ACS Chemical Neuroscience最新文献

Alzheimer's disease (AD) presents a critical therapeutic gap, necessitating novel multitarget strategies. Excitotoxicity via NMDA receptor overactivation and oxidative stress is a key driver of Tau hyperphosphorylation and neuronal loss. While the tripeptide Gly-Pro-Glu (GPE) derived from IGF-1 exhibits NMDA receptor antagonism, its clinical potential is limited by poor blood-brain barrier penetration and rapid hydrolysis. Herein, we rationally designed three novel GPE-derived oligopeptide conjugates (SAC-PE, SPE, and SAR-SPE) by replacing the N-terminal glycine with antioxidant moieties ((S)-allyl-l-cysteine or thioproline derivatives) while preserving the active C-terminal Pro-Glu (PE) dipeptide core. This design aimed to confer dual-targeting capabilities against both excitotoxicity and oxidative stress. Among them, SAC-PE demonstrated superior properties, including the highest calculated lipophilicity and excellent cellular safety. In Aβ_1-42-stimulated HT-22 hippocampal neurons, SAC-PE effectively scavenged reactive oxygen species (ROS), released endogenous H₂S, and significantly reduced p-Tau and p-CaMKII levels while upregulating the expression of the neurotrophic factor BDNF, synaptic proteins (SYN, PSD-95) and the antioxidant regulator Nrf2, outperforming GPE. In AD model mice, SAC-PE administration robustly improved cognitive deficits in Morris water maze (MWM), novel object recognition, and passive avoidance tests. Molecular and histological analyses confirmed its superior efficacy in reducing hippocampal p-Tau and p-CaMKII levels, enhancing Nrf2 expression, and preventing neuronal loss compared with GPE. These findings establish SAC-PE as a promising dual-targeting therapeutic candidate that synergistically inhibits excitotoxicity and oxidative stress, offering a novel strategic approach for AD modification.

Transferrin-functionalized chitosan nanoparticles (TfCZNP) were developed for the intranasal delivery of Cariprazine to enhance brain targeting and minimize systemic exposure. The optimized nanoparticles exhibited favorable physicochemical properties (size, 207 nm; PDI, 0.403; zeta potential, +34.1 mV) with confirmed transferrin conjugation (gel electrophoresis, surface plasmon resonance, and FTIR spectroscopy) and uniform morphology (TEM). TfCZNP showed sustained in vitro release, improved ex vivo nasal permeation, and excellent biocompatibility. Gamma-scintigraphy revealed preferential brain accumulation (44 ± 4%) with a minimal systemic distribution. Pharmacokinetics demonstrated higher brain exposure (C_max 132.35 ± 7.79 ng/mL; AUC_0-24h 498.67 ng·h/mL) and favorable targeting indices (DTE 6.26, DTI 6.04, direct transport percentage 90.69%) versus controls. Behavioral studies in ketamine-induced schizophrenia models confirmed the normalization of locomotor activity, anxiolytic effects, and reduced catalepsy. These findings establish TfCZNP as a safe, effective nose-to-brain delivery platform that enhances Cariprazine's therapeutic potential in neuropsychiatric disorders.

The human dopamine transporter (DAT) is a presynaptic transmembrane protein that facilitates the reuptake of synaptically released dopamine. Several lines of evidence indicate that DAT dysfunction is linked to neuropsychiatric disorders. Moreover, the lateral membrane diffusion and clustering propensity of DAT are emergent properties that may factor into functional dopamine signaling. The disorder-associated DAT missense mutant A559V undergoes anomalous dopamine efflux (ADE) and increased lateral mobility and diffuse localization. The D2 dopamine autoreceptor short isoform (D2S), a popular antipsychotic target, signaling augments ADE in DAT A559V and may form stable DAT-D2S complexes. Using quantum dot (Qdot)-based single-molecule localization microscopy, we investigated the effect of D2S antagonism on DAT and DAT A559V membrane mobility in transfected HEK-293 cells. Single-color Qdot-DAT tracking shows phenotypic rescue of DAT A559V mobility upon D2S antagonism, while aberrant DAT A559V mobility is insensitive to ADE-linked CaMKII activity. Using two-color Qdot tracking of both the transporter and receptor, we report the first DAT-D2S colocalization lifetime in live cells. We show an increased propensity for both transporter types to colocalize with D2S, without impacting D2S diffusion speed under D2S antagonism. Downregulating D2S activity may stabilize DAT coconfinement in D2S microdomains on the cell surface.

Parkinson's disease (PD) is characterized by mitochondrial dysfunction and impaired protein homeostasis, with the mitochondrial unfolded protein response (mtUPR) emerging as a key regulatory pathway in mitigating mitochondrial stress. This study aimed to explore the impact of shRNAs targeting CHCHD2 or FBXO7 on the mitochondrial unfolded protein response (mtUPR) in a Parkinson's disease (PD) cell model, clarify the mitochondrial-nuclear signaling pathways involving CHCHD2 and FBXO7, elucidate the mechanisms underlying mitochondrial dysfunction induced by these genes, and identify new therapeutic targets for early stage PD. An in vitro PD model was established by treating SH-SY5Y cells with MPP⁺; mitochondrial morphology was evaluated using transmission electron microscopy, and qRT-PCR and Western blot were employed to determine the expression levels of mRNAs and proteins associated with mtUPR, autophagy, CHCHD2, and FBXO7 under oxidative stress. In the MPP⁺-induced PD cell model, we knocked down CHCHD2 and FBXO7 via shRNA and treated the cells with JNK and AKT agonists to observe their effects on mtUPR protein expression. The results showed that mtUPR was activated in MPP⁺-exposed SH-SY5Y cells, and the expression of CHCHD2 and FBXO7 genes was significantly upregulated after MPP⁺ intervention; knockdown of CHCHD2 via shRNA resulted in a marked decrease in the expression of mtUPR-related proteins such as HSPA9, HSPD1, YME1L1, and CLPP, while shRNA targeting FBXO7 exerted only a minimal effect on these mtUPR proteins. Furthermore, the administration of JNK or AKT agonists significantly enhanced the expression of MPP⁺-induced mtUPR proteins, including HSPA9, HSPD1, YME1L1, and CLPP. Collectively, these findings indicate that CHCHD2, rather than FBXO7, plays an essential role in modulating the MPP⁺-induced mtUPR and suggest that CHCHD2 may regulate mitochondrial protein homeostasis by activating the mtUPR through the JNK/c-Jun and AKT/ERα pathways.

One way to protect neurons is to protect them from oxidative damage by reducing lipid peroxidation (LPO). Therapeutic medicines that target the inflammatory response have antioxidant activities and can also block inflammatory cascade pathways and counteract cell lyses. The goal of this investigation was to see if new maleic acid derivatives could protect the brain from scopolamine-induced amnesia. To evaluate and characterize the maleic acid derivatives, spectroscopic techniques such as ¹H NMR and Fourier Transform Infrared Spectroscopy (FTIR) were used. To further evaluate the synthesized compounds, an in vitro DPPH antioxidant assay was performed, compound 2f exhibited the best antioxidant potential, and along this side, an acetylcholinesterase (ACE) inhibition assay was performed. Compounds 2a and 2f showed promising results with IC₅₀ 20.15 and 22.09 nM, respectively. Scopolamine-treated rats trigger neurodegeneration, raise the level of antioxidant enzymes, and increase oxidative stress. The elevated levels of Tumor Necrosis Factor α (TNF-α), cyclooxygenase-2 (COX-2), Jun N-terminal kinase (JNK), and Nuclear Factor kappa-light-chain-enhancer of activated B cells (NFκB), which are neuroinflammatory mediators, along with neuronal damage, were also seen. The anti-Alzheimer's activity of maleic acid derivatives was performed in these rats by performing the Y-maze test, Morris water maze (MWM) models, immunohistochemistry, and hematoxylin and eosin staining. In vivo antioxidant assays revealed that compounds 2a and 2f significantly restored enzymatic defenses and reduced lipid peroxidation, with 2a showing slightly superior activity. The maleic acid derivatives (2a and 2f) cause increased spontaneous changes in the rat behavior and the number of entries of rats in the Y-maze test. The observation from the MWM model showed a decrease in the escape latency time in the rats. Finally, the AutoDock Vina program was used to check ligand-protein interaction using COX-2, and TNF-α, JNK, NFκB, GSK-3β, and ACE were used as targets.

Parkinson's disease (PD) still lacks robust tools for early diagnosis, as current methods rely on motor symptoms that manifest after extensive neurodegeneration. Aggregated α-synuclein (α-Syn), a pathological hallmark of PD, represents a promising biomarker, yet its low abundance, polymorphic structure, and poor antibody recognition limit reliable detection. Notably, all toxic α-Syn species share a conserved cross-β motif. Building on previous findings that doxycycline binds this motif in α-Syn aggregates, we performed a structure-based selection of tetracycline derivatives to assess both binding affinity and immobilization on biosensor surfaces. Among these, 9-amino-4-dedimethylaminodoxycycline (9AD) showed improved selectivity for aggregated over monomeric α-Syn. Electrochemical and immunoassay validations confirmed its potential as a capture agent for α-Syn aggregates, supported by robust surface binding consistent with efficient immobilization. These results position 9AD as a promising biorecognition element for next-generation biosensors aimed at early PD diagnosis and pave the way for future validation in complex biological samples.

Progressive aggregation of TAR DNA-binding protein 43 (TDP-43) is a hallmark of numerous neurodegenerative diseases, including amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's disease, and limbic predominant age-related TDP-43 encephalopathy (LATE). This highly conserved nuclear RNA/DNA-binding protein is involved in the regulation of RNA processing. The C-terminal domain (CTD) of TDP-43 plays a key role in protein solubility, cellular localization, and protein-protein interactions. CTD is rich in glycine, glutamine, and asparagine, which facilitate TDP-43 aggregation into amyloid oligomers and fibrils observed in the brain. In this study, we examine the role of lipid bilayers in the aggregation properties of the CTD of TDP-43. We found that lipid bilayers composed of anionic phosphatidylserine and cardiolipin accelerated TDP-43 aggregation. Although lipids did not alter the secondary structure, they altered the cytotoxicity that TDP-43 fibrils exerted to rat dopaminergic cells. Using molecular methods, we showed that TDP-43 fibrils damage cell endosomes. This causes aggregate leakage into the cytosol, where TDP-43 fibrils impair cell autophagy, simultaneously triggering a severe unfolded protein response in the endoplasmic reticulum. Our results indicate that TDP-43 aggregation may be linked to pathological changes in the lipid profiles of neurons.

The striatum serves as the primary input nucleus of the basal ganglia. Reversible protein phosphorylation in the post synaptic density (PSD) of medium spiny neurons (MSNs) modulates inputs from striatal afferents. The context dependent regulation of PSD protein phosphorylation in direct-pathway medium spiny neurons (dMSNs) and indirect-pathway medium spiny neurons (iMSNs) works to differentially and synergistically impact striatal physiology and the execution of motor programs. An important regulator of PSD protein phosphorylation is protein phosphatase 1 (PP1), which obtains substrate specificity through the action of PP1 targeting proteins. While prior work has demonstrated the global and cell type-specific impact of the PP1 targeting protein, spinophilin, on striatal motor behaviors like the accelerating rotarod task and amphetamine sensitization, the role of its homologue, neurabin, is yet to be elucidated. Using proteomics approaches, we determined that striatal neurabin associates with pre and postsynaptic proteins that mediate glutamatergic synapse function. Moreover, we found that global loss of neurabin enhanced rotarod motor learning but had no impact on amphetamine sensitization. Interestingly, using novel conditional neurabin knockout mouse lines, we found that loss of neurabin in dMSNs, but not iMSNs, enhanced performance on the accelerating rotarod task and that these effects were specific for male mice. These data highlight neurabin's particular importance to the striatal glutamatergic synapse and uncover a sex and cell type specific role for this synaptic protein in uniquely limiting skill motor learning but not psychomotor sensitization.

Alzheimer's disease (AD) remains an incurable neurodegenerative disorder, requiring novel therapeutic strategies. We developed multitarget-directed ligands designed to inhibit human butyrylcholinesterase (hBChE) and activate the sigma-1 receptor (S1R), addressing both cholinergic dysfunction and neuroinflammation, the latter being reduced through action on both targets. The (pseudo-)irreversible carbamate inhibitor 18c emerged as the most promising compound, exhibiting potent and selective hBChE inhibition (IC₅₀ = 3.3 nM, 45-fold selectivity over human acetylcholinesterase) and strong S1R agonistic activity (IC₅₀ = 25 nM, EC₅₀ = 99 nM) determined in a radioligand binding assay and by S1R-BiP dissociation, respectively. Its cleavage product 14c (after carbamate hydrolysis by hBChE) retained dual activity (IC₅₀(hBChE) = 269 nM, IC₅₀(S1R) = 20 nM, and EC₅₀(S1R) = 279 nM). Both compounds reduced the lipopolysaccharide-induced pro-inflammatory activation profile in microglial N9 cells while preserving anti-inflammatory marker expression, thereby indicating an overall immunomodulatory effect. In vivo, inhibitor 18c improved cognitive deficits in a mouse model with Aβ_25-35-induced neurotoxicity, enhancing short- and long-term memory in Y-maze and passive avoidance tests at dosages as low as 0.1-1 mg/kg. These findings highlight the potential of dual-targeting hBChE/S1R strategies for AD therapy.