scholarly journals An in vitro model for the cultivation of polymicrobial biofilms under continuous-flow conditions

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 801
Author(s):  
Thomas James O'Brien ◽  
Marwa Mohsen Hassan ◽  
Freya Harrison ◽  
Martin Welch
Keyword(s):  
Continuous Flow ◽  
In Vitro Model ◽  
Fungal Species ◽  
Airway Infection ◽  
Vitro Model ◽  
Major Alteration ◽  
Planktonic Community

The airways of people with cystic fibrosis (CF) are often chronically colonised with a diverse array of bacterial and fungal species. However, little is known about the relative partitioning of species between the planktonic and biofilm modes of growth in the airways. Existing in vivo and in vitro models of CF airway infection are ill-suited for the long-term recapitulation of mixed microbial communities. Here we describe a simple, in vitro continuous-flow model for the cultivation of polymicrobial biofilms and planktonic cultures on different substrata. Our data provide evidence for inter-species antagonism and synergism in biofilm ecology. We further show that the type of substratum on which the biofilms grow has a profound influence on their species composition. This happens without any major alteration in the composition of the surrounding steady-state planktonic community. Our experimentally-tractable model enables the systematic study of planktonic and biofilm communities under conditions that are nutritionally reminiscent of the CF airway microenvironment, something not possible using any existing in vivo models of CF airway infection.

Schlafen 11 is a novel target for mucosal regeneration in Ulcerative Colitis

2021 ◽  
Author(s):  
Sho Watanabe ◽  
Ryu Nishimura ◽  
Tomoaki Shirasaki ◽  
Nobuhiro Katsukura ◽  
Shuji Hibiya ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Microarray Analysis ◽  
In Vitro Model ◽  
Mucosal Injury ◽  
Mucosal Regeneration ◽  
Vitro Model ◽  
Novel Target

Abstract Background and Aims Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with an intractable course. Although the goal of UC therapy is to achieve mucosal healing, the pathogenesis of mucosal injury caused by chronic inflammation remains unknown. We therefore aim to elucidate molecular mechanisms of mucosal injury by establishing in vitro and in vivo humanized UC mimicking models. Methods An in vitro model using human colon organoids was established by 60 weeks of inflammatory stimulation. The key gene for mucosal injury caused by long-term inflammation was identified by microarray analysis. An in vivo model was established by xenotransplantation of organoids into mouse colonic mucosa. Results An in vitro model demonstrated that long-term inflammation induced irrecoverable changes in organoids: inflammatory response and apoptosis with oxidative stress and suppression of cell viability. This model also mimicked organoids derived from patients with UC at the gene expression and phenotype levels. Microarray analysis revealed Schlafen11 (SLFN11) was irreversibly induced by long-term inflammation. Consistently, SLFN11 was highly expressed in UC mucosa but absent in normal mucosa. The knockdown of SLFN11 (SLFN11-KD) suppressed apoptosis of IECs induced by inflammation. Moreover, SLFN11-KD improved the take rates of xenotransplantation and induced regenerative changes of crypts observed in patients with UC in remission. Conclusions In vitro and in vivo UC mimicking models were uniquely established using human colonic organoids. They revealed SLFN11 is significant for mucosal injury in UC, and its potential as a novel target for mucosal regeneration.

scholarly journals Generation of a Novel In Vitro Model to Study Endothelial Dysfunction from Atherothrombotic Specimens

2021 ◽  
Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
In Vitro Model ◽  
Umbilical Vein ◽  
Coronary Syndrome ◽  
Coronary Endothelial Cells ◽  
Vitro Model ◽  
Umbilical Vein Endothelial Cells

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.

scholarly journals 3D Environment Is Required In Vitro to Demonstrate Altered Bone Metabolism Characteristic for Type 2 Diabetics

2021 ◽  
Vol 22 (6) ◽  
pp. 2925
Author(s):  
Victor Häussling ◽  
Romina H Aspera-Werz ◽  
Helen Rinderknecht ◽  
Fabian Springer ◽  
Christian Arnscheidt ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
In Vitro Model ◽  
Bone Diseases ◽  
3D Environment ◽  
Type 2 Diabetics ◽  
Mineralized Matrix ◽  
Vitro Model

A large British study, with almost 3000 patients, identified diabetes as main risk factor for delayed and nonunion fracture healing, the treatment of which causes large costs for the health system. In the past years, much progress has been made to treat common complications in diabetics. However, there is still a lack of advanced strategies to treat diabetic bone diseases. To develop such therapeutic strategies, mechanisms leading to massive bone alterations in diabetics have to be well understood. We herein describe an in vitro model displaying bone metabolism frequently observed in diabetics. The model is based on osteoblastic SaOS-2 cells, which in direct coculture, stimulate THP-1 cells to form osteoclasts. While in conventional 2D cocultures formation of mineralized matrix is decreased under pre-/diabetic conditions, formation of mineralized matrix is increased in 3D cocultures. Furthermore, we demonstrate a matrix stability of the 3D carrier that is decreased under pre-/diabetic conditions, resembling the in vivo situation in type 2 diabetics. In summary, our results show that a 3D environment is required in this in vitro model to mimic alterations in bone metabolism characteristic for pre-/diabetes. The ability to measure both osteoblast and osteoclast function, and their effect on mineralization and stability of the 3D carrier offers the possibility to use this model also for other purposes, e.g., drug screenings.

scholarly journals Exposure of ichnovirus particles to digitonin leads to enhanced infectivity and induces fusion from without in an in vitro model system

2007 ◽  
Vol 88 (11) ◽  
pp. 2977-2984 ◽  
Author(s):  
Don Stoltz ◽  
Renée Lapointe ◽  
Andrea Makkay ◽  
Michel Cusson
Keyword(s):  
Outer Membrane ◽  
In Vitro Model ◽  
Model System ◽  
Host Cells ◽  
Fusion Event ◽  
Susceptible Host ◽  
In Vitro Model System ◽  
Vitro Model

Unlike most viruses, the mature ichnovirus particle possesses two unit membrane envelopes. Following loss of the outer membrane in vivo, nucleocapsids are believed to gain entry into the cytosol via a membrane fusion event involving the inner membrane and the plasma membrane of susceptible host cells; accordingly, experimentally induced damage to the outer membrane might be expected to increase infectivity. Here, in an attempt to develop an in vitro model system for studying ichnovirus infection, we show that digitonin-induced disruption of the virion outer membrane not only increases infectivity, but also uncovers an activity not previously associated with any polydnavirus: fusion from without.

Uptake and Retention of Hematoporphyrin Derivative in an in Vivo/in Vitro Model of Cerebral Glioma

Neurosurgery ◽  
1985 ◽  
Vol 17 (6) ◽  
pp. 883-890 ◽  
Author(s):  
Andrew H. Kaye ◽  
George Morstyn ◽  
Robert G. Ashcroft
Keyword(s):  
In Vitro Model ◽  
Hematoporphyrin Derivative ◽  
Cerebral Glioma ◽  
Vitro Model
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