The sodium leak channel non-selective (NALCN) belongs to the ion channel family. Ion channels are expressed in nearly every neuron of the central nervous system. NALCN is a key regulator of resting membrane potential of neurons and endocrine cells. NALCN is involved in fundamental physiological processes such as breathing, sleep, circadian rhythm, locomotion and nociception. Variants of the NALCN gene cause rare but severe neurodevelopmental disorders.
In new research study published in Biomedicine & Pharmacotherapy, researchers at Thammasat University (Thailand) developed and validated a robust and reliable functional assay to study pharmacological properties of the NALCN channelosome (a channelosome being a collection of proteins associated with an ion channel). There have been no modulators of NALCN identified to date since its constitutive expression is usually toxic to commonly used cellular models like the HEK293 cell line.
Researchers overcame these challenges by engineering an inducible, multi-transposon-based system that enables stable expression of the full NALCN channelosome for both wild-type and mutant forms, using HEK293 cells.
Induction of NALCN expression was achieved by adding Doxycycline Hyclate ReadyMade Solution at a concentration of 0.1 µg/ml in the culture medium for 48 hours. The expression of the NALCN current, detected using patch-clamp electrophysiology, was detected in almost very cell and found to be stable for at least 4 days after induction of NALCN expression with Doxycycline.
Authors found that NALCN current expression is cell cycle-dependent, enabling the definition of optimal conditions for obtaining consistent and reliable electrophysiological recordings. Nearly all M-phase-arrested cells exhibited robust activity, so authors speculate that NALCN activity is linked to mitotic state rather than compound-specific effects. Using these innovative cellular tools and methods, they characterized the pharmacological properties of the NALCN current.
This work established a robust framework to identify elective NALCN modulators and lays the foundation for future compound discovery to identify potential therapeutic avenues for those with NALCN-associated neurodevelopmental diseases, and potentially even for those with chronic pain and cancer.
Reference
Thongsepee N et al (2026) An improved electrophysiological cellular assay to unlock the pharmacological modulation of the NALCN channelosome. Biomed. Pharmacother. 199:119458 Link.