TSH receptor gene expression in retroocular fibroblasts

RNA was isolated from fibroblasts from the retroocular area, from endomysial fibroblasts obtained from orbital lateral rectus muscle, and from abdominal skin fibroblasts. The RNA was reverse transcribed into cDNA which was then used as a template for PCR with primers encompassing a portion (nucleotides 989-1235) of the extra-cellular domain of the human TSH receptor (hTSH-R). A definite 247 BP product was detected from fibroblast RNA by ethidium bromide staining, and was confirmed by hybridization with labelled hTSH-R cDNA. The product had homology with the known TSH-R cDNA. These studies indicate that human fibroblasts can express hTSH-R, and they suggest that a cross reactive immunologic response between anti-hTSH-R and these fibroblast TSH receptors may play a role in the genesis of Graves' ophthalmopathy.