Thyroid dysfunction in megalin deficient mice

Mol Cell Endocrinol. 2005 May 31;236(1-2):43-7. doi: 10.1016/j.mce.2005.03.009.


Megalin mediates transcytosis of thyroglobulin (Tg), the thyroid hormone precursor, resulting in its passage into the bloodstream. The process involves especially hormone-poor Tg, which may favour hormone secretion by preventing competition with hormone-rich Tg for proteolytic degradation. To gain more insight into the role of megalin, here we studied thyroid function and histology in megalin deficient mice compared with WT mice. As expected from the knowledge that megalin mediates Tg transcytosis, serum Tg levels were significantly reduced in homozygous (megalin-/-) mice, which, more importantly, were found to be hypothyroid, as demonstrated by significantly reduced serum free thyroxine and significantly increased serum thyroid stimulating hormone (TSH) levels. In heterozygous (megalin+/-) mice, in which megalin expression was normal, thyroid function was unaffected. Although the serological phenotype in megalin-/- mice was not associated with histological alterations or goiter, our results support a major role of megalin in thyroid hormone secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Heterozygote
  • Homozygote
  • Low Density Lipoprotein Receptor-Related Protein-2 / deficiency
  • Low Density Lipoprotein Receptor-Related Protein-2 / physiology*
  • Mice
  • Mice, Knockout
  • Thyroglobulin / blood
  • Thyroglobulin / metabolism
  • Thyroid Gland / metabolism
  • Thyroid Gland / physiopathology*
  • Thyroid Hormones / blood
  • Thyroid Hormones / metabolism
  • Thyrotropin / blood
  • Thyroxine / blood


  • Low Density Lipoprotein Receptor-Related Protein-2
  • Thyroid Hormones
  • Thyrotropin
  • Thyroglobulin
  • Thyroxine