scholarly journals Degeneration of Aortic Valves in a Bioreactor System with Pulsatile Flow

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 462
Author(s):  
Naima Niazy ◽  
Mareike Barth ◽  
Jessica I. Selig ◽  
Sabine Feichtner ◽  
Babak Shakiba ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aortic Valve ◽  
Pulsatile Flow ◽  
Ex Vivo ◽  
Bioreactor Cultivation ◽  
Ex Vivo Model ◽  
Pulsatile Pressure ◽  
Static Cultivation ◽  
Bioreactor System ◽  
The Impact

Calcific aortic valve disease is the most common valvular heart disease in industrialized countries. Pulsatile pressure, sheer and bending stress promote initiation and progression of aortic valve degeneration. The aim of this work is to establish an ex vivo model to study the therein involved processes. Ovine aortic roots bearing aortic valve leaflets were cultivated in an elaborated bioreactor system with pulsatile flow, physiological temperature, and controlled pressure and pH values. Standard and pro-degenerative treatment were studied regarding the impact on morphology, calcification, and gene expression. In particular, differentiation, matrix remodeling, and degeneration were also compared to a static cultivation model. Bioreactor cultivation led to shrinking and thickening of the valve leaflets compared to native leaflets while gross morphology and the presence of valvular interstitial cells were preserved. Degenerative conditions induced considerable leaflet calcification. In comparison to static cultivation, collagen gene expression was stable under bioreactor cultivation, whereas expression of hypoxia-related markers was increased. Osteopontin gene expression was differentially altered compared to protein expression, indicating an enhanced protein turnover. The present ex vivo model is an adequate and effective system to analyze aortic valve degeneration under controlled physiological conditions without the need of additional growth factors.

Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates on Knee Osteoarthritic Chondrocytes and Cartilage in vitro

2019 ◽  
Vol 20 (11) ◽  
pp. 920-933 ◽  
Author(s):  
Lucía Gato-Calvo ◽  
Tamara Hermida-Gómez ◽  
Cristina R. Romero ◽  
Elena F. Burguera ◽  
Francisco J. Blanco
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Cartilage Explants ◽  
Ex Vivo Model ◽  
Chondrocyte Viability ◽  
Platelet Concentration ◽  
The Absolute ◽  
Anti Inflammatory

Background: Platelet Rich Plasma (PRP) has recently emerged as a potential treatment for osteoarthritis (OA), but composition heterogeneity hampers comparison among studies, with the result that definite conclusions on its efficacy have not been reached. Objective: 1) To develop a novel methodology to prepare a series of standardized PRP releasates (PRP-Rs) with known absolute platelet concentrations, and 2) To evaluate the influence of this standardization parameter on the anti-inflammatory properties of these PRP-Rs in an in vitro and an ex vivo model of OA. Methods: A series of PRPs was prepared using the absolute platelet concentration as the standardization parameter. Doses of platelets ranged from 0% (platelet poor plasma, PPP) to 1.5·105 platelets/µl. PRPs were then activated with CaCl2 to obtain releasates (PRP-R). Chondrocytes were stimulated with 10% of each PRP-R in serum-free culture medium for 72 h to assess proliferation and viability. Cells were co-stimulated with interleukin (IL)-1β (5 ng/ml) and 10% of each PRP-R for 48 h to determine the effects on gene expression, secretion and intra-cellular content of common markers associated with inflammation, catabolism and oxidative stress in OA. OA cartilage explants were co-stimulated with IL-1β (5 ng/ml) and 10% of either PRP-R with 0.75·105 platelets/µl or PRP-R with 1.5·105 platelets/µl for 21 days to assess matrix inflammatory degradation. Results: Chondrocyte viability was not affected, and proliferation was dose-dependently increased. The gene expression of all pro-inflammatory mediators was significantly and dose-independently reduced, except for that of IL-1β and IL-8. Immunoblotting corroborated this effect for inducible NO synthase (NOS2). Secreted matrix metalloproteinase-13 (MMP-13) was reduced to almost basal levels by the PRP-R from PPP. Increasing platelet dosage led to progressive loss to this anti-catabolic ability. Safranin O and toluidine blue stains supported the beneficial effect of low platelet dosage on cartilage matrix preservation. Conclusion: We have developed a methodology to prepare PRP releasates using the absolute platelet concentration as the standardization parameter. Using this approach, the composition of the resulting PRP derived product is independent of the donor initial basal platelet count, thereby allowing the evaluation of its effects objectively and reproducibly. In our OA models, PRP-Rs showed antiinflammatory, anti-oxidant and anti-catabolic properties. Platelet enrichment could favor chondrocyte proliferation but is not necessary for the above effects and could even be counter-productive.

scholarly journals Cell–cell coupling and DNA methylation abnormal phenotypes in the after-hours mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Federico Tinarelli ◽  
Elena Ivanova ◽  
Ilaria Colombi ◽  
Erica Barini ◽  
Edoardo Balzani ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Neuronal Networks ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Neuronal Cultures ◽  
Functional Impairments ◽  
After Hours ◽  
The Impact

Abstract Background DNA methylation has emerged as an important epigenetic regulator of brain processes, including circadian rhythms. However, how DNA methylation intervenes between environmental signals, such as light entrainment, and the transcriptional and translational molecular mechanisms of the cellular clock is currently unknown. Here, we studied the after-hours mice, which have a point mutation in the Fbxl3 gene and a lengthened circadian period. Methods In this study, we used a combination of in vivo, ex vivo and in vitro approaches. We measured retinal responses in Afh animals and we have run reduced representation bisulphite sequencing (RRBS), pyrosequencing and gene expression analysis in a variety of brain tissues ex vivo. In vitro, we used primary neuronal cultures combined to micro electrode array (MEA) technology and gene expression. Results We observed functional impairments in mutant neuronal networks, and a reduction in the retinal responses to light-dependent stimuli. We detected abnormalities in the expression of photoreceptive melanopsin (OPN4). Furthermore, we identified alterations in the DNA methylation pathways throughout the retinohypothalamic tract terminals and links between the transcription factor Rev-Erbα and Fbxl3. Conclusions The results of this study, primarily represent a contribution towards an understanding of electrophysiological and molecular phenotypic responses to external stimuli in the Afh model. Moreover, as DNA methylation has recently emerged as a new regulator of neuronal networks with important consequences for circadian behaviour, we discuss the impact of the Afh mutation on the epigenetic landscape of circadian biology.

Precision cut lung slices: an ex vivo model for assessing the impact of immunomodulatory therapeutics on lung immune responses

2021 ◽  
Author(s):  
Guanghui Liu ◽  
Linnea Särén ◽  
Helena Douglasson ◽  
Xiao-Hong Zhou ◽  
Per M. Åberg ◽  
...  
Keyword(s):  
Immune Responses ◽  
Ex Vivo ◽  
Ex Vivo Model ◽  
Precision Cut Lung Slices ◽  
The Impact

scholarly journals Experimental Models to Study COVID-19 Effect in Stem Cells

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 91
Author(s):  
Rishi Man Chugh ◽  
Payel Bhanja ◽  
Andrew Norris ◽  
Subhrajit Saha
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
Drug Efficacy ◽  
Cell Loss ◽  
Experimental Models ◽  
Model Systems ◽  
Virus Infectivity ◽  
Ex Vivo Model ◽  
Global Pandemic ◽  
The Impact

The new strain of coronavirus (severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)) emerged in 2019 and hence is often referred to as coronavirus disease 2019 (COVID-19). This disease causes hypoxic respiratory failure and acute respiratory distress syndrome (ARDS), and is considered as the cause of a global pandemic. Very limited reports in addition to ex vivo model systems are available to understand the mechanism of action of this virus, which can be used for testing of any drug efficacy against virus infectivity. COVID-19 induces tissue stem cell loss, resulting inhibition of epithelial repair followed by inflammatory fibrotic consequences. Development of clinically relevant models is important to examine the impact of the COVID-19 virus in tissue stem cells among different organs. In this review, we discuss ex vivo experimental models available to study the effect of COVID-19 on tissue stem cells.

Corticosteroids alter alveolar macrophage control of Lichtheimia corymbifera spores in an ex vivo mouse model

2020 ◽  
Author(s):  
Kévin Brunet ◽  
François Arrivé ◽  
Jean-Philippe Martellosio ◽  
Isabelle Lamarche ◽  
Sandrine Marchand ◽  
...  
Keyword(s):  
Mouse Model ◽  
Alveolar Macrophage ◽  
Oxidative Burst ◽  
Ex Vivo ◽  
Fungal Growth ◽  
Invasive Infection ◽  
Ex Vivo Model ◽  
Lichtheimia Corymbifera ◽  
The Impact

Abstract Alveolar macrophages (AM) are the first-line lung defense against Mucorales in pulmonary mucormycosis. Since corticosteroid use is a known risk factor for mucormycosis, the aim of this study was to describe the role of corticosteroids on AM capacities to control Lichtheimia corymbifera spore growth using a new ex vivo model. An in vivo mouse model was developed to determine the acetate cortisone dose able to trigger pulmonary invasive infection. Then, in the ex vivo model, male BALB/c mice were pretreated with the corticosteroid regimen triggering invasive infection, before AM collection through bronchoalveolar lavage. AMs from corticosteroid-treated mice and untreated control AMs were then exposed to L. corymbifera spores in vitro (ratio 1:5). AM control of fungal growth, adherence/phagocytosis, and oxidative burst were assessed using optical densities by spectrophotometer, flow cytometry, and 2', 7'-dichlorofluoresceine diacetate fluorescence, respectively. Cortisone acetate at 500 mg/kg, at D-3 and at D0, led to pulmonary invasive infection at D3. Co-incubated spores and AMs from corticosteroid-treated mice had significantly higher absorbance (fungal growth) than co-incubated spores and control AMs, at 24 h (P = .025), 36 h (P = .004), and 48 h (P = .001). Colocalization of spores with AMs from corticosteroid-treated mice was significantly lower than for control AMs (7.6 ± 1.9% vs 22.3 ± 5.8%; P = .003), reflecting spore adherence and phagocytosis inhibition. Finally, oxidative burst was significantly increased when control AMs were incubated with spores (P = 0.029), while corticosteroids hampered oxidative burst from treated AMs (P = 0.321). Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease in our ex vivo model. Lay Summary The aim of this study was to describe the impact of corticosteroids on alveolar macrophage (AM) capacities to control Mucorales growth in a new murine ex vivo model. Corticosteroids enhanced fungal growth of L. corymbifera through AM phagocytosis inhibition and burst oxidative decrease.

scholarly journals A New Ex Vivo Model to Evaluate the Hair Protective Effect of a Biomimetic Exopolysaccharide against Water Pollution

Cosmetics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 78
Author(s):  
Claire Tubia ◽  
Alfonso Fernández-Botello ◽  
Jan Dupont ◽  
Eni Gómez ◽  
Jérôme Desroches ◽  
...  
Keyword(s):  
Water Pollution ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Adverse Effects ◽  
Inductively Coupled Plasma ◽  
Ex Vivo ◽  
Polluted Water ◽  
Ex Vivo Model ◽  
Fiber Damage ◽  
The Impact

As an external appendage, hair is exposed to multiple stresses of different origins such as particles and gases in air, or heavy metals and chemicals in water. So far, little research has addressed the impact of water pollution on hair. The present study describes a new ex vivo model that allowed us to document the adverse effects of water pollutants on the structure of hair proteins, as well as the protective potential of active cosmetic ingredients derived from a biomimetic exopolysaccharide (EPS). The impact of water pollution was evaluated on hair from a Caucasian donor repeatedly immersed in heavy metal-containing water. Heavy metal retention in and on hair was then quantified using Inductively Coupled Plasma Spectrometry (ICP/MS). The adverse effects of heavy metals on the internal structure of hair and its prevention by the EPS were assessed through measurement of keratin birefringence. Notably, the method allows the monitoring of the organization of keratin fibers and therefore the initial change on it in order to modulate the global damage in the hair. Results revealed an increasing amount of lead, cadmium and copper, following multiple exposures to polluted water. In parallel, the structure of keratin was also altered with exposures. However, heavy metal-induced keratin fiber damage could be prevented in the presence of the tested EPS, avoiding more drastic hair problems, such as lack of shine, or decrease in strength, due to damage accumulation.

scholarly journals A Novel Ex Vivo Model of Aortic Valve Calcification. A Preliminary Report

2020 ◽  
Vol 11 ◽  
Author(s):  
Arsenii Zabirnyk ◽  
Maria del Mar Perez ◽  
Marc Blasco ◽  
Kåre-Olav Stensløkken ◽  
Miguel D. Ferrer ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Growth Medium ◽  
Ex Vivo ◽  
Growth Media ◽  
Dependent Manner ◽  
Ex Vivo Model ◽  
Aortic Valves ◽  
Valve Calcification ◽  
Calcium Accumulation ◽  
Aortic Valve Leaflets

Background: No pharmacological treatment exists to prevent or stop the calcification process of aortic valves causing aortic stenosis. The aim of this study was to develop a robust model of induced calcification in whole aortic valve leaflets which could be suitable for studies of the basic mechanisms and for testing potentially inhibitory drugs.Methods: Pig hearts were obtained from a commercial abattoir. The aortic valve leaflets were dissected free and randomized between experimental groups. Whole leaflets were cultured in individual wells. Two growth media were used for cultivation: standard growth medium and an antimyofibroblastic growth medium. The latter was employed to inhibit contraction of the leaflet into a ball-like structure. Calcification was induced in the growth medium by supplementation with an osteogenic medium. Leaflets were cultivated for four weeks and medium was changed every third day. To block calcification, the inhibitor SNF472 (a formulation of the hexasodium salt of myo-inositol hexaphosphate hexasodium salt) was used at concentrations between 1 and 100 µM. After cultivation for four weeks the leaflets were snap frozen in liquid nitrogen and kept at −80 °C until blind assessment of the calcium amount in leaflets by inductively coupled plasma optical emission spectroscopy. For statistical analysis, a Kruskal–Wallis test with Dunn’s post-test was applied.Results: Osteodifferentiation with calcium accumulation was in principle absent when standard medium was used. However, when the antimyofibroblastic medium was used, a strong calcium accumulation was induced (p = 0.006 compared to controls), and this was blocked in a dose-dependent manner by the calcification inhibitor SNF472 (p = 0.008), with an EC50 of 3.3 µM.Conclusion: A model of experimentally induced calcification in cultured whole leaflets from porcine aortic valves was developed. This model can be useful for studying the basic mechanisms of valve calcification and to test pharmacological approaches to inhibit calcification.

scholarly journals Ex vivo Model of Human Aortic Valve Bacterial Colonization

BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (11) ◽  
Author(s):  
Alejandro Avilés-Reyes ◽  
Irlan Freires ◽  
Pedro Rosalen ◽  
José Lemos ◽  
Jacqueline Abranches
Keyword(s):  
Aortic Valve ◽  
Ex Vivo ◽  
Bacterial Colonization ◽  
Ex Vivo Model ◽  
Human Aortic Valve

scholarly journals Unravelling the role of Mesenchymal Stem/Stromal Cells Secretome in intervertebral disc degeneration in a pro-inflammatory/degenerative ex vivo model

2020 ◽  
Author(s):  
JR Ferreira ◽  
GQ Teixeira ◽  
E Neto ◽  
C Ribeiro-Machado ◽  
AM Silva ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Stromal Cells ◽  
Ex Vivo ◽  
Low Oxygen ◽  
Ex Vivo Model ◽  
A Cell ◽  
New Perspective ◽  
Regulated Gene Expression ◽  
Ivd Degeneration

Abstract Background: Mesenchymal stem/stromal cells (MSCs) have been increasingly used in clinical trials for intervertebral disc (IVD) degeneration. Here, we aimed to evaluate the potential of a cell-free approach to degenerated IVD, testing if MSCs secretome can stimulate a regenerative response by modulating the IVD inflammatory cascade. Methods: Human bone marrow-derived MSCs were pre-conditioned with IL-1β (10 ng/mL) and low oxygen (6% O2). The secretome of MSCs (MSCsec) was collected after 48h. Bovine IVD tissue explants cultured in pro-inflammatory/degenerative conditions (needle puncture + IL-1β) were treated with MSCsec or co-cultured with MSCs. Results: MSCsec obtained upon IL-1β-pre-conditioning, as well as MSCs co-culture, down-regulated gene expression of pro-inflammatory cytokines, bIL-6 and bIL-8 after 48h, in IVD. IVD matrix degrading enzymes, bMMP1 and bMMP3, were downregulated and upregulated, respectively, in the presence of MSCsec, but not MSCs. After 14 days, MSCsec-treated IVDs revealed increased aggrecan content at the protein level, contrarily to MSCs/IVD co-cultures. Interestingly, IL-1β-preconditioning only, but not IL-1β-IVD, increased gene expression of hADAMTS5 and hTIMP-1in MSCs. Additionally, conditioned medium from MSCsec-treated IVDs did not promote angiogenesis or neurogenesis. In MSCsec-treated IVD, an increase in MCP-3 and GCP-2 was observed, while SDF-1α, TNF-α, IGF-1, Eotaxin 3, FGF-9, MIP-1δ, IFN-γ, IL-5, TNF-β, IL-4, TGF-β1, IL-16, IGFBP-3 and IGFBP-4 were decreased, compared with MSCs/IVD co-cultures. Conclusions: MSCsec obtained upon IL1β-preconditioning, present an immunomodulatory role in degenerated IVD, as well as MSCs. Nevertheless, MSCsec but not MSCs, potentiate aggrecan deposition in IVD in pro-inflammatory/degenerative conditions. This finding can open new perspective on the use of MSCsec as a cell-based/cell-free approach to LBP.

scholarly journals Interleukin-6 actions in the hypothalamus protects against obesity and is involved in the regulation of neurogenesis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Vanessa C. Bobbo ◽  
Daiane F. Engel ◽  
Carlos Poblete Jara ◽  
Natalia F. Mendes ◽  
Roberta Haddad-Tovolli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Interleukin 6 ◽  
Ex Vivo ◽  
Cell Types ◽  
Cell Labeling ◽  
Specific Cell ◽  
Related Gene ◽  
Sequencing Data ◽  
Ex Vivo Model ◽  
Diet Induced Obesity

Abstract Background Interleukin-6 (IL6) produced in the context of exercise acts in the hypothalamus reducing obesity-associated inflammation and restoring the control of food intake and energy expenditure. In the hippocampus, some of the beneficial actions of IL6 are attributed to its neurogenesis-inducing properties. However, in the hypothalamus, the putative neurogenic actions of IL6 have never been explored, and its potential to balance energy intake can be an approach to prevent or attenuate obesity. Methods Wild-type (WT) and IL6 knockout (KO) mice were employed to study the capacity of IL6 to induce neurogenesis. We used cell labeling with Bromodeoxyuridine (BrdU), immunofluorescence, and real-time PCR to determine the expression of markers of neurogenesis and neurotransmitters. We prepared hypothalamic neuroprogenitor cells from KO that were treated with IL6 in order to provide an ex vivo model to further characterizing the neurogenic actions of IL6 through differentiation assays. In addition, we analyzed single-cell RNA sequencing data and determined the expression of IL6 and IL6 receptor in specific cell types of the murine hypothalamus. Results IL6 expression in the hypothalamus is low and restricted to microglia and tanycytes, whereas IL6 receptor is expressed in microglia, ependymocytes, endothelial cells, and astrocytes. Exogenous IL6 reduces diet-induced obesity. In outbred mice, obesity-resistance is accompanied by increased expression of IL6 in the hypothalamus. IL6 induces neurogenesis-related gene expression in the hypothalamus and in neuroprogenitor cells, both from WT as well as from KO mice. Conclusion IL6 induces neurogenesis-related gene expression in the hypothalamus of WT mice. In KO mice, the neurogenic actions of IL6 are preserved; however, the appearance of new fully differentiated proopiomelanocortin (POMC) and neuropeptide Y (NPY) neurons is either delayed or disturbed.

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