title: Intranasal delivery of HMGB1-binding heptamer peptide confers a robust neuroprotection in the postischemic brain.
abstract: High mobility group box 1 (HMGB1) is an endogenous danger signal molecule. In a previous report, we showed that HMGB1 is massively released during NMDA-induced acute damaging process in the postischemic brain and triggers inflammatory processes and induces neuronal apoptosis. We have also reported a robust neuroprotection of intranasally delivered HMGB1 siRNA in the postischemic rat brain (middle cerebral artery occlusion (MCAO), 60 min). In the present study, we investigated the therapeutic efficacy of intranasally delivered HMGB1 binding heptamer peptide (HBHP; HMSKPVQ), which was selected using a phage display approach, in the same stroke animal model. A pull-down assay using biotin-labeled HBHP showed that HBHP binds directly to HMGB1, specifically to HMGB1 A box, confirming HMGB1/HBHP interaction. HBHP significantly suppressed HMGB1-mediated neuronal cell death in primary cortical cultures and HMGB1/HBHP binding was detected in NMDA-conditioned culture media. However, a heptamer peptide composed of a scrambled sequence of the seven amino acids in HBHP failed to bind HMGB1 and had no protective effect. Furthermore, HBHP (300 ng) delivered intranasally at 30 min before MCAO significantly suppressed infarct volume in the postischemic rat brain (maximal reduction by 41.8±5.4%) and ameliorated neurological and behavioral deficits. In contrast, scrambled heptamer peptide had no protective effect at the same dose. Together these results suggest that intranasal HBHP ameliorates neuronal damage in the ischemic brain by binding HMGB1, which might inhibit the function of HMGB1 as an endogenous danger signal molecule.
authors.affiliation: Department of Anatomy and Center for Advanced Medical Education (BK21 Project), Inha University School of Medicine, Inchon, Republic of Korea.
authors.forename: Il-Doo
authors.initials: ID
authors.lastname: Kim
authors.forename: Joo-Hyun
authors.initials: JH
authors.lastname: Shin
authors.forename: Hye-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Yin-Chuan
authors.initials: YC
authors.lastname: Jin
authors.forename: Ja-Kyeong
authors.initials: JK
authors.lastname: Lee
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D002478:Cells, Cultured; D024243:HMGB1 Protein / Q000378:metabolism*; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D008297:Male; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D019151:Peptide Library; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D024243:HMGB1 Protein; C000601033:His-Met-Ser-Lys-Pro-Val-Gln; D018696:Neuroprotective Agents; D009842:Oligopeptides; D019151:Peptide Library