Molecular Neurodegeneration最新文献

{"title":"Regulation of disease-associated microglia in the optic nerve by lipoxin B4 and ocular hypertension","authors":"Shubham Maurya, Maggie Lin, Shruthi Karnam, Tanirika Singh, Matangi Kumar, Emily Ward, Jeremy Sivak, John G. Flanagan, Karsten Gronert","doi":"10.1186/s13024-024-00775-z","DOIUrl":"https://doi.org/10.1186/s13024-024-00775-z","url":null,"abstract":"The resident astrocyte-retinal ganglion cell (RGC) lipoxin circuit is impaired during retinal stress, which includes ocular hypertension-induced neuropathy. Lipoxin B4 produced by homeostatic astrocytes directly acts on RGCs to increase survival and function in ocular hypertension-induced neuropathy. RGC death in the retina and axonal degeneration in the optic nerve are driven by the complex interactions between microglia and macroglia. Whether LXB4 neuroprotective actions include regulation of other cell types in the retina and/or optic nerve is an important knowledge gap. Cellular targets and signaling of LXB4 in the retina were defined by single-cell RNA sequencing. Retinal neurodegeneration was induced by injecting silicone oil into the anterior chamber of mouse eyes, which induced sustained and stable ocular hypertension. Morphological characterization of microglia populations in the retina and optic nerve was established by MorphOMICs and pseudotime trajectory analyses. The pathways and mechanisms of action of LXB4 in the optic nerve were investigated using bulk RNA sequencing. Transcriptomics data was validated by qPCR and immunohistochemistry. Differences between experimental groups were assessed by Student’s t-test and one-way ANOVA. Single-cell transcriptomics identified microglia as a primary target for LXB4 in the healthy retina. LXB4 downregulated genes that drive microglia environmental sensing and reactivity responses. Analysis of microglial function revealed that ocular hypertension induced distinct, temporally defined, and dynamic phenotypes in the retina and, unexpectedly, in the distal myelinated optic nerve. Microglial expression of CD74, a marker of disease-associated microglia in the brain, was only induced in a unique population of optic nerve microglia, but not in the retina. Genetic deletion of lipoxin formation correlated with the presence of a CD74 optic nerve microglia population in normotensive eyes, while LXB4 treatment during ocular hypertension shifted optic nerve microglia toward a homeostatic morphology and non-reactive state and downregulated the expression of CD74. Furthermore, we identified a correlation between CD74 and phospho-phosphoinositide 3-kinases (p-PI3K) expression levels in the optic nerve, which was reduced by LXB4 treatment. We identified early and dynamic changes in the microglia functional phenotype, reactivity, and induction of a unique CD74 microglia population in the distal optic nerve as key features of ocular hypertension-induced neurodegeneration. Our findings establish microglia regulation as a novel LXB4 target in the retina and optic nerve. LXB4 maintenance of a homeostatic optic nerve microglia phenotype and inhibition of a disease-associated phenotype are potential neuroprotective mechanisms for the resident LXB4 pathway.","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"8 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678252","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}

{"title":"Stearoyl-CoA desaturase-1: a potential therapeutic target for neurological disorders","authors":"Melanie Loix, Sam Vanherle, Marta Turri, Stephan Kemp, Karl J. L. Fernandes, Jerome J. A. Hendriks, Jeroen F. J. Bogie","doi":"10.1186/s13024-024-00778-w","DOIUrl":"https://doi.org/10.1186/s13024-024-00778-w","url":null,"abstract":"Disturbances in the fatty acid lipidome are increasingly recognized as key drivers in the progression of various brain disorders. In this review article, we delve into the impact of Δ9 fatty acid desaturases, with a particular focus on stearoyl-CoA desaturase-1 (SCD1), within the setting of neuroinflammation, neurodegeneration, and brain repair. Over the past years, it was established that inhibition or deficiency of SCD1 not only suppresses neuroinflammation but also protects against neurodegeneration in conditions such as multiple sclerosis, Alzheimer’s disease, and Parkinson’s disease. This protective effect is achieved through different mechanisms including enhanced remyelination, reversal of synaptic and cognitive impairments, and mitigation of α-synuclein toxicity. Intriguingly, metabolic rerouting of fatty acids via SCD1 improves the pathology associated with X-linked adrenoleukodystrophy, suggesting context-dependent benign and harmful effects of SCD1 inhibition in the brain. Here, we summarize and discuss the cellular and molecular mechanisms underlying both the beneficial and detrimental effects of SCD1 in these neurological disorders. We explore commonalities and distinctions, shedding light on potential therapeutic challenges. Additionally, we touch upon future research directions that promise to deepen our understanding of SCD1 biology in brain disorders and potentially enhance the clinical utility of SCD1 inhibitors.","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"250 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670724","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}

{"title":"Are oligodendrocytes the missing link in Alzheimer's disease and related dementia research?","authors":"Sharyn L Rossi, Diane E Bovenkamp","doi":"10.1186/s13024-024-00760-6","DOIUrl":"10.1186/s13024-024-00760-6","url":null,"abstract":"","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"19 1","pages":"84"},"PeriodicalIF":14.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11569602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142644402","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}

{"title":"Contribution of amyloid deposition from oligodendrocytes in a mouse model of Alzheimer’s disease","authors":"Akihiro Ishii, Joseph A. Pathoulas, Omar MoustafaFathy Omar, Yingying Ge, Annie Y. Yao, Tressa Pantalena, Neeraj Singh, John Zhou, Wanxia He, Patrick Murphy, Riqiang Yan, Xiangyou Hu","doi":"10.1186/s13024-024-00759-z","DOIUrl":"https://doi.org/10.1186/s13024-024-00759-z","url":null,"abstract":"The accumulation of β-amyloid (Aβ) peptides into insoluble plaques is an early pathological feature of Alzheimer’s disease (AD). BACE1 is the sole β-secretase for Aβ generation, making it an attractive therapeutic target for AD therapy. While BACE1 inhibitors have been shown to reduce Aβ levels in people with AD, clinical trials targeting BACE1 have failed due to unwanted synaptic deficits. Understanding the physiological role of BACE1 in individual cell types is essential for developing effective BACE inhibitors for the treatment of AD. Recent single-cell RNA transcriptomic assays revealed that oligodendrocytes are enriched with genes required for generating Aβ. However, the contribution of oligodendrocytes to amyloid plaque burden in AD and the side effects of oligodendrocyte-specific Bace1 deletion remain to be explored. We generated an oligodendrocyte-specific Bace1 knockout model (Bace1fl/fl;Olig2-Cre) to monitor potential disruptions in myelination using standard electron microscopy. Long-term potentiation (LTP) was monitored to measure synaptic integrity. We crossed the Bace1fl/fl;Olig2-Cre model with heterozygous AppNL−G−F/wt knock-in AD mice to generate AD mice lacking oligodendrocyte Bace1 (Bace1fl/fl;Olig2-Cre; AppNL−G−F/wt) and examined amyloid plaque number and insoluble Aβ levels and gliosis in these animals. Single nuclei RNA sequencing experiments were conducted to examine molecular changes in response to Bace1 deficiency in oligodendrocytes in the wild type or APP knock-in background. Bace1 deletion in oligodendrocytes caused no change in myelin thickness in the corpus callosum but a marginal reduction in myelin sheath thickness of the optic nerve. Synaptic strength measured by LTP was not different between Bace1fl/fl;Olig2-Cre and age-matched Bace1fl/fl control animals, suggesting no major effect on synaptic plasticity. Intriguingly, deletion of Bace1 in 12-month-old heterozygous AD knock-in mice (Bace1fl/fl;Olig2-Cre; AppNL−G−F/wt mice) caused a significant reduction of amyloid plaques by ~ 33% in the hippocampus and ~ 29% in the cortex compared to age-matched AD mice (Bace1fl/fl;AppNL−G−F/wt). Insoluble Aβ1–40 and Aβ1–42 levels were reduced comparably while more astrocytes and microglia were observed in surrounding amyloid plaques. Unbiased single-nuclei RNA sequencing results revealed that deletion of oligodendrocyte Bace1 in APPNL−G−F/wt knock-in mice increased expression of genes associated with Aβ generation and clearance such as ADAM10, Ano4, ApoE, Il33, and Sort1. Our results provide compelling evidence that the amyloidogenic pathway in oligodendrocytes contributes to Aβ plaque formation in the AD brain. While specifically targeting BACE1 inhibition in oligodendrocytes for reducing Aβ pathology in AD is likely challenging, this is a potentially explorable strategy in future studies.","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"21 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642661","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}

{"title":"CSF proteins of inflammation, proteolysis and lipid transport define preclinical AD and progression to AD dementia in cognitively unimpaired individuals","authors":"Marta del Campo, Carlos Quesada, Lisa Vermunt, Carel F. W. Peeters, Yanaika S. Hok-A-Hin, Calvin Trieu, Anouk den Braber, Inge M. W. Verberk, Pieter J. Visser, Betty M. Tijms, Wiesje M. van der Flier, Charlotte E. Teunissen","doi":"10.1186/s13024-024-00767-z","DOIUrl":"https://doi.org/10.1186/s13024-024-00767-z","url":null,"abstract":"This preclinical AD CSF proteome study identified a panel of 12-CSF markers detecting amyloid positivity and clinical progression to AD with high accuracy; some of these CSF proteins related to immune function, neurotrophic processes, energy metabolism and endolysosomal functioning (e.g., ITGB2, CLEC5A, IGFBP-1, CST3) changed before amyloid positivity is established.","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"37 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598316","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}

{"title":"Proteomic analysis of APOEε4 carriers implicates lipid metabolism, complement and lymphocyte signaling in cognitive resilience","authors":"Keenan A. Walker, Yang An, Abhay Moghekar, Ruin Moaddel, Michael R. Duggan, Zhongsheng Peng, Qu Tian, Luke C. Pilling, Shannon M. Drouin, Mark A. Espeland, Stephen R Rapp, Kathleen M Hayden, Aladdin H. Shadyab, Ramon Casanova, Madhav Thambisetty, Peter R. Rapp, Dimitrios Kapogiannis, Luigi Ferrucci, Susan M. Resnick","doi":"10.1186/s13024-024-00772-2","DOIUrl":"https://doi.org/10.1186/s13024-024-00772-2","url":null,"abstract":"Apolipoprotein E (APOE) ε4 allele is the strongest genetic risk factor for late onset Alzheimer’s disease (AD). This case-cohort study used targeted plasma biomarkers and large-scale proteomics to examine the biological mechanisms that allow some APOEε4 carriers to maintain normal cognitive functioning in older adulthood. APOEε4 carriers and APOEε3 homozygotes enrolled in the Women’s Health Initiative Memory Study (WHIMS) from 1996 to 1999 were classified as resilient if they remained cognitively unimpaired beyond age 80, and as non-resilient if they developed cognitive impairment before or at age 80. AD pathology (Aß42/40) and neurodegeneration (NfL, tau) biomarkers, as well as 1007 proteins (Olink) were quantified in blood collected at study enrollment (on average 14 years prior) when participants were cognitively normal. We identified plasma proteins that distinguished between resilient and non-resilient APOEε4 carriers, examined whether these associations generalized to APOEε3 homozygotes, and replicated these findings in the UK Biobank. A total of 1610 participants were included (baseline age: 71.3 [3.8 SD] years; all White; 42% APOEε4 carriers). Compared to resilient APOEε4 carriers, non-resilient APOEε4 carriers had lower Aß42/40/tau ratio and greater NfL at baseline. Proteomic analyses identified four proteins differentially expressed between resilient and non-resilient APOEε4 carriers at an FDR-corrected P < 0.05. While one of the candidate proteins, a marker of neuronal injury (NfL), also distinguished resilient from non-resilient APOEε3 homozygotes, the other three proteins, known to be involved in lipid metabolism (ANGPTL4) and immune signaling (PTX3, NCR1), only predicted resilient vs. non-resilient status among APOEε4 carriers (protein*genotype interaction-P < 0.05). Three of these four proteins also predicted 14-year dementia risk among APOEε4 carriers in the UK Biobank validation sample (N = 9420). While the candidate proteins showed little to no association with targeted biomarkers of AD pathology, protein network and enrichment analyses suggested that natural killer (NK) cell and T lymphocyte signaling (via PKC-θ) distinguished resilient from non-resilient APOEε4 carriers. We identified and replicated a plasma proteomic signature associated with cognitive resilience among APOEε4 carriers. These proteins implicate specific immune processes in the preservation of cognitive status despite elevated genetic risk for AD. Future studies in diverse cohorts will be needed to assess the generalizability of these results.","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"131 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555723","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}

{"title":"Repetitive transcranial magnetic stimulation alleviates motor impairment in Parkinson’s disease: association with peripheral inflammatory regulatory T-cells and SYT6","authors":"Fen Xie, Bibiao Shen, Yuqi Luo, Hang Zhou, Zhenchao Xie, Shuzhen Zhu, Xiaobo Wei, Zihan Chang, Zhaohua Zhu, Changhai Ding, Kunlin Jin, Chengwu Yang, Lucia Batzu, K Ray Chaudhuri, Ling-Ling Chan, Eng-King Tan, Qing Wang","doi":"10.1186/s13024-024-00770-4","DOIUrl":"https://doi.org/10.1186/s13024-024-00770-4","url":null,"abstract":"Repetitive transcranial magnetic stimulation (rTMS) has been used to treat various neurological disorders. However, the molecular mechanism underlying the therapeutic effect of rTMS on Parkinson’s disease (PD) has not been fully elucidated. Neuroinflammation like regulatory T-cells (Tregs) appears to be a key modulator of disease progression in PD. If rTMS affects the peripheral Tregs in PD remains unknown. Here, we conducted a prospective clinical study (Chinese ClinicalTrials. gov: ChiCTR 2100051140) involving 54 PD patients who received 10-day rTMS (10 Hz) stimulation on the primary motor cortex (M1) region or sham treatment. Clinical and function assessment as well as flow cytology study were undertaken in 54 PD patients who were consecutively recruited from the department of neurology at Zhujiang hospital between September 2021 and January 2022. Subsequently, we implemented flow cytometry analysis to examine the Tregs population in spleen of MPTP-induced PD mice that received rTMS or sham treatment, along with quantitative proteomic approach reveal novel molecular targets for Parkinson's disease, and finally, the RNA interference method verifies the role of these new molecular targets in the treatment of PD. We demonstrated that a 10-day rTMS treatment on the M1 motor cortex significantly improved motor dysfunction in PD patients. The beneficial effects persisted for up to 40 days, and were associated with an increase in peripheral Tregs. There was a positive correlation between Tregs and motor improvements in PD cases. Similarly, a 10-day rTMS treatment on the brains of MPTP-induced PD mice significantly ameliorated motor symptoms. rTMS reversed the downregulation of circulating Tregs and tyrosine hydroxylase neurons in these mice. It also increased anti-inflammatory mediators, deactivated microglia, and decreased inflammatory cytokines. These effects were blocked by administration of a Treg inhibitor anti-CD25 antibody in MPTP-induced PD mice. Quantitative proteomic analysis identified TLR4, TH, Slc6a3 and especially Syt6 as the hub node proteins related to Tregs and rTMS therapy. Lastly, we validated the role of Treg and rTMS-related protein syt6 in MPTP mice using the virus interference method. Our clinical and experimental studies suggest that rTMS improves motor function by modulating the function of Tregs and suppressing toxic neuroinflammation. Hub node proteins (especially Syt6) may be potential therapeutic targets. Chinese ClinicalTrials, ChiCTR2100051140. Registered 15 December 2021, https://www.chictr.org.cn/bin/project/edit?pid=133691 rTMS is a safe and non-invasive method for Parkinson's disease. In this study, we showed the proportion of CD4+CD25+CD127- regulatory T-cells (Tregs) in the peripheral blood was significantly increased after rTMS treatment. Similar effects of rTMS treatment were verified in MPTP-induced PD mice. Proteomic analysis and RNA interference analyses identified TLR4, TH, Slc6a3 and especially Syt6 as hub ","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"99 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142490289","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}

{"title":"HDGFL2 cryptic protein: a portal to detection and diagnosis in neurodegenerative disease","authors":"Ellen A. Albagli, Anna Calliari, Tania F. Gendron, Yong-Jie Zhang","doi":"10.1186/s13024-024-00768-y","DOIUrl":"https://doi.org/10.1186/s13024-024-00768-y","url":null,"abstract":"&lt;p&gt;In 2006, TAR DNA-binding protein of 43 kDa (TDP-43) was discovered as the major ubiquitinated and aggregated protein in approximately 95% of amyotrophic lateral sclerosis (ALS) cases and 45% of frontotemporal lobar degeneration (FTLD) cases [1]. Since then, TDP-43 pathology has been identified in Alzheimer’s disease (AD), limbic-predominant age-related TDP-43 encephalopathy (LATE), and other neurodegenerative diseases [2]. This discovery initiated copious studies uncovering the pathomechanisms through which TDP-43, an RNA-binding protein with roles in alternative splicing, causes neurodegeneration [2] – chief among them, its loss of function owing to its aggregation in the cytoplasm and concurrent depletion from the nucleus.&lt;/p&gt;&lt;p&gt;TDP-43 proteinopathies share clinical, genetic, and pathological features, and this is particularly true of frontotemporal dementia (FTD) and ALS. While no treatments for FTD, ALS, or other TDP-43 proteinopathies yet exist, developing effective therapies for these fatal neurodegenerative diseases would benefit from biomarkers that facilitate an early and accurate diagnosis. Indeed, therapies are expected to be most effective when initiated early in the disease course. Biomarkers that identify the underlying pathology of patients with FTD in life would also aid in selecting appropriate participants for clinical trials targeting TDP-43 proteinopathy. As patients with behavioral variant FTD are essentially just as likely to develop TDP-43 or tau pathology, biomarkers that inform the presence of TDP-43 pathology would be particularly useful for this group, as would patients with AD who often develop mixed pathologies [3]. Although studies have examined whether TDP-43 itself could fulfill these biomarker needs, multiple efforts in detecting pathological TDP-43 species in biofluids have so far been unsuccessful [4]. Nevertheless, an exciting avenue being pursued harnesses the consequences of TDP-43 loss of function; more specifically, TDP-43’s inability to repress the splicing of non-conserved cryptic exons (CE) [5]. This engenders the production of novel RNA isoforms bearing non-conserved intronic sequences that often introduce frameshifts, premature stop codons, or premature polyadenylation sequences. For example, inclusion of a CE in &lt;i&gt;STMN2&lt;/i&gt; mRNA produces a truncated stathmin-2 protein at the expense of its full-length counterpart, whereas inclusion of a CE in &lt;i&gt;UNC13A&lt;/i&gt; mRNA reduces UNC13A protein expression (Fig. 1A) [6]. While cryptic RNAs including &lt;i&gt;STMN2&lt;/i&gt;-CE and &lt;i&gt;UNC13A&lt;/i&gt;-CE have been detected in postmortem brain tissue [6], they have yet to be detected in biofluids, hindering their application for biomarker development. Perhaps most pertinent to biomarker development, consequently, are the cryptic transcripts that generate &lt;i&gt;de novo&lt;/i&gt; proteins.&lt;/p&gt;&lt;figure&gt;&lt;figcaption&gt;&lt;b data-test=\"figure-caption-text\"&gt;Fig. 1&lt;/b&gt;&lt;/figcaption&gt;&lt;picture&gt;&lt;source srcset=\"//media.springernature.com/lw685/springer-stat","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"1 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489521","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}

{"title":"Gut-first Parkinson’s disease is encoded by gut dysbiome","authors":"Mário F. Munoz-Pinto, Emanuel Candeias, Inês Melo-Marques, A. Raquel Esteves, Ana Maranha, João D. Magalhães, Diogo Reis Carneiro, Mariana Sant’Anna, A. Raquel Pereira-Santos, António E Abreu, Daniela Nunes-Costa, Susana Alarico, Igor Tiago, Ana Morgadinho, João Lemos, Pedro N. Figueiredo, Cristina Januário, Nuno Empadinhas, Sandra Morais Cardoso","doi":"10.1186/s13024-024-00766-0","DOIUrl":"https://doi.org/10.1186/s13024-024-00766-0","url":null,"abstract":"In Parkinson's patients, intestinal dysbiosis can occur years before clinical diagnosis, implicating the gut and its microbiota in the disease. Recent evidence suggests the gut microbiota may trigger body-first Parkinson Disease (PD), yet the underlying mechanisms remain unclear. This study aims to elucidate how a dysbiotic microbiome through intestinal immune alterations triggers PD-related neurodegeneration. To determine the impact of gut dysbiosis on the development and progression of PD pathology, wild-type male C57BL/6 mice were transplanted with fecal material from PD patients and age-matched healthy donors to challenge the gut-immune-brain axis. This study demonstrates that patient-derived intestinal microbiota caused midbrain tyrosine hydroxylase positive (TH +) cell loss and motor dysfunction. Ileum-associated microbiota remodeling correlates with a decrease in Th17 homeostatic cells. This event led to an increase in gut inflammation and intestinal barrier disruption. In this regard, we found a decrease in CD4 + cells and an increase in pro-inflammatory cytokines in the blood of PD transplanted mice that could contribute to an increase in the permeabilization of the blood–brain-barrier, observed by an increase in mesencephalic Ig-G-positive microvascular leaks and by an increase of mesencephalic IL-17 levels, compatible with systemic inflammation. Furthermore, alpha-synuclein aggregates can spread caudo-rostrally, causing fragmentation of neuronal mitochondria. This mitochondrial damage subsequently activates innate immune responses in neurons and triggers microglial activation. We propose that the dysbiotic gut microbiome (dysbiome) in PD can disrupt a healthy microbiome and Th17 homeostatic immunity in the ileum mucosa, leading to a cascade effect that propagates to the brain, ultimately contributing to PD pathophysiology. Our landmark study has successfully identified new peripheral biomarkers that could be used to develop highly effective strategies to prevent the progression of PD into the brain. ","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"125 1","pages":""},"PeriodicalIF":15.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489593","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}

{"title":"Amyloid-β (Aβ) immunotherapy induced microhemorrhages are linked to vascular inflammation and cerebrovascular damage in a mouse model of Alzheimer's disease.","authors":"Xavier Taylor, Harun N Noristani, Griffin J Fitzgerald, Herold Oluoch, Nick Babb, Tyler McGathey, Lindsay Carter, Justin T Hole, Pascale N Lacor, Ronald B DeMattos, Yaming Wang","doi":"10.1186/s13024-024-00758-0","DOIUrl":"10.1186/s13024-024-00758-0","url":null,"abstract":"<p><strong>Background: </strong>Anti-amyloid-β (Aβ) immunotherapy trials have revealed amyloid-related imaging abnormalities (ARIA) as the most prevalent and serious adverse events linked to pathological changes in cerebral vasculature. Recent studies underscore the critical involvement of perivascular macrophages and the infiltration of peripheral immune cells in regulating cerebrovascular damage. Specifically, Aβ antibodies engaged at cerebral amyloid angiopathy (CAA) deposits trigger perivascular macrophage activation and the upregulation of genes associated with vascular permeability. Nevertheless, further research is needed to understand the immediate downstream consequences of macrophage activation, potentially exacerbating CAA-related vascular permeability and microhemorrhages linked to Aβ immunotherapy.</p><p><strong>Methods: </strong>This study investigates immune responses induced by amyloid-targeting antibodies and CAA-induced microhemorrhages using RNA in situ hybridization, histology and digital spatial profiling in an Alzheimer's disease (AD) mouse model of microhemorrhage.</p><p><strong>Results: </strong>In the present study, we have demonstrated that bapineuzumab murine surrogate (3D6) induces profound vascular damage, leading to smooth muscle cell loss and blood-brain barrier (BBB) breakdown. In addition, digital spatial profiling (DSP) reveals that distinct immune responses contribute to vascular damage with peripheral immune responses and perivascular macrophage activation linked to smooth muscle cell loss and vascular fibrosis, respectively. Finally, RNA in situ hybridization identifies two distinct subsets of Trem2⁺ macrophages representing tissue-resident and monocyte-derived macrophages around vascular amyloid deposits. Overall, these findings highlight multifaceted roles of immune activation and vascular damage in driving the development of microhemorrhage.</p><p><strong>Conclusions: </strong>In summary, our study has established a significant link between CAA-Aβ antibody immune complex formation, immune activation and vascular damage leading to smooth muscle cell loss. However, the full implications of this cascade on the development of microhemorrhages requires further exploration. Additional investigations are warranted to unravel the precise molecular mechanisms leading to microhemorrhage, the interplay of diverse immune populations and the functional roles played by various Trem2⁺ macrophage populations in response to Aβ immunotherapy.</p>","PeriodicalId":18800,"journal":{"name":"Molecular Neurodegeneration","volume":"19 1","pages":"77"},"PeriodicalIF":14.9,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11494988/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142470236","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}