caa a22 4500 463254627 CHVBK 20180405153351.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10571-007-9202-9 doi (NATIONALLICENCE)springer-10.1007/s10571-007-9202-9 Increased β2-Adrenergic Receptor Activity by Thyroid Hormone Possibly Leads to Differentiation and Maturation of Astrocytes in Culture [Elektronische Daten] [Mausam Ghosh, Sumantra Das] Summary: (1) Our earlier studies indicate a downsteam regulatory role of the β-adrenergic receptor (β-AR) system in thyroid hormone induced differentiation and maturation of astrocytes. In the present study we have investigated the contributions of the subtypes of β-AR in the above phenomenon. (2) Primary astrocyte cultures were grown under thyroid hormone deficient as well as under euthyroid conditions. [125I]Pindolol ([125I]PIN) binding studies showed a gradual increase in the specific binding to β2-AR when observed at 5, 10, 15, and 20days under both cultural conditions. Thyroid hormone caused an increase in binding of [125I]PIN to β2-AR compared to thyroid hormone deficient controls at all ages of astrocyte culture. (3) Saturation studies using [125I]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) β2-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 24h. None of the conditions caused any significant change in the β2-adrenergic receptor mRNA levels when compared with corresponding hypothyroid controls. (5) Over expression of β2-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 [125I]PIN binding to β2-AR due to increase in receptor affinity, which may lead to maturation of astrocytes. Springer Science+Business Media, LLC, 2007 Astrocytes nationallicence Brain nationallicence Thyroid hormone nationallicence β2-adrenergic receptor nationallicence Quantitative PCR nationallicence Ghosh Mausam Neurobiology Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, 700032, Jadavpur, Kolkata, India aut Das Sumantra Neurobiology Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, 700032, Jadavpur, Kolkata, India aut Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/8(2007-12-01), 1007-1021 0272-4340 27:8<1007 2007 27 10571 https://doi.org/10.1007/s10571-007-9202-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10571-007-9202-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ghosh Mausam Neurobiology Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, 700032, Jadavpur, Kolkata, India aut NATIONALLICENCE 700 1- Das Sumantra Neurobiology Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, 700032, Jadavpur, Kolkata, India aut NATIONALLICENCE 773 0- Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/8(2007-12-01), 1007-1021 0272-4340 27:8<1007 2007 27 10571 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer