Department of Urology, Hunan Cancer Hospital, The Affiliated Cancer Hospital of Xiangya Medical College, Central South University, Changsha, Hunan 410013, P.R. China.
School of Life Sciences, Hunan Normal University, Changsha, Hunan 410006, P.R. China.
Mol Med Rep. 2018 Feb;17(2):2341-2348. doi: 10.3892/mmr.2017.8168. Epub 2017 Nov 27.
Tissue engineering technology offers an appealing approach for tissue reconstruction of the urothelium. Adipose‑derived mesenchymal stem cells (ADSCs) represent an abundant source for tissue engineering applications. However, ASCs primarily possess mesoderm lineage differentiation potential. It is difficult to induce differentiation of ASCs towards urothelial cells that are derived from the endoderm, although a recent findings have reported that a conditioned medium may drive ADSCs towards differentiation into the urothelium phenotype. In the present study, human ADSCs were isolated from abdominal adipose tissues and incubated in this conditioned medium for indicated time periods. Western blotting showed that protein expression levels of urothelial specific marks, including CK7, CK20 and UPIII, were increased after seven days' incubation, but immunofluorescence microscopy determined that cells with CK7 and UPIII staining were scarce, which suggested a low‑efficiency for the differentiation. Prolonging the incubation time did not further increase CK20 and UPIII expression. Furthermore, miR‑33a expression was increased with ADSC differentiation. Using synthetic miRNAs to mimic or inhibit the action of miR‑33a revealed that miR‑33a hinders the differentiation of ADSCs towards urothelial cells. Furthermore, luciferase reporter assay confirmed that β‑catenin and transforming growth factor‑β receptor (TGFR) are targets of miR‑33a. Inhibition of miR‑33a expression increased β‑catenin and TGFR expression and improved the efficiency of ADSCs towards differentiation into the urothelium phenotype. The present novel finding suggests that miR‑33 may be an important target in tissue engineering and regenerative medicine for urothelium repair.
组织工程技术为尿路上皮组织重建提供了一种有吸引力的方法。脂肪来源间充质干细胞（ADSCs）是组织工程应用的丰富来源。然而，ADSCs 主要具有中胚层谱系分化潜能。尽管最近的研究结果表明，条件培养基可能会促使 ADSC 向尿路上皮细胞分化，但诱导 ADSC 向源自内胚层的尿路上皮细胞分化仍然具有一定的难度。在本研究中，从腹部脂肪组织中分离出人 ADSC，并在该条件培养基中孵育指定时间。Western blot 结果显示，在孵育 7 天后，尿路上皮特异性标志物 CK7、CK20 和 UPIII 的蛋白表达水平增加，但免疫荧光显微镜检测到 CK7 和 UPIII 染色的细胞很少，这表明分化效率较低。延长孵育时间不会进一步增加 CK20 和 UPIII 的表达。此外，miR-33a 的表达随着 ADSC 分化而增加。使用合成 miRNA 模拟或抑制 miR-33a 的作用表明，miR-33a 阻碍 ADSC 向尿路上皮细胞分化。此外，荧光素酶报告基因检测证实 β-连环蛋白和转化生长因子-β受体（TGFR）是 miR-33a 的靶标。抑制 miR-33a 的表达增加了 β-连环蛋白和 TGFR 的表达，提高了 ADSC 向尿路上皮细胞分化的效率。本研究的新发现表明，miR-33 可能是尿路上皮修复组织工程和再生医学中的一个重要靶点。
