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 study the mutations at 1 573 fragment of TNF receptor II (TNFR-II) gene in patients with keloid. Methods The tissue DNA was extracted from 22 samples of keloids donated by 22 patients (6 males and 16 females, aged 18-53 years), and all keloids were examined and classified by pathologist. The peri pheral blood DNA was extracted from the same patients as the control. PCR was used to ampl ify the 1 573 fragment of TNFR-II gene from the keloid tissue DNA and peripheral blood DNA. The PCR products were sequenced directly and then compared with the GeneBankdata. Results All the concentration of the extracted DNA in trial were higher than 0.50 μg/μL and the purity (A260/A280) ofthe extracted DNA were higher than 1.5. It closed to the magnitude of the design DNA fragment by agarose gel electrophoresis examining, and corresponded with the test requirement. Mutations at 1 573 fragment of TNFR-II gene were detected in 13 out of 22 keloids. The mutation incidence was 59.1%. Among them, 9 had point mutation at codon 1 663, accounting 40.9%. No TNFR-II gene mutation was detected in all peripheral blood samples. There were significant difference between keloids DNA and peripheral blood DNA (P lt;0.01). The mutations involved point mutation, deletion and insertion as well as multisite and multitype. Conclusion There is a correlation between the mutation at 1 573 fragment of TNFR-II gene and keloid.
Objective To observe the protein expression of c-Jun amino-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in normal skin and keloid and to explore their influences on the formation of kloid. Methods Keloid tissues and normal skin tissues were collected from 16 keloid resection patients (experimental group) and 10 voluntary plastic surgery patients (control group). In the experimental group, the keloid formation time ranged from 8 months to 10 years; the keloid tissues were collected from the chest in 6 cases, the ear lobe in 4 cases, the perineum in 2 cases, the shoulder in 3 cases, and the abdomen in 1 case; and all keloid tissues were confirmed by pathological examination. In the control group, normal skin tissues were collected from the abdomen in 4 cases, the thighs in 3 cases, the shoulder in 2 cases, and the back in 1 case. Two-step l ine of Envision immunohistochemical staining was performed to observe the expressions of nonphosphorylated and phosphorylated JNK and ERK; Image Pro Plus 4.5 image analysis system was used to measure the integrated absorbance (IA) and to observe the positive staining strength. Results The immunohistochemical staining showed that no obvious expressions of phosphorylated and non-phosphorylated ERK, JNK were observed in the fibroblasts of the control group, and the expressions of phosphorylated JNK and ERK proteins were significantly higher in the experimental group than in the control group (P lt; 0.05). There was no significant difference in the expressions of non-phosphorylated JNK and ERK proteins between 2 groups (P gt; 0.05). Conclusion Activation of ERK and JNK pathways might be involved in formation of keloid.
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 build animal models of keloid by method of tissue engineering and to discuss the feasibility of using it in clinical and lab researches. Methods Fibroblasts(FB) were isolated from keloids and cultured. The seventh and eighth generation of the cultured FBs were inoculated into the copolymers of polylactic acid and polyglycolic PLGA. After being cultured in rotatory cell culture system （RCCS）for 1 week,the FB was transplanted into athymic mice. The specimens were obtained 4 weeks and 8 weeks and examined histologically. Results All mice survived.The collagen patterns of all keloids were pressed in every specimen obtained 8 weeks. Fibrocytes andFB were observed in specimens by electronic microscope. There were abundent rough endoplasmic reticulum (RER) in FB， which indicated that FB’s capability of synthesizing and secreting collagen was preserved and the cellular characteristicwas remained. Conclusion There is a good affinity between PLGAand FB. The composition of PLGA and FB can form keloids in athymic mice,so that it deserves further researching and developing.
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.
ObjectiveTo investigate the expression and significance of peroxisome proliferator activated receptor γ(PPAR-γ) in human keloid. MethodsTwenty-three keloid samples were harvested from the patients undergoing keloid and auto-skin grafting operation as the experimental group (keloid group), and the residual normal skin after auto-skin grafting operation was collected as the control group. The expression of PPAR-γ protein was examined by immunohistochemistry staining in both keloid and normal skin. Referring to Shimizu immunohistochemical standard, the result was graded; the positive rate of samples and the rate of positive cells were calculated. ResultsImmunohistochemistry staining showed that PPAR-γ protein was expressed in both keloid and normal skin. In keloid, it located in the pricle cell layer, and granular layer of epidermis, and the dermal vessel; the degree of dyeing was very light. However, in normal skin, it located in the base layer of epidermis, dermal vessel walls, sweat glands and sebaceous glands; the dyeing degree was deeper. Immunohistochemical staining score in the keloid group (2.65±0.78) was significantly lower than that in the control group (3.65±1.19) (t=5.030, P=0.000). The positive rate of samples in the keloid group (52.17%, 12/23) was significantly lower than that in the control group (82.61%, 19/23) (χ2=4.847, P=0.028). The rate of positive cells was 46.04%±8.61% in the keloid group, which was significantly lower than that in the control group (59.39%±11.26%) (t=5.974, P=0.000). ConclusionCompared with normal skin, the expression of PPAR-γ protein in keloid is down-regulated in in human keloid, indicating that PPAR-γ may be related to the formation of keloid.
【Abstract】 Objective To summarize the recent progress in related research on transforming growth factor β1 （TGF-β1）/Smad3 signal transduction pathway and post-traumatic scar formation. Methods Recent related literature at home and abroad on TGF-β1/Smad3 signal transduction pathway and post-traumatic scar formation was reviewed and summarized. Results TGF-β1 is an important influence factor of fibrotic diseases, and it plays biological effects by TGF-β1/Smad3 signal transduction pathway. The pathway is regulated by many factors and has crosstalk with other signal pathways at cellular and molecular levels. The pathway is involved in the early post-traumatic inflammatory response, wound healing, and late pathological scar formation. Intervening the transduction pathway at the molecular level can influence the process of fibrosis and extracellular matrix deposition. Conclusion TGF-β1/Smad3 signal transduction pathway is an important way to affect post-traumatic scar formation and extracellular matrix deposition. The further study on the pathway will provide a theoretical basis for promotion of wound healing, as well as prevention and treatment of pathological scar formation.
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.