瘢痕疙瘩中Smads表达的研究

目的 探讨不同类型Smads在瘢痕疙瘩、正常瘢痕和正常皮肤中的差异表达及其意义.方法 采用RT-PCR和Western Blot法分别对10例瘢痕疙瘩、10例正常瘢痕及10例正常皮肤组织,以及体外培养瘢痕疙瘩、正常瘢痕及正常皮肤成纤维细胞中的Smads mRNA及蛋白的表达水平进行检测.用t检验比较其表达差异,P<0.05为差异具有统计学意义.结果 在瘢痕疙瘩组织及瘢痕疙瘩成纤维细胞中,Smad7的mRNA及蛋白水平表达明显低于正常瘢痕(P<0.05)和正常皮肤(P<0.05),而Smad2、3的mRNA及蛋白水平表达以及磷酸化的Smad2、3的蛋白水平表达并无明显改变(P>0.05).结论 在瘢痕疙瘩中,存在有Smad7的表达缺陷,这可能是增高的转化生长因子-β1(TGF-β1)/Smads信号传导不能被自身负反馈循环终止的重要原因.     

Tenascin-C在瘢痕疙瘩和增生性瘢痕中的基因表达研究

目的 探讨Tenascin-C基因在瘢痕疙瘩和增生性瘢痕中的表达。方法 取正常成人皮肤组织RNA，构建正义、反义Tenascin-C(Tn-C)mRNA探针，运用原位杂交技术，观测10例瘢痕疙瘩、10例增生性瘢痕和5例正常成人皮肤组织中Tn-C mRNA的表达。结果 Tn-C mRNA在正常皮肤表皮中无表达，真皮中表达稀少，局限于乳头真皮层的成纤维细胞和皮肤附属器；10例瘢痕疙瘩表皮均有表达，真皮分布较广，如成纤维细胞、血管内皮和皮肤附属器；Tn-C mRNA在3例增生性瘢痕表皮表达，7例无表达，真皮中表达与瘢痕疙瘩相同但较弱，比正常皮肤增多，但差异无显著性。结论 Tenascin-C mRNA在瘢痕疙瘩表皮和真皮中有高表达。     

Fibronectin gene expression differs in normal and abnormal human wound healing

The overproduction of fibronectin and type I collagen in keloids and hypertrophic scars implicates altered regulation of extracellular matrix components as an important aspect of these wound healing pathologies. However, little is known about the similarities and differences in extracellular matrix gene expression during normal and abnormal wound healing. This study compared the content of fibronectin messenger RNA and rates of fibronectin protein biosynthesis in fibroblasts derived from normal skin, normal scar, keloid, and hypertrophic scar. Fibronectin expression was enhanced in cells from both normal and abnormal wounds relative to cells from quiescent normal skin. Matched pairs of normal and keloid fibroblasts from the same individuals were also compared, and three of the four pairs showed higher fibronectin expression by the keloid cells at the levels of messenger RNA and protein synthesis. This was consistent with previous studies showing elevated steady state content of fibronectin in keloid cells relative to normal cells from the same individual. Fibronectin messenger RNA and protein content in the tissues from which these cells were derived was examined by in situ hybridization and immunohistochemistry. These studies revealed that in vivo, the steady state content of fibronectin messenger RNA and protein was highest in abnormal wounds, less in most normal scars, and lowest in normal skin. Thus, fibroblasts from keloids and hypertrophic scars overexpressed fibronectin in vivo relative to normal skin and normal scar and retain this characteristic in vitro relative to normal skin. Although normal scars contained little fibronectin protein and messenger RNA, cultured fibroblasts derived from these scars had contents of fibronectin messenger RNA and rates of biosynthesis in vitro similar to those of keloid fibroblasts. This indicates that the fibronectin regulatory pathway in scar fibroblasts is influenced by the tissue environment. These results are discussed with respect to the relationship of fibronectin expression in keloids, hypertrophic scars, and normal wounds in human beings.     

整合素α5β1在病理性瘢痕中的表达及意义

目的　研究整合素α5β1 在病理性瘢痕中的表达情况 ,探讨其在瘢痕发生、发展中的作用和意义。方法　运用SP免疫组化及SPA 胶体金免疫电镜技术对 15例增生性瘢痕、15例瘢痕疙瘩及 10例正常皮肤进行整合素α5β1 的检测 ,并对结果进行半定量及定量分析。结果　在瘢痕疙瘩和增生性瘢痕的成纤维细胞中整合素α5β1 呈阳性表达 ,较正常皮肤强 (P <0 0 1) ;在瘢痕疙瘩中的表达较增生性瘢痕强 (P <0 0 1)。结论　整合素α5β1 与病理性瘢痕发生、发展关系密切。设法减少整合素α5β1 在成纤维细胞的过度表达或许是抑制瘢痕增生、软化瘢痕的新途径     

性激素受体在瘢痕中的表达及与细胞周期调控蛋白相互关系的研究

目的　了解雄激素受体 (AR)、雌激素受体 (ER)在病理性瘢痕中的表达及其与细胞周期调节蛋白D1(cyclinD1)、p16之间的相互关系 ,以探讨他们在瘢痕形成过程中的作用及机制。方法　采用免疫组化方法 (SP法 )对 30例瘢痕标本进行研究 ,以正常皮肤组织为对照 ,观察上述指标的表达。结果　正常皮肤及普通瘢痕成纤维细胞中所有指标均为阴性 ;增生性瘢痕与瘢痕疙瘩成纤维细胞中cyclinD1、p16、AR与正常皮肤相比差异均有显著性意义 (P <0 0 5 ) ;瘢痕疙瘩成纤维细胞cyclinD1和AR的表达高于增生性瘢痕 ,且有显著性意义 (P <0 0 5 ) ;p16在瘢痕疙瘩成纤维细胞的表达比增生性瘢痕为高 ,但两者之间差异无显著性意义。在病理性瘢痕中cyclinD1和AR的表达具有明显的相关性。结论　AR在病理性瘢痕的发生及发展中起一定的作用 ,它可能是通过与其配体结合后促使与cyclinD1有关的基因表达而发挥作用的。在瘢痕疙瘩里可能存在cyclinD1的促细胞增生作用超过P16细胞抑制 ,所以细胞呈现持续增殖状态 ;而在增生性瘢痕里cyclinD1与p16可能处于相对的平衡状态 ,细胞生长具有一定的自限性。     

Differential expression of growth differentiation factor-9 in keloids

Objective

The mechanisms of keloid invasion are largely unknown. This study aims to analyze the differentially expressed genes between keloid peripheral and central areas and thus to define the molecule that might be responsible for keloid invasion.

Methods

The gene chip of transforming growth factor-β (TGF-β) superfamily signaling pathway was used to analyze differentially expressed genes of the fibroblasts derived from peripheral area and central area of 3 keloids. The differential expression of growth differentiation factor-9 (GDF-9) was also confirmed by quantitative PCR and Western-blot. Moreover, GDF-9 expression levels were compared among the fibroblasts derived from 3 keloids, hypertrophic scars and normal skin with quantitative PCR and immunofluorescent staining.

Results

GDF-9 expression level was significantly higher in the peripheral area than in the central area (p < 0.05) and was significantly higher in keloid than in hypertrophic scar and normal skin (p < 0.05).

Conclusion

Up-regulated GDF-9 expression in keloid peripheral area may play a role in keloid invasive behavior.     

增殖瘢痕成纤维细胞接触后增殖及生物合成特性对异常瘢痕形成的机理

目的 为明确不同异常瘢痕成纤维细胞在体外完全接触后其增殖活性及生物全成功能的特性。方法 以瘢痕疙瘩、增生性瘢痕和正常皮肤（各6例）为材料，通过细胞培养、免疫组织化学及分子生物学等方法，对不同成纤维细胞在细胞接触及未接触时通过检测增殖细胞核内抗原、P16、Ⅰ、Ⅲ型胶原蛋白及前胶原基因表达对成纤维细胞的增殖、抑制及生物合成进行了研究。结果 瘢痕疙瘩成纤维细胞接触表现为细胞交叉重叠及较高的增殖活性及旺盛的生物合成功能，提示其失去了接触性抑制及密度抑制。皮肤成纤维细胞接触后则增殖及生物合成功能明显下降。增生性瘢痕成纤维细胞接触后表现为旺盛的生物合成功能，但其增殖活性处于瘢痕疙瘩和正常皮肤成纤维细胞之间。结论 不同瘢痕成纤维细胞接触后增殖及生物合成的特性可能是形成不同瘢痕的机理之一。     

TNFR1及Bcl-2在病理性瘢痕组织细胞凋亡中的表达及意义

目的　研究TNFR1和Bcl- 2在病理性瘢痕组织细胞中的表达及其对成纤维细胞凋亡与增殖的影响。方法　取手术切除的增生性瘢痕和瘢痕疙瘩患者各 15例标本 ,正常皮肤 12例标本 ,应用免疫组织化学方法进行检测 ,分析TNFR1和Bcl- 2的表达及分布规律。结果　TNFR1在正常皮肤、增生性瘢痕及瘢痕疙瘩中成纤维细胞的表达阳性率分别为 10 .70 %、3.2 3%和 7.72 % ,TNFR1在正常皮肤组中的阳性表达率明显高于增生性瘢痕组和瘢痕疙瘩组 ,而瘢痕疙瘩组阳性表达率却又明显高于增生性瘢痕组 ,三组间阳性表达率相互比较差异均有显著意义 (P <0 .0 1) ;Bcl- 2在增生性瘢痕组 (19.35 % )和瘢痕疙瘩组 (48.33% )的阳性表达率明显高于正常皮肤组 (4.0 7% ) ,三组间阳性表达率相互比较差异亦均有显著意义 (P <0 .0 1)。结论　Bcl- 2的持续过表达可能是瘢痕疙瘩呈瘤样增生的原因之一。介导的死亡受体凋亡通路受阻及TNFR1介导核转录因子NF -kB的激活 ,表明TNFR1对成纤维细胞的增殖与凋亡具有双重的调节作用。     

The effect of the anti-allergic agent avil on abnormal scar fibroblasts.

Abnormal wound healing in humans leads to the formation of hypertrophic scar and keloids. These abnormal scars accumulate excessive extracellular matrix proteins through increased synthesis as well as decreased degradation. In order to find a therapeutic control for scar formation, we investigated the effect of avil (pheniramine maleate) on fibroblasts cultured from abnormal scars in comparison to normal skin. We observed a decrease in the proliferation rate in cells from normal skin (39%), hypertrophic scar (44%), keloid (63%) and in DNA synthesis in cells from normal skin (50%), hypertrophic scar (55%) and keloid (63%) treated with 8 mM avil (72 h). The rate of decrease in collagen synthesis in normal skin (44%), hypertrophic scar (74%) and keloid fibroblast (73%) correlated with changes in DNA synthesis.     

The role of altered fatty acid in pathological scars and their dermal fibroblasts

PurposeThe proposed pathological mechanism for scar formation is controversial, and increased attention has been paid to the fatty acids (FAs) in the formation of pathological scars. Notably, FAs are known to be important in inflammation and mechanotransduction, which is closely related to scar formation. Therefore, it is necessary to clarify the roles of FA in scar formation.MethodsHypertrophic scar and keloid formed for more than a year and without other treatment, as well as normal skin samples were obtained from patients who underwent plastic surgery. Finally, keloids (n = 10), hypertrophic scars (n = 10), and normal skin samples (n = 10) were collected under informed consent. Primary dermal fibroblasts were isolated and cultured. The amount and variety of FAs were detected by lipid chromatography-mass spectrometry. Immunohistochemistry, real-time PCR, and western blotting were used to verify the expression of sterol regulatory element-binding protein-1 (SREBP1) and fatty acid synthase (FASN) in the samples and their fibroblasts. Student's t-test, ANOVA, and orthogonal partial least square discriminant analysis were performed for statistical analysis (1p < 0.05, 7p < 0.01, 71p < 0.001, 77p < 0.0001).ResultsCompared with full-thickness normal skin, there were 27 differential FAs in keloids and 15 differential FAs in hypertrophic scars (1p < 0.05 and variable influence on projection >1.0). The expression of SREBP1 and FASN was lower in pathological scars both at mRNA and protein levels (all 1p < 0.05). However, the mRNA levels of SREBP1 (71p = 0.0002) and FASN (71p = 0.0021) in keloid-derived fibroblasts were higher than that in normal skin fibroblasts (NFBs), while the expression in hypertrophic scar-derived fibroblasts was lower than that in NFBs (both 1p < 0.05). Whereas there was no significant difference in FASN protein expression between keloid-derived fibroblasts and NFBs (p > 0.05).ConclusionFAs involved in pathological scars are abnormally changed in scar formation. Thus, fatty acid-derived inflammation and de novo synthesis pathway of FA may play a key role in the formation of pathological scars.     

Gene expression patterns in isolated keloid fibroblasts

Keloid scars after skin trauma are a significant clinical problem, especially in black populations, in which the incidence of keloids has been estimated at 4-16%. Keloids are abnormal dermal proliferative scars secondary to dysregulated wound healing. Despite several biochemical studies on the role of extracellular matrix proteins and growth factors during keloid formation, we still do not know what molecules and signals induce this change. Fibroblasts are thought to be the major inductive cell for keloid scar formation. The aim of this study was to identify gene expression patterns that characterize keloid fibroblasts; identifying such genetic disequilibrium may shed light on the molecular signaling events responsible for keloid formation. In this study, we performed gene expression analysis of fibroblasts isolated from keloid lesions from three individuals in comparison with the fibroblasts isolated from normal skin using the Affymetrix U133a chip (22,284 genes and expression sequence tags). We found through J5 test score expression analysis that among 22,284 genes, there were 43 genes that were overexpressed and five genes were underexpressed in keloid fibroblasts when compared with dermal fibroblasts from persons without keloids. The overexpression of three genes not previously reported as being up-regulated in keloids (annexin A2, Transgelin, and RPS18) was confirmed by real-time polymerase chain reaction. Certain overexpressed genes were similar to previous biochemical observations on the protein levels of these overexpressed genes during keloid formation. We also report for the first time that a few tumor-related genes are overexpressed in keloid fibroblasts.     

Involvement of KGF in the Wound Healing Process of Tracheal Cartilage in Rat Longitudinal Tracheotomy Model

Aim:  To investigate the expression of human HtrA1 in keloid lesions, and to clarify a possible role of human HtrA1 in keloid pathogenesis.
Methods:  Total RNA was isolated from six keloids and two normal skins by single‐step method. The expression level of human HtrA1 was examined by using Northern blot analysis. Keloid and normal skin tissue samples were fixed in paraformaldehyde, and paraffin sections were obtained. Immunohistochemical analysis was performed with anti‐human HtrA1 polyclonal antibody.
Results:  The mRNA level of human HtrA1 was markedly elevated in keloid samples, compared with normal skin. Using immunohistochemical analysis, fibroblast‐like cells abundantly found in the margin of keloid lesions, were stained with anti‐human HtrA1 antibody. No human HtrA1 staining of fibroblasts in normal skin was observed. Interestingly, no significant staining was detected in hypertrophyic scar lesions, which is a similar dermal disease to keloid.
Conclusion:  Human HtrA1 expression was found to be up‐regulated in keloid lesions, especially in their margin, compared to normal skins and hypertrophic scars. Our data suggest that human HtrA1 could play a critical role in an expression of keloid specific phenotype and in the development of keloid lesions.     

细胞信号传导在激素和干扰素诱导的增殖瘢痕成纤维细胞凋亡中的作用

目的 探讨对瘢痕疙瘩和增生性瘢痕成纤维细胞在激素和干扰素α-2b(IFNα-2b)作用后是否产生凋亡,以及相关细胞信号传导通路的激活或抑制是否一致.方法 对6例瘢痕疙瘩、增生性瘢痕及6例皮肤标本,采用细胞培养、免疫组织化学、凝胶电泳及FACE ELISA方法通过检测Bax和Bcl-2蛋白表达、特异性DNA梯状条带以及激活(磷酸化)的ERK1/2和JNK的吸光度A值,对不同成纤维细胞在地塞米松(0.1 mg/ml)和干扰素α-2b(1000U/ml)作用后的细胞凋亡及相关细胞信号传导通路进行了研究.结果 地塞米松可通过激活ERK1/2和JNK细胞传导通路诱导三类不同来源成纤维细胞发生细胞凋亡;干扰素α-2b不能诱导这三类不同来源成纤维细胞发生明显细胞凋亡,且IFN α-2b抑制增殖瘢痕的ERK1/2通路,而对JNK通路无影响,其不引起正常皮肤成纤维细胞ERK1/2和JNK通路的变化.结论 激素类药物和干扰素α-2b对瘢痕疙瘩、增生性瘢痕和正常皮肤成纤维细胞的作用机制不同.     

p53 and apoptosis alterations in keloids and keloid fibroblasts

Keloids are the result of a dysregulated wound-healing process and are characterized by formation of excess scar tissue that proliferates beyond the boundaries of the inciting wound. In this study, we investigated the expression of key proteins involved in regulating apoptosis in keloids. Twenty archival paraffin-embedded keloid samples were randomly selected for an immunoperoxidase assay with antibodies against fas, p53, bcl-2, and bcl-x proteins using the target antigen-retrieval technique. Apoptosis was assessed in keloids and normal skin and in keloid and normal fibroblasts by the TdT-mediated dUTP nick-end labeling (tunel) assay on tissue sections, fibroblast cultures, and by flow cytometry for cell suspensions. We found that 18 of 20 keloids expressed p53 protein; bcl-2 was expressed by keloid fibroblasts in 19 of 20 keloids, and all specimens had prominent fas expression throughout the tissue. The distribution of these three antigens was regional within each lesion and followed a consistent pattern of p53 and bcl-2 expression colocalized to the hypercellular, peripheral areas of each keloid in a perinuclear pattern (p < .001). In contrast, an inverse distribution of fas expression was shown, with staining being more diffuse across the cell surfaces and limited to the central, more hypocellular regions in 16 of 17 keloids (p < .001). There was no specific staining pattern in these keloids with antihuman bcl-x. In vitro studies on cultured keloid fibroblasts (derived from six patients) revealed maintenance of the p53+, bcl-2+ phenotype up to passage 10. Neither neonatal nor normal adult skin fibroblasts expressed either antigen but could be induced to express p53 by exposure to adriamycin. Keloid lesions and keloid fibroblasts were found to have lower rates of apoptosis than normal controls. Keloid fibroblasts displayed enhanced apoptosis rates in response to hydrocortisone, γ interferon and hypoxia treatment as compared with normal adult fibroblasts. Focal dysregulation of p53 combined with upregulation of bcl-2 may help produce a combination of increased cell proliferation and decreased cell death in the younger hypercellular areas of the keloid. This phenotype is reversed in the older areas of the keloid and may prevent malignan degeneration, thus favoring normal apoptosis as evidenced by prominent fas expression.     

曲安奈德、干扰素α-2b和维拉帕米治疗增殖瘢痕的作用机制比较

目的 比较曲安奈德、干扰素α-2b和维拉帕米局部注射对瘢痕疙瘩和增生性瘢痕增殖、凋亡和TGF-β1表达的影响. 方法 增生性瘢痕和瘢痕疙瘩各6例,局部注射曲安奈德(40 mg/ml)、干扰素α-2b(150万U/ml)和维拉帕米(2.5 mg/ml)后7 d,切取标本,采用免疫组织化学、末端脱氧核苷酸介导的生物素化的脱氧尿嘧啶DNA切口末端标记方法,检测细胞增殖核抗原和TGF-β1的表达及细胞发生的凋亡情况,并以未注射药物的瘢痕疙瘩和增生性瘢痕以及健康皮肤为对照. 结果 ①曲安奈德可抑制瘢痕疙瘩和增生性瘢痕细胞增殖和诱导细胞凋亡,同时抑制细胞TGF-β1表达从而抑制瘢痕的增殖增生;②干扰素α-2b可通过抑制瘢痕疙瘩、增生性瘢痕细胞的增殖和TGF-β1表达而抑制瘢痕的增殖增生,但其不能诱导细胞凋亡;③维拉帕米可通过抑制瘢痕疙瘩、增生性瘢痕细胞的增殖和诱导细胞凋亡而抑制瘢痕的增殖,同时抑制细胞TGF-β1表达,其诱导细胞凋亡的作用妹强于曲安奈德,但抑制TGF-β1表达作用弱于曲安奈德和干扰素α-2b. 结论 曲安奈德、干扰素α-2b和维拉帕米局部注射后,对瘢痕疙瘩和增生性瘢痕在临床上虽均有效,但作用机制不尽相同.     

Detection of apoptosis in keloids and a comparative study on apoptosis between keloids, hypertrophic scars, normal healed flat scars, and dermatofibroma

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and the development of pathological scarring. In this study, we demonstrate that keloid fibroblasts can be identified as apoptotic cells because of their highly condensed chromatin and discrete nuclear fragments. To further reveal the phenomenon of apoptosis, we quantified the number of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in surgically resected tissues of keloids (N = 10), hypertrophic scars (N = 10), normal healed flat scars (N = 10), and dermatofibroma (N = 10). The number of TUNEL-positive cells was relatively low, but was significantly higher for the keloid group compared with the normally healed flat scar group (p = 0.004), suggesting reduced cell survival and increased apoptotic cell death in a subpopulation of keloid fibroblasts. Furthermore, the number of TUNEL-positive cells was significantly higher for the keloid group compared with the dermatofibroma group (p = 0.044), suggesting that a subpopulation of keloid fibroblasts may suppress tumorgenicity at a greater rate than dermatofibroma by undergoing cell death. Hypertrophic scars had significantly higher levels of apoptosis than normally healed flat scars (p = 0.033). Therefore, these results suggest that selected fibroblasts in keloids and hypertrophic scars undergo apoptosis, which may play a role in the process of pathological scarring.     

A wound contraction experimental model for studying keloids and wound-healing modulators

Preventing and treating hypertrophic and keloid scars is difficult because of the lack of knowledge about their genesis. Tissue repair can be studied with biocompatible matrices and ex vivo cultures of different cell types. We used an experimental model where collagen gels populated by human fibroblasts underwent progressive contraction, allowing the study of wound healing remodeling. The fibroblast-populated lattices showed the greater contraction of the gel populated by fibroblasts from keloids versus fibroblasts from normal skin. Moreover, fibroblast growth factor (FGF) and transforming growth factor beta (TGF-beta) involved in scar formation were added to the collagen gels populated by normal skin fibroblasts. TGF-beta caused an increase in gel contraction; FGF did not. The mean percentages of contraction of the gels populated by keloid fibroblasts were very similar to the percentages of gels populated by normal skin fibroblasts with added TGF-beta. These observations confirm the existing hypothesis that TGF-beta may be involved in keloid formation.