P3.50. FROM GENES TO ACTIVITY: INTEGRATED ANALYSIS OF PROTEASOME FUNCTION IN MICROGLIA AND
BRAIN REGIONS IN NEUROPATHIC PAIN
Natalia Stelmach1, Katarzyna Popiołek-Barczyk2, Marta Kamińska3, Natalia Małek1
1 Department of Chemical Biology and Bioimaging, Wroclaw University of Science and Technology
2 Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków
3 Broegelmann Research Laboratory, University of Bergen
INTRODUCTION: Neuropathic pain(NP) targets 7-10% of population, however only 30-40% of
patients experience relief from the available treatments and a look for new molecular targets remains an urgent
challenge. The nerve injuries lead to the release of TLR-4 agonists
triggering the activation of
NF-kB, which leads to the transcription of proinflammatory cytokines. The mechanism is regulated by the degradation via constitutive (c20S) and
immuno-(i20S) proteasome.
AIM(S): The aim was to determine the expression levels of β subunits of c20S/i20S in murine Chronic Constriction Injury (CCI) model adopting a multiomic approach.
METHOD(S): We employed the multiomic approach by simultaneous analysis of transcriptome, proteome and single-cell
proteome via RT-qPCR, Western Blot, and IMC via Hyperion
System within 6 CNS regions.
RESULTS: Multilevel profiling shows that proteasome expression in
NP is highly region-specific. Only the ipsilateral spinal cord displays a full
inflammatory switch, exhibiting parallel upregulation of β1/β5 and LMP2/LMP7. On the other hand, remaining structures
favor hybrid cores in which MECL-1 replaces β2 without full induction.
IMC analysis of spinal cord further revealed that LMP2 and LMP7
are differentially expressed across distinct cell clusters. LMP2 expression was
enriched in cluster 10, co-expressing IL-17RA and TLR4, suggesting association with
inflammatory microglia. LMP7 showed upregulation in cluster 1,
alongside GFAP, indicating involvement of astrocytes.
CONCLUSIONS: We demonstrate that i20S and c20S expression in
neuropathic pain is region-specific within the CNS. The ipsilateral spinal cord emerges as
the principal neuroinflammatory site, whereas the remaining regions display adaptive signatures of heightened proteotoxic stress.
The formation of hybrid catalytic cores containing MECL-1 in supraspinal regions led to
identifying MECL-1 as a putative regulator of the chronic phase. These findings argue for site and subunit-directed modulation of the proteasome rather than pan-complex inhibition.
FINANCIAL SUPPORT: The project was funded by the National Science Centre (OPUS grant no. 2023/49/B/NZ7/02172).