Differential expression of heme oxygenase-1 in cultured cortical neurons and astrocytes determined by the aid of a new heme oxygenase antibody. Response to oxidative stress

• Published in: Brain research. Molecular brain research. Vol. 30; no. 1; pp. 37 - 47
• Main Authors: Dwyer, Barney E., Nishimura, Robert N., Lu, Shi-Yi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.1995; Elsevier
• Subjects: Antibodies - immunology; Astrocyte; Astrocytes - enzymology; Astrocytes - metabolism; Autoradiography; Biological and medical sciences; Blotting, Western; Cells, Cultured; Electrophoresis; Fundamental and applied biological sciences. Psychology; Heat shock protein; Heme oxygenase; Heme Oxygenase (Decyclizing) - biosynthesis; Heme Oxygenase (Decyclizing) - genetics; Immunohistochemistry; Isolated neuron and nerve. Neuroglia; Neuron; Neuronal injury; Neurons - enzymology; Neurons - metabolism; Oxidative injury; Oxidative Stress - physiology; Polymerase Chain Reaction; Recombinant Proteins; Stress protein; Vertebrates: nervous system and sense organs; Neuron; Stress protein; Heme oxygenase; Heat shock protein; HO; HO-L; Neuronal injury; HO-1; Astrocyte; HO-2; Oxidative injury; Oxidative stress; Rat; Enzyme; Neuroglia; Rodentia; Central nervous system; Heme oxygenase (decyclizing); In vitro; Vertebrata; Mammalia; Oxidoreductases; Brain (vertebrata)
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/0169-328X(94)00273-H

Heme oxygenase exists as two isoenzymes designated heme oxygenase-1 (HO-1)and heme oxygenase-2 (HO-2). HO-2 is made constitutively in many cell types whereas HO-1 is a stress protein inducible by heat, heavy metals, ultraviolet irradiation, and oxidative stress. Recombinant rat HO-1 was expressed in bacteria and antiserum designated HO-1713 was raised against the purified protein. HO-1713 detected recombinant rat HO-1 and recombinant rat HO-2. In rat tissues it detected HO-1 and a second, unidentified band designated HO-L (heme oxygenase-like immunoreactivity)which was not HO-2. Cultured rat cortical neurons and forebrain astrocytes were exposed to hydrogen peroxide (0.14-0.7 micromolar for 30 or 60 min). Neurons which contained little detectable HO-1 and which were sensitive to hydrogen peroxide at the high end of the dose curve failed to induce HO-1 by Western blot analysis. In contrast, cultured rat forebrain astrocytes which contained HO-1 under normal culture conditions and which were resistant to injury by hydrogen peroxide, increased their content of immunoreactive HO-1 by 7-fold within 3 h after exposure. Our results support a protective role for HO-1 in oxidative injury and suggest that the relative inability of neurons to increase HO-1 after oxidative stress may contribute to their selective vulnerability vis-a-vis astrocytes. They also suggest that differential expression of heme oxygenase in studies utilizing CNS cultures may alter normal cell physiology and cell survival.