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Biology subjects

Kuehnel, M. P.

Publications and source records attributed to Kuehnel, M. P..

4 recordsLinked to original sources

The use of cultured human alveolar basal cells to mimic honeycomb formation in idiopathic pulmonary fibrosis

Honeycomb cysts (HC) within the alveolar region are distinct histopathological features in the lungs of idiopathic pulmonary fibrosis (IPF) patients. HC are lined with basal cells (BC), or with a bronchiolar-like epithelium composed of basal-, ciliated- and secretory epithelial cells. By using cultured IPF patient-derived alveolar BC, we aimed to establish in vitro- and in vivo models to mimic HC formation in IPF. In order to do so, we cultured the cells (1) on an air liquid interface (ALI) or (2) in a three dimensional (3D) organoid model in vitro, and (3) investigated the cells behavior after instillation into bleomycin-challenged mice in vivo. Under the here tested in vitro- and in vivo conditions, alveolar BC differentiate and formed HC-like structures, which closely resemble HC within the IPF lung. These models therefore represent powerful tools to study HC formation, and its potential therapeutic inhibition in IPF.

cell biology↗

Ex Vivo Validation of Six FDA-Approved Non-Receptor Tyrosine Kinase Inhibitors (NRTKIs) as Antivirals to Pandemic and Seasonal Influenza A Viruses

Influenza viruses are important respiratory pathogens that cause substantial morbidity and mortality annually. In addition to seasonal influenza outbreaks, new emerging influenza A viruses (IAV) can cause pandemic influenza outbreaks. Apart from effective vaccines, there is a need for better treatment options to combat infections with these viruses when vaccines are not available or show reduced efficacy (e.g., in immmunocompromised patients). The limited range of licensed antiviral drugs and emergence of drug-resistance mutations highlight the need for novel intervention strategies like host-targeted antivirals. Repurposing FDA-approved kinase inhibitors may offer a fast-track for a new generation of host-targeted antivirals. Small molecule kinase inhibitors (SMKIs) can inhibit replication of viruses and improve survival in vivo; however, no SMKI has been approved for clinical use against IAV infections. In the present study, we tested eight non-receptor tyrosine kinase-inhibitors (NRTKIs) used to treat cancer and autoimmune diseases for their antiviral potential. Six of those potently inhibited virus replication ([≥]1,000-fold) in A549 cells infected with either A(H1N1)pdm09 or seasonal A(H3N2) strains. These compounds were validated in a biologically relevant ex vivo model of human precision-cut lung slices (hPCLS) to provide proof of principle and show efficacy against contemporary seasonal and pandemic IAVs. We identified the steps of the virus infection cycle affected by these inhibitors and assessed the effect of these NRTKIs on the host response. Considering their established safety profiles, our studies show that the use of these NRTKI shows promise and warrants further development as an alternative strategy to treat influenza virus infections.

microbiology↗

3D virtual Histopathology of Cardiac Tissue from Covid-19 Patients based on Phase-Contrast X-ray Tomography

For the first time, we have used phase-contrast x-ray tomography to characterize the three-dimensional (3d) structure of cardiac tissue from patients who succumbed to Covid-19. By extending conventional histopatholocigal examination by a third dimension, the delicate pathological changes of the vascular system of severe Covid-19 progressions can be analyzed, fully quantified and compared to other types of viral myocarditis and controls. To this end, cardiac samples with a cross section of 3.5mm were scanned at the synchrotron in a parallel beam configuration. The vascular network was segmented by a deep learning architecture suitable for 3d datasets (V-net), trained by sparse manual annotations. Pathological alterations of vessels, concerning the variation of diameters and the amount of small holes, were observed, indicative of elevated occurrence of intussusceptive angiogenesis, also confirmed by scanning electron microscopy. Further, we implemented a fully automated analysis of the tissue structure in form of shape measures based on the structure tensor. The corresponding distributions show that the histopathology of Covid-19 differs from both influenza and typical coxsackie virus myocarditis.

pathology↗

In vitro culture of aberrant basal-like cells from fibrotic lung tissue

RationaleIn idiopathic pulmonary fibrosis (IPF) atypical epithelial cells are present in the alveolar compartment. Their origin and contribution to IPF pathogenesis is unknown. We recently cultured a distinct population of cells, which readily grew from fibrotic lung tissue, but only rarely from non-fibrotic tissue. Here we aimed to characterize these fibrosis-enriched cells and determine transcriptomic differences between cells derived from IPF and patients with other interstitial lung diseases (ILD). MethodsCells were cultured from peripheral lung tissue of ILD patients and analysed by bulk or single cell RNA sequencing (scRNA-seq), TaqMan-PCR, immunofluorescence (IF), immunoblotting or electron microscopy (EM). ResultsscRNA-seq demonstrated an overall homogeneity and epithelial origin of the cells. The majority of cells expressed basal cell markers (Cytokeratin (KRT) 5 and 17, TP63), of which a fraction co-expressed mesenchymal cell markers (VIM, FN1, CDH2), alveolar (SLC34A2, ABCA3, LPCAT1, EMP2, HOPX) and/or secretory epithelial cell markers (SCGB1A1, MUC4). Interestingly, most of the cells showed closest transcriptomic similarity to recently described aberrant basal-like cells. Cells derived from IPF versus other ILD patients revealed significant transcriptomic differences with an up-regulation of fibrosis-associated and a down-regulation of inflammatory pathways in IPF cells. ConclusionWe here confirm the presence of aberrant basal-like cells in fibrotic lung tissue and, importantly, are the first to describe their in vitro characteristics and a way of culturing these cells in vitro. Cultured basal-like cells co-express epithelial and mesenchymal markers, suggesting a partial epithelial to mesenchymal transition (EMT). A subset of cells co-express alveolar, ciliated or secretory epithelial cell markers, possibly indicating differentiation towards these cell linages. Furthermore, cultured basal-like cells display a disease-specific transcriptome, possibly induced by their specific microenvironment. Our findings will contribute to a better understanding of the cells origin and their potential contribution to IPF pathogenesis.

cell biology↗