Keloids are disfiguring, fibroproliferative growths and their pathogenesis remains unclear, inhibiting therapeutic development. Available treatment options have limited efficacy and harbor safety ...concerns. Thus, there is a great need to clarify keloid pathomechanisms that may lead to novel treatments. In this study, we aimed to elucidate the profile of lesional and non-lesional keloid skin compared to normal skin. We performed gene (RNAseq, qRT-PCR) and protein (immunohistochemistry) expression analyses on biopsy specimens obtained from lesional and non-lesional skin of African American (AA) keloid patients compared to healthy skin from AA controls. Fold-change≥2 and false-discovery rate (FDR)<0.05 was used to define significance. We found that lesional versus normal skin showed significant up-regulation of markers of T-cell activation/migration (ICOS, CCR7), Th2- (IL-4R, CCL11, TNFSF4/OX40L), Th1- (CXCL9/CXCL10/CXCL11), Th17/Th22- (CCL20, S100As) pathways, and JAK/STAT-signaling (JAK3) (false-discovery rate FDR<0.05). Non-lesional skin also exhibited similar trends. We observed increased cellular infiltrates in keloid tissues, including T-cells, dendritic cells, mast cells, as well as greater IL-4rα
, CCR9
, and periostin
immunostaining. In sum, comprehensive molecular profiling demonstrated that both lesional and non-lesional skin show significant immune alternations, and particularly Th2 and JAK3 expression. This advocates for the investigation of novel treatments targeting the Th2 axis and/or JAK/STAT-signaling in keloid patients.
Background Tofacitinib is an oral Janus kinase inhibitor being investigated for psoriasis. Objective We sought to elucidate the molecular mechanisms underlying the clinical efficacy of tofacitinib in ...patients with psoriasis. Methods Twelve patients with plaque psoriasis were randomized (3:1) to receive 10 mg of tofacitinib or placebo twice daily for 12 weeks. Biopsy specimens were taken from nonlesional (baseline) and lesional (baseline, days 1 and 3, and weeks 1, 2, 4, and 12) skin. Biopsy specimens were examined for psoriatic epidermal features (thickness, Ki67+ keratinocytes and keratin 16 KRT16 mRNA expression, and phosphorylated signal transducer and activator of transcription pSTAT+ nuclei) and T-cell and dendritic cell (DC) subsets by using immunohistochemistry, and mRNA transcripts were quantified by using a microarray. Results In lesional skin keratinocyte pSTAT1 and pSTAT3 staining was increased at baseline but reduced after 1 day of tofacitinib (baseline, median of 1290 pSTAT1+ cells/μm2 ; day 1, median of 332 pSTAT1+ cells/μm2 ; and nonlesional, median of 155 pSTAT1+ cells/μm2 ). Epidermal thickness and KRT16 mRNA expression were significantly and progressively reduced after days 1 and 3 of tofacitinib administration, respectively (eg, KRT16 decreased 2.74-fold, day 3 vs baseline, P = .016). Decreases in DC and T-cell numbers were observed after weeks 1 and 2, respectively. At week 4, significant decreases in IL-23/TH 17 pathways were observed that persisted through week 12. Improvements in clinical and histologic features were strongly associated with changes in expression of psoriasis-related genes and reduction in IL-17 gene expression. Conclusions Tofacitinib has a multitiered response in patients with psoriasis: (1) rapid attenuation of keratinocyte Janus kinase/STAT signaling; (2) removal of keratinocyte-induced cytokine signaling, leading to reductions in pathologic DC and T-cell numbers to nonlesional levels; and (3) inhibition of the IL-23/TH 17 pathway.
Targeted inhibition of Rho-associated kinase (ROCK)2 downregulates the proinflammatory T cell response while increasing the regulatory arm of the immune response in animals models of autoimmunity and ...Th17-skewing human cell culture in vitro. In this study, we report that oral administration of a selective ROCK2 inhibitor, KD025, reduces psoriasis area and severity index scores by 50% from baseline in 46% of patients with psoriasis vulgaris, and it decreases epidermal thickness as well as T cell infiltration in the skin. We observed significant reductions of IL-17 and IL-23, but not IL-6 and TNF-α, whereas IL-10 levels were increased in peripheral blood of clinical responders after 12 wk of treatment with KD025. Collectively, these data demonstrate that an orally available selective ROCK2 inhibitor downregulates the Th17-driven autoimmune response and improved clinical symptoms in psoriatic patients via a defined molecular mechanism that involves concurrent modulation of cytokines without deleterious impact on the rest of the immune system.
Activation of Sirtuin (silent mating type information regulation 2 homolog) 1, or SIRT1, is an unexplored therapeutic approach for treatment of inflammatory diseases. We randomized 40 patients with ...moderate-to-severe psoriasis (4:1) to three escalating doses of SRT2104, a selective activator of SIRT1, or placebo. Across all SRT2104 groups, 35% of patients (p<0.0001) achieved good to excellent histological improvement based on skin biopsies taken at baseline and day 84 but was not consistently in agreement with PASI. Improvement in histology was associated with modulation of IL-17 and TNF-α signaling pathways and keratinocyte differentiation target genes. 27 subjects (69%) across all treatment groups, including placebo, experienced at least one treatment emergent adverse event. The majority of AEs were either mild or moderate. Most common were headache (8%), dizziness (8%), upper respiratory tract infection (8%), and psoriatic arthropathy (8%). Average drug exposure increased in a dose-dependent manner for escalating doses of SRT2104 and had high intra-subject variability in exposure (AUC %CV: 51–89%). Given the interesting signals of clinical activity, impact on gene expression and the generally favorable safety profile seen in this study, further investigation of SIRT1 activators for the treatment of psoriasis is warranted.
Clinicaltrials.gov NCT01154101.
Durable psoriasis improvement has been reported in a subset of psoriasis patients after treatment withdrawal of biologics blocking IL-23/Type 17 T-cell (T17) autoimmune axis. However, it is not well ...understood if systemic blockade of the IL-23/T17 axis promotes immune tolerance in psoriasis skin. The purpose of the study was to find translational evidence that systemic IL-17A blockade promotes regulatory transcriptome modification in human psoriasis skin immune cell subsets. We analyzed human psoriasis lesional skin 6 mm punch biopsy tissues before and after systemic IL-17A blockade using the muti-genomics approach integrating immune cell-enriched scRNA-seq (n = 18), microarray (n = 61), and immunohistochemistry (n = 61) with repository normal control skin immune cell-enriched scRNA-seq (n = 10) and microarray (n = 8) data. For the T17 axis transcriptome, systemic IL-17A blockade depleted 100% of
T-cells and 95% of
T-cells in psoriasis skin. The expression of
in DC subsets was also downregulated by IL-17A blockade. The expression of IL-17-driven inflammatory mediators (
,
,
, and
) in suprabasal keratinocytes was correlated with psoriasis severity and was downregulated by IL-17A blockade. For the regulatory DC transcriptome, the proportion of regulatory semimature DCs expressing regulatory DC markers of
(
) and
(
) was increased in posttreatment psoriasis lesional skin compared to pretreatment psoriasis lesional skin. In addition, IL-17A blockade induced higher expression of
and
, which are markers of CD1c
CD14
dendritic cell (DC) subset that suppresses antigen-specific T-cell responses, in posttreatment regulatory semimature DCs compared to pretreatment regulatory semimature DCs. In conclusion, systemic IL-17A inhibition not only blocks the entire IL-23/T17 cell axis but also promotes regulatory gene expression in regulatory DCs in human psoriasis skin.
Background Topical glucocorticosteroids are considered an efficient treatment option for atopic dermatitis (AD), but a global assessment of glucocorticosteroid responses on key disease circuits upon ...weeks to months of treatment is currently lacking. Objective We sought to assess short (4 weeks) and long-term (16 weeks) application of topical glucocorticosteroids on AD skin and define response biomarkers. Methods The effects of triamcinolone acetonide cream 0.025% were assessed based on gene expression and immunohistochemistry studies at baseline, 4 weeks, and 16 weeks in biopsy specimens from 15 patients with moderate-to-severe AD. Results At 16 weeks, only 3 patients were clinical responders (by using SCORAD50 criteria), but 6 patients qualified as responders based on histologic criteria. Baseline characteristics indicated more severe disease in nonresponders. While 3 of 15 patients experienced only transient benefit after 4 weeks, others showed progressive improvements toward 16 weeks. Topical glucocorticosteroid use in patients with AD resulted in improvements of the AD genomic signature of 25.6% at 4 weeks and 71.8% at 16 weeks, respectively, and even 123.9% in the histologic responder group. Cytokines (IL-12p40, IL-13, IL-22, CCL17, CCL18, peptidase inhibitor 3 PI3/elafin, and S100As) showed consistent decreases from baseline toward 16 weeks with corresponding improvements in epidermal disease hallmarks (keratin 16 and loricrin) in lesional skin from responders ( P < .05). Nonresponders largely showed lesser/nonsignificant reductions in key inflammatory and barrier markers (keratin 16, IL-13, IL-22, CCL17, CCL18, PI3/elafin, S100As, and loricrin). The combination of IL-21 and IFN-γ baseline expression closely predicted individual clinical glucocorticosteroid responses at 16 weeks of treatment. Conclusion Our study indicates that even low-potency glucocorticosteroids can broadly affect immune and barrier responses in patients with moderate-to-severe AD, associating higher baseline severity with increased steroid resistance in patients with AD.
Highlights • IL-1β/IL-6/LL-37/IL-19/IL-17A/CXCL1/CXCL2 increased in PPPP as compared to NPPPP. • No significant difference of IL-23 in PPPP as compared to NPPPP. • IL-22+ but not IL-17A+ mast cells ...were higher in PPPP as compared to NPPPP. • IL-17A pathway may play a more important role in PPPP than in NPPPP
The acute response of human skin to UVB radiation has not been fully characterized. We sought to define the cutaneous response at 24hours following narrowband UVB (NB-UVB, 312-nm peak), a ...therapeutically relevant source of UVB, using transcriptional profiling, immunohistochemistry, and immunofluorescence. There were 1,522 unique differentially regulated genes, including upregulated genes encoding antimicrobial peptides (AMPs) (S100A7, S100A12, human beta-defensin 2, and elafin), as well as neutrophil and monocyte/dendritic cell (DC) chemoattractants (IL-8, CXCL1, CCL20, CCL2). Ingenuity pathway analysis demonstrated activation of innate defense and early adaptive immune pathways. Immunohistochemistry confirmed increased epidermal staining for AMPs (S100A7, S100A12, human beta-defensin 2, and elafin). Inflammatory myeloid CD11c+BDCA1− DCs were increased in irradiated skin, which were immature as shown by minimal colocalization with DC-LAMP, and coexpressed inflammatory markers tumor necrosis factor (TNF) and TNF–related apoptosis-inducing ligand in irradiated skin. There were increased BDCA3+ DCs, a cross-presenting DC subtype with immunosuppressive functions, and these cells have not been previously characterized as part of the response to UVB. These results show that the acute response of human skin to erythemogenic doses of NB-UVB includes activation of innate defense mechanisms, as well as early infiltration of multiple subtypes of inflammatory DCs, which could serve as a link between innate and adaptive immunity.
To understand the development of new psoriasis lesions, we studied a group of moderate-to-severe psoriasis patients who experienced a relapse after ceasing efalizumab (anti-CD11a, Raptiva, ...Genentech). There were increased CD3(+) T cells, neutrophils, CD11c(+) and CD83(+) myeloid dendritic cells (DCs), but no increase in CD1c(+) resident myeloid DCs. In relapsed lesions, there were many CD11c(+)CD1c(-), inflammatory myeloid DCs identified by TNFSF10/TRAIL, TNF, and iNOS. CD11c(+) cells in relapsed lesions co-expressed CD14 and CD16 in situ. Efalizumab induced an improvement in many psoriasis genes, and during relapse, the majority of these genes reversed back to a lesional state. Gene Set Enrichment Analysis (GSEA) of the transcriptome of relapsed tissue showed that many of the gene sets known to be present in psoriasis were also highly enriched in relapse. Hence, on ceasing efalizumab, T cells and myeloid cells rapidly enter the skin to cause classic psoriasis.
Clinicaltrials.gov NCT00115076.
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.
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