Constitutive expression of Hsp27 in the rat cochlea

• Published in: Hearing research Vol. 163; no. 1; pp. 61 - 70
• Main Authors: Leonova, Elena V., Fairfield, Damon A., Lomax, Margaret I., Altschuler, Richard A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2002; Elsevier
• Subjects: Actins - metabolism; Animals; Biological and medical sciences; Blotting, Western; Cochlea - metabolism; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Fundamental and applied biological sciences. Psychology; Heat shock protein-27; Heat-Shock Proteins; HSP27 Heat-Shock Proteins; Immunofluorescence; Immunohistochemistry; Male; Neoplasm Proteins - metabolism; Outer hair cell; Rat; Rats; Rats, Sprague-Dawley; Reference Values; Reverse Transcriptase Polymerase Chain Reaction; Reverse transcription-polymerase chain reaction; Tension fibroblast; Tissue Distribution; Vertebrates: nervous system and sense organs; Tension fibroblast; Heat shock protein-27; Rat; Immunofluorescence; Reverse transcription-polymerase chain reaction; Outer hair cell; Rodentia; Gene expression; Cuticular plate; Inner ear; Organ of hearing; Vertebrata; Mammalia; Actin; Heat shock protein; Cochlea; Cytoskeleton; Fibroblast; Reissner membrane; Protection
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(01)00379-3

Heat shock protein-27 (Hsp27) is known to function as both a stress-inducible molecular chaperone and regulator of actin polymerization. For many cells in the cochlea, actin is part of the cytoskeleton and plays an important role in the maintenance of cochlear function. To understand the molecular processes by which the cochlear actin cytoskeleton is maintained and regulated during normal auditory function, we examined the expression and localization of Hsp27 in the normal rat cochlea. Reverse transcription-polymerase chain reaction and Western blot showed constitutive expression of Hsp27 in the normal rat cochlea. Immunofluorescence microscopy showed Hsp27-like staining is localized to the cuticular plate and lateral wall of outer hair cells. Hsp27-like immunostaining is also found in tension fibroblasts, in the root cells of the spiral limbus and in Reissner’s membrane. The presence of Hsp27 in the actin-rich tension fibroblasts and outer hair cells suggests a potential role in the regulation and maintenance of the actin cytoskeleton in these cells. The presence of high levels of constitutive Hsp27 may also provide a mechanism for pre-protecting these cells against environmental stressors.