Cerebral hypoxia and ischemia trigger endogenous protective mechanisms that can prevent or limit brain damage. Understanding these mechanisms may lead to new therapeutic strategies for stroke and related disorders. Neuroglobin (Ngb), a recently discovered monomeric globin that is distantly related to hemoglobin and myoglobin, is expressed predominantly in brain neurons, and appears to modulate hypoxic-ischemic brain injury. We have found that neuronal hypoxia and cerebral ischemia induce Ngb expression, that enhancing Ngb expression reduces and knocking down Ngb expression increases hypoxic neuronal injury in vitro and ischemic cerebral injury in vivo, and that Ngb-overexpressing transgenic mice are resistant to cerebral infarction from occlusion of the middle cerebral artery. However, the mechanisms that underlie hypoxic induction of an neuroprotection by Ngb are unknown. This application is based on the hypothesis that Ngb is a key mediator of endogenous neuroprotection from hypoxic-ischemic injury, and has the long-term goal of identifying new treatments for stroke.
The specific aims of the proposed project are to: (1) Determine the role of hypoxia-inducible factor-1 (HIF-1) in hypoxic induction of Ngb expression in vitro;(2) Determine how Ngb protects neurons against hypoxia in vitro;and (3) Evaluate the extent to which mechanisms for hypoxic induction of Ngb and protection from hypoxia by Ngb in vitro are recapitulated during focal cerebral ischemia in vivo.

Public Health Relevance

Neuronal hypoxia and brain ischemia activate protective mechanisms , and understanding these mechanisms may lead to new treatments for stroke. Neuroglobin (Ngb), a recently discovered protein related to blood hemoglobin and muscle myoglobin, is found primarily in the brain. In previous work, we found that hypoxia and ischemia increase Ngb expression, that this reduces hypoxic and ischemic neuronal injury, and that mice overexpressing Ngb are resistant to experimental stroke. In this application, we propose to investigate the mechanisms involved in the induction of Ngb expression and in Ngb's protective effects, concentrating on the roles of hypoxia-inducible factor-1 and nitric oxide synthases. The goal of this research is to find new ways to treat stroke and related neurological disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS062040-04
Application #
8207932
Study Section
Brain Injury and Neurovascular Pathologies Study Section (BINP)
Program Officer
Bosetti, Francesca
Project Start
2009-01-01
Project End
2013-12-31
Budget Start
2012-01-01
Budget End
2012-12-31
Support Year
4
Fiscal Year
2012
Total Cost
$415,888
Indirect Cost
$201,513
Name
Buck Institute for Age Research
Department
Type
DUNS #
786502351
City
Novato
State
CA
Country
United States
Zip Code
94945
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Haines, Bryan; Demaria, Marco; Mao, Xiao et al. (2012) Hypoxia-inducible factor-1 and neuroglobin expression. Neurosci Lett 514:137-40
Jin, Kunlin; Mao, Xiao Ou; Xie, Lin et al. (2011) Pharmacological induction of neuroglobin expression. Pharmacology 87:81-4
Jin, Kunlin; Mao, XiaoOu; Xie, Lin et al. (2011) Neuroglobin expression in human arteriovenous malformation and intracerebral hemorrhage. Acta Neurochir Suppl 111:315-9
Jin, Kunlin; Mao, Ying; Mao, Xiao et al. (2010) Neuroglobin expression in ischemic stroke. Stroke 41:557-9