Katsouri Loukia, Lim Yau M, Blondrath Katrin, Eleftheriadou Ioanna, Lombardero Laura, Birch Amy M, Mirzaei Nazanin, Irvine Elaine E, Mazarakis Nicholas D, Sastre Magdalena
Division of Brain Sciences, Imperial College London, London W12 0NN, United Kingdom.
Gene Therapy, Division of Brain Sciences, Imperial College London, London W12 0NN, United Kingdom.
Proc Natl Acad Sci U S A. 2016 Oct 25;113(43):12292-12297. doi: 10.1073/pnas.1606171113. Epub 2016 Oct 10.
Current therapies for Alzheimer's disease (AD) are symptomatic and do not target the underlying Aβ pathology and other important hallmarks including neuronal loss. PPARγ-coactivator-1α (PGC-1α) is a cofactor for transcription factors including the peroxisome proliferator-activated receptor-γ (PPARγ), and it is involved in the regulation of metabolic genes, oxidative phosphorylation, and mitochondrial biogenesis. We previously reported that PGC-1α also regulates the transcription of β-APP cleaving enzyme (BACE1), the main enzyme involved in Aβ generation, and its expression is decreased in AD patients. We aimed to explore the potential therapeutic effect of PGC-1α by generating a lentiviral vector to express human PGC-1α and target it by stereotaxic delivery to hippocampus and cortex of APP23 transgenic mice at the preclinical stage of the disease. Four months after injection, APP23 mice treated with hPGC-1α showed improved spatial and recognition memory concomitant with a significant reduction in Aβ deposition, associated with a decrease in BACE1 expression. hPGC-1α overexpression attenuated the levels of proinflammatory cytokines and microglial activation. This effect was accompanied by a marked preservation of pyramidal neurons in the CA3 area and increased expression of neurotrophic factors. The neuroprotective effects were secondary to a reduction in Aβ pathology and neuroinflammation, because wild-type mice receiving the same treatment were unaffected. These results suggest that the selective induction of PGC-1α gene in specific areas of the brain is effective in targeting AD-related neurodegeneration and holds potential as therapeutic intervention for this disease.
目前用于治疗阿尔茨海默病(AD)的疗法只是缓解症状,并未针对潜在的Aβ病理及包括神经元丢失在内的其他重要特征。过氧化物酶体增殖物激活受体γ共激活因子1α(PGC-1α)是包括过氧化物酶体增殖物激活受体γ(PPARγ)在内的转录因子的辅因子,参与代谢基因、氧化磷酸化和线粒体生物发生的调控。我们之前报道过,PGC-1α还可调节β-淀粉样前体蛋白裂解酶(BACE1)的转录,BACE1是参与Aβ生成的主要酶,其在AD患者中的表达会降低。我们旨在通过构建慢病毒载体来表达人PGC-1α,并在疾病的临床前阶段通过立体定位将其递送至APP23转基因小鼠的海马体和皮质,以探索PGC-1α的潜在治疗效果。注射四个月后,接受hPGC-1α治疗的APP23小鼠的空间记忆和识别记忆得到改善,同时Aβ沉积显著减少,这与BACE1表达降低有关。hPGC-1α的过表达减弱了促炎细胞因子的水平和小胶质细胞的激活。这种作用伴随着CA3区锥体神经元的显著保留以及神经营养因子表达的增加。这些神经保护作用继发于Aβ病理和神经炎症的减轻,因为接受相同治疗的野生型小鼠未受影响。这些结果表明,在大脑特定区域选择性诱导PGC-1α基因可有效靶向与AD相关的神经退行性变,具有作为该疾病治疗干预手段的潜力。