Antifibrotic Drug Nintedanib Inhibits CSF1R to Promote IL-4-associated Tissue Repair Macrophages.

Profibrotic and prohomeostatic macrophage phenotypes remain ill-defined, both in vivo and in vitro, impeding the successful development of drugs that reprogram macrophages as an attractive therapeutic approach to manage fibrotic disease. The goal of this study was to reveal profibrotic and prohomeostatic macrophage phenotypes that could guide the design of new therapeutic approaches targeting macrophages to treat fibrotic disease. This study used nintedanib, a broad kinase inhibitor approved for idiopathic pulmonary fibrosis, to dissect lung macrophage phenotypes during fibrosis-linked inflammation by combining in vivo and in vitro bulk and single-cell RNA-sequencing approaches. In the bleomycin model, nintedanib drove the expression of IL-4/IL-13-associated genes important for tissue regeneration and repair at early and late time points in lung macrophages. These findings were replicated in vitro in mouse primary bone marrow-derived macrophages exposed to IL-4/IL-13 and nintedanib. In addition, nintedanib promoted the expression of IL-4/IL-13 pathway genes in human macrophages in vitro. The molecular mechanism was connected to inhibition of the colony stimulating factor 1 (CSF1) receptor in both human and mouse macrophages. Moreover, nintedanib counterbalanced the effects of TNF on IL-4/IL-13 in macrophages to promote expression of IL-4/IL-13-regulated tissue repair genes in fibrotic contexts in vivo and in vitro. This study demonstrates that one of nintedanib's antifibrotic mechanisms is to increase IL-4 signaling in macrophages through inhibition of the CSF1 receptor, resulting in the promotion of tissue repair phenotypes.

Cigarette Smoke Specifically Affects Small Airway Epithelial Cell Populations and Triggers the Expansion of Inflammatory and Squamous Differentiation Associated Basal Cells.

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD) and causes remodeling of the small airways. However, the exact smoke-induced effects on the different types of small airway epithelial cells (SAECs) are poorly understood. Here, using air-liquid interface (ALI) cultures, single-cell RNA-sequencing reveals previously unrecognized transcriptional heterogeneity within the small airway epithelium and cell type-specific effects upon acute and chronic cigarette smoke exposure. Smoke triggers detoxification and inflammatory responses and aberrantly activates and alters basal cell differentiation. This results in an increase of inflammatory basal-to-secretory cell intermediates and, particularly after chronic smoke exposure, a massive expansion of a rare inflammatory and squamous metaplasia associated KRT6A+ basal cell state and an altered secretory cell landscape. ALI cultures originating from healthy non-smokers and COPD smokers show similar responses to cigarette smoke exposure, although an increased pro-inflammatory profile is conserved in the latter. Taken together, the in vitro models provide high-resolution insights into the smoke-induced remodeling of the small airways resembling the pathological processes in COPD airways. The data may also help to better understand other lung diseases including COVID-19, as the data reflect the smoke-dependent variable induction of SARS-CoV-2 entry factors across SAEC populations.

Riboswitch-mediated Attenuation of Transgene Cytotoxicity Increases Adeno-associated Virus Vector Yields in HEK-293 Cells.

Cytotoxicity of transgenes carried by adeno-associated virus (AAV) vectors might be desired, for instance, in oncolytic virotherapy or occur unexpectedly in exploratory research when studying sparsely characterized genes. To date, most AAV-based studies use constitutively active promoters (e.g., the CMV promoter) to drive transgene expression, which often hampers efficient AAV production due to cytotoxic, antiproliferative, or unknown transgene effects interfering with producer cell performance. Therefore, we explored artificial riboswitches as novel tools to control transgene expression during AAV production in mammalian cells. Our results demonstrate that the guanine-responsive GuaM8HDV aptazyme efficiently attenuates transgene expression and associated detrimental effects, thereby boosting AAV vector yields up to 23-fold after a single addition of guanine. Importantly, riboswitch-harboring vectors preserved their ability to express functional transgene at high levels in the absence of ligand, as demonstrated in a mouse model of AAV-TGFß1-induced pulmonary fibrosis. Thus, our study provides the first application-ready biotechnological system-based on aptazymes, which should enable high viral vector yields largely independent of the transgene used. Moreover, the RNA-intrinsic, small-molecule regulatable mode of action of riboswitches provides key advantages over conventional transcription factor-based regulatory systems. Therefore, such riboswitch vectors might be ultimately applied to temporally control therapeutic transgene expression in vivo.

Modeling Pulmonary Disease Pathways Using Recombinant Adeno-Associated Virus 6.2.

Viral vectors have been applied successfully to generate disease-related animal models and to functionally characterize target genes in vivo. However, broader application is still limited by complex vector production, biosafety requirements, and vector-mediated immunogenic responses, possibly interfering with disease-relevant pathways. Here, we describe adeno-associated virus (AAV) variant 6.2 as an ideal vector for lung delivery in mice, overcoming most of the aforementioned limitations. In a proof-of-concept study using AAV6.2 vectors expressing IL-13 and transforming growth factor-ß1 (TGF-ß1), we were able to induce hallmarks of severe asthma and pulmonary fibrosis, respectively. Phenotypic characterization and deep sequencing analysis of the AAV-IL-13 asthma model revealed a characteristic disease signature. Furthermore, suitability of the model for compound testing was also demonstrated by pharmacological intervention studies using an anti-IL-13 antibody and dexamethasone. Similarly, the AAV-TGF-ß1 fibrosis model showed several disease-like pathophenotypes monitored by micro-computed tomography imaging and lung function measurement. Most importantly, analyses using stuffer control vectors demonstrated that in contrast to a common adenovirus-5 vector, AAV6.2 vectors did not induce any measurable inflammation and therefore carry a lower risk of altering relevant readouts. In conclusion, we propose AAV6.2 as an ideal vector system for the functional characterization of target genes in the context of pulmonary diseases in mice.

Monocyte-derived alveolar macrophages are key drivers of smoke-induced lung inflammation and tissue remodeling.

Smoking is a leading risk factor of chronic obstructive pulmonary disease (COPD), that is characterized by chronic lung inflammation, tissue remodeling and emphysema. Although inflammation is critical to COPD pathogenesis, the cellular and molecular basis underlying smoking-induced lung inflammation and pathology remains unclear. Using murine smoke models and single-cell RNA-sequencing, we show that smoking establishes a self-amplifying inflammatory loop characterized by an influx of molecularly heterogeneous neutrophil subsets and excessive recruitment of monocyte-derived alveolar macrophages (MoAM). In contrast to tissue-resident AM, MoAM are absent in homeostasis and characterized by a pro-inflammatory gene signature. Moreover, MoAM represent 46% of AM in emphysematous mice and express markers causally linked to emphysema. We also demonstrate the presence of pro-inflammatory and tissue remodeling associated MoAM orthologs in humans that are significantly increased in emphysematous COPD patients. Inhibition of the IRAK4 kinase depletes a rare inflammatory neutrophil subset, diminishes MoAM recruitment, and alleviates inflammation in the lung of cigarette smoke-exposed mice. This study extends our understanding of the molecular signaling circuits and cellular dynamics in smoking-induced lung inflammation and pathology, highlights the functional consequence of monocyte and neutrophil recruitment, identifies MoAM as key drivers of the inflammatory process, and supports their contribution to pathological tissue remodeling.

Application of human iPSC-derived macrophages in a miniaturized high-content-imaging-based efferocytosis assay.

Macrophages play a pivotal role in drug discovery due to their key regulatory functions in health and disease. Overcoming the limited availability and donor variability of human monocyte-derived macrophages (MDMs), human induced pluripotent stem cell (iPSC)-derived macrophages (IDMs) could provide a promising tool for both disease modeling and drug discovery. To access large numbers of model cells for medium- to high-throughput application purposes, an upscaled protocol was established for differentiation of iPSCs into progenitor cells and subsequent maturation into functional macrophages. These IDM cells resembled MDMs both with respect to surface marker expression and phago- as well as efferocytotic function. A statistically robust high-content-imaging assay was developed to quantify the efferocytosis rate of IDMs and MDMs allowing for measurements both in the 384- and 1536-well microplate format. Validating the applicability of the assay, inhibitors of spleen tyrosine kinase (Syk) were shown to modulate efferocytosis in IDMs and MDMs with comparable pharmacology. The miniaturized cellular assay with the upscaled provision of macrophages opens new routes to pharmaceutical drug discovery in the context of efferocytosis-modulating substances.

Induced Syk deletion leads to suppressed allergic responses but has no effect on neutrophil or monocyte migration in vivo.

The spleen tyrosine kinase (Syk) is a key mediator of immunoreceptor signaling in immune cells. Thus, interfering with the function of Syk by genetic deletion or pharmacological inhibition might influence a variety of allergic and autoimmune processes. Since conventional Syk knockout mice are not viable, studies addressing the effect of Syk deletion in adult animals have been limited. To further explore functions of Syk in animal models of allergy and to shed light on the role of Syk in the in vivo migration of neutrophils and monocytes, we generated inducible Syk knockout mice. These mice harbor a floxed Syk gene and a tamoxifen-inducible Cre recombinase under the control of the ubiquitously active Rosa26-promoter. Thus, treatment of mice with tamoxifen leads to the deletion of Syk in all organs. Syk-deleted mice were analyzed in mast cell-dependent models and in models focusing on neutrophil and monocyte migration. We show that Syk deletion in adult mice reduces inflammatory responses in mast cell-driven animal models of allergy and asthma but has no effect on the migration of neutrophils and monocytes. Therefore, the inducible Syk knockout mice presented here provide a valuable tool to further explore the role of Syk in disease-related animal models.

Time and phenotype-dependent transcriptome analysis in AAV-TGFß1 and Bleomycin-induced lung fibrosis models.

We have previously established a novel mouse model of lung fibrosis based on Adeno-associated virus (AAV)-mediated pulmonary overexpression of TGFß1. Here, we provide an in-depth characterization of phenotypic and transcriptomic changes (mRNA and miRNA) in a head-to-head comparison with Bleomycin-induced lung injury over a 4-week disease course. The analyses delineate the temporal state of model-specific and commonly altered pathways, thereby providing detailed insights into the processes underlying disease development. They further guide appropriate model selection as well as interventional study design. Overall, Bleomycin-induced fibrosis resembles a biphasic process of acute inflammation and subsequent transition into fibrosis (with partial resolution), whereas the TGFß1-driven model is characterized by pronounced and persistent fibrosis with concomitant inflammation and an equally complex disease phenotype as observed upon Bleomycin instillation. Finally, based on an integrative approach combining lung function data, mRNA/miRNA profiles, their correlation and miRNA target predictions, we identify putative drug targets and miRNAs to be explored as therapeutic candidates for fibrotic diseases. Taken together, we provide a comprehensive analysis and rich data resource based on RNA-sequencing, along with a strategy for transcriptome-phenotype coupling. The results will be of value for TGFß research, drug discovery and biomarker identification in progressive fibrosing interstitial lung diseases.

Functional and biochemical rationales for the 24-hour-long duration of action of olodaterol.

ß(2)-Adrenoceptor (ß(2)-AR) agonists are powerful bronchodilators and play a pivotal role in the management of pulmonary obstructive diseases, such as asthma and chronic obstructive pulmonary disease. Although these agents first were used many years ago, progress in drug development has resulted in better tolerated, long-acting ß(2)-AR agonists (LABAs), such as formoterol and salmeterol. Although LABAs have been on the market for several years, relatively little is known on the rationale(s) behind their long duration of action. In this study, we focused on olodaterol (previously known as BI1744CL), a novel inhaled LABA, which provides a bronchodilating effect lasting 24 h and is currently in Phase III clinical trials. To understand the rationale behind its long duration of action, different aspects of olodaterol were analyzed (i.e., its lipophilicity and propensity to accumulate in the lipid bilayer as well as its tight binding to the ß(2)-AR). In line with its physicochemical properties, olodaterol associated moderately with lipid bilayers. Instead, kinetic as well as equilibrium binding studies indicated the presence of a stable [(3)H]olodaterol/ß(2)-AR complex with a dissociation half-life of 17.8 h due to ternary complex formation. The tight binding of olodaterol to the human ß(2)-AR and stabilization of the ternary complex were confirmed in functional experiments monitoring adenylyl cyclase activity after extensive washout. Taken together, binding, kinetic, and functional data support the existence of a stable complex with the ß(2)-AR that, with a dissociation half-life >17 h, might indeed be a rationale for the 24-h duration of action of olodaterol.

TLR agonist mediated suppression of allergic responses is associated with increased innate inflammation in the airways.

Toll-like receptor (TLR) mediated signaling induces pro-inflammatory responses and can both suppress and exacerbate allergic responses in the airways. The aim of our study was to directly compare the efficacy of different TLR agonists in inhibiting or exacerbating the development of Th2-mediated responses in the airways and investigate if the suppressive effects were associated with increased pro-inflammatory responses. Mice were immunized on day 0, 14 and 21 by intraperitoneal injection of ovalbumin/alum and exposed to ovalbumin aerosol on day 26 and 27. TLR2, TLR3, TLR4, TLR7 and TLR9 agonists (0.001, 0.01, 0.1, or 1 mg/kg) were administered intratracheally 1 h before each allergen exposure. Both the TLR7 and TLR9 agonists dose dependently reduced airway eosinophilia, while the TLR3 agonist only reduced airway eosinophilia at a dose of 1.0 mg/kg. The TLR2 and TLR4 agonists potentiated eosinophilia. All TLR agonists enhanced neutrophil numbers at doses as low as 0.01 mg/kg, in particular TLR2 and TLR4 agonists. TLR7 and TLR9 agonists also significantly reduced IL-4 and IL-5 levels and all TLR agonists, with the exception of TLR7, enhanced the amount IL-1ß, IL-6, and TNF-α detected in the whole lung lavage. Only application of TLR9 agonist induced detectable levels of IL-10 in the lung. Suppressive effects of the TLR agonists were not dependent upon IFN-γ and IL-10 or associated with increased numbers of Foxp3(+)CD4(+) Tr cells in the lavage fluid. Airway resistance was reduced significantly only when TLR7 agonist was administered. When applied therapeutically 2 days after allergen exposure, all TLR agonists, except TLR2, similarly reduced airway eosinophilia and IL-4 levels. Taken together our results show that TLR7 agonists had the strongest anti-asthmatic effects with the lowest pro-inflammatory potential, suggesting that activating TLR7 may have the greatest potential to treat allergic disorders in humans.

Functional human iPSC-derived alveolar-like cells cultured in a miniaturized 96­Transwell air-liquid interface model.

In order to circumvent the limited access and donor variability of human primary alveolar cells, directed differentiation of human pluripotent stem cells (hiPSCs) into alveolar-like cells, provides a promising tool for respiratory disease modeling and drug discovery assays. In this work, a unique, miniaturized 96-Transwell microplate system is described where hiPSC-derived alveolar-like cells were cultured at an air-liquid interface (ALI). To this end, hiPSCs were differentiated into lung epithelial progenitor cells (LPCs) and subsequently matured into a functional alveolar type 2 (AT2)-like epithelium with monolayer-like morphology. AT2-like cells cultured at the physiological ALI conditions displayed characteristics of AT2 cells with classical alveolar surfactant protein expressions and lamellar-body like structures. The integrity of the epithelial barriers between the AT2-like cells was confirmed by applying a custom-made device for 96-parallelized transepithelial electric resistance (TEER) measurements. In order to generate an IPF disease-like phenotype in vitro, the functional AT2-like cells were stimulated with cytokines and growth factors present in the alveolar tissue of IPF patients. The cytokines stimulated the secretion of pro-fibrotic biomarker proteins both on the mRNA (messenger ribonucleic acid) and protein level. Thus, the hiPSC-derived and cellular model system enables the recapitulation of certain IPF hallmarks, while paving the route towards a miniaturized medium throughput approach of pharmaceutical drug discovery.

IL36 is a critical upstream amplifier of neutrophilic lung inflammation in mice.

IL-36, which belongs to the IL-1 superfamily, is increasingly linked to neutrophilic inflammation. Here, we combined in vivo and in vitro approaches using primary mouse and human cells, as well as, acute and chronic mouse models of lung inflammation to provide mechanistic insight into the intercellular signaling pathways and mechanisms through which IL-36 promotes lung inflammation. IL-36 receptor deficient mice exposed to cigarette smoke or cigarette smoke and H1N1 influenza virus had attenuated lung inflammation compared with wild-type controls. We identified neutrophils as a source of IL-36 and show that IL-36 is a key upstream amplifier of lung inflammation by promoting activation of neutrophils, macrophages and fibroblasts through cooperation with GM-CSF and the viral mimic poly(I:C). Our data implicate IL-36, independent of other IL-1 family members, as a key upstream amplifier of neutrophilic lung inflammation, providing a rationale for targeting IL-36 to improve treatment of a variety of neutrophilic lung diseases.

The constitutive activity of the human muscarinic M3 receptor unmasks differences in the pharmacology of anticholinergics.

An activator protein 1-driven luciferase reporter assay was developed to monitor the activation of the human muscarinic M3 receptor (hM3-R) and evaluate functional potencies of different anticholinergics in Chinese hamster ovary cells. This assay proved to be superior to previously used functional assays [i.e., inositol phosphate accumulation (J Pharmacol Exp Ther 330:660-668, 2009)], thanks to the longer incubation times that allow reaching of pseudoequilibrium for ligands with slower dissociation kinetics, the long-acting muscarinic antagonists. Interestingly, within this system the hM3-R efficiently signaled in an agonist-independent manner. All the antagonists tested were able to inhibit the hM3-R constitutive activity in a concentration-dependent fashion, behaving as full inverse agonists. Curiously, significant differences in potency as antagonists (against carbachol) and inverse agonists were seen for some compounds (N-methyl scopolamine and tiotropium). Given the potential for inverse agonists to cause receptor up-regulation, the effect of chronic exposure to anticholinergics on the expression levels of hM3-R was also tested. Again, significant differences were seen, with some ligands (e.g., tiotropium) producing less than half of the receptor up-regulation caused by other anticholinergics. This study shows that anticholinergics can exhibit differential behaviors, which depend on the pathway investigated, and therefore provides evidence that the molecular mechanism of inverse agonism is likely to be more complex than the stabilization of a single inactive receptor conformation. In addition, differences in the potential of anticholinergics to induce hM3-R up-regulation might have clinical relevance, because many are on the market or in clinical trials as chronic treatment for chronic obstructive pulmonary disease, for example.

Development of a miniaturized 96-Transwell air-liquid interface human small airway epithelial model.

In order to overcome the challenges associated with a limited number of airway epithelial cells that can be obtained from clinical sampling and their restrained capacity to divide ex vivo, miniaturization of respiratory drug discovery assays is of pivotal importance. Thus, a 96-well microplate system was developed where primary human small airway epithelial (hSAE) cells were cultured at an air-liquid interface (ALI). After four weeks of ALI culture, a pseudostratified epithelium containing basal, club, goblet and ciliated cells was produced. The 96-well ALI cultures displayed a cellular composition, ciliary beating frequency, and intercellular tight junctions similar to 24-well conditions. A novel custom-made device for 96-parallelized transepithelial electric resistance (TEER) measurements, together with dextran permeability measurements, confirmed that the 96-well culture developed a tight barrier function during ALI differentiation. 96-well hSAE cultures were responsive to transforming growth factor ß1 (TGF-ß1) and tumor necrosis factor α (TNF-α) in a concentration dependent manner. Thus, the miniaturized cellular model system enables the recapitulation of a physiologically responsive, differentiated small airway epithelium, and a robotic integration provides a medium throughput approach towards pharmaceutical drug discovery, for instance, in respect of fibrotic distal airway/lung diseases.

Linagliptin and telmisartan induced effects on renal and urinary exosomal miRNA expression in rats with 5/6 nephrectomy.

Dipeptidyl peptidase 4 inhibitors and angiotensin II receptor blockers attenuate chronic kidney disease progression in experimental diabetic and non-diabetic nephropathy in a blood pressure and glucose independent manner, but the exact molecular mechanisms remain unclear. MicroRNAs (miRNAs) are short, non-coding RNA species that are important post-transcriptional regulators of gene expression and play an important role in the pathogenesis of nephropathy. miRNAs are present in urine in a remarkably stable form, packaged in extracellular vesicles. Here, we investigated linagliptin and telmisartan induced effects on renal and urinary exosomal miRNA expression in 5/6 nephrectomized rats. In the present study, renal miRNA profiling was conducted using the Nanostring nCounter technology and mRNA profiling using RNA sequencing from the following groups of rats: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus telmisartan; and 5/6 nephrectomy plus linagliptin. TaqMan Array miRNA Cards were used to evaluate which of the deregulated miRNAs in the kidney are present in urinary exosomes. In kidneys from 5/6 nephrectomized rats, the expression of 13 miRNAs was significantly increased (>1.5-fold, P < 0.05), whereas the expression of 7 miRNAs was significantly decreased (>1.5-fold, P < 0.05). Most of the deregulated miRNA species are implicated in endothelial-to-mesenchymal transition and inflammatory processes. Both telmisartan and linagliptin suppressed the induction of pro-fibrotic miRNAs, such as miR-199a-3p, and restored levels of anti-fibrotic miR-29c. In conclusion, the linagliptin and telmisartan-induced restorative effects on miR-29c expression were reflected in urinary exosomes, suggesting that miRNA profiling of urinary exosomes might be used as a biomarker for CKD progression and monitoring of treatment effects.

Fecal MicroRNAs Show Promise as Noninvasive Crohn's Disease Biomarkers.

BACKGROUND: Short non-coding microRNAs (miRNAs) are involved in various cellular processes during disease progression of Crohn's disease (CD) and remarkably stable in feces, which make them attractive biomarker candidates for reflecting intestinal inflammatory processes. Here we investigated the potential of fecal miRNAs as noninvasive and translational CD biomarkers. METHODS: MiRNAs were screened in feces of 52 patients with CD and 15 healthy controls using RNA sequencing and the results were confirmed by PCR. The relationship between fecal miRNA levels and the clinical CD activity index (CDAI) or CD endoscopic index of severity (CDEIS) was explored, respectively. Additionally, fecal miRNAs were investigated in dextran sodium sulfate, adoptive T-cell transfer, and Helicobacter typhlonius/stress-induced murine colitis models using the NanoString platform. RESULTS: Nine miRNAs (miR-15a-5p, miR-16-5p, miR-128-3p, miR-142-5p, miR-24-3p, miR-27a-3p, miR-223-3p, miR-223-5p, and miR-3074-5p) were significantly (adj. P < 0.05, >3-fold) increased whereas 8 miRNAs (miR-10a-5p, miR-10b-5p, miR-141-3p, miR-192-5p, miR-200a-3p, miR-375, miR-378a-3p, and let-7g-5p) were significantly decreased in CD. MiR-192-5p, miR-375, and miR-141-3p correlated (P < 0.05) with both CDAI and CDEIS whereas miR-15a-5p correlated only with CDEIS. Deregulated expression of miR-223-3p, miR-16-5p, miR-15a-5p, miR-24-3p, and miR-200a-3p was also observed in murine models. The identified altered fecal miRNA levels reflect pathophysiological mechanisms in CD, such as Th1 and Th17 inflammation, autophagy, and fibrotic processes. CONCLUSIONS: Our translational study assessed global fecal miRNA changes of patients with CD and relevant preclinical models. These fecal miRNAs show promise as translational and clinically useful noninvasive biomarkers for mechanistic investigation of intestinal pathophysiology, including monitoring of disease progression.

Erratum to Template for the description of cell-based toxicological test methods to allow evaluation and regulatory use of the data.

In this manuscript, which appeared in ALTEX (2019), 36(4), 682- 699, doi:10.14573/altex.1909271 , the affiliation of Hennicke Kamp should be Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany. Further, the reference to an article by Bal-Price et al. (2015) should have the following doi:10.1007/s00204-015-1464-2 .

Preclinical evaluation of long-acting muscarinic antagonists: comparison of tiotropium and investigational drugs.

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation caused by persistent inflammatory processes in the airways. An increased cholinergic tone mediates different pathophysiological features of COPD, such as bronchoconstriction and mucus hypersecretion, mostly through activation of the human muscarinic M(3) receptor (hM(3)) subtype. Tiotropium bromide (Spiriva) is a well established muscarinic antagonist in the pharmacological management of COPD with a once-daily posology. The rationale behind the sustained bronchodilation obtained with tiotropium consists in its slow dissociation from hM(3) receptors. In this study, we performed a comprehensive preclinical comparison of tiotropium with other long-acting muscarinic antagonists (LAMAs) currently in clinical development, namely aclidinium bromide and glycopyrrolate. The different muscarinic antagonists were characterized for their 1) affinity toward the different human muscarinic receptor subtypes expressed in Chinese hamster ovary cells and kinetics of receptor dissociation, 2) potency in inhibiting the agonist-induced activation of muscarinic receptors through measurement of second messengers, and 3) efficacy and duration of bronchoprotection, as tested in a model of acetylcholine-induced bronchoconstriction in anesthetized dogs over a period of 24 h. All of the tested LAMAs showed high affinity and potency toward the hM(3) receptor (tiotropium, pA(2) = 10.4; aclidinium, pA(2) = 9.6; and glycopyrrolate, pA(2) = 9.7). However, dissociation half-lives of the LAMAs from the hM(3) receptor differed significantly (tiotropium, t((1/2)) = 27 h; aclidinium, t((1/2)) = 10.7 h; and glycopyrrolate, t((1/2)) = 6.1 h). In line with their kinetic properties at the hM(3), the tested LAMAs provided different levels of bronchoprotection in the in vivo setting 24 h after administration (tiotropium = 35%, aclidinium = 21%, and glycopyrrolate = 0% at 24 h) when applied at equieffective doses.

Differentiation of hiPS Cells into Definitive Endoderm for High-Throughput Screening.

In drug discovery, there is an increasing demand for more physiological in vitro models that recapitulate the disease situation in patients. Human induced pluripotent stem (hiPS) cell-derived model cells could serve this purpose. To date, several directed differentiation approaches have been described to generate definitive endoderm (DE) from hiPS cells, but protocols suitable for drug development and high-throughput screening (HTS) have not been reported yet. In this work, a large-scale expansion of hiPS cells for high-throughput adaption is presented and an optimized stepwise differentiation of hiPS cells into DE cells is described. The produced DE cells were demonstrated to express classical DE markers on the gene expression and protein level. The here described DE cells are multipotent progenitors and act as starting points for a broad spectrum of endodermal model cells in HTS and other areas of drug discovery.

DMSO cryopreservation is the method of choice to preserve cells for droplet-based single-cell RNA sequencing.

Combining single-cell RNA sequencing (scRNA-seq) with upstream cell preservation procedures such as cryopreservation or methanol fixation has recently become more common. By separating cell handling and preparation, from downstream library generation, scRNA-seq workflows are more flexible and manageable. However, the inherent transcriptomic changes associated with cell preservation and how they may bias further downstream analysis remain unknown. Here, we present a side-by-side droplet-based scRNA-seq analysis, comparing the gold standard - fresh cells - to three different cell preservation workflows: dimethyl sulfoxide based cryopreservation, methanol fixation and CellCover reagent. Cryopreservation proved to be the most robust protocol, maximizing both cell integrity and low background ambient RNA. Importantly, gene expression profiles from fresh cells correlated most with those of cryopreserved cells. Such similarities were consistently observed across the tested cell lines (R ≥ 0.97), monocyte-derived macrophages (R = 0.97) and immune cells (R = 0.99). In contrast, both methanol fixation and CellCover preservation showed an increased ambient RNA background and an overall lower gene expression correlation to fresh cells. Thus, our results demonstrate the superiority of cryopreservation over other cell preservation methods. We expect our comparative study to provide single-cell omics researchers invaluable support when integrating cell preservation into their scRNA-seq studies.