Lithium-associated intracellular signaling pathways

Lithium-associated intracellular signaling pathways refer to the collective molecular cascades and enzymatic targets through which lithium ions exert their therapeutic effects, primarily in bipolar disorder (NIH, 2024). The primary components of these pathways include glycogen synthase kinase-3 beta (GSK-3β) and enzymes of the phosphoinositide cycle, such as inositol monophosphatase (IMPase) and inositol polyphosphate 1-phosphatase (IPPase) (Frontiers in Pharmacology, 2023). Lithium acts as a direct and indirect inhibitor of GSK-3β, which leads to the stabilization of β-catenin and the modulation of gene expression related to neuroprotection and synaptic plasticity (PubMed, 2018). Simultaneously, the inhibition of IMPase and IPPase results in the depletion of intracellular myo-inositol, thereby dampening overactive phosphoinositide signaling—a mechanism known as the inositol depletion hypothesis (Nature, 2022). These pathways also involve the modulation of protein kinase C (PKC) and adenylyl cyclase, contributing to the stabilization of mood and enhancement of cellular resilience (AAT Bioquest, 2023). Due to the broad nature of these effects and the narrow therapeutic index of lithium, clinical use requires careful monitoring of serum levels to avoid systemic toxicity (StatPearls, 2024).

Other names

Lithium targetsLithium signaling networkPhosphoinositide cycle and GSK-3 signalingLithium-sensitive enzymes

Lithium exerts its therapeutic effects through the direct and indirect inhibition of glycogen synthase kinase-3 beta (GSK-3β) and the uncompetitive inhibition of inositol monophosphatase (IMPase) and inositol polyphosphate 1-phosphatase (IPPase). These actions lead to the stabilization of β-catenin, depletion of intracellular myo-inositol, and modulation of protein kinase C (PKC) and adenylyl cyclase activity.