Psoriasis
IL-17 and IL-22 Promote Keratinocyte Stemness in the Germinative Compartment in Psoriasis
Psoriasis is an inflammatory skin disorder characterized by the hyperproliferation of basal epidermal cells. It is regarded as T-cell mediated, but the role of keratinocytes (KCs) in the disease pathogenesis has reemerged, with genetic studies identifying KC-associated genes. We applied flow cytometry on KCs from lesional and nonlesional epidermis to characterize the phenotype in the germinative compartment in psoriasis, and we observed an overall increase in the stemness markers CD29 (2.4-fold), CD44 (2.9-fold), CD49f (2.8-fold), and p63 (1.4-fold).Impact of Secukinumab on Endothelial Dysfunction and Other Cardiovascular Disease Parameters in Psoriasis Patients over 52 Weeks
Psoriasis increases the risk of cardiovascular (CV) disease. Secukinumab, a fully human monoclonal antibody against IL-17A, shows significant efficacy in psoriasis, but effects on CV markers are unknown. CARIMA (Evaluation of Cardiovascular Risk Markers in Psoriasis Patients Treated with Secukinumab) was a 52-week, randomized, double-blind, placebo-controlled, exploratory trial in patients with moderate to severe plaque psoriasis without clinical CV disease. Patients were randomly assigned to receive 300 mg or 150 mg secukinumab until week 52 or to receive placebo until week 12 and then 300 mg or 150 mg secukinumab until week 52.TRPA1 Acts in a Protective Manner in Imiquimod-Induced Psoriasiform Dermatitis in Mice
This study revealed the modulatory role of transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) cation channels in the Aldara-induced (5% imiquimod) murine psoriasis model using selective antagonists and genetically altered animals. We have also developed a refined localized model to enable internal controls and reduce systemic effects. Skin pathology was quantified by measuring skin thickness, scaling, blood flow, and analyzing dermal cellular infiltrate, whereas nocifensive behaviors were also observed.Toll-Like Receptor-Mediated Upregulation of CXCL16 in Psoriasis Orchestrates Neutrophil Activation
Innate immune processes are central in the development of the chronic inflammatory skin disease psoriasis. Studying stimulation of keratinocytes, monocytes, and dendritic cells by type I interferons or ligation of Toll-like receptors 1/2, 2/6, or 7, but not 7/8, resulted in enhanced surface expression and secretion of CXC chemokine ligand (CXCL) 16. The corresponding CXC chemokine receptor 6 was expressed on neutrophils whose recruitment into skin is important, especially in early psoriatic disease.Lack of Galanin Receptor 3 Alleviates Psoriasis by Altering Vascularization, Immune Cell Infiltration, and Cytokine Expression
The neuropeptide galanin is distributed in the central and peripheral nervous systems and in non-neuronal peripheral organs, including the skin. Galanin acts via three G protein-coupled receptors which, except galanin receptor 1, are expressed in various skin structures. The galanin system has been associated with inflammatory processes of the skin and of several other organs. Psoriasis is an inflammatory skin disease with increased neovascularization, keratinocyte hyperproliferation, a proinflammatory cytokine milieu, and immune cell infiltration.miR-146b Probably Assists miRNA-146a in the Suppression of Keratinocyte Proliferation and Inflammatory Responses in Psoriasis
miR-146a inhibits inflammatory responses in human keratinocytes and in different mouse models of skin inflammation. Little is known about the role of miR-146b in the skin. In this study, we confirmed the increased expression of miR-146a and miR-146b (miR-146a/b) in the lesional skin of patients with psoriasis. The expression of miR-146a was approximately twofold higher than that of miR-146b in healthy human skin, and it was more strongly induced by stimulation of proinflammatory cytokines in keratinocytes and fibroblasts.Nrf2 Promotes Keratinocyte Proliferation in Psoriasis through Up-Regulation of Keratin 6, Keratin 16, and Keratin 17
Psoriasis is a chronic inflammatory skin disease characterized by keratinocyte hyperproliferation of epidermis. Although hyperproliferation-associated keratins K6, K16, and K17 are considered to be the hallmarks of psoriasis, the molecular basis underlying the overexpression of these keratins remains unclear. Nrf2 regulates cell proliferation. Therefore, we investigated whether Nrf2 regulates keratinocyte proliferation via promoting expression of K6, K16, and K17 in psoriasis. We initially found that psoriatic epidermis exhibited elevated expression of Nrf2.Topically Delivered Tumor Necrosis Factor-α–Targeted Gene Regulation for Psoriasis
Psoriasis is a highly visible, chronic, immune-mediated inflammatory skin disorder that affects 2–3% of the US population (Lowes et al., 2014). Tumor necrosis factor-α (TNF-α) and IL-17A synergistically up-regulate the production of other cytokines, chemokines, and antimicrobial peptides from keratinocytes and regional immune cells, initiating and perpetuating the immune activation of psoriasis (Chiricozzi et al., 2011; Di Cesare et al., 2009; Ettehadi et al., 1994; Harden et al., 2015; Lowes et al., 2005).TNF-α Antagonist and Vascular Inflammation in Patients with Psoriasis Vulgaris: A Randomized Placebo-Controlled Study
Vascular inflammation is increased in patients with psoriasis. This randomized, double-blind, multicenter study evaluated the effects of tumor necrosis factor-α antagonist adalimumab on vascular inflammation in patients with psoriasis. A total of 107 patients were randomized (1:1) to receive adalimumab for 52 weeks or placebo for 16 weeks followed by adalimumab for 52 weeks. Vascular inflammation was assessed with positron emission tomography-computed tomography. There were no differences in the change from baseline in vessel wall target-to-background ratio (TBR) from the ascending aorta (primary endpoint) (adalimumab: TBR = 0.002, 95% confidence interval [CI] = –0.048 to 0.053; placebo: TBR = –0.002, 95% CI = –0.053 to 0.049; P = 0.916) and the carotids (adalimumab: TBR = 0.031, 95% CI = –0.005 to 0.066; placebo: TBR = 0.018, 95% CI = –0.019 to 0.055; P = 0.629) at week 16 between adalimumab and placebo.Recent Highlights in Psoriasis Research
This article highlights recent advances in the immunology, epidemiology, and genetics/genomics of psoriasis. Advances sometimes generate more questions, and this article makes an attempt to point out where controversies might exist in the literature. Many of the articles mentioned were published in the Journal of Investigative Dermatology, but many articles from the broader scientific literature are also cited, to provide context and to add further validity for some of these key findings. Among the themes we explore are the identification of antigens in psoriasis, the co-morbidities of psoriasis, and novel integrative approaches to genome-wide association studies.microRNAs in Psoriasis
Psoriasis is a chronic inflammatory skin condition resulting from a complex interplay among the immune system, keratinocytes, susceptibility genes, and environmental factors. However, the pathogenesis of psoriasis is not completely elucidated. microRNAs represent a promising class of small, noncoding RNA molecules that function to regulate gene expression. Although microRNA research in psoriasis and dermatology is still relatively new, evidence is rapidly accumulating for the role of microRNAs in the pathogenesis of psoriasis and other chronic inflammatory conditions.Landscape of Long Noncoding RNAs in Psoriatic and Healthy Skin
We used RNA sequencing to study and characterize the long noncoding RNA (lncRNA) transcriptome in lesional skin from psoriasis patients before (PP) and after treatment (PT) with adalimumab and in normal skin from healthy individuals (NN). To this end, we sequenced total RNA from 18 psoriasis patients and 16 healthy controls. We merged three lncRNA reference datasets to create a single combined reference of 67,157 lncRNA transcripts with no overlaps. We identified differential expression of 971 lncRNAs between PP and NN, 157 between PP and PT, and 377 between PT and NN.
