air-liquid (A-L) interface, liquid-liquid/liquid-submersion (L-S) and bioreactor (Bio) ex vivo skin culture models. All three ex vivo platforms were effective for culturing skin samples up to day-14, with the tissue architecture and integrity remaining intact for at least 3 days for healthy skin while for 14 days for HS skin. Up to day-3, no significant differences were observed in % early apoptotic cells among all three platforms. However, an increase was observed in late apoptotic/necrotic cells in HS skin at day-3 in A-L and Bio culture of HS skin. These cultures efficiently support the growth of various cells populations, including keratinocytes and immune cells. Profiling of the inflammatory genes using HS skin from these ex vivo cultures showed dynamic expression changes at day-3 and day-14. All of these cultures are necessary to represent the inflammatory gene status of HS skin at day-0 suggesting that not all gene clusters are identically altered in each culture method. Similarly, cytokine/chemokine profiling of the supernatant from vehicle- and drug-treated ex vivo HS cultures again showed better prediction of drug efficacy against HS. Overall, development of these three systems collectively provide a powerful tool to uncover the pathobiology of HS progression and screen various drugs against HS.