Meloni Bruno P, Brookes Laura M, Clark Vince W, Cross Jane L, Edwards Adam B, Anderton Ryan S, Hopkins Richard M, Hoffmann Katrin, Knuckey Neville W
1] Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Western Australia, Australia [2] Department of Neurosurgery, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Western Australia, Australia [3] Western Australian Neuroscience Research Institute, Nedlands, Western Australia, Australia.
1] Western Australian Neuroscience Research Institute, Nedlands, Western Australia, Australia [2] School of Heath Sciences, The University Notre Dame, Fremantle, Western Australia, Australia.
J Cereb Blood Flow Metab. 2015 Jun;35(6):993-1004. doi: 10.1038/jcbfm.2015.11. Epub 2015 Feb 11.
Using cortical neuronal cultures and glutamic acid excitotoxicity and oxygen-glucose deprivation (OGD) stroke models, we demonstrated that poly-arginine and arginine-rich cell-penetrating peptides (CPPs), are highly neuroprotective, with efficacy increasing with increasing arginine content, have the capacity to reduce glutamic acid-induced neuronal calcium influx and require heparan sulfate preotoglycan-mediated endocytosis to induce a neuroprotective effect. Furthermore, neuroprotection could be induced with immediate peptide treatment or treatment up to 2 to 4 hours before glutamic acid excitotoxicity or OGD, and with poly-arginine-9 (R9) when administered intravenously after stroke onset in a rat model. In contrast, the JNKI-1 peptide when fused to the (non-arginine) kFGF CPP, which does not rely on endocytosis for uptake, was not neuroprotective in the glutamic acid model; the kFGF peptide was also ineffective. Similarly, positively charged poly-lysine-10 (K10) and R9 fused to the negatively charged poly-glutamic acid-9 (E9) peptide (R9/E9) displayed minimal neuroprotection after excitotoxicity. These results indicate that peptide positive charge and arginine residues are critical for neuroprotection, and have led us to hypothesize that peptide-induced endocytic internalization of ion channels is a potential mechanism of action. The findings also question the mode of action of different neuroprotective peptides fused to arginine-rich CPPs.
利用皮质神经元培养物以及谷氨酸兴奋性毒性和氧糖剥夺（OGD）中风模型，我们证明了聚精氨酸和富含精氨酸的细胞穿透肽（CPPs）具有高度神经保护作用，其功效随着精氨酸含量的增加而增强，能够减少谷氨酸诱导的神经元钙内流，并且需要硫酸乙酰肝素蛋白聚糖介导的内吞作用来诱导神经保护作用。此外，在谷氨酸兴奋性毒性或OGD之前立即进行肽处理或在2至4小时内进行处理，以及在大鼠模型中风发作后静脉注射聚精氨酸-9（R9）均可诱导神经保护作用。相比之下，与（非精氨酸）kFGF CPP融合的JNKI-1肽在谷氨酸模型中不具有神经保护作用，因为其摄取不依赖内吞作用；kFGF肽同样无效。类似地，带正电荷的聚赖氨酸-10（K10）与带负电荷的聚谷氨酸-9（E9）肽融合的R9（R9/E9）在兴奋性毒性后显示出最小的神经保护作用。这些结果表明肽的正电荷和精氨酸残基对神经保护至关重要，并使我们推测肽诱导的离子通道内吞内化是一种潜在的作用机制。这些发现还对与富含精氨酸的CPPs融合的不同神经保护肽的作用方式提出了质疑。
