23834 research outputs found
Sort by
Motion impact score for detecting spurious brain-behavior associations
Full text linkIn-scanner head motion introduces systematic bias to resting-state fMRI functional connectivity (FC) not completely removed by denoising algorithms. Researchers studying traits associated with motion (e.g. psychiatric disorders) need to know if their trait-FC relationships are impacted by residual motion to avoid reporting false positive results. We devised Split Half Analysis of Motion Associated Networks (SHAMAN) to assign a motion impact score to specific trait-FC relationships. SHAMAN distinguishes between motion causing overestimation or underestimation of trait-FC effects. We assessed 45 traits from n = 7270 participants in the Adolescent Brain Cognitive Development (ABCD) Study. After standard denoising with ABCD-BIDS and without motion censoring, 42% (19/45) of traits had significant (p \u3c 0.05) motion overestimation scores and 38% (17/45) had significant underestimation scores. Censoring at framewise displacement (FD) \u3c 0.2 mm reduced significant overestimation to 2% (1/45) of traits but did not decrease the number of traits with significant motion underestimation scores
A single high-zinc activation enhancer can control two genes oriented head-to-head in Caenorhabditis elegans
Full text linkEnhancers play critical roles in gene expression, but a full understanding of their complex functions has yet to be defined. The cellular response to excess zinc levels in Caenorhabditis elegans requires the HIZR-1 transcription factor, which binds the high-zinc activation (HZA) enhancer in the promoters of multiple target genes. Cadmium hijacks the excess zinc response by binding and activating HIZR-1. By analyzing the genome-wide transcriptional response to excess zinc and cadmium, we identified two positions in the genome where head-to-head oriented genes are both induced by metals. In both examples, a single predicted HZA enhancer is positioned between the two translational start sites. We hypothesized that a single enhancer can control both head-to-head genes, an arrangement that has not been extensively characterized. To test this hypothesis, we used CRISPR genome editing to precisely delete the HZAmT enhancer positioned between mtl-2 and T08G5.1; in this mutant, both head-to-head genes display severely reduced zinc-activated transcription, whereas zinc-activated transcription of more distant genes was not strongly affected. Deleting the HZAcF enhancer positioned between cdr-1 and F35E8.10 caused both head-to-head genes to display reduced cadmium-activated transcription, whereas cadmium-activated transcription of more distant genes was not strongly affected. These studies rigorously document that a single HZA enhancer can control two head-to-head genes, advancing our understanding of the diverse functions of enhancers
Phase I study of NT-I7, a long-acting interleukin-7, in severe treatment-related lymphopenia following standard radiation and temozolomide for high-grade glioma
Full text linkBACKGROUND: High-grade gliomas (HGG) have a poor prognosis despite aggressive treatment. Severe, persistent lymphopenia occurring in HGG patients after concurrent chemoradiation is associated with worse survival. NT-I7, a long-acting interleukin-7 analog, has been shown to increase CD4 and CD8 counts in healthy, septic, and HIV-positive adults. This multi-institutional, NCI-funded dose-escalation trial is the first to evaluate NT-I7 safety and activity in HGG patients with severe treatment-related lymphopenia (TRL) and the effect of co-administered glucocorticoids.
METHODS: Eligible HGG patients had CD4 counts \u3c 300 cells/mm
RESULTS: NT-I7 was well tolerated in all 12 patients (median age 64; median CD4 count 161 cells/mm³) before the study closed prematurely. Absolute lymphocyte counts doubled in 83% (10/12; 95% CI: 51.6%-97.9%) of patients, and CD4 counts doubled in 42% (5/12; 95% CI: 15.2%-72.3%) of patients. Glucocorticoid use did not significantly affect CD4 or lymphocyte increases. Correlative immune profiling revealed increased Ki67 expression in CD4 (
CONCLUSIONS: NT-I7 is well tolerated and effectively increases lymphocyte and CD4 counts in severe TRL patients, regardless of glucocorticoid use, suggesting its potential to mitigate TRL and improve outcomes in HGG
LRP8 is an entry receptor for tick-borne encephalitis viruses
Full text linkOrthoflaviviruses are a genus of arthropod-transmitted RNA viruses that infect humans and other vertebrate animals on a global scale, resulting in extensive morbidity and mortality. Among the orthoflaviviruses, tick-borne encephalitis viruses (TBEV) are an antigenic group that causes severe neurological disease in humans. However, the entry receptors for TBEV, which contribute to cell and tissue tropism, remain largely unknown. Because recent studies identified members of the low-density lipoprotein receptor (LDLR) family as possible receptors for some orthoflaviviruses and distantly related alphaviruses, we performed a targeted screen in transgenic cells expressing different LDLR members and identified LRP8 (also called ApoER2) as a candidate receptor for TBEV strains from the five different subtypes. Genetic ablation o
NsrM (All0345) and NsrX (Alr1976), two FurC (PerR)-targeted transcriptional regulators, modulate nitrogen metabolism and heterocyst differentiation genes in the cyanobacterium Anabaena sp. strain PCC 7120
No full textUNLABELLED: The control of nitrogen metabolism in the model cyanobacterium
IMPORTANCE: Filamentous, nitrogen-fixing cyanobacteria are valuable organisms for biotechnology applications and as models for the study of multicellularity in prokaryotes. Understanding the regulation of nitrogen fixation and heterocyst development is essential for optimizing their use in synthetic biology and as biofertilizers. This study identifies two novel nitrogen secondary regulators, Alr1976 (NsrX) and All0345 (NsrM), as part of the intricate regulatory circuit governing nitrogen metabolism in the model cyanobacteriu
Shared and disease-specific pathways in frontotemporal dementia and Alzheimer\u27s and Parkinson\u27s diseases
No full textNeurodegenerative diseases (NDs), such as Alzheimer\u27s disease (AD), Parkinson\u27s disease (PD) and frontotemporal dementia (FTD), exhibit distinct yet overlapping pathological mechanisms. Leveraging large-scale plasma proteomics data from the Global Neurodegeneration Proteomics Consortium, we analyzed 10,527 plasma samples (1,936 AD, 525 PD, 163 FTD, 1,638 dementia and 6,265 controls) to identify disease-specific and shared proteins across NDs. We identified 5,187 proteins significantly associated with AD, 3,748 with PD and 2,380 with FTD that revealed both common and divergent proteomic signatures, which were confirmed by multiple analytical approaches and orthogonal validation. PD and FTD showed the highest overlap (
Rapamycin treatment for Alzheimer\u27s disease and related dementias: A pilot phase 1 clinical trial
No full textBACKGROUND: Rapamycin has been shown to extend lifespan and acts on pathologies underlying Alzheimer\u27s disease and related dementias in animal models. However, rapamycin\u27s clinical application remains underexplored.
METHODS: We conducted a single-site open-label phase 1 clinical trial (ClinicalTrials.gov: NCT04200911) to examine the effects of rapamycin in humans. Eligible participants were people 55-85 years old with mild cognitive impairment or early-stage dementia, which was defined as having a Global Clinical Dementia Rating Scale Score of 0.5-1. All participants received rapamycin (1 mg/day) for eight weeks. The primary aim was to evaluate rapamycin\u27s central nervous system penetrance by assaying drug levels in the cerebrospinal fluid (CSF) before and after treatment. Secondary aims evaluated safety, cognition, Alzheimer\u27s disease, and inflammatory biomarkers in the CSF and plasma.
RESULTS: In ten participants (mean age 74 ± 4 years, 60% female), we find that rapamycin is not detectable in the CSF before or after treatment. After treatment, we find that twenty, mostly mild adverse events occur, systolic blood pressure and hemoglobin A1c increase, multiple erythrocyte parameters decrease, and there are no significant cognitive changes. Furthermore, we find that CSF phosphorylated tau-181 (mean change (95% confidence interval) pg/ml), 2.64 [0.70-4.59]), glial fibrillary acidic protein (6262.21 [3787.44-9373.84]), and neurofilament light (367.19 [204.28-561.61]) and plasma interferon gamma (4.37 [3.01-5.74]), interleukin 5 (0.33 [0.12-0.64]), vascular endothelial growth factor D (3741.03 [1505.98-5976.07]), soluble fms-like tyrosine kinase-1 (258.88 [89.03-428.74]) and placental growth factor (20.81 [12.38-29.25]) significantly increase (FDR-corrected p-value \u3c 0.05).
CONCLUSIONS: Rapamycin is not detectable in the CSF before or after treatment, but several Alzheimer\u27s disease and inflammatory biomarkers increase after treatment. Our results highlight the need to better understand the biological effects and clinical impact of repurposing rapamycin for Alzheimer\u27s disease
Development of a leucine-rich repeat-containing protein 15-targeted radio-immunotheranostic approach to deplete pro-tumorigenic mechanisms and immunotherapy resistance
No full textLeucine-rich repeat containing 15 (LRRC15) has emerged as an attractive biomarker and target for cancer therapy. Transforming growth factor-β (TGFβ) induces the expression of this plasma membrane protein specifically in aggressive and treatment resistant tumor cells derived from mesenchymal stem cells, with minimal expression observed in non-neoplastic tissues. We have developed a humanized monoclonal antibody, DUNP19, that specifically binds with high affinity to a phylogenetically conserved LRRC15 epitope and is rapidly internalized upon LRRC15 binding. In multiple subcutaneous and orthotopic tumor xenograft mouse models, Lutetium-177 labeled DUNP19 (
Sporadic ALS induced pluripotent stem cell derived neurons reveal hallmarks of TDP-43 loss of function
No full textNuclear loss and cytoplasmic buildup of the RNA-binding protein TDP-43 is a hallmark of ALS and related disorders. While studies using artificial TDP-43 depletion in neurons have revealed changes in gene expression and splicing, their relevance to actual patients remained unclear. Induced pluripotent stem cell (iPSC)-derived neurons (iPSNs) from 180 individuals, including controls, C9orf72 ALS/FTD, and sporadic ALS (sALS) patients were used to generate and analyze ~32,500 qRT-PCR data points across 20 genes which identified variable, time-dependent signatures of TDP-43 loss of function in individual lines. Notably, the same changes were also seen in postmortem brain tissue from the same patients, confirming that iPSNs accurately model disease. Inducing damage to the nuclear pore complex, specifically by reducing the nucleoporin POM121 in healthy iPSNs, was enough to replicate the molecular changes associated with ALS/FTD TDP-43 dysfunction. This directly links nuclear pore integrity to TDP-43-related pathology. Encouragingly, repairing nuclear pore injury in sALS iPSNs restored normal gene processing disrupted by TDP-43 loss. This study (1) provides a valuable population-scale resource for studying TDP-43 dysfunction in ALS, (2) confirms that patient-derived iPSNs closely reflect disease processes seen in the brain, and (3) demonstrates that targeting nuclear pore injury may offer a promising therapeutic strategy in ALS