Inflammatory mediators causing cutaneous chronic itch in some diseases via transient receptor potential channel subfamily V member 1 and subfamily A member 1

Chronic itch with an itch–scratch vicious circle is a significant problem in a large amount of diseases. Some of these diseases, such as psoriasis, atopic dermatitis, prurigo nodularis, Sézary syndrome, uremic pruritus, diabetes and jaundice, are common. For a very long time, chronic itch has been a thorny problem with few effective treatments. Because of this, itch researchers and dermatologists seek to find the mechanisms among chronic itch, inflammatory cytokines and neurons. As an immediate area of research focus, we are going to find the peripheral cross‐talk between neurons and skin cells. Two receptors, named transient receptor potential channel vanilloid 1 and transient receptor potential channel ankyrin transmembrane protein 1, have been shown to play important roles in chronic itch. Many advances have been made so far this decade. This review talks about the updated mechanism of itch‐related inflammatory cytokines via transient receptor potential channels in cutaneous chronic itch and corresponding diseases. The search for itch‐related inflammatory mediators and the structure of transient receptor potential channels this decade could deepen our understanding of the mechanism of itch and help us find more treatments of chronic itch in the future.     

Topical pimecrolimus and tacrolimus transiently induce neuropeptide release and mast cell degranulation in murine skin

BACKGROUND: The topical calcineurin inhibitors pimecrolimus and tacrolimus have been demonstrated to be an effective new anti-inflammatory therapy. The only clinically relevant side-effect reported is transient application site burning and stinging itch at the beginning of topical therapy. OBJECTIVES: In order to understand the underlying mechanism of this effect, we examined whether or not the compounds are able to stimulate neuropeptide release in normal murine skin as well as in a mouse model of experimentally induced irritant contact dermatitis. METHODS: Balb/c mice were treated with 1% pimecrolimus cream or 0.1% tacrolimus ointment. Untreated and corresponding vehicle-treated mice served as controls. Skin specimens were investigated by light, immunofluorescence and electron microscopy as well as enzyme-linked immunosorbent assay and polymerase chain reaction. RESULTS: Topical application of pimecrolimus and tacrolimus was followed by an initial release of substance P and calcitonin gene-related peptide from primary afferent nerve fibres in murine skin during the early inflammatory response. The release of the neuropeptides and their binding to mast cells (MCs) led to MC degranulation. Mediators of MCs such as histamine and tryptase may induce pruritus and burning by binding to the corresponding receptors (histamine receptor 1, proteinase-activated receptor 2) on sensory nerve fibres, which explains the initial side-effects during therapy with calcineurin inhibitors. CONCLUSIONS: It may be speculated that calcineurin inhibitors directly stimulate intracellular signalling pathways or bind to ion channels such as transient receptor potential vanilloid 1 or receptors involved in nociception.     

外用他克莫司治疗男性肛门瘙痒症疗效及其神经源机制分析

目的探讨他克莫司软膏对肛门瘙痒症的疗效及其机制。方法采用瘙痒程度评分及参照由温度敏感的瞬时受体电位通道建立的痛痒觉基本规则和分子底物(即分子精神物理学)方法评估外用0.1%他克莫司软膏治疗前后的肛门瘙痒症患者瘙痒程度及皮肤感觉的变化。结果外用0.1%他克莫司软膏可终止或显著降低41例男性肛门瘙痒症患者瘙痒程度评分(P0.05)。在41例患者中,34例(82.9%)患者外用0.1%他克莫司软膏后,应用部位产生辣椒素样效应(即灼热感后随之瘙痒和/或烧灼感迅速改善),7例(17.1%)患者缺乏辣椒素样反应。结论外用他克莫司软膏可终止或降低肛门瘙痒症患者瘙痒,其治疗机制与调节皮肤感觉神经上的瞬时受体电位香草类受体1(TRPV1)功能有关。     

Interaction of peripheral nerves and mast cells,eosinophils, and basophils in the development of pruritus

Mast cells, eosinophils and basophils are central effector immune cells in allergic skin inflammation including atopic dermatitis (AD). Recent studies revealed that the bidirectional interaction between these three immune cell types (mast cells, eosinophils and basophils) and the nervous system is involved in the pathogenesis of neurogenic inflammation, pain and pruritus. Emerging evidence shows that these cells are the main source of pruritogens such as histamine, neuropeptides and cytokines, which are potential new therapeutic targets for drug development in chronic pruritus. For instance, many Th2 cytokines including interleukin (IL)‐4, 13 and 31 have been recognized as some of the most promising targets for the treatment of chronic pruritus in AD. In this review, we highlight the link between these three immune cell subsets and peripheral nerves, with emphasis on the development of chronic pruritus such as AD. We present cytokines and receptors of these three immune cells and peripheral nerves, and discuss the therapeutic potential of targeting these neuro‐immunological processes.     

Toll样受体2、4 和9在皮肤结核皮损中的表达

目的 研究Toll样受体2、4和9 （TLR-2、TLR-4、TLR-9）在寻常狼疮和疣状皮肤结核皮损中的表达,探讨其在皮肤结核发病中的作用。方法 经临床与病理确诊的皮肤结核（包括寻常狼疮和疣状皮肤结核）患者皮损标本18份,斑块状银屑病皮损15份为阳性对照,色素痣边缘正常皮肤10份为阴性对照。用免疫组化法观察TLR-2、TLR-4、TLR-9的表达情况。采用SPSS 13.0统计软件进行统计学分析,组间比较行t检验。结果 TLR-2在正常皮肤表达于除基底层外的表皮全层,而在皮肤结核和银屑病皮损表达于表皮的中上层,3组的表达强度均为高表达（A值分别为0.28 ± 0.03、0.25 ± 0.04和0.25 ± 0.05）,3组差异无统计学意义（P > 0.05）。TLR-4在正常皮肤和银屑病呈低或无表达（A值分别为0.07 ± 0.09和0.02 ± 0.05）,而皮肤结核（0.16 ± 0.07）呈低表达,其表达强度高于正常皮肤（t = 2.58,P ＜ 0.05）和银屑病皮损（t = 6.24,P ＜ 0.01）。TLR-9在正常皮肤和皮肤结核表达于表皮全层、附属器及血管壁,而皮肤结核的表达强度（A值为0.25 ± 0.05）高于正常皮肤（0.19 ± 0.05）,两组比较,t = 2.88,P ＜ 0.05。结论 TLR-2、TLR-4和TLR-9在皮肤结核皮损中均存在表达,其中TLR-4和TLR-9的表达高于正常皮肤,提示其在皮肤结核的免疫应答中可能起一定的作用。     

Dihydroavenanthramide D inhibits mast cell degranulation and exhibits anti‐inflammatory effects through the activation of neurokinin‐1 receptor

Chronic pruritus is difficult to treat. Current treatment options are frequently ineffective and new therapeutic approaches are urgently needed. Avenanthramides are active substances in oats that exhibit anti‐inflammatory effects. Their potential to interrupt pruritus mechanisms was investigated in this study. It was found that the synthetic analog dihydroavenanthramide D (DHAvD) can interact with the neurokinin‐1 receptor (NK1R) and inhibit mast cell degranulation. DHAvD also affects inflammatory processes and reduces secretion of the cytokine interleukin‐6. Our findings indicate that DHAvD may act as a NK1R inhibitor and could be a promising candidate for topical treatments of chronic pruritus.     

Positive correlation of vanilloid receptor subtype1 and prostaglandin E2 expression with pain in leiomyomas

Cutaneous leiomyomas are benign smooth muscle tumors that are occasionally painful. The mechanism of pain related to leiomyoma is not fully understood. To investigate the possible involvement of algoneic factors in pain from cutaneous leiomyomas. We present a case of cutaneous leiomyoma with severe, diffused pain in a large area and collected 10 more specimens of cutaneous leiomyoma with or without pain in patient histories. We immunohistochemiacally examined the expression of algoneic factors: serotonin, histamin, Substance P, PGE2, BDKRB2, VR1 and CGRP. We compared the pain area and expression of algoneic factors to reveal possible correlations. We describe here a patient with a cutaneous leiomyoma 1‐cm in diameter, which caused severe pain diffused throughout an area of 20‐cm around the tumor. The pain completely resolved after surgical excision of the leiomyoma. We observed that the leiomyoma cells expressed CGRP, PGE2 and VR1 in this case. We found a positive correlation between VR1 and PGE2 expression in the leiomyoma cells and areas with pain around the tumors among 11 specimens in total. VR1 and PGE2 might be key algogenic substances in painful leiomyoma.     

Expression of keratins in cutaneous epithelial tumors and related disorders--distribution and clinical significance

Keratins are a highly diverse family of cytoskeletal proteins and important markers of epithelial cell differentiation. In this review, applying the new keratin nomenclature recently introduced, we summarize and discuss the distribution and significance of keratin patterns in cutaneous epithelial tumors in relation to the epithelial structures of normal human skin. The available literature data show that the analysis of keratin profiles broadens our understanding of the differentiation, nature and histogenetic origin of the various, highly singular epithelial tumors arising in the skin. Moreover, keratins may aid in histological diagnosis and, in certain instances, may be helpful for the recognition of tumor malignancy and aggressiveness. Furthermore, we briefly address the topic of keratin-related skin disorders.     

A simple immunofluorescence technique for simultaneous visualization of mast cells and nerve fibers reveals selectivity and hair cycle – dependent changes in mast cell – nerve fiber contacts in murine skin

Close contacts between mast cells (MC) and nerve fibers have previously been demonstrated in normal and inflamed skin by light and electron microscopy. A key step for any study in MC-nerve interactions in situ is to simultaneously visualize both communication partners, preferably with the option of double labelling the nerve fibers. For this purpose, we developed the following triple-staining technique. After paraformaldehyde-picric acid perfusion fixation, cryostat sections of back skin from C57BL/6 mice were incubated with a primary rat monoclonal antibody to substance P (SP), followed by incubation with a secondary goat-anti-rat TRITC-conjugated IgG. A rabbit antiserum to CGRP was then applied, followed by a secondary goat-anti-rabbit FITC-conjugated IgG. MCs were visualized by incubation with AMCA-labelled avidin, or (for a more convenient quantification of close MC-nerve fiber contacts) with a mixture of TRITC- and FITC-labelled avidins. Using this simple, novel covisualization method, we were able to show that MC-nerve associations in mouse skin are, contrary to previous suggestions, highly selective for nerve fiber types, and that these interactions are regulated in a hair cycle-dependent manner: in telogen and early anagen skin, MCs preferentially contacted CGRP-immunoreactive (IR) or SP/CGRP-IR double-labelled nerve fibers. Compared with telogen values, there was a significant increase in the number of close contacts between MCs and tyrosine hydroxylase-IR fibers during late anagen, and between MCs and peptide histidine-methionine-IR and choline acetyl transferase-IR fibers during catagen. Received: 14 June 1996     

Axin1、Gsk-3β和CD82在皮肤鳞状细胞癌中的表达

目的：检测Axin1、Gsk-3β和CD82蛋白在皮肤鳞癌中的表达。方法：40例皮肤鳞状细胞癌（cSCC）作为实验组，15例正常皮肤组织作为对照组，采用免疫组织化学方法检测Axin1、Gsk-3β和CD82在两组中的表达。结果：Axin1在正常皮肤、cSCC I级、II级、III级的阳性表达率分别为86.7%、66.7%、40.0%、10.0%，Gsk-3β分别为80.0%、73.3%、20.0%、20.0%，CD82阳性表达率分别为73.3%、60.0%、26.7%、10.0%。在cSCC中Axin1与Gsk-3β表达呈正相关（r=0.677，P＜0.05）。结论：Axin1、Gsk-3β和CD82可能与cSCC肿瘤发展有关。     

Distribution of cannabinoid receptor 1 (CB1) and 2 (CB2) on sensory nerve fibers and adnexal structures in human skin

BACKGROUND: Cannabinoid receptors mediate the psychopharmacological action of marijuana and have been localized in the central and peripheral nervous system as well as on cells of the immune system. OBJECTIVE: Up to now, two cannabinoid receptors (CB1 and CB2) have been cloned and recent studies on animal tissue gave evidence for the presence of cannabinoid receptors in the skin. METHODS: In the present immunohistochemical investigation we determined the precise localization of CB1 and CB2 in sections of human skin and in one case of mastocytosis. RESULTS: CB1 and CB2 immunoreactivity was observed in cutaneous nerve fiber bundles, mast cells, macrophages, epidermal keratinocytes, and the epithelial cells of hair follicles, sebocytes and eccrine sweat glands. In epidermal keratinocytes, hair follicle and sebaceous glands, CB1 and CB2 were distributed in a complementary fashion. Double-immunostaining with an anti-CGRP antibody suggested the presence of cannabinoid receptors on small afferent peptidergic nerves. CONCLUSION: The abundant distribution of cannabinoid receptors on skin nerve fibers and mast cells provides implications for an anti-inflammatory, anti-nociceptive action of cannabinoid receptor agonists and suggests their putatively broad therapeutic potential.     

Caveolin-1、Met蛋白在日光性角化病、鲍温病和皮肤鳞状细胞癌中的表达

目的：检测Caveolin-1、Met蛋白在肿瘤边缘正常皮肤、日光性角化病、鲍温病和皮肤鳞状细胞癌组织中的表达情况。方法：通过免疫组化SP法，对肿瘤边缘正常皮肤、日光性角化病(Actinic keratosis，AK)、鲍温病(Bowen's Disease，BD)、皮肤鳞状细胞癌(cutaneous squamous cell carcinoma，cSCC)标本中Caveolin-1、Met进行检测。结果：Caveolin-1在正常皮肤、AK、BD、SCC中阳性率依次为16.7%、36.8%、52.9%、78.9%，四组间采用Kruskal-wallis H秩和检验，差异具有统计学意义(P<0.05)。Met在正常皮肤、AK、BD、SCC中阳性率依次为8.3%、26.3%、58.8%、84.2%，四组间采用Kruskal-wallis H秩和检验，P<0.05，差异具有统计学意义。在cSCC组中，Caveolin-1、Met阳性表达之间呈现正相关(r=0.484,P=0.036)。结论：Caveolin-1、Met在AK、BD和cSCC细胞中表达强度与恶性程度相关，且Caveolin-1、Met可能在cSCC发生、发展中具有协同作用。     

Natural course and characteristics of cutaneous neurofibromas in neurofibromatosis 1

Neurofibromatosis 1 (NF1) is characterized by cutaneous, neurological and osseous manifestations. Most NF1 patients develop cutaneous neurofibromas. However, time‐dependent change with aging and the predilection site of cutaneous neurofibromas remain unclear. To clarify the natural course and characteristics of cutaneous neurofibromas, a retrospective study was conducted for 57 NF1 patients who were treated at the Department of Dermatology of Tottori University Hospital between January 2007 and April 2016. For each patient, we investigated the time‐dependent changes and the numbers of cutaneous neurofibromas in four body surface regions. There was a positive correlation between age and number of cutaneous neurofibromas (r = 0.75, P < 0.001). Cutaneous neurofibromas were located on the trunk (60.2%), lower limbs (16.1%), upper limbs (14.4%), and head and neck (9.2%). There was no significant relationship between each body type (e.g. obese or thin) and cutaneous neurofibromas. With respect to the year‐to‐year percentage change in cutaneous neurofibromas, the average annual rate of increase was 0.21 (range, ?0.71 to 1.2). The number of cutaneous neurofibromas had increased in approximately 61% of the patients 1 year later. Our data will enable physicians to estimate the overall state of cutaneous neurofibromas in NF1 and will be useful for handling cutaneous manifestations before they become a serious condition.     

Expression of insulin-like growth factor-1 receptor, p-AKT and p-ERK1/2 protein in extramammary Paget's disease

BACKGROUND: The insulin-like growth factor-1 (IGF-1) receptor (R)-induced phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK)/ERK signal transduction cascade, which have critical roles in prevention of apoptosis and regulation of cell cycle progression, plays an important role in tumorigenesis. The expression of IGF-1R, AKT and ERK1/2 has been described in some human malignancies, but not in extramammary Paget's disease (EMPD). OBJECTIVES: To study the expression of IGF-1R, p-AKT and p-ERK1/2 in EMPD and to evaluate the relationships among them. METHODS: Thirty-six tissue samples of 34 patients with primary EMPD were subjected to immunohistochemical staining for IGF-1R, p-AKT and p-ERK1/2. RESULTS: Of thirty-six EMPD tissue samples, 34, 34 and 28 were positive for IGF-IR, p-AKT and p-ERK1/2 expression, respectively; 27, 23 and 17 of the 36 specimens stained positive for IGF-IR, p-AKT and p-ERK1/2 in more than half of Paget's cells, respectively. There were significant correlations between the IGF-1R and p-AKT expression as well as between IGF-1R and p-ERK1/2 expression. Taken together, these results indicate that IGF-1R is overexpressed, and AKT and ERK1/2 are frequently phosphorylated in EMPD. CONCLUSIONS: Our study shows that the expression of IGF-1R and the induction of p-AKT and the p-ERK1/2 pathway may play an important role in the pathogenesis of EMPD. The IGF-IR system might be a potential therapeutic target in EMPD.     

The role of AHI1 and CDKN1C in cutaneous T‐cell lymphoma progression

Cutaneous T‐cell lymphoma (CTCL) is the most common lymphoma of the skin. Recent reports suggest that AHI1 is overexpressed in a subset of CTCL‐derived cell lines, where it downregulates the expression of CDKN1C tumor suppressor gene. In the current work, we test the expression of these genes in 60 patients with Mycosis Fungoides and Sezary Syndrome by RT‐PCR and correlate our findings with 6 years of clinical follow‐up. These findings reveal that AHI1 and CDKN1C exhibit opposite expression patterns, where AHI1 is expressed in poor and intermediate prognosis patients, while CDKN1C is expressed in favourable prognosis patients. Kaplan–Meier analysis documents that downregulation of CDKN1C is associated with poor disease outcome in patients with CTCL, while upregulation of AHI1 shows a weak association with aggressive disease course.     

Expression of melanocortin-1 receptor in normal, malformed and neoplastic skin glands and hair follicles

Melanocortin receptors (MC-Rs) are G-protein coupled receptors that mediate pleiotropic actions of melanocyte-stimulating hormones and adrenocorticotropin. There is increasing evidence that one of the five so far identified melanocortin receptors, i.e. melanocortin-1 receptor (MC-1R), has a more ubiquitous distribution in the skin than originally expected. In the present study, the expression of MC-1R in normal skin glands and hair follicles, various malformations and neoplasms with adnexal differentiation is described. Using an anti-MC-1R antibody directed against the amino acids 2-18 of the human MC-1R, specimens of normal healthy skin (n = 10) as well as hamartomas, cysts, hyperplasias, and benign or malignant neoplasms with eccrine, apocrine, sebaceous gland, and hair follicle differentiation (n = 98) were immunostained. MC-1R expression was widely preserved in various adnexal malformations and neoplasms as compared with normal skin and did not show major differences with regard to maturation of the neoplasms. The majority of adnexal epithelia showed an intracytoplasmically granular staining and, to a lesser extent, an intercellular staining pattern. Immunoelectron microscopical investigations revealed expression of MC-1R both along the cell surface and intracytoplasmically within tubular endosomes, the latter suggesting internalisation of the receptor. In conclusion, preserved MC-1R expression in adnexal epithelia suggests a functional role of proopiomelanocortin (POMC) in various malformations and neoplasms of the skin.     

神经性皮炎皮损处神经纤维的数量及其与朗格汉斯细胞关系的研究

目的探讨神经性皮炎患者皮损处神经纤维的数量变化及其与朗格汉斯细胞接触的关系.方法用辣根过氧化物酶结合的链霉亲和素-生物素技术观察24例神经性皮炎患者皮损处神经纤维的表达及数量变化.用免疫荧光双标记及共聚焦激光扫描显微镜技术观察神经性皮炎患者皮损处神经纤维与朗格汉斯细胞接触数量关系.用实时定量PCR方法检测皮损处神经生长因子mRNA的表达情况.结果 神经性皮炎患者皮损处神经纤维长度显著增加,与皮损周边对照(t=6.90,P<0.001)及正常人对照(t=5.71,P<0.001)比较差异有统计学意义.皮损表皮内有神经纤维接触的朗格汉斯细胞占朗格汉斯细胞总数的百分数明显增多,与皮损周边对照(X²=43.91,P<0.001)及正常人对照(X²=46.11,P<0.001)比较差异有统计学意义.皮损处神经生长因子mRNA高表达,与皮损周边对照(t=3.25,P<0.01)及正常人对照(t=3.67,P<0.01)比较差异有统计学意义.结论 神经性皮炎患者皮损处存在高水平活性的NGF导致神经纤维增生.     

人黑素浓集素受体1抗原表位肽的表达、纯化及其在白癜风患者中的检测

目的 表达及纯化人黑素浓集素受体1抗原表位肽,探讨其在白癜风患者自身抗体检测中的应用。方法 人黑素浓集素受体1抗原表位肽编码基因合成后克隆至原核表达载体pGEX-4T-2,转化大肠杆菌BL21菌株,异丙基-β-D-硫代半乳糖苷（IPTG）诱导蛋白表达,通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分析和Western印迹鉴定目的蛋白表达。以提取的黑素细胞膜蛋白作为阻断抗原,进行阻断ELISA分析。以目的蛋白为抗原,检测100例进展期白癜风患者和30例正常人血清IgG抗体情况。结果 成功构建重组表达载体,重组蛋白成功表达并纯化,上样量低于0.0625 μg时纯化率达100％。目的蛋白与白癜风患者血清IgG抗体间的结合能被天然黑素细胞膜抗原抑制。100例进展期白癜风患者血清中有36例与目的蛋白结合反应呈阳性。结论 成功表达并纯化了人黑素浓集素受体1抗原表位肽,该目的蛋白能够结合白癜风患者血清中IgG抗体,可以用于抗人黑素浓集素受体1抗体的检测。