Neuroscience
Abstract
Effective psychotherapeutic interventions for post-traumatic stress disorder (PTSD) rely on fear extinction to suppress maladaptive fear responses, yet their long-term efficacy is limited by high relapse rates. Notably, extinction involves not only fear inhibition but also affective engagement. However, whether and how internal affective components contribute to extinction retrieval and long-term persistence remain unclear. Here, we demonstrate that positive affective experiences arising during extinction govern the long-term persistence of extinction and resistance to spontaneous recovery. We identify a subpopulation of medial prefrontal cortex (mPFC) extinction neurons projecting to supramammillary nucleus glutamatergic (SuMGlu) neurons that encodes positive affective experience during extinction and selectively governs long-term extinction persistence. This ensemble is spatially, anatomically, and transcriptionally distinct from mPFC extinction neurons projecting to zona incerta somatostatin-expressing (ZISST) neurons, which primarily support extinction retrieval. Transcriptomic profiling reveals enrichment of sirtuin 1 (Sirt1) within SuM-projecting extinction ensembles, and bidirectional manipulation of SIRT1 alters extinction relapse vulnerability in a PTSD mouse model. These findings provide a cortical–hypothalamic framework incorporating molecular features that governs the long-term persistence of fear extinction and resistance to relapse through positive affective processes.
Authors
Ze-Jie Lin, Xin-Rong Wu, Ming-Yang Wei, Zheng-Kai Lao, Xiang Lan, Yan-Jiao Wu, Wei-Guang Li, Tian-Le Xu, Li-Na Huang, Xue Gu
Abstract
Loss-of-function mutations in PSMB8/beta5i and other components of the 20S proteasome result in multi-organ diseases, such as Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) syndrome. Neurocognitive dysfunction associated with CANDLE suggests that proteasomal mutations may impact neuronal function and development early in life. We generated cerebral organoids (COs) from induced pluripotent stem cells (iPSCs) made from CANDLE patients. The COs from CANDLE iPSCs exhibited impaired neuronal development when compared to COs from healthy control iPSCs. Impaired neuronal maturation in CANDLE COs was correlated with increased polyamines, which were also elevated in CANDLE patient CSF. The proteasome-regulated Ornithine decarboxylase (ODC), the rate limiting enzyme in polyamine biosynthesis, was elevated in CANDLE neurons. Inhibition of ODC reversed polyamine overproduction and repaired neuronal maturation in CANDLE COs, suggesting a potential therapeutic avenue for intervention. These findings demonstrate that dysfunction of the proteasome affects neuronal development through overproduction of polyamines via dysregulation of ODC and offer insight into potential therapeutic strategies for CNS-related proteasomal dysfunction.
Authors
Clayton W. Winkler, Benjamin Schwarz, Katie Williams, Sara Alehashemi, Simote T. Foliaki, Joseph Snow, Lisa Joseph, Audrey Thurm, Christopher L. Friend, Gwendolyn Cooper, Eric Bohrnsen, Farzana Bhuyan, Nathan T. Brandes, Ruin Moaddel, Manfred Boehm, Guibin Chen, Cole D. Kimzey, Bibiana Bielekova, Joanna Kocot, Peter Kosa, Cathryn L. Haigh, Raphaela Goldbach-Mansky, Karin E. Peterson
Abstract
Cockayne Syndrome (CS) is an autosomal recessive, progressive developmental and neurodegenerative disease. Approximately 30% of cases are caused by mutations in the ERCC8/CSA gene. Patients with CS present with cutaneous photosensitivity, growth failure, shorter life span, and a progressive degeneration of the central nervous system. Loss-of-function mutations in CSA result in deficiencies in the transcription-coupled nucleotide excision repair (TC-NER). Currently, no therapies are available for these patients. Adeno-associated virus (AAV)-mediated gene therapy offers an opportunity to address this unmet need. We designed a new AAV vector encoding human CSA under a ubiquitous promoter. We tested the therapeutic efficacy of this AAV9-CSA vector by neonatal intracerebroventicular injection in the Csa–/–;Xpa–/– mouse model. Treatment with AAV9-CSA resulted in a significant increase in lifespan, and broad distribution of human CSA in the brain and heart, without evidence of vector-related toxicity. Despite clear therapeutic benefit, we also observed neuroradiological abnormalities, and neuropathologic alterations, including hypomyelination, astrocytosis, and microgliosis, as well as likely life-limiting transcriptomic alterations in liver at endpoint. Nonetheless, the success of these experiments paves the way for the first clinical translation of an AAV gene therapy for CS patients into humans.
Authors
Ana Rita Batista, Aine C. Scholand, William S. Callahan, McKenna K. Watson, Cassandra M. Sion, Tyler Mola, Kennedy O'Hara, Simon A. Wentworth, William S. Sena-Esteves, Oliver D. King, Robert M. King, Miguel Sena-Esteves
Abstract
Chronic primary pain conditions (CPPCs), such as fibromyalgia and vestibulodynia, affect over 100 million Americans, predominantly women, and pose a substantial healthcare challenge. CPPCs arise from genetic and environmental factors that enhance catecholamine tone, potentially through miRNA dysregulation following catecholamine activation of beta-adrenergic receptors. Here, we identified miR-133a-3p as a biomarker of CPPC status and investigated its functions using in vivo and in vitro approaches. Plasma levels of miR-133a-3p were consistently downregulated in humans with ≥1 CPPC and in rat and mouse models of primary pain. Our data suggest that miR-133a-3p is packaged in extracellular vesicles that are secreted by adipocytes and trafficked to the spinal cord. Activation of adrenergic receptors on white adipocytes resulted in downregulation of miR-133a-3p which negatively regulated pain-related genes in the spinal cord, such as MAP3K3, which is critical for sensory neuron activation. Adipose-specific overexpression of miR-133a-3p in a mouse model of primary pain reversed mechanical hypersensitivity in both sexes. These findings implicate miR-133a-3p dysregulation in primary pain across conditions and species and establish its role in multi-site mechanical hypersensitivity. Further, miR-133a-3p overexpression shows therapeutic potential for the millions of individuals with CPPCs.
Authors
Nathaniel P. Hernandez, Jiegen Chen, Yiling Qian, Xin Zhang, Yaomin Wang, Brittney P. Ciszek, Xianglong Gao, Marguerita E. Klein, Yun-Ling Pai, Mohamad Karaky, Carolina B. Meloto, Francesca Montagna, Matt Kanke, Clair Crewe, Luda Diatchenko, Praveen Sethupathy, Andrea G. Nackley
Abstract
Epilepsy affects approximately 50 million people worldwide, yet more than half of individuals with a presumed genetic cause still lack a molecular diagnosis despite the identification of over 1,000 monogenic epilepsy genes. This diagnostic gap is unlikely to be resolved by improved variant detection alone, suggesting that variants affecting the same biological pathway may combine to cause disease. By studying epilepsy-associated actin regulatory genes, we identified a conserved “actin-mitochondria-glutamate (AMG) pathway”. We demonstrate that reduced actin polymerization promotes DRP1-mediated mitochondrial fission, increases reactive oxygen species (ROS) levels, and enhances glutamatergic transmission, leading to seizures. The glial innate immune pathway, a recently recognized contributor to epilepsy, is activated when the AMG pathway is affected. Reducing mitochondrial fission with the DRP1 inhibitor Mdivi-1, or suppressing ROS with N-acetyl-L-cysteine amide (NACA), significantly alleviates seizures. Importantly, digenic heterozygous loss‑of‑function variants in AMG‑pathway genes combine to cause seizures, and individuals with epilepsy of unknown etiology show an increased burden of such variants when compared to the controls. Modeling patient‑specific digenic combinations in Drosophila confirms that many combinations promote seizure susceptibility. Together, these findings establish the AMG pathway as a mechanistic framework for identifying digenic etiologies in epilepsy and highlight potential therapeutic targets.
Authors
Shenzhao Lu, Mengqi Ma, Shabab B. Hannan, Mingxi Deng, Hu Chen, Zhijian Yu, Lindsey D. Goodman, Haein Kim, Yun Zhao, Sandeep Kumar Dubey, Wen-Wen Lin, Xueyang Pan, Debdeep Dutta, Vishnu Anand Cuddapah, Jill A. Rosenfeld, Xi Luo, Zhandong Liu, Joshua M. Shulman, Hugo J. Bellen
Abstract
Opioids are essential analgesics for managing severe pain but can paradoxically increase pain sensitivity (hyperalgesia) and diminish analgesic efficacy (tolerance). Hyperactivity of NMDA-type glutamate receptors (NMDARs) at primary afferent terminals in the spinal cord contributes to both phenomena; however, the underlying signaling mechanisms remain unclear. Here, we report that morphine administration in rats promoted the translocation of monomeric BRAF, an oncogenic kinase, from the dorsal root ganglion (DRG) to spinal cord synaptosomes, leading to increased MEK-ERK phosphorylation at nociceptor central terminals. BRAF physically interacted with NMDARs in both rat and human spinal cords. Inhibition of BRAF activity with vemurafenib reversed morphine-induced NMDAR phosphorylation and synaptic localization of α2δ-1–bound NMDARs. Vemurafenib also abolished morphine-induced presynaptic NMDAR hyperactivity in spinal dorsal horn neurons. Correspondingly, conditional Braf knockout in DRG neurons normalized morphine-enhanced NMDAR phosphorylation, synaptic trafficking of α2δ-1–bound NMDARs, and NMDAR hyperactivity in the spinal cord. Furthermore, pharmacological inhibition of BRAF or MEK, or Braf deletion in DRG neurons, enhanced morphine analgesia while mitigated morphine-induced hyperalgesia and tolerance. These findings identify BRAF overactivity at nociceptor central terminals as a key mediator of opioid-induced NMDAR hyperactivity. Clinically approved BRAF inhibitors could be repurposed to enhance opioid analgesia while minimizing adverse effects.
Authors
Daozhong Jin, Hong Chen, Yuying Huang, Shao-Rui Chen, Hui-Lin Pan
Abstract
Trigeminal neuralgia (TN) is a severe orofacial pain disorder accompanied by anxiety, yet its central mechanisms remain elusive. Analysis of human fMRI data identified the parafascicular nucleus (PF) as a candidate region. Using a TN mouse model, we uncovered two spatially and functionally distinct PF neuronal ensembles that separately encoded sensory and affective dimensions of pain. One population received inhibitory input from GABAergic neurons in the oral spinal trigeminal nucleus (Sp5O) and mediated nociception. The second population, driven by a glutamatergic Sp5O-lateral parabrachial nucleus (lPBN)-PF pathway, encoded pain-related anxiety. The engagement of the anxiety-encoding ensemble lagged behind that of the pain-encoding ensemble, with a shorter delay in females. Single-nucleus RNA sequencing identified Col25a1 and Syn2 as markers of the anxiety-encoding ensemble. Notably, this population, localized in the medial PF, formed a reciprocal lPBN-mPF-lPBN excitatory-feedback loop that sustained affective pain. These findings positioned PF as a key node linking pain and emotion in TN.
Authors
Yitian Lu, Yangyang Yi, Jiao Liu, Hao Zhi, Qing Chang, Zihao Huang, Yumeng Chen, Han L. Tan, Yiheng Tu, Yun Wang, Cheng Cen
Abstract
Sarcopenia is the age-related loss of muscle strength and size that leads to mobility limitations and loss of independence in older adults. The underlying cellular mechanisms remain unclear, and treatments are limited. As the critical interface between the nervous system and muscle, the neuromuscular junction (NMJ) is essential for muscle activation and force production. Here, we demonstrate that weak older individuals exhibit NMJ transmission failure that correlates with muscle weakness severity. Preclinical experiments showed similar NMJ transmission failure in aged rodents that was associated with localized loss of muscle fiber excitability at the NMJ. This excitability defect, distinct from potential synaptic cholinergic transmission abnormalities, represents a novel disease mechanism of sarcopenia. Across species, immunohistochemistry identified a localized reduction in the voltage-gated sodium channel specific for skeletal muscle (NaV1.4) at the post-synaptic NMJ membrane. Acute NaV1.4 inhibition with μ-conotoxin GIIIB in adult rats reproduced findings of NMJ transmission failure observed in aged rodents and humans. Finally, ClC-1 chloride ion channel inhibition enhanced muscle excitability and improved NMJ transmission and muscle function in old rodents. Together, these findings demonstrate that NMJ transmission deficits are a key, reversible driver of sarcopenia and reveal a novel therapeutic target for addressing muscle weakness in aging.
Authors
W. David Arnold, Jeanette Jeppesen Morgen, Pernille Bogetofte Thomasen, Martin Broch-Lips, Leatha A. Clark, Thomas Groennebaek, Martin Skov, Jeppe Blichfeldt Winther, Abdullah F. Ramadan, Philippa A. Rust, Jessica H. Myers, Fereshteh B. Darvishi, Anna R. Dashtmian, Lauren A. Fish, Deepti Chugh, Jane Bold, Jorge A. Quiroz, John Hutchison, Hiroshi Nishimune, Ross A. Jones, Xueyong Wang, Justin R. Fallon, Thomas H. Gillingwater, Mark M. Rich, Thomas Holm Pedersen, Brian C. Clark
Abstract
Kleefstra syndrome (KLEFS1) results from EHMT1 haploinsufficiency and is characterized by variable neurodevelopmental delays and psychopathology. Developmental regression, marked by the sudden loss of previously acquired daily life skills during late puberty or early adulthood, has emerged as a severe complication in individuals with KLEFS1. To investigate the clinical and molecular mechanisms underlying developmental regression and assess the therapeutic potential of olanzapine, we conducted a sequential study in an international cohort of fifty-four individuals with KLEFS1. Among sixteen individuals treated with olanzapine, ten exhibited a beneficial response based upon improvement of their adaptive functioning, and four showed temporary improvement. These clinical findings informed preclinical studies using human induced pluripotent stem cell-derived and ex-vivo cortical slices from a mouse model of KLEFS1. We identified hyperactivity in EHMT1+/– neuronal networks co-cultured with EHMT1+/– astrocytes, a dysfunction reversible by olanzapine. Mechanistically, EHMT1+/– astrocytes displayed elevated levels of S100B, a neuroinflammatory marker contributing to neuronal network hyperactivity. Notably, olanzapine treatment reduced S100B levels, and pharmacological inhibition or genetic knockdown of S100B in EHMT1+/– astrocytes was sufficient to rescue the neuronal hyperactivity phenotype. These findings underscore a critical role for astrocytes in KLEFS1 pathophysiology and identify a potential cellular target for olanzapine in mitigating developmental regression.
Authors
Karlijn Vermeulen-Kalk, Shan Wang, Joost Kummeling, Britt Mossink, Kim N. Wijnant, Carlos O. González Jiménez, Zoe J. Frazier, Brian J. Rozumny, Anne O'Donnell-Luria, Ellen Hanson, Monica Frega, Katrin Linda, Moritz Negwer, Bas Lendemeijer, Astrid Oudakker, Monica Pop-Purceleanu, Joost G.E. Janzing, Linde van Dongen, Femke M.S. de Vrij, Steven A. Kushner, Ilse van der Werf, Chantal Schoenmaker, Wouter Oomens, Siddharth Srivastava, Jos I.M. Egger, Hans van Bokhoven, Dirk Schubert, Nael Nadif Kasri, Tjitske Kleefstra
Abstract
Dominant mutations in Progranulin (GRN) gene cause frontotemporal lobar degeneration (FTLD-GRN), whereas homozygous GRN mutations lead to neuronal ceroid lipofuscinosis, a childhood neurodegenerative disorder. While recent transcriptomic studies reveal profound glial and neuronal pathology in FTLD-GRN at the disease end stage, the mechanism that disrupts glia-neuron homeostasis remains unclear. Using induced pluripotent stem cell (iPSC)-derived cortical organoids, we showed that GRN-/- and GRNR493X mutations lead to precocious astrogliosis that promotes neuronal stress and synaptic loss. Single-cell transcriptomics and histopathology analyses revealed a robust activation in TGFb signaling pathway in GRN-/- and GRNR493X/R493X astrocytes, which was accompanied by features of immune activation, loss of synaptic support, and abundant pTDP-43+ fibrils in astroglial cytoplasm, a feature characteristic of FTLD-GRN. Intriguingly, blocking TGFb signaling mitigated astroglial activation and pTDP-43 proteinopathy in GRN-/- organoids. Together, these results provide new insights into the cell-autonomous role of astroglial activation in neurodegeneration caused by Progranulin deficiency.
Authors
Arren C. Ramsey, Xiao-Yan Tang, Magdalena J. Macias, Patricia R. Nano, Rufei Lu, Brian Benito, Cameron M. Lau, Jisu Park, Jiasheng Zhang, Wandy Beatty, Tanzila Mukhtar, Arnold R. Kriegstein, Aparna Bhaduri, Elise Marsan, Eric J. Huang
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)