Biology subjects

Beermann, M. L.

Publications and source records attributed to Beermann, M. L..

6 recordsLinked to original sources

bioRxiv2024

The role of GPR87 in Pulmonary Fibrosis

RationaleG- protein coupled receptor 87 (GPR87), an alternative lysophosphatidic acid (LPA) receptor previously implicated in cancer, is highly expressed in basal and aberrant basaloid cells in idiopathic pulmonary fibrosis (IPF). We sought to determine whether signaling through GPR87 is important to the development of pulmonary fibrosis. MethodsReanalysis of bulk and single cell RNA sequencing dataset was performed to confirm the increased expression of GPR87 in pulmonary fibrosis. The role of GPR87 in fibrosis in-vivo was assessed using global GPR87 knockout (GPR87-/-) and wildtype mice in the bleomycin model of pulmonary fibrosis, in-vitro in induced pluripotent stem cells (iPSCs) derived airway basal cells (iBC) using GPR87 siRNAs, and ex-vivo in human precision cut slices using disease free tissues in the fibrotic cocktail model as well as IPF tissues treated with GPR87 siRNA. ResultsGPR87 is highly expressed in IPF lungs, and its expression correlates with disease severity. Furthermore, It is highly expressed in basal and aberrant basaloid cells. GPR87-/- mice are protected against bleomycin induced pulmonary fibrosis. GPR87 knockdown is protective against fibrosis development in normal PCLS treated with fibrotic cocktail and leads to fibrosis regression in IPF PCLS. In iBC, GPR87 knockdown leads to decreased expression of fibrosis related genes, proteins and microRNAs. GPR87 stimulation with LPA leads to the opposite results. The main downstream pathways are PI3K, mTOR, and TNF/NFkB; stimulation or inhibition of PI3K pathway mimics GPR87 stimulation or inhibition responses, respectively. ConclusionGPR87 is highly expressed in basal and aberrant basaloid cells in IPF lungs and seems to mediate profibrotic effects based on in-vivo, ex-vivo and in-vitro models of disease, suggesting that it should be studied as a potential epithelial specific therapeutic target in pulmonary fibrosis.

cell biology↗

bioRxiv2021

Human airway lineages derived from pluripotent stem cells reveal the epithelial responses to SARS-CoV-2 infection

There is an urgent need to understand how SARS-CoV-2 infects the airway epithelium and in a subset of individuals leads to severe illness or death. Induced pluripotent stem cells (iPSCs) provide a near limitless supply of human cells that can be differentiated into cell types of interest, including airway epithelium, for disease modeling. We present a human iPSC-derived airway epithelial platform, composed of the major airway epithelial cell types, that is permissive to SARS-CoV-2 infection. Subsets of iPSC-airway cells express the SARS-CoV-2 entry factors ACE2 and TMPRSS2. Multiciliated cells are the primary initial target of SARS-CoV-2 infection. Upon infection with SARS-CoV-2, iPSC-airway cells generate robust interferon and inflammatory responses and treatment with remdesivir or camostat methylate causes a decrease in viral propagation and entry, respectively. In conclusion, iPSC-derived airway cells provide a physiologically relevant in vitro model system to interrogate the pathogenesis of, and develop treatment strategies for, COVID-19 pneumonia. Highlights and eTOC blurbO_LISubsets of human iPSC-airway epithelial cells express SARS-Co-V entry factors ACE2 and TMPRSS2. C_LIO_LIiPSC-airway cells are permissive to SARS-CoV-2 infection via multiciliated cells. C_LIO_LISARS-CoV-2 infection of iPSC-airway leads to a robust interferon and inflammatory response. C_LIO_LIiPSC-airway is a physiologically relevant model to study SARS-CoV-2 infection. C_LI

cell biology↗

bioRxiv2021

A multimodal iPSC platform for cystic fibrosis drug testing

Cystic fibrosis (CF) is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane regulator (CFTR) anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of the CFTR channel using established animal and cell-based models led to the recent discovery of effective CFTR modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies. In this study, we assembled a panel of iPSCs derived from individuals with common or rare variants representative of three distinct classes of CFTR dysfunction. To measure CFTR function in patient-specific iPSCs we adapted two established in vitro assays of CFTR function to iPSC-derived airway cells. In both a 3-D spheroid assay using forskolin-induced swelling as well as planar cultures composed of polarized mucociliary airway epithelial cells, we quantified CFTR baseline function and response to CFTR modulators and detected genotype-specific differences. Our results demonstrate the potential of the human iPSC platform as a research tool to study cystic fibrosis and in particular accelerate therapeutic development for CF caused by rare mutations.

developmental biology↗

bioRxiv2020

SARS-CoV-2 Infection of Pluripotent Stem Cell-derived Human Lung Alveolar Type 2 Cells Elicits a Rapid Epithelial-Intrinsic Inflammatory Response

The most severe and fatal infections with SARS-CoV-2 result in the acute respiratory distress syndrome, a clinical phenotype of coronavirus disease 2019 (COVID-19) that is associated with virions targeting the epithelium of the distal lung, particularly the facultative progenitors of this tissue, alveolar epithelial type 2 cells (AT2s). Little is known about the initial responses of human lung alveoli to SARS-CoV-2 infection due in part to inability to access these cells from patients, particularly at early stages of disease. Here we present an in vitro human model that simulates the initial apical infection of the distal lung epithelium with SARS-CoV-2, using AT2s that have been adapted to air-liquid interface culture after their derivation from induced pluripotent stem cells (iAT2s). We find that SARS-CoV-2 induces a rapid global transcriptomic change in infected iAT2s characterized by a shift to an inflammatory phenotype predominated by the secretion of cytokines encoded by NF-kB target genes, delayed epithelial interferon responses, and rapid loss of the mature lung alveolar epithelial program. Over time, infected iAT2s exhibit cellular toxicity that can result in the death of these key alveolar facultative progenitors, as is observed in vivo in COVID-19 lung autopsies. Importantly, drug testing using iAT2s confirmed an antiviral dose-response to remdesivir and demonstrated the efficacy of TMPRSS2 protease inhibition, validating a putative mechanism used for viral entry in human alveolar cells. Our model system reveals the cell-intrinsic responses of a key lung target cell to infection, providing a physiologically relevant platform for further drug development and facilitating a deeper understanding of COVID-19 pathogenesis.

molecular biology↗

bioRxiv2020

Human iPSC-derived alveolar and airway epithelial cells can be cultured at air-liquid interface and express SARS-CoV-2 host factors

Development of an anti-SARS-CoV-2 therapeutic is hindered by the lack of physiologically relevant model systems that can recapitulate host-viral interactions in human cell types, specifically the epithelium of the lung. Here, we compare induced pluripotent stem cell (iPSC)-derived alveolar and airway epithelial cells to primary lung epithelial cell controls, focusing on expression levels of genes relevant for COVID-19 disease modeling. iPSC-derived alveolar epithelial type II-like cells (iAT2s) and iPSC-derived airway epithelial lineages express key transcripts associated with lung identity in the majority of cells produced in culture. They express ACE2 and TMPRSS2, transcripts encoding essential host factors required for SARS-CoV-2 infection, in a minor subset of each cell sub-lineage, similar to frequencies observed in primary cells. In order to prepare human culture systems that are amenable to modeling viral infection of both the proximal and distal lung epithelium, we adapt iPSC-derived alveolar and airway epithelial cells to two-dimensional air-liquid interface cultures. These engineered human lung cell systems represent sharable, physiologically relevant platforms for SARS-CoV-2 infection modeling and may therefore expedite the development of an effective pharmacologic intervention for COVID-19.

molecular biology↗

bioRxiv2020

Derivation of Airway Basal Stem Cells from Human Pluripotent Stem Cells

The derivation of self-renewing tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would shorten the time needed to engineer mature cell types in vitro and would have broad reaching implications for the field of regenerative medicine. Here we report the directed differentiation of human iPSCs into putative airway basal cells ("iBCs"), a population resembling the epithelial stem cell of lung airways. Using a dual fluorescent reporter system (NKX2-1GFP;TP63tdTomato) we track and purify these cells over time, as they first emerge from iPSC-derived foregut endoderm as developmentally immature NKX2-1GFP+ lung progenitors which then augment a TP63 program during subsequent proximal airway epithelial patterning. These cells clonally proliferate, initially as NKX2-1GFP+/TP63tdTomato+ immature airway progenitors that lack expression of the adult basal cell surface marker NGFR. However, in response to primary basal cell medium, NKX2-1GFP+/ TP63tdTomato+ cells upregulate NGFR and display the molecular and functional phenotype of airway basal stem cells, including the capacity to clonally self-renew or undergo multilineage ciliated and secretory epithelial differentiation in air-liquid interface cultures. iBCs and their differentiated progeny recapitulate several fundamental physiologic features of normal primary airway epithelial cells and model perturbations that characterize acquired and genetic airway diseases. In an asthma model of mucus metaplasia, the inflammatory cytokine IL-13 induced an increase in MUC5AC+ cells similar to primary cells. CFTR-dependent chloride flux in airway epithelium generated from cystic fibrosis iBCs or their syngeneic CFTR-corrected controls exhibited a pattern consistent with the flux measured in primary diseased and normal human airway epithelium, respectively. Finally, multiciliated cells generated from an individual with primary ciliary dyskinesia recapitulated the ciliary beat and ultrastructural defects observed in the donor. Thus, we demonstrate the successful de novo generation of a tissue-resident stem cell-like population in vitro from iPSCs, an approach which should facilitate disease modeling and future regenerative therapies for a variety of diseases affecting the lung airways.

developmental biology↗