Immune signaling in rosacea

Investigation of Thiol/Disulfide Homeostasis and Clinical Parameters in Rosacea Patients According to Skin Subtypes

Background/Objective: The aim of this study was to compare thiol/disulfide homeostasis and clinical parameters of rosacea patients across skin subtypes of the disease and healthy controls. Methods: This prospective study included 90 rosacea patients with different skin subtypes (phymatous, erythematotelangiectatic and papulopustular) and ocular involvement and 30 healthy controls. Plasma native thiol (NT), total thiol (TT) and disulfide levels of the patients and controls were measured using an automated spectrophotometric method, and disulfide/native thiol ratio (DNTR), disulfide/total thiol ratio (DTTR) and native thiol/total thiol ratio (NTTR) were calculated. Tear breakup time (TBUT), meiboscore, Schirmer, ocular surface disease index (OSDI) and rosacea-specific quality of life scale (RosaQoL) were measured clinically. Results: Disulfide, DNTR and DTTR were significantly higher, and NT, TT and NTTR were significantly lower in the rosacea patients compared to the controls (p < 0.001). TBUT and Schirmer were significantly lower, and meiboscore and OSDI were significantly higher in the patients compared to the controls (p < 0.01). According to the skin subtypes, disulfide, DNTR and DTTR were significantly higher, and NTTR was significantly lower in the erythematotelangiectatic subtype compared to the other subtypes (p < 0.002). TBUT was significantly lower, and RosaQol was significantly higher in the erythematotelangiectatic subtype (p < 0.0083). Strong correlations were found between DNTR and TBUT and between DNTR and Meiboscore in all subtypes (p < 0.005), while there were strong correlations between DNTR and OSDI and between DNTR and RosaQol only in the erythematotelangiectatic and papulopustular subtypes (p < 0.05). Conclusions: The thiol/disulfide homeostasis shifted towards disulfides, an indicator of oxidative stress in rosacea, and this was more pronounced in the erythematotelangiectatic subtype. The impairment in TBUT and RosaQol was also more prominent in the erythematotelangiectatic subtype and strongly associated with the DNTR.

Safety and tolerability of topical trametinib in rosacea: Results from a phase I clinical trial

Purpose

Overactivation of the mitogen activated kinase pathway has been associated with rosacea. We hypothesised that inhibitors of this pathway can be repurposed to alleviate rosacea symptoms.

Methods

In order to test this hypothesis, we designed a double-blind, randomised, placebo-controlled phase I clinical trial to assess the safety and tolerability of a first-in-kind topical formulation of a MEK kinase inhibitor, trametinib. Subjects applied daily trametinib-containing cream (0.05 mg in 0.5 mL) to one cheek and cream without inhibitor to the other for consecutive 21 days. Skin irritation scores and blood samples were obtained during visits on days 8, 15 and 22.

Results

On analysis of high-performance liquid chromatography, no systemic trametinib absorption was detected during this treatment period. Subjects demonstrated a slight but significant improvement in both cheeks, regardless of drug contents. No adverse effects were reported during this time.

Conclusions

Topical trametinib was well tolerated at a dose of 0.05 mg per day without meaningful systemic absorption or local adverse events. A dose escalation trial is warranted to determine optimal dosing to treat rosacea while avoiding the adverse effects of systemic treatment.

Rosacea, microbiome and probiotics: the gut-skin axis

Rosacea is an inflammatory skin disease involving diverse symptoms with a variable clinical progress which can severely impact the patient's quality of life as well as their mental health. The pathophysiological model of rosacea involves an unbalanced immune system predisposed to excessive inflammation, in addition to vascular and nervous alterations, being certain cutaneous microorganisms' triggers of the symptoms onset. The gut-skin axis explains a bidirectional interaction between skin and gut microbiota in some inflammatory skin diseases such as atopic dermatitis, psoriasis, or rosacea. The introduction and consolidation of the next-generation sequencing in recent years has provided unprecedented information about the microbiome. However, the characterization of the gut and skin microbiota and the impact of the gut-skin axis in patients with rosacea has been little explored, in contrast to other inflammatory skin diseases such as atopic dermatitis or psoriasis. Furthermore, the clinical evolution of patients with rosacea is not always adequate and it is common for them to present a sustained symptomatology with frequent flare-ups. In this context, probiotic supplementation could improve the clinical evolution of these patients as happens in other pathologies. Through this review we aim to establish and compile the basics and directions of current knowledge to understand the mechanisms by which the microbiome influences the pathogenesis of rosacea, and how modulation of the skin and gut microbiota could benefit these patients.

The Mind Body Connection in Dermatologic Conditions: A Literature Review

Psychodermatology pertains to the relationship between the skin and brain. This review aims to summarize the evidence of the mind body connection in four psychophysiological conditions: rosacea, atopic dermatitis (AD), acne vulgaris (AV), and psoriasis. A literature search was conducted using several English language databases. All four conditions share similar psychiatric co-morbidities, including but not limited to anxiety, depression, and suicidality. In rosacea, the upregulation of transient receptor potential vanilloid type 1, Toll like receptor 2, and Th17 cells releases downstream products that are simultaneously implicated in mood disorders. Stress exacerbates AV through the hypothalamic-pituitary-adrenal (HPA) system, which alters functioning of sebocytes and Cutibacterium acnes. In AD and psoriasis, the HPA axis influences Th1, Th2, Th22, and Th1, Th17 immune mediated responses, respectively. This leads to the secretion of pro-inflammatory cytokines which are also involved in the pathogenesis of anxiety and depression. Neurotransmitters implicated in mental illness, such as gamma-aminobutyric acid and serotonin, may also play a role in the development of AD and psoriasis. The management of cutaneous disease may mitigate psychological distress, and future research may show the corollary to also be true.

Treatment strategies, including antibiotics, to target the immune component of rosacea

INTRODUCTION

Recent advances in the understanding of the pathophysiology of rosacea have led to increased focus on the disease's immunologic etiology and to the development of immunologically based treatments. With many patients suffering from incomplete control, addressing the immune components of the disease process may provide a more effective treatment option for rosacea patients that may improve quality of life.

AREAS COVERED

This review will provide a brief overview of the pathophysiology of rosacea, as well as specific immunologic contributions to the disease state. Current standard-of-care treatments will be described, including anti-parasitic, anti-inflammatory agents, and antibiotics. Emphasis will be placed on treatments that target the immune components of the disease process.

EXPERT OPINION

Rosacea remains a difficult dermatologic disease to treat, partially due to an incomplete understanding of the disease pathophysiology. The immune pathophysiology of rosacea, particularly the key role of inflammation, has been clarified over the past decade. Identification of specific molecules, including cytokines and nuclear transcription factors, may allow for the development of targeted rosacea-specific biologic and topical treatments. However, medication nonadherence is a limiting factor to achieving symptomatic control among rosacea patients. Focusing on the development of oral or injectable forms of therapy may circumvent poor adherence.

SH2 domain-containing protein tyrosine phosphatase-2 is enriched in eyelid specimens of rosacea

Background

Rosacea is a cutaneous disease that may secondarily affect the ocular surface. Due to the vision threatening, cosmetic, psychological, and work productivity impact, the identification of cellular targets that govern rosacea would enhance our understanding of the biology of the disease and delineate targets for therapeutic manipulation.

Objective

To characterize the involvement of SH2 domain-containing protein tyrosine phosphatase-2 (SHP2) in the pathogenesis of rosacea.

Methods

Specimens from elective ectropion surgery (n = 20) were processed from patients with rosacea (n = 10) and control patients (n = 10). Immunohistochemistry (IHC) and quantitative western blotting (WB) were performed to identify and quantify the presence of SHP2 and 4G10 (a phosphotyrosine antibody) in rosacea compared to normal tissue. IHC samples were graded according to an intensity scale (0-4). Mann-Whitney statistical analyses were performed via a dedicated computerized software package.

Results

On WB, SHP2 was expressed in higher concentrations in rosacea specimens (p < 0.05). On IHC, SHP2 was enriched in the epidermis in rosacea (p < 0.05), although 4G10 levels were not statistically significantly different between the two groups (p > 0.05).

Conclusions

SHP2 is enriched in cutaneous specimens of rosacea, suggesting a critical role for this protein in the disease and indicating a modifiable therapeutic moiety.