Epidermal overexpression of interleukin-19 and -20 mRNA in psoriatic skin disappears after short-term treatment with cyclosporine a or calcipotriol

Interleukin-19, 20, and 24 are new members of the IL-10 family binding and signaling through the IL-20R1/IL-20R2 heterodimer, while IL-20 and 24 also bind to the IL-20R2/IL-22R1 heterodimer. Using in situ hybridization we have studied mRNA expression of IL-19, 20, and 24 and their related receptor chains in skin from psoriatic patients before and during short-term treatment with either oral cyclosporine A or topical calcipotriol. In untreated lesions IL-19 and IL-20 mRNA was expressed focally in epidermis above the dermal papillae, whereas IL-24 was expressed in mononuclear cells in the dermal infiltrate. The expression of IL-19 and 20 mRNA was confined to the basal and suprabasal keratinocytes. No expression of IL-19 and 20 mRNA could be detected in uninvolved psoriatic skin. Treatment with cyclosporine A and calcipotriol resulted in disappearance of the IL-19 and 20 mRNA. Expression of mRNA for the receptor chains IL-20R1 and IL-20R2 was found throughout the psoriatic epidermal layer, whereas IL-22R1 mRNA was predominantly expressed in the superficial part of the psoriatic epidermis. These findings show that IL-19 and IL-20 are synthesized by a distinct population of keratinocytes. It remains to be clarified whether IL-19 and IL-20 are implicated in the pathogenesis of psoriasis.     

Interleukin-11 production is increased in organ cultures of lesional skin of patients with active plaque-type psoriasis as compared with nonlesional and normal skin. Similarity to interleukin-1β, interleukin-6 and interleukin-8

Increased levels of several cytokines, mainly proinflammatory mediators, have been reported in psoriatic lesions. Little information, if any, is available concerning other cytokines, especially those initially studied as marrow differentiation agents. Using the experimental approach of measuring cytokines released by skin organ cultures. IL-11 and three other proinflammatory cytokines (IL-1β, IL-6 and IL-8) were determined using commercially available ELISA kits in supernatants of ten biopsies from lesional and nonlesional psoriatic skin areas and in supernatants of biopsies from ten normal volunteers. The results obtained showed that the amounts of IL-11 and the other three modulators were significantly increased in the material from the lesional areas ( P < 0.01). The amounts of IL-11, which is known to have functional activity similar to the proinflammatory cytokines and to share a receptor component with IL-6, were also correlated with the disease severity index ( R = 0.69, P = 0.04). In addition, a nearly significant correlation was noted between the amounts of IL-11 released by the lesional and the nonlesional skin biopsies ( R = 0.66, P = 0.05). More detailed studies are needed to clarify whether IL-11 plays a specific functional role in psoriasis, but this study emphasizes the complexity of the pathogenesis of psoriasis and the cytokine network, including activation of proinflammatory and haemopoietic biological response modifiers, in this disease. Received: 14 October 1996     

Prominent production of IL-20 by CD68+/CD11c+ myeloid-derived cells in psoriasis: Gene regulation and cellular effects

We assessed expression of IL-20 and its receptors in psoriasis, given the recent implication of IL-20 in epidermal hyperplasia. Psoriatic lesional (LS) skin consistently expressed more IL-20 mRNA than nonlesional (NL) skin. Immunoreactivity to IL-20 protein was greater in LS tissue and mainly localized to infiltrating CD68+/CD11c+ (myeloid-derived) dermal leukocytes. Because this contrasted with earlier reports of a keratinocyte source, we assessed IL-20 mRNA expression in a variety of cells in vitro, and confirmed a myeloid-derived cellular source (monocytes). Plastic adhesion, activation of beta2 integrins, and incubation with tumor necrosis factor-alpha stimulated expression in these cells. IL-20 receptor (IL-20R)alpha and IL-20Rbeta mRNA was decreased in LS versus NL skin, which also contrasted with earlier findings. To investigate the relationship between IL-20 and disease activity, we examined psoriasis patients treated with the CD2-targeted agent alefacept. In therapeutic responders, lesional IL-20 mRNA decreased to NL levels, suggesting that CD2+ leukocytes may proximally regulate IL-20. Finally, to assess IL-20 function, we used microarrays to screen IL-20-treated keratinocytes, which demonstrated upregulation of disease-related and IFN-gamma-induced genes. Hence, IL-20 may influence inflammation through IFN-like effects. Together, these data indicate that IL-20 may be an important effector cytokine in psoriasis, and that its inhibition may represent a potential therapeutic target.     

Interleukin-20 plays a critical role in maintenance and development of psoriasis in the human xenograft transplantation model

Background  Interleukin (IL)-20 is a recently discovered cytokine displaying increased levels in psoriatic lesions. Interestingly, IL-20 levels decrease with antipsoriatic treatment, correlating with clinical improvement. However, the role of IL-20 in the aetiology of psoriasis is unknown.
Objectives  In this study, we investigate the effects both of blocking IL-20 signalling in psoriatic plaques and of adding IL-20 to nonlesional psoriasis skin.
Methods  We employed the human skin xenograft transplantation model in which psoriatic plaques and nonlesional keratome skin biopsies obtained from donors with moderate to severe plaque psoriasis were transplanted on to immuno-deficient mice. The transplanted mice were treated with anti-IL-20 antibodies or recombinant human IL-20.
Results  We demonstrate that blocking IL-20 signalling with anti-IL-20 antibodies induces psoriasis resolution and inhibits psoriasis induction. We also demonstrate that continuous IL-20 infusion, together with injection of additional nonactivated leucocytes, promotes induction of psoriasis in nonlesional skin from patients with psoriasis.
Conclusions  The results suggest that IL-20 plays a critical role in the induction and maintenance of psoriasis, and IL-20 is suggested as a new possible specific target in psoriasis treatment.     

In situ expression of messenger RNA of interleukin-1 and interleukin-6 in psoriasis: interleukin-6 involved in formation of psoriatic lesions

Summary Psoriasis is a disease of abnormal proliferation and differentiation of epidermal cells. Several cytokines released by keratinocytes are implicated as factors responsible for this pathological condition of the epidermis. In order to elucidate the role of these cytokines in psoriasis, messenger RNA (mRNA) expression of interleukin-1 (IL-1) and IL-6 in psoriatic epidermis was investigated using biotin-labelled complementary DNA (cDNA) of the cytokines. Messenger RNA of IL-1 was weakly detected in some normal healthy epidermis specimens and more strongly in all the perilesional uninvolved psoriatic epidermis specimens. It was also expressed in the transitional zone between uninvolved and fully developed psoriatic skin, but was not expressed in lesional skin. In contrast, IL-6 mRNA was rarely expressed in normal healthy epidermis, but was expressed in perilesional uninvolved psoriatic epidermis, in the transitional zone and in the fully developed lesional epidermis, with the maximum intensity in the transitional zone. Expression of mRNA of IL-6 receptor showed a similar tendency to that of IL-6. It was expressed in psoriatic epidermis, most strongly in the transitional zone, but not in normal healthy epidermis. IL-6 was demonstrated immunohistochemically in psoriatic epidermis, but IL-6 receptor was demonstrated only in the transitional zone. Thus IL-6 and its receptor expression correlated well with the formation of psoriatic lesions where IL-1 may initiate their expression. IL-6 may play an important role in the pathogenesis of psoriasis.     

Up-regulation of interleukin-13 receptor alpha1 on human keratinocytes in the skin of psoriasis and atopic dermatitis

BACKGROUND: Interleukin (IL)-13 is a pleiotropic cytokine, which shares many biological functions with IL-4. The receptor subunits of IL-13 consist of IL-4Ralpha, IL-13Ralpha1 and IL-13Ralpha2. The regulatory mechanisms of the IL-13Ralpha expression in the keratinocytes of certain skin disease have not been known. OBJECTIVE: To clear the roles of IL-13 and the regulatory mechanisms of its receptor in atopic dermatitis (AD) and psoriasis. METHOD: The expression of IL-13Ralpha1 in the skin of AD and psoriasis was investigated by immunohistochemistry. The regulation of IL-13Ralpha mRNA in the skin and human primary keratinocyte (HPK) was investigated by quantitative PCR. The secretion of IL-6 and RANTES from HPK was measured by ELISA. RESULTS: The expression of IL-13Ralpha1 was more prominent on the suprabasal keratinocytes in the skin of AD and striking increase of staining was observed on all layers of keratinocyte in the skin of psoriasis. The mRNA of IL-13Ralpha1, but not of IL-13Ralpha2 was overexpressed in both skin of AD and psoriasis. In vitro experiment using HPK demonstrated that IFN-gamma, IL-13 but not IL-4 could up-regulate the mRNA expression of IL-13Ralpha1. In contrast, IL-13Ralpha2 mRNA expression was up-regulated by IFN-gamma plus IL-4. Furthermore, the stimulation of HPK with IFN-gamma plus IL-13 and/or IL-4 resulted in significant enhancement of IL-6 and RANTES secretion. CONCLUSION: These findings indicate that IL-4 and IL-13 have different regulatory effects on the expression of IL-13Ralpha1 and alpha2, and the overexpression of IL-13Ralpha1 may play some roles in the pathogenesis of chronic stage of AD or psoriasis.     

Spontaneous release of leukemia inhibitory factor and oncostatin-M is increased in supernatants of short-term organ cultures from lesional psoriatic skin

Several cytokines are increased in psoriatic skin, mainly at the lesional level. Some of these mediators seem to be very important in the pathogenesis of psoriasis since they are thought to stimulate keratinocyte proliferation and/or to drive the inflammatory changes associated with psoriasis. Among the proinflammatory modulators, hematopoietins, which are a family of cytokines sharing a receptor component (the gp130 subunit), have been under intensive investigation in recent years. The hematopoietin family includes interleukin-6 (IL-6), interleukin-11 (IL-11,) leukemia inhibitory factor (LIF), oncostatin-M (OSM), granulocyte colony-stimulating factor (G-CSF), ciliary neurotrophic factor (CNTF) and cardiotrophin. Amounts of two of these molecules, IL-6 and IL-11, have been found to be increased in psoriatic lesions. The present study adds new information concerning the spontaneous release of two hematopoietins, namely LIF and OSM, in 48-h culture supernatants of lesional and nonlesional skin punch biopsies from psoriatic patients and normal subjects. The cytokine determinations were performed using commercially availabe ELISA kits. The results are expressed as picograms per milligram of tissue, after weight normalization. The levels of LIF released by lesional skin (median 2.4 pg/mg, range 0.05– 13.4 pg/mg) were significantly higher than from nonlesional (median 0.4 pg/mg, range under detection limit (UDL)-4.4 pg/mg; P = 0.001) and normal skin (median 0.4 pg/mg, range UDL–0.9 pg/mg; P = 0.005). The OSM levels were also significantly higher in supernatants of lesional skin (median 0.9 pg/mg, range 0.4–5.2 pg/mg) than in supernatants of nonlesional (median 0.2 pg/mg, range UDL–0.8 pg/mg; P = 0.001) and normal skin (median 0.1 pg/mg, range UDL–0.4 pg/mg; P = 0.0001). In addition, interleukin-8 (IL-8), a cytokine involved in the pathomechanisms of psoriasis, showed a similar behaviour when measured in the same samples. Lesional skin showed a median value of 752.5 pg/mg, range 98.8–2063.8 pg/mg, nonlesional skin a median value of 58.3 pg/mg, range UDL–1252.5 pg/mg ( P = 0.007) and normal skin a median value of 44.6 pg/mg, range UDL–176.7 pg/mg ( P = 0.004). No significant differences were found between nonlesional and normal skin for the three molecules analyzed. Taken together with the fact that at least two other hematopoietins (namely IL-6 and IL-11) are also increased in supernatants of lesional psoriatic skin, these data point to a possible involvement of the hematopoietins in inflammatory processes associated with psoriasis. Received: 21 April 1997     

Apoptosis, P53 and Bcl-2 expression in response to topical calcipotriol therapy for psoriasis

BACKGROUND: The histopathologic changes characteristic of psoriasis might be related to suppressed apoptosis. The P53 and Bcl-2 proteins play a central role in the regulation of apoptosis. This study aimed to evaluate P53 and Bcl-2 expression and apoptotic cells in the psoriatic skin before and after topical calcipotriol therapy. METHODS: Skin biopsies were obtained from nonlesional and lesional skin of 10 patients with generalized plaque psoriasis before and after treatment with topical calcipotriol ointment. The P53 and Bcl-2 expression was evaluated using immunoperoxidase technique and apoptotic cells by the terminal deoxynucleotide transferase (TdT) mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. RESULTS: After topical calcipotriol therapy, keratinocytes of psoriatic skin showed significant decrease of P53 (P = 0.002) and increase of Bcl-2 (P = 0.01) expression. On the other hand lymphocytes showed significant decrease of Bcl-2 (P = 0.01). There were no apoptotic cells before treatment but after calcipotriol therapy, apoptosis was more detectable in keratinocytes than in lymphocytes. CONCLUSIONS: The results of the study suggested that one of the actions of calcipotriol in psoriasis might be exerted through induction of apoptosis, especially of keratinocytes, through a P53-independent pathway. Meanwhile, suppression of Bcl-2 expression in lymphocytes may promote apoptosis of dermal lymphocytes leading to healing of psoriasis.     

Mast cell density and IL-8 expression in nonlesional and lesional psoriatic skin

BACKGROUND: An important cellular aberration at sites of psoriatic inflammation is an increase in the number of dermal mast cells. Being multifactorial immune effector cells, it is believed that mast cells play an essential role in perpetuating the inflammatory process of psoriasis. However, factors responsible for the infiltration and accumulation of mast cells in psoriatic lesions are largely unknown. Recent studies have demonstrated that Interleukin-8 (IL-8) exerts strong chemotactic effects on mast cells in vitro. Overexpression of IL-8 has also been reported in psoriatic lesions. In this study, we have found a correlation between the expression of IL-8 and dermal mast cell density in lesional psoriatic skin as compared to nonlesional psoriatic skin. METHODS: Four-mm punch biopsies were taken from 14 psoriatic patients and eight healthy volunteers. Using immunohistochemical techniques, 8 microm sections of lesional psoriatic, nonlesional psoriatic, and normal control samples were evaluated for dermal mast cell density and the density of IL-8 expressing keratinocytes. RESULTS: It was found that dermal mast cell density in lesional psoriatic, nonlesional psoriatic, and normal skin was 105.4 +/- 71.2, 42.3 +/- 30.1, and 47.5 +/- 32.5 mast cells/mm(2), respectively. IL-8+ keratinocyte density in lesional psoriatic, non lesional psoriatic, and normal skin was 171.5 +/- 67.1, 25.4 +/- 14.9 and 20.6 +/- 8.7 IL-8+ Keratinocytes/mm(2), respectively. CONCLUSIONS: The results of this study suggest that increased levels of IL-8 in the keratinocytes of psoriatic plaques play a contributing role in the migration of mast cells to lesion sites.     

银屑病皮损中IL—1受体拮抗物的蛋白和mRNA表达

采用抗人ＩＬ－１ｒａ单抗和地高辛标记的ＲＮＡ探针,在银屑病破损和正常人皮肤切片上进行ＡＰＡＡＰ染色和原位杂交,检测并比较ＩＬ－Ｉｒａ的蛋白表达和ｍＲＮＡ转录水平。结果发现,正常人皮肤中ＩＬ－１ｒａ蛋白染色阴性,ＩＬ－１ｒａｍＲＮＡｗ信号微弱;相比之下,银屑病皮损中ＩＬ－１ｒａ蛋白和ｍＲＮＡ的表达均异常增高,统计学比较相差显著。上述结果显示：ＩＬ－１ｒａ在银屑病皮损中增强表达,提示银屑病病理过程中Ｉ     

T cells and mast cells as a major source of interleukin-13 in atopic dermatitis

BACKGROUND: Interleukin (IL)-13 is a T-cell-derived cytokine that shares several functions with IL-4, including the induction of immunoglobulin E synthesis. Recent studies suggest that cytokines expressed locally in the skin play several critical roles in atopic dermatitis (AD), however, little is known about the role of IL-13 in AD lesions. OBJECTIVES: The present study was designed to characterize the involvement of IL-13 in AD in the skin and peripheral blood mononuclear cells (PBMC). METHODS: Using lesional and nonlesional skin from adult AD patients and normal skin from healthy volunteers, we performed RT-PCR, in situ RT and immunostaining to determine the IL-13 expression at the mRNA and protein levels. The actual numbers of IL-13 expressing cells in biopsy specimens were counted under the microscope. IL-13 mRNA expression in PBMC from AD patients and healthy volunteers was examined by RT-PCR analysis. RESULTS: IL-13 mRNA expression was detected by RT-PCR in lesional and nonlesional skin and in PBMC from AD patients, but not in normal skin or PBMC from healthy volunteers. In AD lesional skin, numerous IL-13 mRNA-positive cells were demonstrated by in situ RT, and similar numbers of IL-13-positive cells were also detected immunohistochemically. Smaller numbers of IL-13-positive cells were observed in AD nonlesional skin and in normal skin. The differences in the numbers of IL-13-expressing cells between lesional and nonlesional skin were statistically significant. Double immunostaining revealed that IL-13 was produced in approximately 40% of T cells and 20% of mast cells in AD lesional skin, suggesting that T cells and mast cells are major sources of IL-13 in AD lesions. CONCLUSION: IL-13 may play a local as well as a systemic role in the development of AD lesions.     

The mitogen-activated protein kinases p38 and ERK1/2 are increased in lesional psoriatic skin

BACKGROUND: Alterations in specific signal transduction pathways may explain the hyperproliferation and abnormal differentiation of the keratinocytes as well as the increased expression of inflammatory cytokines seen in psoriasis. Major signalling pathways used by eukaryotic cells to transduce extracellular signals into cellular responses impinge on the mitogen-activated protein kinases (MAPKs). OBJECTIVES: To investigate the expression of the MAPK p38, extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) in psoriatic skin. METHODS: Keratome biopsies were taken from patients with plaque-type psoriasis. Western blot analysis was used to determine p38, ERK and JNK activity and protein levels, whereas kinase assays were used to examine the kinase activity of p38. RESULTS: We demonstrated increased levels of the phosphorylated forms of p38 and ERK1/2 in lesional psoriatic skin compared with nonlesional psoriatic skin. No abnormality was found in the activation and expression of JNK1/2. Ex vivo kinase assays confirmed the increased activation of p38, and furthermore demonstrated increased kinase activity of the p38 isoforms p38alpha, p38beta and p38delta in lesional compared with nonlesional psoriatic skin. p38gamma was not detected in the psoriatic skin. Clearance of the psoriatic lesions, induced by climatotherapy at the Dead Sea for 4 weeks, led to a normalization in the activity of both p38 and ERK1/2. CONCLUSIONS: Taken together, our results demonstrate that the activity of the MAPKs p38alpha, p38beta and p38delta and ERK1/2 are increased in lesional psoriatic skin compared with nonlesional psoriatic skin, and that clearance of psoriasis normalizes the p38 and ERK1/2 activity. Thus, p38 and ERK1/2 might be potential targets in the treatment of psoriasis.     

寻常性银屑病皮损及非皮损中IL-23(p19/p40)和IL-12(p35/p40)mRNA的表达

目的检测寻常性银屑病患者皮损及非皮损处IL-23(p19/p40)和IL-12(p35/p40)mRNA表达,探讨其临床意义。方法采用逆转录-聚合酶链反应(RT-PCR)检测寻常性银屑病患者皮损、非皮损处及正常人皮肤中IL-23(p19/p40)和IL-12(p35/p40)mRNA的表达水平。结果寻常性银屑病患者皮损中IL-23p19及p40(IL-23/IL-12)mRNA的表达均高于非皮损组织和正常皮肤组织(P<0.05),且非皮损处高于正常对照组,差异有显著性(P<0.05);IL-12p35mRNA在银屑病皮损处、非皮损处和正常对照中表达水平差异无显著性(P>0.05)。结论在寻常性银屑病发病过程中,IL-23可能发挥较IL-12更重要的作用。     

Expression and localization of peroxisome proliferator-activated receptors and nuclear factor kappaB in normal and lesional psoriatic skin

Abnormal epidermal proliferation and differentiation characterize the inflammatory skin disease psoriasis. Here we demonstrate that expression of PPARdelta mRNA and protein is markedly upregulated in psoriatic lesions and that lipoxygenase products accumulating in psoriatic lesions are potent activators of PPARdelta. The expression levels of NF-kappaB p50 and p65 were not significantly altered in lesional compared with nonlesional psoriatic skin. In the basal layer of normal epidermis both p50 and p65 were sequestered in the cytoplasm, whereas p50, but not p65, localized to nuclei in the suprabasal layers, and this distribution was maintained in lesional psoriatic skin. In normal human keratinocytes PPAR agonists neither impaired IL-1beta-induced translocation of p65 nor IL-1beta-induced NF-kappaB DNA binding. We show that PPARdelta physically interacts with the N-terminal Rel homology domain of p65. Irrespective of the presence of agonists none of the PPAR subtypes decreased p65-mediated transactivation in keratinocytes. In contrast p65, but not p50, was a potent repressor of PPAR-mediated transactivation. The p65-dependent repression of PPARdelta- but not PPARalpha- or PPARgamma-mediated transactivation was partially relieved by forced expression of the coactivators p300 or CBP. We suggest that deficient NF-kappaB activation in chronic psoriatic plaques permitting unabated PPARdelta-mediated transactivation contributes to the pathologic phenotype of psoriasis.