Biology subjects

Weintraub, N. L.

Publications and source records attributed to Weintraub, N. L..

9 recordsLinked to original sources

bioRxiv2026

Atypical Chemokine Receptor DARC/ACKR1 Is Expressed Selectively by Neurons with Regional Heterogeneity and Protects against Neuroinflammation and Cognitive Impairment

Atypical chemokine receptors (ACKRs) regulate inflammatory responses by scavenging and sequestering chemokines. The Duffy antigen receptor for chemokines (DARC), also known as ACKR1, binds multiple inflammatory chemokines and regulates inflammation in peripheral tissues. However, the distribution and functional role of DARC/ACKR1 in the brain remain to be defined. Here, we show that DARC/ACKR1 is widely expressed throughout the mouse brain, with marked regional heterogeneity. DARC/ACKR1 is predominantly expressed by neurons and is not detected in microglia or astrocytes. Importantly, this neuronal expression pattern was also observed in the human brain. Furthermore, DARC/ACKR1 deficiency resulted in enhanced neuroinflammation, characterized by increased microglial activation and astrogliosis across multiple brain regions, particularly the hippocampus, and was accompanied by cognitive deficits. Together, these findings identify DARC/ACKR1 as a previously unrecognized neuron-specific atypical chemokine receptor that plays an important role in restraining neuroinflammation and preserving cognitive function.

neuroscience↗

bioRxiv2026

Immunometabolic Remodeling of Perivascular Adipose Tissue in Murine Lupus: Implications for Lupus Vasculopathy

BackgroundPatients with systemic lupus erythematosus (SLE) face markedly increased cardiovascular disease (CVD) risk driven by mechanisms beyond traditional risk factors. Thoracic aortic perivascular adipose tissue (tPVAT) is dysfunctional in lupus and exacerbates endothelial dysfunction, yet the molecular basis of this dysfunction remains poorly defined. MethodsIntegrated multi-omics profiling, including bulk RNA-seq, untargeted proteomics, lipidomics, and high-dimensional spectral flow cytometry, was performed on tPVAT from 15-week-old MRL/lpr mice (active lupus, n = 4-6) and MRL control mice (n = 5-6). Adipogenic differentiation capacity of tPVAT adipose stromal and progenitor cells (ASPCs) from MRL/lpr was assessed by Oil Red O staining at 5 (pre-dieasea) and 15 weeks (active disease), with subcutaneous ASPCs used as depot controls. ResultsTranscriptomic profiling of tPVAT from MRL/lpr mice identified 2,742 upregulated and 1,494 downregulated genes (adjusted p < 0.001, |log2FC| > 1), with strong activation of interferon, IL6-JAK-STAT3, and TNFA signaling pathways together with suppression of fatty acid metabolism, oxidative phosphorylation, and adipogenic pathways. Proteomic and lipidomic analyses were concordant, revealing broad downregulation of mitochondrial bioenergetic machinery, depletion of cardiolipin and acylcarnitines, and enrichment of ceramide phosphoinositols and lysophosphatidylcholines. Cardiolipin strongly correlated with the mitochondrial/metabolic protein module (r = 0.95) and inversely with the immune/inflammatory protein module (r = -0.92). Spectral flow cytometry confirmed marked CD45+ leukocyte infiltration dominated by T cells, together with a significantly reduced Treg/CD4+ ratio indicating loss of local immunoregulatory balance. ASPCs derived from PVAT of 15-week-old MRL/lpr mice exhibited impaired white and beige adipogenic differentiation, while APCs from PVAT of 5-week-old MRL/lpr mice, and from subcutaneous adipose tissues of 15-week-old MRL/lpr mice, had normal white and beige differentiation, consistent with an acquired, depot-specific, disease-stage-dependent progenitor defect in PVAT of MRL/lpr mice. ConclusionsLupus tPVAT undergoes a concordant cross-platform molecular reprogramming of mitochondrial bioenergetic genes coupled with establishment of an interferon-dominant immune niche and acquired loss of ASPC adipogenic capacity. These findings provide a molecular framework for lupus PVAT dysfunction and identify restoration of mitochondrial function, suppression of interferon-driven inflammation, and renewal of progenitor differentiation as potential therapeutic strategies for lupus vasculopathy.

molecular biology↗

bioRxiv2026

A regulatory role of novel long non-coding RNA, BAZ1A-AS1, in vascular smooth muscle cell functions during neointima formation in human saphenous veins

BackgroundNeointimal proliferation (NP) is a major cause of stenosis and occlusion in arteries and veins. Human saphenous veins (HSV), often used for coronary artery bypass grafting, frequently fail in part due to NP. Long non-coding RNAs (lncRNAs) have emerged as critical regulators of vascular smooth muscle cell (VSMC) phenotype, yet lncRNAs governing NP in human veins remain largely uncharacterized. Methods and ResultsUsing an ex vivo model of NP in human SV, we performed bulk RNA sequencing on SV tissues with and without NP. Among differentially expressed lncRNAs, we identified a previously uncharacterized transcript, Bromodomain Adjacent to Zinc Finger A1 antisense 1 (BAZ1A-AS1), and its predicted cis-regulatory partner gene BAZ1A, as markedly upregulated during NP and predominantly enriched in VSMCs. Both transcripts were induced by genotoxic stimuli, with BAZ1A-AS1 showing transient induction preceding sustained BAZ1A upregulation, consistent with a priming role in the DNA damage response. Silencing of either BAZ1A-AS1 or BAZ1A attenuated VSMC proliferation and migration, accompanied by upregulation of contractile markers and suppression of proliferative and inflammatory transcriptional programs. ChIRP-qPCR demonstrated that BAZ1A-AS1 physically interacts with 3' distal exons of BAZ1A at the DNA level while selectively engaging CNN1, CCND1, and IL6 mRNAs, indicating mechanistically distinct chromatin- and RNA-level regulatory functions. Baz1a haploinsufficiency attenuated neointima formation and preserved VSMC contractile identity in a mouse carotid artery ligation model. ConclusionsWe identify BAZ1A-AS1 and BAZ1A as stress-responsive regulators of VSMC phenotype, operating through dual mechanisms of cis-regulatory chromatin interaction and selective mRNA engagement, and demonstrate a novel role for the BAZ1A-AS1/BAZ1A axis in promoting NP.

physiology↗

bioRxiv2025

Neuronal HDAC9: A key regulator of cognitive and synaptic aging, rescuing Alzheimer's disease-related phenotypes

Epigenetic regulation is a key determinant of the aging process, and its dysregulation contributes to cognitive aging and increased vulnerability to Alzheimers disease (AD). As major regulators of epigenetic processes, histone deacetylases (HDACs) have emerged as potential therapeutic targets for cognitive enhancement in neurodegenerative diseases. However, the distinct roles of individual HDAC isoforms remain to be defined. Here, we report that HDAC9 is specifically expressed in neurons of human and mouse brains, and its expression declines with age. HDAC9 deficiency impairs cognitive function and synaptic plasticity in young mice. Selective deletion of HDAC9 in hippocampal CA1 neurons also induces cognitive impairment. In contrast, overexpression of HDAC9 in forebrain glutamatergic neurons preserves cognitive function in aged mice. Moreover, HDAC9 is also downregulated in the brain of AD mouse models, whereas neuronal overexpression of HDAC9 alleviates AD-related cognitive and synaptic deficits and reduces A{beta} deposition. Together, these findings suggest neuronal HDAC9 is necessary and sufficient for maintaining cognitive and synaptic functions in the context of aging and AD.

neuroscience↗

bioRxiv2024

The Ubiquitin Ligase RBX2/SAG Regulates Mitochondrial Ubiquitination and Mitophagy

Clearance of damaged mitochondria via mitophagy is crucial for cellular homeostasis. While the role of ubiquitin (Ub) ligase PARKIN in mitophagy has been extensively studied, increasing evidence suggests the existence of PARKIN-independent mitophagy in highly metabolically active organs such as the heart. Here, we identify a crucial role for Cullin-RING Ub ligase 5 (CRL5) in basal mitochondrial turnover in cardiomyocytes. CRL5 is a multi-subunit Ub ligase comprised by the catalytic RING box protein RBX2 (also known as SAG), scaffold protein Cullin 5 (CUL5), and a substrate-recognizing receptor. Analysis of the mitochondrial outer membrane-interacting proteome uncovered a robust association of CRLs with mitochondria. Subcellular fractionation, immunostaining, and immunogold electron microscopy established that RBX2 and Cul5, two core components of CRL5, localizes to mitochondria. Depletion of RBX2 inhibited mitochondrial ubiquitination and turnover, impaired mitochondrial membrane potential and respiration, and increased cell death in cardiomyocytes. In vivo, deletion of the Rbx2 gene in adult mouse hearts suppressed mitophagic activity, provoked accumulation of damaged mitochondria in the myocardium, and disrupted myocardial metabolism, leading to rapid development of dilated cardiomyopathy and heart failure. Similarly, ablation of RBX2 in the developing heart resulted in dilated cardiomyopathy and heart failure. Notably, the action of RBX2 in mitochondria is not dependent on PARKIN, and PARKIN gene deletion had no impact on the onset and progression of cardiomyopathy in RBX2-deficient hearts. Furthermore, RBX2 controls the stability of PINK1 in mitochondria. Proteomics and biochemical analyses further revealed a global impact of RBX2 deficiency on the mitochondrial proteome and identified several mitochondrial proteins as its putative substrates. These findings identify RBX2-CRL5 as a mitochondrial Ub ligase that controls mitophagy under physiological conditions in a PARKIN-independent, PINK1-dependent manner, thereby regulating cardiac homeostasis.

pathology↗

bioRxiv2023

Integrative multiomics analysis of neointima proliferation in human saphenous vein: implications for bypass graft disease

IntroductionHuman saphenous veins (SV) are widely used as grafts in coronary artery bypass (CABG) surgery but often fail due to neointima proliferation (NP). NP involves complex interplay between vascular smooth muscle cells (VSMC) and fibroblasts. Little is known, however, regarding the transcriptomic and proteomic dynamics of NP. Here, we performed multi-omics analysis in an ex vivo tissue culture model of NP in human SV procured for CABG surgery. Methods and resultsHistological examination demonstrated significant elastin degradation and NP (indicated by increased neointima area and neointima/media ratio) in SV subjected to tissue culture. Analysis of data from 73 patients suggest that the process of SV adaptation and NP may differ according to sex and body mass index. RNA sequencing confirmed upregulation of pro-inflammatory and proliferation-related genes during NP and identified novel processes, including increased cellular stress and DNA damage responses, which may reflect tissue trauma associated with SV harvesting. Proteomic analysis identified upregulated extracellular matrix-related and coagulation/thrombosis proteins and downregulated metabolic proteins. Spatial transcriptomics detected transdifferentiating VSMC in the intima on the day of harvesting and highlighted dynamic alterations in fibroblast and VSMC phenotype and behavior during NP. Specifically, we identified new cell subpopulations contributing to NP, including SPP1+, LGALS3+ VSMC and MMP2+, MMP14+ fibroblasts. ConclusionDynamic alterations of gene and protein expression occur during NP in human SV. Identification of the human-specific molecular and cellular mechanisms may provide novel insight into SV bypass graft disease.

genomics↗

bioRxiv2023

The actin binding protein profilin 1 is critical for mitochondria function

Profilin 1 (PFN1) is an actin binding protein that is vital for the polymerization of monomeric actin into filaments. Here we screened knockout cells for novel functions of PFN1 and discovered that mitophagy, a type of selective autophagy that removes defective or damaged mitochondria from the cell, was significantly upregulated in the absence of PFN1. Despite successful autophagosome formation and fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells still accumulate damaged, dysfunctional mitochondria. Subsequent imaging and functional assays showed that loss of PFN1 significantly affects mitochondria morphology, dynamics, and respiration. Further experiments revealed that PFN1 is located to the mitochondria matrix and is likely regulating mitochondria function from within rather than through polymerizing actin at the mitochondria surface. Finally, PFN1 mutants associated with amyotrophic lateral sclerosis (ALS) fail to rescue PFN1 knockout mitochondrial phenotypes and form aggregates within mitochondria, further perturbing them. Together, these results suggest a novel function for PFN1 in regulating mitochondria and identify a potential pathogenic mechanism of ALS-linked PFN1 variants.

cell biology↗

bioRxiv2023

Hepatocyte-specific disruption of soluble epoxide hydrolase attenuates abdominal aortic aneurysm formation: novel role of the liver in aneurysm pathogenesis

IntroductionInflammation is a key pathogenic feature of abdominal aortic aneurysm (AAA). Soluble epoxide hydrolase (sEH) is a pro-inflammatory enzyme that converts cytochrome P450-derived epoxides of fatty acids to the corresponding diols, and pharmacological inhibition of sEH prevented AAA formation. Both cytochrome P450 enzymes and sEH are highly expressed in the liver. Here, we investigated the role of hepatic sEH in AAA using a selective pharmacological inhibitor of sEH and hepatocyte-specific Ephx2 (which encodes sEH gene) knockout (KO) mice in two models of AAA [angiotensin II (AngII) infusion and calcium chloride (CaCl2) application]. Methods and resultssEH expression and activity were strikingly higher in mouse liver compared with aorta and further increased the context of AAA, in conjunction with elevated expression of the transcription factor Sp1 and the epigenetic regulator Jarid1b, which have been reported to positively regulate sEH expression. Pharmacological sEH inhibition, or liver-specific sEH disruption, achieved by crossing sEH floxed mice with albumin-cre mice, prevented AAA formation in both models, concomitant with reduced expression of hepatic sEH as well as complement factor 3 (C3) and serum amyloid A (SAA), liver-derived factors linked to AAA formation. Moreover, sEH antagonism markedly reduced C3 and SAA protein accumulation in the aortic wall. Co-incubation of liver ex vivo with aneurysm-prone aorta resulted in induction of sEH in the liver, concomitant with upregulation of Sp1, Jarid1b, C3 and SAA gene expression, suggesting that the aneurysm-prone aorta secretes factors that activate sEH and downstream inflammatory signaling in the liver. Using an unbiased proteomic approach, we identified a number of dysregulated proteins [e.g., plastin-2, galectin-3 (gal-3), cathepsin S] released by aneurysm-prone aorta as potential candidate mediators of hepatic sEH induction. ConclusionWe provide the first direct evidence of the livers role in orchestrating AAA via the enzyme sEH. These findings not only provide novel insight into AAA pathogenesis, but they have potentially important implications with regard to developing effective medical therapies for AAA.

pharmacology and toxicology↗

bioRxiv2023

INKILN is a novel long noncoding RNA promoting vascular smooth muscle inflammation

BackgroundActivation of vascular smooth muscle cells (VSMCs) inflammation is vital to initiate vascular disease. However, the role of human-specific long noncoding RNAs (lncRNAs) in VSMC inflammation is poorly understood. MethodsBulk RNA-seq in differentiated human VSMCs revealed a novel human-specific lncRNA called INflammatory MKL1 Interacting Long Noncoding RNA (INKILN). INKILN expression was assessed in multiple in vitro and ex vivo models of VSMC phenotypic modulation and human atherosclerosis and abdominal aortic aneurysm (AAA) samples. The transcriptional regulation of INKILN was determined through luciferase reporter system and chromatin immunoprecipitation assay. Both loss- and gain-of-function approaches and multiple RNA-protein and protein-protein interaction assays were utilized to uncover the role of INKILN in VSMC proinflammatory gene program and underlying mechanisms. Bacterial Artificial Chromosome (BAC) transgenic (Tg) mice were utilized to study INKLIN expression and function in ligation injury-induced neointimal formation. ResultsINKILN expression is downregulated in contractile VSMCs and induced by human atherosclerosis and abdominal aortic aneurysm. INKILN is transcriptionally activated by the p65 pathway, partially through a predicted NF-{kappa}B site within its proximal promoter. INKILN activates the proinflammatory gene expression in cultured human VSMCs and ex vivo cultured vessels. Mechanistically, INKILN physically interacts with and stabilizes MKL1, a key activator of VSMC inflammation through the p65/NF-{kappa}B pathway. INKILN depletion blocks ILI{beta}-induced nuclear localization of both p65 and MKL1. Knockdown of INKILN abolishes the physical interaction between p65 and MKL1, and the luciferase activity of an NF-{kappa}B reporter. Further, INKILN knockdown enhances MKL1 ubiquitination, likely through the reduced physical interaction with the deubiquitinating enzyme, USP10. INKILN is induced in injured carotid arteries and exacerbates ligation injury-induced neointimal formation in BAC Tg mice. ConclusionsThese findings elucidate an important pathway of VSMC inflammation involving an INKILN/MKL1/USP10 regulatory axis. Human BAC Tg mice offer a novel and physiologically relevant approach for investigating human-specific lncRNAs under vascular disease conditions.

molecular biology↗