Biology subjects

Wanner, N.

Publications and source records attributed to Wanner, N..

6 recordsLinked to original sources

bioRxiv2026

High-Dimensional Immunophenotyping Identifies Circulating Immune Signatures Associated with FeNO-Defined Asthma Phenotypes

Background: Asthma is a heterogeneous inflammatory airway disease traditionally classified into T2 high (eosinophilic) and T2 low inflammatory phenotypes. Fractional exhaled nitric oxide (FeNO) is commonly used as a biomarker of T2 inflammation, although nitric oxide also regulates monocyte maturation and T cell polarization. We hypothesized that FeNO identifies distinct systemic immune phenotypes in asthma. Methods: Peripheral immune cell subsets were characterized using OMIP - 69, a 40 - color high dimensional immunophenotyping panel encompassing innate and adaptive immune populations. Adults with asthma and healthy controls underwent peripheral blood immunophenotyping. FeNO was dichotomized at 25 ppb (FeNO - high [≥] 25 vs FeNO - low <25). Immune-cell subset proportions were summarized as medians (IQRs) and compared using the Wilcoxon rank-sum test. Logistic regression was used to evaluate associations between immune subsets and FeNO status. Results: Eighteen participants with asthma and seven healthy controls were enrolled. Asthmatic participants had higher BMI than healthy controls (median [IQR] asthma: 35.1 [28.9 - 37.7] vs healthy: 25.4 [22.6 - 26.7] kg/m2; p=0.003), although demographics were otherwise similar. Among asthmatics, 10 participants had FeNO - low asthma, and eight had FeNO - high asthma. FeNO - high asthma demonstrated increased classical monocytes (CD14++CD16 -) and compared with healthy controls (p=0.027), whereas FeNO - low asthma more closely resembled healthy controls. Intermediate monocytes (CD14++CD16+) were increased in FeNO - high versus FeNO - low (p= 0.08); a similar association was noted for classical monocytes (p = 0.13). In contrast, CCR7+ TCR; T - cells were significantly enriched in FeNO - low asthma (p=0.002). Logistic regression demonstrated positive associations between high - FeNO and classical monocytes (OR 16.06, 95% CI 1.56 - 1304.69; p=0.007) and intermediate monocytes (OR 4.19, 1.22 - 132.30; p=0.017), whereas CCR7+ {gamma} {delta} T - cells were negatively associated with high FeNO (OR 0.06, 0.00 - 0.47; p=0.001). Conclusions: Distinct systemic immune signatures identified by high-dimensional cytometry support the existence of biologically divergent FeNO - defined asthma endotypes and may inform future biomarker-driven approaches to patient stratification and precision therapy.

immunology↗

bioRxiv2025

Hypoxia responses in arginase 2 deficient mice enhance cardiovascular health

RATIONALEPhysiological responses to hypoxia involve adaptations in the hematopoietic and cardiovascular systems, which work together to ensure adequate oxygen delivery to tissues for energy production. The arginine/nitric oxide (NO) pathway regulates both systems through its effects on erythropoiesis and vasodilation. In Tibetan populations native to high-altitude hypoxia, increased NO production from arginine and decreased arginine metabolism by arginase contribute to these adaptive mechanisms. These metabolic changes enhance tissue oxygen delivery and reduce the risk of hypoxic pulmonary hypertension. Here, we hypothesize that genetic deletion of mitochondrial arginase 2 (Arg2) in mice will enhance cardiovascular effects and mitigate hypoxia-induced pulmonary hypertension. METHODSComplete blood counts, bone marrow erythroid differentiation, plasma arginine and NO (measured as nitrite), right ventricular systolic pressure (RVSP), heart rate, heart weight, and blood pressure were measured in wild-type (WT) and Arg2 knockout (Arg2KO) mice exposed to short-term (6, 12, 48, or 72 hours) or long-term (3 weeks) hypoxia. RESULTSUnder normoxic conditions, Arg2KO and WT mice exhibit similar RBC counts, hemoglobin levels, hematocrit, heart rate, systolic and diastolic blood pressures, and heart weight (all P > 0.05). WT mice increase erythropoiesis at 12 hours of hypoxia, including proerythroblasts (stage I, P = 0.004), polychromatic erythroblasts (stage III, P = 0.0004), and orthochromatic erythroblasts (stage IV, P = 0.03), but Arg2KO mice do not increase erythropoiesis. After 48 hours of hypoxia, Arg2KO mice increase proerythroblasts (stage I, P = 0.0008), but levels remain significantly lower than in WT mice. Plasma arginine and NO levels increase under hypoxia. NO levels peak at 12 hours of hypoxia in WT mice, then decline rapidly. In contrast, NO levels in Arg2KO mice are higher than in WT mice, with sustained elevations at 48 hours of hypoxia (P = 0.03). Arg2KO mice have significantly higher plasma arginine levels than WT at 6, 12, and 72 hours of hypoxia (all P < 0.05). Under chronic hypoxia, Arg2KO and WT mice show similar RBC counts, hemoglobin levels, hematocrit, and NO levels. Unlike WT, Arg2KO mice do not increase RVSP (P = 0.4) and have lower mean arterial (P = 0.03) and diastolic blood pressures (P = 0.01), as well as much lower heart rates (P < 0.0001). Additionally, small blood vessels increase in lungs of Arg2KO mice (CD31, P = 0.02; vWF, P = 0.6). CONCLUSIONSArginine metabolism in the mitochondria plays a key role in modulating adaptive responses to hypoxia. Deletion of Arg2 results in delayed erythropoiesis under acute hypoxia, but better cardiovascular health, as indicated by higher levels of nitrite and arginine, and lower RVSP, blood pressure, and heart rate with chronic hypoxia.

physiology↗

bioRxiv2021

Synuclein alpha accumulation mediates podocyte injury in Fabry nephropathy

Current therapies for Fabry disease are based on reversing intra-cellular accumulation of globotriaosylceramide (Gb3) by enzyme replacement therapy (ERT) or chaperone-mediated stabilization of the defective enzyme, thereby alleviating lysosome dysfunction. However, their effect in the reversal of endorgan damage, like kidney injury and chronic kidney disease remains unclear. First, ultrastructural analysis of serial human kidney biopsies showed that longterm use of ERT reduced Gb3 accumulation in podocytes but did not reverse podocyte injury. Then, a CRISPR/CAS9-mediated -Galactosidase knockout podocyte cell line confirmed ERT-mediated reversal of Gb3 accumulation without resolution of lysosomal dysfunction. Transcriptome-based connectivity mapping and SILAC-based quantitative proteomics identified alpha-synuclein (SNCA) accumulation as a key event mediating podocyte injury. Genetic and pharmacological inhibition of SNCA improved lysosomal structure and function in Fabry podocytes, exceeding the benefits of ERT. Together, this work reconceptualizes Fabry-associated cell injury beyond Gb3 accumulation, and introduces SNCA modulation as a potential intervention, especially for patients with Fabry nephropathy.

molecular biology↗

bioRxiv2021

The Mitochondrial Genome and Epigenome of the Golden Lion Tamarin from Fecal DNA using Nanopore Adaptive Sequencing

The golden lion tamarin (Leontopithecus rosalia) is an endangered Platyrrhine primate endemic to the Atlantic coastal forests of Brazil. Despite ongoing conservation efforts, genetic data on this species remains scarce. Complicating factors include limitations on sample collection and a lack of high-quality reference sequences. Here, we used nanopore adaptive sampling to resequence the L. rosalia mitogenome from feces, a sample which can be collected non-invasively. Adaptive sampling doubled the fraction of both host-derived and mitochondrial sequences compared to sequencing without enrichment. 258x coverage of the L. rosalia mitogenome was achieved in a single flow cell by targeting the unfinished genome of the distantly related emperor tamarin (Saguinus imperator) and the mitogenome of the closely related black lion tamarin (Leontopithecus chrysopygus). The L. rosalia mitogenome has a length of 16,597 bp, sharing 99.68% sequence identity with the L. chrysopygus mitogenome. A total of 38 SNPs between them were identified, with the majority being found in the non-coding D-loop region. DNA methylation and hydroxymethylation were directly detected using a neural network model applied to the raw signal from the MinION sequencer. In contrast to prior reports, DNA methylation was negligible in mitochondria in both CpG and non-CpG contexts. Surprisingly, a quarter of the 642 CpG sites exhibited DNA hydroxymethylation greater than 1% and 44 sites were above 5%, with concentration in the 3 side of several coding regions. Overall, we report a robust new mitogenome assembly for L. rosalia and direct detection of cytosine base modifications in all contexts.

genomics↗

bioRxiv2020

beta-blocker reverses inhibition of beta-2 adrenergic receptor resensitization by hypoxia

Ischemia/hypoxia is major underlying cause for heart failure and stroke. Although beta-adrenergic receptor ({beta}AR) is phosphorylated in response to hypoxia, less is known about the underlying mechanisms. Hypoxia results in robust GRK2-mediated {beta}2AR phosphorylation but does not cause receptor internalization. However, hypoxia leads to significant endosomal-{beta}2AR phosphorylation accompanied by inhibition of {beta}2AR-associated protein phosphatase 2A (PP2A) activity impairing resensitization. Phosphoinositide 3-kinase {gamma} (PI3K{gamma}) impedes resensitization by phosphorylating endogenous inhibitor of protein phosphatase 2A, I2PP2A that inhibits PP2A activity. Hypoxia increased PI3K{gamma} activity leading to significant phosphorylation of I2PP2A resulting in inhibition of PP2A and consequently resensitization. Surprisingly, {beta}-blocker abrogated hypoxia-mediated {beta}2AR phosphorylation instead of phosphorylation in normoxia. Subjecting mice to hypoxia leads to significant cardiac dysfunction and {beta}2AR phosphorylation showing conservation of non-canonical hypoxia-mediated pathway in vivo. These findings provide mechanistic insights on hypoxia-mediated {beta}AR dysfunction which is rescued by {beta}-blocker and will have significant implications in heart failure and stroke.

biochemistry↗

bioRxiv2020

Deep learning-based molecular morphometrics for kidney biopsies

Morphologic examination of tissue biopsies is essential for histopathological diagnosis. However, accurate and scalable cellular quantification in human samples remains challenging. Here, we present a deep learning-based approach for antigen-specific cellular morphometrics in human kidney biopsies, which combines indirect immunofluorescence imaging with U-Net-based architectures for image-to-image translation and dual segmentation tasks, achieving human-level accuracy. In the kidney, podocyte loss represents a hallmark of glomerular injury and can be estimated in diagnostic biopsies. Thus, we profiled over 27,000 podocytes from 110 human samples, including patients with anti-neutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN), an immune-mediated disease with aggressive glomerular damage and irreversible loss of kidney function. Previously unknown morphometric signatures of podocyte depletion were identified in patients with ANCA-GN, which allowed patient classification and showed potential for risk stratification in combination with routine clinical tools. Together, our approach enables robust and scalable molecular morphometric analysis of human tissues, yielding deeper biological insights into the human kidney pathophysiology. SummaryDeep learning enables robust and scalable molecular morphometric analysis of human tissues, yielding deeper biological insights into the human kidney pathophysiology.

pathology↗