A Pentapeptide Monocyte Locomotion Inhibitory Factor Protects Brain Ischemia Injury by Targeting the eEF1A1/Endothelial Nitric Oxide Synthase Pathway

Abstract

Background and Purpose-Ischemic stroke is a major cause of death worldwide but lacks viable treatment or treatment targets. Monocyte locomotion inhibitory factor (MLIF) is a small heat-stable pentapeptide produced by Entamoeba histolytica in axenic culture, which is supposed to protect the brain from ischemic injury; the mechanism, however, remains unknown. In this study, we further investigated the mechanism underlying the protective role of MLIF in brain ischemia. Methods-A middle cerebral artery occlusion model in rats was used for detecting the effect of MLIF in the brain ischemia in vivo. To identify targets of MLIF in brain endothelial cells, we performed immunoprecipitation of biotin-conjugated MLIF and mass spectrometry. Results-MLIF can protect the brain from ischemic injury in vivo, yielding decreased ischemic volume, prolonged survival, and improved neurological outcome. In vitro studies showed that MLIF displayed protective effects through inhibition of expression of pathological inflammatory adhesion molecules and enhancing endothelial nitric oxide synthase expression and nitric oxide release in the cerebrovascular endothelium. The target screening experiments demonstrated binding of MLIF to the ribosomal protein translation elongation factor eEF1A1. MLIF enhanced endothelial nitric oxide synthase expression through stabilization of endothelial nitric oxide synthase mRNA, and eEF1A1 was shown to be necessary for this enhanced expression. Knockdown of eEF1A1 or inhibition of endothelial nitric oxide synthase attenuated MLIF-mediated inhibition of adhesion molecule expression. Conclusions-In this study, we identified a new potential pharmacologically targetable mechanism underlying MLIF's protective effects in brain ischemia through the eEF1A1/endothelial nitric oxide synthase pathway. (Stroke. 2012;43:2764-2773.)

EF1A1/HSC70 Cooperatively Suppress Brain Endothelial Cell Apoptosis via Regulating JNK Activity

“…After incubation with eEF1A1 antibodies and the lysis of bEnd.3 cells, the interacting protein of eEF1A1 was deposited, and the deposition was separated by SDS-PAGE followed by Coomassie brilliant blue staining. After a serial affinity purification to eliminate the circumstance interference as previous reported [3], we found the interacting protein of eEF1A1 may be a protein with an apparent molecular mass of 71 kDa ( Figure 1A). After in-gel digestion, the 71 kDa protein was analyzed with EF1A1 by MALDI-TOF MS ( Figure 1B) and MASCOT search engine searching.…”

Protective Effect of Stachydrine Against Cerebral Ischemia-Reperfusion Injury by Reducing Inflammation and Apoptosis Through P65 and JAK2/STAT3 Signaling Pathway

“…), the neck shaved and cleaned with 75% ethanol. The left MCAO surgery was performed as previously described (Zhang et al, 2012). The left common carotid artery (CCA) was exposed through an incision in the middle of neck.…”

MLIF Alleviates SH-SY5Y Neuroblastoma Injury Induced by Oxygen-Glucose Deprivation by Targeting Eukaryotic Translation Elongation Factor 1A2

“…It is involved in the inflammatory response and in the repair process, it regulates the expression of immunomodulatory genes, and it plays a role in cell proliferation, extracellular matrix production and degradation, vasculogenesis, axon guidance and cellular movement [ 3 , 4 ]. We previously found that MLIF attenuates the inflammatory response and oxidative damage in focal ischemia and protects cerebrovascular endothelial cells following hypoxic injury by inhibiting the expression of adhesion molecules and by targeting the eEF1A1/eNOS pathway [ 5 ]. Yao and colleagues also reported that MLIF is neuroprotective against cerebral ischemia [ 6 ].…”