ACS Chemical Neuroscience最新文献

Glioblastoma multiforme (GBM) is a highly aggressive brain cancer with a median survival of 15 months. Despite advancements in conventional treatment approaches such as surgery and chemotherapy, the prognosis remains poor. This study investigates the use of rapid evaporative ionization mass spectrometry (REIMS) for real-time overall survival time classification of GBM samples and uses matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) to compare lipidomic differences within GBM tumors. A total of 45 GBM biopsies were analyzed to develop a survival prediction model for IDH-wild type GBM. REIMS patterns from 28 patients were classified with a 97.7% correct classification rate, identifying key discriminators between short-term (0-12 months) and prolonged (>12 months) survivors. Cross-validation with additional samples showed that the model correctly classified short-term and prolonged survival with 66.7 and 69.4% accuracy, respectively. MALDI-MSI was performed to confirm the discriminators derived from REIMS data. Results indicated 42 and 33 discriminating features for short-term and prolonged survival, respectively. Proteomic profiling was performed by isolating tumor regions via laser-capture microdissection (LMD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Subsequently, 1387 proteins were identified, of which 79 were significantly altered. In conclusion, this study shows that REIMS rapidly predicts glioblastoma survival times based on lipidomic profiles during electrosurgical dissection. MALDI-MSI confirmed that these differences were specific to the tumor region in the glioblastoma sections. LMD-guided LC-MS/MS-based proteomics revealed significantly altered pathways between short-term and prolonged survival. This research, including the comprehensive predictive survival model for GBM, could guide tumor resection surgeries based on accurate real-time tumor tissue identification as well as provide insights into overall survival mechanisms, possibly related to therapy response.

Voltage-gated sodium channels are the main targets of antiepileptic drugs, such as sodium valproate (VPA). Single nucleotide polymorphisms (SNPs) in the Nav1.6 isoform (SCN8A) have been reported to be closely associated with motor dysfunction in pediatric akathisia epileptica. In this study, we conducted a genetic screening of pediatric patients with seizures treated solely with VPA and identified two novel missense mutations of SCN8A (A1534V and Q1853H). Electrophysiological results revealed that the peak currents of the A1534V variant were smaller compared to that of the wild-type (WT) channel. The A1534V variant also caused a positive shift in the I-V curve, indicating a change in the voltage dependence of activation compared to the WT channels. In contrast, VPA induced a significant negative shift in the inactivation of both WT and A1534V mutant. However, the inhibition of currents by VPA was weaker in the A1534V variant than in WT. Furthermore, the recovery time constant of the A1534V variant was shorter than that of WT when treated with VPA. Regrettably, although the Q1853H variant can be expressed in HEK293T cells, the detected current is too small (approximately 50 pA). In conclusion, our results suggest that the A1534V mutation is a novel loss-of-function variant that exhibits moderate insensitivity to VPA. These results underscore the importance of Nav1.6 as a key target in epilepsy and highlight the necessity of analyzing its role in the pathological process.

Bri2 BRICHOS, a folded domain of the transmembrane protein Bri2 expressed in both the brain and pancreas, is an experimentally known substoichiometric inhibitor of amyloid aggregation. The molecular chaperone effectively delays fibrillization at low molar ratios for both β-amyloid (Aβ) in Alzheimer's disease (AD) and islet amyloid polypeptide (IAPP) in type 2 diabetes (T2D). While discovering effective antiamyloid inhibitors that work at low doses is an appealing strategy to mitigate amyloid toxicity, the molecular mechanism underlying the broad and efficient antiamyloid activity of Bri2 BRICHOS remains unknown. Here, we computationally demonstrated that Bri2 BRICHOS exhibits a stronger binding affinity to fibril seeds than to monomers using atomistic discrete molecular dynamic simulations. By competing with monomers to bind the active elongation sites on newly nucleated, weakly populated fibril seeds, a small amount of Bri2 BRICHOS could block rapid fibril growth via monomer addition. The experimentally observed differential inhibition efficiency against IAPP and Aβ aggregation was found to depend on the relative fibril-binding affinities of the inhibitor compared to those of self-seeding monomers. Our computationally derived determinants for substoichiometric inhibition against amyloid aggregation by Bri2 BRICHOS may inform the future design of potent antiamyloid therapies for AD, T2D, and other amyloid diseases.

The causes of neurodegeneration remain elusive. There is growing evidence linking viral infection to dysregulated neurotransmission as a causative factor in Alzheimer's disease. Studies suggest that viral infection may result in dysregulated glutamatergic and l-arginine/NO neurotransmission that can initiate neurodegeneration and neuroinflammation within AD. This involves viral infection (HIV-1/HSV-1) altering glutamate biosynthesis and receptor activation resulting in excessive influxes of glutamate and subsequent dysregulation of Ca²⁺ influx that all contribute to reduced dendrite growth and tau phosphorylation. For l-arginine/NO neurotransmission, the mechanism derives from the "protective" antiviral mechanisms of NO that correlate with pathologies such as β-amyloid peptide accumulation and functional degeneration of hippocampal neurons, respectively. More research is required to underpin the direct mechanisms that viruses might impact to induce specific pathologies.

Studies have revealed that inhibition of glycine transporter type 1 (GlyT1) may provide a balanced regulation between excitation and inhibition in some brain structures and, thereby, modulate seizure activity. Data on the role of GlyT1 in epilepsy are, however, very limited. Here, we examined the effect of SSR504734, a highly selective and reversible GlyT1 inhibitor, on three acute seizure tests in mice. We also evaluated its impact on neurotransmitter levels in the relevant brain structures following seizures, possible adverse effects, and changes in the levels of inflammatory mediators in the serum and liver. In addition, in vivo pharmacokinetic profile and in vitro ADME-Tox properties of SSR504734 were investigated. The results show that SSR504734 significantly increased the threshold for tonic hindlimb extension in the MEST test after acute and repeated treatment but had no influence on seizure thresholds in the 6 Hz and i.v. PTZ seizure tests. SSR504734 did not affect the levels of glutamate, GABA, glycine, or adenosine in brain structures of mice with MES-induced seizures. However, after acute treatment, the concentration of glutamate and adenosine in the brainstem of control animals (i.e., without seizures) decreased. Moreover, SSR504734 increased the levels of inflammatory markers (TNF-α, Il-1β, IL-6, IL-10, and TLR4) in serum. In vivo pharmacokinetic profiling and in vitro ADME-Tox data confirmed suitable drug-like properties of SSR504734, including its notable penetration into brain tissue. However, possible hepatotoxicity at higher doses should be taken into account. Further studies should be considered to better characterize the SSR504734-mediated effects as well as to validate GlyT1 as a potential new molecular target in epilepsy treatment.

The protein misfolding and aggregation of α-synuclein (α-Syn) into neurotoxic amyloids underlies the pathogenesis of neurodegenerative diseases such as Parkinson's disease (PD). Emerging evidence suggests that 4-phenylbutyrate (PBA) may play a role as a potential chemical chaperone for targeting α-Syn aggregation, but its molecular mechanism remains largely unknown. Using in vitro assays, we demonstrate that PBA treatment alters the pattern of α-Syn aggregation, as evidenced by reduced formation of oligomeric species and its increased susceptibility to proteolytic cleavage under the influence of PBA. Proteinase K (PK) assays, surface plasmon resonance (SPR), Nile red assays, and cytotoxicity assays indicate that PBA interacts with the extensive hydrophobic contacts of α-Syn oligomers and significantly reduces α-Syn-amyloid-induced toxicity. Furthermore, using thioflavin T-based assays, we elucidated the kinetics of PBA-mediated modulation of α-Syn aggregation, highlighting its role in accelerating the formation of α-Syn amyloid fibrils. Molecular dynamics (MD) simulations suggest PBA's role in the destabilization of the C-terminus in α-Syn oligomers through multiple residue interactions. Collectively, our findings provide compelling evidence for the neuroprotective potential of PBA in targeting protein misfolding and aggregation in PD and suggest an avenue for disease-modifying interventions in neurodegenerative disorders.

Evidence from previous research demonstrates a relationship between diabetes mellitus (DM) and Parkinson's disease (PD). T2DM is associated with chronic glucose dysregulation, as an etiological factor. It inhibits neuronal function through disrupted insulin signaling and oxidative stress, which ultimately lead to the loss of dopaminergic neurons in the substantia nigra (SN). Interactions between T2DM and PD were analyzed by gene expression, coexpression, and gene set enrichment via NCBI and STRING databases following pathways like KEGG and Reactome. The study identified nine key gene interactions through published literature on different databases and search engines that are involved in the progression of these chronic diseases. Furthermore, some genetic and nongenetic risk factors, gene mutations and environmental factors, are also involved in the progression of T2DM and PD. This review highlights the limitations of currently available drug treatments for these diseases and examines modern therapeutic approaches to address neurodegenerative and metabolic abnormalities. We critically assess the current experimental methodologies aimed at unraveling the pathophysiological mechanisms linking PD and T2DM while addressing the key challenges impeding a comprehensive understanding of the concurrent emergence of these debilitating age-related conditions.

[¹⁸F]PI-2620 is a promising radiopharmaceutical for positron emission tomography (PET) imaging of both Alzheimer's disease (AD) and non-Alzheimer's disease (non-AD) tauopathies in humans. An array of fluorinated derivatives of the carbazole scaffold of PI-2620 were synthesized and evaluated. In vitro binding assays with [³H]PI-2620 in human tissues with AD, progressive supranuclear palsy, and corticobasal degeneration, combined with in silico predictions of blood-brain barrier permeability, led to the selection and radiosynthesis of [¹⁸F]F-4 as a promising radiotracer. In vivo PET imaging with [¹⁸F]F-4 in healthy rats showed brain uptake and kinetics suitable for neuroimaging, similar to those of [¹⁸F]PI-2620. A first-in-human PET imaging study in a healthy subject as well as a patient with AD, in comparison with [¹⁸F]PI-2620 in the same AD subject, confirmed that [¹⁸F]F-4 is an alternative radiopharmaceutical for imaging tau protein.

Numerous studies have demonstrated a positive correlation between sleep disorders and hyperalgesia. These sleep disorders adversely affect the descending pain regulatory system. Researchers have extensively studied the midbrain dopamine system in relation to pain associated with sleep disturbances. Our study shows that chronic sleep deprivation decreases dopamine responses to noxious stimuli within the mouse nucleus accumbens, regulated by dopamine release and intracellular signals. Furthermore, we confirmed that the dopamine D₂ receptors play a critical role in the pain associated with chronic sleep deprivation. Importantly, we revealed that homer1a in D₂ receptor neurons enhances AMPA receptors expression.

Among serotonin receptors, the 5-HT₆ subtype is an important protein target and its ligands may play a key role in the innovative treatment of cognitive disorders. This study aimed to extend the body of preclinical research on two naphthyl-derived methylpiperazine-1,3,5-triazine analogues with thioether (WA-22) or Se-ether (PPK-32) linkers, the newly described compounds having high affinity and selectivity for 5-HT₆ receptors and drug-like parameters in vitro. Thus, crystallography-supported deeper insight into their chemical properties, the comparison of their neuroprotective and pharmacokinetic profiles, and especially their impact on memory disturbances after chronic administration to rats were investigated. As a result, the chronic administration of WA-22 completely reversed (+)MK-801-induced memory disturbances evaluated in the novel object recognition test (NORT) in rats. The pharmacokinetic and biochemical results support the notion that this 1,3,5-triazine 5-HT₆ receptor ligand could offer a promising therapeutic tool in CNS-related disorders. The selenium compound PPK-32, with a similar range of activity at acute administration, has shown even broader neuroprotective profiles, especially at the genetic level. However, for therapeutic use, its weaker pharmacokinetics (stability), which is a probable limit for action upon chronic administration, would require improvement, e.g., by an appropriate formulation.