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Clinical genetics of familial keloids.   总被引:58,自引:0,他引:58  
BACKGROUND: Keloids are proliferative fibrous growths that result from an excessive tissue response to skin trauma. Most keloids occur sporadically, but some cases are familial. However, the genetics of keloid formation have only rarely been documented, and the mode of inheritance is not known. OBJECTIVE: To elucidate the clinical genetic characteristics of keloid wound-healing disorder. OBSERVATIONS: We studied the clinical and genetic characteristics of 14 pedigrees with familial keloids. The ethnicity of these families is mostly African American (n = 10), but also white (n = 1), Japanese (n = 2), and African Caribbean (n = 1). The pedigrees account for 341 family members, of whom 96 displayed keloids. Of the affected family members, 36 are male and 60 are female. The age of onset varies from early childhood to late adulthood. There is variable expression of keloids within the same families: some affected members have only minor earlobe keloids, whereas others have very severe keloids affecting large areas of the body. In the described pedigrees, 7 individuals are obligate unaffected carriers, revealing nonpenetrance in about 6.8% of keloid gene carriers. Syndromes associated with keloids, namely Rubinstein-Taybi and Goeminne syndrome, were not found in these families. Additionally, linkage to the gene loci of these syndromes and X-chromosomal linkage were excluded. CONCLUSIONS: The pattern of inheritance observed in these families is consistent with an autosomal dominant mode with incomplete clinical penetrance and variable expression. This is the most comprehensive collection of keloid families described to date, and it allows for the first time the elucidation of the clinical genetic characteristics of the familial form of this wound-healing disorder.  相似文献   

3.
Please cite this paper as: Enhanced MCP‐1 release by keloid CD14+ cells augments fibroblast proliferation: role of MCP‐1 and Akt pathway in keloids. Experimental Dermatology 2010; 19 : e142–e150. Abstract: Keloids are fibrous overgrowth induced by cutaneous injury. The pathogenesis of keloids is poorly understood, and no convincing animal model exists. Current hypotheses of the pathogenesis classify keloids as an entity of aberrant fibrosis. Hyperactivation of the MCP‐1/CCR2 axis reportedly causes fibrosis in liver cirrhosis, atherosclerosis and lung fibrosis. Circulating CD14+ monocytes are precursors of circulating fibrocytes and contribute to fibrogenesis by a MCP‐1/CCR2‐dependent loop. As there is an increase in monocyte lineages in keloids, the aim of this study is to determine whether peripheral CD14+ monocytes in keloid patients trigger fibroblast proliferation through MCP‐1. Expressions of MCP‐1 and its receptor CCR2 in keloid lesions were measured by immunohistochemistry and real‐time PCR. The results revealed an increase in MCP‐1 and CCR2 in the keloid tissues. Co‐culture of keloid CD14+ cells and normal fibroblasts enhanced fibroblast proliferation and a parallel increase in extracellular MCP‐1. We further found that MCP‐1 modest enhanced fibroblast proliferation via Akt activation. Blockade of either MCP‐1 or Akt signaling suppressed the mediation of fibroblast proliferation by CD14+ cells from patients. These results demonstrated that enhanced MCP‐1 release by keloid CD14+ cells augments fibroblast proliferation via Akt pathway in keloids. We concluded that enhanced MCP‐1 release by keloid CD14+ cells augments fibroblast proliferation, which might initiate keloid development.  相似文献   

4.
Background Keloid disease is a benign, quasineoplastic disease with a high recurrence rate. Mesenchymal‐like stem cells (MLSC) have previously been demonstrated in keloid scars and may be involved in keloid pathobiology. However, as these cells have only been examined by single colour fluorescence activated cell sorting (FACS) alone, they need to be more comprehensively characterized so that the key cellular contributors to keloid scars can be better understood. Objectives To identify and characterize MLSC in intralesional and extralesional keloid, and to distinguish haematopoietic stem cells (HSC) from mesenchymal stem cells (MSC). Methods and patients Punch biopsies from intralesional (top, middle and margin) and extralesional keloid scar sites were obtained from 17 patients with a keloid. Multicolour FACS analysis using antibodies specific for HSC markers CD34 and CD117 and MSC markers CD13, CD29, CD44 and CD90 was performed on freshly isolated keloid scar cells and on passage 0 and 1 cells. This was complemented by real‐time quantitative polymerase chain reaction (PCR) and immunohistological in situ analyses. Results Keloid scars contain distinct subpopulations of MLSCs. Cells positive for CD13, CD29, CD44 and CD90 were found to be significantly (P < 0·05) higher in the top and middle compartments of keloid scars compared with extralesional skin, where cells positive for CD34, CD90 and CD117 (representing HSCs) predominated. A unique population of CD34+ cells (cells positive for CD13, CD29, CD34, CD44 and CD90) were found in keloid scars and in extralesional skin. FACS and quantitative PCR analysis showed that many of the MSC markers were progressively downregulated and all HSC markers were lost during extended keloid fibroblast culture up to passage 1. Conclusion We have found distinct subpopulations of haematopoietic and nonhaematopoietic MSC in keloid scars, whereby HSC accumulate extralesionally, while keloids seem to provide a niche environment for nonhaematopoietic MSC. Future therapy of keloids may have to target differentially both stem cell populations in order to deprive these tumours of their regenerative cell pools.  相似文献   

5.
Keloid disorder, a group of fibroproliferative skin diseases, is characterized by unremitting accumulation of the extracellular matrix (ECM) of connective tissue, primarily collagen, to develop cutaneous tumors on the predilection sites of skin. There is a strong genetic predisposition for keloid formation, and individuals of African and Asian ancestry are particularly prone. The principal cell type responsible for ECM accumulation is the myofibroblast derived from quiescent resident skin fibroblasts either through trans‐differentiation or from keloid progenitor stem cells with capacity for multi‐lineage differentiation and self‐renewal. The biosynthetic pathways leading to ECM accumulation are activated by several cytokines, but particularly by TGF‐β signalling. The mechanical properties of the cellular microenvironment also play a critical role in the cell's response to TGF‐β, as demonstrated by culturing of fibroblasts derived from keloids and control skin on substrata with different degrees of stiffness. These studies also demonstrated that culturing of fibroblasts on tissue culture plastic in vitro does not reflect their biosynthetic capacity in vivo. Collectively, our current understanding of the pathogenesis of keloids suggests a complex network of interacting cellular, molecular and mechanical factors, with distinct pathways leading to myofibroblast differentiation and activation. Keloids can serve as a model system of fibrotic diseases, a group of currently intractable disorders, and deciphering of the critical pathogenetic steps leading to ECM accumulation is expected to identify targets for pharmacologic intervention, not only for keloids but also for a number of other, both genetic and acquired, fibrotic diseases.  相似文献   

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BACKGROUND: A keloid results from excessive collagen deposition, the cause of which remains elusive. A thorough understanding of the pathophysiology of keloid tissue can help determine the most appropriate treatment strategy. OBJECTIVES: To assess the differences in gene expression between keloids and adjacent normal skin in order to define the genes involved in keloid formation. METHODS: Three Korean patients with keloids underwent excision of the keloid and adjacent normal skin, which was used as the control. We investigated expression patterns of genes in the keloids and the normal skin using cDNA microarray and in situ hybridization techniques. RESULTS: Nine genes in the keloid tissue were consistently upregulated over the 2.0 ratio compared with the normal control from the cDNA microarray composed of 3063 clones: collagen type I alpha1 (NM_000088), DNA segment on chromosome 21 (unique) 2056 expressed sequence (D21S2056E, NNP-1, NM_003683), suppressor of Ty 5 homologue (NM_003169), phosphoglycerate dehydrogenase (NM_032692), adenosine triphosphate synthase beta (NM_001686), serine (or cysteine) proteinase inhibitor, clade H (heat shock protein 47, NM_001235), LIV-1 protein, oestrogen regulated (LIV-1, NM_012319), interleukin-11 receptor alpha (IL11RA, NM_004512) and carbonyl reductase 3 (CBR3, NM_001236). From the in situ hybridization study, the staining signals in the keloid tissue hybridized with anti sense probes of NNP-1 mRNA were stronger than signals in normal controls. Further, endothelial epithelium, but not the epidermis, expressed the signal equally in both keloid and normal control tissue. CONCLUSIONS: We identified nine upregulated genes in keloid tissue using cDNA microarray. Of the nine, the NNP-1 gene was confirmed by topological information using the in situ hybridization technique. We conclude that these nine genes, especially NNP-1, probably contribute either directly or indirectly to keloid formation.  相似文献   

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Keloids are benign skin tumours occurring during wound healing in genetically predisposed patients. They are characterized by an abnormal deposition of extracellular matrix components, particularly collagen. There is uncertain evidence that transforming growth factor-beta (TGFss) is involved in keloid formation. Therefore we investigated the expression of TGFss1, 2 and 3 and their receptors in keloids, hypertrophic scars and normal skin. Dermal fibroblasts were obtained from punch biopsies of patients with keloids and hypertrophic scars and from normal skin of healthy individuals. Total RNA was isolated and the expression of TGFss1, 2 and 3 and of TGFss receptors I and II (TGFssRI and II) was analysed by real-time PCR using the Lightcycler technique. Our data demonstrate significantly lower TGFss2 mRNA expression in hypertrophic scar fibroblasts as compared with fibroblasts derived from keloids and normal skin (p<0.05). In contrast, TGFss3 mRNA expression was significantly lower in keloid fibroblasts in comparison with fibroblasts derived from hypertrophic scar and normal skin (p<0.01). TGFssRI mRNA expression was significantly decreased in hypertrophic scar fibroblasts (p<0.01) and TGFssRII mRNA expression was decreased in keloids compared with hypertrophic scar fibroblasts (p<0.001). The ratio of TGFssRI/TGFssRII expression was increased in keloids compared with hypertrophic scar and normal skin fibroblasts. As recently supposed, an increased TGFssRI/TGFssRII ratio could promote fibrosis. Therefore our data support a possible role of TGFssRI and TGFssRII in combination with a certain TGFss expression pattern as fibrosis-inducing factors in keloids.  相似文献   

10.
结缔组织生长因子在瘢痕疙瘩中表达的研究   总被引:7,自引:4,他引:7  
目的探讨结缔组织生长因子(CTGF)在瘢痕疙瘩发病中的作用。方法应用半定量逆转录聚合酶链反应技术检测30例瘢痕疙瘩患者皮损及对应邻近未受累皮肤中CTGFmRNA的表达,并以15例正常人皮肤组织作为对照。同时应用SP免疫组化技术对5例瘢痕疙瘩组织和5例正常人皮肤标本进行了检测。结果CTGFmRNA在瘢痕疙瘩及其边缘正常皮肤中的表达均明显高于正常人对照,差异有显著性(P<0.01)。瘢痕疙瘩CTGF的表达高低与病程无相关性(P>0.05)。免疫组化研究证实CTGF在瘢痕疙瘩中呈强表达,而在正常人皮肤中无表达。在瘢痕疙瘩组织边缘,CTGF表达呈现由强至弱的过渡现象。结论CTGF在瘢痕疙瘩中持续高度表达,提示其与瘢痕疙瘩的慢性纤维化有关。CTGF可能成为临床治疗瘢痕疙瘩的一个有力靶位。  相似文献   

11.
BACKGROUND: For nearly a century, the terms "keloid morphea" and "nodular scleroderma" have been used interchangeably without defined clinical or histologic criteria. OBJECTIVE: To define the conditions "keloid morphea" and "nodular scleroderma" by correlating the clinical and histologic features. METHODS: We retrospectively identified six patients with keloidal lesions and nodules from 70 consecutive patients with scleroderma seen in the dermatology clinic. The clinical presentation and histopathological findings were reviewed. RESULTS: Six of 70 patients with scleroderma (45 systemic and 25 morphea) exhibited keloidal or nodular lesions. All these patients had systemic sclerosis. Clinically one patient (case 1) had nodules; five (cases 2-6) had keloids. The nodular lesions had histologic findings consistent with keloid, while the keloidal plaques were variably keloids or morphea histopathologically. There was no correlation between the clinical morphology and the histologic findings, except for cases 5 and 6. These patients were African-American, with a family history of keloids and typical keloids clinically and histologically that developed from sites with normal skin. CONCLUSION: Keloid morphea and nodular scleroderma are clinical terms that describe keloidal and nodular lesions in patients most commonly with scleroderma. The clinicopathologic association is variable. Based on a review of the English literature and our series of six patients, we identified two clinical variants; (1) keloidal or nodular lesions arising from sclerodermatous skin with histologic findings of keloid or scleroderma, (2) typical keloids clinically and histologically, arising in normal skin in patients with a family history of keloids. Awareness of these entities is important for proper diagnosis of the cutaneous lesions and for recognizing that the cutaneous findings may be a sign of systemic sclerosis  相似文献   

12.
目的 探讨瘢痕旁和瘢痕下扩张器埋植治疗前胸部大面积瘢痕疙瘩的疗效。方法 从2006年3月至2009年6月,17例前胸部大面积瘢痕疙瘩患者共接受21个扩张器埋植。瘢痕面积最大15.7 cm × 5.5 cm,最小4.5 cm × 3.0 cm。其中瘢痕旁埋植12个,瘢痕下埋植9个。瘢痕旁埋植扩张器容量70 ~ 400 ml,瘢痕下埋植80 ~ 500 ml。经6 ~ 8周注水扩张后,行瘢痕疙瘩切除、扩张器取出和扩张皮瓣转移术,同时给予术中即时皮内注射复方倍他米松注射液、术后浅表电子束照射联合治疗,随访12 ~ 50个月。结果 除1个扩张器瘢痕下埋植后感染导致提前取出手术失败外,余20个扩张器均顺利完成整个治疗过程。主要并发症为扩张器外露4个,其中瘢痕旁1个,瘢痕下埋植3个,但未影响二期手术。扩张不满意2个,其中瘢痕旁和瘢痕下各1个。除2例复发外,余15例自觉症状均明显缓解,效果满意。2例复发患者均为扩张不满意,缝合时切口张力较大、且术后延期拆线者。结论 瘢痕旁和瘢痕下扩张器埋植为治疗前胸部大面积瘢痕疙瘩的较为理想的选择方法。切口缝合的张力是决定瘢痕疙瘩术后是否复发的关键。  相似文献   

13.

Background

Reactive oxygen species (ROS) play an important role in the induction of apoptosis under pathological conditions. Recently, a significant increase in ROS production and disrupted apoptosis mechanisms in keloids have been reported. Nuclear factor erythroid 2-related factor 2 (Nrf2) represents one of the most important cellular defense mechanisms against oxidative stress and is implicated in the regulation of apoptosis. Recently, it has been reported that Nrf2 upregulates Bcl-2, an anti-apoptotic protein.

Objective

To compare Nrf2 protein expression in normal skin tissues to keloid tissues.

Methods

ROS generation in keloid tissues was evaluated with OxyBlot analysis. Western blotting and/or immunohistochemical staining approaches were used to study expression of Nrf2 or Bcl-2 in keloid and normal skin tissues. Cellular fractionation was performed to examine subcellular distribution of Nrf2. Transfection of fibroblasts with Nrf2-specific small interfering RNA (siRNA) was conducted to understand the relationship between Nrf2 expression and apoptosis induction.

Results

Protein oxidation, a marker of oxidative stress, is increased in keloid tissues. Western blot analysis clearly showed that Nrf2 and Bcl-2 are downregulated in keloid tissues. Immunohistochemical staining of Nrf2 confirmed the results of the western blot analysis. Transfection of fibroblasts with the Nrf2-specific siRNA results in increased apoptosis and decreased cell viability.

Conclusion

Collectively, our data indicate that Nrf2 expression is downregulated in keloid tissues, and that Nrf2 is involved in the development of apoptosis in Nrf2 siRNA-transfected fibroblasts. We propose that a defective antioxidant system and apoptotic dysregulation may participate in keloid pathogenesis.  相似文献   

14.
 目的:了解成纤维细胞活化蛋白(FAP)在瘢痕疙瘩组织中的表达情况,探讨FAP在瘢痕疙瘩发病机制中的作用。方法:采用免疫组化染色技术检测30例瘢痕疙瘩组织(病例组)和20例正常皮肤组织(对照组)中FAP的表达强度,并比较两组间及瘢痕疙瘩不同临床分级之间FAP表达阳性率的差异。结果:病例组瘢痕疙瘩组织中FAP在成纤维细胞和血管内皮细胞内表达,阳性率为73.33%;对照组正常皮肤组织中未见FAP表达,两组间FAP表达阳性率比较,差异有统计学意义(  X2=26.19,P=0.001);瘢痕疙瘩临床分级中,轻度与重度之间及中度与重度之间比较,FAP表达阳性率差异均有统计学意义(P值分别为0.002、0.006)。结论:瘢痕疙瘩组织中FAP表达阳性率明显高于正常皮肤组织;瘢痕疙瘩临床分级越严重,FAP表达阳性率越高;FAP可能参与瘢痕疙瘩的发病机制,针对FAP的干预可能有助于瘢痕疙瘩的治疗。  相似文献   

15.
Keloids are proliferative fibrous growths that result from an excessive tissue response to skin trauma. They often occur sporadically, but in some families a genetic predisposition to keloids has been observed. Here we studied two families with an autosomal dominant inheritance pattern of keloids. One African-American family showed a high degree of variability in the extent of keloid formation between family members, whereas the second family from Japan showed a pattern of full penetrance and the formation of only small keloids. We performed a genome-wide linkage search for genes predisposing to keloid formation in these two families. We identified linkage to chromosome 2q23 (maximal two-point LOD score of 3.01) for the Japanese family. The African-American family showed evidence for a keloid susceptibility locus on chromosome 7p11 (maximal two-point LOD score of 3.16). The observed locus heterogeneity in autosomal dominant keloid disease is consistent with the clinical heterogeneity of this scarring disorder. Dense microsatellite analysis in these two loci was performed and candidate genes were identified. This study provides the first genetic evidence for keloid susceptibility loci and serves as a basis for the identification of responsible genes.  相似文献   

16.
瘢痕疙瘩组织中一氧化氮含量测定   总被引:5,自引:0,他引:5  
目的 检测瘢痕疙瘩组织中一氧化氮(NO)的含量,探讨NO在瘢痕组织增生中的作用。方法 活检标本,奶疙瘩组、正常瘢痕组与正常皮肤组,每组8例。组织匀浆,用Griess试剂检测上清液中的NO2/NO3含量,以代表组织中NO的含量。结果 瘢痕疙瘩组织中NO含量显著高于正常瘢痕与正常皮肤组织中NO的含量,P值皆小于0.01。正常瘢痕组与正常皮肤组之间差异无显著性。结论 NO可能在瘢痕疙瘩形成中起一定作用。  相似文献   

17.
BACKGROUND: Keloids are a major cause of morbidity, and arise after operation, injury, or cutaneous infection. Clinically, keloids differ from hypertrophic scars in that they grow beyond the original borders of the injury. Keloids occur most commonly for patients of African and Asian descent, and treatment options are multiple, indicating that there is no entirely satisfactory treatment for keloids. Angiogenesis inhibition has been shown to be effective in treatment of malignancy in both animal models and human beings. OBJECTIVE: We sought to determine whether keloids produce the potent angiogenic factor vascular endothelial growth factor (VEGF). METHODS: We performed in situ hybridization for VEGF on keloid tissue and normal skin. RESULTS: Our study demonstrated abundant production of VEGF in keloids and, surprisingly, the major source of VEGF was the overlying epidermis. CONCLUSIONS: Our results suggest that the overlying epidermis is the major source of keloid angiogenesis. These findings demonstrate that keloids are angiogenic lesions. Topical antiangiogenic therapy, directed at either down-regulating epidermal VEGF or inhibiting keratinocyte-derived VEGF activity on its endothelial receptors, may be useful in the treatment of keloids.  相似文献   

18.
Hypertrophic scars and keloids are characterized by excessive dermal deposition of extracellular matrix due to fibroblast‐to‐myofibroblast differentiation. Endothelin‐1 (ET‐1) is primarily produced by vascular endothelial cells and plays multiple roles in the wound‐healing response and organ fibrogenesis. In this study, we investigated the pathophysiological significance of ET‐1 and involvement of RhoA, a member of the Rho GTPases, in hypertrophic scar/keloid formation. We found that ET‐1 expression on dermal microvascular endothelial cells (ECs) in hypertrophic scars and keloids was higher than that in normal skin and mature scars. We also confirmed that ET‐1 induced myofibroblast differentiation and collagen synthesis in cultured human dermal fibroblasts through the RhoA/Rho‐kinase pathway. Finally, since hypertrophic scar/keloid formation was most prominent in areas exposed to mechanical stretch, we examined how mechanical stretch affected ET‐1 secretion in human dermal microvascular ECs, and found that mechanical stretch increased ET‐1 gene expression and secretion from ECs. Taken together, these results suggest that dermal microvascular ECs release ET‐1 in response to mechanical stretch, and thereby contribute to the formation of hypertrophic scars and keloids through the RhoA/Rho‐kinase pathway.  相似文献   

19.
端粒酶在瘢痕疙瘩及其周围外观正常皮肤中的表达   总被引:4,自引:1,他引:4  
目的 探讨端粒酶的活性与瘢痕疙瘩发病的关系。方法 采用链霉亲和素-过氧化物酶(SP)免疫组化法,对17例瘢痕疙瘩标本、10例瘢痕疙瘩周围外观正常皮肤标本及9例正常人对照组标本的成纤维细胞中端粒酶的活性进行检测,用SPSS统计软件进行相应统计学分析。结果 在瘢痕疙瘩标本中,50.5%的成纤维细胞中端粒酶活性检出阳性,且阳性细胞平均染色较深;在瘢痕疙瘩周围外观正常皮肤标本中,21.1%的成纤维细胞中端粒酶活性检出阳性;在正常人皮肤标本中,7.9%的成纤维细胞中端粒酶活性检出阳性,且阳性细胞平均染色深度明显浅于前两组。各组间两两比较,差异均有显著性(P<0.05)。结论 端粒酶的活性增高在瘢痕疙瘩的发病机制中有重要作用。  相似文献   

20.
Decorin is a natural transforming growth factor‐β1 (TGF‐β1) antagonist. Reduced decorin synthesis is associated with dermal scarring, and increased decorin expression appears to reduce scar tissue formation. To investigate the therapeutic potential of decorin for keloids, human dermal fibroblasts (HDFs) and keloid‐derived fibroblasts (KFs) were transduced with decorin‐expressing adenovirus (dE1‐RGD/GFP/DCN), and we examined the therapeutic potential of decorin‐expressing Ad for treating pathologic skin fibrosis. Decorin expression was examined by immunofluorescence assay on keloid tissues. HDFs and KFs were transduced with dE1‐RGD/GFP/DCN or control virus, and protein levels of decorin, epidermal growth factor receptor (EGFR) and secreted TGF‐β1 were assessed by Western blotting and ELISA. And type I and III collagen, and matrix metalloproteinase‐1 (MMP‐1) and matrix metalloproteinase‐3 (MMP‐3) mRNA levels were measured by real‐time RT‐PCR. Additionally, we immunohistochemically investigated the expression levels of the major extracellular matrix (ECM) proteins in keloid spheroids transduced with dE1‐RGD/GFP/DCN. Lower decorin expression was observed in the keloid region compared to adjacent normal tissues. After treatment with dE1‐RGD/GFP/DCN, secreted TGF‐β1 and EGFR protein expressions were decreased in TGF‐β1‐treated HDFs and KFs. Also, type I and III collagen mRNA levels were decreased, and the expression of MMP‐1 and MMP‐3 mRNA was strongly upregulated. In addition, the expression of type I and III collagen, fibronectin and elastin was significantly reduced in dE1‐RGD/GFP/DCN‐transduced keloid spheroids. These results support the utility of decorin‐expressing adenovirus to reduce collagen synthesis in KFs and keloid spheroid, which may be highly beneficial in treating keloids.  相似文献   

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