| 1. |
- Andersson, Henrik, et al.
(författare)
-
Assaying cardiac biomarkers for toxicity testing using biosensing and cardiomyocytes derived from human embryonic stem cells
- 2010
-
Ingår i: JOURNAL OF BIOTECHNOLOGY. - : Elsevier Science B.V., Amsterdam.. - 0168-1656 .- 1873-4863. ; 150:1, s. 175-181
-
Tidskriftsartikel (refereegranskat)abstract
- Human embryonic stem cell (hESC) derived cardiomyocytes are in the present study being used for testing drug-induced cardiotoxicity in a biosensor set-up. The design of an in vitro testing alternative provides a novel opportunity to surpass previous methods based on rodent cells or cell lines due to its significantly higher toxicological relevance. In this report we demonstrate how hESC-derived cardiomyocytes release detectable levels of two clinically decisive cardiac biomarkers, cardiac troponin T and fatty acid binding protein 3, when the cardiac cells are exposed to the well-known cardioactive drug compound. doxorubicin. The release is monitored by the immuno-biosensor technique surface plasmon resonance, particularly appropriate due to its capacity for parallel and high-throughput analysis in complex media.
|
|
| 2. |
- Asp, Julia, 1973, et al.
(författare)
-
Cardiomyocyte clusters derived from human embryonic stem cells share similarities with human heart tissue.
- 2010
-
Ingår i: Journal of molecular cell biology. - : Oxford University Press (OUP). - 1759-4685 .- 1674-2788. ; 2:5, s. 276-83
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiotoxicity testing is a key activity in the pharmaceutical industry in order to detect detrimental effects of new drugs. A reliable human in vitro model would both be beneficial in selection of lead compounds and be important for reducing animal experimentation. However, the human heart is a complex organ composed of many distinct types of cardiomyocytes, but cardiomyocyte clusters (CMCs) derived from human embryonic stem cells could be an option for a cellular model. Data on functional properties of CMCs demonstrate similarities to their in vivo analogues in human. However, development of an in vitro model requires a more thorough comparison of CMCs to human heart tissue. Therefore, we directly compared individually isolated CMCs to human fetal, neonatal, adult atrial and ventricular heart tissues. Real-time qPCR analysis of mRNA levels and protein staining of ion channels and cardiac markers showed in general a similar expression pattern in CMCs and human heart. Moreover, a significant decrease in beat frequency was noted after addition of Zatebradine, a blocker to I(f) involved in regulation of spontaneous contraction in CMCs. The results underscore the similarities of CMCs to human cardiac tissue, and further support establishment of novel cardiotoxicity assays based on the CMCs in drug discovery.
|
|
| 3. |
- Gäbel, Jakob, 1971, et al.
(författare)
-
Cell salvage of cardiotomy suction blood improves the balance between pro- and anti-inflammatory cytokines after cardiac surgery.
- 2013
-
Ingår i: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. - : Oxford University Press (OUP). - 1873-734X. ; 44:3, s. 506-11
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The inflammatory response after cardiac surgery is characterized by a profound release of pro- and anti-inflammatory cytokines. Recent data suggest that the balance between pro- and anti-inflammatory cytokines is of greater importance than the absolute levels. Retransfusion of unwashed cardiotomy suction blood contributes to the inflammatory response, but the balance between pro- and anti-inflammatory cytokines in cardiotomy suction blood and whether cell salvage before retransfusion influences the systemic balance have not been investigated previously. METHODS: Twenty-five coronary artery bypass grafting patients were randomized to either cell salvage of cardiotomy suction blood or no cell salvage before retransfusion. Plasma levels of three anti-inflammatory cytokines [interleukin (IL)-1 receptor antagonist, IL-4 and IL-10] and two proinflammatory cytokines (tumour necrosis factor-alpha and IL-6), and the IL-6-to-IL-10 ratio was measured in cardiotomy suction blood before and after cell salvage, and in the systemic circulation before, during and after surgery. RESULTS: Plasma levels of all cytokines except IL-4 and IL-10 were significantly higher in cardiotomy suction blood than in the systemic circulation. The IL-6-to-IL-10 ratio was 6-fold higher in cardiotomy suction blood than in the systemic circulation [median 10.2 (range 1.1-75) vs 1.7 (0.2-24), P < 0.001]. Cell salvage reduced plasma levels of cytokines in cardiotomy suction blood and improved the systemic IL-6-to-IL-10 ratio 24 h after surgery [median 5.2 (3.6-17) vs 12.4 (4.9-31)] compared with no cell salvage (P = 0.032). CONCLUSIONS: The balance of pro- and anti-inflammatory cytokines in cardiotomy suction blood is unfavourable. Cell salvage reduces the absolute levels of both pro- and anti-inflammatory cytokines in cardiotomy suction blood and improves the balance in the systemic circulation after surgery.
|
|
| 4. |
- Jonsson, Marianne, 1962, et al.
(författare)
-
Novel 3D culture system with similarities to the human heart for studies of the cardiac stem cell niche.
- 2010
-
Ingår i: Regenerative medicine. - : Future Medicine Ltd. - 1746-076X .- 1746-0751. ; 5:5, s. 725-36
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: The aim of this study was to develop a 3D culture system with similarities to the human heart, which was suitable for studies of adult cardiac stem or progenitor cells. MATERIALS & METHODS: Dissociated cells from human cardiac biopsies were placed in high-density pellet cultures and cultured for up to 6 weeks. Gene and protein expressions, analyzed by quantitative real-time PCR and immunohistochemistry, and morphology were studied in early and late pellets. RESULTS: Cells cultured in the 3D model showed similarities to human cardiac tissue. Moreover, markers for cardiac stem and progenitor cells were also detected after 6 weeks of culture, in addition to markers for signaling pathways active in stem cell niche regulation. CONCLUSIONS: The described 3D culture model could be a valuable tool when studying the influence of different compounds on proliferation and differentiation processes in cardiac stem or progenitor cells in cardiac regenerative research.
|
|
| 5. |
- Radulovic, Vladimir, 1969, et al.
(författare)
-
Sustained heparin effect contributes to reduced plasma thrombin generation capacity early after cardiac surgery.
- 2012
-
Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 130:5
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Thrombin is a key component in the coagulation cascade, and impaired thrombin generation has been linked to increased bleeding after surgical procedures. The aim was to evaluate postoperative thrombin generation capacity in plasma after cardiac surgery, and its potential associations to activity of individual coagulation factors and heparin. MATERIAL AND METHODS: Forty-eight coronary artery bypass grafting patients were included in a prospective observational cohort study. Thrombin generation capacity was analysed in plasma with calibrated automated thrombogram with tissue factor as activator before (baseline), and 2h and 24h after surgery. In addition, plasma activity of coagulation factors II, V, VII, VIII, IX, X, XI, XIII, were determined. Heparin effect was assessed by anti-Xa activity, APTT and thrombin time. RESULTS: Thrombin generation was markedly reduced 2h after surgery compared to baseline. Peak levels decreased with median 74% (interquartile range 52-90), p<0.001, and endogenous thrombin generation potential decreased with 65% (43-86), p<0.001. Postoperative changes in endogenous thrombin generation potential correlated inversely to changes in anti-Xa activity (r=-0.51, p=0.010) and to changes in thrombin time (r=-0.51, p=0.009), but there were no correlations to changes in individual coagulation factor activity. CONCLUSIONS: A marked reduction in thrombin generation potential was observed in the early postoperative phase after cardiac surgery. The decrease was independent of reductions in individual coagulation factor activity but correlated to heparin effects. The results indicate that a sustained heparin effect contributes to the postoperative reduction in thrombin generation capacity.
|
|
| 6. |
- Sandstedt, Joakim, et al.
(författare)
-
C-kit+ CD45- cells found in the adult human heart represent a population of endothelial progenitor cells.
- 2010
-
Ingår i: Basic research in cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 105:4, s. 545-56
-
Tidskriftsartikel (refereegranskat)abstract
- Although numerous reports support the existence of stem cells in the adult heart, few studies have been conducted using human cardiac tissue. Therefore, cells from human cardiac atrial biopsies were analyzed regarding progenitor properties. Expression of stem cell markers was analyzed using fluorescence-activated cell sorting. This identified a small population of C-kit+ cells, which could be further subdivided based on expression of CD45. The C-kit+ CD45+ population was determined to be of mast cell identity, while the C-kit+ CD45- population expressed mRNA of the endothelial lineage. Since the number of cells obtainable from biopsies was limited, a comparison between directly isolated and monolayer and explant cultured cells, respectively, was carried out. While both cultures retained a small population of mast cells, only monolayer culture produced a stable and relatively high percentage of C-kit+ CD45- cells. This population was found to co-express endothelial progenitor cell markers such as CD31, CD34, CXCR4, and FLK-1. The mRNA expression profile was similar to the one from directly isolated cells. When sorted cells were cultured in endothelial differentiation medium, the C-kit+ CD45- population retained its expression of endothelial markers to a large extent, but downregulated progenitor markers, indicating further differentiation into endothelial cells. We have confirmed that the human cardiac atrium contains a small C-kit+ CD45- population expressing markers commonly found on endothelial progenitor cells. The existence of an endothelial progenitor population within the heart might have future implications for developing methods of inducing neovascularization after myocardial infarction.
|
|
| 7. |
- Sandstedt, Joakim, et al.
(författare)
-
Human C-kit+CD45- cardiac stem cells are heterogeneous and display both cardiac and endothelial commitment by single-cell qPCR analysis.
- 2014
-
Ingår i: Biochemical and biophysical research communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 443:1
-
Tidskriftsartikel (refereegranskat)abstract
- C-kit expressing cardiac stem cells have been described as multipotent. We have previously identified human cardiac C-kit+CD45- cells, but only found evidence of endothelial commitment. A small cardiac committed subpopulation within the C-kit+CD45- population might however be present. To investigate this at single-cell level, right and left atrial biopsies were dissociated and analyzed by FACS. Only right atrial biopsies contained a clearly distinguishable C-kit+CD45- population, which was single-cell sorted for qPCR. A minor portion of the sorted cells (1.1%) expressed early cardiac gene NKX2.5 while most of the cells (81%) expressed late endothelial gene VWF. VWF- cells were analyzed for a wider panel of genes. One group of these cells expressed endothelial genes (FLK-1, CD31) while another group expressed late cardiac genes (TNNT2, ACTC1). In conclusion, human C-kit+CD45- cells were predominantly localized to the right atrium. While most of these cells expressed endothelial genes, a minor portion expressed cardiac genes.
|
|
| 8. |
- Sandstedt, Joakim, et al.
(författare)
-
Left atrium of the human adult heart contains a population of side population cells.
- 2012
-
Ingår i: Basic research in cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 107:2
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiac "side population" (SP) cells have previously been found to differentiate into both endothelial cells and cardiomyocytes in mice and rats, but there are no data on SP cells in the human adult heart. Therefore, human cardiac atrial biopsies were dissociated, stained for SP cells and analyzed with FACS. Identified cell populations were analyzed for gene expression by quantitative real-time PCR and subjected to in vitro differentiation. Only biopsies from the left atrium contained a clearly distinguishable population of SP cells (0.22 ± 0.08%). The SP population was reduced by co-incubation with MDR1 inhibitor Verapamil, while the ABCG2 inhibitor FTC failed to decrease the number of SP cells. When the gene expression was analyzed, SP cells were found to express significantly more MDR1 than non-SP cells. For ABCG2, there was no detectable difference. SP cells also expressed more of the stem cell-associated markers C-KIT and OCT-4 than non-SP cells. On the other hand, no significant difference in the expression of endothelial and cardiac genes could be detected. SP cells were further subdivided based on CD45 expression. The CD45-SP population showed evidence of endothelial commitment at gene expression level. In conclusion, the results show that a SP population of cells is present also in the human adult heart.
|
|
| 9. |
- Sandstedt, Joakim, et al.
(författare)
-
SSEA-4+ CD34- Cells in the Adult Human Heart Show the Molecular Characteristics of a Novel Cardiomyocyte Progenitor Population.
- 2014
-
Ingår i: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 199:2-3, s. 103-116
-
Tidskriftsartikel (refereegranskat)abstract
- Stage-specific embryonic antigen (SSEA) expression is used to describe the differentiation state of an embryonic stem cell (ESC). In human ESCs, SSEA-3 and SSEA-4 are highly expressed in undifferentiated cells and downregulated upon differentiation. SSEA-4 has also been described as a marker for adult stem cells in various tissues, including human neonatal cardiac tissue. However, there is currently little data on the expression of SSEAs in human adult cardiac tissue. We obtained right and left atrial biopsies from patients undergoing cardiac surgery. These were dissociated, stained for SSEAs and other cardiac stem cell markers and analyzed by flow cytometry. Directly isolated cells expressed variable levels of SSEA-1, SSEA-3 and SSEA-4. The SSEA-1+ population was established as contaminating hematopoietic cells. The SSEA-4+ population, on the other hand, could be subdivided based on the endothelial progenitor marker CD34. The SSEA-4+ CD34- population in the right atrium had a high gene expression of both early (TBX5, NKX2.5) and late (TNNT2) cardiomyocyte markers. The SSEA-4+ CD34+ population, on the other hand, overlapped with previously described C-kit+ CD45- cardiac stem cells. Primary monolayer-cultured cells retained expression of SSEAs while the cardiomyogenic specification in the SSEA-4+ CD34- population was lost. In tissue sections, SSEA-4+ cells could be identified both within and outside the myocardium. Within the myocardium, some SSEA-4+ cells coexpressed cardiomyogenic markers. In conclusion, the results show that the adult human heart expresses SSEAs and that there is a subpopulation of SSEA-4+ CD34- cells that show features of a cardiomyocyte progenitor population. © 2014 S. Karger AG, Basel.
|
|
| 10. |
|
|
