TSH receptor and thyroid-specific gene expression in human skin

Area of Science:

• Endocrinology
• Dermatology
• Immunology

Background:

• Autoimmune thyroid diseases (AITDs) involve autoantibodies against thyroid antigens.
• The skin's role in AITDs and the function of thyroid-specific genes in skin are not well understood.

Purpose of the Study:

• To investigate the expression and function of thyroid-specific genes (TSH-R, Tg, NIS, TPO) in human skin.
• To determine the effect of TSH and autoantibodies on skin cells.

Main Methods:

• Analysis of gene transcripts (mRNA) in skin biopsies and cultured keratinocytes/fibroblasts.
• Western blot and immunohistochemistry to detect TSH-R protein.
• Treatment of cultured cells with TSH and IgGs from AITD patients.

Main Results:

• TSH-R, Tg, NIS, and TPO transcripts were found in skin biopsies.
• TSH-R mRNA and protein were consistently detected in keratinocytes and fibroblasts.
• TSH stimulated keratinocyte and fibroblast proliferation and increased cAMP levels.
• IgGs from Graves' disease patients, but not chronic lymphocytic thyroiditis, induced keratinocyte proliferation and cAMP accumulation.

Conclusions:

• Thyroid-specific genes are expressed in skin cells.
• TSH and thyroid autoantibodies can directly affect skin cell proliferation.
• These findings support the role of autoantibodies in AITD-related skin manifestations.