Slc:Wistar/ST rats develop unilateral thyroid dysgenesis: A novel animal model of thyroid hemiagenesis

PLoS One. 2019 Aug 29;14(8):e0221939. doi: 10.1371/journal.pone.0221939. eCollection 2019.

Abstract

Developmental anomalies of the thyroid gland lead to congenital malformations such as thyroglossal duct cysts and thyroid dysgenesis. However, the pathogenesis of thyroid dysgenesis remains unclear due to the lack of suitable animal models. This study demonstrated that Slc:Wistar/ST rats frequently developed unilateral thyroid dysgenesis, including hemiagenesis, characterized by the absence of one lobe. In Wistar/ST rats, each thyroid lobe was frequently different in size, and approximately 27% and 20% of the rats presented with hemihypoplasia and hemiagenesis of the thyroid gland, respectively. Dysgenesis was predominant on the left side in both sexes, without sex differences. At a young age, thyroid hemiagenesis did not alter body weight. In rats of both sexes with thyroid hemiagenesis, plasma total triiodothyronine and total triiodothyronine levels remained unchanged while plasma thyroid-stimulating hormone levels were significantly elevated in young rats. The remaining thyroid lobes increased in weight, but the follicular epithelial cells appeared normal in terms of their height and proliferating activities. On the side of thyroid dysgenesis, the parathyroid glands were normally localized and were situated at the same location as the contralateral glands. The ultimobranchial body remnants were localized at the level of the thyroid gland along with the cranial thyroid artery and vein, forming cell clusters or cystic structures and containing calcitonin-positive C-cells. In conclusion, Wistar/ST rats developed unilateral thyroid dysgenesis and may be novel and useful animal models for thyroid hemiagenesis in humans and for morphogenesis of pharyngeal pouch-derived organs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Disease Models, Animal*
  • Female
  • Immunohistochemistry
  • Male
  • Models, Biological
  • Rats
  • Rats, Wistar
  • Thyroid Dysgenesis / etiology*
  • Thyroid Dysgenesis / metabolism
  • Thyroid Dysgenesis / pathology*
  • Thyroid Hormones / metabolism

Substances

  • Thyroid Hormones

Grants and funding

This study was funded by JSPS KAKENHI, Grant Number: JP18K0703708. There was no additional external funding received for this study. TN, TY, HH, OT, and KN are employed by Japan Food Research Laboratories. Japan Food Research Laboratories provided support in the form of salaries for authors TN, TY, HH, OT, and KN, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the “author contributions” section.