SEARCH · PubMed Health

Results for “TREM2”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

12 recordsLinked to original sources

PubMed2022

Biological correlates of elevated soluble TREM2 in cerebrospinal fluid.

Cerebrospinal fluid (CSF) soluble triggering receptor expressed on myeloid cells-2 (sTREM2) is an emerging biomarker of neuroinflammation in Alzheimer's disease (AD). Yet, sTREM2 expression has not been systematically evaluated in relation to concomitant drivers of neuroinflammation. While associations between sTREM2 and tau in CSF are established, we sought to determine additional biological correlates of CSF sTREM2 during the prodromal stages of AD by evaluating CSF Aβ species (Aβx-40), a fluid biomarker of blood-brain barrier integrity (CSF/plasma albumin ratio), and CSF biomarkers of neurodegeneration measured in 155 participants from the Vanderbilt Memory and Aging Project. A novel association between high CSF levels of both sTREM2 and Aβx-40 was observed and replicated in an independent dataset. Aβx-40 levels, as well as the CSF/plasma albumin ratio, explained additional and unique variance in sTREM2 levels above and beyond that of CSF biomarkers of neurodegeneration. The component of sTREM2 levels correlated with Aβx-40 levels best predicted future cognitive performance. We highlight potential contributions of Aβ homeostasis and blood-brain barrier integrity to elevated CSF sTREM2, underscoring novel biomarker associations relevant to disease progression and clinical outcome measures.

Alzheimer Disease↗

PubMed2026

Ionizing radiation induces bidirectional transcriptomic reprogramming and dynamic NOS2/TREM2 regulation in triple-negative breast cancer cells.

PURPOSE: To characterize irradiation-associated transcriptomic changes in murine triple-negative breast cancer cells and examine dose- and time-response patterns of selected radiation-responsive candidates. MATERIALS AND METHODS: RNA sequencing (RNA-seq) was performed in 4T1 cells collected 24 h after 4 Gy irradiation, followed by Reactome and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and gene set enrichment analyses. Representative RNA-seq-derived genes were examined by reverse transcription quantitative PCR (RT-qPCR), and selected immune- and inflammation-related transcripts were further assessed across additional radiation doses and post-irradiation time points. Inducible nitric oxide synthase (NOS2) and triggering receptor expressed on myeloid cells 2 (TREM2) protein abundance was assessed by Western blotting, and nitrite accumulation in culture supernatants was measured using a Griess reagent-based assay as an indirect readout of nitric oxide production. RESULTS: RNA sequencing identified 757 differentially expressed genes, including 285 upregulated and 472 downregulated genes. Irradiation was associated with enrichment of inflammatory, interferon-related, immune-system, and cell-adhesion transcriptional signatures, whereas downregulated genes were enriched in cell-cycle-, chromosome-cohesion-, DNA-damage-response-, DNA-repair-, and SUMOylation-related pathways. Selected immune- and inflammation-related transcripts showed distinct temporal patterns. Nos2 mRNA increased across the examined 0-6 Gy dose range and at later post-irradiation time points, whereas NOS2 protein showed different kinetics, with an early peak after 4 Gy irradiation and no clear further increase above 6 Gy. Nitrite accumulation increased after irradiation. Trem2 showed the largest fold increase among strongly upregulated transcripts identified by RNA-seq, but RT-qPCR detected a significant increase only at 24 h, and TREM2 protein abundance remained unchanged across the examined doses and time points. CONCLUSIONS: Ionizing radiation was associated with broad bidirectional transcriptional remodeling in 4T1 cells, involving immune-, inflammatory-, and interferon-related signatures together with reduced representation of cell-cycle- and DNA-repair-related gene sets. The discordant mRNA and protein patterns of NOS2 and TREM2 indicate that transcript-level responses do not necessarily translate into corresponding protein-level changes. These findings define irradiation-associated molecular responses requiring further functional investigation.

Triple-negative breast cancer↗

PubMed2024

Plasticity of Human Microglia and Brain Perivascular Macrophages in Aging and Alzheimer's Disease.

The complex roles of myeloid cells, including microglia and perivascular macrophages, are central to the neurobiology of Alzheimer's disease (AD), yet they remain incompletely understood. Here, we profiled 832,505 human myeloid cells from the prefrontal cortex of 1,607 unique donors covering the human lifespan and varying degrees of AD neuropathology. We delineated 13 transcriptionally distinct myeloid subtypes organized into 6 subclasses and identified AD-associated adaptive changes in myeloid cells over aging and disease progression. The GPNMB subtype, linked to phagocytosis, increased significantly with AD burden and correlated with polygenic AD risk scores. By organizing AD-risk genes into a regulatory hierarchy, we identified and validated MITF as an upstream transcriptional activator of GPNMB, critical for maintaining phagocytosis. Through cell-to-cell interaction networks, we prioritized APOE-SORL1 and APOE-TREM2 ligand-receptor pairs, associated with AD progression. In both human and mouse models, TREM2 deficiency disrupted GPNMB expansion and reduced phagocytic function, suggesting that GPNMB's role in neuroprotection was TREM2-dependent. Our findings clarify myeloid subtypes implicated in aging and AD, advancing the mechanistic understanding of their role in AD and aiding therapeutic discovery.

Journal Article↗

PubMed2026

Plasticity of human microglia and brain perivascular macrophages in aging and Alzheimer's disease.

Myeloid cells, including microglia and perivascular macrophages, are central to Alzheimer's disease (AD) neurobiology, yet their role remains incompletely understood. We profiled 832,505 human myeloid cells from the prefrontal cortex of 1,607 donors spanning the lifespan and showing varying degrees of AD neuropathology. We delineated six subclasses comprising 13 transcriptionally distinct subtypes and identified adaptive changes associated with aging and AD progression. Here we show that a disease-associated microglial subtype, characterized by elevated GPNMB expression and enriched for polygenic AD risk, expands with AD pathology and shows increased phagocytic activity. We identify MITF as an upstream regulator required to maintain this microglial state. Cell-cell interaction analyses prioritize APOE-SORL1 and APOE-TREM2 signaling pairs associated with disease progression. Using human and mouse models, we demonstrate that the neuroprotective effects of this microglial subtype depend on TREM2. These findings provide mechanistic insights into myeloid cell function in aging and AD, aiding therapeutic discovery.

Humans↗

PubMed2026

Elevated Triggering Receptor Expressed on Myeloid Cells 2 Expression in Tumor-Associated Macrophages Suppresses Cytotoxic T Cell Infiltration and Facilitates Immune Escape in Colorectal Cancer.

BACKGROUND & AIMS: Emerging evidence supports a crucial role for tumor-associated macrophages in shaping the immunosuppressive tumor microenvironment. Furthermore, research has identified that the triggering receptor expressed on myeloid cells 2 has immunomodulatory functions. The present investigated the potential effect of triggering receptor expressed on myeloid cells 2 expression in tumor-associated macrophages on facilitating immune evasion in colorectal cancer. METHODS: Immunohistochemical analysis of clinical specimens, complemented by extensive data mining from The Cancer Genome Atlas, revealed a significant upregulation of triggering receptor expressed on myeloid cells 2 in colorectal cancer-associated tumor-associated macrophages, with this upregulation exhibiting a correlation with poor patient prognosis. RESULTS: Mechanistically, triggering receptor expressed on myeloid cells 2+ tumor-associated macrophages were found to drive fibroblast activation through transforming growth factor-β signaling, inducing fibroblast-activated protein-positive cancer-associated fibroblasts that secrete collagen I/III to establish dense peritumoral barriers. Spatial profiling revealed that these fibrous structures physically impede CD8+ T-cell infiltration, restricting cytotoxic lymphocytes to stromal compartments. Intriguingly, triggering receptor expressed on myeloid cells 2 deficiency enhanced the secretion of matrix metalloproteinase 13 by macrophages, thereby promoting extracellular matrix degradation and improving T-cell penetration. In vivo, Trem2-knockout mice showed a reduction in tumor growth with enhanced intratumoral CD8+ T-cell infiltration compared with wild-type controls. CONCLUSIONS: Our findings establish triggering receptor expressed on myeloid cells 2+ tumor-associated macrophages as central regulators of stromal remodeling and suggest that therapeutic targeting of the triggering receptor expressed on myeloid cells 2/transforming growth factor-β/fibroblast-activated protein pathway may overcome immune resistance in patients with colorectal cancer.

Colorectal Neoplasms↗

PubMed2026

ARID5A RNA-binding coordinates microglial defense and ferroptosis in iPSC-derived models.

RNA-binding proteins (RBPs) are key regulators of gene expression that shape cellular function in health and disease. However, the roles of RBPs in immune cells within the central nervous system (CNS) remain poorly understood. Here, we identify ARID5A as an RBP highly expressed in microglia and uncover its RNA-mediated regulatory functions using integrated multi-omics analyses of its RNA, DNA, and protein interactions. ARID5A regulates the splicing and translation of its RNA targets, many of which are integral to lysosomal, immune, and iron metabolism pathways. We confirm the functional relevance of this ARID5A-dependent RNA regulatory network by demonstrating that ARID5A modulates lysosomal activity, cytokine secretion, iron accumulation, and ferroptosis in iPSC-derived microglia. We further demonstrate that knockdown of microglial ARID5A reduces neuronal ferroptosis in co-cultures, underscoring the interconnected nature of these pathways. Moreover, in microglia harboring the TREM2-T66M mutation, ARID5A depletion restores dysregulated lysosomal and metabolic functions. Our results highlight the importance of protein-RNA interactions in regulating microglial cell biology.

Microglia↗

PubMed2026

Effects of Acute Low- and Moderate-Dose Alcohol on Chronic Disease-Related Biomarkers in Healthy Light and Heavy Drinkers.

BACKGROUND: Alcohol consumption is a major contributor to global chronic disease, with growing evidence indicating health risks even at low levels of intake. However, mechanistic understanding of these risks relies heavily on preclinical models and observational data, leaving a critical gap in controlled experimental evidence regarding how alcohol perturbs human biological systems in vivo. METHODS: The present study utilized plasma samples from a randomized, placebo-controlled trial to evaluate the effects of low-dose (0.35 g/kg) and moderate-dose (0.60 g/kg) alcohol on disease-relevant biomarkers in 32 healthy adults (mean age = 25.0 ± 3.8 years; 21 female/11 male), characterized by light (n = 15) or heavy (n = 17) drinking. This design enabled evaluation of effects across dose, timescale, and drinking history, as well as assessment of their interactions. Plasma was collected at prebeverage baseline and hourly for 4 h afterward. Immunoassays quantified 10 disease-related biomarkers: adiponectin, angiogenin, D-dimer, high-sensitivity C-reactive protein (hsCRP), Intercellular Adhesion Molecule-1 (ICAM-1), Lipocalin-2 (LCN2), Matrix Metalloproteinase-7 (MMP-7), Matrix Metalloproteinase-9 (MMP-9), soluble Receptor for Advanced Glycation End-products (sRAGE), and Triggering Receptor Expressed on Myeloid cells 2 (TREM2). RESULTS: Main effects of group indicated that even in this young healthy sample, heavy drinking status was associated with higher levels of adiponectin, angiogenin, ICAM-1, LCN2, and sRAGE, a profile suggesting altered vascular and metabolic activity. Acute alcohol administration induced changes in sRAGE and hsCRP. Specifically, moderate-dose alcohol triggered an increase in the immunoglobulin sRAGE, which may reflect an acute compensatory response to inflammation and/or oxidative stress. Compared to placebo, hsCRP was lower in the low-dose alcohol condition; however, this finding should be interpreted in light of CRP biology. MMP-7, MMP-9, and LCN2 showed time-dependent fluctuations that were independent of experimental condition, highlighting the critical importance of placebo-controlled designs to account for diurnal/postprandial variation in immune biomarkers. CONCLUSION: Findings provide translational evidence that alcohol is associated with multisystem biomarker changes relevant to chronic disease and that alcohol-related biomarker perturbations vary by dose and chronicity.

Humans↗

PubMed2025

Multi-ancestry genome-wide meta-analysis of 56,241 individuals identifies known and novel cross-population and ancestry-specific associations as novel risk loci for Alzheimer's disease.

BACKGROUND: Limited ancestral diversity has impaired our ability to detect risk variants more prevalent in ancestry groups of predominantly non-European ancestral background in genome-wide association studies (GWAS). We construct and analyze a multi-ancestry GWAS dataset in the Alzheimer's Disease Genetics Consortium (ADGC) to test for novel shared and population-specific late-onset Alzheimer's disease (LOAD) susceptibility loci and evaluate underlying genetic architecture in 37,382 non-Hispanic White (NHW), 6728 African American, 8899 Hispanic (HIS), and 3232 East Asian individuals, performing within ancestry fixed-effects meta-analysis followed by a cross-ancestry random-effects meta-analysis. RESULTS: We identify 13 loci with cross-population associations including known loci at/near CR1, BIN1, TREM2, CD2AP, PTK2B, CLU, SHARPIN, MS4A6A, PICALM, ABCA7, APOE, and two novel loci not previously reported at 11p12 (LRRC4C) and 12q24.13 (LHX5-AS1). We additionally identify three population-specific loci with genome-wide significance at/near PTPRK and GRB14 in HIS and KIAA0825 in NHW. Pathway analysis implicates multiple amyloid regulation pathways and the classical complement pathway. Genes at/near our novel loci have known roles in neuronal development (LRRC4C, LHX5-AS1, and PTPRK) and insulin receptor activity regulation (GRB14). CONCLUSIONS: Using cross-population GWAS meta-analyses, we identify novel LOAD susceptibility loci in/near LRRC4C and LHX5-AS1, both with known roles in neuronal development, as well as several novel population-unique loci. Reflecting the power of diverse ancestry in GWAS, we detect the SHARPIN locus with only 13.7% of the sample size of the NHW GWAS study (n = 409,589) in which this locus was first observed. Continued expansion into larger multi-ancestry studies will provide even more power for further elucidating the genomics of late-onset Alzheimer's disease.

Humans↗

PubMed2026

Impact of sex differences on microglial function in Alzheimer's disease.

Aging is the strongest risk factor for Alzheimer's disease (AD), a multifactorial neurodegenerative disorder characterized by amyloid-β (Aβ) accumulation, tau pathology (hyperphosphorylated tau and neurofibrillary tangles [NFTs]), and associated neuroinflammatory processes. Age-related cellular and molecular stressors, including mitochondrial dysfunction, genomic instability, and chronic low-grade inflammation, progressively increase vulnerability to neurodegeneration. In parallel, sex is increasingly recognized as a biological variable that shapes AD risk, clinical course, and neuropathological burden. Women account for roughly two-thirds of AD cases, a disparity not fully explained by longevity. Multiple factors likely contribute, including hormonal transitions across the lifespan (particularly menopausal estrogen decline), sex chromosome-linked immune regulation, sex-dependent interactions between genetic risk factors (e.g., APOE4 and TREM2) and brain aging, and differences in vascular risk, cognitive reserve, and sociocultural exposures that influence disease expression and detection. Microglia, the brain's resident immune cells, are sexually dimorphic, and respond to Aβ and tau pathology, modulating inflammatory signaling, synaptic remodeling, and neurovascular dysfunction implicated in AD. Emerging human and experimental evidence indicate that microglial activation states, immunometabolism, and functional responses differ between males and females and may contribute to sex-specific AD trajectories. Here, we synthesize current evidence supporting microglial sexual dimorphism across aging and AD, highlight possible candidates (hormonal signaling, immuno-aging, disease-associated microglial states, and immunometabolic remodeling), and discuss key knowledge gaps toward sex-informed precision approaches for prevention and treatment.

Humans↗

PubMed2026

Hepatocyte-Specific Deficiency of Endoplasmic Reticulum-Associated Degradation Induces Coordinated Innate-Adaptive Immune Responses.

Hepatic inflammation is a defining feature of Metabolic Dysfunction-Associated Steatohepatitis (MASH), yet the specific contributions of individual immune cell populations and their reciprocal interactions remain incompletely understood. In this study, we combined flow cytometry with single-cell transcriptomic profiling to characterize the hepatic immune landscape in a novel model of spontaneous MASH caused by hepatocyte-specific deficiency of endoplasmic reticulum-associated degradation (ERAD). Hepatic ERAD deficiency led to the expansion of multiple immune cell populations in the liver, including CD8+ T cells, macrophages, monocytes, and dendritic cells, accompanied by extensive functional reprogramming of both innate and adaptive immune compartments. Myeloid cells exhibited enhanced phagocytic activity and increased antigen processing and presentation, whereas CD8+ T cells displayed elevated proliferation capacity, DNA repair activity and cytotoxicity. Notably, two functionally distinct triggering receptor expressed on myeloid cells 2 (TREM2)-expressing macrophage subsets emerged during the progression of ERAD deficiency-induced MASH. Depletion of CD8+ T cells increased monocyte infiltration and aggravated liver injury, suggesting that CD8+ T cells exert a previously unrecognized protective role by restraining monocyte recruitment. Collectively, these findings reveal highly coordinated interactions between innate and adaptive cells during MASH progression and identify CD8+ T cells as potential regulators of monocyte infiltration and hepatic injury.

Animals↗

PubMed2026

Genetic risk factors of late-onset Alzheimer's disease: Insights into pathophysiology and emerging therapeutic directions.

Late-onset Alzheimer's disease is a devastating and complex neurodegenerative disorder with a multifactorial etiology. Over the past decade, advances in genetic research have identified novel risk genes, shedding light on the underlying pathogenic mechanisms of late-onset Alzheimer's disease. This review provides a comprehensive overview of several of these crucial genetic factors and their potential mechanisms in the pathogenesis of Alzheimer's disease. Genome-wide association studies, whole-genome sequencing, and multi-omics studies have played a crucial role in identifying key risk genes, particularly those involved in amyloid-β metabolism and clearance, such as CLU and APOE, which influence amyloid-β aggregation. Tau pathology, characterized by neurofibrillary tangles, is another hallmark of Alzheimer's disease, with genes such as BIN1 implicated in tau-mediated neurodegeneration. Additionally, immune regulatory genes, including CR1, MS4A6A, CD33, and TREM2, play crucial roles in microglial activation and neuroinflammation, thereby contributing to disease progression. Synaptic dysfunction is also a critical factor in Alzheimer's disease pathology, with genes such as IQCK, EPHA1, and CD2AP linked to synaptic function and plasticity, highlighting their potential impact on cognitive decline. Understanding these genetic risk factors provides valuable insights into the complex genetic landscape of Alzheimer's disease and its highly heterogeneous pathological mechanisms, including amyloid-β metabolism, tau pathology, immune response and neuroinflammation, and synaptic dysfunction. Future research should focus on elucidating the functional roles of these individual genes and their potential as therapeutic targets for altering the course of Alzheimer's disease.

Alzheimer’s disease↗

PubMed2026

Retinal Transcriptome-Wide Association Study Identifies Novel Alzheimer's Disease Risk Genes.

INTRODUCTION: Alzheimer's disease (AD) is the leading cause of dementia worldwide. The retina shares molecular pathways with the brain, yet no study has systematically linked retinal gene expression to AD risk. METHODS: We performed transcriptome-wide association studies (TWAS) using two independent retinal eQTL panels (Strunz et al., n = 311; EyeGEx, n = 406) and a large meta-analyzed AD genome-wide association study (GWAS) (Bellenguez et al., 111,326 cases, 677,663 controls). Genes were further validated with GWAS in the independent Alzheimer's Disease Sequencing Project (ADSP) using a matched eQTL-panel strategy. RESULTS: We identified 62 AD-associated genes across the two eQTL panels using Bellenguez et al. as the discovery cohort. Of these, 31 were replicated in the ADSP cohort. The findings highlight shared complement-mediated immune dysregulation (CD55, CD46, TREM2) and provide functional transcriptomic evidence to prioritize novel causal drivers of AD pathogenesis, including STYX and the LRRC37 gene family. DISCUSSION: Retinal data capture core AD genetic architecture and reveal novel risk genes, highlighting the retina as a molecularly informative tissue for dementia research.

Alzheimer’s disease↗