Claudin reduction may relate to an impaired skin barrier in rosacea

Keratin 6A promotes skin inflammation through JAK1-STAT3 activation in keratinocytes

BACKGROUND

Skin barrier dysfunction and immune activation are hallmarks of inflammatory skin diseases such as rosacea and psoriasis, suggesting shared pathogenic mechanisms. While barrier disruption may trigger or exacerbate skin inflammation, the precise underlying mechanisms remain unclear. Notably, epidermal barrier compromise leads to a marked increase in barrier alarmin expression. Among these, keratin 6A (KRT6A) plays a role in maintaining skin barrier integrity.

METHODS

We treated mouse skin and human keratinocytes, with and without KRT6A expression, with LL37/TNF-α and assessed the severity of inflammation. The specific mechanism by which KRT6A promotes skin inflammation was investigated using mass spectrometry and immunoprecipitation assays.

RESULTS

KRT6A expression was elevated in lesional skin from patients and mouse models of rosacea and psoriasis. In mice with LL37-induced rosacea-like and imiquimod (IMQ)-induced psoriasis-like skin inflammation, KRT6A knockdown alleviated inflammation, whereas KRT6A overexpression exacerbated inflammatory responses. Mechanistically, KRT6A activated signal transducer and activator of transcription 3 (STAT3) and enhanced proinflammatory cytokine expression in keratinocytes by reducing Janus kinase 1 (JAK1) ubiquitination. This occurred through inhibition of ring finger protein 41 (RNF41)-mediated JAK1 binding.

CONCLUSIONS

Our findings indicate that KRT6A expression increases following epidermal barrier disruption and contributes to exacerbated skin inflammation in disease conditions. Targeting KRT6A may represent a novel therapeutic approach for inflammatory skin diseases associated with epidermal dysfunction.

Naturally-occurring carnosic acid as a promising therapeutic agent for skin inflammation via targeting STAT1

BACKGROUND

Psoriasis and rosacea are prevalent chronic inflammatory skin disorders driven by aberrant interactions between skin-resident keratinocytes and immune cells. Natural products represent a largely untapped source of novel therapeutic agents for various diseases. This study aimed to identify an effective natural product for treating psoriasis and rosacea and to elucidate its underlying mechanism of action.

METHODS

Bioinformatics and network pharmacology approaches were employed to identify potential drug candidates for these conditions. Psoriasis-like and rosacea-like inflammation models were established in mice to assess the in vivo therapeutic effects of carnosic acid. In vitro experiments were performed to investigate the molecular mechanisms underlying carnosic acid's anti-inflammatory activity.

RESULTS

Through bioinformatics and network pharmacology, carnosic acid, a plant-derived phenolic diterpene, was identified as a promising candidate for these skin disorders. Functional assays demonstrated that carnosic acid effectively inhibited skin inflammation in both imiquimod-induced psoriasis and LL37-induced rosacea mouse models. Mechanistically, carnosic acid bound directly to STAT1, inhibiting its phosphorylation and subsequent transcriptional activation, which led to a reduction in the production of STAT1-mediated inflammatory factors in keratinocytes. Topical application of carnosic acid significantly alleviated clinical symptoms in both psoriasis and rosacea models.

CONCLUSION

These findings suggest that carnosic acid holds potential as a therapeutic agent for STAT1-mediated skin inflammation.

Claudin-1 expression in acne and its correlation with disease severity: clinical and in silico validation

The pilosebaceous unit is the site of a common chronic inflammatory skin disorder called acne. Tight junctions (TJ) are present in sebocytes and are primarily composed of claudin-1. When claudin-1 is knocked down, the TJ barrier leaks, and holocrine secretion is compromised. This leads to the accumulation of partially degenerated sebocytes in the pilosebaceous ducts and the creation of microcomedos, which can cause acne lesions. The study's aim was to measure the claudin-1 gene and protein expression in acne patients' blood samples and establish a correlation with the severity of the condition and their levels. 48 acne patients were involved and 48 matched control for age and sex. First samples were obtained from both groups and RNA was extracted from the whole blood sample followed by qPCR to measure the relative expression of the claudin-1 gene. Enzyme-linked immunosorbent assay (ELISA) was used to measure claudin-1 protein level. There were statistically significant lower relative expression of claudin-1 gene (p = 0.001) and its protein level (p = 0.001) in acne patients compared to controls (0.34 ± 0.32 vs 1.0 ± 0.0, 0.64 ± 0.62 vs 3.85 ± 2.14, respectively). There was a statistically significant inverse correlation between claudin-1 protein expression and acne severity (R = -0.374, p = 0.009). Computational and bioinformatics tools were used for enrichment analysis to better understand claudin-1 role in the context of the disease and provide possible therapeutic approaches. Claudin-1 dysregulation in acne patients, suggest that it have an impact on the severity and course of acne through affecting the epidermal barrier and facilitating inflammation.

Analysis of the clinical application and treatment effects of Ultra-Pulse Shockwave technology in facial rejuvenation

Facial aging involves structural changes in the skin, subcutaneous tissues, and skeletal framework. Ultra-Pulse Shockwave (UPSW) therapy, a non-thermal, high-frequency shockwave technology, has emerged as a promising, non-invasive option for facial rejuvenation. This study evaluates the efficacy and safety of UPSW in improving skin texture, reducing subcutaneous fat, and enhancing skin tightness. A clinical study was conducted with 20 participants (ages 25-60) undergoing three UPSW treatment sessions over six weeks. Objective assessments included standardized photography, VISIA skin analysis, and Paragon XHD ultrasound imaging to document and analyze treatment effects. Subjective evaluations were performed using the Global Aesthetic Improvement Scale (GAIS) to measure aesthetic outcomes and the Visual Analog Scale (VAS) to assess pain levels experienced during and after treatment. UPSW therapy significantly improved skin texture (p = 0.010) and showed promising effects on subcutaneous fat reduction and skin tightness. Wrinkles (p = 0.069) and pores (p = 0.232) did not reach statistical significance. Adverse effects, including transient erythema and mild edema, were minor and self-limiting. The mean VAS pain score was 2.8, indicating high tolerability. Ultra-Pulse Shockwave (UPSW) therapy demonstrated both safety and efficacy as a non-invasive treatment for facial rejuvenation. The findings indicate that UPSW significantly enhances skin texture while exerting positive effects on skin tightening and subcutaneous fat reduction. Despite the limitations of a small sample size, limited treatment sessions, and a short follow-up period, this study highlights UPSW's potential as a valuable addition to aesthetic medicine. Further research involving larger cohorts, more frequent treatments, and extended follow-up durations is recommended to optimize treatment protocols and comprehensively evaluate its long-term benefits.

The epithelial barrier theory and its associated diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Single-cell transcriptomics reveals aberrant skin-resident cell populations and identifies fibroblasts as a determinant in rosacea

Rosacea is a chronic inflammatory skin disorder, whose underlying cellular and molecular mechanisms remain obscure. Here, we generate a single-cell atlas of facial skin from female rosacea patients and healthy individuals. Among keratinocytes, a subpopulation characterized by IFNγ-mediated barrier function damage is found to be unique to rosacea lesions. Blocking IFNγ signaling alleviates rosacea-like phenotypes and skin barrier damage in mice. The papulopustular rosacea is featured by expansion of pro-inflammatory fibroblasts, Schwann, endothelial and macrophage/dendritic cells. The frequencies of type 1/17 and skin-resident memory T cells are increased, and vascular mural cells are characterized by activation of inflammatory pathways and impaired muscle contraction function in rosacea. Most importantly, fibroblasts are identified as the leading cell type producing pro-inflammatory and vasodilative signals in rosacea. Depletion of fibroblasts or knockdown of PTGDS, a gene specifically upregulated in fibroblasts, blocks rosacea development in mice. Our study provides a comprehensive understanding of the aberrant alterations of skin-resident cell populations and identifies fibroblasts as a key determinant in rosacea development.

Probiotics suppress LL37 generated rosacea-like skin inflammation by modulating the TLR2/MyD88/NF-κB signaling pathway

Rosacea, a chronic inflammatory dermatological condition, is characterized by facial erythema and pustules. Recent investigations have delved into the interplay between the gut microbiota and rosacea pathogenesis, unveiling promising avenues for therapeutic intervention. In this study, we screened and isolated strains Ligilactobacillus salivarius 23-006 and Lacticaseibacillus paracasei 23-008 from the feces of healthy volunteers and evaluated the intervention effects of probiotics on rosacea by constructing an LL37 induced rosacea-like mouse model. Our results showed that both L. salivarius 23-006 and L. paracasei 23-008 were probiotic strains with favourable properties. In specific, we observed that both L. salivarius 23-006 and L. paracasei 23-008 alleviated skin lesions, reduced skin inflammatory infiltrates, and decreased the expression of inflammatory factors in mice, with the combination of L. salivarius 23-006 and L. paracasei 23-008 having the most significant effect. Moreover, the combination of strains reduced the expression of cathelicidin LL37 and rosacea-associated factors by inhibiting the TLR2/MyD88/NF-κB pathway. The 16S rRNA analysis showed that the combination enhanced the intestinal barrier, restored intestinal microbiota homeostasis, and up-regulated the abundance of Lactobacillus while down-regulating the abundance of Coprococcus and Oscillospira. We also explored the effects of postbiotics of L. salivarius 23-006 and L. paracasei 23-008 on rosacea. While postbiotics could also ameliorate the rosacea-like phenotype in mice via the TLR2/MyD88/NF-κB pathway, the effects were not as pronounced as those observed with probiotic treatment. However, the postbiotics still enhanced the intestinal barrier, up-regulated the Lactobacillus abundance, and modulated the intestinal microbiota. In conclusion, our study revealed that L. salivarius 23-006 and L. paracasei 23-008 improved rosacea by regulating the TLR2/MyD88/NF-κB pathway and intestinal microbiota, providing a theoretical basis for the treatment of rosacea.

SERPINB3/B4 Is Increased in Psoriasis and Rosacea Lesions and Has Proinflammatory Effects in Mouse Models of these Diseases

Psoriasis and rosacea are both chronic inflammatory skin disorders resulted from aberrant keratinocyte-immune cell crosstalk, but the common molecular foundations for these 2 conditions are poorly understood. In this study, we reveal that both patients with psoriasis and those with rosacea as well as their mouse models have significantly elevated expressions of SERPINB3/B4 (members of serine protease inhibitor) in the lesional skin. Skin inflammation in mice that resembles both psoriasis and rosacea is prevented by SERPINB3/B4 deficiency. Mechanistically, we demonstrate that SERPINB3/B4 positively induces NF-κB signaling activation, thereby stimulating disease-characteristic inflammatory chemokines and cytokines production in keratinocytes and promoting the chemotaxis of CD4+ T cells. Our results suggest that in keratinocytes, SERPINB3/B4 may be involved in the pathogenesis of both psoriasis and rosacea by stimulating NF-κB signaling, and they indicate a possible treatment overlap between these 2 diseases.

Zinc penetration through the skin barrier in atopic dermatitis and rosacea using reflectance confocal microscopy

Atopic dermatitis (AD) is a chronic, recurrent eczematous disorder with a complex pathophysiology caused by skin barrier abnormalities. Rosacea is a common chronic immune-mediated inflammatory disorder that results in diminished skin barrier function. Reflectance confocal microscopy (RCM) is a non-invasive method for visualizing the dynamic status of epidermal and upper dermal structures. In this study, we compared skin barrier permeability among normal, AD and rosacea groups. To assess skin barrier permeability, zinc was applied to lesional skin and the RCM reflectance intensity of zinc penetration was measured. Reflectance confocal microscopy revealed that the intensity in patients with rosacea and AD was higher than that in the normal group at depths of 8-24 μm in both the face and forearm, which were considered as the stratum corneum (SC) and tight junction (TJ) level (p < 0.0001). When comparing AD and rosacea, the intensity of rosacea was higher than that of AD at a depth of 8 μm in the face (p < 0.0001). The intensity of AD was higher than that of rosacea at a depth of 24 μm (p = 0.009). This suggests that skin barrier permeability is increased in the upper epidermis of patients with AD and rosacea. On the face, patients with rosacea had more SC weakness than did those with AD, whereas patients with AD had more TJ weakness than those with rosacea.

Rosacea and seborrheic dermatitis differentially respond to lactic acid sting and capsaicin tests in Chinese women

BACKGROUND

Although rosacea and seborrheic dermatitis share some symptoms of sensitive skin, whether they respond differently to lactic acid sting and capsaicin tests, common tests for diagnosis of sensitive skin, is unknown.

OBJECTIVES

To reveal the cutaneous responses to lactic acid sting (LAST) and capsaicin test (CAT) in females with either rosacea vs. seborrheic dermatitis.

METHODS

A total of 60 patients with rosacea, 20 patients with seborrheic dermatitis and 40 normal controls were enrolled in the study. Their skin sensitivity to stimuli were evaluated following topical application of either 10% lactic acid solution or 0.001% capsaicin solution. Transepidermal water loss (TEWL) rates and erythema indexes were also measured on the face.

RESULTS

In comparison to normal controls, the positive rate to either LAST or CAT was significantly higher in subjects with rosacea (p < 0.001), but not in that with seborrheic dermatitis. Similarly, individuals with rosacea displayed a higher positive rate to both LAST and CAT than those with seborrheic dermatitis and normal controls (p < 0.001). In parallel, the LAST scores and CAT scores in individuals with rosacea were significantly higher than in that with either seborrheic dermatitis or normal controls (p < 0.001). The baseline TEWL rates and erythema indexes were higher in individual with rosacea than in normal controls (p < 0.001). But the baseline TEWL rates and erythema indexes did not differ significantly between subjects with rosacea and that with seborrheic dermatitis. Moreover, LAST scores and CAT scores correlated positively with TEWL (p < 0.0001). TEWL rates were higher in CAT positive than in CAT negative subjects (p < 0.0001). Finally, erythema index correlated positively with CAT scores (p < 0.0001), but not with LAST scores (p = 0.0842).

CONCLUSIONS

Skin responses to LAST and CAT differ between individuals with rosacea and those with seborrheic dermatitis, possibly due to the differences in epidermal permeability barrier and the neurovascular hyperreactivity. The higher LAST and CAT scores, as well as positive rates of both LAST and CAT can be attributable to inferior permeability barrier and the neurovascular hyperreactivity in subjects with rosacea.

Are the Cutaneous Microbiota a Guardian of the Skin's Physical Barrier? The Intricate Relationship between Skin Microbes and Barrier Integrity

The skin is a tightly regulated, balanced interface that maintains our integrity through a complex barrier comprising physical or mechanical, chemical, microbiological, and immunological components. The skin's microbiota affect various properties, one of which is the establishment and maintenance of the physical barrier. This is achieved by influencing multiple processes, including keratinocyte differentiation, stratum corneum formation, and regulation of intercellular contacts. In this review, we summarize the potential contribution of Cutibacterium acnes to these events and outline the contribution of bacterially induced barrier defects to the pathogenesis of acne vulgaris. With the combined effects of a Westernized lifestyle, microbial dysbiosis, epithelial barrier defects, and inflammation, the development of acne is very similar to that of several other multifactorial diseases of barrier organs (e.g., inflammatory bowel disease, celiac disease, asthma, atopic dermatitis, and chronic rhinosinusitis). Therefore, the management of acne requires a complex approach, which should be taken into account when designing novel treatments that address not only the inflammatory and microbial components but also the maintenance and strengthening of the cutaneous physical barrier.

TLR7 promotes skin inflammation via activating NFκB-mTORC1 axis in rosacea

Rosacea is a chronic inflammatory skin disease originated from damaged skin barrier and innate/adaptive immune dysregulation. Toll-like receptors (TLRs) sense injured skin and initiate downstream inflammatory and immune responses, whose role in rosacea is not fully understood. Here, via RNA-sequencing analysis, we found that the TLR signaling pathway is the top-ranked signaling pathway enriched in rosacea skin lesions, in which TLR7 is highlighted and positively correlated with the inflammation severity of disease. In LL37-induced rosacea-like mouse models, silencing TLR7 prevented the development of rosacea-like skin inflammation. Specifically, we demonstrated that overexpressing TLR7 in keratinocytes stimulates rapamycin-sensitive mTOR complex 1 (mTORC1) pathway via NFκB signaling. Ultimately, TLR7/NFκ B/mTORC1 axis promotes the production of cytokines and chemokines, leading to the migration of CD4+T cells, which are infiltrated in the lesional skin of rosacea. Our report reveals the crucial role of TLR7 in rosacea pathogenesis and indicatesa promising candidate for rosacea treatments.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

Whole genome sequencing identifies genetic variants associated with neurogenic inflammation in rosacea

Rosacea is a chronic inflammatory skin disorder with high incidence rate. Although genetic predisposition to rosacea is suggested by existing evidence, the genetic basis remains largely unknown. Here we present the integrated results of whole genome sequencing (WGS) in 3 large rosacea families and whole exome sequencing (WES) in 49 additional validation families. We identify single rare deleterious variants of LRRC4, SH3PXD2A and SLC26A8 in large families, respectively. The relevance of SH3PXD2A, SLC26A8 and LRR family genes in rosacea predisposition is underscored by presence of additional variants in independent families. Gene ontology analysis suggests that these genes encode proteins taking part in neural synaptic processes and cell adhesion. In vitro functional analysis shows that mutations in LRRC4, SH3PXD2A and SLC26A8 induce the production of vasoactive neuropeptides in human neural cells. In a mouse model recapitulating a recurrent Lrrc4 mutation from human patients, we find rosacea-like skin inflammation, underpinned by excessive vasoactive intestinal peptide (VIP) release by peripheral neurons. These findings strongly support familial inheritance and neurogenic inflammation in rosacea development and provide mechanistic insight into the etiopathogenesis of the condition.

RNA sequencing and metabolic analysis of imiquimod-induced psoriasis-like mice with chronic restrain stress

AIM

Psoriasis is one of the most common dermatological disorders, characterized by increased epidermal hyperplasia and immune cell infiltration. Psychological stress has been reported to contribute to the severity, aggravation, and relapse of psoriasis. However, the exact mechanism involved in psychological stress's impact on psoriasis is still unclear. We aim to investigate the role of psychological stress in psoriasis from a transcriptomic and metabolomic perspective.

MAIN METHOD

We developed a chronic restrain stress (CRS)-imiquimod (IMQ)-induced psoriasis-like mouse model and performed a comprehensive comparative transcriptomic and metabolic analysis with control mice, CRS-treated mice, and IMQ-treated mice to investigate how psychological stress affects psoriasis.

KEY FINDING

We found that CRS-IMQ-induced psoriasis-like mice showed significant exacerbation of psoriasis-like skin inflammation compared with mice treated with IMQ only. Mice of the CRS + IMQ group showed increased expression of keratinocyte proliferation and differentiation genes, differential regulation of cytokines, and promotion of linoleic acid metabolism. Correlation analysis of differentially expressed genes in the CRS-IMQ-induced psoriasis-like mice and human psoriasis datasets compared with respective controls revealed 96 overlapping genes of which 30 genes showed consistent induced or repressed expression in all human and mouse datasets.

SIGNIFICANCE

Our study provides new insights into the effects of psychological stress on psoriasis pathogenesis and the mechanisms involved, which provides clues for development of therapeutics or biomarkers.

The leaky gut and the gut microbiome in sepsis - targets in research and treatment

Both a leaky gut (a barrier defect of the intestinal surface) and gut dysbiosis (a change in the intestinal microbial population) are intrinsic to sepsis. While sepsis itself can cause dysbiosis, dysbiosis can worsen sepsis. The leaky gut syndrome refers to a status with which there is an increased intestinal permeability allowing the translocation of microbial molecules from the gut into the blood circulation. It is not just a symptom of gastrointestinal involvement, but also an underlying cause that develops independently, and its presence could be recognized by the detection, in blood, of lipopolysaccharides and (1→3)-β-D-glucan (major components of gut microbiota). Gut-dysbiosis is the consequence of a reduction in some bacterial species in the gut microbiome, as a consequence of intestinal mucosal immunity defect, caused by intestinal hypoperfusion, immune cell apoptosis, and a variety of enteric neuro-humoral-immunity responses. A reduction in bacteria that produce short-chain fatty acids could change the intestinal barriers, leading to the translocation of pathogen molecules, into the circulation where it causes systemic inflammation. Even gut fungi might be increased in human patients with sepsis, even though this has not been consistently observed in murine models of sepsis, probably because of the longer duration of sepsis and also antibiotic use in patients. The gut virobiome that partly consists of bacteriophages is also detectable in gut contents that might be different between sepsis and normal hosts. These alterations of gut dysbiosis altogether could be an interesting target for sepsis adjuvant therapies, e.g., by faecal transplantation or probiotic therapy. Here, current information on leaky gut and gut dysbiosis along with the potential biomarkers, new treatment strategies, and future research topics are mentioned.

LncRNA-WAKMAR2 regulates expression of CLDN1 to affect skin barrier through recruiting c-Fos

BACKGROUND

Chronic actinic dermatitis (CAD) is an immune-mediated photo-allergic skin disease. In the clinic, the treatment of this disease is hampered by the lack of proper understanding of the skin barrier dysfunction mechanism.

OBJECTIVE

To illuminate the mechanism of skin barrier dysfunction in CAD.

METHODS

Transcriptome sequencing and protein profiling were used to detect skin barrier injury-related genes. RNA pull down, a promoter-reporter gene assay, and chromatin isolation by RNA purification-sequencing were used to elucidate the effect of WAKMAR2 in skin barrier functionality.

RESULTS

Transcriptome sequencing from patient's tissues showed a significantly decreased expression of WAKMAR2. Down-regulation of WAKMAR2 destroyed the keratinocyte barrier. Moreover, WAKMAR2 can directly bind to the c-Fos protein. This novel long non-coding RNA (LncRNA)-protein complexes were targeted to the CLDN1 promotor. Overexpression of WAKMAR2 enhanced the promoter activity of CLDN1, while the addition of AP-1 inhibitor could reverse this phenomenon. Furthermore, our in vivo results suggested that expression of WAKMAR2 was required for the repair of skin damage in mice induced by ultraviolet irradiation.

CONCLUSIONS

We identified a crucial LncRNA (WAKMAR2) for the protection of the skin barrier in vitro and in vivo. Mechanically, it can specifically interact with c-Fos protein for the regulation of CLDN1, a finding which could be applied for CAD treatment.

Treatment of sensitive skin by short-wave radiofrequency combined with intense pulsed light

BACKGROUND

Sensitive skin is a widespread dermatologic condition, and no optimal treatments have been established so far.

OBJECTIVE

To investigated the efficacy and safety of the combined therapy of short-wave radiofrequency (SWRF) and intense pulsed light (IPL) in improving transepidermal water loss (TEWL) and facial erythema in sensitive skin patients.

METHODS

Twenty-two patients with sensitive skin received the SWRF treatment once per week for 4 weeks and IPL treatment once. Digital photographs and three-dimensional images were taken at each follow-up. The clinical efficacy was evaluated by the improvement of sensitive scale-10 including irritant symptoms and facial erythema. In addition, erythema area and TEWL values were measured.

RESULTS

All patients showed subjective and objective improvement in irritant sensations and facial erythema after treatment. The TEWL values decreased from 20.29 ± 5.97 g·h^-1 ·m^-2 at baseline to 14.70 ± 6.02 g·h^-1 ·m^-2 after SWRF treatment and 13.78 ± 4.70 g·h^-1 ·m^-2 after combined therapy (p = 0.000). The clearance of the erythema area was statistically significant, with 14.05% ± 5.71% at baseline, 9.38% ± 4.08% after SWRF treatment, and 5.73% ± 2.79% after combined therapy (p = 0.000). No adverse events were observed.

CONCLUSIONS

The combination of SWRF with IPL was effective in relieving skin irritant sensations and facial erythema of sensitive skin by repairing skin barrier function.

Current research and clinical trends in rosacea pathogenesis

BACKGROUND

Rosacea is a common and complex chronic inflammatory skin disorder, the pathophysiology and etiology of which remain unclear. Recently, significant new insights into rosacea pathogenesis have enriched and reshaped our understanding of the disorder. A systematic analysis based on current studies will facilitate further research on rosacea pathogenesis.

OBJECTIVE

To establish an international core outcome and knowledge system of rosacea pathogenesis and develop a challenge, trend and hot spot analysis set for research and clinical studies on rosacea using bibliometric analysis and data mining.

METHODS

A search of the WoS, and PubMed, MEDLINE, Embase and Cochrane collaboration databases was conducted to perform visual bibliometric and data analysis.

RESULTS

A total of 2,654 studies were used for the visualization and 302 of the 6,769 outcomes for data analysis. It reveals an increased trend line in the field of rosacea, in which its fast-growing pathogenesis attracted attention closely related to risk, comorbidity and therapeutic strategies. The rosacea pathogenesis has undergone the great development on immunology, microorganisms, genes, skin barriers and neurogenetics. The major of studies have focused on immune and microorganisms. And keyword visualization and data analyses demonstrated the cross-talk between cells or each aspect of pathogenesis, such as gene-gene or gene-environment interactions, and neurological mechanisms associated with the rosacea phenotype warrant further research.

LIMITATIONS

Inherent limitations of bibliometrics; and reliance on research and retrospective studies.

CONCLUSIONS

The understanding of rosacea's pathogenesis has been significantly enhanced with the improved technology and multidisciplinary integration, but high-quality, strong evidence in favor of genomic and neurogenic requires further research combined with a better understanding of risks and comorbidities to guide clinical practice.

Lithocholic acid promotes rosacea-like skin inflammation via G protein-coupled bile acid receptor 1

BACKGROUND

Rosacea is a chronic inflammatory skin disorder with unclear etiology. Evidence showed that immunoinflammatory dysregulation was involved in the pathogenesis. Bile acids, as important participants of hepatoenteric circulation, play a vital role in immunoinflammatory regulation through peripheral blood circulation. However, whether it has effects on rosacea remains unknown.

METHODS

Here, we performed a bile acid analysis on the serum samples of rosacea patients and healthy controls. Then we gavage G protein-coupled bile acid receptor 1 (TGR5) knockout mice with lithocholic acid (LCA) based on a LL37-induced rosacea-like model. We further overexpress TGR5 in HaCaT keratinocytes to figure out the downstream pathway.

RESULTS

We found varied bile acid profile in the peripheral blood circulation of patients, especially the most significant increase in LCA. LCA promoted skin inflammation in LL37-induced rosacea-like mouse model. Our in vivo and in vitro results further demonstrated that LCA induced inflammatory cytokines and chemokines, thus exacerbated rosacea-like skin inflammation, via TGR5 in keratinocytes and LL37-induced rosacea-like mouse model.

CONCLUSIONS

Therefore, we conclude that LCA promotes skin inflammation of rosacea via TGR5, and LCA-TGR5 axis may be a novel therapeutic target for rosacea.

The Fate of Epidermal Tight Junctions in the stratum corneum: Their Involvement in the Regulation of Desquamation and Phenotypic Expression of Certain Skin Conditions

We evaluated the presence of tight junction (TJ) remnants in the stratum corneum (SC) of in vitro reconstructed human epidermis and human skin explants subjected or not to an aggressive topical treatment with beta-lipohydroxy salicylic acid (LSA) for 24 h. LSA-treated samples showed an increased presence of TJ remnants in the two lowermost layers of the SC, as quantified with standard electron microscopy. The topical aggression-induced overexpression of TJ-like cell–cell envelope fusions may influence SC functions: (1) directly, through an enhanced cohesion, and (2) indirectly, by impeding accessibility of peripheral corneodesmosomes to extracellular hydrolytic enzymes and, thus, slowing down desquamation. Observations of ichthyotic epidermis in peeling skin disease (PSD; corneodesmosin deficiency; two cases) and ichthyosis hypotrichosis sclerosing cholangitis syndrome (IHSC/NISCH; absence of claudin-1; two cases) also demonstrated increased persistence of TJ-like intercellular fusions in pathological SC and contributed to the interpretation of the diseases’ pathological mechanisms.

N2-Polarized Neutrophils Reduce Inflammation in Rosacea by Regulating Vascular Factors and Proliferation of CD4+ T Cells

The infiltration of neutrophils is implicated in rosacea, which is a common chronic inflammatory facial disease. This study explores the biological function of neutrophils and their underlying mechanism in rosacea. A rosacea-like mouse model was established to explore the polarization of neutrophils. RNA sequencing was used to investigate the underlying mechanisms. Our results show that neutrophils partly switched to N2 phenotypes in both patients with rosacea and rosacea-like mouse models. The rosacea-like phenotype and inflammation in both a genetic mutation (Genista mice) and the Gr-1 antibody‒induced neutropenia mice were significantly aggravated compared with that in the control groups. In vitro, lipopolysaccharide + IFN-γ and IL4 stimulation of neutrophils successfully induced the N1 and N2 polarization of neutrophils, respectively. Replenishment of N2 neutrophils in the lesions of wild-type and Genista mice ameliorated the rosacea-like phenotype and inflammation. RNA sequencing suggested that N2 neutrophils relieved the rosacea-like phenotype, possibly by regulating the expression of blood circulation‒associated factors, such as ACE, AGTR2, and NOS1. Finally, N2 neutrophils regulated the proliferation of CD4⁺ lymphocytes, which could explain the remission of inflammation in mice. Our results suggest that N2 polarization of neutrophils in rosacea exerts anti-inflammatory effects by regulating vascular factors and proliferation of CD4⁺ T cells.

Multi-Transcriptomic Analysis and Experimental Validation Implicate a Central Role of STAT3 in Skin Barrier Dysfunction Induced Aggravation of Rosacea

Objective

Methods

Results

Conclusion

Rosacea: Treatment targets based on new physiopathology data

Over the past 15 years, numerous clinical, epidemiological and physiopathological articles have been published on rosacea. There is now increasing evidence that rosacea is an inflammatory disease characterised by abnormal innate immune response, major vascular changes, and increased colonisation by Demodex mites, along with a genetic predisposition and multiple external aggravating factors. It is thus possible to define treatment targets and possible treatments: 1) permanent vascular changes (medical and instrumental treatments); 2) flushing (betablockers, botulinum toxin); 3) innate immunity (antibiotics, nonspecific antioxidants and anti-inflammatory molecules); 4) a neurovascular component (analgesics, antidepressants); 5) Demodex (antiparasitic drugs); 6) microbiome; 7) skin barrier impairment (cosmetics and certain systemic drugs); 8) sebaceous glands (isotretinoin, surgery); 9) environmental factors (alcohol, coffee, UV exposure). Treatment recommendations are now available in many countries and benefit from the new phenotypic approach to rosacea, in which every sign or symptom is considered separately rather than having to deal with overlapping subtypes. Since the 2000s, many good quality clinical trials have been published in the field of rosacea and many others are still ongoing. Rosacea is a complex disease involving many different mechanisms and with numerous possible treatments, but there are still some important unmet needs with regard to optimal care.

Interaction between body weight status and spicy food consumption on the risk of rosacea: A multi-central, hospital-based, case-control study

BACKGROUND

No researches about the interaction among the risk factors for rosacea were conducted. Some studies prompted obesity and spicy food may have some common pathways.

AIMS

To clarify the relationship between body mass index (BMI) and rosacea, and explore the interaction between BMI and spicy food consumption in rosacea.

METHODS

This hospital-based case-control study enrolled 1347 rosacea patients and 1290 healthy subjects. The demographic data and clinical data were collected. The association between BMI and rosacea, and the relative excess risk due to interaction of BMI and spicy food consumption was calculated.

RESULTS

No interaction was found between underweight, overweight/obesity, and spicy food consumption with regard to the risk of rosacea, mild-to-moderate rosacea, papulopustular rosacea (PPR), or phymatous rosacea (PhR). And underweight and overweight/obesity were not significant associated with rosacea, mild-to-moderate rosacea, PPR, or PhR (p > 0.05). However, spicy food consumption was significantly interacted with underweight on the risk of erythematotelangiectatic rosacea (ETR), and with overweight/obesity on the risk of severe rosacea. Underweight was associated with increased risk of ETR (adjusted odds ratio [aOR] = 1.91, 95% confidence interval [CI]: 1.21, 3.03) among spicy no users, but the association was attenuated into insignificant level when mixed with spicy food factor (p > 0.05). Among moderated spicy food consumers, overweight/obesity was associated with decreased risk of severe rosacea (aOR = 0.70, 95% CI: 0.50, 0.98), but overweight/obesity was insignificant associated with severe rosacea among spicy no users and heavy spicy food consumers (p > 0.05).

CONCLUSIONS

Body weight status alone was not significantly associated with rosacea, but the interaction between body weight status and spicy food consumption is involved in the rosacea.

Autophagy induction regulates aquaporin 3-mediated skin fibroblasts aging

BACKGROUND

Long- and short-term ultraviolet (UV) exposure have distinct biological effects on human fibroblasts.

OBJECTIVES

This study aimed to elucidate the underlying mechanisms of the biological effects of UV exposure on human skin fibroblasts.

METHOD

We subjected human skin fibroblast cells with or without AQP3, DEDD, or Beclin1 manipulation to UVA treatment and evaluated autophagy and senescence/aging in them.

RESULTS

Short-term UVA irradiation induced autophagy and upregulated AQP3 but not senescence, whereas long-term UVA irradiation inhibited autophagy, AQP3, and senescence/aging in vitro and in vivo. Silencing AQP3 abolished short-term UVA irradiation-induced autophagy and led to cellular senescence, whereas AQP3 overexpression partially rescued the senescence and autophagy inhibition induced by long-term UVA exposure in vitro. Mechanistically, the transcription factor JUN was found to bind to the AQP3 promoter to activate its transcription following short-term UVA exposure. Subsequently, AQP3 interacted with DEDD to induce its ubiquitination-mediated degradation and promote autophagy, and bound to Beclin1 to directly activate autophagy. Finally, autophagy induced by AQP3 overexpression robustly prevented UVA-induced senescence/aging in vitro and in vivo.

CONCLUSIONS

Thus, our study indicates that AQP3 controls skin fibroblasts photoaging by regulating autophagy and represents a potential target for future interventions against skin aging.

Efficacy and safety of non-insulated fractional microneedle radiofrequency for treating difficult-to-treat rosacea: a 48-week, prospective, observational study

Rosacea is a common chronic facial inflammatory skin disease. However, treatment for "difficult-to-treat rosacea" cases has not been established. This 48-week, prospective, observational study analyzed patients who underwent three non-insulated fractional microneedle radiofrequency (NFMRF) sessions at 2-month intervals. Therapy efficacy, epidermal barrier function, and side effects were evaluated. 34 subjects completed the trial. NFMRF resulted in CEA score reduction from 2.65 ± 0.59 to 1.56 ± 0.50 (P < 0.001) and mean DLQI reduction from 16.70 ± 3.55 to 10.48 ± 2.92 (P < 0.001). The successes of CEA (44.12 vs. 2.94%), IGA (91.67 vs. 25.00%), and flushing (58.82 vs. 26.47%) were observed. Among 34 patients, 22 reported "excellent" or "good" improvement and 30 were "very" or "relatively" satisfied. Skin barrier results revealed that hemoglobin content significantly decreased from 376.47 ± 71.29 at visit 0 to 161.32 ± 52.86 at visit 3. 2 of 30 patients followed-up at 6 months had a relapse at 18 and 20 weeks, respectively. No serious side effects were observed. NFMRF alone results in visible improvement and has great efficacy for difficult-to-treat rosacea without compromising patient safety or damaging the skin barrier.

A positive feedback loop between mTORC1 and cathelicidin promotes skin inflammation in rosacea

Rosacea is a chronic inflammatory skin disorder whose pathogenesis is unclear. Here, several lines of evidence were provided to demonstrate that mTORC1 signaling is hyperactivated in the skin, especially in the epidermis, of both rosacea patients and a mouse model of rosacea-like skin inflammation. Both mTORC1 deletion in epithelium and inhibition by its specific inhibitors can block the development of rosacea-like skin inflammation in LL37-induced rosacea-like mouse model. Conversely, hyperactivation of mTORC1 signaling aggravated rosacea-like features. Mechanistically, mTORC1 regulates cathelicidin through a positive feedback loop, in which cathelicidin LL37 activates mTORC1 signaling by binding to Toll-like receptor 2 (TLR2) and thus in turn increases the expression of cathelicidin itself in keratinocytes. Moreover, excess cathelicidin LL37 induces both NF-κB activation and disease-characteristic cytokine and chemokine production possibly via mTORC1 signaling. Topical application of rapamycin improved clinical symptoms in rosacea patients, suggesting mTORC1 inhibition can serve as a novel therapeutic avenue for rosacea.

Efficacy and safety of non-surgical short-wave radiofrequency treatment of mild-to-moderate erythematotelangiectatic rosacea: a prospective, open-label pilot study

Although various treatments have been proposed for the management of rosacea, achieving complete remission of persistent erythema remains challenging. Short-wave radiofrequency (SWRF) treatment has been shown to repair skin barriers and reduce chronic inflammation. However, limited studies have evaluated the effectiveness of SWRF treatment for erythematotelangiectatic rosacea (ETR). A prospective, open-label pilot study using SWRF therapy was conducted on 30 patients with mild-to-moderate ETR. During the first stage, the patients underwent a single, full-face treatment and were evaluated before and after the session, as well as on the 7th and 15th day post-treatment. During the second stage, ten treatment sessions were administered, and the patients were evaluated before and after the tenth session, as well as 1 month after the treatment. Adverse events were recorded during each treatment session, and the patients were followed up for 3 months after the last session. Twenty-eight patients completed the entire trial. On the 7th day after the single treatment, the global score (total score of flushing, persistent erythema, and telangiectasia) of ETR improved from 5.23 ± 1.09 to 4.00 ± 0.76 relative to the baseline value (p < 0.05); moreover, the overall treatment satisfaction improved from 7.27 ± 0.89 to 4.90 ± 0.91 (p < 0.05). 1 month after the tenth treatment session, the global score improved from 5.30 ± 1.01 to 3.85 ± 0.93 (p < 0.05), and the overall treatment satisfaction improved from 7.13 ± 0.85 to 5.17 ± 1.19 (p < 0.05). During the 3 month follow-up period, there were two cases of recurrence. Therefore, this report indicates that SWRF might be an effective auxiliary treatment for mild-to-moderate ETR.

The association between rosacea and the condition of low tolerance to skincare of the facial skin: a case-control study in China

BACKGROUND

Patients with rosacea often complained of low tolerance to skincare.

AIM

To examine if the preexisted low tolerance to skincare is associated with rosacea the occurrence of the Chinese population.

METHODS

A retrospective case-control survey of 997 rosacea cases and 1012 skin-healthy controls was carried out in China. Low tolerance to skincare was evaluated based on the history of facial skin allergic reactions related to skincare in the past 5 years before the onset of rosacea. A comparative analysis was performed between the case and control groups by the chi-square test and the logistic regression analysis.

RESULTS

History of facial skin allergic reaction due to skin care products (OR = 5.110, 95% CI = 3.893-6.706) and skin care in beauty salons (OR = 3.002, 95% CI = 1.506-5.981) both presented a positive correlations with the occurrence of rosacea. Facial masks and cosmetics were two of the most common products causing facial allergic reaction. The OR values increased with the increased frequency of allergic reactions related to facial mask and cosmetics. In addition, the history of facial skin allergic reaction had a significantly associated with the severity of self-reported symptoms of rosacea including dryness, burning, stinging and itching.

CONCLUSIONS

The condition of low tolerance of the facial skin to skincare was closely associated with the occurrence of rosacea.

Platelet factor 4 inhibits human hair follicle growth and promotes androgen receptor expression in human dermal papilla cells

Platelet-rich plasma (PRP) has been reported recently as a potential therapeutic approach for alopecia, such as androgenetic alopecia, but the exact mechanisms and effects of specific components of this recipe remain largely unknown. In this study, we identified that platelet factor 4 (PF4), a component of PRP, significantly suppressed human hair follicle growth and restrained the proliferation of human dermal papilla cells (hDPCs). Furthermore, our results showed that PF4 upregulated androgen receptor (AR) in human dermal papilla cells in vitro and via hair follicle organ culture. Among the hair growth-promoting and DP-signature genes investigated, PF4 decreased the expression of Wnt5a, Wnt10b, LEF1, HEY1 and IGF-1, and increased DKK1 expression, but did not affect BMP2 and BMP4 expression. Collectively, Our data demonstrate that PF4 suppresses human hair follicle growth possibly via upregulating androgen receptor signaling and modulating hair growth-associated genes, which provides thought-provoking insights into the application and optimization of PRP in treating hair loss.

Cutibacterium acnes regulates the epidermal barrier properties of HPV-KER human immortalized keratinocyte cultures

Our skin provides a physical barrier to separate the internal part of our body from the environment. Maintenance of complex barrier functions is achieved through anatomical structures in the skin, the stratified squamous epithelium specialized junctional organelles, called tight junctions (TJs). Several members of our microbial communities are known to affect the differentiation state and function of the colonized organ. Whether and how interactions between skin cells and cutaneous microbes, including Cutibacterium acnes (C. acnes), modify the structure and/or function of our skin is currently only partly understood. Thus, in our studies, we investigated whether C. acnes may affect the epidermal barrier using in vitro model systems. Real-time cellular analysis showed that depending on the keratinocyte differentiation state, the applied C. acnes strains and their dose, the measured impedance values change, together with the expression of selected TJ proteins. These may reflect barrier alterations, which can be partially restored upon antibiotic–antimycotic treatment. Our findings suggest that C. acnes can actively modify the barrier properties of cultured keratinocytes, possibly through alteration of tight cell-to-cell contacts. Similar events may play important roles in our skin, in the maintenance of cutaneous homeostasis.

Efficacy of non-ablative fractional 1440-nm laser therapy for treatment of facial acne scars in patients with rosacea: a prospective, interventional study

Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was designed to evaluate the efficacy and safety of non-ablative fractional 1440-nm laser (1440-nm NAFL) therapy for treatment of atrophic acne scars in patients with rosacea. In this prospective, interventional study, 32 patients with rosacea and acne scars underwent three sessions of 1440-nm NAFL therapy. Therapy efficacy, epidermal barrier function, and side effects were evaluated. Thirty patients completed and the median acne scar scores significantly reduced from 45 (30, 50) to 15 (15, 30) after three treatments (P < 0.001). The improvement score of acne scars was 2.7 ± 0.7; 22 (73.3%) were satisfied or highly satisfied. The rosacea erythema scores changed from 2.1 ± 0.4 to 1.9 ± 0.5 (P = 0.326), and flushing, burning, and stinging were not worse. The oil content after treatments was significantly reduced (P < 0.001), while there was no significant difference in other indicators of skin barrier function. The quality-of-life score decreased from 17.5 ± 3.8 to 14.1 ± 3.0 (P < 0.001). No serious side effects were observed. The 1440-nm NAFL therapy is effective in the treatment of acne scaring in patients with rosacea with little damage to the skin barrier.

Excessive cleansing: an underestimating risk factor of rosacea in Chinese population

Appropriate skincare is essential in the prevention and management of rosacea. We sought to investigate whether cleansing habits, the initial step of skin care, would influence the onset and progression of rosacea and their associations with clinical features of rosacea in the Chinese population. We analyzed the daily cleansing habits data collected from 999 rosacea cases and 1010 skin-healthy controls from China. Overall, the high frequency of cleansing (more than once daily) (OR = 1.450) and the large amount of cleansers (> 5 pieces/year) (OR = 1.612) presented a positive correlation with rosacea occurring. The cleansing duration and types of cleansers appeared not to be correlated with the onset of rosacea in this study. Significant risk factors also included the deep cleansing habits, such as the overuse of cleansing tool (more than four times/week) (OR 2.179) and oil control and exfoliating behaviors via daily used products (OR 2.435), facial mask (OR 1.459) or projects in beauty salons (OR 2.688). The analysis of the clinical features of rosacea showed that patients who prefer deep cleansing were more prone to present an initial symptom of papule and pustule (OR 1.63-3.15). What is more, using daily exfoliating products presented a positive correlation with the progression of the symptoms from flushing to erythema (OR = 2.01), papule and pustule (OR = 2.28) and telangiectasis (OR = 2.14), and the affected areas from a single area to pan facial (OR = 1.650). In conclusion, excessive cleansing habits were substantial risk factors for the incidence and progression of rosacea in the Chinese population.

Effects of skin care habits on the development of rosacea: A multi-center retrospective case-control survey in Chinese population

BACKGROUND

Certain cosmetic habits may trigger or aggravate rosacea, while there is little published epidemiologic evidence to support this point.

PURPOSE

To examine if daily skin care habits have an effect on the development of rosacea in Chinese population.

METHODS

A multi-center retrospective case-control survey of 1,245 rosacea cases and 1,538 skin-healthy controls was conducted in China. Participants completed the questionnaire comprised of demographic characteristics, socioeconomic data and daily skin care habits. Data were collected retrospectively and analyzed using the chi-square test and t-test. Multivariate logistic regression analyses were used to predict rosacea.

RESULTS

The multivariate logistic regression analysis highlighted some results: Dry, oily or mixed skin (OR = 6.3-6.9, P< .001), the usage of foaming cleanser (OR = 1.45, 95%CI 1.115-1.886, P = .01), make up more than 6 times a week (OR = 2.839, 95%CI 1.962-4.108, P< .001), using facial mask more than 4 times a week (OR = 2.56-3.069, P< .001), facial treatments at beauty salon more than once a week (OR = 4.946, 95%CI 2.005-12.198, P = .0018) and using beauty salon products (OR = 2.334, 95%CI 1.435-3.976, P = .0018) are positively correlated with the development of rosacea. Using of moisturizing products (OR = 0.602, 95%CI 0.386-0.983, P = .035) and sunscreen cream (OR = 0.303-0.507, P< .001 or P = .0167 for different frequency) presented significantly negative correlations with rosacea. Frequency of cleansing showed a nonlinear association with rosacea: using facial cleansers 1~3 times per week (OR = 0.647, 95%CI 0.429-0.975, P  =  .038) showed beneficial effects while using facial cleanser excessively (twice or more daily) (OR = 2.131, 95%CI 1.394-3.256, P< .001) positively correlated to rosacea strongly.

CONCLUSIONS

Excessive use of facial cleanser (twice or more a day) and facial mask (more than 4 times a week), frequent makeup (more than 6 times a week), regular skin care in beauty salon (more than once a week), and using beauty salon products were closely correlated to the development of rosacea in Chinese population.

A Preliminary Clinical Evaluation of a Topical Product for Reducing Slight Rosacea Imperfections

Introduction

Rosacea is a chronic multifactorial skin disorder mainly affecting facial skin with an estimated prevalence of about 5% worldwide. Its main symptoms, occurring early during pathology development, are skin dehydration, redness, erythema, and telangiectasia. Given the lack of a resolutive cure, therapeutic approaches able to relieve the main symptoms are needed.

Purpose

The aim of this research article is to evaluate the beneficial effect of a topical product (Serum BK46) on rosacea symptoms.

Patients and Methods

A monocentric single-arm, non-blinded study was performed to assess the clinical effect of Serum BK46 in relieving the main symptoms of rosacea: skin dryness, increased trans epidermal water loss (TEWL), redness, and abnormal vascularization. Twenty patients with mild to moderate rosacea were enrolled in the study and asked to apply the product twice per day for 56 days. Skin moisturization, TEWL, and erythema index were instrumentally assessed at baseline and following 24 h and 14, 28 and 56 days of treatment. Clinical parameters, including redness and telangiectasia imperfection visibility, were evaluated on a 5-point scale by a specialized dermatologist at baseline and after 14, 28, and 56 days of treatment. Finally, the visibility of vessel diameter was evaluated at baseline and after 28 and 56 days of treatment.

Results

Serum BK46 application restored skin hydration and prevented the loss of water by the skin. Long-term treatment with Serum BK46 significantly reduced skin redness, erythema index, and the visibility of telangiectasia imperfections and superficial vessels. The investigated product's clinical effect was demonstrated by both instrumental and clinical evaluation. Furthermore, Serum BK46 was completely tolerated and no adverse effects were recorded.

Conclusion

The moisturizing and skin barrier restoring action of Serum BK46 has been clearly proven in patients displaying mild to moderate rosacea; thus, this product is a good candidate for rosacea treatment.

Rosacea Is Characterized by a Profoundly Diminished Skin Barrier

Rosacea is a common chronic inflammation of sebaceous gland-rich facial skin characterized by severe skin dryness, elevated pH, transepidermal water loss, and decreased hydration levels. Until now, there has been no thorough molecular analysis of permeability barrier alterations in the skin of patients with rosacea. Thus, we aimed to investigate the barrier alterations in papulopustular rosacea samples compared with healthy sebaceous gland-rich skin, using RNA sequencing analysis (n = 8). Pathway analyses by Cytoscape ClueGO revealed 15 significantly enriched pathways related to skin barrier formation. RT-PCR and immunohistochemistry were used to validate the pathway analyses. The results showed significant alterations in barrier components in papulopustular rosacea samples compared with sebaceous gland-rich skin, including the cornified envelope and intercellular lipid lamellae formation, desmosome and tight junction organizations, barrier alarmins, and antimicrobial peptides. Moreover, the barrier damage in papulopustular rosacea was unexpectedly similar to atopic dermatitis; this similarity was confirmed by immunofluorescent staining. In summary, besides the well-known dysregulation of immunological, vascular, and neurological functions, we demonstrated prominent permeability barrier alterations in papulopustular rosacea at the molecular level, which highlight the importance of barrier repair therapies for rosacea.

How Probiotics Affect the Microbiota

Probiotics have been used to treat a variety of diseases for decades; however, what is the rationale for their application? Such a treatment was first proposed in the early nineteenth century based on observations of decreased bifidobacterial populations in children suffering from diarrhea, suggesting that oral intake of bifidobacteria could replete this subpopulation of the microbiota and improve health. Since then, studies have shown modifications in the gut or skin microbiota in the course of a variety of diseases and suggested positive effects of certain probiotics. Most studies failed to report any impact on the microbiota. The impact of probiotics as well as of bacteria colonizing food does not reside in their ability to graft in the microbiota but rather in sharing genes and metabolites, supporting challenged microbiota, and directly influencing epithelial and immune cells. Such observations argue that probiotics could be associated with conventional drugs for insulin resistance, infectious diseases, inflammatory diseases, and psychiatric disorders and could also interfere with drug metabolism. Nevertheless, in the context of a plethora of probiotic strains and associations produced in conditions that do not allow direct comparisons, it remains difficult to know whether a patient would benefit from taking a particular probiotic. In other words, although several mechanisms are observed when studying a single probiotic strain, not all individual strains are expected to share the same effects. To clarify the role of probiotics in the clinic, we explored the relation between probiotics and the gut and skin microbiota.

ADAMDEC1 promotes skin inflammation in rosacea via modulating the polarization of M1 macrophages

Rosacea is a chronic inflammatory cutaneous disease which mainly affects central face, leading to cosmetic disfigurement and compromised social psychology in billions of rosacea patients. Though the exact etiology of rosacea remains elusive, accumulating evidence has highlighted the dysfunction of innate immunity and inflammation in rosacea pathogenesis. Disintegrin Metalloprotease ADAM-like Decysin-1 (ADAMDEC1) is an orphan ADAM-like metalloprotease which is believed to be closely related to inflammation. Here for the first time, we reported that Adamdec1 expression was significantly increased in the skin lesions of rosacea patients and LL37-induced rosacea-like mouse models. Immunofluorescence analysis revealed co-localization of ADAMDEC1 and macrophages in patient and mouse biopsies. In cellular experiment, the expression of ADAMDEC1 was prominently elevated in M1 but not M2 macrophages. Knocking down of ADAMDEC1 significantly blunted M1 polarization in macrophages induced from human monocytes and THP-1 cell lines. Furthermore, silencing of Adamdec1 in LL-37-induced mouse model also suppressed the expression of M1 signature genes such as IL-6, iNOS and TNF-α, resulting in attenuated rosacea-like phenotype and inflammation. Taken together, our results demonstrate that ADAMDEC1 plays a pro-inflammatory role in rosacea via modulating the M1 polarization of macrophages.