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Rike, W. A.

Publications and source records attributed to Rike, W. A..

6 recordsLinked to original sources

iPSC-derived extracellular vesicles rescue deficits in human and mouse models of Parkinsons disease

Parkinsons disease (PD) pathogenesis often involves progressive -synuclein (-Syn)-mediated neuronal dysfunction, yet the earliest cellular events that link -Syn pathology to circuit failure remain poorly defined. Here, we used human induced pluripotent stem cell (iPSC)-derived dopaminergic (DA) neurons from patients carrying the familial A53T SNCA mutation to reconstruct a temporal course of dysfunction in vitro. We identified a biphasic trajectory with an early phase of hyperexcitability, characterized by elevated spontaneous firing, followed by a progressive transition into hypoexcitability as the neurons mature, accompanied by reduced network activity, synaptic dysfunction, and -Syn accumulation. Transcriptomic profiling at the critical transition point revealed a dual transcriptional signature, with upregulation of stress-inflammatory pathways (p53, JAK-STAT, apoptosis) coupled with systematic downregulation of metabolic and synaptic maintenance genes. This molecular profile preceded functional collapse, linking early hyperactivity-driven metabolic stress to subsequent neuronal exhaustion. To counteract this pathology, we used extracellular vesicles (EVs), small membrane-bound particles carrying intercellular signals, as a cell-free treatment approach. Strikingly, treatment with EVs derived from healthy iPSCs completely rescued both electrophysiological deficits and pathological -Syn accumulation, restoring normal firing patterns, synaptic function, and network activity. Consistent with these observations, EV treatment reduced -Syn aggregation and improved motor responses in -Syn fibril-injected mice, which are characterized by pathological -Syn accumulation and motor deficits. Overall, these findings demonstrate that EVs derived from healthy iPSCs can reverse PD-related phenotypes in human and mouse models.

neuroscience↗

Digestive Dimensions of Autism: A Multiscale Exploration of Gut-Brain Interactions

Social communication difficulties characterize autism spectrum disorders (ASD). Gastrointestinal (GI) symptoms are more common in ASD than in the general population. The identification of GI problems in individuals with ASD is challenging due to their altered pain perception and irregular behaviors. Importantly, GI symptoms and ASD can potentially aggravate each other. However, it is unclear if GI problems cause ASD symptoms or vice versa. A crosstalk between the digestive system, gut microbiota, and the central and enteric nervous systems has been repeatedly reported. The enteric nervous system (ENS) regulates the GI tract with the central nervous system (CNS) and the autonomic nervous system (ANS), as well as independently through specific neural circuits. Several mechanisms contribute to GI problems in ASD, including genetic mutations that affect the enteric nervous system (ENS), dysregulation of the ANS, alterations in gut microbiota, unhealthy dietary preferences, and changes in metabolomic profiles. Furthermore, studies have shown molecular and cellular differences in the GI biopsy of children with and without ASD. These findings highlight the unique nature of GI issues in ASD, underscoring the importance of further investigating the changes that occur in the digestive system and enteric nervous system (ENS) in ASD models.

neuroscience↗

Dysregulation of Multiple Solute Carrier genes and Metabolic Deficits in SLC1A4-Mutant Human iPSC-Derived Hippocampal Neurons

Mutations in SLC1A4, which encodes the neuronal amino acid transporter ASCT1, disrupt metabolic and synaptic homeostasis, contributing to neurodevelopmental deficits commonly observed in autism spectrum disorder (ASD). To investigate the underlying molecular mechanisms of SLC1A4-related disorders, we utilized human iPSC-derived hippocampal neurons and applied an integrated multi-omics approach, combining electrophysiology, calcium imaging, metabolomics, proteomics, and transcriptomics. Our findings reveal an initial phase of early neuronal hyperexcitability, driven by increased sodium and potassium currents, followed by a progressive decline in synaptic activity at later stages. Metabolomic analysis identified elevated glycine, serine, and glutamate levels during early differentiation, contributing to excitotoxicity, whereas later glutamate depletion and extracellular matrix (ECM) disruption were associated with synaptic dysfunction. Proteomics data further showed dysregulation in metabolic pathways, amino acid biosynthesis, and fatty acid metabolism pathways during early time points, and in later stage dysregulation in metabolic and ECM-receptor interactions. Additionally, transcriptomic analysis revealed dysregulation in calcium signaling, amino acid metabolism pathways such as valine, leucine and isoleucine degradation, tryptophan metabolism, and glycine, serine, and threonine metabolism. Further investigation of SLC-family transporter genes uncovered disruptions in glutamate and glycine transport, establishing a direct link between amino acid transport dysfunction and neuronal deficits. Collectively, our study demonstrates that SLC1A4 mutations lead to dysregulation of multiple solute carrier protein genes causing metabolic stress, excitability defects, and synaptic abnormalities, providing a molecular framework for understanding SLC1A4-related neurodevelopmental disorders and identifying potential therapeutic targets.

neuroscience↗

Exosomes can modulate the early hyperexcitability in cortical neurons with ASD-associated Shank3 mutation.

Extracellular vesicles (EVs) are lipid membrane-bound structures that mediate intercellular communication by transferring diverse cargoes, including RNA and proteins. Shank3, a synaptic scaffolding protein critical for synapse structure and function, is implicated in autism spectrum disorder (ASD) and Phelan-McDermid Syndrome (PMS). Early hyperexcitability in cortical neurons is a recognized endophenotype in ASD. Here, we investigated EV-mediated effects in the context of Shank3 deficiency using human iPSC-derived cortical neurons and Shank3B-/- mice. Switching EVs between Shank3 mutant and control neurons revealed that Shank3 mutant-derived EVs transferred the hyperexcitability and accelerated maturation phenotypes to control neurons. This was driven by enriched synaptic proteins (e.g., ACTB, CFL1, AGRN, CLSTN1) in Shank3 mutant-derived EVs as confirmed by proteomic analysis. Conversely, control EVs failed to rescue mutant phenotypes consistent with their lower enrichment for synaptic proteins and related pathways. Further, EVs from mesenchymal stem cells (MSCs) and healthy donor iPSCs, containing synaptic modulators such as complement proteins (C1R, C1S), plasticity-related proteins (MDK, IGFBP3), and homeostatic regulators (FGF2, SFRP1), rescued the hyperexcitability and normalized the maturation in Shank3 mutant neurons. Moreover, intranasal administration of iPSC-derived EVs in Shank3B-/- mice significantly ameliorated ASD-like behavioral deficits, underscoring their therapeutic potential. Together, these findings reveal a novel EV-mediated mechanism for modulating dysregulated excitability and synaptic maturation, addressing a critical unmet need in ASD and related neurodevelopmental disorders treatment.

neuroscience↗

Predicting Suicide Risk in Bipolar Disorder patients from Lymphoblastoid Cell Lines genetic signatures

This research investigates the genetic signatures associated with a high risk of suicide in Bipolar disorder (BD) patients through RNA sequencing analysis of lymphoblastoid cell lines (LCLs). By identifying differentially expressed genes (DEGs) and their enrichment in pathways and disease associations, we uncover insights into the molecular mechanisms underlying suicidal behavior. LCL gene expression analysis reveals significant enrichment in pathways related to primary immunodeficiency, ion channel, and cardiovascular defects. Notably, genes such as LCK, KCNN2, and GRIA1 emerged as pivotal in these pathways, suggesting their potential roles as biomarkers. Machine learning models trained on a subset of the patients and then tested on other patients demonstrate high accuracy in distinguishing low and high-risk of suicide in BD patients. Moreover, the study explores the genetic overlap between suicide-related genes and several psychiatric disorders. This comprehensive approach enhances our understanding of the complex interplay between genetics and suicidal behavior, laying the groundwork for future prevention strategies.

neuroscience↗

Synaptic dysfunction and dysregulation of extracellular matrix-related genes in dopaminergic neurons derived from Parkinson's disease sporadic patients and with GBA1 mutations

Parkinsons disease (PD) is a neurodegenerative disease with both genetic and sporadic origins. In this study, we investigated the electrophysiological properties, synaptic activity, and gene expression differences in dopaminergic (DA) neurons derived from induced pluripotent stem cells (iPSCs) of healthy controls, sporadic PD (sPD) patients, and PD patients with GBA1 mutations. Our results demonstrate reduced sodium currents and synaptic activity in DA neurons derived from PD patients with GBA1 mutations, suggesting a potential contribution to PD pathophysiology. We also observed distinct electrophysiological alterations in sPD DA neurons that were dependent on the age of disease onset. RNA sequencing analysis revealed unique dysregulated pathways in early and late-onset sPD neurons, further supporting the notion that molecular mechanisms driving PD may be different between PD patients. In agreement with our previous reports, ECM and focal adhesion genes were the top dysregulated pathways in DA neurons from sPD patients and from patients with GBA1 mutations. Overall, this study gives further confirmation that the convergent functional phenotypes of DA neurons derived from PD patients are synaptic abnormalities and at the transcriptome level, ECM and focal adhesion pathways are highly involved in PD pathology across multiple PD-associated mutations as well as sPD.

neuroscience↗