ACS Chemical Neuroscience最新文献

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.

Neurodegenerative diseases are conditions characterized by neuronal loss in the nervous system, leading to diverse symptoms associated with complex pathological mechanisms. Dysregulation of metal ions such as iron and copper is linked to oxidative stress and consequently contributes to neuronal toxicity. Considering this, multitarget agents represent promising therapeutic strategies for the treatment of neurodegenerative disorders. In this study, a series of 24 novel multitarget compounds were designed to interact with histamine H₃ receptors (H₃R) and acetyl- and butyrylcholinesterases (AChE and BChE, respectively), incorporating additional metal-chelating groups. The compounds were synthesized and evaluated for their potency at H₃R, for cholinesterase inhibitionand for metal-chelating activity toward Fe²⁺, Fe³⁺, and Cu²⁺ using spectrophotometric assays. The compounds displayed considerable affinities for H₃R, AChE and BChE, with isoquinoline derivatives LINS05413 and LINS05414 standing out as multitarget agents due to their nanomolar affinities for H₃R (pK_i = 6.41 and 6.37, respectively), moderate AChE inhibitory activities (pIC₅₀ = 4.31 and 4.03, respectively) and metal-chelating properties. Isoquinoline-based compounds exhibited the strongest metal-chelating properties, particularly against copper, whereas 4-pyridylpiperazine derivatives were more effective in chelating iron ions. Molecular docking analyses revealed the role of aromatic substituents on multitargeting through interactions with key aromatic residues from each target. Structure–activity relationship and ligand efficiency analyses underscored the importance of the benzylpiperazine moiety for multitarget activity, while metal-chelating groups contributed to increased lipophilic ligand efficiency.

Excessive glutamate release during excitotoxic events such as stroke and neurodegeneration leads to elevated mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane depolarization, contributing to dysfunction of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) and subsequent endoplasmic reticulum (ER) stress. SERCA is critical for maintaining ER Ca²⁺ homeostasis, and its impairment exacerbates ER stress and neuronal excitotoxicity. In this study, we investigated the neuroprotective potential of CDN1163 (4-(1-methylethoxy)-N-(2-methyl-8-quinolinyl)-benzamide), a small-molecule SERCA activator, in an in vitro model of glutamate-induced toxicity using N2a cells. Glutamate exposure markedly reduced cell viability and induced apoptosis, as evidenced by increased caspase-3 and Bax expression along with suppression of the antiapoptotic protein Bcl-2. These cytotoxic effects were accompanied by excessive intracellular and mitochondrial ROS generation and dissipation of the mitochondrial membrane potential (ΔΨm), indicating mitochondrial dysfunction. Glutamate further disrupted mitochondrial quality control by impairing mitophagy initiation, reflected by reduced PINK1 and Parkin expression and altered LC3-II and phospho-p62 levels. This mitochondrial impairment coincided with pronounced ER stress, characterized by activation of unfolded protein response signaling pathways, including increased expression of BiP, p-IRE1α, XBP 1s, p-PERK, p-eIF2α, ATF4, CHOP, and ATF6, together with downregulation of SERCA1a and SERCA2b, leading to ER Ca²⁺ dyshomeostasis. Treatment with CDN1163 significantly reversed glutamate-induced cytotoxicity by restoring cell viability, suppressing apoptosis, reducing mitochondrial and cellular ROS, stabilizing mitochondrial membrane potential, reactivating mitophagy, and alleviating ER stress through restoration of SERCA expression and ER Ca²⁺ homeostasis. Collectively, these findings demonstrate that CDN1163 confers neuroprotection against glutamate-induced excitotoxic injury by targeting interconnected mitochondrial and ER stress pathways, highlighting its therapeutic potential in excitotoxic neurodegenerative conditions.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and a growing public health concern globally due to the lack of effective treatments. The primary pathological characteristics of AD include the accumulation of amyloid-β (Aβ) as extracellular senile plaques and intracellular neurofibrillary tangles (NFTs) of hyperphosphorylated tau. Additionally, oxidative stress and neuroinflammation are implicated in the disease’s pathogenesis. Developing therapeutic approaches to target multiple pathways or disease routes to address the complex pathological processes driven by Aβ remains challenging. In this context, multifunctional small molecules present a promising therapeutic strategy to address the multiple etiologies of AD. In this study, we designed and synthesized a series of multifunctional azo compounds (ACs) based on Griess’s reagent. These compounds modulate amyloid aggregation, suppress oxidative stress, mitigate mitochondrial damage, and provide neuroprotection against Aβ-induced toxicity. Among the ACs, AC5 effectively prevents Aβ-induced ROS generation, as indicated by Nrf2 translocation, and exhibits anti-inflammatory activity by targeting inflammatory mediators, suppressing induced nitric oxide synthase (iNOS) expression, and reducing nitric oxide (NO) generation. Furthermore, AC5 effectively combats ferroptosis via modulating lipid peroxidation and restores the master regulator Gpx4 activity. Our findings suggest that AC5 is a promising therapeutic candidate for addressing the multifaceted pathogenesis of AD.

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.