Biology subjects

Egan, M.

Publications and source records attributed to Egan, M..

6 recordsLinked to original sources

bioRxiv2026

Functional Connectivity Differences Underly Variable Centralized Symptom Relief After Hysterectomy

Approximately 1 in 4 women with chronic pelvic pain (CPP) report persistent pelvic pain after hysterectomy. Centralized symptoms-fatigue, multisite pain, and sleep disturbance, quantified using the Fibromyalgia Survey Score (FSS)-often co-occur with this risk, but the trajectory of centralized symptom burden after surgery, independent of pelvic pain outcome, is not well understood. Whether presurgical differences in central nervous system pain processing distinguish women whose centralized symptoms improve (improvers) from those whose do not (non-improvers) has not been tested. In this observational study, we assessed whether individuals who do and do not report improvement in FSS scores six months post-operatively differ in their baseline/pre-operative phenotypes and brain function. Sensory sensitivity scores were significantly higher in non-improvers than in improvers at baseline. We identified no significant, presurgical differences in age, average pelvic pain intensity, widespread pain, or pain interference between improvers and non-improvers. Functional connectivity was examined at rest and during the application of a distal, sustained pressure pain. We identified no significant group differences at rest. During sustained pressure pain, non-improvers showed greater connectivity than improvers between primary somatosensory cortex and posterior thalamic seeds with frontal, motor, cerebellar and limbic regions, but lower connectivity between the periaqueductal gray and subgenual cingulate cortex. Non-improvers also showed a greater pain-evoked increase in connectivity between the pelvic and leg representations of the primary sensory cortex and other sensorimotor regions in the pain-versus-rest contrast. Overall, non-improvers showed increased functional connectivity between regions associated with the multisensory integration of ascending pain, and decreased connectivity between regions associated with descending pain modulation. In exploratory analyses, some of these connections were additionally associated with symptom burden: sensory sensitivity, number of painful regions, and pain interference. This work may inform mechanisms of persistent symptom burden and guide surgical decision-making in patients with high central sensitization.

neuroscience↗

bioRxiv2025

Non-Visual Light Sensing Enhances Behavioral Memory and Drives Gene Expression in C. elegans

Visible light influences a range of physiological processes, yet how animals respond to it independently of the visual system remains largely unknown. Here, we uncover a previously undescribed light-induced transcriptional pathway that modulates behavioral plasticity in C. elegans, a roundworm without eyes. We demonstrate that ambient visible light or controlled-intensity visible-spectrum LED activates an effector gene cyp-14A5 in non-neuronal tissues through the bZIP transcription factors ZIP-2 and CEBP-2. Light induction of cyp-14A5 is more prominent at shorter wavelengths but is independent of the known blue light receptors LITE-1 and GUR-3 in C. elegans. This bZIP-dependent genetic pathway in non-neuronal tissues enhances behavioral adaptability and olfactory memory, suggesting a body-brain communication axis. Furthermore, we use the light-responsive cyp-14A5 promoter to drive ectopic gene expression, causing synthetic light-induced sleep and rapid aging phenotypes in C. elegans. These findings advance our understanding of light-responsive mechanisms outside the visual system and offer a new genetic tool for visible light-inducible gene expression in non-neuronal tissues.

physiology↗

bioRxiv2024

CHRONIC LUNG INFLAMMATION LEADS TO MYELOID SKEWING OF HEMATOPOIETIC STEM CELLS IN A CYSTIC FIBROSIS MOUSE MODEL

Persistent lung inflammation is a hallmark of Cystic fibrosis (CF) lung disease. Inflammation can lead to functional decline in hematopoietic stem cell (HSCs), tipping the balance towards myelopoiesis and contributing to chronic inflammation. However, its unknown whether the HSCs are dysfunctional in CF. We tested whether chronic lung inflammation impacts hematopoietic stem and progenitor cells (HSPCs) in a CF mouse model. Wild-type (WT) and Cftr-/- mice were nebulized with lipopolysaccharide (LPS) from Pseudomonas aeruginosa for 5 weeks. The mice were euthanized before the exposure (T0), 24 hours after the last LPS nebulization (T1), or 6 weeks (T2) after the last LPS nebulization. The bone marrow (BM) and lung tissue were collected for flow cytometry analysis of the HSPC population and immune cells in the lungs, respectively. Peripheral blood was collected for complete blood count analysis. At baseline, Cftr-/- mice show a larger HSPC population with a myeloid bias, indicated by higher frequencies of LSK, LT-HSC, CD41+ LT-HSC, GMPs, and MkPs. Following chronic LPS nebulization, Cftr-/- mice exhibit greater HSPC expansion and myeloid differentiation, alongside increased peripheral myeloid cell counts. Post-recovery, while most HSPC populations return to baseline, Cftr-/- mice retain elevated myeloid-biased LT-HSCs, suggesting a persistent myeloid bias. These findings underscore a prominent shift toward myeloid hematopoiesis in CF, which is accentuated by chronic inflammation and remains even after recovery. Further experiments are underway to assess maladaptive epigenetic changes in HSC as well as if chronic lung inflammation impacts HSC functionality.

immunology↗

bioRxiv2022

A highly attenuated Vesiculovax vaccine rapidly protects nonhuman primates against lethal Marburg virus challenge

BackgroundMarburg virus (MARV), an Ebola-like virus, remains an eminent threat to public health as demonstrated by its high associated mortality rate (23-90%) and recent emergence in West Africa for the first time. Although a recombinant vesicular stomatitis virus (rVSV)-based vaccine (Ervebo) is licensed for Ebola virus disease (EVD), no approved countermeasures exist against MARV. Results from clinical trials indicate Ervebo prevents EVD in 97.5-100% of vaccinees 10 days onwards post-immunization. Methodology/FindingsGiven the rapid immunogenicity of the Ervebo platform against EVD, we tested whether a similar, but highly attenuated, rVSV-based Vesiculovax vector expressing the glycoprotein (GP) of MARV (rVSV-N4CT1-MARV-GP) could provide swift protection against Marburg virus disease (MVD). Here, groups of cynomolgus monkeys were vaccinated 7, 5, or 3 days before exposure to a lethal dose of MARV (Angola variant). All subjects (100%) immunized one week prior to challenge survived; 80% and 20% of subjects survived when vaccinated 5- and 3-days pre-exposure, respectively. Lethality was associated with higher viral load and aberrant innate immunity signaling, whereas survival correlated with development of MARV GP-specific antibodies and early expression of NK cell-, B-cell-, and cytotoxic T-cell-related transcriptional signatures. Conclusions/SignificanceThese results emphasize the utility of Vesiculovax vaccines for MVD outbreak management. The highly attenuated nature of rVSV-N4CT1 vaccines, which are clinically safe in humans, may be preferable to vaccines based on the same platform as Ervebo (rVSV "delta G" platform), which in some trial participants induced vaccine-related adverse events in association with viral replication including arthralgia/arthritis, dermatitis, and cutaneous vasculitis. Author SummaryMarburg virus (MARV) is one of the deadliest viruses known to man. One of the most effective vaccines against this pathogen uses a recombinant vesicular stomatitis virus (rVSV) platform to express MARV glycoprotein (GP) immunogen. As rVSV-based vaccines may be used as medical interventions to mitigate or prevent outbreaks of MARV, defining the time window needed to elicit protection is vital. Here, a rVSV vector expressing MARV glycoprotein (rVSV-N4CT1-MARV-GP) fully protected nonhuman primates from lethality and disease when given as soon as 1 week prior to exposure. At 5- and 3-days pre-exposure, partial protection (80% and 20% survival, respectively) was achieved. Vaccination with rVSV-N4CT1-MARV-GP appears to "jump-start" the immune system to allow sufficient time for MARV-specific adaptive responses to form. This fast- acting vaccine is based on a similar platform as Ervebo, the only FDA- and EU-approved vaccine for preventing Ebola virus infection. The rVSV-N4CT1-MARV-GP vaccine features additional attenuations in the rVSV backbone that may contribute to a more acceptable safety profile in vaccinees, as Ervebo in some recipients induced vaccine- related adverse events including rashes and joint pain.

microbiology↗

bioRxiv2021

Human NAIP/NLRC4 and NLRP3 inflammasomes detect Salmonella type III secretion system activities to restrict intracellular bacterial replication

Salmonella enterica serovar Typhimurium is a Gram-negative pathogen that uses two distinct type III secretion systems (T3SSs), termed Salmonella pathogenicity island (SPI)-1 and SPI-2, to deliver virulence factors into the host cell. The SPI-1 T3SS enables Salmonella to invade host cells, while the SPI-2 T3SS facilitates Salmonellas intracellular survival. In mice, a family of cytosolic immune sensors, including NAIP1, NAIP2, and NAIP5/6, recognizes the SPI-1 T3SS needle, inner rod, and flagellin proteins, respectively. Ligand recognition triggers assembly of the NAIP/NLRC4 inflammasome, which mediates caspase-1 activation, IL-1 family cytokine secretion, and pyroptosis of infected cells. In contrast to mice, humans encode a single NAIP that broadly recognizes all three ligands. The role of NAIP/NLRC4 or other inflammasomes during Salmonella infection of human macrophages is unclear. We find that although the NAIP/NLRC4 inflammasome is essential for detecting SPI-1 T3SS ligands in human macrophages, it is partially required for responses to infection, as Salmonella also activated the NLRP3 and CASP4/5 inflammasomes. Importantly, we demonstrate that combinatorial NAIP/NLRC4 and NLRP3 inflammasome activation restricts Salmonella replication in human macrophages. In contrast to SPI-1, the SPI-2 T3SS inner rod is not sensed by human or murine NAIPs, which is thought to allow Salmonella to evade host recognition and replicate intracellularly. Intriguingly, we find that human NAIP detects the SPI-2 T3SS needle protein. Critically, in the absence of both flagellin and the SPI-1 T3SS, the NAIP/NLRC4 inflammasome still restricted intracellular Salmonella replication. These findings reveal that recognition of Salmonella SPI-1 and SPI-2 T3SSs and engagement of both the NAIP/NLRC4 and NLRP3 inflammasomes control Salmonella infection in human macrophages. Author summarySalmonella enterica serovar Typhimurium is a gastrointestinal bacterial pathogen that causes diarrheal disease and is a major cause of morbidity and mortality worldwide. Salmonella uses molecular syringe-like machines called type III secretion systems (T3SSs) to inject virulence factors into host cells. These T3SSs enable Salmonella to infect and survive within host cells such as macrophages. However, host cells contain a family of cytosolic immune receptors, termed NAIPs, that recognize T3SS and flagellin components. Upon detecting these components, NAIPs recruit the adaptor protein NLRC4 to form signaling complexes called inflammasomes. Inflammasomes activate host proteases called caspases that mount robust immune responses against the invading pathogen. While mice encode multiple NAIPs that have been extensively studied, much remains unknown about how the single human NAIP mediates inflammasome responses to Salmonella in macrophages. Our study reveals that while NAIP is necessary to detect individual T3SS ligands in human macrophages, it is only partially required for inflammasome responses to Salmonella infection. We found that the NLRP3 and CASP4/5 inflammasomes are also activated, and the combination of NAIP- and NLRP3-mediated recognition limits intracellular Salmonella replication in human macrophages. Our results demonstrate that human macrophages employ multiple inflammasomes to mount robust host defense against Salmonella infection.

microbiology↗

bioRxiv2019

Chemical Impacts of the Microbiome Across Scales Reveal Novel Conjugated Bile Acids

A mosaic of cross-phyla chemical interactions occurs between all metazoans and their microbiomes. In humans, the gut harbors the heaviest microbial load, but many organs, particularly those with a mucosal surface, associate with highly adapted and evolved microbial consortia1. The microbial residents within these organ systems are increasingly well characterized, yielding a good understanding of human microbiome composition, but we have yet to elucidate the full chemical impact the microbiome exerts on an animal and the breadth of the chemical diversity it contributes2. A number of molecular families are known to be shaped by the microbiome including short-chain fatty acids, indoles, aromatic amino acid metabolites, complex polysaccharides, and host lipids; such as sphingolipids and bile acids3-11. These metabolites profoundly affect host physiology and are being explored for their roles in both health and disease. Considering the diversity of the human microbiome, numbering over 40,000 operational taxonomic units12, a plethora of molecular diversity remains to be discovered. Here, we use unique mass spectrometry informatics approaches and data mapping onto a murine 3D-model13-15 to provide an untargeted assessment of the chemical diversity between germ-free (GF) and colonized mice (specific-pathogen free, SPF), and report the finding of novel bile acids produced by the microbiome in both mice and humans that have evaded characterization despite 170 years of research on bile acid chemistry16.

microbiology↗