Tissue Specificity: SOCE: Implications for Ca²⁺ Handling in Endothelial Cells.

Area of Science:

• Cellular Biology
• Physiology
• Vascular Biology

Background:

• Vascular endothelial cell (VEC) functions depend on precise cytosolic free Ca2+ ([Ca2+](i)) regulation.
• Agonist stimulation triggers IP3 receptor-mediated Ca2+ release from the endoplasmic reticulum (ER) and subsequent store-operated Ca2+ entry (SOCE).

Purpose of the Study:

• To review the mechanisms of intracellular Ca2+ regulation in VECs.
• To elucidate the specific roles of SOCE in endothelial functions.

Main Methods:

• This review synthesizes existing research on Ca2+ signaling in VECs.
• Focuses on the mechanisms and functional consequences of SOCE.

Main Results:

• SOCE is graded with ER Ca2+ store depletion and occurs in specific subcellular microdomains.
• In calf pulmonary artery endothelial cells, SOCE uniquely drives nitric oxide production and NFAT activation.
• These functions are unaffected by Ca2+ signals of similar magnitude from intracellular stores alone.

Conclusions:

• SOCE represents a distinct Ca2+ signaling mechanism controlling specific endothelial functions.
• SOCE is vital for endothelium-dependent smooth muscle relaxation, NO signaling, and excitation-transcription coupling.
• Understanding SOCE is key to comprehending endothelial cell physiology and therapeutic interventions.