ACS Chemical Neuroscience最新文献

Brain organoids are stem cell-derived, three-dimensional models that more accurately mimic the cellular complexity and architecture of human brain tissues compared to traditional two-dimensional (2D) cultures or animal models. Their physiological relevance and human-specific neurobiology enhance translational research while aligning with current regulatory shifts toward reducing animal testing in biomedical science. A thorough understanding of the molecular landscape of various biomolecules, such as lipids, metabolites, proteins, and glycans in physiologically relevant brain models, such as organoids, is essential to deciphering complex neurobiology. While mass spectrometry has long been used to understand such molecular landscape in tissues, a single-omics approach is insufficient to fully capture the complexity of brain biology. Therefore, multiomics strategies, such as high-resolution mass spectrometry imaging (MSI), mass spectrometry-based proteomics, and lipidomics, together can provide a holistic view of biomolecular interplay within tissue microenvironments. Moreover, since MSI retains spatial information within tissues, MSI-based multiomics approaches hold immense potential to uncover complex neurobiology within brain organoids. In this article, we present our perspectives on leveraging MSI-based multiomics in brain organoids to understand the complex molecular interplay underlying neurobiology.

Infantile-onset Ascending Hereditary Spastic Paralysis (IAHSP) is an ultrarare, autosomal recessive form of Hereditary Spastic Paraplegia (HSP), caused by mutations in the ALS2 gene, which encodes the protein ALSIN. In a previous study, we proposed a personalized therapeutic strategy for an Italian IAHSP patient (AO), aiming to correct the aberrant function of the R1611W mutant ALSIN using Menatetrenone (MK4). While our results supported compassionate-use approval for a patient-specific therapeutic regimen, further investigation was needed to highlight the treatment's benefits in the absence of tractable biophysical assays and in vivo models. In this respect, we first characterized MK4's interaction with the mutation site through Molecular Dynamics simulations. Next, we established and characterized a skin fibroblast cell line derived from patient AO. We analyzed the expression and stability of the mutant ALSIN protein in AO's fibroblasts and observed elevated oxidative stress levels. Using advanced microscopy and automated image analysis, we identified a characteristic mitochondrial phenotype associated with AO's IAHSP. One specific morphological parameter of mitochondria (Mean Branch Diameter) accurately reflected the IAHSP phenotype and was selected as a cell marker. Treatment of IAHSP fibroblasts with MK4 highlighted the rescue of Mean Branch Diameter and ALSIN levels, supporting cellular efficacy. Overall, this work presents an approach that integrates computational and cell-based methodologies to overcome the data scarcity challenges of drug discovery in rare diseases. Our study provides a framework for preclinical, alternative drug discovery programs in monogenic rare disorders such as IAHSP.

Aberrant proteolytic processing of amyloid precursor protein (APP) can alter amyloid-β (Aβ) peptide trafficking, with recent studies implicating MUC1-type O-glycosylation as a modulatory factor. In this study, we synthesized native and Swedish-mutated (Lys670Asn/Met671Leu) APP glycopeptides spanning the Aβ(1-23) region, including the β- and α-secretase cleavage sites, and introduced O-GalNAc moieties at Thr⁶⁶³, Ser⁶⁶⁷, and/or Tyr⁶⁸¹. Circular dichroism (CD) revealed conformational changes governed by the glycosylation site and glycan density. Increased glycan valency favored the stabilization of β-turn-rich structures typically associated with oligomeric and prefibrillar intermediates. The Swedish mutation enhanced β-secretase (BACE1) cleavage, especially when Ser⁶⁶⁷ was glycosylated, while additional glycans favored α-secretase (ADAM10) processing. However, this shift was not sufficient to counterbalance the amyloidogenic pathway. Similarly, Ser⁶⁶⁷ glycosylation promoted fibril formation in coincubation assays with Aβ40, while di- and triglycosylated peptides disrupted fibril architecture and favored oligomer formation, as confirmed by ThT kinetics, AFM/TEM imaging, and dynamic light scattering. These findings highlight the critical role of mutation and site-specific glycosylation in shaping APP proteolytic processing, secondary structure, and aggregation behavior, underscoring their importance for understanding APP function in both healthy and diseased states.

The global aging population has led to a rising incidence of neurodegenerative diseases, casting a significant shadow on global health due to their complex and multifactorial nature. In addition to genetic predispositions, cellular senescence, particularly in microglia, the innate immune cells of the central nervous system, has become a significant contributor to neurodegeneration. In this review, we examine the mechanism of microglial senescence in neurodegenerative disease. We emphasize the need for continuous exploration of microglial senescence mechanisms and provide a future perspective for developing preventive drugs, encouraging researchers to develop new therapies for patients with neurodegenerative diseases.

Ischemic stroke is one of the leading causes of death and disability worldwide. Currently, there are few drugs available for treatment of ischemic stroke, and the lack of high-quality targets has severely restricted the development of innovative drugs. Glial cells play crucial roles in the pathophysiological process of ischemic stroke, particularly through the regulation of the inflammatory response and immunomodulation. Transient receptor potential (TRP) channels, as a crucial class of membrane proteins, are sensors for a variety of cellular and environmental signals in the central nervous system. Accumulating evidence indicates that alterations in the expression and function of TRP channels in glial cells significantly regulate the onset and progression of ischemic stroke. Notably, pharmacological inhibition or genetic knockout of specific TRP channels can effectively alleviate ischemic stroke-induced neuronal damage, highlighting their potential as therapeutic targets. We summarize and discuss the molecular and cellular mechanisms of TRP channels regulation in glial cells during ischemic stroke, as well as the mechanisms of neuroprotective agents targeting TRP channels. Furthermore, we propose a series of recommendations for future experiments aimed at developing neuroprotective drugs for ischemic stroke by targeting TRP channels.

G protein-coupled receptors (GPCRs) are lipid-dependent membrane receptors that serve as important cell signaling hubs. Phosphoinositide (PIP) lipids represent an important class of anionic lipids that play vital roles in neuronal function and signaling. PIP lipids have been reported to modulate GPCR function, although the specificity and molecular details of the interactions are still not clear. An important GPCR in this context is the serotonin_1A receptor, a neurotransmitter GPCR, which has been reported to interact with phosphatidylinositol 4-phosphate (PIP1) lipids. In this work, we computationally analyzed the specificity of the serotonin_1A receptor-PIP lipid interactions using coarse-grain molecular dynamics simulations. Our results predict that four anionic lipid sites are present at the receptor surface, although the relative populations are dependent on the lipid type. PIP1 lipids exhibit the highest interaction at a charged cleft formed by transmembrane helices VI and VII. We observed electrostatic interactions at a cluster of charged residues (Arg341, Lys342, Lys345) and hydrophobic and aromatic interactions at residue Ile349 and Tyr402. In contrast, phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3) lipids interact more with transmembrane helix IV. We observed that anionic phospholipids such as phosphatidylserine (PS) interact at these sites, although their occupancy at these sites is much reduced. By elucidating the molecular determinants of these interactions in silico, this study generates novel, testable hypotheses regarding the functional role of specific lipid-receptor contacts. Our work constitutes an important step in analyzing molecular signatures of phosphoinositide lipid-GPCR interactions in the overall context of diverse roles of phosphoinositides in neuronal function and signaling.

We herein report the design, Pictet-Spengler reaction-mediated synthesis, and neuroprotective evaluation of new 10,11-dihydro-5H-benzo[e]imidazo[1,2-a][1,4]diazepines without (7a) or with iminic anchor (8a-8f), along with representative 5H-benzo[e]imidazo[1,2-a][1,4]diazepines (oxidized compounds; 7ao and 8co), and some nonrigid benzodiazepine analogues (4, 5a-5c, and 6a-6c). Compounds 8b, 8c, and 8e did not show any neurotoxic effects in the Neuro2a and SHSY-5Y cell lines up to 10 μM concentration and increased the number of neurite-bearing cells and neurite length, suggesting the protective abilities of compounds. In pentylenetetrazole (PTZ)-treated cells, 8b, 8c, and 8e exerted neuroprotective effects by increasing cell viability and reducing ROS levels. Notably, 8b at 10 μM reduced ROS formation more than diazepam and other compounds. Further, protein expression studies indicated that compounds at 10 μM concentration upregulated the GABA_Aα1 expression compared to PTZ alone-treated cells. The binding analysis at the GABA_A site, using molecular docking and MD simulations, suggested a neuroprotective effect of these compounds via GABA_A targeting. In vivo, compound 8b demonstrated a dose-dependent anticonvulsant effect in the PTZ-induced kindling mouse model, significantly delaying seizure onset while reducing the seizure duration, frequency, and severity with efficacy comparable to that of diazepam.

Parkinson's disease (PD) is a classic neurodegenerative disorder characterized by both motor and nonmotor symptoms, with circadian rhythm disruption being particularly prominent. This disruption leads to issues such as sleep disturbances, cognitive decline, and mood fluctuations in patients. Research has shown a close relationship between circadian rhythm dysregulation and these symptoms, making circadian rhythm regulation an emerging therapeutic strategy. Exercise, as a nonpharmacological treatment, has been demonstrated to modulate circadian rhythms through various mechanisms, thereby improving sleep quality, cognitive function, and emotional state in PD patients. Furthermore, exercise regulates the biological clocks of peripheral tissues such as muscle, liver, and adipose tissue, and affects the central nervous system's rhythms through neuroendocrine pathways, leading to improvements in PD symptoms. This paper introduces the concept of "exercise as chronotherapy," highlighting its role in regulating circadian rhythms and alleviating nonmotor symptoms of PD. It also discusses the future design of personalized exercise prescriptions and technological applications, aiming to provide new perspectives and strategies for the comprehensive treatment of PD.

Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) plays a critical role in calcium signaling. Several studies have shown that mice with single Camk2a or Camk2b gene knockouts are viable, yet exhibit distinct phenotypes, whereas the double knockout of both genes is lethal. These findings indicate that each gene can have distinct roles and that they also partially compensate for each other in yet unknown essential brain functions. In order to provide insight into potential novel CaMKII functions, we performed parallel phosphoproteomic analyses on nonstimulated cortex tissues from inducible Camk2a and Camk2b double knockout (Camk2a^f/f;Camk2b^f/f;CAG-Cre^ESR) mice and from wild type mice. A total of 5622 phosphorylated peptides derived from 2080 proteins were identified. Phosphorylation at serine/threonine residues in 130 proteins was downregulated in the double knockout mice, including residues in 113 proteins that have not previously been identified as potential CaMKII substrates. Comparison of amino acid sequences surrounding the downregulated phosphorylation residues provided new insights into the CaMKII-substrate consensus sequences in vivo. This data set provides an important resource for future studies examining novel roles for CaMKII in the brain.