Biology subjects

Karalis, K.

Publications and source records attributed to Karalis, K..

11 recordsLinked to original sources

bioRxiv2025

Revealing the impact of Pseudomonas aeruginosa quorum sensing molecule 2'-aminoacetophenone on human bronchial-airway epithelium and pulmonary endothelium using a human airway-on-a-chip

Pseudomonas aeruginosa (PA) causes severe respiratory infections utilizing multiple virulence functions. Our previous findings on PA quorum sensing (QS)-regulated small molecule, 2-aminoacetophenone (2-AA), secreted by the bacteria in infected tissues, revealed its effect on immune and metabolic functions favouring a long-term presence of PA in the host. However, studies on 2-AAs specific effects on bronchial-airway epithelium and pulmonary endothelium remain elusive. To evaluate 2AAs spatiotemporal changes in the human airway, considering endothelial cells as the first point of contact when the route of lung infection is hematogenic, we utilized the microfluidic airway-on-chip lined by polarized human bronchial-airway epithelium and pulmonary endothelium. Using this platform, we performed RNA-sequencing to analyse responses of 2-AA-treated primary human pulmonary microvascular endothelium (HPMEC) and adjacent primary normal human bronchial epithelial (NHBE) cells from healthy female donors and potential cross-talk between these cells. Analyses unveiled specific signaling and biosynthesis pathways to be differentially regulated by 2-AA in epithelial cells, including HIF-1 and pyrimidine signaling, glycosaminoglycan, and glycosphingolipid biosynthesis, while in endothelial cells were fatty acid metabolism, phosphatidylinositol and estrogen receptor signaling, and proinflammatory signaling pathways. Significant overlap in both cell types in response to 2-AA was found in genes implicated in immune response and cellular functions. In contrast, we found that genes related to barrier permeability, cholesterol metabolism, and oxidative phosphorylation were differentially regulated upon exposure to 2-AA in the cell types studied. Murine in-vivo and additional in vitro cell culture studies confirmed cholesterol accumulation in epithelial cells. Results also revealed specific biomarkers associated with cystic fibrosis and idiopathic pulmonary fibrosis to be modulated by 2-AA in both cell types, with the cystic fibrosis transmembrane regulator expression to be affected only in endothelial cells. The 2-AA-mediated effects on healthy epithelial and endothelial primary cells within a microphysiological dynamic environment mimicking the human lung airway enhance our understanding of this QS signaling molecule. This study provides novel insights into their functions and potential interactions, paving the way for innovative, cell-specific therapeutic strategies to combat PA lung infections.

molecular biology↗

bioRxiv2024

A Human Brain-Chip for modelling brain pathologies and screening of BBB crossing therapeutic strategies

The limited translatability of preclinical experimental findings to human patients remains an obstacle for successful treatment of brain diseases. Relevant models to elucidate mechanisms behind brain pathogenesis, such as human cell-based systems, and support successful targeting and prediction of drug responses in humans are in urgent need given the species differences in brain and blood-brain barrier (BBB) functions. Here, we examined and advanced a Brain-Chip which recapitulates aspects of the human cortical parenchyma and the BBB in one model. We utilized human primary astrocytes and pericytes, hiPSC-derived cortical neurons, hiPSC-derived brain microvascular endothelial-like cells, and included for the first time on chip hiPSC-derived microglia. Using TNF to emulate neuroinflammation, we demonstrate that our model recapitulates in vivo-relevant responses. Importantly, we show microglia-derived responses, highlighting the ability of the model to capture cell-specific contributions in human disease associated pathology. We next tested BBB crossing of human transferrin receptor antibodies and conjugated adeno-associated viruses, and demonstrate successful in vitro/in vivo correlation in identifying crossing differences. These findings highlight the potential of the Brain-Chip as a time-saving and reliable model to support therapeutic development for brain diseases.

bioengineering↗

bioRxiv2022

A Microengineered Brain-Chip to Model Neuroinflammation in Humans

Species differences in the brain and the blood-brain barrier (BBB) biology hamper the translation from animal models to humans and impede the development of specific therapeutics for brain diseases. Here we present a human Brain-Chip engineered to recapitulate critical aspects of the complex brain cell-cell interactions that mediate neuroinflammation development. Our human organotypic microphysiological system (MPS) includes endothelial-like cells, pericytes, glia, and cortical neurons and maintains BBB permeability at in vivo relevant levels, providing a significant improvement in complexity and clinical mimicry compared to previous MPS models. This is the first report of a Brain-Chip with an RNA expression profile close to that of the adult human cortex and that demonstrates advantages over Transwell culture. Through perfusion of TNF-, we recreated key inflammatory features, such as glia activation, the release of proinflammatory cytokines, and increased barrier permeability. Our model may provide a reliable tool for mechanistic studies in neuron-glial interactions and dysregulation of BBB function during neuroinflammation.

bioengineering↗

bioRxiv2021

Human immunocompetent Organs-on-Chips platforms allow safety profiling of tumor-targeted T-cell bispecific antibodies

AbstractTraditional drug safety assessment often fails to predict complications in humans, especially when the drug targets the immune system. Here, we show the unprecedented capability of two Organs-on-Chips to evaluate the safety profile of T-cell bispecific antibodies (TCBs) targeting tumor antigens. Although promising for cancer immunotherapy, TCBs are associated with an on-target, off-tumor risk due to low levels of expression of tumor antigens in healthy tissues. We leveraged in vivo target expression and toxicity data of TCBs targeting folate receptor 1 (FOLR1) or carcinoembryonic antigen (CEA) to design and validate human immunocompetent Organs-on-Chips safety platforms. We discovered that the Lung-Chip and Intestine-Chip could reproduce and predict target-dependent TCB safety liabilities, based on sensitivity to key determinants thereof, such as target expression and antibody affinity. These novel tools broaden the research options available for mechanistic understandings of engineered therapeutic antibodies and assessing safety in tissues susceptible to adverse events.

cancer biology↗

bioRxiv2020

A Micro-engineered Human Colon Intestine-Chip Platform to Study Leaky Barrier

The intestinal epithelial barrier supports the symbiotic relationship between the microbiota colonizing the intestinal epithelium and the host immune system to maintain homeostasis. Leaky barrier is increasingly recognized as part of the pathogenesis of a number of chronic conditions in addition to inflammatory and infectious diseases. As our understanding on the regulation of the barrier remains limited, effective therapeutic targeting for the compromised barrier is still an unmet need. Here we combined advancements on the organoids and Organ-on-Chip technologies to establish a micro-engineered Colon Intestine-Chip for studying development and regulation of the human intestinal barrier. Our data demonstrate the significance of the endothelium in co-culture with the epithelial cells within a tissue-relevant microenvironment for the establishment of a tight epithelial barrier of polarized cells. Pathway analysis of the RNA sequencing (RNA-Seq), revealed significant upregulation of mechanisms relevant to the maturation of the intestinal epithelium in organoid-derived epithelial cells in co-culture with endothelium as compared to organoids maintained in suspension. We provide evidence that the Colon Intestine-Chip platform responds to interferon gamma (IFN{gamma}), a prototype cytokine utilized to model inflammation-induced barrier disruption, by induction of apoptosis and reorganization of the apical junctional complexes as shown with other systems. We also describe the mechanism of action of interleukin 22 (IL-22) on mature, organoid-derived intestinal epithelial cells that is consistent with barrier disruption. Overall we propose the Colon Intestine-Chip as a promising human organoid-derived platform to decipher mechanisms driving the development of leaky gut in patients and enable their translation for this unmet medical need.

bioengineering↗

bioRxiv2020

Modeling Alpha-Synuclein Pathology in a Human Brain-Chip to Assess Blood-Brain Barrier Disruption in Parkinson's Disease

Parkinsons disease and related synucleinopathies are characterized by the abnormal accumulation of alpha-synuclein aggregates, loss of dopaminergic neurons, and gliosis in the substantia nigra. Although clinical evidence and in vitro studies indicate disruption of the Blood-Brain Barrier in Parkinsons disease, the mechanisms mediating the endothelial dysfunction remain elusive. Lack of relevant models able to recapitulate the order of events driving the development of the disease in humans has been a significant bottleneck in the identification of specific successful druggable targets. Here we leveraged the Organs-on-Chips technology to engineer a human Brain-Chip representative of the substantia nigra area of the brain containing dopaminergic neurons, astrocytes, microglia, pericytes, and microvascular brain endothelial cells, cultured under fluid flow. Our Syn fibril-induced model was capable of reproducing several key aspects of Parkinsons disease, including accumulation of phosphorylated Syn (pSer129-Syn), mitochondrial impairment, neuroinflammation, and compromised barrier function. This model is poised to enable research into the dynamics of cell-cell interactions in human synucleinopathies and to serve as testing platform for novel therapeutic interventions, including target identification and target validation.

bioengineering↗

bioRxiv2020

Modeling alcoholic liver disease in a human Liver-Chip

Fatty liver disease (FLD), is a major public health burden that affects up to 30% of people in Western countries and leads to progressive liver injury, comorbidities, and increased mortality. Key risk factors for developing FLD are obesity and alcohol consumption, both of which are growing in prevalence worldwide. There is an urgent need for human-relevant preclinical models to improve our understanding of FLD progression to steatohepatitis and for the development of sensitive noninvasive diagnostics and therapies. Alcohol-induced liver disease (ALD) represents an ideal case for modeling FDL as ethanol exposure is a comparatively simpler trigger for experimental induction of the pathology, as opposed to the complexity of modeling the diet- and life-style induced FLD. Further, despite their different root causes, the two pathologies share several common characteristics in disease progression and deterioration of liver function, highlighting the potential of an ALD microphysiological model for broad application in translational research. Here, we leverage our recently reported human Liver-Chip for toxicity applications, to expand the capabilities of the platform for broad application in translational research. We report the first in vitro modeling of ALD that uses human relevant blood alcohol concentrations (BAC) and affords multimodal profiling of clinically relevant endpoints. Our ALD Liver-Chip recapitulates established FLD markers in response to ethanol in a concentration-dependent manner, including lipid accumulation and oxidative stress. Importantly, we show that the ALD Liver-Chip supports the study of secondary insults common in patients with advanced ALD, such as high blood endotoxin levels due to alcohol-associated increased intestinal permeability and barrier dysfunction. Moreover, owing to new developments in the design, the ALD Liver-Chip enables the measurement of structural changes of the bile canaliculi (BC) network as a novel in vitro quantitative readout of alcoholic liver toxicity. In summary, we report the development of a human ALD Liver-Chip as a new platform for modeling the progression of alcohol-induced liver injury with direct translation to clinical research.

bioengineering↗

bioRxiv2020

A Micro-Engineered Airway Lung-Chip Models Key Features of Viral-Induced Exacerbation of Asthma

RationaleViral-induced exacerbation of asthma remain a major cause of hospitalization and mortality. New human relevant models of the airways are urgently needed to understand how respiratory infections may trigger asthma attacks, and to advance treatment development. ObjectivesTo develop a new human relevant model of rhinovirus-induced asthma exacerbation that recapitulates viral infection of asthmatic airway epithelium, neutrophil transepithelial migration, and enables evaluation of immunomodulatory therapy. MethodsA micro-engineered model of fully differentiated human mucociliary airway epithelium was stimulated with IL-13 to induce a Th2-type asthmatic phenotype and infected with live human rhinovirus 16 (HRV16) to reproduce key features of viral-induced asthma exacerbation. Measurements and Main ResultsInfection with HRV16 replicated key hallmarks of the cytopathology and inflammatory responses observed in human airways. Generation of a Th2 microenvironment through exogenous IL-13 stimulation induced features of asthmatics airways, including goblet cell hyperplasia, reduction of cilia beating frequency, and endothelial activation, but did not alter rhinovirus infectivity or replication. High resolution kinetic analysis of secreted inflammatory markers revealed that IL-13 treatment altered the IL-6, IFN-{lambda}1, and CXCL10 secretion in response to HRV16. Neutrophil transepithelial migration was greatest when viral infection was combined with IL-13 treatment, while treatment with MK-7123, a CXCR2 antagonist, reduced neutrophil diapedesis in all conditions. ConclusionsThis micro-engineered Airway Lung-Chip provides a novel human-relevant platform for exploring the complex mechanisms underlying viral-induced asthma exacerbation. Our data suggest that IL-13 may impair the hosts ability to mount an appropriate and coordinated immune response to rhinovirus infection. We also show that the Airway Lung-Chip can be used to assess the efficacy of modulators of the immune response. NoteEmulate(R), Human Emulation System(R), S-1, ER-1, and ER-2 are trademarks of Emulate, Inc., and any other trademarks used herein remain with their respective holders. The technology disclosed in this document may be covered by one or more patents or patent applications, and no license to these is granted herein. You are solely responsible for determining whether you have all intellectual property rights that are necessary for your intended use of any of the disclosed materials, and whether you are required to obtain any additional intellectual property rights from a third party. Further information is available by contacting the authors. At a Glance CommentaryO_ST_ABSScientific Knowledge on the SubjectC_ST_ABSNew therapies for asthma exacerbations remain a significant unmet medical need. Development of human relevant preclinical models are needed to further elucidate the complex mechanisms underlying asthma exacerbation and investigate new therapeutic strategies. What This Study Adds to the FieldUsing a human Airway Lung-Chip model, we show here for the first time a live human rhinovirus (HRV) infection of the asthmatic epithelium that recapitulates complex features of viral-induced asthma exacerbation. The dynamic microenvironment of the chip enables the real-time study of virus infection, epithelial response, and immune cell recruitment under healthy and asthmatic conditions. The model reproduces key endpoints that have been observed in asthmatics and individuals infected with rhinovirus including the ciliated cell sloughing, altered cilia beating frequency, goblet cell hyperplasia, increased expression of adhesion molecules in microvascular endothelial cells, and inflammatory mediator release. High-resolution temporal analysis of secreted inflammatory markers enabled by dynamic sampling revealed alteration of IL-6, IFN-{lambda}1 and CXCL10 secretory phases after rhinovirus infection in an IL-13 high environment. Leveraging high-content imaging and analysis of circulating inflammatory cells, we demonstrated the efficacy of a CXCR2 antagonist to reduce adhesion, motility, and transmigration of perfused human neutrophils. Thus, this micro-engineered chip may offer a powerful addition to preclinical models for understanding mechanisms underlying asthma exacerbation pathology and developing new therapeutic strategies.

bioengineering↗

bioRxiv2020

A lung-on-chip infection model reveals protective and permissive roles of alveolar epithelial cells in tuberculosis

Mycobacterium tuberculosis (Mtb) makes first contact with a host in the alveolar space, an interaction largely inaccessible to experimental observation. We establish a lung-on-chip model for early tuberculosis and use time-lapse imaging to reveal the dynamics of host-Mtb interactions at an air-liquid interface with a spatiotemporal resolution unattainable in animal models. By reconstituting host physiology in a modular manner, we probe the role of pulmonary surfactant secreted by alveolar epithelial cells (AECs) in early infection. This is difficult to study directly in animal models, as surfactant-deficient animals are either non-viable or develop acute lung pathologies. We demonstrate that surfactant deficiency results in rapid and uncontrolled Mtb growth in both macrophages and AECs. In contrast, under normal surfactant levels, a significant fraction of intracellular bacteria are non-growing. The surfactant-deficient phenotype is rescued by exogenous addition of surfactant replacement formulations, which have no effect on bacterial viability in the absence of host cells. Surfactant partially removes virulence-associated lipids and proteins 1,2 from the bacterial cell surface and consistent with this mechanism of action, we show that attenuation of bacteria lacking the virulence-associated ESX-1 secretion system is independent of surfactant levels. These findings may partly explain why individuals with compromised surfactant function, such as smokers and elderly persons, are at increased risk of developing active tuberculosis.

microbiology↗

bioRxiv2019

Organoid-derived Duodenum Intestine-Chip for preclinical drug assessment in a human relevant system

Induction of intestinal drug metabolizing enzymes can complicate the development of new drugs, owing to potential to cause drug-drug interactions (DDIs) leading to changes in pharmacokinetics, safety and efficacy. The development of a human relevant model of the adult intestine that accurately predicts CYP450 induction could help address this challenge as species differences preclude extrapolation from animals. Here, we combined organoids and Organ-Chip technology to create a human Duodenum Intestine-Chip that emulates intestinal tissue architecture and functions, that are relevant for the study of drug transport, metabolism, and DDI. Duodenum Intestine-Chip demonstrates the polarized cell architecture, intestinal barrier function, presence of specialized cell subpopulations, and in vivo-relevant expression, localization, and function of major intestinal drug transporters. Notably, in comparison to Caco-2, it displays improved CYP3A4 expression and induction capability. This model could enable improved in vitro to in vivo extrapolation for better predictions of human pharmacokinetics and risk of DDIs.

cell biology↗

bioRxiv2019

Liver-Chip: Reproducing Human and Cross-Species Toxicities

Nonclinical rodent and non-rodent toxicity models used to support clinical trials of candidate drugs may produce discordant results or fail to predict complications in humans contributing to drug failures in the clinic. Here we applied microengineered Organ-on-Chip (Organ-Chip) technology to design rat, dog, and human Liver-Chips containing species-specific primary hepatocytes interfaced with liver sinusoidal endothelial cells, with or without Kupffer cells and hepatic stellate cells, cultured under physiological fluid flow. The Liver-Chips detected diverse phenotypes of liver toxicity including hepatocellular injury, steatosis, cholestasis, and fibrosis as well as species-specific toxicities when treated with tool compounds. Multi-species Liver-Chips may provide a useful platform for prediction of liver toxicity and inform human relevance of liver toxicities detected in animal studies to better determine safety and human risk.\n\nOne Sentence SummaryMicroengineered Organ-Chip technology has been used to design rat, dog and human Liver-Chips that recapitulate species-specific liver toxicities.

pharmacology and toxicology↗