衰老真皮成纤维细胞胶原基因调控研究

目的针对衰老真皮成纤维细胞胶原基因表达减少的特点，应用胎儿皮肤源性活性蛋白（ＳＣＦ）进行调控，以增加胶原基因的表达。方法应用真皮成纤维细胞培养、胶原基因ｍＲＮＡ裂隙杂交和图像分析技术，观察胎儿皮肤源性活性蛋白对真皮胶原基因的调控作用。结果以Ａｃｔｉｎ作为对照，ＳＣＦ对老人成纤维细胞胶原基因有明显的调控作用，可以使Ⅰ、Ⅲ型胶原基因表达增加，处理后，Ｉ型胶原基因表达增加１５０％，Ⅲ型胶原基因增加５０％。结论ＳＣＦ可以促进衰老真皮成纤维细胞胶原基因的表达。     

UVB诱导人皮肤成纤维细胞Ⅰ、Ⅲ型胶原下调机制的研究

目的 观察紫外线对原代人皮肤成纤维细胞Ⅰ、Ⅲ型胶原的影响并探讨其作用的分子机制.方法 使用组织块法分离培养原代人皮肤成纤维细胞,以不同剂量紫外线照射人皮肤成纤维细胞,倒置显微镜观察细胞形态学的改变;β-半乳糖苷酶(β-gal)细胞衰老试剂盒染色;western blot检测衰老标志物P16蛋白的表达;RT-PCR检测中波紫外线处理皮肤成纤维细胞不同时相Ⅰ、Ⅲ型胶原的改变及对MMP1、MMP3的影响.结果 20～40 mJ/cm2 UVB单次照射后可以成功诱导人皮肤成纤维细胞出现衰老形态学的改变,β-gal染色阳性率达到约90%,P16蛋白表达随时相明显升高;紫外处理成纤维细胞后,Ⅰ、Ⅲ型胶原表达水平明显降低;而MMP1、MMP3表达水平明显升高.结论 利用20～40 mJ/cm2中波紫外线照射可诱导人皮肤成纤维细胞衰老,不仅伴随Ⅰ、Ⅲ型胶原合成减少,而且通过升高MMP1、MMP3来降解已形成的Ⅰ、Ⅲ型胶原.以上数据表明,中波紫外线可以诱导人皮肤成纤维细胞衰老并在皮肤衰老过程中发挥重要作用,为了解及干预皮肤衰老过程提供了线索.     

雌激素对皮肤衰老的调控

衰老是机体随着时间推移出现的自然变化过程,随着人体内分泌功能减退,机能出现衰退,适应环境能力下降,内环境稳定性下降,同时在紫外线等的外在损伤下,皮肤下结缔组织的胶原纤维和基质结构以及代谢发生改变,出现胶原交联、溶解性下降、脂褐素堆积、血管弹性下降等问题,导致皮肤松弛变薄、色斑产生、毛发变白等一系列皮肤衰老表现。雌     

胶原注射在面部皮肤美容中的应用

对18例不同类型的皮肤病损采用胶原注射治疗修复获得满意效果,讨论胶原注射在皮肤美容中的适应证、注射方法和效果。作者认为胶原注射方法安全、简便、有效,在皮肤美容领域值得推广应用。     

基础皮肤护理与角质层屏障保护

皮肤长期在外界环境的侵蚀下很容易出现老化，老化的皮肤真皮胶原变性，表皮变薄、细胞新陈代谢显著减慢，角质层的屏障功能失调。越来越多的文献资料表明稳定的皮肤角质层屏障功能是保持肌肤健康的关键。而要保持稳定的角质层屏障功能与常规的基础皮肤护理密不可分。基础皮肤护理通常包括皮肤清洁、皮肤保湿、皮肤防晒三个环节。合理的基础皮肤护理是维持角质层生理屏障功能的基础。随着研究的深入，人们开始越来越清楚地意识到皮肤护理的核心问题就是能否更好地维持角质层屏障保护功能的问题。当角质层屏障功能稳定时，皮肤就会显示良好的健康状态。本文就皮肤的基础护理与角质层的屏障关系综述如下。     

皮肤衰老与延缓皮肤衰老方法的研究进展

衰老是机体的自然衰变过程，皮肤衰老是人体衰老的外部表现。皮肤老化分为时程老化与光老化，但病理上均表现为皮肤变薄、弹性减退、皮脂腺汗腺分泌减少、弹力纤维变性、胶原含量减少、皮肤中过氧化脂质和变性蛋白沉积等。分子生物学方面的改变显示衰老皮肤细胞的表皮生长因子受体减少，Ⅲ型胶原基因表达增加而Ⅰ型胶原基因表达降低。有人认为ＤＮＡ复制与衰老密切相关，基因表达调控的改变是引起衰老的主要原因。目前延缓皮肤衰老的方法主要有两大类：一是从细胞水平和分子水平进行调控、延缓细胞衰老；二是根据皮肤结构变化进行结构重塑。     

射频电流对皮肤胶原含量的影响

目的探讨射频电流对兔皮肤胶原含量的影响,以便为应用于除皱提供实验依据。方法采用GP699A型射频热能皮肤治疗仪作用于兔背部皮肤,输出频率为5MHz,处理后当天及第8、19、33、43、59天切取实验组和对照组部位皮肤,行常规HE染色及苦味酸天狼猩红染色,检测皮肤胶原含量及观察组织学改变。结果射频电流作用可使兔皮肤真皮层胶原增生,排列更加紧密,促进兔皮肤I型、Ⅲ型胶原增生,且Ⅲ型胶原相对分泌较多,真皮层中Ⅲ型胶原与I型胶原比值增大。在应用射频电流后第8天,即可以观察到明显的真皮层胶原增生,在随后的几个时间点中,可以明显的发现随着时问的推移,真皮层胶原增生更为明显,同时Ⅲ型胶原所占比例更大。结论射频电流可促进皮肤真皮成纤维细胞分泌I型、Ⅲ型胶原,增加真皮的厚度,改变胶原纤维的排列,是用于除皱的理论基础之一。     

皮肤伸展术对真皮成纤维细胞Ⅰ、Ⅲ型前胶原mRNA表达的影响

目的:观察皮肤伸展术对真皮组织中成纤维细胞Ⅰ、Ⅲ型前胶原mRNA表达的影响,从分子学水平解释皮肤伸展术后皮肤间质生物性生长的机理。方法:分别于皮肤牵张1周时及牵张后1、2、3、4、6、8周的皮肤和正常皮肤取1cm×1cm×0.5cm皮肤组织块,用Ⅰ、Ⅲ型前胶原cDNA探针原位杂交技术观察真皮组织中成纤维细胞内Ⅰ、Ⅲ型前胶原mRNA表达。结果:皮肤伸展术后成纤维细胞的Ⅰ、Ⅲ型前胶原mRNA表达较对照组明显增强,以2～4周时最强。Ⅰ型前胶原、mRNA表达高于Ⅲ型。对照组Ⅰ、Ⅲ型前胶原mRNA表达在1、2周时高于正常皮肤,此后逐渐减弱。结论:伸展术能刺激真皮中成纤维细胞Ⅰ、Ⅲ型前胶原mRNA表达,并持续较长的时间。这是皮肤伸展术能够获得生物性增长的分子学基础。     

扩张后皮肤挛缩动力环境的实验研究

目的　研究皮肤扩张后真皮内环境的变化及其与挛缩过程的关系。方法　采用兔头部扩张模型进行皮肤扩张实验,通过免疫组化、放射免疫测定等方法研究了真皮Ⅰ、Ⅲ型胶原以及透明质酸的变化。结果　Ⅰ型胶原在皮肤扩张后出现破坏和修复的现象,而Ⅲ型胶原有一过性增多。透明质酸的含量在皮肤扩张后由30ng/ml增加到80ng/ml,而且在相当长时间内呈增高状态,快速扩张变化较常规扩张明显。结论　扩张后真皮中的胶原结构发生重组,透明质酸的增加为扩张后皮肤挛缩提供重要的动力环境基础,快速扩张产生透明质酸多因此更易发生挛缩。     

胶原基人工皮肤的研究进展

组织工程人工皮肤的出现为救治大面积皮肤缺损病人提供了一种有效的新方法。人工皮肤按照常见的分类方法可分为:人工表皮替代物、人工真皮替代物及人工复合皮替代物。胶原作为脊椎动物细胞外基质中含量最为丰富的生物大分子,具有极重要的生理作用,能够促进细胞黏附、生长、增殖、分化、迁徙。作为研究最早、了解最为透彻的一种重要的支架材料,胶原被广泛用于人工皮肤。文中介绍了近年来国内外胶原基人工皮肤的研制情况。     

Thermal damage to skin collagen

The effect of temperature upon the solubility of frozen skin collagen in vitro and its susceptibility to digestion by proteolytic enzymes has been studied. Both of these parameters are increased with temperature. Above 52 degrees C there is a sudden increase in both the solubility of collagen and its susceptibility to digestion, suggesting that this temperature is associated with changes in the structure of the skin collagen. This increase in susceptibility to digestion may have an influence upon the nature of the healing process in the burn wound.     

Reconstruction of full-thickness loss skin wounds using skin collagen allografts.

Sheets of allogeneic dermal collagen measuring 20 X 15 mm and prepared by trypsin treatment of full-thickness skin were grafted under skin flaps in rats. After 2 to 5 weeks the protective recipient skin was excised and replaced by split-thickness skin isografts which remained viable on their supportive collagen beds. On average such composite grafts maintained 84 per cent of their original size over 3 to 28 weeks and in contrast with split-thickness skin grafts achieved full-thickness reconstruction of the excised skin.     

The redistribution of collagen in expanded pig skin

Silicone tissue expanders were inserted subcutaneously in the buttocks of nine young pigs and gradually inflated to maximum capacity over 5 weeks. On the control side the expanders were left uninflated. Island buttock flaps were then raised, the expanders removed and the flaps spread into the same sites for 10 days. The tissue was harvested. Area measurements and full thickness skin biopsies were taken 10 days after flap inset in order to study the changes in collagen composition and isotypes in the skin layers. Ten days after inset of the flap the expanded skin had a mean 47% increase in surface area, was 9% thinner (from surface to implant), mostly due to thinning of the subcutaneous zone, but was not significantly different in water content, relative to the control skin. The expanded skin had a significant 9.3% increase (p less than 0.01, t test) in collagen content of the dermis. The relative proportions of Types I and III were not significantly changed by skin expansion in either the dermal/epidermal or subcutaneous/capsular zones. It is speculated that tensile factors during expansion stimulate the biosynthetic activity and/or mitotic activity of fibroblasts in the dermis to produce this gain in collagen in the expanded compared with unexpanded tissue.     

Correlation between collagen solubility and skin optical clearing using sugars

BACKGROUND AND OBJECTIVE: Light scattering from collagen within skin limits light-based therapeutics while increasing the risk of epidermal thermal injury. Specific chemicals show the ability to reduce light scattering by reversibly altering the optical properties of skin. This study examines the correlation between collagen solubility and the optical clearing potential (OCP) of sugars and sugar-alcohols using in vitro rodent skin. MATERIALS AND METHODS: Collagen solubility in dextrose, fructose, sucrose, and sorbitol was measured using near-UV spectroscopy. Light transmittance, reflectance, and rodent skin thickness were measured (giving skin reduced scattering coefficient) before and after exposure of the dermal surface to sugars and sugar-alcohols. OCP was calculated as the ratio of reduced scattering coefficients before and after exposures. RESULTS: Dextrose, fructose, sucrose, and sorbitol had at least twice the collagen solubility and twice the OCP as compared to glycerol. In general, collagen solubility correlated with each agent's ability to optically clear rodent skin. CONCLUSION: These results demonstrate that sugar and sugar-alcohol interaction with collagen are a primary event in tissue optical clearing.     

戊二醛胶原人工皮的特点和临床应用

我们将 Burke 的方法加以改进,制作出了戊二醛胶原人工皮,经动物实验测定丁蒸发量、粘附力及抑菌作用,证明其透气性能好,粘附力强,具有抑菌作用,可减少水分蒸发和蛋白质电解质的丢失,且无排异反应,是一种理想的人工皮。我们还将其应用于临床30例病人创面,其创面愈合时间为24±3天,对绿脓杆菌感染及慢性溃疡病人的创面效果尤佳。值得推广。     

戊二醛胶原人工皮的特点和临床应用

我们将Ｂｕｒｋｅ的方法加以改进，制作出了戊二醛胶原人工皮，经动物实验测定了蒸发量、粘附力及抑菌作用，证明其透气性能好，粘附力强，具有抑菌作用，可减少水分蒸发和蛋白质电解质的丢失，且无排异反应，是一种理想的人工皮。我们还将其应用于临床３０例病人创面，其创面愈合时间为２４±３天，对绿脓杆菌感染及慢性溃疡病人的创面效果尤佳。值得推广。     

口服胶原蛋白水解产物对皮肤的作用

胶原蛋白是结缔组织主要的结构蛋白,占全身总蛋白的25%～30%。皮肤中胶原蛋白主要分布于真皮层,含量约为70%,主要为I(85%)、III和Ⅴ型[1]。胶原蛋白纤维的网状架构为皮肤提供了弹性,纤维间分布着大量的水分、细胞外基质和细胞,是皮肤重要的生化反应场所[2]。随着人体衰老,皮肤中胶原