Glycogen synthase kinase 3 beta (GSK-3β) is a serine/threonine kinase that plays a central role in Parkinson's disease pathogenesis through its effects on tau hyperphosphorylation, alpha-synuclein (α-syn) phosphorylation and aggregation, mitochondrial dysfunction, and neuroinflammation. GSK-3β represents one of the most compelling therapeutic targets for disease modification in PD[1].
GSK-3β is constitutively active in neurons and its activity is regulated by inhibitory phosphorylation at Ser9. In PD, this inhibitory mechanism is impaired, leading to increased kinase activity that promotes pathological protein aggregation and neuronal death. The kinase also phosphorylates α-syn at Ser129, a modification abundant in Lewy bodies[2].
GSK-3β is one of the principal kinases responsible for tau hyperphosphorylation in PD, phosphorylating tau at multiple sites including Thr181, Ser202, Thr205, Ser396, and Ser404, promoting microtubule disassembly and neurofibrillary tangle formation.
GSK-3β phosphorylates α-syn at multiple sites, with Ser129 being the most studied. The relationship between GSK-3β activity and α-syn pathology is context-dependent.
GSK-3β contributes to mitochondrial dysfunction in PD through inhibition of mitochondrial biogenesis via PGC-1α, promotion of mitochondrial permeability transition, regulation of mitophagy through Parkin and PINK1, and enhancement of mitochondrial oxidative stress.
Lithium is a first-generation GSK3 inhibitor used clinically for bipolar disorder. It inhibits GSK-3β both directly and indirectly through Akt-mediated Ser9 phosphorylation[3]:
Tideglusib is a selective, irreversible GSK3 inhibitor developed by Nostrum. It has been evaluated in clinical trials for Alzheimer's disease with a favorable safety profile[4]:
AR-A014418 is a selective ATP-competitive GSK3 inhibitor developed by AstraZeneca:
CHIR99021 is a selective GSK3 inhibitor used in research to enhance Wnt signaling:
| Compound | Indication | Phase | Status |
|---|---|---|---|
| Tideglusib | Alzheimer's | Phase II | Completed |
| Lithium | PD | Various | Completed |
GSK3β represents a compelling therapeutic target in Parkinson's disease. While no selective GSK3 inhibitors have reached late-stage clinical development specifically for PD, lithium remains the most clinically tested GSK3 inhibitor for neurological applications.
See also GSK3 in Parkinson's Disease, GSK3 in Parkinson's Disease - Disease Focus, and PD Kinase Inhibitor Companies.
Golpich M, et al. Glycogen synthase kinase 3 beta (GSK-3β) signaling in Parkinson's disease. Cell Mol Neurobiol. 2017. ↩︎
Yuan YH, et al. GSK-3β and α-synuclein in Parkinson's disease. Behav Brain Res. 2020. ↩︎
Chiu CC, et al. Lithium therapy for Parkinson's disease. Transl Neurodegener. 2013. ↩︎
Lovestone S, et al. A phase II trial of tideglusib in Alzheimer's disease. J Alzheimers Dis. 2015. ↩︎