Endoplasmic reticulum (ER) stress and activation of the three unfolded protein response pathways, in particular the protein kinase RNA-like ER kinase (PERK) pathway, contribute to the pathophysiology of various neurodegenerative conditions including type 2 diabetes mellitus (T2DM). T2DM is an increasingly prevalent metabolic disorder affecting millions. Even with strict glucose control, patients with T2DM frequently experience mild cognitive impairment and exhibit a significantly increased risk of developing dementia. We previously demonstrated that impaired cognitive flexibility is associated with shortening of axon initial segment (AIS) length in the prefrontal cortex in the T2DM model db/db mice. The AIS plays the crucial roles of regulation of action potential initiation and neuronal output. Even subtle shortening of AIS length can reduce excitability of neurons. In this study, we hypothesized that ER stress mediates AIS shortening in diabetic conditions. Utilizing primary mouse cortical cultures, we show that sodium 4-phenylbutyrate, a well-documented ER stress inhibitor, prevents AIS shortening and PERK activation induced by the T2DM factor methylglyoxal. Exposure of cortical cultures to an established ER stress inducer tunicamycin caused dose-dependent reduction of AIS length in the generalized population of the neurons without affecting neuronal viability. Co-exposure to a PERK-specific inhibitor GSK2606414 prevented AIS shortening induced by tunicamycin. These results demonstrate ER stress is sufficient and necessary for AIS shortening in vitro. Our findings identify ER stress and AIS shortening as potential therapeutic targets in T2DM-related cognitive impairment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12031-025-02448-y.

Ischemic stroke (IS) is one of the leading causes of mortality and long-term disability worldwide. Electroacupuncture (EA) is commonly used in the treatment of IS, meaning that may reduce cerebral ischemia–reperfusion injury (CIRI). The middle cerebral artery occlusion/reperfusion (MCAO/R) rat models were created by the modified Zea Longa suture method. EA treatment was performed for 7 consecutive days at the acupoints Neiguan (PC6), Shuigou (GV26), and Sanyinjiao (SP6). The neurological function was assessed using the Zausinger six-point neurological deficiency score. The cerebral infarct volume was detected by 2,3,5-triphenyl tetrazolium chloride (TTC) staining. Hematoxylin and eosin (HE) staining was employed to observe the pathological changes in brain tissues. Prussian blue staining was employed to investigate iron deposition within the brain tissues. Transmission electron microscopy (TEM) was utilized to examine the morphological characteristics of mitochondria. Simultaneously, flow cytometry was utilized to detect the fluorescence intensity of reactive oxygen species (ROS). Assay kits were employed to measure the levels of Fe2+ and glutathione (GSH). Additionally, western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) assays were performed to evaluate the expression levels of proteins associated with ferroptosis. Compared with the MCAO/R group, both the MCAO/R + EA and MCAO/R + DFO groups exhibited significant improvements in neurological function following cerebral ischemia–reperfusion (CIR), attenuated the pathological brain tissue injury, and reduced the cerebral infarct volume and iron deposition in brain tissue. Furthermore, both the MCAO/R + EA and MCAO/R + DFO groups displayed a marked reduction in mitochondrial injury. There was a substantial decrease in Fe2+ and ROS levels, accompanied by a notable increase in GSH level and glutathione peroxidase 4 (GPX4) activity. Compared with the MCAO/R group, the levels of ferroportin1 (FPN1) protein and mRNA expression were significantly increased in the MCAO/R + EA and MCAO/R + DFO groups, and the expression levels of transferrin (TF), transferrin receptor 1 (TFR1), divalent metal transporter 1 (DMT1) protein and mRNA, as well as ferritin (FER) protein, were significantly decreased. EA inhibits ferroptosis by modulating iron metabolism and oxidative stress to alleviate CIRI, exerting neuroprotective effects.Graphical

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with multifactorial etiopathogenesis, where oxidative stress (OS) has been implicated as a key contributing factor. This study aimed to evaluate the plasma dynamic thiol/disulfide homeostasis (DTDH) parameters—a relatively novel OS biomarker—alongside classical OS biomarkers, including total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), glutathione, and glutathione peroxidase (GPx), in preschool children diagnosed with ASD. A total of 49 children with ASD and 31 age- and sex-matched typically developing children between the ages of 2 and 6 years were included. In addition to sociodemographic data collection, the Childhood Autism Rating Scale (CARS) and Clinical Global Impression-Severity Scale (CGI-S) were administered to assess autism severity. Blood samples were analyzed using automated spectrophotometric techniques to determine OS biomarkers. The results demonstrated that DTDH parameters and classical OS markers exhibited parallel changes; however, no statistically significant differences were detected between the ASD and control groups across all OS markers. Furthermore, no significant association was found between OS biomarkers and autism severity. Moreover, we intentionally restricted our sample to a younger age group to enable a focused examination of OS dynamics during early developmental stages. This study underscores the potential impact of age as a critical determinant in OS-related alterations in autism and highlights the need for further age-stratified investigations to elucidate the role of OS in ASD pathophysiology and its potential diagnostic relevance.

The transcription factor SOX10 is a key regulator of myelinated glial cell phenotype and function, with a known role in multiple sclerosis (MS). SOX10 is also expressed in enteric glial cells (EGC) within the gut, yet its regulatory functions in EGC remain poorly understood. This study aimed to identify SOX10 target genes that influence EGC phenotype and may have implications for MS. An EGC cell line was established for doxycycline-inducible SOX10 overexpression. Impact of SOX10 overexpression on EGC phenotype was assessed by genome-wide expression analysis and results were validated via RT-qPCR and western blot. Data were compared with SOX10 ChIP-seq and transcriptomic datasets from MS patients to identify pan-glial SOX10 target genes potentially linked to neuroinflammatory disorders. SOX10 overexpression was associated with ectopic upregulation of genes related to myelin regulation and glial differentiation, as evidenced by increased PLP1 expression at mRNA and protein levels. Comparison to ChIP-seq and MS datasets highlight SOX10 target genes, including PLP1, RNF130, NES and APOD potentially involved in central and peripheral manifestations of MS pathology. Our findings support a cell-specific regulation of EGC phenotype through SOX10 expression level and identify SOX10-regulated genes relevant to EGC function. This research advances the understanding of EGC diversity and provide information about glial cells targeting in neuroinflammatory disorders.

The protein composition of tear fluid (TF) reflects the severity and progression of many age-related diseases. Here, we evaluated TF proteins from patients with mild Alzheimer’s disease (AD) and cognitively healthy controls (CO) to explore potential new biomarker molecules. The aim of this study was to explore potential new biomarker molecules by examining the expression of TF proteins whose function is related to neuroinflammation. We examined 53 participants (34 COs, mean age 71 years, Mini-Mental State Examination (MMSE) score 28.9 ± 1.4; 19 with AD, Clinical Dementia Rating 0.5–1, mean age 72 years, MMSE 23.8 ± 2.8). All participants underwent neurological status examination, cognitive testing, and ophthalmological examination. TF was collected using Schirmer strips, and TF protein content was evaluated using mass spectrometry-based proteomics and label-free quantification. We report 14 TF proteins that showed altered protein expression in the AD group compared to the CO group. Twelve proteins were significantly upregulated (SERPINA3, FGA, SIAS, ORM1, ANXA3, G6PI/NLK, CH3L2, MSLN, CPPED1, JCHAIN, IGHV5-51, SPARCL1) and two were downregulated (PIP, SCGB2A1) (p ≤ 0.05). Observed altered expression of TF proteins in the AD group may have potential in AD pathology. Since inflammation is one of the earliest signs of neurodegeneration in AD, these proteins are putative new biomarker candidates of early AD.

Ataxin-1 (ATXN1) is a nuclear-cytoplasmic shuttling protein, which, when expanded in its polyglutamine coding stretch, causes the progressive neurodegenerative disease Spinocerebellar Ataxia Type 1 (SCA1). While the role of nuclear ATXN1 as a repressor of transcription and regulator of splicing is well studied, its potential cytoplasmic role is more ambiguous. We previously demonstrated mitochondrial dysfunction- including altered respiration and enhanced oxidative stress- is associated with early SCA1 pathogenesis in mice. Moreover, intervention with the electron transport chain substrate succinic acid ameliorated Purkinje cell atrophy and cerebellar behavioral deficits. We now hypothesize that mitochondrial dysfunction in SCA1 may be at least partially due to cytoplasmic interactions between ATXN1 and mitochondria, rather than a result of mutant ATXN1’s altered nuclear function. In order to characterize the extent of mitochondrial dysfunction due to mutant ATXN1, we turned to cerebellar-derived Daoy cells which endogenously express human wild type ATXN1. Our SCA1 Daoy model stably over-express phosphorylation-prone, nuclear-aggregating ATXN1[82]. Despite the short lifespan (~ 33 h), Daoy SCA1 cells reveal gross morphological, compositional, and physiological deficits. Conversely, expression in Daoy of a phosphorylation-resistant, cytoplasm-degradable, non-aggregating ATXN1 (ATXN1[82Q-A776]) selectively resulted in intermediate physiological phenotypes and altered mitochondrial protein composition. Finally, our meta-analysis of previously published data supports direct interactions between mutant polyglutamine-expanded ATXN1 and mitochondrial proteins involved in apoptosis, oxidative phosphorylation, composition, and transcription. Our data therefore suggest that irrespective of a disease context and ATXN1[82Q] nuclear aggregation, mitochondrial deficits occur. Overall, the results of this study show mutant ATXN1 can affect metabolic processes outside of its deleterious effect on transcription and splicing, and highlights its multifaceted and multicompartmental function.

Studies on the relationship between the adenosinergic system and schizophrenia have been released, but none has explored the relationship between adenosine deaminase and psychosis risk. Our primary objective is to investigate the sensitivity and specificity of peripheral adenosine deaminase enzyme levels regarding susceptibility to psychosis. In this cross-sectional case–control study, the serum levels of adenosine deaminase were compared among patients with schizophrenia, first-degree relatives of schizophrenia patients, and healthy controls. The patient and relative groups were classified as high-risk groups and healthy controls as low-risk groups. A binary logistic regression analysis was conducted to determine whether serum ADA levels can distinguish the low-risk group from the high-risk group. Healthy controls had higher serum ADA levels than the patient and relative groups (p = 0.019; p = 0.027). There was no statistically significant difference between patients and relatives (p = 0.998). Binary logistic regression analysis showed that serum ADA levels were 62.2% accurate in predicting psychosis risk, with a sensitivity of 82%. The results showed that serum ADA levels were significantly different between individuals at relatively low genetic risk (healthy controls) for schizophrenia and those at relatively high genetic risk (patients and relatives). According to the risk model based on serum ADA level, measuring serum ADA level may help distinguish genetically high-risk individuals from genetically low-risk individuals.

Traumatic brain injury (TBI) remains a major global health challenge with a need for improved diagnostic and prognostic biomarkers. This study aimed to evaluate the biomarker potential of extracellular vesicle (EV)-encapsulated glial fibrillary acidic protein (EV-GFAP), neurofilament light chain (EV-NfL), total tau (EV-T-Tau), and ubiquitin carboxy-terminal hydrolase L1 (EV-UCH-L1) in TBI. A cohort of 93 trauma patients (75 with TBI and 18 without TBI) was analyzed. Patients were sampled on admission, as well as 15 and 72 h post-injury. Following initial method validation, EVs were isolated from plasma using size exclusion chromatography (SEC), and plasma levels and EV cargo levels of biomarkers were measured using an ultra-sensitive Single Molecule Array. EV-GFAP levels were significantly elevated in TBI patients compared to non-TBI trauma patients at admission and 15 h. A positive head CT was associated with 2.85 (95% CI: 1.18–6.91) fold increased EV-GFAP, whereas EV-NfL, EV-T-Tau, and EV-UCH-L1 levels were not affected. None of the tested EV biomarkers were associated with 1-year mortality or 6–12 months’ functional outcome. Plasma-GFAP levels increased 3.4 (95% CI: 1.72–6.70) fold with a positive head CT but were not associated with outcomes. EV-GFAP shows potential as an early biomarker of TBI, but plasma-GFAP remains a practical and reliable alternative. Future studies should explore the potential complementary roles of EV-based biomarkers on alternative aspects of TBI pathophysiology and prediction of long-term outcomes. Studies should refine methods to enhance reproducibility and clinical applicability.

Transfer RNAs (tRNAs) are small non-coding RNA molecules transcribed from tRNA genes. tRNAs cleaved into a diverse population tRNA fragments (tRFs) ranging in length from 18 to 40 nucleotides, they interact with RNA binding proteins and influence the stability and translation. Stress is one of the reasons for tRFs cleavage. In our study, we modeled oxidative stress conditions with hydrogen peroxide (H2O2) exposure and dealt with one of the frequently expressed tRF in the hippocampus region of the brain, which is tRF-Glu-CTC. For this purpose, neural stem cells (NSCs) were exposed to H2O2, and tRF-Glu-CTC levels were increased in various H2O2 concentrations. A decrease was seen in microtubule-associated protein 2 (MAP2) marker expression. To understand the H2O2 oxidative stress condition on the expression of tRNA fragments, 72 hpf zebrafish embryos exposed to different H2O2 concentrations, an increase in the level of tRF-Glu-CTC was observed in all concentrations of H2O2 compared to control. Subsequently, neurogenesis markers were figured out via Calb2a (calbindin 2a) in situ hybridization (ISH) and HuC/D immunofluorescence staining (IF) staining experiments. Under H2O2 exposure, a decline was observed in Calb2a and HuC/D markers. To understand the inhibitory role of tRF-Glu-CTC on neurogenesis, NSCs were transfected via tRF-Glu-CTC inhibitor, and neurogenesis markers (ßIII-tubulin, MAP2, and GFAP) were determined with qRT-PCR and IF staining. tRF-Glu-CTC inhibitor reversed the diminished neuronal markers expression under the exposure of H2O2. Gene Ontology (GO) enrichment analysis showed us that targets of tRF-Glu-CTC are generally related to neuronal function and synaptic processes.

While Parkinson’s disease (PD) is predominantly sporadic, various mutations in the PTEN-induced putative kinase 1 (PINK1) gene have been linked to the autosomal recessive form of PD. PINK1, a serine/threonine protein kinase, holds a pivotal role in mitophagy - a process that selectively eliminates damaged mitochondria, overseeing mitochondrial quality control and ultimately safeguarding against neuronal cell loss in PD. Understanding the regulation of PINK1 stability is essential in comprehending PD pathology, given its involvement in a pro-survival pathway. Although some components of the ubiquitin-proteasome system (UPS) are recognized for mediating the proteolysis of PINK1, the specific enzyme(s) responsible for positively influencing PINK1 stability have remained elusive. In this study, we demonstrated that ubiquitin-specific protease 20 (USP20) functions as a novel deubiquitinating enzyme targeting PINK1. We found that USP20 positively regulates PINK1 levels by hydrolyzing Lys 48-linked polyubiquitin chains, promoting mitophagy under the treatment of mitochondrial depolarizing agent carbonyl cyanide m-chlorophenyl hydrazine (CCCP). Furthermore, CCCP treatment accelerates the deubiquitinating activity of USP20, facilitating the degradation of impaired mitochondria and enhancing mitochondrial quality control via PINK1 accumulation. Taken together, these findings unveil a novel enzyme, USP20, positively impacting PINK1 level and promoting CCCP-induced mitophagy. In addition, this study establishes a comprehensive map depicting how PINK1 can be regulated both positively and negatively through the coordinated action of multiple members in the UPS.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12031-025-02457-x.