The C-Cell Hyperplasia in Cellular Retinoic Acid Binding Protein 1 (CRABP1) Knockout Male Thyroid Gland

Abstract

The thyroid gland consists of follicles lined by thyrocyte, while parafollicular cells or C-cells reside between follicles. C-cell hyperplasia is the increase of C-cell proliferation that might progress to medullary thyroid carcinoma (MTC). MTC accounts for 4% of thyroid cancer. Despite that the thyrocytes are derived from the endoderm layer, and C-cells derived from the neural crest layer. Several transcription factors are shared between C-cells and thyrocyte progenitors. Cellular retinoic acid binding protein 1 (CRABP1) is highly expressed in the human thyroid gland. Previously, CRABP1 was reported to play a crucial role in maintaining thyrocytes’ functioning. Here, we evaluate several transcription factors and the histopathologic features of CRABP1 knocking out (CKO) mice. 

The SOX17 and Calca gene expression in 15 month old mice are significantly higher in CKO mice than those of wild-type (W.T.) The FOXa2 gene expression in 3 months old mice is significantly higher in CKO than that of W.T. The histopathological examination indicated the significantly smaller follicle sizes and greater number of cells in CKO mice than that of W.T. CKO in 15 months old mice is associated with altered thyroid transcriptional factors, suggesting a potential role for CRABP1 in maintaining thyrocytes and C-cell balance in the thyroid gland.