scholarly journals Extracellular vesicles secreted by human cardiosphere-derived cells attenuate electrophysiological remodelling in an in vitro model of atrial fibrillation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
L Gomez-Cid ◽  
M Moro-Lopez ◽  
A S De La Nava ◽  
A I Fernandez ◽  
M E Fernandez-Santos ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Conduction Velocity ◽  
Extracellular Vesicles ◽  
In Vitro Model ◽  
Optical Mapping ◽  
Rotor Dynamics ◽  
Antiarrhythmic Effect ◽  
Electrophysiological Properties ◽  
Vitro Model

Abstract Background Stem cells and their secreted extracellular vesicles (EVs) have shown different cardioprotective effects. However, their impact on the electrophysiological properties of the heart tissue remains controversial. While the use of some progenitor cells seems to have antiarrhythmic potential, the use of cardiomyocyte-like cells may be proarrhythmic. The mechanisms behind, and whether these effects are linked to cell engraftment and not to their secreted products is not fully known. Purpose The aim of this study was to investigate the electrophysiological modifications induced by extracellular vesicles secreted by human cardiosphere-derived cells (CDC-EVs) in an in vitro model of atrial fibrillation in order to explore their potential antiarrhythmic effect. Methods CDCs were derived from cardiac biopsies of patients who underwent cardiac surgery for other reasons. Purified CDC-EVs resuspended in serum-free media (SFM) vs. SFM alone were added to HL-1 atrial myocyte monolayers presenting spontaneous fibrillatory activity. After 48 hours, the monolayers were fully confluent, and the electrophysiological properties were analysed through optical mapping in both the treated (n=9) and control plates (n=9). Optical mapping recordings of the monolayers were analysed with Matlab for the activation frequency, activation complexity, rotor dynamics (curvature and meandering) and conduction velocity. Results CDC-EVs reduced activation complexity of the fibrillating atrial monolayers by ∼40% (2.74±0.59 vs. 1.61±0.16 PS/cm2, p<0.01). This reduction in activation complexity was accompanied by larger rotor meandering (1.47±0.82 vs. 4.32±2.25 cm/s, p<0.01) and decreased curvature (1.79±0.40 vs. 0.87±0.24 rad/cm, p<0.01) in the treated group. Despite reduction in the activation complexity, activation frequency did not change significantly between both groups. This could be in part because CDC-EVs increased conduction velocity by 80% (1.32±0.57 vs. 2.65±0.87 cm/s, p<0.01). Low conduction velocity has been linked to higher reentry recurrence, and lower meandering and higher curvature to higher rotor stability and harder AF termination. Therefore, CDC-EVs seem to drive cardiomyocytes to a less arrhythmic profile reducing activation complexity and preventing remodelling by increasing conduction velocity and modifying rotor dynamics. Conclusions CDC-EVs significantly modify conduction velocity and rotor dynamics, therefore reducing fibrillation complexity and remodelling to drive atrial myocytes to a less arrhythmogenic profile. Testing CDC-EVs in more robust models of atrial fibrillation, the most common sustained arrhythmia in humans with significant morbidity and mortality, is of special interest. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III, Ministerio de Ciencia e Innovaciόn,CIBERCV, Spain Figure 1

scholarly journals Extracellular Vesicles Are More Potent Than Adipose Mesenchymal Stromal Cells to Exert an Anti-Fibrotic Effect in an In Vitro Model of Systemic Sclerosis

2021 ◽  
Vol 22 (13) ◽  
pp. 6837
Author(s):  
Pauline Rozier ◽  
Marie Maumus ◽  
Claire Bony ◽  
Alexandre Thibault Jacques Maria ◽  
Florence Sabatier ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Extracellular Vesicles ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
In Vitro Model ◽  
Specific Treatment ◽  
Complex Disorder ◽  
Molecular Features ◽  
Vitro Model

Systemic sclerosis (SSc) is a complex disorder resulting from dysregulated interactions between the three main pathophysiological axes: fibrosis, immune dysfunction, and vasculopathy, with no specific treatment available to date. Adipose tissue-derived mesenchymal stromal cells (ASCs) and their extracellular vesicles (EVs) have proved efficacy in pre-clinical murine models of SSc. However, their precise action mechanism is still not fully understood. Because of the lack of availability of fibroblasts isolated from SSc patients (SSc-Fb), our aim was to determine whether a TGFβ1-induced model of human myofibroblasts (Tβ-Fb) could reproduce the characteristics of SSc-Fb and be used to evaluate the anti-fibrotic function of ASCs and their EVs. We found out that Tβ-Fb displayed the main morphological and molecular features of SSc-Fb, including the enlarged hypertrophic morphology and expression of several markers associated with the myofibroblastic phenotype. Using this model, we showed that ASCs were able to regulate the expression of most myofibroblastic markers on Tβ-Fb and SSc-Fb, but only when pre-stimulated with TGFβ1. Of interest, ASC-derived EVs were more effective than parental cells for improving the myofibroblastic phenotype. In conclusion, we provided evidence that Tβ-Fb are a relevant model to mimic the main characteristics of SSc fibroblasts and investigate the mechanism of action of ASCs. We further reported that ASC-EVs are more effective than parental cells suggesting that the TGFβ1-induced pro-fibrotic environment may alter the function of ASCs.

An In Vitro Model of the Kitten Retinogeniculate Pathway

1997 ◽  
Vol 77 (1) ◽  
pp. 511-516 ◽  
Author(s):  
William Guido ◽  
Fu-Sun Lo ◽  
Reha S. Erzurumlu
Keyword(s):  
In Vitro Model ◽  
Ganglion Cells ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Glutamate Antagonists ◽  
Electrophysiological Properties ◽  
Functional Connections ◽  
Retinal Axons ◽  
Retinal Explants ◽  
Vitro Model

Guido, William, Fu-Sun Lo, and Reha S. Erzurumlu. An in vitro model of the kitten retinogeniculate pathway. J. Neurophysiol. 77: 511–516, 1997. An organotypic explant coculture method is described for the developing retinogeniculate pathway of the cat. Retinal explants and thalamic slices containing the dorsal lateral geniculate nucleus (LGN), derived from early postnatal kittens, can be grown in serum-free culture medium for several days. In such cultures, retinal ganglion cells (RGCs) and LGN neurons retained their age-specific morphological features and developed functional connections. Labeling of RGCs and their processes with DiI showed that all three major classes of RGCs (α/Y, β/X, γ/W) were present in cocultured retinal explants. Retinal axons readily regenerated into thalamic slices and, over time, developed arbors within the LGN. Retrograde labeling from the LGN traced the origin of these axons almost exclusively to α-cells in the retina. In vitro intracellular recordings indicated that LGN cells maintained their basic electrophysiological properties in coculture. Current injection generated action potentials, and, at hyperpolarized levels, it led to low-threshold Ca2+ spiking. Regenerated retinal axons also formed functional connections with LGN neurons. Electrical stimulation of the retinal explant elicited excitatory postsynaptic responses (EPSPs) in LGN cells. Drop application of specific glutamate antagonists indicated that EPSPs had both N-methyl-d-aspartate (NMDA) and non-NMDA receptor components. The morphology of the LGN neurons was examined after intracellular injections of biocytin during recording. Labeled cells were very similar to those of early postnatal kittens. Although, in general, they had relatively small soma and simple dendritic branching patterns, a few could be recognized as X- or Y-cells. Thus the coculture model can be used to assay the regenerative propensity of different types of RGCs during development.

scholarly journals Characterization of extracellular vesicles derived from cardiac cells in an in vitro model of preconditioning

2017 ◽  
Vol 6 (1) ◽  
pp. 1390391 ◽  
Author(s):  
Sebastian Borosch ◽  
Eva Dahmen ◽  
Christian Beckers ◽  
Christian Stoppe ◽  
Eva Miriam Buhl ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
In Vitro Model ◽  
Cardiac Cells ◽  
Vitro Model

scholarly journals P.149: Extracellular Vesicles From Patients With Diabetic Nephropathy Induce Endothelial Dysfunction Through ICAM-1 and VCAM-1 in an In Vitro Model

2021 ◽  
Vol 105 (12S1) ◽  
pp. S61-S61
Author(s):  
Enrique Montagud-Marrahi ◽  
Sergi Torramade-Moix ◽  
Maria José Ramírez-Bajo ◽  
Jordi Rovira ◽  
Elisenda Bañón-Maneus ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Endothelial Dysfunction ◽  
Extracellular Vesicles ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals Comparison of two ASC-derived therapeutics in an in vitro OA model: secretome versus extracellular vesicles

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chiara Giannasi ◽  
Stefania Niada ◽  
Cinzia Magagnotti ◽  
Enrico Ragni ◽  
Annapaola Andolfo ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Stromal Cells ◽  
In Vitro Model ◽  
Articular Chondrocytes ◽  
Therapeutic Potential ◽  
Donor Cells ◽  
Beneficial Action ◽  
A Cell ◽  
Vitro Model

Abstract Background In the last years, several clinical trials have proved the safety and efficacy of adipose-derived stem/stromal cells (ASC) in contrasting osteoarthritis (OA). Since ASC act mainly through paracrine mechanisms, their secretome (conditioned medium, CM) represents a promising therapeutic alternative. ASC-CM is a complex cocktail of proteins, nucleic acids, and lipids released as soluble factors and/or conveyed into extracellular vesicles (EV). Here, we investigate its therapeutic potential in an in vitro model of OA. Methods Human articular chondrocytes (CH) were induced towards an OA phenotype by 10 ng/ml TNFα in the presence of either ASC-CM or EV, both deriving from 5 × 105 cells, to evaluate the effect on hypertrophic, catabolic, and inflammatory markers. Results Given the same number of donor cells, our data reveal a higher therapeutic potential of ASC-CM compared to EV alone that was confirmed by its enrichment in chondroprotective factors among which TIMP-1 and -2 stand out. In details, only ASC-CM significantly decreased MMP activity (22% and 29% after 3 and 6 days) and PGE2 expression (up to 40% at day 6) boosted by the inflammatory cytokine. Conversely, both treatments down-modulated of ~ 30% the hypertrophic marker COL10A1. Conclusions These biological and molecular evidences of ASC-CM beneficial action on CH with an induced OA phenotype may lay the basis for its future clinical translation as a cell-free therapeutic in the management of OA.

scholarly journals Electrophysiological Effects of Extracellular Vesicles Secreted by Cardiosphere-Derived Cells: Unraveling the Antiarrhythmic Properties of Cell Therapies

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 924
Author(s):  
Lidia Gómez-Cid ◽  
Marina Moro-López ◽  
Ana de la Nava ◽  
Ismael Hernández-Romero ◽  
Ana Fernández ◽  
...  
Keyword(s):  
Gene Expression ◽  
Conduction Velocity ◽  
Extracellular Vesicles ◽  
Gene Expression Analysis ◽  
Optical Mapping ◽  
Cell Therapies ◽  
Electrophysiological Properties ◽  
Electrophysiological Effects ◽  
Rotor Curvature ◽  
Antiarrhythmic Effects

Although cell-based therapies show potential antiarrhythmic effects that could be mediated by their paracrine action, the mechanisms and the extent of these effects were not deeply explored. We investigated the antiarrhythmic mechanisms of extracellular vesicles secreted by cardiosphere-derived cell extracellular vesicles (CDC-EVs) on the electrophysiological properties and gene expression profile of HL1 cardiomyocytes. HL-1 cultures were primed with CDC-EVs or serum-free medium alone for 48 h, followed by optical mapping and gene expression analysis. In optical mapping recordings, CDC-EVs reduced the activation complexity of the cardiomyocytes by 40%, increased rotor meandering, and reduced rotor curvature, as well as induced an 80% increase in conduction velocity. HL-1 cells primed with CDC-EVs presented higher expression of SCN5A, CACNA1C, and GJA1, coding for proteins involved in INa, ICaL, and Cx43, respectively. Our results suggest that CDC-EVs reduce activation complexity by increasing conduction velocity and modifying rotor dynamics, which could be driven by an increase in expression of SCN5A and CACNA1C genes, respectively. Our results provide new insights into the antiarrhythmic mechanisms of cell therapies, which should be further validated using other models.

A Transient Survival Model of Alteration of Electrophysiological Properties Due to Amyloid-Beta Toxicity Based on SH-SY5Y Cell Line

2021 ◽  
Vol 18 ◽  
Author(s):  
M. Abbaszadeh ◽  
M. Sahin ◽  
A. Ozgun ◽  
G. Oncu ◽  
B. Garipcan ◽  
...  
Keyword(s):  
Cell Death ◽  
Retinoic Acid ◽  
Amyloid Beta ◽  
Neurotrophic Factor ◽  
In Vitro Model ◽  
Brain Derived Neurotrophic Factor ◽  
Survival Model ◽  
Electrophysiological Properties ◽  
Vitro Model

Background: Accumulation of toxic strands of Amyloid Beta (AB), which cause neurofibrillary tangles and, ultimately, cell death, is suspected to be the main culprit behind clinical symptoms of Alzheimer’s disease. Although the mechanism of cell death due to Amyloid-Beta accumulation is well known, the intermediate phase between the start of accumulation and cell death is less known and investigated, partially due to technical challenges in identifying partially affected cells. Objective: First, we aimed to establish an in-vitro model that would show resilience against amyloid-beta toxicity. Then we used morphological, molecular and electrophysiological assays to investigate how the characteristics of the surviving cells changed after amyloid-beta toxicity. Method : To investigate this phase, we used differentiation of SH-SY5Y neuroblastoma stem cells by Retinoic Acid (RA) and Brain Derived Neurotrophic Factor (BDNF) to establish an in-vitro model which would be able to demonstrate various levels of resistance to Amyloid Beta toxicity. We utilized fluorescent microscopy and whole cell patch clamp recordings to investigate behavior of the model. Results: We observed significantly higher morphological resilience against Amyloid Beta toxicity in cells which were differentiated by both Retinoic Acid and Brain Derived Neurotrophic Factor compared to Retinoic Acid only. However, the electrophysiological properties of the Retinoic Acid + Brain-Derived Neurotrophic Factor differentiated cells were significantly altered after Amyloid Beta treatment. Conclusion: We established a transient survival model for amyloid-beta toxicity and observed the effects of Amyloid beta on transmembrane currents of differentiated neurons.

Cardiac muscle tissue engineering: toward an in vitro model for electrophysiological studies

1999 ◽  
Vol 277 (2) ◽  
pp. H433-H444 ◽  
Author(s):  
N. Bursac ◽  
M. Papadaki ◽  
R. J. Cohen ◽  
F. J. Schoen ◽  
S. R. Eisenberg ◽  
...  
Keyword(s):  
Cardiac Muscle ◽  
Cardiac Myocytes ◽  
In Vitro Model ◽  
Neonatal Rat ◽  
Electrophysiological Properties ◽  
Impulse Propagation ◽  
Ventricular Cells ◽  
Electrophysiological Studies ◽  
Vitro Model

The objective of this study was to establish a three-dimensional (3-D) in vitro model system of cardiac muscle for electrophysiological studies. Primary neonatal rat ventricular cells containing lower or higher fractions of cardiac myocytes were cultured on polymeric scaffolds in bioreactors to form regular or enriched cardiac muscle constructs, respectively. After 1 wk, all constructs contained a peripheral tissue-like region (50–70 μm thick) in which differentiated cardiac myocytes were organized in multiple layers in a 3-D configuration. Indexes of cell size (protein/DNA) and metabolic activity (tetrazolium conversion/DNA) were similar for constructs and neonatal rat ventricles. Electrophysiological studies conducted using a linear array of extracellular electrodes showed that the peripheral region of constructs exhibited relatively homogeneous electrical properties and sustained macroscopically continuous impulse propagation on a centimeter-size scale. Electrophysiological properties of enriched constructs were superior to those of regular constructs but inferior to those of native ventricles. These results demonstrate that 3-D cardiac muscle constructs can be engineered with cardiac-specific structural and electrophysiological properties and used for in vitro impulse propagation studies.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

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