Influence of neonatal hypothyroidism on hepatic gene expression and lipid metabolism in adulthood.
Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology, but its specific influence in liver is less understood. Here, we studied how CH influences the liver gene expression program in adulthood. Pregnant rats were given the antithyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as reductions in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, the feed efficiency increased in CH, and this was accompanied by significant catch-up growth. On PND80, significant reductions in body mass, tail length, and circulating IGF-I levels remained in CH rats. Conversely, the mRNA levels of known GH target genes were significantly upregulated. The serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in the expression of hepatic genes involved in lipid metabolism, including an increased transcription of PPARα and a reduced expression of genes involved in fatty acid and cholesterol uptake, cellular sterol efflux, triglyceride assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to the onset of hypothyroidism in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters and to T3 replacement with an enhanced activation of malic enzyme. In summary, we provide in vivo evidence that neonatal hypothyroidism influences the hepatic transcriptional program and tissue sensitivity to hormone treatment in adulthood. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood.
Department of Clinical Sciences, Molecular and Translational Endocrinology Group, University of Las Palmas de GC - Cancer Research Institute of The Canary Islands, Las Palmas de Gran Canaria, Spain. lfernandez@dcc.ulpgc.es
Ruymán
R
Santana-Farré
Mercedes
M
Mirecki-Garrido
Carlos
C
Bocos
Luis A
LA
Henríquez-Hernández
Nusrat
N
Kahlon
Emilio
E
Herrera
Gunnar
G
Norstedt
Paolo
P
Parini
Amilcar
A
Flores-Morales
Leandro
L
Fernández-Pérez
D000818:Animals; D000831:Animals, Newborn; D003409:Congenital Hypothyroidism / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006706:Homeostasis; D020249:Hormone Replacement Therapy; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014158:Transcription, Genetic; D059467:Transcriptome
D013006:Growth Hormone