Cathelicidin Antimicrobial Peptide LL37 Induces Toll-Like Receptor 8 and Amplifies IL-36γ and IL-17C in Human Keratinocytes.

LL37 is produced by skin injury and bacterial infection and plays an important role in the early stages of psoriasis. In particular, the intracellular receptors toll-like receptors (TLR)3, TLR7, TLR8, and TLR9 are thought to be involved in the pathogenesis of psoriasis in conjunction with LL37, but the interaction between TLR7/8 and LL37 in keratinocytes (KCs) remains unclear. This study aimed to clarify the relationship between LL37 and TLR7/8 in KCs and their involvement in the pathogenetic pathways seen in psoriasis using cultured KCs and skin samples of patients with psoriasis. TLR7/8 was induced by LL37 in KCs. TLR8 but not TLR7 functionally induced many psoriasis-related molecules, whereas IL-17C was not altered by the blockade of TLR7/8. Although costimulation of LL37 with self-RNA/DNA did not show any interaction, LL37 itself would promote psoriasis-related genes. IL-36 receptor antagonistic antibody suppressed IL-17C induced by LL37. In psoriatic epidermis, LL37, TLRs, IL-17C, and IL-36γ expressions were increased and coexpressed with each other. Thus, we concluded that LL37 activates TLR8 in KCs and induces IL-17C through the induction of IL-36γ. Regulation of TLR8 or LL37 in KCs could be a potential therapeutic strategy for psoriatic inflammation.

Activated Platelets Induce Endothelial Cell Inflammatory Response in Psoriasis via COX-1.

OBJECTIVE: Patients with psoriasis have impaired vascular health and increased cardiovascular disease (CVD). Platelets are key players in the pathogenesis of vascular dysfunction in cardiovascular disease and represent therapeutic targets in cardiovascular prevention. The object of this study was to define the platelet phenotype and effector cell properties on vascular health in psoriasis and evaluate whether aspirin modulates the platelet-induced phenotype. Approach and Results: Platelets from psoriasis patients (n=45) exhibited increased platelet activation (relative to age- and gender-matched controls, n=18), which correlated with psoriasis skin severity. Isolated platelets from psoriasis patients demonstrated a 2- to 3-fold (P<0.01) increased adhesion to human aortic endothelial cells and induced proinflammatory transcriptional changes, including upregulation of IL 8 (interleukin 8), IL1ß, and Cox (cyclooxygenase)-2 Platelet RNA sequencing revealed an interferon signature and elevated expression of COX-1, which correlated with psoriasis disease severity (r=0.83, P=0.01). In a randomized trial of patients with psoriasis, 2 weeks of 81 mg low-dose aspirin, a COX-1 inhibitor, reduced serum thromboxane (Tx) B2 and reduced brachial vein endothelial proinflammatory transcript expression >70% compared with the no-treatment group (P<0.01). Improvement in brachial vein endothelial cell inflammation significantly correlated with change in serum TxB2 (r=0.48, P=0.02). CONCLUSIONS: In patients with psoriasis, platelets are activated and induce endothelial cell inflammation. Low-dose aspirin improved endothelial cell health in psoriasis via platelet COX-1 inhibition. These data demonstrate a previously unappreciated role of platelets in psoriasis and endothelial cell inflammation and suggests that aspirin may be effective in improving vascular health in patients with psoriasis. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03228017.

A retrospective review of the dermatologic manifestations of chronic arsenic poisoning in the Philippines.

BACKGROUND: The Section of Dermatology of the University of the Philippines, Philippine General Hospital, reported a case of chronic arsenic poisoning from a community in Luzon island to the Department of Health resulting in the conduct of two health and environmental assessment missions in December 2014. OBJECTIVE: To describe the demographic profile and cutaneous manifestations of chronic arsenic poisoning among affected residents in Luzon, Philippines. METHODS: A review of the medical records of 116 residents screened during the health assessment missions in December 2014 was conducted. RESULTS: Among the 116 residents screened, 81 (70%) had clinically confirmed arsenic keratoses and hyperpigmentation. Among them, 52 were males and 29 were females with age range of 4-82 years. Two cases of squamous cell carcinoma in situ were detected through skin biopsy. High levels of arsenic in the tap water and topsoil supported the occurrence of an epidemic of chronic arsenic poisoning. CONCLUSION: Specific dermatologic findings of arsenic keratoses and pigmentation were common among the residents screened. Significantly higher occurrence of arsenic keratoses was seen in adults.

Speckled pigmentation and palmoplantar keratoses leading to the mass detection of chronic arsenic poisoning

Arsenic is a known human carcinogen and skin manifestations are the earliest and most specific markers of chronic arsenic poisoning. A 43-year-old man from Luzon presented at the Section of Dermatology with a one-year history of hyperkeratotic papules and plaques on the palms and soles. Numerous round hypopigmented macules were scattered on the upper back. Initial 24-hour urine arsenic level was elevated at 288mcg/liter. The patient underwent successful chelation with N-acetylpenicillamine and the palmoplantar keratoses were treated with cryotherapy and topical 20% salicylic acid in white petrolatum. In cooperation with the Department of Health, a comprehensive health and environmental assessment was conducted in the affected communities. This case highlights the role of dermatologists in the diagnosis and management of this public health problem.