title: Intranasal administration of recombinant Netrin-1 attenuates neuronal apoptosis by activating DCC/APPL-1/AKT signaling pathway after subarachnoid hemorrhage in rats.
abstract: Neuronal apoptosis is a crucial pathological process in early brain injury after subarachnoid hemorrhage (SAH). The effective therapeutic strategies to ameliorate neuronal apoptosis are still absent. We intended to determine whether intranasal administration of exogenous Netrin-1 (NTN-1) could attenuate neuronal apoptosis after experimental SAH, specifically via activating DCC-dependent APPL-1/AKT signaling cascade. Two hundred twenty-five male Sprague-Dawley rats were subjected to the endovascular perforation model of SAH. Recombinant human NTN-1 (rNTN-1) was administered intranasally. NTN-1 small interfering RNA (siRNA), APPL-1 siRNA, and AKT inhibitor MK2206 were administered through intracerebroventricular (i.c.v.) injection. SAH grade, neurological score, neuronal apoptosis assessed by cleaved caspase-3 (CC-3) expression and Fluoro-Jade C (FJC) staining, double immunofluorescence staining, and Western blot were examined. Our results revealed that endogenous NTN-1 level was increased after SAH. Administration of rNTN-1 improved neurological outcomes at 24 h and 72 h after SAH, while knockdown of endogenous NTN-1 worsened neurological impairments. Furthermore, exogenous rNTN-1 treatment promoted APPL-1 activation, increased phosphorylated-AKT and Bcl-2 expression, as well as decreased apoptotic marker CC-3 expression and the number of FJC-positive neurons, thereby alleviated neuronal apoptosis. Conversely, APPL-1 siRNA and MK2206 abolished the anti-apoptotic effect of exogenous rNTN-1 at 24 h after SAH. Collectively, intranasal administration of exogenous rNTN-1 attenuated neuronal apoptosis and improved neurological function in SAH rats, at least in apart via activating DCC/APPL-1/AKT signaling pathway.
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China; Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Zongyi
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States; Department of Anesthesiology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Budbazar
authors.initials: B
authors.lastname: Enkhjargal
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Cesar
authors.initials: C
authors.lastname: Reis
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Wan
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States.
authors.forename: Jiping
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China. Electronic address: chengyuan023@aliyun.com.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States; Department of Anesthesiology, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States; Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA 92354, United States. Electronic address: johnzhang3910@yahoo.com.
authors.forename: John H
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D006801:Humans; D007276:Injections, Intraventricular; D008297:Male; D009414:Nerve Growth Factors / Q000008:administration & dosage* / Q000235:genetics / Q000494:pharmacology*; D000075388:Netrin-1; D009460:Neurologic Examination; D009474:Neurons / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D025521:Tumor Suppressor Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000494:pharmacology*
chemical_list: C000617351:NTN1 protein, human; D009414:Nerve Growth Factors; D018696:Neuroprotective Agents; C000617354:Ntn1 protein, rat; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; D000075388:Netrin-1; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3; D010751:Phosphopyruvate Hydratase
keywords: APPL-1; Apoptosis; Early brain injury; Netrin-1; Subarachnoid hemorrhage