寻常性银屑病皮损表皮中TGF-β受体活化Smad蛋白表达的检测

目的:探讨转化生长因子(transforming growth factor,TGF)-β受体活化Smad-[Smad1、Smad2、smad3(Smad1/2/3)]和磷酸化Smad2/3(p-Smad2/3)蛋白在寻常性银屑病皮损中的表达及其意义.方法:采用EliVision法免疫组化技术分别检测寻常性银屑病皮损与正常对照皮肤中Smad1/2/3和p-Smad2/3蛋白的表达情况.结果:与正常对照皮肤相比,Smad1/2/3和P-Smad2/3蛋白在寻常性银屑病皮损表皮中的表达显著降低.结论:寻常性银屑病皮损表皮中Smad1/2/3和p-Smad2/3蛋白表达降低,可通过阻断TGF-β信号转导,有助于寻常性银屑病皮损角质形成细胞过度增殖状态的发生和发展.     

脂溢性角化病皮损表皮中负性调节因子Smad7的表达

目的：探讨负性调节因子Smad7在脂溢性角化病皮损中表达水平的变化及其意义。方法：采用实时定量（quantitative real-time）PCR和免疫组化技术分别检测脂溢性角化病皮损及正常对照皮肤中Smad7的表达。结果：Smad7在脂溢性角化病皮损中的表达较正常表皮显著升高（P〈0.01）。结论：脂溢性角化病皮损表皮中Smad7过度表达可能有助于表皮细胞的异常增生,促进脂溢性角化病的形成。     

尖锐湿疣皮损中Smad7、Smurf1和Smurf2的表达及意义

目的:探讨转化生长因子(TGF)-β信号转导途径中重要的负性调节因子Smad7、Smurf1和Smurf2在尖锐湿疣皮损中的表达及其意义.方法:采用EliVisionz(TM)plus免疫组化技术分别检测尖锐湿疣和正常对照皮肤中Smad 7、Smurf1和Smurf2的表达.结果:与对照正常皮肤相比,尖锐湿疣表皮中Smad 7、Smurf1和Smurf2的表达水平显著上调.结论:尖锐湿疣皮损中Smad 7、Smurf1和Smurf2的表达增强可能干扰TGF-β信号转导,有助于表皮角质形成细胞异常增殖,导致尖锐湿疣表皮过度增殖的组织病理学改变.     

尖锐湿疣皮损中Smad7、Smur-f 1和Smur-f 2的表达及意义

目的：探讨转化生长因子（TGF）-β信号转导途径中重要的负性调节因子Smad7、Smuff1和Smuff2在尖锐湿疣皮损中的表达及其意义。方法：采用EliVision^TM plus免疫组化技术分别检测尖锐湿疣和正常对照皮肤中Smad7、Smuff1和Smuff2的表达。结果：与对照正常皮肤相比，尖锐湿疣表皮中Smad7、Smuff1和Smuff2的表达水平显著上调。结论：尖锐湿疣皮损中Smad7、Smuff1和Smuff2的表达增强可能干扰TGF-β信号转导，有助于表皮角质形成细胞异常增殖，导致尖锐湿疣表皮过度增殖的组织病理学改变。     

Smad泛素化调节因子1在寻常性银屑病皮损区的表达

转化生长因子β(TGFβ)信号转导途径与银屑病的关系已基本明确.除了发现血清TGFβ水平变化与银屑病的关系外^[1,2],在该病皮损区的表皮中还发现Ⅰ型和Ⅱ型TGFβ受体表达减少或缺失M^[3],提示TGFβ信号转导途径障碍参与了寻常性银屑病的发病过程.Smad泛素化调节因子1(Smadubiquitination regulatory factor1,Smurf1)能与Ⅰ型TGFβ受体相互作用,诱导该受体降解^[4].为此,我们采用免疫组化和逆转录-聚合酶链反应(RT-PCR)扩增技术对寻常性银屑病皮损区Smurf1的表达情况进行了研究.     

寻常型银屑病皮损中Smad2、Smad3 mRNA的表达降低

目的：检测寻常型银屑病皮损中Smad2和Smad3的mRNA表达水平。方法：采用反转录一实时定量聚合酶链式反应技术对寻常型银屑病皮损与正常对照皮肤中Smad2和Smad3mRNA的表达水平进行分析。结果：与正常对照皮肤相比，寻常型银屑病皮损Smad2和Smad3mRNA的表达水平均显著降低。结论：寻常型银屑病皮损中Smad2和Smad3表达下调，可能通过干扰TGF-β信号向下游转导，有助于寻常型银屑病皮损角质形成细胞过度增殖状态的形成。     

窄谱UVB治疗前后银屑病患者皮损中TGF-βs的表达

采用免疫组化方法检测TGF-β1、TGF-β2及TGF-β3在经NB-UVB治疗后银屑病患者皮损中的表达.结果:TGF-β1 、TGF-β2 、TGF-β3在银屑病皮损表皮基底层及棘层表达明显减少;而经NB-UVB照射后其表达明显增强.NB-UVB照射对银屑病的治疗作用可能与其上调银屑病表皮中TGF-βs的表达有关.     

寻常性银屑病患者表皮中表皮生长因子的检测

寻常性银屑病患者表皮中表皮生长因子的检测王俊民，王万卷，谭升顺西安医科大学第二临床医学院皮肤科（邮政编码７１０００４）表皮生长因子（ＥＧＦ）是一种由５３个氨基酸构成的活性肽［１］，对于多种组织来源的表皮细胞有明显的促进增殖作用［２］。银屑病发病的免疫...     

转化生长因子β及其受体Ⅰ、Ⅱ在银屑病皮损中的表达

目的　探讨转化生长因子 β(TGF β)及其受体Ⅰ、Ⅱ在银屑病角质形成细胞中的表达及其与银屑病的关系。方法　采用免疫组化方法检测TGF β1,TGF β2 ,TGF βRI,TGF βRⅡ在银屑病皮损、皮损周边正常皮肤及正常对照皮肤的原位表达。结果　与正常皮肤相比 ,TGF β1、TGF β2 、TGF βRⅠ和TGF βRⅡ在银屑病表皮基底层表达明显减弱或缺失 ;TGF βRⅡ在棘层至颗粒层的阳性表达率增加。结论　TGF β/TGF βR在银屑病皮损基底层的表达下调或缺乏 ,可能在银屑病角质形成细胞过度增殖中发挥作用 ,而且TGF β/TGF βR系统也可能与银屑病细胞异常分化有关     

硬皮病皮损中TGF-β1,Smad_3和Smad_7的检测及意义

目的探讨TGF-β1,Smad3和Smad7在硬皮病发病机制中的作用。方法采用免疫组化SABC法检测30例硬皮病患者皮损中TGF-β1,Smad3和Smad7的表达,并以10例正常人皮肤组织作为对照。结果TGF-β1,Smad3和Smad7在硬皮病皮损中的表达强度均高于正常对照组(P<0.05)。直线相关分析显示,TGF-β1和Smad3呈正相关。结论TGF-β1,Smad3和Smad7在硬皮病皮损中均表达上调,提示它们在硬皮病病理过程中起一定作用;TGF-β1和Smad3在硬皮病的发病机制中可能起着协同作用;Smad7作为细胞内Smad信号的抑制剂在硬皮病皮损中表达上调,可能为机体的一种负反馈调节作用。     

In situ localization of IFN-gamma-positive cells in psoriatic lesional epidermis.

Interferon-gamma (IFN-gamma) is believed to be an important mediator in the cytokine cascade of psoriasis. Lesional T cells in the epidermis may play a role in psoriasis. We examined whether IFN-gamma-producing T cells were present in the epidermis of psoriasis in situ by immunohistochemical techniques. Mixtures of CD4+ T cells and CD8+ T cells were found to be present in the papillary dermis and the epidermis of the psoriatic lesions. CD8+ T cells seemed to be dominant in the epidermis. Considerable amounts of IFN-gamma-positive cells were detected in infiltrates of the papillary dermis. IFN-gamma-positive cells were found to be present in the epidermis. The pattern of IFN-gamma staining appeared to be a combination of intracellular staining in mononuclear lymphoid cells and extracellular deposition in the surrounding areas. The staining was considered to be highly specific because it could be completely blocked by preabsorption with recombinant IFN-gamma. Our data suggest that psoriatic epidermal T cells produce and secrete IFN-gamma within the lesion and that these T cells are involved in the pathogenesis of psoriasis.     

The activity of caspase-1 is increased in lesional psoriatic epidermis

Caspase-1 belongs to the group of inflammatory caspases and is the activating enzyme for the proinflammatory cytokine IL-18, a cytokine known to play an important role in the pathogenesis of psoriasis. The purpose of this study was to determine the expression of caspase-1 in psoriatic skin and the signaling mechanisms involved in stress-induced activation of caspase-1 and IL-18. Interestingly, increased caspase-1 activity in lesional compared with non-lesional psoriatic skin was seen. In vitro experiments in cultured human keratinocytes demonstrated anisomycin-induced, p38 mitogen-activated protein kinase (p38 MAPK)-dependent increased secretion of procaspase-1 and active caspase-1. Furthermore, anisomycin increased the mRNA expression of IL-18 through a p38 MAPK-dependent but caspase-1-independent mechanism, reaching a maximum level after 12 hours of stimulation. Finally, anisomycin caused a rapid (4 hours) increase in the secretion of proIL-18 and active IL-18. Secretion of active IL-18 was mediated through a p38 MAPK/caspase-1-dependent mechanism, whereas secretion of proIL-18 was mediated by a p38 MAPK-dependent but caspase-1-independent mechanism. These data demonstrate that the activity of caspase-1 is increased in psoriatic skin and that IL-18 secretion is regulated by a p38 MAPK/caspase-1-dependent mechanism, making caspase-1 a potential target in the treatment of psoriasis.     

Alefacept therapy reduces the effector T-cell population in lesional psoriatic epidermis

Alefacept, a LFA-3/IgG1 fusion protein, interferes with the activation and proliferation of T cells by binding to the CD2 receptor on their surfaces. The clinical efficacy of this drug has been demonstrated in chronic plaque psoriasis. We performed a single-center, open-label study to investigate the immunohistochemical effects in psoriatic lesional skin. A group of 11 patients with plaque psoriasis all received 12 weekly doses of 7.5 mg alefacept intravenously. Skin biopsies were obtained at baseline and on days 8, 43 and 92, and were evaluated by digital image analysis after immunohistochemical staining. After completion of treatment, 8 out of the 11 patients experienced a reduction in PASI of 50% or more compared to baseline. Immunohistochemical analysis displayed a gradual decrease in the number of cutaneous T cells during therapy, with a significant reduction in epidermal CD8⁺ cells and dermal CD4⁺ cells on day 92. Patients with a reduction in PASI of 50% or more after therapy had a clearance of effector/memory T cells from the epidermis, in contrast to patients with a reduction in PASI of less than 50%. These findings support the hypothesis that effector/memory T cells play a prominent role in the pathogenesis of psoriasis, and that alefacept is capable of reducing these cells in lesional psoriatic skin.     

Mechanisms of cyclosporine A inhibition of antigen-presenting activity in uninvolved and lesional psoriatic epidermis

To elucidate how cyclosporine A affects antigen-presenting cell subsets and their function in human skin, we studied patients with psoriasis undergoing a therapeutic trial of cyclosporine A. Immunologic parameters abnormal in psoriatic epidermis were evaluated before and early in the course of therapy. We quantitated function and numbers of skin biopsy-derived epidermal cells with potential antigen-presenting cell (APC) activity. The antigen-presenting capacity of epidermal cells from normal-appearing skin to activate allogeneic T cells was profoundly inhibited (81% decrease) 7 d after the onset of therapy (p less than 0.05). Thus, cyclosporine A therapy inhibited T-cell activation mediated by Langerhans cells in uninvolved skin. By contrast, in lesional skin epidermal allo-antigen presenting activity was only partially inhibited at this early time point (55 +/- 7% decrease) (p less than 0.01, n = 8). The percentage decrease in allo-antigen-presenting cell activity correlated with reduced clinical activity of the lesions, r = 0.84. In three patients also examined at 14 d, we found an additional 42 +/- 5% decrease between day 7 and 14. Decreased allo-antigen-presenting activity in lesional skin was not associated with a decrease in the number of CD1+ Langerhans cells or epidermal cell release of detectable amounts of cyclosporine A or other soluble factors that abrogate T-cell alloreactivity. The time course and degree of inhibition of antigen-presenting capacity within involved psoriatic skin correlated best with a significant (p less than 0.01) reduction in non-Langerhans cell DR+ leukocytes (from 3.0 +/- 1.2% to 1.0 +/- 0.6% at day 7) (r = 0.71). Cyclosporine A therapy was associated with a rapid and complete loss of HLe1-DR+ keratinocytes (94% decrease at 7 d) in lesional skin despite the skin still being quite involved with psoriasis at this point and antigen-presenting cell activity being only 60% reduced. In conclusion, cyclosporine A interferes with T-cell activation by human epidermis through at least two mechanisms: 1) in uninvolved skin, rapid inhibition of Langerhans cell-mediated activation of T cells, and 2) in lesional skin, delayed inhibition of antigen-presenting activity which appears to correlate with the time course and level of reductions in non-Langerhans cell DR+ leukocytes. The antigen-presenting activity of the latter cells appears to be cyclosporine A resistant. In psoriatic lesions, early and complete loss of DR expression on lesional keratinocytes during cyclosporine A therapy is likely due to decreased lesional T-cell lymphokine production critical for keratinocyte DR expression.(ABSTRACT TRUNCATED AT 400 WORDS)     

Partial characterization of phospholipase C activity in normal, psoriatic uninvolved, and lesional epidermis

Arachidonic acid (AA), the precursor of prostaglandins and leukotrienes, can be directly liberated from membrane phospholipids by phospholipase A2 or indirectly by phospholipase C. One or both of these enzymes may be responsible for the increased content of AA found in psoriatic lesional epidermis. Keratome biopsies were obtained from normal and psoriatic individuals. After homogenization and sonication, a 10,000 g supernatant was used as the enzyme source. The activities of both phospholipase A2 and C were assayed in each sample using phosphatidylcholine and phosphatidylinositol, respectively, as substrates. Phospholipase A2 activity was found to be significantly higher than normal in both uninvolved and lesional psoriatic epidermis. In contrast, phospholipase C activity was significantly higher than normal in only the psoriatic plaque on the basis of wet weight (p less than 0.001), protein (p = 0.01), and DNA (p = 0.004) content. Phospholipase C activity in pmol diacylglycerol formed/min/microgram DNA was: normal 4.96 +/- 0.80, n = 13; uninvolved 7.29 +/- 1.06, n = 18; plaque 14.44 +/- 2.50, n = 18. Analysis (pH profile, calcium requirement, substrate specificity, and saturation kinetics) of pooled epidermal extracts showed no inherent differences in phospholipase C from normal and psoriatic epidermis, suggesting either a higher concentration or the presence of an activated form of the enzyme in psoriatic plaque. Since phospholipase C activity, in contrast to phospholipase A2 activity, is elevated only in lesional epidermis, it is possible that this enzyme contributes to AA accumulation observed in this tissue.     

Alterations in the desquamation-related proteolytic cleavage of corneodesmosin and other corneodesmosomal proteins in psoriatic lesional epidermis

Background  Desquamation occurs after proteolysis of corneodesmosomal proteins, including corneodesmosin (CDSN), by proteases of the kallikrein family, particularly KLK7. Impaired desquamation is one of the features of psoriasis, and psoriasis-associated single nucleotide polymorphisms of the CDSN gene may potentially modify the proteolysis of the encoded protein.
Objectives  To test whether the proteolysis of CDSN and other corneodesmosomal components is altered in psoriatic epidermis.
Methods  Total protein extracts obtained by tape-stripping of nonlesional and lesional skin from 11 patients were compared by immunoblotting experiments.
Results  An almost intact form of CDSN that has never been observed previously in the normal upper stratum corneum was detected in the lesional skin extracts, showing an altered proteolytic processing of the protein. This form was also observed in the nonlesional skin extracts, but in lower amounts. For most patients, increased amounts of desmoglein 1, plakoglobin and of high molecular weight fragments of desmocollin 1 were detected in the lesional skin. For most of them, similar amounts of KLK7 were immunodetected in both nonlesional and lesional skin extracts. No particular differences were observed related to the psoriasis type, the HLA-Cw6 status of the patients or any particular CDSN polymorphisms.
Conclusions  We detected a near full-length form of CDSN that has not been previously observed in normal stratum corneum. The results suggest a reduced degradation of all corneodesmosomal proteins in psoriatic lesions which probably reflects the persistence of corneodesmosomes.     

Key component of inflammasome,NLRC4, was identified in the lesional epidermis of psoriatic patients

Inflammasomes are multimolecular complexes that control the inflammatory response. The function of inflammasomes in the pathogenesis of psoriasis is still unclear. To clarify the relationship between inflammasomes and the pathophysiology of psoriasis, and in particular, to identify molecules interacting with caspase‐1, a crucial component of inflammasomes, scale extracts obtained from patients with psoriasis were immunoprecipitated with anti‐caspase‐1 antibody and analyzed by liquid chromatography coupled with electrospray tandem mass spectrometry (LC‐MS/MS). The expression of the inflammasome component was assessed by immunohistochemical analysis and an in vitro assay. We identified several candidates for caspase‐1‐interacting proteins from the psoriatic scale extracts by immunoprecipitation and LC‐MS/MS. Nucleotide‐binding oligomerization domain‐containing protein‐like receptor family CARD domain‐containing protein 4 (NLRC4) was the only inflammasome component among the candidates; thus, the protein is considered to be a key factor of inflammasomes in psoriasis. No inflammasome component was found in the extracts of atopic dermatitis or normal skin by LC‐MS/MS. Immunohistochemical analysis demonstrated upregulation of NLRC4 in the lesional epidermis of some psoriatic patients whereas weak expression of NLRC4 was detected in the normal and non‐lesional epidermis. The mRNA expression of the NLRC4 gene increased in keratinocytes at confluency, 48 h after air exposure and after the addition of 1.5 mmol/L calcium chloride. Our findings suggest that NLRC4 may be involved in the exacerbation or modification of psoriatic lesions.     

Increased lysophosphatidylcholine content in lesional psoriatic skin

Various cell stimuli occur via activation of phospholipase A₂, which hydrolyses polyunsaturated fatty acids from the sn-2 position of membrane phospholipids, resulting in the formation of polyunsaturated fatty acids and lysophospholipids. The level of lysophospholipids is determined by the balance between phospholipase A₂ activity and the rate of catabolism of the lysophospholipids. One of the lysophospholipid classes, lysophosphatidylcholine, has been shown to stimulate certain leucocyte activities which are of importance for the induction and maintenance of inflammation. In addition, it has been demonstrated that phospholipase A₂ activity is increased in psoriatic skin. In the present study, we analysed the levels of lysophosphatidylcholine, by thin layer chromatography, in lesional psoriatic skin, uninvolved psoriatic skin and normal skin. The lysophosphatidylcholine content, expressed as μmol lysophosphatidylcholine/μmol phosphatidylcholine, was 1.55, 0.21 and 0.12% in lesional psoriatic skin, uninvolved psoriatic skin and normal skin, respectively. The level of lysophosphatidylcholine was significantly elevated in lesional compared with uninvolved psoriatic skin (P= 0.004) and normal skin (P= 0.002). The increased lysophosphatidylcholine levels in psoriatic skin indicate that the phospholipase A₂ activation is not accompanied by a corresponding increase in the activity of enzymes catabolizing lysoPC. If present in biologically active concentrations, lysophosphatidylcholine may contribute to the induction and maintenance of the inflammatory and immunological processes occurring in lesional psoriatic skin.