Increased beta(2)-adrenergic receptor activity by thyroid hormone possibly leads to differentiation and maturation of astrocytes in culture
Metadata of CSIR Papers
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| Title |
Increased beta(2)-adrenergic receptor activity by thyroid hormone possibly leads to differentiation and maturation of astrocytes in culture
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| Creator |
Ghosh, M
Das, S |
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| Subject |
Cell Biology; Neurosciences
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| Description |
(1) Our earlier studies indicate a downsteam regulatory role of the beta-adrenergic receptor (beta-AR) system in thyroid hormone induced differentiation and maturation of astrocytes. In the present study we have investigated the contributions of the subtypes of beta-AR in the above phenomenon. (2) Primary astrocyte cultures were grown under thyroid hormone deficient as well as under euthyroid conditions. [I-125]Pindolol ([I-125]PIN) binding studies showed a gradual increase in the specific binding to beta(2)-AR when observed at 5, 10, 15, and 20 days under both cultural conditions. Thyroid hormone caused an increase in binding of [I-125]PIN to beta(2)-AR compared to thyroid hormone deficient controls at all ages of astrocyte culture. (3) Saturation studies using [I-125]PIN in astrocyte membranes prepared from 20-day-old cultures showed a significant increase in the affinity of the receptors (K (D)) in the thyroid hormone treated cells without any change in receptor number (B (max)). (4) beta(2)-AR mRNA levels were measured by real-time PCR during ontogenic development as well as during exposure of 10-day-old hypothyroid cultures to normal levels of thyroid hormone for 2, 6, 12, and 24 h. None of the conditions caused any significant change in the beta(2)-adrenergic receptor mRNA levels when compared with corresponding hypothyroid controls. (5) Over expression of beta(2)-AR cDNA in hypothyroid astrocytes caused morphological transformation in spite of the absence of thyroid hormone in the medium. (6) Taken together, results suggest thyroid hormone causes a selective increase in [I-125]PIN binding to beta(2)-AR due to increase in receptor affinity, which may lead to maturation of astrocytes.
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| Publisher |
SPRINGER/PLENUM PUBLISHERSNEW YORK233 SPRING ST, NEW YORK, NY 10013 USA
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| Date |
2011-09-20T12:12:24Z
2011-09-20T12:12:24Z 2007 |
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| Type |
Article
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| Identifier |
CELLULAR AND MOLECULAR NEUROBIOLOGY
0272-4340 http://hdl.handle.net/123456789/14258 |
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| Language |
English
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