Comparison of stress-induced PRINS gene expression in normal human keratinocytes and HaCaT cells

Psoriasis is a chronic inflammatory skin disease that affects approximately 2–4% of the population. We recently described a novel non-coding RNA, psoriasis susceptibility related RNA gene induced by stress (PRINS), that was overexpressed in non-lesional psoriatic epidermis, and its expression was induced by various stress factors such as serum starvation, contact inhibition, ultraviolet (UV)-B irradiation, viral infection and translational inhibition in HaCaT cells. In the present work we set out to compare the stress and microbial agent-induced PRINS expression in normal human keratinocytes (NHKs) and HaCaT cells. Since nuclear factor-κB (NF-κB) is involved in the cellular stress response, we sought to explore whether there is a connection between the NF-κB and PRINS-mediated signal transduction pathways in NHKs and HaCaT cells. We found that the PRINS expression responded differentially to various stress signals and microbial agents in HaCaT cells and in NHKs: after translational inhibition and UV-B treatment, similar induction of PRINS expression occurred with different time courses while after microbial agent treatment, the PRINS expression was significantly induced in HaCaT cells, whereas we could not detect similar changes in NHKs. To explore whether the known NF-κB abnormalities in HaCaT cells could be related to this differential PRINS expression, we silenced the PRINS gene expression with small interfering RNA (siRNA) in both HaCaT cells and in NHKs and monitored NF-κB signal transduction after lipopolysaccharide (LPS) treatment. Silencing of PRINS had no effect on LPS-induced NF-κB activity either in HaCaT cells or in NHKs. Our results indicate that PRINS probably affects keratinocytes functions independently of NF-κB signalling.     

Roxithromycin downregulates production of CTACK/CCL27 and MIP-3α/CCL20 from epidermal keratinocytes

Cutaneous T cell-attracting chemokine (CTACK)/CCL27 and macrophage inflammatory protein (MIP)-3α/CCL20 are the major inflammatory chemokines involved in skin inflammation. The present study showed that roxithromycin (RXM) suppressed the TNFα-induced production of CCL27 and CCL20 in HaCaT keratinocytes and normal human keratinocytes (NHKs) in a dose-dependent manner. The production of CCL20 induced by TNFα was suppressed by the addition of inhibitors of nuclear factor kappa B (NFκB). RXM suppressed NFκB activity induced by TNFα. RXM, by regulating CCL27 and CCL20, may contribute to the modulation of inflammation.     

miR-20a靶向STAT3抑制角质形成细胞增殖参与银屑病的机制

目的探讨miR-20a是否可靶向调控STAT3表达影响角质形成细胞增殖参与银屑病发生发展过程。方法QPCR检测银屑病患者正常皮肤和皮损组织中miR-20a、STAT3的表达情况,统计分析二者间的表达相关性;QPCR检测miR-20a表达变化对STAT3水平的影响;LUC验证miR-20a和STAT3间的靶向关系;miRNA mimics和STAT3过表达载体共转染后,MTT检测HaCaT细胞的增殖活性。结果miR-20a在银屑病患者皮损组织中特异性低表达,STAT3在皮损组织中高表达,且miR-20a与STAT3表达呈负相关性;QPCR检测miR-20a表达变化对STAT3的影响后发现miR-20a可抑制STAT3表达;LUC实验发现miR-20a可靶向结合STAT3;MTT功能实验结果表明STAT3过表达可增强角质形成细胞增殖活性,而过表达miR-20a不仅可抑制细胞增殖活性和STAT3的表达,还可部分逆转STAT3对细胞增殖的促进作用。结论miR-20a可靶向STAT3抑制角质形成细胞过度增殖,在银屑病发生发展中发挥保护作用。     

The effect of IFN-γ on healthy and psoriatic keratinocytes in a skin equivalent model is influenced by the source of the keratinocytes and by their interactions with fibroblasts

We investigated the effect of interferon-gamma (IFN-γ) on skin equivalents. Keratinocytes from involved and uninvolved skin from psoriatic subjects and from healthy subjects were grown on preproduced dermal equivalents (DE) containing fibroblasts from healthy skin or psoriatic lesions. Healthy keratinocytes were added when the dermal equivalents were either 22 days (DE(22)) or 37 days old (DE(37)) and psoriatic keratinocytes when the dermal equivalents were 28–52 days old (DE(28–52)). The skin equivalents were cultured for 11 days in a serum-free medium, and then with or without 500 U/ml IFN-γ for 6 days. The expression of markers associated with differentiation and proliferation were investigated by immunohistochemistry. Differentiation was assessed by computed scores for the expression of cytokeratin 16, involucrin, filaggrin and the receptor for epidermal growth factor. The differentiating effect of IFN-γ on healthy keratinocytes grown on DE(37) was significantly stronger than on psoriatic keratinocytes grown on DE(28–52). In healthy keratinocytes, the differentiating effect of IFN-γ was significantly stronger in skin equivalents containing DE(37) than in those containing DE(22). The proliferation rate, i.e. the percentage of Ki-67 ⁺ keratinocytes in the basal layer, was studied in healthy keratinocytes grown on DE(22). In these cultures IFN-γ increased the proliferation rate in the presence of psoriatic fibroblasts but not in the presence of healthy fibroblasts. HLA-DR expression was induced only in healthy keratinocytes grown on DE(22). We conclude that the influence of IFN-γ on epidermal differentiation and proliferation is influenced by the origins of both the keratinocytes and the fibroblasts. These findings suggest that interactions between keratinocytes and fibroblasts might be involved in the pathogenesis of psoriasis. Received: 12 March 1996     

阿维A对缺氧培养的HaCaT细胞体外增殖和缺氧诱导因子1α及血管内皮生长因子表达的影响

目的 通过阿维A作用于缺氧培养的HaCaT细胞,初步探讨阿维A治疗银屑病的可能机制.方法 将浓度为10-5、10-6、10-7、10-8mol/L的阿维A分别作用于HaCaT细胞,用CCK-8法检测缺氧培养12、24、36h对HaCaT细胞体外增殖的影响.反转录PCR和Western印迹检测不同浓度阿维A对缺氧培养24 h的HaCaT细胞HIF-1α、血管内皮生长因子(VEGF)蛋白及mRNA表达的影响.结果 阿维A 10-8、10-7、10-6、10-5 mol/L作用24 h,HaCaT细胞体外增殖抑制率分别为(13.31±1.15)％、(21.86±5.31)％、(32.05±2.99)％、(37.28±3.21)％,且随着缺氧培养时间延长和阿维A浓度增加,对HaCaT细胞体外增殖的抑制作用逐渐增强.当阿维A浓度为10-5mol/L时,HIF-1α蛋白的表达由1.196±0.088降至0.319±0.180(P＜ 0.05),而HIF-1α mRNA表达水平无明显下降;VEGF mRNA的表达由1.108±0.073降至0.442±0.090(P＜ 0.05),VEGF蛋白的表达则由1.174±0.186降至0.216±0.066(P＜ 0.05).结论 阿维A可抑制缺氧培养的HaCaT细胞体外增殖,并在蛋白水平下调HIF-1α及VEGF的表达,在mRNA水平下调VEGF的表达.     

The action of a novel vitamin D3 analogue, OCT, on immunomodulatory function of keratinocytes and lymphocytes

Abstract Topical vitamin D₃ has relatively recently been introduced for the treatment of psoriasis. Synthetic vitamin D₃ analogues with a high potential for inducing differentiation of cells, but with a low hypercalcemic effect have recently been developed. One such synthetic analogue of 1,25-dihydroxyvitamin D₃ (calcitriol), 22-oxacalcitriol (OCT), is a novel agent for the topical treatment of psoriasis. The activity of OCT in vitro was investigated and compared with that of a series of vitamin D₃ analogues as to their ability to inhibit murine T lymphocyte proliferation stimulated by con-A, to suppress IL-6 and IL-8 production by keratinocytes stimulated with IL-1α and TNFα, and to inhibit AP-1- and NFκB-dependent reporter gene expression. OCT inhibited the proliferation of lymphocytes and suppressed IL-8 and IL-6 production by keratinocytes to the same extent as the other vitamin D₃ analogues. It also inhibited AP-1- and NFκB-controlled luciferase activity to the same extent as the other vitamin D₃ analogues, which demonstrates its mechanism of action in the suppression of inflammatory processes. Received: 26 January 1999 / Received after revision: 10 June 1999 / Accepted: 11 June 1999     

Decisive role of tumor necrosis factor-α for spongiosis formation in acute eczematous dermatitis

Apoptosis of single keratinocytes (KC) is a characteristic feature of spongiosis formation, the histopathologic hallmark of acute eczematous dermatitis. In acute eczema, activated dermis-infiltrating T cells secrete several proinflammatory cytokines which might be decisive for KC apoptosis or survival. We analyzed the role of tumor necrosis factor alpha (TNF-α) in the determination of KC fate during spongiosis formation in acute eczematous dermatitis. Supernatants of activated human CD4⁺ T cells induced apoptosis in primary KC, which could be fully inhibited by individual blockade of interferon-γ (IFN-γ) and CD95 but not by neutralization of TNF-α activity. As compared to CD95-triggering alone, synchronous CD95 and TNF receptor cross-linking in the presence of IFN-γ only marginally enhanced KC apoptosis. Importantly, pre-treatment of KC with TNF-α followed by CD95 stimulation, but not vice versa, significantly amplified KC apoptosis as compared to CD95 stimulation alone. This TNF-α-mediated sensitization to CD95-induced KC cell death could be abrogated by blocking TNF receptor 1 (TNF-R1) but not TNF-R2 mAb. In eczematous dermatitis, the CD95 receptor was expressed throughout the epidermis, whereas immunohistological detection of TNF-R1 was rather restricted to KC around spongiotic vesicle formation. Thus, TNF-α primes KC for CD95-mediated signals which results in an increased susceptibility to apoptosis. TNF-R1 expression and spatial action of TNF-α restricted to spongiotic vesicles promote both CD95-induced KC apoptosis and limitation of spreading KC damage.     

Association of interferon-gamma and tumor necrosis factor alpha polymorphisms with susceptibility to vitiligo in Iranian patients

Vitiligo is a common skin disorder that is caused by selective destruction of melanocytes, resulting in disfiguring loss of pigment. There are convincing evidences that cytokines and T cell mediated immunity may have a role in its pathogenesis. Given the fact that cytokine production is under genetic control, in this study, we have investigated IFN-γ +874 T/A and TNF-α −308 G/A gene polymorphisms in a total of 176 vitiligo patients and 545 controls. IFN-γ +874 T/A and TNF-α −308 G/A gene polymorphisms were genotyped via Allele Specific Oligonucleotide PCR (ASO-PCR) method. The results showed that the TNF-α −308 G/A polymorphism was more common in vitiligo patients than controls (P = 0.0004). This difference was only significant between female patients and controls (P < 0.0001), while there was no significant difference between male patients and male controls (P = 0.90). The distribution of IFN-γ genotypes in vitiligo patients did not differ significantly from that in control subjects (P = 0.56). Since the presence of A nucleotide at position −308 of TNF-α gene is associated with increased cytokine production, therefore, the higher frequency of TNF-α −308 A allele in vitiligo patients compared to controls may be considered as a genetic susceptibility factor towards the development of vitiligo.     

Psoriatic fibroblasts secrete lower amounts of IL-6 than healthy fibroblasts before and after stimulation with TNF-α

Abstract Altered function of the fibroblasts is thought to contribute to the pathogenesis of psoriasis. To further elucidate this point, we compared the ability of fibroblasts from psoriatic lesions and of fibroblasts from healthy individuals to produce interleukin-6 (IL-6). The IL-6 levels were measured by ELISA in serum-free culture medium before and after stimulation of monolayer fibroblasts with various concentrations of tumour necrosis factor-α (TNF-α), platelet-derived growth factor (PDGF), and interferon-γ (IFN-γ), alone and in different combinations. The production of IL-6 in the fibroblast cultures was stimulated by TNF-α (0.01–10 nm/ml medium) in a dose-dependent way. Fibroblasts from psoriatic lesions produced lower amounts of IL-6 than fibroblasts from healthy individuals both before and after stimulation with the different concentrations of TNF-α (P = 0.012). The ratios between the IL-6 concentrations before and after stimulation with TNF-α were similar in both types of fibroblasts, indicating that the capacity to produce IL-6 is reduced in psoriatic fibroblasts compared with healthy ones. The production of IL-6 was not influenced by either PDGF or IFN-γ. These findings support the view that the phenotype of the fibroblast is altered in psoriasis. Received: 11 January 1999 / Received after revision: 16 March 1999 / Accepted: 18 June 1999     

Involvement of insulin-like growth factor-I in psoriasis as a paracrine growth factor: dermal fibroblasts play a regulatory role in developing psoriatic lesions

Abstract To investigate the contribution of dermal fibroblasts to the development of psoriasis, we examined the expression of mRNA for insulin-like growth factor-I (IGF-I) and its regulator IGF-I binding proteins (IGFBPs) in psoriatic fibroblasts by RT-PCR. We also studied the effect of inflammatory cytokines including interferon gamma (IFN-γ), tumor necrosis factor alfa (TNF-α), and IFN-α on the expression of IGF-I and IGFBPs in the fibroblasts. Semiquantitative analysis revealed that IGF-I mRNA expression in psoriatic fibroblasts (PF) was significantly higher than in control fibroblasts (CF). However, no significant difference in IGF-I mRNA was shown between nonlesional psoriatic fibroblasts (NF) and CF. Treatment with IFN-α in vitro upregulated IGF-I mRNA in PF and in CF. TNF-α appeared to downregulate IGF-I mRNA in PF but had no effect on CF. IFN-γ did not show a significant effect on IGF-I mRNA levels in any type of fibroblast. IGFBP-3 mRNA was expressed equally in PF and CF, and was not affected by cytokines. The expression of IGFBP-5 mRNA in PF was downregulated by IFN-γ and TNF-α. Taken together, these results indicate that dermal fibroblasts may contribute to the epidermal hyperplasia of psoriasis by promoting keratinocyte proliferation through IGF-I, whose secretion could be modulated by inflammatory cytokines. Received: 8 May 2000 / Revised: 25 August 2000 / Accepted: 24 October 2000     

Analysis of the protective potential of antigens released by Leishmania (Viannia) shawi promastigotes

Leishmania (Viannia) shawi causes cutaneous lesions in humans. Parasite antigens conferring significant protection against American tegumentar leishmaniosis (ATL) might be important for the development of effective vaccine. Therefore, this work evaluates the protective effect of antigenic fractions released by L. shawi. Antigens released by promastigotes to culture medium were concentrated and isolated by SDS-PAGE. The three main fractions LsPass1 (>75 kDa), LsPass2 (75–50 kDa) and LsPass3 (<50 kDa) were electro-eluted according with their molecular mass. Immunized BALB/c mice were challenged with L. shawi promastigotes and the course of infection monitored during 5 weeks. LsPass1-challenged mice showed no protection, however, a strong degree of protection associated to smaller lesions and high expression of IFN-γ and TNF-α by CD4⁺ T, CD8⁺ T and double negative CD4CD8 cells was achieved in LsPass3-challenged mice. Furthermore, LsPass2-challenged mice showed an intermediated degree of protection associated to high levels of IFN-γ, IL-4 and IL-10 mRNA. In spite of increased expression of IFN-γ and TNF-α, high amounts of IL-4 and IL-10 mRNA were also detected in LsPass3-challenged mice indicating a possible contribution of these cytokines for the persistence of a residual number of parasites that may be important in inducing long-lasting immunity. Therefore, LsPass3 seems to be an interesting alternative that should be considered in the development of an effective vaccine against ATL.     

Cyclosporin A induces the unfolded protein response in keratinocytes

Psoriasis vulgaris is a chronic inflammatory disorder of the skin, in which activation of keratinocytes and crosstalk between keratinocytes and T cells or dendritic cells are considered to be involved in the pathogenesis of psoriasis vulgaris. Cyclosporin (Cy) A, an immunomodulator, has been used for the treatment of psoriasis vulgaris, but the mechanism of its action on keratinocytes has not been well elucidated as its function on T cells is well known. Previous study indicated that the expression of the unfolded protein response (UPR) markers, GRP78/Bip and HRD1 were poorly expressed in psoriasis vulgaris. To investigate if the UPR in keratinocytes is involved in the pathogenesis of psoriasis vulgaris we assessed immunocytochemistry of normal human skin and psoriatic lesions, quantitative PCR of keratinocyte cell line (HaCaT) treated with TGFβ. Moreover, to elucidate how CyA effects on the UPR in keratinocytes, we set out quantitative PCR and western blotting, HaCaT and squamous cell carcinoma cell lines (HSC-1) treated with CyA and CyA analog, cyclosporin D. Furthermore, the siRNA-mediated knockdown effect of cyclophilin (Cyp) A, Cyp B and Cyp C on HaCaT cells were also examined. As a result, the UPR was downregulated in keratinocytes from psoriatic lesions, characterized by immunocytochemical staining of GRP78/Bip, CHOP/GADD153, HRD1 and C/EBPβ. TGFβ induced UPR markers in HaCaT cells. CyA treatment and siRNA-mediated knockdown of Cyp B induced the UPR in HaCaT cells or HSC-1 cells. Altogether, we demonstrate that in psoriasis vulgaris CyA or reduction in Cyp B by RNA interference might induce the UPR in keratinocytes.     

芳维A酸氨丁三醇对HaCaT细胞分化的影响

目的观察芳维A酸氨丁三醇作用于无血清培养的HaCaT细胞后,细胞内分化相关基因TGase1表达的变化,探讨其剂量-时间曲线,并比较芳维A酸氨丁三醇与依曲替酸对HaCaT分化的影响。方法将不同浓度的芳维A酸氨丁三醇和依曲替酸(0.001～1.0μm/L)分别加入无血清培养的HaCaT细胞培养液中,在添加芳维A酸氨丁三醇6h、12h和24h后分别回收总RNA,逆转录PCR(RT-PCR)法检测HaCaT细胞分化的特异性标记基因TGase1 mRNA的表达情况;芳维A酸氨丁三醇和依曲替酸分别在孵育24h后回收总RNA,用RT-PCR法检测TGase1 mRNA的表达,比较这两种药物对HaCaT细胞分化的差异。结果0.001～1.0μm/L浓度的芳维A酸氨丁三醇作用于HaCaT细胞6h、12h和24h后能显著促进HaCaT细胞内分化基因TGase1mRNA表达,且呈剂量和时间依赖性(P<0.05)。芳维A酸氨丁三醇及依曲替酸都可促进TGase1 mRNA表达,且TGase1mRNA的表达呈剂量依赖性,这两种药物的剂量曲线非常相似,其促进TGase1 mRNA表达程度比较,差异无显著性意义(P>0.05)。结论芳维A酸氨丁三醇能显著促进HaCaT细胞内分化基因TGase1 mRNA的表达,且呈时间和剂量依赖性,其促进HaCaT细胞分化的作用与依曲替酸的效果类同。     

雷公藤内酯醇对HaCaT细胞IFN-γ信号转导途径的影响

目的 研究雷公藤内酯醇对人角质形成细胞永生化株HaCaT细胞中IFN-γ信号转导途径的影响。方法 不同浓度雷公藤内酯醇（10-10 ～ 10-7 mol/L）预处理HaCaT细胞2 h后,用重组人IFN-γ（rhIFN-γ,500 U/mL）刺激诱导细胞,在不同的时间收集细胞,提取细胞总蛋白,免疫印迹法检测IFN-γ信号途径中IFN-γ受体α（IFN-γRα）、磷酸化Janus激酶2（pJAK2）、细胞因子信号转导抑制因子1（SOCS1）表达情况。结果 10-8 mol/L及10-7 mol/L雷公藤内酯醇可明显抑制HaCaT细胞中IFN-γ诱导的IFN-γRα蛋白表达（P < 0.05,P < 0.05）;10-9 mol/L及10-8 mol/L雷公藤内酯醇可明显抑制IFN-γ诱导的pJAK2蛋白表达（P < 0.05,P < 0.05）。雷公藤内酯醇对IFN-γRα表达及JAK2磷酸化的抑制作用呈剂量依赖性,其半数抑制浓度（IC50值）分别为1.37 × 10-8 mol/L和2.83 × 10-9 mol/L。10-10,10-9,10-8 mol/L的雷公藤内酯醇作用HaCaT细胞2 h后可明显上调IFN-γ诱导的SOCS1蛋白表达（P < 0.05,P < 0.01,P < 0.01）,其半数有效剂量（ED50值）为3.32 × 10-11 mol/L。结论 雷公藤内酯醇可分别通过抑制HaCaT细胞中IFN-γRα表达、JAK2磷酸化以及上调SOCS1表达,从不同时相的3个环节,共同抑制HaCaT细胞中STAT-1磷酸化,从而抑制IFN-γ信号所诱导的多种炎症相关基因转录。这种抑制作用可能是雷公藤治疗银屑病等IFN-γ依赖性炎症性皮肤病有效的重要机制之一。     

阿维A对HaCaT细胞体外凋亡和胰岛素样生长因子结合蛋白7及血管内皮生长因子表达的影响

目的 探讨阿维A对HaCaT细胞体外凋亡和胰岛素样生长因子结合蛋白7（IGFBP7）及血管内皮生长因子（VEGF）表达的影响。 方法 将10-5、10-6、10-7、10-8 mol/L的阿维A分别作用于HaCaT细胞24、48、72 h后,采用CCK8法检测细胞增殖情况;流式细胞仪检测阿维A对HaCaT细胞凋亡率的影响;Western印迹和RT-PCR法检测阿维A对HaCaT细胞IGFBP7、VEGF蛋白及其mRNA表达的影响。 结果 10-8 mol/L阿维A处理HaCaT细胞48 h时表现出对细胞增殖的抑制作用,随着时间延长和药物浓度升高,抗增殖作用亦增强,当药物浓度增加到10-5 mol/L时,48 h和72 h的抑制率分别为39.94% ± 2.27%和49.77% ± 1.87%。与对照组相比,10-5 mol/L阿维A作用48 h后,凋亡率由1.803% ± 0.313%（对照组）上升至7.617% ± 0.767%（阿维A组）（P ＜ 0.05）,IGFBP7的表达由0.436 ± 0.013上升至0.939 ± 0.040（P ＜ 0.05）,IGFBP7 mRNA的表达由0.190 ± 0.056上升至0.872 ± 0.079（P ＜ 0.05）,VEGF的表达由0.798 ± 0.036下降至0.213 ± 0.032（P ＜ 0.05）,VEGF mRNA的表达由0.933 ± 0.054下降至0.274 ± 0.041（P ＜ 0.05）。 结论 阿维A可促进HaCaT细胞的体外凋亡,并可在蛋白及mRNA水平上调IGFBP7及下调VEGF的表达。     

Induction by interferon-γ of its receptor varies with epithelial differentiation and cell type

Abstract Normal keratinocytes from epidermis and from buccal mucosa were cultured to confluence in three media with graded differentiation potential and treated with interferon-γ (IFN-γ). RT-PCR was used to measure the gene expression of the IFN-γ receptor (IFNGR-1), as well as the immunomodulator HLA-DR and two enzymes of the 2–5 A pathway. We have previously reported results for a number of structural and regulatory genes in the same system (and include here involucrin for comparison). In epidermal keratinocytes, the induction of IFNGR-1 was upregulated by incubation with IFN-γ, and this increased with the differentiation potential of the culture medium. A roughly similar pattern occurred for the other genes. In mucosal keratinocytes, in contrast, IFN-γ failed to induce expression of IFNGR-1 or the other genes. A unique characteristic of HLA-DR was that its induction by IFN-γ was uniform, for both tissues and all media. The gene expression of the receptor IFNGR-1 appears to be the dominant factor in the sensitivity of other genes to IFN-γ, although there are substantial disparities among them that presumably reflect functional differences. The difference between the two tissues may be linked to differentiation, as the epidermis has a much more extensive maturation pattern than the buccal mucosa. A clinical implication is a better prognosis for IFN-γ treatment for more differentiated tumors. Indeed, a previous study has found that the maturation pattern of condylomas responding to interferon treatment resembles that of epidermis, whereas the maturation of nonresponders is more akin to that of buccal mucosa. Received: 10 September 1997     

Avenanthramides,polyphenols from oats,exhibit anti-inflammatory and anti-itch activity

Oatmeal has been used for centuries as a soothing agent to relieve itch and irritation associated with various xerotic dermatoses; however few studies have sought to identify the active phytochemical(s) in oat that mediate this anti-inflammatory activity. Avenanthramides are phenolic compounds present in oats at approximately 300 parts per million (ppm) and have been reported to exhibit anti-oxidant activity in various cell-types. In the current study we investigated whether these compounds exert anti-inflammatory activity in the skin. We found that avenanthramides at concentrations as low as 1 parts per billion inhibited the degradation of inhibitor of nuclear factor kappa B-α (IκB-α) in keratinocytes which correlated with decreased phosphorylation of p65 subunit of nuclear factor kappa B (NF-κB). Furthermore, cells treated with avenanthramides showed a significant inhibition of tumor necrosis factor-α (TNF-α) induced NF-κB luciferase activity and subsequent reduction of interleukin-8 (IL-8) release. Additionally, topical application of 1–3 ppm avenanthramides mitigated inflammation in murine models of contact hypersensitivity and neurogenic inflammation and reduced pruritogen-induced scratching in a murine itch model. Taken together these results demonstrate that avenanthramides are potent anti-inflammatory agents that appear to mediate the anti-irritant effects of oats.     

正常人角质形成细胞维A酸受体γmRNA在依曲替酸处理前后的改变

目的研究正常人角质形成细胞维甲酸受体(RAR)γmRNA在依曲替酸处理前后的改变。方法用0.1μmol/L和1.0μmol/L依曲替酸处理正常人角质形成细胞后12h,用RT-PCR和实时荧光定量RT-PCR法检测维甲酸受体γmRNA表达的改变。结果正常人角质形成细胞可表达少量的维甲酸受体γmRNA;0.1μmol/L依曲替酸处理后,RARγmRNA的表达无明显增高,为正常对照组的1.8倍(P>0.05);1.0μmol/L依曲替酸处理后,RARγmRNA的表达明显增高,为正常对照组4.0倍(P<0.01)。结论低浓度依曲替酸(低于0.1μmol/L)对正常人角质形成细胞RARγmRNA的表达无明显影响,但较高浓度的伊曲替酸可明显诱导RARγmRNA的表达。