Physiological thyroid hormone levels regulate numerous skeletal muscle transcripts

WE Visser, KA Heemstra… - The Journal of …, 2009 - academic.oup.com
WE Visser, KA Heemstra, SMA Swagemakers, Z Ozgur, EP Corssmit, J Burggraaf…
The Journal of Clinical Endocrinology & Metabolism, 2009academic.oup.com
Context: Skeletal muscle is an important target tissue for thyroid hormone (TH). It is currently
unknown which genes are regulated by physiological TH levels. Objective: We examined
the effects of l-thyroxine on human skeletal muscle transcriptome. Design: Microarray
analysis of transcript levels was performed using skeletal muscle biopsies from patients
under euthyroid and hypothyroid conditions. Setting: The study was conducted in a
university hospital laboratory. Patients: We studied skeletal muscle obtained from 10 …
Context: Skeletal muscle is an important target tissue for thyroid hormone (TH). It is currently unknown which genes are regulated by physiological TH levels.
Objective: We examined the effects of l-thyroxine on human skeletal muscle transcriptome.
Design: Microarray analysis of transcript levels was performed using skeletal muscle biopsies from patients under euthyroid and hypothyroid conditions.
Setting: The study was conducted in a university hospital laboratory.
Patients: We studied skeletal muscle obtained from 10 thyroidectomized patients with differentiated thyroid carcinoma on and after 4 wk off l-thyroxine replacement.
Mean Outcome Measures: Gene expression changes were measured using microarrays. Results were analyzed using dedicated statistical methods.
Results: We detected 607 differentially expressed genes on l-thyroxine treatment, of which approximately 60% were positively and approximately 40% were negatively regulated. Representative genes were validated by quantitative PCR. Genes involved in energy and fuel metabolism were overrepresented among the up-regulated genes, of which a large number were newly associated with thyroid state. l-thyroxine therapy induced a large down-regulation of the primary transcripts of the noncoding microRNA pair miR-206/miR-133b.
Conclusion: We demonstrated that physiological levels of TH regulate a myriad of genes in human skeletal muscle. The identification of novel putatively TH-responsive genes may provide the molecular basis of clinical effects in subjects with different TH status. The observation that TH regulates microRNAs reveals a new layer of complexity by which TH influences cellular processes.
Skeletal muscle has a major contribution to the metabolic rate in humans; data demonstrate that skeletal muscle transcriptome is largely changed in different thyroid states.
Oxford University Press