Reappraisal of in situ immunophenotypic analysis of psoriasis skin: interaction of activated HLA-DR+ immunocompetent cells and endothelial cells is a major feature of psoriatic lesions

Psoriasis is an inflammatory skin disease of unknown aetiology. Many observations indicate that T cells play an important role in the pathogenesis of the disease. Upregulation of MHC class-II molecules on immunocompetent cells, endothelial cells and keratinocytes on lesional psoriatic skin has been regarded as a hallmark of the disease. However, there is some controversy in the literature regarding the cell types expressing class-II molecules and there is limited information about the presence of immune cells other than T cells and antigen presenting cells in the cellular infiltrates of psoriatic skin. We therefore reinvestigated the subject using immunocytochemical single and multiple staining techniques. In agreement with earlier reports, our studies showed that the cellular infiltrates in lesional skin consist largely of HLA-DR⁺/IL-2R⁺ T cells, HLA-DR⁺/CD1a⁺ Langerhans cells, and HLA-DR⁺/CD68⁺ macrophages. We found increased HLA-DR expression mostly on immunocompetent cells and endothelial cells, but no prominent HLA-DR expression on keratinocytes in lesional psoriatic skin. Upregulation of HLA-DR on endothelial cells and in mononuclear infiltrates was also evident in the non-lesional skin of psoriatic patients as compared with normal controls. B cells and natural killer cells were also found in the cellular infiltrates in lesional psoriatic skin. In spite of the presence of a large amount of activated T cells in the epidermis, we found that HLA-DR expression on keratinocytes was not a major feature of psoriatic skin.     

The development of manifest psoriatic lesions is linked with the invasion of CD8+ T cells and CD11c+ macrophages into the epidermis

Koebner response was studied in 35 psoriatic patients. Two punch biopsies per patient were taken from non-lesional psoriatic skin before, and 6 h, 2 days, 7 days, 14 days and 21 days after, tape stripping. Alterations in the numbers of CD1+ Langerhans cells, CD4+ and CD8+ T cells and CD11c+ macrophages were mapped morphometrically. Results were compared with lesional and non-lesional psoriatic skin, and control skin. Nine of 35 patients were Koebner-positive. No statistically significant differences were noted between non-lesional psoriatic and control skin. CD4+ T cells increased in number 2 days after trauma in both the epidermis and the dermis, whereas epidermal CD8+ T cells and CD11c+ macrophages increased only in the Koebner-positive lesional skin after 7 days. The changes in lesions induced by tapestripping resembled those seen in lesional psoriatic skin (mature plaques). The number of CD1+ cells increased in mature psoriatic lesions only. It seems possible that trauma per se stimulates the accumulation of CD4+ T cells at the site of injury, but the development of manifest psoriatic lesions correlates with invasion of CD8+ T cells and CD11c+ macrophages into the epidermis.     

银屑病患者血清和皮损中血管内皮细胞粘附分子的对比研究

目的 探讨银屑病患者血清和皮损中4种血管内皮粘附分子表达与银屑病疾病活动性之间的关系。方法 采用ELISA法检测36例银屑病患者治疗前后和36例健康人的血清中可溶性粘附分子（sICAM-1、sICAM-3、sVCAM-1、sELAM）的浓度。同时用ABC免疫组化染色技术检测了36例银屑病患者皮损和临床治愈处皮肤粘附分子（ICAM－1、ICAM－3、VCAM－1、ELAM）的表达情况。结果 与正常人相比，银屑病患者皮损部位4种粘附分子的原位表达呈明显上调（P＜0.005），同时患者血清中4种可溶性粘附分子浓度也明显升高（P＜0.001）。经治疗后银屑病患者皮损部位4种粘附分子的原位表达明显下调（P＜0.05），同时血清中4种可溶性粘附分子浓度比前也下降（P＜0.05）；血清中4种可溶性粘附分子的浓度与银屑病疾病活动严重指数（PASI）均呈正相关，但治疗前后sVCAM-1的水平上升和下降的幅度最大，且与PASI的相关性最好。结论 血管内皮细胞粘附分子参与银屑病的发病机制；患者血清中可溶性粘附分子浓度的升高可能与皮损部位血管内皮细胞上相应的粘附分子高表达有关；血清VCAM－1的水平可以作为反映银屑病疾病活动的一个新的敏感指标。     

The development of manifest psoriatic lesions is linked with the appearance of ICAM-1 positivity on keratinocytes

The development of psoriatic lesions was studied in 36 psoriatic patients using the Koebner reaction induced by tape stripping. Two biopsies per patient were taken from non-lesional psoriatic skin before, and 6 h, 2 days, 7 days, 14 days and 21 days after tape stripping. Alterations in HLA-DR, ICAM-1, Ki-67 and FXIIIa positivities in both the dermis and the epidermis were estimated using immunohistochemical methods. A double staining for CD4⁺ and CD8⁺ T cells was also carried out to show their possible Ki-67 positivity. Results were compared with those from lesional (mature plaque) and non-lesional psoriatic skin, and control skin. Of the 36 patients, 9 were Koebner-positive. The most important finding in Koebner-positive psoriatic skin was the appearance of ICAM-1 positivity on epidermal keratinocytes simultaneously with the clinically observed lesion on day 7. The number of FXIIIa⁺ dendrocytes in the dermis was quite constant, and increased in mature psoriatic lesions only. The number of active HLA-DR⁺ immunocompetent cells increased in developing psoriatic lesions, being highest in mature lesions, but no Ki-67 positivity was detected in epidermal or dermal T cells in the psoriatic specimens. Based on these results, it is concluded that T cells divide and are activated extracutaneously in psoriasis, and also that ICAM-1/LFA-1 interactions are important in the recruitment of inflammatory cells and in controlling the effector cell functions.     

Immunopathologic characterization of the tissue response in endemic pemphigus foliaceus (fogo selvagem)

BACKGROUND: The research on endemic pemphigus foliaceus (fogo selvagem) has mainly focused on the humoral immune response, but little attention has been given to the function of cell-mediated immune response and the nature of the cellular elements of the tissue reaction in the lesions of fogo selvagem. OBJECTIVE: The purpose of this study was the immunophenotype characterization of the inflammatory cells as well as the expression of adhesion molecules and HLA-DR in the perilesional and lesional skin of fogo selvagem. METHODS: Twenty biopsy specimens of lesional and perilesional skin were analyzed by immunohistochemical techniques. The panel of monoclonal antibodies consisted of CD8, CD4, CD1a, HLA-DR, IL-2R, LFA-1, ICAM-1, and PAN-B. RESULTS: The semiquantitative analysis of the cell population revealed a predominance of CD4 T lymphocytes in the tissue response of perilesional and lesional skin. The population of epidermal Langerhans cells was decreased in lesional skin when compared with the perilesional skin, whereas CD1a(+) dermal dendritic cells predominated in lesional skin. Keratinocyte expression of ICAM-1 and HLA-DR was negative in both lesional and perilesional skin. CONCLUSION: The overall results suggest the participation of the cell-mediated immunity in endemic pemphigus foliaceus (fogo selvagem). The lack of keratinocyte ICAM-1 expression may be related to the pattern of cytokines secreted by the CD4(+) T cells of the tissue reaction in fogo selvagem.     

Perforin and granzyme B may contribute to skin inflammation in atopic dermatitis and psoriasis

BACKGROUND: Infiltration of the skin by pathogenic T cells is regarded as a key factor in the development of inflammatory skin diseases such as atopic dermatitis (AD) and psoriasis. OBJECTIVES: To investigate whether T cells containing cytotoxic proteins may contribute to the generation of skin inflammation in these skin diseases. METHODS: Skin biopsy specimens were obtained from non-lesional and lesional skin of patients with chronic AD (n = 8) and psoriasis (n = 6), and from non-atopic controls with normal skin (n = 6). Expression of perforin and granzyme B was investigated by immunohistochemistry. RESULTS: A significant enhancement of perforin and granzyme B expression was observed in lesional AD skin as compared with normal skin, non-lesional AD skin and psoriasis. Expression of these cytotoxic proteins was also increased in psoriasis as compared with normal skin and non-lesional psoriatic skin. Immunoreactivity for perforin and granzyme B was mainly found in the cytoplasm of lymphocytic cells located in the perivascular infiltrate. In AD increased numbers of positive cells were also observed focally at sites of spongiosis in the epidermis. Double immunostaining revealed that both CD4+ and CD8+ T cells are capable of expressing perforin and granzyme B. CONCLUSIONS: Our data suggest that cytotoxic CD4+ and CD8+ T cells containing perforin and granzyme B may play an integral part in eliciting cutaneous inflammation in AD.     

Expression of interferon-gamma receptors in normal and psoriatic skin.

Psoriatic keratinocytes have a reduced antiproliferative response to interferon (IFN)-gamma, and HLA-DR expression is usually not observed on keratinocytes in psoriatic plaques despite the presence of activated T cells. We have therefore compared the expression of IFN-gamma receptors in psoriatic skin with that of normal human skin. Using mouse monoclonal antibodies and immunoperoxidase staining on cryostat cut sections, we detected IFN-gamma receptors on keratinocytes throughout the epidermal layers except stratum corneum in normal skin (n = 11). Biopsy specimens from involved psoriatic skin (n = 17) consistently showed a staining pattern that differed from that of normal skin in that only the lower part of epidermis reacted with the antibodies to IFN-gamma receptors, whereas the upper layers showed no or minimal staining. Expression of IFN-gamma receptors in uninvolved psoriatic skin (n = 16) did not differ from that of healthy controls. Forty-five percent of the biopsies from lesional psoriatic skin displayed ICAM-1 positive keratinocytes, and only two specimens had a limited expression of HLA-DR reactive keratinocytes. The decreased binding of antibodies against the IFN-gamma receptors in the upper part of psoriatic epidermis might be secondary to abnormal maturation of psoriatic keratinocytes or a primary defect involving abnormal modulation of IFN-gamma receptors.     

Quantitation of tryptase- and chymase-containing mast cells in cutaneous lichen planus.

The distribution and density of tryptase- and chymase-positive mast cells in lesional and non-lesional cutaneous lichen planus (LP) was analysed. For this, enzyme-histochemical staining techniques and morphometrical measurements were applied. In non-lesional LP skin, chymase-positive cells (TC mast cells) showed a distribution similar to that found in both non-lesional psoriatic skin and in normal skin. Tryptase-positive cells (reflecting both T and TC mast cells), however, were increased in number in the upper dermis of non-lesional LP skin. In lesional LP skin, there were fewer chymase-positive cells in the upper dermis, whereas there were more tryptase-positive cells. In the upper dermis, no differences in the number of tryptase containing cells were detected between lesional and nonlesional LP skin. In lesions of LP and psoriasis, tryptase-positive mast cells are increased but differ in their distribution in the papillary dermis. In psoriatic lesions, tryptase-positive cells are frequently observed in epidermal contact, a feature very rarely seen in LP lesions. The present results suggest that the increased numbers of T mast cells in the upper dermis of nonlesional LP skin may be involved in initiating the LP lesion. It seems unlikely that mast cells could be responsible for the epidermal basal cell damage, though T mast cells do participate in the general inflammatory reaction.     

Fc epsilon R11/CD23 receptor distribution in patch test reactions to aeroallergens in atopic dermatitis.

There is increasing evidence that exposure to organic allergens may induce or exacerbate lesional skin in patients with atopic dermatitis. In this study, patients with atopic dermatitis were patch tested to 11 common organic allergens and to control chambers containing 0.4% phenol and 50% glycerin in 0.9% saline. In biopsies from positive patch test reactions, patch test control skin, lesional eczematous and non-lesional skin from atopic individuals, and normal skin from non-atopic volunteers, the presence and distribution of macrophages (RFD7+), dendritic cells (RFD1+), and Langerhans cells, and the expression of the low-affinity receptor for IgE (CD23) were investigated. In patch test reactions and lesional skin samples, inflammatory infiltrates of diffusely distributed macrophages (RFD7+), dendritic cells (RFD1+), T lymphocytes (RFTmix+), and Langerhans cells (CD1+) were seen, the latter being present in both the epidermis and the dermis. The numbers of Langerhans cells were reduced in the epidermis and increased in the dermis in patch test reactions and lesional skin compared to their controls. Double staining revealed a change in the distribution of CD23 antigen. In patch test control and non-lesional biopsies many macrophages and only a few Langerhans cells within the dermal infiltrates expressed this antigen. In patch test reaction and lesional skin samples, however, the proportion of CD23+ dermal Langerhans cells had increased compared to macrophages. Furthermore, in these latter samples an increased proportion of dermal CD1+ cells expressed the dendritic cell (RFD1+) marker. These results show that following antigen challenge there are marked similarities between the phenotype of the cellular infiltrate in patch test reaction and lesional skin biopsies, and also demonstrate a changing distribution of CD23 on antigen-presenting cells.     

ENDOTHELIAL CELL ADHESION MOLECULES IN PSORIASIS

Skin biopsies from patients with psoriasis and normal controls were examined for the expression of cell adhesion molecules including intercellular adhesion molecule-1 (ICAM-1) endothelial leukocyte adhesion molecule-1 (ELAM-1), HECA-452 and 4D10, using an immunoperoxidase techique. This study demonstrates that psoriatic skin exhibits a wide variety of markers of endothelial cell activation which are either induced or increased expression (ICAM-1, ELAM-1 & 4D10). Moreover, ICAM-1 & HECA-452 are also on leukocytes. These antigens may facilitate the adhesion of inflammatory cells to endothelium and antigen-presenting cells in psoriatic skin. Thus, they may play a role in faciliating the infiltration of leukocytes into psoriatic skin.     

Immunolocalization of adhesion molecules in psoriatic arthritis, psoriatic and normal skin

Adhesion molecule expression in synovial membrane obtained from patients with psoriatic arthritis (PA) has previously been compared with rheumatoid arthritis (RA). Although expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was similar in both psoriatic and rheumatoid synovium, in contrast, little or no endothelial leucocyte adhesion molecule-1 (ELAM-1) was observed in psoriatic synovium. In the present study, the expression of ICAM-1. ELAM-1 and VCAM-1 was examined in the involved and uninvolved skin from patients with PA (n= 15), patients with psoriasis (Ps) but no arthritis (n= 5) and in normal skin (n= 4). ICAM-1 was intensely expressed on endothelium and keratinocytes of involved skin from patients with Ps with or without arthritis. There was constitutive expression of ICAM-1 on endothelium only in uninvolved and normal skin. In contrast, ELAM-1 expression was restricted to endothelial cells; it was widespread and intense in involved skin, but was minimal in uninvolved and normal skin. VCAM-1 was expressed on endothelium, and also on some dendritic cells in involved psoriatic skin. There was minimal VCAM-1 staining on endothelial cells in uninvolved and normal skin. In conclusion, in involved psoriatic skin from patients with and without arthritis ICAM-1, ELAM-1 and VCAM-1 expression is up-regulated on vascular endothelium, and ICAM-1 is expressed on keratinocytes. However, ELAM-1 and VCAM-1 expression seen in dermal vessels is not found in psoriatic synovial vessels. These differences suggest a mechanism for controlling cellular traffic in Ps and in PA.     

系统性红斑狼疮患者CD1a、CD68、HLA-DR等的研究

目的 研究系统性红斑狼疮(SLE)患者外观正常及病变皮肤中朗格汉斯细胞(LC)一些重要表面标志的变化。方法 应用CD1a、CD68和HLA-DR等单克隆抗体和ABC免疫组化技术对9例SLE患者外观正常和皮损部位的组织进行了免疫表型检测。结果 ①SLE皮损中LC的数量减少,且其形态与表面标志亦有变化;②SLE病损处的角质形成细胞(KC)强弱不等地表达HLA-DR抗原,个别病例的外观正常皮肤KC也可局灶性表达HLA-DR抗原;③SLE外观正常皮肤或皮损的表皮中均未见细胞间粘附分子1和CD4阳性LC,仅在真皮的浸润细胞中见到较多的阳性细胞;④发现在SLE外观正常皮肤和皮损表皮内出现两类CD68阳性的树枝状细胞;在SLE皮损的浸润细胞中CD68阳性树枝状细胞大量增加;⑤细纤维状CD68阳性物质呈网状围绕基底部的KC,这些细纤维状阳性物质有些与表皮树枝状细胞相连,有些则没有明显的关系。结论 SLE外观正常和病变皮肤中LC一些重要表面标志的变化有所不同。外观正常皮肤和皮损表皮内出现两类树枝状细胞,一类可能为LC,而另一类则来源不清;在SLE皮损的浸润细胞中这些CD68阳性树枝状细胞大量增加,表皮内存在CD68阳性纤维状染色,其意义尚需进一步研究。     

Expression of ICAM-3/CD50 in normal and diseased skin

ICAM-3 is a newly recognized adhesion molecule, which is a member of the immunoglobulin supergene family of ICAMs. and has been shown to be identical with the CD50 antigen. Recent functional studies have shown that ICAM-3 is a ligand for LFA-1, and plays an important part in immune reactions. To date, very few data exist in the literature concerning its expression in the skin. In the present study, we investigated the expression of ICAM-3 in normal skin and in 98 biopsy specimens of various inflammatory and neoplastic dermatoses. ICAM-3 was found to be expressed by epidermal CD la⁺ Langerhans cells, by cells of Langerhans cell hisliocytosis, by T and B lymphocytes infiltrating the dermis in cutaneous lymphomas and in a wide spectrum of inflammatory dermaloses. Epidermal keralinocytes were consistently negative: endothelial expression of ICAM-3 was observed in six of the 48 cases. These results show that ICAM-3 is constitutively and widely expressed by cells participating in inflammatory dermaloses (including Langerhans cells and T and B lymphocytes), and that it can be albeit rarely, induced on endothelial cells and dermal dendrocytes. These results highlight the important part that ICAM-3 may play in cutaneous inflammatory and immune reactions.     

Vascular adhesion protein-1 (VAP-1) is overexpressed in psoriatic patients

BACKGROUND: Vascular adhesion protein (VAP)-1 is an adhesion molecule with an enzymatic activity that partakes in the migration process of lymphocytes. OBJECTIVES: The aim of this study was to investigate the expression of VAP-1 in the skin and serum of psoriatic patients. MATERIAL AND METHODS: Seventy-one patients suffering from psoriasis aged between 23 and 89 years were included in the study. The mean psoriasis severity assessed according to the psoriasis area and severity index was 14.2+/-9.6 points. The soluble VAP-1 serum concentration was evaluated by ELISA and VAP-1 expression in the skin (nine patients) immunohistochemically. RESULTS: The serum concentration of soluble VAP-1 was significantly higher in psoriatic patients than in healthy controls (403.4+/-130.8 ng/mL vs. 246.4+/-68.0 ng/mL; P<0.0001). No significant relationships were found between sVAP-1 concentration and studied clinical parameters, except the presence of pruritus. Mean number of VAP-1 positive vessels in psoriatic skin, both lesional (19.8+/-1.4) and non-lesional (9.4+/-1.4), was significantly higher than in healthy skin (5.4+/-1.5; P<0.005). Lesional psoriatic skin demonstrated significantly more VAP-1 positive vessels than non-lesional skin (P<0.01). CONCLUSIONS: Significant overexpression of VAP-1 in both lesional and non-lesional psoriatic skin and higher serum level of soluble VAP-1 in psoriatic patients may indicate the role of VAP-1 in chronic inflammation occurring in psoriasis. However, because of lack of correlation between soluble VAP-1 serum levels and psoriasis severity this hypothesis needs further investigation.     

Increased expression of TRAIL and its death receptors DR4 and DR5 in plaque psoriasis

TNF-related apoptosis-inducing ligand (TRAIL) is recognized as an important regulator of immune responses during infections and various autoimmune-mediated pathologies. Its role in inflammatory dermatoses is largely unknown. We aimed to investigate the expression of TRAIL and its receptors DR4 and DR5 in psoriasis vulgaris. Immunohistochemistry for TRAIL, DR4 and DR5 was performed on samples of lesional (n = 10) and non-lesional (n = 10) skin of patients with plaque psoriasis and skin of healthy volunteers (n = 10). Expression of TRAIL and its receptors was further examined by means of double immunofluorescence staining and co-localization with CD4, CD8, CD11c, CD68, CD16 and CD56 markers. Immunohistochemical staining for TRAIL was significantly enhanced in psoriatic lesional as well as non-lesional epidermis compared to the epidermis of healthy skin. Lesional epidermis also showed increased immunoreactivity for DR5. In addition, expression of TRAIL and both of its receptors was significantly increased in the dermis of lesional skin. As evidenced by double immunofluorescence, TRAIL was readily expressed by most of the examined cells of the inflammatory infiltrate in psoriatic lesions. In contrast, the expression of DR4 was found mostly among CD4+ and CD8+ cells but was only nuclear, while DR5 showed cytoplasmic staining in rare CD16+, CD56+ and CD68+ cells. According to abundant in situ presence of TRAIL and its receptors in lesional psoriatic skin, it seems that this cytokine participates in the complex interplay between keratinocytes and cells of the dermal infiltrate and thus contributes to the inflammatory cycle in psoriasis vulgaris.     

Alterations of glucosylceramide-beta-glucosidase levels in the skin of patients with psoriasis vulgaris

Hydrolysis of glucosylceramides by the enzyme glucosylceramide-beta-glucosidase (GlcCer'ase) results in ceramide, a critical component of the intercellular lamellae that mediates the epidermal permeability barrier. A disturbance of ceramide formation is supposed to influence the transepidermal water loss in common skin diseases like atopic eczema or psoriasis. The aim of this study was to investigate whether GlcCer'ase levels were altered in the skin of subjects with psoriasis vulgaris. Skin punch biopsies were taken from lesional and non-lesional psoriatic skin and GlcCer'ase was evaluated both at the RNA and at the protein level. Normal skin from surgical patients provided the baseline GlcCer'ase expression in healthy subjects. Our results show that GlcCer'ase mRNA expression was decreased in psoriatic non-lesional skin compared to normal controls in all cases. Interestingly, in lesional psoriatic skin the level of GlcCer'ase was increased compared to non-lesional skin in all cases. For the immunohistochemical analysis, we used a newly synthesized monoclonal antibody anti-human GBC (GlcCer'ase-GST fusion protein). The results confirmed that GlcCer'ase, mainly present in the upper epidermis, was decreased in psoriatic skin compared to normal control and was increased in lesional compared to non-lesional psoriatic skin. Our findings support the concept that alteration in water permeability barrier in lesional psoriatic skin can serve as a trigger for the upregulation of the expression of enzymes like GlcCer'ase with consequent stimulation of ceramide generation.     

Epidermal Langerhans cells, HIV-1 infection and psoriasis

Summary Langerhans cells (LCs) subserve an important antigen-presenting function in the skin immune system. They bear CD4 receptors, which make them potential targets for infection with the human immunodeficiency virus (HIV-1).
The observation of reduced numbers of LCs in the skin of patients with the acquired immunodeficiency syndrome (AIDS), and the association of severe psoriasis with HIV-1 infection, raise interesting questions regarding the role of LCs in the skin of HIV-1-positive psoriatic patients.
In this study, LCs were quantified in the lesional and non-lesional skin of seven HIV-1-positive psoriatic patients, and the results were compared with age-, sex- and site-matched HIV-1-negative psoriatic patients. The number of LCs was determined by staining skin sections with S-100 polyclonal antibody, using the three-step avidin—biotin immunoperoxidase method. The S-100-positive cells above the basal layer were quantified in two ways: cells/mm² of epidermal area, and cells/mm of length of basement membrane.
HIV-1-positive psoriatic patients showed a reduction in the number of epidermal LCs compared with HIV-1-negative psoriatic patients using both methods of quantification, in both lesional and non- lesional skin (P <0·05, Mann-Whitney test). In addition, a reduction in the number of LCs in lesional compared with non-lesional skin was observed in both HIV-1-positive and -negative patients when LCs were quantified per mm² of epidermal area (P<0·05, Wilcoxon test). This reduction was also observed when LCs were quantified per mm length of basement membrane, but the reduction was not statistically significant in the control group of HIV-1-negative psoriatic patients. Our findings of a reduced number of LCs in the epidermis of HIV-1 -positive psoriatic patients may be associated with the clinical deterioration of psoriasis in these patients.     

过氧化物酶增殖物激活受体β/δ在银屑病角质形成细胞中的表达

【摘要】 目的 探讨过氧化物酶增殖物激活受体β/δ（PPARβ/δ）在银屑病患者表皮角质形成细胞（KC）中的表达和调节因素。 方法 免疫组化方法检测PPARβ/δ在银屑病患者皮损及非皮损表皮中的表达。分离、培养银屑病患者非皮损区和皮损区的KC,以RT-PCR和Western印迹法分别检测银屑病患者皮损区和非皮损区KC中PPARβ/δ mRNA和蛋白质的表达水平。利用PPARβ/δ外源性激动剂GW501516及Ca2+刺激银屑病非皮损区KC,观察其对PPARβ/δ表达的调节影响。 结果 免疫组化显示,银屑病皮损区PPARβ/δ的表达强度显著高于正常对照组（t = 19.28,P < 0.01）和非皮损区（t = 23.26,P < 0.01）。银屑病皮损区PPARβ/δ mRNA和蛋白质的表达水平均高于正常对照组（P < 0.01）和非皮损区（P < 0.01）。10 ng/ml GW501516最大效能促进PPARβ/δ的表达（P < 0.01）;1.0 mmol/L Ca2+对KC中PPARβ/δ的表达促进效应最明显（P < 0.01）。 结论 PPARβ/δ在银屑病患者皮损区表达显著升高,GW501516 和Ca2+能够促进角质形成细胞PPARβ/δ表达水平。     

结合珠蛋白在银屑病皮损及皮损周边外观正常皮肤中的表达

目的 从mRNA及蛋白质水平研究结合珠蛋白在银屑病皮损及皮损周边外观正常皮肤中的表达,探讨其与朗格汉斯细胞的关系及在银屑病发病中的作用.方法采用免疫组化、免疫荧光双标记和原位杂交技术检测银屑病皮损及皮损周边外观正常皮肤中结合珠蛋白的表达.结果与正常人皮肤相比,银屑病皮损处角质形成细胞中结合珠蛋白mRNA的表达均明显增强(P＜0.001);皮损周边外观正常皮肤中的表达与正常人皮肤差异无显著性(P＞0.05).免疫组化显示:皮损处部分角质形成细胞胞浆中有结合珠蛋白表达;皮损及皮损周边外观正常皮肤中均可见结合珠蛋白在部分朗格汉斯细胞中呈阳性表达,且两者中结合珠蛋白阳性朗格汉斯细胞与朗格汉斯细胞总计数的比值较正常皮肤显著增高(P＜0.001).结论银屑病皮损处角质形成细胞中结合珠蛋白mRNA的表达增强,并能合成结合珠蛋白.合成结合珠蛋白的角质形成细胞可能在银屑病发病机理中起负反馈调节作用。