Biology subjects

English, M.

Publications and source records attributed to English, M..

6 recordsLinked to original sources

bioRxiv2026

Cell autonomous inflammation in VEXAS is mediated by cGAS-STING

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a severe adult-onset inflammatory disease caused by somatic mutations that reduce cytoplasmic activity of UBA1, the primary initiating enzyme for ubiquitylation. How this hypomorphic state drives cell-intrinsic immune activation in mature myeloid cells is unknown. Using unbiased multi-omic, biochemical, and cell biological analyses of model systems and patient-derived cells, we show that loss of cytoplasmic UBA1 activity convergently disrupts endoplasmic reticulum- associated degradation (ERAD) and mitochondrial homeostasis. ERAD failure arises from preferential under-charging of ERAD E2 enzymes, explaining hallmark VEXAS features, including ER-derived vacuoles and unfolded protein response activation, and promotes accumulation of the ERAD substrate STING. Simultaneously, mitochondrial dysfunction drives cytosolic leakage of mitochondrial DNA, inducing cGAS-dependent STING signaling and inflammatory cytokine production. STING inhibition or reversal of mitochondrial DNA leakage resolves multi-cytokine inflammation in VEXAS models and patient myeloid cells, establishing the cGAS-STING pathway as a therapeutically actionable vulnerability.

genetics↗

bioRxiv2025

Neonatal Mouse Ovary Culture: An In Vitro Model for Studying Primordial Follicle Regulation

In mammalian females, primordial follicles form during fetal ovarian development and serve as the only source to sustain adult ovarian function. Mechanisms underlying how primordial follicles assemble, maintain dormancy, activate for follicular development, and undergo cell death are important for understanding ovarian physiology and pathological conditions. Here, we demonstrate a protocol of culturing postnatal mouse ovaries on membrane inserts - an approach allowing culture, pharmaceutical treatment, and live-imaging of intact ovaries for up to 10 days depending on the developmental stage of the ovary. The change of culture conditions can be done by transferring inserts containing cultured ovaries between wells on a plate, avoiding physical interference with tissues during culture. In this experiment, we use postnatal day 5 (P5) CD1 mouse ovary culture as an example. P5 ovaries were isolated and placed on a 12 mm insert in a 24-well plate. Each ovary was separated within a droplet of DMEM/F12 medium supplemented with 10% FBS, 3 mg/ml BSA, 10 mIU/ml FSH, and Gibco Antibiotic-Antimycotic, and gently stabilized to the membrane insert. The medium was changed every two days, and the culture was maintained for five days. Following the culture, ovaries were fixed in 4% paraformaldehyde for two hours and processed for whole-mount antibody staining. Primordial follicles were visualized using confocal microscopy with anti-DDX4 antibody, allowing for the analysis of oocyte number and morphology. We showed that the number of primordial follicles in each ovary was significantly affected by whether tissues were properly placed on the membrane insert. Difference in the number of ovaries on each insert may contribute to non-biological variations and should be avoided.

developmental biology↗

bioRxiv2024

Geographic, ecological, and temporal patterns of seabird mortality during the 2022 HPAI H5N1 outbreak on the island of Newfoundland

Highly pathogenic avian influenza (HPAI) H5N1 caused mass seabird mortality across the North Atlantic in 2022. Following outbreaks in Europe, the first case in North America was detected on the island of Newfoundland (NFLD), Canada in November 2021, before spreading through all North American flyways. During the following breeding season, NFLD experienced the second-highest number of seabird mortalities in Canadian provinces. Surveys and citizen reports identified 13543 seabird mortalities from April to September 2022. Many carcasses occurred on the west coast of NFLD in May and June 2022. Reported mortalities peaked in July along the southeastern coast. In August and September, mortalities were concentrated along the northeastern coast. With the exception of two colony surveys, reported mortalities decreased in September. Most mortality was found among Northern Gannet (6622), Common Murre (5992), Atlantic Puffin (282), and Black-legged Kittiwake (217). Using comprehensive knowledge of seabird ecology, we formulated exploratory hypotheses regarding traits that could contribute to mortality. Species differences in mortality were most strongly associated with nesting density, timing of breeding, and at-sea overlap with allospecifics from other colonies. Unprecedented seabird mortality and ongoing transmission within the circulating avian influenza viruses highlight the need for continued monitoring and development of conservation strategies.

zoology↗

bioRxiv2024

Wild bird mass mortalities in eastern Canada associated with the Highly Pathogenic Avian Influenza A(H5N1) virus, 2022

In 2022, a severe outbreak of clade 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) H5N1 virus resulted in unprecedented mortality among wild birds in eastern Canada. Tens of thousands of birds were reported sick or dead, prompting a comprehensive assessment of mortality spanning the breeding season between April 1 and September 30, 2022. Mortality reports were collated from federal, Indigenous, provincial, and municipal agencies, the Canadian Wildlife Health Cooperative, non-governmental organizations, universities, and citizen science platforms. A scenario analysis was conducted to refine mortality estimates, accounting for potential double counts from multiple sources under a range of spatial and temporal overlap. Correcting for double counting, an estimated 40,966 wild birds were reported sick or dead in eastern Canada during the spring and summer of 2022. Seabirds and sea ducks, long-lived species that are slow to recover from perturbations, accounted for 98.7% of reported mortalities. Mortalities were greatest among Northern Gannets (Morus bassanus; 26,193), Common Murres (Uria aalge; 8,133), and American Common Eiders (Somateria mollissima dresseri; 1,945), however, these figures underestimate total mortality as they exclude unreported deaths on land and at sea. In addition to presenting mortality estimates, we compare mortalities with known population sizes and trends and make an initial assessment of whether population-level impacts are possible for the Northern Gannet, a species that has suffered significant global mortality, and two harvested species, Common Murre and American Common Eider, to support management decisions. We hypothesize that population-level impacts in eastern Canada are possible for Northern Gannets and American Common Eiders but are unlikely for Common Murres. This study underscores the urgent need for further research to understand the broader ecological ramifications of the HPAI outbreak on wild bird populations.

zoology↗

bioRxiv2023

Shared and Distinct Mechanisms of UBA1 Inactivation Across Different Diseases

Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.

biochemistry↗

bioRxiv2019

PURPOSEFUL DESIGN OF A SURVEY TOOL TO EVALUATE THE ADEQUACY OF HOSPITALS WATER SANITATION AND HYGIENE AND ALLOCATE RESPONSIBILITY FOR ACTION - FROM WASH FIT to WASH FAST

BackgroundPoor water sanitation and hygiene (WASH) in health care facilities increases hospital associated infections and results in greater use of second line antibiotics, which drives antimicrobial resistance. The existing assessment tool, Water and Sanitation for Health Facility Improvement Tool (WASH FIT), is designed for self-assessment in smaller primary facilities. A tool is needed for larger facilities with multiple inpatient units, that supports comparison of multiple facilities and identifies who is responsible for action at different levels of the health system.\n\nMethodsWe adapted the WASH FIT tool to: 1) create a simple numeric scoring approach to enable comparison of hospitals and facilitate tracking of WASH performance over time; (2) identify indicators that can be assessed and scored for each hospital ward to help identify variation within facilities and; (3) identify those responsible to effect positive change at different levels of the health system. We used a pilot, analysis of interview data and consultative stakeholder meetings to establish the feasibility and face validity of the WASH Facility Survey Tool (WASH FAST).\n\nResultsWASH FAST can be used to produce an aggregate percentage score at facility level to summarise hospitals overall WASH status and illustrate variation across hospitals. Thirty-four of the 65 indicators spanning four WASH domains can be assessed at ward level enabling between ward variations to be highlighted. Three levels of responsibility for WASH service monitoring and improvement were identified that were supported by qualitative data and multiple stakeholders: the county/regional level, hospital senior management and the infection prevention and control committee within the healthcare facility.\n\nConclusionWe propose WASH FAST can be used as a survey tool to assess, improve and monitor progress of WASH and IPC in hospitals in resource-limited settings, providing useful data for decision making and contributing to wider quality improvement efforts.

epidemiology↗