mapping-dysfunctional-protein-protein-interactions-in-disease

Mapping Dysfunctional Protein-Protein Interactions in Disease

Protein-protein interaction (PPI) networks are dynamically remodeled in disease, yet most systems biology approaches focus on changes in protein ...

Memorial Sloan Kettering Cancer Center

Alzheimer's disease (AD) progresses as a continuum, from preclinical stages to late-stage cognitive decline, yet the molecular mechanisms driving this progression remain poorly understood. Here, we provide a systems-level map of protein-protein interaction (PPI) network dysfunction across the AD spectrum and uncover epichaperomes-stable scaffolding platforms formed by chaperones and co-factors-as central drivers of this process. Using over 100 human brain specimens, mouse models, and human neurons, we show that epichaperomes emerge early, even in preclinical AD, and progressively disrupt multiple PPI networks critical for synaptic function and neuroplasticity. Glutamatergic neurons, essential for learning and memory, exhibit heightened vulnerability, with their dysfunction driven by protein sequestration into epichaperome scaffolds, independent of changes in protein expression. Notably, pharmacological disruption of epichaperomes with PU-AD restores PPI network integrity and reverses synaptic and cognitive deficits, directly linking epichaperome-driven network dysfunction to AD pathology. These findings establish epichaperomes as key mediators of molecular collapse in AD and identify network-centric intervention strategies as a promising avenue for disease-modifying therapies.

Systems-Level Interactome Mapping Reveals Actionable Protein Network Dysregulation Across the Alzheimer's Disease Spectrum.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron (MN) loss. The most common genetic cause, a hexanucleotide repeat expansion in C9orf72 (C9-ALS), disrupts microglial function, contributing to neuroinflammation, a key disease driver. To investigate this, we developed a three-dimensional spinal microtissue (SM) model incorporating human induced pluripotent stem cell (hiPSC)-derived MNs, astrocytes, and microglia. Screening 190 Food and Drug Administration (FDA)-approved compounds, we identified sartans-angiotensin II receptor I blockers (ARBs)-as potent inhibitors of neuroinflammation. Telmisartan, a highly brain-penetrant ARB, significantly reduced the levels of pro-inflammatory cytokines interleukin (IL)-6 and IL-8 and rescued MN loss in C9-ALS SMs. Our findings suggest that C9-ALS microglia drive MN toxicity and that telmisartan can effectively mitigate inflammation and preserve MN viability. This work lays the groundwork for modeling disease-related neuroinflammation and points to telmisartan as a therapeutic candidate worth further exploration for treating C9-ALS.

Telmisartan is neuroprotective in a hiPSC-derived spinal microtissue model for C9orf72 ALS via inhibition of neuroinflammation.

Phenotype switching is a form of cellular plasticity in which cancer cells reversibly move between two opposite extremes: proliferative versus invasive states. Although it has long been hypothesized that such switching is triggered by external cues, the identity of these cues remains unclear. Here we demonstrate that mechanical confinement mediates phenotype switching through chromatin remodelling. Using a zebrafish model of melanoma coupled with human samples, we profiled tumour cells at the interface between the tumour and surrounding microenvironment. Morphological analysis of interface cells showed elliptical nuclei, suggestive of mechanical confinement by the adjacent tissue. Spatial and single-cell transcriptomics demonstrated that interface cells adopted a gene program of neuronal invasion, including the acquisition of an acetylated tubulin cage that protects the nucleus during migration. We identified the DNA-bending protein HMGB2 as a confinement-induced mediator of the neuronal state. HMGB2 is upregulated in confined cells, and quantitative modelling revealed that confinement prolongs the contact time between HMGB2 and chromatin, leading to changes in chromatin configuration that favour the neuronal phenotype. Genetic disruption of HMGB2 showed that it regulates the trade-off between proliferative and invasive states, in which confined HMGB2 tumour cells are less proliferative but more drug-resistant. Our results implicate the mechanical microenvironment as a mechanism that drives phenotype switching in melanoma.

Article	Year
Systems-Level Interactome Mapping Reveals Actionable Protein Network Dysregulation Across the Alzheimer's Disease Spectrum. Research square\| PubMed ID: 39989971	2025
Telmisartan is neuroprotective in a hiPSC-derived spinal microtissue model for C9orf72 ALS via inhibition of neuroinflammation. Stem cell reports\| PubMed ID: 40541176	2025
Mechanical confinement governs phenotypic plasticity in melanoma. Nature\| PubMed ID: 40866703	2025

Laura Tuffery

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