神经酰胺与皮肤屏障

神经酰胺是人体角质层脂质的主要成分,在皮肤的合成和分布有一定的规律。其质和量的变化可以导致脂质结构的改变,从而影响皮肤屏障功能。不同亚型神经酰胺作用不同,在角质形成细胞增殖、分化及凋亡中起重要作用,是皮肤屏障损伤修复后期重要的效应物质。许多皮肤病可导致角质层屏障功能的破坏,而屏障功能的破坏又是一些皮肤病的病因或加重因素。故神经酰胺在皮肤中的作用越来越受重视。     

神经酰胺在人皮肤中的主要功能

皮肤中神经酰胺主要位于表皮,是表皮中的主要脂质,具有保湿、信号转导、免疫调节等功能。其含量的变化可能导致皮肤屏障功能受损,甚至一些皮肤疾病的发生,如特应性皮炎、银屑病等。本文对皮肤中神经酰胺的主要作用进行综述。     

神经酰胺与相关皮肤病的研究进展

神经酰胺（ceramide,Cer）由长链鞘氨醇碱和脂肪酸组成,参与皮肤屏障的构成、调节皮肤免疫及细胞周期、分化与凋亡等过程。神经酰胺的合成代谢异常与多种皮肤疾病相关，如特应性皮炎、银屑病等。本文就神经酰胺与相关皮肤病的研究进展进行综述。     

皮肤屏障与银屑病研究进展

皮肤作为人体的第一道防线,对抵御外界有害因素的损伤以及维持人体内环境的稳态有着至关重要的作用。皮肤屏障的结构和功能与一些皮肤病的发生发展有着重要的联系。研究发现皮肤屏障功能受损可能是银屑病发生的重要诱因,然而皮肤屏障缺陷与银屑病发生的确切机制仍不清楚。该文主要对近年来皮肤屏障与银屑病的研究进展作一综述。     

皮肤屏障的中西医研究进展

 皮肤屏障作为人类表皮的基本生理结构，具有抵御外界微生物侵袭、维持体内环境稳定等重要作用。本文从现代医学的角度对皮肤屏障结构组成、生理功能等方面的研究进展作一综述，并从中医角度阐释其与五脏、气血津液的关系。     

皮肤屏障功能解析

本文从皮肤的基本结构和生化组成入手,对表皮角蛋白分化、中间丝相关蛋白表达、角质层细胞间脂质以及皮肤水脂膜等不同层次上的皮肤物理性屏障功能进行了逐层分析,同时密切结合临床相关皮肤疾病的病因病理,对皮肤屏障结构的异常变化进行了讨论。皮肤屏障功能是皮肤科最基本的问题之一。深入研究皮肤的屏障功能,从皮肤屏障功能的视角审视众多皮肤病,可能会有新的启发和认识。     

痤疮与皮肤屏障的研究进展

寻常痤疮是皮肤科的常见疾病之一,好发于青少年及20～30岁人群.近年来,许多研究均表明痤疮患者存在皮肤屏障功能异常:皮脂含量增高、皮脂膜成分改变、经表皮水分丢失(TEWL)增多、皮肤含水量降低、PH值增高等,且皮肤屏障功能损害与痤疮严重程度成正相关.本文对痤疮与皮肤屏障功能相关性的研究进展综述如下.     

GentleYAG 1064nm激光治疗对小鼠皮肤屏障功能及弹性的影响

目的研究GentleYAG1064nm激光嫩肤治疗对皮肤屏障功能的影响。方法GentleYAG1064nm激光照射小鼠背部皮肤,每周1次,在激光照射前、首次照射后1周、连续3次照射后1周和连续4次照射后4周时检测皮肤经表皮失水(tramsepidermalwaterloss,TEWL)、含水量和皮肤弹性的变化。结果首次激光照射小鼠皮肤后1周时TEWL,皮肤含水量和皮肤弹性基本上较正常对照组无显著性改变(P>0.05);连续3次激光照射小鼠皮肤后1周时TEWL值和皮肤含水量仍较正常对照组无显著性改变(P>0.05),但是皮肤弹性较正常对照组有显著性改善(P<0.05);连续4次激光照射小鼠皮肤后4周时TEWL值和皮肤含水量仍较正常对照组无显著性改变(P>0.05),皮肤弹性较正常对照组有显著性改善(P<0.05),其值高于连续3次激光照射后1周时,但两者间差异无显著性(P>0.05);用动态冷却系统(dynamiccoolingdevice,DCD)组和不用DCD组的TEWL值、皮肤含水量和皮肤弹性值在各个时间点上均无显著性差异(P>0.05)。结论①单次GentleYAG1064nm激光照射小鼠皮肤对皮肤屏障功能无明显的损伤。②多次GentleYAG1064nm激光照射可以改善皮肤弹性,说明多次GentleYAG1064nm激光照射有显著的嫩肤效果。③使用DCD对激光嫩肤效果无明显的促进作用。     

主观皮肤类型与皮肤屏障功能的关系

目的:比较不同主观皮肤类型(油性、中性和干性皮肤)屏障功能指标的差异。方法:利用无创性方法对自评为油性、中性和干性皮肤的20~25岁北京城市女性(各30例)进行皮脂分泌率(SER)、角质层含水量、p H值和经皮肤水分丢失(TEWL)值的检测,并采用胶带连续粘脱后监测TEWL值变化的方法评价角质层完整性,采用角质层取样蛋白定量的方法评价角质层黏合力和丝氨酸蛋白酶活性。结果:主观皮肤类型为中性皮肤者具有最佳的屏障功能;干性皮肤和油性皮肤者面颊部的屏障功能均有不同程度的受损,表现为TEWL值明显升高、p H值升高、丝氨酸蛋白酶活性增加;但二者也有区别,油性皮肤者角质层完整性下降更明显,而干性皮肤主要是角质层黏合力明显减弱。结论:自评为油性和干性皮肤者与中性皮肤者相比,屏障功能均存在一定程度的缺陷,油性皮肤与干性皮肤均具有不同特点,且与其屏障受损的机制不同有关。     

皮肤屏障与病毒感染的研究进展

病毒感染性皮肤病在人群中具有患病率高、分布广的特点,其发病具有两大关键因素：即屏障破坏与病毒感染宿主细胞。本文就近年来皮肤在抗病毒方面发挥屏障功能以及病毒感染的机制研究进展进行综述。     

Dietary sphingolipids improve skin barrier functions via the upregulation of ceramide synthases in the epidermis

Sphingolipids are ubiquitous in eukaryotic organisms and are significant components in foods. It has been reported that treatment with sphingolipids prevents colon cancer, improves skin barrier function and suppresses inflammatory responses. However, the mechanisms for those effects of dietary sphingolipids are not well understood. In this study, to investigate the effects of dietary glucosylceramide (GluCer) and sphingomyelin (SM) on skin function, we characterized the recovery of skin barrier function and the change in sphingolipid metabolism‐related enzymes in the epidermis using a special Mg‐deficient diet–induced atopic dermatitis‐like skin and tape‐stripping damaged skin murine models. Our results show that dietary GluCer and SM accelerate the recoveries of damaged skin barrier functions. Correspondingly, dietary sphingolipids significantly upregulated the expression of ceramide synthases 3 and 4 in the epidermis of the atopic dermatitis‐like skin model (P < 0.05). In the case of cultured cells, the expression of ceramide synthases 2‐4 in normal human foreskin keratinocytes was significantly upregulated by treatment with 0.001–0.1 μm sphingoid bases (sphinganine, sphingosine and trans‐4,cis‐8‐sphingadienine) (P < 0.05). These results suggest that the effects of dietary sphingolipids might be due to the activation of ceramide synthesis in the skin, rather than the direct reutilization of dietary sphingolipids. Our findings provide a novel insight into the mechanisms of the skin barrier improving effect and a more comprehensive understanding of dietary sphingolipids.     

表皮通透屏障功能对皮肤的调节作用及意义

表皮通透屏障功能除调节水分经表皮进出机体外,还对皮肤的其他生物功能如炎症、表皮增生、pH及离子的分布等也具有重要地调节作用。而且,维持表皮通透屏障功能在最佳水平有利于预防某些皮肤病的发生;改善皮肤屏障功能有助于某些皮肤病的治疗。     

Incorporation of ceramide 3B in dermatocosmetic emulsions: effect on the transepidermal water loss of sodium lauryl sulphate-damaged skin

BACKGROUND: In previous work we reported on the efficacy of cosmetic body lotions enriched with skin-identical lipids to reduce the transepidermal water loss (TEWL) of ageing and sodium lauryl sulphate (SLS)-damaged skin. The observations made depended on the experimental design and clearly raised the question of the importance of the galenic formulation of skin ceramide-containing products. OBJECTIVES: The aim of the present work was to study the different galenic forms in which ceramide 3B (0.2% w/v) can be incorporated into common o/w emulsions. In addition, we investigated whether supplementation of skin care products with ceramide 3B enriched with penetration enhancers and coemulsifiers could exert a beneficial effect on barrier function, done by measuring their effects on the TEWL of SLS-induced scaly skin. RESULTS: We found that the technique of incorporating ceramide 3B into the o/w emulsions was important for their final stability. However, no additional positive effect on the TEWL values of SLS-damaged skin could be observed when the efficacy of the ceramide-containing emulsions was compared with that of proper controls. CONCLUSIONS: Although suitable galenic formulas were developed, no positive effect on TEWL could be observed when ceramide 3B was added in a final concentration of 0.2% (w/v) to different o/w emulsions and applied to SLS-damaged skin.     

Effect of a lipid-rich emollient containing ceramide 3 in experimentally induced skin barrier dysfunction

In the present study we compared the effect of a ceramide 3-containing emollient (Locobase(R) Repair) with a control emollient (vaselinum album/cremor lanette ana) and untreated damaged skin using clinical, bioengineering and immunohistochemical methods in two different models of experimentally induced skin barrier dysfunction. In model A (n = 13) skin barrier dysfunction was inflicted at three investigation sites by tape stripping. In model B (n = 13) the volunteers were patch tested at three investigation sites with sodium dodecyl sulphate (0.2%) for 4 h a day for 4 consecutive days. The investigation sites were treated once a day with the above-mentioned agents. Irritant reaction was assessed daily by erythema scoring and measurements of transepidermal water loss (TEWL). After 5D, punch biopsies were taken from all sites. Immunohistochemical assessment was carried out with respect to epidermal proliferation, epidermal differentiation and Langerhans cells. Tape stripping resulted in an erythematous reaction and an increase of TEWL associated with up-regulation of cycling cells, involucrin and expression of cytokeratin 16. At day 4, ceramide 3-containing emollient significantly decreased (p < 0.03) the erythema score, TEWL and cycling cells in comparison with the untreated site. Repetitive exposure to SDS induced a variable degree of erythema, gradual increase of TEWL, an increase of cycling cells, and up-regulation of involucrin, E-FABP and SKALP. The treatment with the control emollient significantly prevented erythema, increase of TEWL and cycling cells at day 4 compared to the untreated site. In summary, the present study demonstrated that both tested emollients improve skin barrier in different conditions compared to the untreated skin. There is some indication that formulations containing skin-related lipids might be of benefit in barrier disruption following tape stripping. Different models and clinical trials are needed to establish the usefulness in specific conditions of emollients containing skin-related lipids.