| 1. |
- Lundqvist, Annika, 1969, et al.
(författare)
-
The Arachidonate 15-Lipoxygenase Enzyme Product 15-HETE Is Present in Heart Tissue from Patients with Ischemic Heart Disease and Enhances Clot Formation
- 2016
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:8
-
Tidskriftsartikel (refereegranskat)abstract
- Ischemic heart disease is a major cause of death and morbidity and the search for novel therapeutic targets is still required. We have previously shown that the enzyme arachidonate 15 lipoxygenase (ALOX15), which catalyzes the conversion of arachidonic acid to 15-hydroxy eicosatetraenoic acid (15-HETE), is highly expressed in ischemic heart tissue, but its role in the pathogenesis of ischemic heart disease is unclear. Here we showed that expression of ALOX15, but not ALOX12 or ALOX15B, was increased in ischemic versus non-ischemic human heart biopsy samples. A similar ALOX expression pattern was found in hypoxic human cardiomyocytes and cardiac endothelial cells. We also showed that levels of 15-HETE were significantly higher in ischemic versus non-ischemic human heart biopsy samples and showed a tendency to increase in serum from the patients with ischemic heart disease. Moreover, hypoxia increased the production of 15-HETE levels from human cardiomyocytes and cardiac endothelial cells. The hypoxia-induced increase in 15-HETE levels from human cardiomyocytes was inhibited by the ALOX15 inhibitor baicalein. Finally, by using intrinsic rotational thromboelastometry, we showed that human whole blood clotted faster in the presence of 15-HETE. In summary, we propose that increased ALOX15 expression in heart tissue under ischemic conditions may lead to increased production of 15-HETE, potentially contributing to thrombosis.
|
|
| 2. |
- Muth, Andreas, 1974, et al.
(författare)
-
Genetic testing and surveillance guidelines in hereditary pheochromocytoma and paraganglioma
- 2019
-
Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 285:2, s. 187-204
-
Tidskriftsartikel (refereegranskat)abstract
- Pheochromocytoma and paraganglioma (PPGL) are rare tumours and at least 30% are part of hereditary syndromes. Approximately 20% of hereditary PPGL are caused by pathogenic germ line variants in genes of the succinate dehydrogenase complex (SDHx), TMEM127 or MAX. Herein we present guidelines regarding genetic testing of family members and their surveillance based on a thorough literature review. All cases of PPGL are recommended genetic testing for germ line variants regardless of patient and family characteristics. At minimum, FH, NF1, RET, SDHB, SDHD and VHL should be tested. In addition, testing of MEN1, SDHA, SDHAF2, SDHC, TMEM127 and MAX is recommended. Healthy first-degree relatives (and second-degree relatives in the case of SDHD and SDHAF2 which are maternally imprinted) should be offered carrier testing. Carriers of pathogenic variants should be offered surveillance with annual biochemical measurements of methoxy-catecholamines and bi-annual rapid whole-body magnetic resonance imaging and clinical examination. Surveillance should start 5 years before the earliest age of onset in the family and thus only children eligible for surveillance should be offered pre-symptomatic genetic testing. The surveillance of children younger than 15 years needs to be individually designed. Our guidelines will provide a framework for patient management with the possibility to follow outcome via national registries and/or follow-up studies. Together with improved insights into the disease, this may enable optimisation of the surveillance scheme in order to minimise both anxiety and medical complications while ensuring early disease detection.
|
|
| 3. |
- Sandstedt, Joakim, et al.
(författare)
-
Human cardiac fibroblasts isolated from patients with severe heart failure are immune-competent cells mediating an inflammatory response.
- 2019
-
Ingår i: Cytokine. - : Elsevier BV. - 1096-0023 .- 1043-4666. ; 113, s. 319-325
-
Tidskriftsartikel (refereegranskat)abstract
- This study was aimed to elucidate the immunoregulatory properties of human cardiac fibroblasts cultured under pro-inflammatory and hypoxic conditions. Human heart tissue for isolating cardiac cells is generally hard to obtain, particularly from all four chambers of the same heart. Since different parts of the heart have different functions and therefore may have different immunoregulatory properties, ability to analyse cells from all chambers allows for a unique and comprehensive investigation. Cells were isolated from all four chambers of the heart from patients undergoing cardiac transplantation surgery due to severe chronic heart failure (CHF) (n=6). Cells isolated from one donor heart, were used for comparison with the experimental group. Primary cultured human cardiac fibroblasts were treated with Lipopolysaccharide (LPS) to induce an inflammatory response. Cells were also subjected to hypoxia. To determine immunoregulatory properties of the cells, cytokine and chemokine profiles were determined using multiplex ELISA. RESULTS: On average, the fibroblasts population constituted approximately 90% of the expanded non-myocytes. Levels of cytokines and chemokines were markedly increased in human cardiac fibroblasts cultured under inflammatory conditions, with a similar response in fibroblasts from all compartments of the heart. Unexpectedly, hypoxia did not further augment cytokine and chemokine secretion. In conclusion, human cardiac fibroblasts are a robust source of pro-inflammatory mediators in the failing heart, independent of hypoxia, and might play a critical role in inflammation associated with the pathogenesis of CHF.
|
|
| 4. |
- Sandstedt, Mikael, 1990, et al.
(författare)
-
Hypoxic cardiac fibroblasts from failing human hearts decrease cardiomyocyte beating frequency in an ALOX15 dependent manner
- 2018
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 13:8
-
Tidskriftsartikel (refereegranskat)abstract
- A common denominator for patients with heart failure is the correlation between elevated serum levels of proinflammatory cytokines and adverse clinical outcomes. Furthermore, lipoxygenase-induced inflammation is reportedly involved in the pathology of heart failure. Cardiac fibroblasts, which are abundant in cardiac tissue, are known to be activated by inflammation. We previously showed high expression of the lipoxygenase arachidonate 15 lipoxygenase (ALOX15), which catalyzes the conversion of arachidonic acid to 15-hydroxy eicosatetraenoic acid (15-HETE), in ischemic cardiac tissue. The exact roles of ALOX15 and 15-HETE in the pathogenesis of heart failure are however unknown. Biopsies were collected from all chambers of explanted failing human hearts from heart transplantation patients, as well as from the left ventricles from organ donors not suffering from chronic heart failure. Biopsies from the left ventricles underwent quantitative immunohistochemical analysis for ALOX15/B. Gene expression of ALOX enzymes, as well as 15-HETE levels, were examined in cardiac fibroblasts which had been cultured in either hypoxic or normoxic conditions after isolation from failing hearts. After the addition of fibroblast supernatants to human induced pluripotent stem cell-derived cardiomyocytes, intracellular calcium concentrations were measured to examine the effect of paracrine signaling on cardiomyocyte beating frequency. While ALOX15 and ALOX15B were expressed throughout failing hearts as well as in hearts from organ donors, ALOX15 was expressed at significantly higher levels in donor hearts. Hypoxia resulted in a significant increase in gene and protein expression of ALOX15 and ALOX15B in fibroblasts isolated from the different chambers of failing hearts. Finally, preconditioned medium from hypoxic fibroblasts decreased the beating frequency of human cardiomyocytes derived from induced pluripotent stem cells in an ALOX15-dependent manner. In summary, our results demonstrate that ALOX15/B signaling by hypoxic cardiac fibroblasts may play an important role in ischemic cardiomyopathy, by decreasing cardiomyocyte beating frequency.
|
|
| 5. |
- Sandstedt, Mikael, 1990, et al.
(författare)
-
Intracellular flow cytometry may be combined with good quality and high sensitivity RT-qPCR analysis.
- 2015
-
Ingår i: Cytometry. Part A : the journal of the International Society for Analytical Cytology. - : Wiley. - 1552-4930. ; 87:12, s. 1079-1089
-
Tidskriftsartikel (refereegranskat)abstract
- Flow cytometry (FCM) has become a well-established method for analysis of both intracellular and cell-surface proteins, while quantitative RT-PCR (RT-qPCR) is used to determine gene expression with high sensitivity and specificity. Combining these two methods would be of great value. The effects of intracellular staining on RNA integrity and RT-qPCR sensitivity and quality have not, however, been fully examined. We, therefore, intended to assess these effects further. Cells from the human lung cancer cell line A549 were fixed, permeabilized and sorted by FCM. Sorted cells were analyzed using RT-qPCR. RNA integrity was determined by RNA quality indicator analysis. A549 cells were then mixed with cells of the mouse cardiomyocyte cell line HL-1. A549 cells were identified by the cell surface marker ABCG2, while HL-1 cells were identified by intracellular cTnT. Cells were sorted and analyzed by RT-qPCR. Finally, cell cultures from human atrial biopsies were used to evaluate the effects of fixation and permeabilization on RT-qPCR analysis of nonimmortalized cells stored prior to analysis by FCM. A large amount of RNA could be extracted even when cells had been fixed and permeabilized. Permeabilization resulted in increased RNA degradation and a moderate decrease in RT-qPCR sensitivity. Gene expression levels were also affected to a moderate extent. Sorted populations from the mixed A549 and HL-1 cell samples showed gene expression patterns that corresponded to FCM data. When samples were stored before FCM sorting, the RT-qPCR analysis could still be performed with high sensitivity and quality. In summary, our results show that intracellular FCM may be performed with only minor impairment of the RT-qPCR sensitivity and quality when analyzing sorted cells; however, these effects should be considered when comparing RT-qPCR data of not fixed samples with those of fixed and permeabilized samples. © 2015 International Society for Advancement of Cytometry.
|
|
| 6. |
- Vukusic, Kristina, 1979, et al.
(författare)
-
The Atrioventricular Junction: A Potential Niche Region for Progenitor Cells in the Adult Human Heart
- 2019
-
Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 28:16, s. 1078-1088
-
Tidskriftsartikel (refereegranskat)abstract
- A stem cell niche is a microenvironment where stem cells reside in a quiescent state, until activated. In a previous rat model, we combined 5-bromo-2-deoxy-uridine labeling with activation of endogenous stem cells by physical exercise and revealed a distinct region, in the atrioventricular junction (AVj), with features of a stem cell niche. In this study, we aim to investigate whether a similar niche exists in the human heart. Paired biopsies from AVj and left ventricle (LV) were collected both from explanted hearts of organ donors, not used for transplantation (N = 7) and from severely failing hearts from patients undergoing heart transplantation (N = 7). Using antibodies, we investigated the expression of stem cell, hypoxia, proliferation and migration biomarkers. In the collagen-dense region of the AVj in donor hearts, progenitor markers, MDR1, SSEA4, ISL1, WT1, and hypoxia marker, HIF1-alpha, were clearly detected. The expression gradually decreased with distance from the valve. At the myocardium border in the AVj costaining of the proliferation marker Ki67 with cardiomyocyte nuclei marker PCM1 and cardiac Troponin-T (cTnT) indicated proliferation of small cardiomyocytes. In the same site we also detected ISL1(+)/WT1(+)/cTnT cells. In addition, heterogeneity in cardiomyocyte sizes was noted. Altogether, these findings indicate different developmental stages of cardiomyocytes below the region dense in stem cell marker expression. In patients suffering from heart failure the AVj region showed signs of impairment generally displaying much weaker or no expression of progenitor markers. We describe an anatomic structure in the human hearts, with features of a progenitor niche that coincided with the same region previously identified in rats with densely packed cells expressing progenitor and hypoxia markers. The data provided in this study indicate that the adult heart contains progenitor cells and that AVj might be a specific niche region from which the progenitors migrate at the time of regeneration.
|
|
| 7. |
- Caddeo, Andrea, et al.
(författare)
-
Molecular analysis of three known and one novel LPL variants in patients with type I hyperlipoproteinemia.
- 2018
-
Ingår i: Nutrition, metabolism, and cardiovascular diseases : NMCD. - : Elsevier BV. - 1590-3729 .- 0939-4753. ; 28, s. 158-164
-
Tidskriftsartikel (refereegranskat)abstract
- Type I hyperlipoproteinemia, also known as familial chylomicronemia syndrome (FCS), is a rare autosomal recessive disorder caused by variants in LPL, APOC2, APOA5, LMF1 or GPIHBP1 genes. The aim of this study was to identify novel variants in the LPL gene causing lipoprotein lipase deficiency and to understand the molecular mechanisms.A total of 3 individuals with severe hypertriglyceridemia and recurrent pancreatitis were selected from the Lipid Clinic at Sahlgrenska University Hospital and LPL was sequenced. Invitro experiments were performed in human embryonic kidney 293T/17 (HEK293T/17) cells transiently transfected with wild type or mutant LPL plasmids. Cell lysates and media were used to analyze LPL synthesis and secretion. Media were used to measure LPL activity. Patient 1 was compound heterozygous for three known variants: c.337T>C (W113R), c.644G>A (G215E) and c.1211T>G (M404R); patient 2 was heterozygous for the known variant c.658A>C (S220R) while patient 3 was homozygous for a novel variant in the exon 5 c.679G>T (V227F). All the LPL variants identified were loss-of-function variants and resulted in a substantial reduction in the secretion of LPL protein.We characterized at the molecular level three known and one novel LPL variants causing type I hyperlipoproteinemia showing that all these variants are pathogenic.
|
|
| 8. |
- De Geer, Jakob, et al.
(författare)
-
Software-based on-site estimation of fractional flow reserve using standard coronary CT angiography data.
- 2016
-
Ingår i: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 57:10, s. 1186-1192
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The significance of a coronary stenosis can be determined by measuring the fractional flow reserve (FFR) during invasive coronary angiography. Recently, methods have been developed which claim to be able to estimate FFR using image data from standard coronary computed tomography angiography (CCTA) exams.PURPOSE: To evaluate the accuracy of non-invasively computed fractional flow reserve (cFFR) from CCTA.MATERIAL AND METHODS: A total of 23 vessels in 21 patients who had undergone both CCTA and invasive angiography with FFR measurement were evaluated using a cFFR software prototype. The cFFR results were compared to the invasively obtained FFR values. Correlation was calculated using Spearman's rank correlation, and agreement using intraclass correlation coefficient (ICC). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for significant stenosis (defined as both FFR ≤0.80 and FFR ≤0.75) were calculated.RESULTS: The mean cFFR value for the whole group was 0.81 and the corresponding mean invFFR value was 0.84. The cFFR sensitivity for significant stenosis (FFR ≤0.80/0.75) on a per-lesion basis was 0.83/0.80, specificity was 0.76/0.89, and accuracy 0.78/0.87. The positive predictive value was 0.56/0.67 and the negative predictive value was 0.93/0.94. The Spearman rank correlation coefficient was ρ = 0.77 (P < 0.001) and ICC = 0.73 (P < 0.001).CONCLUSION: This particular CCTA-based cFFR software prototype allows for a rapid, non-invasive on-site evaluation of cFFR. The results are encouraging and cFFR may in the future be of help in the triage to invasive coronary angiography.
|
|
| 9. |
- Pavanello, Chiara, et al.
(författare)
-
Individuals with familial hypercholesterolemia and cardiovascular events have higher circulating Lp(a) levels.
- 2019
-
Ingår i: Journal of clinical lipidology. - : Elsevier BV. - 1933-2874. ; 13:5
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular disease (CVD) is a major cause of mortality and morbidity. Increased low-density lipoprotein cholesterol (LDL-C) level is its major risk factor. Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated LDL-C since birth and subsequent premature CVD. There is a heterogeneity in the CVD onset in patients with FH. This is potentially due to the presence of other independent risk factors. Lipoprotein(a) [Lp(a)] is an LDL-like particle and represents a strong risk factor for CVD.Our objective was to understand the contribution of Lp(a) in the susceptibility to CVD in individuals with genetic diagnosis of FH.We measured Lp(a) levels in 2 independent and well-characterized genetic-FH cohorts: the FH-Gothenburg cohort (n=190) and the FH-CEGP Milan cohort (n=160). The genetic diagnosis was performed by targeted next-generation sequencing (FH-Gothenburg and part of the FH-CEGP Milan cohort), or by Sanger sequencing.We show that among individuals with genetic diagnosis of FH, those with previous CVD had higher Lp(a) levels. In addition, analyzing the response to the lipid-lowering therapies, we have also shown that statins had the same LDL-C-lowering effect irrespective of the type of FH-causative mutation. However, when we examined the lipid-lowering effect of proprotein convertase subtilisin/kexin type 9 inhibition by antibodies, we observed a trend in a better reduction of the LDL-C level in carriers of nonsense mutations.In conclusion, our results suggest that Lp(a) contributes to CVD onset in individuals with genetic diagnosis of FH. Our finding supports the importance to identify an efficacious therapy to lower Lp(a) in patients with FH to prevent CVD onset or recurrence.
|
|
| 10. |
- Rotter Sopasakis, Victoria, 1972, et al.
(författare)
-
Toll-like receptor-mediated inflammation markers are strongly induced in heart tissue in patients with cardiac disease under both ischemic and non-ischemic conditions.
- 2019
-
Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 293, s. 238-247
-
Tidskriftsartikel (refereegranskat)abstract
- A sustained low grade inflammatory state is a recognized feature of various diseases, including cardiovascular disease. This state of chronic inflammation involves activation of Toll-like receptor (TLR) signaling. However, little is known regarding the genetic profile of TLR components in cardiac tissue from patients with cardiac disease.In this study we investigated the genetic profile of 84 TLR markers in a unique set of cardiac tissue from patients that had undergone either coronary artery bypass grafting (CABG) or aortic valve replacement (AVR). In addition, we compared the gene data from the cardiac tissue with the same gene profile in blood as well as circulating cytokines to elucidate possible targets in blood that could be used to estimate the inflammatory state of the heart in cardiac disease.We found a marked upregulation of TLR-induced inflammation in cardiac tissue from both patient groups compared to healthy controls. The inflammation appeared to be primarily mediated through TLR1, 3, 7, 8 and 10, resulting in a marked induction of mediators of the innate immune response. Furthermore, the gene expression data in combination with unbiased multivariate analysis suggested a difference in inflammatory response in ischemic cardiac tissue compared to non-ischemic cardiac tissue. Serum levels of IL-13 were significantly elevated in both CABG and AVR patients compared to controls, whereas other cytokines did not appear to coincide with cardiac TLR-induced inflammation.We propose that cardiac disease in humans may be mediated by local cardiac TLR signaling under both ischemic and non-ischemic conditions.
|
|
