In ALS, TBK1 loss-of-function traps microglia in a senescence-like, SASP-producing state that drives neurodegeneration. By analogy, partial TBK1 insufficiency in AD microglia may similarly lock cells into an aged, pro-inflammatory transcriptional program, shifting them from a protective amyloid-clearance phenotype toward a destructive,tau-propagating one. This predicts that microglial TBK1 activity inversely correlates with AD severity, and that restoring TBK1 signaling attenuates neuroinflammation and tau spreading.

Analogy rationale: Both ALS and AD feature microglial dysfunction as a central pathogenic driver, and aging is the dominant risk factor for both—making the senescence/SASP axis a plausible convergent mechanism.

Disanalogies: AD genetics implicate TREM2 and APOE rather than TBK1 directly, and the amyloid-driven cascade may precede microglial senescence rather than follow it, unlike the more neuron-intrinsic onset in ALS.

In ALS, TBK1 loss-of-function traps microglia in a senescence-like, SASP-producing state that drives neurodegeneration. By analogy, partial TBK1 insufficiency in AD microglia may similarly lock cells into an aged, pro-inflammatory transcriptional program, shifting them from a protective amyloid-clearance phenotype toward a destructive,tau-propagating one. This predicts that microglial TBK1 activity inversely correlates with AD severity, and that restoring TBK1 signaling attenuates neuroinflammation and tau spreading.

Analogy rationale: Both ALS and AD feature microglial dysfunction as a central pathogenic driver, and aging is the dominant risk factor for both—making the senescence/SASP axis a plausible convergent mechanism.

Disanalogies: AD genetics implicate TREM2 and APOE rather than TBK1 directly, and the amyloid-driven cascade may precede microglial senescence rather than follow it, unlike the more neuron-intrinsic onset in ALS.

Falsifiable prediction: Single-nucleus RNA-seq of post-mortem AD prefrontal cortex will show a negative correlation between TBK1 expression and senescence markers (p21, p16, IL-6) specifically in microglia, replicating the aged-like signature observed in ALS mouse models.
This hypothesis was generated from `h-31ca9240f9fc` in `ALS` — judge it on its own merits but acknowledge the source.