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Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by MeCP2 mutations. Nonetheless, the pathophysiological roles of MeCP2 mutations in the etiology of intrinsic cardiac abnormality and sudden death remain unclear. In this study, we performed a detailed functional studies (calcium and electrophysiological analysis) and RNA-sequencing-based transcriptome analysis of a pair of isogenic RTT female patient-specific induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs) that expressed either MeCP2wildtype or MeCP2mutant allele and iPSC-CMs from a non-affected female control. The observations were further confirmed by additional experiments, including Wnt signaling inhibitor treatment, siRNA-based gene silencing, and ion channel blockade. Compared with MeCP2wildtype and control iPSC-CMs, MeCP2mutant iPSC-CMs exhibited prolonged action potential and increased frequency of spontaneous early after polarization. RNA sequencing analysis revealed up-regulation of various Wnt family genes in MeCP2mutant iPSC-CMs. Treatment of MeCP2mutant iPSC-CMs with a Wnt inhibitor XAV939 significantly decreased the β-catenin protein level and CACN1AC expression and ameliorated their abnormal electrophysiological properties. In summary, our data provide novel insight into the contribution of activation of the Wnt/β-catenin signaling cascade to the cardiac abnormalities associated with MeCP2 mutations in RTT. [ABSTRACT FROM AUTHOR]

Background: A high proportion of COVID-19 patients were reported to have cardiac involvements. Data pertaining to cardiac sequalae is of urgent importance to define subsequent cardiac surveillance. Methods: We performed a systematic cardiac screening for 97 consecutive COVID-19 survivors including electrocardiogram (ECG), echocardiography, serum troponin and NT-proBNP assay 1–4 weeks after hospital discharge. Treadmill exercise test and cardiac magnetic resonance imaging (CMR) were performed according to initial screening results. Results: The mean age was 46.5 ± 18.6 years; 53.6% were men. All were classified with non-severe disease without overt cardiac manifestations and did not require intensive care. Median hospitalization stay was 17 days and median duration from discharge to screening was 11 days. Cardiac abnormalities were detected in 42.3% including sinus bradycardia (29.9%), newly detected T-wave abnormality (8.2%), elevated troponin level (6.2%), newly detected atrial fibrillation (1.0%), and newly detected left ventricular systolic dysfunction with elevated NT-proBNP level (1.0%). Significant sinus bradycardia with heart rate below 50 bpm was detected in 7.2% COVID-19 survivors, which appeared to be self-limiting and recovered over time. For COVID-19 survivors with persistent elevation of troponin level after discharge or newly detected T wave abnormality, echocardiography and CMR did not reveal any evidence of infarct, myocarditis, or left ventricular systolic dysfunction. Conclusion: Cardiac abnormality is common amongst COVID-survivors with mild disease, which is mostly self-limiting. Nonetheless, cardiac surveillance in form of ECG and/or serum biomarkers may be advisable to detect more severe cardiac involvement including atrial fibrillation and left ventricular dysfunction. [ABSTRACT FROM AUTHOR]

A bstract Recent pre-clinical and clinical studies have suggested that endogenous cardiospheres (eCS) are potentially safe and effective for cardiac regeneration following myocardial infarction (MI). Nevertheless the preparation of autologous eCS requires invasive myocardial biopsy with limited yield. We describe a novel approach to generate induced cardiospheres (iCS) from adult skin fibroblasts via somatic reprogramming. After infection with Sox2, Klf4, and Oct4, iCS were generated from mouse adult skin fibroblasts treated with Gsk3β inhibitor-(2′Z,3′E)- 6-Bromoindirubin-3′-oxime and Oncostatin M. They resembled eCS, but contained a higher percentage of cells expressing Mesp1, Isl1, and Nkx2.5. They were differentiated into functional cardiomyocytes in vitro with similar electrophysiological properties, calcium transient and contractile function to eCS and mouse embryonic stem cell-derived cardiomyocytes. Transplantation of iCS (1 × 106 cells) into mouse myocardium following MI had similar effects to transplantation of eCS but significantly better than saline or fibroblast in improving left ventricular ejection fraction, increasing anterior/septal ventricular wall thickness and capillary density in the infarcted region 4 weeks after transplantation. No tumor formation was observed. iCS generated from adult skin fibroblasts by somatic reprogramming and a cocktail of Gsk3β inhibitor-6-Bromoindirubin-3′-oxime and Oncostatin M may represent a novel source for cell therapy in MI. S tem C ells 2016;34:2693-2706 [ABSTRACT FROM AUTHOR]

Aims: Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear.Methods and Results: We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05).Conclusions: In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover. [ABSTRACT FROM AUTHOR]

Background/Aims: Multiple sclerosis (MS) causes significant neurological disability. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS. Human bone marrow mesenchymal stem cells (hMSCs) possess anti-inflammatory and immunosuppressive effects. We studied whether hMSCs affect CD1dhighCD5+ regulatory B-cell activity in EAE. Methods: EAE was induced in C57BL/6N mice by immunization with MOG35-55 peptide. hMSCs were injected intravenously into EAE mice on day 3 and day 12 after first immunization. Mice were sacrificed on day 26. Immunohistochemistry of the spinal cord, serum cytokines levels, production of cytokines by cultured splenic cells, and flow cytometry for splenic Th17 and CD1dhighCD5+ regulatory B cells were studied. Results: EAE mice with hMSC treatment on day 3 and day 12 had reduced EAE scores from day 14 to day 26 compared to EAE mice without hMSC treatment, and reduced infiltration of inflammatory cells and demyelination in the spinal cord. EAE mice with hMSC treatment on day 3 and day 12 had: (1) lower serum levels of IL-6, TNF-α (p < 0.0005), and IL-17 (p < 0.005 for day 3, p < 0.0005 for day 12); (2) reduced splenic cell production and secretion of IL-6, TNF-α (p < 0.05), and IL-17 (p < 0.05), and increased splenic production of IL-10; (3) reduced splenic Th17 cells (p < 0.05 for day 3, p < 0.005 for day 12), and (4) increased CD1dhighCD5+ regulatory B cells (p < 0.005) compared to EAE mice without hMSC treatment. Conclusion: hMSC treatment on day 3 and day 12 suppresses EAE severity. The underlying mechanisms involve downregulation of Th17 cells and upregulation of CD1dhighCD5+ regulatory B-cell activity. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Functional endothelial-like cells (EC) have been successfully derived from different cell sources and potentially used for treatment of cardiovascular diseases; however, their relative therapeutic efficacy remains unclear. We differentiated functional EC from human bone marrow mononuclear cells (BM-EC), human embryonic stem cells (hESC-EC) and human induced pluripotent stem cells (hiPSC-EC), and compared their in-vitro tube formation, migration and cytokine expression profiles, and in-vivo capacity to attenuate hind-limb ischemia in mice. Successful differentiation of BM-EC was only achieved in 1/6 patient with severe coronary artery disease. Nevertheless, BM-EC, hESC-EC and hiPSC-EC exhibited typical cobblestone morphology, had the ability of uptaking DiI-labeled acetylated low-density-lipoprotein, and binding of Ulex europaeus lectin. In-vitro functional assay demonstrated that hiPSC-EC and hESC-EC had similar capacity for tube formation and migration as human umbilical cord endothelial cells (HUVEC) and BM-EC (P>0.05). While increased expression of major angiogenic factors including epidermal growth factor, hepatocyte growth factor, vascular endothelial growth factor, placental growth factor and stromal derived factor-1 were observed in all EC cultures during hypoxia compared with normoxia (P<0.05), the magnitudes of cytokine up-regulation upon hypoxic were more dramatic in hiPSC-EC and hESC-EC (P<0.05). Compared with medium, transplanting BM-EC (n = 6), HUVEC (n = 6), hESC-EC (n = 8) or hiPSC-EC (n = 8) significantly attenuated severe hind-limb ischemia in mice via enhancement of neovascularization. In conclusion, functional EC can be generated from hECS and hiPSC with similar therapeutic efficacy for attenuation of severe hind-limb ischemia. Differentiation of functional BM-EC was more difficult to achieve in patients with cardiovascular diseases, and hESC-EC or iPSC-EC are readily available as “off-the-shelf” format for the treatment of tissue ischemia. [ABSTRACT FROM AUTHOR]

Background The potential clinical application of bone marrow or peripheral blood-derived progenitor cells for cardiovascular regeneration in patients with diabetes mellitus (DM) is limited by their functional impairment. We sought to determine the mechanisms of impaired therapeutic efficacy of peripheral blood-derived progenitor cells in type 2 DM patients and evaluated the use of cell-free conditioned medium obtained from human embryonic stem cell-derived endothelial-like cells (ESC-ECs) to reverse their functional impairment. Methods The angiogenic potential of late outgrowth endothelial cells (OECs) and cytokine profile of the conditional medium of proangiogenic cells (PACs) derived from peripheral blood-mononuclear cells of healthy control and DM patients and ESC-ECs was compared by in vitro tube formation assay and a multiplex bead-based immunoassay kit, respectively. The in vivo angiogenic potential of ESC-ECs derived conditioned medium in rescuing the functional impairment of PB-PACs in DM patients was investigated using a hindlimb ischemia model. Results Human ESC-ECs had similar functional and phenotypic characteristics as OECs in healthy controls. Cytokine profiling showed that vascular endothelial growth factor, stromal cell-derived factor 1 and placental growth factor were down-regulated in PACs from DM patients. Tube formation assay that revealed functional impairment of OECs from DM patients could be rescued by ESC-ECs conditioned medium. Administration of ESC-ECs conditioned medium restored the therapeutic efficacy of PB-PACs from DM patients in a mouse model of hindlimb ischemia. Conclusions Our results showed that peripheral blood-derived progenitor cells from DM patients have impaired function because of defective secretion of angiogenic cytokines, which could be restored by supplementation of ESC-ECs conditioned medium. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Aim:To investigate the effects of the cardiotonic steroid, ouabain, on cardiac differentiation of murine embyronic stem cells (mESCs).Methods:Cardiac differentiation of murine ESCs was enhanced by standard hanging drop method in the presence of ouabain (20 μmol/L) for 7 d. The dissociated ES derived cardiomyocytes were examined by flow cytometry, RT-PCR and confocal calcium imaging.Results:Compared with control, mESCs treated with ouabain (20 μmol/L) yielded a significantly higher percentage of cardiomyocytes, and significantly increased expression of a panel of cardiac markers including Nkx 2.5, α-MHC, and β-MHC. The α1 and 2- isoforms Na+/K+-ATPase, on which ouabain acted, were also increased in mESCs during differentiation. Among the three MAPKs involved in the cardiac hypertrophy pathway, ouabain enhanced ERK1/2 activation. Blockage of the Erk1/2 pathway by U0126 (10 μmol/L) inhibited cardiac differentiation while ouabain (20 μmol/L) rescued the effect. Interestingly, the expression of calcium handling proteins, including ryanodine receptor (RyR2) and sacroplasmic recticulum Ca2+ ATPase (SERCA2a) was also upregulated in ouabain-treated mESCs. ESC-derived cardiomyocyes (CM) treated with ouabain appeared to have more mature calcium handling. As demonstrated by confocal Ca2+ imaging, cardiomyocytes isolated from ouabain-treated mESCs exhibited higher maximum upstroke velocity (P<0.01) and maximum decay velocity (P<0.05), as well as a higher amplitude of caffeine induced Ca2+ transient (P<0.05), suggesting more mature sarcoplasmic reticulum (SR).Conclusion:Ouabain induces cardiac differentiation and maturation of mESC-derived cardiomyocytes via activation of Erk1/2 and more mature SR for calcium handling. [ABSTRACT FROM AUTHOR]

Aims: To determine whether the number of circulating endothelial progenitor cells (EPCs) in patients with persistent atrial fibrillation (AF) predicts arrhythmia recurrence after direct current cardioversion (DCCV). [ABSTRACT FROM PUBLISHER]

Abstract: Objective: To determine the optimal bone marrow (BM) cell types, and their potential mechanisms of action for neovascularization in chronic ischaemic myocardium. Methods and results: The functional effects, angiogenic potential and cytokine expression of direct intramyocardial implantation of autologous BM CD31-positive endothelial progenitor cells (EPC, n =9), BM mononuclear cells (MNCs, n =9), and saline (n =9) were compared in a swine model of chronic ischaemic myocardium. Autologous BM cells were harvested and catheter-based electromechanical mapping-guided direct intramyocardial injection was performed to target ischaemic myocardium. After 12 weeks, injection of BM-MNC resulted in significant improvements in left ventricular dP /dt (+21±8%, P =0.032), left ventricular pressure (+17±4%, P =0.048) and regional microsphere myocardial perfusion over ischaemic endocardium (+74±28%, P <0.05) and epicardium (+73±29%, P <0.05). No significant effects were observed following injection of BM-EPC or saline. Capillary density (1132±69 versus 903±44 per mm2, P =0.047) and expression of mRNA of vascular endothelial growth factor (VEGF, 32.3±5.6 versus 13.1±3.7, P <0.05,) and angiopoietin-2 (23.9±3.6 versus 13.7±3.1, P <0.05) in ischaemic myocardium was significantly greater in the BM-MNC group than the saline group. The capillary density in ischaemic myocardium demonstrated a significant positive correlation with VEGF expression (r =0.61, P <0.001). Conclusion: Catheter-based direct intramyocardial injection of BM-MNC enhanced angiogenesis more effectively than BM-EPC or saline, possibly via a paracrine effect, with increased expression of VEGF that subsequently improved cardiac performance of ischaemic myocardium. [Copyright &y& Elsevier]

To recapitulate progressive human dilated cardiomyopathy (DCM) and heart block in the Lmna R225X mutant mice model and investigate the molecular basis of LMNA mutation induced cardiac conduction disorders (CD); To investigate the potential interventional impact of exercise endurance. A Lmna R225X knock-in mice model in either heterozygous or homozygous genotype was generated. Electrical remodeling was observed with higher occurrence of AV block from neonatal and aged mutant mice as measured by surface electrocardiogram and atrio-ventricular Wenckebach point detection. Histological and molecular profiles revealed an increase in apoptotic cells and activation of caspase-3 activities in heart tissue. Upon aging, extracellular cellular matrix (ECM) remodeling appeared with accumulation of collagen in Lmna R225X mutant hearts as visualized by Masson's trichrome stain. This could be explained by the upregulated ECM gene expression, such as Fibronectin: Fn1, collagen: Col12a1, intergrin: Itgb2 and 3, as detected by microarray gene chip. Also, endurance exercise for 3 month improved the ventricular ejection fraction, attenuated fibrosis and cardiomyocytes apoptosis in the aged mutant mice. The mechanism of LMNA nonsense mutation induced cardiac conduction defects through AV node fibrosis is due to upregulated ECM gene expression upon activation of cardiac apoptosis. Lmna R225X mutant mice hold the potential for serving as in vivo models to explore the mechanism and therapeutic methods for AV block or myopathy associated with the aging process. • Despite high prevalence of LMNA-mutation related premature onset of heart block and/or dilated cardiomyopathy, the pathophysiogy the mutation to the arrhythmic manifestation have yet to be discovered. • In current study, a Lmna-R225X knockin mice model successfully served as a platform for the disease recapitulation and development of drug screening. • We understood that the presentation of heart block phenotype was accompanied by cardiac fibrosis, especially localized at AV node, which impeded electrical propagation. • Progression to DCM phenotype was observed after electrical modeling events from 18 months of age thereafter. • Surprisingly, endurance exercise by swimming seems to alleviate such phenotype. [ABSTRACT FROM AUTHOR]

Dilated cardiomyopathy (DCM) is cardiac disease characterized by increased left ventricular chamber volume and decreased systolic function. DCM patient-specific human induced-pluripotent stem cells-derived cardiomyocytes (DCM-hiPSC-CMs) were generated. We found that uniaxial stretch elicited a cytosolic [Ca 2 + ] i rise in hiPSC-CMs. Compared to control-hiPSC-CMs, DCM-hiPSC-CMs displayed a greater magnitude of [Ca 2 + ] i responses to the cell stretch of 10–15% elongation in length. This stretch-induced [Ca 2 + ] i rise was abolished by removal of extracellular Ca 2 + and markedly attenuated by TRPV4 inhibitors HC-067047 and RN-1734. Application of nifedipine and tranilast also reduced the [Ca 2 + ] i response but to a lesser degree. Moreover, the augmented [Ca 2 + ] i was decreased by cytochalasin D treatment. Taken together, our study for the first time demonstrated an abnormal TRPV4-related mechanosensitive Ca 2 + signaling in DCM-hiPSC-CMs. [ABSTRACT FROM AUTHOR]

Background Friedreich's ataxia (FRDA), a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy, is caused by silencing of the frataxin (FXN) gene encoding the mitochondrial protein involved in iron–sulfur cluster biosynthesis. Methods Application of our previously established FRDA human induced pluripotent stem cell (hiPSC) derived cardiomyocytes model as a platform to assess the efficacy of treatment with either the antioxidant coenzyme Q10 analog, idebenone (IDE) or the iron chelator, deferiprone (DFP), which are both under clinical trial. Results DFP was able to more significantly suppress synthesis of reactive oxygen species (ROS) than IDE at the dosages of 25 μM and 10 nM respectively which agreed with the reduced rate of intracellular accumulation of iron by DFP treatment from 25 to 50 μM. With regard to cardiac electrical-contraction (EC) coupling function, decay velocity of calcium handling kinetics in FRDA-hiPSC-cardiomyocytes was significantly improved by DFP treatment but not by IDE. Further mechanistic studies revealed that DFP also modulated iron induced mitochondrial stress as reflected by mitochondria network disorganization and decline level of respiratory chain protein, succinate dehydrogenase (CxII) and cytochrome c oxidase (COXIV). In addition, iron-response protein (IRP-1) regulatory loop was overridden by DFP as reflected by resumed level of ferritin (FTH) back to basal level and the attenuated transferrin receptor (TSFR) mRNA level suppression thereby reducing further iron uptake. Conclusions DFP modulated iron homeostasis in FRDA-hiPSC-cardiomyocytes and effectively relieved stress-stimulation related to cardiomyopathy. The resuming of redox condition led to the significantly improved cardiac prime events, cardiac electrical-coupling during contraction. [ABSTRACT FROM AUTHOR]

Abstract: Hypoxia plays an important role in the proliferation, differentiation and maintenance of the cardiovascular system during development. While low oxygen tension appears to direct the cultured embryonic stem cells (ESCs) to differentiate into cardiomyocytes, the underlying molecular mechanism remains unclear. At a molecular level, hypoxia inducible factor-1 (HIF-1) plays an important role in handling the hypoxia signal. In the present study, we demonstrated that expression of exogenous HIF-1α cDNA into murine ESCs significantly promoted cardiogenesis as indicated by a higher percentage of beating embryoid body and troponin-T positive cell counts as well as increased expression of early and late cardiac markers, such as GATA-binding protein 4 and 6, NK2 transcription factor related locus 5, α-myosin heavy chain, β-myosin heavy chain and myosin light chain 2 ventricular transcripts. In addition, the transduced cells exhibited increased mRNA levels of cardiotrophin-1 and vascular endothelial growth factor, along with phosphorylation of eNOS [p-eNOS (ser1171)]. Application of NOS inhibitors, diphenyleneiodonium chloride (DPI), N ω-Nitro-l-arginine methyl ester hydrochloride (l-NAME) or N ω-Nitro-l-arginine (l-NNA) abolished the HIF-1α stimulated cardiac differentiation. With the clues of upregulated mRNA expression of calcium handling proteins, ryanodine receptor 2, sodium calcium exchanger and sarcoplasmic/endoplasmic reticulum calcium ATPase, in the transduced HIF-1α ESCs, further study indicated that the maximum upstroke and decay velocity was significantly increased in both non-caffeine and caffeine-induced calcium transient in ESCs-derived cardiomyocytes. This suggests a well developed function of the sarcoplasmic reticulum in ESC-derived cardiomyocytes. Electrophysiological study also indicated that a portion of the HIF-1α-transduced cells exhibited prominent phase-4 depolarization. These findings suggest that keen activation of the HIF-1 pathway enhances differentiation and maturation of cardiomyocytes derived from ESCs. [Copyright &y& Elsevier]

Abstract: The therapeutic potential of transplantation of embryonic stem cells (ESCs) in animal model of myocardial infarction has been consistently demonstrated. The development of superparamagnetic iron oxide (SPIO) nanoparticles labeling and cardiac magnetic resonance imaging (MRI) have been increasingly used to track the migration of transplanted cells in vivo allowing cell fate determination. However, the impact of SPIO- labeling on cell phenotype and cardiac differentiation capacity of ESCs remains unclear. In this study, we demonstrated that ESCs labeled with SPIO compared to their unlabeled counterparts had similar cardiogenic capacity, and SPIO-labeling did not affect calcium-handling property of ESC-derived cardiomyocytes. Moreover, transplantation of SPIO-labeled ESCs via direct intra-myocardial injection to infarct myocardium resulted in significant improvement in heart function. These findings demonstrated the feasibility of in vivo ESC tracking using SPIO-labeling and cardiac MRI without affecting the cardiac differentiation potential and functional properties of ESCs. [Copyright &y& Elsevier]

Background: Researchers have developed machine learning-based ECG diagnostic algorithms that match or even surpass cardiologist level of performance. However, most of them cannot be used in real-world, as older generation ECG machines do not permit installation of new algorithms., Objective: To develop a smartphone application that automatically extract ECG waveforms from photos and to convert them to voltage-time series for downstream analysis by a variety of diagnostic algorithms built by researchers., Methods: A novel approach of using objective detection and image segmentation models to automatically extract ECG waveforms from photos taken by clinicians was devised. Modular machine learning models were developed to sequentially perform waveform identification, gridline removal, and scale calibration. The extracted data were then analysed using a machine learning-based cardiac rhythm classifier., Results: Waveforms from 40 516 scanned and 444 photographed ECGs were automatically extracted. 12 828 of 13 258 (96.8%) scanned and 5399 of 5743 (94.0%) photographed waveforms were correctly cropped and labelled. 11 604 of 12 735 (91.1%) scanned and 5062 of 5752 (88.0%) photographed waveforms achieved successful voltage-time signal extraction after automatic gridline and background noise removal. In a proof-of-concept demonstration, an atrial fibrillation diagnostic algorithm achieved 91.3% sensitivity, 94.2% specificity, 95.6% positive predictive value, 88.6% negative predictive value and 93.4% F1 score, using photos of ECGs as input., Conclusion: Object detection and image segmentation models allow automatic extraction of ECG signals from photos for downstream diagnostics. This novel pipeline circumvents the need for costly ECG hardware upgrades, thereby paving the way for large-scale implementation of machine learning-based diagnostic algorithms., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: International guidelines recommend natriuretic peptide biomarker-based screening for patients at high heart failure (HF) risk to allow early detection. There have been few reports about the incorporation of screening procedure to existing clinical practice., Objective: To implement screening of left ventricular dysfunction in patients with type 2 diabetes mellitus (DM)., Method: A prospective screening study at the DM complication screening centre was performed., Results: Between 2018 and 2019, 1043 patients (age: 63.7±12.4 years; male: 56.3%) with mean glycated haemoglobin of 7.25%±1.34% were recruited. 81.8% patients had concomitant hypertension, 31.1% had coronary artery disease, 8.0% had previous stroke, 5.5% had peripheral artery disease and 30.7% had chronic kidney disease (CKD) stages 3-5. 43 patients (4.1%) had an elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration above the age-specific diagnostic thresholds for HF, and 43 patients (4.1%) had newly detected atrial fibrillation (AF). The prevalence of elevated NT-proBNP increased with age from 0.85% in patients aged <50 years to 7.14% in those aged 70-79 years and worsening kidney function from 0.43% in patients with CKD stage 1 to 42.86% in CKD stage 5. In multivariate logistic regression, male gender (OR: 3.67 (1.47-9.16), p = 0.005*), prior stroke (OR: 3.26 (1.38-7.69), p = 0.007*), CKD (p<0.001*) and newly detected AF (OR: 7.02 (2.65-18.57), p<0.001*) were significantly associated with elevated NT-proBNP. Among patients with elevated NT-proBNP, their mean left ventricular ejection fraction (LVEF) was 51.4%±14.7%, and 45% patients had an LVEF <50%., Conclusion: NT-proBNP and ECG screening could be implemented with relative ease to facilitate early detection of cardiovascular complication and improve long-term outcomes., (© The Author(s) 2022. Published by Oxford University Press on behalf of Postgraduate Medical Journal. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background & Aims: Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism caused by loss-of-function mutations in ATP7B , which encodes a copper-transporting protein. It is characterized by excessive copper deposition in tissues, predominantly in the liver and brain. We sought to investigate whether gene-corrected patient-specific induced pluripotent stem cell (iPSC)-derived hepatocytes (iHeps) could serve as an autologous cell source for cellular transplantation therapy in WD., Methods: We first compared the in vitro phenotype and cellular function of ATP7B before and after gene correction using CRISPR/Cas9 and single-stranded oligodeoxynucleotides (ssODNs) in iHeps (derived from patients with WD) which were homozygous for the ATP7B R778L mutation (ATP7B R778L/R778L ). Next, we evaluated the in vivo therapeutic potential of cellular transplantation of WD gene-corrected iHeps in an immunodeficient WD mouse model ( Atp7b -/- / Rag2 -/- / Il2rg -/- ; ARG)., Results: We successfully created iPSCs with heterozygous gene correction carrying 1 allele of the wild-type ATP7B gene (ATP7B WT/- ) using CRISPR/Cas9 and ssODNs. Compared with ATP7B R778L/R778L iHeps, gene-corrected ATP7B WT/- iHeps restored i n vitro ATP7B subcellular localization, its subcellular trafficking in response to copper overload and its copper exportation function. Moreover, in vivo cellular transplantation of ATP7B WT/- iHeps into ARG mice via intra-splenic injection significantly attenuated the hepatic manifestations of WD. Liver function improved and liver fibrosis decreased due to reductions in hepatic copper accumulation and consequently copper-induced hepatocyte toxicity., Conclusions: Our findings demonstrate that gene-corrected patient-specific iPSC-derived iHeps can rescue the in vitro and in vivo disease phenotypes of WD. These proof-of-principle data suggest that iHeps derived from gene-corrected WD iPSCs have potential use as an autologous ex vivo cell source for in vivo therapy of WD as well as other inherited liver disorders., Lay Summary: Gene correction restored ATP7B function in hepatocytes derived from induced pluripotent stem cells that originated from a patient with Wilson's disease. These gene-corrected hepatocytes are potential cell sources for autologous cell therapy in patients with Wilson's disease., Competing Interests: The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2021 The Author(s).)

Rationale: Poor survival and engraftment are major hurdles of stem cell therapy in the treatment of myocardial infarction (MI). We sought to determine whether pre-transplantation systemic intravenous administration of human induced pluripotent stem cell (hiPSC)-derived mesenchymal stromal cells (hiPSC-MSCs) could improve the survival of hiPSC-MSCs or hiPSC-derived cardiomyocytes (hiPSC-CMs) following direct intramyocardial transplantation in a mouse model of MI. Methods: Mice were randomized to undergo intravenous administration of saline or 5×10 5 hiPSC-MSCs one week prior to MI, induced by ligation of the left anterior descending coronary artery. Mice were further assigned to undergo direct intramyocardial transplantation of hiPSC-MSCs (1×10 6 ) or hiPSC-CMs (1×10 6 ) 10 minutes following MI. Echocardiographic and invasive hemodynamic assessment were performed to determine cardiac function. In-vivo fluorescent imaging analysis, immunofluorescence staining and polymerase chain reaction were performed to detect cell engraftment. Flow cytometry of splenic regulatory T cells (Tregs) and natural killer (NK) cells was performed to assess the immunomodulatory effects. Results: Pre-transplantation systemic administration of hiPSC-MSCs increased systemic Tregs activation, decreased the number of splenic NK cells and inflammation, and enhanced survival of transplanted hiPSC-MSCs and hiPSC-CMs. These improvements were associated with increased neovascularization and decreased myocardial inflammation and apoptosis at the peri-infract zone with consequent improved left ventricular function four weeks later. Co-culture of splenic CD4 cells with hiPSC-MSCs also modulated their cytokine expression profile with a decreased level of interferon-γ, tumor necrosis factor-α, and interleukin (IL)-17A, but not IL-2, IL-6 and IL-10. Conclusion: Pre-transplantation systemic intravenous administration of hiPSC-MSCs induced immunomodulation and facilitated the survival of intramyocardially transplanted cells to improve cardiac function in MI., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The human transcription factor NKX2-5 plays an important role in cardiac formation and development, and thus it can be used for isolation of cardiomyocytes (CMs) differentiated from human pluripotent stem cells (hPSCs). Here, we knocked-in enhanced GFP (eGFP) and Pac (a puromycin resistant gene; Puro R ) into the exon 1 coding region of NKX2-5 from a human iPSC line iPSN0003 using TALENs. The generated GIBHi002-A-2 enables us to monitor and optimize cardiac differentiation procedures via the cardiac progenitor cells (CPCs), as well as to isolate iPSC-derived CMs for drug screening., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: SARS-CoV-2 infection is associated with myocardial injury, but there is a paucity of experimental platforms for the condition., Methods and results: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) infected by SARS-CoV-2 for 3 days ceased beating and exhibited cytopathogenic changes with reduced viability. Active viral replication was evidenced by an increase in supernatant SARS-CoV-2 and the presence of SARS-CoV-2 nucleocaspid protein within hiPSC-CMs. Expressions of BNP, CXCL1, CXCL2, IL-6, IL-8 and TNF-α were upregulated, while ACE2 was downregulated., Conclusions: Our hiPSC-CM-based in-vitro SARS-CoV-2 myocarditis model recapitulated the cytopathogenic effects and cytokine/chemokine response. It could be exploited as a drug screening platform.

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major causes of mortality and morbidity around the world. Cell-based therapies for cardiac repair and improvement of left ventricular function after MI have attracted considerable attention. Accordingly, the safety and efficacy of these cell transplantations should be tested in a preclinical large animal model of HF prior to clinical use. Pigs are widely used for cardiovascular disease research due to their similarity to humans in terms of heart size and coronary anatomy. Therefore, we sought to present an effective protocol for the establishment of a porcine chronic HF model using closed-chest coronary balloon occlusion of the left circumflex artery (LCX), followed by rapid ventricular pacing induced with pacemaker implantation. Eight weeks later, the stem cells were administered by intramyocardial injection in the peri-infarct area. Then the infarct size, cell survival, and left ventricular function (including echocardiography, hemodynamic parameters, and electrophysiology) were evaluated. This study helps establish a stable preclinical large animal HF model for stem cell treatment.

Familial hypercholesterolemia (FH) is mostly caused by low-density lipoprotein receptor (LDLR) mutations and results in an increased risk of early-onset cardiovascular disease due to marked elevation of LDL cholesterol (LDL-C) in blood. Statins are the first line of lipid-lowering drugs for treating FH and other types of hypercholesterolemia, but new approaches are emerging, in particular PCSK9 antibodies, which are now being tested in clinical trials. To explore novel therapeutic approaches for FH, either new drugs or new formulations, we need appropriate in vivo models. However, differences in the lipid metabolic profiles compared to humans are a key problem of the available animal models of FH. To address this issue, we have generated a human liver chimeric mouse model using FH induced pluripotent stem cell (iPSC)-derived hepatocytes (iHeps). We used Ldlr -/- /Rag2 -/- /Il2rg -/- (LRG) mice to avoid immune rejection of transplanted human cells and to assess the effect of LDLR-deficient iHeps in an LDLR null background. Transplanted FH iHeps could repopulate 5-10% of the LRG mouse liver based on human albumin staining. Moreover, the engrafted iHeps responded to lipid-lowering drugs and recapitulated clinical observations of increased efficacy of PCSK9 antibodies compared to statins. Our human liver chimeric model could thus be useful for preclinical testing of new therapies to FH. Using the same protocol, similar human liver chimeric mice for other FH genetic variants, or mutations corresponding to other inherited liver diseases, may also be generated.

Background & Aims: Hirschsprung disease is caused by failure of enteric neural crest cells (ENCCs) to fully colonize the bowel, leading to bowel obstruction and megacolon. Heterozygous mutations in the coding region of the RET gene cause a severe form of Hirschsprung disease (total colonic aganglionosis). However, 80% of HSCR patients have short-segment Hirschsprung disease (S-HSCR), which has not been associated with genetic factors. We sought to identify mutations associated with S-HSCR, and used the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing system to determine how mutations affect ENCC function., Methods: We created induced pluripotent stem cell (iPSC) lines from 1 patient with total colonic aganglionosis (with the G731del mutation in RET) and from 2 patients with S-HSCR (without a RET mutation), as well as RET +/- and RET -/- iPSCs. IMR90-iPSC cells were used as the control cell line. Migration and differentiation capacities of iPSC-derived ENCCs were analyzed in differentiation and migration assays. We searched for mutation(s) associated with S-HSCR by combining genetic and transcriptome data from patient blood- and iPSC-derived ENCCs, respectively. Mutations in the iPSCs were corrected using the CRISPR/Cas9 system., Results: ENCCs derived from all iPSC lines, but not control iPSCs, had defects in migration and neuronal lineage differentiation. RET mutations were associated with differentiation and migration defects of ENCCs in vitro. Genetic and transcriptome analyses associated a mutation in the vinculin gene (VCL M209L) with S-HSCR. CRISPR/Cas9 correction of the RET G731del and VCL M209L mutations in iPSCs restored the differentiation and migration capacities of ENCCs., Conclusions: We identified mutations in VCL associated with S-HSCR. Correction of this mutation in iPSC using CRISPR/Cas9 editing, as well as the RET G731del mutation that causes Hirschsprung disease with total colonic aganglionosis, restored ENCC function. Our study demonstrates how human iPSCs can be used to identify disease-associated mutations and determine how they affect cell functions and contribute to pathogenesis., (Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Renal denervation (RD) is a potential novel nonpharmacological therapy for heart failure (HF). We performed bilateral catheter-based RD in 10 adult pigs and compared them with 10 control subjects after induction of HF to investigate the long-term beneficial effects of RD on left ventricular (LV) function and regional norepinephrine gradient after conventional HF pharmacological therapy. Compared with control subjects, animals treated with RD demonstrated an improvement in LV function and reduction of norepinephrine gradients over the myocardium and kidney at 10-week follow-up. Our results demonstrated that effective bilateral RD decrease regional norepinephrine gradients and improve LV contractile function compared with medical therapy alone.

Familial hypercholesterolemia (FH) causes elevation of low-density lipoprotein cholesterol (LDL-C) in blood and carries an increased risk of early-onset cardiovascular disease. A caveat for exploration of new therapies for FH is the lack of adequate experimental models. We have created a comprehensive FH stem cell model with differentiated hepatocytes (iHeps) from human induced pluripotent stem cells (iPSCs), including genetically engineered iPSCs, for testing therapies for FH. We used FH iHeps to assess the effect of simvastatin and proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies on LDL-C uptake and cholesterol lowering in vitro. In addition, we engrafted FH iHeps into the liver of Ldlr -/- /Rag2 -/- /Il2rg -/- mice, and assessed the effect of these same medications on LDL-C clearance and endothelium-dependent vasodilation in vivo. Our iHep models recapitulate clinical observations of higher potency of PCSK9 antibodies compared with statins for reversing the consequences of FH, demonstrating the utility for preclinical testing of new therapies for FH patients., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Laminopathy is a disease closely related to deficiency of the nuclear matrix protein lamin A/C or failure in prelamin A processing, and leads to accumulation of the misfold protein causing progeria. The resultant disrupted lamin function is highly associated with abnormal nuclear architecture, cell senescence, apoptosis, and unstable genome integrity. To date, the effects of loss in nuclear integrity on the susceptible organ, striated muscle, have been commonly associated with muscular dystrophy, dilated cardiac myopathy (DCM), and conduction defeats, but have not been studied intensively. In this review, we aim to summarize recent breakthroughs in an in vivo laminopathy model and in vitro study using patient-specific human induced pluripotent stem cells (iPSCs) that reproduce the pathophysiological phenotype for further drug screening. We describe several in-vivo transgenic mouse models to elucidate the effects of Lmna H222P, N195K mutations, and LMNA knockout on cardiac function, in terms of hemodynamic and electrical signal propagation; certain strategies targeted on stress-related MAPK are mentioned. We will also discuss human iPSC cardiomyocytes serving as a platform to reveal the underlying mechanisms, such as the altered mechanical sensation in electrical coupling of the heart conduction system and ion channel alternation in relation to altered nuclear architecture, and furthermore to enable screening of drugs that can attenuate this cardiac premature aging phenotype by inhibition of prelamin misfolding and oxidative stress, and also enhancement of autophagy protein clearance and cardiac-protective microRNA.

Patients with Danon disease may suffer from severe cardiomyopathy, skeletal muscle dysfunction as well as varying degrees of mental retardation, in which the primary deficiency of lysosomal membrane-associated protein-2 (LAMP2) is considerably associated. Owing to the scarcity of human neurons, the pathological role of LAMP2 deficiency in neural injury of humans remains largely elusive. However, the application of induced pluripotent stem cells (iPSCs) may shed light on overcoming such scarcity. In this study, we obtained iPSCs derived from a patient carrying a mutated LAMP2 gene that is associated with Danon disease. By differentiating such LAMP2-deficient iPSCs into cerebral cortical neurons and with the aid of various biochemical assays, we demonstrated that the LAMP2-deficient neurons are more susceptible to mild oxidative stress-induced injury. The data from MTT assay and apoptotic analysis demonstrated that there was no notable difference in cellular viability between the normal and LAMP2-deficient neurons under non-stressed condition. When exposed to mild oxidative stress (10 μM H 2 O 2 ), the LAMP2-deficient neurons exhibited a significant increase in apoptosis. Surprisingly, we did not observe any aberrant accumulation of autophagic materials in the LAMP2-deficient neurons under such stress condition. Our results from cellular fractionation and inhibitor blockade experiments further revealed that oxidative stress-induced apoptosis in the LAMP2-deficient cortical neurons was caused by increased abundance of cytosolic cathepsin L. These results suggest the involvement of lysosomal membrane permeabilization in the LAMP2 deficiency associated neural injury.

Aims: Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear., Methods and Results: We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05)., Conclusions: In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Background/aims: Multiple sclerosis (MS) causes significant neurological disability. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS. Human bone marrow mesenchymal stem cells (hMSCs) possess anti-inflammatory and immunosuppressive effects. We studied whether hMSCs affect CD1d(high)CD5(+) regulatory B-cell activity in EAE., Methods: EAE was induced in C57BL/6N mice by immunization with MOG35-55 peptide. hMSCs were injected intravenously into EAE mice on day 3 and day 12 after first immunization. Mice were sacrificed on day 26. Immunohistochemistry of the spinal cord, serum cytokines levels, production of cytokines by cultured splenic cells, and flow cytometry for splenic Th17 and CD1d(high)CD5(+) regulatory B cells were studied., Results: EAE mice with hMSC treatment on day 3 and day 12 had reduced EAE scores from day 14 to day 26 compared to EAE mice without hMSC treatment, and reduced infiltration of inflammatory cells and demyelination in the spinal cord. EAE mice with hMSC treatment on day 3 and day 12 had: (1) lower serum levels of IL-6, TNF-α (p < 0.0005), and IL-17 (p < 0.005 for day 3, p < 0.0005 for day 12); (2) reduced splenic cell production and secretion of IL-6, TNF-α (p < 0.05), and IL-17 (p < 0.05), and increased splenic production of IL-10; (3) reduced splenic Th17 cells (p < 0.05 for day 3, p < 0.005 for day 12), and (4) increased CD1d(high)CD5(+) regulatory B cells (p < 0.005) compared to EAE mice without hMSC treatment., Conclusion: hMSC treatment on day 3 and day 12 suppresses EAE severity. The underlying mechanisms involve downregulation of Th17 cells and upregulation of CD1d(high)CD5(+) regulatory B-cell activity., (Copyright © 2013 S. Karger AG, Basel.)

Aims: We identified an autosomal dominant non‐sense mutation (R225X) in exon 4 of the lamin A/C (LMNA) gene in a Chinese family spanning 3 generations with familial dilated cardiomyopathy (DCM). In present study, we aim to generate induced pluripotent stem cells derived cardiomyocytes (iPSC‐CMs) from an affected patient with R225X and another patient bearing LMNA frame‐shift mutation for drug screening., Methods and Results: Higher prevalence of nuclear bleb formation and micronucleation was present in LMNA(R225X/WT) and LMNA(Framshift/WT) iPSC‐CMs. Under field electrical stimulation, percentage of LMNA‐mutated iPSC‐CMs exhibiting nuclear senescence and cellular apoptosis markedly increased. shRNA knockdown of LMNA replicated those phenotypes of the mutated LMNA field electrical stress. Pharmacological blockade of ERK1/2 pathway with MEK1/2 inhibitors, U0126 and selumetinib (AZD6244) significantly attenuated the pro‐apoptotic effects of field electric stimulation on the mutated LMNA iPSC‐CMs., Conclusion: LMNA‐related DCM was modeled in‐vitro using patient‐specific iPSC‐CMs. Our results demonstrated that haploinsufficiency due to R225X LMNA non‐sense mutation was associated with accelerated nuclear senescence and apoptosis of iPSC‐ CMs under electrical stimulation, which can be significantly attenuated by therapeutic blockade of stress‐related ERK1/2 pathway.

Our previous study demonstrated the direct involvement of the HIF-1α subunit in the promotion of cardiac differentiation of murine embryonic stem cells (ESCs). We report the use of cobalt chloride to induce HIF-1α stabilization in human ESCs to promote cardiac differentiation. Treatment of undifferentiated hES2 human ESCs with 50 μM cobalt chloride markedly increased protein levels of the HIF-1α subunit, and was associated with increased expression of early cardiac specific transcription factors and cardiotrophic factors including NK2.5, vascular endothelial growth factor, and cardiotrophin-1. When pretreated cells were subjected to cardiac differentiation, a notable increase in the occurrence of beating embryoid bodies and sarcomeric actinin-positive cells was observed, along with increased expression of the cardiac-specific markers, MHC-A, MHC-B, and MLC2V. Electrophysiological study revealed increased atrial- and nodal-like cells in the cobalt chloride-pretreated group. Confocal calcium imaging analysis indicated that the maximum upstroke and decay velocities were significantly increased in both noncaffeine and caffeine-induced calcium transient in cardiomyocytes derived from the cobalt chloride-pretreated cells, suggesting these cells were functionally more mature. In conclusion, our study demonstrated that cobalt chloride pretreatment of hES2 human ESCs promotes cardiac differentiation and the maturation of calcium homeostasis of cardiomyocytes derived from ESCs.

The cardioprotective effects of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA-I) are well documented, but their effects in the direction of the cardiac differentiation of embryonic stem cells are unknown. We evaluated the effects of exogenous apoA-I expression on cardiac differentiation of ESCs and maturation of ESC-derived cardiomyocytes. We stably over-expressed full-length human apoA-I cDNA with lentivirus (LV)-mediated gene transfer in undifferentiated mouse ESCs and human induced pluripotent stem cells. Upon cardiac differentiation, we observed a significantly higher percentage of beating embryoid bodies, an increased number of cardiomyocytes as determined by flow cytometry, and expression of cardiac markers including α-myosin heavy chain, β-myosin heavy chain and myosin light chain 2 ventricular transcripts in LV-apoA-I transduced ESCs compared with control (LV-GFP). In the presence of noggin, a BMP4 antagonist, activation of BMP4-SMAD signaling cascade in apoA-I transduced ESCs completely abolished the apoA-I stimulated cardiac differentiation. Furthermore, co-application of recombinant apoA-I and BMP4 synergistically increased the percentage of beating EBs derived from untransduced D3 ESCs. These together suggests that that pro-cardiogenic apoA-I is mediated via the BMP4-SMAD signaling pathway. Functionally, cardiomyocytes derived from the apoA-I-transduced cells exhibited improved calcium handling properties in both non-caffeine and caffeine-induced calcium transient, suggesting that apoA-I plays a role in enhancing cardiac maturation. This increased cardiac differentiation and maturation has also been observed in human iPSCs, providing further evidence of the beneficial effects of apoA-I in promoting cardiac differentiation. In Conclusion, we present novel experimental evidence that apoA-I enhances cardiac differentiation of ESCs and iPSCs and promotes maturation of the calcium handling property of ESC-derived cardiomyocytes via the BMP4/SMAD signaling pathway.

The term laminopathies defines a group of genetic disorders caused by defects in the nuclear envelope, mostly the lamins. Lamins are the main constituents of the nuclear lamina, a filamentous meshwork associated with the inner nuclear membrane that provides mechanical stability and plays important roles in processes such as transcription, DNA replication and chromatin organization. More than 300 mutations inlamin A/C have been associated with diverse clinical phenotypes, understanding the molecular basis of these diseases may provide a rationale for treating them. Here we describe the generation of induced pluripotent stem cells (iPSCs) from a patient with inherited dilated cardiomiopathy and 2 patients with distinct accelerated forms of aging, atypical Werner syndrome and Hutchinson Gilford progeria, all of which are caused by mutations in lamin A/C. These cell lines were pluripotent and displayed normal nuclear membrane morphology compared to donor fibroblasts. Their differentiated progeny reproduced the disease phenotype, reinforcing the idea that they represent excellent tools for understanding the role of lamin A/C in normal physiology and the clinical diversity associated with these diseases.