n-Butyrate enhances induction of thyroid hormone-responsive nuclear protein.
Effects of n-butyrate on nuclear thyroid hormone receptors and on thyroid hormone-responsive nuclear protein were investigated by means of a perfusion system in rat liver. Treatment with 5 mM n-butyrate resulted in an increase (150%) in the maximal binding capacity of 3,5,3'-L-triiodothyronine (T3) nuclear receptors without altering the affinity of receptor for T3. However, further perfusion for 4 h decreased the number of the receptors to the control level. n-Butyrate increased the amount of acetylated histone H4. The ability of nuclear T3 receptors to bind to core histones was diminished by acetylation of the core histones. Thyroid hormone-responsive nuclear protein (n protein) was increased by T3. The induction of the n protein by T3 was augmented by n-butyrate. These results suggested that n-butyrate modulates thyroid hormone-responsive gene expression in rat liver via the increased number of nuclear receptors or changes in the chromatin constitution.
Department of Geriatrics, Endocrinology and Metabolism, Shinshu University School of Medicine, Matsumoto, Japan.
Y
Y
Nishii
K
K
Ichikawa
T
T
Miyamoto
T
T
Takeda
M
M
Kobayashi
S
S
Suzuki
A
A
Sakurai
K
K
Hashizume
D000107:Acetylation; D000818:Animals; D002087:Butyrates / Q000494:pharmacology*; D020148:Butyric Acid; D002467:Cell Nucleus / Q000737:chemistry*; D002843:Chromatin / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006657:Histones / Q000096:biosynthesis / Q000235:genetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D010477:Perfusion; D011499:Protein Processing, Post-Translational; D051381:Rats; D017208:Rats, Wistar; D011988:Receptors, Thyroid Hormone / Q000096:biosynthesis* / Q000187:drug effects; D014284:Triiodothyronine / Q000378:metabolism*; D015854:Up-Regulation
D002087:Butyrates; D002843:Chromatin; D006657:Histones; D009687:Nuclear Proteins; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D020148:Butyric Acid