The ultrastructures of 14 keloids and 7 hypertrophic scars were examined by electron micrascopy.Both lesions were found to be comprised of fibroblasts, macrophages, microfi brils of collagen andmicrovessels which were partly or completely obliterated. Most fibroblasts were of active cell types.They contained abundant coarse endoplasmic reticulum and prominent Golgi complexes. The fibrils inthe lesions were irtegularly arranged. Meanwhile myofibroblasts were often seen in the keloid.In the cytoplasm of the myofibroblasts, in addition to coarse endoplasmic reticulum and Golgi complexes, many fine myofilaments, dense bodies, dense patches and distrupted basal lamina were present. These characteristic features might help to differentiate keloid from hypertrophic sacr.
OBJECTIVE: To investigate the expression and distribution of platelet derived growth factor receptor-beta(PDGFR-beta) in normal skin and keloid and to discuss its biological function in keloid formation. METHODS: 1. To detect the expression and distribution of PDGFR-beta in normal skin and keloid tissue by immunohistochemistry; 2. To detect the receptor expression in vitro by Flow cytometry (FCM); 3. To detect the subcellular distribution of receptor by Laser confocal microscope. RESULTS: 1. Immunohistochemistry showed that normal skin and keloid tissue were almost the same in expression but different in distribution of PDGFR-beta; 2. There was more expression of PDGFR-beta in normal fibroblasts than that in keloid fibroblasts in vitro by FCM; 3. Laser confocal microscope revealed that the PDGFR-beta concentrated on the surface of cell membrane in keloid fibroblasts, but in normal skin fibroblasts, the receptors were coagulated on the nuclear membrane and intranucleus. CONCLUSION: Compared with the fibroblasts in vivo, there was a difference of the PDGFR-beta expression in fibroblasts in vitro, more expression of PDGFR-beta in normal fibroblast than that in keloid fibroblast in vitro; and the subcellular distribution of PDGFR-beta was different in normal skin and keloid fibroblasts. The characteristics of the expression and distribution of PDGFR-beta in keloid may contribute to the formation of keloid.
Objective To seek for a method of constructing the tissue microarray which contains keloid, skin around keloid, and normal skin. Methods The specimens were gained from patients of voluntary donation between March and May2009, including the tissues of keloid (27 cases), skin around keloid (13 cases), and normal skin (27 cases). The specimens were imbedded by paraffin as donor blocks. The traditional method of constructing the tissue microarray and section were modified according to the histological characteristics of the keloid and skin tissue and the experimental requirement. The tissue cores were drilled from donor blocks and attached securely on the adhesive platform which was prepared. The adhesive platform with tissue cores in situ was placed into an imbedding mold, which then was preheated briefly. Paraffin at approximately 70℃ was injected to fill the mold and then cooled to room temperature. Then HE staining, immunohistochemistry staining were performed and the results were observed by microscope. Results The constructed tissue microarray block contained 67 cores as designed and displayed smooth surface with no crack. All the cores distributed regularly, had no disintegration or manifest shift. HE staining of tissue microarray section showed that all cores had equal thickness, distinct layer, manifest contradistinction, well-defined edge, and consistent with original pathological diagnosis. Immunohistochemistry staining results demonstrated that all cores contained enough tissue dose to apply group comparison. However, in tissue microarray which was made as traditional method, many cores missed and a few cores shifted obviously. Conclusion Applying modified method can successfully construct tissue microarray which is composed of keloid, skin around keloid, and normal skin. This tissue microarray will become an effective tool of researching the pathogenesis of keloid.
Objective To study the expression of heat shock protein 47 (HSP47) and its correlation to collagen deposition in pathological scar tissues. Methods The tissues of normal skin(10 cases), hypertrophic scar(19 cases), and keloid(16 cases) were obtained. The expression ofHSP47 was detected by immunohistochemistry method. The collagen fiber content was detected by Sirius red staining and polarization microscopy method. Results Compared with normal skin tissues(Mean IOD 13 050.17±4 789.41), the expression of HSP47 in hypertrophic scar(Mean IOD -521 159.50±272994.13) and keloid tissues(Mean IOD 407 440.30±295 780.63) was significantly high(Plt;0.01). And there was a direct correlation between the expression of HSP47 and the total collagen fiber content（r＝0.386，Plt;0.05）. Conclusion The HSP47 is highly expressed in pathological scartissues and it may play an important role in the collagen deposition of pathological scar tissues.
Objective To detect the expression of heat shock protein 47 mRNA in pathological scar tissue by using real-time fluorescent quantitative reversetranscription-polymerase chain reaction (RT-PCR). Methods The tissues of normal skin(n=6), hypertrophic scar(n=6) and keloid(n=6) were adopted, which were diagnosised by Pathology Department. Based on fluorescent TaqMan methodology, the real-time fluorescent quantitative RT-PCR were adopted to detect the expression ofheat shock protein 47 mRNA. Results Compared with normal skin tissue（0.019±0.021）×105, the expressions of heat shock protein47 cDNA of hypertrophic scar tissue（1.233±1.039）×105 and keloid tissue（1.222±0.707）×105 were higher， being significant differences（Plt;0.05）. Conclusion A fluorescent quantitative method was successfully applied to detecting the expression of heat shock protein 47 mRNA. Heat shock protein 47 may play an important role in promoting the formation of pathological scar tissue.
Objective To study the effect of myofibroblast on the development of pathological scar. Methods From 1998 to 2000， 14 cases of keloid(k), 13 cases of hypertrophic scar(HS), and 7 cases of scar were studied through immunohistochemistry and electronical microscope. Results Myofibroblasts were often observed in the hypertrophic HS by electronical microscope, but no myofibroblast was observed in the K and NS. αSMactin was expressed in fibroblast of HS, but was not expressed in K and NS. Conclusion Myofibroblast may play a role in the development of hypertrophic scar. The difference between the absence of myofibroblast in keloid and the invasion of keloid deserves further study.
ObjectiveTo investigate the effectiveness of internal mammary artery perforator (IMAP) propeller flap repair combined with radiotherapy for chest keloid in female patients.MethodsBetween January 2015 and December 2016, 15 female patients with chest keloids were treated, aged 28-75 years (mean, 45.2 years). The keloid disease duration was 1-28 years (median, 6 years). The causes of disease included secondary keloid caused by folliculitis in 7 cases, cardiac surgery in 4 cases, skin abrasion in 2 cases, mosquito bite in 1 case, and unknown etiology in 1 case. The size of keloid ranged from 5 cm×3 cm to 17 cm×6 cm. The IMAP propeller flaps were used to repair the defects after chest keloid excision. The size of flaps ranged from 7 cm×5 cm to 14 cm×8 cm. The donor sits were sutured directly. The routine radiotherapy was performed after operation.ResultsAll IMAP propeller flaps survived well, and the donor sites healed by first intention. All 15 patients were followed up 12-24 months (mean, 16 months). No telangiectasia or incision dehiscence occurred. No radiation-related carcinogenesis occurred during follow-up. The patients were satisfied with the breast shape and symmetry after operation. The symptoms of pain and itching relieved at keloid area in 13 cases (86.7%), with no obvious recurrence of keloid at the donor site and the primary site. Only 2 cases (13.3%) recurred and were treated with continuously conservative treatment.ConclusionIMAP propeller flap is an ideal reconstruction method for repairing the wounds after chest keloid excision in female patients, which can preserve the good breast shape. The IMAP propeller flap repair combined with early postoperative radiotherapy can effectively reduce the recurrence rate, and the effectiveness is satisfactory.
Objective To explore the effect of connective tissue growth factor on the pathogenesis of hypertrophic scar and keloid tissue. Methods The content of hydroxyproline was determined and the expression of connective tissue growth factor gene was detected by the reverse transcription-polymerase chain reaction and image analysis technique in 5 normal skins, 15 hypertrophic scars and 7 keloid tissues. Results The contents of hydroxyproline in the hypertrophic scar(84.10±1.76) and keloid tissue (92.38±2.04) were significantly higher than that of normal skin tissue (26.52 ± 4.10) (P lt; 0.01). The index of connective tissue growth factor mRNA in the hypertrophic scar (0.78 ± 0.63) and keloid tissue (0.84 ± 0.04) were higher than that of normal skin tissue ( 0.09 ± 0.25) (P lt; 0.01). Conclusion Connective tissue growth factor may play an important role in promoting the fibrotic process of hypertrophic scar and keloid tissue.
Objective To investigate the relationship between p53 codon 72 polymorphism and susceptibility to keloid. Methods The p53 genotypes were detected by polymerase chain reactionreverse dot blot(PCRRDB) and DNA direct sequencing among 15 healthy controls and 15 patients with keloid. Results The frequency of the Proallele(P=0.035) and Pro/Pro genotype(P=0.030) in patients was significantly higher than that in the controlls. There was no significant difference in the frequency of Pro/Arg and Arg/Arg genotypes between patients and controls. Conclusion The p53 gene codon 72 polymorphism may play a role in susceptibility to keloid.
Keloids are benign skin tumors resulting from the excessive proliferation of connective tissue in wound skin. Precise prediction of keloid risk in trauma patients and timely early diagnosis are of paramount importance for in-depth keloid management and control of its progression. This study analyzed four keloid datasets in the high-throughput gene expression omnibus (GEO) database, identified diagnostic markers for keloids, and established a nomogram prediction model. Initially, 37 core protein-encoding genes were selected through weighted gene co-expression network analysis (WGCNA), differential expression analysis, and the centrality algorithm of the protein-protein interaction network. Subsequently, two machine learning algorithms including the least absolute shrinkage and selection operator (LASSO) and the support vector machine-recursive feature elimination (SVM-RFE) were used to further screen out four diagnostic markers with the highest predictive power for keloids, which included hepatocyte growth factor (HGF), syndecan-4 (SDC4), ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2), and Rho family guanosine triphophatase 3 (RND3). Potential biological pathways involved were explored through gene set enrichment analysis (GSEA) of single-gene. Finally, univariate and multivariate logistic regression analyses of diagnostic markers were performed, and a nomogram prediction model was constructed. Internal and external validations revealed that the calibration curve of this model closely approximates the ideal curve, the decision curve is superior to other strategies, and the area under the receiver operating characteristic curve is higher than the control model (with optimal cutoff value of 0.588). This indicates that the model possesses high calibration, clinical benefit rate, and predictive power, and is promising to provide effective early means for clinical diagnosis.
