[Expression and effect of microRNA-296 in rabbit hypertrophic scar].

Objective: To investigate the expression and effect of microRNA-296 (miR-296) in rabbit hypertrophic scar. Methods: The experimental method was used. Twelve healthy adult New Zealand long-eared rabbits were divided into normal control group and scar group, with 6 rabbits in each group. The hypertrophic scar model of long-eared rabbit was made according to the literature, and the rats in normal control group were subjected to no disposal. At 60 days after modeling, hematoxylin eosin(HE) staining was used to detect the morphology of skin tissue cells in the two groups. The mRNA expressions of miR-296 and transforming growth factor-s1(TGF-s1) were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction. Human fibroblasts (HFbs) were divided into psiCHECK-WT-TGF-s1+miR-296 negative control group, psiCHECK-WT-TGF-s1+miR-296 mimic group, psiCHECK-MUT-TGF-s1+miR-296 negative control group, and psiCHECK-MUT-TGF-s1+miR-296 mimic group. And the corresponding sequence were transfected respectively. At 48 h after transfection, luciferase reporter gene detection kit was used to detect the luciferase and renal luciferase expression of miR-296 and TGF-s1 in each group, and the ratio was used to reflect the gene expression level. Two batches of HFbs were used and divided into miR-296 negative control group and miR-296 mimic group, transfecting the corresponding sequence. The first batch of cells were used. At 0 (immediately), 12, 24, 36 and 48 h after transfection, the cell proliferation was detected by thiazolyl blue method. The second batch of cells were used. At 24 h after transfection, the expression of TGF-s1 and collagen type I was detected by Western blotting. The number of samples in cell experiment was 3. Data were statistically analyzed with analysis of variance factorial design, one-way analysis of variance, independent-samples t test, LSD-t test and Pearson correlation coefficient regression. Results: At 60 days after modeling, Fbs in scar group were hyperplastic and arranged abnormally; Fbs in normal control group were evenly arranged without morphological abnormality. The mRNA expression of miR-296 in scar group(0.652±0.107) was significantly lower than that in normal control group(1.192±0.121, t=5.175, P<0.01). The mRNA expression of TGF-s1 in scar group(1.467±0.065) was significantly higher than that in normal control group(1.105±0.030, t=12.410, P<0.01). Pearson correlation coefficient analysis showed that there was a negative correlation between the mRNA expression of miR-296 and TGF-s1(F=7.278, P<0.05), and the equation was y=-1.151x+2.066, R2=0.421. At 48 h after transfection, the expression of TGF-s1 luciferase / renal luciferase in psiCHECK-WT-TGF-s1+ miR-296 mimic group was significantly lower than that in psiCHECK-WT-TGF-s1 + miR-296 negative control group(t=35.190, P<0.01). At 12, 24, 36 and 48 h after transfection, the HFbs proliferation ability in miR-296 mimic group were significantly lower than that in miR-296 negative control group(t=3.275a€11.980a€10.460a€17.260i¼ŒP<0.05 or P<0.01). At 24 h after transfection, the protein expression of TGF-s1 and type I collagen in negative control group was significantly higher than that in miR-296 mimic group(t=3.758, 29.390, P<0.05 or P<0.01). Conclusions: miR-296 expression in rabbit hypertrophic scars is down-regulated; miR-296 can inhibit the proliferation of HFbs and the expression of type I collagen by down regulating the expression of TGF-s1.