PTP1B in astrocytes drives pathogen-induced neurodegeneration

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Pathogen infections are increasingly linked to Alzheimer's disease (AD) pathogenesis.
• Astrocyte-neuron interactions are crucial for neuroinflammation and synaptic homeostasis.
• The precise cellular mechanisms of infection-induced neurodegeneration are not fully understood.

Purpose of the Study:

• To investigate the role of astrocytic protein tyrosine phosphatase 1B (PTP1B) in infection-induced neurodegeneration.
• To elucidate the mechanisms by which PTP1B contributes to cognitive decline and synaptic damage.
• To assess the translational relevance of PTP1B in human AD and infection.

Main Methods:

• Utilized a murine model of chronic Toxoplasma gondii (T. gondii) infection.
• Employed conditional deletion and pharmacological inhibition of astrocytic PTP1B.
• Assessed neuroinflammation, synaptic integrity, cognitive function, astrocyte reactivity, and neuronal senescence.
• Analyzed human serum samples and AD patient transcriptomes.

Main Results:

• Elevated astrocytic PTP1B levels correlated with neuroinflammation and cognitive impairment in T. gondii infected mice.
• Deletion or inhibition of astrocytic PTP1B ameliorated neuroinflammation, restored synaptic integrity, and rescued cognitive function.
• Astrocytic PTP1B promoted A1-like reactive astrocytes, excitotoxicity, and neuronal senescence, leading to synaptic damage.
• Elevated PTP1B and senescence markers were found in T. gondii infected individuals and AD patients.

Conclusions:

• Astrocytic PTP1B is a key regulator of astrocyte reactivity during infection, impairing astrocyte-neuron crosstalk.
• PTP1B-mediated disruption of astrocyte-neuron communication contributes to pathogen-driven neurodegeneration and cognitive decline.
• Targeting astrocytic PTP1B offers a potential therapeutic strategy for infection-associated neurodegenerative diseases like AD.