Jeon Hui-Jeon, Byun Jun-Kyu, Lee Sang Bong, Son Kwang Hee, Lim Ji-Youn, Lee Da Sol, Kim Kil Soo, Park Jin Woo, Shin Gyeong Rim, Kim Ye Jin, Jin Jonghwa, Kim Daehoon, Kim Dong-Ho, Yu Ji Hoon, Choi Yeon-Kyung, Park Keun-Gyu, Jeon Yong Hyun
New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation (KMEDIhub), 80 Chembok-Ro, Daegu, 41061, South Korea.
BK21 FOUR Community-Based Intelligent Novel Drug Discovery Education Unit, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Kyungpook National University, Daegu, 41566, South Korea.
Cell Biosci. 2023 Mar 30;13(1):69. doi: 10.1186/s13578-023-01007-5.
N-methyl-D-aspartate receptors (NMDARs) are considered to be involved in several physiological and pathophysiological processes in addition to the progression of neurological disorders. However, how NMDARs are involved in the glycolytic phenotype of M1 macrophage polarization and the possibility of using them as a bio-imaging probe for macrophage-mediated inflammation remain unclear.
We analyzed cellular responses to NMDAR antagonism and small interfering RNAs using mouse bone marrow-derived macrophages (BMDMs) treated with lipopolysaccharide (LPS). An NMDAR targeting imaging probe, N-TIP, was produced via the introduction of NMDAR antibody and the infrared fluorescent dye FSD Fluor™ 647. N-TIP binding efficiency was tested in intact and LPS-stimulated BMDMs. N-TIP was intravenously administered to mice with carrageenan (CG)- and LPS-induced paw edema, and in vivo fluorescence imaging was conducted. The anti-inflammatory effects of dexamethasone were evaluated using the N-TIP-mediated macrophage imaging technique.
NMDARs were overexpressed in LPS-treated macrophages, subsequently inducing M1 macrophage polarization. Mechanistically, NMDAR-mediated Ca accumulation resulted in LPS-stimulated glycolysis via upregulation of PI3K/AKT/mTORC1 signaling. In vivo fluorescence imaging with N-TIP showed LPS- and CG-induced inflamed lesions at 5 h post-inflammation, and the inflamed lesions could be detected until 24 h. Furthermore, our N-TIP-mediated macrophage imaging technique helped successfully visualize the anti-inflammatory effects of dexamethasone in mice with inflammation.
This study demonstrates that NMDAR-mediated glycolysis plays a critical role in M1 macrophage-related inflammation. Moreover, our results suggest that NMDAR targeting imaging probe may be useful in research on inflammatory response in vivo.
N-甲基-D-天冬氨酸受体（NMDARs）除了参与神经疾病进展外，还被认为参与多种生理和病理生理过程。然而，NMDARs如何参与M1巨噬细胞极化的糖酵解表型以及将其用作巨噬细胞介导炎症的生物成像探针的可能性仍不清楚。
我们使用经脂多糖（LPS）处理的小鼠骨髓来源巨噬细胞（BMDMs）分析了细胞对NMDAR拮抗作用和小干扰RNA的反应。通过引入NMDAR抗体和红外荧光染料FSD Fluor™ 647制备了靶向NMDAR的成像探针N-TIP。在完整的和LPS刺激的BMDMs中测试了N-TIP的结合效率。将N-TIP静脉注射到角叉菜胶（CG）和LPS诱导爪肿胀的小鼠体内，并进行体内荧光成像。使用N-TIP介导的巨噬细胞成像技术评估地塞米松的抗炎作用。
NMDARs在LPS处理的巨噬细胞中过表达，随后诱导M1巨噬细胞极化。机制上，NMDAR介导的钙积累通过上调PI3K/AKT/mTORC1信号导致LPS刺激的糖酵解。用N-TIP进行的体内荧光成像显示在炎症后5小时出现LPS和CG诱导的炎症病变，并且炎症病变可持续检测到24小时。此外，我们的N-TIP介导的巨噬细胞成像技术有助于成功观察到地塞米松对炎症小鼠的抗炎作用。
本研究表明NMDAR介导的糖酵解在M1巨噬细胞相关炎症中起关键作用。此外，我们的结果表明靶向NMDAR的成像探针可能有助于体内炎症反应的研究。
