scholarly journals Genomic and transcriptomic data analyses highlight KPNB1 and MYL4 as novel risk genes for congenital heart disease

Author(s):  
Martin Broberg ◽  
Minna Ampuja ◽  
Samuel Jones ◽  
Tiina Ojala ◽  
Otto Rahkonen ◽  
...  

AbstractCongenital heart defects (CHD) are structural defects of the heart affecting approximately 1% of newborns. CHDs exhibit a complex inheritance pattern. While genetic factors are known to play an important role in the development of CHD, relatively few variants have been discovered so far and very few genome-wide association studies (GWAS) have been conducted. We performed a GWAS of general CHD and five CHD subgroups in FinnGen followed by functional fine-mapping through eQTL analysis in the GTEx database, and target validation in human induced pluripotent stem cell - derived cardiomyocytes (hiPS-CM) from CHD patients. We discovered that the MYL4-KPNB1 locus (rs11570508, beta = 0.24, P = 1.2×10−11) was associated with the general CHD group. An additional four variants were significantly associated with the different CHD subgroups. Two of these, rs1342740627 associated with left ventricular outflow tract obstruction defects and rs1293973611 associated with septal defects, were Finnish population enriched. The variant rs11570508 associated with the expression of MYL4 (normalized expression score (NES) = 0.1, P = 0.0017, in the atrial appendage of the heart) and KPNB1 (NES = -0.037, P = 0.039, in the left ventricle of the heart). Furthermore, lower expression levels of both genes were observed in human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM) from CHD patients compared to healthy controls. Together, the results demonstrate KPNB1 and MYL4 as in a potential genetic risk loci associated with the development of CHD.

2019 ◽  
Vol 115 (5) ◽  
pp. 949-959 ◽  
Author(s):  
Nazish Sayed ◽  
Mohamed Ameen ◽  
Joseph C Wu

Abstract Treatment of cancer has evolved in the last decade with the introduction of new therapies. Despite these successes, the lingering cardiotoxic side-effects from chemotherapy remain a major cause of morbidity and mortality in cancer survivors. These effects can develop acutely during treatment, or even years later. Although many risk factors can be identified prior to beginning therapy, unexpected toxicity still occurs, often with lasting consequences. Specifically, cardiotoxicity results in cardiac cell death, eventually leading to cardiomyopathy and heart failure. Certain risk factors may predispose an individual to experiencing adverse cardiovascular effects, and when unexpected cardiotoxicity occurs, it is generally managed with supportive care. Animal models of chemotherapy-induced cardiotoxicity have provided some mechanistic insights, but the precise mechanisms by which these drugs affect the heart remains unknown. Moreover, the genetic rationale as to why some patients are more susceptible to developing cardiotoxicity has yet to be determined. Many genome-wide association studies have identified genomic variants that could be associated with chemotherapy-induced cardiotoxicity, but the lack of validation has made these studies more speculative rather than definitive. With the advent of human induced pluripotent stem cell (iPSC) technology, researchers not only have the opportunity to model human diseases, but also to screen drugs for their efficacy and toxicity using human cell models. Furthermore, it allows us to conduct validation studies to confirm the role of genomic variants in human diseases. In this review, we discuss the role of iPSCs in modelling chemotherapy-induced cardiotoxicity.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Sherri M Biendarra-tiegs ◽  
Sergey Yechikov ◽  
Laura Houshmand ◽  
R. E Gonzalez ◽  
Zhi Hong Lu ◽  
...  

Atrial fibrillation (AF) poses a notable healthcare burden due to a high incidence in the increasing population over age 65 and limitations of current treatment approaches. One challenge to effectively treat AF is patient-to-patient heterogeneity in the underlying mechanisms of disease. Therefore, a better understanding of AF pathogenesis and more personalized approaches to therapy could reduce risk of side effects and improve therapeutic efficacy. Genome wide association studies (GWAS) have revealed several candidate genes for AF including TBX5 , which encodes for a transcription factor involved in heart development. While work in animal models suggests that loss of TBX5 promotes atrial arrythmias, experimental evidence in human cells is lacking. We created an in vitro model of human atrial conduction using day 60+ induced pluripotent stem cell-derived atrial-like cardiomyocytes (iPSC-aCMs) differentiated from three established healthy iPSC lines. Over 90% atrial-like purity (out of 350+ alpha-actinin positive cardiomyocytes) could be achieved based on MLC2v-/MLC2a+ immunofluorescent staining. TBX5 knockdown via esiRNA resulted in downregulation of genes related to conduction velocity ( GJA5 and SCN5A ), consistent with an enhanced risk of AF. Single cell optical electrophysiology demonstrated slightly reduced action potential amplitude and upstroke velocity for TBX5 knockdown cells versus GFP esiRNA controls, suggesting a functional effect of SCN5A downregulation. Additionally, microelectrode array studies have revealed a trend towards slowed conduction velocity with TBX5 knockdown compared to GFP esiRNA controls (13.1±3.0 cm/s vs 17.0±3.8 cm/s respectively). By further investigating the functional effects of modulating transcription factors such as TBX5 in iPSC-aCMs, our results provide enhanced insight into the regulation of atrial conduction and identify potential AF-related pathways for therapeutic targeting.


2017 ◽  
Vol 37 (11) ◽  
pp. 2000-2006 ◽  
Author(s):  
Hanrui Zhang ◽  
Muredach P. Reilly

Despite a substantial appreciation for the critical role of macrophages in cardiometabolic diseases, understanding of human macrophage biology has been hampered by the lack of reliable and scalable models for cellular and genetic studies. Human induced pluripotent stem cell (iPSC)–derived macrophages (IPSDM), as an unlimited source of subject genotype-specific cells, will undoubtedly play an important role in advancing our understanding of the role of macrophages in human diseases. In this review, we summarize current literature in the differentiation and characterization of IPSDM at phenotypic, functional, and transcriptomic levels. We emphasize the progress in differentiating iPSC to tissue resident macrophages, and in understanding the ontogeny of in vitro differentiated IPSDM that resembles primitive hematopoiesis, rather than adult definitive hematopoiesis. We review the application of IPSDM in modeling both Mendelian genetic disorders and host–pathogen interactions. Finally, we highlighted the potential areas of research using IPSDM in functional validation of coronary artery disease loci in genome-wide association studies, functional genomic analyses, drug testing, and cell therapeutics in cardiovascular diseases.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Jordan J Lancaster ◽  
Ike Chinyere ◽  
Bin Na Kim ◽  
Sherry Daugherty ◽  
Samuel Kim ◽  
...  

Introduction: Previously we have demonstrated that a tissue engineered heart patch comprised of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) and fibroblasts improves both left ventricular (LV) systolic and diastolic function in a rat model of CHF. In this study we tested the feasibility of upscaling cardiac patch size and surgical deployment in a swine model of CHF to test clinical utility. Methods: Four male Gottingen mini swine 20-25kg and three domestic swine 50-60kg were infarcted using percutaneous methods. Embolizing coils were deployed via catheter distal to the first diagonal branch of the left anterior descending (LAD) coronary artery and animals recovered for 4 weeks. Cardiac patches engineered with bio absorbable polygalactin-910 knitted mesh, dermal fibroblasts and hiPSC-CMs were cultured and implanted on the infarcted epicardium 4 weeks after MI. Cardiac magnetic resonance imaging was performed at baseline, 4 and 8 weeks post MI. All swine were implanted with continuous event recorders to acquire surface electrocardiogram during the entire study. In addition quality of life and functional capacity were assessed through video monitoring and treadmill exertion testing respectively. Infarct size was determined through 2,3,5-triphenyltetrazolium chloride staining. Results: LAD occlusion resulted in a significant (P<0.05) decrease EF (15%), and increase in EDV (59%) and ESV (100%). Average TIMI score decreased from 3.0±0 at time of MI to 1.5±0.6 4wks post MI. Cardiac patches were upsized to 6cm diameter for application in the swine. Patches displayed synchronous and spontaneous contractions within 48hrs. The 6cm patches, when implanted effectively covered the infarcted region bridging viable myocardium. Surgical handling and epicardial deployment was successfully accomplished via median sternotomy. The patches were robust in nature and could be deployed via a minimally invasive robotic procedure. No adverse arrhythmic activity was observed. Implantation of the cardiac patch restored activity levels (quality of life) of patch treated swine vs CHF controls. Conclusion: Our hiPSC-CM cardiac patch can be constructed in a clinical size, easily handled and implanted on the epicardium of the infarcted heart.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Wenyi Chen ◽  
Johannes Riegler ◽  
Elena Matsa ◽  
Qi Shen ◽  
Haodi Wu ◽  
...  

Introduction: Both human embryonic stem cell-derived cardiomyocytes (ESC-CMs) and human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) can serve as an unlimited cell source for cardiac regenerative therapy. However, the functional equivalency of both approaches has not been previously reported. Here we performed head-to-head comparison on the beneficial effects of ESC-CM and iPSC-CMs in restoring cardiac function in a rat myocardial infarction (MI) model. Methods & Results: Human ESCs and iPSCs were differentiated into cardiomyocytes using small molecules. FACS analysis confirmed ~85% and ~83% of cells differentiated from ESCs and iPSCs, respectively, were positive for cardiac troponin T, and immunofluorescence staining demonstrated that ESC-CMs and iPSC-CMs have striated sarcomeric structure (Figure A-B). Both ESC-CMs and iPSC-CMs displayed similar maturity for calcium handling (transient amplitude: ΔF/F 0 = 3.8±0.3; time to peak: ~200 ms; 50% transient duration: ~400 ms). qRT-PCR showed that ESC-CMs and iPSC-CMs expressed CASQ2, GJA5, KCNJ2, KCNJ5, MYH6, MYH7, and SCN5A at comparable levels to human fetal heart tissue. Next, ESC-CMs and iPSC-CMs were injected into the left ventricular free wall of infarcted hearts (adult nude rats; n=14, 10, respectively). Cardiac function was assessed by MRI one month post cell injection and the hearts were harvested and stained for human cardiac markers. Both ESC-CMs and iPSC-CMs could engraft in ischemic rat hearts (Figure C). Comprehensive functional analysis with small animal magnetic resonance imaging (MRI), echocardiography, and pressure-volume loop analysis are underway. Conclusion: We set out to perform head to head comparison for the first time that iPSC-CMs may facilitate cardiac repair at comparable levels to ESC-CMs. Unlike allogeneic ESC-CM therapy, autologous iPSC-CMs could be used to overcome immune rejection for cardiac cell transplantation in the future.


2019 ◽  
Vol 116 (3) ◽  
pp. 671-685 ◽  
Author(s):  
Xi Lou ◽  
Meng Zhao ◽  
Chengming Fan ◽  
Vladimir G Fast ◽  
Mani T Valarmathi ◽  
...  

Abstract Aims In regenerative medicine, cellular cardiomyoplasty is one of the promising options for treating myocardial infarction (MI); however, the efficacy of such treatment has shown to be limited due to poor survival and/or functional integration of implanted cells. Within the heart, the adhesion between cardiac myocytes (CMs) is mediated by N-cadherin (CDH2) and is critical for the heart to function as an electromechanical syncytium. In this study, we have investigated whether the reparative potency of human-induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) can be enhanced through CDH2 overexpression. Methods and results CDH2-hiPSC-CMs and control wild-type (WT)-hiPSC-CMs were cultured in myogenic differentiation medium for 28 days. Using a mouse MI model, the cell survival/engraftment rate, infarct size, and cardiac functions were evaluated post-MI, at Day 7 or Day 28. In vitro, conduction velocities were significantly greater in CDH2-hiPSC-CMs than in WT-hiPSC-CMs. While, in vivo, measurements of cardiac functions: left ventricular (LV) ejection fraction, reduction in infarct size, and the cell engraftment rate were significantly higher in CDH2-hiPSC-CMs treated MI group than in WT-hiPSC-CMs treated MI group. Mechanistically, paracrine activation of ERK signal transduction pathway by CDH2-hiPSC-CMs, significantly induced neo-vasculogenesis, resulting in a higher survival of implanted cells. Conclusion Collectively, these data suggest that CDH2 overexpression enhances not only the survival/engraftment of cultured CDH2-hiPSC-CMs, but also the functional integration of these cells, consequently, the augmentation of the reparative properties of implanted CDH2-hiPSC-CMs in the failing hearts.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Connor G OBrien ◽  
Evgeniya Vaskova ◽  
Yuko Tada ◽  
Jihye Jung ◽  
Gentaro Ikeda ◽  
...  

Introduction: Coronary artery disease is a leading cause of death worldwide. Ischemic injury leads to myocardial dysfunction, resulting in heart failure. Exosomes have emerged as a promising therapeutic for restoring the failing heart. Fundamental questions such as cell of origin and molecular cargo for optimal therapeutic effect are areas of intense research. Our lab has shown that the exosomes from bone marrow derived mesenchymal stem cells (MSC-Ex) and induced pluripotent stem cell derived cardiomyocytes (iCM-Ex) both restore injured murine myocardium. These results led us to compare the therapeutic effects of MSC-Ex vs. iCM-Ex in a porcine myocardial ischemia reperfusion (IR) injury model, a step toward predicting efficacy in humans. Hypothesis: iCM-Ex is superior to MSC-Ex in restoring the injured porcine myocardium. Methods and Results: Pigs underwent ischemia reperfusion (IR) injury, consisting of 1 hour percutaneous balloon occlusion of the proximal left anterior descending artery immediately distal to the first septal artery. Following IR injury, 5 x 10 11 exosomes were delivered in ten, 500μL intramyocardial injections using a BioCardio Helix™ catheter. Biplane ventriculography was used to target the peri-infarct region. At 2- and 4-weeks post-infarct, pigs underwent cardiac MRI (cMRI) with ciné, delayed-enhanced (DEMRI) and manganese-enhanced (MEMRI) MRI. Pigs treated with iCM-Ex (n = 5) demonstrated a 41% improvement in left ventricular ejection fraction (LVEF, p = 0.004) and 35% reduction in indexed left ventricular end diastolic volume (p = 0.008) compared to controls while MSC-Ex (N = 5) did not demonstrate significant functional improvement. Furthermore, DEMRI and MEMRI showed a 21% reduction in myocardial scar (p = 0.14) in iCM-Ex treated animals compared to control while MSC-Ex group showed no difference. RNA-seq of the exosomes and transcriptomic analysis of the ex vivo myocardium will delineate the molecular mechanism of action and the putative intracellular pathway. Conclusion: iCM-Ex is superior to MSC-Ex in improving LVEF and reducing myocardial scar formation following ischemic insult. Comparative analysis between iCM-Ex and MSC-Ex is underway to identify the molecular targets that restore the failing heart.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Kota Suzuki ◽  
Shigeru Miyagawa ◽  
Emiko Ito ◽  
Akima Harada ◽  
Takuji Kawamura ◽  
...  

Introduction: The progression of dilated cardiomyopathy (DCM) mainly involves genetic mutations or ischemia at the cellular level, leading to microvascular dysfunction associated with cell death, interstitial fibrosis, and high wall stress. Radical treatment of DCM requires how to ameliorate its microcirculation and integrate cardiomyocytes created ex vivo into recipient myocardium. Hypothesis: The induced pluripotent stem cell derived cardiomyocyte sheets (iPS-sheet) has therapeutic potential by the improvement of microcirculation in a porcine DCM model. Methods: The iPS-sheets were generated from clinical grade human iPS cells. A DCM model was created by tachycardia pacing, and iPS-sheet was transplanted with immunosuppressive agents 1 month after the initiation of the pacing. We compared the therapeutic efficacy functionally and pathologically between the iPS-sheet transplant group (iPS-group) and the sham group after 1 month of transplantation. Results: On echocardiography, the iPS group showed a significant improvement in contractility compared to the sham group (LVEF 4 weeks after transplantation iPS vs. sham 49.0±6.5% vs. 36.4±3.3%, p<0.05, Figure A). Pressure-volume loop analysis revealed that a significant decrease in left ventricular end diastolic pressure and an improvement in end-systolic pressure-volume relationship in the iPS group (Figure B). Ammonia PET showed improvement in myocardial blood flow at both rest and stress in iPS group (Figure C). Histological analysis revealed that the density of CD31-positive capillaries in transplanted area was significantly greater in the iPS group than the sham group. Immunostaining revealed iPS-sheet were detected on the epicardium of the distressed myocardium (Figure D). Conclusions: The iPS sheet showed engraftment in distressed myocardium, leading to amelioration in cardiac function through improving microcirculation with angiogenesis in porcine DCM model.


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