Signalling by senescent melanocytes hyperactivates hair growth.

Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration1. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity. Here, using genetic mouse models of nevi2,3, we show that dermal clusters of senescent melanocytes drive epithelial hair stem cells to exit quiescence and change their transcriptome and composition, potently enhancing hair renewal. Nevus melanocytes activate a distinct secretome, enriched for signalling factors. Osteopontin, the leading nevus signalling factor, is both necessary and sufficient to induce hair growth. Injection of osteopontin or its genetic overexpression is sufficient to induce robust hair growth in mice, whereas germline and conditional deletions of either osteopontin or CD44, its cognate receptor on epithelial hair cells, rescue enhanced hair growth induced by dermal nevus melanocytes. Osteopontin is overexpressed in human hairy nevi, and it stimulates new growth of human hair follicles. Although broad accumulation of senescent cells, such as upon ageing or genotoxic stress, is detrimental for the regenerative capacity of tissue4, we show that signalling by senescent cell clusters can potently enhance the activity of adjacent intact stem cells and stimulate tissue renewal. This finding identifies senescent cells and their secretome as an attractive therapeutic target in regenerative disorders.

SIRT7 activates quiescent hair follicle stem cells to ensure hair growth in mice.

Hair follicle stem cells (HFSCs) are maintained in a quiescent state until activated to grow, but the mechanisms that reactivate the quiescent HFSC reservoir are unclear. Here, we find that loss of Sirt7 in mice impedes hair follicle life-cycle transition from telogen to anagen phase, resulting in delay of hair growth. Conversely, Sirt7 overexpression during telogen phase facilitated HSFC anagen entry and accelerated hair growth. Mechanistically, Sirt7 is upregulated in HFSCs during the telogen-to-anagen transition, and HFSC-specific Sirt7 knockout mice (Sirt7f/f ;K15-Cre) exhibit a similar hair growth delay. At the molecular level, Sirt7 interacts with and deacetylates the transcriptional regulator Nfatc1 at K612, causing PA28γ-dependent proteasomal degradation to terminate Nfatc1-mediated telogen quiescence and boost anagen entry. Cyclosporin A, a potent calcineurin inhibitor, suppresses nuclear retention of Nfatc1, abrogates hair follicle cycle delay, and promotes hair growth in Sirt7-/- mice. Furthermore, Sirt7 is downregulated in aged HFSCs, and exogenous Sirt7 overexpression promotes hair growth in aged animals. These data reveal that Sirt7 activates HFSCs by destabilizing Nfatc1 to ensure hair follicle cycle initiation.

Exploring metformin as a candidate drug for rosacea through network pharmacology and experimental validation.

Rosacea is a common chronic inflammatory disease that affects the middle of the face. Due to the unclear pathogenesis, the effective treatment options for rosacea remain limited. In this study, weighted gene co-expression network analyses (WGCNA) identified three rosacea-related hub modules, which were involved in immune-, metabolic- and development- related signaling pathways. Next, the key genes from green and brown modules were submitted to CMap database for drug prediction and metformin was identified as a candidate drug for rosacea. Moreover, network pharmacology analysis identified pharmacological targets of metformin and demonstrated that metformin could help in treating rosacea partly by modulating inflammatory and angiogenesis signaling pathways. Finally, we verified the therapeutic role and mechanism of metformin on rosacea in vivo and vitro. We found that metformin treatment significantly improved rosacea-like skin lesions including immune cells infiltration, cytokines/chemokines expression and angiogenesis. Moreover, metformin suppressed LL37- and TNF-α-induced the ROS production and MAPK-NF-κB signal activation in keratinocytes cells. In conclusion, our findings identified and verified metformin as a novel therapeutic candidate for rosacea, and it alleviates the pathological symptoms, possibly by suppressing inflammatory responses, angiogenesis in rosacea.

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.

[Expression pattern of mTOR subunits Raptor and Rictor in mouse hair follicle cycle].

OBJECTIVE: To detemine the expression pattern of mTOR complex subunits Raptor and Rictor in the hair follicles of mice at different hair follicle stages, and to explore its significance. 
 Methods: Immunostaining of Ki-67, a proliferative marker, was used to determine the precise hair follicle stages of mouse dorsal skin at different postnatal time points. Real-time PCR was used to detect the mRNA expression of Raptor and Rictor in mouse dorsal skin at 43 days after birth (P43, early telogen), 56 days after birth (P56, mid-telogen), 69 days after birth (P69, late telogen) and 74 days after birth (P74, early anagen). The expression intensity and localization of Raptor and Rictor at different stages of hair cycle were tested by co-immumostaining.
 Results: Ki-67 immunostaining showed that the time points (P43, P56, P69, P74) and hair follicle stages (early telogen, mid-telogen, late telogen, early anagen) of the dorsal skin were consistent with each other. The results of real-time PCR and immunostaining were consistent, showing that the expression of Raptor and Rictor did not changed in the early-, mid-, late telogen, and early anagen. However, Raptor was specifically expressed in the bulge where hair follicle stem cells (HFSCs) are residing in, and Rictor was mainly detected in inner root sheath (IRS) cells. 
 Conclusion: The expression of Raptor and Rictor does not altered in the hair follicles at different hair follicle stages, but Raptor and Rictor are specifically expressed in the HFSCs and IRS cells, respectively, indicating that Raptor might be a molecular marker for HFSCs, and Rictor might be involved in the maintenance of IRS and formation of hair shaft.

Senescence of human skin-derived precursors regulated by Akt-FOXO3-p27(KIP¹)/p15(INK4b) signaling.

Multipotent skin-derived precursors (SKPs) are dermal stem cells with the capacity to reconstitute the dermis and other tissues, such as muscles and the nervous system. Thus, the easily available human SKPs (hSKPs) hold great promises in regenerative medicine. However, long-term expansion is difficult for hSKPs in vitro. We previously demonstrated that hSKPs senesced quickly under routine culture conditions. To identify the underlying mechanisms so as to find an effective way to expand hSKPs, time-dependent microarray analysis of gene expression in hSKPs during in vitro culture was performed. We found that the senescence of hSKPs had a unique gene expression pattern that differs from reported typical senescence. Subsequent investigation ruled out the role of DNA damage and classical p53 and p16(INK4a) signaling in hSKP senescence. Examination of cyclin-dependent kinase inhibitors revealed the involvement of p15(INK4b) and p27(KIP1). Further exploration about upstream signals indicated the contribution of Akt hypo-activity and FOXO3 to hSKP senescence. Forced activation of Akt and knockdown of FOXO3, p15(INK4b) and p27(KIP1) effectively inhibited hSKP senescence and promoted hSKP proliferation. The unique senescent phenotype of human dermal stem cells and the role of Akt-FOXO3-p27(KIP1)/p15(INK4b) signaling in regulating hSKP senescence provide novel insights into the senescence and self-renewal regulation of adult stem cells. The present study also points out a way to propagate hSKPs in vitro so as to fulfill their promises in regenerative medicine.

Exogenous R-Spondin1 Induces Precocious Telogen-to-Anagen Transition in Mouse Hair Follicles.

R-spondin proteins are novel Wnt/ß-catenin agonists, which signal through their receptors leucine-rich repeat-containing G-protein coupled receptor (LGR) 4/5/6 and substantially enhance Wnt/ß-catenin activity. R-spondins are reported to function in embryonic development. They also play important roles in stem cell functions in adult tissues, such as the intestine and mammary glands, which largely rely on Wnt/ß-catenin signaling. However, in the skin epithelium and hair follicles, the information about R-spondins is deficient, although the expressions and functions of their receptors, LGR4/5/6, have already been studied in detail. In the present study, highly-enriched expression of the R-spondin family genes (Rspo1/2/3/4) in the hair follicle dermal papilla is revealed. Expression of Rspo1 in the dermal papilla is specifically and prominently upregulated before anagen entry, and exogenous recombinant R-spondin1 protein injection in mid-telogen leads to precocious anagen entry. Moreover, R-spondin1 activates Wnt/ß-catenin signaling in cultured bulge stem cells in vitro, changing their fate determination without altering the cell proliferation. Our pioneering study uncovers a role of R-spondin1 in the activation of cultured hair follicle stem cells and the regulation of hair cycle progression, shedding new light on the governance of Wnt/ß-catenin signaling in skin biology and providing helpful clues for future treatment of hair follicle disorders.

Ovine Hair Follicle Stem Cells Derived from Single Vibrissae Reconstitute Haired Skin.

Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to isolate them have not been well addressed. Here, we report an efficient strategy to obtain multipotent ovine HFSCs. Through microdissection and organ culture, we obtained keratinocytes that grew from the bulge area of vibrissa hair follicles, and even abundant keratinocytes were harvested from a single hair follicle. These bulge-derived keratinocytes are highly positive for Krt15, Krt14, Tp63, Krt19 and Itga6; in addition to their strong proliferation abilities in vitro, these keratinocytes formed new epidermis, hair follicles and sebaceous glands in skin reconstitution experiments, showing that these are HFSCs from the bulge outer root sheath. Taken together, we developed an efficient in vitro system to enrich ovine HFSCs, providing enough HFSCs for the investigations about the ovine hair cycle, aiming to promote wool production in the future.

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.

Genetic deletion of Cxcl14 in mice alters uterine NK cells.

The uterine natural killer cells (uNK cells) are the major immune cells in pregnant uterus and the number of uNK cells is dramatically increased during placentation and embryo development. The uNK cells are necessary for the immune tolerance, cytokine secretion and angiogenesis of placenta. Former studies indicated that the population expansion of uNK cells was accomplished through recruitment of NK cell precursors from the spleen and bone marrow, but not proliferation of NK cells. However, the necessary molecules within this process were little understood. Here in our study, we found the co-localized expression of Cxcl14 protein with uNK cells in E13.5 pregnant uterus. Moreover, we used Cxcl14 knockout mice to examine uNK cells in mesometrial lymphoid aggregate of pregnancy (MLAp) and decidua basalis (DB) of E13.5 pregnant uterus and found significantly decreased uNK cells in Cxcl14(-/-) pregnant uteri compared with Cxcl14(+/-) pregnant uteri. To further explorer the molecular change in MLAp and DB after Cxcl14 knockout, we isolated the MLAp and DB from Cxcl14(+/+) and Cxcl14(-/-) pregnant uteri and performed microarray analysis. We found many genes were up and down regulated after Cxcl14 knockout. In conclusion, our results suggested the important function of Cxcl14 in uNK cells and the proper level of Cxcl14 protein were required to recruit NK cells to pregnant uterus.

EGCG identified as an autophagy inducer for rosacea therapy.

Background: Rosacea is a common facial skin inflammatory disease featured by hyperactivation of mTORC1 signaling in the epidermis. Due to unclear pathogenesis, the effective treatment options for rosacea remain limited. Methods: Weighted gene co-expression network analysis (WGCNA) analyzed the relationship between epidermis autophagy and mTOR pathways in rosacea, and further demonstrated it through immunofluorescence and qPCR analysis. A potential therapeutic agent for rosacea was predicted based on the key genes of the WGCNA module. In vivo and in vitro experiments were conducted to verify its therapeutic role. Drug-target prediction (TargetNet, Swiss, and Tcmsp) and molecular docking offered potential pharmacological targets. Results: WGCNA showed that epidermis autophagy was related to the activation of mTOR pathways in rosacea. Next, autophagy was downregulated in the epidermis of rosacea, which was regulated by mTOR. In addition, the in vivo experiment demonstrated that autophagy induction could be an effective treatment strategy for rosacea. Subsequently, based on the key genes of the WGCNA module, epigallocatechin-3-gallate (EGCG) was predicted as a potential therapeutic agent for rosacea. Furthermore, the therapeutic role of EGCG on rosacea was confirmed in vivo and in vitro. Finally, drug-target prediction and molecular docking revealed that AKT1/MAPK1/MMP9 could be the pharmacological targets of EGCG in rosacea. Conclusion: Collectively, our findings revealed the vital role of autophagy in rosacea and identified that EGCG, as a therapeutic agent for rosacea, attenuated rosacea-like inflammation via inducing autophagy in keratinocytes.

Targeting Aquaporin-3 Attenuates Skin Inflammation in Rosacea.

Rosacea is a common inflammatory skin disorder mediated by the dysregulation of both keratinocytes and T cells. Here, we report that aquaporin 3 (AQP3), a channel protein that mediates the transport of water/glycerol, was highly expressed in the epidermis and CD4+ T cells of both rosacea patients and experimental mice. Specifically, AQP3 deletion blocked the development of rosacea-like skin inflammation in model mice with LL37-induced rosacea-like disease. We also present mechanistic evidence showing that AQP3 was essential to the activation of NF-κB signaling and subsequent production of disease-characteristic chemokines in keratinocytes. Moreover, we show that AQP3 was upregulated during T cell differentiation and promotes helper T (Th) 17 differentiation possibly via the activation of STAT3 signaling. Our findings reveal that AQP3-mediated activation of NF-κB in keratinocytes and activation of STAT3 in CD4+ T cells acted synergistically and contributed to the inflammation in rosacea.

Efficacy and safety of antibiotic agents in the treatment of rosacea: a systemic network meta-analysis.

Background: Antibiotics are considered the backbone of rosacea management, especially for controlling inflammatory papules and pustules. We aim to evaluate the efficacy and safety of varied prescriptions and doses of antibiotics in treating rosacea by network meta-analysis. Methods: In this study, we compared all available randomized controlled trials (RCTs) that have studied systemic and topical antibiotics and placebo in rosacea therapy. We searched databases such as the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PubMed, Web of Science, and LILACS for published and unpublished RCTs on ClinicalTrials.gov before April 2023. The primary outcome was the improvement of the Investigator's Global Assessment (IGA) scores, and the secondary outcomes consisted of the improvement of the Patient's Global Assessment (PaGA) scores, Clinician's Erythema Assessment (CEA) scores, and adverse events (AEs). We used Bayesian random effects models for multiple treatment comparisons. Results: We identified 1,703 results through these databases. Thirty-one randomized trials with 8,226 patients were included. The heterogeneity and inconsistency between the trials were low, with a low risk of bias of all trials. Oral doxycycline 40 mg, minocycline 100 mg, and minocycline 40 mg, as well as topical ivermectin and metronidazole 0.75%, were effective in treating papules and pustules, thereby decreasing IGA in rosacea. Among these, minocycline 100 mg ranked top in efficacy. As for improving the PaGA scores, topical ivermectin, metronidazole 1%, and systemic oxytetracycline were effective, of which oxytetracycline worked the best. Both doxycycline 40 mg and metronidazole 0.75% presented no therapeutic effect for erythema. Considering the safety of the agents, systemic application of azithromycin and doxycycline 100 mg significantly increase the risk of AEs. Conclusion: Our review suggests that a high dosage of systemic minocycline is the most effective in treating rosacea phenotypes with papules and pustules with a low risk of AEs. However, there were no sufficient evidence-based data in exploring the influence of antibiotics on erythema. The phenotype of rosacea should be taken into consideration along with benefit and safety when making prescriptions due to AEs. Clinical Trial Registration: NCT(2016): http://cochranelibrary-wiley.com/o/cochrane/clcentral/articles/962/CN-01506962/frame.html NCT(2017): http://cochranelibrary-wiley.com/o/cochrane/clcentral/articles/764/CN-01565764/frame.html.

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.

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.

Neuroimmune Interaction: A Widespread Mutual Regulation and the Weapons for Barrier Organs.

Since the embryo, the nervous system and immune system have been interacting to regulate each other's development and working together to resist harmful stimuli. However, oversensitive neural response and uncontrolled immune attack are major causes of various diseases, especially in barrier organs, while neural-immune interaction makes it worse. As the first defense line, the barrier organs give a guarantee to maintain homeostasis in external environment. And the dense nerve innervation and abundant immune cell population in barrier organs facilitate the neuroimmune interaction, which is the physiological basis of multiple neuroimmune-related diseases. Neuroimmune-related diseases often have complex mechanisms and require a combination of drugs, posing challenges in finding etiology and treatment. Therefore, it is of great significance to illustrate the specific mechanism and exact way of neuro-immune interaction. In this review, we first described the mutual regulation of the two principal systems and then focused on neuro-immune interaction in the barrier organs, including intestinal tract, lungs and skin, to clarify the mechanisms and provide ideas for clinical etiology exploration and treatment.

Mediation roles of neutrophils and high-density lipoprotein (HDL) on the relationship between HLA-DQB1 and rosacea.

BACKGROUND: Though the previous genome-wide association studies found the association between HLA alleles and rosacea in the European populations, the data is lacking among the Asians. Moreover, neutrophils are important in the immune-related mechanism of rosacea, and dyslipidemia is closely related to rosacea. We aimed to explore the association between HLA genes and rosacea in Chinese rosacea patients, as well as the mediation effect of neutrophils, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) on the relationship between HLA genes and rosacea. METHODS: A total of 249 rosacea and 150 controls were ranked by the international investigator global rosacea severity scores. HLA genes, neutrophils, HDL, and LDL were detected. And their mediation effects on the relationship between HLA and rosacea risk or severity were analysed. RESULTS: HLA-DQB1*03:03 allele (OR = 41.89, 95% CI: 9.80 ∼ 179.09, p = 4.7*10-7), HLA-DQB1*04:02 allele (OR = 0.16, 95% CI: 0.03 ∼ 0.81, p = 0.026) and HLA-DQB1*03:03/05:02 genotype (OR = 5.57, 95% CI: 1.13 ∼ 27.52, p = 0.0351) were significantly associated with rosacea. Moreover, HLA-DQB1*03:03 allele (b = 1.434, SE = 0.217, p = 2.0*10-10), HLA-DQB1*05:01 allele (b = 0.894, SE = 0.33520, p = 0.008) and HLA-DQB1*03:03/06:01 genotype (b = 0.998, SE = 0.472, p = 0.040) were positively associated with rosacea severity. Furthermore, we found both neutrophils and HDL, instead of LDL, have mediation effects on the relationship between HLA-DQB1*03:03 and risk or severity of rosacea. CONCLUSIONS: We discovered novel susceptible HLA alleles for rosacea in the Chinese population, and disclosed the mediation effect of neutrophils and HDL on the relationship between HLA-DQB1 and rosacea, implying a possible correlation between rosacea and inflammatory or metabolic factors, providing hints for future studies in the mechanism of rosacea. Key messagesHLA-DQB1*03:03 allele, HLA-DQB1*04:02 allele and HLA-DQB1*03:03/05:02 genotype were significantly associated with rosacea.HLA-DQB1*03:03 allele, HLA-DQB1*05:01 allele and HLA-DQB1*03:03/06:01 genotype were positively associated with rosacea severity.Neutrophils and HDL have mediation effects on the relationship between HLA-DQB1*03:03 and risk or severity of rosacea.

Increased serum levels of CCL3, CXCL8, CXCL9, and CXCL10 in rosacea patients and their correlation with disease severity.

Rosacea is a common chronic inflammatory skin disease involving millions of patients worldwide. Previous studies have highlighted the upregulation of a variety of chemokines in the skin lesions of both rosacea patient and rosacea-like mouse model. However, the serum levels of these chemokines and their clinical significance have not been explored before. In this study, we aimed at examining the serum levels of a series of chemokines (including CCL2, CCL3, CCL20, CXCL1, CXCL8, CXCL9, CXCL10, and CXCL12) implicated in rosacea and their correlation with disease severity. Bio-Plex Pro Human Chemokine Assays were used to measure the serum levels of these chemokines. Investigator's Global Assessment (IGA) was applied for assessing the papules/pustules of rosacea patients, while persistent erythema was evaluated by the Clinician's Erythema Assessment (CEA). Our results revealed that the serum concentration of CCL3, CXCL8, CXCL9, and CXCL10 were markedly elevated in rosacea patients compared to healthy controls. Among them, the levels of CCL3, CXCL8, and CXCL9 were positively correlated with the IGA score, while serum CXCL9 and CXCL10 were positively related with the CEA score of rosacea patients. What's more, the expression of the corresponding receptors of CCL3 (Ccr1), CXCL8 (Cxcr1 and Cxcr2), CXCL9, and CXCL10 (Cxcr3) were all significantly increased in the skin lesions of rosacea-like mouse model with CXCR2 and CXCR3 highly expressed in rosacea patient skins. Our results indicated that CCL3, CXCL8, CXCL9, and CXCL10 might potentially serve as serum indicators for rosacea and could assist the severity evaluation of disease. Findings in this study would also potentially help to develop new targeted therapies for rosacea in future. © 2022 Japanese Dermatological Association.

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.

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.