Objective: To explore the effects of porcine urinary bladder matrix (UBM) on the motility and polarization of bone marrow-derived macrophages in mice, so as to provide evidence for the rational selection of stent in clinical wound repair. Methods: The method of experimental research was used. The microstructure of porcine UBM and absorbable dressing was observed under scanning electron microscope. Polyacrylamide gel electrophoresis was used to observe the protein distribution of the two stent extracts. The primary macrophages were induced from bone marrow-derived cells isolated from six 6-8-week-old male C57BL/6J mice (mouse age, sex, and strain, the same below) and identified. Three batches of macrophages were divided into porcine UBM extract group and absorbable dressing extract group. The cells in each group were cultured with Dulbecco's modified Eagle medium/F12 medium containing the corresponding extracts. The cell migration rate was detected and calculated on 1, 3, and 7 d after scratching by scratch test. The number of migrated cells at 12 and 24 h of culture was detected by Transwell experiment. The percentages of CD206 and CD86 positive cells at 24 h of culture was detected by flow cytometer. The numbers of sample in the above cell experiments were all 3. An incision was prepared on the left and right back of twelve mice, respectively. The left incision of each mouse was included in porcine UBM group and the right incision was included in absorbable dressing group, and the corresponding stents were implanted into the incisions respectively. On post operation day (POD) 7 and 14, the number of inflammatory cells infiltrated in the stent was detected by hematoxylin-eosin staining; the number of F4/80, transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), and matrix metalloprotein-9 (MMP-9) positive cells and type Ⅰ collagen deposition in stents were observed by immunohistochemistry; the percentages of F4/80, CD86, and CD206 positive cells were observed by immunofluorescence staining. The numbers of sample in the above animal experiments were all 6. Data were statistically analyzed with analysis of variance for factorial design, analysis of variance for repeated measurement, and independent sample t test. Results: Porcine UBM has a dense basement membrane structure on one side and porous propria containing a fibrous structures on the other. Both sides of the absorbable dressing had three-dimensional porous structure. In the molecular weight range of (50-70)×103, multiple non-type Ⅰ collagen bands appeared in the lanes of porcine UBM extract, while no obvious bands appeared in the lanes of absorbable dressing extract. It had been identified that mouse bone marrow-derived cells had been successfully induced into macrophages. The cell migration rates in porcine UBM extract group were significantly higher than those in absorbable dressing extract group on 1, 3, and 7 d after scratching (with t values of 15.31, 19.76, and 20.58, respectively, P<0.05). The numbers of migrated cells in porcine UBM extract group were significantly more than those in absorbable dressing extract group at 12 and 24 h of culture (with t values of 12.20 and 33.26, respectively, P<0.05). At 24 h of culture, the percentage of CD86 positive cells in porcine UBM extract group ((1.27±0.19)%) was significantly lower than (7.34±0.14)% in absorbable dressing extract group (t=17.03, P<0.05);the percentage of CD206 positive cells in porcine UBM extract group was (73.4±0.7)%, significantly higher than (32.2±0.5)% in absorbable dressing extract group (t=119.10, P<0.05). On POD 7 and 14, the numbers of inflammatory cells infiltrated in the stents in porcine UBM group was significantly more than those in absorbable dressing group (with t values of 6.58 and 10.70, respectively, P<0.05). On POD 7 and 14, the numbers of F4/80, TGF-β1, VEGF, and MMP-9 positive cells in the stents in porcine UBM group were significantly more than those in absorbable dressing group (with t values of 46.11, 40.69, 13.90, 14.15, 19.79, 32.93, 12.16, and 13.21, respectively, P<0.05); type Ⅰ collagen deposition in the stents in porcine UBM group was more pronounced than that in absorbable dressing group; the percentages of CD206 positive cells in the stents in porcine UBM group were significantly higher than those in absorbable dressing group (with t values of 5.05 and 4.13, respectively, P<0.05), while the percentages of CD86 positive cells were significantly lower than those in absorbable dressing group (with t values of 20.90 and 19.64, respectively, P<0.05), and more M2-type macrophages were seen in the stents in porcine UBM group and more M1-type macrophages were seen in the stents in absorbable dressing group. Conclusions: Porcine UBM can enhance macrophage motility, induce M2 polarization and paracrine function, create a microenvironment containing growth factors such as TGF-β1 and MMP-9 tissue remodeling molecules, and promote tissue regeneration and extracellular matrix remodeling in mice.
目的： 探讨猪膀胱脱细胞基质（UBM）对小鼠骨髓源巨噬细胞的运动和极化情况的影响，为临床创面修复中支架的合理选用提供依据。 方法： 采用实验研究方法。采用扫描电子显微镜观察猪UBM和可吸收敷料的微观结构。采用聚丙烯酰胺凝胶电泳观察2种支架浸提液的蛋白质分布。取6只6~8周龄雄性C57BL/6J小鼠（小鼠周龄、性别、品系下同）并提取骨髓源细胞后诱导原代巨噬细胞并鉴定。取3批次巨噬细胞，均分为猪UBM浸提液组和可吸收敷料浸提液组，加入含有相应浸提液的DMEM/F12培养基培养，行划痕试验检测并计算划痕后1、3、7 d的细胞迁移率；行Transwell实验检测培养12、24 h的细胞迁移数量；培养24 h，采用流式细胞仪检测CD206或CD86阳性细胞百分比。以上细胞实验样本数均为3。取12只小鼠，于每只小鼠背部左右两侧各制作1个切口，左侧切口纳入猪UBM组、右侧切口纳入可吸收敷料组，分别植入相应支架。术后7、14 d，行苏木精-伊红染色观测支架中浸润的炎症细胞数量，采用免疫组织化学法观测支架中F4/80、转化生长因子β1（TGF-β1）、血管内皮生长因子（VEGF）和基质金属蛋白酶9（MMP-9）阳性细胞数量和Ⅰ型胶原蛋白沉积情况，采用免疫荧光染色检测F4/80、CD86、CD206阳性细胞百分比。以上动物实验样本数均为6。对数据行析因设计方差分析、重复测量方差分析、独立样本t检验。 结果： 猪UBM的一面为致密的基底膜结构，另一面为含有纤维结构的多孔固有层。可吸收敷料的两面均呈三维多孔结构。在（50~70）×103的分子量区间，猪UBM浸提液的泳道出现多条非Ⅰ型胶原蛋白条带，可吸收敷料浸提液的泳道中未出现明显条带。经鉴定，小鼠骨髓源细胞已被成功诱导为巨噬细胞。划痕后1、3、7 d，猪UBM浸提液组细胞迁移率均明显高于可吸收敷料浸提液组（t值分别为15.31、19.76、20.58，P<0.05）。培养12、24 h，猪UBM浸提液组细胞迁移数量均明显多于可吸收敷料浸提液组（t值分别为12.20、33.26，P<0.05）。培养24 h，猪UBM浸提液组细胞中CD86阳性细胞百分比为（1.27±0.19）%，明显低于可吸收敷料浸提液组的（7.34±0.14）%（t=17.03，P<0.05）；猪UBM浸提液组细胞中CD206阳性细胞百分比为（73.4±0.7）%，明显高于可吸收敷料浸提液组的（32.2±0.5）%（t=119.10，P<0.05）。术后7、14 d，猪UBM组支架中浸润的炎症细胞数量均明显多于可吸收敷料组（t值分别为6.58、10.70，P<0.05）；猪UBM组支架中F4/80、TGF-β1、VEGF和MMP-9阳性细胞数量均明显多于可吸收敷料组（t值分别为46.11、40.69、13.90、14.15，19.79、32.93、12.16、13.21，P<0.05）；猪UBM组支架中Ⅰ型胶原蛋白沉积较可吸收敷料组更显著；猪UBM组支架中CD206阳性细胞百分比均明显高于可吸收敷料组（t值分别为5.05、4.13，P<0.05），CD86阳性细胞百分比均明显低于可吸收敷料组（t值分别为20.90、19.64，P<0.05），猪UBM组支架中可见更多的M2型巨噬细胞、可吸收敷料组支架中可见更多的M1型巨噬细胞。 结论： 猪UBM可增强小鼠巨噬细胞运动，诱导其发生M2型极化和发挥旁分泌功能，营造含有TGF-β1等生长因子和MMP-9组织重塑分子的微环境，促进组织新生和细胞外基质重塑。.