Kenji Ohba, Melvin Khee-Shing Leow, Brijesh Kumar Singh, Rohit Anthony Sinha, Ronny Lesmana,Xiao-Hui Liao, Paul Michael Yen
Here, we examined changes in hepatic gene expression and serum TH/thyrotropin (TSH) levels in adult male mice treated either with a single T3 (20 g/100 g body weight) injection (acute T3) or daily injections for 14 days (chronic T3) followed by 10 days withdrawal. Chromatin immunoprecipitation analysis of representative positively-regulated target genes suggested that acetylation of H3K9/K14 was associated with acute stimulation, whereas trimethylation of H3K4 was associated with chronic stimulation. In an in vivo model of chronic intrahepatic hyperthyroidism since birth, adult male monocarboxylate transporter-8 knockout mice also demonstrated desensitization of most acutely stimulated target genes that were examined. In summary, we have identified transcriptional desensitization and incomplete recovery of gene expression during chronic hyperthyroidism and recovery. Our findings may be a potential reason for discordance between clinical symptoms and serum TH levels observed in these conditions.