[Effects of sodium tanshinone II A sulfonate on proliferation of fibroblasts in scar and the mRNA and protein expressions of transforming growth factor beta 1 and alpha smooth muscle actin].

OBJECTIVE: To study the effects of sodium tanshinone II A sulfonate (STS) on proliferation of fibroblasts (Fbs) in human hypertrophic scar (HS), the mRNA and protein expressions of transforming growth factor beta 1 (TGF-ß1) and alpha smooth muscle actin (α-SMA), and to investigate the scar inhibition mechanism of STS. METHODS: Fbs were isolated from HS tissues that were removed from eight patients after burn injury, and they were cultured in vitro. Cells from the 3rd to the 6th passages were used in the experiment. Fbs were divided into control group and experimental group according to the random number table, and cells in the experimental group was divided into 0.050, 0.075, 0.100, 0.125, 0.150, 0.200 mg/mL STS subgroups. Cells in each subgroup were cultured with the corresponding concentration of STS, and cells in control group were cultured in equal volume of serum-free medium. After being cultured for 24 and 48 h, cell morphology was observed with inverted phase contrast microscope; cell proliferation was determined with MTT method and the proliferation inhibition rate (IR) was calculated. After being cultured for 48 h, the protein levels of TGF-ß1 and α-SMA were determined with Western blotting; the mRNA expressions of TGF-ß1 and α-SMA were determined with RT-PCR (no 0.200 mg/mL STS subgroup was set for these two indicators). Data were processed with factorial analysis of variance; differences between groups were processed with LSD test or Games-Howell test for unequal variances. RESULTS: (1) Fbs grew well in control group, but reduction in adherence and disorderly arranged Fbs were observed in experimental group. The cells in experimental group became smaller and round, with increasing intracellular particles and necrosis. A large amount of necrotic debris of cells was observed in 0.200 mg/mL STS subgroup. (2) The absorbance value of Fbs in each experimental subgroup was significantly lower than that in control group (with P values all below 0.01). Along with the increase in the concentration of STS and extension of culture time, the IR value increased, showing a certain degree of time-concentration dependence. After being cultured with STS for 24 and 48 h, IR values of cells in the experimental subgroups were respectively 23.58%, 32.11%, 37.56%, 57.98%, 79.53%, 96.69% and 34.72%, 38.48%, 47.62%, 64.40%, 89.70%, 98.01%. (3) Except for the 0.050 mg/mL STS subgroup, the protein levels of TGF-ß1 and α-SMA in the other subgroups were significantly lower than those in control group (with F values respectively 57.674, 47.795, P values all below 0.001). The protein levels of TGF-ß1 and α-SMA reached the nadir in 0.150 mg/mL STS subgroup, respectively 0.34 ± 0.06, 0.33 ± 0.07. The relative expression amounts of TGF-ß1 and α-SMA mRNA in the experimental subgroups were obviously decreased compared with those in control group (with F values respectively 68.548, 47.522, P values all below 0.001), which was most significant in 0.150 mg/mL STS subgroup, with TGF-ß1 mRNA and α-SMA mRNA respectively 0.39 ± 0.07 and 0.42 ± 0.08. CONCLUSIONS: STS can inhibit the proliferation of Fbs, reduce the protein and mRNA expressions of TGF-ß1 and α-SMA, which may be beneficial to ameliorate the formation and contracture of HS, and it is assumed as a potential drug for treating scars.

Inhibition of vascular endothelial growth factor expression in keloid fibroblasts by vector-mediated vascular endothelial growth factor shRNA: a therapeutic potential strategy for keloid.

Vascular endothelial growth factor (VEGF) plays important roles in the regulation of angiogenesis and inflammation in both pathological and physiological wound repair. Several strategies have been developed for keloid therapy; however, a universally effective treatment has not been explored to date. In this study, three potential short interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into keloid fibroblasts. PGC-VEGF shRNA 2 (short hairpin RNA 2) plasmid significantly inhibited VEGF expression determined by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and fibroblasts growth was also significantly by (methyl thiazolyl tetrazolium) MTT assay and apoptosis detection, whereas the control transfection showed no obviously effects. Plasminogen activator inhibitor-1 (PAI-1) expression in pGC-VEGF shRNA2 group was also obviously downregulated when compared to the pGC-VEGF shRNA negative control and mock group. These results suggest that modulation of VEGF production by vector-based RNAi in keloid fibroblasts may be a therapeutic potential strategy for keloid.

Proliferation hemangiomas formation through dual mechanism of vascular endothelial growth factor mediated endothelial progenitor cells proliferation and mobilization through matrix metalloproteinases 9.

Infantile hemangioma is the most common tumor of infancy and the mechanism leading to proliferation hemangiomas formation is poorly understood and currently no successful treatment modality exists. We hypothesize that EPCs formed during proliferation hemangiomas, as the result of vascular endothelial growth factor (VEGF) stimulation through MMP9, play the major role in the control of cell proliferation and capillary-like vessels production. Accepting the hypothesis to be correct, a therapy that inhibits EPC mobilization and proliferation can be used to prevent the proliferation hemangiomas formation. Current therapies are only partially effective and safe because they could not eliminate all the relative factors of proliferation hemangiomas formation at all, such as: EPCs in the peripheral blood, and at the same time inducing death (apoptosis and necrosis) of other normal cells. A more efficient prevention of proliferation hemangiomas could be achieved using specific drugs or biologic methods that inhibit EPC mobilization and proliferation. Therapy based on gene therapy, capable to specifically inhibit VEGF and MMP9 expression in gene level, can be possibly effective.

[An investigation of bacterial ecology and analysis of bacterial resistance to antibiotics in a burn ward in Nanning district].

OBJECTIVE: To investigate the changes in the bacterial ecology and to analyze the bacterial resistance to antibiotics in a burn ward in Nanning district during the past 15 years, so as to provide reference to the clinical management of burn infection under subtropical climate. METHODS: Five thousand eight hundred and fifty-five strains of bacteria were isolated from the wounds and blood of 2269 burn patients admitted to our hospital from April of 1989 to March of 2004. Kiry-Bauer method was employed for the detection of antibiotic sensitivity test. The bacterial examination and bacterial resistance were analyzed in spans of every five years. RESULTS: Burn patients in our district were mainly infected by the gram negative bacilli (3559 strains, accounting for 60.79%), among which Pseudomonas aeruginosa, Enterobacter cloacae and Nitrate negative bacilli were major ones in every period. Gram positive cocci accounted for 33.99% (1990 strains), which ranked the second, among which Staphylococcus aureus, Staphylococcus epidermidis, and Coagulase negative staphylococci (MRCNS) were the most predominant ones. The bacterial resistance to multiple antibiotics, such as Gentamicin, third generation of Cephalosporin, and Norfloxacin showed a tendency of increase or maintained at high level while the incidence of resistance to Imipenem and Vancomycin was very low. CONCLUSION: The climate and the way of using antibiotics exerted direct effects on the status of the bacterial ecology and change in bacterial resistance to various antibiotics.