BACKGROUND: The hippocampal representation of space, formed by the collective activity of populations of place cells, is considered as a substrate of spatial memory. Alzheimer's disease (AD), a widespread severe neurodegenerative condition of multifactorial origin, typically exhibits spatial memory deficits among its early clinical signs before more severe cognitive impacts develop. OBJECTIVE: To investigate mechanisms of spatial memory impairment in a double transgenic rat model of AD. METHODS: In this study, we utilized 9-12-month-old double-transgenic TgF344-AD rats and age-matched controls to analyze the spatial coding properties of CA1 place cells. We characterized the spatial memory representation, assessed cells' spatial information content and direction-specific activity, and compared their population coding in familiar and novel conditions. RESULTS: Our findings revealed that TgF344-AD animals exhibited lower precision in coding, as evidenced by reduced spatial information and larger receptive zones. This impairment was evident in maps representing novel environments. While controls instantly encoded directional context during their initial exposure to a novel environment, transgenics struggled to incorporate this information into the newly developed hippocampal spatial representation. This resulted in impairment in orthogonalization of stored activity patterns, an important feature directly related to episodic memory encoding capacity. CONCLUSIONS: Overall, the results shed light on the nature of impairment at both the single-cell and population levels in the transgenic AD model. In addition to the observed spatial coding inaccuracy, the findings reveal a significantly impaired ability to adaptively modify and refine newly stored hippocampal memory patterns.
- MeSH
- Alzheimerova nemoc * patofyziologie MeSH
- amyloidový prekurzorový protein beta genetika MeSH
- hipokampální oblast CA1 patofyziologie MeSH
- hipokampus patofyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech * MeSH
- poruchy paměti etiologie patofyziologie MeSH
- potkani inbrední F344 MeSH
- potkani transgenní * MeSH
- prostorová paměť fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Myasthenia gravis is a chronic antibody-mediated autoimmune disease disrupting neuromuscular synaptic transmission. Informative biomarkers remain an unmet need to stratify patients with active disease requiring intensified monitoring and therapy; their identification is the primary objective of this study. We applied mass spectrometry-based proteomic serum profiling for biomarker discovery. We studied an exploration and a prospective validation cohort consisting of 114 and 140 anti-acetylcholine receptor antibody (AChR-Ab)-positive myasthenia gravis patients, respectively. For downstream analysis, we applied a machine learning approach. Protein expression levels were confirmed by ELISA and compared to other myasthenic cohorts, in addition to myositis and neuropathy patients. Anti-AChR-Ab levels were determined by a radio receptor assay. Immunohistochemistry and immunofluorescence of intercostal muscle biopsies were employed for validation in addition to interactome studies of inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3). Machine learning identified ITIH3 as potential serum biomarker reflective of disease activity. Serum levels correlated with disease activity scores in the exploration and validation cohort and were confirmed by ELISA. Lack of correlation between anti-AChR-Ab levels and clinical scores underlined the need for biomarkers. In a subgroup analysis, ITIH3 was indicative of treatment responses. Immunostaining of muscle specimens from these patients demonstrated ITIH3 localization at the neuromuscular endplates in myasthenia gravis but not in controls, thus providing a structural equivalent for our serological findings. Immunoprecipitation of ITIH3 and subsequent proteomics lead to identification of its interaction partners playing crucial roles in neuromuscular transmission. This study provides data on ITIH3 as a potential pathophysiological-relevant biomarker of disease activity in myasthenia gravis. Future studies are required to facilitate translation into clinical practice.
- MeSH
- autoprotilátky krev MeSH
- biologické markery * krev metabolismus MeSH
- dospělí MeSH
- kohortové studie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- myasthenia gravis * krev diagnóza patologie metabolismus MeSH
- proteomika metody MeSH
- receptory cholinergní imunologie metabolismus MeSH
- sekreční inhibitory proteinas krev MeSH
- senioři MeSH
- strojové učení MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Vedecká obec postupne rozuzluje etiologické faktory a patogenetické mechanizmy neurodegeneratívnych ochorení. Z roka na rok pribúdajú dôkazy o čoraz väčšej sile genetického pozadia ako etiologického faktora. V našom príspevku integrujeme dve roviny pohľadu na genetiku Alzheimerovej choroby a príbuzných demencií. V prvej časti článku sumarizujeme súčasné poznatky o genetickom pozadí neurodegeneratívnych demencií s hlavným zameraním sa na Alzheimerovu chorobu. Okrem "klasických" kauzálnych génov a génov susceptibility prinášame prehľad vybraných "nových" génov, ktorých polymorfizmy môžu zvyšovať náchylnosť na Alzheimerovu chorobu. V druhej časti - Skúsenosti z jedného centra - prinášame pohľad na vývoj a súčasný koncept genetického testovania na I. neurologickej klinike v Bratislave. Predstavujeme panel génov pre demencie, ktorý v súčasnosti zahŕňa 45 génov zapojených do patogenézy Alzheimerovej choroby, frontotemporálnej demencie, Parkinsonovej choroby a zriedkavých demencií. V blízkej budúcnosti ho plánujeme rozšíriť na 150-génový panel a postupne kontinuálne aktualizovať. Rozsah genetického testovania, ktorý prinášame v tomto príspevku, sa vzťahuje hlavne na kliniky špecializované na demencie a špecializované centrá pre demencie. Načrtávame koncept, akým by sa mohlo testovanie uberať do budúcnosti na príklade konceptu testovania na našej I. neurologickej klinike. V každom prípade sa snažíme priblížiť problematiku aj ostatným neurologickým klinikám, oddeleniam a ambulanciám, ktoré sa rovnako môžu zapojiť do tohto systému, ak majú vhodných pacientov. Článok ukončujeme kapitolou o relativite súčasných poznatkov, ktorá odzrkadľuje turbulentnú tému genetiky Alzheimerovej choroby, ktorá sa neustále mení, rozširuje, aktualizuje a možno prinesie odpovede na množstvo v súčasnosti nezodpovedaných otázok.
The scientific community is gradually unraveling the etiological factors and pathogenetic mechanisms of neurodegenerative diseases. From year to year there is the robust evidence of the increasing power of the genetic background as an etiological factor. In our paper, we integrate two levels of insight into the genetics of Alzheimer's disease and related dementias. In the first part of the article, we summarize current knowledge about the genetic background of neurodegenerative dementias, with the main focus on Alzheimer's disease. In addition to "classic" causal genes and susceptibility genes, we provide an overview of selected "new" genes whose polymorphisms can increase susceptibility to Alzheimer's disease. In the second part - Experience from one center - we present an insight into the development and current concept of genetic testing at the I. Neurological Clinic. We present a dementia gene panel that currently includes 45 genes involved in the pathogenesis of Alzheimer's disease, Frontotemporal dementia, Parkinson's disease and rare dementias. In the near future, we plan to expand it to a 150 gene panel and gradually update it continuously. The scope of genetic testing that we present in this manuscript mainly applies to dementia clinics and dementia centers. We outline the concept of how testing should proceed in the future using the example of the testing concept at our I. Neurological Clinic. In any case, we are trying to bring this issue closer to other neurological clinics, departments and outpatient clinics, which can also join this system if they have suitable patients. We conclude the article with a chapter on the relativity of current knowledge, which reflects the turbulent topic of the genetics of Alzheimer's disease, which is constantly changing, expanding and updating, and may bring answers to a number of currently unanswered questions.
- MeSH
- Alzheimerova nemoc * diagnóza genetika klasifikace MeSH
- amyloidový prekurzorový protein beta analýza genetika MeSH
- apolipoproteiny E analýza genetika klasifikace MeSH
- epigeneze genetická genetika MeSH
- genetické pozadí MeSH
- genetické testování * metody MeSH
- lidé MeSH
- preseniliny analýza genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- Geografické názvy
- Slovenská republika MeSH
AIM: Astrocytes respond to stressors by acquiring a reactive state characterized by changes in their morphology and function. Molecules underlying reactive astrogliosis, however, remain largely unknown. Given that several studies observed increase in the Amyloid Precursor Protein (APP) in reactive astrocytes, we here test whether APP plays a role in reactive astrogliosis. METHODS: We investigated whether APP instigates reactive astroglios by examining in vitro and in vivo the morphology and function of naive and APP-deficient astrocytes in response to APP and well-established stressors. RESULTS: Overexpression of APP in cultured astrocytes led to remodeling of the intermediate filament network, enhancement of cytokine production, and activation of cellular programs centered around the interferon (IFN) pathway, all signs of reactive astrogliosis. Conversely, APP deletion abrogated remodeling of the intermediate filament network and blunted expression of IFN-stimulated gene products in response to lipopolysaccharide. Following traumatic brain injury (TBI), mouse reactive astrocytes also exhibited an association between APP and IFN, while APP deletion curbed the increase in glial fibrillary acidic protein observed canonically in astrocytes in response to TBI. CONCLUSIONS: The APP thus represents a candidate molecular inducer and regulator of reactive astrogliosis. This finding has implications for understanding pathophysiology of neurodegenerative and other diseases of the nervous system characterized by reactive astrogliosis and opens potential new therapeutic avenues targeting APP and its pathways to modulate reactive astrogliosis.
- MeSH
- amyloidový prekurzorový protein beta * metabolismus genetika MeSH
- astrocyty * metabolismus patologie MeSH
- glióza * metabolismus patologie MeSH
- kultivované buňky MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- traumatické poranění mozku metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
We aim to report the ocular phenotype and molecular genetic findings in two Czech families with Sorsby fundus dystrophy and to review all the reported TIMP3 pathogenic variants. Two probands with Sorsby fundus dystrophy and three first-degree relatives underwent ocular examination and retinal imaging, including optical coherence tomography angiography. The DNA of the first proband was screened using a targeted ocular gene panel, while, in the second proband, direct sequencing of the TIMP3 coding region was performed. Sanger sequencing was also used for segregation analysis within the families. All the previously reported TIMP3 variants were reviewed using the American College of Medical Genetics and the Association for Molecular Pathology interpretation framework. A novel heterozygous variant, c.455A>G p.(Tyr152Cys), in TIMP3 was identified in both families and potentially de novo in one. Optical coherence tomography angiography documented in one patient the development of a choroidal neovascular membrane at 54 years. Including this study, 23 heterozygous variants in TIMP3 have been reported as disease-causing. Application of gene-specific criteria denoted eleven variants as pathogenic, eleven as likely pathogenic, and one as a variant of unknown significance. Our study expands the spectrum of TIMP3 pathogenic variants and highlights the importance of optical coherence tomography angiography for early detection of choroidal neovascular membranes.
- MeSH
- lidé MeSH
- makulární degenerace * MeSH
- mutace MeSH
- neovaskularizace choroidey * MeSH
- oči MeSH
- tkáňový inhibitor metaloproteinasy 3 genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Experimental studies in flies, mice, and humans suggest a significant role of impaired axonal transport in the pathogenesis of Alzheimer's disease (AD). The mechanisms underlying these impairments in axonal transport, however, remain poorly understood. Here we report that the Swedish familial AD mutation causes a standstill of the amyloid precursor protein (APP) in the axons at the expense of its reduced anterograde transport. The standstill reflects the perturbed directionality of the axonal transport of APP, which spends significantly more time traveling in the retrograde direction. This ineffective movement is accompanied by an enhanced association of dynactin-1 with APP, which suggests that reduced anterograde transport of APP is the result of enhanced activation of the retrograde molecular motor dynein by dynactin-1. The impact of the Swedish mutation on axonal transport is not limited to the APP vesicles since it also reverses the directionality of a subset of early endosomes, which become enlarged and aberrantly accumulate in distal locations. In addition, it also reduces the trafficking of lysosomes due to their less effective retrograde movement. Altogether, our experiments suggest a pivotal involvement of retrograde molecular motors and transport in the mechanisms underlying impaired axonal transport in AD and reveal significantly more widespread derangement of axonal transport pathways in the pathogenesis of AD.
- MeSH
- Alzheimerova nemoc * metabolismus genetika patologie MeSH
- amyloidový prekurzorový protein beta * genetika metabolismus MeSH
- axonální transport * genetika MeSH
- axony metabolismus patologie MeSH
- dynaktinový komplex metabolismus genetika MeSH
- dyneiny metabolismus MeSH
- endozomy metabolismus genetika MeSH
- genetická variace MeSH
- lidé MeSH
- lyzozomy metabolismus MeSH
- mutace MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Right ventricular pacing (RVP) can result in pacing-induced cardiomyopathy (PICM). It is unknown whether specific biomarkers reflect differences between His bundle pacing (HBP) and RVP and predict a decrease in left ventricular function during RVP. AIMS: We aimed to compare the effect of HBP and RVP on the left ventricular ejection fraction (LVEF) and to study how they affect serum markers of collagen metabolism. METHODS: Ninety-two high-risk PICM patients were randomized to HBP or RVP groups. Their clinical characteristics, echocardiography, and serum levels of transforming growth factor β1 (TGF-β1), matrix metalloproteinase 9 (MMP-9), suppression of tumorigenicity 2 interleukin (ST2-IL), tissue inhibitor of metalloproteinase 1 (TIMP-1), and galectin 3 (Gal-3) were studied before pacemaker implantation and six months later. RESULTS: Fifty-three patients were randomized to the HBP group and 39 patients to the RVP group. HBP failed in 10 patients, who crossed over to the RVP group. Patients with RVP had significantly lower LVEF compared to HBP patients after six months of pacing (-5% and -4% in as-treated and intention-to-treat analysis, respectively). Levels of TGF-β1 after 6 months were lower in HBP than RVP patients (mean difference -6 ng/ml; P = 0.009) and preimplant Gal-3 and ST2-IL levels were higher in RVP patients, with a decline in LVEF ≥5% compared to those with a decline of <5% (mean difference 3 ng/ml and 8 ng/ml; P = 0.02 for both groups). CONCLUSION: In high-risk PICM patients, HBP was superior to RVP in providing more physiological ventricular function, as reflected by higher LVEF and lower levels of TGF-β1. In RVP patients, LVEF declined more in those with higher baseline Gal-3 and ST2-IL levels than in those with lower levels.
- MeSH
- biologické markery MeSH
- elektrokardiografie MeSH
- funkce levé komory srdeční * fyziologie MeSH
- Hisův svazek MeSH
- interleukin-1 receptor-like 1 protein MeSH
- kardiomyopatie * MeSH
- kardiostimulace umělá škodlivé účinky MeSH
- kolagen MeSH
- lidé MeSH
- tepový objem fyziologie MeSH
- tkáňový inhibitor metaloproteinasy 1 MeSH
- transformující růstový faktor beta1 MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
Transplanted lungs suffer worse outcomes than other organ transplants with many developing chronic lung allograft dysfunction (CLAD), diagnosed by physiologic changes. Histology of transbronchial biopsies (TBB) yields little insight, and the molecular basis of CLAD is not defined. We hypothesized that gene expression in TBBs would reveal the nature of CLAD and distinguish CLAD from changes due simply to time posttransplant. Whole-genome mRNA profiling was performed with microarrays in 498 prospectively collected TBBs from the INTERLUNG study, 90 diagnosed as CLAD. Time was associated with increased expression of inflammation genes, for example, CD1E and immunoglobulins. After correcting for time, CLAD manifested not as inflammation but as parenchymal response-to-wounding, with increased expression of genes such as HIF1A, SERPINE2, and IGF1 that are increased in many injury and disease states and cancers, associated with development, angiogenesis, and epithelial response-to-wounding in pathway analysis. Fibrillar collagen genes were increased in CLAD, indicating matrix changes, and normal transcripts were decreased-dedifferentiation. Gene-based classifiers predicted CLAD with AUC 0.70 (no time-correction) and 0.87 (time-corrected). CLAD related gene sets and classifiers were strongly prognostic for graft failure and correlated with CLAD stage. Thus, in TBBs, molecular changes indicate that CLAD primarily reflects severe parenchymal injury-induced changes and dedifferentiation.
The amyloid cascade hypothesis, focusing on pathological proteins aggregation, has so far failed to uncover the root cause of Alzheimer's disease (AD), or to provide an effective therapy. This traditional paradigm essentially explains a mechanism involved in the development of sporadic AD rather than its cause. The failure of an overwhelming majority of clinical studies (99.6%) demonstrates that a breakthrough in therapy would be difficult if not impossible without understanding the etiology of AD. It becomes more and more apparent that the AD pathology might originate from brain infection. In this review, we discuss a potential role of bacteria, viruses, fungi, and eukaryotic parasites as triggers of AD pathology. We show evidence from the current literature that amyloid beta, traditionally viewed as pathological, actually acts as an antimicrobial peptide, protecting the brain against pathogens. However, in case of a prolonged or excessive activation of a senescent immune system, amyloid beta accumulation and aggregation becomes damaging and supports runaway neurodegenerative processes in AD. This is paralleled by the recent study by Alam and colleagues (2022) who showed that alpha-synuclein, the protein accumulating in synucleinopathies, also plays a critical physiological role in immune reactions and inflammation, showing an unforeseen link between the 2 unrelated classes of neurodegenerative disorders. The multiplication of the amyloid precursor protein gene, recently described by Lee and collegues (2018), and possible reactivation of human endogenous retroviruses by pathogens fits well into the same picture. We discuss these new findings from the viewpoint of the infection hypothesis of AD and offer suggestions for future research.
- MeSH
- Alzheimerova nemoc * metabolismus MeSH
- amyloidní beta-protein metabolismus MeSH
- amyloidový prekurzorový protein beta metabolismus MeSH
- antibakteriální látky terapeutické užití MeSH
- antiinfekční látky * metabolismus MeSH
- lidé MeSH
- mozek patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
