Objective To investigate the effects of asiaticoside onthe proliferation and the Smad signal pathway of the hypertrophic scar fibroblasts.Methods The hypertrophic scar fibroblasts were cultured with tissue culture method. The expressions of Smad2 and Smad7 mRNA after asiaticoside treatment were determined by reverse transcriptionpolymerase chain reaction 48 hours later. Thecell cycle, the cell proliferation, the cell apoptosis and the expression of phosphorylated Smad2 and Smad7 with(experimental group) or without(control group) asiaticoside were detected with flow cytometry, immunocytochemistry and Western blot. Results Asiaticoside inhibited the hypertrophic scar fibroblasts from phase S to phase M. The Smad7 content and the expression of Smad7 mRNA were (1.33±1.26)% and (50.80±22.40)% in experimental group, and (9.15±3.36)% and (32.18±17.84)% in control group; there were significant differences between two groups (P＜0.05). While the content and the mRNA expression of Smad2 had no significant difference between two groups. Conclusion Asiaticoside inhibits the scar formation through Smad signal pathway.
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 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.
Objective To explore the change of gene expression of stress activated protein kinase (SAPK) and its upstream signalregulated molecule ——mitogen activated protein kinases(MAPKs) (MKK4 and MKK7) in hypertrophic scar and autocontrol normal skin. Methods The total RNA was isolated from 8 hypertrophic scars and 8 auto-control skin, and then mRNA was purified. The gene expressions of MKK4, MKK7 and SAPK were examined with reverse transcriptionpolymerase chain reaction(RT-PCR) method. Results In hypertrophic scar, both MKK7 and SAPK genes weakly expressed. In auto-control skin, the expression of these 2 genes was significantly elevated in comparison with hypertrophic scar (Plt;0.01). The expression levelsof these 2 genes were 1.5 times and 2.6 times as long as those of hypertrophic scar, respectively. Gene expression of MKK4 had no significant difference between autocontrol skin and hypertrophic scar (Pgt;0.05). Conclusion Decreased gene expression of MKK7 and SAPK which results in reducing cell apoptosis might be one of the mechanisms for controlling the formation of hypertrophic scar.
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.
To study the variations of l ipid peroxidation products and copper, zinc-superoxide dismutase(CuZn-SOD) in pathological scars (hypertrophic scars and keloids). Methods The specimens were gained from patients of voluntary contributions from May 2005 to August 2005. The tissues of hypertrophic scar (10 cases, aged 16-35 years, the mean course of disease was 2.2 years), keloid (10 cases, aged 17-32 years, the mean course of disease was 8 months) and normal skin (8 cases, aged 16-34 years) were obtained. The content of malonaldehyde (MDA)and CuZn-SOD activity were detected by spectrophotometric method. The expression of CuZn-SOD was evaluated by immunohistochemistry technique. Results The contents of MDA and CuZn-SOD activity were significantly higher in hypertrophic scars[MDA (1.139 0 ± 0.106 7)nmoL/mg prot, CuZn-SOD (31.65 ± 2.21)U/mg prot, (P lt; 0.05)]and keloids[MDA (1.190 0 ± 0.074 8)nmoL/ mg prot, CuZn-SOD (34.36 ± 5.01)U/mg prot (P lt; 0.05)] than those of normal skin tissues [MDA (0.821 3 ± 0.086 4)nmoL/mg prot, CuZn-SOD (20.60 ± 5.56)U/mg prot]. Immunohistochemical studies indicated that the brown particles were CuZn-SOD positive signals, which mainly located cytoplasm in normal skin tissues, hypertrophic scars as well as keloids epidermal keratinocytes and dermal fibroblasts. CuZn-SOD expression evaluation in hypertrophic scars (4.14 ± 0.90, P lt; 0.05) and keloids epidermal keratinocytes (4.43 ± 0.79, P lt; 0.05) markedly increased when compared with normal skin tissues (2.20 ± 0.45). The expression of CuZn-SODin hypertrophic scars (4.00 ± 0.82, P lt; 0.05) and keloids dermal fibroblasts (4.43 ± 0.53, P lt; 0.05) were significantly higher than that of normal skin tissues (1.60 ± 0.89). There were no differences in the content of MDA, CuZn-SOD activity and expression evaluation between hypertrophic scars and keloids (P gt; 0.05). Conclusion In pathological scars, the contents of MDA and CuZn-SOD activity increase and the expressions of CuZn-SOD are enlarged.
OBJECTIVE: To localize the distribution of basic fibroblast growth factor (bFGF) and transforming growth factor-beta(TGF-beta) in tissues from dermal chronic ulcer and hypertrophic scar and to explore their effects on tissue repair. METHODS: Twenty-one cases were detected to localize the distribution of bFGF and TGF-beta, among them, there were 8 cases with dermal chronic ulcers, 8 cases with hypertrophic scars, and 5 cases of normal skin. RESULTS: Positive signal of bFGF and TGF-beta could be found in normal skin, mainly in the keratinocytes. In dermal chronic ulcers, positive signal of bFGF and TGF-beta could be found in granulation tissues. bFGF was localized mainly in fibroblasts cells and endothelial cells and TGF-beta mainly in inflammatory cells. In hypertrophic scar, the localization and signal density of bFGF was similar with those in granulation tissues, but the staining of TGF-beta was negative. CONCLUSION: The different distribution of bFGF and TGF-beta in dermal chronic ulcer and hypertrophic scar may be the reason of different results of tissue repair. The pathogenesis of wound healing delay in a condition of high concentration of growth factors may come from the binding disorder of growth factors and their receptors. bFGF may be involved in all process of formation of hypertrophic scar, but TGF-beta may only play roles in the early stage.
Objective Col I A1 antisense oligodeoxyneucleotide (ASODN) has inhibitory effect on collagen synthesis in cultured human hypertrophic scar fibroblasts. To investigate the effects of intralesional injection of Col I A1 ASODN on collagen synthesis in human hypertrophic scar transplanted nude mouse model. Methods The animal model of humanhypertrophic scar transplantation was established in the 60 BALB/c-nunu nude mice (specific pathogen free grade, weighing about 20 g, and aged 6-8 weeks) by transplanting hypertrophic scar without epidermis donated by the patients into the interscapular subcutaneous region on the back, with 1 piece each mouse. Fifty-eight succeed models mice were randomly divided into 3 groups in accordance with the contents of injection. In group A (n=20): 5 μL Col I A1 ASODN (3 mmol/L), 3 μL l iposome, and 92 μL Opti-MEM I; in group B (n=20): 3 μL l iposome and 97 μL Opti-MEM I; in group C (n=18): only 100 μL Opti-MEM I. The injection was every day in the first 2 weeks and once every other day thereafter. The scar specimens were harvested at 2, 4, and 6 weeks after injection, respectively and the hardness of the scar tissue was measured. The collagens type I and III in the scar were observed under polarized l ight microscope after sirius red staining. The ultrastructures of the scar tissues were also observed under transmission electronic microscope (TEM). Additionally, the Col I A1 mRNAs expression was determined by RT-PCR and the concentrations of Col I A1 protein were measured with ELISA method. Results Seventeen mice died after intralesional injection. Totally 40 specimens out of 41 mice were suitable for nucleic acid and protein study, including 14 in group A, 13 in group B, and 14 in group C. The hardness of scars showed no significant difference (P gt; 0.05) among 3 groups at 2 weeks after injection, whereas the hardness of scars in group A was significantly lower than those in groups B and C at 4 and 6 weeks (P lt; 0.05), and there was no significant difference between groups B and C (P gt; 0.05). The collagen staining showed the increase of collagentype III in all groups, especially in group A with a regular arrangement of collagen type I fibers. TEM observation indicated that there was degeneration of fibroblasts and better organization of collagen fibers in group A, and the structures of collagen fibers in all groups became orderly with time. The relative expressions of Col I A1 mRNA and the concentrations of Col I A1 protein at 2 and 4 weeks after injection were significant difference among 3 groups (P lt; 0.05), and they were significantly lower in group A than in groups B and C (P lt; 0.05) at 6 weeks after injection, but no significant difference was found between groups B and C (P gt; 0.05). Conclusion Intralesional injection of Col I A1 ASODN in the nude mice model with human hypertrophic scars can inhibit the expression of Col I A1 mRNA and collagen type I, which enhances the mature and softening of the scar tissue. In this process, l iposome shows some assistant effect.
OBJECTIVE: To observe the protein expression of phosphorylated form of P38 mitogen-activated protein kinase(P38MAPK) and c-Jun in hypertrophic scar skin and to explore their influences on the formation and maturation of hypertrophic scar. METHODS: The expression intensity and distribution of phosphorylated form of P38MAPK and c-Jun were examined with immunohistochemistry and pathological methods in 16 cases of hypertrophic scar skin and 8 cases of normal skin. RESULTS: In normal skin, the positive signals of phosphorylated form of P38MAPK mostly distributed in basal lamina cells of epidermis, while c-Jun was mainly located in epidermal cells and endothelial cells. The positive cellular rates of two proteins were 21.3% +/- 3.6% and 33.4% +/- 3.5% respectively. In proliferative hypertrophic scar skin, the particles of phosphorylated P38MAPK and c-Jun were mainly located in epidermal cells and some fibroblasts. The positive cellular rates of two proteins were significantly elevated to 69.5% +/- 3.3% and 59.6% +/- 4.3% respectively (P lt; 0.01). In mature hypertrophic scar, the expression of these proteins decreased but was still higher than that of normal skin. CONCLUSION: The formation and maturation of hypertrophic scar might be associated with the alteration of phosphorylated P38MAPK and c-Jun protein expression in hypertrophic scar.