Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe studies in a canine model aimed at establishing methods for ex vivo gene delivery to thyroid follicular cells. Canine follicular cells were harvested from tissue obtained by unilateral lobectomy, grown in thyrotropin-containing media, and transduced with amphotropic retroviral vectors carrying Escherichia coli beta-galactosidase or Tn7 neomycin-resistance genes. Up to 30% of cells were transduced with retroviral vectors containing the neomycin resistance gene, and transduced cells could be selected with G418. Significantly, transduced and selected cells exhibited the morphology of thyroid follicular cells and continued to express thyroglobulin. To assess the viability of cultivated and transduced cells for transplantation, cells were stained with the vital fluorescent dye DiI, recovered by trypsinization, and transplanted into the contralateral thyroid lobe of autologous animals. Engraftment was demonstrated by fluorescence microscopy and identification of proviral sequences 7-10 days after transplantation. Proviral transcripts were evident using coupled reverse transcription and the polymerase chain reaction using total RNA from transplanted glands. Thyroid follicular cells may represent an attractive target for gene therapy due to their proliferative potential, their large protein synthetic and secretory capacity, and their susceptibility to regulation. The thyroid might be a target for therapy of congenital or acquired thyroid diseases as well as disorders requiring regulated expression of proteins in the circulation. This work demonstrates the feasibility of ex vivo gene delivery to thyroid follicular cells that may be used in future investigations.
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PMID:Retrovirus-mediated gene transfer into canine thyroid using an ex vivo strategy. 849 26

Thyroid hormone, acting through thyroid hormone receptors (TRs), plays an important role in amphibian metamorphosis and vertebrate development. To identify where and when TR beta 1 promoter is activated during fetal life, we carried out an in vivo functional study of a 1.3 kilobase (kb) TR beta 1 gene promoter using transgenic mice that express the beta-galactosidase gene under control of the TR beta 1 promoter. Transactivation of the gene was determined by blue staining of tissues after incubation with X-gal. High expression of transgene was detected in the limbs and face of the 12.5-day-old fetus (12.5 F) and 14.5 F, reminiscent of the changes occurring during amphibian metamorphosis, and this disappeared at 17.5 F. The expression was confined to the tip of finger bones, between fingers in the limb buds, and was detected in the root of whisker follicles, nose, and around the eyes. Signal was detected in the oral cavity, nasal cavity, lung, and urogenital sinus of 14.5 F, and disappeared at 17.5 F. Signal was detected in the midbrain and auditory vesicles of 9.5 F but was reduced between 12.5F and 17.5F, and there was no expression in the cerebral cortex layer of 0 days old neonates (PO). Expression was detected in the cortex after P5. There was signal in the cerebral cortex, cerebellum, kidney, and liver of adult mice. TR beta 1 messenger RNA was detected by RT-PCR in the developing limbs and face. Transgene expression in the interdigital tissues, which regress during development, suggests that TR beta 1 is expressed in mammals in areas undergoing apoptosis as well as in areas undergoing differentiation.
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PMID:Thyroid hormone receptor beta 1 expression in developing mouse limbs and face. 904 36

Thyroid hormone (T3) is essential for brain development and most of its actions are exerted at the gene expression level after interaction with nuclear receptors. In particular, genes encoding cytoskeletal proteins are influenced by the thyroidal status. Thyroid hormone is involved in the normal downregulation of the Talpha1 alpha-tubulin gene during postnatal growth. The action of T3 on Talpha1 tubulin expression is complex and is exerted at least at two levels. In cultured cells, T3 induces a transient and fast decrease of Talpha1 mRNA concentration. This effect is enhanced when transcription is blocked by actinomycin D, suggesting that T3 increases mRNA degradation. In transgenic animals T3 affects the expression of beta-galactosidase under control of the Talpha1 promoter in the same way as the endogenous gene, supporting an effect mediated through the Talpha1 promoter. However, the Talpha1 promoter is not regulated by T3 in transfected cells and, therefore, the effects of the hormone in vivo are likely to be indirect. It is concluded that regulation of Talpha1 alpha-tubulin by thyroid hormone is the result of multiple influences including effects on mRNA half life and indirect effects at the promoter level.
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PMID:Thyroid hormone-dependent regulation of Talpha1 alpha-tubulin during brain development. 1190 7

Premature senescence may play an important role as an acute, drug-, or ionizing radiation (IR)-inducible growth arrest program along with interphase apoptosis and mitotic catastrophe. The aim of the study was to evaluate whether IR can induce senescence-like phenotype (SLP) associated with terminal growth arrest in the thyroid cells, and if so, to evaluate impact of terminal growth arrest associated with SLP in intrinsic radiosensitivity of various thyroid carcinomas. The induction of SLP in thyroid cells were identified by: (1) senescence associated beta-galactosidase (SA-beta-Gal) staining method, (2) dual-flow cytometric analysis of cell proliferation and side light scatter using vital staining with PKH-2 fluorescent dye, (3) double labeling for 5-bromodeoxyuridine and SA- beta-Gal, (4) Staining for SA-beta-Gal with consequent antithyroglobulin immunohistochemistry. IR induced SLP associated with terminal growth arrest in four thyroid cancer cells lines and in primary thyrocytes in time- and dose-dependent manner. Analysis of relationship between induction of SLP and radiosensitivity revealed a trend in which more radioresistant cell lines strongly tended to show lower specific SLP yields (r = -0.93, p = 0.068). We find out that SA-beta-Gal staining is detectable in irradiated ARO xenotransplants, but not in control tumors. We, therefore, conclude that induction of SLP with terminal growth arrest contribute to the elimination of clonogenic populations after IR.
Thyroid 2005 Apr
PMID:Radiation-induced senescence-like terminal growth arrest in thyroid cells. 1587 51