Dendrimer-2PMPA selectively blocks upregulated microglial GCPII activity and improves cognition in a mouse model of multiple sclerosis.
Dendrimer-2PMPA selectively blocks upregulated microglial GCPII activity and improves cognition in a mouse model of multiple sclerosis.
复制标题
DOI：
10.7150/ntno.63158
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Slusher BS
中科院分区：
文献类型：
--
作者：
Hollinger KR;Sharma A;Tallon C;Lovell L;Thomas AG;Zhu X;Wiseman R;Wu Y;Kambhampati SP;Liaw K;Sharma R;Rojas C;Rais R;Kannan S;Kannan RM;Slusher BS
认知障碍是多发性硬化症（MS）的一个常见方面，目前尚无治疗方法。降低的脑N-乙酰基谷氨酸盐（NAAG）水平与各种神经系统疾病（包括MS）中的认知受损有关。NAAG水平受谷氨酸羧肽酶II（GCPII）调节，其将神经肽水解为N-乙酰基-天冬氨酸盐和谷氨酸盐。GCPII活性在神经炎症后的小胶质细胞中上调数倍。尽管在临床前研究中，当以高全身剂量或通过直接脑注射给予时，几种GCPII抑制剂（如2-PMPA）可提高脑NAAG水平并恢复认知功能，但由于生物利用度差和脑渗透有限，没有一种在临床上可用。羟基树枝状聚合物已成功地用于选择性地将药物递送到活化的胶质细胞。方法：我们使用点击化学方法将2-PMPA连接到羟基聚酰胺胺（PAMAM）树枝状聚合物（D-2PMPA）上。Cy 5-标记的-D-2PMPA用于在体外和体内可视化选择性神经胶质摄取。在LPS处理的神经胶质培养物中评价D-2PMPA的抗炎作用。在实验性自身免疫性脑脊髓炎（EAE）免疫小鼠中，从疾病发作开始每两周给药一次D-2 PMPA，并使用巴恩斯迷宫评估认知，并在CD 11 b+海马细胞中测量GCPII活性。结果如下：D-2PMPA显示优先摄取到小胶质细胞中，并具有强大的抗炎活性，包括神经胶质细胞培养物中NAAG、TGFβ和mGluR 3的升高。D-2PMPA显著改善EAE小鼠的认知，即使身体严重程度不受影响。GCPII活性在来自EAE小鼠的CD 11b+细胞中增加>20倍，这被D-2PMPA治疗显著减轻。结论：羟基树枝状聚合物有助于靶向药物输送到活化的小胶质细胞。这些数据支持进一步开发D-2PMPA以减弱升高的小胶质细胞GCPII活性并治疗MS中的认知障碍。
Cognitive impairment is a common aspect of multiple sclerosis (MS) for which there are no treatments. Reduced brain N-acetylaspartylglutamate (NAAG) levels are linked to impaired cognition in various neurological diseases, including MS. NAAG levels are regulated by glutamate carboxypeptidase II (GCPII), which hydrolyzes the neuropeptide to N-acetyl-aspartate and glutamate. GCPII activity is upregulated multifold in microglia following neuroinflammation. Although several GCPII inhibitors, such as 2-PMPA, elevate brain NAAG levels and restore cognitive function in preclinical studies when given at high systemic doses or via direct brain injection, none are clinically available due to poor bioavailability and limited brain penetration. Hydroxyl-dendrimers have been successfully used to selectively deliver drugs to activated glia. Methods: We attached 2-PMPA to hydroxyl polyamidoamine (PAMAM) dendrimers (D-2PMPA) using a click chemistry approach. Cy5-labelled-D-2PMPA was used to visualize selective glial uptake in vitro and in vivo. D-2PMPA was evaluated for anti-inflammatory effects in LPS-treated glial cultures. In experimental autoimmune encephalomyelitis (EAE)-immunized mice, D-2PMPA was dosed biweekly starting at disease onset and cognition was assessed using the Barnes maze, and GCPII activity was measured in CD11b+ hippocampal cells. Results: D-2PMPA showed preferential uptake into microglia and robust anti-inflammatory activity, including elevations in NAAG, TGFβ, and mGluR3 in glial cultures. D-2PMPA significantly improved cognition in EAE mice, even though physical severity was unaffected. GCPII activity increased >20-fold in CD11b+ cells from EAE mice, which was significantly mitigated by D-2PMPA treatment. Conclusions: Hydroxyl dendrimers facilitate targeted drug delivery to activated microglia. These data support further development of D-2PMPA to attenuate elevated microglial GCPII activity and treat cognitive impairment in MS.