Coordinate and independent regulation of alpha B-crystallin and hsp27 expression in response to physiological stress.
alpha-Crystallins share structural and functional properties with the stress protein hsp27. These polypeptides are expressed at low constitutive levels in many tissues including brain, and alpha B-crystallin and hsp27 can accumulate in central nervous system glia in a variety of neurological conditions. We report here that heat shock and exposure to transition metals result in an increase in the steady state mRNA level of alpha B-crystallin and hsp27 in primary cultures of rat forebrain astrocytes. Both exposure to tumour necrosis factor-alpha and hypertonic conditions result in alpha B-crystallin mRNA accumulation but no change in the hsp27 mRNA level. Under some of these conditions increased synthesis and accumulation of alpha B-crystallin and hsp27 protein are also evident. We are unable to detect alpha A-crystallin mRNA in resting or stressed astrocytes. A novel phenomenon involving a transitory change in stress protein mRNA mobility in Northern blots during induction is reported, which is stress type and cell type independent. The results demonstrate multiple stress regulation of alpha B-crystallin and hsp27 in cultured astrocytes, suggesting that they can legitimately be regarded as stress proteins in the central nervous system.
Head
M W
MW
Department of Pathology, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Corbin
E
E
Goldman
J E
JE
D000818:Animals; D001253:Astrocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D002104:Cadmium / Q000494:pharmacology; D019256:Cadmium Chloride; D002452:Cell Count; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D003459:Crystallins / Q000235:genetics*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D014644:Genetic Variation; D006360:Heat-Shock Proteins / Q000235:genetics*; D006358:Hot Temperature; D007003:Hypoglycemia / Q000503:physiopathology; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D002712:Chlorides; D003459:Crystallins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D002104:Cadmium; D019256:Cadmium Chloride