Aging exacerbates intracerebral hemorrhage-induced brain injury.
Aging may be an important factor affecting brain injury by intracerebral hemorrhage (ICH). In the present study, we investigated the responses of glial cells and monocytes to intracerebral hemorrhage in normal and aged rats. ICH was induced by microinjecting autologous whole blood (15 microL) into the striatum of young (4 month old) and aged (24 month old) Sprague-Dawley rats. Age-dependent relations of brain tissue damage with glial and macrophageal responses were evaluated. Three days after ICH, activated microglia/macrophages with OX42-positive processes and swollen cytoplasm were more abundantly distributed around and inside the hemorrhagic lesions. These were more dramatic in aged versus the young rats. Western blot and immunohistochemistry analyses showed that the expression of interleukin-1beta protein after ICH was greater in aged rats, whereas the expression of GFAP and ciliary neurotrophic factor protein after ICH was significantly lower in aged rats. These results suggest that ICH causes more severe brain injury in aged rats most likely due to overactivation of microglia/macrophages and concomitant repression of reactive astrocytes.
Lee
Jae-Chul
JC
Department of Neuroscience, College of Medicine, Korea University, Seoul, Republic of Korea.
Cho
Geum-Sil
GS
Choi
Byung-Ok
BO
Kim
Hyoung Chun
HC
Kim
Won-Ki
WK
D000375:Aging / Q000502:physiology*; D000818:Animals; D001804:Blood Transfusion, Autologous; D015153:Blotting, Western; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000378:metabolism / Q000473:pathology*; D020934:Ciliary Neurotrophic Factor / Q000096:biosynthesis / Q000235:genetics; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis / Q000235:genetics; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000235:genetics; D020300:Intracranial Hemorrhages / Q000378:metabolism / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D009457:Neuroglia / Q000473:pathology; D009930:Organic Chemicals; D051381:Rats; D017207:Rats, Sprague-Dawley
D020934:Ciliary Neurotrophic Factor; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein; D053583:Interleukin-1beta; D009419:Nerve Tissue Proteins; D009930:Organic Chemicals; C435731:fluoro jade