Inate immunity in rosacea. Langerhans cells, plasmacytoid dentritic cells, Toll-like receptors and inducible oxide nitric synthase (iNOS) expression in skin specimens: case-control study

S100A9 Exacerbates the Inflammation in Rosacea through Toll-Like Receptor 4/MyD88/NF-κB Signaling Pathway

Rosacea is a chronic inflammatory skin disorder characterized by immune response-dependent erythema and pustules. S100A9, a proinflammatory alarmin, has been associated with various inflammation-related diseases. However, the specific role of S100A9 in rosacea remains unexplored. Therefore, our objective was to unravel the role of S100A9 in the pathogenesis of rosacea and its underlying molecular mechanisms. In this study, we show that expression levels of S100A9 were elevated in both the lesions and serum of patients with papulopustular rosacea as well as in lesions of the LL37-induced rosacea-like mouse model. Moreover, the upregulation of S100A9 was correlated with clinical severity and levels of inflammatory cytokines. In addition, we demonstrated that S100A9 promoted the production of proinflammatory factors in HaCaT cells by activating toll-like receptor 4/MyD88/NF-κB signaling pathways. Notably, inhibition of S100A9 suppressed the progression of rosacea-like dermatitis and inflammatory responses in the LL37-induced rosacea-like mouse model through toll-like receptor 4/MyD88/NF-κB signaling pathways. In conclusion, this study illustrated that S100A9 participates in the pathogenesis of rosacea by upregulating toll-like receptor 4/MyD88/NF-κB signaling pathways, thereby promoting rosacea-associated skin inflammation. These results not only expand our understanding of the potential role of S100A9 in the development of rosacea but also offer greater insight toward targeted therapies.

Screening of Diagnostic Biomarkers and Immune Infiltration Characteristics Linking Rheumatoid Arthritis and Rosacea Based on Bioinformatics Analysis

Introduction

Both rheumatoid arthritis (RA) and rosacea represent common chronic systemic autoimmune conditions. Recent research indicates a heightened RA risk among individuals with rosacea. However, the molecular mechanisms linking these diseases remain largely unknown. This study aims to uncover shared molecular regulatory networks and immune cell infiltration patterns in both rosacea and RA.

Methods

The gene expression profiles of RA (GSE12021, GSE55457), and the rosacea gene expression profile (GSE6591), were downloaded from Gene Expression Omnibus (GEO) databases, and obtained to screen differentially expressed genes (DEGs) by using "limma" package in R software. Various analyses including GO, KEGG, protein-protein interaction (PPI) network, and weighted gene co-expression network analyses (WGCNA) were conducted to explore potential biological functions and signaling pathways. CIBERSORT was used to assess the abundance of immune cells. Pearson coefficients were used to calculate the correlations between overlapped genes and the leukocyte gene signature matrix. Flow cytometry (FCM) analysis confirmed the most abundant immune cells detected in rheumatoid arthritis and rosacea. Receiver operator characteristic (ROC) analysis, enzyme-linked immunosorbent assay (ELISA), and qRT-PCR were used to confirm biomarkers and functions.

Results

Two hundred seventy-seven co-expressed DEGs were identified from these datasets. Functional enrichment analysis indicated that these DEGs were associated with immune processes and chemokine-mediated signaling pathways. Fourteen and 17 hub genes overlapped between cytoHubba and WGCNA were identified in RA and rosacea, respectively. Macrophages and dendritic cells were RA and rosacea's most abundant immune cells, respectively. The ROC curves demonstrated potential diagnostic values of CXCL10 and CCL27, showing higher levels in the serum of patients with RA or rosacea, and suggesting possible regulation in the densities and functions of macrophages and dendritic cells from RA and rosacea, which were validated by FCM and qRT-PCR.

Conclusion

Importantly, our findings may contribute to the scientific basis for biomarkers and therapeutic targets for patients with RA and rosacea in the future.

Elevated plasma levels of calcitonin gene-related peptide in individuals with rosacea: A cross-sectional case-control study

BACKGROUND

Understanding the role of calcitonin gene-related peptide (CGRP) in the pathogenesis of rosacea might provide new therapeutic avenues for individuals with this disease.

OBJECTIVE

To compare plasma levels of CGRP between individuals with rosacea and healthy controls.

METHODS

In this cross-sectional case-control study conducted in Copenhagen, Denmark, we collected blood samples from the antecubital vein from adults with rosacea and from healthy controls.

RESULTS

We enrolled 123 individuals with rosacea and 68 healthy controls. After adjusting for age and sex, plasma levels of CGRP were significantly higher in individuals with rosacea (mean, 95% confidence interval: 140.21 pmol/L, 128.50-151.92 pmol/L), compared with controls (110.77 pmol/L, 99.91-120.14 pmol/L, p = 0.002). Plasma levels of CGRP were not affected by age, sex, BMI, concomitant migraine, rosacea sub- or phenotype, concomitant disease or current treatment.

LIMITATIONS

Participants were not age-, sex- and BMI-matched.

CONCLUSIONS AND RELEVANCE

Elevated plasma levels of CGRP in individuals with rosacea suggest a role of CGRP in the pathogenesis of rosacea. Targeting CGRP signalling might hold therapeutic promise in people affected by this disease.

CLINICALTRIALS

GOV LISTING

NCT03872050.

A Randomized, Controlled Clinical Trial of a Dermocosmetic Containing Vichy Volcanic Mineralizing Water and Probiotic Fractions in Subjects with Rosacea Associated with Erythema and Sensitive Skin and Wearing Protective Masks

Purpose

Rosacea is a common facial dermatosis, with flares induced by exposome factors. M89PF containing Vichy mineralizing water, probiotic fractions, hyaluronic acid, niacinamide and tocopherol repairs the skin barrier and reinforces skin defences against exposome factors. This study assessed the benefit of M89PF in subjects with rosacea associated with erythema and sensitive skin during the Covid-19 pandemic using protective face masks.

Methods

M89PF was compared to usual skin care in a randomized, split-face study, for 30 days in subjects with rosacea associated with erythema and sensitive skin. Clinical evaluations included erythema, desquamation, skin tightness, dryness, burning sensation, itching, stinging, stinging test, and local tolerability. Instrument evaluations included erythema, skin hydration and TEWL. Subject satisfaction was also assessed.

Results

Erythema significantly improved with M89PF at both time points (p<0.01 at D15, and p<0.001 at D30). Skin sensitivity assessed by the skin stinging test improved significantly (p<0.01) with M89PF at D30, compared to baseline and usual skin care. Skin erythema, tightness, dryness, hydration and TEWL significantly improved (p≤0.05) with M89PF at D15 and D30, versus baseline and the untreated side. Subjects were highly satisfied with M89PF at D15 and D30. Tolerance was very good in all subjects.

Conclusion

In subjects with rosacea, M89PF significantly reduces erythema, skin tightness, dryness and TEWL, and improves skin hydration and skin sensitivity, even when using protective masks. M89PF is well tolerated and received high satisfaction ratings.

ClinicalTrialsgov No

NCT05562661.

MMP-9 Levels in the Gingival Crevicular Fluid of Chilean Rosacea Patients

Rosacea is a chronic inflammatory skin disease whose prevalence rates remain unknown in Chile. Laboratory benchmark testing for this disease is not useful, therefore, we aimed to evaluate the gingival crevicular fluid (GCF) levels of extracellular metalloproteinases (MMP)-2 and MMP-9 as novel rosacea biomarkers. We designed a cross-sectional study with a control group. Participants were systemically healthy adults (n = 20) and persons with rosacea (n = 18). We performed a periodontal evaluation and collected gingival crevicular fluid to measure MMP-2 and MMP-9 levels. Analysis showed mean and standard deviation of MMP-9 concentrations in the GCF for patients with rosacea was 764.52 ± 569.83 pg/mL; for healthy patients, it was 260.69 ± 170.43 pg/mL (p < 0.05). The diagnosis of rosacea was responsible for the levels of MMP-9 in the GCF (p < 0.05), as opposed to periodontitis, smoking, and age (p > 0.05). The Area under ROC for MMP-9 was 0.869 (95%, C.I: 0.719−0.956), with a sensitivity of 72.22% and specificity of 81.58% for the diagnosis of rosacea. We conclude that the quantification of MMP-9 in the GCF could be used as a biomarker of rosacea. Also, rosacea was responsible for increasing the levels of MMP-9 in the GCF independent of periodontal status.

Lymphocyte subsets and Langerhans cells in the skin of kidney transplant recipients under three different immunosuppressive regimens

BACKGROUND

Renal transplant recipients (RTRs) are at increased risk of developing skin cancer; however, the role of immunosuppression is not yet fully understood. In this study, we evaluated the immunohistochemical changes in the skin of RTRs under three different immunosuppression regimens: mTOR inhibitors (mTORi), sirolimus or everolimus, mycophenolic acid (MPA) precursors such as mycophenolate sodium or mofetil, or azathioprine (AZA).

METHODS

We evaluated biopsies of sun-exposed and sun-protected skin for immunohistochemical quantification of B lymphocytes (CD20+), T lymphocytes (CD3+, CD4+, and CD8+), and Langerhans cells (LCs) (CD1a+) in 30 RTRs and 10 healthy controls. The RTRs were divided into three groups: mTORi (n = 10), MPA (n = 10), and AZA (n = 10).

RESULTS

No differences were observed in the number of B lymphocytes. However, a significant decrease in the number of T lymphocytes and LCs was observed in both sun-protected and sun-exposed skin in the AZA and MPA groups, although to a lesser degree in the latter group. The skin of the mTORi group did not differ from that of the control group in terms of the number of B and T lymphocytes and LCs.

CONCLUSIONS

Patients treated with mTORi exhibit preserved cellular elements related to cutaneous immune surveillance. The use of AZA induced a greater degree of skin immunosuppression than in the control group, as demonstrated by the decrease in T lymphocytes and LCs.

Recent advances on endogenous gasotransmitters in inflammatory dermatological disorders

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Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H₂S), and potential candidates sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃) and carbon dioxide (CO₂), are generated within the human body.

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Endogenous and potential gasotransmitters regulate inflammation, vasodilation, and oxidation in inflammatory dermatological disorders.

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Endogenous and potential gasotransmitters play potential roles in psoriasis, atopic dermatitis, acne, and chronic skin ulcers.

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Further research should explore the function of these gases and gas donors and inhibitors in inflammatory dermatological disorders.

Background

Endogenous gasotransmitters are small gaseous mediators that can be generated endogenously by mammalian organisms. The dysregulation of the gasotransmitter system is associated with numerous disorders ranging from inflammatory diseases to cancers. However, the relevance of these endogenous gasotransmitters, prodrug donors and inhibitors in inflammatory dermatological disorders has not yet been thoroughly reviewed and discussed.

Aim of review

This review discusses the recent progress and will provide perspectives on endogenous gasotransmitters in the context of inflammatory dermatological disorders.

Key scientific concepts of review

Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S) are signaling molecules that regulate several physiological and pathological processes. In addition, sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃), and carbon dioxide (CO₂) can also be generated endogenously and may take part in physiological and pathological processes. These signaling molecules regulate inflammation, vasodilation, and oxidative stress, offering therapeutic potential and attracting interest in the field of inflammatory dermatological disorders including psoriasis, atopic dermatitis, acne, rosacea, and chronic skin ulcers. The development of effective gas donors and inhibitors is a promising alternative to treat inflammatory dermatological disorders with controllable and precise delivery in the future.

A Novel Mechanism of Carvedilol Efficacy for Rosacea Treatment: Toll-Like Receptor 2 Inhibition in Macrophages

Background

Rosacea, a chronic inflammatory skin disorder etiologically associated with immune cells and the antibacterial peptide cathelicidin LL-37, can be effectively treated by oral carvedilol administration.

Objective

To investigate the molecular mechanisms underlying carvedilol efficacy in rosacea treatment.

Methods

Skin samples of patients with rosacea were subjected to histopathological (hematoxylin and eosin) and immunohistochemical (CD68, Toll-like receptor 2 (TLR2), kallikrein 5, cathelicidin, TNF-α, and IL-1β) evaluation. An in vivo murine rosacea-like inflammation model was established by LL-37 intradermal injection with or without carvedilol gavage-based pretreatment. Erythema proportion (Image J) and skin redness (L*a*b colorimetry) were quantified. Murine skin samples underwent pathological examination for inflammatory status and immunofluorescence staining. Murine skin and lipopolysaccharide-stimulated RAW 264.7 cells with or without carvedilol pretreatment were evaluated by quantitative reverse transcription-polymerase chain reaction and western blotting. Clinical facial images of patients were obtained using the VISIA skin analysis system before, 4, and 6 months following oral carvedilol administration.

Results

Rosacea skin lesions exhibited more pronounced inflammatory cell infiltration than peripheral areas, with profound macrophage infiltration and inflammatory cytokines (TLR2, kallikrein 5, cathelicidin, TNF-α, and IL-1β). In vivo, carvedilol alleviated inflammation in LL-37 mice, down-regulating TLR2, KLK5, and cathelicidin expression. In vitro, carvedilol decreased TLR2 expression in RAW 264.7 cells, further reducing KLK5 secretion and LL-37 expression and ultimately inhibiting rosacea-like inflammatory reactions. Clinical manifestations and facial redness obviously improved during 6-month follow-up with systemic carvedilol administration.

Conclusion

Carvedilol is effective against rosacea, with inhibition of macrophage TLR2 expression as a novel anti-inflammatory mechanism.

Anti-Inflammatory Activity of Calendula officinalis L. Flower Extract

The use of calendula for its lenitive properties’ dates to the XII century. This plant contains several bioactive compounds, including terpenoids, terpenes, carotenoids, flavonoids and polyunsaturated fatty acids. Calendula flower extract is used in soothing cosmetics, such as after-sun, sensitive skin and eye contour products. The anti-inflammatory properties of this ingredient were demonstrated in an animal model, but the mechanism of action is poorly understood. Therefore, our work explored the effect of a calendula flower extract on NO production, a pro-inflammatory radical produced by nitric oxide synthase (iNOS) and highly released by innate immune cells in inflammatory-related pathologies. NO production was evoked by the Toll-like receptor 4 agonist lipopolysaccharide (LPS) in macrophages, using concentrations that did not compromise cells viability. This ingredient exhibited a dose-dependent NO inhibition, reaching 50% at 147 μL/mL without cytotoxicity. Together with previous literature, these results provide experimental evidence on the anti-inflammatory properties of calendula flower extract, as well as its usefulness in cosmetics with soothing properties and adjunctive skin care in the treatment of the diseases associated with dysregulation of the NO signaling cascade.

Identification of novel candidate genes in rosacea by bioinformatic methods

BACKGROUND

Rosacea is a chronic inflammatory skin disease whose psychological consequences severely affect patient's quality of life.

OBJECTIVE

To identify candidate genes of rosacea for potential development of new target therapies.

METHODS

Gene Expression Omnibus datasets were retrieved to obtain differentially expressed genes (DEGs) between rosacea patients and healthy controls. Gene ontology (GO) analyses were used to identify functions of candidate genes. Related signaling pathways of DEGs were analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set enrichment analysis. Protein-protein interaction (PPI) networks were applied using search tools for the retrieval of interacting genes/proteins and modulations involving PPI networks were evaluated with use of the MCODE app.

RESULTS

Samples from 19 rosacea patients and 10 healthy controls of dataset GSE65914 were enrolled. A total of 215 DEGs, 115 GO terms and 6 KEGG pathways were identified. A total of 182 nodes and 456 edges were enriched in PPI networks. Maximal clusters showed 15 central nodes and 96 edges. The toll-like receptor (TLR) signaling pathway was the most significant pathway detected and 5 DEGs were identified as candidate genes which included TLR2, C-C motif chemokine (CCL) 5, C-X-C motif chemokine ligand (CXCL) 9, CXCL10 and CXCL11. The results were verified in rosacea patients with use of real-time polymerase chain reaction and immunohistochemistry. Cell-type enrichment analysis revealed 8 lymphocytes that were enriched in rosacea patients.

CONCLUSIONS

The results suggest that both innate and adaptive immune responses were involved in the etiology of rosacea. Five DEGs in the TLR signaling pathway may serve as potential therapeutic target genes.

Demodex positive discoid lupus erythematosus: Is it a separate entity or an overlap syndrome?

Discoid lupus erythematosus (DLE) is a chronic inflammatory erythematous skin disease that can be triggered by several factors. Rosacea is another skin disease that causes facial redness and tenderness. Demodex mites have been reported in rosacea and DLE patients commonly in the literature. These two diseases can be seen concomitant, mimic each other clinically and share common possible etiologic factors. To assess demodex mite infestation in both clinical and histopathological findings in DLE patients. We retrospectively evaluated the files of 42 patients with DLE who had been diagnosed DLE based on clinical and histopathological findings between August 2018 and August 2019. Demodex positivity was detected 50% of patients (n = 21). Neutrophile percentages in the dermal and perivascular area were higher in the demodex positive patients (4.43%) than in the Demodex negative patients (2.19%). The intensity of demodex mites correlated positively with dermal neutrophile percentages. ANA was negative in 29 patients (69%) and positive in 13 patients (31%). Anti-dsDNA was negative in serology and follicular plugging was positive in histopathology in all 42 patients (100%). This was a retrospective study. DLE and rosacea share common features in etiopathogenesis and clinical presentation. Inflammation and exacerbations caused by the demodex mites may increase the clinical severity of DLE. Although the position of demodex mites in DLE etiopathogenesis is not known exactly, the presence of high demodex in DLE patients has been determined. Standard skin surface biopsy can be a routine procedure for the evaluation of DLE patients in daily clinical practice.

Is rosacea a systemic disease?

Rosacea is a chronic inflammatory facial disease occurring world-wide. The incidence of rosacea is increasing with age, with the clinical course being characterized by relapses. The pathogenesis of rosacea is not completely understood, but neurovascular and immunologic mechanisms are involved. Rosacea has a number of known extrinsic triggers that should be avoided, such as sun exposure, heat and cold, alcoholic beverages, and spicy food. Of greater importance is the observation that rosacea may develop as a manifestation of systemic diseases with a significant morbidity and even mortality. Obesity, Helicobacter pylori infection, smoking, and inflammatory bowel disease bear a significant risk for the development of rosacea. Metabolic, psychiatric, and neurologic disorders and certain types of cancer show a significant association with rosacea. The possible link to cardiovascular events is debatable. There are extrafacial and extracutaneous manifestations of rosacea, such as the red scalp syndrome, ocular rosacea, and migraine. Rosacea should be considered a systemic disease.

Role of serum 25-hydroxyvitamin D levels and vitamin D receptor gene polymorphisms in patients with rosacea: a case-control study

BACKGROUND

Vitamin D has significant effects on the immune system and thereby on the pathogenesis of rosacea. However, there is a lack of information on the vitamin D status and vitamin D receptors (VDRs) of patients with rosacea.

AIM

To evaluate the role of vitamin D in rosacea susceptibility.

METHODS

A case-control study was conducted, enrolling patients with rosacea and healthy controls (HCs). Five VDR gene single nucleotide polymorphisms (SNPs) (Cdx2, FokI, ApaI, BsmI and TaqI) and serum 25-hydroxyvitamin D₃ [25(OH)D₃ ] levels were compared between patients and HCs.

RESULTS

The study enrolled 60 patients (M/F: 14/46) and 60 age- and sex-matched HCs (M/F: 14/46). Age (mean ± SD) was 48 ± 11 years for both groups. The serum 25(OH)D₃ levels (median ± interquartile range) were higher in patients with rosacea (12.9 ± 6.8 ng/mL) than in HCs (10.5 ± 3.7 ng/mL) (P < 0.001). Subjects with high serum 25(OH)D₃ levels had a 1.36-fold increased risk of rosacea (95% CI 1.17-1.58). Heterozygous and mutant ApaI polymorphisms increased rosacea risk by 5.26-fold (95% CI 1.51-18.35) and 3.69-fold (95% CI 1.19-11.48), respectively, whereas mutant TaqI polymorphisms decreased the risk by 4.69 times (95% CI 1.37-16.67). Heterozygosity for Cdx2 alleles increased rosacea risk, whereas wildtype ApaI and mutant TaqI alleles decreased it.

CONCLUSIONS

The present study suggests that an increase in vitamin D levels may contribute to the development of rosacea. ApaI and TaqI polymorphisms, and heterozygous Cdx2, wildtype ApaI and mutant TaqI alleles were significantly associated with rosacea. These results indicate a possible role of vitamin D and VDR pathways in the pathogenesis of rosacea, although causality could not be assessed.