microRNA在炎症性皮肤病中作用的研究进展

【摘要】 microRNA（miRNA）是一类转录后调控基因表达的非编码RNA分子,参与皮肤各种病理生理过程。近年来,miRNA表达谱的变化已被报道与部分炎症性皮肤病相关,例如miR-203、miR-146a、miR-21在银屑病皮损中表达上调;miR-155、miR-146a在特应性皮炎皮损中表达上调;miR-21、miR-223、miR-142-3p、miR142-5p在过敏性接触性皮炎皮损表达上调;而miR-146a、miR-155在系统性红斑狼疮患者外周血表达下调;miR-223在皮肌炎皮损中表达下调等。本文综述miRNA与部分炎症性皮肤病发生、发展之间的联系。     

Circulating miR-142-3p levels in patients with systemic sclerosis

Background. Recently, increased evidence has shown that serum micro (mi)RNA levels are a useful biomarker for the diagnosis, prognosis and therapeutic value of various diseases. However, serum miRNA has not been investigated in patients with systemic sclerosis (SSc), to our knowledge. Aim. To investigate the possibility that serum levels of Homo sapiens miR‐142 stem‐loop (hsa‐miR‐142‐3p), one of the miRNAs regulating the expression of integrin αV, could be a specific disease marker for SSc. Methods. Serum samples were obtained from 61 patients with SSc and 20 healthy controls. Patients with systemic lupus erythematosus (SLE), dermatomyositis (DM) and scleroderma spectrum disorder (SSD), who did not fulfil American College of Rheumatology criteria for SSc but might develop SSc in the future, were included as disease controls in this study. miRNAs were purified from serum, and miR‐142‐3p levels were measured with a quantitative real‐time PCR assay. Results. Serum miR‐142‐3p levels in patients with SSc were significantly higher than in patients with SSD, SLE or DM, and healthy control groups. Patients with increased miR‐142‐3p levels tended to have a short sublingual frenulum. Conclusions. Our data indicate that serum levels of miR‐142‐3p may be elevated specifically in patients with SSc, correlating with the severity of this disease, and may be useful diagnostic markers for the presence of SSc and for the differentiation of SSc from SSD.     

Allergic contact dermatitis beyond IL‐1β role of additional family members

Contact dermatitis is one of the most frequent pathological manifestations of the skin and plays a central role in clinical dermatology. The IL‐1 family consists a large group of cytokines, which currently contains 11 members with different pro‐ and anti‐inflammatory properties. Among the more pro‐inflammatory‐acting cytokines from the IL‐1 family, IL‐1β, IL‐18, IL‐33 and IL‐36 have been shown to be upregulated in different inflammatory mouse experimental models or skin diseases. The article by Mattii et al. represents a thorough analysis of the expression of IL‐1 family members including IL‐33 in skin samples from patients with allergic contact dermatitis. Although a lot of research is performed in this area, data from human samples are rather scarce. Therefore, Mattii et al. support the development of novel therapeutic concepts, which might include the use of antagonistic molecules targeting the IL‐1 family network.     

microRNA-mediated keratinocyte hyperproliferation in psoriasis vulgaris

Background Psoriasis is a chronic inflammatory skin disease characterized by intense proliferation and abnormal differentiation of keratinocytes, although the pathogenesis is still not completely clarified. Objectives We investigated the mechanism of keratinocyte proliferation seen in psoriasis, focusing on microRNA (miRNA). Materials and methods miRNAs were extracted from tissues and sera of psoriasis, atopic dermatitis and healthy control. To determine pathogenic miRNAs, we performed miRNA polymerase chain reaction (PCR) array analysis. The results were confirmed with quantitative real‐time PCR, in situ hybridization, immunohistochemistry, transient transfection of siRNA and inhibitor in cultured keratinocytes and Western blotting. Results PCR array analysis using tissue miRNA demonstrated miR‐424 level was markedly decreased in psoriasis skin in vivo. Protein expression of mitogen‐activated protein kinase kinase 1 (MEK1) or cyclin E1, predicted target genes of miR‐424, was increased in psoriatic skin, although their mRNA levels were not. The transfection of specific inhibitor of miR‐424 in normal human keratinocytes led to upregulation of MEK1 or cyclin E1 protein, and resulted in increased cell proliferation. On the other hand, cell number was significantly decreased when cells were transfected with siRNA for MEK1 or cyclin E1. Furthermore, we first investigated serum miRNA levels in psoriasis. Although not significant, serum miR‐424 concentration tended to be decreased in patients with psoriasis compared with healthy controls. Conclusions Decreased miR‐424 expression and subsequently increased MEK1 or cyclin E1 may play a key role in the pathogenesis of psoriasis. Investigation of the regulatory mechanisms of keratinocyte proliferation by miRNA may lead to new treatments and a disease activity marker.     

Hair miR‐29a levels are decreased in patients with scleroderma

In the present study, we evaluated the possibility that we can utilize hair shaft miR‐29a levels as disease marker of scleroderma. Hair samples were obtained from 20 scleroderma patients, five dermatomyositis patients and 13 controls. microRNAs were purified from hairs as well as skins or sera, and miR‐29a levels were measured with quantitative real‐time polymerase chain reaction. Mean hair miR‐29a levels in scleroderma patients were significantly lower than those in control subjects or dermatomyositis, while expression levels of hair shaft marker keratin 34 were similar among them. There was no strong correlation among the miR‐29a levels in the hair, skin and serum of each patient, suggesting that hair microRNAs can be independent biomarkers. We found scleroderma patients with decreased miR‐29a levels had contracture of the phalanges at a significantly higher prevalence than those without. To confirm the clinical usefulness of hair microRNAs, large‐scale researches are needed in the future.     

MicroRNA expression differs in cutaneous squamous cell carcinomas and healthy skin of immunocompetent individuals

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers, but the influence of microRNA (miRNA) expression has only been sporadically analysed. We hypothesized that miRNAs are differentially expressed in cSCC and hence influence its development. We therefore isolated total miRNA from well‐differentiated cSCCs and from controls without SCC. Expression analyses of 12 miRNAs showed three significantly differentially expressed miRNAs. We identified a significant upregulation of the miR‐21 and the miR‐31, a proto‐oncogene like miR‐21. While the upregulated expression of miR‐21 has been known for some time, the increased expression of miR‐31 was never shown so clearly. Furthermore, we showed the upregulation of miRNA‐205, which has never been described before. The miR‐205 induces specific keratinocyte migration and could be a characteristic marker for cSCC. It has to be determined in following studies whether these upregulated expressions are specific for cSCC and if so, for which cSCC stages.     

miR‐424 levels in hair shaft are increased in psoriatic patients

Objective diagnostic markers have not been in clinical use for psoriasis. In this study, we investigated the levels of miR‐424 in hair roots and hair shafts in psoriatic patients, and evaluated the possibility that miR‐424 can be a biomarker of the disease. A single hair root and five pieces of hair shafts (~5 cm in length) were obtained from the non‐lesional occiput of each individual of 26 psoriatic patients. Control hair samples were collected from nine normal subjects. Samples from 10 atopic dermatitis patients were also included as the disease control. miR‐424 levels were determined by quantitative real‐time polymerase chain reaction. Hair shaft miR‐424 levels were significantly upregulated only in patients with psoriasis compared with normal controls and those with atopic dermatitis. By receiver–operator curve analysis of hair shaft miR‐424 to distinguish psoriatic patients from normal subjects, the area under the curve was 0.77. However, relative miR‐424 levels were not correlated with disease activity markers including disease duration, body surface area and Psoriasis Area and Severity Index. Hair root miR‐424 was not useful for evaluating both diagnosis and severity of the disease. Our results indicated hair shaft miR‐424 levels may be useful as a diagnostic marker of psoriasis.     

早期蕈样肉芽肿微小RNA表达谱的研究

目的：筛选与早期蕈样肉芽肿（MF）相关的微小RNA（miRNA ）。方法用高通量miRNA PCR芯片检测6例早期MF与6例湿疹和扁平苔藓皮损中miRNA的表达差异。针对差异表达的miRNA，进行13例早期MF、13例湿疹和扁平苔藓皮损组织及Myla细胞株的实时荧光定量PCR（RT?qPCR）验证。结果芯片结果示，相对于对照组，早期MF hsa?miR?378a?5p、hsa?miR?107、hsa?miR?302c?3p显著高表达，差异有统计学意义（P<0.05）。皮损组织的RT?qPCR验证结果与芯片结果一致。与正常人外周血T淋巴细胞相比，Myla细胞株中hsa?miR?378a?5p、hsa?miR?107显著上调，与芯片结果一致；未见hsa?miR?302c?3p的差异性表达。结论与炎症性皮肤病相比，早期MF存在差异表达的miRNA表达谱。     

In vitro and in vivo analysis of pro‐ and anti‐inflammatory effects of weak and strong contact allergens

Please cite this paper as: In vitro and in vivo analysis of pro‐ and anti‐inflammatory effects of weak and strong contact allergens. Experimental Dermatology 2010; 19 : 1007–1013. Abstract: Inflammation is a crucial step in the development of allergic contact dermatitis. The primary contact with chemical allergens, called sensitization, and the secondary contact, called elicitation, result in an inflammatory response in the skin. The ability of contact allergens to induce allergic contact dermatitis correlates to a great extent with their inflammatory potential. Therefore, the analysis of the sensitizing potential of a putative contact allergen should include the examination of its ability and potency to cause an inflammation. In this study, we examined the inflammatory potential of different weak contact allergens and of the strong sensitizer 2,4,6‐trinitrochlorobenzene (TNCB) in vitro and in vivo using the contact hypersensitivity model, the mouse model for allergic contact dermatitis. Cytokine induction was analysed by PCR and ELISA to determine mRNA and protein levels, respectively. Inflammation‐dependent recruitment of skin‐homing effector T cells was measured in correlation with the other methods. We show that the sensitizing potential of a contact allergen correlates with the strength of the inflammatory response. The different methods used gave similar results. Quantitative cytokine profiling may be used to determine the sensitizing potential of chemicals for hazard identification and risk assessment.     

CD4+ T cells producing interleukin (IL)‐17, IL‐22 and interferon‐γ are major effector T cells in nickel allergy

Background It has been suggested that interleukin (IL)‐17 and IL‐22 play important roles in the elicitation of human allergic contact dermatitis; however, the frequencies of T cell subtypes producing IL‐17 and IL‐22 in human allergic contact dermatitis are unknown. Objectives To determine the frequencies of CD4⁺, CD8⁺ and γδ T cells producing IL‐17, IL‐22 and interferon (IFN)‐γ in the blood and skin from nickel‐allergic patients. Patients/materials/methods Blood samples were collected from 14 patients and 17 controls, and analysed by flow cytometry. Biopsies were taken from 5 patients and 6 controls, and analysed by immunohistochemistry and flow cytometry of skin lymphocytes. Results We found an increased frequency of γδ T cells in the blood, but no differences in the distribution of cytokine‐producing CLA⁺ T cell subtypes in nickel‐allergic patients as compared with controls. In nickel‐allergic patients, there was massive cellular infiltration dominated by CD4⁺ T cells producing IL‐17, IL‐22 and IFN‐γ in nickel‐challenged skin but not in vehicle‐challenged skin. Conclusion CD4⁺ T cells producing IL‐17, IL‐22 and IFN‐γ are important effector cells in the eczematous reactions of nickel‐induced allergic contact dermatitis in humans.     

miRNA miR‐17‐92 cluster is differentially regulated in the imiqumod‐treated skin but is not required for imiqumod‐induced psoriasis‐like dermatitis in mice

MicroRNAs (miRNAs) play very important roles in the control of immune cell and keratinocyte development and function and are implicated in skin inflammatory diseases, including psoriasis. miRNA miR‐17‐92 was reported to promote the differentiation of Th1 and Th1 cells and to regulate cell proliferation and apoptosis. Here we showed that imiquimod (IMQ) differentially regulates the expression of miR‐17‐92 cluster in the mouse skin, upregulating miR‐17 and miR‐19 families and downregulating miR‐92. To investigate whether miR‐17‐92 cluster is functionally involved in the psoriasis, we have generated three mutant mice with specific deletion or overexpression of miR‐17‐92 cluster in keratinocytes, or with deletion of miR‐17‐92 cluster in T cells. Interestingly, deletion or overexpression of miR‐17‐92 cluster in keratinocytes, or deletion of miR‐17‐92 in T cells did not significantly affect IMQ‐induced psoriasis‐like dermatitis development in the mutant mice compared with wild‐type littermates. Thus, miRNA miR‐17‐92 cluster may not be a key factor regulating imiqumod‐induced psoriasis‐like dermatitis.     

Expression analysis of multiple microRNAs in each patient with scleroderma

In this study, we compared expression pattern of multiple microRNAs in individual patient with scleroderma with that in normal subject. Serum levels of six microRNAs (miR‐7 g, miR‐21, miR‐29b, miR‐125, miR‐145 and miR‐206) were evaluated using real‐time PCR in 15 patients with scleroderma and 15 normal subjects. While levels of the six microRNAs were similar between the two groups, we found significant difference in the ranks between miRNAs in patients with scleroderma. Additionally, levels of let‐7 g and miR‐125b showed strong and significant correlation in normal subjects, but not in patients with scleroderma. Thus, miRNA expression pattern may be different in patients with scleroderma. We also found the combination of serum levels of miR‐206 and miR‐21 was more useful in distinguishing patients with scleroderma from normal subjects than either miR‐206 or miR‐21 alone. Our study is the first to demonstrate different expression profiles of multiple microRNAs in each patient with scleroderma and examine its clinical significance.     

Tenascin-C is upregulated in the skin lesions of patients with atopic dermatitis

BACKGROUND: Tenascin-C is a large, hexameric extracellular matrix glycoprotein that is expressed during embryogenesis, carcinogenesis and wound healing. In normal adult human skin the expression level of tenascin-C is low, but levels are elevated in skin tumors and rise significantly in the dermal compartment during wound healing. Although the expression of tenascin-C could be upregulated by inflammatory cytokines, the role of tenascin-C in atopic dermatitis (AD) is still unclear. OBJECTIVE: To identify genes that plays a role in AD. METHODS: We screened for differentially expressed genes in lesional and non-lesional skin of AD patients using DNA microarray. Then we monitored with quantitative PCR the expression of the novel disease related genes in human keratinocytes or pinnae from NC/Nga mice. RESULTS: We found that tenascin-C gene expression was expressed at higher levels in lesional skin compared to non-lesional skin of the patients, whereas it was not upregulated in the skin of psoriatic patients or healthy controls. In human cultured keratinocytes, tenascin-C was markedly upregulated by IL-4 and IL-13, and moderately upregulated by IFN-gamma. Tenascin-C expression was also upregulated in the AD-like skin lesions induced in NC/Nga mice ears by intradermal injection of mite antigen, and this upregulation was inhibited by prednisolone. CONCLUSION: These results suggest that upregulation of the tenascin-C expression is specific to AD lesions, and that tenascin-C may therefore play a critical role in regulating the underlining inflammatory processes, which are involved in the pathology of AD.