Daniele, S. | Search bioRxiv

bioRxiv2026

Unconventional Small Molecule MNP-021 Protects Neuronal and Glial Function from Diabetes-Associated Glucotoxicity and Neuroinflammation

BackgroundDiabetes-associated neurodegeneration is amplified by methylglyoxal (MGO)-driven dicarbonyl stress linking hyperglycemia to neuronal insulin resistance and maladaptive neuroinflammation. We tested the neuroprotective activity of MNP-021, a non-electrophilic TRPA1 modulator, in neurons and glial cells in vitro. MethodsSH-SY5Y neurons were pretreated with MNP-021 and challenged with MGO, then profiled by high-content imaging, RNA-seq, Seahorse OCR/ECAR, glycolytic stress assays and AKT/ERK/CREB immunoblotting {+/-} insulin. In parallel, HMC3 glial cells were treated with MNP-021, exposed to LPS/TNF- or A{beta}(25-35) and tested for viability and inflammatory markers by ELISA and qRT-PCR. ResultsMGO increased nucleus-to-cytoplasm area ratio by 49% and dysregulated glucose handling, increasing 2-NBDG uptake by [~]25%, with GLUT1/GLUT4 membrane redistribution; MNP-021 normalized morphology, uptake, and transporter localization without cytotoxicity up to 10 {micro}M. RNA-seq identified 754 MGO-deregulated genes, including ISR/metabolic nodes (GCK, SESN2, PHGDH/PSAT1, PCK2); MNP-021 buffered stress-induced transcription with limited baseline effects, remodeled mitochondrial redox readouts consistent with controlled ROS signaling, while improving mitochondrial content/architecture and blunting stress-evoked compensatory glycolysis. MNP-021 restored pro-survival signaling (pAKT/pERK and nuclear pCREB), including insulin responsiveness during MGO exposure. MNP-021 reduced IL-6/TNF- release while increasing IL-10 and ARG1 ([~]1.9-fold vs LPS/TNF-) in HMC3 glial cells, shifting them toward a pro-resolving IL-10/ARG1 program with reduced A{beta}(25-35)-evoked cytokine release with GLP-1 remaining very low ([≤]10 pg/mL) and not significantly increased in this system. ConclusionsMNP-021 coordinates transcriptomic restraint, transporter-level glucose handling, mitochondrial resilience, and pro-survival/pro-resolving signaling across neuron-microglia compartments, supporting TRPA1-tuned small-molecule modulation as a candidate strategy against dicarbonyl-linked neuro-metabolic stress.

physiology↗

bioRxiv2023

Structural basis for differential p19 targeting by IL-23 biologics

BackgroundIL-23 is central to the pathogenesis of psoriasis, and is structurally comprised of p19 and p40 subunits. "Targeted" IL-23 inhibitors risankizumab, tildrakizumab, and guselkumab differ mechanistically from ustekinumab because they bind p19, whereas ustekinumab binds p40; however, a knowledge gap exists regarding the structural composition of their epitopes and how these molecular properties relate to their clinical efficacy. ObjectivesTo characterize and differentiate the structural epitopes of the IL-23 inhibitors risankizumab, guselkumab, tildrakinumab, and ustekinumab, and correlate their molecular characteristics with clinical response in plaque psoriasis therapy. MethodsWe utilized epitope data derived from hydrogen-deuterium exchange studies for risankizumab, tildrakizumab, and guselkumab, and crystallographic data for ustekinumab to map drug epitope locations, hydrophobicity, and surface charge onto the IL-23 molecular surface (Protein Data Bank ID Code 3D87) using UCSF Chimera. PDBePISA was used to calculate solvent accessible surface area (SASA). Epitope composition was determined by classifying residues as acidic, basic, polar, or hydrophobic and calculating their contribution to epitope SASA. Linear regression and analysis of variance was performed. ResultsAll the p19-specific inhibitor epitopes differ in location and size, with risankizumab and guselkumab having large epitope surface areas (SA), and tildrakizumab and ustekinumab having smaller SA. The tildrakizumab epitope was mostly hydrophobic (56%), while guselkumab, risankizumab, and ustekinumab epitopes displayed >50% non-hydrophobic residues. Risankizumab and ustekinumab exhibited acidic surface charges, while tildrakizumab and guselkumab were net neutral. Each inhibitor binds an epitope with a unique size and composition, and with mostly distinct locations except for a 10-residue overlap region that lies outside of the IL-23 receptor epitope. We observed a strong correlation between epitope SA and PASI-90 rates (R2 = 0.9969, p = 0.0016), as well as between epitope SA and KD (R2 = 0.9772, p = 0.0115). In contrast, we found that total epitope hydrophobicity, polarity, and charge content do not correlate with clinical efficacy. ConclusionsStructural analysis of IL-23 inhibitor epitopes reveals strong association between epitope SA and early drug efficacy in plaque psoriasis therapy, exemplifying how molecular data can explain clinical observations, inform future innovation, and help clinicians in specific drug selection for patients.

molecular biology↗