Patterns of distribution of oxygen-binding globins, neuroglobin and cytoglobin in human retina.
OBJECTIVE
To determine the distribution of 2 intracellular oxygen-carrying molecules, neuroglobin (NGB) and cytoglobin (CYGB), in specific retinal cell types of human retinas.


METHODS
Specific antibodies against NGB and CYGB were used in immunohistochemical studies to examine their distribution patterns in human retinal sections. Double-labeling studies were performed with the anti-NGB and anti-CYGB antibodies along with antibodies against neuronal (microtubule-associated protein 2, class III beta-tubulin [TUJ1], protein kinase C alpha, calretinin) and glial (vimentin, glial fibrillary acid protein) markers. Confocal microscopy was used to examine the retinal sections.


RESULTS
Immunohistochemical analysis of human retinal tissue showed NGB and CYGB immunoreactivity in the ganglion cell layer, inner nuclear layer, inner and outer plexiform layers, and retinal pigment epithelium. Neuroglobin immunoreactivity was also present in the outer nuclear layer and photoreceptor inner segments. Neuroglobin and CYGB were coexpressed in the neurons in the ganglion cell layer and inner nuclear layer but not within glial cells.


CONCLUSIONS
Neuroglobin and CYGB are colocalized within human retinal neurons and retinal pigment epithelium but not within glial cells. Clinical Relevance Our results suggest that NGB and CYGB may serve a neuroprotective role as scavengers of reactive oxygen species and therefore should be considered when developing therapeutic strategies for treatment of hypoxia-related ocular diseases.
Ostojić
Jelena
J
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011, USA.
Grozdanić
Sinisa D
SD
Syed
Nasreen A
NA
Hargrove
Mark S
MS
Trent
James T
JT
Kuehn
Markus H
MH
Kwon
Young H
YH
Kardon
Randy H
RH
Sakaguchi
Donald S
DS
D000369:Aged, 80 and over; D015153:Blotting, Western; D064032:Calbindin 2; D002648:Child; D000078842:Cytoglobin; D019084:Fluorescent Antibody Technique, Indirect; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005914:Globins / Q000378:metabolism*; D006801:Humans; D007223:Infant; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D000078787:Neuroglobin; D010100:Oxygen / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D051571:Protein Kinase C-alpha / Q000378:metabolism; D012160:Retina / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
C576764:CALB2 protein, human; C000627265:CYGB protein, human; D064032:Calbindin 2; D000078842:Cytoglobin; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D064030:S100 Calcium Binding Protein G; C498585:TUBB3 protein, human; D014404:Tubulin; D014746:Vimentin; D005914:Globins; D051571:Protein Kinase C-alpha; D010100:Oxygen