Abstract 139: Using Cyclic Strain to Improve Cardiac Progenitor Cell Cooperation

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Kristin M French ◽  
Marcos J Fierro ◽  
Todd D Johnson ◽  
Karen L Christman ◽  
Michael E Davis
Keyword(s):  
Connexin 43 ◽  
Matrix Protein ◽  
Mechanical Strain ◽  
Cyclic Strain ◽  
Culture Conditions ◽  
Cardiac Cells ◽  
Rhodamine Phalloidin ◽  
Cell Therapies ◽  
Static Conditions

Introduction: Cell therapies have grown in popularity for myocardial regeneration post-infarction, but still suffer from poor retention, maturation and integration of delivered cells. Mechanical strain has been shown to alter cell size, shape, adherence and gene expression in cardiac cells. As a more recently identified cell type, the effect of mechanical strain on cardiac progenitor cells (CPCs) is unknown. This work aims to elucidate the role mechanical strain plays in CPC phenotype and if this response is matrix protein specific. We hypothesize that mechanical strain will improve CPC alignment and potential for connectivity. Methods: To examine the role of mechanical strain on CPCs, CPCs were seeded on FlexCell plates in the presence of a naturally-derived cardiac extracellularmatrix (cECM), collagen I (COL) or no protein (TCP) and strained 0% (static) or 10% at 1 Hz for 24 hours in a BioFlex system. CPC elongation, alignment, and size were evaluated by rhodamine-phalloidin staining. Connexin-43 expression was measured by Western and normalized to GAPDH. Data were analyzed by two-way ANOVA and Bonferroni post-test. Results: CPC area, independent of culture conditions, was 1020 ± 40 um2, corresponding to neonatal cardiomyocyte area. The aspect ratio (major/minor axis) of CPCs showed a trend for increased elongation with strain at (e.x. 2.0±0.2 for unstrained cECM compared to 2.7±0.1 for strained cECM; n=4, p>0.05). Static culture conditions, independent of matrix coating, showed 20±3% alignment of CPCs. Under strain, alignment increased to 30±2% on COL (n=4; p>0.05 for strained COL verus static COL) and 48±8% on cECM (n=4; p< 0.01 for strained cECM versus strained COL and p<0.001 for strained cECM verus static cECM). A fold change >2 for connexin-43 protein in strained versus static conditions, independent of matrix, was observed (n=2, p>0.05) and confirmed by immunocytochemistry. Conclusion: This work suggests that mechanical strain alters CPC phenotype. Increased strain-induced alignment appears to be matrix dependent. In conclusion, these studies provide insight into the role of both mechanical forces and biochemical responses in the function of CPCs; which could lead to improved outcomes following cellular transplantation.

Shear Stress Mediates Angiogenic Gene Expression in a Microfluidic Tumor Vascular Model

2012 ◽  
Author(s):  
Cara F. Buchanan ◽  
Elizabeth Voigt ◽  
Christopher S. Szot ◽  
Joseph W. Freeman ◽  
Pavlos P. Vlachos ◽  
...  
Keyword(s):  
Breast Cancer Cells ◽  
Culture Conditions ◽  
Treatment Modalities ◽  
Vascular Endothelial ◽  
Fluid Shear ◽  
Static Conditions ◽  
Angiopoietin 2 ◽  
Endothelial Growth Factor ◽  
Insight Into

While research has shown that the fluid mechanics of the tumor vasculature reduce transport and uptake of therapeutics, the underlying role of these stresses in regulating tumor-endothelial cell signaling and neovascularization are not well understood. Understanding the reciprocal interaction between endothelial and tumor cells to mediate angiogenesis, and the effect of fluid shear on this process, may offer insight into the development of improved treatment modalities to control highly vascularized tumors. We have previously shown that breast cancer cells cultured under 2D, static conditions with endothelial cells significantly increase expression of pro-angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietin 2 (ANG2) [1]. These preliminary results motivated the investigation of tumor-endothelial cross-talk under 3D, dynamic co-culture conditions.

scholarly journals NSCs Under Strain—Unraveling the Mechanoprotective Role of Differentiating Astrocytes in a Cyclically Stretched Coculture With Differentiating Neurons

2021 ◽  
Vol 15 ◽  
Author(s):  
Jella-Andrea Abraham ◽  
Stefan Blaschke ◽  
Samar Tarazi ◽  
Georg Dreissen ◽  
Sabine U. Vay ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mechanical Strain ◽  
Protective Role ◽  
Culture Conditions ◽  
Cytoskeletal Organization ◽  
Rhoa Activation ◽  
Pdms Elastomer ◽  
Mature Neurons ◽  
Developing Neurons

The neural stem cell (NSC) niche is a highly vascularized microenvironment that supplies stem cells with relevant biological and chemical cues. However, the NSCs’ proximity to the vasculature also means that the NSCs are subjected to permanent tissue deformation effected by the vessels’ heartbeat-induced pulsatile movements. Cultivating NSCs under common culture conditions neglects the—yet unknown—influence of this cyclic mechanical strain on neural stem cells. Under the hypothesis that pulsatile strain should affect essential NSC functions, a cyclic uniaxial strain was applied under biomimetic conditions using an in-house developed stretching system based on cross-linked polydimethylsiloxane (PDMS) elastomer. While lineage commitment remained unaffected by cyclic deformation, strain affected NSC quiescence and cytoskeletal organization. Unexpectedly, cyclically stretched stem cells aligned in stretch direction, a phenomenon unknown for other types of cells in the mammalian organism. The same effect was observed for young astrocytes differentiating from NSCs. In contrast, young neurons differentiating from NSCs did not show mechanoresponsiveness. The exceptional orientation of NSCs and young astrocytes in the stretch direction was blocked upon RhoA activation and went along with a lack of stress fibers. Compared to postnatal astrocytes and mature neurons, NSCs and their young progeny displayed characteristic and distinct mechanoresponsiveness. Data suggest a protective role of young astrocytes in mixed cultures of differentiating neurons and astrocytes by mitigating the mechanical stress of pulsatile strain on developing neurons.

Platelet and Shear Rate Promote Tumor Cell Adhesion to Human Endothelial Extracellular Matrix - Absence of a Role for Platelet Cyclooxygenase

1989 ◽  
Vol 61 (03) ◽  
pp. 485-489 ◽  
Author(s):  
Eva Bastida ◽  
Lourdes Almirall ◽  
Antonio Ordinas
Keyword(s):  
Cell Adhesion ◽  
Shear Rate ◽  
Tumor Cell ◽  
Umbilical Vein ◽  
Blood Platelets ◽  
Flow Conditions ◽  
Tumor Cell Adhesion ◽  
Rate Dependent ◽  
Static Conditions

SummaryBlood platelets are thought to be involved in certain aspects of malignant dissemination. To study the role of platelets in tumor cell adherence to vascular endothelium we performed studies under static and flow conditions, measuring tumor cell adhesion in the absence or presence of platelets. We used highly metastatic human adenocarcinoma cells of the lung, cultured human umbilical vein endothelial cells (ECs) and extracellular matrices (ECM) prepared from confluent EC monolayers. Our results indicated that under static conditions platelets do not significantly increase tumor cell adhesion to either intact ECs or to exposed ECM. Conversely, the studies performed under flow conditions using the flat chamber perfusion system indicated that the presence of 2 × 105 pl/μl in the perfusate significantly increased the number of tumor cells adhered to ECM, and that this effect was shear rate dependent. The maximal values of tumor cell adhesion were obtained, in presence of platelets, at a shear rate of 1,300 sec-1. Furthermore, our results with ASA-treated platelets suggest that the role of platelets in enhancing tumor cell adhesion to ECM is independent of the activation of the platelet cyclooxygenase pathway.

Baboon Fibrinogen Adsorption and Platelet Adhesion to Polymeric Materials

1991 ◽  
Vol 65 (05) ◽  
pp. 608-617 ◽  
Author(s):  
Joseph A Chinn ◽  
Thomas A Horbett ◽  
Buddy D Ratner
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Polymeric Materials ◽  
Platelet Suspension ◽  
Perfusion Chamber ◽  
Static Conditions ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Fibrinogen Adsorption

SummaryThe role of fibrinogen in mediating platelet adhesion to polymers exposed to blood plasma was studied by comparison of the effect of plasma dilution on fibrinogen adsorption and platelet adhesion, and by the use of coagulation factor deficient plasmas. Polyetherurethane substrates were first preadsorbed with dilute plasma, then contacted with washed platelets suspended in a modified, apyrase containing Tyrode’s buffer. Platelet adhesion was studied under static conditions in Multiwell dishes, and also under shearing conditions using a parallel plate perfusion chamber. Fibrinogen adsorption and platelet adhesion were measured using 125I radiolabeled baboon fibrinogen and min radiolabeled baboon platelets, respectively. Surfaces were characterized by electron spectroscopy for chemical analysis (ESCA).When fibrinogen adsorption to Biomer was measured after 2 h contact with a series of dilute plasma solutions under static conditions, a peak in adsorption was observed from 0.26% plasma, i.e., adsorption was greater from 0.26% plasma than from either more or less dilute plasma. A peak in subsequent platelet adhesion to the plasma preadsorbed surfaces, measured after 2 h static incubation with washed platelets, was also observed but occurred on Biomer preadsorbed with 1.0% plasma.When fibrinogen adsorption was measured after 5 min contact under shearing conditions, the fibrinogen adsorption peak occurred on surfaces that had been exposed to 1.0% plasma. A peak in platelet adhesion to these preadsorbed surfaces, measured after 5 min contact with the platelet suspensions under shearing conditions, was observed on Biomer preadsorbed with 0.1% plasma. Shifts between the positions of the peaks in protein adsorption and platelet adhesion occurred on other polymers tested as well.Platelet adhesion was almost completely inhibited when baboon and human plasmas lacking fibrinogen (i. e., serum, heat defibrinogenated plasma, and congenitally afibrinogénémie plasma) were used. Platelet adhesion was restored to near normal when exogenous fibrinogen was added to fibrinogen deficient plasmas. Adhesion was also inhibited completely when a monoclonal antibody directed against the glycoprotein IIb/IIIa complex was added to the platelet suspension. Platelet adhesion to surfaces preadsorbed to von Willebrand factor deficient plasma was the same as to surfaces preadsorbed with normal plasma.While it appears that surface bound fibrinogen does mediate the initial attachment of platelets to Biomer, the observation that the fibrinogen adsorption and platelet adhesion maxima do not coincide exactly also suggests that the degree of subsequent platelet adhesion is dictated not only by the amount of surface bound fibrinogen but also by its conformation.

Endometrial Regeneration in Asherman's Syndrome: Clinical and Translational evidence of Stem Cell Therapies

2019 ◽  
Vol 14 (6) ◽  
pp. 454-459
Author(s):  
Xuejing Hou ◽  
Ying Liu ◽  
Isabelle Streuli ◽  
Patrick Dällenbach ◽  
Jean Dubuisson ◽  
...  
Keyword(s):  
Stem Cell ◽  
Molecular Mechanisms ◽  
Uterine Cavity ◽  
Stem Cell Therapies ◽  
Intrauterine Adhesions ◽  
Asherman’S Syndrome ◽  
Cell Therapies ◽  
Fibrotic Process ◽  
Physical Barriers

Asherman’s Syndrome or Intrauterine adhesions is an acquired uterine condition where fibrous scarring forms within the uterine cavity, resulting in reduced menstrual flow, pelvic pain and infertility. Until recently, the molecular mechanisms leading to the formation of fibrosis were poorly understood, and the treatment of Asherman’s syndrome has largely focused on hysteroscopic resection of adhesions, hormonal therapy, and physical barriers. Numerous studies have begun exploring the molecular mechanisms behind the fibrotic process underlying Asherman’s Syndrome as well as the role of stem cells in the regeneration of the endometrium as a treatment modality. The present review offers a summary of available stem cell-based regeneration studies, as well as highlighting current gaps in research.

Role of matrix protein in cytopathogenesis of vesicular stomatitis virus.

1990 ◽  
Vol 64 (4) ◽  
pp. 1716-1725 ◽  
Author(s):  
D Blondel ◽  
G G Harmison ◽  
M Schubert
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Matrix Protein ◽  
Vesicular Stomatitis

scholarly journals Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 767
Author(s):  
Courtney Davis ◽  
Sean I. Savitz ◽  
Nikunj Satani
Keyword(s):  
Ischemic Stroke ◽  
Extracellular Vesicles ◽  
Neurovascular Unit ◽  
Culture Conditions ◽  
Therapeutic Effects ◽  
Stroke Treatment ◽  
Inflammatory Molecules ◽  
The Brain

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

scholarly journals Self-organization and culture of Mesenchymal Stem Cell spheroids in acoustic levitation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathan Jeger-Madiot ◽  
Lousineh Arakelian ◽  
Niclas Setterblad ◽  
Patrick Bruneval ◽  
Mauricio Hoyos ◽  
...  
Keyword(s):  
Cell Culture ◽  
3D Cell Culture ◽  
Culture Conditions ◽  
Acoustic Levitation ◽  
Cell Sheets ◽  
Cell Therapies ◽  
Cellular Models ◽  
Cell Spheroids

AbstractIn recent years, 3D cell culture models such as spheroid or organoid technologies have known important developments. Many studies have shown that 3D cultures exhibit better biomimetic properties compared to 2D cultures. These properties are important for in-vitro modeling systems, as well as for in-vivo cell therapies and tissue engineering approaches. A reliable use of 3D cellular models still requires standardized protocols with well-controlled and reproducible parameters. To address this challenge, a robust and scaffold-free approach is proposed, which relies on multi-trap acoustic levitation. This technology is successfully applied to Mesenchymal Stem Cells (MSCs) maintained in acoustic levitation over a 24-h period. During the culture, MSCs spontaneously self-organized from cell sheets to cell spheroids with a characteristic time of about 10 h. Each acoustofluidic chip could contain up to 30 spheroids in acoustic levitation and four chips could be ran in parallel, leading to the production of 120 spheroids per experiment. Various biological characterizations showed that the cells inside the spheroids were viable, maintained the expression of their cell surface markers and had a higher differentiation capacity compared to standard 2D culture conditions. These results open the path to long-time cell culture in acoustic levitation of cell sheets or spheroids for any type of cells.

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