Complex sentence: It is thought that fibroblast stimulation by the thyroid stimulating hormone (TSH) receptor increases the deposition of glycosaminoglycan, which results in an osmotic edema and fluid retention.
Split into simpler sentences: It is thought that fibroblast stimulation by the thyroid stimulating hormone (TSH) receptor increases the deposition of glycosaminoglycan. This results in an osmotic edema and fluid retention.