Biology subjects

Davis, V.

Publications and source records attributed to Davis, V..

3 recordsLinked to original sources

bioRxiv2026

Molecular Imaging of the TGF-β Activating Integrin αvβ6 Detects Chronic Lung Allograft Dysfunction

TGF-{beta}-activating integrins promote solid-organ fibrosis, suggesting their use as a molecular marker of disease. Chronic lung allograft dysfunction (CLAD), a progressive fibrotic complication that limits lung transplant survival, is driven by intragraft TGF-{beta} activation. However, the expression patterns of TGF-{beta}-activating integrins remain undefined in lung transplants. Single-cell RNA sequencing in a mouse CLAD model revealed high levels of the TGF-{beta}-activating integrin v{beta}6, which was mainly localized to fibrosis-associated Krt8+ transitional alveolar cells (AT1/2), while tolerant transplants lacked both v{beta}6 expression and Krt8+AT1/2 cells. Molecular imaging with a newly developed positron emission tomography radiotracer specific for v{beta}6, [64Cu]Cu-DOTA-A20-K16R, showed significantly higher uptake in CLAD versus tolerant transplants. In contrast, [64Cu]Cu-DOTA-A20-K16R allograft uptake was reduced by treatments that lowered v{beta}6 expression and CLAD severity. Finally, [64Cu]Cu-DOTA-A20-K16R autoradiographic analysis on human explanted lungs with CLAD showed elevated activity that correlated with v{beta}6 expression. Collectively, these findings demonstrate the potential utility of v{beta}6 molecular imaging to detect CLAD pathogenesis.

immunology↗

bioRxiv2025

Atg16l1 promotes lung transplant tolerance by regulating glycolysis in macrophages

Lung transplant survival is limited by the development of chronic lung allograft dysfunction (CLAD), a type of graft rejection that lacks effective treatments. Autophagy plays a crucial role in maintaining cellular homeostasis. In a single-nucleotide polymorphism screen, we found that lung recipients with two copies of a common hypofunctional genetic variant of autophagy-related 16-like 1 rs2241880 (ATG16L1T300A/T300A), known to deplete this protein from macrophages, were more likely to develop early CLAD. To understand this, we used a mouse orthotopic lung transplant model. Recipients encoding myeloid cell-specific deletion of Atg16l1 (Atg16l1{Delta}/{Delta}) or who harbor an engineered orthologous mutation (Atg16l1T316A/T316A) showed similar susceptibility to CLAD. Transcript profiling and mitochondrial tracking studies indicated that increased mitochondrial damage and decreased autophagic removal of mitochondria in Atg16l1-deficient macrophages were associated with heightened activation of the hypoxia-inducible factor 1 (Hif1) pathway and accumulation of glycolytic transcripts. Metabolic analysis revealed reduced oxidative phosphorylation, increased glycolytic activity, and higher IL-1{beta} expression in Atg16l1-deficient macrophages. Notably, the development of CLAD in Atg16l1{Delta}/{Delta} lung recipients could be significantly prevented by additionally deleting Hif1 in myeloid cells or by treating with the glycolysis inhibitor 2-deoxyglucose. Our results show how a common autophagy-related genetic variant disrupts macrophage metabolism and impairs lung transplant tolerance, pointing toward potential therapeutic strategies to combat CLAD.

immunology↗

bioRxiv2024

A spontaneous mutation in ADIPOR1 causes retinal degeneration in mice

Adiponectin receptor 1 (ADIPOR1) is a transmembrane protein necessary for normal anatomy and physiology in the retina. In a recent study of complement factor H knockout mice (Cfh-/-), our lab discovered a flecked retina phenotype and retinal thinning by fundus imaging and optical coherence tomography (OCT), respectively. The phenotype was observed in a subset (50%) of Cfh-/- mice. The thinning observed in vivo is due to an early degeneration of rod photoreceptors. This phenotype has not been reported in published studies of Cfh-/- mice. AdipoR1 knockout mice (AdipoR1-/-) and mice deficient in Membrane Frizzled Related Protein (MFRP) exhibit this phenotype, suggesting an involvement in the emergence of the retinal degeneration observed in a subset of Cfh-/- mice. Cfh and AdipoR1 are located in close proximity on mouse Chromosome 1 (Chr1) and a complementation cross between Cfh and AdipoR1 mice with retinal degeneration produced 100% progeny with retinal degeneration. Sequencing of the Cfh-/- mice revealed a c.841 C > T mutation in AdipoR1. Furthermore, one Cfh wildtype (of Cfh+/+) and 2 heterozygous (of Cfh+/-) mice exhibited retinal degeneration and were homozygous for the point mutation. The c.841 C > T mutation results in a proline to serine conversion at position 281 (P281S) in ADIPOR1. This residue is critical for ADIPOR1 open and closed conformations in the membrane. In silico modeling of candidate ADIPOR1 ligands, 11-cis-retinaldehyde and docosahexaenoic acid (DHA), that are deficient in AdipoR1-/-, suggests that ADIPOR1 is involved in trafficking retinoids and fatty acids and their combined deficiency in the ADIPOR1 mutant retinas might explain the retinal degeneration phenotype.

neuroscience↗