Deep Proteome Profiling of Rat Dorsal Striatal Synaptoneurosomes Following Methamphetamine Exposure

Understanding how drug exposure alters synaptic proteins
is essential
for uncovering the molecular mechanisms underlying addiction and identifying
new therapeutic targets. Synaptoneurosomes (SNs), subcellular fractions
enriched in pre- and postsynaptic components, provide a powerful resource
for studying synaptic adaptations in the brain. Here, we applied a
deep, discovery-based proteomic strategy to profile SNs isolated from
the dorsal striatum (DS) of rats 1 h after acute methamphetamine (Meth)
administration. To maximize proteome coverage, we combined tandem
mass tag (TMT) labeling, offline high-pH fractionation, and low-pH
nanoflow liquid chromatography coupled to high-resolution (orbitrap)
mass spectrometry (HRMS). This approach enabled identification of
∼6100 cytosolic and membrane proteins from ∼500 ng of
SN proteome digestrepresenting the most comprehensive DS SN
proteome reported to date. A comparative analysis between Meth-treated
and saline control animals revealed 147 differentially abundant proteins
(81 with increased abundance; 66 with decreased abundance) enriched
in pathways related to dopamine biosynthesis, synaptic vesicle cycling,
mitochondrial energy metabolism, and proteasomal degradation. These
findings highlight coordinated molecular remodeling of striatal synapses
in response to Meth and demonstrate the utility of deep SN proteomics
in addiction research. Deep, low-input SN proteomics nominates vesicle
acidification, mitochondrial ATP supply, and proteasome function as
testable pathway-level targets in addiction.