Biology subjects

Haensel, M.

Publications and source records attributed to Haensel, M..

5 recordsLinked to original sources

bioRxiv2026

The hybrid yeast Saccharomyces pastorianus TUM 34/70 repurposes the pseudohyphal growth signaling network to establish a flocculation phenotype

Lager is the most produced beer style world-wide and makes use of the bottom-fermenting hybrid yeast Saccharomyces pastorianus (S. cerevisiae x S. eubayanus). Previous research showed that flocculation in S. pastorianus, in contrast to the top-fermenting ale yeast S. cerevisiae, is triggered by nitrogen starvation. However, the cellular events leading to flocculation in S. pastorianus are not well characterized. Therefore, we conducted a proteomic screen of S. pastorianus TUM 34/70 and identified the protein kinase Ste20p and protein phosphatase regulatory subunit Ypi1p as higher abundant during flocculation. Overexpression of these genes caused a consistent and strong increase in flocculation rate over the complete duration of beer fermentation. Characterization of Ste20p and Ypi1p via a phospho-proteomics screen showed their targeting of proteins whose S. cerevisiae orthologues are involved in pseudohyphal growth. However, in contrast to this, the overexpression of STE20 and YPI1 led instead to the establishment of a flocculation morphology, giving first-time evidence that S. pastorianus repurposes the pseudohyphal signaling network for this phenotype.

microbiology↗

bioRxiv2026

Organ on chip model of respiratory vascular interactions under COPD relevant oxidative stress

Oxidative stress-induced airway injury contributes to chronic obstructive pulmonary disease (COPD). Cardiovascular complications increase COPD morbidity and mortality, but mechanistic links between airway injury and vascular dysfunction remain unclear, largely due to limitations of in vitro models that fail to replicate the multicellular lung environment. We developed REVAS, a modular organ-on-chip platform to study human respiratory-vascular cell-cell interactions at baseline and under oxidative stress conditions. REVAS consists of two respiratory chips hosting airway epithelium and microvascular endothelium, and a vascular chip hosting pulmonary artery endothelial cells co-cultured with vascular support cells, including smooth muscle cells, pericytes and fibroblasts. We studied effects of vascular support and respiratory cells on vascular endothelial phenotype at baseline and under H2O2-induced epithelial oxidative stress using functional assays, proteomic and transcriptomic analyses. Multicellular environment enhanced vascular endothelial barrier function and promoted respiratory and vascular cell differentiation at baseline. Mural cells altered endothelial cell-matrix interactions, metabolism and cytoskeletal remodelling, while respiratory cells promoted endothelial aerobic respiration and quiescent phenotype. Epithelial oxidative stress triggered inflammatory gene expression across all respiratory and vascular cells alongside apoptotic, reparative and pro-angiogenic signalling in endothelial and mural cells, accompanied by increased release of COPD-relevant cytokines and chemokines, including IL-6, TNF-/{beta}, IL-8, CCL5, CXCL9, PDGF, TGF-{beta}. Comparative analyses with COPD endothelial datasets confirmed that REVAS recapitulates key features of disease-associated endothelial dysfunction. These findings demonstrate that airway epithelial injury drives downstream vascular responses linked to inflammation and vascular remodelling, establishing REVAS as a human-relevant platform for mechanistic and therapeutic evaluation of cell-cell interactions in COPD and related lung diseases. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=164 HEIGHT=200 SRC="FIGDIR/small/730087v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@e29fd8org.highwire.dtl.DTLVardef@6c3d22org.highwire.dtl.DTLVardef@21a53forg.highwire.dtl.DTLVardef@e7f432_HPS_FORMAT_FIGEXP M_FIG C_FIG REVAS: a microfluidic platform developed to model multicellular interactions between airway epithelium and pulmonary vasculature under basal and oxidative stress. COPD: Chronic Obstructive Pulmonary Disease; EMT: endothelial-to-mesenchymal transition; HsEpCs: human small airway epithelial cells; HPMVECs: human pulmonary microvascular endothelial cells; HPAECs: human pulmonary artery endothelial cells; HPASMCs: human pulmonary artery smooth mucle cells; HPFs: human pulmonary fibcroblasts; HPCs: human pericytes.

bioengineering↗

bioRxiv2025

A short cut to sample coverage standardization in meta-barcoding data provides new insights into land use effects on insect diversity

The use of metabarcoding for insect species identification has grown rapidly, but the absence of abundance data hinders meaningful diversity metrics like sample coverage-standardized species richness. Additionally, the vast number of taxa often lacks a unified phylogeny or trait database. We present a framework for constructing a phylogenetic tree encompassing the majority of insect families, standardisation of sample coverage (an objective measure of sample completeness) and assessment of both taxonomic and phylogenetic diversity using the Hill series for metabarcoding data. Applied to central Europe, our framework analysed insect diversity from 400 families along a land-use gradient. Results revealed land-use intensity significantly affects sample coverage, emphasizing the need for biodiversity standardization. After standardization, taxonomic diversity declined by 27-44%, and phylogenetic diversity by 13-29% across 39,000 Operational Taxonomic Units, from forests to agricultural areas. Rare species exhibited greater phylogenetic diversity loss than taxonomic, while dominant species showed smaller phylogenetic losses but stronger declines in taxonomic diversity. Our findings underscore agricultures detrimental effects on specific insect taxa, even after adjusting for sample coverage, and provide new insights into the loss of functional diversity, as represented by phylogeny.

ecology↗

bioRxiv2022

Landscape diversity and local temperature, but not climate, affect arthropod predation among habitat types

Arthropod predators are important for ecosystem functioning by providing top-down regulation of insect herbivores. As predator communities and activity are influenced by biotic and abiotic factors on different spatial scales, the strength of top-down regulation ( arthropod predation) is also likely to vary. Understanding the combined effects of potential drivers on arthropod predation is urgently needed with regard to anthropogenic climate and land-use change. In a large-scale study, we recorded arthropod predation rates using artificial caterpillars on 113 plots of open herbaceous vegetation embedded in contrasting habitat types (forest, grassland, arable field, settlement) along climate and land-use gradients in Bavaria, Germany. As potential drivers we included habitat characteristics (habitat type, plant species richness, local mean temperature and mean relative humidity during artificial caterpillar exposure), landscape diversity (0.5-3.0-km, six scales), climate (multi-annual mean temperature, MAT) and interactive effects of habitat type with other drivers. We observed no substantial differences in arthropod predation rates between the studied habitat types, related to plant species richness and across the Bavarian-wide climatic gradient, but predation was limited when local mean temperatures were low and tended to decrease towards higher relative humidity. Arthropod predation rates increased towards more diverse landscapes at a 2-km scale. Interactive effects of habitat type with local weather conditions, plant species richness, landscape diversity and MAT were not observed. We conclude that landscape diversity favours high arthropod predation rates in open herbaceous vegetation independent of the dominant habitat in the vicinity. This finding may be harnessed to improve top-down control of herbivores, e.g. agricultural pests, but further research is needed for more specific recommendations on landscape management. The absence of MAT effects suggests that high predation rates may occur independent of moderate increases of MAT in the near future.

ecology↗

bioRxiv2021

Disentangling effects of climate and land use on biodiversity and ecosystem services - a multi-scale experimental design

O_LIClimate and land-use change are key drivers of environmental degradation in the Anthropocene, but too little is known about their interactive effects on biodiversity and ecosystem services. Long-term data on biodiversity trends are currently lacking. Furthermore, previous ecological studies have rarely considered climate and land use in a joint design, did not achieve variable independence or lost statistical power by not covering the full range of environmental gradients. C_LIO_LIHere, we introduce a multi-scale space-for-time study design to disentangle effects of climate and land use on biodiversity and ecosystem services. The site selection approach coupled extensive GIS-based exploration and correlation heatmaps with a crossed and nested design covering regional, landscape and local scales. Its implementation in Bavaria (Germany) resulted in a set of study plots that maximizes the potential range and independence of environmental variables at different spatial scales. C_LIO_LIStratifying the state of Bavaria into five climate zones and three prevailing land-use types, i.e. near-natural, agriculture and urban, resulted in 60 study regions covering a mean annual temperature gradient of 5.6-9.8 {degrees}C and a spatial extent of 380x360 km. Within these regions, we nested 180 study plots located in contrasting local land-use types, i.e. forests, grasslands, arable land or settlement (local climate gradient 4.5-10 {degrees}C). This approach achieved low correlations between climate and land-use (proportional cover) at the regional and landscape scale with |r [≤]0.33| and |r [≤]0.29|, respectively. Furthermore, using correlation heatmaps for local plot selection reduced potentially confounding relationships between landscape composition and configuration for plots located in forests, arable land and settlements. C_LIO_LIThe suggested design expands upon previous research in covering a significant range of environmental gradients and including a diversity of dominant land-use types at different scales within different climatic contexts. It allows independent assessment of the relative contribution of multi-scale climate and land use on biodiversity and ecosystem services. Understanding potential interdependencies among global change drivers is essential to develop effective restoration and mitigation strategies against biodiversity decline, especially in expectation of future climatic changes. Importantly, this study also provides a baseline for long-term ecological monitoring programs. C_LI

ecology↗