The Journal of investigative dermatology
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J. Invest. Dermatol. · Nov 2020
Sensory Neuron-Expressed TRPC4 Is a Target for the Relief of Psoriasiform Itch and Skin Inflammation in Mice.
Psoriasis is an inflammatory skin disease associated with itch, which is a troublesome symptom with a few therapeutic options. TRPC4 is highly expressed in dorsal root ganglia (DRGs). Recently, we have revealed itch signaling in DRG neurons by which TRPC4 mediates itch to serotonergic antidepressants and demonstrated the antipruritic effect of the TRPC4 inhibitor ML204. ⋯ We have also shown that silencing TRPC4 in DRG and its inhibition by intradermal injections were also effective in decreasing psoriatic itch after the repeated application of imiquimod, which is a preclinical model of psoriasis. Of clinical relevance, intradermal injections of ML204 in psoriasiform skin significantly reversed imiquimod-established chronic itch and cutaneous inflammation. Given that TRPC4 is expressed in human DRGs and a specific inhibitor is in clinical trials, our data not only expand our understanding of itch and psoriasis, but also reveal TRPC4 as a potential therapeutic target with considerable translational benefits.
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Artificial intelligence is becoming increasingly important in dermatology, with studies reporting accuracy matching or exceeding dermatologists for the diagnosis of skin lesions from clinical and dermoscopic images. However, real-world clinical validation is currently lacking. ⋯ We address the following three primary applications: (i) teledermatology, including triage for referral to dermatologists; (ii) augmenting clinical assessment during face-to-face visits; and (iii) dermatopathology. We discuss equity and ethical issues related to future clinical adoption and recommend specific standardization of metrics for reporting model performance.
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J. Invest. Dermatol. · Mar 2020
Innate Immune Dysfunction in Rosacea Promotes Photosensitivity and Vascular Adhesion Molecule Expression.
Rosacea is a chronic skin disease characterized by photosensitivity, abnormal dermal vascular behavior, inflammation, and enhanced expression of the antimicrobial peptide LL-37. We observed that dermal endothelial cells in rosacea had an increased expression of VCAM1 and hypothesized that LL-37 could be responsible for this response. The digestion of double-stranded RNA from keratinocytes exposed to UVB blocked the capacity of these cells to induce adhesion molecules on dermal microvascular endothelial cells. ⋯ Functional relevance was demonstrated as double-stranded RNA and LL-37 promoted adhesion and transmigration of monocytes across the endothelial cell monolayers. Gene knockdown of TLR3, RIGI, or IRF1 decreased monocyte adhesion in endothelial cells, confirming the role of the double-stranded RNA recognition pathways. These observations show how the expression of LL-37 can lead to enhanced sensitivity to UVB radiation in rosacea.
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J. Invest. Dermatol. · May 2019
Cochrane Reviews and Dermatological Trials Outcome Concordance: Why Core Outcome Sets Could Make Trial Results More Usable.
Evidence-based health care requires that relevant outcomes for patients are included in clinical trials investigating treatment effects, allowing subsequent systematic reviews to summarize all relevant evidence to guide clinical practice. Currently, no gold standard of outcome choice for dermatology trials and reviews exists. We systematically assessed concordance between efficacy outcomes in a random sample of 10 Cochrane Skin systematic reviews and the 220 dermatology trials included. ⋯ This small overlap of review/trial outcomes could suggest that trials are not measuring the outcomes perceived to be the most important by patients, clinicians, systematic reviewers, and trialists. The lack of standardized outcome measures, poor reporting of outcomes in trials, and low concordance of outcomes between reviews and primary studies could be improved by the development and implementation of Core Outcome Sets. These are an agreed-upon minimum set of key outcomes, for specified conditions, to be reported in all trials.
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J. Invest. Dermatol. · Apr 2019
Pharmacological Inhibition of Serine Palmitoyl Transferase and Sphingosine Kinase-1/-2 Inhibits Merkel Cell Carcinoma Cell Proliferation.
The majority of Merkel cell carcinoma, a highly aggressive neuroendocrine cancer of the skin, is associated with Merkel cell polyomavirus infection. Polyomavirus binding, internalization, and infection are mediated by glycosphingolipids. Besides receptor function, bioactive sphingolipids are increasingly recognized as potent regulators of several hallmarks of cancer. ⋯ Aberrant sphingolipid homeostasis was associated with reduced cell viability, increased necrosis, procaspase-3 and PARP processing, caspase-3 activity, and decreased AKTS473 phosphorylation. Myriocin and SKI-II decreased tumor size and Ki-67 staining of xenografted MKL-1 and WaGa tumors on the chorioallantoic membrane. Our data suggest that pharmacological inhibition of sphingolipid synthesis could represent a potential therapeutic approach in Merkel cell carcinoma.