# Identification of plasma biomarkers in a PTZ-induced Sudden Unexpected Death-like model through integrated proteomics and metabolomics methods **Authors:** Gaolin Zheng, Xinyan Yang, Yinyu Chen, Peng Zhang, Qianyun Nie PMC · DOI: 10.3389/fmed.2026.1774546 · Frontiers in Medicine · 2026-03-09 ## Abstract Sudden Unexpected Death in Epilepsy (SUDEP) refers to the unexplained, sudden death of individuals with epilepsy, and its incidence is closely linked to the severity and duration of seizures. This study aimed to identify plasma biomarkers associated with SUDEP through a combined proteomics and metabolomics approach. A PTZ-induced seizure-related sudden death (SUDEP-like) paradigm was established in Sprague-Dawley (SD) rats via intraperitoneal injection of pentylenetetrazol (PTZ). Hippocampal histology was included to provide pathological context for plasma proteomic and metabolomic changes in the SUDEP-like model. Hippocampal tissue was extracted for hematoxylin and eosin (HE) staining to observe pathological changes. Blood was collected for plasma separation, followed by combined analysis using Data-dependent ion acquisition (dDIA) with Nanoflow Liquid Chromatography-Tandem Mass Spectrometry (nanoLC-MS/MS) for proteomics and Ultra-High Performance Liquid Chromatography-Quadrupole-Orbitrap Mass Spectrometry (UHPLC-QE-MS) for metabolomics. Hematoxylin and eosin staining revealed a reduction in the number and morphological alterations of hippocampal neurons in SUDEP rats. Proteomic analysis identified 284 proteins that were significantly differentially expressed in the plasma of SUDEP rats. Key proteins such as mitogen-activated protein kinase 3 (Mapk3), protein BUD31 homolog (Bud31), heterogeneous nuclear ribonucleoprotein K (Hnrnpk), elongation factor 1-alpha (Eef1a1, Eef1a2), small ribosomal subunit proteins (Rps10, 11, 17, 20), and large ribosomal subunit proteins (Rpl23, 24, 38) were found to be highly associated with SUDEP and identified as potential plasma biomarkers. Metabolomic analysis revealed 565 metabolites that were significantly differentially expressed, leading to the identification of seven metabolic pathways potentially linked to the mechanisms of SUDEP. Combined analysis highlighted three pathways of significant association: β-alanine metabolism, sphingolipid metabolism, and pantothenate and Coenzyme A (CoA) biosynthesis. Furthermore, the integrated proteomic and metabolomic analysis highlighted 14 candidate plasma biomarkers. Among these, 11 molecules were identified in the metabolomic dataset, including sphinganine (DHS), phytosphingosine (PHS), sphingosine (SPH), sphingosine 1-phosphate (S1P), sphingomyelin (SM), glucosylceramide (GlcCer), β-alanine, carnosine, uracil, pantothenic acid, and L-histidine, whereas phosphatidylcholine:ceramide cholinephosphotransferase 2 (Sgms2), lysosomal acid glucosylceramidase precursor (Gba1), and aspartate 1-decarboxylase (Gadl1/Csad) were quantified in the plasma proteomic dataset and incorporated into the integrated pathway interpretation. These findings nominate candidate circulating signatures associated with seizure-related sudden death in this SUDEP-like paradigm. Translation to SUDEP risk stratification or forensic application requires independent validation in well-phenotyped human cohorts using standardized SUDEP classification. ## Full-text entities - **Genes:** Eef1a1 (eukaryotic translation elongation factor 1 alpha 1) [NCBI Gene 171361] {aka EEF-1, EEF1A, EF1A, Eef1a2, Eef1a2l1, SI}, Sgms2 (sphingomyelin synthase 2) [NCBI Gene 310849] {aka RGD1305778, Sms2, spermatin}, Csad (cysteine sulfinic acid decarboxylase) [NCBI Gene 60356], Bud31 (BUD31 spliceosome associated protein) [NCBI Gene 89819] {aka Edg2, G10, LPA1}, Mapk3 (mitogen activated protein kinase 3) [NCBI Gene 50689] {aka ERK1, ERT2, Erk-1, Esrk1, MAPK1, MNK1}, Eef1a2 (eukaryotic translation elongation factor 1 alpha 2) [NCBI Gene 24799] {aka EEF1AL, Ps10, RATPS10, STN, Stnl}, Gadl1 (glutamate decarboxylase-like 1) [NCBI Gene 367181] {aka RGD1565145}, Hnrnpk (heterogeneous nuclear ribonucleoprotein K) [NCBI Gene 117282] {aka Csbp, Hnrpk} - **Diseases:** seizures (MESH:D012640), epilepsy (MESH:D004827), SUDEP (MESH:D000080485), seizure-related sudden death (MESH:D003645) - **Chemicals:** pantothenate (MESH:D010205), PHS (MESH:C012491), sphingolipid (MESH:D013107), S1P (MESH:C060506), CoA (MESH:D003065), uracil (MESH:D014498), Hematoxylin (MESH:D006416), L-histidine (MESH:D006639), beta-alanine (MESH:D015091), GlcCer (MESH:D005963), HE (-), PTZ (MESH:D010433), sphinganine (MESH:C005682), SM (MESH:D013109), SPH (MESH:D013110), eosin (MESH:D004801) - **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606] ## Full text _Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC13006514/full.md ## Figures 7 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13006514/full.md ## References 68 references — full list in the complete paper: https://tomesphere.com/paper/PMC13006514/full.md --- Source: https://tomesphere.com/paper/PMC13006514