Biology subjects

Marquez, M.

Publications and source records attributed to Marquez, M..

11 recordsLinked to original sources

bioRxiv2026

IL-27 Reduces Cell-Surface LDLR in Human Macrophages and Restricts VSV-G-Pseudotyped HIV infection

The low-density lipoprotein receptor (LDLR) is a major cellular receptor for vesicular stomatitis virus glycoprotein (VSV-G), which is widely used to pseudotyped virus vectors. A replication incompetent VSV-G-pseudotyped HIV (VSV-G-HIVLuc) has been used in HIV infection studies. Although IL-27-polarized macrophages induce multiple antiviral genes and resist replication-competent HIV infection, their impact on VSV-GHIVLuc infection has not been studied. Here, we evaluated the role of IL-27 polarization on VSV-G-HIVLuc infection. Infection was monitored by luciferase activity. Cell-surface LDLR was analyzed by flow cytometry. LDLR transcripts and protein expression were quantified by qRT-PCR and Western blotting, respectively. Viral binding was assessed by measuring cell-associated p24 antigen, while post-entry events were evaluated by quantifying late reverse-transcription products. VSV-G-HIVLuc infection in IL-27-polarized M-CSF-induced macrophages (27M-Mac) and IL-27-polarized GM-CSFinduced macrophages (27GM-Mac) was reduced to 5.8{+/-}0.4% and 5.9{+/-}2.1%, respectively (both p<0.0001), compared to unpolarized macrophages. 27M-Mac and 27GM-Mac reduced cell-surface LDLR to 38.3{+/-}2.6% (p<0.01) and 31.4{+/-}3.2% (p<0.01). Western blotting showed that total LDLR protein decreased to 48{+/-}0.8% in 27M-Mac (p<0.01), whereas 27GM-Mac showed no significant change. However, LDLR transcripts increased approximately 1.6-1.9-fold following IL-27 treatment in both macrophage types (p<0.01). Viral binding to 27M-Mac decreased modestly, while binding to 27GM-Mac decreased significantly to 67.5 {+/-} 7.5% of that to GM-Mac (p<0.05, n=3). In contrast, late reverse-transcription products decreased to 23{+/-}2.1% (p<0.0001) and 44{+/-}1.5% (p<0.0001). These findings demonstrate that IL-27 downregulates cell-surface LDLR expression in macrophages despite increasing LDLR transcript abundance, suggesting that IL-27 restricts VSV-G-pseudotyped Lentiviral infection through both receptor-associated and additional post-entry mechanisms.

immunology↗

bioRxiv2026

A Metabolic Enzyme, Pyruvate Carboxylase, Functions as a Sequence-Selective Small RNA Sensor for Antiviral Immunity

Interleukin-27 (IL-27) is an anti-HIV cytokine that induces 14 novel microRNAs (miRNAs) in primary CD4(+) T cells. We previously reported that transfection of two of these miRNA mimics, miRTC10 and miRTC14 into human primary macrophages, differentially induced interferon (IFN)-2, -8, -13, and -{lambda}1 expression. However, the mechanism underlying this activation remains unclear. Here, we demonstrate that miRTC14 does not directly target canonical IFN-regulatory genes but instead engages with pyruvate carboxylase (PC) and laboratory of genetics and physiology-2 (LGP2/DHX58) as direct binding partner proteins. Functional analysis revealed that miRTC14 transfection induces IFN expression by more than 100-fold (p<0.001), whereas PC or LGP2 depletion by siRNAs markedly attenuated this response (50-100-fold reduction, p<0.01). Reconstitution of PC and LGP2 in deficient HEK293 cells restored miRTC14-driven IFN induction. Notably, IFN activation depended on sequence features at the duplex termini. However, PC-miRTC14-LGP2 axis activates TBK1-dependent phosphorylation of IRF3/7, similarly to canonical RNA sensors (RIG-I/MDA5), but this process induced differential IFN subtype. These findings establish PC as a miRNA-binding protein and define a previously unrecognized RNA-sensing mechanism, linking metabolic enzymes to RNA sequence-dependent innate immunity. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC="FIGDIR/small/735367v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@ea70d3org.highwire.dtl.DTLVardef@1953a73org.highwire.dtl.DTLVardef@305f16org.highwire.dtl.DTLVardef@1b2daff_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract:C_FLOATNO microRNA sequence-dependent activation of innate immunity by pyruvate carboxylase (PC). PC-miRTC14-LGP2 axis induces TBK1 phosphorylation via an as-yet-unidentified adapter(s). The activated TBK1 (p-TBK1) subsequently phosphorylates IRF3 and/or IRF7 leading to selective IFN subtypes (IFN-2, IFN-8, IFN-13, and IFN-{lambda}1). (Created in BioRender. Kariyawasam, U. (2027) https://BioRender.com/u82s04p) C_FIG

immunology↗

bioRxiv2026

Lessening the bottleneck: reduced spatiotemporal overlap between krill fishing vessels and post-fledging chinstrap penguins led to increased apparent survival

Fledging is a critical period of a seabird life cycle. Using satellite telemetry, we compared movements and survival proxies (transmission duration) of chinstrap penguin fledglings tracked in 2017 (n=8) and 2025 (n=17) relative to krill fishing vessel activity. In 2017, fishing vessels operated intensively near colonies during summer, resulting in early, frequent encounters (median 1.3 days post-fledging) and short transmission durations (median 9.2 days). In 2025, reduced fishing delayed encounters (median 10.0 days) and tripled tracking duration (median 24.0 days). Hidden Markov Models revealed that vessel encounters reduced the probability of transitioning from foraging to transit behavior ({beta} = -0.76), an effect stronger than the productivity ({beta} = -0.11). While 87.5% of 2017 fledglings ceased transmission prematurely within weeks (half of those right after entering areas intensively used by fishing vessels), 65% of 2025 fledglings survived beyond March, with half of those five transmitting until May after dispersing eastward to the South Orkney Islands. These findings suggest that spatiotemporal overlap with krill fisheries during the critical post-fledging window affected foraging behavior and was associated with shorter transmission durations. Our results support further research of post-fledging penguin ecology to better understand the potential impact of fishery, and, following the precautionary principle, support fishing seasonal protection of important areas during critical periods of krill predators life cycle.

ecology↗

bioRxiv2025

Selective Activation of NaV1.3 Restores Lymphatic Contractility in Age and Injury

BackgroundIntrinsic lymphatic contractility is essential for tissue fluid balance, immunity and organ function, yet no FDA-approved pharmacologic treatments specifically restore lymphatic contractility. Lymph is returned to the circulation by ion channel-driven cyclic contractions of collecting lymphatic vessels. Although voltage-gated sodium (NaV) channels drive cardiomyocyte excitability, their role in lymphatic muscle cell (LMC) physiology is not well defined. We identified NaV1.3, a NaV channel historically viewed as developmentally restricted and limited in adult tissues, as unexpectedly and selectively expressed in adult lymphatic muscle but absent from heart, vascular smooth muscle, and mature brain. We tested whether selective NaV1.3 activation restores impaired lymphatic pumping in aging and radiation injury. MethodsNaV1.3 expression in LMCs was confirmed through single-cell RNA sequencing analysis and immunostaining of mouse and human lymphatic vessels. Lymphatic contractility was quantified by in vivo fluorescence lymphangiography and interstitial fluid clearance was measured with a new bioluminescence assay. NaV1.3 function was assessed in young, aged, and radiation-injured mice. NaV1.3 knockout (Scn3a-/-) mice established the requirement of NaV1.3 for basal lymphatic excitability and responsiveness to the NaV1.3-specific activator, Tf2. ResultsIn mouse and human lymphatic vessels, NaV1.3 is expressed in adult LMCs. Although dispensable for basal lymphatic contractions, NaV1.3 acted as a pharmacologically recruitable reserve that amplified contractile output. Acute NaV1.3 activation with Tf2 increased lymphangion ejection fraction and accelerated interstitial fluid clearance. Tf2 fully restored lymphatic pumping in aged mice and partially rescued radiation-induced contractile deficits. All Tf2 responses were abolished in Scn3a-/- mice, confirming NaV1.3 dependence. ConclusionsNaV1.3 is a selectively druggable ion channel in adult lymphatic muscle that can be recruited to restore lymphatic pump function across aging and injury. Targeted NaV1.3 activation provides a molecular entry point for treating diseases characterized by lymphatic pump failure, a domain with no existing pharmacologic therapies.

physiology↗

bioRxiv2024

A Multiresolution Approach with Method-Informed Statistical Analysis for Quantifying Lymphatic Pumping Dynamics

Despite significant strides in lymphatic system imaging, the timely diagnosis of lymphatic disorders remains elusive. One main cause for this is the absence of standardized, quantitative methods for real-time analysis of lymphatic contractility. Here, we address this unmet need by combining near-infrared lymphangiography imaging with an innovative analytical workflow. We combined data acquisition, signal processing, and statistical analysis to integrate traditional peak and-valley with advanced wavelet time-frequency analyses. Decision theory was used to evaluate the primary drivers of attributable variance in lymphangiography measurements to generate a strategy for optimizing the number of repeat measurements needed per subject to increase measurement reliability. This approach not only offers detailed insights into lymphatic pumping behaviors across species, sex and age, but also significantly boosts the reliability of these measurements by incorporating multiple regions of interest and evaluating the lymphatic system under various gravitational loads. By addressing the critical need for improved imaging and quantification methods, our study offers a new standard approach for the imaging and analysis of lymphatic function that can improve our understanding, diagnosis, and treatment of lymphatic diseases. The results highlight the importance of comprehensive data acquisition strategies to fully capture the dynamic behavior of the lymphatic system.

physiology↗

bioRxiv2024

Escherichia coli grown in cost-effective conical tubes produces more plasmid DNA

Before the COVID-19 pandemic, we grew plasmid-transformed Escherichia coli in Falcon round-bottom-polypropylene tubes (F-Round-PP) and isolated plasmid using a Miniprep kit. When obtaining sufficient quantities of F-Round-PP became problematic during the pandemic and the inflation, we grew them using any available tubes. Notably, we observed that plasmid yield from cells grown in a cost-effective Oxford conical-polypropylene tubes (O-Conical-PP) was higher than that from F-Round-PP. We assessed the impact using O-Conical-PP and other conical brand tubes. As a result, the plasmid yield from O-Conical-PP (the list price is nearly 1/3 of F-Round-PP) was 1.5-fold higher than other PP tubes (p<0.001). We propose that researchers may need to re-assess the effectiveness of their laboratory supplies to optimize the budget during this inflationary period.

microbiology↗

bioRxiv2024

m6A-dependent circular RNA formation mediatestau-induced neurotoxicity

Circular RNAs (circRNAs), covalently closed RNA molecules that form due to back-splicing of RNA transcripts, have recently been implicated in Alzheimers disease and related tauopathies. circRNAs are regulated by N6-methyladenosine (m6A) RNA methylation, can serve as "sponges" for proteins and RNAs, and can be translated into protein via a cap-independent mechanism. Mechanisms underlying circRNA dysregulation in tauopathies and causal relationships between circRNA and neurodegeneration are currently unknown. In the current study, we aimed to determine whether pathogenic forms of tau drive circRNA dysregulation and whether such dysregulation causally mediates neurodegeneration. We identify circRNAs that are differentially expressed in the brain of a Drosophila model of tauopathy and in induced pluripotent stem cell (iPSC)-derived neurons carrying a tau mutation associated with autosomal dominant tauopathy. We leverage Drosophila to discover that depletion of circular forms of muscleblind (circMbl), a circRNA that is particularly abundant in brains of tau transgenic Drosophila, significantly suppresses tau neurotoxicity, suggesting that tau-induced circMbl elevation is neurotoxic. We detect a general elevation of m6A RNA methylation and circRNA methylation in tau transgenic Drosophila and find that tau-induced m6A methylation is a mechanistic driver of circMbl formation. Interestingly, we find that circRNA and m6A RNA accumulate within nuclear envelope invaginations of tau transgenic Drosophila and in iPSC-derived cerebral organoid models of tauopathy. Taken together, our studies add critical new insight into the mechanisms underlying circRNA dysregulation in tauopathy and identify m6A-modified circRNA as a causal factor contributing to neurodegeneration. These findings add to a growing literature implicating pathogenic forms of tau as drivers of altered RNA metabolism.

neuroscience↗

bioRxiv2023

Lymphatic muscle cells are unique cells that undergo aging induced changes

Lymphatic muscle cells (LMCs) within the wall of collecting lymphatic vessels exhibit tonic and autonomous phasic contractions, which drive active lymph transport to maintain tissue-fluid homeostasis and support immune surveillance. Damage to LMCs disrupts lymphatic function and is related to various diseases. Despite their importance, knowledge of the transcriptional signatures in LMCs and how they relate to lymphatic function in normal and disease contexts is largely missing. We have generated a comprehensive transcriptional single-cell atlas--including LMCs--of collecting lymphatic vessels in mouse dermis at various ages. We identified genes that distinguish LMCs from other types of muscle cells, characterized the phenotypical and transcriptomic changes in LMCs in aged vessels, and uncovered a pro-inflammatory microenvironment that suppresses the contractile apparatus in advanced-aged LMCs. Our findings provide a valuable resource to accelerate future research for the identification of potential drug targets on LMCs to preserve lymphatic vessel function as well as supporting studies to identify genetic causes of primary lymphedema currently with unknown molecular explanation.

cell biology↗

bioRxiv2023

Microbiome Analysis of the Eastern Oyster As a Function of Ploidy and Seasons

Shellfish, such as the eastern oysters (Crassostrea virginica) are not only valued as seafood but also for the ecosystem services they provide, including improving water quality and reducing eutrophication. Excess N causes eutrophication, harmful algal blooms, fish kills and overall decline of estuarine ecosystems resulting in economic losses. Oyster reefs sequester N and enhance denitrification processes, however, information on the N cycling oyster microbiome is scarce with most studies focusing on random grab samples or on pathogens, such as Vibrio spp. Further, triploid oysters are often used for aquaculture, as they grow faster than diploids, but there is little information on potential microbiome differences with ploidy. To address these knowledge gaps, diploid and triploid farmed oysters were collected at monthly intervals over one year and analyzed using a coupled approach encompassing shotgun metagenomics and quantitative microbial elemental cycling (QMEC) qPCR assays. Overall, the genus Psychrobacter dominated the core microbiome across all samples, regardless of season or ploidy, followed by Synechococcus, Pseudomonas, Pseudoalteromonas and Clostridium. Psychrobacter abundances increased significantly in the colder months; the same trend was also observed in the alpha and beta diversity. However, warmer months had increased bacterial diversity relative to colder months. Gene functional profiles were similar among seasons and ploidy, with respiration and metabolism of carbohydrates, RNA, and proteins as dominant functions. There were strong positive correlations between abundance of the "core" microbiome taxa and gene functions associated with central metabolism, DNA and carbohydrate metabolism, strongly suggesting the functional role of Psychrobacter in the microbiome. Metagenome assembly was performed to characterize dominant species, followed by phylogenetic analysis of select MAGs (metagenome-assembled genomes), further supporting the presence of multiple Psychrobacter spp. Sequence-based identification of denitrification genes in the Pyschrobacter MAGs indicated the presence of norB, narH, narI, nirK, and norB. QMEC analysis indicated C and N cycling genes were most abundant, with no discernable patterns due to seasons or ploidy. Among N cycling genes, the nosZII clade was dominant, which is likely responsible for the eastern oysters potential for bioextraction and enhancing water quality via denitrification.

microbiology↗

bioRxiv2023

The RNA binding protein IMP1/ZBP1 drives mRNA local translation in microglia and mediates polarized migration and phagocytosis in response to inflammation

Polarized cells in the brain, such as neurons and glia, rely on the asymmetric distribution of their proteins compartmentalizing the function of dendrites, axons, glial projections and endfeet. Subcellular proteomes can be assembled either by the transport of proteins synthesized in the cell soma or by the delivery of mRNAs to target compartments where they are locally translated into protein. This latter mechanism is known as local protein synthesis or local translation, and it has been best studied in neurons. Increasing evidence suggest it is also required to maintain local protein homeostasis in glial cells, however, in microglia, local translation remains largely unexplored. Given the scant evidence, we aimed at exploring the existence of local translation in peripheral microglial processes (PeMPs) and unravel its functional significance in response to inflammation, a major hallmark of neurodegenerative diseases. We report that local translation in PeMPs is enhanced by triggering a microglial inflammatory response with bacterial lipopolysaccharides (LPS). We found that Actb mRNA polarizes to PeMPs and is locally translated upon LPS exposure. mRNA localization in eukaryotic cells is driven by RNA binding proteins. Interestingly, downregulation of the Actb binding protein IMP1/ZBP1 impaired Actb mRNA polarization and its localized translation, and led to defects in filopodia distribution, PeMP motility, lamellar directed migration and phagocytosis in microglia. Thus, our work contributes to recent findings that mRNA localization and localized translation occur in microglia and gives a mechanistic insight into the relevance of this molecular mechanism in fundamental microglial functions in response to inflammation.

neuroscience↗

bioRxiv2020

A multilayered post-GWAS assessment on genetic susceptibility to pancreatic cancer

Pancreatic cancer (PC) is a complex disease in which both non-genetic and genetic factors interplay. To-date, 40 GWAS hits have been associated with PC risk in individuals of European descent, explaining 4.1% of the phenotypic variance. Here, we complemented a classical new PC GWAS (1D) with spatial autocorrelation analysis (2D) and Hi-C maps (3D) to gain additional insight into the inherited basis of PC. In-silico functional analysis of public genomic information allowed prioritization of potentially relevant candidate variants. We replicated 17/40 previous PC-GWAS hits and identified novel variants with potential biological functions. The spatial autocorrelation approach prioritized low MAF variants not detected by GWAS. These were further expanded via 3D interactions to 54 target regions with high functional relevance. This multi-step strategy, combined with an in-depth in-silico functional analysis, offers a comprehensive approach to advance the study of PC genetic susceptibility and could be applied to other diseases.

genetics↗