Thyroid hormone-regulated gene expression in juvenile mouse liver: identification of thyroid response elements using...

Area of Science:

• Endocrinology
• Molecular Biology
• Genomics

Background:

• Thyroid hormone signaling is crucial for growth, development, and metabolism.
• Thyroid hormones mediate effects via thyroid receptors binding to thyroid response elements (TREs) and altering gene transcription.
• Short-term thyroid hormone perturbation in juvenile mice was used to study hepatic mRNA transcription.

Purpose of the Study:

• To identify genes with active TREs affected by thyroid hormone disruption.
• To characterize novel TREs and their associated genes.
• To gain insight into TRE sequence motif characteristics.

Main Methods:

• Thyroid hormone disruption induced using goitrogens (hypothyroid), with replacement or hyperthyroid hormone administration.
• Hepatic mRNA extracted and hybridized to Agilent mouse microarrays for transcriptional profiling.
• Bioinformatic analysis of gene promoter regions to identify TREs and their association with thyroid receptors.

Main Results:

• Identified 28 genes potentially under direct thyroid hormone regulation.
• Discovered 33 TREs in the promoter regions of 13 genes.
• Validated TREs in Tor1a, 2310003H01Rik, Hect3d, and Slc25a45, confirming in vivo and in vitro thyroid receptor binding.
• Observed TREs located upstream of transcription start sites (> 7 kb).

Conclusions:

• Novel TREs linked to previously unrecognized thyroid hormone-responsive genes were discovered.
• The study provides new insights into the characteristics of TRE sequence motifs.
• This research advances the understanding of thyroid hormone action on gene expression.