Academic Appointments


Honors & Awards


  • Stanford Cardiovascular Institute Seed Grant, Stanford University (2024-)
  • K99/R00 Career Transition Award/Research Transition Award, NIH/NHLBI (2024-)
  • TRISH Postdoctoral Fellowship, TRISH/NASA (2021-2023)
  • TRAM pilot grant, Stanford University (2021-2022)

Professional Education


  • PhD, York University, Biology (2020)
  • BSc, University of Toronto, Biology (2010)

All Publications


  • Consequences of ionizing radiation exposure to the cardiovascular system. Nature reviews. Cardiology Jahng, J. W., Little, M. P., No, H. J., Loo, B. W., Wu, J. C. 2024

    Abstract

    Ionizing radiation is widely used in various industrial and medical applications, resulting in increased exposure for certain populations. Lessons from radiation accidents and occupational exposure have highlighted the cardiovascular and cerebrovascular risks associated with radiation exposure. In addition, radiation therapy for cancer has been linked to numerous cardiovascular complications, depending on the distribution of the dose by volume in the heart and other relevant target tissues in the circulatory system. The manifestation of symptoms is influenced by numerous factors, and distinct cardiac complications have previously been observed in different groups of patients with cancer undergoing radiation therapy. However, in contemporary radiation therapy, advances in treatment planning with conformal radiation delivery have markedly reduced the mean heart dose and volume of exposure, and these variables are therefore no longer sole surrogates for predicting the risk of specific types of heart disease. Nevertheless, certain cardiac substructures remain vulnerable to radiation exposure, necessitating close monitoring. In this Review, we provide a comprehensive overview of the consequences of radiation exposure on the cardiovascular system, drawing insights from various cohorts exposed to uniform, whole-body radiation or to partial-body irradiation, and identify potential risk modifiers in the development of radiation-associated cardiovascular disease.

    View details for DOI 10.1038/s41569-024-01056-4

    View details for PubMedID 38987578

    View details for PubMedCentralID 9512240

  • The role of metabolism in directed differentiation versus trans-differentiation of cardiomyocytes. Seminars in cell & developmental biology Jahng, J. W., Zhang, M., Wu, J. C. 2021

    Abstract

    The advent of induced pluripotent stem cells (iPSCs) and identification of transcription factors for cardiac reprogramming have raised hope to cure heart disease, the leading cause of death in the world. Our knowledge in heart development and molecular barriers of cardiac reprogramming is advancing, but many hurdles are yet to be overcome for clinical translation. Importantly, we lack a full understanding of molecular mechanisms governing cell fate conversion toward cardiomyocytes. In this review, we will discuss the role of metabolism in directed differentiation versus trans-differentiation of cardiomyocytes. Cardiomyocytes exhibit a unique metabolic feature distinct from PSCs and cardiac fibroblasts, and there are multiple overlapping molecular mechanisms underlying metabolic reprogramming during cardiomyogenesis. We will discuss key metabolic changes occurring during cardiomyocytes differentiation from PSCs and cardiac fibroblasts, and the potential role of metabolic reprogramming in the enhancement strategies for cardiomyogenesis. Only when such details are discovered will more effective strategies to enhance the de novo production of cardiomyocytes be possible.

    View details for DOI 10.1016/j.semcdb.2021.05.018

    View details for PubMedID 34074592

  • Laminin: guardian against DNA damage by transcription stress. Cardiovascular research Jahng, J. W., Wu, J. C. 2024

    View details for DOI 10.1093/cvr/cvae122

    View details for PubMedID 38887919

  • Generation of induced pluripotent stem cell lines from patients with LQT1 caused by heterozygous mutations in the KCNQ1 gene. Stem cell research Ren, L., Jahng, J. W., Belbachir, N., Cook, Z., Rivero, G. C., Perez, M. V., Wu, J. C. 2024; 78: 103443

    Abstract

    Long QT Syndrome (LQTS) is a genetic heart disorder that can induce cardiac arrhythmias. The most prevalent subtype, LQT1, stems from rare variants in the KCNQ1 gene. Utilizing induced pluripotent stem cells (iPSCs) enables detailed cellular studies and personalized medicine approaches for this life-threatening condition. We generated two LQT1 iPSC lines with single nucleotide nonsense mutations, c.1031 C>T and c.1121T>A in KCNQ1. Both lines exhibited typical iPSC morphology, expressed high levels of pluripotent markers, maintained normal karyotype, and possessed the capability to differentiate into three germ layers. These cell lines serve as important tools for investigating the biological mechanisms underlying LQT1 due to mutations in the KCNQ1 gene.

    View details for DOI 10.1016/j.scr.2024.103443

    View details for PubMedID 38763038

  • Incomplete-penetrant hypertrophic cardiomyopathy MYH7 G256E mutation causes hypercontractility and elevated mitochondrial respiration. Proceedings of the National Academy of Sciences of the United States of America Lee, S., Vander Roest, A. S., Blair, C. A., Kao, K., Bremner, S. B., Childers, M. C., Pathak, D., Heinrich, P., Lee, D., Chirikian, O., Mohran, S. E., Roberts, B., Smith, J. E., Jahng, J. W., Paik, D. T., Wu, J. C., Gunawardane, R. N., Ruppel, K. M., Mack, D. L., Pruitt, B. L., Regnier, M., Wu, S. M., Spudich, J. A., Bernstein, D. 2024; 121 (19): e2318413121

    Abstract

    Determining the pathogenicity of hypertrophic cardiomyopathy-associated mutations in the β-myosin heavy chain (MYH7) can be challenging due to its variable penetrance and clinical severity. This study investigates the early pathogenic effects of the incomplete-penetrant MYH7 G256E mutation on myosin function that may trigger pathogenic adaptations and hypertrophy. We hypothesized that the G256E mutation would alter myosin biomechanical function, leading to changes in cellular functions. We developed a collaborative pipeline to characterize myosin function across protein, myofibril, cell, and tissue levels to determine the multiscale effects on structure-function of the contractile apparatus and its implications for gene regulation and metabolic state. The G256E mutation disrupts the transducer region of the S1 head and reduces the fraction of myosin in the folded-back state by 33%, resulting in more myosin heads available for contraction. Myofibrils from gene-edited MYH7WT/G256E human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) exhibited greater and faster tension development. This hypercontractile phenotype persisted in single-cell hiPSC-CMs and engineered heart tissues. We demonstrated consistent hypercontractile myosin function as a primary consequence of the MYH7 G256E mutation across scales, highlighting the pathogenicity of this gene variant. Single-cell transcriptomic and metabolic profiling demonstrated upregulated mitochondrial genes and increased mitochondrial respiration, indicating early bioenergetic alterations. This work highlights the benefit of our multiscale platform to systematically evaluate the pathogenicity of gene variants at the protein and contractile organelle level and their early consequences on cellular and tissue function. We believe this platform can help elucidate the genotype-phenotype relationships underlying other genetic cardiovascular diseases.

    View details for DOI 10.1073/pnas.2318413121

    View details for PubMedID 38683993

  • Elucidating effects of the environmental pollutant benzo[a]pyrene [BaP] on cardiac arrhythmogenicity. Journal of molecular and cellular cardiology Yang, J. Y., Mondéjar-Parreño, G., Jahng, J. W., Lu, Y., Hamburg, N., Nadeau, K. C., Conklin, D. J., Liao, R., Chandy, M., Wu, J. C. 2024; 191: 23-26

    View details for DOI 10.1016/j.yjmcc.2024.04.013

    View details for PubMedID 38648962

  • Generation of two induced pluripotent stem cell lines from patients suffering from pulmonary hypertension. Stem cell research Chen, G., Orozco, L., Parmisano, S., Jahng, J. W., Vera, C. D., Zhuge, Y., Wu, J. C., Obal, D. 2023; 72: 103218

    Abstract

    Idiopathic pulmonary arterial hypertension (IPAH) is a rare disease, with an estimated 500-1000 new cases diagnosed every year. A portion of these cases may be caused by mutations in the BMPR2 gene, suggesting a possible genetic component in the development of the disease. Here, we report two human induced pluripotent stem cell (iPSC) lines generated from IPAH patients. Both cell lines provide valuable insight into the molecular and cellular mechanisms of IPAH and can be used to further understand the disease.

    View details for DOI 10.1016/j.scr.2023.103218

    View details for PubMedID 37804546

  • SGLT2 inhibitor ameliorates endothelial dysfunction associated with the common ALDH2 alcohol flushing variant. Science translational medicine Guo, H., Yu, X., Liu, Y., Paik, D. T., Justesen, J. M., Chandy, M., Jahng, J. W., Zhang, T., Wu, W., Rwere, F., Zhao, S. R., Pokhrel, S., Shivnaraine, R. V., Mukherjee, S., Simon, D. J., Manhas, A., Zhang, A., Chen, C. H., Rivas, M. A., Gross, E. R., Mochly-Rosen, D., Wu, J. C. 2023; 15 (680): eabp9952

    Abstract

    The common aldehyde dehydrogenase 2 (ALDH2) alcohol flushing variant known as ALDH2*2 affects ∼8% of the world's population. Even in heterozygous carriers, this missense variant leads to a severe loss of ALDH2 enzymatic activity and has been linked to an increased risk of coronary artery disease (CAD). Endothelial cell (EC) dysfunction plays a determining role in all stages of CAD pathogenesis, including early-onset CAD. However, the contribution of ALDH2*2 to EC dysfunction and its relation to CAD are not fully understood. In a large genome-wide association study (GWAS) from Biobank Japan, ALDH2*2 was found to be one of the strongest single-nucleotide polymorphisms associated with CAD. Clinical assessment of endothelial function showed that human participants carrying ALDH2*2 exhibited impaired vasodilation after light alcohol drinking. Using human induced pluripotent stem cell-derived ECs (iPSC-ECs) and CRISPR-Cas9-corrected ALDH2*2 iPSC-ECs, we modeled ALDH2*2-induced EC dysfunction in vitro, demonstrating an increase in oxidative stress and inflammatory markers and a decrease in nitric oxide (NO) production and tube formation capacity, which was further exacerbated by ethanol exposure. We subsequently found that sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin mitigated ALDH2*2-associated EC dysfunction. Studies in ALDH2*2 knock-in mice further demonstrated that empagliflozin attenuated ALDH2*2-mediated vascular dysfunction in vivo. Mechanistically, empagliflozin inhibited Na+/H+-exchanger 1 (NHE-1) and activated AKT kinase and endothelial NO synthase (eNOS) pathways to ameliorate ALDH2*2-induced EC dysfunction. Together, our results suggest that ALDH2*2 induces EC dysfunction and that SGLT2i may potentially be used as a preventative measure against CAD for ALDH2*2 carriers.

    View details for DOI 10.1126/scitranslmed.abp9952

    View details for PubMedID 36696485

  • Ferroptosis of Pacemaker Cells in COVID-19. Circulation research Nishiga, M., Jahng, J. W., Wu, J. C. 2022; 130 (7): 978-980

    View details for DOI 10.1161/CIRCRESAHA.122.320951

    View details for PubMedID 35357897

  • Generation of two iPSC lines from hypertrophic cardiomyopathy patients carrying MYBPC3 and PRKAG2 variants. Stem cell research Manhas, A., Jahng, J. W., Vera, C. D., Shenoy, S. P., Knowles, J. W., Wu, J. C. 2022; 61: 102774

    Abstract

    Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disorder characterized by a thick left ventricular wall and an increased risk of arrhythmias, heart failure, and sudden cardiac death. The MYBPC3 and PRAKG2 are known causal genes for HCM. Here we generated two human-induced pluripotent stem cell lines from two HCM patients carrying two heterozygous mutations in MYBPC3 (c.459delC) and PRKAG2 (c.1703C > T). Both iPSC lines expressed pluripotent markers, had a normal karyotype, and were able to differentiate into three germ layers, making them potentially valuable tools for modeling HCM in vitro and investigating the pathological mechanisms related to these two variants.

    View details for DOI 10.1016/j.scr.2022.102774

    View details for PubMedID 35413566

  • Cardiac reprogramming via chromatin remodeling by CRISPR activation. Molecular therapy : the journal of the American Society of Gene Therapy Jahng, J. W., Wu, J. C. 1800

    View details for DOI 10.1016/j.ymthe.2021.12.005

    View details for PubMedID 34895515

  • Generation of three induced pluripotent stem cell lines (SCVIi014-A, SCVIi015-A, and SCVIi016-A) from patients with LQT1 caused by heterozygous mutations in the KCNQ1 gene. Stem cell research Zhang, H., Jahng, J. W., Liu, Y., Chase, A. J., Perez, M. V., Wu, J. C. 2021; 55: 102492

    Abstract

    Congenital long QT syndrome type 1 (LQT1) results from KCNQ1 mutations that cause loss of Kv7.1 channel function, leading to arrhythmias, syncope, and sudden cardiac death. Here, we generated three human-induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of LQT1 patients carrying pathogenic variants (c.569 G>A, c.585delG, and c.573_577delGCGCT) in KCNQ1. All lines show typical iPSC morphology, high expression of pluripotent markers, normal karyotype, and are able to differentiate into three germ layers in vitro. These lines are valuable resources for studying the pathological mechanisms of LQT1 caused by KCNQ1 mutations.

    View details for DOI 10.1016/j.scr.2021.102492

    View details for PubMedID 34411974

  • Generation of three induced pluripotent stem cell lines from hypertrophic cardiomyopathy patients carrying MYH7 mutations. Stem cell research Cao, X., Jahng, J. W., Lee, C., Zha, Y., Wheeler, M. T., Sallam, K., Wu, J. C. 2021; 55: 102455

    Abstract

    MYH7 heterozygous mutations are common genetic causes of hypertrophic cardiomyopathy (HCM). HCM is characterized by hypertrophy of the left ventricle and diastolic dysfunction. We generated three human induced pluripotent stem cell (iPSC) lines from three HCM patients each carrying a single heterozygous mutation in MYH7, c.2167C>T, c.4066G>A, and c.5135G>A, respectively. All lines expressed high levels of pluripotent markers, had normal karyotype, and possessed capability of differentiation into derivatives of the three germ layers, which can serve as valuable tools for modeling HCM in vitro and investigating the pathological mechanisms related to MYH7 mutations.

    View details for DOI 10.1016/j.scr.2021.102455

    View details for PubMedID 34352619

  • Generation of three heterozygous KCNH2 mutation-carrying human induced pluripotent stem cell lines for modeling LQT2 syndrome. Stem cell research Mondejar-Parreno, G., Jahng, J. W., Belbachir, N., Wu, B. C., Zhang, X., Perez, M. V., Badhwar, N., Wu, J. C. 2021; 54: 102402

    Abstract

    Congenital long QT syndrome type 2 (LQT2) results from KCNH2 mutations that cause loss of Kv11.1 channel function which can lead to arrhythmias, syncope, and sudden death. Here, we generated three human-induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of two LQT2 patients carrying pathogenic variants (c.1714G>A and c.2960del) and one LQT2 patient carrying a variant of uncertain significance (c.1870A>T) in KCNH2. All lines show typical iPSC morphology, high expression of pluripotent markers, normal karyotype, and differentiate into three germ layers in vitro. These lines are valuable resources for studying the pathological mechanisms of LQTS caused by caused by KCNH2 mutations.

    View details for DOI 10.1016/j.scr.2021.102402

    View details for PubMedID 34051449

  • Generation of three induced pluripotent stem cell lines, SCVIi003-A, SCVIi004-A, SCVIi005-A, from patients with ARVD/C caused by heterozygous mutations in the PKP2 gene. Stem cell research Jahng, J. W., Black, K. E., Liu, L., Bae, H. R., Perez, M., Ashley, E. A., Sallam, K., Wu, J. C. 2021; 53: 102284

    Abstract

    Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited heart disease which can cause life-threatening ventricular arrhythmias and cardiac dysfunction. The autosomal dominant form of ARVD/C is caused by mutations in the cardiac desmosome, such as those in the plakoglobin plakophilin-2 (PKP2) gene. Here, we generated three human induced pluripotent stem cell (iPSC) lines from the peripheral blood mononuclear cells (PBMCs) of three ARVD/C patients carrying pathogenic variants in their PKP2 genes (c.2065_2070delinsG; c.235C>T; c.1725_1728dup). All lines show the typical morphology of pluripotent stem cells, demonstrate high expression of pluripotent markers, display normal karyotype, and differentiate into all three germ layers in vitro. These lines are valuable resources for studying the pathological mechanisms of ARVD/C caused by PKP2 mutation.

    View details for DOI 10.1016/j.scr.2021.102284

    View details for PubMedID 33743362

  • Generation of two heterozygous MYBPC3 mutation-carrying human iPSC lines, SCVIi001-A and SCVIi002-A, for modeling hypertrophic cardiomyopathy. Stem cell research Liu, L., Shenoy, S. P., Jahng, J. W., Liu, Y., Knowles, J. W., Zhuge, Y., Wu, J. C. 2021; 53: 102279

    Abstract

    Hypertrophic cardiomyopathy (HCM) is an inherited heart disease that can cause sudden cardiac death and heart failure. HCM often arises from mutations in sarcomeric genes, among which the MYBPC3 is the most frequently mutated. Here we generated two human induced pluripotent stem cell (iPSC) lines from a HCM patient who has a familial history of HCM and his daughter who carries the pathogenic non-coding mutation. All lines show the typical morphology of pluripotent cells, a high expression of pluripotency markers, normal karyotype, and in vitro capacity to differentiate into all three germ layers. These lines provide a valuable resource for studying the molecular basis of HCM and drug screening for HCM.

    View details for DOI 10.1016/j.scr.2021.102279

    View details for PubMedID 33743363

  • Tumor Repressor Circular RNA as a New Target for Preventative Gene Therapy Against Doxorubicin-Induced Cardiotoxicity. Circulation research Jahng, J. W., Liu, L. n., Wu, J. C. 2020; 127 (4): 483–85

    View details for DOI 10.1161/CIRCRESAHA.120.317568

    View details for PubMedID 32762533