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Nature Communications Jun 2024Which isoforms of apolipoprotein E (apoE) we inherit determine our risk of developing late-onset Alzheimer's Disease (AD), but the mechanism underlying this link is...
Which isoforms of apolipoprotein E (apoE) we inherit determine our risk of developing late-onset Alzheimer's Disease (AD), but the mechanism underlying this link is poorly understood. In particular, the relevance of direct interactions between apoE and amyloid-β (Aβ) remains controversial. Here, single-molecule imaging shows that all isoforms of apoE associate with Aβ in the early stages of aggregation and then fall away as fibrillation happens. ApoE-Aβ co-aggregates account for ~50% of the mass of diffusible Aβ aggregates detected in the frontal cortices of homozygotes with the higher-risk APOE4 gene. We show how dynamic interactions between apoE and Aβ tune disease-related functions of Aβ aggregates throughout the course of aggregation. Our results connect inherited APOE genotype with the risk of developing AD by demonstrating how, in an isoform- and lipidation-specific way, apoE modulates the aggregation, clearance and toxicity of Aβ. Selectively removing non-lipidated apoE4-Aβ co-aggregates enhances clearance of toxic Aβ by glial cells, and reduces secretion of inflammatory markers and membrane damage, demonstrating a clear path to AD therapeutics.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Humans; Apolipoproteins E; Animals; Apolipoprotein E4; Protein Isoforms; Mice; Female; Protein Aggregates; Male; Protein Aggregation, Pathological; Mice, Transgenic; Neuroglia
PubMed: 38824138
DOI: 10.1038/s41467-024-49028-z -
BioRxiv : the Preprint Server For... May 2024Regulation of transcription during embryogenesis is key to development and differentiation. To study transcript expression throughout embryogenesis at single-molecule...
Regulation of transcription during embryogenesis is key to development and differentiation. To study transcript expression throughout embryogenesis at single-molecule resolution, we developed a high-throughput single-molecule fluorescence in situ hybridization (smFISH) method that relies on computational methods to developmentally stage embryos and quantify individual mRNA molecules in single embryos. We applied our system to , a zygotically transcribed gene essential for hermaphrodite development and dosage compensation. We found that is rapidly activated during early embryogenesis by increasing both the number of mRNAs produced per transcription site and the frequency of sites engaged in transcription. Knockdown of and , a subunit of the dosage compensation complex (DCC), increased the number of active transcription sites for the X chromosomal gene but not the autosomal gene , suggesting that the DCC reduces the frequency of transcription. The temporal resolution from staging of embryos showed that the deletion of a single DCC recruitment element near the gene causes higher mRNA expression after the start of dosage compensation, which could not be resolved using mRNAseq from mixed-stage embryos. In summary, we have established a computational approach to quantify temporal regulation of transcription throughout embryogenesis and demonstrated its potential to provide new insights into developmental gene regulation.
PubMed: 38798598
DOI: 10.1101/2024.05.15.594414 -
Antioxidants (Basel, Switzerland) May 2024BRCA1 mutations predispose women to breast and ovarian cancer. The anticancer effect of zinc is typically linked to its antioxidant abilities and protecting cells...
BRCA1 mutations predispose women to breast and ovarian cancer. The anticancer effect of zinc is typically linked to its antioxidant abilities and protecting cells against oxidative stress. Zinc regulates key processes in cancer development, including DNA repair, gene expression, and apoptosis. We took a blood sample from 989 female BRCA1 mutation carriers who were initially unaffected by cancer and followed them for a mean of 7.5 years thereafter. There were 172 incident cases of cancer, including 121 cases of breast cancer, 29 cases of ovarian cancers, and 22 cancers at other sites. A zinc level in the lowest tertile was associated with a modestly higher risk of ovarian cancer compared to women with zinc levels in the upper two tertiles (HR = 1.65; 95% CI 0.80 to 3.44; = 0.18), but this was not significant. Among those women with zinc levels in the lowest tertile, the 10-year cumulative risk of ovarian cancer was 6.1%. Among those in the top two tertiles of zinc level, the ten-year cumulative risk of ovarian cancer was 4.7%. There was no significant association between zinc level and breast cancer risk. Our preliminary study does not support an association between serum zinc level and cancer risk in BRCA1 mutation carriers.
PubMed: 38790714
DOI: 10.3390/antiox13050609 -
Cardiovascular Diagnosis and Therapy Apr 2024Sarcomeric hypertrophic cardiomyopathy (HCM) must be differentiated from phenotypically similar conditions because clinical management and prognosis may greatly differ....
BACKGROUND
Sarcomeric hypertrophic cardiomyopathy (HCM) must be differentiated from phenotypically similar conditions because clinical management and prognosis may greatly differ. Patients with unexplained left ventricular hypertrophy require an early, confirmed genetic diagnosis through diagnostic or predictive genetic testing. We tested the feasibility and practicality of the application of a 17-gene next-generation sequencing (NGS) panel to detect the most common genetic causes of HCM and HCM phenocopies, including treatable phenocopies, and report detection rates. Identification of transthyretin cardiac amyloidosis (ATTR-CA) and Fabry disease (FD) is essential because of the availability of disease-specific therapy. Early initiation of these treatments may lead to better clinical outcomes.
METHODS
In this international, multicenter, cross-sectional pilot study, peripheral dried blood spot samples from patients of cardiology clinics with an unexplained increased left ventricular wall thickness (LVWT) of ≥13 mm in one or more left ventricular myocardial segments (measured by imaging methods) were analyzed at a central laboratory. NGS included the detection of known splice regions and flanking regions of 17 genes using the Illumina NextSeq 500 and NovaSeq 6000 sequencing systems.
RESULTS
Samples for NGS screening were collected between May 2019 and October 2020 at cardiology clinics in Colombia, Brazil, Mexico, Turkey, Israel, and Saudi Arabia. Out of 535 samples, 128 (23.9%) samples tested positive for pathogenic/likely pathogenic genetic variants associated with HCM or HCM phenocopies with double pathogenic/likely pathogenic variants detected in four samples. Among the 132 (24.7%) detected variants, 115 (21.5%) variants were associated with HCM and 17 (3.2%) variants with HCM phenocopies. Variants in (n=60, 11.2%) and (n=41, 7.7%) were the most common HCM variants. The HCM phenocopy variants included variants in the (n=7, 1.3%) and (n=2, 0.4%) genes. The mean (standard deviation) ages of patients with HCM or HCM phenocopy variants, including and variants, were 42.8 (17.9), 54.6 (17.0), and 69.0 (1.4) years, respectively.
CONCLUSIONS
The overall diagnostic yield of 24.7% indicates that the screening strategy effectively identified the most common forms of HCM and HCM phenocopies among geographically dispersed patients. The results underscore the importance of including ATTR-CA ( variants) and FD ( variants), which are treatable disorders, in the differential diagnosis of patients with increased LVWT of unknown etiology.
PubMed: 38716318
DOI: 10.21037/cdt-23-191 -
Journal of Psychiatry & Neuroscience :... 2024Critical adolescent neural refinement is controlled by the DCC (deleted in colorectal cancer) protein, a receptor for the netrin-1 guidance cue. We sought to describe...
Disproportionate neuroanatomical effects of haploinsufficiency in adolescence compared with adulthood: links to dopamine, connectivity, covariance, and gene expression brain maps in mice.
BACKGROUND
Critical adolescent neural refinement is controlled by the DCC (deleted in colorectal cancer) protein, a receptor for the netrin-1 guidance cue. We sought to describe the effects of reduced on neuroanatomy in the adolescent and adult mouse brain.
METHODS
We examined neuronal connectivity, structural covariance, and molecular processes in a -haploinsufficient mouse model, compared with wild-type mice, using new, custom analytical tools designed to leverage publicly available databases from the Allen Institute.
RESULTS
We included 11 -haploinsufficient mice and 16 wild-type littermates. Neuroanatomical effects of haploinsufficiency were more severe in adolescence than adulthood and were largely restricted to the mesocorticolimbic dopamine system. The latter finding was consistent whether we identified the regions of the mesocorticolimbic dopamine system a priori or used connectivity data from the Allen Brain Atlas to determine de novo where these dopamine axons terminated. Covariance analyses found that haploinsufficiency disrupted the coordinated development of the brain regions that make up the mesocorticolimbic dopamine system. Gene expression maps pointed to molecular processes involving the expression of , (encoding DCC's co-receptor), and (encoding its ligand, netrin-1) as underlying our structural findings.
LIMITATIONS
Our study involved a single sex (males) at only 2 ages.
CONCLUSION
The neuroanatomical phenotype of haploinsufficiency described in mice parallels that observed in -haploinsufficient humans. It is critical to understand the haploinsufficient mouse as a clinically relevant model system.
Topics: Animals; DCC Receptor; Haploinsufficiency; Brain; Dopamine; Mice; Male; Gene Expression; Neural Pathways; Age Factors; Female; Mice, Inbred C57BL; Aging
PubMed: 38692693
DOI: 10.1503/jpn.230106 -
MSystems May 2024The efficacy of prebiotics and probiotics (synbiotics when combined) to improve symptoms associated with autism spectrum disorder (ASD) has shown considerable...
UNLABELLED
The efficacy of prebiotics and probiotics (synbiotics when combined) to improve symptoms associated with autism spectrum disorder (ASD) has shown considerable inter-study variation, likely due to the complex, heterogeneous nature of the disorder and its associated behavioral, developmental, and gastrointestinal symptoms. Here, we present a precision synbiotic supplementation study in 296 children and adults diagnosed with ASD versus 123 age-matched neurotypical controls. One hundred seventy ASD participants completed the study. Baseline and post-synbiotic assessment of ASD and gastrointestinal (GI) symptoms and deep metagenomic sequencing were performed. Within the ASD cohort, there were significant differences in microbes between subpopulations based on the social responsiveness scale (SRS2) survey ( spp., and others) and gluten and dairy-free diets ( spp., spp., and others). At the baseline, the ASD cohort maintained a lower taxonomic alpha diversity and significant differences in taxonomic composition, metabolic pathways, and gene families, with a greater proportion of potential pathogens, including and and lower proportions of beneficial microbes, including compared to controls. Following the 3-month synbiotic supplementation, the ASD cohort showed increased taxonomic alpha diversity, shifts in taxonomy and metabolic pathway potential, and improvements in some ASD-related symptoms, including a significant reduction in GI discomfort and overall improved language, comprehension, cognition, thinking, and speech. However, the open-label study design may include some placebo effects. In summary, we found that precision synbiotics modulated the gut microbiome and could be used as supplementation to improve gastrointestinal and ASD-related symptoms.
IMPORTANCE
Autism spectrum disorder (ASD) is prevalent in 1 out of 36 children in the United States and contributes to health, financial, and psychological burdens. Attempts to identify a gut microbiome signature of ASD have produced varied results. The limited pre-clinical and clinical population sizes have hampered the success of these trials. To understand the microbiome associated with ASD, we employed whole metagenomic shotgun sequencing to classify microbial composition and genetic functional potential. Despite being one of the most extensive ASD post-synbiotic assessment studies, the results highlight the complexity of performing such a case-control supplementation study in this population and the potential for a future therapeutic approach in ASD.
Topics: Humans; Autism Spectrum Disorder; Gastrointestinal Microbiome; Male; Female; Pilot Projects; Child; Synbiotics; Adult; Adolescent; Child, Preschool; Young Adult; Probiotics
PubMed: 38661344
DOI: 10.1128/msystems.00503-24 -
Genes Feb 2024The UNC-5 family of netrin receptor genes, predominantly expressed in brain tissues, plays a pivotal role in various neuronal processes. Mutations in genes involved in...
The UNC-5 family of netrin receptor genes, predominantly expressed in brain tissues, plays a pivotal role in various neuronal processes. Mutations in genes involved in axon development contribute to a wide spectrum of human diseases, including developmental, neuropsychiatric, and neurodegenerative disorders. The NTN1/DCC signaling pathway, interacting with UNC5C, plays a crucial role in central nervous system axon guidance and has been associated with psychiatric disorders during adolescence in humans. Whole-exome sequencing analysis unveiled two compound heterozygous causative mutations within the gene in a patient diagnosed with psychiatric disorders. In silico analysis demonstrated that neither of the observed variants affected the allosteric linkage between UNC5C and NTN1. In fact, these mutations are located within crucial cytoplasmic domains, specifically ZU5 and the region required for the netrin-mediated axon repulsion of neuronal growth cones. These domains play a critical role in forming the supramodular protein structure and directly interact with microtubules, thereby ensuring the functionality of the axon repulsion process. We emphasize that these mutations disrupt the aforementioned processes, thereby associating the gene with psychiatric disorders for the first time and expanding the number of genes related to psychiatric disorders. Further research is required to validate the correlation of the gene with psychiatric disorders, but we suggest including it in the genetic analysis of patients with psychiatric disorders.
Topics: Humans; Axon Guidance; Netrin-1; Netrin Receptors; Axons; Mental Disorders
PubMed: 38540364
DOI: 10.3390/genes15030306 -
British Journal of Cancer Jun 2024Advances in upper gastrointestinal endoscopic technology have enabled early detection and treatment of hypopharyngeal cancer. However, in-depth pharyngeal observations...
BACKGROUND
Advances in upper gastrointestinal endoscopic technology have enabled early detection and treatment of hypopharyngeal cancer. However, in-depth pharyngeal observations require sedation and are invasive. It is important to establish a minimally invasive and simple evaluation method to identify high-risk patients.
METHODS
Eighty-seven patients with superficial hypopharyngeal cancer and 51 healthy controls were recruited. We assessed the methylation status of DCC, PTGDR1, EDNRB, and ECAD, in tissue and saliva samples and verified the diagnostic accuracy by methylation analyses of their promoter regions using quantitative methylation-specific PCR.
RESULTS
Significant differences between cancer and their surrounding non-cancerous tissues were observed in the methylation values of DCC (p = 0.003), EDNRB (p = 0.001), and ECAD (p = 0.043). Using receiver operating characteristic analyses of the methylation values in saliva samples, DCC showed the highest area under the curve values for the detection of superficial hypopharyngeal cancer (0.917, 95% confidence interval = 0.864-0.970), compared with those for EDNRB (0.680) and ECAD (0.639). When the cutoff for the methylation values of DCC was set at ≥0.163, the sensitivity to detect hypopharyngeal cancer was 82.8% and the specificity was 90.2%.
CONCLUSIONS
DCC methylation in saliva samples could be a non-invasive and efficient tool for early detection of hypopharyngeal cancer in high-risk patients.
Topics: Humans; Hypopharyngeal Neoplasms; Saliva; DNA Methylation; Male; Female; Middle Aged; Aged; DCC Receptor; Biomarkers, Tumor; Promoter Regions, Genetic; Genes, DCC; Case-Control Studies; Early Detection of Cancer; Receptor, Endothelin B; ROC Curve
PubMed: 38538728
DOI: 10.1038/s41416-024-02654-2 -
Journal of Integrative Neuroscience Feb 2024Bone cancer pain (BCP) is a common primary or metastatic bone cancer complication. Netrin-1 plays an essential role in neurite elongation and pain sensitization. This...
BACKGROUND
Bone cancer pain (BCP) is a common primary or metastatic bone cancer complication. Netrin-1 plays an essential role in neurite elongation and pain sensitization. This study aimed to determine the role of netrin-1 from the metastatic bone microenvironment in BCP development and identify the associated signaling pathway for the strategy of BCP management.
METHODS
The rat BCP model was established by intratibial implantation of Walker 256 cells. Von Frey filaments measured the mechanical pain threshold. Movement-induced pain was assessed using limb use scores. Expressions of associated molecules in the affected tibias or dorsal root ganglia (DRG) were measured by immunofluorescence, immunohistochemistry, real-time quantitative polymerase chain reaction, or western blotting. Transduction of deleted in colorectal cancer (DCC) signaling was inhibited by intrathecal injection of DCC-siRNA.
RESULTS
In BCP rats, the presence of calcitonin gene-related peptide (CGRP)-positive nerve fibers increased in the metastatic bone lesions. The metastatic site showed enrichment of well-differentiated osteoclasts and expressions of netrin-1 and its attractive receptor DCC. Upregulation of DCC and increased phosphorylation levels of focal adhesion kinase (FAK) and Rac family small GTPase 1/Cell division cycle 42 (Rac1/Cdc42) were found in the DRG. Intrathecal administration of DCC-siRNA led to a significant reduction in FAK and Rac1/Cdc42 phosphorylation levels in the DRG, decreased nociceptive nerve innervation, and improved pain behaviors.
CONCLUSIONS
Netrin-1 may contribute to the activation of the BCP by inducing nociceptive nerve innervation and improving pain behaviors.
Topics: Animals; Rats; Bone Neoplasms; Cancer Pain; DCC Receptor; Nerve Growth Factors; Netrin-1; Nociceptors; Receptors, Cell Surface; RNA, Small Interfering; Signal Transduction; Tumor Microenvironment; Tumor Suppressor Proteins
PubMed: 38538215
DOI: 10.31083/j.jin2303047 -
BioRxiv : the Preprint Server For... Mar 2024The mechanisms driving late relapse in uveal melanoma (UM) patients remains a medical mystery and major challenge. Clinically it is inferred that UM disseminated cancer...
UNLABELLED
The mechanisms driving late relapse in uveal melanoma (UM) patients remains a medical mystery and major challenge. Clinically it is inferred that UM disseminated cancer cells (DCCs) persist asymptomatic for years-to-decades mainly in the liver before they manifest as symptomatic metastasis. Here we reveal using Gαq/11 /BAP human uveal melanoma models and human UM metastatic samples, that the neural crest lineage commitment nuclear receptor NR2F1 is a key regulator of spontaneous UM DCC dormancy in the liver. Using a quiescence reporter, RNA-seq and multiplex imaging we revealed that rare dormant UM DCCs upregulate NR2F1 expression and genes related to neural crest programs while repressing gene related to cell cycle progression. Gain and loss of function assays showed that NR2F1 silences YAP1/TEAD1 transcription downstream of Gαq/11 signaling and that NR2F1 expression can also be repressed by YAP1. YAP1 expression is repressed by NR2F1 binding to its promoter and changing the histone H3 tail activation marks to repress YAP1 transcription. CRISPR KO of NR2F1 led dormant UM DCCs to awaken and initiate relentless liver metastatic growth. Cut&Run and bulk RNA sequencing further confirmed that NR2F1 epigenetically stimulates neuron axon guidance and neural lineage programs, and it globally represses gene expression linked to G-protein signaling to drive dormancy. Pharmacological inhibition of Gαq/11 signaling resulted in NR2F1 upregulation and robust UM growth arrest, which was also achieved using a novel NR2F1 agonist. Our work sheds light on the molecular underpinnings of UM dormancy revealing that transcriptional programs driven by NR2F1 epigenetically short-circuit Gαq/11 signaling to its downstream target YAP1.
HIGHLIGHTS
Quiescent solitary uveal melanoma (UM) DCCs in the liver up- and down-regulate neural crest and cell cycle progression programs, respectively.NR2F1 drives solitary UM DCC dormancy by antagonizing the Gαq/11-YAP1 pathway; small molecule Gαq/11 inhibition restores NR2F1 expression and quiescence. NR2F1 short-circuits oncogenic YAP1 and G-protein signaling a chromatin remodeling program. Loss of function of NR2F1 in dormant UM DCCs leads to aggressive liver metastasis.
PubMed: 38496663
DOI: 10.1101/2024.03.05.583565