Orai storeoperated Ca²⁺ entry channels modulate urethral smooth muscle contractility

Area of Science:

• Physiology
• Cell Biology
• Urology

Background:

• Urinary incontinence (UI) affects 45% of adults, posing a significant clinical and socio-economic burden.
• Dysfunctional urethral smooth muscle (USM) contraction, leading to hypo- or hypercontractility, is a key contributor to UI.
• Current UI treatments are inadequate, partly due to limited understanding of the cellular mechanisms governing USM contraction.

Purpose of the Study:

• To review the critical role of store-operated calcium entry (SOCE) in urethral smooth muscle cell (USMC) calcium signaling.
• To explore the potential of SOCE as a therapeutic target for improving USM contractility and treating UI.

Main Methods:

• Literature review of studies investigating calcium signaling pathways in USMCs.
• Analysis of evidence implicating Orai-STIM proteins in SOCE within USMCs.
• Examination of species-specific data on L-type calcium channel function in urethral contraction.

Main Results:

• USM contraction is dependent on intracellular calcium (Ca2+) signaling, involving both internal Ca2+ release and extracellular influx.
• L-type calcium channel inhibitors show inconsistent effects on urethral contractions across species.
• Evidence suggests SOCE, mediated by Orai-STIM proteins, is crucial for maintaining Ca2+ signaling in USMCs.

Conclusions:

• SOCE is a critical determinant of Ca2+ signaling in USMCs across multiple species.
• Targeting SOCE represents a promising therapeutic strategy for modulating USM contractility and addressing UI.
• Further research into the cellular mechanisms of SOCE in USMCs is warranted to develop effective UI treatments.