Department of Pharmacology, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China Departments of Behavioral Medicine & Psychiatry and Physiology & Pharmacology, West Virginia University Health Sciences Center, Morgantown, WV, USA.
J Alzheimers Dis. 2014;38(2):269-80. doi: 10.3233/JAD-122236.
Phosphodiesterase-4 (PDE4) inhibitors enhance memory, increase hippocampal neurogenesis, and reverse amyloid-β (Aβ)-induced memory deficits. Here, we examined whether long-form PDE4D knockdown by lentiviral RNA construct containing a specific microRNA/miRNA-mir hairpin structure (4DmiRNA) reversed memory impairment caused by amyloid-β1-42 (Aβ42) in mice using the Morris water maze (MWM) and novelty object recognition tests. Western blotting analysis was used to assess protein levels of cAMP response element-binding protein (CREB, unphosphorylated and phosphorylated [pCREB]), brain-derived neurotrophic factor (BDNF), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB) to explore the neurochemical mechanisms. Aggregated Aβ42 (0.5 μg/side) bilaterally infused in dentate gyrus decreased cAMP levels (p < 0.01) and produced memory deficits in the MWM (p < 0.01) and object recognition tests (p < 0.01). Microinfusions of lentiviruses resulted in downregulated expression of PDE4D4 and 4D5 proteins and reversed Aβ42-induced cAMP decline (p < 0.05) and memory deficits. Treatment also concomitantly increased pCREB (p < 0.05) and BDNF (p < 0.01) and reduced IL-1β (p < 0.05), TNF-α (p < 0.01), and NF-κB (p65) (p < 0.05) in the hippocampus of Aβ42-challenged mice. These results suggest that long-form PDE4D knockdown may offer a promising treatment for memory loss associated with Alzheimer's disease.
磷酸二酯酶 4（PDE4）抑制剂可增强记忆、增加海马神经发生并逆转淀粉样β（Aβ）诱导的记忆障碍。在这里，我们通过 Morris 水迷宫（MWM）和新颖物体识别测试，使用含有特定 microRNA/miRNA 发夹结构（4DmiRNA）的慢病毒 RNA 构建体检查长形式 PDE4D 的敲低是否逆转了淀粉样β 1-42（Aβ42）引起的小鼠记忆障碍。Western blot 分析用于评估 cAMP 反应元件结合蛋白（CREB，未磷酸化和磷酸化[pCREB]）、脑源性神经营养因子（BDNF）、白细胞介素 1β（IL-1β）、肿瘤坏死因子-α（TNF-α）和核因子-κB（NF-κB）的蛋白水平，以探讨神经化学机制。双侧齿状回内注射聚集的 Aβ42（0.5 μg/侧）降低了 cAMP 水平（p<0.01），并在 MWM（p<0.01）和物体识别测试（p<0.01）中产生了记忆障碍。慢病毒的微注射导致 PDE4D4 和 4D5 蛋白的表达下调，并逆转了 Aβ42 诱导的 cAMP 下降（p<0.05）和记忆障碍。治疗还同时增加了 pCREB（p<0.05）和 BDNF（p<0.01），并减少了海马中的 IL-1β（p<0.05）、TNF-α（p<0.01）和 NF-κB（p65）（p<0.05）在 Aβ42 挑战的小鼠中。这些结果表明，长形式 PDE4D 的敲低可能为与阿尔茨海默病相关的记忆丧失提供有希望的治疗方法。
