Curated Optogenetic Publication Database

Abstract: The aggregation of the microtubule-associated protein tau into oligomeric complexes is strongly correlated with the onset and progression of neurodegeneration in Alzheimer's disease (AD). Increasing evidence implicates nuclear membrane disruption in AD and related tauopathies; however, whether this is a cause or consequence of neurodegeneration remains unresolved. Here, we show that nuclear lamina disruption emerges at the early Braak stages, coinciding with the initial formation of pathological tau aggregates in post-mortem AD brain tissue. Using the tauopathy mouse model (P301S PS19), we demonstrate that oligomeric tau (oTau) directly binds to the Lamin B Receptor (LBR), inducing nuclear envelope invaginations as revealed by electron microscopy. These structural alterations are accompanied by chromatin remodeling and gene expression dysregulation. To dissect the underlying mechanism, we employed a light-inducible OptoTau system (4R1N Tau::mCherry::Cry2Olig) in human iPSC-derived neurons, enabling real-time visualization of tau aggregation dynamics. This system revealed selective recruitment of oTau to the nuclear envelope and direct interactions with LBR and Lamin B2, leading to nuclear deformation and activation of the protein translational stress response. Together, these findings identify nuclear membrane disruption as an early and potentially causative event in tau-mediated neurodegeneration, establishing a mechanistic link between tau oligomerization, nuclear stress, and chromatin remodeling. Targeting nuclear destabilization may offer new therapeutic avenues for mitigating AD pathogenesis.

Abstract: The microtubule-associated protein tau aggregates into oligomeric complexes that highly correlate with Alzheimer’s disease (AD) progression. Increasing evidence suggests that nuclear membrane disruption occurs in AD and related tauopathies, but whether this is a cause or consequence of neurodegeneration remains unclear. Using the optogenetically inducible 4R1N Tau::mCherry::Cry2Olig (optoTau) system in iPSC-derived neurons, we demonstrate that tau oligomerization triggers nuclear rupture and nuclear membrane invagination. Pathological tau accumulates at sites of invagination, inducing structural abnormalities in the nuclear envelope and piercing into the nuclear space. These findings were confirmed in the humanized P301S tau (PS19) transgenic mouse model, where nuclear envelope disruption appeared as an early-onset event preceding neurodegeneration. Further validation in post-mortem AD brain tissues revealed nuclear lamina disruption correlating with pathological tau emergence in early-stage patients. Notably, electron microscopy shows that tau-induced nuclear invagination triggers global chromatin reorganization, potentially driving aberrant gene expression and protein translation associated with AD. These findings suggest that nuclear membrane disruption is an early and possibly causative event in tau-mediated neurodegeneration, establishing a mechanistic link between tau oligomerization and nuclear stress. Further investigation into nuclear destabilization could inform clinical strategies for mitigating AD pathogenesis.

Abstract: The microtubule-associated protein tau oligomerizes, but the actions of oligomeric tau (oTau) are unknown. We have used Cry2-based optogenetics to induce tau oligomers (oTau-c). Optical induction of oTau-c elicits tau phosphorylation, aggregation, and a translational stress response that includes stress granules and reduced protein synthesis. Proteomic analysis identifies HNRNPA2B1 as a principle target of oTau-c. The association of HNRNPA2B1 with endogenous oTau was verified in neurons, animal models, and human Alzheimer brain tissues. Mechanistic studies demonstrate that HNRNPA2B1 functions as a linker, connecting oTau with N6-methyladenosine (m6A) modified RNA transcripts. Knockdown of HNRNPA2B1 prevents oTau or oTau-c from associating with m6A or from reducing protein synthesis and reduces oTau-induced neurodegeneration. Levels of m6A and the m6A-oTau-HNRNPA2B1 complex are increased up to 5-fold in the brains of Alzheimer subjects and P301S tau mice. These results reveal a complex containing oTau, HNRNPA2B1, and m6A that contributes to the integrated stress response of oTau.