Insulin-Degrading Enzyme Dynamics in Alzheimer's Disease

The insulin-degrading enzyme (IDE) is a zinc-dependent metallopeptidase with a pivotal role in modulating cerebral levels of both insulin and amyloid β peptides. In the healthy brain, IDE contributes to synaptic homeostasis by cleaving extracellular amyloid β and internalised insulin, thus maintaining proteostatic balance. In Alzheimer’s disease (AD), IDE expression and catalytic efficiency are disrupted by oxidative and redox-mediated modifications, leading to impaired amyloid β clearance, synaptic dysfunction and downstream cognitive decline. Recent work has uncovered non-enzymatic functions of IDE in glial cells that influence neuroinflammation, while structural studies reveal dynamic conformational states that govern substrate specificity. Understanding these multifaceted roles of IDE is essential for the development of therapeutic strategies aimed at restoring proteolytic clearance of amyloid β, rebalancing insulin signalling and mitigating neurodegeneration on a global scale.

Research from Nature Portfolio

Studies in the past decade have illuminated how metabolic stress and pathogenic peptides converge to impair IDE function. One seminal investigation demonstrated that elevated glucose levels and oligomeric amyloid β synergise to increase neuronal nitric oxide production, inducing S-nitrosylation of IDE and thereby inhibiting its catalytic activity. The resulting accumulation of amyloid β and mitochondrial dysregulation drives synaptic loss, an effect attenuated by NMDA receptor antagonism. A complementary structural study employed kinetic-target guided synthesis to develop a small-molecule inhibitor that locks IDE into its closed conformation. Crystal and scattering analyses revealed how stabilising this state abrogates enzyme activity, leading to altered insulin and peptide homeostasis in vivo. Together, these works provide a mechanistic framework for redox-control of IDE and highlight conformational modulation as a potential therapeutic axis.

Insulin-Degrading Enzyme Dynamics in Alzheimer's Disease publication trend

The graph below shows the total number of articles in insulin-degrading enzyme dynamics in alzheimer's disease across all publications each year (not limited to Nature Index journals).

Technical terms

Insulin-degrading enzyme (IDE): A zinc-metallopeptidase responsible for proteolysis of insulin, amyloid β and other peptides in the brain and periphery.

Amyloid β: A peptide derived from amyloid precursor protein that aggregates into oligomers and plaques in Alzheimer’s disease.

Microglia: Resident immune cells of the central nervous system that clear debris and modulate neuroinflammation.

S-nitrosylation: A post-translational modification involving covalent attachment of a nitric oxide moiety to a cysteine thiol, altering protein function.

Metallopeptidase: An enzyme that utilises a metal ion in its active site to catalyse peptide bond hydrolysis.

References

1. Elevated glucose and oligomeric β-amyloid disrupt synapses via a common pathway of aberrant protein S-nitrosylation. Nature Communications (2016).
2. Catalytic site inhibition of insulin-degrading enzyme by a small molecule induces glucose intolerance in mice. Nature Communications (2015).
3. Insulin-degrading enzyme: Roles and pathways in ameliorating cognitive impairment associated with Alzheimer's disease and diabetes. Ageing Research Reviews (2023).
4. Insulin-degrading enzyme (IDE) as a modulator of microglial phenotypes in the context of Alzheimer’s disease and brain aging. Journal of Neuroinflammation (2023).
5. Insulin-degrading Enzyme Regulates Extracellular Levels of Amyloid β-Protein by Degradation*. Journal of Biological Chemistry (1998).