微囊化基因工程耳蜗前体细胞移植对噪声性耳聋的作用及相关机制研究

Facing the growing incidence of noise-induced hearing loss, a common trouble in modern medicine, man has made no breakthroughs in its treatment. Stem cell transplantation is considered as a hot spot in current otology, but limit progress has been made. We have demonstrated that cochlear pregenitor cells can differentiate into cochlear cells easily, and the cell proliferation can be promoted by regulate factors like cyclinA2 and c-myc. On the basis of these data, we are scheduling to transfect cyclinA2 and c-myc genes into rat cochlear pregenitor cells with adenovirus, so as to promote cell proliferation and enter mitosis. Then these cells are encapsulated and transplanted into the cochlea of guinea pig in order to investigate the follows: whether the genetic engineering cells will secret nutritional factors to repair the injured cochlear cells; whether the capsule-broken cells will differentiate into cochlear cells to replace the missed cells. Taken together, their rehabilitation effects for cochlear cells will be evaluated from morphology and auditory electrophysiology, and the mechanism will be explored further. Basing on the technology of both genetic engineering and tissue engineering, our project tries to investigate an innovative approach to cure noise-induced hearing loss through promoting the regeneration of hair cells and spiral ganglion neurons.

噪声性耳聋的发病率逐年上升却无特效的治疗方法，因而成为现代医学中常见的棘手问题。基于干细胞耳蜗移植的细胞治疗策略是耳科学的研究热点，但一直未有突破性进展。我们的前期工作表明，耳蜗前体细胞具有较强的向耳蜗细胞定向分化的能力；此外，应用细胞周期正性调控因子cyclinA2和c-myc可促其增殖，克服增殖能力弱的劣势。在此基础上，本研究拟利用腺病毒载体转染cyclinA2和c-myc基因，促进大鼠耳蜗前体细胞体外增殖、进入有丝分裂期，之后采用微囊化技术将其包裹并移植入噪声性耳聋的豚鼠耳蜗模型，观察微囊化基因工程耳蜗前体细胞在破囊前能否分泌干细胞营养因子修复耳蜗损伤细胞；在破囊后能否定向分化替代耳蜗缺失细胞；从形态学与听觉电生理等方面评价在噪声条件下其对耳蜗细胞的治疗修复作用，进而探索其作用机制。本课题为在医学上解决噪声性耳聋治疗过程中的毛细胞、螺旋神经节再生问题提供一种全新的思路和方法。

噪声性耳聋的发病率逐年上升却无特效的治疗方法，因而成为现代医学中常见的棘手问题。基于干细胞耳蜗移植的细胞治疗策略是耳科学的研究热点，但一直未有突破性进展。我们的前期工作表明，耳蜗前体细胞具有较强的向耳蜗细胞定向分化的能力；但是这类细胞的缺点是增殖能力弱。我们利用腺病毒载体转染细胞周期正性调控因子cyclinA2和c-myc基因，促进大鼠耳蜗前体细胞体外增殖、进入有丝分裂期，促进部分前体细胞从静止期重新返回细胞周期，初步研究其调控机制，表明为经典的 CKI-cyclin-CDK 途径。克服了耳蜗前体细胞增殖能力弱的劣势后，我们应用微囊化技术将其包裹并移植入噪声性耳聋的豚鼠耳蜗模型，观察微囊化基因工程耳蜗前体细胞能否定植于耳蜗并定向分化替代耳蜗缺失细胞；从形态学方面评价在噪声条件下其对耳蜗细胞的治疗修复作用，进而探索其作用机制。本课题为在医学上解决噪声性耳聋治疗过程中的毛细胞、螺旋神经节再生问题提供一种全新的思路和方法。