[The physiologic and pathophysiologic role of stimulating growth factor ST2.]

Area of Science:

• Cardiovascular Biology
• Immunology
• Molecular Medicine

Context:

• The ST2 receptor, existing as ST2L (transmembrane) and sST2 (soluble) isoforms, is part of the interleukin-1 (IL-1) receptor family.
• The IL-33/ST2 system is activated in cardiomyocytes and fibroblasts by mechanical stress or damage, playing a role in cardiovascular pathophysiology.
• IL-33 binding to the IL-1R/ST2L receptor complex mediates cellular functions.

Purpose:

• To elucidate the dual role of the ST2 receptor system in cardiovascular health and disease.
• To investigate the cardioprotective effects mediated by the IL-33/ST2L interaction.
• To understand how the soluble ST2 (sST2) isoform antagonizes these protective mechanisms.

Summary:

• The interaction between IL-33 and its transmembrane receptor ST2L (ST2L) demonstrates cardioprotective effects, including reduced myocardial fibrosis, prevention of cardiomyocyte hypertrophy, decreased apoptosis, and improved cardiac function.
• Conversely, the soluble ST2 (sST2) isoform binds to IL-33, blocking the beneficial IL-33/ST2L interaction and eliminating its cardioprotective effects.
• Dysregulation of the IL-33/ST2 system is implicated in myocardial dysfunction, fibrosis, remodeling, and potentially atherosclerosis development.

Impact:

• The IL-33/ST2L system presents therapeutic potential for conditions involving myocardial overload or trauma.
• sST2 acts as a decoy receptor, inhibiting the protective IL-33/ST2L pathway, highlighting its pathological role.
• This research broadens the understanding of ST2's involvement in cardiovascular diseases, suggesting targeted therapeutic strategies.