Neuroscience
Abstract
D1-type receptor (D1R)-mediated dopaminergic signaling within the nucleus accumbens shell (NAcSh) is essential for forming adaptive circuit changes that embed persistent memories associated with drug seeking and craving. While D1R is expressed in both NAcSh neurons and astrocytes, the specific contribution of astrocytic D1R to drug-related circuit plasticity remains poorly understood. Here, we demonstrated in mouse NAcSh slices that D1R agonists increased astrocytic Ca2+ activity, an effect that was attenuated by astrocyte-specific D1R knockdown. Furthermore, selective knockdown of astrocytic D1R in the NAcSh prior to cocaine self-administration inhibited cocaine-induced generation of silent synapses, thereby hampering the associated remodeling of NAcSh circuits. Behaviorally, knockdown of NAcSh astrocytic D1R expedited the extinction of cocaine seeking and reduced cue-induced reinstatement. These results identified astrocytic D1R as a fundamental component of NAcSh dopamine signaling during cocaine experience that remodeled synaptic connections and neural networks underlying drug seeking and relapse.
Authors
Shi Yan, Qize Li, Yao Wang, Wanqiu Chen, Zhong Chen, Alexander K. Zinsmaier, Paloma R. Huguet, Zhengsong Lu, Xiguang Qi, Zheng Xu, Yi Han, Gouri Sharma, Charles Wang, Eric J. Nestler, Oliver M. Schlüter, Yan Dong
Abstract
Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Breathing instability and exaggerated chemoreflex activation contribute to adverse HF outcomes, yet the central mechanisms linking respiratory control to cardiac dysfunction remain poorly defined. The retrotrapezoid nucleus (RTN) is a key brainstem chemosensory region regulating ventilatory and autonomic output, but whether glial dysfunction within this circuit contributes to HF pathophysiology is unknown. We hypothesized that loss of astrocytic glutamate transporter 1 (GLT-1) in the RTN disrupts glutamate homeostasis, producing chemoreflex hyperactivity and cardiorespiratory dysfunction in HF. In a rat model of nonischemic HF, reduced astrocytic GLT-1 expression in the RTN was accompanied by extracellular glutamate accumulation and heightened excitability of chemosensitive neurons. These changes were associated with exaggerated central chemoreflex responses, breathing instability, autonomic imbalance, and impaired cardiac function. Astrocyte-specific GLT-1 restoration normalized RTN glutamate levels, reduced central chemoreceptor neuron hyperexcitability, stabilized breathing, and improved cardiac performance. Systemic riluzole, an FDA-approved glutamate-modulating drug, similarly reduced RTN glutamate accumulation and attenuated chemoreflex-driven respiratory instability. These findings identify loss of astrocytic GLT-1-mediated glutamate homeostasis in the RTN as a mechanism contributing to cardiorespiratory dysfunction in HF and support pharmacological targeting of brainstem glutamate homeostasis as a therapeutic strategy requiring further investigation.
Authors
Esteban Diaz-Jara, Sinay C. Vicencio, Katherin V. Pereyra, Karla G. Schwarz, Fernando C. Ortiz, Camilo Toledo, Ignacio Bernal-Santander, Sandeep Kaur, Bisan El Dakkak, Rodrigo Del Rio
Abstract
Friedreich’s ataxia (FRDA) is a multisystemic neurodegenerative disorder caused by GAA repeat expansion in intron 1 of frataxin (FXN), resulting in FXN deficiency and mitochondrial dysfunction. Current therapies do not correct the underlying genetic defect. Here, we demonstrate that ex vivo CRISPR/Cas9 excision of the GAA expansion in hematopoietic stem and progenitor cells (HSPCs) provides durable, systemic therapy for FRDA. A single infusion of gene-edited Sca1+ HSPCs, mPPL-001, into myeloablative, humanized YG8JR mice resulted in long-term engraftment of donor-derived cells across hematopoietic and FRDA-affected tissues. mPPL-001 increased FXN expression and corrected multiple key pathogenic drivers of FRDA, including mitochondrial stress, microglial and macrophage activation, and inflammatory signaling. These coordinated effects improved motor functions, preserved cerebellar architecture, mitigated cardiac pathology, and promoted survival of insulin-producing β cells in the pancreatic islets of Langerhans. Collectively, these findings establish FXN-edited autologous HSPCs as a one-time, disease-modifying therapy for FRDA and support advancement toward a first-in-human trial.
Authors
Anusha Sivakumar, Alexis N. Corl, Keneth Jordan Muñoz, Subhashini Arumugam, Betul B. Gunes, Angelyn B. Solis, Rishika Murthy, Lilas Rony El-Hachem, Donald P. Pizzo, Ian A. Blair, Teerapat Rojsajjakul, Clementina Mesaros, Xinlong Wan, Joseph N. Rainaldi, Rafael A. Badell-Grau, Veenita Khare, Kevin Eric Thai, Kavya Biederman, Stephanie Cherqui
Abstract
SEC16A encodes a scaffold protein that organizes the endoplasmic reticulum (ER) exit sites, specialized ER subdomains that mediate export of newly synthesized proteins and regulate early secretory pathway steps. The role of SEC16A in human nervous system diseases has not been established yet. Here, we report six individuals with bi-allelic SEC16A variants who presented with early-onset neurological symptoms, including cognitive impairment, motor delays, and seizures. Using Drosophila, we show the Sec16 ortholog is essential for normal development and that its loss causes early lethality. Neuron-specific knockdown of Sec16 causes neurological phenotypes including locomotor defects, seizure-like bang sensitivity, and impaired synaptic transmission, which can be associated with the clinical features observed in affected individuals. Neurons differentiated from patient-derived induced pluripotent stem cells (iPSCs) carrying SEC16A variants display reduced SEC16A protein, impaired neurite outgrowth and increased excitability, which are rescued in isogenic control neurons when the variants are corrected, consistent with a loss-of-function mechanism. Increased ER stress was observed in both patient iPSC-derived neurons and fly models. In summary, our findings indicate a conserved requirement for SEC16A in neurodevelopment and neuronal function and implicate ER stress as a key cellular phenotype underlying the SEC16A-associated neurodevelopmental disorder.
Authors
Mengqi Ma, Xiaowei Lei, Juan Li, Yiming Zheng, Yu Yuan, Yohei Nitta, Xiao Mao, Zhenming Guo, Shenzhao Lu, Mingxi Deng, Xueyang Pan, Oguz Kanca, Shiyi Liu, Hua Wang, Bo Xiao, Rachel Schot, Serwet Demirdas, Yolande van Bever, Marjon van Slegtenhorst, Tahsin Stefan Barakat, Shan Bian, Hugo J. Bellen, Lili Long
Abstract
During organogenesis, stem cells undergo cellular and metabolic remodelling, facilitated by autophagy-mediated turnover of organelles. Autophagy impairment has been linked to human diseases, including neurodevelopmental disorders associated with disrupted neural stem/precursor cell (NPC) homeostasis, but the underlying mechanisms and pathogenic processes governing these connections remain poorly understood. Here, we report three de novo variants of uncertain significance (p.Gly223Asp, p.Gly889Glu, p.Met978Val) in the deubiquitinase USP15 in human probands with diverse clinical features, including a spectrum of brain malformations and metabolic phenotypes. Proband variants differentially altered USP15 activity and nucleocytoplasmic localization. USP15 showed dynamic localization in NPCs of embryonic mouse cerebral cortex. Using a knock-in mouse model carrying the p.Met978Val variant, we showed that aberrant cytoplasmic accumulation of USP15, but not its loss-of-function, impaired NPC self-renewal and differentiation, leading to reduced neuronal output and enlarged lateral ventricles. Mechanistically, USP15 deubiquitinated autophagy regulator ATG16L1, impeded its normal turnover, and impaired autophagy. Concurrently, lipid droplet mobilization and mitochondrial dynamics were attenuated. Reestablishing the ubiquitination-deubiquitination balance restored autophagy activity and normal neurogenesis. Our findings suggest that nucleocytoplasmic shuttling of USP15 creates a switch-like autophagy signal controlling NPC homeostasis, and its disruption may contribute to the pathogenesis of complex neurodevelopmental conditions.
Authors
Kaylan M.L. Burns, Mashiat Zaman, Daniel Young, Michelle Hua, Yu-Yun Gao, Yvonne Yan Yan Or, Farzaneh Nobakht, Bryn D. Webb, Julie A. Jurgens, Francis Ramond, Xing-Chang Wei, Caroline D. Robson, Alistair T. Pagnamenta, Marvel Megaly, Belal Tafech, Antoine Dufour, Timothy E. Shutt, Ping Yee Billie Au, Guang Yang
Abstract
Distress sharing within an ingroup instinctively motivates caregiving-like prosocial behavior in social animals and humans, yet how aversive social stimuli paradoxically trigger such behavior remains unclear. Here, we show that stress-state matching in observer mice elicits caregiving-like behaviors (allogrooming and injury-targeted allolicking) toward cagemates in pain, resulting in synchronized social buffering. Importantly, we identify that the excitation of vasopressin receptor 1a–expressing (V1aR-expressing) neurons in the central medial amygdala (CeM) underlies both emotional-state matching and subsequent allogrooming/allolicking. This excitation is accomplished by arginine vasopressin (AVP) release from presynaptic terminals of the hypothalamic paraventricular nucleus (PVN) to act specifically on postsynaptic V1aR in the CeM. The CeMV1aR neurons then project to the ventral tegmental area (VTA) to drive caregiving-like actions through positive reinforcement, manifested as prosocial preference and recurrent allogrooming/allolicking, and to produce anxiolysis in the caregiver. Collectively, we unravel a dedicated trisynaptic PVNAVP-CeMV1aR-VTA circuit driving and gating caregiving-like behaviors and advance the mechanistic understanding of AVP-V1aR signaling in prosociality.
Authors
Kai-Wen Geng, Rui-Rui Wang, Yan Yang, Yan Wang, Ting He, Chun-Li Li, Chong-Shun Xu, Jun Chen
Abstract
Familial Episodic Pain Syndrome (FEPS) is a rare inherited disorder characterized by recurrent episodes of severe upper-body pain triggered by stimuli such as cold, stress, or fasting. A gain-of-function mutation (N855S) in the Transient Receptor Potential Ankyrin 1 (TRPA1) ion channel has been identified in affected individuals, yet the cellular mechanisms driving FEPS pain remain poorly defined. Although TRPA1 has been primarily studied in sensory neurons, emerging evidence suggests that non-neuronal cells may contribute to pain signaling. To define the cell-specific role of mutant TRPA1 (TRPA1mut), we generated mouse models selectively expressing TRPA1mut in Schwann cells or sensory neurons, using CRISPR-based and Cre-loxP strategies. Patch-clamp recordings confirmed enhanced agonist-evoked currents in TRPA1mut compared with wild-type channels. Behavioral analyses revealed that neuronal TRPA1mut mediates acute nociceptive responses, whereas Schwann cell TRPA1mut drives mechanical allodynia induced by subthreshold TRPA1 agonists and physiological triggers relevant to FEPS, including fasting, cold exposure, and restraint stress. These responses were associated with increased reactive oxygen species and accumulation of 4-hydroxynonenal in sciatic nerves and were attenuated by antioxidant treatment. These findings uncover a previously unrecognized Schwann cell-dependent mechanism of TRPA1-driven pain and identify non-neuronal TRPA1 signaling as a potential therapeutic target in FEPS and related pain channelopathies.
Authors
Matilde Marini, Martina Chieca, Elisabetta Coppi, Marco Montini, Lorenzo Bonacchi, Lorenzo Landini, Irene Scuffi, Kelvin Y. Kwan, Alice Papini, Gaetano De Siena, Elisa Bellantoni, Lucrezia Timotei, Elena Colzi, Valentina Albanese, Gabriele Ferroni, Evelynn D. N. Melo, Marie-Christine Birling, Romain Lorentz, Romina Nassini, Francesco De Logu
Abstract
Cyclin-dependent kinase like 5 (CDKL5) is a serine-threonine kinase enriched in the mammalian brain whose loss of function causes a severe developmental and epileptic encephalopathy named CDKL5 Deficiency Disorder. We previously showed that CDKL5 phosphorylates the microtubule-associated protein MAP1S, but how this regulates microtubule-dependent functions is not well understood. To address this question, we generated MAP1S phosphomutant mice in which the CDKL5 phosphorylation sites S786 and S812 were mutated to alanine (MAP1S S786/812A; MAP1S SA). Using a microtubule cosedimentation assay, we found that dynein binding to microtubules was reduced in MAP1S SA and CDKL5 knockout (KO) brain lysates, and time-lapse imaging showed impaired dynein motility in dendrites from both genotypes. MAP1S SA mice also exhibited reduced AMPA receptor transport, dendritic spine density, and excitatory synapses, accompanied by anxiety-like behavior and motor, social, and memory deficits relevant to CDD. Mechanistically, MAP1S SA and CDKL5 KO neurons showed increased microtubule stability and reduced tubulin tyrosination, consistent with excessive MAP1S-mediated stabilization. Restoring tubulin tyrosination by expressing tubulin-tyrosine ligase rescued dynein transport defects. Together, these findings identify MAP1S phosphorylation as a critical regulator of microtubule dynamics and dynein-dependent transport.
Authors
André T. Lopes, Ondine Janiv, Suzanne Claxton, Sila K. Ultanir
Abstract
STXBP1 variants are a frequent cause of early-onset developmental and epileptic encephalopathies and related neurodevelopmental disorders, but the clinical interpretation of these variants remains a major challenge. Most reported STXBP1 missense variants are classified as variants of uncertain significance (VUS), complicating diagnosis, counseling, and patient eligibility for precision therapies. Here, we developed EpiPred, a gene-specific machine learning classifier that predicts the pathogenicity of STXBP1 missense variants and tests these predictions using empirical evidence from well-established cellular assays. Trained on a curated set of pathogenic and benign variants, EpiPred outperformed global prediction tools in accuracy, sensitivity, and specificity. We validated the model’s predictions using variant effect assays that measure protein abundance, solubility, stability, and interaction with the SNARE complex partner syntaxin 1. These biochemical readouts aligned closely with model outputs and enabled reclassification of several possibly misdiagnosed variants, which warrant further validation and clinical reevaluation. We deployed EpiPred in an interactive web application that allows clinicians, researchers, and patients to explore predictions for all possible STXBP1 missense variants. By identifying likely pathogenic STXBP1 variants, including those that may respond to emerging therapies such as protein stabilizers. By coupling gene-calibrated machine learning with orthogonal variant-effect assays and public deployment, EpiPred provides a transferable framework for VUS resolution, trial enrichment, and precision diagnosis across clinically actionable Mendelian disease genes.
Authors
Jeffrey D. Calhoun, Chengbing Wang, Carina G. Biar, Jonathan R. Gunti, John S. Lee, Aaron M. Geller, Jung H. Hong, Santiago Schnell, Louis T. Dang, Yu Wang, Jack M. Parent, Lori L. Isom, Michael D. Uhler, Heather C. Mefford, M. Elizabeth Ross, Vanessa Aguiar-Pulido, Gemma L. Carvill
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss, skeletal muscle atrophy, paralysis, and eventually death. Mitochondrial dysfunction plays a pivotal role in ALS pathogenesis, although the precise pathogenic mechanisms remain elusive, and effective therapeutic strategies are extremely limited. In this study, we developed a small-molecule inhibitor, UA-30, which directly targets RalA, and explored its potential for the treatment of ALS. We found that when administered via oral gavage for 6 weeks following the onset of motor deficit, UA-30 extended lifespan and improved motor function of SOD1G93A mice, a model of ALS. UA-30 ameliorated motor neuron loss, neuroinflammation, fibrosis, and mitochondrial dysfunction, as evidenced by energy recovery, decreased oxidative stress, and enhanced mitophagy. Mechanistically, UA-30 inhibited RalA activity and thereby modulated ERK/FOXO3a signaling, which inhibited FOXO3a degradation via the ubiquitin-proteasome pathway; enhanced FOXO3a stability; and upregulated the expression of mitophagy-related genes in this ALS mouse model. The beneficial effects of UA-30 in ALS were abolished by overexpression of the constitutively active form of RalA (RalAG23V) or Mdivi-1 treatment. These findings support RalA inhibition as a therapeutic strategy for enhancing mitophagy and mitigating ALS-like pathology and support UA-30 as an orally active candidate for further preclinical development.
Authors
Bingge Zhang, Ye He, Ting Su, Xiaomei Li, Xiufen Zhang, Ruijuan Liu, Xiao Han, Ruiming Zhang, Chao Yang, Xinlei Liu, Qinghua Hou, Zaijun Zhang, Yongmei Xie, Gongping Liu, Xifei Yang
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)