Biology subjects

Reynolds, A. M.

Publications and source records attributed to Reynolds, A. M..

7 recordsLinked to original sources

bioRxiv2026

Avian uropygial secretions as a novel bioinsecticide for mosquito vector control

Background: Malaria control relies heavily on interventions targeting mosquito vectors, but the rapid emergence of insecticide resistance threatens the effectiveness of existing approaches. Identifying novel, effective, and environmentally sustainable insecticides is therefore a priority. Birds produce uropygial secretions with well-documented antimicrobial properties, but their potential insecticidal activity against mosquitoes, including malaria vectors, remains unexplored. Methods: We evaluated the insecticidal activity of uropygial secretions from wild house sparrows (Passer domesticus) against the malaria vector Anopheles stephensi and four additional mosquito species of medical importance (Aedes aegypti, Aedes albopictus, Culex pipiens, and Culiseta longiareolata). A total of 2,293 adult mosquitoes were tested using CDC bottle bioassays at three secretion concentrations (0.5, 0.25, and 0.125) and an untreated control. Mosquito mortality was monitored for 120 min. Results: Uropygial secretions caused substantial mosquito knockdown/mortality, with effects increasing with concentration and exposure time. Susceptibility differed significantly among species after 120 min. Notably, An. stephensi was particularly susceptible, reaching knockdown/mortality of 92%, 94%, and 83% at 0.5, 0.25, and 0.125 concentrations, respectively. Conclusions: Our findings provide the first experimental evidence that avian uropygial secretions possess direct insecticidal activity against mosquitoes and identify them as a previously overlooked source of naturally derived insecticidal compounds. The high susceptibility of An. stephensi highlights their potential relevance for developing novel bioinsecticides for malaria vector control.

ecology↗

bioRxiv2025

The origin, invasion history and resistance architecture of Anopheles stephensi in Africa.

The invasion of Africa by the Asian urban malaria vector, Anopheles stephensi, endangers 126 million people across a rapidly urbanising continent where malaria is primarily a rural disease. Control of An. stephensi requires greater understanding of its origin, invasion dynamics, and mechanisms of widespread resistance to vector control insecticides. We present a genomic surveillance study of 551 An. stephensi sampled across the invasive and native ranges in Africa and Asia. Our findings support a hypothesis that an initial invasion from Asia to Djibouti seeded separate incursions to Sudan, Ethiopia, and Yemen before spreading inland, aided by favourable temperature, vegetation cover, and human transit conditions. Insecticide resistance in invasive An. stephensi is conferred by detoxification genes introduced from Asia. These findings, and a companion genomic data catalogue, will form the foundation of an evidence base for surveillance and management strategies for An. stephensi.

genomics↗

bioRxiv2023

Age-dependent ventilator-induced lung injury: Mathematical modeling, experimental data, and statistical analysis

A variety of pulmonary insults can result in the necessity for mechanical ventilation, which, when misused, used for prolonged periods of time, or associated with an excessive inflammatory response, can result in ventilator-induced lung injury. Older patients have been observed to have an increased risk for respiratory distress with ventilation and more recent studies suggest that this could be linked to disparities in the inflammatory response. To address this, we ventilated young (2-3 months) and old (20-25 months) mice for 2 hours using high pressure mechanical ventilation and extracted data for inflammatory cell ratios, namely macrophage phenotypes, and lung tissue integrity. A large difference in naive macrophages at baseline, alternatively-activated (M2) macrophages at baseline, and airspace enlargement after ventilation was observed in the old mice. The experimental data was used to fit a mathematical model for the inflammatory response to lung injury. Model variables include inflammatory markers and cells, namely neutrophils and macrophages, epithelial cells at varying states, and repair mediators. Parameter sampling was performed using an iterative sampling method and parameter sets were selected based on their ability to fit either the old or young macrophage phenotype percentages and epithelial variables at zero and two hours. Classification methods were performed to identify influential parameters separating the old and young parameter sets as well as user-defined health states. Parameters involved in repair and damage to epithelial cells and parameters regulating the pro-inflammatory response were shown to be important. Local sensitivity analysis preformed for the different epithelial cell variables produced similar results. A pseudo-intervention was also performed on the parameter sets. The results were most influential for the old parameter sets, specifically those with poorer lung health. These results indicate potential targets for therapeutic interventions prior to and during ventilation, particularly for old subjects. Author summaryA variety of inhaled pathogens and other pulmonary insults prompt the need for mechanical ventilation; a procedure that has become increasingly necessary following the 2019 coronavirus pandemic. A proportion of patients respond poorly to ventilation, some resulting in ventilator-induced lung injury. Observational data has shown increased instance of severe disease in older patients as well as differences in the inflammatory response to injury, although more research is needed to confirm this. We performed high-pressure ventilation on young (2-3 months) and old (20-25 months) mice and observed large disparities in inflammatory cell ratios at baseline and lung tissue integrity after ventilation. The experimental data was then used to fit a mathematical model of the inflammatory response to lung injury. We used a variety of analysis methods to identify important parameters separating the young and old parameter sets and user-defined health states of the resulting simulations. Parameters involved in damage and repair of epithelial cells in the lung as well as parameters controlling the pro-inflammatory response to injury were important in both classifying between old and young sets and determining predicted health after ventilation. These results indicate potential targets for therapeutic interventions prior to and during ventilation.

systems biology↗

bioRxiv2022

Agent-based vs. equation-based multi-scale modeling for macrophage polarization

Macrophages show high plasticity and result in heterogenic subpopulations or polarized states identified by specific cellular markers. These immune cells are typically characterized as pro-inflammatory, or classically activated M1, and anti-inflammatory, or alternatively activated M2. However, a more precise definition places them along a spectrum of activation where they may exhibit a number of pro- or anti-inflammatory roles. To gain a greater understanding of the mechanisms of the immune response from macrophages and the balance between M1 and M2 activation, we utilized two different modeling techniques, ordinary differential equation (ODE) modeling and agent-based modeling (ABM), to simulate the spectrum of macrophage activation to general pro- and anti-inflammatory stimuli on an individual and multi-cell level. The ODE model includes two hallmark pro- and anti-inflammatory signaling pathways and the ABM incorporates similar M1-M2 dynamics but in a spatio-temporal platform. Both models link molecular signaling with cellular-level dynamics. We then performed simulations with various initial conditions to replicate different experimental setups. Similar results were observed in both models after tuning to a common calibrating experiment. Comparing the two models results sheds light on the important features of each modeling approach. When more data is available these features can be considered when choosing techniques to best fit the needs of the modeler and application.

systems biology↗

bioRxiv2020

Lymphocyte-Specific Biomarkers Associated with Preterm Birth and Bronchopulmonary Dysplasia

Many premature babies who are born with neonatal respiratory distress syndrome (RDS) go on to develop Bronchopulmonary Dysplasia (BPD) and later Post-Prematurity Respiratory Disease (PRD) at one year corrected age, characterized by persistent or recurrent lower respiratory tract symptoms frequently related to inflammation and viral infection. Transcriptomic profiles were generated from sorted peripheral blood CD8+ T cells of preterm and full-term infants enrolled with consent in the NHLBI Prematurity and Respiratory Outcomes Program (PROP) at the University of Rochester and the University at Buffalo. We identified outcome-related gene expression patterns following standard methods to identify markers for oxygen utilization and BPD as outcomes in extremely premature infants. We further identified predictor gene sets for BPD based on transcriptomic data adjusted for gestational age at birth (GAB). RNA-Seq analysis was completed for CD8+ T cells from 145 subjects. Among the subjects with highest risk for BPD (born at <29 weeks gestational age (GA); n=72), 501 genes were associated with oxygen utilization. In the same set of subjects, 571 genes were differentially expressed in subjects with a diagnosis of BPD and 105 genes were different in BPD subjects as defined by physiologic challenge. A set of 92 genes could predict BPD with a moderately high degree of accuracy. We consistently observed dysregulation of NRF2, HIPPO and CD40-associated pathways in BPD. Using gene expression data from both premature and full-term subjects (n=116), we identified a 28 gene set that predicted the PRD status with a moderately high level of accuracy. Transcriptomic data from sort-purified peripheral blood CD8+ T cells from 145 preterm and full-term infants identified sets of molecular markers associated with independent development of BPD in extremely premature infants at high risk for the disease and of PRD among the preterm and full-term subjects.

genomics↗

bioRxiv2020

Understanding the Role of Macrophages in Lung Inflammation Through Mathematical Modeling

Respiratory infections, such as the novel coronavirus (SARS-COV-2) and other lung injuries, damage the pulmonary epithelium. In the most severe cases this leads to acute respiratory distress syndrome (ARDS). Due to respiratory failure associated with ARDS, the clinical intervention is the use of mechanical ventilation. Despite the benefits of mechanical ventilators, prolonged or misuse of these ventilators may lead to ventilation-associated/ventilation-induced lung injury (VILI). Damage caused to epithelial cells within the alveoli can lead to various types of complications and increased mortality rates. A key component of the immune response is recruitment of macrophages, immune cells that differentiate into phenotypes with unique pro- and/or anti-inflammatory roles based on the surrounding environment. An imbalance in pro- and anti-inflammatory responses can have deleterious effects on the individuals health. To gain a greater understanding of the mechanisms of the immune response to VILI and post-ventilation outcomes, we develop a mathematical model of interactions between the immune system and site of damage while accounting for macrophage polarization. Through Latin hypercube sampling we generate a virtual cohort of patients with biologically feasible dynamics. We use a variety of methods to analyze the results, including a random forest decision tree algorithm and parameter sensitivity with eFAST. Analysis shows that parameters and properties of transients related to epithelial repair and M1 activation and de-activation best predicted outcome. Using this new information, we hypothesize inter-ventions and use these treatment strategies to modulate damage in select virtual cases.

systems biology↗

bioRxiv2017

The Influence of Aging and Mechanical Stretch in Alveolar Epithelium ER Stress and Inflammation

Ventilator-Induced lung injury (VILI) is a form of acute lung injury that is initiated or exacerbated by mechanical ventilation. The aging lung is more susceptible to lung injury. Harmful mechanical stretch of the alveolar epithelium is a recognized mechanism of VILI, yet little is known about how mechanical stretch affects aged epithelial cells. An activated response known as Endoplasmic Reticulum (ER) Stress occurs at the cellular level, which is increased with aging. The disrupted ER function results in disruption in cellular homeostasis, apoptosis, and inflammation. We hypothesized that age and mechanical stretch increase proinflammatory gene expression that is mediated by ER stress. Type II alveolar epithelial cells (ATII) were harvested from C57Bl6/J mice 8 weeks (young) and 20 months (old) of age. The cells were cyclically mechanically stretched at 15% change in surface area for up to 24 hours. Prior to stretch, groups were administered 4-PBA or vehicle as a control. Mechanical stretch upregulated both ER stress and proinflammatory gene expression in ATIIs. Age-matched and mis-matched monocyte recruitment by ATII conditioned media was quantified. Administration of 4-PBA attenuated both the ER stress and proinflammatory increases from stretch and/or age and significantly reduced monocyte migration to ATII conditioned media. Age increases susceptibility to stretch-induced ER stress and downstream inflammation in a primary ATII epithelial cell model.

bioengineering↗