Thyroid-stimulating hormone acutely increases monocyte gene expression in vivo

Area of Science:

• Endocrinology
• Immunology
• Vascular Biology

Background:

• Thyroid-stimulating hormone (TSH) is known to induce pro-inflammatory and pro-coagulant states.
• The effect of TSH on blood monocyte activation, particularly in response to vascular stress, is not well understood.

Purpose of the Study:

• To investigate whether recombinant human (rh) TSH administration alters blood monocyte gene expression.
• To determine if acute TSH stimulation affects monocyte activation in patients undergoing screening for thyroid cancer recurrence.

Main Methods:

• Patients with a history of thyroid cancer treated with total thyroidectomy and radioablation received two intramuscular doses of rhTSH.
• Blood samples were collected at baseline, day 3, and day 5 post-rhTSH administration.
• Monocyte gene expression, including MCP-1, IL-1β, and CD36 mRNA, was analyzed.

Main Results:

• Monocyte MCP-1 mRNA expression significantly increased by 1.7-fold on day 5 after rhTSH stimulation (p=0.03).
• Expression of IL-1β and CD36 mRNA showed increasing trends on day 5, though not reaching statistical significance.
• Significant correlations were observed between patients' body mass index (BMI) and their TSH-stimulated monocyte mRNA responses for CD11a, CD14, and CD16.

Conclusions:

• Acute administration of TSH increases pro-atherogenic gene expression in blood monocytes.
• TSH may play a role in promoting inflammatory and pro-coagulant states through monocyte activation.