To determine the state of fibroblast during the process of development of hypertrophic scar (HS), 40 specimens of HS in different periods were collected. The expressions of prolifrating cell nuclear antigen (PCNA) and Ag-protein in nucleolar organizer regions (Ag NORs) as well as the content of total amino acids in the tissues were examined. The hypertrophic scar of 1st and 3rd month old, the expression of PCND and Ag NORs were the highest. In the 9th and 12th month old, althrough PCNA was nearly negative, but the expression of Ag NORs was low. The content of total amino acid was increased gradually as HS developed but the increase of amount of hydroxyproline was markedly slowed down in 9 month old HS. It was suggested that: (1) in the developing process of HS the proecess of overproliferation of fibroblasts was short and limitted in 1-3 months period in the process of wound lealing; (2) the synthesis of collagen was nearly stopped at 6 months, but that of other extracellular matrix such as fibronectin and proteoglycan might be continued to aggregate after 12 months.
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 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.
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 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.
To investigate the inhibitory effect of Col I A1 antisense ol igodeoxyneucleotide (ASODN) transfection mediated by cationic l iposome on Col I A1 expression in human hypertrophic scar fibroblasts. Methods Scar tissue was obtained from volunteer donor. Human hypertrophic scar fibroblasts were cultured by tissue block method. The cells at passage 4 were seeded in a 6 well cell culture plate at 32.25 × 104 cells/well, and then divided into 4 groups: group A, l iposomeand Col I A1 ASODN; group B, Col I A1 ASODN; group C, l iposome; group D, blank control. At 8 hours, 1, 2, 3 and 4 days after transfection, total RNA of the cells were extracted, the expression level of Col I A1 mRNA was detected by RT-PCR, the Col I A1 protein in ECM was extracted by pepsin-digestion method, its concentration was detected by ELISA method. Results Agarose gel electrophoresis detection of ampl ified products showed clear bands without occurrence of indistinct band, obvious primer dimmer and tailing phenomenon. Relative expression level of Col I A1 mRNA: at 8 hours after transfection, group A was less than groups B, C and D (P lt; 0.05), and groups B and C were less than group D (P lt; 0.05), and no significant difference was evident between group B and group C (Pgt; 0.05); at 1 day after transfection, groups A and B were less than groups C and D (P lt; 0.05), and there was no significant difference between group A and group B, and between group C and group D (P gt; 0.05 ); at 2 days after transfection, there were significant differences among four groups (P lt; 0.05); at 3 and 4 days after transfection, group A was less than groups B, C and D (P lt; 0.05), group B was less than groups C and D (P lt; 0.05), and no significant difference was evident between group C and group D (P gt; 0.05). Concentration of Col I protein: at 8 hours after transfection, group A was less than groups B, C and D (P lt; 0.05), groups B and C were less than group D (P lt; 0.05), and no significant difference was evident between group B and group C (P gt; 0.05); at 1 day after transfection, significant differences were evident among four groups (P lt; 0.05); at 2, 3 and 4 days after tranfection, groups A and B were less than groups C and D (P lt; 0.05), and no significant difference was evident between group A and group B (P gt; 0.05). Conclusion Col I A1 ASODN can inhibit mRNA and protein expression level of Col I A1. Cationic l iposome, as the carrier, can enhance the inhibition by facil itating the entry of ASODN into cells and introducing ASODN into cell nucleus.
【Abstract】 Objective To investigate the effects on forming of hypertrophic scar after BMSCs infected with adenovirus carrying TGF-β3c2s2 were transplanted into the wound of animal scar model. Methods The third passage of rabbit’ s BMSCs were infected with 150 mutiple infection, and were cultured 24 hours. The concentration of the BMSCs infected with recombinant adenovirus containing the TGF-β3c2s2 gene was 1×105cell/mL. The purified and evaporated recombinant adenovirus grains containing the TGF-β3c2s2 gene were diluted by DMEM/F12 (without FBS) to 1×108 pfu/mL. The animal scar model of the standard Japanese big ear rabbit was establ ished. Eighty wounds were generated on the gastroside of ear and were randomized to 4 groups in each rabbit, which were divided into 3 control groups (A: control, B: Ad-TGF-β3c2s2, C: BMSCs) and 1 experimental group (D: BMSCs/Ad-TGF-β3c2s2). Then the wounds were tranplanted with cells. On 45 days and 90 days after wounded, thicknessand hardness of scars were measured with color ultrasound diagnostic unit and especial measurement for skin and scar hardness. On 21, 45 and 90 days, three specimens were harvested respectively for further histological study. Results The wound of groups A, B, C gradually formed the different degree scars after epithel ial ization. The hyperplasty of scars reached peak on 45 days after wounded and lasted about 90 days. There was no prominent scar formed in group D during the whole observed procedure. Thickness and hardness of scar of group D and group E were approximate on 45 days and 90 days. Thickness and hardness of scar of groups A, B and C were lower than those of group D (P lt; 0.01), and group B showed more lower than group A and group C (P lt; 0.01). Disorder structure and overlapping arrangement, enlargement collagen fibers were showed in the HE histological sections of the scars of groups A, C. The structure of the scars of groups B, C were similar to Group E. The constitutionsof groups A, B, C, D on 90 days resembled to each one on 45 days. In section of immunohistochemistry after wounded on21 days and 45 days, positive expressions of BrdU in nucleus of Groups C, D were observed. Negative expressions of BrdU in Groups A, B, E were showed. Conclusion BMSCs with Ad-TGF-β3c2s2 gene transplanted into wound could inhibit the forming of hypertrophic scar.
Objective To identify the effect of β-endorphin in the development of paresthesia in hypertrophic scar by detecting the expression and content of β-endorphin in human normal skin and hypertrophic scar. Methods Hypertrophic scar samples were collected from 42 patients with hypertrophic scar for 1-20 years (mean, 4.5 years), including 15 males and27 females with an average age of 32.6 years (range, 16-50 years). According to the kind of paresthesia, they were divided into 3 gourps: non-pain-pruritus group (n=20), pruritus group (n=14), and pain-pruritus group (n=8). Normal skin samples (normal skin group) were harvested from 5 patients undergoing skin grafting surgery, including 3 males and 2 females with an average age of 24.6 years (range, 15-37 years). The immunofluorescence method was used to observe the expression of β-endorphin and ELISA method to detect the concentrations of β-endorphin in the tissues. Results The β-endorphin expressed in all samples, and it expressed around peri pheral nerve fibers in the dermis, fibroblasts, and monocytoid cells princi pally; and it expressed significantly ber in pruritus group and pain-pruritus group than in non-pain-pruritus group and normal skin group. The β-endorphin content was (617.401 ± 97.518) pg/mL in non-pain-pruritus group, (739.543 ± 94.149) pg/mL in pruritus group, (623.294 ± 149.613) pg/mL in pain-pruritus group, and (319.734 ± 85.301) pg/mL in normal skin group; it was significantly higher in non-pain-pruritus group, pruritus group, and pain-pruritus group than in normal skin group (P lt; 0.05); it was significantly higher in pruritus group than in non-pain-pruritus group and pain-pruritus group (P lt; 0.05); and there was no significant difference between non-pain-pruritus group and pain-pruritus group (P gt; 0.05). Conclusion The expression of β-endorphin is high in hypertrophic scar, it may paly an important role in process of pruritus in these patients.
OBJECTIVE: To explore the expression of alpha-smooth muscle actin (alpha-SMA) induced by transforming growth factor beta 1 (TGF-beta 1). METHODS: Five samples of hypertrophic scars and three samples of normal mature scars were collected as the experimental and control groups respectively. The fibroblasts were isolated from scars, and cultured in 2-dimension or 3-dimension culture system. The immunohistochemical staining method of LSAB were used to investigate the expression of alpha-SMA in fibroblasts in the different concentration of TGF-beta 1. RESULTS: The expression of alpha-SMA in 3-dimension culture system were markedly lower than those in 2-dimension culture system with respect to the fibroblasts in the experimental group. The expression of alpha-SMA in fibroblasts were different in response to various TGF-beta 1 concentration, it was more effective at the concentration of 5 ng/ml. The expression of alpha-SMA in the fibroblasts from hypertrophic scars seemed to be more sensitive to TGF-beta 1 compared to that of the normal mature scars. CONCLUSION: There are concentration-dependent in the expression of alpha-SMA induced by TGF-beta 1 in scar fibroblasts in vitro. The biological characteristics of the fibroblasts from hypertrophic scars and normal mature scars and their sensitivity to the inducement of TGF-beta 1 were different. The inducement of TGF-beta 1 may be depressed by extracellular matrix components and that may decrease the expression of alpha-SMA.