microRNA expressions in CD4+ and CD8+ T-cell subsets in autoimmune thyroid diseases

Area of Science:

• Immunology
• Molecular Biology
• Endocrinology

Background:

• Graves' disease (GD) and Hashimoto's thyroiditis (HT) are the most prevalent autoimmune thyroid diseases (AITDs).
• MicroRNAs (miRNAs) are critical regulators of gene expression and immune responses.
• Understanding miRNA involvement in AITDs is crucial for elucidating disease pathogenesis.

Purpose of the Study:

• To investigate significant variations in key immunoregulatory miRNAs within peripheral blood mononuclear cells (PBMCs) and specific T-cell subsets (CD4+ and CD8+) of AITD patients.
• To correlate these miRNA alterations with the presence of GD and HT.

Main Methods:

• Semiquantitative SYBR Green PCR was employed to amplify selected miRNAs.
• Analysis was performed on PBMCs and purified CD4+ and CD8+ T-cells from 59 patients with GD, HT, and healthy controls.

Main Results:

• Both GD and HT patients exhibited significantly decreased levels of miRNA 200a (miRNA 200a_1 and miRNA 200a2*) in CD4+ and CD8+ T-cells compared to controls.
• Significantly reduced levels of miRNA 155 (miRNA 155_2 and miRNA 155*_1) were observed in CD8+ T-cells of HT and GD patients relative to controls.

Conclusions:

• This study confirms significant in vivo variations of miRNA 200a and miRNA 155 in CD4+ and CD8+ T-cells of patients with GD and HT.
• These findings contribute to a better understanding of gene regulation in the immune cells driving autoimmune thyroid diseases.
• The results expand the limited knowledge of miRNAs in the context of thyroid diseases.