Wu H Y, Baskin L S, Liu W, Li Y W, Hayward S, Cunha G R
Department of Urology, University of California-San Francisco, USA.
J Urol. 1999 Sep;162(3 Pt 2):1101-5. doi: 10.1016/S0022-5347(01)68082-0.
We determined the origin of smooth muscle cells in acellular bladder matrix grafts.
A total of 15 female Sprague-Dawley rats underwent partial cystectomy and grafting with an acellular matrix derived from rat bladder. The grafts were examined 1, 2, 3 and 4 weeks after grafting by immunohistochemical studies for smooth muscle markers and by transmission electron microscopy for smooth muscle morphology. Bladder matrix and bladder epithelium recombinants were created and grafted subcutaneously and under the renal capsule in nude mice. Recombinants were examined 1, 2, 3 and 4 weeks postoperatively by immunohistochemical studies for bladder epithelium and bladder smooth muscle.
Smooth muscle ingrowth into acellular matrix was initially seen at 2 weeks. The immunohistochemical and electron microscopic characteristics of the cells were similar to those of fetal smooth muscle 2 weeks and newborn smooth muscle 4 weeks after grafting. Matrix epithelium recombinants displayed mature bladder epithelium with 3 to 7 layers but they did not support the ingrowth of smooth muscle cells.
Mature bladder smooth muscle cells undergo dedifferentiation, migration and redifferentiation to repopulate an acellular matrix graft. It is unlikely that adult fibroblasts from the surrounding tissue are induced by epithelium and matrix to form smooth muscle. The contractile behavior of bladder substitute materials likely reflects the properties of the host bladder.
我们确定了脱细胞膀胱基质移植物中平滑肌细胞的来源。
总共15只雌性Sprague-Dawley大鼠接受了部分膀胱切除术，并用源自大鼠膀胱的脱细胞基质进行移植。在移植后1、2、3和4周，通过免疫组织化学研究检测移植物中的平滑肌标志物，并通过透射电子显微镜观察平滑肌形态。制备膀胱基质和膀胱上皮重组体，并将其皮下和肾包膜下移植到裸鼠体内。术后1、2、3和4周通过免疫组织化学研究检测重组体中的膀胱上皮和膀胱平滑肌。
在2周时首次观察到平滑肌长入脱细胞基质。移植后2周时，这些细胞的免疫组织化学和电子显微镜特征与胎儿平滑肌相似，4周时与新生平滑肌相似。基质上皮重组体显示出具有3至7层的成熟膀胱上皮，但它们不支持平滑肌细胞的长入。
成熟的膀胱平滑肌细胞经历去分化、迁移和再分化，以重新填充脱细胞基质移植物。周围组织中的成年成纤维细胞不太可能被上皮和基质诱导形成平滑肌。膀胱替代材料的收缩行为可能反映了宿主膀胱的特性。
