Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
Biomaterials. 2012 Nov;33(33):8383-94. doi: 10.1016/j.biomaterials.2012.08.020. Epub 2012 Aug 30.
Autosomal Dominant Polycystic Kidney Disease (ADPKD) remains a major health care concern affecting several million patients worldwide and for which there is no specific treatment. We have employed a 3D tissue engineered disease-like system to emulate cystic structures in vitro and analyzed the extracellular matrix (ECM) interactions in it. The tissue system was developed by culturing normal or polycystin-1 silenced mouse Inner Medullary Collecting Duct (mIMCD) cells in ECM infused into 3D porous silk protein biomaterial scaffolds. In this system, the silk scaffolds provide slow degradation, biocompatibility, and maintain structure and transport for the 3D system, while the ECM molecules retain biological signaling. Using this 3D tissue system we provide evidence for an autocrine signaling loop involving abnormal matrix deposition (collagen type IV and laminin) and its integrin receptor subunit protein (Integrin-β1) in Pkd1 silenced mIMCD cells. In addition, we report that abnormal pericystic ECM interactions between matrix molecules and integrin subunit proteins regulate the rate of cystogenesis in the disease system. Molecular signaling showed abnormalities in cyclin proteins and cell-cycle progression upon Pkd1 knockdown. Importantly, disruption of the abnormal matrix interactions by an additional knockdown (double-silencing) of integrin-β1 in Pkd1 silenced cells reversed the abnormalities and reduced the rate of cystogenesis. Together, these findings indicate that abnormal matrix deposition and altered integrin profile distribution as observed in ADPKD and are critical in cystogenesis and should be considered a target for the development of therapeutics.
常染色体显性多囊肾病（ADPKD）仍然是一个主要的医疗保健问题，影响着全球数百万人，而目前尚无特定的治疗方法。我们采用了 3D 组织工程疾病样系统在体外模拟囊性结构，并分析了其中的细胞外基质（ECM）相互作用。该组织系统是通过在 3D 多孔丝蛋白生物材料支架中培养正常或多囊蛋白-1沉默的小鼠内髓集合管（mIMCD）细胞，并注入 ECM 而开发的。在该系统中，丝支架提供缓慢降解、生物相容性，并为 3D 系统维持结构和转运，而 ECM 分子保留生物信号。使用这种 3D 组织系统，我们为涉及多囊蛋白-1 沉默的 mIMCD 细胞中异常基质沉积（IV 型胶原和层粘连蛋白）及其整联蛋白受体亚基蛋白（Integrin-β1）的自分泌信号环路提供了证据。此外，我们报告称，基质分子和整联蛋白亚基蛋白之间异常的囊周 ECM 相互作用调节疾病系统中囊肿形成的速度。分子信号显示，在 Pkd1 敲低时，细胞周期蛋白蛋白和细胞周期进程出现异常。重要的是，通过在 Pkd1 沉默的细胞中进一步敲低（双重敲低）Integrin-β1 破坏异常基质相互作用，可逆转异常并降低囊肿形成速度。总之，这些发现表明，ADPKD 中观察到的异常基质沉积和整合素谱分布在囊肿形成中至关重要，应将其视为治疗开发的目标。
