Herdy, J. | Search bioRxiv

bioRxiv2026

A Toxic Tau-PFKFB3 Circuit Reduces F2,6BP Levels and Drives Neurodegeneration

Alzheimers disease (AD) and related dementias are progressive neurodegenerative disorders manifested by aggregation of Tau and Amyloid beta (A{beta}). Emerging evidence suggests that metabolic dysregulation contributes to AD pathogenesis, yet how metabolic alterations interface with neuronal integrity remains unclear. Here, we identify dysfunction in PFKFB3-F2,6BP (fructose-2,6-bisphosphate) metabolic axis as a key feature of AD. We show that pathological Tau aggregates aberrantly sequester PFKFB3, limiting its activity and resulting in F2,6BP depletion. F2,6BP exerts protective effects through multiple convergent mechanisms: (i) direct activation of polynucleotide kinase 3-phosphatase (PNKP) to facilitate DNA strand break repair; (ii) transcriptional upregulation of the protein phosphatase 2A catalytic subunit (PP2CA) to limit Tau phosphorylation; (iii) stabilization of PFKFB3 to diminish its sequestration into aggregates; and (iv) direct inhibition of Tau aggregation. These findings establish F2,6BP as a central node linking metabolic regulation to both genomic stability and proteostasis in AD. Importantly, exogenous F2,6BP supplementation rescues multiple pathological features across diverse model systems, including induced neuronal cell lines (iN), primary neurons, organotypic hippocampal slice cultures, and in a Drosophila model of AD. These findings redefine F2,6BP as a metabolite that directly coordinates genome maintenance and proteostasis in neurons. Overall, this study identifies the PFKFB3-F2,6BP axis as a central driver of AD pathogenesis and a promising therapeutic target. HighlightsO_LITau aggregates sequester PFKFB3 depletes neuronal F2,6BP C_LIO_LIF2,6BP links metabolism to DNA repair and Tau proteostasis C_LIO_LIF2,6BP activates PNKP and upregulates PP2A to counter Tau pathology C_LIO_LIF2,6BP supplementation rescues AD phenotypes across models C_LI

neuroscience↗

bioRxiv2026

DNA damage drives a unique, Alzheimer's disease-relevant senescent state in neurons

Alzheimers disease (AD) shares molecular hallmarks with the canonical drivers of cellular senescence. Senescent cells have also been shown to accumulate in the brain with age, yet the mechanisms linking AD pathology to the accumulation of senescent cells in the brain remain unclear. Here, we demonstrate that DNA damage in patient-derived directly induced neurons (iNs) drives a senescent-like cell state with relevance to AD. DNA damage-induced senescent iNs show significant transcriptional concordance with human AD neurons and a weighted gene co-expression network analysis (WGCNA) uncovers candidate regulators associated with the senescent-like state in neurons. Direct comparison of iNs to the original patient fibroblasts reveals striking cell-type specific senescence signatures following DNA damage. iNs adopt a p21-associated senescent-like state characterized by a senescence-associated secretory phenotype (SASP) and predicted activation of NF-{kappa}1. In contrast, fibroblasts develop a p16-associated senescent state lacking a SASP phenotype and show a predicted repression of NF-{kappa}1. Early responses to DNA damage further reveal divergent DNA damage response (DDR), with neurons exhibiting higher accumulation of damage lesions relative to fibroblasts. Together, these findings demonstrate that DNA damage drives a unique senescent-like neuronal state that models molecular features of AD, while also revealing fundamental cell-type specific differences in senescent-like phenotypes and DDR.

cell biology↗