BrainPub Date : 2025-06-06DOI: 10.1093/brain/awaf085
Sarah McGlasson, Katy Reid, Anna Klingseisen, Bastien Rioux, Samuel Chauvin, Cathrine A Miner, Joe Holley, Deborah Forbes, Bethany Geary, Jeffrey Kimber, Katrina Wood, Candice Roufosse, Colin Smith, David Kavanagh, Jonathan Miner, David P J Hunt
{"title":"Misdirected yet intact TREX1 exonuclease activity causes human cerebral and systemic small vessel disease.","authors":"Sarah McGlasson, Katy Reid, Anna Klingseisen, Bastien Rioux, Samuel Chauvin, Cathrine A Miner, Joe Holley, Deborah Forbes, Bethany Geary, Jeffrey Kimber, Katrina Wood, Candice Roufosse, Colin Smith, David Kavanagh, Jonathan Miner, David P J Hunt","doi":"10.1093/brain/awaf085","DOIUrl":"https://doi.org/10.1093/brain/awaf085","url":null,"abstract":"<p><p>Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is an incurable microvascular disease caused by C-terminus truncation of the TREX1 exonuclease. There is a pressing need to understand disease mechanisms and identify therapeutic targets. We evaluated TREX1 sequencing data from 469 229 UK Biobank participants together with RVCL-S-related microvascular clinical and imaging outcomes. We show that mono-allelic truncating mutations in TREX1 require intact nuclease activity in order to cause endothelial disease. Differential proteomics identifies loss of interaction with endoplasmic reticulum insertion proteins such as Guided Entry of Tail-Anchored Proteins Factor 3 as a major consequence of pathogenic TREX1 truncation, and this altered trafficking results in the unregulated presence of enzymatically active TREX1 in the nucleus. In endothelial cells with a patient mutation, mislocalized yet enzymatically active TREX1 causes accumulation of a spectrum of DNA damage. These pathological changes can be rescued by inhibiting exonuclease activity. In summary, our data implicate exonuclease-dependent DNA damage in endothelial cells as a key therapeutic target in the pathogenesis of RVCL-S.</p>","PeriodicalId":9063,"journal":{"name":"Brain","volume":" ","pages":""},"PeriodicalIF":10.6,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144233113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-05DOI: 10.1093/brain/awaf214
Jean Chemin, Vanessa Soubeyre, Stephanie Shiers, Amaury François, Gaëtan Poulen, Nicolas Lonjon, Florence Vachiery-Lahaye, Luc Bauchet, Pierre François Mery, Theodore J Price, Emmanuel Bourinet
{"title":"Functional expression of the T-type Cav3.2 calcium channel in female and male human dorsal root ganglion neurons","authors":"Jean Chemin, Vanessa Soubeyre, Stephanie Shiers, Amaury François, Gaëtan Poulen, Nicolas Lonjon, Florence Vachiery-Lahaye, Luc Bauchet, Pierre François Mery, Theodore J Price, Emmanuel Bourinet","doi":"10.1093/brain/awaf214","DOIUrl":"https://doi.org/10.1093/brain/awaf214","url":null,"abstract":"T-type/Cav3 calcium channels are key in neuronal excitability and pain processing with Cav3.2 being the prominent isoform in primary sensory neurons of the dorsal root ganglion (DRG). Cav3.2 pharmacological inhibition or gene silencing induces analgesia in several preclinical models of inflammatory and neuropathic pain. However, the presence of Cav3.2, encoded by the CACNA1H gene, in human DRG neurons remains unresolved. Using RNA in-situ hybridization and electrophysiological recordings, we show that human DRGs express Cav3.2 in a subset of neurons positive for the neurotrophic factor receptor TrkB (NTRK2 gene). The Cav3.2 current exhibits typical biophysical and pharmacological properties, including inhibition by a low concentration of nickel and by Z944, a specific T-type calcium channel blocker in advanced clinical development. Conversely, ABT-639, a T-type calcium channel inhibitor that failed in Phase 2 trials for pain relief, does not inhibit Cav3.2 currents in human DRG neurons. Importantly, Cav3.2 currents are prominent in neurons from female organ donors, supporting the presence of sex differences in pain mechanisms in humans. These findings underscore the potential of continued exploration of Cav3.2 as a therapeutic target for pain treatment and highlight a specific subset of human neurons that likely rely on this channel to modulate their excitability.","PeriodicalId":9063,"journal":{"name":"Brain","volume":"25 1","pages":""},"PeriodicalIF":14.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144228637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-05DOI: 10.1093/brain/awaf218
Ryan P Coburn, Hugo Botha
{"title":"The converging paths to hippocampal sclerosis of ageing: insights from LATE-NC and vascular disease","authors":"Ryan P Coburn, Hugo Botha","doi":"10.1093/brain/awaf218","DOIUrl":"https://doi.org/10.1093/brain/awaf218","url":null,"abstract":"This scientific commentary refers to ‘Common neuropathologic change drivers of hippocampal sclerosis of ageing’ by Woodworth et al. (https://doi.org/10.1093/brain/awaf158).","PeriodicalId":9063,"journal":{"name":"Brain","volume":"248 1","pages":""},"PeriodicalIF":14.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144228459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-05DOI: 10.1093/brain/awaf213
Charissa Millevert, Anthony Sze Hon Kan, Moritz Hanke, Mahmoud Koko, Maryam Erfanian Omidvar, Ulrike B S Hedrich, Thomas V Wuttke, Nina Barišić, Lieven Lagae, Ángel Aledo-Serrano, Eva-Maria Niehoff, Konrad Platzer, Pia Zacher, Tilman Polster, Robertino Dilena, Edoardo Monfrini, David Geneviève, Agathe Roubertie, Ange-Line Bruel, Frederic Tran Mau-Them, Majed Dasouki, Stacey Cohen, Ingo Helbig, Alicia G Harrison, Ellis Colin, Holly A Dubbs, Eric D Marsh, Sébastien Lebon, Na He, Heng Meng, Mary Chebib, Rikke S Møller, Carla Marini, Philip K Ahring, Holger Lerche, Sarah Weckhuysen
{"title":"The genetic and phenotypic spectrum of GABRB1-related disorders","authors":"Charissa Millevert, Anthony Sze Hon Kan, Moritz Hanke, Mahmoud Koko, Maryam Erfanian Omidvar, Ulrike B S Hedrich, Thomas V Wuttke, Nina Barišić, Lieven Lagae, Ángel Aledo-Serrano, Eva-Maria Niehoff, Konrad Platzer, Pia Zacher, Tilman Polster, Robertino Dilena, Edoardo Monfrini, David Geneviève, Agathe Roubertie, Ange-Line Bruel, Frederic Tran Mau-Them, Majed Dasouki, Stacey Cohen, Ingo Helbig, Alicia G Harrison, Ellis Colin, Holly A Dubbs, Eric D Marsh, Sébastien Lebon, Na He, Heng Meng, Mary Chebib, Rikke S Møller, Carla Marini, Philip K Ahring, Holger Lerche, Sarah Weckhuysen","doi":"10.1093/brain/awaf213","DOIUrl":"https://doi.org/10.1093/brain/awaf213","url":null,"abstract":"Pathogenic variants in GABAA receptor subunits genes (GABR*) are important contributors to rare and common genetic epilepsies. Here, we present a comprehensive analysis of variants in GABRB1, which encodes the GABAA receptor β1 subunit, by revealing their functional implications, establishing genotype-phenotype correlations, and evaluating treatment response. Clinical information on individuals carrying a GABRB1 variant was obtained through an international collaboration and literature review. Our cohort included 19 individuals (7 males, 12 females) from 15 families harboring 13 different GABRB1 variants (11 missense, 1 indel, 1 stop). Functional analysis was performed using two-electrode voltage-clamp recordings in Xenopus laevis oocytes. For all eleven missense variants, α1β1γ2 GABAA receptors with a single mutant β1 subunit were used. Four missense variants were selected for further functional analysis using α5β1γ2 GABAA receptors with two mutant β1 subunits. Gain-of-function (GoF) effects, characterised by increased GABA-sensitivity, were observed for eight missense variants. Loss-of-function (LoF) effects were observed for one, and no functional effects for two variants. Clinically, GoF variants were only observed in individuals with severe early-onset disease including profound intellectual disability, hypotonia, and early mortality. Additionally, cortical visual impairment, dysmorphisms and cortical atrophy were exclusive to this cohort. By integrating previously reported clinical data for variants in other GABR* genes we validated that these features were associated with GoF variants more broadly. The only LoF variant was identified in a nuclear family with the relatively milder syndrome of genetic epilepsy with febrile seizures plus. Seizures were therapy-resistant in all individuals with GoF variants, and in a single individual with a LoF variant. The GABAergic anti-seizure medication (ASM) vigabatrin caused life-threatening side-effects in two individuals with GoF variants, while the sodium-channel blocker (SCB) lamotrigine exacerbated seizures in a single individual carrying a LoF variant. By integrating data from literature on all GABR* variants, we observed a potential dichotomy in treatment responses: GABAergic and broad-spectrum ASMs, such as valproate and levetiracetam, were more effective for individuals with LoF variants in GABR* genes, while SCBs showed greater benefit for GoF variants. Additionally, there is an increased risk of adverse effects of SCBs in LoF and vigabatrin in GoF variants. Our results highlight the importance of functional characterisation of variants and clinical predictors in guiding treatment strategies for individuals with GABRB1 and other GABR* variants, though larger prospective studies are needed to confirm these observations.","PeriodicalId":9063,"journal":{"name":"Brain","volume":"10 1","pages":""},"PeriodicalIF":14.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144228635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-04DOI: 10.1093/brain/awaf211
Lei Yu, Lianlian Du, Tianhao Wang, Lisa L Barnes, Jeffrey L Dage, Kristen A Russ, Tatiana Foroud, David A Bennett, Julie A Schneider, Patricia A Boyle
{"title":"Neuropathologic correlates of distinct plasma biomarker profiles in community-living older adults","authors":"Lei Yu, Lianlian Du, Tianhao Wang, Lisa L Barnes, Jeffrey L Dage, Kristen A Russ, Tatiana Foroud, David A Bennett, Julie A Schneider, Patricia A Boyle","doi":"10.1093/brain/awaf211","DOIUrl":"https://doi.org/10.1093/brain/awaf211","url":null,"abstract":"There has been a rapid growth in research on peripheral fluid biomarkers for Alzheimer’s Disease and Alzheimer’s Disease related dementias (AD/ADRD) because they are non-invasive, relatively inexpensive, and easily accessible. The most commonly used plasma biomarkers include β-amyloid (Aβ), phosphorylated tau (p-tau), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP). The extent to which distinct profiles of multiple plasma biomarkers correlate with common neuropathologies is unclear. Using clinicopathologic data from 405 community-dwelling older adults, we applied latent profile analysis on 4 plasma biomarkers, i.e., Aβ42/40 ratio, p-tau217, NfL and GFAP, and examined the correlates of the latent profiles with 4 degeneration measures of AD, Lewy bodies, limbic-predominant age-related TDP-43 encephalopathy (LATE), hippocampal sclerosis, and 5 vascular measures including chronic macroscopic infarcts, microinfarcts, cerebral amyloid angiopathy, atherosclerosis and arteriosclerosis. On average, participants died at the age of 89 and blood samples for plasma biomarkers were measured 3.9 years before death. Over 75% were female and 24% were non-Latino Black. We observed 3 distinct biomarker profiles. Profile #1, characterized by low p-tau217, low GFAP, low NfL and high Aβ42/40, represents most participants (55.6%) with better than average biomarker levels. Both Profile #2 and Profile #3 showed worse than average biomarker levels. Profile #2, representing 34.8% of the participants, was high in p-tau217 and GFAP. By contrast, Profile #3, representing 9.6% of the participants, was high in NfL and GFAP. Examination of neuropathologic correlates of these plasma biomarker profiles revealed that Profile #2 exemplifies older adults with a high burden of neurodegeneration; almost all participants (92.9%) in Profile #2 had a diagnosis of pathologic AD, and the group also had the highest percentage of participants with Lewy bodies (41.1%). In comparison, Profile #3 exemplifies older adults with more severe vascular conditions; participants in this group had the highest percentage of macroscopic infarcts (31.6%) and moderate or severe atherosclerosis (42.1%). Together, these findings suggest that common plasma biomarkers may exhibit profiles reflective of distinct pathophysiologic processes.","PeriodicalId":9063,"journal":{"name":"Brain","volume":"247 1","pages":""},"PeriodicalIF":14.5,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144218885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-03DOI: 10.1093/brain/awae391
Federica Agosta, Silvia Basaia, Edoardo G Spinelli, Federica Facente, Laura Lumaca, Alma Ghirelli, Elisa Canu, Veronica Castelnovo, Elisa Sibilla, Chiara Tripodi, Fabiola Freri, Giordano Cecchetti, Giuseppe Magnani, Francesca Caso, Federico Verde, Nicola Ticozzi, Vincenzo Silani, Paola Caroppo, Sara Prioni, Cristina Villa, Lucio Tremolizzo, Ildebrando Appollonio, Ashish Raj, Massimo Filippi
{"title":"Modelling pathological spread through the structural connectome in the frontotemporal dementia clinical spectrum.","authors":"Federica Agosta, Silvia Basaia, Edoardo G Spinelli, Federica Facente, Laura Lumaca, Alma Ghirelli, Elisa Canu, Veronica Castelnovo, Elisa Sibilla, Chiara Tripodi, Fabiola Freri, Giordano Cecchetti, Giuseppe Magnani, Francesca Caso, Federico Verde, Nicola Ticozzi, Vincenzo Silani, Paola Caroppo, Sara Prioni, Cristina Villa, Lucio Tremolizzo, Ildebrando Appollonio, Ashish Raj, Massimo Filippi","doi":"10.1093/brain/awae391","DOIUrl":"10.1093/brain/awae391","url":null,"abstract":"<p><p>The ability to predict the spreading of pathology in patients with frontotemporal dementia (FTD) is crucial for early diagnosis and targeted interventions. In this study, we examined the relationship between network vulnerability and longitudinal progression of atrophy in FTD patients, using the network diffusion model (NDM) of the spread of pathology. Thirty behavioural variant FTD (bvFTD), 13 semantic variant primary progressive aphasia (svPPA), 14 non-fluent variant primary progressive aphasia (nfvPPA) and 12 semantic behavioural variant FTD (sbvFTD) patients underwent longitudinal T1-weighted MRI. Fifty young controls (20-31 years of age) underwent multi-shell diffusion MRI scan. An NDM was developed to model progression of FTD pathology as a spreading process from a seed through the healthy structural connectome, using connectivity measures from fractional anisotropy and intracellular volume fraction in young controls. Four disease epicentres were initially identified from the peaks of atrophy of each FTD variant: left insula (bvFTD), left temporal pole (svPPA), right temporal pole (sbvFTD) and left supplementary motor area (nfvPPA). Pearson's correlations were calculated between NDM-predicted atrophy in young controls and the observed longitudinal atrophy in FTD patients over a follow-up period of 24 months. The NDM was then run for all 220 brain seeds to verify whether the four epicentres were among those that yielded the highest correlation. Using the NDM, predictive maps in young controls showed progression of pathology from the peaks of atrophy in svPPA, nfvPPA and sbvFTD over 24 months. svPPA exhibited early involvement of the left temporal and occipital lobes, progressing to extensive left hemisphere impairment. nfvPPA and sbvFTD spread in a similar manner bilaterally to frontal, sensorimotor and temporal regions, with sbvFTD additionally affecting the right hemisphere. Moreover, the NDM-predicted atrophy of each region was positively correlated with longitudinal real atrophy, with a greater effect in svPPA and sbvFTD. In bvFTD, the model starting from the left insula (the peak of atrophy) demonstrated a highly left-lateralized pattern, with pathology spreading to frontal, sensorimotor, temporal and basal ganglia regions, with minimal extension to the contralateral hemisphere by 24 months. However, unlike the atrophy peaks observed in the other three phenotypes, the left insula did not show the strongest correlation between the estimated and real atrophy. Instead, the bilateral superior frontal gyrus emerged as optimal seeds for modelling atrophy spread, showing the highest correlation ranking in both hemispheres. Overall, NDM applied on the intracellular volume fraction connectome yielded higher correlations relative to NDM applied on fractional anisotropy maps. The NDM implementation using the cross-sectional structural connectome is a valuable tool to predict patterns of atrophy and spreading of pathology in FTD clinical vari","PeriodicalId":9063,"journal":{"name":"Brain","volume":" ","pages":"1994-2007"},"PeriodicalIF":10.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12129736/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142749866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BrainPub Date : 2025-06-03DOI: 10.1093/brain/awaf046
Richard S Bedlack
{"title":"Overstating harms can have consequences.","authors":"Richard S Bedlack","doi":"10.1093/brain/awaf046","DOIUrl":"10.1093/brain/awaf046","url":null,"abstract":"","PeriodicalId":9063,"journal":{"name":"Brain","volume":" ","pages":"e52-e53"},"PeriodicalIF":10.6,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}