Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198-5850, USA.
Biomaterials. 2010 Jul;31(19):5218-26. doi: 10.1016/j.biomaterials.2010.03.026. Epub 2010 Apr 7.
Adenoviral-mediated overexpression of the intracellular superoxide (O(2)(-)) scavenging enzyme copper/zinc superoxide dismutase (CuZnSOD) in the brain attenuates central angiotensin II (AngII)-induced cardiovascular responses. However, the therapeutic potential for adenoviral vectors is weakened by toxicity and the inability of adenoviral vectors to target the brain following peripheral administration. Therefore, we developed a non-viral delivery system in which CuZnSOD protein is electrostatically bound to a synthetic poly(ethyleneimine)-poly(ethyleneglycol) (PEI-PEG) polymer to form a polyion complex (CuZnSOD nanozyme). We hypothesized that PEI-PEG polymer increases transport of functional CuZnSOD to neurons, which inhibits AngII intra-neuronal signaling. The AngII-induced increase in O(2)(-), as measured by dihydroethidium fluorescence and electron paramagnetic resonance spectroscopy, was significantly inhibited in CuZnSOD nanozyme-treated neurons compared to free CuZnSOD- and non-treated neurons. CuZnSOD nanozyme also attenuated the AngII-induced inhibition of K(+) current in neurons. Intracarotid injection of CuZnSOD nanozyme into rabbits significantly inhibited the pressor response of intracerebroventricular-delivered AngII; however, intracarotid injection of free CuZnSOD or PEI-PEG polymer alone failed to inhibit this response. Importantly, neither the PEI-PEG polymer alone nor the CuZnSOD nanozyme induced neuronal toxicity. These findings indicate that CuZnSOD nanozyme inhibits AngII intra-neuronal signaling in vitro and in vivo.
腺病毒介导的脑内细胞内超氧阴离子（O2(-)）清除酶铜/锌超氧化物歧化酶（CuZnSOD）过表达可减轻中枢血管紧张素 II（AngII）引起的心血管反应。然而，腺病毒载体的治疗潜力因毒性和腺病毒载体在周围给药后不能靶向大脑而减弱。因此，我们开发了一种非病毒递送系统，其中 CuZnSOD 蛋白通过静电结合到合成的聚（亚乙基亚胺）-聚（乙二醇）（PEI-PEG）聚合物上，形成聚离子复合物（CuZnSOD 纳米酶）。我们假设 PEI-PEG 聚合物增加了功能性 CuZnSOD 向神经元的转运，从而抑制了 AngII 神经元内信号。与游离 CuZnSOD 和未经处理的神经元相比，用 CuZnSOD 纳米酶处理的神经元中，由二氢乙啶荧光和电子顺磁共振波谱测量的 AngII 诱导的 O2(-)增加显著受到抑制。CuZnSOD 纳米酶还抑制了 AngII 诱导的神经元中 K(+)电流的抑制。将 CuZnSOD 纳米酶经颈动脉内注射到兔体内，可显著抑制脑室内给予的 AngII 引起的升压反应；然而，单独颈动脉内注射游离 CuZnSOD 或 PEI-PEG 聚合物均不能抑制这种反应。重要的是，PEI-PEG 聚合物单独或 CuZnSOD 纳米酶本身均不会引起神经元毒性。这些发现表明，CuZnSOD 纳米酶在体外和体内抑制 AngII 神经元内信号。
