Multiple protective activities of neuroglobin in cultured neuronal cells exposed to hypoxia re-oxygenation injury.

Abstract

Oxidative stress is associated with the pathology of acute and chronic neurodegenerative disease. We have cloned a human neuroglobin (Nb) construct and over-expressed this protein in cultured human neuronal cells to assess whether Nb ameliorates the cellular response to experimental hypoxia-reoxygenation (H/R) injury. Parental cells transfected with a blank (pDEST40) vector responded to H/R injury with a significant decrease in cellular ATP at 5 and 24 h after insult. This was coupled with increases in the cytosolic Ca(2+), and the transition metals iron (Fe), copper (Cu), and zinc (Zn) within the cell body, as monitored simultaneously using X-ray fluorescence microprobe imaging. Parental cell viability decreased over the same time period with a approximately 4 to 5-fold increase in cell death (maximum approximately 25%) matched by an increase in caspase 3/7 activation (peaking at a 15-fold increase after 24 h) and condensation of beta-actin along axonal processes. Over-expression of Nb inhibited ATP loss and except for significant decreases in the sulfur (S), chlorine (Cl), potassium (K) and Ca(2+) contents, maintained cellular ion homeostasis after H/R insult. This resulted in increased cell viability, significantly diminished caspase activation and maintenance of the beta-actin cytoskeletal structure and receptor-mediated endocytosis. These data indicate that bolstering the cellular content of Nb inhibits neuronal cell dysfunction promoted by H/R insult through multiple protective actions including: (i) maintenance of cellular bioenergetics; (ii) inhibition of Ca(2+) influx; (iii) a reduction in cellular uptake of Fe, Cu and Zn at the expense of S, Cl and K; and (iv) an enhancement of cell viability through inhibiting necrosis and apoptosis.

• Authors: Thi Thuy Hong Duong, Paul Kenneth Witting, Shane Tony Antao, Sarah Nicole Parry, Marina Kennerson, Barry Lai, Stefan Vogt, Peter Andrew Lay, Hugh Hamlyn Harris
• Journal: Journal of neurochemistry (J Neurochem) Vol. 108 Issue 5 Pg. 1143-54 (Mar 2009) ISSN: 1471-4159 [Electronic] England
• PMID: 19154338 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Cytoskeletal Proteins
• Nerve Tissue Proteins
• Neuroglobin
• Copper
• Adenosine Triphosphate
• Globins
• Iron
• Caspases
• Zinc
• Oxygen
• Calcium

Topics

• Adenosine Triphosphate (metabolism)
• Analysis of Variance
• Calcium (metabolism)
• Caspases (metabolism)
• Cell Differentiation
• Cell Hypoxia (drug effects, physiology)
• Cell Line, Tumor
• Copper (metabolism)
• Cytoskeletal Proteins (metabolism)
• Endocytosis
• Flow Cytometry (methods)
• Globins (genetics, metabolism)
• Humans
• Iron (metabolism)
• Nerve Tissue Proteins (genetics, metabolism)
• Neuroblastoma
• Neuroglobin
• Neurons (drug effects, physiology)
• Oxygen (pharmacology)
• Spectrometry, X-Ray Emission (methods)
• Time Factors
• Transfection (methods)
• Zinc (metabolism)