Expression and Regulation of c-erb-A mRNA from Lymphocytes in Patients with Thyroid Dysfunction.

Abstract

To investigate the expression and the regulation of nuclear triiodothyronine (T3) receptor at the gene level, cellular(c)-erb-A mRNA isolated from lymphocytes in patients with thyroid dysfunction was examined by Northern gel analysis and dot blot hybridization using viral (v)-erb-A cDNA probe. Human lymphocytes contained c-erb-A mRNA (approximately 2.0 kilobase (kb) in length), and c-erb-A mRNA, which was determined by dot blot hybridization, was observed to be increased in hypothyroid patients but unaltered in hyperthyroid patients. The high level of c-erb-A mRNA may contribute in part to the increase in nuclear T3 receptor and these results suggest the presence of up-regulation of nuclear T3 receptor at the gene level in the lymphocytes of hypothyroid patients.

Growth hormone (GH) treatment reduces peripheral thyroid hormone action in girls with Turner syndrome

“…Therefore the GH‐induced impairment of TR expression in PBMC suggests a probable reduction of TR levels at tissue level and a diminished peripheral TH action. In agreement, several other reports also paralleled human PBMC TR mRNA expression with peripheral tissue response to TH 18–21 . The lack of modification of α 1 and β 1 TR mRNA levels in PBMC from untreated TS patients compared to control girls, suggested that the reduction of TR expression registered in TS patients under GH treatment was induced by the therapy and disregarded the presence of an altered TR profile in TS girls.…”

“…18 Several reports paralleled TR mRNA expression from PBMC with peripheral tissue responses to TH. [18][19][20][21] In turn, the determination of serum biochemical markers of TH action at tissue level has been extensively used. 22 Serum thyrotropin (TSH), sex hormone binding globulin (SHBG), osteocalcin (OC) and β -crosslaps ( β -CL) were measured as serum biochemical markers reflecting local TH action at the tissue sites: 23 TSH for pituitary, SHBG for liver, and OC and β -CL for bone.…”

“…According to our previous results from an animal model, the supraphysiological IGF‐I levels induced by GH treatment to TS girls could reduce TR expression at tissue level, leading to an impaired peripheral thyroid signalling pathway. TR are expressed in peripheral blood mononuclear cells (PBMC) and blood represents a tissue readily accessible for studies conducted in human beings 18 . Several reports paralleled TR mRNA expression from PBMC with peripheral tissue responses to TH 18–21 .…”

“…TR are expressed in peripheral blood mononuclear cells (PBMC) and blood represents a tissue readily accessible for studies conducted in human beings 18 . Several reports paralleled TR mRNA expression from PBMC with peripheral tissue responses to TH 18–21 . In turn, the determination of serum biochemical markers of TH action at tissue level has been extensively used 22 .…”

Decreased expression of retinoid nuclear receptor (RARα and RARγ) mRNA determined by real-time quantitative RT-PCR in peripheral blood mononuclear cells of hypothyroid patients

“…Indeed, TR mRNA has been found to be upregulated by hypothyroidism in lymphocytes (Nagayama et al 1988). Similarly, Li et al (1990) have described an increase in the maximal binding capacity of TR in hypothyroid conditions.…”