Thalidomide ameliorates rosacea-like skin inflammation and suppresses NF-κB activation in keratinocytes

Skin-permeable gold nanoparticles with modifications azelamide monoethanolamine ameliorate inflammatory skin diseases

BACKGROUND

Traditional topical drug delivery for treating inflammatory skin diseases suffers from poor skin penetration and long-term side effects. Metal nanoparticles show promising application in topical drug delivery for inflammatory skin diseases.

METHODS

Here, we synthesized a new type of nanoparticles, azelamide monoethanolamine-functionalized gold nanoparticles (Au-MEA NPs), based on citrate-capped gold nanoparticles (Au-CA NPs) via the ligand exchange method. The physical and chemical properties of Au-CA NPs and Au-MEA NPs were characterized. In vivo studies were performed using imiquimod-induced psoriasis and LL37-induced rosacea animal models, respectively. For in vitro studies, a model of cellular inflammation was established using HaCaT cells stimulated with TNF-α. In addition, proteomics, gelatin zymography, and other techniques were used to investigate the possible therapeutic mechanisms of the Au-MEA NPs.

RESULTS

We found that Au-MEA NPs exhibited better stability and permeation properties compared to conventional Au-CA NPs. Transcutaneously administered Au-MEA NPs exerted potent therapeutic efficacy against both rosacea-like and psoriasiform skin dermatitis in vivo without overt signs of toxicity. Mechanistically, Au-MEA NPs reduced the production of pro-inflammatory mediators in keratinocytes by promoting SOD activity and inhibiting the activity of MMP9.

CONCLUSION

Au-MEA NPs have the potential to be a topical nanomedicine for the effective and safe treatment of inflammatory skin diseases.

Thalidomide attenuates radiation-induced apoptosis and pro-inflammatory cytokine secretion in oral epithelial cells by promoting LZTS3 expression

Radiation-induced oral mucositis (RIOM) is a prevalent oral complication that occurs in individuals undergoing radiotherapy or radiation treatment for head and neck tumors. The presence of oral mucosal rupture and ulcerative lesions, which are the defining features of this condition, can significantly affect the quality of life of patients. Additionally, it can interfere with tumor therapy and contribute to an unfavorable prognosis. Current evidence suggests that cellular inflammation and programmed cell death are important factors in disease development. Moreover, thalidomide (THD) has been revealed to reduce the incidence and severity of RIOM in patients undergoing chemoradiotherapy for nasopharyngeal carcinoma. However, the mechanism through which THD improves RIOM remains unknown. This study aimed to investigate the role of LZTS3 in RIOM by analyzing various sequencing datasets and conducting knockdown and overexpression experiments. We used small interfering RNA transfection and LZTS3 overexpression, followed by validation through polymerase chain reaction, western blotting, flow cytometry, and enzyme-linked immunosorbent assay. In this study, we identified LZTS3 as a potential target for THD regulation in RIOM. Through a series of experiments, we confirmed that LZTS3 has the ability to inhibit the inflammatory response and apoptosis of cells. In addition, we also found that THD can regulate the expression of LZTS3 by upregulating, thereby affecting inflammatory response and apoptosis. We repeated these results in a live animal model. In summary, THD has the potential to reduce the occurrence of oral mucositis in patients by upregulating LZTS3 levels. These findings provide a promising avenue for future drug research and development to treat RIOM.

Signaling pathways and targeted therapy for rosacea

Rosacea is a chronic skin inflammatory disease with a global prevalence ranging from 1% to 20%. It is characterized by facial erythema, telangiectasia, papules, pustules, and ocular manifestations. Its pathogenesis involves a complex interplay of genetic, environmental, immune, microbial, and neurovascular factors. Recent studies have advanced our understanding of its molecular basis, focusing on toll-like receptor (TLR) 2 pathways, LL37 expression, mammalian target of rapamycin (mTOR) activation, interleukin (IL)-17 signaling, transient receptor potential vanilloid (TRPV) functions, and the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathways. LL37-associated signaling pathways, particularly involving TLR2 and mTORC1, are critical in the pathogenesis of rosacea. LL37 interacts with signaling molecules such as extracellular signal-regulated kinases 1 and 2 (ERK1/2), nuclear factor kappa B (NF-κB), inflammasomes, C-X-C motif chemokine ligand 8 (CXCL8), mas-related G-protein-coupled receptor X2 (MRGPRX2)-TRPV4, and vascular endothelial growth factor (VEGF). This interaction activates macrophages, neutrophils, mast cells, and vascular endothelial cells, leading to cytokine release including tumor necrosis factor-alpha (TNF-α), IL-6, IL-1β, C motif chemokine ligand (CCL) 5, CXCL9, and CXCL10. These processes contribute to immune response modulation, inflammation, and angiogenesis in rosacea pathophysiology. The IL-17 signaling pathway also plays a crucial role in rosacea, affecting angiogenesis and the production of inflammatory cytokines. In addition, recent insights into the JAK/STAT pathways have revealed their integral role in inflammatory and angiogenic mechanisms associated with rosacea. Rosacea treatment currently focuses on symptom management, with emerging insights into these molecular pathways providing more targeted and effective therapies. Biological agents targeting specific cytokines, IL-17 inhibitors, JAK inhibitors, and VEGF antagonists are promising for future rosacea therapy, aiming for enhanced efficacy and fewer side effects. This review provides a comprehensive overview of the current knowledge regarding signaling pathways in rosacea and potential targeted therapeutic strategies.

Therapeutic strategies focusing on immune dysregulation and neuroinflammation in rosacea

Rosacea is a complex inflammatory condition characterized by papulopustular lesions and erythema on the central face for which there is no cure. The development of rosacea is influenced by both external triggers and genetics, but the common pathophysiology is overactivation of the immune system. Here, we review the current data on proinflammatory cytokines and dysregulation of the neurovascular system as targetable components of rosacea. Amelioration of cutaneous and gastrointestinal dysbiosis and other external factors impacts the immune state and has been observed to improve rosacea. While multiple treatments exist, many patients do not achieve their goals for rosacea control and highlights an unmet need for dermatologic care. Current interventions encompass topical/oral drugs, light devices, and avoidance of triggers management. Additional understanding of the underlying pathogenesis may help us develop novel targeted therapeutic strategies to improve 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.

Rosacea treatment with mussel adhesive protein delivered via microneedling: In vivo and clinical studies

BACKGROUND

Rosacea is a prevalent chronic dermatological condition marked by facial inflammation and erythema, significantly compromising the quality of life for affected individuals. Current treatment methods for rosacea are not considered ideal because of the complex etiology of the disease. Mussel adhesive protein (MAP) is a glycoprotein derived from the foot gland of mussels. The protein exhibits anti-inflammatory properties, relieves skin itching, and promotes wound healing.

AIMS

We aimed to explore the feasibility of using MAP administered via microneedle delivery for treating rosacea and the potential molecular mechanism involved.

MATERIALS AND METHODS

The therapeutic effect and mechanism of MAP microneedle delivery in an LL-37-induced rosacea-like mouse model were observed using morphological and histological methods. Twenty-seven patients with erythematotelangiectatic rosacea (ETR) underwent treatment once every 1 month, with three treatments constituting one treatment course. The therapeutic effect was evaluated by comparing the clinical images taken at baseline, after the first treatment course, and after the second treatment course. The red value, CEA, and GFSS score were also calculated.

RESULTS

In response to the microneedle delivery of MAP, innate immunity, inflammatory infiltration, and abnormal neurovascular regulation improved significantly in rosacea-like mice. In the clinical experiments, the microneedle delivery of MAP significantly improved the symptoms of erythema, flushing, and telangiectasia in patients with ETR, and no obvious adverse reactions were observed.

CONCLUSIONS

MAP delivered by microneedling is effective and safe for treating ETR.

NF-κB in biology and targeted therapy: new insights and translational implications

NF-κB signaling has been discovered for nearly 40 years. Initially, NF-κB signaling was identified as a pivotal pathway in mediating inflammatory responses. However, with extensive and in-depth investigations, researchers have discovered that its role can be expanded to a variety of signaling mechanisms, biological processes, human diseases, and treatment options. In this review, we first scrutinize the research process of NF-κB signaling, and summarize the composition, activation, and regulatory mechanism of NF-κB signaling. We investigate the interaction of NF-κB signaling with other important pathways, including PI3K/AKT, MAPK, JAK-STAT, TGF-β, Wnt, Notch, Hedgehog, and TLR signaling. The physiological and pathological states of NF-κB signaling, as well as its intricate involvement in inflammation, immune regulation, and tumor microenvironment, are also explicated. Additionally, we illustrate how NF-κB signaling is involved in a variety of human diseases, including cancers, inflammatory and autoimmune diseases, cardiovascular diseases, metabolic diseases, neurological diseases, and COVID-19. Further, we discuss the therapeutic approaches targeting NF-κB signaling, including IKK inhibitors, monoclonal antibodies, proteasome inhibitors, nuclear translocation inhibitors, DNA binding inhibitors, TKIs, non-coding RNAs, immunotherapy, and CAR-T. Finally, we provide an outlook for research in the field of NF-κB signaling. We hope to present a stereoscopic, comprehensive NF-κB signaling that will inform future research and clinical practice.

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.

Rosacea pathogenesis and therapeutics: current treatments and a look at future targets

Rosacea is a chronic inflammatory skin condition associated with a significant health and economic burden from costs and loss of productivity due to seeking medical treatment. The disease encompasses multiple phenotypic manifestations involving a complex and multi-variate pathogenesis. Although the pathophysiology of rosacea is not completely understood, ongoing research is continually elucidating its mechanisms. In this review, current concepts of rosacea pathogenesis will be addressed which involve skin barrier and permeability dysfunction, the innate and adaptive immune systems, and the neurovascular system. More specifically, the cathelicidin pathway, transient potential receptor channels, mast cells, and the NLRP3 inflammasome pathway are various targets of current pharmacologic regimens. Future therapies may seek different mechanisms to act on current treatment targets, like the potential use of JAK/STAT inhibitors in ameliorating skin barrier dysfunction or TLR antagonists in alleviating cathelicidin mediated inflammation. Other potential treatments aim for entirely different molecular targets such as microvesicle particle mediated local and systemic inflammation. Ultimately rosacea is associated with a significant health and economic burden which warrants deeper research into its pathogenesis and resultant new treatment discovery.

Decoding the role of m6A Regulators in identifying and characterizing molecular subtypes of rosacea

Rosacea is a common skin disease that predominantly affects individuals aged between 30 and 50 years. While the exact cause of the disease remains unclear, various factors have been shown to trigger or exacerbate its symptoms. N6-methyladenosine (m6A) modification is one of the most abundant epigenetic methylation modification in messenger RNA (mRNA) and non-coding RNA (ncRNA), plays a crucial role in RNA splicing, export, stability, and translation. In this study, we aimed to characterize m6A genes in rosacea, identify molecular subtypes based on m6A gene expression, characterize the immune features among subtypes, explore key molecules based on co-expression analysis, and identify potential targets and drugs. To achieve our objectives, we first compared the expression pattern and immune regulation of m6A genes between healthy and diseased groups. Then, we performed clustering to stratify disease samples into different subtypes and analyzed immune regulation and functional enrichment among the subtypes. Then, we conducted differential analysis between subtypes and applied weighted gene co-expression network analysis (WGCNA) in three subtypes. We found hub differential expression analysis (DEG) genes and their potential drug based on the WGCNA results and the drug-gene interaction database (DGIdb). Finally, in vivo and in vitro studies showed significant differences in m6A methyltransferase METTL3 levels in rosacea mice and control mice, as well as in the skin of rosacea patients and healthy people, while reducing METTL3 significantly inhibited the inflammatory response of human fibroblasts (HDFs) stimulated by LL37, suggesting that METTL3 may be associated with changes in overall m6A levels in rosacea. Taken together, our findings provide valuable insights into therapeutic targets and drug predictions for rosacea.

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.

Polynucleotides Suppress Inflammation and Stimulate Matrix Synthesis in an In Vitro Cell-Based Osteoarthritis Model

Osteoarthritis (OA) is characterized by degeneration of the joint cartilage, inflammation, and a change in the chondrocyte phenotype. Inflammation also promotes cell hypertrophy in human articular chondrocytes (HC-a) by activating the NF-κB pathway. Chondrocyte hypertrophy and inflammation promote extracellular matrix degradation (ECM). Chondrocytes depend on Smad signaling to control and regulate cell hypertrophy as well as to maintain the ECM. The involvement of these two pathways is crucial for preserving the homeostasis of articular cartilage. In recent years, Polynucleotides Highly Purified Technology (PN-HPT) has emerged as a promising area of research for the treatment of OA. PN-HPT involves the use of polynucleotide-based agents with controlled natural origins and high purification levels. In this study, we focused on evaluating the efficacy of a specific polynucleotide sodium agent, known as CONJURAN, which is derived from fish sperm. Polynucleotides (PN), which are physiologically present in the matrix and function as water-soluble nucleic acids with a gel-like property, have been used to treat patients with OA. However, the specific mechanisms underlying the effect remain unclear. Therefore, we investigated the effect of PN in an OA cell model in which HC-a cells were stimulated with interleukin-1β (IL-1β) with or without PN treatment. The CCK-8 assay was used to assess the cytotoxic effects of PN. Furthermore, the enzyme-linked immunosorbent assay was utilized to detect MMP13 levels, and the nitric oxide assay was utilized to determine the effect of PN on inflammation. The anti-inflammatory effects of PN and related mechanisms were investigated using quantitative PCR, Western blot analysis, and immunofluorescence to examine and analyze relative markers. PN inhibited IL-1β induced destruction of genes and proteins by downregulating the expression of MMP3, MMP13, iNOS, and COX-2 while increasing the expression of aggrecan (ACAN) and collagen II (COL2A1). This study demonstrates, for the first time, that PN exerted anti-inflammatory effects by partially inhibiting the NF-κB pathway and increasing the Smad2/3 pathway. Based on our findings, PN can potentially serve as a treatment for OA.

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.

New Insights into the Mutual Promotion of Rosacea, Anxiety, and Depression from Neuroendocrine Immune Aspects

Rosacea is a common chronic inflammatory skin disease with a complex etiology and undefined pathogenesis, and there is still a lack of targeted clinical treatment. Patients with rosacea are at a higher risk of anxiety and depression compared to the healthy population. Compared to skin conditions such as acne and psoriasis, rosacea has been much less studied in relation to multiple-etiology psychiatric disorders such as anxiety and depression. In contrast to the mainstream belief that the causal association between rosacea and psychiatric disorders is that rosacea increases the psychological burden of patients and thus triggers psychiatric disorders simply by altering their facial appearance, this review outlines the possible common mechanisms between rosacea and anxiety and depression disorders, starting from the pathophysiological mechanisms of transient receptor potential family cation channels, HPA axis, and Th1/Th17 cell polarization. It envisages the possibility of the neuroendocrine-immune interplay between rosacea and anxiety and depression, and new ideas on the complex causal relationship between rosacea and psychiatric disorders, offering more orientations to open up new therapeutic approaches for rosacea.

Supramolecular salicylic acid ameliorates rosacea-like eruptions by suppressing NLRP3-mediated inflammasome activation in mice

BACKGROUND

Rosacea is a chronic inflammatory skin disease with immunological dysfunction. Supramolecular salicylic acid (SSA) has the properties of keratolytic, antibacterial, and anti-inflammatory. However, the mechanism of SSA in the treatment of rosacea is still unclear.

OBJECTIVE

To investigate the efficiencies and molecular mechanisms of SSA in rosacea.

METHODS

Forty mice were randomly divided into four groups (10 in each group): control, LL-37, LL-37 + azelaic acid (AzA), and LL-37 + SSA. Forty μl LL-37 (320 μM) was administered intradermally into the dorsal skin of the mice in the latter 3 groups every 12 h and 4 times altogether (0 h, 12 h, 24 h, 36 h). Twenty % AzA was applied on the eruptions after the first and third LL-37 injection (0 h, 24 h) in LL-37 + AzA group, while 30 % SSA was applied after the first injection (0 h) in LL-37 + SSA group. The redness score and redness area were evaluated. The skin barrier function was measured by the transepidermal water loss (TEWL) and pH. The infiltration of inflammatory cells was evaluated by hematoxylin-eosin staining, and the inflammatory biomarkers were analyzed by RT-PCR and immunohistochemistry.

RESULTS

SSA alleviated LL-37-induced rosacea-like inflammation. The increased TEWL and pH induced by LL-37 were also reversed by SSA. In addition, SSA reduced inflammatory cell infiltration and suppressed the production of Toll-like receptor 2, Matrix metallopeptidase 9, kallikrein 5, LL-37 associated with rosacea, and inhibited LL-37-induced NOD-like receptor family, pyrin domain containing 3 (NLRP3)-mediated inflammasome activation in mice.

CONCLUSIONS

Our findings indicated that SSA ameliorated LL-37-induced rosacea-like lesions by suppressing NLRP3-mediated inflammasome activation in mice.

Thalidomide Attenuates Mast Cell Activation by Upregulating SHP-1 Signaling and Interfering with the Action of CRBN

Allergy is a chronic inflammatory disease, and its incidence has increased worldwide in recent years. Thalidomide, which was initially used as an anti-emetic drug but was withdrawn due to its teratogenic effects, is now used to treat blood cancers. Although the anti-inflammatory and immunomodulatory properties of thalidomide have been reported, little is known about its influence on the mast cell-mediated allergic reaction. In the present study, we aimed to evaluate the anti-allergic activity of thalidomide and the underlying mechanism using mouse bone marrow-derived mast cells (BMMCs) and passive cutaneous anaphylaxis (PCA) mouse models. Thalidomide markedly decreased the degranulation and release of lipid mediators and cytokines in IgE/Ag-stimulated BMMCs, with concurrent inhibition of FcεRI-mediated positive signaling pathways including Syk and activation of negative signaling pathways including AMP-activated protein kinase (AMPK) and SH2 tyrosine phosphatase-1 (SHP-1). The knockdown of AMPK or SHP-1 with specific siRNA diminished the inhibitory effects of thalidomide on BMMC activation. By contrast, the knockdown of cereblon (CRBN), which is the primary target protein of thalidomide, augmented the effects of thalidomide. Thalidomide reduced the interactions of CRBN with Syk and AMPK promoted by FcεRI crosslinking, thereby relieving the suppression of AMPK signaling and suppressing Syk signaling. Furthermore, oral thalidomide treatment suppressed the PCA reaction in mice. In conclusion, thalidomide suppresses FcεRI-mediated mast cell activation by activating the AMPK and SHP-1 pathways and antagonizing the action of CRBN, indicating that it is a potential anti-allergic agent.

Thalidomide Attenuates Skin Lesions and Inflammation in Rosacea-Like Mice Induced by Long-Term Exposure of LL-37

Purpose

Most of the existing studies focus on the early inflammation of rosacea, with few interventions on the later development of fibrosis and the relationship between thalidomide and rosacea. The purpose of this study was to construct a long-term induction model and explore the effects of thalidomide on the later stage of inflammation and early stage of fibrosis in rosacea.

Patients and Methods

BALB/c male mice were randomly divided into four groups: control group, control plus thalidomide group, LL-37 group and LL-37 plus thalidomide group, Intradermal and intraperitoneal injections were given. After repeated induction, skin changes were recorded by taking photos. The animals were sacrificed, the back skin was used for HE staining and VG staining to detect histomorphological characteristics. Immunofluorescence staining and Western blot were used to detect the expression of inflammatory and fibrosis-related factors.

Results

The results were compared with the early stage of the model, wherein the skin inflammation of the 20-day mice was more obvious with a trend of fibrosis. Compared with the control group, histopathological examination showed that the inflammatory cell infiltration in the LL-37 group was significantly increased, and the skin was thickened with collagen deposition. LL-37 induction significantly increased the expression of inflammatory markers (eg, TNF-α and IL-1β) and fibrotic markers (eg, COL1, α-SMA, vimentin and N-Cadherin). Intervention with thalidomide significantly reduced erythema, inflammatory cell infiltration, collagen deposition, and down-regulate the expression of inflammation and fibrosis related factors in rosacea mice.

Conclusion

The long-term continuous induction of LL-37 in mice could simulate the occurrence and development of rosacea, and thalidomide could ameliorate the rosacea induced by long-term exposure to LL-37 by regulating inflammatory infiltration, collagen deposition and fibrosis-related processes.

Role of MrgprB2 in Rosacea-Like Inflammation in Mice: Modulation by β-Arrestin 2

Cathelicidin LL-37‒mediated activation of mast cells (MCs) has been implicated in the pathogenesis of rosacea, but the receptor involved and the mechanism of its activation and regulation remain unknown. We found that skin biopsies from patients with rosacea display higher frequencies of MCs expressing MRGPRX2 (mouse counterpart MrgprB2) than normal skin. Intradermal injection of LL-37 in wild-type mice resulted in MC recruitment, expression of inflammatory mediators, and development of rosacea-like inflammation. These responses were substantially reduced in MrgprB2‒/‒ mice and abolished in MC deficient Wsh/Wsh mice. β-arrestin 2 is an adaptor protein that regulates G protein-coupled receptor function by receptor desensitization and also by activation of downstream signaling. We found that LL-37‒induced rosacea-like inflammation was significantly reduced in mice with MC-specific deletion of β-arrestin 2 compared with that in control mice. Interestingly, the absence of β-arrestin 2 resulted in enhanced cofilin phosphorylation and substantial inhibition of LL-37‒induced chemotaxis of mouse peritoneal MCs. Furthermore, LL-37‒induced extracellular signal‒regulated kinase 1/2 phosphorylation, NF-κB activation, and proinflammatory cytokine/chemokine production were reduced in β-arrestin 2‒/‒ peritoneal MCs compared with those in wild-type cells. These findings suggest that MRGPRX2/B2 participates in rosacea and that β-arrestin 2 contributes to its pathogenesis by promoting cofilin dephosphorylation, extracellular signal‒regulated kinase 1/2 and NF-κB phosphorylation, MC chemotaxis, and chemokine/cytokine generation.

P38 MAPK, NF-κB, and JAK-STAT3 Signaling Pathways Involved in Capecitabine-Induced Hand-Foot Syndrome via Interleukin 6 or Interleukin 8 Abnormal Expression

Hand-foot syndrome (HFS) is a major adverse reaction to capecitabine (CAP). The exact pathogenesis of this disease remains unclear. In this study, metabolomics combined with cell RNA sequencing was used to study the mechanisms of CAP-induced HFS. The murine model of HFS was constructed by intragastric administration of CAP or its metabolites. Quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays were used to verify the mechanisms. Metabolomics showed the phosphatidylinositol signaling pathway and amino acid and fatty acid metabolism to be the major metabolic alterations related to the occurrence of HFS. Transcriptomics profiles further revealed that the cytokine-cytokine receptor interaction, IL17 signaling pathway, Toll-like receptor signaling pathway, arachidonic acid metabolism, MAPK signaling pathway, and JAK-STAT3 signaling pathway were the vital steps in skin toxicity induced by CAP or its metabolites. We also verified that the inflammation mechanisms were primarily mediated by the abnormal expression of interleukin (IL) 6 or IL8 and not exclusively by COX-2 overexpression. Finally, the P38 MAPK, NF-κB, and JAK-STAT3 signaling pathways, which mediate high levels of expression of IL6 or IL8, were identified as potential pathways underlying CAP-induced HFS.

mTORC1-Mediated Angiogenesis is Required for the Development of Rosacea

Although multiple evidences suggest that angiogenesis is associated with the pathophysiology of rosacea, its role is still in debate. Here, we showed that angiogenesis was enhanced in skin lesions of both rosacea patients and LL37-induced rosacea-like mice. Inhibition of angiogenesis alleviated LL37-induced rosacea-like features in mice. Mechanistically, we showed that mTORC1 was activated in the endothelial cells of the lesional skin from rosacea patients and LL37-induced rosacea-like mouse model. Inhibition of mTORC1 decreased angiogenesis and blocked the development of rosacea in mice. On the contrary, hyperactivation of mTORC1 increased angiogenesis and exacerbated rosacea-like phenotypes. Our in vitro results further demonstrated that inhibition of mTORC1 signaling significantly declined LL37-induced tube formation of human endothelial cells. Taken together, our findings revealed that mTORC1-mediated angiogenesis responding to LL37 might be essential for the development of rosacea and targeting angiogenesis might be a novel potential therapy.

Bioinformatics and Network Pharmacology Identify the Therapeutic Role and Potential Mechanism of Melatonin in AD and Rosacea

Rosacea is significantly associated with dementia, particularly Alzheimer’s disease (AD). However, the common underlying molecular mechanism connecting these two diseases remains limited. This study aimed to reveal the common molecular regulatory networks and identify the potential therapeutic drugs for rosacea and AD. There were 747 overlapped DEGs (ol-DEGs) that were detected in AD and rosacea, enriched in inflammation-, metabolism-, and apoptosis-related pathways. Using the TF regulatory network analysis, 37 common TFs and target genes were identified as hub genes. They were used to predict the therapeutic drugs for rosacea and AD using the DGIdb/CMap database. Among the 113 predicted drugs, melatonin (MLT) was co-associated with both RORA and IFN-γ in AD and rosacea. Subsequently, network pharmacology analysis identified 19 pharmacological targets of MLT and demonstrated that MLT could help in treating AD/rosacea partly by modulating inflammatory and vascular signaling pathways. Finally, we verified the therapeutic role and mechanism of MLT on rosacea in vivo and in vitro. We found that MLT treatment significantly improved rosacea-like skin lesion by reducing keratinocyte-mediated inflammatory cytokine secretion and repressing the migration of HUVEC cells. In conclusion, this study contributes to common pathologies shared by rosacea and AD and identified MLT as an effective treatment strategy for rosacea and AD via regulating inflammation and angiogenesis.

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.

Immunomodulatory effects of thalidomide in an experimental brain death liver donor model

Brain death is characterized by a generalized inflammatory response that results in multiorgan damage. This process is mainly mediated through cytokines, which amplify graft immunogenicity. We investigated the immunological response in a brain death liver donor model and analysed the effects of thalidomide, a drug with powerful immunomodulatory properties. Brain death was induced in male Lewis rats. We studied three groups: Control (sham-operated rats in which trepanation was performed without inserting the balloon catheter), BD (rats subjected to brain death by increasing intracranial pressure) and BD + Thalid (BD rats receiving thalidomide after brain death). After 6 h, serum levels of AST, ALT, LDH, and ALP as well as systemic and hepatic levels of TNF-α, IL1-β, IL-6, and IL-10 were analysed. We also determined the mRNA expression of MHC Class I and Class II, NF-κB, and macrophage infiltration. NF-κB was also examined by electrophoretic mobility shift assay. Thalidomide treatment significantly reduced serum levels of hepatic enzymes and TNF-α, IL-1-β, and IL-6. These cytokines were evaluated at either the mRNA expression or protein level in liver tissue. In addition, thalidomide administration resulted in a significant reduction in macrophages, MHC Class I and Class II, and NF-κB activation. This study reveals that thalidomide significantly inhibited the immunologic response and graft immunogenicity, possibly through suppression of NF-κB activation.

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.

Aspirin alleviates skin inflammation and angiogenesis in rosacea

Rosacea is a chronic, relapsing inflammatory skin disease featured by abnormal activation of immune responses, vascular dysfunction and prominent permeability barrier alterations. Aspirin, as the first nonsteroidal anti-inflammatory drug (NSAID), is widely used for various inflammatory conditions due to its anti-inflammatory and anti-angiogenic properties. However, its effects on rosacea are unclear. In this study, we demonstrated that aspirin dramatically improved pathological phenotypes in LL37-induced rosacea-like mice. The RNA-sequencing analysis revealed that aspirin alleviated rosacea-like skin dermatitis mainly via modulating immune responses. Mechanically, we showed that aspirin decreased the production of chemokines and cytokines associated with rosacea, and suppressed the Th1- and Th17-polarized immune responses in LL37-induced rosacea-like mice. Besides, aspirin administration decreased the microvessels density and the VEGF expression in rosacea-like skin. We further demonstrated that aspirin inhibited the activation of NF-κB signaling and the release of its downstream pro-inflammatory cytokines. Collectively we showed that aspirin exerts a curative effect on rosacea by attenuating skin inflammation and angiogenesis, suggesting a promising therapeutic candidate for the treatment of rosacea.

Thalidomide reduces glycerol-induced acute kidney injury by inhibition of NF-κB, NLRP3 inflammasome, COX-2 and inflammatory cytokines

Acute kidney injury (AKI) is an important clinical complication of rhabdomyolysis. The inflammatory processes are involved in the pathogenesis of AKI induced by rhabdomyolysis. Thalidomide is an anti-inflammatory agent that has been used in the treatment of inflammatory disorders. The aim of this study was to investigate the therapeutic effect of thalidomide and its underlying mechanisms on a mouse model of rhabdomyolysis-induced AKI. Mice were injected with a single dose of glycerol (50%, 10 ml/kg, im) to induce AKI, and treated with thalidomide (40 and 80 mg/kg/day, orally) for 2 days. Renal tissue and blood samples were collected for histological and biochemical analysis. In thalidomide treated mice, blood urea nitrogen (BUN) (59.3 ± 19.6 vs. 223 ± 33 mg/dl), plasma creatinine (0.58 ± 0.3 vs. 1.28 ± 0.3 mg/dl), relative kidney weight (0.93 ± 0.13% vs. 1.22 ± 0.1%) and histopathological damage (1.5 ± 0.8 vs. 3.3 ± 1.1 score) were significantly lower as compared to the glycerol group. The results also showed that the levels of malondialdehyde (MDA) (0.13 ± 0.02 vs. 0.2 ± 0.01 µM/mg), myeloperoxidase (MPO) (0.1 ± 0.05 vs. 0.25 ± 0.02 U/mg) and the expression of nuclear factor kappa B (NF-κB) (1.7-fold), NLRP3 inflammasome (1.4-fold) and cyclooxygenase (COX)-2 (3-fold) in renal tissue were significantly lower in thalidomide treated group than those in the glycerol group. Thalidomide treatment resulted in lower renal pro-inflammatory cytokines tumor necrosis factor (TNF)-α (6.7 ± 0.8 vs. 12.3 ± 1.2 ng/ml), interleukin (IL)-1β (3.2 ± 0.5 vs. 5.1 ± 0.3 pg/mg), IL-6 (24.7 ± 2.4 vs. 33 ± 3 pg/mg) and transforming growth factor (TGF)-β1 (0.6 ± 0.17 vs. 1.56 ± 0.24 ng/ml) than those in the glycerol treated mice. In addition the levels of monocyte chemoattractant protein (MCP)-1 (9.5 ± 1 vs. 12.8 ± 1.1 pg/mg) and intercellular adhesion molecule (ICAM)-1 (22.8 ± 7.8 vs. 53.3 ± 5.5 pg/mg) were significantly lower in renal tissue of mice treated with thalidomide as compared to the glycerol treated mice. In conclusion these data revealed that thalidomide may be a potential therapeutic approach against rhabdomyolysis-induced AKI through inhibition of inflammatory responses.

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.

Murine models of rosacea: a review

Rosacea is a chronic inflammatory disease characterized by facial flushing, erythema, telangiectasia, papules, and pustules. Its pathogenesis has not been fully understood. In 2017, the global ROSacea COnsensus (ROSCO) panel updated the diagnosis, classification, and assessment of rosacea. Phenotype-based treatments and long-term managements have also been recommended. Murine models are a powerful tool in unveiling and dissecting the mechanisms of human diseases. Here, we summarized murine models of rosacea developed or used in previous research, including LL-37 intradermal injection model, KLK-5-induced inflammation model, croton oil inflammation model, 12-O-Tetradecanoylphorbol-13-acetate inflammation model, arachidonic acid inflammation model, RTX-induced vasodilation model, and UVB-induced model. LL-37 injection model has become the most intensively used model in rosacea research. Each model could show the pathophysiological and clinical features of rosacea to some extent. However, no model can show the full picture of the characteristics of rosacea. Improving existed murine models, developing new murine models, and applying them to pathogenesis and treatment research on rosacea are highly warranted in the future.

Prevalence and Risk Factors of Anxiety and Depression in Rosacea Patients: A Cross-Sectional Study in China

Rosacea is a chronic inflammatory skin disease characterized by facial redness and bothersome symptoms. It can exert significant psychological effects and impair the quality of life of patients. To investigate the prevalence and risk predictors of anxiety and depression in rosacea patients, we conducted a cross-sectional study in an outpatient setting. Consecutive patients completed a questionnaire, which included questions on sociodemographic information and severity of signs and symptoms; they also completed the Patient Health Questionnaire and the Generalized Anxiety Disorder scale. Disease burden was assessed using Dermatology Life Quality Index (DLQI), Willing-to-Pay, and Time trade-off. Multivariate analysis was conducted to determine the risk factors for anxiety and depression. A total of 774 patients completed the survey. The prevalence of anxiety was 53.9% (95% CI: 50.4-57.4%) and that of depression was 58.1% (95% CI: 54.7-61.6%). The factors associated with anxiety were age, gender, the need to make appearances at work, severity of self-reported symptoms, the number of rosacea signs and adaptive behaviors, and disease burden. Depression was associated with younger age, more severe self-reported symptoms, more adaptive behaviors, and higher disease burden. After adjusting for demographics, the risk of anxiety or depression increased in young patients who had severe self-reported symptoms, high DLQI scores, and many adaptive behaviors. Taken together, there is a high prevalence of anxiety and depression among Chinese rosacea patients. Younger rosacea patients who have more severe self-reported symptoms and higher disease burden are prone to anxiety and depression.

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.

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.

Exploring the wound healing, anti-inflammatory, anti-pathogenic and proteomic effects of lactic acid bacteria on keratinocytes

The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders.

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.