抗角蛋白16抗体对角质形成细胞外皮蛋白、Toll样受体2和4的调节

目的 研究抗角蛋白16抗体对角质形成细胞分化、Toll样受体2和4的调节。方法 将抗角蛋白16抗体加入培养的角质形成细胞中,以同种型抗体作对照,研究外皮蛋白和Toll样受体2和4mRNA表达。结果 抗角蛋白16抗体作用角质形成细胞6h、24h、36h后,Toll样受体2mRNA表达分别上调1.73、1.60、2.52倍:12 h和36h后Toll样受体4mRNA表达分别上调3.62和2.21倍;12 h、36h后外皮蛋白mRNA表达分别上调2.33倍和2.0倍。结论 抗角蛋白16抗体可能是联系Toll样受体2和4与角质形成细胞分化的重要环节。     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

目的 研究金黄色葡萄球菌肽聚糖对正常人表皮角质形成细胞(NHEK)分泌IL-8、调节激活正常T细胞表达和分泌的细胞因子(RANTES)以及巨噬细胞来源的趋化因子(MDC)的影响以及Toll样受体2在其中的作用.方法 分别用不同浓度金黄色葡萄球菌肽聚糖(3、10、30、100 mg/L)处理NHEK24 h,以及100 mg/L肽聚糖处理NHEK 3、6、12、36 h后,采用ELISA检测细胞培养上清液中IL-8、RANTES以及MDC的水平.预先加用功能性Toll样受体2单克隆抗体处理培养细胞,再以100 mg/L肽聚糖处理NHEK 12 h,检测上述趋化因子的浓度.结果 NHEK可以自发地分泌IL-8和RANTES.3、10、30、100 mg/L的肽聚糖可诱导NHEK分泌IL-8(分别为209.96±10.31、250.28±9.52、285.11±10.28、359.40±6.93 ng/L),且较未处理组(135.41±14.37 ng/L)明显升高(P<0.05);10、30、100 mg/L的肽聚糖可抑制NHEK分泌RANTES(分别为110.72±8.51、90.50±2.45、49.89±13.74 ng/L),且较未处理组(149.94±18.71 ng/L)明显降低(P<0.05).Toll样受体2单克隆抗体可以明显抑制肽聚糖诱导分泌IL-8,但对其分泌RANTES无明显影响.未检测到NHEK自发性产生或肽聚糖刺激作用下产生MDC.结论 肽聚糖可能通过激活Toll样受体2途径诱导NHEK增加分泌IL-8.肽聚糖能够抑制NHEK产生RANTES.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

肽聚糖对正常人表皮角质形成细胞分泌趋化因子的影响及Toll样受体2的作用

Objective To investigate the effect ofpeptidoglycan from Staphylococcus aureus on the release of several chemokines including intedeukin 8 (IL-8), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-derived chemokine (MDC) by normal human epidermal keratinocytes (KCs) and the role of Toll-like receptor 2 (TLR2) in this process. Methods KCs were derived from the foreskin of a healthy boy and propagated. After 2 - 4 passages, KCs were collected and treated with various concentrations (3, 10, 30 and 100 mg/L) of peptidoglycan for 24 hours or with peptidoglycan of 100 mg/L for varying durations (3, 6, 12, 36 hours). A fi'action of KCs were pretreated with functional grade purified anti-TLR2 monoclonal antibody before the treatment with peptidoglycan of 100 mg/L. After additional 12-hour culture following the treatment, enzyme linked immunosorbent assay was used to detect the level of IL-8, RANTES and MDC in culture supernatants of KCs. Results KCs spontaneously released IL-8 and RANTES. Peptidoglycan increased the production of IL-8 but decreased that of RANTES by KCs. The levels of IL-8 were 209.96 ± 10.31 ng/L, 250.28 ± 9.52 ng/L, 285.11 ± 10.28 ng/L, 359.40 ± 6.93 ng/L in KCs treated with peptidoglycan of 3, 10, 30, 100 mg/L, respectively, compared to 135.41 ± 14.37 ng/L in untreated KCs (all P < 0.05). On the contrary, a significant decrement was seen in the secretion of RANTES by KCs treated with peptidoglycan of 10, 30, 100 mg/L compared with untreated KCs (110.72 ± 8.51 ng/L, 90.50 ±2.45 ng/L, 49.89 ± 13.74 ng/L vs 149.94 ± 18.71 ng/L, all P < 0.05). The monoclonal antibody to TLR-2 could markedly suppress the promotion of IL-8 production by peptidoglycan, but had no obvious influence on the inhibition of RANTES production by peptidoglycan. MDC could not be detected in the culture super-natants of KCs with or without peptidoglycan stimulation. Conclusion Peptidoglycan could inhibit RANTES secretion but induce IL-8 production by KCs likely via TLR2.     

Expression of functional Toll-like receptor 2 on human epidermal keratinocytes

Epidermal keratinocytes secrete cytokines, chemokines, and anti-microbial peptides in response to various microbial pathogens and their components including lipopolysaccharide (LPS). To identify the receptor(s) involved in the anti-microbial responses of epidermal keratinocytes, we analyzed expression of CD14, Toll-like receptor 2 (TLR2), and TLR4 on cultured normal human epidermal keratinocytes (NHEK). Although CD14 and TLR2 mRNA were expressed in cultured NHEK, only TLR2 was detected on the cell surface. Cultured NHEK did not express TLR4 mRNA or protein. Commercial LPS preparations could stimulate epidermal keratinocytes to produce β-defensin-2 and IL-8, and the LPS response was inhibited with mAb specific for TLR2, but not for CD14 or TLR4. Repurified LPS and lipid A did not stimulate epidermal keratinocytes, whereas peptidoglycan (PGN) from Gram-positive bacteria and yeast cell wall particle induced β-defensin-2 and IL-8 production. Thus, cultured NHEK express functional TLR2, but not CD14 or TLR4, and the “LPS” response of epidermal keratinocytes shown in the previous studies might be mediated by TLR2-dependent recognition of non-LPS bacterial components contaminating in commercial LPS preparations. In the normal human skin, however, epidermal keratinocytes expressed both TLR2 and TLR4. Because TLR4 was induced in epidermal keratinocytes by in vitro stimulation with PGN from Gram-positive bacteria, constitutive expression of TLR4 on epidermal keratinocytes in vivo might also be induced by continuous recognition of the resident skin flora containing Gram-positive bacteria through TLR2.     

Expression of functional Toll-like receptor 2 on human epidermal keratinocytes

Recently it has been reported that the molecular size of decorin dermatan sulfate (DS) was increased in healing skin after hapten application and that the elongated DS was distributed in enlarged interfibrillar space among thin collagen fibrils in situ. Here we show that such modulation of the length of decorin DS is temporary. Although the size of decorin DS was evidently increased on day 15, it decreased to almost normal size on day 35 when the altered disaccharide composition of DS was also recovered. Electron microscopic observation revealed that elongated decorin DS was localized among thin collagen fibrils packed loosely in hapten-treated skin on day 15. In contrast, decorin DS of normal size was distributed among thick collagen fibrils packed tightly on day 35. These results suggest that size control of decorin DS plays important roles in organization of collagen fibrils into bundles by regulating interfibrillar space in healing skin, particularly in maturation of collagen fibrils through shortening of decorin DS in later stages of healing.     

Candida albicans phospholipomannan triggers inflammatory responses of human keratinocytes through Toll-like receptor 2

Abstract:  The Toll-like receptors (TLRs) play an important role in the recognition of Candida albicans components and activation of innate immunity. Phospholipomannan (PLM), a glycolipid, is expressed at the surface of C. albicans cell wall, which acts as a member of the pathogen-associated molecular patterns family. In this study, we sought to clarify whether C. albicans -native PLM could induce an inflammation response in human keratinocytes and to determine the underlying mechanisms. Exposure of cultured human primary keratinocytes to PLM led to the increased gene expression and secretion of proinflammatory cytokines (IL-6) and chemokines (IL-8). PLM hydrolysed with β- d -mannoside mannohydrolase failed to induce gene expression and secretion of IL-6 and IL-8. PLM up-regulated the mRNA and protein levels of TLR2, whereas the mRNA level of TLR4 was not altered. Keratinocytes challenged with PLM resulted in the activation of NF-κB and mitogen-activated protein kinase (MAPKs) including p38. Anti-TLR2 neutralizing antibody, NFκB and p38MAPK inhibitors blocked the PLM-induced secretion of IL-6, IL-8 in keratinocytes, but no such effect was observed in pretreatment with anti-TLR4-neutralizing antibody and lipopolysaccharide inhibitor (polymyxin B). These data suggest C. albicans -native PLM may contribute to the inflammatory responses of cutaneous candidiasis in the TLR2-NF-κB and p38MAPK signalling pathway dependent manner.     

Glucocorticoids enhance Toll-like receptor 2 expression in human keratinocytes stimulated with Propionibacterium acnes or proinflammatory cytokines

Toll-like receptors (TLRs) on keratinocytes are important cell surface receptors involved in the innate and acquired immune response to invading microorganisms. In acne vulgaris, TLR2 activation by Propionibacterium acnes (P. acnes) may induce skin inflammation via induction of various proinflammatory molecules that stimulate the invasion of inflammatory cells. Although corticosteroids themselves exert immunosuppressive or anti-inflammatory effects, it is well known clinically that systemic or topical glucocorticoid treatment provokes an acneiform reaction. Nevertheless, the effect of steroids on TLR2 expression in human keratinocytes remains unknown. Here, we found that the addition of glucocorticoids, such as dexamethasone and cortisol, to cultured human keratinocytes increased their TLR2 gene expression. Moreover, these glucocorticoids markedly enhanced TLR2 gene expression, which was further stimulated by P. acnes, tumor necrosis factor-alpha, and IL-1alpha. Gene expression of mitogen-activated protein kinase (MAPK) phosphatase-1 was also increased by the addition of dexamethasone. By using several inhibitors and activators, we found that TLR2 gene induction by glucocorticoids was mediated by the suppression of p38 MAPK activity following induction of MAPK phosphatase-1. These findings strongly suggest that steroid-induced TLR2 together with P. acnes existing as normal resident flora plays an important role in the exacerbation of acne vulgaris as well as in possible induction of corticosteroid-induced acne or in that of rosacea-like dermatitis.     

Toll-like receptor 2 (TLR2) mediates intracellular signalling in human keratinocytes in response to Malassezia furfur

Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the β-defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety of M. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human β-defensin 2 (HBD-2), HBD-3 and interleukin-8 (IL-8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD-2, HBD-3 and IL-8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD-2 and IL-8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity.     

他克莫司对人角质形成细胞蛋白酶活化受体2表达及功能的影响

【摘要】 目的 研究他克莫司对体外培养的人角质形成细胞蛋白酶活化受体2（PAR-2）表达及功能的影响。方法 10-9～10-5 mol/L他克莫司与人角质形成细胞共培养24 h后,采用半定量反转录-聚合酶链反应、免疫荧光和Western印迹分别检测人角质形成细胞PAR-2 mRNA和蛋白表达水平的变化,应用Fluo-4钙荧光探针检测不同浓度他克莫司对人角质形成细胞激活PAR-2后引起的细胞内钙离子浓度变化的影响,以不加他克莫司处理组为对照组。采用单因素方差分析比较各组人角质形成细胞PAR-2表达和细胞内钙离子浓度,LSD-t检验进行两两比较。结果 PAR-2在角质形成细胞的胞膜和胞质表达。角质形成细胞与10-9～10-5 mol/L他克莫司共培养24 h后,PAR-2 mRNA的表达水平与对照组比较均显著降低（均P < 0.05）,且与他克莫司浓度呈负相关（r = -0.962,P = 0.009）。免疫荧光和Western印迹显示,与对照组比较,10-5和10-6 mol/L他克莫司组PAR-2蛋白表达水平显著降低（均P < 0.05）,10-7 mol/L他克莫司组PAR-2蛋白表达水平亦降低（免疫荧光法P < 0.05;Western印迹法P > 0.05）,但10-8和10-9 mol/L他克莫司组PAR-2表达水平变化无统计学意义（均P > 0.05）。共培养24 h后,10-5、10-6和10-7 mol/L他克莫司组PAR-2激活后细胞内钙离子峰浓度（峰值吸光度分别为1 463 ± 283、1 455 ± 270、1 423 ± 291）较对照组（1 602 ± 407）显著降低（t值分别为2.582、2.821、2.923,P值分别为0.032、0.022、0.019）,10-8和10-9 mol/L他克莫司组（分别为1 649 ± 379、1 633 ± 415）变化无统计学意义（t值分别为0.846、0.462,P值分别为0.422、0.657）。结论 他克莫司可抑制人角质形成细胞PAR-2的表达,并抑制PAR-2激动剂所引起的钙离子动员。     

Zinc salts inhibit in vitro Toll-like receptor 2 surface expression by keratinocytes

Propionibacterium acnes (P. acnes) plays an important role in the induction and maintenance of the inflammatory phase of acne. At the therapeutic level, it has been shown that zinc salts could have a beneficial effect on mild and moderate inflammatory acne lesions. However, their mechanisms of action are still only partially known. Immediate early immune response is a crucial route in the development of inflammatory reaction and, specifically, activation of Toll-like Receptors (TLRs) leading to nuclear factor (NF)-kappaB translocation and production of inflammatory cytokines such as interleukin-8 (IL-8). The aim of this work was to determine if cytokine secretion and innate immunity could be targets of zinc salts. Normal Human Epidermal Keratinocytes (NHEK) and skin explants were stimulated by P. acnes extracts and incubated (3 h) with zinc salts (1 microg/mL). Then we successively studied TLR2 expression by immunohistochemistry and IL-8 production by ELISA. After incubation with zinc salts, the increase of TLR2 surface expression in skin upon membrane fraction (FM) of P. acnes challenge was decreased as compared to that in control samples. However, this inhibition does not modify IL-8 secretion by keratinocytes. In conclusion the inhibition of TLR2 surface expression by keratinocytes could be one of the anti-inflammatory mechanisms of zinc salts in acne.     

Effects of detergents on proliferation and metabolism of human keratinocytes

Abstract Effects of low concentrations of detergents on cultured human foreskin keratinocytes were assessed in vitro. The viability and activity of keratinocytes were assessed by measuring reduction of a tetrazolium dye as an indicator of mitochondrial metabolism. The keratinocyte proliferative responses after incubation with detergents were assessed by a spectrophotometric assay employing crystal violet dye and a fluormetric assay determining total DNA content. Both the cationic detergent cetyltrimelhylammonium bromide [CTAB] and the anionic detergent sodium lauryl sulfate [SLS] showed toxic effects on keratinocytes at concentrations as low as 3 μg/mg, but SLS was less toxic. However, both SLS and CTAB activated keratinocytes at very low concentrations. Proliferalive activity and mitochondrial metabolism increased. Serum partially protected keratinocytes against toxic and stimulatory activities of both detergents. We suggest that detergents may directly damage keratinocytes and thereby produce irritant contact dermatitis, but activation of keratinocytes by low concentrations may also produce dermatitis, perhaps by causing keralinocvtes to release cytokines