Suppression of postsynaptic density protein 95 by antisense oligonucleotides diminishes postischemic pyramidal cell death in rat hippocampal CA1 subfield

• Published in: Neuroscience letters Vol. 385; no. 3; pp. 230 - 233
• Main Authors: Hou, Xiao-Yu, Zhang, Guang-Yi, Wang, De-Guang, Guan, Qiu-Hua, Yan, Jing-Zhi
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 16.09.2005; Elsevier
• Subjects: Animals; Biological and medical sciences; Brain ischemia; Brain Ischemia - metabolism; Brain Ischemia - pathology; Cell Death - drug effects; Disks Large Homolog 4 Protein; Focal Adhesion Kinase 2; Fundamental and applied biological sciences. Psychology; Immunoblotting; Immunoprecipitation; Injections, Intraventricular; Intracellular Signaling Peptides and Proteins; Male; Medical sciences; Membrane Proteins; N-methyl- d-aspartate receptor; Nerve Tissue Proteins - deficiency; Nerve Tissue Proteins - drug effects; Nerve Tissue Proteins - metabolism; Neurology; Neuroprotection; Neuroprotective Agents - administration & dosage; Oligonucleotides, Antisense - administration & dosage; Postsynaptic density protein 95; Proline-rich tyrosine kinase 2; Protein-Tyrosine Kinases - drug effects; Pyramidal Cells - drug effects; Pyramidal Cells - pathology; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate - drug effects; Reperfusion Injury - prevention & control; Vascular diseases and vascular malformations of the nervous system; Vertebrates: nervous system and sense organs; Brain ischemia; Neuroprotection; N-methyl- d-aspartate receptor; Proline-rich tyrosine kinase 2; Postsynaptic density protein 95; Rat; Central nervous system; Proline; Cardiovascular disease; Glutamate receptor; Encephalon; Ischemia; Pyramidal neuron; Protein-tyrosine kinase; Enzyme; Transferases; Rodentia; Antisense oligonucleotide; Protein; Vertebrata; Mammalia; Cell death; Animal; N-methyl-D-aspartate receptor; Postsynaptic density; NMDA receptor; Hippocampus
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2005.05.054

Our previous investigation has shown that postsynaptic density protein 95 (PSD-95) is critical for the Src family kinases-mediated tyrosine phosphorylation of N-methyl- d-aspartate receptor subunit 2A (NR2A) in the postischemic hippocampus. To clarify the roles of PSD-95 in the ischemic brain damage, histological method was performed to examine the effects of PSD-95 antisense oligonucleotides (AS) on the postischemic delayed cell death in rat hippocampus. Transient (15 min) brain ischemia was induced by the four-vessel occlusion method in Sprague–Dawley rats. Five days of reperfusion following brain ischemia (I/R5d) led to hippocampal CA1 pyramidal cell death upward of 90%. Intracerebroventricular infusion of AS (every 24 h for 3 days before ischemia) not only decreased the PSD-95 expression but also increased the number of surviving pyramidal neurons, while missense oligonucleotides (MS) had no effects. To further investigate the mechanisms underlying the neuroprotection of PSD-95 deficiency, the interaction of proline-rich tyrosine kinase 2 (Pyk2) with NR2A as well as autophosphorylation (Tyr402) of Pyk2 were detected. Immunoprecipitation and immunoblot analysis showed that preischemic treatment with AS, but not MS or vehicle, attenuated the I/R6h-induced increases in Pyk2–NR2A association and Pyk2 autophosphorylation. The protein levels of NR2A and Pyk2 had no differences under the above conditions. Our data suggest that the recruitments of ion channels and signaling molecules may be involved in the PSD-95 neurotoxicity in the postischemic hippocampus.