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Inhibition of LTP-Induced Translation by IL-1β Reduces the Level of Newly Synthesized Proteins in Hippocampal Dendrites
journal contribution
posted on 2019-01-29, 00:00 authored by G. Aleph Prieto, Erica D. Smith, Liqi Tong, Michelle Nguyen, Carl W. CotmanIn
rodent hippocampus, the inflammatory cytokine interleukin-1β
(IL-1β) impairs memory and long-term potentiation (LTP), a major
form of plasticity that depends on protein synthesis. A better understanding
of the mechanisms by which IL-1β impairs LTP may help identify
targets for preventing cognitive deterioration. We tested whether
IL-1β inhibits protein synthesis in hippocampal neuron cultures
following chemically induced LTP (cLTP). Fluorescent-tagging using
click-chemistry showed that IL-1β reduces the level of newly
synthesized proteins in proximal dendrites of cLTP stimulated neurons.
Relative to controls, in cLTP stimulated neurons, IL-1β inhibited
Akt/mTOR signaling, as well as the upregulation of GluA1, an AMPA
receptor subunit, and LIMK1, a kinase that promotes actin polymerization.
Notably, a novel TIR domain peptidomimetic (EM163) blocked both the
activation of p38 and the suppression of cLTP-dependent protein synthesis
by IL-1β. Our data support a model where IL-1β suppresses
LTP directly in neurons by inhibiting mTOR-dependent translation.