Dexamethasone protects organ of corti explants against tumor necrosis factor-alpha–induced loss of auditory hair cells and alters the expression levels of apoptosis-related genes
| Autor: | Christine T. Dinh, Scott M. Haake, T. R. Van De Water, Kimberly Hoang, Adrien A. Eshraghi, Shibing Chen, Th.J. Balkany, E. Nong |
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| Rok vydání: | 2008 |
| Předmět: |
Programmed cell death
Pathology medicine.medical_specialty Time Factors bcl-X Protein Gene Expression Apoptosis Biology Dexamethasone Rats Sprague-Dawley Andrology Organ Culture Techniques Ototoxicity Hair Cells Auditory Gene expression medicine Animals Glucocorticoids Organ of Corti Cochlea bcl-2-Associated X Protein Analysis of Variance Tumor Necrosis Factor-alpha General Neuroscience medicine.disease Rats medicine.anatomical_structure Animals Newborn Proto-Oncogene Proteins c-bcl-2 Receptors Tumor Necrosis Factor Type I Tumor necrosis factor alpha Hair cell medicine.drug |
| Zdroj: | Neuroscience. 157:405-413 |
| ISSN: | 0306-4522 |
| Popis: | Objective: Determine the molecular mechanism(s) behind tumor necrosis factor-alpha (TNFα)–induced loss of auditory hair cells and the ability of dexamethasone base (DXMb) to protect against TNFα ototoxicity. Methods: Hair cell counts: Three-day-old rat organ of Corti explants were cultured under three different conditions: 1) untreated-control; 2) TNFα (2 μg/ml); and 3) TNFα (2 μg/ml)+DXMb (70 μg/ml) for 4 days, fixed, and stained with FITC–phalloidin. Hair cells were counted in the basal and middle turns. Gene expression: total RNA was extracted from the three different groups of explants at 0, 12, 24 and 48 h. Using quantitative real-time RT-PCR, mRNAs were transcribed into cDNAs and amplification was performed using primers for rat s-actin (housekeeping gene), TNFR1, Bcl-2, Bax, and Bcl-xl. Results: DXMb protected explant hair cells from TNFα-induced loss. Bax gene expression was greater in TNFα-exposed explants compared with TNFα+DXMb-treated explants at 48 h (P=0.023), confirmed by the increase in the Bax/Bcl-2 ratio at 48 h (P |
| Databáze: | OpenAIRE |
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