Biology subjects

Hannah, L.

Publications and source records attributed to Hannah, L..

5 recordsLinked to original sources

bioRxiv2026

Adipose tissue as a site of immune activation and dysfunction in individuals with obesity and asthma

Obesity increases local inflammatory responses in adipose tissue. Individuals with obesity have increased asthma incidence and severity and reduced responses to asthma therapeutics through unknown mechanisms. To identify mechanisms by which increased fat mass augments asthma pathogenesis, single cell RNA sequencing of the immune-rich stromovascular fraction of subcutaneous adipose tissue was conducted from well-characterized adults with obesity-associated asthma matched to adults without asthma. Individuals with asthma had increased abundance of perivascular macrophages and lymphoid-associated macrophages (LAMs) and reduced abundance of classical monocytes and CD4+ and CD8+ naive T cells. Pseudo-bulk differential expression (DE) identified upregulation of cellular metabolism, specifically oxidative phosphorylation, and decreased immune homeostatic pathways in asthma across immune cell subsets. Cell type specific DE analysis of effector cell subtypes identified significant induction of metallothionein gene expression in asthma, a signature of immune cell dysfunction characterized by both an activation and exhaustion phenotype. Gene co-expression analysis identified gene modules associated with asthma diagnosis, lung function, and biomarkers of type 2 inflammation were enriched in effector cells. These data identify adipose tissue dysfunction occurs in obesity-associated asthma and support adipose tissue as therapeutic target to address the enhanced asthma risk among those with obesity. Grant SupportNIH U01AI155299, P30DK020593, R01AI182159, K23HL159351, UL1RR024975-03, P30CA68485, P30EY08126, G20RR030956, 5UL1TR002243, KL2TR002245, P30AI110527, DK020593, American Heart Association 17SFRN33520017.

immunology↗

bioRxiv2025

Megafauna show pervasive yet distinct affinity to ocean fronts: the urgent need for adaptive conservation in a warming world

Fronts are ephemeral structures in the ocean that mark the boundaries between water masses of different properties, attracting a wide range of marine organisms, from plankton to whales. Despite their fundamental role in marine ecosystem functioning, the association with biodiversity has mainly focused on single species in regions with high data availability. Here, using multidecadal datasets on dynamical and thermal fronts, satellite tracking, and aerial observations, we assess marine megafauna associations with ocean fronts in the ecologically rich yet highly turbulent Mozambique Channel. We find that a diverse array of species associate with various ocean fronts, although the strength and type of affinity vary across taxa. Downscaled climate change simulations predict significant spatial shifts in front-rich areas by the end of the century. As climate change reshapes ocean front dynamics, adaptive management strategies will be essential to balance conservation and resource use in these critical ecosystems. TeaserOcean fronts attract marine megafauna, but climate change might alter these habitats, requiring adaptive conservation strategies.

ecology↗

bioRxiv2022

Critical pollination chemistry: Specific sesquiterpene floral volatiles in carrot inhibit honey bee feeding.

O_LIAlthough many plant species are reliant on insect pollination, agricultural plant breeding programs have primarily focused on traits that appeal to growers and consumers, rather than on floral traits that enhance pollinator attraction. In some vegetable seed production systems, this has led to declining pollinator attraction and poor seed yields. C_LIO_LIWe predicted that low-yielding crop varieties would be less attractive to pollinators due to deficiencies in nectar rewards or volatile floral attractants. To test our prediction, we used a chemical phenotyping approach to examine how floral chemical traits of five carrot lines affect honey bee visitation. C_LIO_LIIn bioassays, honey bees avoided feeders containing nectar from all carrot lines indicating a general non-attractant effect. Certain compounds in carrot flowers and nectar not only failed to elicit attraction but functioned as repellents, including the sesquiterpenes -selinene and {beta}-selinene. Others enhanced attraction, e.g. {beta}-ocimene. C_LIO_LIThe repellent sesquiterpenes have previously been implicated in plant defense suggesting a fine balance between pollination and plant protection, which when disrupted in artificial selection in plant breeding programs can impact the crop yield. These new insights highlight the importance of bioactive compounds in attracting pollinators toward floral resources in both ecological and agricultural settings. C_LI

plant biology↗

bioRxiv2022

A Single-Cell Molecular Atlas of White Adipose Tissue Shows Differences in Myeloid and Lymphoid Cell Polarization in Type 2 Diabetes and HIV Infection

Subcutaneous adipose tissue (SAT) is a critical regulator of systemic metabolic homeostasis. Persons with HIV (PWH) have an increased risk of metabolic diseases and significant alterations in the SAT immune environment compared with the general population. We generated a comprehensive SAT atlas to characterize cellular compositional and transcriptional changes in 59 PWH with a spectrum of metabolic health. Glucose intolerance was associated with increased lipid-associated macrophages and CD4+ and CD8+ T effector memory cells, and decreased perivascular macrophages. We observed a coordinated intercellular regulatory program which enriched for genes related to inflammation and lipid-processing across multiple cell types as glucose intolerance increased. Increased CD4+ effector memory tissue resident cells most strongly associated with altered expression of adipocyte genes critical for lipid metabolism and cellular regulation. Many of these findings were present in a separate group of 32 diabetic HIV-negative persons, suggesting these changes are not specific to HIV.

immunology↗

bioRxiv2020

Areas of global importance for terrestrial biodiversity, carbon, and water

Summary paragraphTo meet the ambitious objectives of biodiversity and climate conventions, countries and the international community require clarity on how these objectives can be operationalized spatially, and multiple targets be pursued concurrently1. To support governments and political conventions, spatial guidance is needed to identify which areas should be managed for conservation to generate the greatest synergies between biodiversity and natures contribution to people (NCP). Here we present results from a joint optimization that maximizes improvements in species conservation status, carbon retention and water provisioning and rank terrestrial conservation priorities globally. We found that, selecting the top-ranked 30% (respectively 50%) of areas would conserve 62.4% (86.8%) of the estimated total carbon stock and 67.8% (90.7%) of all clean water provisioning, in addition to improving the conservation status for 69.7% (83.8%) of all species considered. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to improve the conservation status of 86.3% of plant and vertebrate species on Earth. Our results provide a global baseline on where land could be managed for conservation. We discuss how such a spatial prioritisation framework can support the implementation of the biodiversity and climate conventions.

ecology↗