Browsing by Author "Chen, Hanying"
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Item Atrial fibrillation and electrophysiology in transgenic mice with cardiac-restricted overexpression of FKBP12(American Physiological Society, 2019-02-01) Pan, Zhenwei; Ai, Tomohiko; Chang, Po-Cheng; Liu, Ying; Liu, Jijia; Maruyama, Mitsunori; Homsi, Mohamed; Fishbein, Michael C.; Rubart, Michael; Lin, Shien-Fong; Xiao, Deyong; Chen, Hanying; Chen, Peng-Sheng; Shou, Weinian; Li, Bai-Yan; Medicine, School of MedicineCardiomyocyte-restricted overexpression of FK506-binding protein 12 transgenic (αMyHC-FKBP12) mice develop spontaneous atrial fibrillation (AF). The aim of the present study is to explore the mechanisms underlying the occurrence of AF in αMyHC-FKBP12 mice. Spontaneous AF was documented by telemetry in vivo and Langendorff-perfused hearts of αMyHC-FKBP12 and littermate control mice in vitro. Atrial conduction velocity was evaluated by optical mapping. The patch-clamp technique was applied to determine the potentially altered electrophysiology in atrial myocytes. Channel protein expression levels were evaluated by Western blot analyses. Spontaneous AF was recorded in four of seven αMyHC-FKBP12 mice but in none of eight nontransgenic (NTG) controls. Atrial conduction velocity was significantly reduced in αMyHC-FKBP12 hearts compared with NTG hearts. Interestingly, the mean action potential duration at 50% but not 90% was significantly prolonged in αMyHC-FKBP12 atrial myocytes compared with their NTG counterparts. Consistent with decreased conduction velocity, average peak Na+ current ( INa) density was dramatically reduced and the INa inactivation curve was shifted by approximately +7 mV in αMyHC-FKBP12 atrial myocytes, whereas the activation and recovery curves were unaltered. The Nav1.5 expression level was significantly reduced in αMyHC-FKBP12 atria. Furthermore, we found increases in atrial Cav1.2 protein levels and peak L-type Ca2+ current density and increased levels of fibrosis in αMyHC-FKBP12 atria. In summary, cardiomyocyte-restricted overexpression of FKBP12 reduces the atrial Nav1.5 expression level and mean peak INa, which is associated with increased peak L-type Ca2+ current and interstitial fibrosis in atria. The combined electrophysiological and structural changes facilitated the development of local conduction block and altered action potential duration and spontaneous AF. NEW & NOTEWORTHY This study addresses a long-standing riddle regarding the role of FK506-binding protein 12 in cardiac physiology. The work provides further evidence that FK506-binding protein 12 is a critical component for regulating voltage-gated sodium current and in so doing has an important role in arrhythmogenic physiology, such as atrial fibrillation.Item BMP10 preserves cardiac function through its dual activation of SMAD-mediated and STAT3-mediated pathways(Elsevier, 2019-12-27) Qu, Xiuxia; Liu, Ying; Cao, Dayan; Chen, Jinghai; Liu, Zhuo; Ji, Hongrui; Chen, Yuwen; Zhang, Wenjun; Zhu, Ping; Xiao, Deyong; Li, Xiaohui; Shou, Weinian; Chen, Hanying; Pediatrics, School of MedicineBone morphogenetic protein 10 (BMP10) is a cardiac peptide growth factor belonging to the transforming growth factor β superfamily that critically controls cardiovascular development, growth, and maturation. It has been shown that BMP10 elicits its intracellular signaling through a receptor complex of activin receptor-like kinase 1 with morphogenetic protein receptor type II or activin receptor type 2A. Previously, we generated and characterized a transgenic mouse line expressing BMP10 from the α-myosin heavy chain gene promoter and found that these mice have normal cardiac hypertrophic responses to both physiological and pathological stimuli. In this study, we report that these transgenic mice exhibit significantly reduced levels of cardiomyocyte apoptosis and cardiac fibrosis in response to a prolonged administration of the β-adrenoreceptor agonist isoproterenol. We further confirmed this cardioprotective function with a newly generated conditional Bmp10 transgenic mouse line, in which Bmp10 was activated in adult hearts by tamoxifen. Moreover, the intraperitoneal administration of recombinant human BMP10 was found to effectively protect hearts from injury, suggesting potential therapeutic utility of using BMP10 to prevent heart failure. Gene profiling and biochemical analyses indicated that BMP10 activates the SMAD-mediated canonical pathway and, unexpectedly, also the signal transducer and activator of transcription 3 (STAT3)-mediated signaling pathway both in vivo and in vitro Additional findings further supported the notion that BMP10's cardioprotective function likely is due to its dual activation of SMAD- and STAT3-regulated signaling pathways, promoting cardiomyocyte survival and suppressing cardiac fibrosis.Item Critical Roles of STAT3 in β-Adrenergic Functions in the Heart(American Heart Association, 2016-01-05) Zhang, Wenjun; Qu, Xiuxia; Chen, Biyi; Snyder, Marylynn; Wang, Meijing; Li, Baiyan; Tang, Yue; Chen, Hanying; Zhu, Wuqiang; Zhan, Li; Yin, Ni; Li, Deqiang; Li, Xie; Liu, Ying; Zhang, J. Jillian; Fu, Xin-Yuan; Rubart, Michael; Song, Long-Sheng; Huang, Xin-Yun; Shou, Weinian; Department of Pediatrics, IU School of MedicineBACKGROUND: β-Adrenergic receptors (βARs) play paradoxical roles in the heart. On one hand, βARs augment cardiac performance to fulfill the physiological demands, but on the other hand, prolonged activations of βARs exert deleterious effects that result in heart failure. The signal transducer and activator of transcription 3 (STAT3) plays a dynamic role in integrating multiple cytokine signaling pathways in a number of tissues. Altered activation of STAT3 has been observed in failing hearts in both human patients and animal models. Our objective is to determine the potential regulatory roles of STAT3 in cardiac βAR-mediated signaling and function. METHODS AND RESULTS: We observed that STAT3 can be directly activated in cardiomyocytes by β-adrenergic agonists. To follow up this finding, we analyzed βAR function in cardiomyocyte-restricted STAT3 knockouts and discovered that the conditional loss of STAT3 in cardiomyocytes markedly reduced the cardiac contractile response to acute βAR stimulation, and caused disengagement of calcium coupling and muscle contraction. Under chronic β-adrenergic stimulation, Stat3cKO hearts exhibited pronounced cardiomyocyte hypertrophy, cell death, and subsequent cardiac fibrosis. Biochemical and genetic data supported that Gαs and Src kinases are required for βAR-mediated activation of STAT3. Finally, we demonstrated that STAT3 transcriptionally regulates several key components of βAR pathway, including β1AR, protein kinase A, and T-type Ca(2+) channels. CONCLUSIONS: Our data demonstrate for the first time that STAT3 has a fundamental role in βAR signaling and functions in the heart. STAT3 serves as a critical transcriptional regulator for βAR-mediated cardiac stress adaption, pathological remodeling, and heart failure.Item Dishevelled-associated activator of morphogenesis 1 (Daam1) is required for heart morphogenesis(2011-01) Li, Deqiang; Hallett, Mark A.; Zhu, Wuqiang; Rubart, Michael; Liu, Ying; Yang, Zhenyun; Chen, Hanying; Haneline, Laura S.; Chan, Rebecca J.; Schwartz, Robert J.; Field, Loren J.; Atkinson, Simon J.; Shou, WeinianDishevelled-associated activator of morphogenesis 1 (Daam1), a member of the formin protein family, plays an important role in regulating the actin cytoskeleton via mediation of linear actin assembly. Previous functional studies of Daam1 in lower species suggest its essential role in Drosophila trachea formation and Xenopus gastrulation. However, its in vivo physiological function in mammalian systems is largely unknown. We have generated Daam1-deficient mice via gene-trap technology and found that Daam1 is highly expressed in developing murine organs, including the heart. Daam1-deficient mice exhibit embryonic and neonatal lethality and suffer multiple cardiac defects, including ventricular noncompaction, double outlet right ventricles and ventricular septal defects. In vivo genetic rescue experiments further confirm that the lethality of Daam1-deficient mice results from the inherent cardiac abnormalities. In-depth analyses have revealed that Daam1 is important for regulating filamentous actin assembly and organization, and consequently for cytoskeletal function in cardiomyocytes, which contributes to proper heart morphogenesis. Daam1 is also found to be important for proper cytoskeletal architecture and functionalities in embryonic fibroblasts. Biochemical analyses indicate that Daam1 does not regulate cytoskeletal organization through RhoA, Rac1 or Cdc42. Our study highlights a crucial role for Daam1 in regulating the actin cytoskeleton and tissue morphogenesis.Item Genome-wide analyses reveal the detrimental impacts of SARS-CoV-2 viral gene Orf9c on human pluripotent stem cell-derived cardiomyocytes(Cell Press, 2022) Liu, Juli; Zhang, Yucheng; Han, Lei; Guo, Shuai; Wu, Shiyong; Doud, Emma Helen; Wang, Cheng; Chen, Hanying; Rubart-von der Lohe, Michael; Wan, Jun; Yang, Lei; Pediatrics, School of MedicinePatients with coronavirus disease 2019 (COVID-19) commonly have manifestations of heart disease. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome encodes 27 proteins. Currently, SARS-CoV-2 gene-induced abnormalities of human heart muscle cells remain elusive. Here, we comprehensively characterized the detrimental effects of a SARS-CoV-2 gene, Orf9c, on human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) by preforming multi-omic analyses. Transcriptomic analyses of hPSC-CMs infected by SARS-CoV-2 with Orf9c overexpression (Orf9cOE) identified concordantly up-regulated genes enriched into stress-related apoptosis and inflammation signaling pathways, and down-regulated CM functional genes. Proteomic analysis revealed enhanced expressions of apoptotic factors, whereas reduced protein factors for ATP synthesis by Orf9cOE. Orf9cOE significantly reduced cellular ATP level, induced apoptosis, and caused electrical dysfunctions of hPSC-CMs. Finally, drugs approved by the U.S. Food and Drug Administration, namely, ivermectin and meclizine, restored ATP levels and ameliorated CM death and functional abnormalities of Orf9cOE hPSC-CMs. Overall, we defined the molecular mechanisms underlying the detrimental impacts of Orf9c on hPSC-CMs and explored potentially therapeutic approaches to ameliorate Orf9c-induced cardiac injury and abnormalities.Item Heterogeneity of Hepatic Stellate Cells in Fibrogenesis of the Liver: Insights from Single-Cell Transcriptomic Analysis in Liver Injury(MDPI, 2021-08-19) Zhang, Wenjun; Conway, Simon J.; Liu, Ying; Snider, Paige; Chen, Hanying; Gao, Hongyu; Liu, Yunlong; Isidan, Kadir; Lopez, Kevin J.; Campana, Gonzalo; Li, Ping; Ekser, Burcin; Francis, Heather; Shou, Weinian; Kubal, Chandrashekhar; Pediatrics, School of MedicineBackground & Aims: Liver fibrosis is a pathological healing process resulting from hepatic stellate cell (HSC) activation and the generation of myofibroblasts from activated HSCs. The precise underlying mechanisms of liver fibrogenesis are still largely vague due to lack of understanding the functional heterogeneity of activated HSCs during liver injury. Approach and Results: In this study, to define the mechanism of HSC activation, we performed the transcriptomic analysis at single-cell resolution (scRNA-seq) on HSCs in mice treated with carbon tetrachloride (CCl4). By employing LRAT-Cre:Rosa26mT/mG mice, we were able to isolate an activated GFP-positive HSC lineage derived cell population by fluorescence-activated cell sorter (FACS). A total of 8 HSC subpopulations were identified based on an unsupervised analysis. Each HSC cluster displayed a unique transcriptomic profile, despite all clusters expressing common mouse HSC marker genes. We demonstrated that one of the HSC subpopulations expressed high levels of mitosis regulatory genes, velocity, and monocle analysis indicated that these HSCs are at transitioning and proliferating phases at the beginning of HSCs activation and will eventually give rise to several other HSC subtypes. We also demonstrated cell clusters representing HSC-derived mature myofibroblast populations that express myofibroblasts hallmark genes with unique contractile properties. Most importantly, we found a novel HSC cluster that is likely to be critical in liver regeneration, immune reaction, and vascular remodeling, in which the unique profiles of genes such as Rgs5, Angptl6, and Meg3 are highly expressed. Lastly, we demonstrated that the heterogeneity of HSCs in the injured mouse livers is closely similar to that of cirrhotic human livers. Conclusions: Collectively, our scRNA-seq data provided insight into the landscape of activated HSC populations and the dynamic transitional pathway from HSC to myofibroblasts in response to liver injury.Item KCa1.1 β4-subunits is not responsible for iberiotoxin-resistance in baroreceptor neurons in adult male rats(Elsevier, 2015) Xu, Wen-Xiao; Ban, Tao; Wang, Lu-Qi; Zhao, Miao; Yin, Lei; Li, Guo; Chen, Hanying; Schild, John H.; Qiao, Guo-Fen; Yan, Jing-Long; Li, Bai-Yan; Biomedical Engineering, School of Engineering and TechnologyItem Molecular mechanism of ventricular trabeculation/compaction and the pathogenesis of the left ventricular noncompaction cardiomyopathy (LVNC)(Wiley, 2013) Zhang, Wenjun; Chen, Hanying; Qu, Xiuxia; Chang, Ching-Pin; Shou, Weinian; Pediatrics, School of MedicineVentricular trabeculation and compaction are two of the many essential steps for generating a functionally competent ventricular wall. A significant reduction in trabeculation is usually associated with ventricular compact zone deficiencies (hypoplastic wall), which commonly leads to embryonic heart failure and early embryonic lethality. In contrast, hypertrabeculation and lack of ventricular wall compaction (noncompaction) are closely related defects in cardiac embryogenesis associated with left ventricular noncompaction (LVNC), a genetically heterogenous disorder. Here we review recent findings through summarizing several genetically engineered mouse models that have defects in cardiac trabeculation and compaction.Item Myocardial Mycn is essential for mouse ventricular wall morphogenesis(Elsevier, 2013) Harmelink, Cristina; Peng, Yin; DeBenedittis, Paige; Chen, Hanying; Shou, Weinian; Jiao, Kai; Pediatrics, School of MedicineMYCN is a highly conserved transcription factor with multifaceted roles in development and disease. Mutations in MYCN are associated with Feingold syndrome, a developmental disorder characterized in part by congenital heart defects. Mouse models have helped elucidate MYCN functions; however its cardiac-specific roles during development remain unclear. We employed a Cre/loxp strategy to uncover the specific activities of MYCN in the developing mouse myocardium. Myocardial deletion of Mycn resulted in a thin-myocardial wall defect with dramatically reduced trabeculation. The mutant heart defects strongly resemble the phenotype caused by disruption of BMP10 and Neuregulin-1 (NRG1) signaling pathways, two central mediators of myocardial wall development. Our further examination showed that expression of MYCN is regulated by both BMP and NRG1 signaling. The thin-wall defect in mutant hearts is caused by a reduction in both cell proliferation and cell size. MYCN promotes cardiomyocyte proliferation through regulating expression of cell cycle regulators (including CCND1, CCND2, and ID2) and promotes cardiomyocyte growth through regulating expression of p70S6K. In addition, expression of multiple sarcomere proteins is altered in Mycn myocardial-inactivation embryos, indicating its essential role for proper cardiomyocyte differentiation. In summary, Mycn acts downstream of BMP and NRG1 cardiogenic signaling pathways to promote normal myocardial wall morphogenesis.Item Na+-induced Ca2+ influx through reverse mode of Na+-Ca2+ exchanger in mouse ventricular cardiomyocyte(Oncotarget, 2015-09-15) Yan, Zhen-Yu; Ban, Tao; Fan, Tao; Chen, Wei-Ran; Sun, Hong-Li; Chen, Hanying; Qiao, Quo-Fen; Li, Bai-Yan; Department of Pediatrics, IU School of MedicineBACKGROUND: Dobutamine is commonly used for clinical management of heart failure and its pharmacological effects have long been investigated as inotropics via β-receptor activation. However, there is no electrophysiological evidence if dobutamine contributes inotropic action due at least partially to the reverse mode of Na+-Ca2+ exchanger (NCX) activation. METHODS: Action potential (AP), voltage-gated Na+ (INa), Ca2+ (ICa), and K+ (Ito and IK1) currents were observed using whole-cell patch technique before and after dobutamine in ventricular cardiomyocytes isolated from adult mouse hearts. Another sets of observation were also performed with Kb-r7943 or in the solution without [Ca2+]o. RESULTS: Dobutamine (0.1-1.0 μM) significantly enhanced the AP depolarization with prolongation of AP duration (APD) in a concentration-dependent fashion. The density of INa was also increased concentration-dependently without alternation of voltage-dependent steady-status of activation and inactivation, reactivation as well. Whereas, the activities for ICa, Ito, and IK1 were not changed by dobutamine. Intriguingly, the dobutamine-mediated changes in AP repolarization were abolished by 3 μM Kb-r7943 pretreatment or by simply removing [Ca2+]o without affecting accelerated depolarization. Additionally, the ratio of APD50/APD90 was not significantly altered in the presence of dobutamine, implying that effective refractory period was remain unchanged. CONCLUSIONS: This novel finding provides evidence that dobutamine upregulates of voltage-gated Na+ channel function and Na+ influx-induced activation of the reverse mode of NCX, suggesting that dobutamine may not only accelerate ventricular contraction via fast depolarization but also cause Ca2+ influx, which contributes its positive inotropic effect synergistically with β-receptor activation without increasing the arrhythmogenetic risk.