Role of Thyroid Hormone in the Morphological Differentiation and Maturation of Astrocytes: Temporal Correlation with Synthesis and Organization of Actin
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
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| Title |
Role of Thyroid Hormone in the Morphological
Differentiation and Maturation of Astrocytes: Temporal
Correlation with Synthesis and Organization of Actin
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| Creator |
Paul, Surojit
Das, Sumantra Poddar, Ranjana Sarkar, Pranab Kumar |
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| Subject |
Cell Biology & Physiology
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| Description |
Morphological changes and the molecular mechanisms associated with the maturation of astrocytes were
studied under normal and thyroid hormone-deficient conditions using long-term (30 days) primary cultures
derived from the neonatal rat brain. lmmunocytochemical staining of cells with a monoclonal antibody specific to
glial fibrillary acidic protein demonstrated for the first time that, similar to their maturation in vivo, astrocytes
maintained in normal serum-containing medium can undergo complete maturation involving two distinct stages of
morphological differentiation (from radial glia to flat polygonal cells with epithelioid morphology and then to
mature process-bearing cells with stellate morphology). Deficiency of thyroid hormone delays the first step and
totally blocks the second stage of differentiation in the maturation process. Comparative staining of normal and
thyroid hormone-deficient astrocytes with filamentous actin-specific fluorescein isothiocyanate-phalloidin and
quantitation of the various forms of intracellular actin using an improved DNase I assay demonstrated that
maturation of astroglial cells is associated with characteristic alterations in the level of cytoskeletal and non-
cytoskeletal filamentous (F) actin. In particular, the maintenance of the epithelioid form of the hypothyroid
astrocytes is associated with a progressive increase in the level of cytoskeletal F-actin and a concomitant
decline in the level of non-cytoskeletal F-actin. Quantitation of actin mRNA by Northern blot analysis and studies
on the rate of actin synthesis at various stages of differentiation showed that the initial transformation into the
epithelioid form is associated with an increase in the rate of synthesis of actin and the expression of its mRNA,
while the final transformation into the mature process-bearing form is correlated with a decline in these
parameters. The results indicate that thyroid hormone plays an obligatory role in promoting the differentiation
and maturation of astrocytes, and that during this process the hormone regulates the expression of actin and its
intracellular organization in a way conducive to morphological differentiation.
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| Date |
1996
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/706/1/EUROPEAN_JOURNAL_OF_NEUROSCIENCE%2C_8(_11)%2C_2361%2D2370[7].pdf
Paul, Surojit and Das, Sumantra and Poddar, Ranjana and Sarkar, Pranab Kumar (1996) Role of Thyroid Hormone in the Morphological Differentiation and Maturation of Astrocytes: Temporal Correlation with Synthesis and Organization of Actin. European Journal of Neuroscience, 8 (11). pp. 2361-2370. |
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| Relation |
http://dx.doi.org/10.1111/j.1460-9568.1996.tb01199.x
http://www.eprints.iicb.res.in/706/ |
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