IL-37 Expression Is Downregulated in Lesional Psoriasis Skin.
Immunohorizons 2020;
4:754-761. [PMID:
33239358 DOI:
10.4049/immunohorizons.2000083]
[Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 11/19/2022] Open
Abstract
IL-37 broadly suppresses inflammation in various disease models. However, studies of the regulation and role of IL-37 in psoriasis are limited and contradictive. Using transcriptome analysis, PCR, protein determination, and immunofluorescence, we demonstrated marked downregulation of IL-37 in biopsies from human lesional psoriasis skin compared with paired samples of nonlesional skin. Immunofluorescence analysis showed that IL-37 was localized to stratum granulosum of the epidermis. TNF-α stimulation of normal human epidermal keratinocytes led to increased IL37 expression through a p38 MAPK-mediated mechanism, whereas IL-17A, IL-17C, IL-17F, and IL-22 acted suppressively. Intradermal injection with recombinant human IL-37 into imiquimod-induced psoriasis skin of C57BL/6J mice demonstrated a trend toward a protective effect, however NS. Altogether, these results demonstrate that IL-37 is downregulated in human lesional psoriasis skin. This may be a consequence of the loss of stratum granulosum, but key cytokines in the development of psoriasis also seem to contribute to this downregulation.
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