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Sample records for mybp-c knockout cardiac

  1. Cardiac-Specific Knockout of ETA Receptor Mitigates Paraquat-Induced Cardiac Contractile Dysfunction.

    PubMed

    Wang, Jiaxing; Lu, Songhe; Zheng, Qijun; Hu, Nan; Yu, Wenjun; Li, Na; Liu, Min; Gao, Beilei; Zhang, Guoyong; Zhang, Yingmei; Wang, Haichang

    2016-07-01

    Paraquat (1,1'-dim ethyl-4-4'-bipyridinium dichloride), a highly toxic quaternary ammonium herbicide widely used in agriculture, exerts potent toxic prooxidant effects resulting in multi-organ failure including the lung and heart although the underlying mechanism remains elusive. Recent evidence suggests possible involvement of endothelin system in paraquat-induced acute lung injury. This study was designed to examine the role of endothelin receptor A (ETA) in paraquat-induced cardiac contractile and mitochondrial injury. Wild-type (WT) and cardiac-specific ETA receptor knockout mice were challenged to paraquat (45 mg/kg, i.p.) for 48 h prior to the assessment of echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties, as well as apoptosis and mitochondrial damage. Levels of the mitochondrial proteins for biogenesis and oxidative phosphorylation including UCP2, HSP90 and PGC1α were evaluated. Our results revealed that paraquat elicited cardiac enlargement, mechanical anomalies including compromised echocardiographic parameters (elevated left ventricular end-systolic and end-diastolic diameters as well as reduced factional shortening), suppressed cardiomyocyte contractile function, intracellular Ca(2+) handling, overt apoptosis and mitochondrial damage. ETA receptor knockout itself failed to affect myocardial function, apoptosis, mitochondrial integrity and mitochondrial protein expression. However, ETA receptor knockout ablated or significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) defect, apoptosis and mitochondrial damage. Taken together, these findings revealed that endothelin system in particular the ETA receptor may be involved in paraquat-induced toxic myocardial contractile anomalies possibly related to apoptosis and mitochondrial damage.

  2. Cathepsin K Knockout Mitigates High-Fat Diet–Induced Cardiac Hypertrophy and Contractile Dysfunction

    PubMed Central

    Hua, Yinan; Zhang, Yingmei; Dolence, Julia; Shi, Guo-Ping; Ren, Jun; Nair, Sreejayan

    2013-01-01

    The cysteine protease cathepsin K has been implicated in pathogenesis of cardiovascular disease. We hypothesized that ablation of cathepsin K protects against obesity-associated cardiac dysfunction. Wild-type mice fed a high-fat diet exhibited elevated heart weight, enlarged cardiomyocytes, increased left ventricular wall thickness, and decreased fractional shortening. All these changes were reconciled in cathepsin K knockout mice. Cathepsin K knockout partly reversed the impaired cardiomyocyte contractility and dysregulated calcium handling associated with high-fat diet. Additionally, cathepsin K knockout alleviated whole-body glucose intolerance and improved insulin-stimulated Akt phosphorylation in high-fat diet–fed mice. High-fat feeding increased the expression of cardiac hypertrophic proteins and apoptotic markers, which were inhibited by cathepsin K knockout. Furthermore, high-fat feeding resulted in cathepsin K release from lysosomes into the cytoplasm. In H9c2 myoblasts, silencing of cathepsin K inhibited palmitic acid–induced release of cytochrome c from mitochondria and expression of proapoptotic signaling molecules. Collectively, our data indicate that cathepsin K contributes to the development of obesity-associated cardiac hypertrophy and may represent a potential target for the treatment to obesity-associated cardiac anomalies. PMID:23069627

  3. Knockout of the Na,K-ATPase α2-isoform in cardiac myocytes delays pressure overload-induced cardiac dysfunction

    PubMed Central

    Rindler, Tara N.; Lasko, Valerie M.; Nieman, Michelle L.; Okada, Motoi; Lorenz, John N.

    2013-01-01

    The α2-isoform of the Na,K-ATPase (α2) is the minor isoform of the Na,K-ATPase expressed in the cardiovascular system and is thought to play a critical role in the regulation of cardiovascular hemodynamics. However, the organ system/cell type expressing α2 that is required for this regulation has not been fully defined. The present study uses a heart-specific knockout of α2 to further define the tissue-specific role of α2 in the regulation of cardiovascular hemodynamics. To accomplish this, we developed a mouse model using the Cre/loxP system to generate a tissue-specific knockout of α2 in the heart using β-myosin heavy chain Cre. We have achieved a 90% knockout of α2 expression in the heart of the knockout mice. Interestingly, the heart-specific knockout mice exhibit normal basal cardiac function and systolic blood pressure, and in addition, these mice develop ACTH-induced hypertension in response to ACTH treatment similar to control mice. Surprisingly, the heart-specific knockout mice display delayed onset of cardiac dysfunction compared with control mice in response to pressure overload induced by transverse aortic constriction; however, the heart-specific knockout mice deteriorated to control levels by 9 wk post-transverse aortic constriction. These results suggest that heart expression of α2 does not play a role in the regulation of basal cardiovascular function or blood pressure; however, heart expression of α2 plays a role in the hypertrophic response to pressure overload. This study further emphasizes that the tissue localization of α2 determines its unique roles in the regulation of cardiovascular function. PMID:23436327

  4. Adiponectin knockout accentuates high fat diet-induced obesity and cardiac dysfunction: role of autophagy.

    PubMed

    Guo, Rui; Zhang, Yingmei; Turdi, Subat; Ren, Jun

    2013-08-01

    Adiponectin (APN), an adipose-derived adipokine, offers cardioprotective effects although the precise mechanism of action remains unclear. This study was designed to examine the role of APN in high fat diet-induced obesity and cardiac pathology. Adult C57BL/6 wild-type and APN knockout mice were fed a low or high fat diet for 22weeks. After 40day feeding, mice were treated with 2mg/kg rapamycin or vehicle every other day for 42days on respective fat diet. Cardiomyocyte contractile and Ca(2+) transient properties were evaluated. Myocardial function was evaluated using echocardiography. Dual energy X-ray absorptiometry was used to evaluate adiposity. Energy expenditure, metabolic rate and physical activity were monitored using a metabolic cage. Lipid deposition, serum triglyceride, glucose tolerance, markers of autophagy and fatty acid metabolism including LC3, p62, Beclin-1, AMPK, mTOR, fatty acid synthase (FAS) were evaluated. High fat diet intake induced obesity, systemic glucose intolerance, cardiac hypertrophy, dampened metabolic ability, cardiac and intracellular Ca(2+) derangements, the effects of which were accentuated by APN knockout. Furthermore, APN deficiency augmented high fat diet-induced upregulation in the autophagy adaptor p62 and the decline in AMPK without affecting high fat diet-induced decrease in LC3II and LC3II-to-LC3I ratio. Neither high fat diet nor APN deficiency altered Beclin-1. Interestingly, rapamycin negated high fat diet-induced/APN-deficiency-accentuated obesity, cardiac hypertrophy and contractile dysfunction as well as AMPK dephosphorylation, mTOR phosphorylation and p62 buildup. Our results collectively revealed that APN deficiency may aggravate high fat diet-induced obesity, metabolic derangement, cardiac hypertrophy and contractile dysfunction possibly through decreased myocardial autophagy. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Adiponectin knockout accentuates high fat diet-induced obesity and cardiac dysfunction: Role of autophagy

    PubMed Central

    Guo, Rui; Zhang, Yingmei; Turdi, Subat; Ren, Jun

    2013-01-01

    Adiponectin (APN), an adipose-derived adipokine, offers cardioprotective effects although the precise mechanism of action remains unclear. This study was designed to examine the role of APN in high fat diet-induced obesity and cardiac pathology. Adult C57BL/6 wild-type and APN knockout mice were fed a low or high fat diet for 22 weeks. After 40 day feeding, mice were treated with 2 mg/kg rapamycin or vehicle every other day for 42 days on respective fat diet. Cardiomyocyte contractile and Ca2+ transient properties were evaluated. Myocardial function was evaluated using echocardiography. Dual energy X-ray absorptiometry was used to evaluate adiposity. Energy expenditure, metabolic rate and physical activity were monitored using a metabolic cage. Lipid deposition, serum triglyceride, glucose tolerance, markers of autophagy and fatty acid metabolism including LC3, p62, Beclin-1, AMPK, mTOR, fatty acid synthase (FAS) were evaluated. High fat diet intake induced obesity, systemic glucose intolerance, cardiac hypertrophy, dampened metabolic ability, cardiac and intracellular Ca2+ derangements, the effects of which were accentuated by APN knockout. Furthermore, APN deficiency augmented high fat diet-induced upregulation in the autophagy adaptor p62 and the decline in AMPK without affecting high fat diet-induced decrease in LC3II and LC3II-to-LC3I ratio. Neither high fat diet nor APN deficiency altered Beclin-1. Interestingly, rapamycin negated high fat diet-induced/APN-deficiency-accentuated obesity, cardiac hypertrophy and contractile dysfunction as well as AMPK dephosphorylation, mTOR phosphorylation and p62 buildup. Our results collectively revealed that APN deficiency may aggravate high fat diet-induced obesity, metabolic derangement, cardiac hypertrophy and contractile dysfunction possibly through decreased myocardial autophagy. PMID:23524376

  6. Cardiac and skeletal muscle abnormality in taurine transporter-knockout mice.

    PubMed

    Ito, Takashi; Oishi, Shohei; Takai, Mika; Kimura, Yasushi; Uozumi, Yoriko; Fujio, Yasushi; Schaffer, Stephen W; Azuma, Junichi

    2010-08-24

    Taurine, a sulfur-containing beta-amino acid, is highly contained in heart and skeletal muscle. Taurine has a variety of biological actions, such as ion movement, calcium handling and cytoprotection in the cardiac and skeletal muscles. Meanwhile, taurine deficiency leads various pathologies, including dilated cardiomyopathy, in cat and fox. However, the essential role of taurine depletion on pathogenesis has not been fully clarified. To address the physiological role of taurine in mammalian tissues, taurine transporter-(TauT-) knockout models were recently generated. TauTKO mice exhibited loss of body weight, abnormal cardiac function and the reduced exercise capacity with tissue taurine depletion. In this chapter, we summarize pathological profile and histological feature of heart and skeletal muscle in TauTKO mice.

  7. Conditional Knockout of Prolyl Hydroxylase Domain Protein 2 Attenuates High Fat-Diet-Induced Cardiac Dysfunction in Mice

    PubMed Central

    Zeng, Heng; Chen, Jian-Xiong

    2014-01-01

    Oxygen sensor prolyl hydroxylases (PHDs) play important roles in the regulation of HIF-α and cell metabolisms. This study was designed to investigate the direct role of PHD2 in high fat-diet (HFD)-induced cardiac dysfunction. In HFD fed mice, PHD2 expression was increased without significant changes in PHD1 and PHD3 levels in the heart. This was accompanied by a significant upregulation of myeloid differentiation factor 88 (MYD88) and NF-κB. To explore the role of PHD2 in HFD-induced cardiac dysfunction, PHD2 conditional knockout mice were fed a HFD for 16 weeks. Intriguingly, knockout of PHD2 significantly reduced MYD88 and NF-κb expression in HFD mouse hearts. Moreover, knockout of PHD2 inhibited TNFα and ICAM-1 expression, and reduced cell apoptosis and macrophage infiltration in HFD mice. This was accompanied by a significant improvement of cardiac function. Most importantly, conditional knockout of PHD2 at late stage in HFD mice significantly improved glucose tolerance and reversed cardiac dysfunction. Our studies demonstrate that PHD2 activity is a critical contributor to the HFD-induced cardiac dysfunction. Inhibition of PHD2 attenuates HFD-induced cardiac dysfunction by a mechanism involving suppression of MYD88/NF-κb pathway and inflammation. PMID:25546437

  8. Increased cardiac remodeling in cardiac-specific Flt-1 receptor knockout mice with pressure overload.

    PubMed

    Mei, Liqin; Huang, Yinqing; Lin, Jiafeng; Chu, Maoping; Hu, Chaohui; Zhou, Ning; Wu, Lianpin

    2015-11-01

    Vascular endothelial growth factor (VEGF) inhibition has previously been shown to have damaging effects on the heart. Because the role of Flt-1 (a phosphotyrosine kinase receptor for VEGF) in cardiac function and hypertrophy is unclear, we generated mice lacking Flt-1 only in their cardiomyocytes (Flt-1 KO). The hearts from 8- to 10-week-old mice were measured by using echocardiography and histology. No significant differences were seen in fraction shortening, cross-sectional area of cardiomyocytes, and interstitial collagen fraction between littermate controls and KO mice at baseline. To test the hypothesis that Flt-1 is involved in cardiac remodeling, we performed transverse aorta constriction (TAC) by ligating the transverse ascending aorta. Four weeks after TAC, echocardiography of the mice was performed, and the hearts were excised for pathological analysis and Western blotting. No difference in mortality was found between Flt-1 KO mice and controls; however, KO mice showed a greater cardiomyocyte cross-sectional area and interstitial collagen fraction than controls. Western blotting indicated that AKT was activated less in Flt-1 KO hearts after TAC compared with that in control hearts. Thus, Flt-1 deletion in cardiomyocytes increased hypertrophy, fibrosis, and regression of AKT phosphorylation. Our study suggests that Flt-1 plays a critical role in cardiac hypertrophy induced by pressure overload via the activation of AKT, which seems to be cardioprotective.

  9. Global Gene Expression Profiling in PAI-1 Knockout Murine Heart and Kidney: Molecular Basis of Cardiac-Selective Fibrosis

    PubMed Central

    Ghosh, Asish K.; Murphy, Sheila B.; Kishore, Raj; Vaughan, Douglas E.

    2013-01-01

    Fibrosis is defined as an abnormal matrix remodeling due to excessive synthesis and accumulation of extracellular matrix proteins in tissues during wound healing or in response to chemical, mechanical and immunological stresses. At present, there is no effective therapy for organ fibrosis. Previous studies demonstrated that aged plasminogen activator inhibitor-1(PAI-1) knockout mice develop spontaneously cardiac-selective fibrosis without affecting any other organs. We hypothesized that differential expressions of profibrotic and antifibrotic genes in PAI-1 knockout hearts and unaffected organs lead to cardiac selective fibrosis. In order to address this prediction, we have used a genome-wide gene expression profiling of transcripts derived from aged PAI-1 knockout hearts and kidneys. The variations of global gene expression profiling were compared within four groups: wildtype heart vs. knockout heart; wildtype kidney vs. knockout kidney; knockout heart vs. knockout kidney and wildtype heart vs. wildtype kidney. Analysis of illumina-based microarray data revealed that several genes involved in different biological processes such as immune system processing, response to stress, cytokine signaling, cell proliferation, adhesion, migration, matrix organization and transcriptional regulation were affected in hearts and kidneys by the absence of PAI-1, a potent inhibitor of urokinase and tissue-type plasminogen activator. Importantly, the expressions of a number of genes, involved in profibrotic pathways including Ankrd1, Pi16, Egr1, Scx, Timp1, Timp2, Klf6, Loxl1 and Klotho, were deregulated in PAI-1 knockout hearts compared to wildtype hearts and PAI-1 knockout kidneys. While the levels of Ankrd1, Pi16 and Timp1 proteins were elevated during EndMT, the level of Timp4 protein was decreased. To our knowledge, this is the first comprehensive report on the influence of PAI-1 on global gene expression profiling in the heart and kidney and its implication in fibrogenesis and

  10. Human CD55 Expression Blocks Hyperacute Rejection and Restricts Complement Activation in Gal Knockout Cardiac Xenografts

    PubMed Central

    McGregor, Christopher G.A.; Ricci, Davide; Miyagi, Naoto; Stalboerger, Paul G.; Du, Zeji; Oehler, Elise A.; Tazelaar, Henry D.; Byrne, Guerard W.

    2012-01-01

    Background Transgenic expression of human complement regulatory proteins (hCRPs) reduces the frequency of hyperacute rejection (HAR) in Gal-positive cardiac xenotransplantation. In this study we examine the impact of human CD55 (hCD55) expression on a Gal knock-out (GTKO) background using pig-to-primate heterotopic cardiac xenotransplantation. Methods Cardiac xenotransplantation was performed with GTKO (Group 1; n=6) and GTKO.hCD55 (Group 2; n=5) donor pigs using similar immunosuppression. Cardiac biopsies were obtained 30 minutes after organ reperfusion. Rejection was characterized by histology and immunohistology. Intragraft gene expression, serum non-Gal antibody and antibody recovered from rejected hearts were analyzed. Results HAR of a GTKO heart was observed. Remaining grafts developed delayed xenograft rejection. Median survival was 21 and 28 days for Groups 1 and 2 respectively. Vascular antibody deposition was uniformly detected 30 minutes after organ reperfusion and at explant. A higher frequency of vascular C5b deposition was seen in GTKO organs at explant. Serum non-Gal antibody, antibody recovered from the graft and intragraft gene expression were similar between the groups. Conclusion HAR of GTKO hearts without hCD55 may occur. Expression of hCD55 appeared to restrict local complement activation, but did not improve graft survival. Chronic vascular antibody deposition with evidence of protracted endothelial cell activation was seen. These observations suggest that non-Gal antibody-induced chronic endothelial cell activation coupled to possible haemostatic incompatibilities may be the primary stimulus for DXR of GTKO hearts. To avoid possible HAR, future clinical studies should employ donors expressing hCRPs in the GTKO background. PMID:22391577

  11. Pressure overload causes cardiac hypertrophy in beta1-adrenergic and beta2-adrenergic receptor double knockout mice.

    PubMed

    Palazzesi, Sergio; Musumeci, Marco; Catalano, Liviana; Patrizio, Mario; Stati, Tonino; Michienzi, Simona; Di Certo, Maria Grazia; Mattei, Elisabetta; Vitelli, Luigi; Marano, Giuseppe

    2006-03-01

    Cardiac hypertrophy arises as an adaptive response to increased afterload. Studies in knockout mice have shown that catecholamines, but not alpha1-adrenergic receptors, are necessary for such an adaptation to occur. However, whether beta-adrenergic receptors are critical for the development of cardiac hypertrophy in response to pressure overload is not known at this time. Pressure overload was induced by transverse aortic banding in beta1-adrenergic and beta2-adrenergic receptor double knockout (DbetaKO) mice, in which the predominant cardiac beta-adrenergic receptor subtypes are lacking. Chronic pressure overload for 4 weeks induced cardiac hypertrophy in both DbetaKO and wild-type mice. There were no significant differences between banded mice in left ventricular weight to body weight ratio, in the left ventricular wall thickness, in the cardiomyocyte size or in the expression levels of the load-sensitive cardiac genes such as ANF and beta-MHC. Additionally, the left ventricular systolic pressure, an index of afterload, and cardiac contractility, evaluated as dp/dtmax, the maximal slope of systolic pressure increment, and Ees, end-systolic elastance, were increased at a similar level in both wild-type and DbetaKO banded mice, and were significantly greater than in sham controls. Despite chronic activation of the cardiac beta-adrenergic system being sufficient to induce a pathological hypertrophy, we show that beta1-adrenergic and beta2-adrenergic receptors are not an obligatory component of the signaling pathway that links the increased afterload to the development of cardiac hypertrophy.

  12. Microarray analysis of active cardiac remodeling genes in a familial hypertrophic cardiomyopathy mouse model rescued by a phospholamban knockout

    PubMed Central

    Rajan, Sudarsan; Pena, James R.; Jegga, Anil G.; Aronow, Bruce J.; Wolska, Beata M.

    2013-01-01

    Familial hypertrophic cardiomyopathy (FHC) is a disease characterized by ventricular hypertrophy, fibrosis, and aberrant systolic and/or diastolic function. Our laboratories have previously developed two mouse models that affect cardiac performance. One mouse model encodes an FHC-associated mutation in α-tropomyosin: Glu → Gly at amino acid 180, designated as Tm180. These mice display a phenotype that is characteristic of FHC, including severe cardiac hypertrophy with fibrosis and impaired physiological performance. The other model was a gene knockout of phospholamban (PLN KO), a regulator of calcium uptake in the sarcoplasmic reticulum of cardiomyocytes; these hearts exhibit hypercontractility with no pathological abnormalities. Previous work in our laboratories shows that when mice were genetically crossed between the PLN KO and Tm180, the progeny (PLN KO/Tm180) display a rescued hypertrophic phenotype with improved morphology and cardiac function. To understand the changes in gene expression that occur in these models undergoing cardiac remodeling (Tm180, PLN KO, PLN KO/Tm180, and nontransgenic control mice), we conducted microarray analyses of left ventricular tissue at 4 and 12 mo of age. Expression profiling reveals that 1,187 genes changed expression in direct response to the three genetic models. With these 1,187 genes, 11 clusters emerged showing normalization of transcript expression in the PLN KO/Tm180 hearts. In addition, 62 transcripts are highly involved in suppression of the hypertrophic phenotype. Confirmation of the microarray analysis was conducted by quantitative RT-PCR. These results provide insight into genes that alter expression during cardiac remodeling and are active during modulation of the cardiomyopathic phenotype. PMID:23800848

  13. In vivo assessment of coronary flow and cardiac function after bolus adenosine injection in adenosine receptor knockout mice.

    PubMed

    Teng, Bunyen; Tilley, Stephen L; Ledent, Catherine; Mustafa, S Jamal

    2016-06-01

    Bolus injections of adenosine and the A2A adenosine receptor (AR) selective agonist (regadenoson) are used clinically as a substitute for a stress test in people who cannot exercise. Using isolated tissue preparations, our lab has shown that coronary flow and cardiac effects of adenosine are mostly regulated by the AR subtypes A1, A2A, and A2B In this study, we used ultrasound imaging to measure the in vivo effects of adenosine on coronary blood flow (left coronary artery) and cardiac function in anesthetized wild-type, A1 knockout (KO), A2AKO, A2BKO, A3KO, A1, and A3 double KO (A1/3 DKO) and A2A and A2B double KO (A2A/2B DKO) mice in real time. Echocardiographic and Doppler studies were performed using a Visualsonic Vevo 2100 ultrasound system. Coronary blood flow (CBF) baseline data were obtained when animals were anesthetized with 1% isoflourane. Diameter (D) and velocity time integral (VTI) were measured on the left coronary arteries (CBF = ((π/4) × D(2) × VTI × HR)/1000). CBF changes were the highest within 2 min of injection (about 10 mg/kg). Heart rate, cardiac output, and stroke volume were measured by tracing the left ventricle long axis. Our data support a role for the A2 AR in CBF and further support our conclusions of previous studies from isolated tissues. Adenosine-mediated decreases in cardiac output and stroke volume may be A2B and/or A3 AR-mediated; however, the A1 and A2 ARs also play roles in overall cardiac function. These data further provide a powerful translational tool in studying the cardiovascular effects of adenosine in disease states.

  14. Knockout of Toll-Like Receptors 2 and 4 Prevents Renal Ischemia-Reperfusion-Induced Cardiac Hypertrophy in Mice

    PubMed Central

    Trentin-Sonoda, Mayra; da Silva, Rogério Cirino; Kmit, Fernanda Vieira; Abrahão, Mariana Vieira; Monnerat Cahli, Gustavo; Brasil, Guilherme Visconde; Muzi-Filho, Humberto; Silva, Paulo André; Tovar-Moll, Fernanda Freire; Vieyra, Adalberto; Medei, Emiliano; Carneiro-Ramos, Marcela Sorelli

    2015-01-01

    We investigated whether the pathways linked to Toll-like receptors 2 and 4 (TLRs) are involved in renal ischemia-reperfusion (I/R)-induced cardiac hypertrophy. Wild type (WT) C57BL/6J, TLR2-/- and TLR4-/- mice were subjected to left kidney ischemia for 60 min followed by reperfusion for 5, 8, 12 and 15 days. Proton density magnetic resonance showed alterations in the injured kidney from WT mice, together with signs of parenchymal edema and higher levels of vimentin mRNA, accompanied by: (i) small, but significant, increase in serum urea after 24 h, (ii) 100% increase in serum creatinine at 24 h. A serum peak of inflammatory cytokines occurred after 5 days of reperfusion. Heart weight/body weight and heart weight/tibia length ratios increased after 12 and 15 days of reperfusion, respectively. Cardiac hypertrophy markers, B-type natriuretic peptide (BNP) and α-actin, left ventricle mass, cardiac wall thickness and myocyte width increased after 15 days of reperfusion, together with longer QTc and action potential duration. Cardiac TLRs, MyD88, HSP60 and HSP70 mRNA levels also increased. After 15 days of reperfusion, absence of TLRs prevented cardiac hypertrophy, as reflected by similar values of left ventricular cardiac mass and heart weight/body weight ratio compared to the transgenic Sham. Renal tissular injury also ameliorated in both knockout mice, as revealed by the comparison of their vimentin mRNA levels with those found in the WT on the same day after I/R. The I/R TLR2-/- group had TNF-α, IFN-γ and IL-1β levels similar to the non-I/R group, whereas the TLR4-/- group conserved the p-NF-κB/NF- κB ratio contrasting with that found in TLR2-/-. We conclude: (i) TLRs are involved in renal I/R-induced cardiac hypertrophy; (ii) absence of TLRs prevents I/R-induced cardiac hypertrophy, despite renal lesions seeming to evolve towards those of chronic disease; (iii) TLR2 and TLR4 selectively regulate the systemic inflammatory profile and NF- κB activation. PMID

  15. Knockout of Toll-Like Receptors 2 and 4 Prevents Renal Ischemia-Reperfusion-Induced Cardiac Hypertrophy in Mice.

    PubMed

    Trentin-Sonoda, Mayra; da Silva, Rogério Cirino; Kmit, Fernanda Vieira; Abrahão, Mariana Vieira; Monnerat Cahli, Gustavo; Brasil, Guilherme Visconde; Muzi-Filho, Humberto; Silva, Paulo André; Tovar-Moll, Fernanda Freire; Vieyra, Adalberto; Medei, Emiliano; Carneiro-Ramos, Marcela Sorelli

    2015-01-01

    We investigated whether the pathways linked to Toll-like receptors 2 and 4 (TLRs) are involved in renal ischemia-reperfusion (I/R)-induced cardiac hypertrophy. Wild type (WT) C57BL/6J, TLR2-/- and TLR4-/- mice were subjected to left kidney ischemia for 60 min followed by reperfusion for 5, 8, 12 and 15 days. Proton density magnetic resonance showed alterations in the injured kidney from WT mice, together with signs of parenchymal edema and higher levels of vimentin mRNA, accompanied by: (i) small, but significant, increase in serum urea after 24 h, (ii) 100% increase in serum creatinine at 24 h. A serum peak of inflammatory cytokines occurred after 5 days of reperfusion. Heart weight/body weight and heart weight/tibia length ratios increased after 12 and 15 days of reperfusion, respectively. Cardiac hypertrophy markers, B-type natriuretic peptide (BNP) and α-actin, left ventricle mass, cardiac wall thickness and myocyte width increased after 15 days of reperfusion, together with longer QTc and action potential duration. Cardiac TLRs, MyD88, HSP60 and HSP70 mRNA levels also increased. After 15 days of reperfusion, absence of TLRs prevented cardiac hypertrophy, as reflected by similar values of left ventricular cardiac mass and heart weight/body weight ratio compared to the transgenic Sham. Renal tissular injury also ameliorated in both knockout mice, as revealed by the comparison of their vimentin mRNA levels with those found in the WT on the same day after I/R. The I/R TLR2-/- group had TNF-α, IFN-γ and IL-1β levels similar to the non-I/R group, whereas the TLR4-/- group conserved the p-NF-κB/NF- κB ratio contrasting with that found in TLR2-/-. We conclude: (i) TLRs are involved in renal I/R-induced cardiac hypertrophy; (ii) absence of TLRs prevents I/R-induced cardiac hypertrophy, despite renal lesions seeming to evolve towards those of chronic disease; (iii) TLR2 and TLR4 selectively regulate the systemic inflammatory profile and NF- κB activation.

  16. Knockout of the ATPase inhibitory factor 1 protects the heart from pressure overload-induced cardiac hypertrophy.

    PubMed

    Yang, Kevin; Long, Qinqiang; Saja, Kamalamma; Huang, Fengyuan; Pogwizd, Steven M; Zhou, Lufang; Yoshida, Masasuke; Yang, Qinglin

    2017-09-05

    Mitochondrial ATP synthase catalyzes the coupling of oxidative phosphorylation. Under pathological conditions, ATP synthase hydrolyzes ATP to replenish protons from the matrix into the intermembrane space, sustaining mitochondrial membrane potential. ATPase inhibitory factor 1 (IF1) is a nuclear-encoded, ATP synthase-interacting protein that selectively inhibits the hydrolysis activity of ATP synthase, which may render the protective role of IF1 in ischemic hearts. However, the in vivo cardiac function of IF1 and the potential therapeutic application targeting IF1 remain obscure. In the present study, we uncovered that IF1 is upregulated in mouse hearts with pressure overload-induced hypertrophy and in human hearts with dilated cardiomyopathy. IF1 knockout (KO) mice were protected against cardiac dysfunction and pathological development induced by transverse aortic constriction (TAC) or isoproterenol infusion. The reduced ATP hydrolysis activated AMPK activity in IF1 KO hearts, which together facilitated autophagy. These results suggest that IF1 upregulation in the failing heart may be a maladaptive response. Inhibiting IF1 in the hypertrophied heart not only prevents cell death from excessive mitochondrial depolarization but also activates AMPK signaling and increases autophagy. Therefore, IF1 inhibition may serve as a potential therapeutic target in treating pathological cardiac hypertrophy and heart failure.

  17. Cardiac Morphology and Function, and Blood Gas Transport in Aquaporin-1 Knockout Mice

    PubMed Central

    Al-Samir, Samer; Wang, Yong; Meissner, Joachim D.; Gros, Gerolf; Endeward, Volker

    2016-01-01

    We have studied cardiac and respiratory functions of aquaporin-1-deficient mice by the Pressure-Volume-loop technique and by blood gas analysis. In addition, the morphological properties of the animals' hearts were analyzed. In anesthesia under maximal dobutamine stimulation, the mice exhibit a moderately elevated heart rate of < 600 min−1 and an O2 consumption of ~0.6 ml/min/g, which is about twice the basal rate. In this state, which is similar to the resting state of the conscious animal, all cardiac functions including stroke volume and cardiac output exhibited resting values and were identical between deficient and wildtype animals. Likewise, pulmonary and peripheral exchange of O2 and CO2 were normal. In contrast, several morphological parameters of the heart tissue of deficient mice were altered: (1) left ventricular wall thickness was reduced by 12%, (2) left ventricular mass, normalized to tibia length, was reduced by 10–20%, (3) cardiac muscle fiber cross sectional area was decreased by 17%, and (4) capillary density was diminished by 10%. As the P-V-loop technique yielded normal end-diastolic and end-systolic left ventricular volumes, the deficient hearts are characterized by thin ventricular walls in combination with normal intraventricular volumes. The aquaporin-1-deficient heart thus seems to be at a disadvantage compared to the wild-type heart by a reduced left-ventricular wall thickness and an increased diffusion distance between blood capillaries and muscle mitochondria. While under the present quasi-resting conditions these morphological alterations have no consequences for cardiac function, we expect that the deficient hearts will show a reduced maximal cardiac output. PMID:27252655

  18. Macrophage Migration Inhibitory Factor (MIF) Knockout Preserves Cardiac Homeostasis through Alleviating Akt-Mediated Myocardial Autophagy Suppression in High Fat Diet-Induced Obesity

    PubMed Central

    Xu, Xihui; Ren, Jun

    2014-01-01

    Background Macrophage migration inhibitory factor (MIF) plays a role in the development of obesity and diabetes. However, whether MIF plays a role in fat diet-induced obesity and associated cardiac anomalies still remains unknown. The aim of this study was to examine the impact of MIF knockout on high fat diet-induced obesity, obesity-associated cardiac anomalies and the underlying mechanisms involved with a focus on Akt-mediated autophagy. Methods Adult male wild-type (WT) and MIF knockout (MIF−/−) mice were placed on 45% high fat diet for 5 months. Oxygen consumption, CO2 production, respiratory exchange ratio (RER), locomotor activity, and heat generation were measured using energy calorimeter. Echocardiographic, cardiomyocyte mechanical and intracellular Ca2+ properties were assessed. Apoptosis was examined using TUNEL staining and western blot analysis. Akt signaling pathway and autophagy markers were evaluated. Cardiomyocytes isolated from WT and MIF−/− mice were treated with recombinant mouse MIF (rmMIF). Results High fat diet feeding elicited increased body weight gain, insulin resistance, and caloric disturbance in WT and MIF−/− mice. High fat diet induced unfavorable geometric, contractile and histological changes in the heart, the effects of which were alleviated by MIF knockout. In addition, fat diet-induced cardiac anomalies were associated with Akt activation and autophagy suppression, which were nullified by MIF deficiency. In cardiomyocytes from WT mice, autophagy was inhibited by exogenous rmMIF through Akt activation. In addition, MIF knockout rescued palmitic acid-induced suppression of cardiomyocyte autophagy, the effect of which was nullified by rmMIF. Conclusions These results indicate that MIF knockout preserved obesity-associated cardiac anomalies without affecting fat diet-induced obesity, probably through restoring myocardial autophagy in an Akt-dependent manner. Our findings provide new insights for the role of MIF in obesity

  19. Taurine transporter knockout depletes muscle taurine levels and results in severe skeletal muscle impairment but leaves cardiac function uncompromised.

    PubMed

    Warskulat, Ulrich; Flögel, Ulrich; Jacoby, Christoph; Hartwig, Hans-Georg; Thewissen, Michael; Merx, Marc W; Molojavyi, Andrej; Heller-Stilb, Birgit; Schrader, Jürgen; Häussinger, Dieter

    2004-03-01

    Taurine is the most abundant free amino acid in heart and skeletal muscle. In the present study, the effects of hereditary taurine deficiency on muscle function were examined in taurine transporter knockout (taut-/-) mice. These mice show an almost complete depletion of heart and skeletal muscle taurine levels. Treadmill experiments demonstrated that total exercise capacity of taut-/- mice was reduced by >80% compared with wild-type controls. The decreased performance of taut-/- mice correlated with increased lactate levels in serum during exercise. Surprisingly, cardiac function of taut-/- mice as assessed by magnetic resonance imaging, echocardiography, and isolated heart studies showed a largely normal phenotype under both control and stimulated conditions. However, analysis of taut-/- skeletal muscle revealed electromyographic abnormalities. (1)H nuclear magnetic resonance spectroscopy of tissue extracts showed that in the heart of taut-/- mice the lack of taurine was compensated by the up-regulation of various organic solutes. In contrast, a deficit of >10 mM in total organic osmolyte concentration was found in skeletal muscle. The present study identifies taurine transport as a crucial factor for the maintenance of skeletal muscle function and total exercise capacity, while cardiac muscle apparently can compensate for the loss of taurine.

  20. TLR4 knockout attenuated high fat diet-induced cardiac dysfunction via NF-κB/JNK-dependent activation of autophagy.

    PubMed

    Hu, Nan; Zhang, Yingmei

    2017-08-01

    Obesity is commonly associated with a low grade systemic inflammation, which may contribute to the onset and development of myocardial remodeling and contractile dysfunction. Toll-like receptor 4 (TLR4) plays an important role in innate immunity and inflammation although its role in high fat diet-induced obesity cardiac dysfunction remains elusive. This study was designed to examine the effect of TLR4 ablation on high fat diet intake-induced cardiac anomalies, if any, and underlying mechanism(s) involved. Wild-type (WT) and TLR4 knockout mice were fed normal or high fat (60% calorie from fat) diet for 12weeks prior to assessment of mechanical and intracellular Ca(2+) properties. The inflammatory signaling proteins (TLR4, NF-κB, and JNK) and autophagic markers (Atg5, Atg12, LC3B and p62) were evaluated. Our results revealed that high fat diet intake promoted obesity, marked decrease in fractional shortening, and cardiomyocyte contractile capacity with dampened intracellular Ca(2+) release and clearance, elevated ROS generation and oxidative stress as measured by aconitase activity, the effects of which were significantly attenuated by TLR4 knockout. In addition, high fat intake downregulated levels of Atg5, Atg12 and LC3B, while increasing p62 accumulation. TLR4 knockout itself did not affect Atg5, Atg12, LC3B and p62 levels while it reconciled high fat diet intake-induced changes in autophagy. In addition, TLR4 knockout alleviated high fat diet-induced phosphorylation of IKKβ, JNK and mTOR. In vitro study revealed that palmitic acid suppressed cardiomyocyte contractile function, the effect of which was inhibited the TLR4 inhibitor CLI-095, the JNK inhibitor AS601245 or the NF-κB inhibitor Celastrol. Taken together, these data showed that TLR4 knockout ameliorated high fat diet-induced cardiac contractile and intracellular Ca(2+) anomalies through inhibition of inflammation and ROS, possibly through a NF-κB/JNK-dependent activation of autophagy. This article is

  1. Cell volume control in phospholemman (PLM) knockout mice: do cardiac myocytes demonstrate a regulatory volume decrease and is this influenced by deletion of PLM?

    PubMed

    Bell, James R; Lloyd, David; Curl, Claire L; Delbridge, Lea M D; Shattock, Michael J

    2009-03-01

    In addition to modulatory actions on Na+-K+-ATPase, phospholemman (PLM) has been proposed to play a role in cell volume regulation. Overexpression of PLM induces ionic conductances, with 'PLM channels' exhibiting selectivity for taurine. Osmotic challenge of host cells overexpressing PLM increases taurine efflux and augments the cellular regulatory volume decrease (RVD) response, though a link between PLM and cell volume regulation has not been studied in the heart. We recently reported a depressed cardiac contractile function in PLM knockout mice in vivo, which was exacerbated in crystalloid-perfused isolated hearts, indicating that these hearts were osmotically challenged. To address this, the present study investigated the role of PLM in osmoregulation in the heart. Isolated PLM wild-type and knockout hearts were perfused with a crystalloid buffer supplemented with mannitol in a bid to prevent perfusate-induced cell swelling and maintain function. Accordingly, and in contrast to wild-type control hearts, contractile function was improved in PLM knockout hearts with 30 mM mannitol. To investigate further, isolated PLM wild-type and knockout cardiomyocytes were subjected to increasing hyposmotic challenges. Initial validation studies showed the IonOptix video edge-detection system to be a simple and accurate 'real-time' method for tracking cell width as a marker of cell size. Myocytes swelled equally in both genotypes, indicating that PLM, when expressed at physiological levels in cardiomyocytes, is not essential to limit water accumulation in response to a hyposmotic challenge. Interestingly, freshly isolated adult cardiomyocytes consistently failed to mount RVDs in response to cell swelling, adding to conflicting reports in the literature. A proposed perturbation of the RVD response as a result of the cell isolation process was not restored, however, with short-term culture in either adult or neonatal cardiomyocytes.

  2. Effects of PPARs agonists on cardiac metabolism in littermate and cardiomyocyte-specific PPAR-γ-knockout (CM-PGKO) mice.

    PubMed

    Barbieri, Michelangela; Di Filippo, Clara; Esposito, Antonietta; Marfella, Raffaele; Rizzo, Maria Rosaria; D'Amico, Michele; Ferraraccio, Franca; Di Ronza, Cristina; Duan, Sheng Zhong; Mortensen, Richard M; Rossi, Francesco; Paolisso, Giuseppe

    2012-01-01

    Understanding the molecular regulatory mechanisms controlling for myocardial lipid metabolism is of critical importance for the development of new therapeutic strategies for heart diseases. The role of PPARγ and thiazolidinediones in regulation of myocardial lipid metabolism is controversial. The aim of our study was to assess the role of PPARγ on myocardial lipid metabolism and function and differentiate local/from systemic actions of PPARs agonists using cardiomyocyte-specific PPARγ -knockout (CM-PGKO) mice. To this aim, the effect of PPARγ, PPARγ/PPARα and PPARα agonists on cardiac function, intra-myocyte lipid accumulation and myocardial expression profile of genes and proteins, affecting lipid oxidation, uptake, synthesis, and storage (CD36, CPT1MIIA, AOX, FAS, SREBP1-c and ADPR) was evaluated in cardiomyocyte-specific PPARγ-knockout (CM-PGKO) and littermate control mice undergoing standard and high fat diet (HFD). At baseline, protein levels and mRNA expression of genes involved in lipid uptake, oxidation, synthesis, and accumulation of CM-PGKO mice were not significantly different from those of their littermate controls. At baseline, no difference in myocardial lipid content was found between CM-PGKO and littermate controls. In standard condition, pioglitazone and rosiglitazone do not affect myocardial metabolism while, fenofibrate treatment significantly increased CD36 and CPT1MIIA gene expression. In both CM-PGKO and control mice submitted to HFD, six weeks of treatment with rosiglitazone, fenofibrate and pioglitazone lowered myocardial lipid accumulation shifting myocardial substrate utilization towards greater contribution of glucose. In conclusion, at baseline, PPARγ does not play a crucial role in regulating cardiac metabolism in mice, probably due to its low myocardial expression. PPARs agonists, indirectly protect myocardium from lipotoxic damage likely reducing fatty acids delivery to the heart through the actions on adipose tissue

  3. Involvement of mitochondrial permeability transition pore (mPTP) in cardiac arrhythmias: Evidence from cyclophilin D knockout mice.

    PubMed

    Gordan, Richard; Fefelova, Nadezhda; Gwathmey, Judith K; Xie, Lai-Hua

    2016-12-01

    In the present study, we have used a genetic mouse model that lacks cyclophilin D (CypD KO) to assess the cardioprotective effect of mitochondrial permeability transition pore (mPTP) inhibition on Ca(2+) waves and Ca(2+) alternans at the single cell level, and cardiac arrhythmias in whole-heart preparations. The protonophore carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) caused mitochondrial membrane potential depolarization to the same extent in cardiomyocytes from both WT and CypD KO mice, however, cardiomyocytes from CypD KO mice exhibited significantly less mPTP opening than cardiomyocytes from WT mice (p<0.05). Consistent with these results, FCCP caused significant increases in CaW rate in WT cardiomyocytes (p<0.05) but not in CypD KO cardiomyocytes. Furthermore, the incidence of Ca(2+) alternans after treatment with FCCP and programmed stimulation was significantly higher in WT cardiomyocytes (11 of 13), than in WT cardiomyocytes treated with CsA (2 of 8; p<0.05) or CypD KO cardiomyocytes (2 of 10; p<0.01). (Pseudo-)Lead II ECGs were recorded from ex vivo hearts. We observed ST-T-wave alternans (a precursor of lethal arrhythmias) in 5 of 7 WT hearts. ST-T-wave alternans was not seen in CypD KO hearts (n=5) and in only 1 of 6 WT hearts treated with CsA. Consistent with these results, WT hearts exhibited a significantly higher average arrhythmia score than CypD KO (p<0.01) hearts subjected to FCCP treatment or chemical ischemia-reperfusion (p<0.01). In conclusion, CypD deficiency- induced mPTP inhibition attenuates CaWs and Ca(2+) alternans during mitochondrial depolarization, and thereby protects against arrhythmogenesis in the heart. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Common arterial trunk and ventricular non-compaction in Lrp2 knockout mice indicate a crucial role of LRP2 in cardiac development.

    PubMed

    Baardman, Maria E; Zwier, Mathijs V; Wisse, Lambertus J; Gittenberger-de Groot, Adriana C; Kerstjens-Frederikse, Wilhelmina S; Hofstra, Robert M W; Jurdzinski, Angelika; Hierck, Beerend P; Jongbloed, Monique R M; Berger, Rolf M F; Plösch, Torsten; DeRuiter, Marco C

    2016-04-01

    Lipoprotein-related receptor protein 2 (LRP2) is important for development of the embryonic neural crest and brain in both mice and humans. Although a role in cardiovascular development can be expected, the hearts ofLrp2knockout (KO) mice have not yet been investigated. We studied the cardiovascular development ofLrp2KO mice between embryonic day 10.5 (E10.5) and E15.5, applying morphometry and immunohistochemistry, using antibodies against Tfap2α (neural crest cells), Nkx2.5 (second heart field), WT1 (epicardium derived cells), tropomyosin (myocardium) and LRP2. TheLrp2KO mice display a range of severe cardiovascular abnormalities, including aortic arch anomalies, common arterial trunk (persistent truncus arteriosus) with coronary artery anomalies, ventricular septal defects, overriding of the tricuspid valve and marked thinning of the ventricular myocardium. Both the neural crest cells and second heart field, which are essential for the lengthening and growth of the right ventricular outflow tract, are abnormally positioned in theLrp2KO. This explains the absence of the aorto-pulmonary septum, which leads to common arterial trunk and ventricular septal defects. Severe blebbing of the epicardial cells covering the ventricles is seen. Epithelial-mesenchymal transition does occur; however, there are fewer WT1-positive epicardium-derived cells in the ventricular wall as compared to normal, coinciding with the myocardial thinning and deep intertrabecular spaces. LRP2 plays a crucial role in cardiovascular development in mice. This corroborates findings of cardiac anomalies in humans withLRP2mutations. Future studies should reveal the underlying signaling mechanisms in which LRP2 is involved during cardiogenesis. © 2016. Published by The Company of Biologists Ltd.

  5. Common arterial trunk and ventricular non-compaction in Lrp2 knockout mice indicate a crucial role of LRP2 in cardiac development

    PubMed Central

    Baardman, Maria E.; Zwier, Mathijs V.; Wisse, Lambertus J.; Gittenberger-de Groot, Adriana C.; Kerstjens-Frederikse, Wilhelmina S.; Hofstra, Robert M. W.; Jurdzinski, Angelika; Hierck, Beerend P.; Jongbloed, Monique R. M.; Berger, Rolf M. F.; Plösch, Torsten; DeRuiter, Marco C.

    2016-01-01

    ABSTRACT Lipoprotein-related receptor protein 2 (LRP2) is important for development of the embryonic neural crest and brain in both mice and humans. Although a role in cardiovascular development can be expected, the hearts of Lrp2 knockout (KO) mice have not yet been investigated. We studied the cardiovascular development of Lrp2 KO mice between embryonic day 10.5 (E10.5) and E15.5, applying morphometry and immunohistochemistry, using antibodies against Tfap2α (neural crest cells), Nkx2.5 (second heart field), WT1 (epicardium derived cells), tropomyosin (myocardium) and LRP2. The Lrp2 KO mice display a range of severe cardiovascular abnormalities, including aortic arch anomalies, common arterial trunk (persistent truncus arteriosus) with coronary artery anomalies, ventricular septal defects, overriding of the tricuspid valve and marked thinning of the ventricular myocardium. Both the neural crest cells and second heart field, which are essential for the lengthening and growth of the right ventricular outflow tract, are abnormally positioned in the Lrp2 KO. This explains the absence of the aorto-pulmonary septum, which leads to common arterial trunk and ventricular septal defects. Severe blebbing of the epicardial cells covering the ventricles is seen. Epithelial-mesenchymal transition does occur; however, there are fewer WT1-positive epicardium-derived cells in the ventricular wall as compared to normal, coinciding with the myocardial thinning and deep intertrabecular spaces. LRP2 plays a crucial role in cardiovascular development in mice. This corroborates findings of cardiac anomalies in humans with LRP2 mutations. Future studies should reveal the underlying signaling mechanisms in which LRP2 is involved during cardiogenesis. PMID:26822476

  6. Homozygous/Compound Heterozygous Triadin Mutations Associated With Autosomal-Recessive Long-QT Syndrome and Pediatric Sudden Cardiac Arrest: Elucidation of the Triadin Knockout Syndrome.

    PubMed

    Altmann, Helene M; Tester, David J; Will, Melissa L; Middha, Sumit; Evans, Jared M; Eckloff, Bruce W; Ackerman, Michael J

    2015-06-09

    Long-QT syndrome (LQTS) may result in syncope, seizures, or sudden cardiac arrest. Although 16 LQTS-susceptibility genes have been discovered, 20% to 25% of LQTS remains genetically elusive. We performed whole-exome sequencing child-parent trio analysis followed by recessive and sporadic inheritance modeling and disease-network candidate analysis gene ranking to identify a novel underlying genetic mechanism for LQTS. Subsequent mutational analysis of the candidate gene was performed with polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing on a cohort of 33 additional unrelated patients with genetically elusive LQTS. After whole-exome sequencing and variant filtration, a homozygous p.D18fs*13 TRDN-encoded triadin frameshift mutation was discovered in a 10-year-old female patient with LQTS with a QTc of 500 milliseconds who experienced recurrent exertion-induced syncope/cardiac arrest beginning at 1 year of age. Subsequent mutational analysis of TRDN revealed either homozygous or compound heterozygous frameshift mutations in 4 of 33 unrelated cases of LQTS (12%). All 5 TRDN-null patients displayed extensive T-wave inversions in precordial leads V1 through V4, with either persistent or transient QT prolongation and severe disease expression of exercise-induced cardiac arrest in early childhood (≤3 years of age) and required aggressive therapy. The overall yield of TRDN mutations was significantly greater in patients ≤10 years of age (5 of 10, 50%) compared with older patients (0 of 24, 0%; P=0.0009). We identified TRDN as a novel underlying genetic basis for recessively inherited LQTS. All TRDN-null patients had strikingly similar phenotypes. Given the recurrent nature of potential lethal arrhythmias, patients fitting this phenotypic profile should undergo cardiac TRDN genetic testing. © 2015 American Heart Association, Inc.

  7. The Knockout Mouse Project

    PubMed Central

    Austin, Christopher P; Battey, James F; Bradley, Allan; Bucan, Maja; Capecchi, Mario; Collins, Francis S; Dove, William F; Duyk, Geoffrey; Dymecki, Susan; Eppig, Janan T; Grieder, Franziska B; Heintz, Nathaniel; Hicks, Geoff; Insel, Thomas R; Joyner, Alexandra; Koller, Beverly H; Lloyd, K C Kent; Magnuson, Terry; Moore, Mark W; Nagy, Andras; Pollock, Jonathan D; Roses, Allen D; Sands, Arthur T; Seed, Brian; Skarnes, William C; Snoddy, Jay; Soriano, Philippe; Stewart, David J; Stewart, Francis; Stillman, Bruce; Varmus, Harold; Varticovski, Lyuba; Verma, Inder M; Vogt, Thomas F; von Melchner, Harald; Witkowski, Jan; Woychik, Richard P; Wurst, Wolfgang; Yancopoulos, George D; Young, Stephen G; Zambrowicz, Brian

    2009-01-01

    Mouse knockout technology provides a powerful means of elucidating gene function in vivo, and a publicly available genome-wide collection of mouse knockouts would be significantly enabling for biomedical discovery. To date, published knockouts exist for only about 10% of mouse genes. Furthermore, many of these are limited in utility because they have not been made or phenotyped in standardized ways, and many are not freely available to researchers. It is time to harness new technologies and efficiencies of production to mount a high-throughput international effort to produce and phenotype knockouts for all mouse genes, and place these resources into the public domain. PMID:15340423

  8. Cardiac catheterization

    MedlinePlus

    Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization; CAD - cardiac catheterization; Coronary artery disease - cardiac catheterization; Heart valve - cardiac catheterization; Heart failure - ...

  9. Knockout, Transfer and Spectroscopic Factors

    NASA Astrophysics Data System (ADS)

    Kemper, Kirby; Keeley, Nicholas; Rusek, Krzysztof

    2011-10-01

    As derived quantities rather than observables, spectroscopic factors extracted from fits to data are model dependent. The main source of uncertainty is the choice of binding potential, but other factors such as adequate modeling of the reaction mechanism, the Perey effect, choice of distorting nuclear potentials etc. can also play a significant role. Recently, there has been some discussion of apparent discrepancies in spectroscopic factors derived from knockout reactions compared to those obtained from low-energy direct reactions. It should be possible to reconcile these discrepancies and we explore this prospect by attempting to describe the 10Be(d,t)9Be data of Nucl. Phys. A157, 305 (1970) using the 10Be/9Be form factors from a recent knockout study, Phys. Rev. Lett. 106, 162502 (2011). The influence of such factors as choice of distorting potentials and multi-step reactions paths will be explored.

  10. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function

    PubMed Central

    Lakhal-Littleton, Samira; Wolna, Magda; Carr, Carolyn A.; Miller, Jack J. J.; Christian, Helen C.; Ball, Vicky; Santos, Ana; Diaz, Rebeca; Biggs, Daniel; Stillion, Richard; Holdship, Philip; Clarke, Kieran; Davies, Benjamin; Robbins, Peter A.

    2015-01-01

    Iron is essential to the cell. Both iron deficiency and overload impinge negatively on cardiac health. Thus, effective iron homeostasis is important for cardiac function. Ferroportin (FPN), the only known mammalian iron-exporting protein, plays an essential role in iron homeostasis at the systemic level. It increases systemic iron availability by releasing iron from the cells of the duodenum, spleen, and liver, the sites of iron absorption, recycling, and storage respectively. However, FPN is also found in tissues with no known role in systemic iron handling, such as the heart, where its function remains unknown. To explore this function, we generated mice with a cardiomyocyte-specific deletion of Fpn. We show that these animals have severely impaired cardiac function, with a median survival of 22 wk, despite otherwise unaltered systemic iron status. We then compared their phenotype with that of ubiquitous hepcidin knockouts, a recognized model of the iron-loading disease hemochromatosis. The phenotype of the hepcidin knockouts was far milder, with normal survival up to 12 mo, despite far greater iron loading in the hearts. Histological examination demonstrated that, although cardiac iron accumulates within the cardiomyocytes of Fpn knockouts, it accumulates predominantly in other cell types in the hepcidin knockouts. We conclude, first, that cardiomyocyte FPN is essential for intracellular iron homeostasis and, second, that the site of deposition of iron within the heart determines the severity with which it affects cardiac function. Both findings have significant implications for the assessment and treatment of cardiac complications of iron dysregulation. PMID:25713362

  11. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function.

    PubMed

    Lakhal-Littleton, Samira; Wolna, Magda; Carr, Carolyn A; Miller, Jack J J; Christian, Helen C; Ball, Vicky; Santos, Ana; Diaz, Rebeca; Biggs, Daniel; Stillion, Richard; Holdship, Philip; Larner, Fiona; Tyler, Damian J; Clarke, Kieran; Davies, Benjamin; Robbins, Peter A

    2015-03-10

    Iron is essential to the cell. Both iron deficiency and overload impinge negatively on cardiac health. Thus, effective iron homeostasis is important for cardiac function. Ferroportin (FPN), the only known mammalian iron-exporting protein, plays an essential role in iron homeostasis at the systemic level. It increases systemic iron availability by releasing iron from the cells of the duodenum, spleen, and liver, the sites of iron absorption, recycling, and storage respectively. However, FPN is also found in tissues with no known role in systemic iron handling, such as the heart, where its function remains unknown. To explore this function, we generated mice with a cardiomyocyte-specific deletion of Fpn. We show that these animals have severely impaired cardiac function, with a median survival of 22 wk, despite otherwise unaltered systemic iron status. We then compared their phenotype with that of ubiquitous hepcidin knockouts, a recognized model of the iron-loading disease hemochromatosis. The phenotype of the hepcidin knockouts was far milder, with normal survival up to 12 mo, despite far greater iron loading in the hearts. Histological examination demonstrated that, although cardiac iron accumulates within the cardiomyocytes of Fpn knockouts, it accumulates predominantly in other cell types in the hepcidin knockouts. We conclude, first, that cardiomyocyte FPN is essential for intracellular iron homeostasis and, second, that the site of deposition of iron within the heart determines the severity with which it affects cardiac function. Both findings have significant implications for the assessment and treatment of cardiac complications of iron dysregulation.

  12. DJ-1 activates autophagy in the repression of cardiac hypertrophy.

    PubMed

    Xue, Ruicong; Jiang, Jingzhou; Dong, Bin; Tan, Weiping; Sun, Yu; Zhao, Jingjing; Chen, Yili; Dong, Yugang; Liu, Chen

    2017-09-21

    Cardiac hypertrophy is the risk factor of heart failure when the heart is confronted with pressure overload or neurohumoral stimuli. Autophagy, a conserved degradative pathway, is one of the important mechanisms involved in the regulation of cardiac hypertrophy. DJ-1 is a traditional anti-oxidative protein and emerging evidence suggested that DJ-1 might modulate autophagy. However, the regulation of autophagy by DJ-1 in the process of cardiac hypertrophy remains unknown. In our study, we firstly discovered that the expression of DJ-1declined in the process of pressure overload cardiac hypertrophy, and its alteration was parallel with the impairment of autophagy. Furthermore, we proved that DJ-1 knockout mice exhibited a more hypertrophied phenotype than wildtype mice in cardiac hypertrophy which indicated that DJ-1 is responsible for the repression of cardiac hypertrophy. Furthermore, DJ-1 knockout significantly exacerbated pulmonary edema due to cardiac hypertrophy. In the process of cardiac hypertrophy, DJ-1 knockout significantly impaired autophagy activation and enhanced mTORC1 and mTORC2 phosphorylation were found. Similarly, our in vitro study proved that DJ-1 overexpression ameliorated phenylephrine (PE)-induced cardiac hypertrophy and promoted autophagy activation. Taken together, DJ-1 might repress both pressure overload and PE-induced cardiac hypertrophy via the activation of autophagy. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Akt2 knockout mitigates chronic iNOS inhibition-induced cardiomyocyte atrophy and contractile dysfunction despite persistent insulin resistance.

    PubMed

    Roe, Nathan D; Ren, Jun

    2011-12-15

    Increased levels of inducible nitric oxide synthase (iNOS) during cardiac stress such as ischemia-reperfusion, sepsis and hypertension may display both beneficial and detrimental roles in cardiac contractile performance. However, the precise role of iNOS in the maintenance of cardiac contractile function remains elusive. This study was designed to determine the impact of chronic iNOS inhibition on cardiac contractile function and the underlying mechanism involved with a special focus on the NO downstream signaling molecule Akt. Male C57 or Akt2 knockout [Akt2(-/-)] mice were injected with the specific iNOS inhibitor 1400W (2 mg/kg/d) or saline for 7 days. Both 1400W and Akt2 knockout dampened glucose and insulin tolerance without additive effects. Treatment of 1400W decreased heart and liver weights as well as cardiomyocyte cross-sectional area in C57 but not Akt2 knockout mice. 1400W but not Akt2 knockout compromised cardiomyocyte mechanical properties including decreased peak shortening and maximal velocity of shortening/relengthening, prolonged relengthening duration, reduced intracellular Ca(2+) release and decay rate, the effects of which were ablated or attenuated by Akt2 knockout. Akt2 knockout but not 1400W increased the levels of intracellular Ca(2+) regulatory proteins including SERCA2a and phospholamban phosphorylation. 1400W reduced the level of anti-apoptotic protein Bcl-2, the effect of which was unaffected by Akt2 knockout. Neither 1400W nor Akt2 knockout significantly affected ER stress, autophagy, the post-insulin receptor signaling Akt, GSK3β and AMPK, as well as the stress signaling IκB, JNK, ERK and p38 with the exception of elevated IκB phosphorylation with jointed effect of 1400W and Akt2 knockout. Taken together, these data indicated that an essential role of iNOS in the maintenance of cardiac morphology and function possibly through an Akt2-dependent mechanism. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. CAP2 in cardiac conduction, sudden cardiac death and eye development.

    PubMed

    Field, Jeffrey; Ye, Diana Z; Shinde, Manasi; Liu, Fang; Schillinger, Kurt J; Lu, MinMin; Wang, Tao; Skettini, Michelle; Xiong, Yao; Brice, Angela K; Chung, Daniel C; Patel, Vickas V

    2015-11-30

    Sudden cardiac death kills 180,000 to 450,000 Americans annually, predominantly males. A locus that confers a risk for sudden cardiac death, cardiac conduction disease, and a newly described developmental disorder (6p22 syndrome) is located at 6p22. One gene at 6p22 is CAP2, which encodes a cytoskeletal protein that regulates actin dynamics. To determine the role of CAP2 in vivo, we generated knockout (KO) mice. cap2(-)/cap2(-) males were underrepresented at weaning and ~70% died by 12 weeks of age, but cap2(-)/cap2(-) females survived at close to the expected levels and lived normal life spans. CAP2 knockouts resembled patients with 6p22 syndrome in that mice were smaller and they developed microphthalmia and cardiac disease. The cardiac disease included cardiac conduction disease (CCD) and, after six months of age, dilated cardiomyopathy (DCM), most noticeably in the males. To address the mechanisms underlying these phenotypes, we used Cre-mediated recombination to knock out CAP2 in cardiomyocytes. We found that the mice developed CCD, leading to sudden cardiac death from complete heart block, but no longer developed DCM or the other phenotypes, including sex bias. These studies establish a direct role for CAP2 and actin dynamics in sudden cardiac death and cardiac conduction disease.

  15. CAP2 in cardiac conduction, sudden cardiac death and eye development

    PubMed Central

    Field, Jeffrey; Ye, Diana Z.; Shinde, Manasi; Liu, Fang; Schillinger, Kurt J.; Lu, MinMin; Wang, Tao; Skettini, Michelle; Xiong, Yao; Brice, Angela K.; Chung, Daniel C.; Patel, Vickas V.

    2015-01-01

    Sudden cardiac death kills 180,000 to 450,000 Americans annually, predominantly males. A locus that confers a risk for sudden cardiac death, cardiac conduction disease, and a newly described developmental disorder (6p22 syndrome) is located at 6p22. One gene at 6p22 is CAP2, which encodes a cytoskeletal protein that regulates actin dynamics. To determine the role of CAP2 in vivo, we generated knockout (KO) mice. cap2−/cap2− males were underrepresented at weaning and ~70% died by 12 weeks of age, but cap2−/cap2− females survived at close to the expected levels and lived normal life spans. CAP2 knockouts resembled patients with 6p22 syndrome in that mice were smaller and they developed microphthalmia and cardiac disease. The cardiac disease included cardiac conduction disease (CCD) and, after six months of age, dilated cardiomyopathy (DCM), most noticeably in the males. To address the mechanisms underlying these phenotypes, we used Cre-mediated recombination to knock out CAP2 in cardiomyocytes. We found that the mice developed CCD, leading to sudden cardiac death from complete heart block, but no longer developed DCM or the other phenotypes, including sex bias. These studies establish a direct role for CAP2 and actin dynamics in sudden cardiac death and cardiac conduction disease. PMID:26616005

  16. Neuron-specific (pro)renin receptor knockout prevents the development of salt-sensitive hypertension.

    PubMed

    Li, Wencheng; Peng, Hua; Mehaffey, Eamonn P; Kimball, Christie D; Grobe, Justin L; van Gool, Jeanette M G; Sullivan, Michelle N; Earley, Scott; Danser, A H Jan; Ichihara, Atsuhiro; Feng, Yumei

    2014-02-01

    The (pro)renin receptor (PRR), which binds both renin and prorenin, is a newly discovered component of the renin-angiotensin system that is highly expressed in the central nervous system. The significance of brain PRRs in mediating local angiotensin II formation and regulating blood pressure remains unclear. The current study was performed to test the hypothesis that PRR-mediated, nonproteolytic activation of prorenin is the main source of angiotensin II in the brain. Thus, PRR knockout in the brain is expected to prevent angiotensin II formation and development of deoxycorticosterone acetate-salt-induced hypertension. A neuron-specific PRR (ATP6AP2) knockout mouse model was generated using the Cre-LoxP system. Physiological parameters were recorded by telemetry. PRR expression, detected by immunostaining and reverse transcription-polymerase chain reaction, was significantly decreased in the brains of knockout mice compared with wild-type mice. Intracerebroventricular infusion of mouse prorenin increased blood pressure and angiotensin II formation in wild-type mice. This hypertensive response was abolished in PRR-knockout mice in association with a reduction in angiotensin II levels. Deoxycorticosterone acetate-salt increased PRR expression and angiotensin II formation in the brains of wild-type mice, an effect that was attenuated in PRR-knockout mice. PRR knockout in neurons prevented the development of deoxycorticosterone acetate-salt-induced hypertension as well as activation of cardiac and vasomotor sympathetic tone. In conclusion, nonproteolytic activation of prorenin through binding to the PRR mediates angiotensin II formation in the brain. Neuron-specific PRR knockout prevents the development of deoxycorticosterone acetate-salt-induced hypertension, possibly through diminished angiotensin II formation.

  17. Cardiac catheterization - discharge

    MedlinePlus

    Catheterization - cardiac - discharge; Heart catheterization - discharge: Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization discharge; CAD - cardiac catheterization discharge; Coronary artery disease - cardiac catheterization ...

  18. Kanamycin ototoxicity in glutamate transporter knockout mice.

    PubMed

    Shimizu, Yoshitaka; Hakuba, Nobuhiro; Hyodo, Jun; Taniguchi, Masafumi; Gyo, Kiyofumi

    2005-06-03

    Glutamate-aspartate transporter (GLAST), a powerful glutamate uptake system, removes released glutamate from the synaptic cleft and facilitates the re-use of glutamate as a neurotransmitter recycling system. Aminoglycoside-induced hearing loss is mediated via a glutamate excitotoxic process. We investigated the effect of aminoglycoside ototoxicity in GLAST knockout mice using the recorded auditory brainstem response (ABR) and number of hair cells in the cochlea. Kanamycin (100 mg/mL) was injected directly into the posterior semicircular canal of mice. Before the kanamycin treatment, there was no difference in the ABR threshold average between the wild-type and knockout mice. Kanamycin injection aggravated the ABR threshold in the GLAST knockout mice compared with the wild-type mice, and the IHC degeneration was more severe in the GLAST knockout mice. These findings suggest that GLAST plays an important role in preventing the degeneration of inner hair cells in aminoglycoside ototoxicity.

  19. UCP2 knockout suppresses mouse skin carcinogenesis.

    PubMed

    Li, Wenjuan; Zhang, Chunjing; Jackson, Kasey; Shen, Xingui; Jin, Rong; Li, Guohong; Kevil, Christopher G; Gu, Xin; Shi, Runhua; Zhao, Yunfeng

    2015-06-01

    Mitochondrial uncoupling (uncouples electron transport from ATP production) has recently been proposed as a novel survival mechanism for cancer cells, and reduction in free radical generation is the accepted mechanism of action. However, there is no direct evidence supporting that uncoupling proteins promote carcinogenesis. Herein, we examined whether mitochondrial uncoupling affects mouse skin carcinogenesis using uncoupling protein 2 (UCP2) homozygous knockout and wild-type mice. The results indicate that knockout of Ucp2 significantly reduced the formation of both benign (papilloma) and malignant (squamous cell carcinoma) tumors. UCP2 knockout did not cause increases in apoptosis during skin carcinogenesis. The rates of oxygen consumption were decreased only in the carcinogen-treated UCP2 knockout mice, whereas glycolysis was increased only in the carcinogen-treated wild-type mice. Finally, the levels of metabolites pyruvate, malate, and succinate showed different trends after carcinogen treatments between the wild-type and UCP2 knockout mice. Our study is the first to demonstrate that Ucp2 knockout suppresses carcinogenesis in vivo. Together with early studies showing that UCP2 is overexpressed in a number of human cancers, UCP2 could be a potential target for cancer prevention and/or therapy. Cancer Prev Res; 8(6); 487-91. ©2015 AACR. ©2015 American Association for Cancer Research.

  20. CARD9 knockout ameliorates myocardial dysfunction associated with high fat diet-induced obesity.

    PubMed

    Cao, Li; Qin, Xing; Peterson, Matthew R; Haller, Samantha E; Wilson, Kayla A; Hu, Nan; Lin, Xin; Nair, Sreejayan; Ren, Jun; He, Guanglong

    2016-03-01

    Obesity is associated with chronic inflammation which plays a critical role in the development of cardiovascular dysfunction. Because the adaptor protein caspase recruitment domain-containing protein 9 (CARD9) in macrophages regulates innate immune responses via activation of pro-inflammatory cytokines, we hypothesize that CARD9 mediates the pro-inflammatory signaling associated with obesity en route to myocardial dysfunction. C57BL/6 wild-type (WT) and CARD9(-/-) mice were fed normal diet (ND, 12% fat) or a high fat diet (HFD, 45% fat) for 5months. At the end of 5-month HFD feeding, cardiac function was evaluated using echocardiography. Cardiomyocytes were isolated and contractile properties were measured. Immunofluorescence was performed to detect macrophage infiltration in the heart. Heart tissue homogenates, plasma, and supernatants from isolated macrophages were collected to measure the concentrations of pro-inflammatory cytokines using ELISA kits. Western immunoblotting analyses were performed on heart tissue homogenates and isolated macrophages to explore the underlying signaling mechanism(s). CARD9 knockout alleviated HFD-induced insulin resistance and glucose intolerance, prevented myocardial dysfunction with preserved cardiac fractional shortening and cardiomyocyte contractile properties. CARD9 knockout also significantly decreased the number of infiltrated macrophages in the heart with reduced myocardium-, plasma-, and macrophage-derived cytokines including IL-6, IL-1β and TNFα. Finally, CARD9 knockout abrogated the increase of p38 MAPK phosphorylation, the decrease of LC3BII/LC3BI ratio and the up-regulation of p62 expression in the heart induced by HFD feeding and restored cardiac autophagy signaling. In conclusion, CARD9 knockout ameliorates myocardial dysfunction associated with HFD-induced obesity, potentially through reduction of macrophage infiltration, suppression of p38 MAPK phosphorylation, and preservation of autophagy in the heart

  1. Angiotensinogen gene knockout delays and attenuates cold-induced hypertension.

    PubMed

    Sun, Zhongjie; Cade, Robert; Zhang, Zhonge; Alouidor, James; Van, Huong

    2003-02-01

    The aim of the present study was to assess our hypothesis that the renin-angiotensin system (RAS) is responsible for cold-induced hypertension and cardiac hypertrophy. Two groups of wild-type (WT) mice and 2 groups of angiotensinogen gene knockout (Agt-KO) mice (6 per group) were used. After blood pressures (BP) of the four groups were measured 3 times at room temperature (25 degrees C), 1 WT and 1 Agt-KO group were exposed to cold (5 degrees C). The remaining groups were kept at 25 degrees C. BP of the cold-exposed WT group increased significantly in 1 week of cold exposure and rose gradually to 168+/-7 mm Hg by week 5, whereas the BP of the Agt-KO group did not increase until week 3. The cold-induced increase in BP (DeltaBP) was decreased significantly in the Agt-KO mice (19+/-3 mm Hg) compared with that of the WT mice (61+/-5 mm Hg) by 5 weeks of exposure to cold. Both WT and Agt-KO groups had cardiac hypertrophy in cold to the same extent. Agt-KO caused a significant increase in nitric oxide (NO) production. Thus, the RAS may inhibit NO formation. Chronic cold exposure decreased NO production, which may be mediated partially by activation of the RAS. These results strongly support that the RAS plays a critical role in the development of cold-induced hypertension but not cardiac hypertrophy. Moreover, the role of the RAS in cold-induced hypertension may be mediated in part by its inhibition on NO production. The findings also reveal the possible relation between the RAS and NO in cardiovascular regulation.

  2. [Knockout mice in the service of reproduction].

    PubMed

    Escalier, D

    2008-12-01

    At least 600 infertile knockout mice have been produced and this review is limited to recent models involving unexpected genes in reproduction or genes involved in recently identified molecular biology pathways. They concern the female meiosis (Brca1), primordial follicles (Lhx8), granulosa cells (Lrh1), and, for both sexes, mitochondria (Immp2l) and meiosis (Ubb). Germ cells can be altered differently following the sex, as it is the case for Dicer, known to be involved in the formation of miRNA. Knockout mice can support data obtained in human, such as for HNRNPGT, whose role in the human spermatogenesis remained questionable. However, due to numerous factors involved, positive results obtained by the "candidate gene approach" remain limited (for example, SCP3 and CREM). Nevertheless, knockout mouse models bring considerable knowledge on genes possibly involved in men and women infertilities.

  3. Proton Knock-Out in Hall A

    SciTech Connect

    Kees de Jager

    2002-06-01

    Proton knock-out is studied in a broad program in Hall A at Jefferson Lab. The first experiment performed in Hall A studied the {sup 16}O(e,e'p) reaction. Since then proton knock-out experiments have studied a variety of aspects of that reaction, from single-nucleon properties to its mechanism, such as final-state interactions and two-body currents, in nuclei from {sup 2}H to {sup 16}O. In this review the results of this program will be summarized and an outlook given of future accomplishments.

  4. Loss of Adult Cardiac Myocyte GSK-3 Leads to Mitotic Catastrophe Resulting in Fatal Dilated Cardiomyopathy.

    PubMed

    Zhou, Jibin; Ahmad, Firdos; Parikh, Shan; Hoffman, Nichole E; Rajan, Sudarsan; Verma, Vipin K; Song, Jianliang; Yuan, Ancai; Shanmughapriya, Santhanam; Guo, Yuanjun; Gao, Erhe; Koch, Walter; Woodgett, James R; Madesh, Muniswamy; Kishore, Raj; Lal, Hind; Force, Thomas

    2016-04-15

    Cardiac myocyte-specific deletion of either glycogen synthase kinase (GSK)-3α and GSK-3β leads to cardiac protection after myocardial infarction, suggesting that deletion of both isoforms may provide synergistic protection. This is an important consideration because of the fact that all GSK-3-targeted drugs, including the drugs already in clinical trial target both isoforms of GSK-3, and none are isoform specific. To identify the consequences of combined deletion of cardiac myocyte GSK-3α and GSK-3β in heart function. We generated tamoxifen-inducible cardiac myocyte-specific mice lacking both GSK-3 isoforms (double knockout). We unexpectedly found that cardiac myocyte GSK-3 is essential for cardiac homeostasis and overall survival. Serial echocardiographic analysis reveals that within 2 weeks of tamoxifen treatment, double-knockout hearts leads to excessive dilatative remodeling and ventricular dysfunction. Further experimentation with isolated adult cardiac myocytes and fibroblasts from double-knockout implicated cardiac myocytes intrinsic factors responsible for observed phenotype. Mechanistically, loss of GSK-3 in adult cardiac myocytes resulted in induction of mitotic catastrophe, a previously unreported event in cardiac myocytes. Double-knockout cardiac myocytes showed cell cycle progression resulting in increased DNA content and multinucleation. However, increased cell cycle activity was rivaled by marked activation of DNA damage, cell cycle checkpoint activation, and mitotic catastrophe-induced apoptotic cell death. Importantly, mitotic catastrophe was also confirmed in isolated adult cardiac myocytes. Together, our findings suggest that cardiac myocyte GSK-3 is required to maintain normal cardiac homeostasis, and its loss is incompatible with life because of cell cycle dysregulation that ultimately results in a severe fatal dilated cardiomyopathy. © 2016 American Heart Association, Inc.

  5. Conditional knockout of Fgf13 in murine hearts increases arrhythmia susceptibility and reveals novel ion channel modulatory roles.

    PubMed

    Wang, Xiangchong; Tang, He; Wei, Eric Q; Wang, Zhihua; Yang, Jing; Yang, Rong; Wang, Sheng; Zhang, Yongjian; Pitt, Geoffrey S; Zhang, Hailin; Wang, Chuan

    2017-03-01

    The intracellular fibroblast growth factors (iFGF/FHFs) bind directly to cardiac voltage gated Na(+) channels, and modulate their function. Mutations that affect iFGF/FHF-Na(+) channel interaction are associated with arrhythmia syndromes. Although suspected to modulate other ionic currents, such as Ca(2+) channels based on acute knockdown experiments in isolated cardiomyocytes, the in vivo consequences of iFGF/FHF gene ablation on cardiac electrical activity are still unknown. We generated inducible, cardiomyocyte-restricted Fgf13 knockout mice to determine the resultant effects of Fgf13 gene ablation. Patch clamp recordings from ventricular myocytes isolated from Fgf13 knockout mice showed a ~25% reduction in peak Na(+) channel current density and a hyperpolarizing shift in steady-state inactivation. Electrocardiograms on Fgf13 knockout mice showed a prolonged QRS duration. The Na(+) channel blocker flecainide further prolonged QRS duration and triggered ventricular tachyarrhythmias only in Fgf13 knockout mice, suggesting that arrhythmia vulnerability resulted, at least in part, from a loss of functioning Na(+) channels. Consistent with these effects on Na(+) channels, action potentials in Fgf13 knockout mice, compared to Cre control mice, exhibited slower upstrokes and reduced amplitude, but unexpectedly had longer durations. We investigated candidate sources of the prolonged action potential durations in myocytes from Fgf13 knockout mice and found a reduction of the transient outward K(+) current (Ito). Fgf13 knockout did not alter whole-cell protein levels of Kv4.2 and Kv4.3, the Ito pore-forming subunits, but did decrease Kv4.2 and Kv4.3 at the sarcolemma. No changes were seen in the sustained outward K(+) current or voltage-gated Ca(2+) current, other candidate contributors to the increased action potential duration. These results implicate that FGF13 is a critical cardiac Na(+) channel modulator and Fgf13 knockout mice have increased arrhythmia

  6. Cardiac Sarcoidosis.

    PubMed

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  7. Sdhd and Sdhd/H19 Knockout Mice Do Not Develop Paraganglioma or Pheochromocytoma

    PubMed Central

    Bayley, Jean-Pierre; van Minderhout, Ivonne; Hogendoorn, Pancras C. W.; Cornelisse, Cees J.; van der Wal, Annemieke; Prins, Frans A.; Teppema, Luc; Dahan, Albert; Devilee, Peter; Taschner, Peter E. M.

    2009-01-01

    Background Mitochondrial succinate dehydrogenase (SDH) is a component of both the tricarboxylic acid cycle and the electron transport chain. Mutations of SDHD, the first protein of intermediary metabolism shown to be involved in tumorigenesis, lead to the human tumors paraganglioma (PGL) and pheochromocytoma (PC). SDHD is remarkable in showing an ‘imprinted’ tumor suppressor phenotype. Mutations of SDHD show a very high penetrance in man and we postulated that knockout of Sdhd would lead to the development of PGL/PC, probably in aged mice. Methodology/Principal Findings We generated a conventional knockout of Sdhd in the mouse, removing the entire third exon. We also crossed this mouse with a knockout of H19, a postulated imprinted modifier gene of Sdhd tumorigenesis, to evaluate if loss of these genes together would lead to the initiation or enhancement of tumor development. Homozygous knockout of Sdhd results in embryonic lethality. No paraganglioma or other tumor development was seen in Sdhd KO mice followed for their entire lifespan, in sharp contrast to the highly penetrant phenotype in humans. Heterozygous Sdhd KO mice did not show hyperplasia of paraganglioma-related tissues such as the carotid body or of the adrenal medulla, or any genotype-related pathology, with similar body and organ weights to wildtype mice. A cohort of Sdhd/H19 KO mice developed several cases of profound cardiac hypertrophy, but showed no evidence of PGL/PC. Conclusions Knockout of Sdhd in the mouse does not result in a disease phenotype. H19 may not be an initiator of PGL/PC tumorigenesis. PMID:19956719

  8. Cardiac arrest

    MedlinePlus

    ... or low levels can cause cardiac arrest. Severe physical stress. Anything that causes a severe stress on your body can lead to cardiac arrest. This can include trauma, electrical shock, or major blood loss. Recreational drugs. Using certain drugs, such as cocaine ...

  9. Cardiac metastases

    PubMed Central

    Bussani, R; De‐Giorgio, F; Abbate, A; Silvestri, F

    2007-01-01

    Tumours metastatic to the heart (cardiac metastases) are among the least known and highly debated issues in oncology, and few systematic studies are devoted to this topic. Although primary cardiac tumours are extremely uncommon (various postmortem studies report rates between 0.001% and 0.28%), secondary tumours are not, and at least in theory, the heart can be metastasised by any malignant neoplasm able to spread to distant sites. In general, cardiac metastases are considered to be rare; however, when sought for, the incidence seems to be not as low as expected, ranging from 2.3% and 18.3%. Although no malignant tumours are known that diffuse preferentially to the heart, some do involve the heart more often than others—for example, melanoma and mediastinal primary tumours. This paper attempts to review the pathophysiology of cardiac metastatic disease, epidemiology and clinical presentation of cardiac metastases, and pathological characterisation of the lesions. PMID:17098886

  10. BK Knockout by TALEN-Mediated Gene Targeting in Osteoblasts: KCNMA1 Determines the Proliferation and Differentiation of Osteoblasts

    PubMed Central

    Hei, Hongya; Gao, Jianjun; Dong, Jibin; Tao, Jie; Tian, Lulu; Pan, Wanma; Wang, Hongyu; Zhang, Xuemei

    2016-01-01

    Large conductance calcium-activated potassium (BK) channels participate in many important physiological functions in excitable tissues such as neurons, cardiac and smooth muscles, whereas the knowledge of BK channels in bone tissues and osteoblasts remains elusive. To investigate the role of BK channels in osteoblasts, we used transcription activator-like effector nuclease (TALEN) to establish a BK knockout cell line on rat ROS17/2.8 osteoblast, and detected the proliferation and mineralization of the BK-knockout cells. Our study found that the BK-knockout cells significantly decreased the ability of proliferation and mineralization as osteoblasts, compared to the wild type cells. The overall expression of osteoblast differentiation marker genes in the BK-knockout cells was significantly lower than that in wild type osteoblast cells. The BK-knockout osteoblast cell line in our study displays a phenotype decrease in osteoblast function which can mimic the pathological state of osteoblast and thus provide a working cell line as a tool for study of osteoblast function and bone related diseases. PMID:27329042

  11. Finite Range Effects in Knockout Reactions

    NASA Astrophysics Data System (ADS)

    Joshi, Bhushan N.

    2010-11-01

    Finite Range DWIA calculations have been performed for the first time. For the (α,2α) reactions, the calculations have indicated extreme sensitivity to the short range component of the t-matrix effective interaction. The vagaries of the energy dependent α-spectroscopic factors, have been understood using well established nuclear data. Using repulsive core α-α interaction two order of magnitude enhancement is explained. FR-DWIA calculation is a new tool to investigate the nature of nuclear potential. Heavy cluster knockout reaction such as ^16O( ^12C,2 ^12C) ^4Hehas been performed for the first time indicating an order of magnitude enhancement compared to the (α,2α) results. The (C,2C) results support a short range repulsive core C-C potential. Similar study can be made to probe the short range behavior of p-p, π-pand K^+nsystems to study the dibaryons, delta resonances and the pentaquarks. A new field of Heavy Cluster Knockout Reaction is opened up to study the core knockout of Halo nuclei. Our FR-DWIA formalism has applications in Atomic and Molecular Physics and neutron multiplication calculations for ADS also.

  12. Knockout mouse production assisted by Blm knockdown

    PubMed Central

    FUKUDA, Mikiko; INOUE, Mayuko; MURAMATSU, Daisuke; MIYACHI, Hitoshi; SHINKAI, Yoichi

    2015-01-01

    Production of knockout mice using targeted embryonic stem cells (ESCs) is a powerful approach for investigating the function of specific genes in vivo. Although the protocol for gene targeting via homologous recombination (HR) in ESCs is already well established, the targeting efficiency varies at different target loci and is sometimes too low. It is known that knockdown of the Bloom syndrome gene, BLM, enhances HR-mediated gene targeting efficiencies in various cell lines. However, it has not yet been investigated whether this approach in ESCs is applicable for successful knockout mouse production. Therefore, we attempted to answer this question. Consistent with previous reports, Blm knockdown enhanced gene targeting efficiencies for three gene loci that we examined by 2.3–4.1-fold. Furthermore, the targeted ESC clones generated good chimeras and were successful in germline transmission. These data suggest that Blm knockdown provides a general benefit for efficient ESC-based and HR-mediated knockout mouse production. PMID:26598326

  13. Heat shock response: lessons from mouse knockouts.

    PubMed

    Christians, E S; Benjamin, I J

    2006-01-01

    Organisms are endowed with integrated regulatory networks that transduce and amplify incoming signals into effective responses, ultimately imparting cell death and/or survival pathways. As a conserved cytoprotective mechanism from bacteria to humans, the heat shock response has been established as a paradigm for inducible gene expression, stimulating the interests of biologists and clinicians alike to tackle fundamental questions related to the molecular switches, lineage-specific requirements, unique and/or redundant roles, and even efforts to harness the response therapeutically. Gene targeting studies in mice confirm HSF1 as a master regulator required for cell growth, embryonic development, and reproduction. For example, sterility of Hsf1-null female but not null male mice established strict requirements for maternal HSF1 expression in the oocyte. Yet Hsf2 knockouts by three independent laboratories have not fully clarified the role of mammalian HSF2 for normal development, fertility, and postnatal neuronal function. In contrast, Hsf4 knockouts have provided a consistent demonstration for HSF4's critical role during lens formation. In the future, molecular analysis of HSF knockout mice will bring new insights to HSF interactions, foster better understanding of gene regulation at the genome level, lead to a better integration of the HSF pathway in life beyond heat shock, the classical laboratory challenge.

  14. Cardiac cachexia.

    PubMed

    Anker, Stefan D; Steinborn, Wolfram; Strassburg, Sabine

    2004-01-01

    Chronic heart failure (CHF) remains an important and increasing public health care problem. It is a complex syndrome affecting many body systems. Body wasting (i.e., cardiac cachexia) has long been recognised as a serious complication of CHF. Cardiac cachexia is associated with poor prognosis, independently of functional disease severity, age, and measures of exercise capacity and cardiac function. Patients with cardiac cachexia suffer from a general loss of fat tissue, lean tissue, and bone tissue. Cachectic CHF patients are weaker and fatigue earlier, which is due to both reduced skeletal muscle mass and impaired muscle quality. The pathophysiologic alterations leading to cardiac cachexia remain unclear, but there is increasing evidence that metabolic, neurohormonal and immune abnormalities may play an important role. Cachectic CHF patients show raised plasma levels of epinephrine, norepinephrine, and cortisol, and they show high plasma renin activity and increased plasma aldosterone level. Several studies have also shown that cardiac cachexia is linked to raised plasma levels of tumour necrosis factor alpha and other inflammatory cytokines. The degree of body wasting is strongly correlated with neurohormonal and immune abnormalities. The available evidence suggests that cardiac cachexia is a multifactorial neuroendocrine and metabolic disorder with a poor prognosis. A complex imbalance of different body systems may cause the development of body wasting.

  15. Cardiac Cephalgia

    PubMed Central

    Wassef, Nancy; Ali, Ali Turab; Katsanevaki, Alexia-Zacharoula; Nishtar, Salman

    2014-01-01

    Although most of the patients presenting with ischemic heart disease have chest pains, there are other rare presenting symptoms like cardiac cephalgia. In this report, we present a case of acute coronary syndrome with an only presentation of exertional headache. It was postulated as acute presentation of coronary artery disease, due to previous history of similar presentation associated with some chest pains with previous left coronary artery stenting. We present an unusual case with cardiac cephalgia in a young patient under the age of 50 which was not reported at that age before. There are four suggested mechanisms for this cardiac presentation. PMID:28352454

  16. Cardiac rhabdomyosarcoma

    PubMed Central

    Chlumský, Jaromír; Holá, Dana; Hlaváček, Karel; Michal, Michal; Švec, Alexander; Špatenka, Jaroslav; Dušek, Jan

    2001-01-01

    Cardiac sarcoma is a very rare neoplasm and is difficult to diagnose. The case of a 51-year-old man with a left atrial tumour, locally recurrent three months after its surgical removal, is presented. Computed tomography showed metastatic spread to the lung parenchyma. On revised histology, the mass extirpated was a sarcoma. Because of the metastatic spread, further therapy was symptomatic only; the patient died 15 months after the first manifestation of his problems. Immunohistochemical staining confirmed cardiac rhabdomyosarcoma with metastatic spread to the lungs. Difficulty in diagnosing and treating cardiac tumours is discussed. PMID:20428274

  17. Cardiac Lymphoma.

    PubMed

    Jeudy, Jean; Burke, Allen P; Frazier, Aletta Ann

    2016-07-01

    Lymphoma of the heart and pericardium may develop in up to 25% of patients with disseminated nodal disease, but primary cardiac lymphoma is rare. The majority are diffuse large B-cell lymphomas, which arise in immunocompetent older individuals, men twice as often as women. Subsets are found in immunocompromised patients, including those with HIV-AIDS or allograft recipients. Cardiac lymphomas tend to arise in the wall of the right heart, especially right atrium, with contiguous infiltration of epicardium and pericardium. Pericardial implants and effusions are common. The disease is often multifocal in the heart, but cardiac valves are usually spared. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Toll-like receptor 4 knockout alleviates paraquat-induced cardiomyocyte contractile dysfunction through an autophagy-dependent mechanism.

    PubMed

    Wang, Shuyi; Zhu, Xiaoling; Xiong, Lize; Zhang, Yingmei; Ren, Jun

    2016-08-22

    Paraquat, a quarternary nitrogen herbicide, is a toxic prooxidant leading to multi-organ failure including the heart although the underlying mechanism remains poorly understood. This study was designed to examine the role of the innate proinflammatory mediator toll-like receptor 4 (TLR4) in paraquat-induced cardiac contractile anomalies and the underlying mechanisms involved with a focus on autophagy, a conservative machinery governing protein and organelle degradation and recycling for cardiac homeostasis. Wild-type (WT) and TLR4 knockout (TLR4(-/-)) mice were challenged with paraquat (45mg/kg, i.p.) for 48h. Paraquat challenge did not affect mRNA levels of TLR2, TLR4 and TLR9 in WT mice nor did paraquat treatment alter TREM-1 levels. Paraquat challenge elicited cardiac mechanical defects including compromised cardiomyocyte contractile function, intracellular Ca(2+) handling, and overt autophagy as manifested by increased LC3BII-to-LC3BI ratio, Atg5, Atg7 and p62 levels. Interestingly, TLR4 knockout significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) derangement as well as alterations of autophagy markers. Paraquat-elicited changes in cardiac autophagy markers (LC3BII, LC3BII-to-LC3BI ratio and p62) were augmented by lysosomal inhibition using bafilomycin A1 in WT mice. TLR4 knockout significantly attenuated or negated paraquat-elicited increase in LC3BII, LC3BII-to-LC3BI ratio and p62 levels in the presence of lysosomal inhibition. In addition, paraquat challenge promoted phosphorylation of AMPK while suppressing the phosphorylation of mTOR and ULK1 (the autophagy inhibitory Ser(757)), the effects of which were significantly attenuated by TLR4 ablation. In vitro study revealed that AMPK activation using AICAR or mTOR inhibition using rapamycin effectively negated the beneficial cardiomyocyte mechanical effects of TLR4 inhibition (CLI-095) against paraquat toxicity, supporting a permissive role for AMPK-mTOR in TLR4 inhibition

  19. Cardiac Rehabilitation

    MedlinePlus

    ... surgery, coronary artery bypass grafting, or percutaneous coronary intervention. Cardiac rehab involves adopting heart-healthy lifestyle changes to address risk factors for cardiovascular disease. To help you adopt lifestyle changes, this program ...

  20. Cardiac Rehabilitation

    MedlinePlus

    ... eating a heart-healthy diet, keeping a healthy weight and quitting smoking. The goals of cardiac rehabilitation include establishing an individualized plan to help you regain strength, preventing your condition from worsening, reducing your ...

  1. Cardiac Med1 deletion promotes early lethality, cardiac remodeling, and transcriptional reprogramming.

    PubMed

    Spitler, Kathryn M; Ponce, Jessica M; Oudit, Gavin Y; Hall, Duane D; Grueter, Chad E

    2017-04-01

    The mediator complex, a multisubunit nuclear complex, plays an integral role in regulating gene expression by acting as a bridge between transcription factors and RNA polymerase II. Genetic deletion of mediator subunit 1 (Med1) results in embryonic lethality, due in large part to impaired cardiac development. We first established that Med1 is dynamically expressed in cardiac development and disease, with marked upregulation of Med1 in both human and murine failing hearts. To determine if Med1 deficiency protects against cardiac stress, we generated two cardiac-specific Med1 knockout mouse models in which Med1 is conditionally deleted (Med1cKO mice) or inducibly deleted in adult mice (Med1cKO-MCM mice). In both models, cardiac deletion of Med1 resulted in early lethality accompanied by pronounced changes in cardiac function, including left ventricular dilation, decreased ejection fraction, and pathological structural remodeling. We next defined how Med1 deficiency alters the cardiac transcriptional profile using RNA-sequencing analysis. Med1cKO mice demonstrated significant dysregulation of genes related to cardiac metabolism, in particular genes that are coordinated by the transcription factors Pgc1α, Pparα, and Errα. Consistent with the roles of these transcription factors in regulation of mitochondrial genes, we observed significant alterations in mitochondrial size, mitochondrial gene expression, complex activity, and electron transport chain expression under Med1 deficiency. Taken together, these data identify Med1 as an important regulator of vital cardiac gene expression and maintenance of normal heart function.NEW & NOTEWORTHY Disruption of transcriptional gene expression is a hallmark of dilated cardiomyopathy; however, its etiology is not well understood. Cardiac-specific deletion of the transcriptional coactivator mediator subunit 1 (Med1) results in dilated cardiomyopathy, decreased cardiac function, and lethality. Med1 deletion disrupted cardiac

  2. Nuclear cardiac

    SciTech Connect

    Slutsky, R.; Ashburn, W.L.

    1982-01-01

    The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques. (KRM)

  3. Cardiac cameras.

    PubMed

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  4. CD38 promotes angiotensin II-induced cardiac hypertrophy.

    PubMed

    Guan, Xiao-Hui; Hong, Xuan; Zhao, Ning; Liu, Xiao-Hong; Xiao, Yun-Fei; Chen, Ting-Tao; Deng, Li-Bin; Wang, Xiao-Lei; Wang, Jian-Bin; Ji, Guang-Ju; Fu, Mingui; Deng, Ke-Yu; Xin, Hong-Bo

    2017-03-12

    Cardiac hypertrophy is an early hallmark during the clinical course of heart failure and regulated by various signalling pathways. Recently, we observed that mouse embryonic fibroblasts from CD38 knockout mice were significantly resistant to oxidative stress such as H2 O2 -induced injury and hypoxia/reoxygenation-induced injury. In addition, we also found that CD38 knockout mice protected heart from ischaemia reperfusion injury through activating SIRT1/FOXOs-mediated antioxidative stress pathway. However, the role of CD38 in cardiac hypertrophy is not explored. Here, we investigated the roles and mechanisms of CD38 in angiotensin II (Ang-II)-induced cardiac hypertrophy. Following 14 days of Ang-II infusion with osmotic mini-pumps, a comparable hypertension was generated in both of CD38 knockout and wild-type mice. However, the cardiac hypertrophy and fibrosis were much more severe in wild-type mice compared with CD38 knockout mice. Consistently, RNAi-induced knockdown of CD38 decreased the gene expressions of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) and reactive oxygen species generation in Ang-II-stimulated H9c2 cells. In addition, the expression of SIRT3 was elevated in CD38 knockdown H9c2 cells, in which SIRT3 may further activate the FOXO3 antioxidant pathway. The intracellular Ca(2+) release induced by Ang-II markedly decreased in CD38 knockdown H9c2 cells, which might be associated with the decrease of nuclear translocation of NFATc4 and inhibition of ERK/AKT phosphorylation. We concluded that CD38 plays an essential role in cardiac hypertrophy probably via inhibition of SIRT3 expression and activation of Ca(2+) -NFAT signalling pathway. Thus, CD38 may be a novel target for treating cardiac hypertrophy.

  5. Universal statistics of the knockout tournament.

    PubMed

    Baek, Seung Ki; Yi, Il Gu; Park, Hye Jin; Kim, Beom Jun

    2013-11-12

    We study statistics of the knockout tournament, where only the winner of a fixture progresses to the next. We assign a real number called competitiveness to each contestant and find that the resulting distribution of prize money follows a power law with an exponent close to unity if the competitiveness is a stable quantity and a decisive factor to win a match. Otherwise, the distribution is found narrow. The existing observation of power law distributions in various kinds of real sports tournaments therefore suggests that the rules of those games are constructed in such a way that it is possible to understand the games in terms of the contestants' inherent characteristics of competitiveness.

  6. Universal statistics of the knockout tournament

    NASA Astrophysics Data System (ADS)

    Baek, Seung Ki; Yi, Il Gu; Park, Hye Jin; Kim, Beom Jun

    2013-11-01

    We study statistics of the knockout tournament, where only the winner of a fixture progresses to the next. We assign a real number called competitiveness to each contestant and find that the resulting distribution of prize money follows a power law with an exponent close to unity if the competitiveness is a stable quantity and a decisive factor to win a match. Otherwise, the distribution is found narrow. The existing observation of power law distributions in various kinds of real sports tournaments therefore suggests that the rules of those games are constructed in such a way that it is possible to understand the games in terms of the contestants' inherent characteristics of competitiveness.

  7. Generating double knockout mice to model genetic intervention for diabetic cardiomyopathy in humans.

    PubMed

    Chavali, Vishalakshi; Nandi, Shyam Sundar; Singh, Shree Ram; Mishra, Paras Kumar

    2014-01-01

    Diabetes is a rapidly increasing disease that enhances the chances of heart failure twofold to fourfold (as compared to age and sex matched nondiabetics) and becomes a leading cause of morbidity and mortality. There are two broad classifications of diabetes: type1 diabetes (T1D) and type2 diabetes (T2D). Several mice models mimic both T1D and T2D in humans. However, the genetic intervention to ameliorate diabetic cardiomyopathy in these mice often requires creating double knockout (DKO). In order to assess the therapeutic potential of a gene, that specific gene is either overexpressed (transgenic expression) or abrogated (knockout) in the diabetic mice. If the genetic mice model for diabetes is used, it is necessary to create DKO with transgenic/knockout of the target gene to investigate the specific role of that gene in pathological cardiac remodeling in diabetics. One of the important genes involved in extracellular matrix (ECM) remodeling in diabetes is matrix metalloproteinase-9 (Mmp9). Mmp9 is a collagenase that remains latent in healthy hearts but induced in diabetic hearts. Activated Mmp9 degrades extracellular matrix (ECM) and increases matrix turnover causing cardiac fibrosis that leads to heart failure. Insulin2 mutant (Ins2+/-) Akita is a genetic model for T1D that becomes diabetic spontaneously at the age of 3-4 weeks and show robust hyperglycemia at the age of 10-12 weeks. It is a chronic model of T1D. In Ins2+/- Akita, Mmp9 is induced. To investigate the specific role of Mmp9 in diabetic hearts, it is necessary to create diabetic mice where Mmp9 gene is deleted. Here, we describe the method to generate Ins2+/-/Mmp9-/- (DKO) mice to determine whether the abrogation of Mmp9 ameliorates diabetic cardiomyopathy.

  8. Proteomic Analysis of Loricrin Knockout Mouse Epidermis.

    PubMed

    Rice, Robert H; Durbin-Johnson, Blythe P; Ishitsuka, Yosuke; Salemi, Michelle; Phinney, Brett S; Rocke, David M; Roop, Dennis R

    2016-08-05

    The crosslinked envelope of the mammalian epidermal corneocyte serves as a scaffold for assembly of the lipid barrier of the epidermis. Thus, deficient envelope crosslinking by keratinocyte transglutaminase (TGM1) is a major cause of the human autosomal recessive congenital ichthyoses characterized by barrier defects. Expectations that loss of some envelope protein components would also confer an ichthyosis phenotype have been difficult to demonstrate. To help rationalize this observation, the protein profile of epidermis from loricrin knockout mice has been compared to that of wild type. Despite the mild phenotype of the knockout, some 40 proteins were incorporated into envelope material to significantly different extents compared to those of wild type. Nearly half were also incorporated to similarly altered extents into the disulfide bonded keratin network of the corneocyte. The results suggest that loss of loricrin alters their incorporation into envelopes as a consequence of protein-protein interactions during cell maturation. Mass spectrometric protein profiling revealed that keratin 1, keratin 10, and loricrin are prominent envelope components and that dozens of other proteins are also components. This finding helps rationalize the potential formation of functional envelopes, despite loss of a single component, due to the availability of many alternative transglutaminase substrates.

  9. Bone status of acetylcholinesterase-knockout mice.

    PubMed

    Kauschke, Vivien; Kneffel, Mathias; Floel, Wolfgang; Hartmann, Sonja; Kampschulte, Marian; Dürselen, Lutz; Ignatius, Anita; Schnettler, Reinhard; Heiss, Christian; Lips, Katrin Susanne

    2015-11-01

    Acetylcholinesterase (AChE) hydrolyzes acetylcholine (ACh) to acetate and choline and thereby terminates nerve impulse transmission. ACh is also expressed in bone tissue and enhances here proliferation and differentiation of osteoblasts, which makes it interesting to investigate effects of AChE deficiency on bone. To our knowledge, this is the first study that analyzed bone of heterozygous acetylcholinesterase-knockout (AChE-KO) mice. Tibia, femur, thoracic and lumbar vertebrae of 16-week-old female heterozygous AChE-KO mice and their corresponding wildtypes (WT) were analyzed using real-time RT-PCR, dual-energy X-ray absorptiometry, biomechanics, micro-computed tomography, histology and histomorphometry. Our data revealed that heterozygous AChE-KO did not cause negative effects upon bone parameters analyzed. In contrast, the number of osteoclasts per perimeter was significantly reduced in lumbar vertebrae. In addition, we found a significant decrease in trabecular perimeter of lumbar vertebrae and cortical area fraction (Ct.Ar/Tt.Ar) in the mid-diaphysis of femurs of AChE-KO mice compared to their WT. Therefore, presumably a local homozygous knockout of AChE or AChE-inhibitor administration might be beneficial for bone formation due to ACh accumulation. However, many other bone parameters analyzed did not differ statistically significantly between AChE-KO and WT mice. That might be reasoned by the compensating effect of butyrylcholinesterase (BChE). Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Altered Reward Circuitry in the Norepinephrine Transporter Knockout Mouse

    PubMed Central

    Hall, F. Scott; Uhl, George R.; Bearer, Elaine L.; Jacobs, Russell E.

    2013-01-01

    Synaptic levels of the monoamine neurotransmitters dopamine, serotonin, and norepinephrine are modulated by their respective plasma membrane transporters, albeit with a few exceptions. Monoamine transporters remove monoamines from the synaptic cleft and thus influence the degree and duration of signaling. Abnormal concentrations of these neuronal transmitters are implicated in a number of neurological and psychiatric disorders, including addiction, depression, and attention deficit/hyperactivity disorder. This work concentrates on the norepinephrine transporter (NET), using a battery of in vivo magnetic resonance imaging techniques and histological correlates to probe the effects of genetic deletion of the norepinephrine transporter on brain metabolism, anatomy and functional connectivity. MRS recorded in the striatum of NET knockout mice indicated a lower concentration of NAA that correlates with histological observations of subtle dysmorphisms in the striatum and internal capsule. As with DAT and SERT knockout mice, we detected minimal structural alterations in NET knockout mice by tensor-based morphometric analysis. In contrast, longitudinal imaging after stereotaxic prefrontal cortical injection of manganese, an established neuronal circuitry tracer, revealed that the reward circuit in the NET knockout mouse is biased toward anterior portions of the brain. This is similar to previous results observed for the dopamine transporter (DAT) knockout mouse, but dissimilar from work with serotonin transporter (SERT) knockout mice where Mn2+ tracings extended to more posterior structures than in wildtype animals. These observations correlate with behavioral studies indicating that SERT knockout mice display anxiety-like phenotypes, while NET knockouts and to a lesser extent DAT knockout mice display antidepressant-like phenotypic features. Thus, the mainly anterior activity detected with manganese-enhanced MRI in the DAT and NET knockout mice is likely indicative of

  11. [Preliminary exploration on knockout drops (Meng Han Agents)].

    PubMed

    Zhang, Z

    1996-05-01

    This author points out, based on relevant materials, that knockout drops were vertigo powder. Due to homophonic reasons in Chinese language, the term "mingxuan" was transliterated into the former Chinese term (menghan). Knockout drops for medicinal use were merely made up of compound recipes containing stramonium flowers. The knockout drops in old fictions and opera books were powder of stramonium flower. The ingredients and application of such recipes are discussed here, the anti-remedies for such recipes are also mentioned.

  12. Novel Protective Role of Endogenous Cardiac Myocyte P2X4 Receptors in Heart Failure

    PubMed Central

    Yang, Tiehong; Shen, Jian-bing; Yang, Ronghua; Redden, John; Dodge-Kafka, Kimberly; Grady, James; Jacobson, Kenneth A.; Liang, Bruce T.

    2014-01-01

    Background Heart failure (HF), despite continuing progress, remains a leading cause of mortality and morbidity. P2X4 receptors (P2X4R) have emerged as potentially important molecules in regulating cardiac function and as potential targets for HF therapy. Transgenic P2X4R overexpression can protect against HF, but this does not explain the role of native cardiac P2X4R. Our goal is to define the physiological role of endogenous cardiac myocyte P2X4R under basal conditions and during HF induced by myocardial infarction or pressure overload. Methods and Results Mice established with conditional cardiac-specific P2X4R knockout were subjected to left anterior descending coronary artery ligation–induced postinfarct or transverse aorta constriction–induced pressure overload HF. Knockout cardiac myocytes did not show P2X4R by immunoblotting or by any response to the P2X4R-specific allosteric enhancer ivermectin. Knockout hearts showed normal basal cardiac function but depressed contractile performance in postinfarct and pressure overload models of HF by in vivo echocardiography and ex vivo isolated working heart parameters. P2X4R coimmunoprecipitated and colocalized with nitric oxide synthase 3 (eNOS) in wild-type cardiac myocytes. Mice with cardiac-specific P2X4R overexpression had increased S-nitrosylation, cyclic GMP, NO formation, and were protected from postinfarct and pressure overload HF. Inhibitor of eNOS, L-N5-(1-iminoethyl)ornithine hydrochloride, blocked the salutary effect of cardiac P2X4R overexpression in postinfarct and pressure overload HF as did eNOS knockout. Conclusions This study establishes a new protective role for endogenous cardiac myocyte P2X4R in HF and is the first to demonstrate a physical interaction between the myocyte receptor and eNOS, a mediator of HF protection. PMID:24622244

  13. PDE1C deficiency antagonizes pathological cardiac remodeling and dysfunction

    PubMed Central

    Knight, Walter E.; Chen, Si; Zhang, Yishuai; Oikawa, Masayoshi; Wu, Meiping; Zhou, Qian; Miller, Clint L.; Cai, Yujun; Mickelsen, Deanne M.; Moravec, Christine; Small, Eric M.; Abe, Junichi; Yan, Chen

    2016-01-01

    Cyclic nucleotide phosphodiesterase 1C (PDE1C) represents a major phosphodiesterase activity in human myocardium, but its function in the heart remains unknown. Using genetic and pharmacological approaches, we studied the expression, regulation, function, and underlying mechanisms of PDE1C in the pathogenesis of cardiac remodeling and dysfunction. PDE1C expression is up-regulated in mouse and human failing hearts and is highly expressed in cardiac myocytes but not in fibroblasts. In adult mouse cardiac myocytes, PDE1C deficiency or inhibition attenuated myocyte death and apoptosis, which was largely dependent on cyclic AMP/PKA and PI3K/AKT signaling. PDE1C deficiency also attenuated cardiac myocyte hypertrophy in a PKA-dependent manner. Conditioned medium taken from PDE1C-deficient cardiac myocytes attenuated TGF-β–stimulated cardiac fibroblast activation through a mechanism involving the crosstalk between cardiac myocytes and fibroblasts. In vivo, cardiac remodeling and dysfunction induced by transverse aortic constriction, including myocardial hypertrophy, apoptosis, cardiac fibrosis, and loss of contractile function, were significantly attenuated in PDE1C-knockout mice relative to wild-type mice. These results indicate that PDE1C activation plays a causative role in pathological cardiac remodeling and dysfunction. Given the continued development of highly specific PDE1 inhibitors and the high expression level of PDE1C in the human heart, our findings could have considerable therapeutic significance. PMID:27791092

  14. Nitric oxide synthase in cardiac sarcoplasmic reticulum.

    PubMed

    Xu, K Y; Huso, D L; Dawson, T M; Bredt, D S; Becker, L C

    1999-01-19

    NO. is a free radical that modulates heart function and metabolism. We report that a neuronal-type NO synthase (NOS) is located on cardiac sarcoplasmic reticulum (SR) membrane vesicles and that endogenous NO. produced by SR-associated NOS inhibits SR Ca2+ uptake. Ca2+-dependent biochemical conversion of L-arginine to L-citrulline was observed from isolated rabbit cardiac SR vesicles in the presence of NOS substrates and cofactors. Endogenous NO. was generated from the vesicles and detected by electron paramagnetic resonance spin-trapping measurements. Immunoelectron microscopy demonstrated labeling of cardiac SR vesicles by using anti-neuronal NOS (nNOS), but not anti-endothelial NOS (eNOS) or anti-inducible NOS (iNOS) antibodies, whereas skeletal muscle SR vesicles had no nNOS immunoreactivity. The nNOS immunoreactivity also displayed a pattern consistent with SR localization in confocal micrographs of sections of human myocardium. Western blotting demonstrated that cardiac SR NOS is larger than brain NOS (160 vs. 155 kDa). No immunodetection was observed in cardiac SR vesicles from nNOS knockout mice or with an anti-nNOS mu antibody, suggesting the possibility of a new nNOS-type isoform. 45Ca uptake by cardiac SR vesicles, catalyzed by Ca2+-ATPase, was inhibited by NO. produced endogenously from cardiac SR NOS, and 7-nitroindazole, a selective nNOS inhibitor, completely prevented this inhibition. These results suggest that a cardiac muscle nNOS isoform is located on SR of cardiac myocytes, where it may respond to intracellular Ca2+ concentration and modulate SR Ca2+ ion active transport in the heart.

  15. Nitric oxide synthase in cardiac sarcoplasmic reticulum

    PubMed Central

    Xu, Kai Y.; Huso, David L.; Dawson, Ted M.; Bredt, David S.; Becker, Lewis C.

    1999-01-01

    NO⋅ is a free radical that modulates heart function and metabolism. We report that a neuronal-type NO synthase (NOS) is located on cardiac sarcoplasmic reticulum (SR) membrane vesicles and that endogenous NO⋅ produced by SR-associated NOS inhibits SR Ca2+ uptake. Ca2+-dependent biochemical conversion of l-arginine to l-citrulline was observed from isolated rabbit cardiac SR vesicles in the presence of NOS substrates and cofactors. Endogenous NO⋅ was generated from the vesicles and detected by electron paramagnetic resonance spin-trapping measurements. Immunoelectron microscopy demonstrated labeling of cardiac SR vesicles by using anti-neuronal NOS (nNOS), but not anti-endothelial NOS (eNOS) or anti-inducible NOS (iNOS) antibodies, whereas skeletal muscle SR vesicles had no nNOS immunoreactivity. The nNOS immunoreactivity also displayed a pattern consistent with SR localization in confocal micrographs of sections of human myocardium. Western blotting demonstrated that cardiac SR NOS is larger than brain NOS (160 vs. 155 kDa). No immunodetection was observed in cardiac SR vesicles from nNOS knockout mice or with an anti-nNOSμ antibody, suggesting the possibility of a new nNOS-type isoform. 45Ca uptake by cardiac SR vesicles, catalyzed by Ca2+-ATPase, was inhibited by NO⋅ produced endogenously from cardiac SR NOS, and 7-nitroindazole, a selective nNOS inhibitor, completely prevented this inhibition. These results suggest that a cardiac muscle nNOS isoform is located on SR of cardiac myocytes, where it may respond to intracellular Ca2+ concentration and modulate SR Ca2+ ion active transport in the heart. PMID:9892689

  16. Maximal Oxygen Consumption Is Reduced in Aquaporin-1 Knockout Mice

    PubMed Central

    Al-Samir, Samer; Goossens, Dominique; Cartron, Jean-Pierre; Nielsen, Søren; Scherbarth, Frank; Steinlechner, Stephan; Gros, Gerolf; Endeward, Volker

    2016-01-01

    We have measured maximal oxygen consumption (V˙O2,max) of mice lacking one or two of the established mouse red-cell CO2 channels AQP1, AQP9, and Rhag. We intended to study whether these proteins, by acting as channels for O2, determine O2 exchange in the lung and in the periphery. We found that V˙O2,max as determined by the Helox technique is reduced by ~16%, when AQP1 is knocked out, but not when AQP9 or Rhag are lacking. This figure holds for animals respiring normoxic as well as hypoxic gas mixtures. To see whether the reduction of V˙O2,max is due to impaired O2 uptake in the lung, we measured carotid arterial O2 saturation (SO2) by pulse oximetry. Neither under normoxic (inspiratory O2 21%) nor under hypoxic conditions (11% O2) is there a difference in SO2 between AQP1null and WT mice, suggesting that AQP1 is not critical for O2 uptake in the lung. The fact that the % reduction of V˙O2,max is identical in normoxia and hypoxia indicates moreover that the limitation of V˙O2,max is not due to an O2 diffusion problem, neither in the lung nor in the periphery. Instead, it appears likely that AQP1null animals exhibit a reduced V˙O2,max due to the reduced wall thickness and muscle mass of the left ventricles of their hearts, as reported previously. We conclude that very likely the properties of the hearts of AQP1 knockout mice cause a reduced maximal cardiac output and thus cause a reduced V˙O2,max, which constitutes a new phenotype of these mice. PMID:27559317

  17. Oxytocin and behavior: Lessons from knockout mice.

    PubMed

    Caldwell, Heather K; Aulino, Elizabeth A; Freeman, Angela R; Miller, Travis V; Witchey, Shannah K

    2017-02-01

    It is well established that the nonapeptide oxytocin (Oxt) is important for the neural modulation of behaviors in many mammalian species. Since its discovery in 1906 and synthesis in the early 1950s, elegant pharmacological work has helped identify specific neural substrates on which Oxt exerts its effects. More recently, mice with targeted genetic disruptions of the Oxt system-i.e., both the peptide and its receptor (the Oxtr)-have further defined Oxt's actions and laid some important scientific groundwork for studies in other species. In this article, we highlight the scientific contributions that various mouse knockouts of the Oxt system have made to our understanding of Oxt's modulation of behavior. We specifically focus on how the use of these mice has shed light on our understanding of social recognition memory, maternal behavior, aggression, and several nonsocial behaviors. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 190-201, 2017.

  18. Relativistic Approach to One Nucleon Knockout Reactions

    NASA Astrophysics Data System (ADS)

    Meucci, Andrea; Giusti, Carlotta; Pacati, Franco Davide

    2003-04-01

    We develop a fully relativistic distorted wave impulse approximation model for electron- and photon-induced one proton knockout reactions. The relativistic mean field for the bound state and the Pauli reduction for the scattering state are used, including a fully relativistic electromagnetic current operator. Results for 16O(e, e'p) cross section and structure functions are shown in various kinematic conditions and compared with nonrelativistic calculations. Nuclear transparency calculations in a Q2 range between 0.3 and 1.8 (GeV/c)2 are presented. Results for 16O(γ,p) differential cross sections are displayed in an energy range between 60 and 150 MeV including two-body seagull contribution in the nuclear current.

  19. Universal statistics of the knockout tournament

    PubMed Central

    Baek, Seung Ki; Yi, Il Gu; Park, Hye Jin; Kim, Beom Jun

    2013-01-01

    We study statistics of the knockout tournament, where only the winner of a fixture progresses to the next. We assign a real number called competitiveness to each contestant and find that the resulting distribution of prize money follows a power law with an exponent close to unity if the competitiveness is a stable quantity and a decisive factor to win a match. Otherwise, the distribution is found narrow. The existing observation of power law distributions in various kinds of real sports tournaments therefore suggests that the rules of those games are constructed in such a way that it is possible to understand the games in terms of the contestants' inherent characteristics of competitiveness. PMID:24217406

  20. Cardiac Rehabilitation

    MedlinePlus

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  1. P2y12 Receptor Promotes Pressure Overload-Induced Cardiac Remodeling via Platelet-Driven Inflammation in Mice.

    PubMed

    Wu, Lujin; Zhao, Fujie; Dai, Meiyan; Li, Huaping; Chen, Chen; Nie, Jiali; Wang, Peihua; Wang, Dao Wen

    2017-10-01

    Inflammation plays a critical role in adverse cardiac remodeling and heart failure. The P2y12 receptor is one of the predominant activating receptors for platelets, thus initiating inflammatory responses under various diseases. In this study, we investigated the functional significance of P2y12-mediated platelet activation in pressure overload-induced cardiac remodeling. Notably, P2y12 knockout (P2y12(-/-)) mice exhibited suppressed transverse aortic constriction-induced changes in cardiac hypertrophy, collagen synthesis, inflammatory cell recruitment, and cardiac dysfunction. Activated platelets and platelet-leukocyte aggregates were markedly downregulated in P2y12 knockout mice compared with wild-type counterparts after transverse aortic constriction. Moreover, bone marrow chimera experiments revealed that wild-type recipients of P2y12 knockout bone marrow markedly improved cardiac function and attenuated cardiac remodeling, reversed by wild-type platelets reinjection. Platelet depletion and P-selectin inhibition mimicked these protective effects by limiting the interaction between activated platelets and leukocytes. Furthermore, activated wild-type platelets directly induced cardiomyocyte hypertrophy and collagen synthesis via α-granule exocytosis, vanished in P2y12 knockout platelets or those administered anti-NSF (N-ethlymalimide-sensitive factor) antibodies. The results suggest that P2y12-mediated platelet activation promotes cardiac remodeling by triggering a series of inflammatory changes and interacting with leukocytes and endotheliocytes. © 2017 American Heart Association, Inc.

  2. Macrophage Migration Inhibitory Factor (MIF) Deficiency Exacerbates Aging-Induced Cardiac Remodeling and Dysfunction Despite Improved Inflammation: Role of Autophagy Regulation.

    PubMed

    Xu, Xihui; Pang, Jiaojiao; Chen, Yuguo; Bucala, Richard; Zhang, Yingmei; Ren, Jun

    2016-03-04

    Aging leads to unfavorable geometric and functional sequelae in the heart. The proinflammatory cytokine macrophage migration inhibitory factor (MIF) plays a role in the maintenance of cardiac homeostasis under stress conditions although its impact in cardiac aging remains elusive. This study was designed to evaluate the role of MIF in aging-induced cardiac anomalies and the underlying mechanism involved. Cardiac geometry, contractile and intracellular Ca(2+) properties were examined in young (3-4 mo) or old (24 mo) wild type and MIF knockout (MIF(-/-)) mice. Our data revealed that MIF knockout exacerbated aging-induced unfavorable structural and functional changes in the heart. The detrimental effect of MIF knockout was associated with accentuated loss in cardiac autophagy with aging. Aging promoted cardiac inflammation, the effect was attenuated by MIF knockout. Intriguingly, aging-induced unfavorable responses were reversed by treatment with the autophagy inducer rapamycin, with improved myocardial ATP availability in aged WT and MIF(-/-) mice. Using an in vitro model of senescence, MIF knockdown exacerbated doxorubicin-induced premature senescence in H9C2 myoblasts, the effect was ablated by MIF replenishment. Our data indicated that MIF knockout exacerbates aging-induced cardiac remodeling and functional anomalies despite improved inflammation, probably through attenuating loss of autophagy and ATP availability in the heart.

  3. Macrophage Migration Inhibitory Factor (MIF) Deficiency Exacerbates Aging-Induced Cardiac Remodeling and Dysfunction Despite Improved Inflammation: Role of Autophagy Regulation

    PubMed Central

    Xu, Xihui; Pang, Jiaojiao; Chen, Yuguo; Bucala, Richard; Zhang, Yingmei; Ren, Jun

    2016-01-01

    Aging leads to unfavorable geometric and functional sequelae in the heart. The proinflammatory cytokine macrophage migration inhibitory factor (MIF) plays a role in the maintenance of cardiac homeostasis under stress conditions although its impact in cardiac aging remains elusive. This study was designed to evaluate the role of MIF in aging-induced cardiac anomalies and the underlying mechanism involved. Cardiac geometry, contractile and intracellular Ca2+ properties were examined in young (3–4 mo) or old (24 mo) wild type and MIF knockout (MIF−/−) mice. Our data revealed that MIF knockout exacerbated aging-induced unfavorable structural and functional changes in the heart. The detrimental effect of MIF knockout was associated with accentuated loss in cardiac autophagy with aging. Aging promoted cardiac inflammation, the effect was attenuated by MIF knockout. Intriguingly, aging-induced unfavorable responses were reversed by treatment with the autophagy inducer rapamycin, with improved myocardial ATP availability in aged WT and MIF−/− mice. Using an in vitro model of senescence, MIF knockdown exacerbated doxorubicin-induced premature senescence in H9C2 myoblasts, the effect was ablated by MIF replenishment. Our data indicated that MIF knockout exacerbates aging-induced cardiac remodeling and functional anomalies despite improved inflammation, probably through attenuating loss of autophagy and ATP availability in the heart. PMID:26940544

  4. Interrater agreement of an observational tool to code knockouts and technical knockouts in mixed martial arts.

    PubMed

    Lawrence, David W; Hutchison, Michael G; Cusimano, Michael D; Singh, Tanveer; Li, Luke

    2014-09-01

    Interrater agreement evaluation of a tool to document and code the situational factors and mechanisms of knockouts (KOs) and technical knockouts (TKOs) in mixed martial arts (MMA). Retrospective case series. Professional MMA matches from the Ultimate Fighting Championship-2006-2012. Two nonmedically trained independent raters. The MMA Knockout Tool (MMA-KT) consists of 20 factors and captures and codes information on match characteristics, situational context preceding KOs and TKOs, as well as describing competitor states during these outcomes. The MMA-KT also evaluates the mechanism of action and subsequent events surrounding a KO. The 2 raters coded 125 unique events for a total of 250 events. The 8 factors of Part A had an average κ of 0.87 (SD = 0.10; range = 0.65-0.98); 7 were considered "substantial" agreement and 1 "moderate." Part B consists of 12 factors with an average κ of 0.84 (SD = 0.16; range = 0.59-1.0); 7 classified as "substantial" agreement, 4 "moderate," and 1 "fair." The majority of the factors in the MMA-KT demonstrated substantial interrater agreement, with an average κ of 0.86 (SD = 0.13; range = 0.59-1.0). The MMA-KT is a reliable tool to extract and code relevant information to investigate the situational factors and mechanism of KOs and TKOs in MMA competitions.

  5. Gene expression profiling of dilated cardiomyopathy in older male EP4 knockout mice

    PubMed Central

    Harding, Pamela; Yang, Xiao-Ping; Yang, James; Shesely, Ed; He, Quan

    2010-01-01

    Using a line of mice with cardiac-specific knockout (KO) of the EP4 receptor gene, experiments were designed to determine whether a cardiac phenotype developed with age. Cardiac function was assessed by echocardiography in 23- to 33-wk-old male and female KO and littermate controls (WT) mice. After echocardiography, hearts were removed to assess weight, and then some were further processed for histology [myocyte cross-sectional area (MCSA), interstitial collagen fraction (ICF), and macrophage infiltration] and some for extraction of total RNA and protein. Older male KO mice had reduced ejection fraction (EF) coupled with left ventricular dilatation. MCSA and infiltrating macrophages were not different between groups, but ICF increased by 39% in KO mice. In contrast to male KO mice, 30- to 32-wk-old female KO mice had only a slight reduction in EF. To understand gene expression differences between male WT and KO mice, we performed whole genome gene expression profiling (Illumina BeadChips) on hearts of 30-to 32-wk-old mice. Data indicated that 156 genes were overexpressed in the KO hearts more than twofold, including genes involved in remodeling, inflammation, and oxidative stress. Overexpressed chemokines/cytokines were further examined in hearts of 10- to 12-wk-old male KO mice, and we found that growth differentiation factor-15 (GDF-15) expression was higher in KO than in WT hearts. In conclusion, EP4 knockdown in cardiac myocytes in aged male KO mice is in part associated with increased fibrosis, reduced EF, and dilated cardiomyopathy. Early overexpression of GDF-15 in hearts of male KO mice may contribute to or be a marker of the disease phenotype. The absence of serious cardiac dysfunction in aged female mice suggests a sexual dimorphism in the phenotype. PMID:20008274

  6. Disruption of mindin exacerbates cardiac hypertrophy and fibrosis

    PubMed Central

    Bian, Zhou-Yan; Wei, Xiang; Deng, Shan; Tang, Qi-Zhu; Feng, Jinghua; Zhang, Yan; Liu, Chen; Jiang, Ding-Sheng; Yan, Ling; Zhang, Lian-Feng; Chen, Manyin; Fassett, John; Chen, Yingjie; He, You-Wen; Yang, Qinglin; Liu, Peter P.

    2013-01-01

    Cardiac hypertrophy is a response of the myocardium to increased workload and is characterised by an increase of myocardial mass and an accumulation of extracellular matrix (ECM). As an ECM protein, an integrin ligand, and an angiogenesis inhibitor, all of which are key players in cardiac hypertrophy, mindin is an attractive target for therapeutic intervention to treat or prevent cardiac hypertrophy and heart failure. In this study, we investigated the role of mindin in cardiac hypertrophy using littermate Mindin knockout (Mindin−/−) and wild-type (WT) mice. Cardiac hypertrophy was induced by aortic banding (AB) or angiotensin II (Ang II) infusion in Mindin−/− and WT mice. The extent of cardiac hypertrophy was quantitated by echocardiography and by pathological and molecular analyses of heart samples. Mindin−/− mice were more susceptible to cardiac hypertrophy and fibrosis in response to AB or Ang II stimulation than wild type. Cardiac function was also markedly exacerbated during both systole and diastole in Mindin−/− mice in response to hypertrophic stimuli. Western blot assays further showed that the activation of AKT/glycogen synthase kinase 3β (GSK3β) signalling in response to hypertrophic stimuli was significantly increased in Mindin−/− mice. Moreover, blocking AKT/GSK3β signalling with a pharmacological AKT inhibitor reversed cardiac abnormalities in Mindin−/− mice. Our data show that mindin, as an intrinsic cardioprotective factor, prevents maladaptive remodelling and the transition to heart failure by blocking AKT/GSK3β signalling. PMID:22367478

  7. ALK7 protects against pathological cardiac hypertrophy in mice.

    PubMed

    Huang, He; Tang, Yanhong; Wu, Gang; Mei, Yang; Liu, Wanli; Liu, Xiaoxiong; Wan, Nian; Liu, Yu; Huang, Congxin

    2015-10-01

    Activin receptor-like kinase 7 (ALK7), one of the type I transforming growth factor-β receptors, is expressed in various tissues, including the heart. However, the participation of ALK7 in the regulation of cardiac hypertrophy has not yet been studied. Here, we sought to determine the regulatory role and underlying mechanisms of ALK7 in cardiac hypertrophy. We performed aortic banding (AB) in ALK7-knockout mice, cardiac-specific ALK7-transgenic mice, and the wild-type littermates of these mice. Cardiac hypertrophy was evaluated using pathological analysis, echocardiographic measurement, haemodynamic measurement, and molecular analysis. Our results revealed that ALK7 disruption led to an aggravated cardiac hypertrophic response that was accompanied by increased cardiac fibrosis and reduced contractile function, whereas cardiac-specific ALK7 overexpression exhibited the opposite phenotype in response to pressure overload. Similarly, ALK7 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, we demonstrated that ALK7-dependent cardioprotection was mediated largely through inhibition of the MEK-ERK1/2 signalling pathway. Our data suggest that ALK7 acts as a novel regulator of pathological cardiac hypertrophy via the negative regulation of MEK-ERK1/2 signalling and may serve as a potential therapeutic target for pathological cardiac hypertrophy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  8. CCR2 mediates the uptake of bone marrow-derived fibroblast precursors in angiotensin II-induced cardiac fibrosis

    PubMed Central

    Xu, Jing; Lin, Song-Chang; Chen, Jiyuan; Miao, Yuanxin; Taffet, George E.; Entman, Mark L.

    2011-01-01

    Angiotensin II plays an important role in the development of cardiac hypertrophy and fibrosis, but the underlying cellular and molecular mechanisms are not completely understood. Recent studies have shown that bone marrow-derived fibroblast precursors are involved in the pathogenesis of cardiac fibrosis. Since bone marrow-derived fibroblast precursors express chemokine receptor, CCR2, we tested the hypothesis that CCR2 mediates the recruitment of fibroblast precursors into the heart, causing angiotensin II-induced cardiac fibrosis. Wild-type and CCR2 knockout mice were infused with angiotensin II at 1,500 ng·kg−1·min−1. Angiotensin II treatment resulted in elevated blood pressure and cardiac hypertrophy that were not significantly different between wild-type and CCR2 knockout mice. Angiotensin II treatment of wild-type mice caused prominent cardiac fibrosis and accumulation of bone marrow-derived fibroblast precursors expressing the hematopoietic markers, CD34 and CD45, and the mesenchymal marker, collagen I. However, angiotensin II-induced cardiac fibrosis and accumulation of bone marrow-derived fibroblast precursors in the heart were abrogated in CCR2 knockout mice. Furthermore, angiotensin II treatment of wild-type mice increased the levels of collagen I, fibronectin, and α-smooth muscle actin in the heart, whereas these changes were not observed in the heart of angiotensin II-treated CCR2 knockout mice. Functional studies revealed that the reduction of cardiac fibrosis led to an impairment of cardiac systolic function and left ventricular dilatation in angiotensin II-treated CCR2 knockout mice. Our data demonstrate that CCR2 plays a pivotal role in the pathogenesis of angiotensin II-induced cardiac fibrosis through regulation of bone marrow-derived fibroblast precursors. PMID:21572015

  9. Investigation of the cardiomyocyte dysfunction in bradykinin type 2 receptor knockout mice.

    PubMed

    Roman-Campos, Danilo; Duarte, Hugo Leonardo; Gomes, Enéas Ricardo; Castro, Carlos Henrique; Guatimosim, Silvia; Natali, Antonio José; Almeida, Alvair Pinto; Pesquero, João Bosco; Pesquero, Jorge Luiz; Cruz, Jader Santos

    2010-12-18

    Bradykinin type 2 receptor (B(2)R) is the key component to trigger the intracellular signaling pathway in response to bradykinin under physiological conditions. The present study sought to investigate whether the B(2)R gene deletion will have an impact on myocardial function. Isolated cell shortening, patch-clamp technique, Western blot and confocal microscopy. Isolated cell shortening measurements showed significant reduction in B(2)R knockout (B(2)R(-/-)) left ventricular cardiac myocytes' shortening. Whole-cell recordings were used to study the electrophysiological aspects of the left ventricular B(2)R(-/-) cardiomyocytes. Results showed: 1) action potential lengthening; 2) unchanged inwardly rectifying K(+) current; 3) reduced transient outward K(+) (I(to)) and L-type Ca(2+) current densities; 5) changes in kinetic properties related to I(to) and I(Ca,L). In addition, transient sarcoplasmic reticulum (SR) Ca(2+) release was found to be smaller in B(2)R(-/-) cardiomyocytes. Importantly, evidence is provided that NO constitutive production is, at least in part, responsible for the reported electrophysiological modifications observed in cardiomyocytes from B(2)R(-/-) mice. Surprisingly, NO is not involved in the SR Ca(2+) release reduction as demonstrated in the present study. Taken together, our findings indicate that B(2)R plays a fundamental role in the regulation of cardiac function and Ca(2+) homeostasis, probably through a NO dependent pathway. These results may contribute to our understanding of the kinins participation in the control of cardiac function. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Cardiac emergencies.

    PubMed

    Barata, Isabel Araujo

    2013-08-01

    The diagnosis and management of pediatric cardiac emergencies can be challenging and complicated. Early presentations are usually the result of ductal-dependent lesions and appear with cyanosis and shock. Later presentations are the result of volume overload or pump failure and present with signs of congestive heart failure. Acquired diseases also present as congestive heart failure or arrhythmias. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Cardiac lipoma

    PubMed Central

    Ismail, Imtiaz; Al-Khafaji, Khalid; Mutyala, Monica; Aggarwal, Saurabh; Cotter, William; Hakim, Hosam; Khosla, Sandeep; Arora, Rohit

    2015-01-01

    Lipomas of the heart are encapsulated tumors that are composed primarily of mature fat cells. Cardiac lipomas can originate either from subendocardium (approximately 50%), subpericardium (25%), or from the myocardium (25%) and may be located more frequently in left ventricle or right atrium. We report a 74-year-old female who presented with dyspnea on exertion and was found to have 5×5 cm mass occupying most of the right atrium on a transesophageal echocardiogram. PMID:26486106

  12. Cardiac Surgery

    PubMed Central

    Weisse, Allen B.

    2011-01-01

    Well into the first decades of the 20th century, medical opinion held that any surgical attempts to treat heart disease were not only misguided, but unethical. Despite such reservations, innovative surgeons showed that heart wounds could be successfully repaired. Then, extracardiac procedures were performed to correct patent ductus arteriosus, coarctation of the aorta, and tetralogy of Fallot. Direct surgery on the heart was accomplished with closed commissurotomy for mitral stenosis. The introduction of the heart-lung machine and cardiopulmonary bypass enabled the surgical treatment of other congenital and acquired heart diseases. Advances in aortic surgery paralleled these successes. The development of coronary artery bypass grafting greatly aided the treatment of coronary heart disease. Cardiac transplantation, attempts to use the total artificial heart, and the application of ventricular assist devices have brought us to the present day. Although progress in the field of cardiovascular surgery appears to have slowed when compared with the halcyon times of the past, substantial challenges still face cardiac surgeons. It can only be hoped that sufficient resources and incentive can carry the triumphs of the 20th century into the 21st. This review covers past developments and future opportunities in cardiac surgery. PMID:22163121

  13. Cardiac optogenetics.

    PubMed

    Entcheva, Emilia

    2013-05-01

    Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart.

  14. Cardiac optogenetics

    PubMed Central

    2013-01-01

    Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart. PMID:23457014

  15. Action of SNAIL1 in Cardiac Myofibroblasts Is Important for Cardiac Fibrosis following Hypoxic Injury

    PubMed Central

    Biswas, Hirak; Longmore, Gregory D.

    2016-01-01

    Hypoxic injury to the heart results in cardiac fibrosis that leads to cardiac dysfunction and heart failure. SNAIL1 is a zinc finger transcription factor implicated in fibrosis following organ injury and cancer. To determine if the action of SNAIL1 contributed to cardiac fibrosis following hypoxic injury, we used an endogenous SNAIL1 bioluminescence reporter mice, and SNAIL1 knockout mouse models. Here we report that SNAIL1 expression is upregulated in the infarcted heart, especially in the myofibroblasts. Utilizing primary cardiac fibroblasts in ex vivo cultures we find that pro-fibrotic factors and collagen I increase SNAIL1 protein level. SNAIL1 is required in cardiac fibroblasts for the adoption of myofibroblast fate, collagen I expression and expression of fibrosis-related genes. Taken together this data suggests that SNAIL1 expression is induced in the cardiac fibroblasts after hypoxic injury and contributes to myofibroblast phenotype and a fibrotic scar formation. Resultant collagen deposition in the scar can maintain elevated SNAIL1 expression in the myofibroblasts and help propagate fibrosis. PMID:27706205

  16. Cardiac hypertrophy: a risk factor for QT-prolongation and cardiac sudden death.

    PubMed

    Kang, Y James

    2006-01-01

    Cardiac hypertrophy was viewed as a compensatory response to hemodynamic stress. However, cumulative evidence obtained from studies using more advanced technologies in human patients and animal models suggests that cardiac hypertrophy is a maladaptive process of the heart in response to intrinsic and extrinsic stimuli. Although hypertrophy can normalize wall tension, it is a risk factor for QT-prolongation and cardiac sudden death. Studies using molecular biology techniques such as transgenic and knockout mice have revealed many important molecules that are involved in the development of heart hypertrophy and have demonstrated signaling pathways leading to the pathogenesis. With the same approach, the consequence of heart hypertrophy has been examined. The significance of hypertrophy in the development of overt heart failure has been demonstrated and several critical molecular pathways involved in the process were revealed. A comprehensive understanding of the threats of heart hypertrophy to patients has helped to develop novel treatment strategies. The recognition of hypertrophy as a major risk factor for QT-prolongation and cardiac sudden death is an important advance in cardiac medicine. Cellular and molecular mechanisms of this risk aspect are currently under extensively exploring. These studies would lead to more comprehensive approaches to prevention of potential life threatening arrhythmia and cardiac sudden death. The adaptation of new approaches such as functional genomics and proteomics will further advance our knowledge of heart hypertrophy.

  17. Cardiac-specific overexpression of caveolin-3 induces endogenous cardiac protection by mimicking ischemic preconditioning

    PubMed Central

    Tsutsumi, Yasuo M.; Horikawa, Yousuke T.; Jennings, Michelle M.; Kidd, Michael W.; Niesman, Ingrid R.; Yokoyama, Utako; Head, Brian P.; Hagiwara, Yasuko; Ishikawa, Yoshihiro; Miyanohara, Atsushi; Patel, Piyush M.; Insel, Paul A.; Patel, Hemal H.; Roth, David M.

    2009-01-01

    Background Caveolae, lipid-rich microdomains of the sarcolemma, localize and enrich cardiac protective signaling molecules. Caveolin-3 (Cav-3), the dominant isoform in cardiac myocytes, is a determinant of caveolae formation. We hypothesized that cardiac myocyte-specific overexpression of Cav-3 would enhance the formation of caveolae and augment cardiac protection in vivo. Methods and Results Ischemic preconditioning (IPC) in vivo increased formation of caveolae. Adenovirus for Cav-3 increased caveolar formation and phosphorylation of survival kinases in cardiac myocytes. A transgenic (TG) mouse with cardiac myocyte-specific overexpression of Cav-3 (Cav-3 OE) showed enhanced formation of caveolae on the sarcolemma. Cav-3 OE mice subjected to ischemia/reperfusion injury had a significantly reduced infarct size relative to TGneg mice. Endogenous cardiac protection in Cav-3 OE mice was similar to wild-type mice undergoing IPC; no increased protection was observed in preconditioned Cav-3 OE mice. Cav-3 knockout mice did not show endogenous protection and showed no protection in response to IPC. Cav-3 OE mouse hearts had increased basal Akt and GSK3β phosphorylation comparable to wild-type mice exposed to IPC. Wortmannin, a PI3K inhibitor, attenuated basal phosphorylation of Akt and GSK3β and blocked cardiac protection in Cav-3 OE mice. Cav-3 OE mice had improved functional recovery and reduced apoptosis at 24 h of reperfusion. Conclusion Expression of caveolin-3 is both necessary and sufficient for cardiac protection, a conclusion that unites long-standing ultrastructural and molecular observations in the ischemic heart. The current results indicate that increased expression of caveolins, apparently via actions that depend on PI3K, has the potential to protect hearts exposed to ischemia-reperfusion injury. PMID:18936328

  18. Increased hepatotoxicity of acetaminophen in Hsp70i knockout mice

    SciTech Connect

    Tolson, J. Keith; Dix, David J.; Voellmy, Richard W.; Roberts, Stephen M. . E-mail: smr@ufl.edu

    2006-01-15

    The effect of the inducible forms of 70 kDa heat shock protein (Hsp70i) on acetaminophen (APAP) hepatotoxicity was assessed in an Hsp70i knockout mouse model. Absence of the Hsp70i protein in liver was verified by monitoring Hsp levels in knockout and control mice after heat stress (41.5 {sup o}C water bath immersion for 30 min). Hsp70i knockout mice were more susceptible to APAP-induced hepatotoxicity than controls, as indicated by elevated serum alanine aminotransferase activities 24 and 48 h after the APAP dose. Increased APAP hepatotoxicity in knockout mice was verified by morphological evaluation of liver sections. The difference in toxic response to APAP between knockout and control strain mice could not be attributed to differences in APAP bioactivation, assessed by measurement of CYP2E1 and glutathione S-transferase activities, hepatic nonprotein sulfhydryl content, or covalent binding of reactive APAP metabolites to proteins. Pretreatment with transient hyperthermia to produce a general upregulation of Hsps resulted in decreased APAP hepatotoxicity in both the knockout and control strains. Among thermally-pretreated mice, hepatotoxicity of APAP was greater in the knockouts compared with the control strain. These observations suggest that increased Hsp70i expression in response to APAP acts to limit the extent of tissue injury. Results further suggest that other factors related to heat stress can also contribute to protection against APAP toxicity.

  19. AMPK: Lessons from transgenic and knockout animals

    PubMed Central

    Viollet, Benoit; Athea, Yoni; Mounier, Remi; Guigas, Bruno; Zarrinpashneh, Elham; Horman, Sandrine; Lantier, Louise; Hebrard, Sophie; Devin-Leclerc, Jocelyne; Beauloye, Christophe; Foretz, Marc; Andreelli, Fabrizio; Ventura-Clapier, Renee; Bertrand, Luc

    2009-01-01

    AMP-activated protein kinase (AMPK), a phylogenetically conserved serine/threonine protein kinase, has been proposed to function as a ‘fuel gauge’ to monitor cellular energy status in response to nutritional environmental variations. AMPK system is a regulator of energy balance that, once activated by low energy status, switches on ATP-producing catabolic pathways (such as fatty acid oxidation and glycolysis), and switches off ATP-consuming anabolic pathways (such as lipogenesis), both by short-term effect on phosphorylation of regulatory proteins and by long-term effect on gene expression. Numerous observations obtained with pharmacological activators and agents that deplete intracellular ATP have been supportive of AMPK playing a role in the control of energy metabolism but none of these studies have provided conclusive evidence. Relatively recent developments in our understanding of precisely how AMPK complexes might operate to control energy metabolism is due in part to the development of transgenic and knockout mouse models. Although there are inevitable caveats with genetic models, some important findings have emerged. In the present review, we discuss recent findings obtained from animal models with inhibition or activation of AMPK signaling pathway. PMID:19273052

  20. Lipid transport in cholecystokinin knockout mice.

    PubMed

    King, Alexandra; Yang, Qing; Huesman, Sarah; Rider, Therese; Lo, Chunmin C

    2015-11-01

    Cholecystokinin (CCK) is released in response to lipid feeding and regulates pancreatic digestive enzymes vital to the absorption of nutrients. Our previous reports demonstrated that cholecystokinin knockout (CCK-KO) mice fed for 10 weeks of HFD had reduced body fat mass, but comparable glucose uptake by white adipose tissues and skeletal muscles. We hypothesized that CCK is involved in energy homeostasis and lipid transport from the small intestine to tissues in response to acute treatment with dietary lipids. CCK-KO mice with comparable fat absorption had increased energy expenditure and were resistant to HFD-induced obesity. Using intraduodenal infusion of butter fat and intravenous infusion using Liposyn III, we determined the mechanism of lipid transport from the small intestine to deposition in lymph and adipocytes in CCK-KO mice. CCK-KO mice had delayed secretion of Apo B48-chylomicrons, lipid transport to the lymphatic system, and triglyceride (TG)-derived fatty acid uptake by epididymal fat in response to acute treatment of intraduodenal lipids. In contrast, CCK-KO mice had comparable TG clearance and lipid uptake by white adipocytes in response to TGs in chylomicron-like emulsion. Thus, we concluded that CCK is important for lipid transport and energy expenditure to control body weight in response to dietary lipid feeding.

  1. Manipulation of Mouse Embryonic Stem Cells for Knockout Mouse Production

    PubMed Central

    Limaye, Advait; Hall, Bradford; Kulkarni, Ashok B

    2009-01-01

    The establishment of mouse embryonic stem (ES) cell liness has allowed for the generation of the knockout mouse. ES cells that are genetically altered in culture can then be manipulated to derive a whole mouse containing the desired mutation. To successfully generate a knockout mouse, however, the ES cells must be carefully cultivated in a pluripotent state throughout the gene targeting experiment. This unit describes detailed step-by-step protocols, reagents, equipment, and strategies needed for the successful generation of gene knockout embryonic stem cells using homologous recombination technologies. PMID:19731225

  2. Human Knockout Carriers: Dead, Diseased, Healthy, or Improved?

    PubMed Central

    Narasimhan, Vagheesh M.; Xue, Yali; Tyler-Smith, Chris

    2016-01-01

    Whole-genome and whole-exome sequence data from large numbers of individuals reveal that we all carry many variants predicted to inactivate genes (knockouts). This discovery raises questions about the phenotypic consequences of these knockouts and potentially allows us to study human gene function through the investigation of homozygous loss-of-function carriers. Here, we discuss strategies, recent results, and future prospects for large-scale human knockout studies. We examine their relevance to studying gene function, population genetics, and importantly, the implications for accurate clinical interpretations. PMID:26988438

  3. Reducing RBM20 activity improves diastolic dysfunction and cardiac atrophy.

    PubMed

    Hinze, Florian; Dieterich, Christoph; Radke, Michael H; Granzier, Henk; Gotthardt, Michael

    2016-12-01

    Impaired diastolic filling is a main contributor to heart failure with preserved ejection fraction (HFpEF), a syndrome with increasing prevalence and no treatment. Both collagen and the giant sarcomeric protein titin determine diastolic function. Since titin's elastic properties can be adjusted physiologically, we evaluated titin-based stiffness as a therapeutic target. We adjusted RBM20-dependent cardiac isoform expression in the titin N2B knockout mouse with increased ventricular stiffness. A ~50 % reduction of RBM20 activity does not only maintain cardiac filling in diastole but also ameliorates cardiac atrophy and thus improves cardiac function in the N2B-deficient heart. Reduced RBM20 activity partially normalized gene expression related to muscle development and fatty acid metabolism. The adaptation of cardiac growth was related to hypertrophy signaling via four-and-a-half lim-domain proteins (FHLs) that translate mechanical input into hypertrophy signals. We provide a novel link between cardiac isoform expression and trophic signaling via FHLs and suggest cardiac splicing as a therapeutic target in diastolic dysfunction. Increasing the length of titin isoforms improves ventricular filling in heart disease. FHL proteins are regulated via RBM20 and adapt cardiac growth. RBM20 is a therapeutic target in diastolic dysfunction.

  4. Arginyltransferase regulates alpha cardiac actin, myofibril formation and contractility during heart development

    PubMed Central

    Rai, Reena; Wong, Catherine C. L.; Xu, Tao; Leu, N. Adrian; Dong, Dawei W.; Guo, Caiying; McLaughlin, K. John; Yates, John R.; Kashina, Anna

    2008-01-01

    Summary Posttranslational arginylation mediated by arginyltransferase (Ate1) is essential for cardiovascular development and angiogenesis in mammals and directly affects the myocardium structure in the developing heart. We recently showed that arginylation exerts a number of intracellular effects by modifying proteins involved in the functioning of actin cytoskeleton and the events of cell motility. Here we investigate the role of arginylation in the development and function of cardiac myocytes and their actin-containing structures during embryogenesis. Biochemical and mass spectrometry analysis shows that alpha cardiac actin undergoes arginylation on multiple sites during development. Ultrastructural analysis of the myofibrils in wild type and Ate1 knockout mouse hearts shows that the absence of arginylation results in defects in myofibril structure that delay their development and affect the continuity of myofibrils throughout the heart, predicting defects in cardiac contractility. Comparison of cardiac myocytes derived from wild type and Ate1 knockout mouse embryos show that the absence of arginylation results in abnormal beating patterns. Our results demonstrate cell-autonomous cardiac myocyte defects in arginylation knockout mice that lead to severe congenital abnormalities similar to those observed in human disease, and outline a new function of arginylation in the regulation of actin cytoskeleton in cardiac myocytes. PMID:18948421

  5. About Cardiac Arrest

    MedlinePlus

    ... Thromboembolism Aortic Aneurysm More About Cardiac Arrest Updated:Mar 10,2017 What is cardiac arrest? Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart ...

  6. Phenotype of the taurine transporter knockout mouse.

    PubMed

    Warskulat, Ulrich; Heller-Stilb, Birgit; Oermann, Evelyn; Zilles, Karl; Haas, Helmut; Lang, Florian; Häussinger, Dieter

    2007-01-01

    This chapter reports present knowledge on the properties of mice with disrupted gene coding for the taurine transporter (taut-/- mice). Study of those mice unraveled some of the roles of taurine and its membrane transport for the development and maintenance of normal organ functions and morphology. When compared with wild-type controls, taut-/- mice have decreased taurine levels in skeletal and heart muscle by about 98%, in brain, kidney, plasma, and retina by 80 to 90%, and in liver by about 70%. taut-/- mice exhibit a lower body mass as well as a strongly reduced exercise capacity compared with taut+/- and wild-type mice. Furthermore, taut-/- mice show a variety of pathological features, for example, subtle derangement of renal osmoregulation, changes in neuroreceptor expression, and loss of long-term potentiation in the striatum, and they develop clinically relevant age-dependent disorders, for example, visual, auditory, and olfactory dysfunctions, unspecific hepatitis, and liver fibrosis. Taurine-deficient animal models such as acutely dietary-manipulated foxes and cats, pharmacologically induced taurine-deficient rats, and taurine transporter knockout mouse are powerful tools allowing identification of the mechanisms and complexities of diseases mediated by impaired taurine transport and taurine depletion (Chapman et al., 1993; Heller-Stilb et al., 2002; Huxtable, 1992; Lake, 1993; Moise et al., 1991; Novotny et al., 1991; Pion et al., 1987; Timbrell et al., 1995; Warskulat et al., 2004, 2006b). Taurine, which is the most abundant amino acid in many tissues, is normally found in intracellular concentrations of 10 to 70 mmol/kg in mammalian heart, brain, skeletal muscle, liver, and retina (Chapman et al., 1993; Green et al., 1991; Huxable, 1992; Timbrell et al., 1995). These high taurine levels are maintained by an ubiquitous expression of Na(+)-dependent taurine transporter (TAUT) in the plasma membrane (Burg, 1995; Kwon and Handler, 1995; Lang et al., 1998

  7. Seinpin knockout exacerbates cerebral ischemia/reperfusion damage in mice.

    PubMed

    Chen, Yong; Wei, Lili; Tian, Jing; Wang, Yu-Hui; Liu, George; Wang, Chun

    2016-05-27

    Seipin, which regulates adipocyte differentiation and lipolysis, inducing severe lipodystrophy and metabolic syndromes, is also highly expressed in the nervous system and affects some neurological diseases. However, the impacts of seipin in stroke remain unclear. In this study, we subjected seipin knockout mice to cerebral ischemia/reperfusion injury and found that seipin knockout mice exhibited exacerbated neurological disorder and enlarged infarct size, companied by blood-brain barrier (BBB) damages. Furthermore, we showed that seipin knockout aggravated endoplasmic reticulum (ER) stress and significantly increased glucose levels, decreased leptin and adiponectin levels in mouse plasma. Our findings reveal that seipin knockout exacerbates cerebral I/R-induced damages by increasing BBB permeability, amplifying ER stress and increasing glucose levels, as well as decreasing leptin and adiponectin levels, indicating that seipin may be a potential therapeutic target for stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Sleep in Kcna2 knockout mice

    PubMed Central

    Douglas, Christopher L; Vyazovskiy, Vladyslav; Southard, Teresa; Chiu, Shing-Yan; Messing, Albee; Tononi, Giulio; Cirelli, Chiara

    2007-01-01

    Background Shaker codes for a Drosophila voltage-dependent potassium channel. Flies carrying Shaker null or hypomorphic mutations sleep 3–4 h/day instead of 8–14 h/day as their wild-type siblings do. Shaker-like channels are conserved across species but it is unknown whether they affect sleep in mammals. To address this issue, we studied sleep in Kcna2 knockout (KO) mice. Kcna2 codes for Kv1.2, the alpha subunit of a Shaker-like voltage-dependent potassium channel with high expression in the mammalian thalamocortical system. Results Continuous (24 h) electroencephalograph (EEG), electromyogram (EMG), and video recordings were used to measure sleep and waking in Kcna2 KO, heterozygous (HZ) and wild-type (WT) pups (P17) and HZ and WT adult mice (P67). Sleep stages were scored visually based on 4-s epochs. EEG power spectra (0–20 Hz) were calculated on consecutive 4-s epochs. KO pups die by P28 due to generalized seizures. At P17 seizures are either absent or very rare in KO pups (< 1% of the 24-h recording time), and abnormal EEG activity is only present during the seizure. KO pups have significantly less non-rapid eye movement (NREM) sleep (-23%) and significantly more waking (+21%) than HZ and WT siblings with no change in rapid eye movement (REM) sleep time. The decrease in NREM sleep is due to an increase in the number of waking episodes, with no change in number or duration of sleep episodes. Sleep patterns, daily amounts of sleep and waking, and the response to 6 h sleep deprivation are similar in HZ and WT adult mice. Conclusion Kv1.2, a mammalian homologue of Shaker, regulates neuronal excitability and affects NREM sleep. PMID:17925011

  9. Immunological phenotype of the murine Lrba knockout.

    PubMed

    Gámez-Díaz, Laura; Neumann, Julika; Jäger, Fiona; Proietti, Michele; Felber, Felicitas; Soulas-Sprauel, Pauline; Perruzza, Lisa; Grassi, Fabio; Kögl, Tamara; Aichele, Peter; Kilimann, Manfred; Grimbacher, Bodo; Jung, Sophie

    2017-10-01

    Biallelic mutations in the human lipopolysaccharide responsive beige-like anchor (LRBA) gene lead to a primary immunodeficiency known as LRBA deficiency, characterized by a broad range of clinical manifestations including autoimmunity, organomegaly, hypogammaglobulinemia and recurrent infections. Considering the phenotypic heterogeneity in patients and the severity of the disease, our aim was to assess the role of LRBA in immune cells and to understand the underlying pathomechanisms through the study of a Lrba knockout (Lrba(-/-)) mouse model. LRBA-deficient mice did not show severe clinical or immunological signs of disease, either at steady state under specific-pathogen-free conditions, after vaccination with T-dependent and T-independent antigens, or in the context of acute infections with lymphocytic choriomeningitis virus (LCMV) or Salmonella Typhimurium. Although Lrba(-/-) mice were able to produce normal serum immunoglobulin M (IgM) and IgG and to mount a specific immune response after immunization, they showed elevated serum and secretory basal IgA levels. LRBA was dispensable for B- and T-cell development, as well as for in vitro B-cell proliferation, survival, isotype switching and plasmablast differentiation. Interestingly, Lrba(-/-) mice displayed decreased cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) expression by regulatory T cells and activated conventional CD4(+) and CD8(+) T lymphocytes, reduced frequency of peritoneal B-1a cells along with diminished interleukin-10 production and increased percentages of T follicular helper cells in Peyer's patches, but without developing overt signs of autoimmunity. Our findings expand the role of LRBA in immune regulatory mechanisms previously reported in patients, and suggest a novel role in IgA production that is crucial for the protection of mucosal surfaces and gut-associated immune tolerance.

  10. Exploring the opioid system by gene knockout.

    PubMed

    Kieffer, Brigitte L; Gavériaux-Ruff, Claire

    2002-04-01

    The endogenous opioid system consists of three opioid peptide precursor genes encoding enkephalins (preproenkephalin, Penk), dynorphins (preprodynorphin, Pdyn) and beta-endorphin (betaend), proopiomelanocortin (POMC) and three receptor genes encoding mu-opiod receptor (MOR), delta-opiod receptor (DOR) and kappa-opiod receptor (KOR). In the past years, all six genes have been inactivated in mice by homologous recombination. The analysis of spontaneous behavior in mutant mice has demonstrated significant and distinct roles of each gene in modulating locomotion, pain perception and emotional behaviors. The observation of opposing phenotypes of MOR- and DOR-deficient mice in several behaviors highlights unexpected roles for DOR to be further explored genetically and using more specific delta compounds. The analysis of responses of mutant mice to exogenous opiates has definitely clarified the essential role of MOR in both morphine analgesia and addiction, and demonstrated that DOR and KOR remain promising targets for pain treatment. These studies also show that prototypic DOR agonists partially require MOR for their biological activity and provide some support for the postulated mu-delta interactions in vivo. Finally, data confirm and define a role for several genes of the opioid system in responses to other drugs of abuse, and the triple opioid receptor knockout mutant allows exploring non-classical opioid pharmacology. In summary, the study of null mutant mice has extended our previous knowledge of the opioid system by identifying the molecular players in opioid pharmacology and physiology. Future studies should involve parallel behavioral analysis of mice lacking receptors and peptides and will benefit from more sophisticated gene targeting approaches, including site-directed and anatomically-restricted mutations.

  11. Pleiotropic effects in Eya3 knockout mice

    PubMed Central

    Söker, Torben; Dalke, Claudia; Puk, Oliver; Floss, Thomas; Becker, Lore; Bolle, Ines; Favor, Jack; Hans, Wolfgang; Hölter, Sabine M; Horsch, Marion; Kallnik, Magdalena; Kling, Eva; Moerth, Corinna; Schrewe, Anja; Stigloher, Christian; Topp, Stefanie; Gailus-Durner, Valerie; Naton, Beatrix; Beckers, Johannes; Fuchs, Helmut; Ivandic, Boris; Klopstock, Thomas; Schulz, Holger; Wolf, Eckhard; Wurst, Wolfgang; Bally-Cuif, Laure; de Angelis, Martin Hrabé; Graw, Jochen

    2008-01-01

    Background In Drosophila, mutations in the gene eyes absent (eya) lead to severe defects in eye development. The functions of its mammalian orthologs Eya1-4 are only partially understood and no mouse model exists for Eya3. Therefore, we characterized the phenotype of a new Eya3 knockout mouse mutant. Results Expression analysis of Eya3 by in-situ hybridizations and β-Gal-staining of Eya3 mutant mice revealed abundant expression of the gene throughout development, e.g. in brain, eyes, heart, somites and limbs suggesting pleiotropic effects of the mutated gene. A similar complex expression pattern was observed also in zebrafish embryos. The phenotype of young adult Eya3 mouse mutants was systematically analyzed within the German Mouse Clinic. There was no obvious defect in the eyes, ears and kidneys of Eya3 mutant mice. Homozygous mutants displayed decreased bone mineral content and shorter body length. In the lung, the tidal volume at rest was decreased, and electrocardiography showed increased JT- and PQ intervals as well as decreased QRS amplitude. Behavioral analysis of the mutants demonstrated a mild increase in exploratory behavior, but decreased locomotor activity and reduced muscle strength. Analysis of differential gene expression revealed 110 regulated genes in heart and brain. Using real-time PCR, we confirmed Nup155 being down regulated in both organs. Conclusion The loss of Eya3 in the mouse has no apparent effect on eye development. The wide-spread expression of Eya3 in mouse and zebrafish embryos is in contrast to the restricted expression pattern in Xenopus embryos. The loss of Eya3 in mice leads to a broad spectrum of minor physiological changes. Among them, the mutant mice move less than the wild-type mice and, together with the effects on respiratory, muscle and heart function, the mutation might lead to more severe effects when the mice become older. Therefore, future investigations of Eya3 function should focus on aging mice. PMID:19102749

  12. Methylphenidate restores novel object recognition in DARPP-32 knockout mice.

    PubMed

    Heyser, Charles J; McNaughton, Caitlyn H; Vishnevetsky, Donna; Fienberg, Allen A

    2013-09-15

    Previously, we have shown that Dopamine- and cAMP-regulated phosphoprotein of 32kDa (DARPP-32) knockout mice required significantly more trials to reach criterion than wild-type mice in an operant reversal-learning task. The present study was conducted to examine adult male and female DARPP-32 knockout mice and wild-type controls in a novel object recognition test. Wild-type and knockout mice exhibited comparable behavior during the initial exploration trials. As expected, wild-type mice exhibited preferential exploration of the novel object during the substitution test, demonstrating recognition memory. In contrast, knockout mice did not show preferential exploration of the novel object, instead exhibiting an increase in exploration of all objects during the test trial. Given that the removal of DARPP-32 is an intracellular manipulation, it seemed possible to pharmacologically restore some cellular activity and behavior by stimulating dopamine receptors. Therefore, a second experiment was conducted examining the effect of methylphenidate. The results show that methylphenidate increased horizontal activity in both wild-type and knockout mice, though this increase was blunted in knockout mice. Pretreatment with methylphenidate significantly impaired novel object recognition in wild-type mice. In contrast, pretreatment with methylphenidate restored the behavior of DARPP-32 knockout mice to that observed in wild-type mice given saline. These results provide additional evidence for a functional role of DARPP-32 in the mediation of processes underlying learning and memory. These results also indicate that the behavioral deficits in DARPP-32 knockout mice may be restored by the administration of methylphenidate.

  13. Galectin-3 blockade inhibits cardiac inflammation and fibrosis in experimental hyperaldosteronism and hypertension.

    PubMed

    Martínez-Martínez, Ernesto; Calvier, Laurent; Fernández-Celis, Amaya; Rousseau, Elodie; Jurado-López, Raquel; Rossoni, Luciana V; Jaisser, Frederic; Zannad, Faiez; Rossignol, Patrick; Cachofeiro, Victoria; López-Andrés, Natalia

    2015-10-01

    Hypertensive cardiac remodeling is accompanied by molecular inflammation and fibrosis, 2 mechanisms that finally affect cardiac function. At cardiac level, aldosterone promotes inflammation and fibrosis, although the precise mechanisms are still unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, is associated with inflammation and fibrosis in the cardiovascular system. We herein investigated whether Gal-3 inhibition could block aldosterone-induced cardiac inflammation and fibrosis and its potential role in cardiac damage associated with hypertension. Aldosterone-salt-treated rats presented hypertension, cardiac inflammation, and fibrosis that were prevented by the pharmacological inhibition of Gal-3 with modified citrus pectin. Cardiac inflammation and fibrosis presented in spontaneously hypertensive rats were prevented by modified citrus pectin treatment, whereas Gal-3 blockade did not modify blood pressure levels. In the absence of blood pressure modifications, Gal-3 knockout mice were resistant to aldosterone-induced cardiac inflammation. In human cardiac fibroblasts, aldosterone increased Gal-3 expression via its mineralocorticoid receptor. Gal-3 and aldosterone enhanced proinflammatory and profibrotic markers, as well as metalloproteinase activities in human cardiac fibroblasts, effects that were not observed in Gal-3-silenced cells treated with aldosterone. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac inflammation and fibrosis, alterations that were prevented by Gal-3 blockade independently of blood pressure levels. These data suggest that Gal-3 could be a new molecular mechanism linking cardiac inflammation and fibrosis in situations with high-aldosterone levels, such as hypertension. © 2015 American Heart Association, Inc.

  14. Cardiac-Specific EPI64C Blunts Pressure Overload-Induced Cardiac Hypertrophy.

    PubMed

    Zhu, Xuehai; Fang, Jing; Gong, Jun; Guo, Jun-Hong; Zhao, Guang-Nian; Ji, Yan-Xiao; Liu, Hong-Yun; Wei, Xiang; Li, Hongliang

    2016-05-01

    The calcium-responsive molecule, calcineurin, has been well characterized to play a causal role in pathological cardiac hypertrophy over the past decade. However, the intrinsic negative regulation of calcineurin signaling during the progression of cardiomyocyte hypertrophy remains enigmatic. Herein, we explored the role of EPI64C, a dual inhibitor of both Ras and calcineurin signaling during T-cell activation, in pressure overload-induced cardiac hypertrophy. We generated a cardiac-specific Epi64c conditional knockout mouse strain and showed that loss of Epi64c remarkably exacerbates pressure overload-induced cardiac hypertrophy. In contrast, EPI64C gain-of-function in cardiomyocyte-specific Epi64c transgenic mice exerts potent protective effects against cardiac hypertrophy. Mechanistically, the cardioprotective effects of EPI64C are largely attributed to the disrupted calcineurin signaling but are independent of its Ras suppressive capability. Molecular studies have indicated that the 406 to 446 C-terminal amino acids in EPI64C directly bind to the 287 to 337 amino acids in the catalytic domain of calcineurin, which is responsible for the EPI64C-mediated suppressive effects. We further extrapolated our studies to cynomolgus monkeys and showed that gene therapy based on lentivirus-mediated EPI64C overexpression in the monkey hearts blunted pressure overload-induced cardiac hypertrophy. Our study thus identified EPI64C as a novel negative regulator in cardiac hypertrophy by targeting calcineurin signaling and demonstrated the potential of gene therapy and drug development for treating cardiac hypertrophy. © 2016 American Heart Association, Inc.

  15. p53 regulates the cardiac transcriptome

    PubMed Central

    Mak, Tak W.; Hauck, Ludger; Grothe, Daniela; Billia, Filio

    2017-01-01

    The tumor suppressor Trp53 (p53) inhibits cell growth after acute stress by regulating gene transcription. The mammalian genome contains hundreds of p53-binding sites. However, whether p53 participates in the regulation of cardiac tissue homeostasis under normal conditions is not known. To examine the physiologic role of p53 in adult cardiomyocytes in vivo, Cre-loxP–mediated conditional gene targeting in adult mice was used. Genome-wide transcriptome analyses of conditional heart-specific p53 knockout mice were performed. Genome-wide annotation and pathway analyses of >5,000 differentially expressed transcripts identified many p53-regulated gene clusters. Correlative analyses identified >20 gene sets containing more than 1,000 genes relevant to cardiac architecture and function. These transcriptomic changes orchestrate cardiac architecture, excitation-contraction coupling, mitochondrial biogenesis, and oxidative phosphorylation capacity. Interestingly, the gene expression signature in p53-deficient hearts confers resistance to acute biomechanical stress. The data presented here demonstrate a role for p53, a previously unrecognized master regulator of the cardiac transcriptome. The complex contributions of p53 define a biological paradigm for the p53 regulator network in the heart under physiological conditions. PMID:28193895

  16. ANGPTL2 activity in cardiac pathologies accelerates heart failure by perturbing cardiac function and energy metabolism

    PubMed Central

    Tian, Zhe; Miyata, Keishi; Kadomatsu, Tsuyoshi; Horiguchi, Haruki; Fukushima, Hiroyuki; Tohyama, Shugo; Ujihara, Yoshihiro; Okumura, Takahiro; Yamaguchi, Satoshi; Zhao, Jiabin; Endo, Motoyoshi; Morinaga, Jun; Sato, Michio; Sugizaki, Taichi; Zhu, Shunshun; Terada, Kazutoyo; Sakaguchi, Hisashi; Komohara, Yoshihiro; Takeya, Motohiro; Takeda, Naoki; Araki, Kimi; Manabe, Ichiro; Fukuda, Keiichi; Otsu, Kinya; Wada, Jun; Murohara, Toyoaki; Mohri, Satoshi; Yamashita, Jun K.; Sano, Motoaki; Oike, Yuichi

    2016-01-01

    A cardioprotective response that alters ventricular contractility or promotes cardiomyocyte enlargement occurs with increased workload in conditions such as hypertension. When that response is excessive, pathological cardiac remodelling occurs, which can progress to heart failure, a leading cause of death worldwide. Mechanisms underlying this response are not fully understood. Here, we report that expression of angiopoietin-like protein 2 (ANGPTL2) increases in pathologically-remodeled hearts of mice and humans, while decreased cardiac ANGPTL2 expression occurs in physiological cardiac remodelling induced by endurance training in mice. Mice overexpressing ANGPTL2 in heart show cardiac dysfunction caused by both inactivation of AKT and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a signalling and decreased myocardial energy metabolism. Conversely, Angptl2 knockout mice exhibit increased left ventricular contractility and upregulated AKT-SERCA2a signalling and energy metabolism. Finally, ANGPTL2-knockdown in mice subjected to pressure overload ameliorates cardiac dysfunction. Overall, these studies suggest that therapeutic ANGPTL2 suppression could antagonize development of heart failure. PMID:27677409

  17. Caveolin-1 knockout mice exhibit airway hyperreactivity

    PubMed Central

    Aravamudan, Bharathi; VanOosten, Sarah K.; Meuchel, Lucas W.; Vohra, Pawan; Thompson, Michael; Sieck, Gary C.; Prakash, Y. S.

    2012-01-01

    Caveolae are flask-shaped plasma membrane invaginations expressing the scaffolding caveolin proteins. Although caveolins have been found in endothelium and epithelium (where they regulate nitric oxide synthase activity), their role in smooth muscle is still under investigation. We and others have previously shown that caveolae of human airway smooth muscle (ASM), which express caveolin-1, contain Ca2+ and force regulatory proteins and are involved in mediating the effects of inflammatory cytokines such as TNF-α on intracellular Ca2+ concentration responses to agonist. Accordingly, we tested the hypothesis that in vivo, absence of caveolin-1 leads to reduced airway hyperresponsiveness, using a knockout (KO) (Cav1 KO) mouse and an ovalbumin-sensitized/challenged (OVA) model of allergic airway hyperresponsiveness. Surprisingly, airway responsiveness to methacholine, tested by use of a FlexiVent system, was increased in Cav1 KO control (CTL) as well as KO OVA mice, which could not be explained by a blunted immune response to OVA. In ASM of wild-type (WT) OVA mice, expression of caveolin-1, the caveolar adapter proteins cavins 1–3, and caveolae-associated Ca2+ and force regulatory proteins such as Orai1 and RhoA were all increased, effects absent in Cav1 KO CTL and OVA mice. However, as with WT OVA, both CTL and OVA Cav1 KO airways showed signs of enhanced remodeling, with high expression of proliferation markers and increased collagen. Separately, epithelial cells from airways of all three groups displayed lower endothelial but higher inducible nitric oxide synthase and arginase expression. Arginase activity was also increased in these three groups, and the inhibitor nor-NOHA (N-omega-nor-l-arginine) enhanced sensitivity of isolated tracheal rings to ACh, especially in Cav1 KO mice. On the basis of these data disproving our original hypothesis, we conclude that caveolin-1 has complex effects on ASM vs. epithelium, resulting in airway hyperreactivity in vivo mediated

  18. p21{sup WAF1/Cip1/Sdi1} knockout mice respond to doxorubicin with reduced cardiotoxicity

    SciTech Connect

    Terrand, Jerome; Xu, Beibei; Morrissy, Steve; Dinh, Thai Nho; Williams, Stuart; Chen, Qin M.

    2011-11-15

    Doxorubicin (Dox) is an antineoplastic agent that can cause cardiomyopathy in humans and experimental animals. As an inducer of reactive oxygen species and a DNA damaging agent, Dox causes elevated expression of p21{sup WAF1/Cip1/Sdi1} (p21) gene. Elevated levels of p21 mRNA and p21 protein have been detected in the myocardium of mice following Dox treatment. With chronic treatment of Dox, wild type (WT) animals develop cardiomyopathy evidenced by elongated nuclei, mitochondrial swelling, myofilamental disarray, reduced cardiac output, reduced ejection fraction, reduced left ventricular contractility, and elevated expression of ANF gene. In contrast, p21 knockout (p21KO) mice did not show significant changes in the same parameters in response to Dox treatment. In an effort to understand the mechanism of the resistance against Dox induced cardiomyopathy, we measured levels of antioxidant enzymes and found that p21KO mice did not contain elevated basal or inducible levels of glutathione peroxidase and catalase. Measurements of 6 circulating cytokines indicated elevation of IL-6, IL-12, IFN{gamma} and TNF{alpha} in Dox treated WT mice but not p21KO mice. Dox induced elevation of IL-6 mRNA was detected in the myocardium of WT mice but not p21KO mice. While the mechanism of the resistance against Dox induced cardiomyopathy remains unclear, lack of inflammatory response may contribute to the observed cardiac protection in p21KO mice. -- Highlights: Black-Right-Pointing-Pointer Doxorubicin induces p21 elevation in the myocardium. Black-Right-Pointing-Pointer Doxorubicin causes dilated cardiomyopathy in wild type mice. Black-Right-Pointing-Pointer p21 Knockout mice are resistant against doxorubicin induced cardiomyopathy. Black-Right-Pointing-Pointer Lack of inflammatory response correlates with the resistance in p21 knockout mice.

  19. Deletion of Pr130 Interrupts Cardiac Development in Zebrafish

    PubMed Central

    Yang, Jie; Li, Zuhua; Gan, Xuedong; Zhai, Gang; Gao, Jiajia; Xiong, Chenling; Qiu, Xueping; Wang, Xuebin; Yin, Zhan; Zheng, Fang

    2016-01-01

    Protein phosphatase 2 regulatory subunit B, alpha (PPP2R3A), a regulatory subunit of protein phosphatase 2A (PP2A), is a major serine/threonine phosphatase that regulates crucial function in development and growth. Previous research has implied that PPP2R3A was involved in heart failure, and PR130, the largest transcription of PPP2R3A, functioning in the calcium release of sarcoplasmic reticulum (SR), plays an important role in the excitation-contraction (EC) coupling. To obtain a better understanding of PR130 functions in myocardium and cardiac development, two pr130-deletion zebrafish lines were generated using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) system. Pr130-knockout zebrafish exhibited cardiac looping defects and decreased cardiac function (decreased fractional area and fractional shortening). Hematoxylin and eosin (H&E) staining demonstrated reduced cardiomyocytes. Subsequent transmission electron microscopy revealed that the bright and dark bands were narrowed and blurred, the Z- and M-lines were fogged, and the gaps between longitudinal myocardial fibers were increased. Additionally, increased apoptosis was observed in cardiomyocyte in pr130-knockout zebrafish compared to wild-type (WT). Taken together, our results suggest that pr130 is required for normal myocardium formation and efficient cardiac contractile function. PMID:27845735

  20. Cardiac xenotransplantation.

    PubMed

    DiSesa, V J

    1997-12-01

    Heart failure is an important medical and public health problem. Although medical therapy is effective for many people, the only definitive therapy is heart transplantation, which is limited severely by the number of donors. Mechanical devices presently are used as "bridges" to transplantation. Their widespread use may solve the donor shortage problem, but at present, mechanical devices are limited by problems related to blood clotting, power supply, and foreign body infection. Cardiac xenotransplantation using animal donors is a potential biologic solution to the donor organ shortage. The immune response, consisting of hyperacute rejection, acute vascular rejection, and cellular rejection, currently prevents clinical xenotransplantation. Advances in the solution of these problems have been made using conventional immunosuppressive drugs and newer agents whose use is based on an understanding of important steps in xenoimmunity. The most exciting approaches use tools of molecular biology to create genetically engineered donors and to induce states of donor and recipient bone marrow chimerism and tolerance in xenogeneic organ recipients. The successful future strategy may use a combination of a genetically engineered donor and a chimeric recipient with or without nonspecific immunosuppressive drugs.

  1. Transgenic and gene knockout mice in gastric cancer research

    PubMed Central

    Jiang, Yannan; Yu, Yingyan

    2017-01-01

    Mouse models are useful tool for carcinogenic study. They will greatly enrich the understanding of pathogenesis and molecular mechanisms for gastric cancer. However, only few of mice could develop gastric cancer spontaneously. With the development and improvement of gene transfer technology, investigators created a variety of transgenic and knockout/knockin mouse models of gastric cancer, such as INS-GAS mice and gastrin knockout mice. Combined with helicobacter infection and carcinogens treatment, these transgenic/knockout/knockin mice developed precancerous or cancerous lesions, which are proper for gene function study or experimental therapy. Here we review the progression of genetically engineered mouse models on gastric cancer research, and emphasize the effects of chemical carcinogens or infectious factors on carcinogenesis of genetically modified mouse. We also emphasize the histological examination on mouse stomach. We expect to provide researchers with some inspirations on this field. PMID:27713138

  2. Generation of conditional knockout alleles for PRL-3.

    PubMed

    Yan, Hong; Kong, Dong; Ge, Xiaomei; Gao, Xiang; Han, Xiao

    2011-11-01

    Phosphatase of regenerating liver-3 (PRL-3) is a member of the protein tyrosine phosphatase (PTP) superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor metastasis, we applied a rapid and efficient method for generating PRL-3 floxed mice and investigated its phenotypes. A BAC retrieval strategy was applied to construct the PRL-3 conditional gene-targeting vector. Exon 4 was selected for deletion to generate a nonfunctional prematurely terminated short peptide as it will cause a frame-shift mutation. Conditional knockout PRL-3 mice were generated by using the Cre-loxP system and were validated by Southern blot and RT-PCR analysis. Further analysis revealed the phenotype characteristics of PRL-3 knockout mice and wildtype mice. In this study, we successfully constructed the PRL-3 conditional knockout mice, which will be helpful to clarify the roles of PRL-3 and the mechanisms in tumor metastasis.

  3. Transgenic and gene knockout mice in gastric cancer research.

    PubMed

    Jiang, Yannan; Yu, Yingyan

    2017-01-10

    Mouse models are useful tool for carcinogenic study. They will greatly enrich the understanding of pathogenesis and molecular mechanisms for gastric cancer. However, only few of mice could develop gastric cancer spontaneously. With the development and improvement of gene transfer technology, investigators created a variety of transgenic and knockout/knockin mouse models of gastric cancer, such as INS-GAS mice and gastrin knockout mice. Combined with helicobacter infection and carcinogens treatment, these transgenic/knockout/knockin mice developed precancerous or cancerous lesions, which are proper for gene function study or experimental therapy. Here we review the progression of genetically engineered mouse models on gastric cancer research, and emphasize the effects of chemical carcinogens or infectious factors on carcinogenesis of genetically modified mouse. We also emphasize the histological examination on mouse stomach. We expect to provide researchers with some inspirations on this field.

  4. Using engineered endonucleases to create knockout and knockin zebrafish models.

    PubMed

    Bedell, Victoria M; Ekker, Stephen C

    2015-01-01

    Over the last few years, the technology to create targeted knockout and knockin zebrafish animals has exploded. We have gained the ability to create targeted knockouts through the use of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR associated system (CRISPR/Cas). Furthermore, using the high-efficiency TALEN system, we were able to create knockin zebrafish using a single-stranded DNA (ssDNA) protocol described here. Through the use of these technologies, the zebrafish has become a valuable vertebrate model and an excellent bridge between the invertebrate and mammalian model systems for the study of human disease.

  5. Exercise, Nrf2 and Antioxidant Signaling in Cardiac Aging

    PubMed Central

    Narasimhan, Madhusudhanan; Rajasekaran, Namakkal S.

    2016-01-01

    Aging is represented by a progressive decline in cellular functions. The age-related deformities in cardiac behaviors are the loss of cardiac myocytes through apoptosis or programmed cell death. Oxidative stress (OS) and its deleterious consequence contribute to age-related mechanical remodeling, reduced regenerative capacity, and apoptosis in cardiac tissue. The pathogenesis of OS in the elderly can predispose the heart to other cardiac complications such as atherosclerosis, hypertension, ischemic heart disease, cardiac myopathy, and so on. At the molecular level, oxidant-induced activation of Nrf2 (Nuclear erythroid-2-p45-related factor-2), a transcription factor, regulates several genes containing AREs (Antioxidant Response Element) and bring the respective translates to counteract the reactive radicals and establish homeostasis. Myriad of Nrf2 gene knockout studies in various organs such as lung, liver, kidney, brain, etc. have shown that dysregulation of Nrf2 severely affects the oxidant/ROS sensitivity and predispose the system to several pathological changes with aberrant cellular lesions. On the other hand, its gain of function chemical interventions exhibited oxidant stress resistance and cytoprotection. However, thus far, only a few investigations have shown the potential role of Nrf2 and its non-pharmacological induction in cardiac aging. Therefore, here we review the involvement of Nrf2 signaling along with its responses and ramifications on the cascade of OS under acute exercise stress (AES), moderate exercise training (MET), and endurance exercise stress (EES) conditions in the aging heart. PMID:27378947

  6. Dickkopf-3 attenuates pressure overload-induced cardiac remodelling.

    PubMed

    Zhang, Yan; Liu, Yu; Zhu, Xue-Hai; Zhang, Xiao-Dong; Jiang, Ding-Sheng; Bian, Zhou-Yan; Zhang, Xiao-Fei; Chen, Ke; Wei, Xiang; Gao, Lu; Zhu, Li-Hua; Yang, Qinglin; Fan, Guo-Chang; Lau, Wayne B; Ma, Xinliang; Li, Hongliang

    2014-04-01

    Dickkopf-3 (DKK3), a secreted protein in the Dickkopf family, is expressed in various tissues, including the heart, and has been shown to play an important role in tissue development. However, the biological function of DKK3 in the heart remains largely unexplored. This study aimed to examine the role of DKK3 in pathological cardiac hypertrophy. We performed gain-of-function and loss-of-function studies using DKK3 cardiac-specific transgenic (TG) mice and DKK3 knockout (KO) mice (C57BL/6J background). Cardiac hypertrophy was induced by aortic banding. Cardiac hypertrophy was evaluated by echocardiographic, haemodynamic, pathological, and molecular analyses. Our results demonstrated that the loss of DKK3 exaggerated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas the overexpression of DKK3 protected the heart against pressure overload-induced cardiac remodelling. These beneficial effects were associated with the inhibition of the ASK1-JNK/p38 (apoptosis signal-regulating kinase 1-c-Jun N-terminal kinase/p38) signalling cascade. Parallel in vitro experiments confirmed these in vivo observations. Co-immunoprecipitation experiments suggested that physical interactions occurred between DKK3 and ASK1. Moreover, rescue experiments indicated that, in DKK3 TG mice, the activation of ASK1 using a cardiac-specific conditional ASK1 transgene reduced the functionality of DKK3 in response to pressure overload; furthermore, the inactivation of ASK1 by dominant-negative ASK1 rescued pressure overload-induced cardiac abnormalities in DKK3 KO mice. Taken together, our findings indicate that DKK3 acts as a cardioprotective regulator of pathological cardiac hypertrophy and that this function largely occurs via the regulation of ASK1-JNK/p38 signalling.

  7. One-neutron knockout from 51-55 Sc

    NASA Astrophysics Data System (ADS)

    Schwertel, S.; Maierbeck, P.; Krücken, R.; Gernhäuser, R.; Kröll, T.; Alvarez-Pol, H.; Aksouh, F.; Aumann, T.; Behr, K.; Benjamim, E. A.; Benlliure, J.; Bildstein, V.; Böhmer, M.; Boretzky, K.; Borge, M. J. G.; Brünle, A.; Bürger, A.; Caamaño, M.; Casarejos, E.; Chatillon, A.; Chulkov, L. V.; Cortina-Gil, D.; Enders, J.; Eppinger, K.; Faestermann, T.; Friese, J.; Fabbietti, L.; Gascón, M.; Geissel, H.; Gerl, J.; Gorska, M.; Hansen, P. G.; Jonson, B.; Kanungo, R.; Kiselev, O.; Kojouharov, I.; Klimkiewicz, A.; Kurtukian, T.; Kurz, N.; Larsson, K.; Le Bleis, T.; Mahata, K.; Maier, L.; Nilsson, T.; Nociforo, C.; Nyman, G.; Pascual-Izarra, C.; Perea, A.; Perez, D.; Prochazka, A.; Rodriguez-Tajes, C.; Rossi, D.; Schaffner, H.; Schrieder, G.; Simon, H.; Sitar, B.; Stanoiu, M.; Sümmerer, K.; Tengblad, O.; Weick, H.; Winkler, S.; Brown, B. A.; Otsuka, T.; Tostevin, J. A.; Rae, W. D. M.

    2012-12-01

    Results are presented from a one-neutron knockout experiment at relativistic energies of ≈ 420 A MeV on 51-55Sc using the GSI Fragment Separator as a two-stage magnetic spectrometer and the MINIBALL array for gamma-ray detection. Inclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the contributions corresponding to knockout from the ν p_{1/2} , ν p_{3/2} , ( L = 1 and ν f_{7/2} , ν f_{5/2} ( L = 3 neutron orbitals. The observed L = 1 and L = 3 contributions are compared with theoretical cross-sections using eikonal knockout theory and spectroscopic factors from shell model calculations using the GXPF1A interaction. The measured inclusive knockout cross-sections generally follow the trends expected theoretically and given by the spectroscopic strength predicted from the shell model calculations. However, the deduced L = 1 cross-sections are generally 30-40% higher while the L = 3 contributions are about a factor of two smaller than predicted. This points to a promotion of neutrons from the ν f_{7/2} to the ν p_{3/2} orbital indicating a weakening of the N = 28 shell gap in these nuclei. While this is not predicted for the phenomenological GXPF1A interaction such a weakening is predicted by recent calculations using realistic low-momentum interactions V_{low k} obtained by evolving a chiral N3LO nucleon-nucleon potential.

  8. Central nervous system-specific knockout of steroidogenic factor 1.

    PubMed

    Kim, Ki Woo; Zhao, Liping; Parker, Keith L

    2009-03-05

    Steroidogenic factor 1 (SF-1) is a nuclear receptor that plays important roles in the hypothalamus-pituitary-steroidogenic organ axis. Global knockout studies in mice revealed the essential in vivo roles of SF-1 in the ventromedial hypothalamic (VMH) nucleus, adrenal glands, and gonads. One limitation of global SF-1 knockout mice is their early postnatal death from adrenocortical insufficiency. To overcome limitations of the global knockout mice and to delineate the roles of SF-1 in the brain, we used Cre/loxP recombination technology to genetically ablate SF-1 specifically in the central nervous system (CNS). Mice with CNS-specific knockout of SF-1 mediated by nestin-Cre showed increased anxiety-like behavior, revealing a crucial role of SF-1 in a complex behavioral phenotype. Our studies with CNS-specific SF-1 KO mice also defined roles of SF-1 in regulating the VMH expression of target genes implicated in anxiety and energy homeostasis. Therefore, this review will focus on our recent studies defining the functional roles of SF-1 in the VMH linked to anxiety and energy homeostasis.

  9. Knockout mice in understanding the mechanism of action of lithium.

    PubMed

    Agam, Galila; Bersudsky, Yuly; Berry, Gerard T; Moechars, Diederik; Lavi-Avnon, Yael; Belmaker, R H

    2009-10-01

    Lithium inhibits IMPase (inositol monophosphatase) activity, as well as inositol transporter function. To determine whether one or more of these mechanisms might underlie lithium's behavioural effects, we studied Impa1 (encoding IMPase) and Smit1 (sodium-myo-inositol transporter 1)-knockout mice. In brains of adult homozygous Impa1-knockout mice, IMPase activity was found to be decreased; however, inositol levels were not found to be altered. Behavioural analysis indicated decreased immobility in the forced-swim test as well as a strongly increased sensitivity to pilocarpine-induced seizures. These are behaviours robustly induced by lithium. In homozygous Smit1-knockout mice, free inositol levels were decreased in the frontal cortex and hippocampus. These animals behave like lithium-treated animals in the model of pilocarpine seizures and in the Porsolt forced-swim test model of depression. In contrast with O'Brien et al. [O'Brien, Harper, Jove, Woodgett, Maretto, Piccolo and Klein (2004) J. Neurosci. 24, 6791-6798], we could not confirm that heterozygous Gsk3b (glycogen synthase kinase 3beta)-knockout mice exhibit decreased immobility in the Porsolt forced-swim test or decreased amphetamine-induced hyperactivity in a manner mimicking lithium's behavioural effects. These data support the role of inositol-related processes rather than GSK3beta in the mechanism of the therapeutic action of lithium.

  10. Cardiac Risk Assessment

    MedlinePlus

    ... helpful? Formal name: Cardiac Risk Assessment Related tests: Lipid Profile , VLDL Cholesterol , hs-CRP , Lp(a) Overview | Common ... on Coronary artery disease: Tests and diagnosis .) The lipid profile is the most important blood test for cardiac ...

  11. Cardiac tamponade (image)

    MedlinePlus

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  12. Cardiac conduction system

    MedlinePlus Videos and Cool Tools

    ... cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components ... the cardiac conduction system's electrical activity in the heart.

  13. Cardiac Resynchronization Therapy (CRT)

    MedlinePlus

    ... Venous Thromboembolism Aortic Aneurysm More Cardiac Resynchronization Therapy (CRT) Updated:Apr 24,2015 If you have heart ... may be a candidate for cardiac resynchronization therapy (CRT). What is CRT and how can it help ...

  14. Loss of Adult Cardiac Myocyte GSK-3 Leads to Mitotic Catastrophe Resulting in Fatal Dilated Cardiomyopathy

    PubMed Central

    Zhou, Jibin; Ahmad, Firdos; Parikh, Shan; Hoffman, Nichole E.; Rajan, Sudarsan; Verma, Vipin K.; Song, Jianliang; Yuan, Ancai; Shanmughapriya, Santhanam; Guo, Yuanjun; Gao, Erhe; Koch, Walter; Woodgett, James R.; Muniswamy, Madesh; Kishore, Raj; Lal, Hind; Force, Thomas

    2016-01-01

    Rationale Cardiac myocyte-specific deletion of either Glycogen Synthase Kinase (GSK)3A or GSK3B leads to cardiac protection following myocardial infarction, suggesting that deletion of both isoforms may provide synergistic protection. This is an important consideration due to the fact that all GSK-3–targeted drugs including the drugs already in clinical trial target both isoforms of GSK-3 and none are isoform specific. Objective To identify the consequences of combined deletion of cardiac myocyte GSK3A and GSK3B in heart function. Methods and Results We generated tamoxifen-inducible cardiac myocyte-specific mice lacking both GSK-3 isoforms (double knockout, DKO). We unexpectedly found that cardiac myocyte GSK-3 is essential for cardiac homeostasis and overall survival. Serial echocardiographic analysis reveals that within 2 weeks of tamoxifen treatment, DKO hearts leads to excessive dilatative remodeling and ventricular dysfunction. Further experimentation with isolated adult cardiac myocytes and fibroblasts from DKO implicated cardiac myocytes intrinsic factors responsible for observed phenotype. Mechanistically, loss of GSK-3 in adult cardiac myocytes resulted in induction of mitotic catastrophe, a previously unreported event in cardiac myocytes. DKO cardiac myocytes showed cell cycle progression resulting in increased DNA content and multi-nucleation. However, increased cell cycle activity was rivaled by marked activation of DNA damage, cell cycle checkpoint activation, and mitotic catastrophe induced apoptotic cell death. Importantly, mitotic catastrophe was also confirmed in isolated adult cardiac myocytes. Conclusion Together, our findings suggest that cardiac myocyte GSK-3 is required to maintain normal cardiac homeostasis and its loss is incompatible with life due to cell cycle dysregulation that ultimately results in a severe fatal dilated cardiomyopathy. PMID:26976650

  15. Exacerbating Pressure Overload-Induced Cardiac Hypertrophy: Novel Role of Adaptor Molecule Src Homology 2-B3.

    PubMed

    Zhu, Xuehai; Fang, Jing; Jiang, Ding-Sheng; Zhang, Peng; Zhao, Guang-Nian; Zhu, Xueyong; Yang, Ling; Wei, Xiang; Li, Hongliang

    2015-09-01

    The adaptor protein Src homology 2-B3 (SH2B3), which belongs to a subfamily of Src homology 2 proteins, is a broad inhibitor of growth factors and cytokine signaling in hematopoietic cells. However, the role of SH2B3 in nonhematopoietic systems, particularly cardiomyocytes, has not been defined. In this study, we observed noticeable increase in SH2B3 protein expression during pathological cardiac remodeling in both humans and rodents. Follow-up in vitro gain- and loss-of-function studies suggested that SH2B3 promotes the cardiomyocyte hypertrophy response. Consistent with the cell phenotype, SH2B3 knockout (SH2B3(-/-)) mice exhibited attenuated cardiac remodeling with preserved cardiac function after chronic pressure overload. Conversely, cardiac-specific SH2B3 overexpression aggravated pressure overload-triggered cardiac hypertrophy, fibrosis, and dysfunction. Mechanistically, SH2B3 accelerates and exacerbates cardiac remodeling through the activation of focal adhesion kinase, which, in turn, activates the prohypertrophic downstream phosphoinositide 3-kinase-AKT-mammalian target of rapamycin/glycogen synthase kinase 3β signaling pathway. Finally, we generated a novel SH2B3 knockout rat line and further confirmed the protective effects of SH2B3 deficiency on cardiac remodeling across species. Collectively, our data indicate that SH2B3 functions as a novel and effective modulator of cardiac remodeling and failure. © 2015 American Heart Association, Inc.

  16. Endothelial Jarid2/Jumonji is required for normal cardiac development and proper Notch1 expression.

    PubMed

    Mysliwiec, Matthew R; Bresnick, Emery H; Lee, Youngsook

    2011-05-13

    Jarid2/Jumonji critically regulates developmental processes including cardiovascular development. Jarid2 knock-out mice exhibit cardiac defects including hypertrabeculation with noncompaction of the ventricular wall. However, molecular mechanisms underlying Jarid2-mediated cardiac development remain unknown. To determine the cardiac lineage-specific roles of Jarid2, we generated myocardial, epicardial, cardiac neural crest, or endothelial conditional Jarid2 knock-out mice using Cre-loxP technology. Only mice with an endothelial deletion of Jarid2 recapitulate phenotypic defects observed in whole body mutants including hypertrabeculation and noncompaction of the ventricle. To identify potential targets of Jarid2, combinatorial approaches using microarray and candidate gene analyses were employed on Jarid2 knock-out embryonic hearts. Whole body or endothelial deletion of Jarid2 leads to increased endocardial Notch1 expression in the developing ventricle, resulting in increased Notch1-dependent signaling to the adjacent myocardium. Using quantitative chromatin immunoprecipitation analysis, Jarid2 was found to occupy a specific region on the endogenous Notch1 locus. We propose that failure to properly regulate Notch signaling in Jarid2 mutants likely leads to the defects in the developing ventricular chamber. The identification of Jarid2 as a potential regulator of Notch1 signaling has broad implications for many cellular processes including development, stem cell maintenance, and tumor formation.

  17. Nrf2-mediated cardiac maladaptive remodeling and dysfunction in a setting of autophagy insufficiency

    PubMed Central

    Qin, Qingyun; Qu, Chen; Niu, Ting; Zang, Huimei; Qi, Lei; Lyu, Linmao; Wang, Xuejun; Nagarkatti, Mitzi; Nagarkatti, Prakash; Janicki, Joseph S; Wang, Xing Li; Cui, Taixing

    2016-01-01

    Nuclear factor erythroid-2 related factor 2 (Nrf2) appears to exert either a protective or detrimental effect on the heart; however, the underlying mechanism remains poorly understood. Herein, we uncovered a novel mechanism for turning off the Nrf2-mediated cardioprotection while switching on Nrf2-mediated cardiac dysfunction. In a murine model of pressure overload-induced cardiac remodeling and dysfunction via transverse aortic arch constriction (TAC), knockout of Nrf2 enhanced myocardial necrosis and death rate during an initial stage of cardiac adaptation when myocardial autophagy function is intact. However, knockout of Nrf2 turned out to be cardioprotective throughout the later stage of cardiac maladaptive remodeling when myocardial autophagy function became insufficient. TAC-induced activation of Nrf2 was dramatically enhanced in the heart with impaired autophagy which is induced by cardiomyocyte-specific knockout of autophagy related gene (Atg)5. Notably, Nrf2 activation coincided with upregulation of angiotensinogen (Agt) only in the autophagy impaired heart after TAC. Agt5 and Nrf2 gene loss of function approaches in combination with Jak2 and Fyn kinase inhibitors revealed that suppression of autophagy inactivated Jak2 and Fyn as well as nuclear translocation of Fyn while enhancing nuclear translocation of Nrf2 and Nrf2-driven Agt expression in cardiomyocytes. Taken together; these results indicate that the pathophysiological consequences of Nrf2 activation are closely linked with the functional integrity of myocardial autophagy during cardiac remodeling. When autophagy is intact, Nrf2 is required for cardiac adaptive responses; however, autophagy impairment most likely turns off Fyn-operated Nrf2 nuclear export thus activating Nrf2-driven Agt transcription, which exacerbates cardiac maladaptation leading to dysfunction. PMID:26573705

  18. Conditional knockout of activin like kinase-1 (ALK-1) leads to heart failure without maladaptive remodeling.

    PubMed

    Morine, Kevin J; Qiao, Xiaoying; Paruchuri, Vikram; Aronovitz, Mark J; Mackey, Emily E; Buiten, Lyanne; Levine, Jonathan; Ughreja, Keshan; Nepali, Prerna; Blanton, Robert M; Karas, Richard H; Oh, S Paul; Kapur, Navin K

    2017-05-01

    Activin like kinase-1 (AlK-1) mediates signaling via the transforming growth factor beta (TGFβ) family of ligands. AlK-1 activity promotes endothelial proliferation and migration. Reduced AlK-1 activity is associated with arteriovenous malformations. No studies have examined the effect of global AlK-1 deletion on indices of cardiac remodeling. We hypothesized that reduced levels of AlK-1 promote maladaptive cardiac remodeling. To test this hypothesis, we employed AlK-1 conditional knockout mice (cKO) harboring the ROSA26-CreER knock-in allele, whereby a single dose of intraperitoneal tamoxifen triggered ubiquitous Cre recombinase-mediated excision of floxed AlK-1 alleles. Tamoxifen treated wild-type (WT-TAM; n = 5) and vehicle treated AlK-1-cKO mice (cKO-CON; n = 5) served as controls for tamoxifen treated AlK-1-cKO mice (cKO-TAM; n = 15). AlK-1 cKO-TAM mice demonstrated reduced 14-day survival compared to cKO-CON controls (13 vs 100%, respectively, p < 0.01). Seven days after treatment, cKO-TAM mice exhibited reduced left ventricular (LV) fractional shortening, progressive LV dilation, and gastrointestinal bleeding. After 14 days total body mass was reduced, but LV and lung mass increased in cKO-TAM not cKO-CON mice. Peak LV systolic pressure, contractility, and arterial elastance were reduced, but LV end-diastolic pressure and stroke volume were increased in cKO-TAM, not cKO-CON mice. LV AlK-1 mRNA levels were reduced in cKO-TAM, not cKO-CON mice. LV levels of other TGFβ-family ligands and receptors (AlK5, TBRII, BMPRII, Endoglin, BMP7, BMP9, and TGFβ1) were unchanged between groups. Cardiomyocyte area and LV levels of BNP were increased in cKO-TAM mice, but LV levels of β-MHC and SERCA were unchanged. No increase in markers of cardiac fibrosis, Type I collagen, CTGF, or PAI-1, were observed between groups. No differences were observed for any variable studied between cKO-CON and WT-TAM mice. Global deletion of AlK-1 is associated with the

  19. Hepatic changes in metabolic gene expression in old ghrelin and ghrelin receptor knockout mice

    USDA-ARS?s Scientific Manuscript database

    Ghrelin knockout (GKO) and ghrelin receptor (growth hormone secretagogue receptor) knockout (GHSRKO) mice exhibit enhanced insulin sensitivity, but the mechanism is unclear. Insulin sensitivity declines with age and is inversely associated with accumulation of lipid in liver, a key glucoregulatory ...

  20. Cardiac ion channels

    PubMed Central

    Priest, Birgit T; McDermott, Jeff S

    2015-01-01

    Ion channels are critical for all aspects of cardiac function, including rhythmicity and contractility. Consequently, ion channels are key targets for therapeutics aimed at cardiac pathophysiologies such as atrial fibrillation or angina. At the same time, off-target interactions of drugs with cardiac ion channels can be the cause of unwanted side effects. This manuscript aims to review the physiology and pharmacology of key cardiac ion channels. The intent is to highlight recent developments for therapeutic development, as well as elucidate potential mechanisms for drug-induced cardiac side effects, rather than present an in-depth review of each channel subtype. PMID:26556552

  1. Mineralocorticoid Receptor Deficiency in T Cells Attenuates Pressure Overload-Induced Cardiac Hypertrophy and Dysfunction Through Modulating T-Cell Activation.

    PubMed

    Li, Chao; Sun, Xue-Nan; Zeng, Meng-Ru; Zheng, Xiao-Jun; Zhang, Yu-Yao; Wan, Qiangyou; Zhang, Wu-Chang; Shi, Chaoji; Du, Lin-Juan; Ai, Tang-Jun; Liu, Yuan; Liu, Yan; Du, Li-Li; Yi, Yi; Yu, Ying; Duan, Sheng-Zhong

    2017-07-01

    Although antagonists of mineralocorticoid receptor (MR) have been widely used to treat heart failure, the underlying mechanisms are incompletely understood. Recent reports show that T cells play important roles in pathologic cardiac hypertrophy and heart failure. However, it is unclear whether and how MR functions in T cells under these pathologic conditions. We found that MR antagonist suppressed abdominal aortic constriction-induced cardiac hypertrophy and decreased the accumulation and activation of CD4(+) and CD8(+) T cells in mouse heart. T-cell MR knockout mice manifested suppressed cardiac hypertrophy, fibrosis, and dysfunction compared with littermate control mice after abdominal aortic constriction. T-cell MR knockout mice had less cardiac inflammatory response, which was illustrated by decreased accumulation of myeloid cells and reduced expression of inflammatory cytokines. Less amounts and activation of T cells were observed in the heart of T-cell MR knockout mice after abdominal aortic constriction. In vitro studies showed that both MR antagonism and deficiency repressed activation of T cells, whereas MR overexpression elevated activation of T cells. These results demonstrated that MR blockade in T cells protected against abdominal aortic constriction-induced cardiac hypertrophy and dysfunction. Mechanistically, MR directly regulated T-cell activation and modulated cardiac inflammation. Targeting MR in T cells specifically may be a feasible strategy for more effective treatment of pathologic cardiac hypertrophy and heart failure. © 2017 American Heart Association, Inc.

  2. Controlled Cardiac Computed Tomography

    PubMed Central

    Wang, Chenglin; Liu, Ying; Wang, Ge

    2006-01-01

    Cardiac computed tomography (CT) has been a hot topic for years because of the clinical importance of cardiac diseases and the rapid evolution of CT systems. In this paper, we propose a novel strategy for controlled cardiac CT that may effectively reduce image artifacts due to cardiac and respiratory motions. Our approach is radically different from existing ones and is based on controlling the X-ray source rotation velocity and powering status in reference to the cardiac motion. We theoretically show that by such a control-based intervention the data acquisition process can be optimized for cardiac CT in the cases of periodic and quasiperiodic cardiac motions. Specifically, we formulate the corresponding coordination/control schemes for either exact or approximate matches between the ideal and actual source positions, and report representative simulation results that support our analytic findings. PMID:23165017

  3. Cardiac gated ventilation

    SciTech Connect

    Hanson, C.W. III; Hoffman, E.A.

    1995-12-31

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart.

  4. Cardiac Alpha1-Adrenergic Receptors: Novel Aspects of Expression, Signaling Mechanisms, Physiologic Function, and Clinical Importance

    PubMed Central

    O’Connell, Timothy D.; Jensen, Brian C.; Baker, Anthony J.

    2014-01-01

    Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate “inside-out” signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure. PMID:24368739

  5. Growth Arrest-Specific 6 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy.

    PubMed

    Zhao, Yi-Fan; Xu, Da-Chun; Zhu, Guo-Fu; Zhu, Meng-Yun; Tang, Kai; Li, Wei-Ming; Xu, Ya-Wei

    2016-01-01

    Growth arrest-specific 6 (GAS6) is a member of the vitamin K-dependent protein family that is involved in the regulation of the cardiovascular system, including vascular remodeling, homeostasis, and atherosclerosis. However, there is still no study that systemically elucidates the role of GAS6 in cardiac hypertrophy. Here, we found that GAS6 was upregulated in human dilated cardiomyopathic hearts, hypertrophic murine hearts, and angiotensin II-treated cardiomyocytes. Next, we examined the influence of GAS6 expression in response to a cardiac stress by inducing chronic pressure overload with aortic banding in wild-type and GAS6-knockout mice or cardiac-specific GAS6 overexpressing mice. Under basal conditions, the GAS6-knockout mice had normal left ventricular structure and function but after aortic banding, the mice demonstrated less hypertrophy, fibrosis, and contractile dysfunction when compared with wild-type mice. Conversely, cardiac-specific overexpression of GAS6 exacerbated aortic banding-induced cardiac hypertrophy, fibrosis, and dysfunction. Furthermore, we demonstrated that GAS6 activated the mitogen-activated protein kinase kinase 1/2-extracellular signal-regulated kinase 1/2 pathway during pressure overload-induced cardiac hypertrophy, and the pharmacological mitogen-activated protein kinase kinase 1/2 inhibitor U0126 almost completely reversed GAS6 overexpression-induced cardiac hypertrophy and fibrosis, resulting in improved cardiac function. Collectively, our data support the notion that GAS6 impairs ventricular adaptation to chronic pressure overload by activating mitogen-activated protein kinase kinase 1/2-extracellular signal-regulated kinase 1/2 signaling. Our findings suggest that strategies to reduce GAS6 activity in cardiac tissue may be a novel approach to attenuate the development of congestive heart failure. © 2015 American Heart Association, Inc.

  6. Loss of TRADD attenuates pressure overload-induced cardiac hypertrophy through regulating TAK1/P38 MAPK signalling in mice.

    PubMed

    Wu, Lianpin; Cao, Zhiyong; Ji, Ling; Mei, Liqin; Jin, Qike; Zeng, Jingjing; Lin, Jiafeng; Chu, Maoping; Li, Lei; Yang, Xiangjun

    2017-02-05

    We investigated the role of tumour necrosis factor receptor (TNFR)-associated death domain (TRADD) on pressure overload-induced cardiac hypertrophy and the underlying molecular mechanisms by using a TRADD deficiency mice model. 6-8 weeks wild-type and TRADD knockout mice were performed to transverse aorta constriction (TAC) or sham operation (6-8 mice for each group). 14 days after TAC, cardiac function was measured by echocardiography, as well as by pathological and molecular analyses of heart samples. The expressions of cardiac hypertrophic and fibrotic markers were detected by qPCR. Phosphorylated and total TAK1, Akt, and p38 MAPK levels were examined by Western blotting. The ratios of lung or heart/body weight, wall thickness/chamber diameter of left ventricular and cross area of cardiomyocyte were significantly reduced in TRADD knockout (KO) mice than those of wild-type mice after TAC. Moreover, cardiac hypertrophic and fibrotic markers were downregulated in TRADD knockout mice than those of wild-type mice following TAC. Protein expression analysis showed phosphorylated TAK1, p38 MAPK and AKT were upregulated after TAC in both wild-type and TRADD KO mice, phosphorylation of TAK1 and p38 MAPK was reduced more remarkably after TRADD deficiency, while phosphorylated AKT expression was similar between TRADD KO and wild-type mice following TAC. Our data suggest that TRADD KO blunts pressure overload-induced cardiac hypertrophy through mediating TAK1/p38 MAPK but not AKT phosphorylation in mice.

  7. A STAT-1 knockout mouse model for Machupo virus pathogenesis

    PubMed Central

    2011-01-01

    Background Machupo virus (MACV), a member of the Arenaviridae, causes Bolivian hemorrhagic fever, with ~20% lethality in humans. The pathogenesis of MACV infection is poorly understood, and there are no clinically proven treatments for disease. This is due, in part, to a paucity of small animal models for MACV infection in which to discover and explore candidate therapeutics. Methods Mice lacking signal transducer and activator of transcription 1 (STAT-1) were infected with MACV. Lethality, viral replication, metabolic changes, hematology, histopathology, and systemic cytokine expression were analyzed throughout the course of infection. Results We report here that STAT-1 knockout mice succumbed to MACV infection within 7-8 days, and presented some relevant clinical and histopathological manifestations of disease. Furthermore, the model was used to validate the efficacy of ribavirin in protection against infection. Conclusions The STAT-1 knockout mouse model can be a useful small animal model for drug testing and preliminary immunological analysis of lethal MACV infection. PMID:21672221

  8. Human Genetic Disorders and Knockout Mice Deficient in Glycosaminoglycan

    PubMed Central

    2014-01-01

    Glycosaminoglycans (GAGs) are constructed through the stepwise addition of respective monosaccharides by various glycosyltransferases and maturated by epimerases and sulfotransferases. The structural diversity of GAG polysaccharides, including their sulfation patterns and sequential arrangements, is essential for a wide range of biological activities such as cell signaling, cell proliferation, tissue morphogenesis, and interactions with various growth factors. Studies using knockout mice of enzymes responsible for the biosynthesis of the GAG side chains of proteoglycans have revealed their physiological functions. Furthermore, mutations in the human genes encoding glycosyltransferases, sulfotransferases, and related enzymes responsible for the biosynthesis of GAGs cause a number of genetic disorders including chondrodysplasia, spondyloepiphyseal dysplasia, and Ehlers-Danlos syndromes. This review focused on the increasing number of glycobiological studies on knockout mice and genetic diseases caused by disturbances in the biosynthetic enzymes for GAGs. PMID:25126564

  9. Creation and Preliminary Characterization of a Leptin Knockout Rat

    PubMed Central

    Vaira, Sergio; Yang, Chang; McCoy, Aaron; Keys, Kelly; Xue, Shurong; Weinstein, Edward J.; Novack, Deborah V.

    2012-01-01

    Leptin, a cytokine-like hormone secreted mainly by adipocytes, regulates various pathways centered on food intake and energy expenditure, including insulin sensitivity, fertility, immune system, and bone metabolism. Here, using zinc finger nuclease technology, we created the first leptin knockout rat. Homozygous leptin null rats are obese with significantly higher serum cholesterol, triglyceride, and insulin levels than wild-type controls. Neither gender produced offspring despite of repeated attempts. The leptin knockout rats also have depressed immune system. In addition, examination by microcomputed tomography of the femurs of the leptin null rats shows a significant increase in both trabecular bone mineral density and bone volume of the femur compared with wild-type littermates. Our model should be useful for many different fields of studies, such as obesity, diabetes, and bone metabolism-related illnesses. PMID:22948215

  10. Knockout driven reactions in complex molecules and their clusters

    NASA Astrophysics Data System (ADS)

    Gatchell, Michael; Zettergren, Henning

    2016-08-01

    Energetic ions lose some of their kinetic energy when interacting with electrons or nuclei in matter. Here, we discuss combined experimental and theoretical studies on such impulse driven reactions in polycyclic aromatic hydrocarbons (PAHs), fullerenes, and pure or mixed clusters of these molecules. These studies show that the nature of excitation is important for how complex molecular systems respond to ion/atom impact. Rutherford-like nuclear scattering processes may lead to prompt atom knockout and formation of highly reactive fragments, while heating of the molecular electron clouds in general lead to formation of more stable and less reactive fragments. In this topical review, we focus on recent studies of knockout driven reactions, and present new calculations of the angular dependent threshold (displacement) energies for such processes in PAHs. The so-formed fragments may efficiently form covalent bonds with neighboring molecules in clusters. These unique molecular growth processes may be important in astrophysical environments such as low velocity shock waves.

  11. Rapid curation of gene disruption collections using Knockout Sudoku.

    PubMed

    Anzai, Isao A; Shaket, Lev; Adesina, Oluwakemi; Baym, Michael; Barstow, Buz

    2017-10-01

    Knockout Sudoku is a method for the construction of whole-genome knockout collections for a wide range of microorganisms with as little as 3 weeks of dedicated labor and at a cost of ∼$10,000 for a collection for a single organism. The method uses manual 4D combinatorial pooling, next-generation sequencing, and a Bayesian inference algorithm to rapidly process and then accurately annotate the extremely large progenitor transposon insertion mutant collections needed to achieve saturating coverage of complex microbial genomes. This method is ∼100× faster and 30× lower in cost than the next comparable method (In-seq) for annotating transposon mutant collections by combinatorial pooling and next-generation sequencing. This method facilitates the rapid, algorithmically guided condensation and curation of the progenitor collection into a high-quality, nonredundant collection that is suitable for rapid genetic screening and gene discovery.

  12. Behavioral and neuroanatomical characterization of the Fmr1 knockout mouse.

    PubMed

    Mineur, Yann S; Sluyter, Frans; de Wit, Sanne; Oostra, Ben A; Crusio, Wim E

    2002-01-01

    Previous studies showed the Fmr1 knockout (KO) mouse to be an excellent animal model for human fragile-X syndrome. The aim of this study was to further characterize the phenotype of these animals. Neuroanatomically, KO male mice were compared to wild-types (littermates) with respect to their sizes of hippocampal intra- and infrapyramidal mossy fiber (IIPMF) terminal fields. Behaviorally, they were tested in four different paradigms, each measuring different aspects of cognitive and emotional behavior: elevated plus maze (anxiety), neutral cage (aggression), open field (exploration), and radial maze (spatial memory). The results showed a diminished ability for radial maze learning associated with smaller sizes of IIPMF terminal fields. In addition, Fmr1 knockout animals exhibited increased locomotor activity, while no differences were found for aggression and anxiety. These data suggest the involvement of FMRP protein in the development of spatial learning and the sprouting of IIPMF terminal fields.

  13. Targeted gene knockout in chickens mediated by TALENs.

    PubMed

    Park, Tae Sub; Lee, Hong Jo; Kim, Ki Hyun; Kim, Jin-Soo; Han, Jae Yong

    2014-09-02

    Genetically modified animals are used for industrial applications as well as scientific research, and studies on these animals contribute to a better understanding of biological mechanisms. Gene targeting techniques have been developed to edit specific gene loci in the genome, but the conventional strategy of homologous recombination with a gene-targeted vector has low efficiency and many technical complications. Here, we generated specific gene knockout chickens through the use of transcription activator-like effector nuclease (TALEN)-mediated gene targeting. In this study, we accomplished targeted knockout of the ovalbumin (OV) gene in the chicken primordial germ cells, and OV gene mutant offspring were generated through test-cross analysis. TALENs successfully induced nucleotide deletion mutations of ORF shifts, resulting in loss of chicken OV gene function. Our results demonstrate that the TALEN technique used in the chicken primordial germ cell line is a powerful strategy to create specific genome-edited chickens safely for practical applications.

  14. Deconstructing mammalian reproduction: using knockouts to define fertility pathways.

    PubMed

    Roy, Angshumoy; Matzuk, Martin M

    2006-02-01

    Reproduction is the sine qua non for the propagation of species and continuation of life. It is a complex biological process that is regulated by multiple factors during the reproductive life of an organism. Over the past decade, the molecular mechanisms regulating reproduction in mammals have been rapidly unraveled by the study of a vast number of mouse gene knockouts with impaired fertility. The use of reverse genetics to generate null mutants in mice through targeted disruption of specific genes has enabled researchers to identify essential regulators of spermatogenesis and oogenesis in vivo and model human disorders affecting reproduction. This review focuses on the merits, utility, and the variations of the knockout technology in studies of reproduction in mammals.

  15. Using engineered endonucleases to create knockout and knockin zebrafish models

    PubMed Central

    Bedell, Victoria M.; Ekker, Stephen C.

    2015-01-01

    Summary Over the last few years, the technology to create targeted knockout and knockin zebrafish animals has exploded. We have gained the ability to create targeted knockouts through the use of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR associated system (CRISPR/Cas). Furthermore, using the high-efficiency TALEN system, we were able to create knockin zebrafish using a single-stranded DNA (ssDNA) protocol described here. Through the use of these technologies, the zebrafish has become a valuable vertebrate model and an excellent bridge between the invertebrate and mammalian model systems for the study of human disease. PMID:25408414

  16. Targeted gene knockout in chickens mediated by TALENs

    PubMed Central

    Park, Tae Sub; Lee, Hong Jo; Kim, Ki Hyun; Kim, Jin-Soo; Han, Jae Yong

    2014-01-01

    Genetically modified animals are used for industrial applications as well as scientific research, and studies on these animals contribute to a better understanding of biological mechanisms. Gene targeting techniques have been developed to edit specific gene loci in the genome, but the conventional strategy of homologous recombination with a gene-targeted vector has low efficiency and many technical complications. Here, we generated specific gene knockout chickens through the use of transcription activator-like effector nuclease (TALEN)-mediated gene targeting. In this study, we accomplished targeted knockout of the ovalbumin (OV) gene in the chicken primordial germ cells, and OV gene mutant offspring were generated through test-cross analysis. TALENs successfully induced nucleotide deletion mutations of ORF shifts, resulting in loss of chicken OV gene function. Our results demonstrate that the TALEN technique used in the chicken primordial germ cell line is a powerful strategy to create specific genome-edited chickens safely for practical applications. PMID:25139993

  17. Generation of Gene Knockout Mice by ES Cell Microinjection

    PubMed Central

    Longenecker, Glenn; Kulkarni, Ashok B

    2009-01-01

    This unit lists and describes protocols used in the production of chimeric mice leading to the generation of gene knockout mice. These protocols include the collection of blastocyst embryos, ES cell injection, and uterine transfer of injected blastocysts. Support protocols in the superovulation of blastocyst donor mice, generation of pseudopregnant recipients, fabrication of glass pipettes, and generation of germline mice are also included. Practical tips and solutions are mentioned to help troubleshoot problems that may occur. PMID:19731226

  18. Murine mentors: transgenic and knockout models of surgical disease.

    PubMed Central

    Arbeit, J M; Hirose, R

    1999-01-01

    OBJECTIVE: Transgenic and knockout technologies have emerged from the "molecular biology revolution" as unprecedented techniques for manipulating gene function in intact mice. The goals of this review are to outline the techniques of creating transgenic and knockout mice, and to demonstrate their use in elucidation of the molecular mechanisms underlying common surgical diseases. SUMMARY BACKGROUND DATA: Gain of gene function is created by transgenic technology, whereas gene function is ablated using gene knockouts. Each technique has distinctive applications and drawbacks. A unique feature of genetically manipulated mice is that combinatorial genetic experiments can be executed that precisely define the functional contribution of a gene to disease progression. Transgenic and knockout mouse models of wound healing, cardiovascular disease, transplant immunology, gut motility and inflammatory bowel disease, and oncology are beginning to illuminate the precise molecular regulation of these diseases. Transgenic technology has also been extended to larger mammals such as pigs, with the goal of using genetic manipulation of the xenogenic immune response to increase the availability of transplant organs. Continual refinements in gene manipulation technology in mice offer the opportunity to turn genes on or off at precise time intervals and in particular tissues, according to the needs of the investigator. Ultimately, investigation of disease development and progression in genetically manipulated mammals may delineate new molecular targets for drug discovery and provide novel platforms for drug efficacy screens. CONCLUSIONS: Emulation of human disease and therapy using genetically manipulated mammals fulfills a promise of molecular medicine: fusion of molecular biochemistry with "classical" biology and physiology. Surgeons have unique skills spanning both worlds that can facilitate their success in this expanding arena. PMID:9923797

  19. In Silico Knockout Studies of Xenophagic Capturing of Salmonella

    PubMed Central

    Scheidel, Jennifer; Amstein, Leonie; Ackermann, Jörg; Dikic, Ivan; Koch, Ina

    2016-01-01

    The degradation of cytosol-invading pathogens by autophagy, a process known as xenophagy, is an important mechanism of the innate immune system. Inside the host, Salmonella Typhimurium invades epithelial cells and resides within a specialized intracellular compartment, the Salmonella-containing vacuole. A fraction of these bacteria does not persist inside the vacuole and enters the host cytosol. Salmonella Typhimurium that invades the host cytosol becomes a target of the autophagy machinery for degradation. The xenophagy pathway has recently been discovered, and the exact molecular processes are not entirely characterized. Complete kinetic data for each molecular process is not available, so far. We developed a mathematical model of the xenophagy pathway to investigate this key defense mechanism. In this paper, we present a Petri net model of Salmonella xenophagy in epithelial cells. The model is based on functional information derived from literature data. It comprises the molecular mechanism of galectin-8-dependent and ubiquitin-dependent autophagy, including regulatory processes, like nutrient-dependent regulation of autophagy and TBK1-dependent activation of the autophagy receptor, OPTN. To model the activation of TBK1, we proposed a new mechanism of TBK1 activation, suggesting a spatial and temporal regulation of this process. Using standard Petri net analysis techniques, we found basic functional modules, which describe different pathways of the autophagic capture of Salmonella and reflect the basic dynamics of the system. To verify the model, we performed in silico knockout experiments. We introduced a new concept of knockout analysis to systematically compute and visualize the results, using an in silico knockout matrix. The results of the in silico knockout analyses were consistent with published experimental results and provide a basis for future investigations of the Salmonella xenophagy pathway. PMID:27906974

  20. A STAT-1 Knockout Mouse Model for Machupo Virus Pathogenesis

    DTIC Science & Technology

    2011-06-14

    animals. The lesions were most prominent in and around pancreatic lobes but the inflammation did not appear to involve the pancreas in day 5 animals...however all animals from day 7 termination had mild to marked pancreatitis . We also investigated the suitability of the MACV STAT-1 knockout model...lymph nodes, spleen and thymus, and pancreatitis (Figure 4). These findings have also been reported to varying degrees in other MACV models. Lymphoid

  1. Genetic Deletion of NOS3 Increases Lethal Cardiac Dysfunction Following Mouse Cardiac Arrest

    PubMed Central

    Beiser, David G.; Orbelyan, Gerasim A.; Inouye, Brendan T.; Costakis, James G.; Hamann, Kimm J.; McNally, Elizabeth M.; Hoek, Terry L. Vanden

    2010-01-01

    Study Aims Cardiac arrest mortality is significantly affected by failure to obtain return of spontaneous circulation (ROSC) despite cardiopulmonary resuscitation (CPR). Severe myocardial dysfunction and cardiovascular collapse further affects mortality within hours of initial ROSC. Recent work suggests that enhancement of nitric oxide (NO) signaling within minutes of CPR can improve myocardial function and survival. We studied the role of NO signaling on cardiovascular outcomes following cardiac arrest and resuscitation using endothelial NO synthase knockout (NOS3-/-) mice. Methods Adult female wild-type (WT) and NOS3-/- mice were anesthetized, intubated, and instrumented with left-ventricular pressure-volume catheters. Cardiac arrest was induced with intravenous potassium chloride. CPR was performed after 8 min of untreated arrest. ROSC rate, cardiac function, whole-blood nitrosylhemoglobin (HbNO) concentrations, heart NOS3 content and phosphorylation (p-NOS3), cyclic guanosine monophosphate (cGMP), and phospho-troponin I (p-TnI) were measured. Results Despite equal quality CPR, NOS3-/- mice displayed lower rates of ROSC compared to WT (47.6% [10/21] vs. 82.4% [14/17], p<0.005). Among ROSC animals, NOS3-/- versus WT mice exhibited increased left-ventricular dysfunction and 120 min mortality. Prior to ROSC, myocardial effectors of NO signaling including cGMP and p-TnI were decreased in NOS3-/- vs. WT mice (p<0.05). Following ROSC in WT mice, significant NOS3-dependent increases in circulating HbNO were seen by 120 min. Significant increases in cardiac p-NOS3 occurred between end-arrest and 15 min post-ROSC, while total NOS3 content was increased by 120 min post-ROSC (p<0.05). Conclusions Genetic deletion of NOS3 decreases ROSC rate and worsens post-ROSC left-ventricular function. Poor cardiovascular outcomes are associated with differences in NOS3-dependent myocardial cGMP signaling and circulating NO metabolites. PMID:20951489

  2. Mammalian enabled (Mena) is a critical regulator of cardiac function.

    PubMed

    Aguilar, Frédérick; Belmonte, Stephen L; Ram, Rashmi; Noujaim, Sami F; Dunaevsky, Olga; Protack, Tricia L; Jalife, Jose; Todd Massey, H; Gertler, Frank B; Blaxall, Burns C

    2011-05-01

    Mammalian enabled (Mena) of the Drosophila enabled/vasodilator-stimulated phosphoprotein gene family is a cytoskeletal protein implicated in actin regulation and cell motility. Cardiac Mena expression is enriched in intercalated discs (ICD), the critical intercellular communication nexus between adjacent muscle cells. We previously identified Mena gene expression to be a key predictor of human and murine heart failure (HF). To determine the in vivo function of Mena in the heart, we assessed Mena protein expression in multiple HF models and characterized the effects of genetic Mena deletion on cardiac structure and function. Immunoblot analysis revealed significant upregulation of Mena protein expression in left ventricle tissue from patients with end-stage HF, calsequestrin-overexpressing mice, and isoproterenol-infused mice. Characterization of the baseline cardiac function of adult Mena knockout mice (Mena(-/-)) via echocardiography demonstrated persistent cardiac dysfunction, including a significant reduction in percent fractional shortening compared with wild-type littermates. Electrocardiogram PR and QRS intervals were significantly prolonged in Mena(-/-) mice, manifested by slowed conduction on optical mapping studies. Ultrastructural analysis of Mena(-/-) hearts revealed disrupted organization and widening of ICD structures, mislocalization of the gap junction protein connexin 43 (Cx43) to the lateral borders of cardiomyoycytes, and increased Cx43 expression. Furthermore, the expression of vinculin (an adherens junction protein) was significantly reduced in Mena(-/-) mice. We report for the first time that genetic ablation of Mena results in cardiac dysfunction, highlighted by diminished contractile performance, disrupted ICD structure, and slowed electrical conduction.

  3. Estrogens Mediate Cardiac Hypertrophy in a Stimulus-Dependent Manner

    PubMed Central

    Haines, Christopher D.; Harvey, Pamela A.

    2012-01-01

    The incidence of cardiac hypertrophy, an established risk factor for heart failure, is generally lower in women compared with men, but this advantage is lost after menopause. Although it is widely believed that estrogens are cardioprotective, there are contradictory reports, including increased cardiac events in postmenopausal women receiving estrogens and enhanced cardiac protection from ischemic injury in female mice without estrogens. We exposed aromatase knockout (ArKO) mice, which produce no estrogens, to both pathologic and physiologic stimuli. This model allows an investigation into the effects of a complete, chronic lack of estrogens in male and female hearts. At baseline, female ArKO mice had normal-sized hearts but decreased cardiac function and paradoxically increased phosphorylation of many progrowth kinases. When challenged with the pathological stimulus, isoproterenol, ArKO females developed 2-fold more hypertrophy than wild-type females. In contrast, exercise-induced physiological hypertrophy was unaffected by the absence of estrogens in either sex, although running performance was blunted in ArKO females. Thus, loss of estrogen signaling in females, but not males, impairs cardiac function and sensitizes the heart to pathological insults through up-regulation of multiple hypertrophic pathways. These findings provide insight into the apparent loss of cardioprotection after menopause and suggest that caution is warranted in the long-term use of aromatase inhibitors in the setting of breast cancer prevention. PMID:22759381

  4. Adipocyte-specific loss of PPARγ attenuates cardiac hypertrophy

    PubMed Central

    Fang, Xi; Stroud, Matthew J.; Ouyang, Kunfu; Fang, Li; Zhang, Jianlin; Dalton, Nancy D.; Gu, Yusu; Wu, Tongbin; Peterson, Kirk L.; Huang, Hsien-Da; Wang, Nanping

    2016-01-01

    Adipose tissue is a key endocrine organ that governs systemic homeostasis. PPARγ is a master regulator of adipose tissue signaling that plays an essential role in insulin sensitivity, making it an important therapeutic target. The selective PPARγ agonist rosiglitazone (RSG) has been used to treat diabetes. However, adverse cardiovascular effects have seriously hindered its clinical application. Experimental models have revealed that PPARγ activation increases cardiac hypertrophy. RSG stimulates cardiac hypertrophy and oxidative stress in cardiomyocyte-specific PPARγ knockout mice, implying that RSG might stimulate cardiac hypertrophy independently of cardiomyocyte PPARγ. However, candidate cell types responsible for RSG-induced cardiomyocyte hypertrophy remain unexplored. Utilizing cocultures of adipocytes and cardiomyocytes, we found that stimulation of PPARγ signaling in adipocytes increased miR-200a expression and secretion. Delivery of miR-200a in adipocyte-derived exosomes to cardiomyocytes resulted in decreased TSC1 and subsequent mTOR activation, leading to cardiomyocyte hypertrophy. Treatment with an antagomir to miR-200a blunted this hypertrophic response in cardiomyocytes. In vivo, specific ablation of PPARγ in adipocytes was sufficient to blunt hypertrophy induced by RSG treatment. By delineating mechanisms by which RSG elicits cardiac hypertrophy, we have identified pathways that mediate the crosstalk between adipocytes and cardiomyocytes to regulate cardiac remodeling. PMID:27734035

  5. The evolution of thymic lymphomas in p53 knockout mice

    PubMed Central

    Dudgeon, Crissy; Chan, Chang; Kang, Wenfeng; Sun, Yvonne; Emerson, Ryan; Robins, Harlan

    2014-01-01

    Germline deletion of the p53 gene in mice gives rise to spontaneous thymic (T-cell) lymphomas. In this study, the p53 knockout mouse was employed as a model to study the mutational evolution of tumorigenesis. The clonality of the T-cell repertoire from p53 knockout and wild-type thymic cells was analyzed at various ages employing TCRβ sequencing. These data demonstrate that p53 knockout thymic lymphomas arose in an oligoclonal fashion, with tumors evolving dominant clones over time. Exon sequencing of tumor DNA revealed that all of the independently derived oligoclonal mouse tumors had a deletion in the Pten gene prior to the formation of the TCRβ rearrangement, produced early in development. This was followed in each independent clone of the thymic lymphoma by the amplification or overexpression of cyclin Ds and Cdk6. Alterations in the expression of Ikaros were common and blocked further development of CD-4/CD-8 T cells. While the frequency of point mutations in the genome of these lymphomas was one per megabase, there were a tremendous number of copy number variations producing the tumors’ driver mutations. The initial inherited loss of p53 functions appeared to delineate an order of genetic alterations selected for during the evolution of these thymic lymphomas. PMID:25452272

  6. Knock-Out Models Reveal New Aquaporin Functions

    PubMed Central

    Verkman, Alan S.

    2013-01-01

    Knockout mice have been informative in the discovery of unexpected biological functions of aquaporins. Knockout mice have confirmed the predicted roles of aquaporins in transepithelial fluid transport, as in the urinary concentrating mechanism and glandular fluid secretion. A less obvious, though predictable role of aquaporins is in tissue swelling under stress, as in the brain in stroke, tumor and infection. Phenotype analysis of aquaporin knockout mice has revealed several unexpected cellular roles of aquaporins whose mechanisms are being elucidated. Aquaporins facilitate cell migration, as seen in aquaporin-dependent tumor angiogenesis and tumor metastasis, by a mechanism that may involve facilitated water transport in lamellipodia of migrating cells. The ‘aquaglyceroporins’, aquaporins that transport both glycerol and water, regulate glycerol content in epidermis, fat and other tissues, and lead to a multiplicity of interesting consequences of gene disruption including dry skin, resistance to skin carcinogenesis, impaired cell proliferation and altered fat metabolism. An even more surprising role of a mammalian aquaporin is in neural signal transduction in the central nervous system. The many roles of aquaporins might be exploited for clinical benefit by modulation of aquaporin expression/function – as diuretics, and in the treatment of brain swelling, glaucoma, epilepsy, obesity and cancer. PMID:19096787

  7. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  8. Cardiac Innervation and Sudden Cardiac Death

    PubMed Central

    Fukuda, Keiichi; Kanazawa, Hideaki; Aizawa, Yoshiyasu; Ardell, Jeffrey L.; Shivkumar, Kalyanam

    2015-01-01

    Afferent and efferent cardiac neurotransmission via the cardiac nerves intricately modulates nearly all physiological functions of the heart (chronotropy, dromotropy, lusitropy and inotropy). Afferent information from the heart is transmitted to higher levels of the nervous system for processing (intrinsic cardiac nervous system, extracardiac-intrathoracic ganglia, spinal cord, brain stem and higher centers) which ultimately results in efferent cardiomotor neural impulses (via the sympathetic and parasympathetic nerves). This system forms interacting feedback loops that provide physiological stability for maintaining normal rhythm and life-sustaining circulation. This system also ensures that there is fine-tuned regulation of sympathetic-parasympathetic balance in the heart under normal and stressed states in the short (beat to beat), intermediate (minutes-hours) and long term (days-years). This important neurovisceral /autonomic nervous system also plays a major role in the pathophysiology and progression of heart disease, including heart failure and arrhythmias leading to sudden cardiac death (SCD). Transdifferentiation of neurons in heart failure, functional denervation, cardiac and extra-cardiac neural remodeling have also been identified and characterized during the progression of disease. Recent advances in understanding the cellular and molecular processes governing innervation and the functional control of the myocardium in health and disease provides a rational mechanistic basis for development of neuraxial therapies for preventing SCD and other arrhythmias. Advances in cellular, molecular, and bioengineering realms have underscored the emergence of this area as an important avenue of scientific inquiry and therapeutic intervention. PMID:26044253

  9. Cardiac innervation and sudden cardiac death.

    PubMed

    Fukuda, Keiichi; Kanazawa, Hideaki; Aizawa, Yoshiyasu; Ardell, Jeffrey L; Shivkumar, Kalyanam

    2015-06-05

    Afferent and efferent cardiac neurotransmission via the cardiac nerves intricately modulates nearly all physiological functions of the heart (chronotropy, dromotropy, lusitropy, and inotropy). Afferent information from the heart is transmitted to higher levels of the nervous system for processing (intrinsic cardiac nervous system, extracardiac-intrathoracic ganglia, spinal cord, brain stem, and higher centers), which ultimately results in efferent cardiomotor neural impulses (via the sympathetic and parasympathetic nerves). This system forms interacting feedback loops that provide physiological stability for maintaining normal rhythm and life-sustaining circulation. This system also ensures that there is fine-tuned regulation of sympathetic-parasympathetic balance in the heart under normal and stressed states in the short (beat to beat), intermediate (minutes to hours), and long term (days to years). This important neurovisceral/autonomic nervous system also plays a major role in the pathophysiology and progression of heart disease, including heart failure and arrhythmias leading to sudden cardiac death. Transdifferentiation of neurons in heart failure, functional denervation, cardiac and extracardiac neural remodeling has also been identified and characterized during the progression of disease. Recent advances in understanding the cellular and molecular processes governing innervation and the functional control of the myocardium in health and disease provide a rational mechanistic basis for the development of neuraxial therapies for preventing sudden cardiac death and other arrhythmias. Advances in cellular, molecular, and bioengineering realms have underscored the emergence of this area as an important avenue of scientific inquiry and therapeutic intervention. © 2015 American Heart Association, Inc.

  10. Morphological observation of the stria vascularis in midkine and pleiotrophin knockout mice.

    PubMed

    Sone, Michihiko; Muramatsu, Hisako; Muramatsu, Takashi; Nakashima, Tsutomu

    2011-02-01

    Midkine and Pleiotrophin are low molecular weight basic proteins with closely related structures and serve as growth/differentiation factors. They have been reported to be expressed in the cochlea during the embryonic and perinatal periods. In the present study, we focused on the roles of midkine and pleiotrophin in the stria vascularis and investigated morphological changes using mice deficient in these genes. Midkine knockout, pleiotrophin knockout, and double knockout mice were used and compared to wild-type mice. Auditory brain stem responses (ABRs) and cochlear blood flows were measured in each type of mice. Pathological changes in the stria vascularis were examined by light microscopy, including immunohistochemical staining with anti-Kir4.1 antibody, and electron microscopy. Hearing thresholds examined by ABRs were significantly higher in midkine knockout and pleiotrophin knockout mice than in wild-type mice. Double knockout mice showed higher thresholds compared to midkine knockout and pleiotrophin knockout mice. Blood flow in the lateral walls did not significantly differ and light microscopy examination showed an almost normal appearance of the stria vascularis in these knockout mice. However, the expression of Kir4.1 was weak in the knockout mice and severe vacuolar degeneration was observed by electron microscopy in the intermediate cells of the double knockout mice. The present study demonstrates that midkine and pleiotrophin play some roles for the morphological maintenance of intermediate cell in the stria vascularis. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Characterization of the phospholemman knockout mouse heart: depressed left ventricular function with increased Na-K-ATPase activity.

    PubMed

    Bell, James R; Kennington, Erika; Fuller, William; Dighe, Kushal; Donoghue, Pamela; Clark, James E; Jia, Li-Guo; Tucker, Amy L; Moorman, J Randall; Marber, Michael S; Eaton, Philip; Dunn, Michael J; Shattock, Michael J

    2008-02-01

    Phospholemman (PLM, FXYD1), abundantly expressed in the heart, is the primary cardiac sarcolemmal substrate for PKA and PKC. Evidence supports the hypothesis that PLM is part of the cardiac Na-K pump complex and provides the link between kinase activity and pump modulation. PLM has also been proposed to modulate Na/Ca exchanger activity and may be involved in cell volume regulation. This study characterized the phenotype of the PLM knockout (KO) mouse heart to further our understanding of PLM function in the heart. PLM KO mice were bred on a congenic C57/BL6 background. In vivo conductance catheter measurements exhibited a mildly depressed cardiac contractile function in PLM KO mice, which was exacerbated when hearts were isolated and Langendorff perfused. There were no significant differences in action potential morphology in paced Langendorff-perfused hearts. Depressed contractile function was associated with a mild cardiac hypertrophy in PLM KO mice. Biochemical analysis of crude ventricular homogenates showed a significant increase in Na-K-ATPase activity in PLM KO hearts compared with wild-type controls. SDS-PAGE and Western blot analysis of ventricular homogenates revealed small, nonsignificant changes in Na- K-ATPase subunit expression, with two-dimensional gel (isoelectric focusing, SDS-PAGE) analysis revealing minimal changes in ventricular protein expression, indicating that deletion of PLM was the primary reason for the observed PLM KO phenotype. These studies demonstrate that PLM plays an important role in the contractile function of the normoxic mouse heart. Data are consistent with the hypothesis that PLM modulates Na-K-ATPase activity, indirectly affecting intracellular Ca and hence contractile function.

  12. Disruption of ROCK1 gene attenuates cardiac dilation and improves contractile function in pathological cardiac hypertrophy.

    PubMed

    Shi, Jianjian; Zhang, Yi-Wei; Summers, Lelia J; Dorn, Gerald W; Wei, Lei

    2008-03-01

    The development of left ventricular cardiomyocyte hypertrophy in response to increased hemodynamic load and neurohormonal stress is initially a compensatory response. However, persistent stress eventually leads to dilated heart failure, which is a common cause of heart failure in human hypertensive and valvular heart disease. We have recently reported that Rho-associated coiled-coil containing protein kinase 1 (ROCK1) homozygous knockout mice exhibited reduced cardiac fibrosis and cardiomyocyte apoptosis, while displaying a preserved compensatory hypertrophic response to pressure overload. In this study, we have tested the effects of ROCK1 deficiency on cardiac hypertrophy, dilation, and dysfunction. We have shown that ROCK1 deletion attenuated left ventricular dilation and contractile dysfunction, but not hypertrophy, in a transgenic model of Galphaq overexpression-induced hypertrophy which represents a well-characterized and highly relevant genetic mouse model of pathological hypertrophy. Although the development of cardiomyocyte hypertrophy was not affected, ROCK1 deletion in Galphaq mice resulted in a concentric hypertrophic phenotype associated with reduced induction of hypertrophic markers indicating that ROCK1 deletion could favorably modify hypertrophy without inhibiting it. Furthermore, ROCK1 deletion also improved contractile response to beta-adrenergic stimulation in Galphaq transgenic mice. Consistent with this observation, ROCK1 deletion prevented down-regulation of type V/VI adenylyl cyclase expression, which is associated with the impaired beta-adrenergic signaling in Galphaq mice. The present study establishes for the first time a role for ROCK1 in cardiac dilation and contractile dysfunction.

  13. Fatty Acid Oxidation in Cardiac and Skeletal Muscle Mitochondria is Unaffected by Deletion of CD36

    PubMed Central

    King, Kristen L.; Stanley, William C.; Rosca, Mariana; Kerner, Janos; Hoppel, Charles L.; Febbraio, Maria

    2009-01-01

    Recent studies found that the plasma membrane fatty acid transport protein CD36 also resides in mitochondrial membranes in cardiac and skeletal muscle. Pharmacological studies suggest that CD36 may play an essential role in mitochondrial fatty acid oxidation. We isolated cardiac and skeletal muscle mitochondria from wild type and CD36 knock-out mice. There were no differences between wild type and CD36 knock-out mice in mitochondrial respiration with palmitoyl-CoA, palmitoyl-carnitine or glutamate as substrate. We investigated a potential alternative role for CD36 in mitochondria, ie. the export of fatty acids generated in the matrix. Palmitate export was not different between wild type and CD36 knock out mice. Taken together, CD36 does not appear to play an essential role in mitochondrial uptake of fatty acids or export of fatty acid anions. PMID:17904092

  14. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology.

    PubMed

    Aragon, Andrea C; Kopf, Phillip G; Campen, Matthew J; Huwe, Janice K; Walker, Mary K

    2008-02-01

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure would disrupt cardiac ECM expression and be associated with changes in cardiac morphology in adulthood. In one study, time-pregnant C57BL/6 mice were dosed with corn oil or 1.5, 3.0, or 6.0 microg TCDD/kg on gestation day (GD) 14.5 and sacrificed on GD 17.5, when changes in fetal cardiac mRNA expression were analyzed using quantitative PCR. TCDD induced mRNA expression of genes associated with ECM remodeling (matrix metalloproteinase 9 and 13, preproendothelin-1 [preproET-1]), cardiac hypertrophy (atrial natriuretic peptide, beta-myosin heavy chain, osteopontin), and aryl hydrocarbon receptor (AHR) activation (cytochrome P4501A1, AHR repressor). Further, all TCDD-induced changes required the AHR since gene expression was not altered in AHR knockout fetuses. In a second study, time-pregnant mice were treated with corn oil or 6.0 microg TCDD/kg on GD 14.5, and male offspring were assessed for changes in cardiac gene expression and cardiac and renal morphology at 3 months. All TCDD-induced changes in cardiac gene expression observed fetally, except for preproET-1, remained induced in the hearts of adult male offspring. Adult male offspring of TCDD-exposed dams also displayed cardiac hypertrophy, decreased plasma volume, and mild hydronephrosis. These results demonstrate that in utero and lactational TCDD exposures alter cardiac gene expression and cardiac and renal morphology in adulthood, which may increase the susceptibility to cardiovascular dysfunction.

  15. Myeloid mineralocorticoid receptor deficiency inhibits aortic constriction-induced cardiac hypertrophy in mice.

    PubMed

    Li, Chao; Zhang, Yu Yao; Frieler, Ryan A; Zheng, Xiao Jun; Zhang, Wu Chang; Sun, Xue Nan; Yang, Qing Zhen; Ma, Shu Min; Huang, Baozhuan; Berger, Stefan; Wang, Wang; Wu, Yong; Yu, Ying; Duan, Sheng Zhong; Mortensen, Richard M

    2014-01-01

    Mineralocorticoid receptor (MR) blockade has been shown to suppress cardiac hypertrophy and remodeling in animal models of pressure overload (POL). This study aims to determine whether MR deficiency in myeloid cells modulates aortic constriction-induced cardiovascular injuries. Myeloid MR knockout (MMRKO) mice and littermate control mice were subjected to abdominal aortic constriction (AAC) or sham operation. We found that AAC-induced cardiac hypertrophy and fibrosis were significantly attenuated in MMRKO mice. Expression of genes important in generating reactive oxygen species was decreased in MMRKO mice, while that of manganese superoxide dismutase increased. Furthermore, expression of genes important in cardiac metabolism was increased in MMRKO hearts. Macrophage infiltration in the heart was inhibited and expression of inflammatory genes was decreased in MMRKO mice. In addition, aortic fibrosis and inflammation were attenuated in MMRKO mice. Taken together, our data indicated that MR deficiency in myeloid cells effectively attenuated aortic constriction-induced cardiac hypertrophy and fibrosis, as well as aortic fibrosis and inflammation.

  16. Dual specific phosphatase 12 ameliorates cardiac hypertrophy in response to pressure overload.

    PubMed

    Li, Wei-Ming; Zhao, Yi-Fan; Zhu, Guo-Fu; Peng, Wen-Hui; Zhu, Meng-Yun; Yu, Xue-Jing; Chen, Wei; Xu, Da-Chun; Xu, Ya-Wei

    2017-01-01

    Pathological cardiac hypertrophy is an independent risk factor of heart failure. However, we still lack effective methods to reverse cardiac hypertrophy. DUSP12 is a member of the dual specific phosphatase (DUSP) family, which is characterized by its DUSP activity to dephosphorylate both tyrosine and serine/threonine residues on one substrate. Some DUSPs have been identified as being involved in the regulation of cardiac hypertrophy. However, the role of DUSP12 during pathological cardiac hypertrophy is still unclear. In the present study, we observed a significant decrease in DUSP12 expression in hypertrophic hearts and cardiomyocytes. Using a genetic loss-of-function murine model, we demonstrated that DUSP12 deficiency apparently aggravated pressure overload-induced cardiac hypertrophy and fibrosis as well as impaired cardiac function, whereas cardiac-specific overexpression of DUPS12 was capable of reversing this hypertrophic and fibrotic phenotype and improving contractile function. Furthermore, we demonstrated that JNK1/2 activity but neither ERK1/2 nor p38 activity was increased in the DUSP12 deficient group and decreased in the DUSP12 overexpression group both in vitro and in vivo under hypertrophic stress conditions. Pharmacological inhibition of JNK1/2 activity (SP600125) is capable of reversing the hypertrophic phenotype in DUSP12 knockout (KO) mice. DUSP12 protects against pathological cardiac hypertrophy and related pathologies. This regulatory role of DUSP12 is primarily through c-Jun N-terminal kinase (JNK) inhibition. DUSP12 could be a promising therapeutic target of pathological cardiac hypertrophy. DUSP12 is down-regulated in hypertrophic hearts. An absence of DUSP12 aggravated cardiac hypertrophy, whereas cardiomyocyte-specific DUSP12 overexpression can alleviate this hypertrophic phenotype with improved cardiac function. Further study demonstrated that DUSP12 inhibited JNK activity to attenuate pathological cardiac hypertrophy. © 2016 The

  17. Adiponectin protects against angiotensin II-induced cardiac fibrosis through activation of PPAR-alpha.

    PubMed

    Fujita, Koichi; Maeda, Norikazu; Sonoda, Mina; Ohashi, Koji; Hibuse, Toshiyuki; Nishizawa, Hitoshi; Nishida, Makoto; Hiuge, Aki; Kurata, Akifumi; Kihara, Shinji; Shimomura, Iichiro; Funahashi, Tohru

    2008-05-01

    Adiponectin is recognized as an antidiabetic, antiatherosclerotic, and anti-inflammatory protein derived from adipocytes. However, the role of adiponectin in cardiac fibrosis remains uncertain. We herein explore the effects of adiponectin on cardiac fibrosis induced by angiotensin II (Ang II). Wild-type (WT), adiponectin knockout (Adipo-KO), and PPAR-alpha knockout (PPAR-alpha-KO) mice were infused with Ang II at 1.2 mg/kg/d. Severe cardiac fibrosis and left ventricular dysfunction were observed in Ang II-infused Adipo-KO mice compared to WT mice. Adenovirus-mediated adiponectin treatment improved the above phenotypes and the dysregulation of reactive oxygen species (ROS)-related mRNAs in Adipo-KO mice, whereas such amelioration was not observed in PPAR-alpha-KO mice despite adiponectin accumulation in heart tissue. In cultured cardiac fibroblasts, adiponectin improved the reduction of AMP-activated protein kinase (AMPK) activity and elevation of extracellular signal-regulated kinase 1/2 (ERK1/2) activity induced by Ang II. Adiponectin significantly enhanced PPAR-alpha activity, whereas the adiponectin-dependent PPAR-alpha activation was diminished by Compound C, an inhibitor of AMPK. The present study suggests that adiponectin protects against Ang II-induced cardiac fibrosis possibly through AMPK-dependent PPAR-alpha activation.

  18. Return of Viable Cardiac Function After Sonographic Cardiac Standstill in Pediatric Cardiac Arrest.

    PubMed

    Steffen, Katherine; Thompson, W Reid; Pustavoitau, Aliaksei; Su, Erik

    2017-01-01

    Sonographic cardiac standstill during adult cardiac arrest is associated with failure to get return to spontaneous circulation. This report documents 3 children whose cardiac function returned after standstill with extracorporeal membranous oxygenation. Sonographic cardiac standstill may not predict cardiac death in children.

  19. Generation of TALEN-mediated FH knockout rat model.

    PubMed

    Yu, Dandan; Zhong, Yali; Li, Xiaoran; Li, Yaqing; Li, Xiaoli; Cao, Jing; Fan, Zhirui; Fan, Huijie; Yuan, Long; Xu, Benling; Yuan, Yuan; Zhang, Hongquan; Ji, Zhenyu; Wen, Jian-Guo; Zhang, Mingzhi; Nesland, Jahn M; Suo, Zhenhe

    2016-09-20

    Transcription activator-like effector nucleases (TALENs) are valuable tools for precise genome engineering of laboratory animals. Here we utilized this technique for efficient site-specific gene modification to create a fumarate hydratase (FH) gene knockout rat model, in which there was an 11 base-pair deletion in the first exon of the FH gene in 111 rats. 18 live-born targeted mutation offsprings were produced from 80 injected zygotes with 22.5% efficiency, indicating high TALEN knockout success in rat zygots. Only heterozygous deletion was observed in the offsprings. Sixteen pairs of heterozygous FH knockout (FH+/-) rats were arranged for mating experiments for six months without any homozygous KO rat identified. Sequencing from the pregnant rats embryo samples showed no homozygous FH KO, indicating that homozygous FH KO is embryonically lethal. Comparatively, the litter size was decreased in both male and female FH+/- KO rats. There was no behaviour difference between the FH+/- KO and the control rats except that the FH+/- KO male rats showed significantly higher body weight in the 16-week observation period. Clinical haematology and biochemical examinations showed hematopoietic and kidney dysfunction in the FH+/- KO rats. Small foci of anaplastic lesions of tubular epithelial cells around glomeruli were identified in the FH+/- kidney, and these anaplastic cells were comparatively positive for Ki67, p53 and Sox9, and such findings are most probably related to the kidney dysfunction reflected by the biochemical examinations of the rats. In conclusion, we have successfully established an FH+/- KO rat model, which will be useful for further functional FH studies.

  20. Generation of TALEN-mediated FH knockout rat model

    PubMed Central

    Yu, Dandan; Zhong, Yali; Li, Xiaoran; Li, Yaqing; Li, Xiaoli; Cao, Jing; Fan, Zhirui; Fan, Huijie; Yuan, Long; Xu, Benling; Yuan, Yuan; Zhang, Hongquan; Ji, Zhenyu; Wen, Jian-Guo; Zhang, Mingzhi; Nesland, Jahn M.; Suo, Zhenhe

    2016-01-01

    Transcription activator-like effector nucleases (TALENs) are valuable tools for precise genome engineering of laboratory animals. Here we utilized this technique for efficient site-specific gene modification to create a fumarate hydratase (FH) gene knockout rat model, in which there was an 11 base-pair deletion in the first exon of the FH gene in 111 rats. 18 live-born targeted mutation offsprings were produced from 80 injected zygotes with 22.5% efficiency, indicating high TALEN knockout success in rat zygots. Only heterozygous deletion was observed in the offsprings. Sixteen pairs of heterozygous FH knockout (FH+/−) rats were arranged for mating experiments for six months without any homozygous KO rat identified. Sequencing from the pregnant rats embryo samples showed no homozygous FH KO, indicating that homozygous FH KO is embryonically lethal. Comparatively, the litter size was decreased in both male and female FH+/− KO rats. There was no behaviour difference between the FH+/− KO and the control rats except that the FH+/− KO male rats showed significantly higher body weight in the 16-week observation period. Clinical haematology and biochemical examinations showed hematopoietic and kidney dysfunction in the FH+/− KO rats. Small foci of anaplastic lesions of tubular epithelial cells around glomeruli were identified in the FH+/− kidney, and these anaplastic cells were comparatively positive for Ki67, p53 and Sox9, and such findings are most probably related to the kidney dysfunction reflected by the biochemical examinations of the rats. In conclusion, we have successfully established an FH+/− KO rat model, which will be useful for further functional FH studies. PMID:27556703

  1. Helicobacter pylori arginase mutant colonizes arginase II knockout mice

    PubMed Central

    Kim, Songhee H; Langford, Melanie L; Boucher, Jean-Luc; Testerman, Traci L; McGee, David J

    2011-01-01

    AIM: To investigate the role of host and bacterial arginases in the colonization of mice by Helicobacter pylori (H. pylori). METHODS: H. pylori produces a very powerful urease that hydrolyzes urea to carbon dioxide and ammonium, which neutralizes acid. Urease is absolutely essential to H. pylori pathogenesis; therefore, the urea substrate must be in ample supply for urease to work efficiently. The urea substrate is most likely provided by arginase activity, which hydrolyzes L-arginine to L-ornithine and urea. Previous work has demonstrated that H. pylori arginase is surprisingly not required for colonization of wild-type mice. Hence, another in vivo source of the critical urea substrate must exist. We hypothesized that the urea source was provided by host arginase II, since this enzyme is expressed in the stomach, and H. pylori has previously been shown to induce the expression of murine gastric arginase II. To test this hypothesis, wild-type and arginase (rocF) mutant H. pylori strain SS1 were inoculated into arginase II knockout mice. RESULTS: Surprisingly, both the wild-type and rocF mutant bacteria still colonized arginase II knockout mice. Moreover, feeding arginase II knockout mice the host arginase inhibitor S-(2-boronoethyl)-L-cysteine (BEC), while inhibiting > 50% of the host arginase I activity in several tissues, did not block the ability of the rocF mutant H. pylori to colonize. In contrast, BEC poorly inhibited H. pylori arginase activity. CONCLUSION: The in vivo source for the essential urea utilized by H. pylori urease is neither bacterial arginase nor host arginase II; instead, either residual host arginase I or agmatinase is probably responsible. PMID:21876618

  2. [Advances in cardiac pacing].

    PubMed

    de Carranza, María-José Sancho-Tello; Fidalgo-Andrés, María Luisa; Ferrer, José Martínez; Mateas, Francisco Ruiz

    2012-01-01

    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed. Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  3. Normal Taste Acceptance and Preference of PANX1 Knockout Mice

    PubMed Central

    Aleman, Tiffany R.; Ellis, Hillary T.; Ohmoto, Makoto; Matsumoto, Ichiro; Shestopalov, Val I.; Mitchell, Claire H.; Foskett, J. Kevin; Poole, Rachel L.

    2015-01-01

    Taste compounds detected by G protein-coupled receptors on the apical surface of Type 2 taste cells initiate an intracellular molecular cascade culminating in the release of ATP. It has been suggested that this ATP release is accomplished by pannexin 1 (PANX1). However, we report here that PANX1 knockout mice do not differ from wild-type controls in response to representative taste solutions, measured using 5-s brief-access tests or 48-h two-bottle choice tests. This implies that PANX1 is unnecessary for taste detection and consequently that ATP release from Type 2 taste cells does not require PANX1. PMID:25987548

  4. Pre-Equilibrium Cluster Emission with Pickup and Knockout

    SciTech Connect

    Betak, E.

    2005-05-24

    We present a generalization of the Iwamoto-Harada-Bisplinghoff pre-equilibrium model of light cluster formation and emission, which is enhanced by allowing for possible admixtures of knockout for strongly coupled ejectiles, like {alpha}'s. The model is able to attain the Weisskopf-Ewing formula for compound-nucleus decay at long-time limit; it keeps the philosophy of pre-equilibrium decay during the equilibration stage and it describes the initial phase of a reaction as direct process(es) expressed using the language of the exciton model.

  5. Cardiac Hegemony of Senescence

    PubMed Central

    Siddiqi, Sailay; Sussman, Mark A.

    2013-01-01

    Cardiac senescence and age-related disease development have gained general attention and recognition in the past decades due to increased accessibility and quality of health care. The advancement in global civilization is complementary to concerns regarding population aging and development of chronic degenerative diseases. Cardiac degeneration has been rigorously studied. The molecular mechanisms of cardiac senescence are on multiple cellular levels and hold a multilayer complexity level, thereby hampering development of unambiguous treatment protocols. In particular, the synergistic exchange of the senescence phenotype through a senescence secretome between myocytes and stem cells appears complicated and is of great future therapeutic value. The current review article will highlight hallmarks of senescence, cardiac myocyte and stem cell senescence, and the mutual exchange of senescent secretome. Future cardiac cell therapy approaches require a comprehensive understanding of myocardial senescence to improve therapeutic efficiency as well as efficacy. PMID:24349878

  6. Functional cardiac tissue engineering

    PubMed Central

    Liau, Brian; Zhang, Donghui; Bursac, Nenad

    2013-01-01

    Heart attack remains the leading cause of death in both men and women worldwide. Stem cell-based therapies, including the use of engineered cardiac tissues, have the potential to treat the massive cell loss and pathological remodeling resulting from heart attack. Specifically, embryonic and induced pluripotent stem cells are a promising source for generation of therapeutically relevant numbers of functional cardiomyocytes and engineering of cardiac tissues in vitro. This review will describe methodologies for successful differentiation of pluripotent stem cells towards the cardiovascular cell lineages as they pertain to the field of cardiac tissue engineering. The emphasis will be placed on comparing the functional maturation in engineered cardiac tissues and developing heart and on methods to quantify cardiac electrical and mechanical function at different spatial scales. PMID:22397609

  7. Utility of Oatp1a/1b-knockout and OATP1B1/3-humanized mice in the study of OATP-mediated pharmacokinetics and tissue distribution: case studies with pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein.

    PubMed

    Higgins, J William; Bao, Jing Q; Ke, Alice B; Manro, Jason R; Fallon, John K; Smith, Philip C; Zamek-Gliszczynski, Maciej J

    2014-01-01

    Although organic anion transporting polypeptide (OATP)-mediated hepatic uptake is generally conserved between rodents and humans at a gross pharmacokinetic level, the presence of three major hepatic OATPs with broad overlap in substrate and inhibitor affinity, and absence of rodent-human orthologs preclude clinical translation of single-gene knockout/knockin findings. At present, changes in pharmacokinetics and tissue distribution of pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein were studied in oatp1a/1b-knockout mice lacking the three major hepatic oatp isoforms, and in knockout mice with liver-specific knockin of human OATP1B1 or OATP1B3. Relative to wild-type controls, oatp1a/1b-knockout mice exhibited 1.6- to 19-fold increased intravenous and 2.1- to 115-fold increased oral drug exposure, due to 33%-75% decreased clearance, 14%-60% decreased volume of distribution, and ≤74-fold increased oral bioavailability, with the magnitude of change depending on the contribution of oatp1a/1b to pharmacokinetics. Hepatic drug distribution was 4.2- to 196-fold lower in oatp1a/1b-knockout mice; distributional attenuation was less notable in kidney, brain, cardiac, and skeletal muscle. Knockin of OATP1B1 or OATP1B3 partially restored control clearance, volume, and bioavailability values (24%-142% increase, ≤47% increase, and ≤77% decrease vs. knockout, respectively), such that knockin pharmacokinetic profiles were positioned between knockout and wild-type mice. Consistent with liver-specific humanization, only hepatic drug distribution was partially restored (1.3- to 6.5-fold increase vs. knockout). Exposure and liver distribution changes in OATP1B1-humanized versus knockout mice predicted the clinical impact of OATP1B1 on oral exposure and contribution to human hepatic uptake of statins within 1.7-fold, but only after correcting for human/humanized mouse liver relative protein expression factor (OATP1B1 = 2.2, OATP1B3 = 0.30).

  8. SIRT2 Acts as a Cardioprotective Deacetylase in Pathological Cardiac Hypertrophy.

    PubMed

    Tang, Xiaoqiang; Chen, Xiao-Feng; Wang, Nan-Yu; Wang, Xiao-Man; Liang, Shu-Ting; Zheng, Wei; Lu, Yun-Biao; Zhao, Xiang; Hao, De-Long; Zhang, Zhu-Qin; Zou, Ming-Hui; Liu, De-Pei; Chen, Hou-Zao

    2017-09-25

    Background -Pathological cardiac hypertrophy induced by stresses such as aging and neurohumoral activation is an independent risk factor for heart failure and is considered a target for the treatment of heart failure. However, the mechanisms underlying pathological cardiac hypertrophy remain largely unknown. We aimed to investigate the roles of SIRT2 in aging-related and angiotensin II (Ang II)-induced pathological cardiac hypertrophy. Methods -Male C57BL/6J wild-type (WT) and Sirt2 knockout (Sirt2-KO) mice were subjected to the investigation of aging-related cardiac hypertrophy. Cardiac hypertrophy was also induced by Ang II (1.3 mg/kg/day for four weeks) in male C57BL/6J Sirt2-KO mice, cardiac-specific SIRT2 transgenic (SIRT2-Tg) mice and their respective littermates (8~12-week-old). Metformin (200 mg/kg/day) was used to treat WT and Sirt2-KO mice that were infused with Ang II. Cardiac hypertrophy, fibrosis, and cardiac function were examined in these mice. Results -SIRT2 protein expression levels were down-regulated in hypertrophic hearts from mice. Sirt2-KO markedly exaggerated cardiac hypertrophy and fibrosis as well as decreases in cardiac ejection fraction and fractional shortening in aged (24-month-old) mice and Ang II-infused mice. Conversely, cardiac-specific SIRT2 overexpression protected the hearts against Ang II-induced cardiac hypertrophy and fibrosis and rescued cardiac function. Mechanistically, SIRT2 maintained the activity of AMP-activated protein kinase (AMPK) in aged and Ang II-induced hypertrophic hearts in vivo as well as in cardiomyocytes in vitro We identified the liver kinase B1 (LKB1), the major upstream kinase of AMPK, as the direct target of SIRT2. SIRT2 bound to LKB1 and deacetylated it at lysine 48, which promoted the phosphorylation of LKB1 and the subsequent activation of LKB1-AMPK signaling. Remarkably, the loss of SIRT2 blunted the response of AMPK to metformin treatment in mice infused with Ang II and repressed the metformin

  9. Core features of frontotemporal dementia recapitulated in progranulin knockout mice

    PubMed Central

    Ghoshal, N.; Dearborn, J.T.; Wozniak, D.F.; Cairns, N.J.

    2011-01-01

    Frontotemporal dementia (FTD) is typified by behavioral and cognitive changes manifested as altered social comportment and impaired memory performance. To investigate the neurodegenerative consequences of progranulin gene (GRN) mutations, which cause an inherited form of FTD, we used previously generated progranulin knockout mice (Grn-/-). Specifically, we characterized two cohorts of early and later middle-age wild type and knockout mice using a battery of tests to assess neurological integrity and behavioral phenotypes analogous to FTD. The Grn-/- mice exhibited reduced social engagement and learning and memory deficits. Immunohistochemical approaches were used to demonstrate the presence of lesions characteristic of frontotemporal lobar degeneration (FTLD) with GRN mutation including ubiquitination, microgliosis, and reactive astrocytosis, the pathological substrate of FTD. Importantly, Grn-/- mice also have decreased overall survival compared to Grn+/+ mice. These data suggest that the Grn-/- mouse reproduces some core features of FTD with respect to behavior, pathology, and survival. This murine model may serve as a valuable in vivo model of FTLD with GRN mutation through which molecular mechanisms underlying the disease can be further dissected. PMID:21933710

  10. Ultrastructural analysis of megakaryocytes in GPV knockout mice.

    PubMed

    Poujol, C; Ramakrishnan, V; DeGuzman, F; Nurden, A T; Phillips, D R; Nurden, P

    2000-08-01

    Lesions in the genes for GPIb alpha, GPIb beta or GPIX result in a bleeding diathesis, the Bernard-Soulier syndrome (BSS), which associates a platelet adhesion defect with thrombocytopenia, giant platelets and abnormal megakaryocytes (MK). The role of GPV, also absent in BSS, was recently addressed by gene targeting in mice. While a negative modulator function for GPV on thrombin-induced platelet responses was found in one model, the absence of GP V had no effect on GPIb-IX expression or platelet adhesion. Our study extends previous results and reports that electron microscopy of bone marrow from the GPV knockout mice revealed a normal MK ultrastructure and development of the demarcation membrane system (DMS). There was a usual presence of MK fragments in the bone marrow vascular sinus. Immunogold labelling of MK from the knockout mice showed a normal distribution of GPIb-IX in the DMS and on the cell surface. The distribution of fibrinogen, vWF and P-selectin was unchanged with, interestingly, P-selectin also localised within the DMS in both situations. Thus GPV is not crucial to MK development and platelet production, consistent with the fact that no mutation in the GPV gene has as yet been described in BSS.

  11. Strain background determines lymphoma incidence in Atm knockout mice.

    PubMed

    Genik, Paula C; Bielefeldt-Ohmann, Helle; Liu, Xianan; Story, Michael D; Ding, Lianghao; Bush, Jamie M; Fallgren, Christina M; Weil, Michael M

    2014-02-01

    About 10% to 30% of patients with ataxia-telangiectasia (A-T) develop leukemias or lymphomas. There is considerable interpatient variation in the age of onset and leukemia/lymphoma type. The incomplete penetrance and variable age of onset may be attributable to several factors. These include competing mortality from other A-T-associated pathologies, particularly neurodegeneration and interstitial lung disease, allele-specific effects of ataxia-telangiectasia mutated (ATM) gene mutations. There is also limited evidence from clinical observations and studies using Atm knockout mice that modifier genes may account for some variation in leukemia/lymphoma susceptibility. We have introgressed the Atm(tm1Awb) knockout allele (Atm(-)) onto several inbred murine strains and observed differences in thymic lymphoma incidence and latency between Atm(-/-) mice on the different strain backgrounds and between their F1 hybrids. The lymphomas that arose in these mice had a pattern of sequence gains and losses that were similar to those previously described by others. These results provide further evidence for the existence of modifier genes controlling lymphomagenesis in individuals carrying defective copies of Atm, at least in mice, the characterized Atm(-) congenic strain set provides a resource with which to identify these genes. In addition, we found that fewer than expected Atm(-/-) pups were weaned on two strain backgrounds and that there was no correlation between body weight of young Atm-/- mice and lymphoma incidence or latency. Copyright © 2014 Neoplasia Press, Inc. All rights reserved.

  12. Strain Background Determines Lymphoma Incidence in Atm Knockout Mice12

    PubMed Central

    Genik, Paula C; Bielefeldt-Ohmann, Helle; Liu, Xianan; Story, Michael D; Ding, Lianghao; Bush, Jamie M; Fallgren, Christina M; Weil, Michael M

    2014-01-01

    About 10% to 30% of patients with ataxia-telangiectasia (A-T) develop leukemias or lymphomas. There is considerable interpatient variation in the age of onset and leukemia/lymphoma type. The incomplete penetrance and variable age of onset may be attributable to several factors. These include competing mortality from other A-T-associated pathologies, particularly neurodegeneration and interstitial lung disease, and allele-specific effects of ataxia-telangiectasia mutated (ATM) gene mutations. There is also limited evidence from clinical observations and studies using Atm knockout mice that modifier genes may account for some variation in leukemia/lymphoma susceptibility. We have introgressed the Atmtm1Awb knockout allele (Atm-) onto several inbred murine strains and observed differences in thymic lymphoma incidence and latency between Atm-/- mice on the different strain backgrounds and between their F1 hybrids. The lymphomas that arose in these mice had a pattern of sequence gains and losses that were similar to those previously described by others. These results provide further evidence for the existence of modifier genes controlling lymphomagenesis in individuals carrying defective copies of Atm, at least in mice, and the characterized Atm- congenic strain set provides a resource with which to identify these genes. In addition, we found that fewer than expected Atm-/- pups were weaned on two strain backgrounds and that there was no correlation between body weight of young Atm-/- mice and lymphoma incidence or latency. PMID:24709420

  13. TALEN-based knockout library for human microRNAs.

    PubMed

    Kim, Young-Kook; Wee, Gabbine; Park, Joha; Kim, Jongkyu; Baek, Daehyun; Kim, Jin-Soo; Kim, V Narry

    2013-12-01

    Various technical tools have been developed to probe the functions of microRNAs (miRNAs), yet their application has been limited by low efficacy and specificity. To overcome the limitations, we used transcription activator-like effector nucleases (TALENs) to knock out human miRNA genes. We designed and produced a library of 540 pairs of TALENs for 274 miRNA loci, focusing on potentially important miRNAs. The knockout procedure takes only 2-4 weeks and can be applied to any cell type. As a case study, we generated knockout cells for two related miRNAs, miR-141 and miR-200c, which belong to the highly conserved miR-200 family. Interestingly, miR-141 and miR-200c, despite their overall similarity, suppress largely nonoverlapping groups of targets, thus suggesting that functional miRNA-target interaction requires strict seed-pairing. Our study illustrates the potency of TALEN technology and provides useful resources for miRNA research.

  14. Defects in ultrasonic vocalization of cadherin-6 knockout mice.

    PubMed

    Nakagawa, Ryoko; Matsunaga, Eiji; Okanoya, Kazuo

    2012-01-01

    Although some molecules have been identified as responsible for human language disorders, there is still little information about what molecular mechanisms establish the faculty of human language. Since mice, like songbirds, produce complex ultrasonic vocalizations for intraspecific communication in several social contexts, they can be good mammalian models for studying the molecular basis of human language. Having found that cadherins are involved in the vocal development of the Bengalese finch, a songbird, we expected cadherins to also be involved in mouse vocalizations. To examine whether similar molecular mechanisms underlie the vocalizations of songbirds and mammals, we categorized behavioral deficits including vocalization in cadherin-6 knockout mice. Comparing the ultrasonic vocalizations of cadherin-6 knockout mice with those of wild-type controls, we found that the peak frequency and variations of syllables were differed between the mutant and wild-type mice in both pup-isolation and adult-courtship contexts. Vocalizations during male-male aggression behavior, in contrast, did not differ between mutant and wild-type mice. Open-field tests revealed differences in locomotors activity in both heterozygote and homozygote animals and no difference in anxiety behavior. Our results suggest that cadherin-6 plays essential roles in locomotor activity and ultrasonic vocalization. These findings also support the idea that different species share some of the molecular mechanisms underlying vocal behavior.

  15. Maize-targeted mutagenesis: A knockout resource for maize.

    PubMed

    May, Bruce P; Liu, Hong; Vollbrecht, Erik; Senior, Lynn; Rabinowicz, Pablo D; Roh, Donna; Pan, Xiaokang; Stein, Lincoln; Freeling, Mike; Alexander, Danny; Martienssen, Rob

    2003-09-30

    We describe an efficient system for site-selected transposon mutagenesis in maize. A total of 43,776 F1 plants were generated by using Robertson's Mutator (Mu) pollen parents and self-pollinated to establish a library of transposon-mutagenized seed. The frequency of new seed mutants was between 10-4 and 10-5 per F1 plant. As a service to the maize community, maize-targeted mutagenesis selects insertions in genes of interest from this library by using the PCR. Pedigree, knockout, sequence, phenotype, and other information is stored in a powerful interactive database (maize-targeted mutagenesis database) that enables analysis of the entire population and the handling of knockout requests. By inhibiting Mu activity in most F1 plants, we sought to reduce somatic insertions that may cause false positives selected from pooled tissue. By monitoring the remaining Mu activity in the F2, however, we demonstrate that seed phenotypes depend on it, and false positives occur in lines that appear to lack it. We conclude that more than half of all mutations arising in this population are suppressed on losing Mu activity. These results have implications for epigenetic models of inbreeding and for functional genomics.

  16. Screening methods to identify TALEN-mediated knockout mice.

    PubMed

    Nakagawa, Yoshiko; Yamamoto, Takashi; Suzuki, Ken-Ichi; Araki, Kimi; Takeda, Naoki; Ohmuraya, Masaki; Sakuma, Tetsushi

    2014-01-01

    Genome editing with site-specific nucleases, such as zinc-finger nucleases or transcription activator-like effector nucleases (TALENs), and RNA-guided nucleases, such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, is becoming the new standard for targeted genome modification in various organisms. Application of these techniques to the manufacture of knockout mice would be greatly aided by simple and easy methods for genotyping of mutant and wild-type pups among litters. However, there are no detailed or comparative reports concerning the identification of mutant mice generated using genome editing technologies. Here, we genotyped TALEN-derived enhanced green fluorescent protein (eGFP) knockout mice using a combination of approaches, including fluorescence observation, heteroduplex mobility assay, restriction fragment length polymorphism analysis and DNA sequencing. The detection sensitivities for TALEN-induced mutations differed among these methods, and we therefore concluded that combinatorial testing is necessary for the screening and determination of mutant genotypes. Since the analytical methods tested can be carried out without specialized equipment, costly reagents and/or sophisticated protocols, our report should be of interest to a broad range of researchers who are considering the application of genome editing technologies in various organisms.

  17. Norepinephrine transporter heterozygous knockout mice exhibit altered transport and behavior.

    PubMed

    Fentress, H M; Klar, R; Krueger, J J; Sabb, T; Redmon, S N; Wallace, N M; Shirey-Rice, J K; Hahn, M K

    2013-11-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET(+/-) ), demonstrating that they display an approximately 50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET(+/-) mouse establishes an activated state of existing surface NET proteins. The NET(+/-) mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris water maze. These data suggest that recovery of near basal activity in NET(+/-) mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET(+/-) mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders.

  18. RAG1/2 knockout pigs with severe combined immunodeficiency.

    PubMed

    Huang, Jiao; Guo, Xiaogang; Fan, Nana; Song, Jun; Zhao, Bentian; Ouyang, Zhen; Liu, Zhaoming; Zhao, Yu; Yan, Quanmei; Yi, Xiaoling; Schambach, Axel; Frampton, Jon; Esteban, Miguel A; Yang, Dongshan; Yang, Huaqiang; Lai, Liangxue

    2014-08-01

    Pigs share many physiological, biochemical, and anatomical similarities with humans and have emerged as valuable large animal models for biomedical research. Considering the advantages in immune system resemblance, suitable size, and longevity for clinical practical and monitoring purpose, SCID pigs bearing dysfunctional RAG could serve as important experimental tools for regenerative medicine, allograft and xenograft transplantation, and reconstitution experiments related to the immune system. In this study, we report the generation and phenotypic characterization of RAG1 and RAG2 knockout pigs using transcription activator-like effector nucleases. Porcine fetal fibroblasts were genetically engineered using transcription activator-like effector nucleases and then used to provide donor nuclei for somatic cell nuclear transfer. We obtained 27 live cloned piglets; among these piglets, 9 were targeted with biallelic mutations in RAG1, 3 were targeted with biallelic mutations in RAG2, and 10 were targeted with a monoallelic mutation in RAG2. Piglets with biallelic mutations in either RAG1 or RAG2 exhibited hypoplasia of immune organs, failed to perform V(D)J rearrangement, and lost mature B and T cells. These immunodeficient RAG1/2 knockout pigs are promising tools for biomedical and translational research.

  19. Efficient CRISPR/Cas9-based gene knockout in watermelon.

    PubMed

    Tian, Shouwei; Jiang, Linjian; Gao, Qiang; Zhang, Jie; Zong, Mei; Zhang, Haiying; Ren, Yi; Guo, Shaogui; Gong, Guoyi; Liu, Fan; Xu, Yong

    2017-03-01

    CRISPR/Cas9 system can precisely edit genomic sequence and effectively create knockout mutations in T0 generation watermelon plants. Genome editing offers great advantage to reveal gene function and generate agronomically important mutations to crops. Recently, RNA-guided genome editing system using the type II clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) has been applied to several plant species, achieving successful targeted mutagenesis. Here, we report the genome of watermelon, an important fruit crop, can also be precisely edited by CRISPR/Cas9 system. ClPDS, phytoene desaturase in watermelon, was selected as the target gene because its mutant bears evident albino phenotype. CRISPR/Cas9 system performed genome editing, such as insertions or deletions at the expected position, in transfected watermelon protoplast cells. More importantly, all transgenic watermelon plants harbored ClPDS mutations and showed clear or mosaic albino phenotype, indicating that CRISPR/Cas9 system has technically 100% of genome editing efficiency in transgenic watermelon lines. Furthermore, there were very likely no off-target mutations, indicated by examining regions that were highly homologous to sgRNA sequences. Our results show that CRISPR/Cas9 system is a powerful tool to effectively create knockout mutations in watermelon.

  20. Norepinephrine Transporter Heterozygous Knockout Mice Exhibit Altered Transport and Behavior

    PubMed Central

    Fentress, HM; Klar, R; Krueger, JK; Sabb, T; Redmon, SN; Wallace, NM; Shirey-Rice, JK; Hahn, MK

    2013-01-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically-driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET+/−), demonstrating that they display an ~50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity, assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET+/− mouse establishes an activated state of existing, surface NET proteins. NET+/− mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris Water Maze. These data suggest recovery of near basal activity in NET+/− mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET+/− mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. PMID:24102798

  1. Hair-Cell Mechanotransduction Persists in TRP Channel Knockout Mice

    PubMed Central

    Niksch, Paul D.; Webber, Roxanna M.; Garcia-Gonzalez, Miguel; Watnick, Terry; Zhou, Jing; Vollrath, Melissa A.; Corey, David P.

    2016-01-01

    Members of the TRP superfamily of ion channels mediate mechanosensation in some organisms, and have been suggested as candidates for the mechanotransduction channel in vertebrate hair cells. Some TRP channels can be ruled out based on lack of an inner ear phenotype in knockout animals or pore properties not similar to the hair-cell channel. Such studies have excluded Trpv4, Trpa1, Trpml3, Trpm1, Trpm3, Trpc1, Trpc3, Trpc5, and Trpc6. However, others remain reasonable candidates. We used data from an RNA-seq analysis of gene expression in hair cells as well as data on TRP channel conductance to narrow the candidate group. We then characterized mice lacking functional Trpm2, Pkd2, Pkd2l1, Pkd2l2 and Pkd1l3, using scanning electron microscopy, auditory brainstem response, permeant dye accumulation, and single-cell electrophysiology. In all of these TRP-deficient mice, and in double and triple knockouts, mechanotransduction persisted. Together with published studies, these results argue against the participation of any of the 33 mouse TRP channels in hair cell transduction. PMID:27196058

  2. Proton-induced knockout reactions with polarized and unpolarized beams

    NASA Astrophysics Data System (ADS)

    Wakasa, T.; Ogata, K.; Noro, T.

    2017-09-01

    Proton-induced knockout reactions provide a direct means of studying the single particle or cluster structures of target nuclei. In addition, these knockout reactions are expected to play a unique role in investigations of the effects of the nuclear medium on nucleon-nucleon interactions as well as the properties of nucleons and mesons. However, due to the nature of hadron probes, these reactions can suffer significant disturbances from the nuclear surroundings and the quantitative theoretical treatment of such processes can also be challenging. In this article, we review the experimental and theoretical progress in this field, particularly focusing on the use of these reactions as a spectroscopic tool and as a way to examine the medium modification of nucleon-nucleon interactions. With regard to the former aspect, the review presents a semi-quantitative evaluation of these reactions based on existing experimental data. In terms of the latter point, we introduce a significant body of evidence that suggests, although does not conclusively prove, the existence of medium effects. In addition, this paper also provides information and comments on other related subjects.

  3. Epidemiology and Outcomes of Cardiac Arrest in Pediatric Cardiac ICUs.

    PubMed

    Alten, Jeffrey A; Klugman, Darren; Raymond, Tia T; Cooper, David S; Donohue, Janet E; Zhang, Wenying; Pasquali, Sara K; Gaies, Michael G

    2017-10-01

    In-hospital cardiac arrest occurs in 2.6-6% of children with cardiac disease and is associated with significant morbidity and mortality. Much remains unknown about cardiac arrest in pediatric cardiac ICUs; therefore, we aimed to describe cardiac arrest epidemiology in a contemporary multicenter cardiac ICU cohort. Retrospective analysis within the Pediatric Cardiac Critical Care Consortium clinical registry. Cardiac ICUs within 23 North American hospitals. All cardiac medical and surgical patients admitted from August 2014 to July 2016. None. There were 15,908 cardiac ICU encounters (6,498 medical, 9,410 surgical). 3.1% had cardiac arrest; rate was 4.8 cardiac arrest per 1,000 cardiac ICU days. Medical encounters had 50% higher rate of cardiac arrest compared with surgical encounters. Observed (unadjusted) cardiac ICU cardiac arrest prevalence varied from 1% to 5.5% among the 23 centers; cardiac arrest per 1,000 cardiac ICU days varied from 1.1 to 10.4. Over half cardiac arrest occur within 48 hours of admission. On multivariable analysis, prematurity, neonatal age, any Society of Thoracic Surgeons preoperative risk factor, and Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality category 4, 5 had strongest association with surgical encounter cardiac arrest. In medical encounters, independent cardiac arrest risk factors were acute heart failure, prematurity, lactic acidosis greater than 3 mmol/dL, and invasive ventilation 1 hour after admission. Median cardiopulmonary resuscitation duration was 10 minutes, return of spontaneous circulation occurred in 64.5%, extracorporeal cardiopulmonary resuscitation in 27.2%. Unadjusted survival was 53.2% in encounters with cardiac arrest versus 98.2% without. Medical encounters had lower survival after cardiac arrest (37.7%) versus surgical encounters (62.5%); Norwood patients had less than half the survival after cardiac arrest (35.6%) compared with all others. Unadjusted survival after

  4. Cardiac tumors: echo assessment.

    PubMed

    Mankad, Rekha; Herrmann, Joerg

    2016-12-01

    Cardiac tumors are exceedingly rare (0.001-0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  5. Cardiac tumors: echo assessment

    PubMed Central

    Mankad, Rekha

    2016-01-01

    Cardiac tumors are exceedingly rare (0.001–0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses. PMID:27600455

  6. Nutrition and cardiac cachexia.

    PubMed

    Azhar, Gohar; Wei, Jeanne Y

    2006-01-01

    Congestive heart failure is a leading cause of morbidity and mortality, especially in older persons. In advanced stages of the disease, congestive heart failure can be associated with serious complications such as cardiac cachexia (defined here as weight loss of more than 6% in 6 months). This review will discuss recent insights into the pathophysiology, anthropometric predictors and potential management of cardiac cachexia. Cardiac cachexia and the associated progressive weight loss are sometimes overlooked by care providers. A delay in diagnosis often results in further loss of vital tissues, progressive weakness, fall-related injuries and potentially long-term care institutionalization and/or death. Emerging data suggest that congestive heart failure is a dynamic disorder of many organ systems, including the myocardial, neurohormonal, immune, vascular, gastrointestinal, renal and musculoskeletal systems. It is becoming more widely appreciated that it is the deterioration of this interactive multisystem complex that results in the systemic inflammation and progressive wasting and atrophy of muscle and other organ tissues, which is the hallmark of cardiac cachexia. Cardiac cachexia in congestive heart failure patients may be associated with a low level of physical activity. A high systemic inflammatory state is another marker of cardiac cachexia. Prudent anti-inflammatory nutrition, dietary supplements and exercise can serve to ameliorate and/or potentially prevent progressive wasting. A better understanding of factors contributing to the development of cardiac cachexia will enable us to design preventive strategies and provide improved care for individuals with this debilitating condition.

  7. Double and multiple knockout simulations for genome-scale metabolic network reconstructions.

    PubMed

    Goldstein, Yaron Ab; Bockmayr, Alexander

    2015-01-01

    Constraint-based modeling of genome-scale metabolic network reconstructions has become a widely used approach in computational biology. Flux coupling analysis is a constraint-based method that analyses the impact of single reaction knockouts on other reactions in the network. We present an extension of flux coupling analysis for double and multiple gene or reaction knockouts, and develop corresponding algorithms for an in silico simulation. To evaluate our method, we perform a full single and double knockout analysis on a selection of genome-scale metabolic network reconstructions and compare the results. A prototype implementation of double knockout simulation is available at http://hoverboard.io/L4FC.

  8. Constitutive phosphorylation of cardiac myosin regulatory light chain in vivo.

    PubMed

    Chang, Audrey N; Battiprolu, Pavan K; Cowley, Patrick M; Chen, Guohua; Gerard, Robert D; Pinto, Jose R; Hill, Joseph A; Baker, Anthony J; Kamm, Kristine E; Stull, James T

    2015-04-24

    In beating hearts, phosphorylation of myosin regulatory light chain (RLC) at a single site to 0.45 mol of phosphate/mol by cardiac myosin light chain kinase (cMLCK) increases Ca(2+) sensitivity of myofilament contraction necessary for normal cardiac performance. Reduction of RLC phosphorylation in conditional cMLCK knock-out mice caused cardiac dilation and loss of cardiac performance by 1 week, as shown by increased left ventricular internal diameter at end-diastole and decreased fractional shortening. Decreased RLC phosphorylation by conventional or conditional cMLCK gene ablation did not affect troponin-I or myosin-binding protein-C phosphorylation in vivo. The extent of RLC phosphorylation was not changed by prolonged infusion of dobutamine or treatment with a β-adrenergic antagonist, suggesting that RLC is constitutively phosphorylated to maintain cardiac performance. Biochemical studies with myofilaments showed that RLC phosphorylation up to 90% was a random process. RLC is slowly dephosphorylated in both noncontracting hearts and isolated cardiac myocytes from adult mice. Electrically paced ventricular trabeculae restored RLC phosphorylation, which was increased to 0.91 mol of phosphate/mol of RLC with inhibition of myosin light chain phosphatase (MLCP). The two RLCs in each myosin appear to be readily available for phosphorylation by a soluble cMLCK, but MLCP activity limits the amount of constitutive RLC phosphorylation. MLCP with its regulatory subunit MYPT2 bound tightly to myofilaments was constitutively phosphorylated in beating hearts at a site that inhibits MLCP activity. Thus, the constitutive RLC phosphorylation is limited physiologically by low cMLCK activity in balance with low MLCP activity.

  9. Cardiac Tamponade Revisited

    PubMed Central

    Ariyarajah, Vignendra; Spodick, David H.

    2007-01-01

    Cardiac tamponade is a life-threatening clinical syndrome that requires timely diagnosis. Herein, we present an instructive case of a patient who had cardiac tamponade. The condition went undiagnosed and resulted in the patient's death because almost all of the pathognomonic clinical findings of tamponade were unrecognized or not manifest. To better prepare health care professionals for similar challenges, we discuss the symptoms and clinical signs typical of cardiac tamponade, review the medical literature, and highlight current investigative methods that enable quick, efficient diagnosis and treatment. PMID:17948086

  10. [Cardiac manifestations of mitochondrial diseases].

    PubMed

    Ritzenthaler, Thomas; Luis, David; Hullin, Thomas; Fayssoil, Abdallah

    2015-05-01

    Mitochondrial diseases are multi-system disorders in relation with mitochondrial DNA and/or nuclear DNA abnormalities. Clinical pictures are heterogeneous, involving endocrine, cardiac, neurologic or sensory systems. Cardiac involvements are morphological and electrical disturbances. Prognosis is worsened in case of cardiac impairment. Treatments are related to the type of cardiac dysfunction including medication or pacemaker implantation.

  11. ZNF307 (Zinc Finger Protein 307) Acts as a Negative Regulator of Pressure Overload-Induced Cardiac Hypertrophy.

    PubMed

    Yu, Chang-Jiang; Liang, Chen; Li, Yu-Xia; Hu, Qing-Qing; Zheng, Wei-Wan; Niu, Na; Yang, Xu; Wang, Zi-Rui; Yu, Xiao-Di; Zhang, Bao-Long; Song, Bin-Lin; Zhang, Zhi-Ren

    2017-04-01

    Pathological cardiac hypertrophy is a key risk factor for heart failure. We found that the protein expression levels of the ZNF307 (zinc finger protein 307) were significantly increased in heart samples from both human patients with dilated cardiomyopathy and mice subjected to aortic banding. Therefore, we aimed to elucidate the role of ZNF307 in the development of cardiac hypertrophy and to explore the signal transduction events that mediate the effect of ZNF307 on cardiac hypertrophy, using cardiac-specific ZNF307 transgenic (ZNF307-TG) mice and ZNF307 global knockout (ZNF307-KO) mice. The results showed that the deletion of ZNF307 potentiated aortic banding-induced pathological cardiac hypertrophy, fibrosis, and cardiac dysfunction; however, the aortic banding-induced cardiac hypertrophic phenotype was dramatically diminished by ZNF307 overexpression in mouse heart. Mechanistically, the antihypertrophic effects mediated by ZNF307 in response to pathological stimuli were associated with the direct inactivation of NF-κB (nuclear factor-κB) signaling and blockade of the nuclear translocation of NF-κB subunit p65. Furthermore, the overexpression of a degradation-resistant mutant of IκBα (IκBα(S32A/S36A)) reversed the exacerbation of cardiac hypertrophy, fibrosis, and dysfunction shown in aortic banding-treated ZNF307-KO mice. In conclusion, our findings demonstrate that ZNF307 ameliorates pressure overload-induced cardiac hypertrophy by inhibiting the activity of NF-κB-signaling pathway.

  12. Tumor necrosis factor receptor-associated factor 3 is a positive regulator of pathological cardiac hypertrophy.

    PubMed

    Jiang, Xi; Deng, Ke-Qiong; Luo, Yuxuan; Jiang, Ding-Sheng; Gao, Lu; Zhang, Xiao-Fei; Zhang, Peng; Zhao, Guang-Nian; Zhu, Xueyong; Li, Hongliang

    2015-08-01

    Cardiac hypertrophy, a common early symptom of heart failure, is regulated by numerous signaling pathways. Here, we identified tumor necrosis factor receptor-associated factor 3 (TRAF3), an adaptor protein in tumor necrosis factor-related signaling cascades, as a key regulator of cardiac hypertrophy in response to pressure overload. TRAF3 expression was upregulated in hypertrophied mice hearts and failing human hearts. Four weeks after aortic banding, cardiac-specific conditional TRAF3-knockout mice exhibited significantly reduced cardiac hypertrophy, fibrosis, and dysfunction. Conversely, transgenic mice overexpressing TRAF3 in the heart developed exaggerated cardiac hypertrophy in response to pressure overload. TRAF3 also promoted an angiotensin II- or phenylephrine-induced hypertrophic response in isolated cardiomyocytes. Mechanistically, TRAF3 directly bound to TANK-binding kinase 1 (TBK1), causing increased TBK1 phosphorylation in response to hypertrophic stimuli. This interaction between TRAF3 and TBK1 further activated AKT signaling, which ultimately promoted the development of cardiac hypertrophy. Our findings not only reveal a key role of TRAF3 in regulating the hypertrophic response but also uncover TRAF3-TBK1-AKT as a novel signaling pathway in the development of cardiac hypertrophy and heart failure. This pathway may represent a potential therapeutic target for this pathological process.

  13. Myocardin-related transcription factors are required for cardiac development and function.

    PubMed

    Mokalled, Mayssa H; Carroll, Kelli J; Cenik, Bercin K; Chen, Beibei; Liu, Ning; Olson, Eric N; Bassel-Duby, Rhonda

    2015-10-15

    Myocardin-Related Transcription Factors A and B (MRTF-A and MRTF-B) are highly homologous proteins that function as powerful coactivators of serum response factor (SRF), a ubiquitously expressed transcription factor essential for cardiac development. The SRF/MRTF complex binds to CArG boxes found in the control regions of genes that regulate cytoskeletal dynamics and muscle contraction, among other processes. While SRF is required for heart development and function, the role of MRTFs in the developing or adult heart has not been explored. Through cardiac-specific deletion of MRTF alleles in mice, we show that either MRTF-A or MRTF-B is dispensable for cardiac development and function, whereas deletion of both MRTF-A and MRTF-B causes a spectrum of structural and functional cardiac abnormalities. Defects observed in MRTF-A/B null mice ranged from reduced cardiac contractility and adult onset heart failure to neonatal lethality accompanied by sarcomere disarray. RNA-seq analysis on neonatal hearts identified the most altered pathways in MRTF double knockout hearts as being involved in cytoskeletal organization. Together, these findings demonstrate redundant but essential roles of the MRTFs in maintenance of cardiac structure and function and as indispensible links in cardiac cytoskeletal gene regulatory networks. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The protective role of tacrine and donepezil in the retina of acetylcholinesterase knockout mice

    PubMed Central

    Yi, Yun-Min; Cai, Li; Shao, Yi; Xu, Man; Yi, Jing-Lin

    2015-01-01

    AIM To determine the effect of different concentrations of the acetylcholinesterase (AChE) inhibitors tacrine and donepezil on retinal protection in AChE+/− mice (AChE knockout mice) of various ages. METHODS Cultured ARPE-19 cells were treated with hydrogen peroxide (H2O2) at concentrations of 0, 250, 500, 1000 and 2000 µmol/L and protein levels were measured using Western blot. Intraperitoneal injections of tacrine and donepezil (0.1 mg/mL, 0.2 mg/mL and 0.4 mg/mL) were respectively given to AChE+/− mice aged 2mo and 4mo and wild-type S129 mice for 7d; phosphate buffered saline (PBS) was administered to the control group. The mice were sacrificed after 30d by in vitro cardiac perfusion and retinal samples were taken. AChE-deficient mice were identified by polymerase chain reaction (PCR) analysis using specific genotyping protocols obtained from the Jackson Laboratory website. H&E staining, immunofluorescence and Western blot were performed to observe AChE protein expression changes in the retinal pigment epithelial (RPE) cell layer. RESULTS Different concentrations of H2O2 induced AChE expression during RPE cell apoptosis. AChE+/− mice retina were thinner than those in wild-type mice (P<0.05); the retinal structure was still intact at 2mo but became thinner with increasing age (P<0.05); furthermore, AChE+/− mice developed more slowly than wild-type mice (P<0.05). Increased concentrations of tacrine and donepezil did not significantly improve the protection of the retina function and morphology (P>0.05). CONCLUSION In vivo, tacrine and donepezil can inhibit the expression of AChE; the decrease of AChE expression in the retina is beneficial for the development of the retina. PMID:26558196

  15. Knock-out of nexilin in mice leads to dilated cardiomyopathy and endomyocardial fibroelastosis.

    PubMed

    Aherrahrou, Zouhair; Schlossarek, Saskia; Stoelting, Stephanie; Klinger, Matthias; Geertz, Birgit; Weinberger, Florian; Kessler, Thorsten; Aherrahrou, Redouane; Moreth, Kristin; Bekeredjian, Raffi; Hrabě de Angelis, Martin; Just, Steffen; Rottbauer, Wolfgang; Eschenhagen, Thomas; Schunkert, Heribert; Carrier, Lucie; Erdmann, Jeanette

    2016-01-01

    Cardiomyopathy is one of the most common causes of chronic heart failure worldwide. Mutations in the gene encoding nexilin (NEXN) occur in patients with both hypertrophic and dilated cardiomyopathy (DCM); however, little is known about the pathophysiological mechanisms and relevance of NEXN to these disorders. Here, we evaluated the functional role of NEXN using a constitutive Nexn knock-out (KO) mouse model. Heterozygous (Het) mice were inter-crossed to produce wild-type (WT), Het, and homozygous KO mice. At birth, 32, 46, and 22 % of the mice were WT, Het, and KO, respectively, which is close to the expected Mendelian ratio. After postnatal day 6, the survival of the Nexn KO mice decreased dramatically and all of the animals died by day 8. Phenotypic characterizations of the WT and KO mice were performed at postnatal days 1, 2, 4, and 6. At birth, the relative heart weights of the WT and KO mice were similar; however, at day 4, the relative heart weight of the KO group was 2.3-fold higher than of the WT group. In addition, the KO mice developed rapidly progressive cardiomyopathy with left ventricular dilation and wall thinning and decreased cardiac function. At day 6, the KO mice developed a fulminant DCM phenotype characterized by dilated ventricular chambers and systolic dysfunction. At this stage, collagen deposits and some elastin deposits were observed within the left ventricle cavity, which resembles the features of endomyocardial fibroelastosis (EFE). Overall, these results further emphasize the role of NEXN in DCM and suggest a novel role in EFE.

  16. Activation of SIRT3 by resveratrol ameliorates cardiac fibrosis and improves cardiac function via the TGF-β/Smad3 pathway.

    PubMed

    Chen, Tongshuai; Li, Jingyuan; Liu, Junni; Li, Na; Wang, Shujian; Liu, Hui; Zeng, Mei; Zhang, Yun; Bu, Peili

    2015-03-01

    Sirtuins [sirtuin (SIRT)1-SIRT7] mediate the longevity-promoting effects of calorie restriction in yeast, worms, flies, and mice. Additionally, SIRT3 is the only SIRT analog whose increased expression has been shown to be associated with longevity in humans. The polyphenol resveratrol (RSV) is the first compound discovered able to mimic calorie restriction by stimulating SIRTs. In the present study, we report that RSV activated SIRT3 in cardiac fibroblasts both in vivo and in vitro. Moreover, in wild-type mice, RSV prevented cardiac hypertrophy in response to hypertrophic stimuli. However, this protective effect was not observed in SIRT3 knockout mice. Additionally, the activation of SIRT3 by RSV ameliorated collagen deposition and improved cardiac function. In isolated cardiac fibroblasts, pretreatment with RSV suppressed fibroblast-to-myoblast transformation by inhibiting the transforming growth factor-β/Smad3 pathway. Therefore, these data indicate that the activation of SIRT3 by RSV could ameliorate cardiac fibrosis and improve cardiac function via the transforming growth factor-β/Smad3 pathway. Copyright © 2015 the American Physiological Society.

  17. Aggravated myocardial infarction-induced cardiac remodeling and heart failure in histamine-deficient mice

    PubMed Central

    Chen, Jinmiao; Hong, Tao; Ding, Suling; Deng, Long; Abudupataer, Mieradilijiang; Zhang, Weiwei; Tong, Minghong; Jia, Jianguo; Gong, Hui; Zou, Yunzeng; Wang, Timothy C.; Ge, Junbo; Yang, Xiangdong

    2017-01-01

    Histamine has pleiotropic pathophysiological effects, but its role in myocardial infarction (MI)-induced cardiac remodeling remains unclear. Histidine decarboxylase (HDC) is the main enzyme involved in histamine production. Here, we clarified the roles of HDC-expressing cells and histamine in heart failure post-MI using HDC-EGFP transgenic mice and HDC-knockout (HDC−/−) mice. HDC+CD11b+ myeloid cell numbers markedly increased in the injured hearts, and histamine levels were up-regulated in the circulation post-MI. HDC−/− mice exhibited more adverse cardiac remodeling, poorer left ventricular function and higher mortality by increasing cardiac fibrogenesis post-MI. In vitro assays further confirmed that histamine inhibited heart fibroblast proliferation. Furthermore, histamine enhanced the signal transducer and activator of transcription (STAT)-6 phosphorylation level in murine heart fibroblasts, and the inhibitive effects of histamine on fibroblast proliferation could be blocked by JAK3/STAT6 signaling selective antagonist. STAT6-knockout (STAT6−/−) mice had a phenotype similar to that of HDC−/− mice post-MI; however, in contrast to HDC−/− mice, the beneficial effects of exogenous histamine injections were abrogated in STAT6−/− mice. These data suggest that histamine exerts protective effects by modulating cardiac fibrosis and remodeling post-MI, in part through the STAT6-dependent signaling pathway. PMID:28272448

  18. Class IA phosphoinositide 3-kinase regulates heart size and physiological cardiac hypertrophy.

    PubMed

    Luo, Ji; McMullen, Julie R; Sobkiw, Cassandra L; Zhang, Li; Dorfman, Adam L; Sherwood, Megan C; Logsdon, M Nicole; Horner, James W; DePinho, Ronald A; Izumo, Seigo; Cantley, Lewis C

    2005-11-01

    Class I(A) phosphoinositide 3-kinases (PI3Ks) are activated by growth factor receptors, and they regulate, among other processes, cell growth and organ size. Studies using transgenic mice overexpressing constitutively active and dominant negative forms of the p110alpha catalytic subunit of class I(A) PI3K have implicated the role of this enzyme in regulating heart size and physiological cardiac hypertrophy. To further understand the role of class I(A) PI3K in controlling heart growth and to circumvent potential complications from the overexpression of dominant negative and constitutively active proteins, we generated mice with muscle-specific deletion of the p85alpha regulatory subunit and germ line deletion of the p85beta regulatory subunit of class I(A) PI3K. Here we show that mice with cardiac deletion of both p85 subunits exhibit attenuated Akt signaling in the heart, reduced heart size, and altered cardiac gene expression. Furthermore, exercise-induced cardiac hypertrophy is also attenuated in the p85 knockout hearts. Despite such defects in postnatal developmental growth and physiological hypertrophy, the p85 knockout hearts exhibit normal contractility and myocardial histology. Our results therefore provide strong genetic evidence that class I(A) PI3Ks are critical regulators for the developmental growth and physiological hypertrophy of the heart.

  19. What Is Cardiac Catheterization?

    MedlinePlus

    ... of Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & ... arteries is called coronary heart disease (CHD) or coronary artery disease. Doctors also can use ultrasound during cardiac catheterization ...

  20. Cardiac glycoside overdose

    MedlinePlus

    ... found in the leaves of the digitalis (foxglove) plant. This plant is the original source of this medicine. People ... Digitoxin (Crystodigin) Digoxin (Lanoxicaps, Lanoxin) Besides the foxglove plant, cardiac glycosides also occur naturally in plants such ...

  1. Cardiac Catheterization (For Kids)

    MedlinePlus

    ... done during a cardiac catheterization include: closing small holes inside the heart repairing leaky or narrow heart ... bandage. It's normal for the site to be black and blue, red, or slightly swollen for a ...

  2. Cardiac Catheterization (For Teens)

    MedlinePlus

    ... a person will have only a small puncture hole where the catheter was put in. Doctors usually ... done using a cardiac catheterization, including: closing small holes inside the heart repairing leaky or narrow heart ...

  3. Cardiac ablation procedures

    MedlinePlus

    ... a registered branch of the European Society of Cardiology (ESC) and the European Cardiac Arrhythmia Society (ECAS); and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific ...

  4. Autonomic cardiac innervation

    PubMed Central

    Hasan, Wohaib

    2013-01-01

    Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targets, upon which target-derived trophic factors take over final maturation, synaptic strength and postnatal survival. Although target-derived neurotrophins have a central role to play in development, alternative sources of neurotrophins may also modulate innervation. Both developing and adult sympathetic neurons express proNGF, and adult parasympathetic cardiac ganglion neurons also synthesize and release NGF. The physiological function of these “non-classical” cardiac sources of neurotrophins remains to be determined, especially in relation to autocrine/paracrine sustenance during development.   Cardiac autonomic nerves are closely spatially associated in cardiac plexuses, ganglia and pacemaker regions and so are sensitive to release of neurotransmitter, neuropeptides and trophic factors from adjacent nerves. As such, in many cardiac pathologies, it is an imbalance within the two arms of the autonomic system that is critical for disease progression. Although this crosstalk between sympathetic and parasympathetic nerves has been well established for adult nerves, it is unclear whether a degree of paracrine regulation occurs across the autonomic limbs during development. Aberrant nerve remodeling is a common occurrence in many adult cardiovascular pathologies, and the mechanisms regulating outgrowth or denervation are disparate. However, autonomic neurons display considerable plasticity in this regard with neurotrophins and inflammatory cytokines having a central regulatory

  5. Cardiac imaging in adults

    SciTech Connect

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  6. [Intrinsic cardiac ganglia].

    PubMed

    Birand, Ahmet

    2008-12-01

    Heart has been considered as the source and the seat of emotions, passion and love. But from the dawn of XIXth century, scientists have emphasized that the heart, though life depends on its ceaseless activity, is merely a electromechanical pump, pumping oxygenated blood. Nowadays, we all know that heart pumps blood commensurate with the needs of the body and this unending toil, and its regulation depends on the intrinsic properties of the myocardium, Frank-Starling Law and neurohumoral contribution. It has been understood, though not clearly enough, that these time-tensions may cause structural or functional cardiac impairments and arrhythmias are related to the autonomic nervous system. Less well known and less taken in account in daily cardiology practice is the fact that heart has an intrinsic cardiac nervous system, or "heart brain" consisting of complex ganglia, intrinsic cardiac ganglia containing afferent (receiving), local circuit (interneurons) and efferent (transmitting) sympathetic and parasympathetic neurons. This review enlightens structural and functional aspects of intrinsic cardiac ganglia as the very first step in the regulation of cardiac function. This issue is important for targets of pharmacological treatment and techniques of cardiac surgery interventions as repair of septal defects, valvular interventions and congenital corrections.

  7. Cardiac applications of optogenetics.

    PubMed

    Ambrosi, Christina M; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia

    2014-08-01

    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Cardiac Applications of Optogenetics

    PubMed Central

    Ambrosi, Christina M.; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia

    2014-01-01

    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics. PMID:25035999

  9. Cardiac septic pulmonary embolism

    PubMed Central

    Song, Xin yu; Li, Shan; Cao, Jian; Xu, Kai; Huang, Hui; Xu, Zuo jun

    2016-01-01

    Abstract Based on the source of the embolus, septic pulmonary embolism (SPE) can be classified as cardiac, peripheral endogenous, or exogenous. Cardiac SPEs are the most common. We conducted a retrospective analysis of 20 patients with cardiac SPE hospitalized between 1991 and 2013 at a Chinese tertiary referral hospital. The study included 14 males and 6 females with a median age of 38.1 years. Fever (100%), cough (95%), hemoptysis (80%), pleuritic chest pain (80%), heart murmur (80%), and moist rales (75%) were common clinical manifestations. Most patients had a predisposing condition: congenital heart disease (8 patients) and an immunocompromised state (5 patients) were the most common. Staphylococcal (8 patients) and Streptococcal species (4 patients) were the most common causative pathogens. Parenchymal opacities, nodules, cavitations, and pleural effusions were the most common manifestations observed via computed tomography (CT). All patients exhibited significant abnormalities by echocardiography, including 15 patients with right-sided vegetations and 4 with double-sided vegetations. All patients received parenteral antimicrobial therapy as an initial treatment. Fourteen patients received cardiac surgery, and all survived. Among the 6 patients who did not undergo surgery, only 1 survived. Most patients in our cardiac SPE cohort had predisposing conditions. Although most exhibited typical clinical manifestations and radiography, they were nonspecific. For suspected cases of SPE, blood culture, echocardiography, and CT pulmonary angiography (CTPA) are important measures to confirm an early diagnosis. Vigorous early therapy, including appropriate antibiotic treatment and timely cardiac surgery to eradicate the infective source, is critical. PMID:27336870

  10. Progranulin Knockout Accelerates Intervertebral Disc Degeneration in Aging Mice

    PubMed Central

    Zhao, Yun-peng; Tian, Qing-yun; Liu, Ben; Cuellar, Jason; Richbourgh, Brendon; Jia, Tang-hong; Liu, Chuan-ju

    2015-01-01

    Intervertebral disc (IVD) degeneration is a common degenerative disease, yet much is unknown about the mechanisms during its pathogenesis. Herein we investigated whether progranulin (PGRN), a chondroprotective growth factor, is associated with IVD degeneration. PGRN was detectable in both human and murine IVD. The levels of PGRN were upregulated in murine IVD tissue during aging process. Loss of PGRN resulted in an early onset of degenerative changes in the IVD tissue and altered expressions of the degeneration-associated molecules in the mouse IVD tissue. Moreover, PGRN knockout mice exhibited accelerated IVD matrix degeneration, abnormal bone formation and exaggerated bone resorption in vertebra with aging. The acceleration of IVD degeneration observed in PGRN null mice was probably due to the enhanced activation of NF-κB signaling and β-catenin signaling. Taken together, PGRN may play a critical role in homeostasis of IVD, and may serve as a potential molecular target for prevention and treatment of disc degenerative diseases. PMID:25777988

  11. SAMHD1 knockout mice: modeling retrovirus restriction in vivo.

    PubMed

    Wu, Li

    2013-11-20

    The host dNTP hydrolase SAMHD1 acts as a viral restriction factor to inhibit the replication of several retroviruses and DNA viruses in non-cycling human immune cells. However, understanding the physiological role of mammalian SAMHD1 has been elusive due to the lack of an animal model. Two recent studies reported the generation of samhd1 knockout mouse models for investigating the restriction of HIV-1 vectors and endogenous retroviruses in vivo. Both studies suggest that SAMHD1 is important for regulating the intracellular dNTP pool and the intrinsic immunity against retroviral infection, despite different outcomes of HIV-1 vector transduction in these mouse models. Here I discuss the significance of these new findings and the future directions in studying SAMHD1-mediated retroviral restriction.

  12. Delayed liver regeneration after partial hepatectomy in adiponectin knockout mice

    SciTech Connect

    Ezaki, Hisao; Yoshida, Yuichi; Saji, Yukiko; Takemura, Takayo; Fukushima, Juichi; Matsumoto, Hitoshi; Kamada, Yoshihiro; Wada, Akira; Igura, Takumi; Kihara, Shinji; Funahashi, Tohru; Shimomura, Iichiro; Tamura, Shinji; Kiso, Shinichi Hayashi, Norio

    2009-01-02

    We previously demonstrated that adiponectin has anti-fibrogenic and anti-inflammatory effects in the liver of mouse models of various liver diseases. However, its role in liver regeneration remains unclear. The aim of this study was to determine the role of adiponectin in liver regeneration. We assessed liver regeneration after partial hepatectomy in wild-type (WT) and adiponectin knockout (KO) mice. We analyzed DNA replication and various signaling pathways involved in cell proliferation and metabolism. Adiponectin KO mice exhibited delayed DNA replication and increased lipid accumulation in the regenerating liver. The expression levels of peroxisome proliferator-activated receptor (PPAR) {alpha} and carnitine palmitoyltransferase-1 (CPT-1), a key enzyme in mitochondrial fatty acid oxidation, were decreased in adiponectin KO mice, suggesting possible contribution of altered fat metabolism to these phenomena. Collectively, the present results highlight a new role for adiponectin in the process of liver regeneration.

  13. One-proton knockout reaction of 20 N

    NASA Astrophysics Data System (ADS)

    Whitmore, K.; Iwasaki, H.; Brown, B. A.; Gade, A.; Loelius, C.; Morse, C.; Stroberg, S. R.; Bazin, D.; Kobayashi, N.; Recchia, F.; Smalley, D.; Weisshaar, D.; Wimmer, K.; Lemasson, A.; Campbell, C. M.; Fallon, P.; Macchiavelli, A. O.; Otsuka, T.; Suzuki, T.; Tostevin, J. A.

    2016-09-01

    Nuclear structure away from stability can change drastically due to the re-ordering of shell-model orbitals. In particular, near the neutron drip line, the neutron 1s1 / 2 orbital and 0d5 / 2 orbitals may become degenerate or even inverted. In order to study the trend of these orbitals across the N = 13 isotones, a one-proton knockout reaction from 20N has been performed. The cross section is sensitive to states in 19C as well as the ground state in 20N. The experiment was performed at the NSCL with a beam of 20N at 70 MeV/nucleon. Gamma rays in coincidence with the 19C fragments were measured with GRETINA to determine exclusive cross sections, and the momentum of 19C recoils were recorded by the S800. Results will be compared to reaction calculations in the eikonal model.

  14. Cardiac Rehabilitation After Acute Myocardial Infarction Resuscitated From Cardiac Arrest

    PubMed Central

    Kim, Chul; Choi, Hee Eun; Kang, Seong Hoon

    2014-01-01

    Objective To examine the safety and effectiveness of cardiac rehabilitation on patients resuscitated from cardiac arrest due to acute myocardial infarction. Methods The study included 23 subjects, including 8 with history of cardiac arrest and 15 without history of cardiac arrest. Both groups underwent initial graded exercise test (GXT) and subsequent cardiac rehabilitation for 6 weeks. After 6 weeks, both groups received follow-up GXT. Results Statistically significant (p<0.05) increase of VO2peak and maximal MVO2 but significant (p<0.05) decrease of submaximal MVO2 and resting heart rate were observed in both groups after 6 weeks of cardiac rehabilitation. An increasing trend of maximal heart rates was observed in both groups. However, the increase was not statistically significant (p>0.05). There was no statistically significant change of resting heart rate, maximal heart rate, maximal MVO2, or submaximal MVO2 in both groups after cardiac rehabilitation. Fatal cardiac complications, such as abnormal ECG, cardiac arrest, death or myocardial infarction, were not observed. All subjects finished the cardiac rehabilitation program. Conclusion Improvement was observed in the exercise capacity of patients after aerobic exercise throughout the cardiac rehabilitation program. Therefore, cardiac rehabilitation can be safely administered for high-risk patients with history of cardiac arrest. Similar improvement in exercise capacity can be expected in patients without cardiac arrest experience. PMID:25566479

  15. Preaxial Polydactyly in Sost/Sostdc1 Double Knockouts

    SciTech Connect

    Yee, C M; Collette, N M; Loots, G G

    2011-07-29

    In the United States, {approx}5% are born with congenital birth defects due to abnormal function of cellular processes and interactions. Sclerosteosis, a rare autosomal recessive disease, causes hyperostosis of the axial and appendicular skeleton, and patients present radial deviation, digit syndactyly, nail dysplasia, and overall high bone mineral density. Sclerosteosis is due to a loss of function of sclerostin (Sost). Sost is a Wnt (abbrev.) antagonist; when mutated, nonfunctional Sost results in hyperactive osteoblast activity which leads to abnormal high bone mass. Previous studies have shown that Sost overexpression in transgenic mice causes reduced bone mineral density and a variety of limb phenotypes ranging from lost, fused, and split phalanges. Consistent with clinical manifestations of Sclerosteosis, Sost knockout mice exhibit increased generalized bone mineral density and syndactyly of the digits. Sostdc1 is a paralog of Sost that has also been described as an antagonist of Wnt signaling, in developing tooth buds. Unlike Sost knockouts, Sostdc1 null mice do not display any limb abnormalities. To determine if Sost and Sostdc1 have redundant functions during limb patterning, we examined Sost; Sostdc1 mice determined that they exhibit a novel preaxial polydactyly phenotype with a low penetrance. LacZ staining, skeletal preparations, and in situ hybridization experiments were used to help characterize this novel phenotype and understand how this phenotype develops. We find Sost and Sostdc1 to have complementary expression patterns during limb development, and the loss of their expression alters the transcription of several key limb regulators, such as Fgf8, Shh and Grem.

  16. Intercellular Adhesion Molecule 1 Knockout Abrogates Radiation Induced Pulmonary Inflammation

    NASA Astrophysics Data System (ADS)

    Hallahan, Dennis E.; Virudachalam, Subbulakshmi

    1997-06-01

    Increased expression of intercellular adhesion molecule 1 (ICAM-1; CD54) is induced by exposure to ionizing radiation. The lung was used as a model to study the role of ICAM-1 in the pathogenesis of the radiation-induced inflammation-like response. ICAM-1 expression increased in the pulmonary microvascular endothelium and not in the endothelium of larger pulmonary vessels following treatment of mice with thoracic irradiation. To quantify radiation-induced ICAM-1 expression, we utilized fluorescence-activated cell sorting analysis of anti-ICAM-1 antibody labeling of pulmonary microvascular endothelial cells from human cadaver donors (HMVEC-L cells). Fluorochrome conjugates and UV microscopy were used to quantify the fluorescence intensity of ICAM in the irradiated lung. These studies showed a dose- and time-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium. Peak expression occurred at 24 h, while threshold dose was as low as 2 Gy. To determine whether ICAM-1 is required for inflammatory cell infiltration into the irradiated lung, the anti-ICAM-1 blocking antibody was administered by tail vein injection to mice following thoracic irradiation. Inflammatory cells were quantified by immunofluorescence for leukocyte common antigen (CD45). Mice treated with the anti-ICAM-1 blocking antibody showed attenuation of inflammatory cell infiltration into the lung in response to ionizing radiation exposure. To verify the requirement of ICAM-1 in the inflammation-like radiation response, we utilized the ICAM-1 knockout mouse. ICAM-1 was not expressed in the lungs of ICAM-1-deficient mice following treatment with thoracic irradiation. ICAM-1 knockout mice had no increase in the inflammatory cell infiltration into the lung in response to thoracic irradiation. These studies demonstrate a radiation dose-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium, and show that ICAM-1 is required for inflammatory cell infiltration

  17. Bioelectric characterization of epithelia from neonatal CFTR knockout ferrets.

    PubMed

    Fisher, John T; Tyler, Scott R; Zhang, Yulong; Lee, Ben J; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R; Engelhardt, John F

    2013-11-01

    Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4'-diisothiocyano-2,2'-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin-stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)-inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin-inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport.

  18. STARS knockout attenuates hypoxia-induced pulmonary arterial hypertension by suppressing pulmonary arterial smooth muscle cell proliferation.

    PubMed

    Shi, Zhaoling; Wu, Huajie; Luo, Jianfeng; Sun, Xin

    2017-03-01

    STARS (STriated muscle Activator of Rho Signaling) is a sarcomeric protein, which expressed early in cardiac development and involved in pathological remodeling. Abundant evidence indicated that STARS could regulate cell proliferation, but it's exact function remains unclear. In this study, we aimed to investigate the role of STARS in the proliferation of pulmonary arterial smooth muscle cells (PASMC) and the potential effect on the progression of pulmonary arterial hypertension (PAH). In this study, we established a PAH mouse model through chronic hypoxia exposure as reflected by the increased RVSP and RVHI. Western blot and RT-qPCR detected the increased STARS protein and mRNA levels in PAH mice. Next, we cultured the primary PASMC from PAH mice. After STARS overexpression in PASMC, STARS, SRF and Egr-1 were up-regulated significantly. The MTT assay revealed an increase in cell proliferation. Flow cytometry showed a marked inhibition of cell apoptosis. However, STARS silence in PASMC exerted opposite effects with STARS overexpression. SRF siRNA transfection blocked the effects of STARS overexpression in PASMC. In order to further confirm the role of STARS in PAH mice in vivo, we exposed STARS knockout mice to hypoxia and found lower RVSP and RVHI in knockout mice as compared with controls. Our results not only suggest that STARS plays a crucial role in the development of PAH by increasing the proliferation of PASMC through activation of the SRF/Egr-1 pathway, but also provides a new mechanism for hypoxia-induced PAH. In addition, STARS may represent a potential treatment target.

  19. Reduced Extinction of Hippocampal-Dependent Memories in CPEB Knockout Mice

    ERIC Educational Resources Information Center

    Zearfoss, N. Ruth; Richter, Joel D.; Berger-Sweeney, Joanne

    2006-01-01

    CPEB is a sequence-specific RNA binding protein that regulates translation at synapses. In neurons of CPEB knockout mice, synaptic efficacy is reduced. Here, we have performed a battery of behavioral tests and find that relative to wild-type animals, CPEB knockout mice, although similar on many baseline behaviors, have reduced extinction of…

  20. Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in Diaphragm Muscle of Acetylcholinesterase Knockout Mice

    DTIC Science & Technology

    2008-04-01

    Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in 5a. CONTRACT NUMBER Diaphragm Muscle of Acetylcholinesterase Knockout Mice...AChE +/+) and acetylcholinesterase knockout (AChE -/-) mice to determine the compensatory mechanism manifested by the neuromuscular junction to...had smaller nerve terminals and diminished pre- and postsynaptic surface contacts relative to neuromuscular junctions of AChE +/+ mice. The

  1. Reduced Extinction of Hippocampal-Dependent Memories in CPEB Knockout Mice

    ERIC Educational Resources Information Center

    Zearfoss, N. Ruth; Richter, Joel D.; Berger-Sweeney, Joanne

    2006-01-01

    CPEB is a sequence-specific RNA binding protein that regulates translation at synapses. In neurons of CPEB knockout mice, synaptic efficacy is reduced. Here, we have performed a battery of behavioral tests and find that relative to wild-type animals, CPEB knockout mice, although similar on many baseline behaviors, have reduced extinction of…

  2. Loss of Myocardial Ischemic Postconditioning in Adenosine A1 and Bradykinin B2 Receptors Gene Knockout Mice

    PubMed Central

    Xi, Lei; Das, Anindita; Zhao, Zhi-Qing; Merino, Vanessa F.; Bader, Michael; Kukreja, Rakesh C.

    2011-01-01

    Background Ischemic postconditioning (PostC) is a recently described cardioprotective modality against reperfusion injury, through series of brief re-flow interruptions applied at the very onset of reperfusion. It is proposed that PostC can activate a complex cellular signaling cascade, in which cell membrane receptors could serve as the upstream triggers of PostC. However, the exact subtypes of such receptors remain controversial or uninvestigated. To this context, the purpose of present study was to determine the definitive role of adenosine A1, bradykinin B1 and B2 receptors in PostC. Methods and Results The hearts isolated from adult male C57BL/6J wild-type mice or the mice lacking adenosine A1, or bradykinin B1 or B2 receptors subjected to zero-flow global ischemia and reperfusion in a Langendorff model. PostC, consisting of 6 cycles of 10 sec of reperfusion and 10 sec of ischemia, demonstrated significantly reduced myocardial infarct size (22.8±3.1%, Mean±SEM) as compared with the non-PostC wild-type controls (35.1±2.8%, P<0.05). The infarct-limiting protection of PostC was absent in adenosine A1 receptor knockout mice (34.9±2.7%) or bradykinin B2 receptor knockout mice (33.3±1.7%) and was partially attenuated in bradykinin B1 receptor deficient mice (25.6±2.9%; P>0.05). On the other hand, PostC did not significantly alter post-ischemic cardiac contractile function and coronary flow. Conclusions With the use of three distinctive strains of gene knockout mice, the current study has provided the first conclusive evidence showing PostC-induced infarct-limiting cardioprotection could be triggered by activation of multiple types of cell membrane receptors, which include adenosine A1 and bradykinin B2 receptors. PMID:18824766

  3. Health and population effects of rare gene knockouts in adult humans with related parents.

    PubMed

    Narasimhan, Vagheesh M; Hunt, Karen A; Mason, Dan; Baker, Christopher L; Karczewski, Konrad J; Barnes, Michael R; Barnett, Anthony H; Bates, Chris; Bellary, Srikanth; Bockett, Nicholas A; Giorda, Kristina; Griffiths, Christopher J; Hemingway, Harry; Jia, Zhilong; Kelly, M Ann; Khawaja, Hajrah A; Lek, Monkol; McCarthy, Shane; McEachan, Rosie; O'Donnell-Luria, Anne; Paigen, Kenneth; Parisinos, Constantinos A; Sheridan, Eamonn; Southgate, Laura; Tee, Louise; Thomas, Mark; Xue, Yali; Schnall-Levin, Michael; Petkov, Petko M; Tyler-Smith, Chris; Maher, Eamonn R; Trembath, Richard C; MacArthur, Daniel G; Wright, John; Durbin, Richard; van Heel, David A

    2016-04-22

    Examining complete gene knockouts within a viable organism can inform on gene function. We sequenced the exomes of 3222 British adults of Pakistani heritage with high parental relatedness, discovering 1111 rare-variant homozygous genotypes with predicted loss of function (knockouts) in 781 genes. We observed 13.7% fewer homozygous knockout genotypes than we expected, implying an average load of 1.6 recessive-lethal-equivalent loss-of-function (LOF) variants per adult. When genetic data were linked to the individuals' lifelong health records, we observed no significant relationship between gene knockouts and clinical consultation or prescription rate. In this data set, we identified a healthy PRDM9-knockout mother and performed phased genome sequencing on her, her child, and control individuals. Our results show that meiotic recombination sites are localized away from PRDM9-dependent hotspots. Thus, natural LOF variants inform on essential genetic loci and demonstrate PRDM9 redundancy in humans.

  4. Health and population effects of rare gene knockouts in adult humans with related parents

    PubMed Central

    Narasimhan, Vagheesh M.; Hunt, Karen A.; Mason, Dan; Baker, Christopher L.; Karczewski, Konrad J.; Barnes, Michael R.; Barnett, Anthony H.; Bates, Chris; Bellary, Srikanth; Bockett, Nicholas A.; Giorda, Kristina; Griffiths, Christopher J.; Hemingway, Harry; Jia, Zhilong; Kelly, M. Ann; Khawaja, Hajrah A.; Lek, Monkol; McCarthy, Shane; McEachan, Rosie; O’Donnell-Luria, Anne; Paigen, Kenneth; Parisinos, Constantinos A.; Sheridan, Eamonn; Southgate, Laura; Tee, Louise; Thomas, Mark; Xue, Yali; Schnall-Levin, Michael; Petkov, Petko M.; Tyler-Smith, Chris; Maher, Eamonn R.; Trembath, Richard C.; MacArthur, Daniel G.; Wright, John; Durbin, Richard; van Heel, David A.

    2016-01-01

    Examining complete gene knockouts within a viable organism can inform on gene function. We sequenced the exomes of 3,222 British Pakistani-heritage adults with high parental relatedness, discovering 1,111 rare-variant homozygous genotypes with predicted loss of gene function (knockouts) in 781 genes. We observed 13.7% fewer than expected homozygous knockout genotypes, implying an average load of 1.6 recessive-lethal-equivalent LOF variants per adult. Linking genetic data to lifelong health records, knockouts were not associated with clinical consultation or prescription rate. In this dataset we identified a healthy PRDM9 knockout mother, and performed phased genome sequencing on her, her child and controls, which showed meiotic recombination sites localised away from PRDM9-dependent hotspots. Thus, natural LOF variants inform upon essential genetic loci, and demonstrate PRDM9 redundancy in humans. PMID:26940866

  5. [Psychosomatic aspects of cardiac arrhythmias].

    PubMed

    Siepmann, Martin; Kirch, Wilhelm

    2010-07-01

    Emotional stress facilitates the occurrence of cardiac arrhythmias including sudden cardiac death. The prevalence of anxiety and depression is increased in cardiac patients as compared to the normal population. The risk of cardiovascular mortality is enhanced in patients suffering from depression. Comorbid anxiety disorders worsen the course of cardiac arrhythmias. Disturbance of neurocardiac regulation with predominance of the sympathetic tone is hypothesized to be causative for this. The emotional reaction to cardiac arrhythmias is differing to a large extent between individuals. Emotional stress may result from coping with treatment of cardiac arrhythmias. Emotional stress and cardiac arrhythmias may influence each other in the sense of a vicious circle. Somatoform cardiac arrhythmias are predominantly of psychogenic origin. Instrumental measures and frequent contacts between physicians and patients may facilitate disease chronification. The present review is dealing with the multifaceted relationships between cardiac arrhythmias and emotional stress. The underlying mechanisms and corresponding treatment modalities are discussed.

  6. Pediatric cardiac emergencies.

    PubMed

    Lee, C; Mason, L J

    2001-06-01

    Successful management of pediatric cardiac emergencies requires an accurate diagnosis to institute an appropriate plan of therapy. The diagnosis, however, is not always straightforward, as evidenced by the nonspecific clinical picture that can be presented by congenital heart defects. Entertaining the possibility of a cardiac problem in neonates with pulmonary symptoms unresponsive to standard therapies is crucial for successful management of patients with congenital heart disease. In addition to ventilatory support, prostaglandin E1 infusions or emergency interventional cardiac catheterization is often a life-saving initial measure in patients with acutely decompensated congenital cardiac lesions that require a patent ductus arteriosus for survival. Pericardial tamponade is associated with various acquired and iatrogenic causes. Emergent pericardiocentesis is mandatory when cardiovascular compromise occurs. The goal of anesthetic management is to maintain cardiac output. With the increasing use of central venous catheters in neonatal ICUs and the high mortality rate for central venous catheter-related cardiac tamponade, the diagnosis must be considered in any patient with a central venous catheter in situ who acutely develops unexplained hypotension, bradycardia, and diminished pulses. Arrhythmias also can cause hemodynamic instability in infants and children. Supraventricular tachycardia is by far the most common emergently presenting arrhythmia in the pediatric population. Unstable patients require immediate intravenous adenosine or synchronized cardioversion. Complete heart block is rare, but it can lead to congestive heart failure and occasionally to cardiovascular collapse and sudden death. Emergency treatment of complete heart block includes pharmacologic support and temporary or permanent pacemaker placement as indicated. In infants, congestive heart failure usually is related to congenital heart disease, whereas in older children, it tends to be secondary

  7. OSM mitigates post-infarction cardiac remodeling and dysfunction by up-regulating autophagy through Mst1 suppression.

    PubMed

    Hu, Jianqiang; Zhang, Lei; Zhao, Zhijing; Zhang, Mingming; Lin, Jie; Wang, Jiaxing; Yu, Wenjun; Man, Wanrong; Li, Congye; Zhang, Rongqing; Gao, Erhe; Wang, Haichang; Sun, Dongdong

    2016-11-04

    The incidence and prevalence of heart failure (HF) in the world are rapidly rising possibly attributed to the worsened HF following myocardial infarction (MI) in recent years. Here we examined the effects of oncostatin M (OSM) on postinfarction cardiac remodeling and the underlying mechanisms involved. MI model was induced using left anterior descending coronary artery (LAD) ligation. In addition, cultured neonatal mouse cardiomyocytes were subjected to simulated MI. Our results revealed that OSM alleviated left ventricular remodeling, promoted cardiac function, restored mitochondrial cristae density and architecture disorders after 4weeks of MI. Enhanced autophagic flux was indicated in cardiomyocytes transduced with Ad-GFP -LC3 in the OSM treated group as compared with the MI group. OSM receptor Oβ knockout blocked the beneficial effects of OSM in postinfarction cardiac remodeling and cardiomyocytes autophagy. OSM pretreatment significantly alleviated left ventricular remodeling and dysfunction in Mst1 transgenic mice, while it failed to reverse further the postinfarction left ventricular dilatation and cardiac function in the Mst1 knockout mice. Our data revealed that OSM alleviated postinfarction cardiac remodeling and dysfunction by enhancing cardiomyocyte autophagy. OSM holds promise as a therapeutic target in treating HF after MI through Oβ receptor by inhibiting Mst1 phosphorylation.

  8. Genetic deletion of NOS3 increases lethal cardiac dysfunction following mouse cardiac arrest.

    PubMed

    Beiser, David G; Orbelyan, Gerasim A; Inouye, Brendan T; Costakis, James G; Hamann, Kimm J; McNally, Elizabeth M; Vanden Hoek, Terry L

    2011-01-01

    Cardiac arrest mortality is significantly affected by failure to obtain return of spontaneous circulation (ROSC) despite cardiopulmonary resuscitation (CPR). Severe myocardial dysfunction and cardiovascular collapse further affects mortality within hours of initial ROSC. Recent work suggests that enhancement of nitric oxide (NO) signaling within minutes of CPR can improve myocardial function and survival. We studied the role of NO signaling on cardiovascular outcomes following cardiac arrest and resuscitation using endothelial NO synthase knockout (NOS3(-/-)) mice. Adult female wild-type (WT) and NOS3(-/-) mice were anesthetized, intubated, and instrumented with left-ventricular pressure-volume catheters. Cardiac arrest was induced with intravenous potassium chloride. CPR was performed after 8min of untreated arrest. ROSC rate, cardiac function, whole-blood nitrosylhemoglobin (HbNO) concentrations, heart NOS3 content and phosphorylation (p-NOS3), cyclic guanosine monophosphate (cGMP), and phospho-troponin I (p-TnI) were measured. Despite equal quality CPR, NOS3(-/-) mice displayed lower rates of ROSC compared to WT (47.6% [10/21] vs. 82.4% [14/17], p<0.005). Among ROSC animals, NOS3(-/-) vs. WT mice exhibited increased left-ventricular dysfunction and 120min mortality. Prior to ROSC, myocardial effectors of NO signaling including cGMP and p-TnI were decreased in NOS3(-/-) vs. WT mice (p<0.05). Following ROSC in WT mice, significant NOS3-dependent increases in circulating HbNO were seen by 120min. Significant increases in cardiac p-NOS3 occurred between end-arrest and 15min post-ROSC, while total NOS3 content was increased by 120min post-ROSC (p<0.05). Genetic deletion of NOS3 decreases ROSC rate and worsens post-ROSC left-ventricular function. Poor cardiovascular outcomes are associated with differences in NOS3-dependent myocardial cGMP signaling and circulating NO metabolites. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  9. Myoglobin-deficient mice activate a distinct cardiac gene expression program in response to isoproterenol-induced hypertrophy.

    PubMed

    Molojavyi, Andrei; Lindecke, Antje; Raupach, Annika; Moellendorf, Sarah; Köhrer, Karl; Gödecke, Axel

    2010-04-01

    Myoglobin knockout mice (myo-/-) adapt to the loss of myoglobin by the activation of a variety of compensatory mechanisms acting on the structural and functional level. To analyze to what extent myo-/- mice would tolerate cardiac stress we used the model of chronic isoproterenol application to induce cardiac hypertrophy in myo-/- mice and wild-type (WT) controls. After 14 days of isoproterenol infusion cardiac hypertrophy in WT and myo-/- mice reached a similar level. WT mice developed lung edema and left ventricular dilatation suggesting the development of heart failure. In contrast, myo-/- mice displayed conserved cardiac function and no signs of left ventricular dilatation. Analysis of the cardiac gene expression profiles using 40K mouse oligonucleotide arrays showed that isoproterenol affected the expression of 180 genes in WT but only 92 genes of myo-/- hearts. Only 40 of these genes were regulated in WT as well as in myo-/- hearts. In WT hearts a pronounced induction of genes of the extracellular matrix occurred suggesting a higher level of cardiac remodeling. myo-/- hearts showed altered transcription of genes involved in carbon metabolism, inhibition of apoptosis and muscular repair. Interestingly, a subset of genes that was altered in myo-/- mice already under basal conditions was differentially expressed in WT hearts under isoproterenol treatment. In summary, our data show a high capacity of myoglobin-deficient mice to adapt to catecholamine induced cardiac stress which is associated with activation of a distinct cardiac gene expression program.

  10. Cardiac radiology: centenary review.

    PubMed

    de Roos, Albert; Higgins, Charles B

    2014-11-01

    During the past century, cardiac imaging technologies have revolutionized the diagnosis and treatment of acquired and congenital heart disease. Many important contributions to the field of cardiac imaging were initially reported in Radiology. The field developed from the early stages of cardiac imaging, including the use of coronary x-ray angiography and roentgen kymography, to nowadays the widely used echocardiographic, nuclear medicine, cardiac computed tomographic (CT), and magnetic resonance (MR) applications. It is surprising how many of these techniques were not recognized for their potential during their early inception. Some techniques were described in the literature but required many years to enter the clinical arena and presently continue to expand in terms of clinical application. The application of various CT and MR contrast agents for the diagnosis of myocardial ischemia is a case in point, as the utility of contrast agents continues to expand the noninvasive characterization of myocardium. The history of cardiac imaging has included a continuous process of advances in our understanding of the anatomy and physiology of the cardiovascular system, along with advances in imaging technology that continue to the present day.

  11. Caffeine and cardiac arrhythmias.

    PubMed

    Myers, M G

    1991-01-15

    To review the evidence supporting the belief that caffeine causes cardiac arrhythmias. Studies published since 1982 identified through computerized searches of MEDLINE, TOXLINE, and Chemical Abstracts and a review of bibliographies of relevant articles on the subject of caffeine and cardiac arrhythmias. All clinical studies examining caffeine as a cause of cardiac arrhythmias and a selection of basic science experiments to illustrate caffeine's effects in vitro. Study quality was assessed and all available clinical data pertaining to caffeine as a cause of arrhythmias were summarized. In one electrophysiologic study, caffeine was associated with an increased susceptibility to provoked cardiac arrhythmias. In five placebo-controlled trials, caffeine in doses up to 500 mg daily (equivalent to 5 to 6 cups of coffee) did not increase the frequency or severity of ventricular arrhythmias. One large epidemiologic study reported an increase in the frequency of ventricular extrasystoles in persons consuming 9 or more cups of coffee daily. Moderate ingestion of caffeine does not increase the frequency or severity of cardiac arrhythmias in normal persons, patients with ischemic heart disease, or those with pre-existing serious ventricular ectopy.

  12. Nucleostemin rejuvenates cardiac progenitor cells and antagonizes myocardial aging.

    PubMed

    Hariharan, Nirmala; Quijada, Pearl; Mohsin, Sadia; Joyo, Anya; Samse, Kaitlen; Monsanto, Megan; De La Torre, Andrea; Avitabile, Daniele; Ormachea, Lucia; McGregor, Michael J; Tsai, Emily J; Sussman, Mark A

    2015-01-20

    Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy in elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. This study sought to demonstrate that NS preserves characteristics associated with "stemness" in CPCs and antagonizes myocardial senescence and aging. CPCs isolated from human fetal (fetal human cardiac progenitor cell [FhCPC]) and adult failing (adult human cardiac progenitor cell [AhCPC]) hearts, as well as young (young cardiac progenitor cell [YCPC]) and old mice (old cardiac progenitor cell [OCPC]), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with 1 functional allele of NS (NS+/-) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. NS expression is decreased in AhCPCs relative to FhCPCs, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble those of OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S-phase progression, diminished expression of stemness markers, and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of "stemness." Early cardiac aging with a decline in cardiac function, an increase in senescence markers p53 and p16, telomere attrition

  13. Dmpk gene deletion or antisense knockdown does not compromise cardiac or skeletal muscle function in mice

    PubMed Central

    Carrell, Samuel T.; Carrell, Ellie M.; Auerbach, David; Pandey, Sanjay K.; Bennett, C. Frank; Dirksen, Robert T.; Thornton, Charles A.

    2016-01-01

    Myotonic dystrophy type 1 (DM1) is a genetic disorder in which dominant-active DM protein kinase (DMPK) transcripts accumulate in nuclear foci, leading to abnormal regulation of RNA processing. A leading approach to treat DM1 uses DMPK-targeting antisense oligonucleotides (ASOs) to reduce levels of toxic RNA. However, basal levels of DMPK protein are reduced by half in DM1 patients. This raises concern that intolerance for further DMPK loss may limit ASO therapy, especially since mice with Dmpk gene deletion reportedly show cardiac defects and skeletal myopathy. We re-examined cardiac and muscle function in mice with Dmpk gene deletion, and studied post-maturity knockdown using Dmpk-targeting ASOs in mice with heterozygous deletion. Contrary to previous reports, we found no effect of Dmpk gene deletion on cardiac or muscle function, when studied on two genetic backgrounds. In heterozygous knockouts, the administration of ASOs reduced Dmpk expression in cardiac and skeletal muscle by > 90%, yet survival, electrocardiogram intervals, cardiac ejection fraction and muscle strength remained normal. The imposition of cardiac stress by pressure overload, or muscle stress by myotonia, did not unmask a requirement for DMPK. Our results support the feasibility and safety of using ASOs for post-transcriptional silencing of DMPK in muscle and heart. PMID:27522499

  14. Taurine depletion caused by knocking out the taurine transporter gene leads to cardiomyopathy with cardiac atrophy.

    PubMed

    Ito, Takashi; Kimura, Yasushi; Uozumi, Yoriko; Takai, Mika; Muraoka, Satoko; Matsuda, Takahisa; Ueki, Kei; Yoshiyama, Minoru; Ikawa, Masahito; Okabe, Masaru; Schaffer, Stephen W; Fujio, Yasushi; Azuma, Junichi

    2008-05-01

    The sulfur-containing beta-amino acid, taurine, is the most abundant free amino acid in cardiac and skeletal muscle. Although its physiological function has not been established, it is thought to play an important role in ion movement, calcium handling, osmoregulation and cytoprotection. To begin examining the physiological function of taurine, we generated taurine transporter- (TauT-) knockout mice (TauTKO), which exhibited a deficiency in myocardial and skeletal muscle taurine content compared with their wild-type littermates. The TauTKO heart underwent ventricular remodeling, characterized by reductions in ventricular wall thickness and cardiac atrophy accompanied with the smaller cardiomyocytes. Associated with the structural changes in the heart was a reduction in cardiac output and increased expression of heart cardiac failure (fetal) marker genes, such as ANP, BNP and beta-MHC. Moreover, ultrastructural damage to the myofilaments and mitochondria was observed. Further, the skeletal muscle of the TauTKO mice also exhibited decreased cell volume, structural defects and a reduction of exercise endurance capacity. Importantly, the expression of Hsp70, ATA2 and S100A4, which are upregulated by osmotic stress, was elevated in both heart and skeletal muscle of the TauTKO mice. Taurine depletion causes cardiomyocyte atrophy, mitochondrial and myofiber damage and cardiac dysfunction, effects likely related to the actions of taurine. Our data suggest that multiple actions of taurine, including osmoregulation, regulation of mitochondrial protein expression and inhibition of apoptosis, collectively ensure proper maintenance of cardiac and skeletal muscular structure and function.

  15. Resveratrol, an activator of SIRT1, upregulates AMPK and improves cardiac function in heart failure.

    PubMed

    Gu, X S; Wang, Z B; Ye, Z; Lei, J P; Li, L; Su, D F; Zheng, X

    2014-01-21

    Reduced AMP-activated protein kinase (AMPK) expression has been shown to play a significant role in the cardiac dysfunction in heart failure. This study was designed to examine the effect of resveratrol, a potent activator of silent information regulator (SIRT1), on cardiac function and AMPK expression in heart failure. Adult male rat left anterior descending arteries were ligated, and they were fed with either a regular diet or a diet enriched with resveratrol. Heart failure was produced by myocardial infarction, and was associated with markedly increased AMPK and SIRT1 protein levels. Resveratrol treatment had a tremendous beneficial effect, both in terms of improving AMPK expression and on cardiac function. Decreased cardiac function and AMPK expression were also found in SIRT1 knockout (+/-) mice. In cultured cardiomyocytes, resveratrol increased AMPK and SIRT1 expressions, and overexpression of SIRT1 was found to be sufficient to activate AMPK in H9c2 cells. In contrast, pretreatment of cardiomyocytes with an SIRT1 antagonist, nicotinamide, blocked these beneficial effects of resveratrol. Therefore, the protective effects of resveratrol were found to be dependent on its ability to activate SIRT1 and improve AMPK expression. These results demonstrated that in heart failure, the enzymatic activity of cardiac SIRT1 is increased, which contributes to increased expression of AMPK, and resveratrol enhances the expression of AMPK and improves cardiac function through the activation of SIRT1.

  16. Nitric Oxide Induces Cardiac Protection by Preventing Extracellular Matrix Degradation through the Complex Caveolin-3/EMMPRIN in Cardiac Myocytes

    PubMed Central

    Cuadrado, Irene; Castejon, Borja; Martin, Ana M.; Saura, Marta; Reventun-Torralba, Paula; Zamorano, Jose Luis

    2016-01-01

    Inhibition of Extracellular Matrix degradation by nitric oxide (NO) induces cardiac protection against coronary ischemia/reperfusion (IR). Glycosylation of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) stimulates enzymatic activation of matrix metalloproteinases (MMPs) in the heart, although the mechanisms leading to EMMPRIN glycosylation are poorly understood. We sought to determine if NO may induce cardiac protection by preventing glycosylation of EMMPRIN in a mouse model of IR. Here we found that Caveolin-3 binds to low glycosylated EMMPRIN (LG-EMMPRIN) in cardiac cells and in the hearts of healthy mice, whereas IR disrupted the complex in nitric oxide synthase 2 (NOS2) knockout (KO) mice. By contrast, the binding was partially restored when mice were fed with an NO donor (DEA-NO) in the drinking water, showing a significant reduction on infarct size (NOS2KO: 34.6±5 vs NOS2KO+DEA-NO: 20.7±9), in expression of matrix metalloproteinases, and cardiac performance was improved (left ventricular ejection fraction (LVEF). NOS2KO: 31±4 vs NOS2KO+DEA-NO: 46±6). The role of Caveolin-3/EMMPRIN in NO-mediated cardiac protection was further assayed in Caveolin-3 KO mice, showing no significant improvement on infarct size (Caveolin-3 KO: 34.8±3 vs Caveolin-3 KO+DEA-NO:33.7±5), or in the expression of MMPs, suggesting that stabilization of the complex Caveolin-3/LG-EMMPRIN may play a significant role in the cardioprotective effect of NO against IR. PMID:27649573

  17. Nitric Oxide Induces Cardiac Protection by Preventing Extracellular Matrix Degradation through the Complex Caveolin-3/EMMPRIN in Cardiac Myocytes.

    PubMed

    Cuadrado, Irene; Castejon, Borja; Martin, Ana M; Saura, Marta; Reventun-Torralba, Paula; Zamorano, Jose Luis; Zaragoza, Carlos

    2016-01-01

    Inhibition of Extracellular Matrix degradation by nitric oxide (NO) induces cardiac protection against coronary ischemia/reperfusion (IR). Glycosylation of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) stimulates enzymatic activation of matrix metalloproteinases (MMPs) in the heart, although the mechanisms leading to EMMPRIN glycosylation are poorly understood. We sought to determine if NO may induce cardiac protection by preventing glycosylation of EMMPRIN in a mouse model of IR. Here we found that Caveolin-3 binds to low glycosylated EMMPRIN (LG-EMMPRIN) in cardiac cells and in the hearts of healthy mice, whereas IR disrupted the complex in nitric oxide synthase 2 (NOS2) knockout (KO) mice. By contrast, the binding was partially restored when mice were fed with an NO donor (DEA-NO) in the drinking water, showing a significant reduction on infarct size (NOS2KO: 34.6±5 vs NOS2KO+DEA-NO: 20.7±9), in expression of matrix metalloproteinases, and cardiac performance was improved (left ventricular ejection fraction (LVEF). NOS2KO: 31±4 vs NOS2KO+DEA-NO: 46±6). The role of Caveolin-3/EMMPRIN in NO-mediated cardiac protection was further assayed in Caveolin-3 KO mice, showing no significant improvement on infarct size (Caveolin-3 KO: 34.8±3 vs Caveolin-3 KO+DEA-NO:33.7±5), or in the expression of MMPs, suggesting that stabilization of the complex Caveolin-3/LG-EMMPRIN may play a significant role in the cardioprotective effect of NO against IR.

  18. TRPA1 mediates changes in heart rate variability and cardiac ...

    EPA Pesticide Factsheets

    Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described; however, the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3ppm acrolein, 0.3ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to ac

  19. Altered Sleep Homeostasis in Rev-erbα Knockout Mice

    PubMed Central

    Mang, Géraldine M.; La Spada, Francesco; Emmenegger, Yann; Chappuis, Sylvie; Ripperger, Jürgen A.; Albrecht, Urs; Franken, Paul

    2016-01-01

    Study Objectives: The nuclear receptor REV-ERBα is a potent, constitutive transcriptional repressor critical for the regulation of key circadian and metabolic genes. Recently, REV-ERBα's involvement in learning, neurogenesis, mood, and dopamine turnover was demonstrated suggesting a specific role in central nervous system functioning. We have previously shown that the brain expression of several core clock genes, including Rev-erbα, is modulated by sleep loss. We here test the consequences of a loss of REV-ERBα on the homeostatic regulation of sleep. Methods: EEG/EMG signals were recorded in Rev-erbα knockout (KO) mice and their wild type (WT) littermates during baseline, sleep deprivation, and recovery. Cortical gene expression measurements after sleep deprivation were contrasted to baseline. Results: Although baseline sleep/wake duration was remarkably similar, KO mice showed an advance of the sleep/wake distribution relative to the light-dark cycle. After sleep onset in baseline and after sleep deprivation, both EEG delta power (1–4 Hz) and sleep consolidation were reduced in KO mice indicating a slower increase of homeostatic sleep need during wakefulness. This slower increase might relate to the smaller increase in theta and gamma power observed in the waking EEG prior to sleep onset under both conditions. Indeed, the increased theta activity during wakefulness predicted delta power in subsequent NREM sleep. Lack of Rev-erbα increased Bmal1, Npas2, Clock, and Fabp7 expression, confirming the direct regulation of these genes by REV-ERBα also in the brain. Conclusions: Our results add further proof to the notion that clock genes are involved in sleep homeostasis. Because accumulating evidence directly links REV-ERBα to dopamine signaling the altered homeostatic regulation of sleep reported here are discussed in that context. Citation: Mang GM, La Spada F, Emmenegger Y, Chappuis S, Ripperger JA, Albrecht U, Franken P. Altered sleep homeostasis in Rev

  20. Complementation Test of Rpe65 Knockout and Tvrm148

    PubMed Central

    Wright, Charles B.; Chrenek, Micah A.; Foster, Stephanie L.; Duncan, Todd; Redmond, T. Michael; Pardue, Machelle T.; Boatright, Jeffrey H.; Nickerson, John M.

    2013-01-01

    Purpose. A mouse mutation, tvrm148, was previously reported as resulting in retinal degeneration. Tvrm148 and Rpe65 map between markers D3Mit147 and D3Mit19 on a genetic map, but the physical map places RPE65 outside the markers. We asked if Rpe65 or perhaps another nearby gene is mutated and if the mutant reduced 11-cis-retinal levels. We studied the impact of the tvrm148 mutation on visual function, morphology, and retinoid levels. Methods. Normal phase HPLC was used to measure retinoid levels. Rpe65+/+, tvrm148/+ (T+/−), tvrm148/tvrm148 (T−/−), RPE65KO/KO (Rpe65−/−), and Rpe65T/− mice visual function was measured by optokinetic tracking (OKT) and electroretinography (ERG). Morphology was assessed by light microscopy and transmission electron microscopy (TEM). qRT-PCR was used to measure Rpe65 mRNA levels. Immunoblotting measured the size and amount of RPE65 protein. Results. The knockout and tvrm148 alleles did not complement. No 11-cis-retinal was detected in T−/− or Rpe65−/− mice. Visual acuity in Rpe65+/+ and T+/− mouse was ∼0.382 c/d, but 0.037 c/d in T−/− mice at postnatal day 210 (P210). ERG response in T−/− mice was undetectable except at bright flash intensities. Outer nuclear layer (ONL) thickness in T−/− mice was ∼70% of Rpe65+/+ by P210. Rpe65 mRNA levels in T−/− mice were unchanged, yet 14.5% of Rpe65+/+ protein levels was detected. Protein size was unchanged. Conclusions. A complementation test revealed the RPE65 knockout and tvrm148 alleles do not complement, proving that the tvrm148 mutation is in Rpe65. Behavioral, physiological, molecular, biochemical, and histological approaches indicate that tvrm148 is a null allele of Rpe65. PMID:23778877

  1. MOMDIS: a Glauber model computer code for knockout reactions

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Gade, A.

    2006-09-01

    A computer program is described to calculate momentum distributions in stripping and diffraction dissociation reactions. A Glauber model is used with the scattering wavefunctions calculated in the eikonal approximation. The program is appropriate for knockout reactions at intermediate energy collisions ( 30 MeV⩽E/nucleon⩽2000 MeV). It is particularly useful for reactions involving unstable nuclear beams, or exotic nuclei (e.g., neutron-rich nuclei), and studies of single-particle occupancy probabilities (spectroscopic factors) and other related physical observables. Such studies are an essential part of the scientific program of radioactive beam facilities, as in for instance the proposed RIA (Rare Isotope Accelerator) facility in the US. Program summaryTitle of program: MOMDIS (MOMentum DIStributions) Catalogue identifier:ADXZ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXZ_v1_0 Computers: The code has been created on an IBM-PC, but also runs on UNIX or LINUX machines Operating systems: WINDOWS or UNIX Program language used: Fortran-77 Memory required to execute with typical data: 16 Mbytes of RAM memory and 2 MB of hard disk space No. of lines in distributed program, including test data, etc.: 6255 No. of bytes in distributed program, including test data, etc.: 63 568 Distribution format: tar.gz Nature of physical problem: The program calculates bound wavefunctions, eikonal S-matrices, total cross-sections and momentum distributions of interest in nuclear knockout reactions at intermediate energies. Method of solution: Solves the radial Schrödinger equation for bound states. A Numerov integration is used outwardly and inwardly and a matching at the nuclear surface is done to obtain the energy and the bound state wavefunction with good accuracy. The S-matrices are obtained using eikonal wavefunctions and the "t- ρρ" method to obtain the eikonal phase-shifts. The momentum distributions are obtained by means of a Gaussian expansion of

  2. Final-state interactions in two-nucleon knockout reactions

    NASA Astrophysics Data System (ADS)

    Colle, Camille; Cosyn, Wim; Ryckebusch, Jan

    2016-03-01

    Background: Exclusive two-nucleon knockout after electroexcitation of nuclei [A (e ,e'N N ) in brief] is considered to be a primary source of information about short-range correlations (SRCs) in nuclei. For a proper interpretation of the data, final-state interactions (FSIs) need to be theoretically controlled. Purpose: Our goal is to quantify the role of FSI effects in exclusive A (e ,e'p N ) reactions for four target nuclei representative of the whole mass region. Our focus is on processes that are SRC driven. We investigate the role of FSIs for two characteristic detector setups corresponding to "small" and "large" coverage of the available phase space. Method: Use is made of a factorized expression for the A (e ,e'p N ) cross section that is proportional to the two-body center-of-mass (c.m.) momentum distribution of close-proximity pairs. The A (e ,e'p p ) and A (e ,e'p n ) reactions for the target nuclei 12C,27Al,56Fe, and 208Pb are investigated. The elastic attenuation mechanisms in the FSIs are included using the relativistic multiple-scattering Glauber approximation (RMSGA). Single-charge exchange (SCX) reactions are also included. We introduce the nuclear transparency TAp N, defined as the ratio of exclusive (e ,e'p N ) cross sections on nuclei to those on "free" nucleon pairs, as a measure for the aggregated effect of FSIs in p N knockout reactions from nucleus A . A toy model is introduced in order to gain a better understanding of the A dependence of TAp N. Results: The transparency TAp N drops from 0.2 -0.3 for 12C to 0.04 -0.07 for 208Pb. For all considered kinematics, the mass dependence of TAp N can be captured by the power law TAp N∝A-λ with 0.4 ≲λ ≲0.5 . Apart from an overall reduction factor, we find that FSIs only modestly affect the distinct features of SRC-driven A (e ,e'p N ) which are dictated by the c.m. distribution of close-proximity pairs. Conclusion: The SCX mechanisms represent a relatively small (order of a few percent

  3. Assessing Cardiac Metabolism

    PubMed Central

    Taegtmeyer, Heinrich; Young, Martin E.; Lopaschuk, Gary D.; Abel, E. Dale; Brunengraber, Henri; Darley-Usmar, Victor; Des Rosiers, Christine; Gerszten, Robert; Glatz, Jan F.; Griffin, Julian L.; Gropler, Robert J.; Holzhuetter, Hermann-Georg; Kizer, Jorge R.; Lewandowski, E. Douglas; Malloy, Craig R.; Neubauer, Stefan; Peterson, Linda R.; Portman, Michael A.; Recchia, Fabio A.; Van Eyk, Jennifer E.; Wang, Thomas J.

    2016-01-01

    In a complex system of interrelated reactions, the heart converts chemical energy to mechanical energy. Energy transfer is achieved through coordinated activation of enzymes, ion channels, and contractile elements, as well as structural and membrane proteins. The heart’s needs for energy are difficult to overestimate. At a time when the cardiovascular research community is discovering a plethora of new molecular methods to assess cardiac metabolism, the methods remain scattered in the literature. The present statement on “Assessing Cardiac Metabolism” seeks to provide a collective and curated resource on methods and models used to investigate established and emerging aspects of cardiac metabolism. Some of those methods are refinements of classic biochemical tools, whereas most others are recent additions from the powerful tools of molecular biology. The aim of this statement is to be useful to many and to do justice to a dynamic field of great complexity. PMID:27012580

  4. Fetal cardiac scanning today.

    PubMed

    Allan, Lindsey

    2010-07-01

    The ability to examine the structure of the fetal heart in real-time started over 30 years ago now. The field has seen very great advances since then, both in terms of technical improvements in ultrasound equipment and in dissemination of operator skills. A great deal has been learnt about normal cardiac function in the human fetus throughout gestation and how it is affected by pathologies of pregnancy. There is increasing recognition of abnormal heart structure during routine obstetric scanning, allowing referral for specialist diagnosis and counselling. It is now possible to make accurate diagnosis of cardiac malformations as early as 12 weeks of gestation. Early diagnosis of a major cardiac malformation in the fetus can provide the parents with a comprehensive prognosis, enabling them to make the most informed choice about the management of the pregnancy.

  5. Toothache of cardiac origin.

    PubMed

    Kreiner, M; Okeson, J P

    1999-01-01

    Pain referred to the orofacial structures can sometimes be a diagnostic challenge for the clinician. In some instances, a patient may complain of tooth pain that is completely unrelated to any dental source. This poses a diagnostic and therapeutic problem for the dentist. Cardiac pain most commonly radiates to the left arm, shoulder, neck, and face. In rare instances, angina pectoris may present as dental pain. When this occurs, an improper diagnosis frequently leads to unnecessary dental treatment or, more significantly, a delay of proper treatment. This delay may result in the patient experiencing an acute myocardial infarction. It is the dentist's responsibility to establish a proper diagnosis so that the treatment will be directed toward the source of pain and not to the site of pain. This article reviews the literature concerning referred pain of cardiac origin and presents a case report of toothache of cardiac origin.

  6. Autoantibodies and Cardiac Arrhythmias

    PubMed Central

    Lee, Hon-Chi; Huang, Kristin T. L.; Wang, Xiao-Li; Shen, Win-Kuang

    2013-01-01

    Autoimmune diseases are associated with significant morbidity and mortality, afflicting about 5% of the population of the United States. They encompass a wide range of disorders that affect all organs of the human body and have a predilection for women. In the past, autoimmune pathogenesis was not thought to be a major mechanism for cardiovascular disorders, and potential relationships remain understudied. However, accumulating evidence suggests that a number of vascular and cardiac conditions are autoimmune-mediated. Recent studies indicate that autoantibodies play an important role in the development of cardiac arrhythmias, including atrial fibrillation, modulation of autonomic influences on heart rate and rhythm, conduction system abnormalities, and ventricular arrhythmias. This manuscript will review the current evidence for the role of autoantibodies in the development of cardiac arrhythmias. PMID:21740882

  7. Antibodies to cardiac receptors.

    PubMed

    Boivin-Jahns, V; Schlipp, A; Hartmann, S; Panjwani, P; Klingel, K; Lohse, M J; Ertl, G; Jahns, R

    2012-12-01

    Inflammation of cardiac tissue is generally associated with an activation of the host's immune system. On the one hand, this activation is mandatory to protect the heart by fighting the invading microbial agents or toxins and by engaging myocardial reparation and healing processes. On the other hand, uncontrolled activation of the immune defense has the risk of an arousal of auto- or cross-reactive immune cells, which in some cases bring more harm than good. Dependent on the individual genetic predisposition, such heart-directed autoimmune reactions most likely occur as a result of myocyte apoptosis or necrosis and subsequent liberation of self-antigens previously hidden to the immune system. During the past two decades, evidence for a pathogenic relevance of autoimmunity in human heart disease has substantially increased. Conformational cardiac (auto)antibodies affecting cardiac function and, in particular, (auto)antibodies that target G protein-coupled cardiac membrane receptors are thought to play a key role in the development of heart failure. Clinical pilot studies even suggest that such antibodies negatively affect survival in heart failure patients. However, the true prevalence and clinical impact of many cardiac (auto)antibodies in human heart diseases are still unclear, as are the events triggering their formation, their titer course, and their patterns of clearance and/or persistence. The present article summarizes current knowledge in the field of cardiac receptor (auto)antibodies including recent efforts to address some of the aforementioned gaps of knowledge, thereby attempting to pave the way for novel, more specific therapeutic approaches.

  8. Mechanisms of Cardiac Regeneration

    PubMed Central

    Uygur, Aysu; Lee, Richard T.

    2016-01-01

    Adult humans fail to regenerate their hearts following injury, and this failure to regenerate myocardium is a leading cause of heart failure and death worldwide. Although all adult mammals appear to lack significant cardiac regeneration potential, some vertebrates can regenerate myocardium throughout life. In addition, new studies indicate that mammals have cardiac regeneration potential during development and very soon after birth. The mechanisms of heart regeneration among model organisms, including neonatal mice, appear remarkably similar. Orchestrated waves of inflammation, matrix deposition and remodeling, and cardiomyocyte proliferation are commonly seen in heart regeneration models. Understanding why adult mammals develop extensive scarring instead of regeneration is a crucial goal for regenerative biology. PMID:26906733

  9. Mechanisms of cardiac arrhythmias

    PubMed Central

    Tse, Gary

    2015-01-01

    Blood circulation is the result of the beating of the heart, which provides the mechanical force to pump oxygenated blood to, and deoxygenated blood away from, the peripheral tissues. This depends critically on the preceding electrical activation. Disruptions in the orderly pattern of this propagating cardiac excitation wave can lead to arrhythmias. Understanding of the mechanisms underlying their generation and maintenance requires knowledge of the ionic contributions to the cardiac action potential, which is discussed in the first part of this review. A brief outline of the different classification systems for arrhythmogenesis is then provided, followed by a detailed discussion for each mechanism in turn, highlighting recent advances in this area. PMID:27092186

  10. Noninvasive Imaging of Cardiac Electrophysiology

    PubMed Central

    Berger, Thomas; Hintringer, Florian; Fischer, Gerald

    2007-01-01

    Noninvasive imaging of cardiac electrophysiology is still a major goal despite all recent technical innovations. This review gives an overview about the historical background, recent developments and possible future applications of noninvasive imaging of cardiac electrophysiology. PMID:17684574

  11. Drug Treatment of Cardiac Failure

    PubMed Central

    Achong, M. R.; Kumana, C. R.

    1982-01-01

    Treatment of cardiac failure should first be aimed at reversing or ameliorating the underlying pathological processes. This review highlights the common problems and pitfalls in the use of digoxin, diuretics and vasodilators in patients with cardiac failure. PMID:21289849

  12. Iron Regulatory Protein-2 Knockout Increases Perihematomal Ferritin Expression and Cell Viability after Intracerebral Hemorrhage

    PubMed Central

    Chen, Mai; Awe, Olatilewa O.; Chen-Roetling, Jing; Regan, Raymond F.

    2010-01-01

    Iron is deposited in perihematomal tissue after an intracerebral hemorrhage (ICH), and may contribute to oxidative injury. Cell culture studies have demonstrated that enhancing ferritin expression by targeting iron regulatory protein (IRP) binding activity reduces cellular vulnerability to iron and hemoglobin. In order to assess the therapeutic potential of this approach after striatal ICH, the effect of IRP1 or IRP2 gene knockout on ferritin expression and injury was quantified. Striatal ferritin in IRP1 knockout mice was similar to that in wild-type controls three days after stereotactic injection of artificial CSF or autologous blood. Corresponding levels in IRP2 knockouts were increased by 11-fold and 8.4-fold, respectively, compared with wild-type. Protein carbonylation, a sensitive marker of hemoglobin neurotoxicity, was increased by 2.4-fold in blood-injected wild-type striata, was not altered by IRP1 knockout, but was reduced by approximately 60% by IRP2 knockout. Perihematomal cell viability in wild-type mice, assessed by MTT assay, was approximately half of that in contralateral striata at three days, and was significantly increased in IRP2 knockouts but not in IRP1 knockouts. Protection was also observed when hemorrhage was induced by collagenase injection. These results suggest that IRP2 binding activity reduces ferritin expression in the striatum after ICH, preventing an optimal response to elevated local iron concentrations. IRP2 binding activity may be a novel therapeutic target after hemorrhagic CNS injuries. PMID:20399759

  13. [An efficient genetic knockout system based on linear DNA fragment homologous recombination for halophilic archaea].

    PubMed

    Xiaoli, Wang; Chuang, Jiang; Jianhua, Liu; Xipeng, Liu

    2015-04-01

    With the development of functional genomics, gene-knockout is becoming an important tool to elucidate gene functions in vivo. As a good model strain for archaeal genetics, Haloferax volcanii has received more attention. Although several genetic manipulation systems have been developed for some halophilic archaea, it is time-consuming because of the low percentage of positive clones during the second-recombination selection. These classical gene knockout methods are based on DNA recombination between the genomic homologous sequence and the circular suicide plasmid, which carries a pyrE selection marker and two DNA fragments homologous to the upstream and downstream fragments of the target gene. Many wild-type clones are obtained through a reverse recombination between the plasmid and genome in the classic gene knockout method. Therefore, it is necessary to develop an efficient gene knockout system to increase the positive clone percentage. Here we report an improved gene knockout method using a linear DNA cassette consisting of upstream and downstream homologous fragments, and the pyrE marker. Gene deletions were subsequently detected by colony PCR analysis. We determined the efficiency of our knockout method by deleting the xpb2 gene from the H. volcanii genome, with the percentage of positive clones higher than 50%. Our method provides an efficient gene knockout strategy for halophilic archaea.

  14. Iron regulatory protein-2 knockout increases perihematomal ferritin expression and cell viability after intracerebral hemorrhage.

    PubMed

    Chen, Mai; Awe, Olatilewa O; Chen-Roetling, Jing; Regan, Raymond F

    2010-06-14

    Iron is deposited in perihematomal tissue after an intracerebral hemorrhage (ICH), and may contribute to oxidative injury. Cell culture studies have demonstrated that enhancing ferritin expression by targeting iron regulatory protein (IRP) binding activity reduces cellular vulnerability to iron and hemoglobin. In order to assess the therapeutic potential of this approach after striatal ICH, the effect of IRP1 or IRP2 gene knockout on ferritin expression and injury was quantified. Striatal ferritin in IRP1 knockout mice was similar to that in wild-type controls 3 days after stereotactic injection of artificial CSF or autologous blood. Corresponding levels in IRP2 knockouts were increased by 11-fold and 8.4-fold, respectively, compared with wild-type. Protein carbonylation, a sensitive marker of hemoglobin neurotoxicity, was increased by 2.4-fold in blood-injected wild-type striata, was not altered by IRP1 knockout, but was reduced by approximately 60% by IRP2 knockout. Perihematomal cell viability in wild-type mice, assessed by MTT assay, was approximately half of that in contralateral striata at 3 days, and was significantly increased in IRP2 knockouts but not in IRP1 knockouts. Protection was also observed when hemorrhage was induced by collagenase injection. These results suggest that IRP2 binding activity reduces ferritin expression in the striatum after ICH, preventing an optimal response to elevated local iron concentrations. IRP2 binding activity may be a novel therapeutic target after hemorrhagic CNS injuries.

  15. Kv4.2 knockout mice demonstrate increased susceptibility to convulsant stimulation

    PubMed Central

    Barnwell, L. Forbes S.; Lugo, Joaquin N.; Lee, Wai Ling; Willis, Sarah E.; Gertz, Shira J.; Hrachovy, Richard A.; Anderson, Anne E.

    2010-01-01

    Purpose Kv4.2 subunits contribute to the pore-forming region of channels that express a transient, A-type K+ current (A-current) in hippocampal CA1 pyramidal cell dendrites. Here, the A-current plays an important role in signal processing and synaptic integration. Kv4.2 knockout mice show a near elimination of the A-current in area CA1 dendrites producing increased excitability in this region. In these studies, we evaluated young adult Kv4.2 knockout mice for spontaneous seizures and the response to convulsant stimulation in the whole animal in vivo and in hippocampal slices in vitro. Methods Electroencephalogram electrode-implanted Kv4.2 knockout and wildtype mice were observed for spontaneous behavioral and electrographic seizures. The latency to seizure and status epilepticus onset in Kv4.2 knockout and wildtype mice was assessed following intraperitoneal injection of kainate. Extracellular field potential recordings were performed in hippocampal slices from Kv4.2 knockout and wildtype mice following the bath application of bicuculline. Results No spontaneous behavioral or electrographic seizures were observed in Kv4.2 knockout mice. Following kainate, Kv4.2 knockout mice demonstrated a decreased seizure and status epilepticus latency as well as increased mortality compared to wildtype littermates. The background strain modified the seizure susceptibility phenotype in Kv4.2 knockout mice. In response to bicuculline, slices from Kv4.2 knockout mice exhibited an increase in epileptiform bursting in area CA1 as compared to wildtype littermates. Discussion These studies show that loss of Kv4.2 channels is associated with enhanced susceptibility to convulsant stimulation, supporting the concept that Kv4.2 deficiency may contribute to aberrant network excitability and regulate seizure threshold. PMID:19453702

  16. Emergency Cardiac Care: An Update

    PubMed Central

    Swanson, Richard W.

    1988-01-01

    The authors review the new guidelines for basic life support and advanced cardiac life support and the recommended changes to the standards. The changes recommended for basic life support will simplify the psychomotor skills required. The recommended changes to the guidelines for advanced cardiac life support, which include discontinuing the use of isoproterenol and limiting the use of sodium bicarbonate in cardiac arrest, are likely to improve survival rates. Controversies in the management of cardiac arrest are also discussed. PMID:21253157

  17. Dynamic Control of Cardiac Alternans

    NASA Astrophysics Data System (ADS)

    Hall, Kevin; Christini, David J.; Tremblay, Maurice; Collins, James J.; Glass, Leon; Billette, Jacques

    1997-06-01

    A dynamic control technique was used to suppress a cardiac arrhythmia called an alternans rhythm in a piece of dissected rabbit heart. Our control algorithm adapted to drifting system parameters, making it well suited for the control of physiological rhythms. Control of cardiac alternans rhythms may have important clinical implications since they often precede serious cardiac arrhythmias and are a harbinger of sudden cardiac death.

  18. A Comprehensive TALEN-Based Knockout Library for Generating Human Induced Pluripotent Stem Cell-Based Models for Cardiovascular Diseases.

    PubMed

    Karakikes, Ioannis; Termglinchan, Vittavat; Cepeda, Diana A; Lee, Jaecheol; Diecke, Sebastian; Hendel, Ayal; Itzhaki, Ilanit; Ameen, Mohamed; Shrestha, Rajani; Wu, Haodi; Ma, Ning; Shao, Ning-Yi; Seeger, Timon; Woo, Nicole A; Wilson, Kitchener D; Matsa, Elena; Porteus, Matthew H; Sebastiano, Vittorio; Wu, Joseph C

    2017-02-28

    Rationale: Targeted genetic engineering using programmable nucleases such as transcription activator-like effector nucleases (TALENs) is a valuable tool for precise, site-specific genetic modification in the human genome. Objective: The emergence of novel technologies such as human induced pluripotent stem cells (iPSCs) and nuclease-mediated genome editing represent a unique opportunity for studying cardiovascular diseases in vitro. Methods and Results: By incorporating extensive literature and database searches, we designed a collection of TALEN constructs to knockout (KO) eighty-eight human genes that are associated with cardiomyopathies and congenital heart diseases. The TALEN pairs were designed to induce double-strand DNA break near the starting codon of each gene that either disrupted the start codon or introduced a frameshift mutation in the early coding region, ensuring faithful gene KO. We observed that all the constructs were active and disrupted the target locus at high frequencies. To illustrate the general utility of the TALEN-mediated KO technique, six individual genes (TNNT2, LMNA/C, TBX5, MYH7, ANKRD1, and NKX2.5) were knocked out with high efficiency and specificity in human iPSCs. By selectively targeting a dilated cardiomyopathy (DCM)-causing mutation (TNNT2 p.R173W) in patient-specific iPSC-derived cardiac myocytes (iPSC-CMs), we demonstrated that the KO strategy ameliorates the DCM phenotype in vitro. In addition, we modeled the Holt-Oram syndrome (HOS) in iPSC-CMs in vitro and uncovered novel pathways regulated by TBX5 in human cardiac myocyte development. Conclusions: Collectively, our study illustrates the powerful combination of iPSCs and genome editing technology for understanding the biological function of genes and the pathological significance of genetic variants in human cardiovascular diseases. The methods, strategies, constructs and iPSC lines developed in this study provide a validated, readily available resource for cardiovascular

  19. Immunosympathectomy as the first phenotypic knockout with antibodies

    PubMed Central

    Cattaneo, Antonino

    2013-01-01

    In a PNAS Classic Article published in 1960, Rita Levi-Montalcini offered formal and conclusive proof that endogenous NGF was responsible for the survival of sympathetic neurons in vivo. Thus ended an experimental tour de force lasting a decade, starting with the demonstration that a humoral factor, produced from a tumor transplanted in a chicken embryo, was responsible for stimulating outgrowth of nerve fibers from sympathetic and sensory neurons. From a more general methodological point of view, this work provided a breakthrough in the quest to achieve targeted loss of function and experimentally validate the function of biological molecules. Finally, this work provided an example of the ablation of a specific neuronal subpopulation in an otherwise intact nervous system, an immunological knife of unsurpassed effectiveness and precision. The novelty and the importance of the PNAS Classic Article is discussed here, collocating it within the context of the particular moment of the NGF discovery saga, of Rita Levi-Montalcini's scientific and academic career, and of the general scientific context of those years. This seminal work, involving the use of antibodies for phenotypic knockout in vivo, planted seeds that were to bear new fruit many years later with the advent of monoclonal antibodies and recombinant antibody technologies. PMID:23515328

  20. Bone growth and turnover in progesterone receptor knockout mice.

    SciTech Connect

    Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda; Hefferan, Theresa E.; Hunter, Jaime C.; Waters, Katrina M.; Lydon, John P.; O'Malley, Bert W.; Khosla, Sundeep; Spelsberg, Thomas C.; Turner, Russell T.

    2008-05-01

    The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bones of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.

  1. One-neutron knockout reaction from 20C

    NASA Astrophysics Data System (ADS)

    Hwang, Jongwon; Samurai Collaboration

    2014-09-01

    Recent researches in neutron-rich nuclei have demonstrated that the depth of each single-particle level varies from that in stable nuclei : some of the well-known magic numbers disappear and new shell closures develop. Cross-shell excitation, transition of a nucleon across a shell gap, can be exploit to probe changes in shell structure. The present work aims at exploration of neutron-unbound states of 19C, especially a hole- state populated by cross-shell excitation, via a one-neutron knockout reaction. The experiment was performed at the RIBF facility in RIKEN. A 20C secondary beam produced by BigRIPS with an energy of 280 MeV/nucleon impinged on a carbon target placed before the SAMURAI spectrometer. By taking full advantage of the analyzer system comprised of a large-acceptance super-conducting dipole magnet, associated tracking detectors, and a large volume neutron detector system, an invariant mass spectrum for the system of 18C + n was reconstructed. Three unbound excited states in 19C were identified including the unknown 1 /21+ state at 2.90 MeV in excitation energy. Details of the measurement and analysis along with results will be presented.

  2. Analyses of glutathione reductase hypomorphic mice indicate a genetic knockout.

    PubMed

    Rogers, Lynette K; Tamura, Toshiya; Rogers, Bryan J; Welty, Stephen E; Hansen, Thomas N; Smith, Charles V

    2004-12-01

    A strain of mice (Gr1a1Neu) that exhibited tissue glutathione reductase (GR) activities that were substantially lower (less than 10% in liver) than the corresponding activities in control mice has been reported. The present report describes characterization of the mutation(s) in the GR gene of these mice. RT-PCR of mRNA from the Neu mice indicated a substantial deletion in the normal GR coding sequence. Southern blots revealed that the deletion involved a region spanning from intron 1 through intron 5. The exact breakpoints of the deletion were characterized by PCR and sequencing through the region encompassing the deletion. The deletion involves nucleotides 10840 through 23627 of the genomic GR gene and functionally deletes exons 2 through 5. In addition, the deletion produces a frame shift in exon 6 and introduces a stop codon in exon 7 that would prevent translation of the remainder of the protein. Consequently, the Neu mice are incapable of producing a functional GR protein and appear to be genetic knockouts for GR. The Neu mice offer live animal models with which to test hypotheses regarding oxidant mechanisms of tissue injury in vivo.

  3. Results of gal-knockout porcine thymokidney xenografts.

    PubMed

    Griesemer, A D; Hirakata, A; Shimizu, A; Moran, S; Tena, A; Iwaki, H; Ishikawa, Y; Schule, P; Arn, J S; Robson, S C; Fishman, J A; Sykes, M; Sachs, D H; Yamada, K

    2009-12-01

    Clinical transplantation for the treatment of end-stage organ disease is limited by a shortage of donor organs. Successful xenotransplantation could immediately overcome this limitation. The development of homozygous alpha1,3-galactosyltransferase knockout (GalT-KO) pigs removed hyperacute rejection as the major immunologic hurdle to xenotransplantation. Nevertheless, GalT-KO organs stimulate robust immunologic responses that are not prevented by immunosuppressive drugs. Murine studies show that recipient thymopoiesis in thymic xenografts induces xenotolerance. We transplanted life-supporting composite thymokidneys (composite thymus and kidneys) prepared in GalT-KO miniature swine to baboons in an attempt to induce tolerance in a preclinical xenotransplant model. Here, we report the results of seven xenogenic thymokidney transplants using a steroid-free immunosuppressive regimen that eliminated whole-body irradiation in all but one recipient. The regimen resulted in average recipient survival of over 50 days. This was associated with donor-specific unresponsiveness in vitro and early baboon thymopoiesis in the porcine thymus tissue of these grafts, suggesting the development of T-cell tolerance. The kidney grafts had no signs of cellular infiltration or deposition of IgG, and no grafts were lost due to rejection. These results show that xenogeneic thymus transplantation can support early primate thymopoiesis, which in turn may induce T-cell tolerance to solid organ xenografts.

  4. Gastrointestinal Pathology in Juvenile and Adult CFTR-Knockout Ferrets

    PubMed Central

    Sun, Xingshen; Olivier, Alicia K.; Yi, Yaling; Pope, Christopher E.; Hayden, Hillary S.; Liang, Bo; Sui, Hongshu; Zhou, Weihong; Hager, Kyle R.; Zhang, Yulong; Liu, Xiaoming; Yan, Ziying; Fisher, John T.; Keiser, Nicholas W.; Song, Yi; Tyler, Scott R.; Goeken, J. Adam; Kinyon, Joann M.; Radey, Matthew C.; Fligg, Danielle; Wang, Xiaoyan; Xie, Weiliang; Lynch, Thomas J.; Kaminsky, Paul M.; Brittnacher, Mitchell J.; Miller, Samuel I.; Parekh, Kalpaj; Meyerholz, David K.; Hoffman, Lucas R.; Frana, Timothy; Stewart, Zoe A.; Engelhardt, John F.

    2015-01-01

    Cystic fibrosis (CF) is a multiorgan disease caused by loss of a functional cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in many epithelia of the body. Here we report the pathology observed in the gastrointestinal organs of juvenile to adult CFTR-knockout ferrets. CF gastrointestinal manifestations included gastric ulceration, intestinal bacterial overgrowth with villous atrophy, and rectal prolapse. Metagenomic phylogenetic analysis of fecal microbiota by deep sequencing revealed considerable genotype-independent microbial diversity between animals, with the majority of taxa overlapping between CF and non-CF pairs. CF hepatic manifestations were variable, but included steatosis, necrosis, biliary hyperplasia, and biliary fibrosis. Gallbladder cystic mucosal hyperplasia was commonly found in 67% of CF animals. The majority of CF animals (85%) had pancreatic abnormalities, including extensive fibrosis, loss of exocrine pancreas, and islet disorganization. Interestingly, 2 of 13 CF animals retained predominantly normal pancreatic histology (84% to 94%) at time of death. Fecal elastase-1 levels from these CF animals were similar to non-CF controls, whereas all other CF animals evaluated were pancreatic insufficient (<2 μg elastase-1 per gram of feces). These findings suggest that genetic factors likely influence the extent of exocrine pancreas disease in CF ferrets and have implications for the etiology of pancreatic sufficiency in CF patients. In summary, these studies demonstrate that the CF ferret model develops gastrointestinal pathology similar to CF patients. PMID:24637292

  5. The biology of novel animal genes: Mouse APEX gene knockout

    SciTech Connect

    MacInnes, M.; Altherr, M.R.; Ludwig, D.; Pedersen, R.; Mold, C.

    1997-07-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The controlled breeding of novel genes into mice, including the gene knockout (KO), or conversely by adding back transgenes provide powerful genetic technologies that together suffice to determine in large part the biological role(s) of novel genes. Inbred mouse remains the best understood and most useful mammalian experimental system available for tackling the biology of novel genes. The major mammalian apurinic/apyrimidinic (AP) endonuclease (APE), is involved in a key step in the repair of spontaneous and induced AP sites in DNA. Efficient repair of these lesions is imperative to prevent the stable incorporation of mutations into the cellular genome which may lead to cell death or transformation. Loss or modulation of base excison repair activity in vivo may elevate the spontaneous mutation rate in cells, and may lead to a substantial increase in the incidence of cancer. Despite extensive biochemical analysis, however, the significance of these individual APE functions in vivo has not been elucidated. Mouse embryonic stem (ES) cells heterozygous for a deletion mutation in APE have been generated and whole animals containing the APE mutation have been derived from these ES cells. Animals homozygous for the APE null mutation die early in gestation, underscoring the biological significance of this DNA repair gene.

  6. Results of Gal-Knockout porcine thymokidney xenografts

    PubMed Central

    Griesemer, Adam D.; Hirakata, Atsushi; Shimizu, Akira; Moran, Shannon; Tena, Aseda; Iwaki, Hideyuki; Ishikawa, Yoshinori; Schule, Patrick; Arn, J. Scott; Robson, Simon C.; Fishman, Jay A.; Sykes, Megan; Sachs, David H.; Yamada, Kazuhiko

    2009-01-01

    Clinical transplantation for the treatment of end-stage organ disease is limited by a shortage of donor organs. Successful xenotransplantation could immediately overcome this limitation. The development of homozygous α1,3-galactosyltransferase knockout (GalT-KO) pigs removed hyperacute rejection as the major immunologic hurdle to xenotransplantation. Nevertheless, GalT-KO organs stimulate robust immunologic responses that are not prevented by immunosuppressive drugs. Murine studies show that recipient thymopoiesis in thymic xenografts induces xenotolerance. We transplanted life-supporting composite thymokidneys prepared in GalT-KO miniature swine to baboons in an attempt to induce tolerance in a pre-clinical xenotransplant model. Here, we report the results of 7 xenogenic thymokidney transplants using a steroid-free immunosuppressive regimen that eliminated whole body irradiation in all but 1 recipient. The regimen resulted in average recipient survival of over 50 days. This was associated with donor-specific unresponsiveness in vitro and early baboon thymopoiesis in the porcine thymus tissue of these grafts, suggesting the development of T cell tolerance. The kidney grafts had no signs of cellular infiltration or deposition of IgG, and no grafts were lost due to rejection. These results show that xenogeneic thymus transplantation can support early human thymopoiesis, which in turn may induce T cell tolerance to solid organ xenografts. PMID:19845583

  7. Sensorimotor development in neonatal progesterone receptor knockout mice.

    PubMed

    Willing, Jari; Wagner, Christine K

    2014-01-01

    Early exposure to steroid hormones can permanently and dramatically alter neural development. This is best understood in the organizational effects of hormones during development of brain regions involved in reproductive behaviors or neuroendocrine function. However, recent evidence strongly suggests that steroid hormones play a vital role in shaping brain regions involved in cognitive behavior such as the cerebral cortex. The most abundantly expressed steroid hormone receptor in the developing rodent cortex is the progesterone receptor (PR). In the rat, PR is initially expressed in the developmentally-critical subplate at E18, and subsequently in laminas V and II/III through the first three postnatal weeks (Quadros et al. [2007] J Comp Neurol 504:42-56; Lopez & Wagner [2009]: J Comp Neurol 512:124-139), coinciding with significant periods of dendritic maturation, the arrival of afferents and synaptogenesis. In the present study, we investigated PR expression in the neonatal mouse somatosensory cortex. Additionally, to investigate the potential role of PR in developing cortex, we examined sensorimotor function in the first two postnatal weeks in PR knockout mice and their wildtype (WT) and heterozygous (HZ) counterparts. While the three genotypes were similar in most regards, PRKO and HZ mice lost the rooting reflex 2-3 days earlier than WT mice. These studies represent the first developmental behavioral assessment of PRKO mice and suggest PR expression may play an important role in the maturation of cortical connectivity and sensorimotor integration. Copyright © 2013 Wiley Periodicals, Inc.

  8. Analyzing power reduction in quasifree pion-nucleon knockout reactions

    NASA Astrophysics Data System (ADS)

    Khayat, Mohammad G.; Roos, P. G.; Chant, N. S.; Dvoredsky, A. P.; Breuer, H.; Kelly, J. J.; Flanders, B. S.; Payerle, T. M.; Adimi, F.; Gu, T.; Huffman, J.; Klein, A.; Dooling, T.; Greco, T.; Kyle, G. S.; Chang, T.; Lin, Z.; Wang, M.; Meier, R.; Ritt, S.; Koch, K.; Konter, J.; Kovalev, S.; Mango, S.; van den Brandt, B.; Lawrie, J.

    2001-12-01

    Unpolarized cross sections and vector target analyzing powers for the 7Li-->(π+,π+'p) proton knockout reaction were measured using a vector polarized 7LiH target and a 240 MeV π+ beam at the πM1 channel of PSI. Typical target polarizations were >30% for 7Li. Coincident π+-p data are presented for three emitted pion angles (60°, 85°, and 108°). For each π+ angle coincident data with adequate statistics were obtained for three proton angles near the quasifree π+-p angle. The π+ angles were chosen to emphasize and isolate contributions to the target analyzing powers from the two-body π-nucleon interaction with a polarized nucleon whose polarization resulted from either the target polarization or from the distortion-induced effective polarization. The data are compared with factorized-amplitude distorted-wave impulse approximation (DWIA) calculations. The unpolarized cross sections are rather well described by these calculations. However, for all three angles the target analyzing powers are substantially reduced from predictions of conventional DWIA calculations. This result suggests a rather strong spin dependence in the Δ-nucleus spreading potential.

  9. Reduced ultrasonic vocalizations in vasopressin 1b knockout mice.

    PubMed

    Scattoni, M L; McFarlane, H G; Zhodzishsky, V; Caldwell, H K; Young, W S; Ricceri, L; Crawley, J N

    2008-03-05

    The neuropeptides oxytocin and vasopressin have been implicated in rodent social and affiliative behaviors, including social bonding, parental care, social recognition, social memory, vocalizations, territoriality, and aggression, as well as components of human social behaviors and the etiology of autism. Previous investigations of mice with various manipulations of the oxytocin and vasopressin systems reported unusual levels of ultrasonic vocalizations in social settings. We employed a vasopressin 1b receptor (Avpr1b) knockout mouse to evaluate the role of the vasopressin 1b receptor subtype in the emission of ultrasonic vocalizations in adult and infant mice. Avpr1b null mutant female mice emitted fewer ultrasonic vocalizations, and their vocalizations were generally at lower frequencies, during a resident-intruder test. Avpr1b null mutant pups emitted ultrasonic vocalizations similar to heterozygote and wildtype littermates when separated from the nest on postnatal days 3, 6, 9, and 12. However, maternal potentiation of ultrasonic vocalizations in Avpr1b null and heterozygote mutants was absent, when tested at postnatal day 9. These results indicate that Avpr1b null mutant mice are impaired in the modulation of ultrasonic vocalizations within different social contexts at infant and adult ages.

  10. Adenylate kinase 1 knockout mice have normal thiamine triphosphate levels.

    PubMed

    Makarchikov, Alexander F; Wins, Pierre; Janssen, Edwin; Wieringa, Bé; Grisar, Thierry; Bettendorff, Lucien

    2002-10-21

    Thiamine triphosphate (ThTP) is found at low concentrations in most animal tissues and it may act as a phosphate donor for the phosphorylation of proteins, suggesting a potential role in cell signaling. Two mechanisms have been proposed for the enzymatic synthesis of ThTP. A thiamine diphosphate (ThDP) kinase (ThDP+ATP if ThTP+ADP) has been purified from brewer's yeast and shown to exist in rat liver. However, other data suggest that, at least in skeletal muscle, adenylate kinase 1 (AK1) is responsible for ThTP synthesis. In this study, we show that AK1 knockout mice have normal ThTP levels in skeletal muscle, heart, brain, liver and kidney, demonstrating that AK1 is not responsible for ThTP synthesis in those tissues. We predict that the high ThTP content of particular tissues like the Electrophorus electricus electric organ, or pig and chicken skeletal muscle is more tightly correlated with high ThDP kinase activity or low soluble ThTPase activity than with non-stringent substrate specificity and high activity of adenylate kinase.

  11. Behavioral and neuroanatomical abnormalities in pleiotrophin knockout mice.

    PubMed

    Krellman, Jason W; Ruiz, Henry H; Marciano, Veronica A; Mondrow, Bracha; Croll, Susan D

    2014-01-01

    Pleiotrophin (PTN) is an extracellular matrix-associated protein with neurotrophic and neuroprotective effects that is involved in a variety of neurodevelopmental processes. Data regarding the cognitive-behavioral and neuroanatomical phenotype of pleiotrophin knockout (KO) mice is limited. The purpose of this study was to more fully characterize this phenotype, with emphasis on the domains of learning and memory, cognitive-behavioral flexibility, exploratory behavior and anxiety, social behavior, and the neuronal and vascular microstructure of the lateral entorhinal cortex (EC). PTN KOs exhibited cognitive rigidity, heightened anxiety, behavioral reticence in novel contexts and novel social interactions suggestive of neophobia, and lamina-specific decreases in neuronal area and increases in neuronal density in the lateral EC. Initial learning of spatial and other associative tasks, as well as vascular density in the lateral EC, was normal in the KOs. These data suggest that the absence of PTN in vivo is associated with disruption of specific cognitive and affective processes, raising the possibility that further study of PTN KOs might have implications for the study of human disorders with similar features.

  12. Boolean network model predicts knockout mutant phenotypes of fission yeast.

    PubMed

    Davidich, Maria I; Bornholdt, Stefan

    2013-01-01

    networks of switches) are extremely simple mathematical models of biochemical signaling networks. Under certain circumstances, Boolean networks, despite their simplicity, are capable of predicting dynamical activation patterns of gene regulatory networks in living cells. For example, the temporal sequence of cell cycle activation patterns in yeasts S. pombe and S. cerevisiae are faithfully reproduced by Boolean network models. An interesting question is whether this simple model class could also predict a more complex cellular phenomenology as, for example, the cell cycle dynamics under various knockout mutants instead of the wild type dynamics, only. Here we show that a Boolean network model for the cell cycle control network of yeast S. pombe correctly predicts viability of a large number of known mutants. So far this had been left to the more detailed differential equation models of the biochemical kinetics of the yeast cell cycle network and was commonly thought to be out of reach for models as simplistic as Boolean networks. The new results support our vision that Boolean networks may complement other mathematical models in systems biology to a larger extent than expected so far, and may fill a gap where simplicity of the model and a preference for an overall dynamical blueprint of cellular regulation, instead of biochemical details, are in the focus.

  13. Accelerated retinal aging in PACAP knock-out mice.

    PubMed

    Kovács-Valasek, Andrea; Szabadfi, Krisztina; Dénes, Viktória; Szalontai, Bálint; Tamás, Andrea; Kiss, Péter; Szabó, Aliz; Setalo, Gyorgy; Reglődi, Dóra; Gábriel, Robert

    2017-02-13

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neurotrophic and neuroprotective peptide. PACAP and its receptors are widely distributed in the retina. A number of reports provided evidence that PACAP is neuroprotective in retinal degenerations. The current study compared retina cell type-specific differences in young (3-4months) and aged adults (14-16months), of wild-type (WT) mice and knock-out (KO) mice lacking endogenous PACAP production during the course of aging. Histological, immunocytochemical and Western blot examinations were performed. The staining for standard neurochemical markers (tyrosine hydroxylase for dopaminergic cells, calbindin 28 kDa for horizontal cells, protein kinase Cα for rod bipolar cells) of young adult PACAP KO retinas showed no substantial alterations compared to young adult WT retinas, except for the specific PACAP receptor (PAC1-R) staining. We could not detect PAC1-R immunoreactivity in bipolar and horizontal cells in young adult PACAP KO animals. Some other age-related changes were observed only in the PACAP KO mice only. These alterations included horizontal and rod bipolar cell dendritic sprouting into the photoreceptor layer and decreased ganglion cell number. Also, Müller glial cells showed elevated GFAP expression compared to the aging WT retinas. Furthermore, Western blot analyses revealed significant differences between the phosphorylation state of ERK1/2 and JNK in KO mice, indicating alterations in the MAPK signaling pathway. These results support the conclusion that endogenous PACAP contributes to protection against aging of the nervous system.

  14. Modeling fragile X syndrome in the Fmr1 knockout mouse.

    PubMed

    Kazdoba, Tatiana M; Leach, Prescott T; Silverman, Jill L; Crawley, Jacqueline N

    2014-11-01

    Fragile X Syndrome (FXS) is a commonly inherited form of intellectual disability and one of the leading genetic causes for autism spectrum disorder. Clinical symptoms of FXS can include impaired cognition, anxiety, hyperactivity, social phobia, and repetitive behaviors. FXS is caused by a CGG repeat mutation which expands a region on the X chromosome containing the FMR1 gene. In FXS, a full mutation (> 200 repeats) leads to hypermethylation of FMR1, an epigenetic mechanism that effectively silences FMR1 gene expression and reduces levels of the FMR1 gene product, fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that is important for the regulation of protein expression. In an effort to further understand how loss of FMR1 and FMRP contribute to FXS symptomology, several FXS animal models have been created. The most well characterized rodent model is the Fmr1 knockout (KO) mouse, which lacks FMRP protein due to a disruption in its Fmr1 gene. Here, we review the behavioral phenotyping of the Fmr1 KO mouse to date, and discuss the clinical relevance of this mouse model to the human FXS condition. While much remains to be learned about FXS, the Fmr1 KO mouse is a valuable tool for understanding the repercussions of functional loss of FMRP and assessing the efficacy of pharmacological compounds in ameliorating the molecular and behavioral phenotypes relevant to FXS.

  15. Boolean Network Model Predicts Knockout Mutant Phenotypes of Fission Yeast

    PubMed Central

    Davidich, Maria I.; Bornholdt, Stefan

    2013-01-01

    Boolean networks (or: networks of switches) are extremely simple mathematical models of biochemical signaling networks. Under certain circumstances, Boolean networks, despite their simplicity, are capable of predicting dynamical activation patterns of gene regulatory networks in living cells. For example, the temporal sequence of cell cycle activation patterns in yeasts S. pombe and S. cerevisiae are faithfully reproduced by Boolean network models. An interesting question is whether this simple model class could also predict a more complex cellular phenomenology as, for example, the cell cycle dynamics under various knockout mutants instead of the wild type dynamics, only. Here we show that a Boolean network model for the cell cycle control network of yeast S. pombe correctly predicts viability of a large number of known mutants. So far this had been left to the more detailed differential equation models of the biochemical kinetics of the yeast cell cycle network and was commonly thought to be out of reach for models as simplistic as Boolean networks. The new results support our vision that Boolean networks may complement other mathematical models in systems biology to a larger extent than expected so far, and may fill a gap where simplicity of the model and a preference for an overall dynamical blueprint of cellular regulation, instead of biochemical details, are in the focus. PMID:24069138

  16. Knockout of Foxp2 disrupts vocal development in mice

    PubMed Central

    Castellucci, Gregg A.; McGinley, Matthew J.; McCormick, David A.

    2016-01-01

    The FOXP2 gene is important for the development of proper speech motor control in humans. However, the role of the gene in general vocal behavior in other mammals, including mice, is unclear. Here, we track the vocal development of Foxp2 heterozygous knockout (Foxp2+/−) mice and their wildtype (WT) littermates from juvenile to adult ages, and observe severe abnormalities in the courtship song of Foxp2+/− mice. In comparison to their WT littermates, Foxp2+/− mice vocalized less, produced shorter syllable sequences, and possessed an abnormal syllable inventory. In addition, Foxp2+/− song also exhibited irregular rhythmic structure, and its development did not follow the consistent trajectories observed in WT vocalizations. These results demonstrate that the Foxp2 gene is critical for normal vocal behavior in juvenile and adult mice, and that Foxp2 mutant mice may provide a tractable model system for the study of the gene’s role in general vocal motor control. PMID:26980647

  17. Drop tests of the Three Mile Island knockout canister

    SciTech Connect

    Box, W.D.; Aaron, W.S.; Shappert, L.B.; Childress, P.C.; Quinn, G.J.; Smith, J.V.

    1986-09-01

    A type of Three Mile Island Unit 2 (TMI-2) defueling canister, called a ''knockout'' canister, was subjected to a series of drop tests at the Oak Ridge National Laboratory's Drop Test Facility. These tests were designed to confirm the structural integrity of internal fixed neutron poisons in support of a request for NRC licensing of this type of canister for the shipment of TMI-2 reactor fuel debris to the Idaho National Engineering Laboratory (INEL) for the Core Examination R and D Program. Work conducted at the Oak Ridge National Laboratory included (1) precise physical measurements of the internal poison rod configuration before assembly, (2) canister assembly and welding, (3) nondestructive examination (an initial hydrostatic pressure test and an x-ray profile of the internals before and after each drop test), (4) addition of a simulated fuel load, (5) instrumentation of the canister for each drop test, (6) fabrication of a cask simulation vessel with a developed and tested foam impact limiter, (7) use of refrigeration facilities to cool the canister to well below freezing prior to three of the drops, (8) recording the drop test with still, high-speed, and normal-speed photography, (9) recording the accelerometer measurements during impact, (10) disassembly and post-test examination with precise physical measurements, and (11) preparation of the final report.

  18. Elevated body temperature during sleep in orexin knockout mice.

    PubMed

    Mochizuki, Takatoshi; Klerman, Elizabeth B; Sakurai, Takeshi; Scammell, Thomas E

    2006-09-01

    Core body temperature (Tb) is influenced by many physiological factors, including behavioral state, locomotor activity, and biological rhythms. To determine the relative roles of these factors, we examined Tb in orexin knockout (KO) mice, which have a narcolepsy-like phenotype with severe sleep-wake fragmentation. Because orexin is released during wakefulness and is thought to promote heat production, we hypothesized that orexin KO mice would have lower Tb while awake. Surprisingly, Tb was the same in orexin KO mice and wild-type (WT) littermates during sustained wakefulness. Orexin KO mice had normal diurnal variations in Tb, but the ultradian rhythms of Tb, locomotor activity, and wakefulness were markedly reduced. During the first 15 min of spontaneous sleep, the Tb of WT mice decreased by 1.0 degrees C, but Tb in orexin KO mice decreased only 0.4 degrees C. Even during intense recovery sleep after 8 h of sleep deprivation, the Tb of orexin KO mice remained 0.7 degrees C higher than in WT mice. This blunted fall in Tb during sleep may be due to inadequate activation of heat loss mechanisms or sustained activity in heat-generating systems. These observations reveal an unexpected role for orexin in thermoregulation. In addition, because heat loss is an essential aspect of sleep, the blunted fall in Tb of orexin KO mice may provide an explanation for the fragmented sleep of narcolepsy.

  19. Environmental enrichment induces behavioural disturbances in neuropeptide Y knockout mice.

    PubMed

    Reichmann, Florian; Wegerer, Vanessa; Jain, Piyush; Mayerhofer, Raphaela; Hassan, Ahmed M; Fröhlich, Esther E; Bock, Elisabeth; Pritz, Elisabeth; Herzog, Herbert; Holzer, Peter; Leitinger, Gerd

    2016-06-16

    Environmental enrichment (EE) refers to the provision of a complex and stimulating housing condition which improves well-being, behaviour and brain function of laboratory animals. The mechanisms behind these beneficial effects of EE are only partially understood. In the current report, we describe a link between EE and neuropeptide Y (NPY), based on findings from NPY knockout (KO) mice exposed to EE. Relative to EE-housed wildtype (WT) animals, NPY KO mice displayed altered behaviour as well as molecular and morphological changes in amygdala and hippocampus. Exposure of WT mice to EE reduced anxiety and decreased central glucocorticoid receptor expression, effects which were absent in NPY KO mice. In addition, NPY deletion altered the preference of EE items, and EE-housed NPY KO mice responded to stress with exaggerated hyperthermia, displayed impaired spatial memory, had higher hippocampal brain-derived neurotrophic factor mRNA levels and altered hippocampal synaptic plasticity, effects which were not seen in WT mice. Accordingly, these findings suggest that NPY contributes to the anxiolytic effect of EE and that NPY deletion reverses the beneficial effects of EE into a negative experience. The NPY system could thus be a target for "enviromimetics", therapeutics which reproduce the beneficial effects of enhanced environmental stimulation.

  20. Environmental enrichment induces behavioural disturbances in neuropeptide Y knockout mice

    PubMed Central

    Reichmann, Florian; Wegerer, Vanessa; Jain, Piyush; Mayerhofer, Raphaela; Hassan, Ahmed M.; Fröhlich, Esther E.; Bock, Elisabeth; Pritz, Elisabeth; Herzog, Herbert; Holzer, Peter; Leitinger, Gerd

    2016-01-01

    Environmental enrichment (EE) refers to the provision of a complex and stimulating housing condition which improves well-being, behaviour and brain function of laboratory animals. The mechanisms behind these beneficial effects of EE are only partially understood. In the current report, we describe a link between EE and neuropeptide Y (NPY), based on findings from NPY knockout (KO) mice exposed to EE. Relative to EE-housed wildtype (WT) animals, NPY KO mice displayed altered behaviour as well as molecular and morphological changes in amygdala and hippocampus. Exposure of WT mice to EE reduced anxiety and decreased central glucocorticoid receptor expression, effects which were absent in NPY KO mice. In addition, NPY deletion altered the preference of EE items, and EE-housed NPY KO mice responded to stress with exaggerated hyperthermia, displayed impaired spatial memory, had higher hippocampal brain-derived neurotrophic factor mRNA levels and altered hippocampal synaptic plasticity, effects which were not seen in WT mice. Accordingly, these findings suggest that NPY contributes to the anxiolytic effect of EE and that NPY deletion reverses the beneficial effects of EE into a negative experience. The NPY system could thus be a target for “enviromimetics”, therapeutics which reproduce the beneficial effects of enhanced environmental stimulation. PMID:27305846

  1. Data analysis in cardiac arrhythmias.

    PubMed

    Rodrigo, Miguel; Pedrón-Torecilla, Jorge; Hernández, Ismael; Liberos, Alejandro; Climent, Andreu M; Guillem, María S

    2015-01-01

    Cardiac arrhythmias are an increasingly present in developed countries and represent a major health and economic burden. The occurrence of cardiac arrhythmias is closely linked to the electrical function of the heart. Consequently, the analysis of the electrical signal generated by the heart tissue, either recorded invasively or noninvasively, provides valuable information for the study of cardiac arrhythmias. In this chapter, novel cardiac signal analysis techniques that allow the study and diagnosis of cardiac arrhythmias are described, with emphasis on cardiac mapping which allows for spatiotemporal analysis of cardiac signals.Cardiac mapping can serve as a diagnostic tool by recording cardiac signals either in close contact to the heart tissue or noninvasively from the body surface, and allows the identification of cardiac sites responsible of the development or maintenance of arrhythmias. Cardiac mapping can also be used for research in cardiac arrhythmias in order to understand their mechanisms. For this purpose, both synthetic signals generated by computer simulations and animal experimental models allow for more controlled physiological conditions and complete access to the organ.

  2. Predicting drug efficacy: knockouts model pipeline drugs of the pharmaceutical industry.

    PubMed

    Zambrowicz, Brian P; Turner, C Alexander; Sands, Arthur T

    2003-10-01

    One of the major challenges for the pharmaceutical industry is to develop innovative drugs to new targets from the human genome. A systematic approach for target selection could significantly increase the rate of successful new drug development, thereby enhancing industry productivity. It has previously been shown that mouse knockout phenotypes for the targets of the 100 best-selling pharmaceutical drugs correlate well with known drug efficacy. Furthermore, physiological validation of novel pipeline targets of the pharmaceutical industry has been provided using mouse knockout data. These data demonstrate an excellent correlation between knockout phenotype and anticipated drug efficacy, establishing an important marker for superior new drug targets from the genome.

  3. Generation of medaka gene knockout models by target-selected mutagenesis

    PubMed Central

    Taniguchi, Yoshihito; Takeda, Shunichi; Furutani-Seiki, Makoto; Kamei, Yasuhiro; Todo, Takeshi; Sasado, Takao; Deguchi, Tomonori; Kondoh, Hisato; Mudde, Josine; Yamazoe, Mitsuyoshi; Hidaka, Masayuki; Mitani, Hiroshi; Toyoda, Atsushi; Sakaki, Yoshiyuki; Plasterk, Ronald HA; Cuppen, Edwin

    2006-01-01

    We have established a reverse genetics approach for the routine generation of medaka (Oryzias latipes) gene knockouts. A cryopreserved library of N-ethyl-N-nitrosourea (ENU) mutagenized fish was screened by high-throughput resequencing for induced point mutations. Nonsense and splice site mutations were retrieved for the Blm, Sirt1, Parkin and p53 genes and functional characterization of p53 mutants indicated a complete knockout of p53 function. The current cryopreserved resource is expected to contain knockouts for most medaka genes. PMID:17156454

  4. Cardiac troponins and high-sensitivity cardiac troponin assays.

    PubMed

    Conrad, Michael J; Jarolim, Petr

    2014-03-01

    Measurement of circulating cardiac troponins I and T has become integral to the diagnosis of myocardial infarction. This article discusses the structure and function of the troponin complex and the release of cardiac troponin molecules from the injured cardiomyocyte into the circulation. An overview of current cardiac troponin assays and their classification according to sensitivity is presented. The diagnostic criteria, role, and usefulness of cardiac troponin for myocardial infarction are discussed. In addition, several examples are given of the usefulness of high-sensitivity cardiac troponin assays for short-term and long-term prediction of adverse events.

  5. Ablation of C/EBP homologous protein increases the acute phase mortality and doesn't attenuate cardiac remodeling in mice with myocardial infarction.

    PubMed

    Luo, Guangjin; Li, Qingman; Zhang, Xiajun; Shen, Liang; Xie, Jiahe; Zhang, Jingwen; Kitakaze, Masafumi; Huang, Xiaobo; Liao, Yulin

    2015-08-14

    Endoplasmic reticulum stress is a proapoptotic and profibrotic stimulus. Ablation of C/EBP homologous protein (CHOP) is reported to reverse cardiac dysfunction by attenuating cardiac endoplasmic reticulum stress in mice with pressure overload or ischemia/reperfusion, but it is unclear whether loss of CHOP also inhibits cardiac remodeling induced by permanent-infarction. In mice with permanent ligation of left coronary artery, we found that ablation of CHOP increased the acute phase mortality. For the mice survived to 4 weeks, left ventricular anterior (LV) wall thickness was larger in CHOP knockout mice than in the wildtype littermates, while no difference was noted on posterior wall thickness, LV dimensions, LV fractional shortening and ejection fraction. Similarly, invasive assessment of LV hemodynamics, morphological analysis of heart and lung weight indexes, myocardial fibrosis and TUNEL-assessed apoptosis showed no significant differences between CHOP knockout mice and their wildtype ones, while in mice with ischemia for 45 min and reperfusion for 1 week, myocardial fibrosis and apoptosis in the infarct area were significantly attenuated in CHOP knockout mice. These findings indicate that ablation of CHOP doesn't ameliorate cardiac remodeling induced by permanent-myocardial infarction, which implicates that early reperfusion is a prerequisite for ischemic myocardium to benefit from CHOP inhibition. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Advanced Cardiac Life Support.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document contains materials for an advanced college course in cardiac life support developed for the State of Iowa. The course syllabus lists the course title, hours, number, description, prerequisites, learning activities, instructional units, required text, six references, evaluation criteria, course objectives by units, course…

  7. Hepato-cardiac disorders

    PubMed Central

    Fouad, Yasser Mahrous; Yehia, Reem

    2014-01-01

    Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases PMID:24653793

  8. Cardiac mitochondria and arrhythmias

    PubMed Central

    Brown, David A.; O'Rourke, Brian

    2010-01-01

    Despite a high prevalence of sudden cardiac death throughout the world, the mechanisms that lead to ventricular arrhythmias are not fully understood. Over the last 20 years, a growing body of evidence indicates that cardiac mitochondria are involved in the genesis of arrhythmia. In this review, we have attempted to describe the role that mitochondria play in altering the heart's electrical function by introducing heterogeneity into the cardiac action potential. Specifically, we have focused on how the energetic status of the mitochondrial network can alter sarcolemmal potassium fluxes through ATP-sensitive potassium channels, creating a ‘metabolic sink’ for depolarizing wave-fronts and introducing conditions that favour catastrophic arrhythmia. Mechanisms by which mitochondria depolarize under conditions of oxidative stress are characterized, and the contributions of several mitochondrial ion channels to mitochondrial depolarization are presented. The inner membrane anion channel in particular opens upstream of other inner membrane channels during metabolic stress, and may be an effective target to prevent the metabolic oscillations that create action potential lability. Finally, we discuss therapeutic strategies that prevent arrhythmias by preserving mitochondrial membrane potential in the face of oxidative stress, supporting the notion that treatments aimed at cardiac mitochondria have significant potential in attenuating electrical dysfunction in the heart. PMID:20621924

  9. Cardiac T1 Imaging

    PubMed Central

    Jerosch-Herold, Michael; Kwong, Raymond Y.

    2014-01-01

    T1 mapping of the heart has evolved into a valuable tool to evaluate myocardial tissue properties, with or without contrast injection, including assessment of myocardial edema and free water content, extra-cellular volume (expansion), and most recently cardiomyocyte hypertrophy. The MRI pulse sequence techniques developed for these applications have had to address at least two important considerations for cardiac applications: measure magnetization inversion recoveries during cardiac motion with sufficient temporal resolution for the shortest expected T1 values, and, secondly, obtain these measurements within a time during which a patient can comfortably suspend breathing. So-called Look-Locker techniques, and variants thereof, which all sample multiple points of a magnetization recovery after each magnetization preparation have therefore become a mainstay in this field. The rapid pace of advances and new findings based on cardiac T1 mapping for assessment of diffuse fibrosis, or myocardial edema show that these techniques enrich the capabilities of MRI for myocardial tissue profiling, which is arguably unmatched by other cardiac imaging modalities. PMID:24509619

  10. c-Myc Alters Substrate Utilization and O-GlcNAc Protein Posttranslational Modifications without Altering Cardiac Function during Early Aortic Constriction

    PubMed Central

    Ledee, Dolena; Smith, Lincoln; Bruce, Margaret; Kajimoto, Masaki; Isern, Nancy; Portman, Michael A.; Olson, Aaron K.

    2015-01-01

    Hypertrophic stimuli cause transcription of the proto-oncogene c-Myc (Myc). Prior work showed that myocardial knockout of c-Myc (Myc) attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we assessed the interplay between Myc, substrate oxidation and cardiac function during early pressure overload hypertrophy. Mice with cardiac specific, inducible Myc knockout (MycKO-TAC) and non-transgenic littermates (Cont-TAC) were subjected to transverse aortic constriction (TAC; n = 7/group). Additional groups underwent sham surgery (Cont-Sham and MycKO-Sham, n = 5 per group). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. In sham hearts, Myc knockout did not affect cardiac function or substrate preferences for the citric acid cycle. However, Myc knockout altered fractional contributions during TAC. The unlabeled fractional contribution increased in MycKO-TAC versus Cont-TAC, whereas ketone and free fatty acid fractional contributions decreased. Additionally, protein posttranslational modifications by O-GlcNAc were significantly greater in Cont-TAC versus both Cont-Sham and MycKO-TAC. In conclusion, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy, which may regulate Myc-induced metabolic changes. PMID:26266538

  11. Engineering of Conditional Class I Hdac Knockout Mice and Generation of a Time-Spatial Knockout by a Dual Recombination System.

    PubMed

    Bayer, Sieglinde; Wirth, Matthias

    2017-01-01

    The protein sequences of class I HDACs in mice and humans are 96-99 % identical. These highly conserved proteins have crucial roles in biological processes, such as proliferation and development, which is reflected in the lethality that occurs in conventional whole body knockout mice. Therefore, conditional knockouts are inevitable to investigate the functions of class I HDACs in mice. Here, we describe the generation of conditional class I Hdac knockout mice, using Hdac1 as an example. We explain a relatively quick procedure to generate the necessary target vectors by recombination-mediated genetic engineering and gateway techniques. Furthermore, we show how to culture, target, and screen for positively recombined ES cells. Additionally, we present a dual recombination system, which allows the deletion of class I Hdacs at any time by a tamoxifen inducible Cre.

  12. Attenuated cardiovascular hypertrophy and oxidant generation in response to angiotensin II infusion in glutaredoxin-1 knockout mice.

    PubMed

    Bachschmid, Markus M; Xu, Shanqin; Maitland-Toolan, Karlene A; Ho, Ye-Shih; Cohen, Richard A; Matsui, Reiko

    2010-10-15

    Glutaredoxin-1 (Glrx) is a thioltransferase that regulates protein S-glutathiolation. To elucidate the role of endogenous Glrx in cardiovascular disease, Glrx knockout (KO) mice were infused with angiotensin II (Ang II) for 6days. After Ang II infusion, body weight and blood pressure were similar between WT and Glrx KO mice. However, compared to WT mice, Glrx KO mice demonstrated (1) less cardiac and aortic medial hypertrophy, (2) less oxidant generation in aorta as assessed by dihydroethidium staining and nitrotyrosine, (3) decreased phosphorylation of Akt in the heart, and (4) less expression of inducible NOS in aorta and heart. In cultured embryonic fibroblasts from Glrx KO mice, S-glutathiolation of actin was enhanced and actin depolymerization was impaired after hydrogen peroxide stimulation compared with WT cells. Furthermore, oxidant generation in phorbol ester-stimulated fibroblasts and RAW 264.7 macrophage-like cells was lower with Glrx siRNA knockdown. These data indicate that Ang II-induced oxidant production and hypertrophic responses were attenuated in Glrx KO mice, which may result from impaired NADPH oxidase activation. Copyright 2010 Elsevier Inc. All rights reserved.

  13. Attenuated cardiovascular hypertrophy and oxidant generation in response to angiotensin II infusion in glutaredoxin-1 knockout mice

    PubMed Central

    Bachschmid, Markus M.; Xu, Shanqin; Maitland-Toolan, Karlene A.; Ho, Ye-Shih; Cohen, Richard A.; Matsui, Reiko

    2010-01-01

    Glutaredoxin-1 (Glrx) is a thioltransferase that regulates protein S-glutathiolation. To elucidate the role of endogenous Glrx in cardiovascular disease, Glrx knockout (KO) mice were infused with angiotensin II (Ang II) for 6 days. After Ang II infusion, body weight and blood pressure were similar between WT and Glrx KO mice. However, compared to WT mice, Glrx KO mice demonstrated (1) less cardiac and aortic medial hypertrophy, (2) less oxidant generation in aorta assessed by dihydroethidium staining and nitrotyrosine, (3) decreased phosphorylation of Akt in the heart, and (4) less expression of inducible NOS (iNOS) in aorta and heart. In cultured embryonic fibroblasts from Glrx KO mice, S-glutathiolation of actin was enhanced and actin depolymerization was impaired after hydrogen peroxide stimulation compared with WT cells. Furthermore, oxidant generation in phorbol ester-stimulated fibroblasts and RAW 264.7 macrophage-like cells was lower with Glrx siRNA knockdown. These data indicate that Ang II-induced oxidant production and hypertrophic responses were attenuated in Glrx KO mice, which may result from impaired NADPH oxidase activation. PMID:20638471

  14. Melatonin alleviates postinfarction cardiac remodeling and dysfunction by inhibiting Mst1.

    PubMed

    Hu, Jianqiang; Zhang, Lei; Yang, Yang; Guo, Yanjie; Fan, Yanhong; Zhang, Mingming; Man, Wanrong; Gao, Erhe; Hu, Wei; Reiter, Russel J; Wang, Haichang; Sun, Dongdong

    2017-01-01

    Melatonin reportedly protects against several cardiovascular diseases including ischemia/reperfusion (I/R), atherosclerosis, and hypertension. The present study investigated the effects and mechanisms of melatonin on cardiomyocyte autophagy, apoptosis, and mitochondrial injury in the context of myocardial infarction (MI). We demonstrated that melatonin significantly alleviated cardiac dysfunction after MI. Four weeks after MI, echocardiography and Masson staining indicated that melatonin notably mitigated adverse left ventricle remodeling. The mechanism may be associated with increased autophagy, reduced apoptosis, and alleviated mitochondrial dysfunction. Furthermore, melatonin significantly inhibited Mst1 phosphorylation while promoting Sirt1 expression after MI, which indicates that Mst1/Sirt1 signaling may serve as the downstream target of melatonin. We thus constructed a MI model using Mst1 transgenic (Mst1 Tg) and Mst1 knockout (Mst1(-/-) ) mice. The absence of Mst1 abolished the favorable effects of melatonin on cardiac injury after MI. Consistently, melatonin administration did not further increase autophagy, decrease apoptosis, or alleviate mitochondrial integrity and biogenesis in Mst1 knockout mice subjected to MI injury. These results suggest that melatonin alleviates postinfarction cardiac remodeling and dysfunction by upregulating autophagy, decreasing apoptosis, and modulating mitochondrial integrity and biogenesis. The attributed mechanism involved, at least in part, Mst1/Sirt1 signaling. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Bithorax complex genes control alary muscle patterning along the cardiac tube of Drosophila.

    PubMed

    LaBeau, Elisa M; Trujillo, Damian L; Cripps, Richard M

    2009-01-01

    Cardiac specification models are widely utilized to provide insight into the expression and function of homologous genes and structures in humans. In Drosophila, contractions of the alary muscles control hemolymph inflow and support the cardiac tube, however embryonic development of these muscles remain largely understudied. We found that alary muscles in Drosophila embryos appear as segmental pairs, attaching dorsally at the seven-up (svp) expressing pericardial cells along the cardiac dorsal vessel, and laterally to the body wall. Normal patterning of alary muscles along the dorsal vessel was found to be a function of the Bithorax Complex genes abdominal-A (abd-A) and Ultrabithorax (Ubx) but not of the orphan nuclear receptor gene svp. Ectopic expression of either abd-A or Ubx resulted in an increase in the number of alary muscle pairs from seven to 10, and also produced a general elongation of the dorsal vessel. A single knockout of Ubx resulted in a reduced number of alary muscles. Double knockouts of both Ubx and abd-A prevented alary muscles from developing normally and from attaching to the dorsal vessel. These studies demonstrate an additional facet of muscle development that depends upon the Hox genes, and define for the first time mechanisms that impact development of this important subset of muscles.

  16. Ethical Issues in Cardiac Surgery

    PubMed Central

    Kavarana, Minoo N.; Sade, Robert M.

    2012-01-01

    While ethical behavior has always been part of cardiac surgical practice, ethical deliberation has only recently become an important component of cardiac surgical practice. Issues such as informed consent, conflict of interest, and professional self-regulation, among many others, have increasingly attracted the attention of cardiac surgeons. This review covers several broad topics of interest to cardiac surgeons and cardiologists, and treats several other topics more briefly. There is much uncertainty about what the future holds for cardiac surgical practice, research, and culture, and we discuss the background of ethical issues to serve as a platform for envisioning what is to come. PMID:22642634

  17. Biomechanics of Early Cardiac Development

    PubMed Central

    Goenezen, Sevan; Rennie, Monique Y.

    2012-01-01

    Biomechanics affect early cardiac development, from looping to the development of chambers and valves. Hemodynamic forces are essential for proper cardiac development, and their disruption leads to congenital heart defects. A wealth of information already exists on early cardiac adaptations to hemodynamic loading, and new technologies, including high resolution imaging modalities and computational modeling, are enabling a more thorough understanding of relationships between hemodynamics and cardiac development. Imaging and modeling approaches, used in combination with biological data on cell behavior and adaptation, are paving the road for new discoveries on links between biomechanics and biology and their effect on cardiac development and fetal programming. PMID:22760547

  18. Maternal cardiac metabolism in pregnancy

    PubMed Central

    Liu, Laura X.; Arany, Zolt

    2014-01-01

    Pregnancy causes dramatic physiological changes in the expectant mother. The placenta, mostly foetal in origin, invades maternal uterine tissue early in pregnancy and unleashes a barrage of hormones and other factors. This foetal ‘invasion’ profoundly reprogrammes maternal physiology, affecting nearly every organ, including the heart and its metabolism. We briefly review here maternal systemic metabolic changes during pregnancy and cardiac metabolism in general. We then discuss changes in cardiac haemodynamic during pregnancy and review what is known about maternal cardiac metabolism during pregnancy. Lastly, we discuss cardiac diseases during pregnancy, including peripartum cardiomyopathy, and the potential contribution of aberrant cardiac metabolism to disease aetiology. PMID:24448314

  19. MR imaging of cardiac masses.

    PubMed

    Syed, Imran S; Feng, Dali; Harris, Scott R; Martinez, Matthew W; Misselt, Andrew J; Breen, Jerome F; Miller, Dylan V; Araoz, Philip A

    2008-05-01

    Cardiac MR imaging is the preferred method for assessment of cardiac masses. A comprehensive cardiac MR imaging examination for a cardiac mass consists of static morphologic images using fast spin-echo sequences, including single-shot techniques, with T1 and T2 weighting and fat suppression pulses as well as dynamic imaging with cine steady-state free precession techniques. Further tissue characterization is provided with perfusion and delayed enhancement imaging. Specific cardiac tumoral characterization is possible in many cases. When specific tumor characterization is not possible, MR imaging often can demonstrate aggressive versus nonaggressive features that help in differentiating malignant from benign tumors.

  20. Cardiac rehabilitation in the Navy.

    PubMed

    Bruzek-Kohler, C M; Love, V; Hendrickson, R; Branford, M; Gates, A; Telvick, C

    1994-10-01

    Cardiac rehabilitation has been effective in the management and recovery of the post-myocardial infarction population for almost 40 years. During that time, the fundamental components of rehabilitation have changed to reflect a growing complexity and number of cardiac patients. Great Lakes Naval Hospital has instituted a structured outpatient cardiac rehabilitation program. It is based on the needs of a large cardiac population with modifiable risk factors identified through quality improvement studies. Future implications and research in the area of cardiac rehabilitation include measurements of self-efficacy, long-term risk factor modification, cost effectiveness, gender-related differences, or morbidity and mortality.

  1. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    EPA Science Inventory

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  2. Dcdc2 knockout mice display exacerbated developmental disruptions following knockdown of doublecortin.

    PubMed

    Wang, Y; Yin, X; Rosen, G; Gabel, L; Guadiana, S M; Sarkisian, M R; Galaburda, A M; Loturco, J J

    2011-09-08

    The dyslexia-associated gene DCDC2 is a member of the DCX family of genes known to play roles in neurogenesis, neuronal migration, and differentiation. Here we report the first phenotypic analysis of a Dcdc2 knockout mouse. Comparisons between Dcdc2 knockout mice and wild-type (wt) littermates revealed no significant differences in neuronal migration, neocortical lamination, neuronal cilliogenesis or dendritic differentiation. Considering previous studies showing genetic interactions and potential functional redundancy among members of the DCX family, we tested whether decreasing Dcx expression by RNAi would differentially impair neurodevelopment in Dcdc2 knockouts and wild-type mice. Consistent with this hypothesis, we found that deficits in neuronal migration, and dendritic growth caused by RNAi of Dcx were more severe in Dcdc2 knockouts than in wild-type mice with the same transfection. These results indicate that Dcdc2 is not required for neurogenesis, neuronal migration or differentiation in mice, but may have partial functional redundancy with Dcx.

  3. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    EPA Science Inventory

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  4. A recombineering based approach for high-throughput conditional knockout targeting vector construction

    PubMed Central

    Chan, Waiin; Costantino, Nina; Li, Ruixue; Lee, Song Choon; Su, Qin; Melvin, David; Court, Donald L.; Liu, Pentao

    2007-01-01

    Functional analysis of mammalian genes in vivo is primarily achieved through analysing knockout mice. Now that the sequencing of several mammalian genomes has been completed, understanding functions of all the genes represents the next major challenge in the post-genome era. Generation of knockout mutant mice has currently been achieved by many research groups but only by making individual knockouts, one by one. New technological advances and the refinements of existing technologies are critical for genome-wide targeted mutagenesis in the mouse. We describe here new recombineering reagents and protocols that enable recombineering to be carried out in a 96-well format. Consequently, we are able to construct 96 conditional knockout targeting vectors simultaneously. Our new recombineering system makes it a reality to generate large numbers of precisely engineered DNA constructs for functional genomics studies. PMID:17426124

  5. Knock-Outs, Stick-Outs, Cut-Outs: Clipping Paths Separate Objects from Background.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1998-01-01

    Outlines a six-step process that allows computer operators, using Photoshop software, to create "knock-outs" to precisely define the path that will serve to separate the object from the background. (SR)

  6. Interleukin-10 deficiency aggravates angiotensin II-induced cardiac remodeling in mice.

    PubMed

    Kwon, Woo-Young; Cha, Hye-Na; Heo, Jung-Yoon; Choi, Jung-Hyun; Jang, Byung Ik; Lee, In-Kye; Park, So-Young

    2016-02-01

    This study examined the role of interleukin (IL)-10 in angiotensin II-induced cardiac remodeling. Angiotensin II was infused subcutaneously (1.1mg/kg/day) for one week in IL-10 knockout and wild-type mice, after which cardiac function and hypertrophy were assessed by echocardiogram. IL-10 gene expression in the heart was increased by angiotensin II infusion. Plasma levels of brain natriuretic peptide (BNP) and gene expression of BNP in the heart were increased by IL-10 deficiency or angiotensin II, and plasma BNP levels were further increased by IL-10 deficiency with angiotensin II. IL-10 deficiency increased the left ventricular dimension, whereas treatment with angiotensin II increased heart weight. Angiotensin II significantly reduced cardiac function in IL-10 knockout mice compared with wild-type mice. Gene expression of tumor necrosis factor-α and interleukin-6 was increased by IL-10 deficiency or angiotensin II infusion, and these increases were further enhanced by IL-10 deficiency with angiotensin II. Gene expression of collagen I/III and collagen III protein levels were increased by angiotensin II but not by IL-10 deficiency. Gene expression of matrix metalloproteinase2/9 was increased by IL-10 deficiency or angiotensin II, and this expression was further increased by IL-10 deficiency with angiotensin II. Akt phosphorylation was increased by IL-10 deficiency or angiotensin II and further increased by IL-10 deficiency with angiotensin II. Phosphorylation of p38 was increased by IL-10 deficiency. These results suggest that IL-10 deficiency causes deterioration in cardiac functions in angiotensin II-infused mice, suggesting that IL-10 plays a protective role against angiotensin II-induced cardiac remodeling. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Symmetry of cardiac function assessment

    PubMed Central

    Bai, Xu-Fang; Ma, Amy X

    2016-01-01

    Both right and left ventricles are developed from two adjacent segments of the primary heart tube. Though they are different with regard to shape and power, they mirror each other in terms of behavior. This is the first level of symmetry in cardiac function assessment. Both cardiac muscle contraction and relaxation are active. This constructs the second level of symmetry in cardiac function assessment. Combination of the two levels will help to find some hidden indexes or approaches to evaluate cardiac function. In this article, four major indexes from echocardiography were analyzed under this principal, another seventeen indexes or measurement approaches came out of the shadow, which is very helpful in the assessment of cardiac function, especially for the right cardiac function and diastolic cardiac function. PMID:27582768

  8. Genetics of sudden cardiac death.

    PubMed

    Bezzina, Connie R; Lahrouchi, Najim; Priori, Silvia G

    2015-06-05

    Sudden cardiac death occurs in a broad spectrum of cardiac pathologies and is an important cause of mortality in the general population. Genetic studies conducted during the past 20 years have markedly illuminated the genetic basis of the inherited cardiac disorders associated with sudden cardiac death. Here, we review the genetic basis of sudden cardiac death with a focus on the current knowledge on the genetics of the primary electric disorders caused primarily by mutations in genes encoding ion channels, and the cardiomyopathies, which have been attributed to mutations in genes encoding a broader category of proteins, including those of the sarcomere, the cytoskeleton, and desmosomes. We discuss the challenges currently faced in unraveling genetic factors that predispose to sudden cardiac death in the setting of sequela of coronary artery disease and present the genome-wide association studies conducted in recent years on electrocardiographic parameters, highlighting their potential in uncovering new biological insights into cardiac electric function.

  9. Female preproenkephalin-knockout mice display altered emotional responses.

    PubMed

    Ragnauth, A; Schuller, A; Morgan, M; Chan, J; Ogawa, S; Pintar, J; Bodnar, R J; Pfaff, D W

    2001-02-13

    The endogenous opioid system has been implicated in sexual behavior, palatable intake, fear, and anxiety. The present study examined whether ovariectomized female transgenic preproenkephalin-knockout (PPEKO) mice and their wild-type and heterozygous controls displayed alterations in fear and anxiety paradigms, sucrose intake, and lordotic behavior. To examine stability of responding, three squads of the genotypes were tested across seasons over a 20-month period. In a fear-conditioning paradigm, PPEKO mice significantly increased freezing to both fear and fear + shock stimuli relative to controls. In the open field, PPEKO mice spent significantly less time and traversed significantly less distance in the center of an open field than wild-type controls. Further, PPEKO mice spent significantly less time and tended to be less active on the light side of a dark-light chamber than controls, indicating that deletion of the enkephalin gene resulted in exaggerated responses to fear or anxiety-provoking environments. These selective deficits were observed consistently across testing squads spanning 20 months and different seasons. In contrast, PPEKO mice failed to differ from corresponding controls in sucrose, chow, or water intake across a range (0.0001-20%) of sucrose concentrations and failed to differ in either lordotic or female approach to male behaviors when primed with estradiol and progesterone, thereby arguing strongly for the selectivity of a fear and anxiety deficit which was not caused by generalized and nonspecific debilitation. These transgenic data strongly suggest that opioids, and particularly enkephalin gene products, are acting naturally to inhibit fear and anxiety.

  10. Diet-Induced Obesity in the Selenocysteine Lyase Knockout Mouse

    PubMed Central

    Gilman, Christy L.; Hashimoto, Ann C.; Ogawa-Wong, Ashley N.; Berry, Marla J.

    2015-01-01

    Abstract Aims: Selenocysteine lyase (Scly) mediates selenocysteine decomposition. It was previously demonstrated that, upon adequate caloric intake (12% kcal fat) and selenium deficiency, disruption of Scly in mice leads to development of metabolic syndrome. In this study, we investigate the effect of a high-fat (45% kcal) selenium-adequate diet in Scly knockout (KO) mice on development of metabolic syndrome. Involvement of selenoproteins in energy metabolism after Scly disruption was also examined in vitro in the murine hepatoma cell line, Hepa1-6, following palmitate treatment. Results: Scly KO mice were more susceptible to diet-induced obesity than their wild-type counterparts after feeding a high-fat selenium-adequate diet. Scly KO mice had aggravated hyperinsulinemia, hypercholesterolemia, glucose, and insulin intolerance, but unchanged inflammatory cytokines and expression of most selenoproteins, except increased serum selenoprotein P (Sepp1). Scly KO mice also exhibited enhanced hepatic levels of pyruvate and enzymes involved in the regulation of pyruvate cycling, such as pyruvate carboxylase (Pcx) and pyruvate dehydrogenase (Pdh). However, in vitro silencing of Scly in Hepa1-6 cells led to diminished Sepp1 expression, and concomitant palmitate treatment decreased Pdh expression. Innovation: The role of selenium in lipid metabolism is recognized, but specific selenium-dependent mechanisms leading to obesity are unclear. This study uncovers that Scly has a remarkable effect on obesity and metabolic syndrome development triggered by high-fat exposure, independent of the expression of most selenoproteins. Conclusion: Diet-induced obesity in Scly KO mice is aggravated, with effects on pyruvate levels and consequent activation of energy metabolism independent of selenoprotein levels. Antioxid. Redox Signal. 23, 761–774. PMID:26192035

  11. Diet-induced obesity in the selenocysteine lyase knockout mouse.

    PubMed

    Seale, Lucia A; Gilman, Christy L; Hashimoto, Ann C; Ogawa-Wong, Ashley N; Berry, Marla J

    2015-10-01

    Selenocysteine lyase (Scly) mediates selenocysteine decomposition. It was previously demonstrated that, upon adequate caloric intake (12% kcal fat) and selenium deficiency, disruption of Scly in mice leads to development of metabolic syndrome. In this study, we investigate the effect of a high-fat (45% kcal) selenium-adequate diet in Scly knockout (KO) mice on development of metabolic syndrome. Involvement of selenoproteins in energy metabolism after Scly disruption was also examined in vitro in the murine hepatoma cell line, Hepa1-6, following palmitate treatment. Scly KO mice were more susceptible to diet-induced obesity than their wild-type counterparts after feeding a high-fat selenium-adequate diet. Scly KO mice had aggravated hyperinsulinemia, hypercholesterolemia, glucose, and insulin intolerance, but unchanged inflammatory cytokines and expression of most selenoproteins, except increased serum selenoprotein P (Sepp1). Scly KO mice also exhibited enhanced hepatic levels of pyruvate and enzymes involved in the regulation of pyruvate cycling, such as pyruvate carboxylase (Pcx) and pyruvate dehydrogenase (Pdh). However, in vitro silencing of Scly in Hepa1-6 cells led to diminished Sepp1 expression, and concomitant palmitate treatment decreased Pdh expression. The role of selenium in lipid metabolism is recognized, but specific selenium-dependent mechanisms leading to obesity are unclear. This study uncovers that Scly has a remarkable effect on obesity and metabolic syndrome development triggered by high-fat exposure, independent of the expression of most selenoproteins. Diet-induced obesity in Scly KO mice is aggravated, with effects on pyruvate levels and consequent activation of energy metabolism independent of selenoprotein levels.

  12. Feeding-elicited cataplexy in orexin knockout mice.

    PubMed

    Clark, E L; Baumann, C R; Cano, G; Scammell, T E; Mochizuki, T

    2009-07-21

    Mice lacking orexin/hypocretin signaling have sudden episodes of atonia and paralysis during active wakefulness. These events strongly resemble cataplexy, episodes of sudden muscle weakness triggered by strong positive emotions in people with narcolepsy, but it remains unknown whether murine cataplexy is triggered by positive emotions. To determine whether positive emotions elicit murine cataplexy, we placed orexin knockout (KO) mice on a scheduled feeding protocol with regular or highly palatable food. Baseline sleep/wake behavior was recorded with ad libitum regular chow. Mice were then placed on a scheduled feeding protocol in which they received 60% of their normal amount of chow 3 h after dark onset for the next 10 days. Wild-type and KO mice rapidly entrained to scheduled feeding with regular chow, with more wake and locomotor activity prior to the feeding time. On day 10 of scheduled feeding, orexin KO mice had slightly more cataplexy during the food-anticipation period and more cataplexy in the second half of the dark period, when they may have been foraging for residual food. To test whether more palatable food increases cataplexy, mice were then switched to scheduled feeding with an isocaloric amount of Froot Loops, a food often used as a reward in behavioral studies. With this highly palatable food, orexin KO mice had much more cataplexy during the food-anticipation period and throughout the dark period. The increase in cataplexy with scheduled feeding, especially with highly palatable food, suggests that positive emotions may trigger cataplexy in mice, just as in people with narcolepsy. Establishing this connection helps validate orexin KO mice as an excellent model of human narcolepsy and provides an opportunity to better understand the mechanisms that trigger cataplexy.

  13. Comprehensive behavioral analysis of cluster of differentiation 47 knockout mice.

    PubMed

    Koshimizu, Hisatsugu; Takao, Keizo; Matozaki, Takashi; Ohnishi, Hiroshi; Miyakawa, Tsuyoshi

    2014-01-01

    Cluster of differentiation 47 (CD47) is a member of the immunoglobulin superfamily which functions as a ligand for the extracellular region of signal regulatory protein α (SIRPα), a protein which is abundantly expressed in the brain. Previous studies, including ours, have demonstrated that both CD47 and SIRPα fulfill various functions in the central nervous system (CNS), such as the modulation of synaptic transmission and neuronal cell survival. We previously reported that CD47 is involved in the regulation of depression-like behavior of mice in the forced swim test through its modulation of tyrosine phosphorylation of SIRPα. However, other potential behavioral functions of CD47 remain largely unknown. In this study, in an effort to further investigate functional roles of CD47 in the CNS, CD47 knockout (KO) mice and their wild-type littermates were subjected to a battery of behavioral tests. CD47 KO mice displayed decreased prepulse inhibition, while the startle response did not differ between genotypes. The mutants exhibited slightly but significantly decreased sociability and social novelty preference in Crawley's three-chamber social approach test, whereas in social interaction tests in which experimental and stimulus mice have direct contact with each other in a freely moving setting in a novel environment or home cage, there were no significant differences between the genotypes. While previous studies suggested that CD47 regulates fear memory in the inhibitory avoidance test in rodents, our CD47 KO mice exhibited normal fear and spatial memory in the fear conditioning and the Barnes maze tests, respectively. These findings suggest that CD47 is potentially involved in the regulation of sensorimotor gating and social behavior in mice.

  14. Increased anxiety-related behaviour in Hint1 knockout mice.

    PubMed

    Varadarajulu, Jeeva; Lebar, Maria; Krishnamoorthy, Gurumoorthy; Habelt, Sonja; Lu, Jia; Bernard Weinstein, I; Li, Haiyang; Holsboer, Florian; Turck, Christoph W; Touma, Chadi

    2011-07-07

    Several reports have implicated a role for the histidine triad nucleotide-binding protein-1 (Hint1) in psychiatric disorders. We have studied the emotional behaviour of male Hint1 knockout (Hint1 KO) mice in a battery of tests and performed biochemical analyses on brain tissue. The behavioural analysis revealed that Hint1 KO mice exhibit an increased emotionality phenotype compared to wildtype (WT) mice, while no significant differences in locomotion or general exploratory activity were noted. In the elevated plus-maze (EPM) test, the Hint1 KO animals entered the open arms of the apparatus less often than WT littermates. Similarly, in the dark-light box test, Hint1 KO mice spent less time in the lit compartment and the number of entries were reduced, which further confirmed an increased anxiety-related behaviour. Moreover, the Hint1 KO animals showed significantly more struggling and less floating behaviour in the forced swim test (FST), indicating an increased emotional arousal in aversive situations. Hint1 is known as a protein kinase C (PKC) interacting protein. Western blot analysis showed that PKCγ expression was elevated in Hint1 KO compared to WT mice. Interestingly, PKCγ mRNA levels of the two groups did not show a significant difference, implying a post-transcriptional PKCγ regulation. In addition, PKC enzymatic activity was increased in Hint1 KO compared to WT mice. In summary, our results indicate a role for Hint1 and PKCγ in modulating anxiety-related and stress-coping behaviour in mice.

  15. Altered Sleep Homeostasis in Rev-erbα Knockout Mice.

    PubMed

    Mang, Géraldine M; La Spada, Francesco; Emmenegger, Yann; Chappuis, Sylvie; Ripperger, Jürgen A; Albrecht, Urs; Franken, Paul

    2016-03-01

    The nuclear receptor REV-ERBα is a potent, constitutive transcriptional repressor critical for the regulation of key circadian and metabolic genes. Recently, REV-ERBα's involvement in learning, neurogenesis, mood, and dopamine turnover was demonstrated suggesting a specific role in central nervous system functioning. We have previously shown that the brain expression of several core clock genes, including Rev-erbα, is modulated by sleep loss. We here test the consequences of a loss of REV-ERBα on the homeostatic regulation of sleep. EEG/EMG signals were recorded in Rev-erbα knockout (KO) mice and their wild type (WT) littermates during baseline, sleep deprivation, and recovery. Cortical gene expression measurements after sleep deprivation were contrasted to baseline. Although baseline sleep/wake duration was remarkably similar, KO mice showed an advance of the sleep/wake distribution relative to the light-dark cycle. After sleep onset in baseline and after sleep deprivation, both EEG delta power (1-4 Hz) and sleep consolidation were reduced in KO mice indicating a slower increase of homeostatic sleep need during wakefulness. This slower increase might relate to the smaller increase in theta and gamma power observed in the waking EEG prior to sleep onset under both conditions. Indeed, the increased theta activity during wakefulness predicted delta power in subsequent NREM sleep. Lack of Rev-erbα increased Bmal1, Npas2, Clock, and Fabp7 expression, confirming the direct regulation of these genes by REV-ERBα also in the brain. Our results add further proof to the notion that clock genes are involved in sleep homeostasis. Because accumulating evidence directly links REV-ERBα to dopamine signaling the altered homeostatic regulation of sleep reported here are discussed in that context. © 2016 Associated Professional Sleep Societies, LLC.

  16. P2X6 Knockout Mice Exhibit Normal Electrolyte Homeostasis

    PubMed Central

    Viering, Daan H. H. M.; Bos, Caro; Bindels, René J. M.; Hoenderop, Joost G. J.

    2016-01-01

    ATP-mediated signaling is an important regulator of electrolyte transport in the kidney. The purinergic cation channel P2X6 has been previously localized to the distal convoluted tubule (DCT), a nephron segment important for Mg2+ and Na+ reabsorption, but its role in ion transport remains unknown. In this study, P2x6 knockout (P2x6-/-) mice were generated to investigate the role of P2X6 in renal electrolyte transport. The P2x6-/- animals displayed a normal phenotype and did not differ physiologically from wild type mice. Differences in serum concentration and 24-hrs urine excretion of Na+, K+, Mg2+ and Ca2+ were not detected between P2x6+/+, P2x6+/- and P2x6-/- mice. Quantitative PCR was applied to examine potential compensatory changes in renal expression levels of other P2x subunits and electrolyte transporters, including P2x1-5, P2x7, Trpm6, Ncc, Egf, Cldn16, Scnn1, Slc12a3, Slc41a1, Slc41a3, Cnnm2, Kcnj10 and Fxyd2. Additionally, protein levels of P2X2 and P2X4 were assessed in P2x6+/+ and P2x6-/- mouse kidneys. However, significant changes in expression were not detected. Furthermore, no compensatory changes in gene expression could be demonstrated in heart material isolated from P2x6-/- mice. Except for a significant (P<0.05) upregulation of P2x2 in the heart of P2x6-/- mice compared to the P2x6+/+ mice. Thus, our data suggests that purinergic signaling via P2X6 is not significantly involved in the regulation of renal electrolyte handling under normal physiological conditions. PMID:27254077

  17. Targeting cancer using KAT inhibitors to mimic lethal knockouts

    PubMed Central

    Brown, James A.L.; Bourke, Emer; Eriksson, Leif A.; Kerin, Michael J.

    2016-01-01

    Two opposing enzyme classes regulate fundamental elements of genome maintenance, gene regulation and metabolism, either through addition of an acetyl moiety by histone acetyltransferases (HATs) or its removal by histone de-acetyltransferases (HDAC), and are exciting targets for drug development. Importantly, dysfunctional acetylation has been implicated in numerous diseases, including cancer. Within the HAT superfamily the MYST family holds particular interest, as its members are directly involved in the DNA damage response and repair pathways and crucially, several members have been shown to be down-regulated in common cancers (such as breast and prostate). In the present study we focus on the development of lysine (K) acetyltransferase inhibitors (KATi) targeting the MYST family member Tip60 (Kat5), an essential protein, designed or discovered through screening libraries. Importantly, Tip60 has been demonstrated to be significantly down-regulated in many cancers which urgently require new treatment options. We highlight current and future efforts employing these KATi as cancer treatments and their ability to synergize and enhance current cancer treatments. We investigate the different methods of KATi production or discovery, their mechanisms and their validation models. Importantly, the utility of KATi is based on a key concept: using KATi to abrogate the activity of an already down-regulated essential protein (effectively creating a lethal knockout) provides another innovative mechanism for targeting cancer cells, while significantly minimizing any off-target effects to normal cells. This approach, combined with the rapidly developing interest in KATi, suggests that KATi have a bright future for providing truly personalized therapies. PMID:27528742

  18. Analysis of microsatellite polymorphism in inbred knockout mice.

    PubMed

    Zuo, Baofen; Du, Xiaoyan; Zhao, Jing; Yang, Huixin; Wang, Chao; Wu, Yanhua; Lu, Jing; Wang, Ying; Chen, Zhenwen

    2012-01-01

    Previously, we found that the genotype of 42 out of 198 mouse microsatellite loci, which are distributed among all chromosomes except the Y chromosome, changed from monomorphism to polymorphism (CMP) in a genetically modified inbred mouse strain. In this study, we further examined whether CMP also relates to the homologous recombination in gene knockout (KO) mouse strains. The same 42 microsatellite loci were analyzed by polymerase chain reaction (PCR) in 29 KO inbred mouse strains via short tandem sequence repeat (STR) scanning and direct sequence cloning to justify microsatellite polymorphisms. The C57BL/6J and 129 mouse strains, from which these 29 KO mice were derived, were chosen as the background controls. The results indicated that 10 out of 42 (23.8%) loci showed CMP in some of these mouse strains. Except for the trinucleotide repeat locus of D3Mit22, which had microsatellite CMP in strain number 9, the core sequences of the remaining 41 loci were dinucleotide repeats, and 9 out of 41 (21.95%) showed CMPs among detected mouse strains. However, 11 out of 29 (37.9%) KO mice strains were recognized as having CMPs. The popular dinucleotide motifs in CMP were (TG)(n) (50%, 2/4), followed by (GT)(n) (27.27%, 3/11) and (CA)(n) (23.08%, 3/13). The microsatellite CMP in (CT)(n) and (AG)(n) repeats were 20% (1/5). According to cloning sequencing results, 6 KO mouse strains showed insertions of nucleotides whereas 1 showed a deletion. Furthermore, 2 loci (D13Mit3 and D14Mit102) revealed CMP in 2 strains, and mouse strain number 9 showed CMPs in two loci (D3Mit22 and D13Mit3) simultaneously. Collectively, these results indicated that microsatellite polymorphisms were present in the examined inbred KO mice.

  19. Analysis of Microsatellite Polymorphism in Inbred Knockout Mice

    PubMed Central

    Zhao, Jing; Yang, Huixin; Wang, Chao; Wu, Yanhua; Lu, Jing; Wang, Ying; Chen, Zhenwen

    2012-01-01

    Previously, we found that the genotype of 42 out of 198 mouse microsatellite loci, which are distributed among all chromosomes except the Y chromosome, changed from monomorphism to polymorphism (CMP) in a genetically modified inbred mouse strain. In this study, we further examined whether CMP also relates to the homologous recombination in gene knockout (KO) mouse strains. The same 42 microsatellite loci were analyzed by polymerase chain reaction (PCR) in 29 KO inbred mouse strains via short tandem sequence repeat (STR) scanning and direct sequence cloning to justify microsatellite polymorphisms. The C57BL/6J and 129 mouse strains, from which these 29 KO mice were derived, were chosen as the background controls. The results indicated that 10 out of 42 (23.8%) loci showed CMP in some of these mouse strains. Except for the trinucleotide repeat locus of D3Mit22, which had microsatellite CMP in strain number 9, the core sequences of the remaining 41 loci were dinucleotide repeats, and 9 out of 41 (21.95%) showed CMPs among detected mouse strains. However, 11 out of 29 (37.9%) KO mice strains were recognized as having CMPs. The popular dinucleotide motifs in CMP were (TG)n (50%, 2/4), followed by (GT)n (27.27%, 3/11) and (CA)n (23.08%, 3/13). The microsatellite CMP in (CT)n and (AG)n repeats were 20% (1/5). According to cloning sequencing results, 6 KO mouse strains showed insertions of nucleotides whereas 1 showed a deletion. Furthermore, 2 loci (D13Mit3 and D14Mit102) revealed CMP in 2 strains, and mouse strain number 9 showed CMPs in two loci (D3Mit22 and D13Mit3) simultaneously. Collectively, these results indicated that microsatellite polymorphisms were present in the examined inbred KO mice. PMID:22509320

  20. Impairment of neuropsychological behaviors in ganglioside GM3-knockout mice.

    PubMed

    Niimi, Kimie; Nishioka, Chieko; Miyamoto, Tomomi; Takahashi, Eiki; Miyoshi, Ichiro; Itakura, Chitoshi; Yamashita, Tadashi

    2011-03-25

    The ganglioside GM3 synthase (SAT-I), encoded by a single-copy gene, is a primary glycosyltransferase for the synthesis of complex gangliosides. Although its expression is tightly controlled during early embryo development and postnatal development and maturation in the brain, the physiological role of ganglioside GM3 in the regulation of neuronal functions has not been elucidated. In the present study, we examined motor activity, cognitive and emotional behaviors, and drug administration in juvenile GM3-knockout (GM3-KO) mice. GM3-KO male and female mice showed hyperactivity in the motor activity test, Y-maze test, and elevated plus maze test. In the Y-maze test, there was significantly less spontaneous alternation behavior in GM3-KO male mice than in wild-type mice. In the elevated plus maze test, the amount of time spent on the open arms by GM3-KO male mice was significantly higher than that of sex-matched wild-type mice. In contrast, there was no significant difference between GM3-KO and wild-type female mice in these tests. Thus, juvenile GM3-KO mice show gender-specific phenotypes resembling attention-deficit hyperactivity disorder (ADHD), namely hyperactivity, reduced attention, and increased impulsive behaviors. However, administration of methylphenidate hydrochloride (MPH) did not ameliorate hyperactivity in either male or female GM3-KO mice. Although these data demonstrate the involvement of ganglioside GM3 in ADHD and the ineffectiveness of MPH, the first-choice psychostimulant for ADHD medication, our studies indicate that juvenile GM3-KO mice are a useful tool for neuropsychological studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Autism-related behavioral abnormalities in synapsin knockout mice

    PubMed Central

    Greco, Barbara; Managò, Francesca; Tucci, Valter; Kao, Hung-Teh; Valtorta, Flavia; Benfenati, Fabio

    2013-01-01

    Several synaptic genes predisposing to autism-spectrum disorder (ASD) have been identified. Nonsense and missense mutations in the SYN1 gene encoding for Synapsin I have been identified in families segregating for idiopathic epilepsy and ASD and genetic mapping analyses have identified variations in the SYN2 gene as significantly contributing to epilepsy predisposition. Synapsins (Syn I/II/III) are a multigene family of synaptic vesicle-associated phosphoproteins playing multiple roles in synaptic development, transmission and plasticity. Lack of SynI and/or SynII triggers a strong epileptic phenotype in mice associated with mild cognitive impairments that are also present in the non-epileptic SynIII−/− mice. SynII−/− and SynIII−/− mice also display schizophrenia-like traits, suggesting that Syns could be involved in the regulation of social behavior. Here, we studied social interaction and novelty, social recognition and social dominance, social transmission of food preference and social memory in groups of male SynI−/−, SynII−/− and SynIII−/− mice before and after the appearance of the epileptic phenotype and compared their performances with control mice. We found that deletion of Syn isoforms widely impairs social behaviors and repetitive behaviors, resulting in ASD-related phenotypes. SynI or SynIII deletion altered social behavior, whereas SynII deletion extensively impaired various aspects of social behavior and memory, altered exploration of a novel environment and increased self-grooming. Social impairments of SynI−/− and SynII−/− mice were evident also before the onset of seizures. The results demonstrate an involvement of Syns in generation of the behavioral traits of ASD and identify Syn knockout mice as a useful experimental model of ASD and epilepsy. PMID:23280234

  2. Neuroaxonal dystrophy in PLA2G6 knockout mice.

    PubMed

    Sumi-Akamaru, Hisae; Beck, Goichi; Kato, Shinsuke; Mochizuki, Hideki

    2015-06-01

    The PLA2G6 gene encodes group VIA calcium-independent phospholipase A2 (iPLA2 β), which belongs to the PLA2 superfamily that hydrolyses the sn-2 ester bond in phospholipids. In the nervous system, iPLA2 β is essential for remodeling membrane phospholipids in axons and synapses. Mutated PLA2G6 causes PLA2G6-associated neurodegeneration (PLAN) including infantile neuroaxonal dystrophy (INAD) and adult-onset dystonia-parkinsonism (PARK14), which have unique clinical phenotypes. In the PLA2G6 knockout (KO) mouse, which is an excellent PLAN model, specific membrane degeneration takes place in neurons and their axons, and this is followed by axonal spheroid formation. These pathological findings are similar to those in PLAN. This review details the evidence that membrane degeneration of mitochondria and axon terminals is a precursor to spheroid formation in this disease model. From a young age before the onset, many mitochondria with damaged inner membranes appear in PLA2G6 KO mouse neurons. These injured mitochondria move anterogradely within the axons, increasing in the distal axons. As membrane degeneration progresses, the collapse of the double membrane of mitochondria accompanies axonal injury near impaired mitochondria. At the axon terminals, the membranes of the presynapses expand irregularly from a young age. Over time, the presynaptic membrane ruptures, causing axon terminal degeneration. Although these processes occur in different degenerating membranes, both contain tubulovesicular structures, which are a specific ultrastructural marker of INAD. This indicates that two unique types of membrane degeneration underlie PLAN pathology. We have shown a new pathological mechanism whereby axons degenerate due to defective maintenance and rupture of both the inner mitochondrial and presynaptic membranes. This degeneration mechanism could possibly clarify the pathologies of PLAN, Parkinson disease and neurodegeneration with iron accumulation (NBIA), which are

  3. HFE gene knockout produces mouse model of hereditary hemochromatosis

    PubMed Central

    Zhou, Xiao Yan; Tomatsu, Shunji; Fleming, Robert E.; Parkkila, Seppo; Waheed, Abdul; Jiang, Jinxing; Fei, Ying; Brunt, Elizabeth M.; Ruddy, David A.; Prass, Cynthia E.; Schatzman, Randall C.; O’Neill, Rosemary; Britton, Robert S.; Bacon, Bruce R.; Sly, William S.

    1998-01-01

    Hereditary hemochromatosis (HH) is a common autosomal recessive disease characterized by increased iron absorption and progressive iron storage that results in damage to major organs in the body. Recently, a candidate gene for HH called HFE encoding a major histocompatibility complex class I-like protein was identified by positional cloning. Nearly 90% of Caucasian HH patients have been found to be homozygous for the same mutation (C282Y) in the HFE gene. To test the hypothesis that the HFE gene is involved in regulation of iron homeostasis, we studied the effects of a targeted disruption of the murine homologue of the HFE gene. The HFE-deficient mice showed profound differences in parameters of iron homeostasis. Even on a standard diet, by 10 weeks of age, fasting transferrin saturation was significantly elevated compared with normal littermates (96 ± 5% vs. 77 ± 3%, P < 0.007), and hepatic iron concentration was 8-fold higher than that of wild-type littermates (2,071 ± 450 vs. 255 ± 23 μg/g dry wt, P < 0.002). Stainable hepatic iron in the HFE mutant mice was predominantly in hepatocytes in a periportal distribution. Iron concentrations in spleen, heart, and kidney were not significantly different. Erythroid parameters were normal, indicating that the anemia did not contribute to the increased iron storage. This study shows that the HFE protein is involved in the regulation of iron homeostasis and that mutations in this gene are responsible for HH. The knockout mouse model of HH will facilitate investigation into the pathogenesis of increased iron accumulation in HH and provide opportunities to evaluate therapeutic strategies for prevention or correction of iron overload. PMID:9482913

  4. High-fat diet induces cardiac remodelling and dysfunction: assessment of the role played by SIRT3 loss.

    PubMed

    Zeng, Heng; Vaka, Venkata Ramana; He, Xiaochen; Booz, George W; Chen, Jian-Xiong

    2015-08-01

    Mitochondrial dysfunction plays an important role in obesity-induced cardiac impairment. SIRT3 is a mitochondrial protein associated with increased human life span and metabolism. This study investigated the functional role of SIRT3 in obesity-induced cardiac dysfunction. Wild-type (WT) and SIRT3 knockout (KO) mice were fed a normal diet (ND) or high-fat diet (HFD) for 16 weeks. Body weight, fasting glucose levels, reactive oxygen species (ROS) levels, myocardial capillary density, cardiac function and expression of hypoxia-inducible factor (HIF)-1α/-2α were assessed. HFD resulted in a significant reduction in SIRT3 expression in the heart. Both HFD and SIRT3 KO mice showed increased ROS formation, impaired HIF signalling and reduced capillary density in the heart. HFD induced cardiac hypertrophy and impaired cardiac function. SIRT3 KO mice fed HFD showed greater ROS production and a further reduction in cardiac function compared to SIRT3 KO mice on ND. Thus, the adverse effects of HFD on cardiac function were not attributable to SIRT3 loss alone. However, HFD did not further reduce capillary density in SIRT3 KO hearts, implicating SIRT3 loss in HFD-induced capillary rarefaction. Our study demonstrates the importance of SIRT3 in preserving heart function and capillary density in the setting of obesity. Thus, SIRT3 may be a potential therapeutic target for obesity-induced heart failure.

  5. High-fat diet induces cardiac remodelling and dysfunction: assessment of the role played by SIRT3 loss

    PubMed Central

    Zeng, Heng; Vaka, Venkata Ramana; He, Xiaochen; Booz, George W; Chen, Jian-Xiong

    2015-01-01

    Mitochondrial dysfunction plays an important role in obesity-induced cardiac impairment. SIRT3 is a mitochondrial protein associated with increased human life span and metabolism. This study investigated the functional role of SIRT3 in obesity-induced cardiac dysfunction. Wild-type (WT) and SIRT3 knockout (KO) mice were fed a normal diet (ND) or high-fat diet (HFD) for 16 weeks. Body weight, fasting glucose levels, reactive oxygen species (ROS) levels, myocardial capillary density, cardiac function and expression of hypoxia-inducible factor (HIF)-1α/-2α were assessed. HFD resulted in a significant reduction in SIRT3 expression in the heart. Both HFD and SIRT3 KO mice showed increased ROS formation, impaired HIF signalling and reduced capillary density in the heart. HFD induced cardiac hypertrophy and impaired cardiac function. SIRT3 KO mice fed HFD showed greater ROS production and a further reduction in cardiac function compared to SIRT3 KO mice on ND. Thus, the adverse effects of HFD on cardiac function were not attributable to SIRT3 loss alone. However, HFD did not further reduce capillary density in SIRT3 KO hearts, implicating SIRT3 loss in HFD-induced capillary rarefaction. Our study demonstrates the importance of SIRT3 in preserving heart function and capillary density in the setting of obesity. Thus, SIRT3 may be a potential therapeutic target for obesity-induced heart failure. PMID:25782072

  6. The organization of adherens junctions and desmosomes at the cardiac intercalated disc is independent of gap junctions.

    PubMed

    Gutstein, David E; Liu, Fang-Yu; Meyers, Marian B; Choo, Andrew; Fishman, Glenn I

    2003-03-01

    Adherens junctions and desmosomes are responsible for mechanically coupling myocytes in the heart and are found closely apposed to gap junction plaques at the intercalated discs of cardiomyocytes. It is not known whether loss of cardiac gap junctions, such as described in cardiac disease states, may influence the expression patterns of other intercalated disc-associated proteins. We investigated whether the major cardiac gap junction protein connexin43 (Cx43) may be responsible for regulating adherens junctions, desmosomes and their associated catenins, in terms of abundance and localization at the intercalated discs of cardiomyocytes. In order to study the effect of loss of cardiac gap junctions on the intercalated disc-associated proteins, we used a combination of immunoblotting, immunofluorescence with confocal microscopy and electron microscopy to evaluate heart tissue from mice with cardiac-specific conditional knockout of Cx43. We found that the cardiac adherens junctions, desmosomes and their associated catenins, as well as vinculin and ZO-1, maintain their normal abundance, structural appearance and localization in the absence of Cx43. We conclude from these data that Cx43 is not required for the organization of the cell adhesion junctions and their associated catenins at the intercalated disc in the adult cardiac myocyte.

  7. Ubiquitin-Specific Protease 4 Is an Endogenous Negative Regulator of Pathological Cardiac Hypertrophy.

    PubMed

    He, Ben; Zhao, Yi-Chao; Gao, Ling-Chen; Ying, Xiao-Ying; Xu, Long-Wei; Su, Yuan-Yuan; Ji, Qing-Qi; Lin, Nan; Pu, Jun

    2016-06-01

    Dysregulation of the ubiquitin proteasome system components ubiquitin ligases and proteasome plays an important role in the pathogenesis of cardiac hypertrophy. However, little is known about the role of another ubiquitin proteasome system component, the deubiquitinating enzymes, in cardiac hypertrophy. Here, we revealed a crucial role of ubiquitin specific protease 4 (USP4), a deubiquitinating enzyme prominently expressed in the heart, in attenuating pathological cardiac hypertrophy and dysfunction. USP4 levels were consistently decreased in human failing hearts and in murine hypertrophied hearts. Adenovirus-mediated gain- and loss-of-function approaches indicated that deficiency of endogenous USP4 promoted myocyte hypertrophy induced by angiotensin II in vitro, whereas restoration of USP4 significantly attenuated the prohypertrophic effect of angiotensin II. To corroborate the role of USP4 in vivo, we generated USP4 global knockout mice and mice with cardiac-specific overexpression of USP4. Consistent with the in vitro study, USP4 depletion exacerbated the hypertrophic phenotype and cardiac dysfunction in mice subjected to pressure overload, whereas USP4 transgenic mice presented ameliorated pathological cardiac hypertrophy compared with their control littermates. Molecular analysis revealed that USP4 deficiency augmented the activation of the transforming growth factor β-activated kinase 1 (TAK1)-(JNK1/2)/P38 signaling in response to hypertrophic stress, and blockage of TAK1 activation abolished the pathological effects of USP4 deficiency in vivo. These findings provide the first evidence for the involvement of USP4 in cardiac hypertrophy, and shed light on the therapeutic potential of targeting USP4 in the treatment of cardiac hypertrophy. © 2016 American Heart Association, Inc.

  8. Interferon regulatory factor 7 functions as a novel negative regulator of pathological cardiac hypertrophy.

    PubMed

    Jiang, Ding-Sheng; Liu, Yu; Zhou, Heng; Zhang, Yan; Zhang, Xiao-Dong; Zhang, Xiao-Fei; Chen, Ke; Gao, Lu; Peng, Juan; Gong, Hui; Chen, Yingjie; Yang, Qinglin; Liu, Peter P; Fan, Guo-Chang; Zou, Yunzeng; Li, Hongliang

    2014-04-01

    Cardiac hypertrophy is a complex pathological process that involves multiple factors including inflammation and apoptosis. Interferon regulatory factor 7 (IRF7) is a multifunctional regulator that participates in immune regulation, cell differentiation, apoptosis, and oncogenesis. However, the role of IRF7 in cardiac hypertrophy remains unclear. We performed aortic banding in cardiac-specific IRF7 transgenic mice, IRF7 knockout mice, and the wild-type littermates of these mice. Our results demonstrated that IRF7 was downregulated in aortic banding-induced animal hearts and cardiomyocytes that had been treated with angiotensin II or phenylephrine for 48 hours. Accordingly, heart-specific overexpression of IRF7 significantly attenuated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of IRF7 led to opposite effects. Moreover, IRF7 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, we identified that IRF7-dependent cardioprotection was mediated through IRF7 binding to inhibitor of κB kinase-β, and subsequent nuclear factor-κB inactivation. In fact, blocking nuclear factor-κB signaling with cardiac-specific inhibitors of κBα(S32A/S36A) super-repressor transgene counteracted the adverse effect of IRF7 deficiency. Conversely, activation of nuclear factor-κB signaling via a cardiac-specific conditional inhibitor of κB kinase-β(S177E/S181E) (constitutively active) transgene negated the antihypertrophic effect of IRF7 overexpression. Our data demonstrate that IRF7 acts as a novel negative regulator of pathological cardiac hypertrophy by inhibiting nuclear factor-κB signaling and may constitute a potential therapeutic target for pathological cardiac hypertrophy.

  9. Interferon Regulatory Factor 7 Functions as a Novel Negative Regulator of Pathological Cardiac Hypertrophy

    PubMed Central

    Jiang, Ding-Sheng; Liu, Yu; Zhou, Heng; Zhang, Yan; Zhang, Xiao-Dong; Zhang, Xiao-Fei; Chen, Ke; Gao, Lu; Peng, Juan; Gong, Hui; Chen, Yingjie; Yang, Qinglin; Liu, Peter P.; Fan, Guo-Chang; Zou, Yunzeng; Li, Hongliang

    2017-01-01

    Cardiac hypertrophy is a complex pathological process that involves multiple factors including inflammation and apoptosis. Interferon regulatory factor 7 (IRF7) is a multifunctional regulator that participates in immune regulation, cell differentiation, apoptosis, and oncogenesis. However, the role of IRF7 in cardiac hypertrophy remains unclear. We performed aortic banding in cardiac-specific IRF7 transgenic mice, IRF7 knockout mice, and the wild-type littermates of these mice. Our results demonstrated that IRF7 was downregulated in aortic banding–induced animal hearts and cardiomyocytes that had been treated with angiotensin II or phenylephrine for 48 hours. Accordingly, heart-specific overexpression of IRF7 significantly attenuated pressure overload–induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of IRF7 led to opposite effects. Moreover, IRF7 protected against angiotensin II–induced cardiomyocyte hypertrophy in vitro. Mechanistically, we identified that IRF7-dependent cardioprotection was mediated through IRF7 binding to inhibitor of κB kinase-β, and subsequent nuclear factor-κB inactivation. In fact, blocking nuclear factor-κB signaling with cardiac-specific inhibitors of κBαS32A/S36A super-repressor transgene counteracted the adverse effect of IRF7 deficiency. Conversely, activation of nuclear factor-κB signaling via a cardiac-specific conditional inhibitor of κB kinase-βS177E/S181E (constitutively active) transgene negated the antihypertrophic effect of IRF7 overexpression. Our data demonstrate that IRF7 acts as a novel negative regulator of pathological cardiac hypertrophy by inhibiting nuclear factor-κB signaling and may constitute a potential therapeutic target for pathological cardiac hypertrophy. PMID:24396025

  10. Effect of vitamin D receptor knockout on cornea epithelium wound healing and tight junctions.

    PubMed

    Elizondo, Rodolfo A; Yin, Zhaohong; Lu, Xiaowen; Watsky, Mitchell A

    2014-07-24

    Our laboratory previously determined that vitamin D3, the vitamin D receptor (VDR), and 1α hydroxylase are present and active in the eye. In this study, we examined the effects of VDR knockout on wound healing, the tight junction-associated proteins occludin and ZO-1, and tight junction numbers in mouse corneas. Epithelial wounds (2-mm) were made with an agar brush on 4-week-old and 10-week-old wild-type, heterozygous, and VDR knockout mouse corneas. Mice were on a normal or high lactose, Ca(2+), and PO₄(-) diet. Wound-healing area was measured over time. Real-time PCR was used to quantify occludin and ZO-1 message expression. Western blot was used for protein expression. Transmission electron microscopy was used to examine corneal epithelium and endothelium tight junctions. Immunofluorescence was used to examine epithelial ZO-1 distribution. Results showed a decreased healing rate in 10-week-old VDR knockout mice compared with wild-types. Vitamin D receptor knockout mice on the special diet had no difference in healing rate compared with wild-types. Real-time PCR showed decreased expression of occludin and ZO-1 in 10-week-old VDR knockout mice compared with wild-types. Western blot of 10-week-old knockout mouse corneas showed decreased occludin expression compared with wild-types. Transmission electron microscopy showed a significant difference in tight junction numbers in VDR knockouts versus wild-types. Immunofluorescence showed a change in ZO-1 distribution among genotypes. Vitamin D receptor knockout affects mouse corneal epithelium wound healing and tight junction integrity. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  11. Knockout of leucine aminopeptidase in Toxoplasma gondii using CRISPR/Cas9.

    PubMed

    Zheng, Jun; Jia, Honglin; Zheng, Yonghui

    2015-02-01

    Leucine aminopeptidases of the M17 peptidase family represent ideal drug targets for therapies directed against the pathogens Plasmodium, Babesia and Trypanosoma. Previously, we characterised Toxoplasma gondii leucine aminopeptidase and demonstrated its role in regulating the levels of free amino acids. In this study, we evaluated the potential of T. gondii leucine aminopeptidase as a drug target in T. gondii by a knockout method. Existing knockout methods for T. gondii have many drawbacks; therefore, we developed a new technique that takes advantage of the CRISPR/Cas9 system. We first chose a Cas9 target site in the gene encoding T. gondii leucine aminopeptidase and then constructed a knockout vector containing Cas9 and the single guide RNA. After transfection, single tachyzoites were cloned in 96-well plates by limiting dilution. Two transfected strains derived from a single clone were cultured in Vero cells, and then subjected to expression analysis by western blotting. The phenotypic analysis revealed that knockout of T. gondii leucine aminopeptidase resulted in inhibition of attachment/invasion and replication; both the growth and attachment/invasion capacity of knockout parasites were restored by complementation with a synonymously substituted allele of T. gondii leucine aminopeptidase. Mouse experiments demonstrated that T. gondii leucine aminopeptidase knockout somewhat reduced the pathogenicity of T. gondii. An enzymatic activity assay showed that T. gondii leucine aminopeptidase knockout reduced the processing of a leucine aminopeptidase-specific substrate in T. gondii. The absence of leucine aminopeptidase activity could be slightly compensated for in T. gondii. Overall, T. gondii leucine aminopeptidase knockout influenced the growth of T. gondii, but did not completely block parasite development, virulence or enzymatic activity. Therefore, we conclude that leucine aminopeptidase would be useful only as an adjunctive drug target in T. gondii. Copyright

  12. Nucleostemin Rejuvenates Cardiac Progenitor Cells and Antagonizes Myocardial Aging

    PubMed Central

    Hariharan, Nirmala; Quijada, Pearl; Mohsin, Sadia; Joyo, Anya; Samse, Kaitlen; Monsanto, Megan; De La Torre, Andrea; Avitabile, Daniele; Ormachea, Lucia; McGregor, Michael J.; Tsai, Emily J; Sussman, Mark A.

    2015-01-01

    BACKGROUND Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy with elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. OBJECTIVES The goal is to demonstrate that NS preserves characteristics associated with “stemness” in CPCs and antagonizes myocardial senescence and aging. METHODS CPCs isolated from human fetal (FhCPC) and adult failing (AhCPC) hearts, as well as young (YCPC) and old mice (OCPC), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with one functional allele of NS (NS+/−) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. RESULTS NS expression is decreased in AhCPCs relative to FhCPC, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S phase progression, diminished expression of stemness markers and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of “stemness.” Early cardiac aging with decline in cardiac function, increase in senescence markers p53 and p16, telomere attrition, and accompanied CPC exhaustion is evident in NS+/− mice. CONCLUSIONS Youthful properties and antagonism of

  13. Factor XI Deficiency Protects Against Atherogenesis in Apolipoprotein E/Factor XI Double Knockout Mice.

    PubMed

    Shnerb Ganor, Reut; Harats, Dror; Schiby, Ginette; Gailani, David; Levkovitz, Hanna; Avivi, Camila; Tamarin, Ilia; Shaish, Aviv; Salomon, Ophira

    2016-03-01

    Atherosclerosis and atherothrombosis are still major causes of mortality in the Western world, even after the widespread use of cholesterol-lowering medications. Recently, an association between local thrombin generation and atherosclerotic burden has been reported. Here, we studied the role of factor XI (FXI) deficiency in the process of atherosclerosis in mice. Apolipoprotein E/FXI double knockout mice, created for the first time in our laboratory. There was no difference in cholesterol levels or lipoprotein profiles between apolipoprotein E knockout and double knockout mice. Nevertheless, in 24-week-old double knockout mice, the atherosclerotic lesion area in the aortic sinus was reduced by 32% (P=0.004) in comparison with apolipoprotein E knockout mice. In 42-week-old double knockout mice, FXI deficiency inhibited atherosclerosis progression significantly in the aortic sinus (25% reduction, P=0.024) and in the aortic arch (49% reduction, P=0.028), with a prominent reduction of macrophage infiltration in the atherosclerotic lesions. FXI deprivation was shown to slow down atherogenesis in mice. The results suggest that the development of atherosclerosis can be prevented by targeting FXI. © 2016 American Heart Association, Inc.

  14. Normal maternal behavior, but increased pup mortality, in conditional oxytocin receptor knockout females.

    PubMed

    Macbeth, Abbe H; Stepp, Jennifer E; Lee, Heon-Jin; Young, W Scott; Caldwell, Heather K

    2010-10-01

    Oxytocin (Oxt) and the Oxt receptor (Oxtr) are implicated in the onset of maternal behavior in a variety of species. Recently, we developed two Oxtr knockout lines: a total body knockout (Oxtr-/-) and a conditional Oxtr knockout (OxtrFB/FB) in which the Oxtr is lacking only in regions of the forebrain, allowing knockout females to potentially nurse and care for their biological offspring. In the current study, we assessed maternal behavior of postpartum OxtrFB/FB females toward their own pups and maternal behavior of virgin Oxtr-/- females toward foster pups and compared knockouts of both lines to wildtype (Oxtr+/+) littermates. We found that both Oxtr-/- and OxtrFB/FB females appear to have largely normal maternal behaviors. However, with first litters, approximately 40% of the OxtrFB/FB knockout dams experienced high pup mortality, compared to fewer than 10% of the Oxtr+/+ dams. We then went on to test whether or not this phenotype occurred in subsequent litters or when the dams were exposed to an environmental disturbance. We found that regardless of the degree of external disturbance, OxtrFB/FB females lost more pups on their first and second litters compared to wildtype females. Possible reasons for higher pup mortality in OxtrFB/FB females are discussed.

  15. What do aquaporin knockout studies tell us about fluid transport in epithelia?

    PubMed Central

    Maclaren, Oliver J; Sneyd, James; Crampin, Edmund J

    2013-01-01

    The investigation of near-isosmotic water transport in epithelia goes back over 100 years; however debates over mechanism and pathway still remain. Aquaporin (AQP) knockouts have been used by various research groups to test the hypothesis of an osmotic mechanism, as well as to explore the paracellular vs transcellular pathway debate. Non-proportional reductions in the water permeability of a water-transporting epithelial cell (e.g. a reduction of around 80–90%) compared to the reduction in overall water transport rate in the knockout animal (e.g. a reduction of 50–60%) are commonly found. This non-proportionality has led to controversy over whether AQP knockout studies support or contradict the osmotic mechanism. Arguments raised for and against an interpretation supporting the osmotic mechanism typically have partially-specified, implicit or incorrect assumptions. We present a simple mathematical model of the osmotic mechanism with clear assumptions and, for models based on this mechanism, establish a baseline prediction of AQP knockout studies. We allow for deviations from isotonic/isosmotic conditions and utilize dimensional analysis to reduce the number of parameters that must be considered independently. This enables a single prediction curve to be used for multiple epithelial systems. We find that a simple, transcellular-only osmotic mechanism sufficiently predicts the results of knockout studies and find criticisms of this mechanism to be overstated. We note, however, that AQP knockout studies do not give sufficient information to definitively rule out an additional paracellular pathway. PMID:23430220

  16. Pyviko: an automated Python tool to design gene knockouts in complex viruses with overlapping genes.

    PubMed

    Taylor, Louis J; Strebel, Klaus

    2017-01-07

    Gene knockouts are a common tool used to study gene function in various organisms. However, designing gene knockouts is complicated in viruses, which frequently contain sequences that code for multiple overlapping genes. Designing mutants that can be traced by the creation of new or elimination of existing restriction sites further compounds the difficulty in experimental design of knockouts of overlapping genes. While software is available to rapidly identify restriction sites in a given nucleotide sequence, no existing software addresses experimental design of mutations involving multiple overlapping amino acid sequences in generating gene knockouts. Pyviko performed well on a test set of over 240,000 gene pairs collected from viral genomes deposited in the National Center for Biotechnology Information Nucleotide database, identifying a point mutation which added a premature stop codon within the first 20 codons of the target gene in 93.2% of all tested gene-overprinted gene pairs. This shows that Pyviko can be used successfully in a wide variety of contexts to facilitate the molecular cloning and study of viral overprinted genes. Pyviko is an extensible and intuitive Python tool for designing knockouts of overlapping genes. Freely available as both a Python package and a web-based interface ( http://louiejtaylor.github.io/pyViKO/ ), Pyviko simplifies the experimental design of gene knockouts in complex viruses with overlapping genes.

  17. What do aquaporin knockout studies tell us about fluid transport in epithelia?

    PubMed

    Maclaren, Oliver J; Sneyd, James; Crampin, Edmund J

    2013-04-01

    The investigation of near-isosmotic water transport in epithelia goes back over 100 years; however, debates over mechanism and pathway remain. Aquaporin (AQP) knockouts have been used by various research groups to test the hypothesis of an osmotic mechanism as well as to explore the paracellular versus transcellular pathway debate. Nonproportional reductions in the water permeability of a water-transporting epithelial cell (e.g., a reduction of around 80-90 %) compared to the reduction in overall water transport rate in the knockout animal (e.g., a reduction of 50-60 %) are commonly found. This nonproportionality has led to controversy over whether AQP knockout studies support or contradict the osmotic mechanism. Arguments raised for and against an interpretation supporting the osmotic mechanism typically have partially specified, implicit, or incorrect assumptions. We present a simple mathematical model of the osmotic mechanism with clear assumptions and, for models based on this mechanism, establish a baseline prediction of AQP knockout studies. We allow for deviations from isotonic/isosmotic conditions and utilize dimensional analysis to reduce the number of parameters that must be considered independently. This enables a single prediction curve to be used for multiple epithelial systems. We find that a simple, transcellular-only osmotic mechanism sufficiently predicts the results of knockout studies and find criticisms of this mechanism to be overstated. We note, however, that AQP knockout studies do not give sufficient information to definitively rule out an additional paracellular pathway.

  18. Experimental and Human Evidence for Lipocalin-2 (Neutrophil Gelatinase-Associated Lipocalin [NGAL]) in the Development of Cardiac Hypertrophy and heart failure.

    PubMed

    Marques, Francine Z; Prestes, Priscilla R; Byars, Sean G; Ritchie, Scott C; Würtz, Peter; Patel, Sheila K; Booth, Scott A; Rana, Indrajeetsinh; Minoda, Yosuke; Berzins, Stuart P; Curl, Claire L; Bell, James R; Wai, Bryan; Srivastava, Piyush M; Kangas, Antti J; Soininen, Pasi; Ruohonen, Saku; Kähönen, Mika; Lehtimäki, Terho; Raitoharju, Emma; Havulinna, Aki; Perola, Markus; Raitakari, Olli; Salomaa, Veikko; Ala-Korpela, Mika; Kettunen, Johannes; McGlynn, Maree; Kelly, Jason; Wlodek, Mary E; Lewandowski, Paul A; Delbridge, Lea M; Burrell, Louise M; Inouye, Michael; Harrap, Stephen B; Charchar, Fadi J

    2017-06-14

    Cardiac hypertrophy increases the risk of developing heart failure and cardiovascular death. The neutrophil inflammatory protein, lipocalin-2 (LCN2/NGAL), is elevated in certain forms of cardiac hypertrophy and acute heart failure. However, a specific role for LCN2 in predisposition and etiology of hypertrophy and the relevant genetic determinants are unclear. Here, we defined the role of LCN2 in concentric cardiac hypertrophy in terms of pathophysiology, inflammatory expression networks, and genomic determinants. We used 3 experimental models: a polygenic model of cardiac hypertrophy and heart failure, a model of intrauterine growth restriction and Lcn2-knockout mouse; cultured cardiomyocytes; and 2 human cohorts: 114 type 2 diabetes mellitus patients and 2064 healthy subjects of the YFS (Young Finns Study). In hypertrophic heart rats, cardiac and circulating Lcn2 was significantly overexpressed before, during, and after development of cardiac hypertrophy and heart failure. Lcn2 expression was increased in hypertrophic hearts in a model of intrauterine growth restriction, whereas Lcn2-knockout mice had smaller hearts. In cultured cardiomyocytes, Lcn2 activated molecular hypertrophic pathways and increased cell size, but reduced proliferation and cell numbers. Increased LCN2 was associated with cardiac hypertrophy and diastolic dysfunction in diabetes mellitus. In the YFS, LCN2 expression was associated with body mass index and cardiac mass and with levels of inflammatory markers. The single-nucleotide polymorphism, rs13297295, located near LCN2 defined a significant cis-eQTL for LCN2 expression. Direct effects of LCN2 on cardiomyocyte size and number and the consistent associations in experimental and human analyses reveal a central role for LCN2 in the ontogeny of cardiac hypertrophy and heart failure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  19. Cardiac arrhythmias in pregnancy.

    PubMed

    Knotts, Robert J; Garan, Hasan

    2014-08-01

    As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias.

  20. Practical cardiac auscultation.

    PubMed

    Shindler, Daniel M

    2007-01-01

    This article focuses on the practical use of the stethoscope. The art of the cardiac physical examination includes skillful auscultation. The article provides the author's personal approach to the patient for the purpose of best hearing, recognizing, and interpreting heart sounds and murmurs. It should be used as a brief introduction to the art of auscultation. This article also attempts to illustrate heart sounds and murmurs by using words and letters to phonate the sounds, and by presenting practical clinical examples where auscultation clearly influences cardiac diagnosis and treatment. The clinical sections attempt to go beyond what is available in standard textbooks by providing information and stethoscope techniques that are valuable and useful at the bedside.

  1. Cardiac nuclear medicine

    SciTech Connect

    Gerson, M.C.

    1987-01-01

    The book begins with a review of the radionuclide methods available for evaluating cardiac perfusion and function. The authors discuss planar and tomographic thallium myocardial imaging, first-pass and equilibrium radionuclide angiography, and imaging with infarct-avid tracers. Several common but more specialized procedures are then reviewed: nonogemetric measurement of left ventricular volume, phase (Fourier) analysis, stroke volume ratio, right ventricular function, and diastolic function. A separate chapter is devoted to drug interventions and in particular the use of radionuclide ventriculography to monitor doxorubicin toxicity and therapy of congestive heart failure. The subsequent chapters provide a comprehensive guide to test selection, accuracy, and results in acute myocardial infarction, in postmyocardial infarction, in chronic coronary artery disease, before and after medical or surgical revascularization, in valvular heart disease, in cardiomyopathies, and in cardiac trauma.

  2. Diuretics prevent thiazolidinedione-induced cardiac hypertrophy without compromising insulin-sensitizing effects in mice.

    PubMed

    Chang, Cherng-Shyang; Tsai, Pei-Jane; Sung, Junne-Ming; Chen, Ju-Yi; Ho, Li-Chun; Pandya, Kumar; Maeda, Nobuyo; Tsai, Yau-Sheng

    2014-02-01

    Much concern has arisen regarding critical adverse effects of thiazolidinediones (TZDs), including rosiglitazone and pioglitazone, on cardiac tissue. Although TZD-induced cardiac hypertrophy (CH) has been attributed to an increase in plasma volume or a change in cardiac nutrient preference, causative roles have not been established. To test the hypothesis that volume expansion directly mediates rosiglitazone-induced CH, mice were fed a high-fat diet with rosiglitazone, and cardiac and metabolic consequences were examined. Rosiglitazone treatment induced volume expansion and CH in wild-type and PPARγ heterozygous knockout (Pparg(+/-)) mice, but not in mice defective for ligand binding (Pparg(P465L/+)). Cotreatment with the diuretic furosemide in wild-type mice attenuated rosiglitazone-induced CH, hypertrophic gene reprogramming, cardiomyocyte apoptosis, hypertrophy-related signal activation, and left ventricular dysfunction. Similar changes were observed in mice treated with pioglitazone. The diuretics spironolactone and trichlormethiazide, but not amiloride, attenuated rosiglitazone effects on volume expansion and CH. Interestingly, expression of glucose and lipid metabolism genes in the heart was altered by rosiglitazone, but these changes were not attenuated by furosemide cotreatment. Importantly, rosiglitazone-mediated whole-body metabolic improvements were not affected by furosemide cotreatment. We conclude that releasing plasma volume reduces adverse effects of TZD-induced volume expansion and cardiac events without compromising TZD actions in metabolic switch in the heart and whole-body insulin sensitivity. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. Novel Protective Role of Myeloid Differentiation 1 in Pathological Cardiac Remodelling

    PubMed Central

    Xiong, Xiaojv; Liu, Yu; Mei, Yang; Peng, Jianye; Wang, Zhiqiang; Kong, Bin; Zhong, Peng; Xiong, Liang; Quan, Dajun; Li, Qi; Wang, Guangji; Huang, He

    2017-01-01

    Myeloid differentiation 1 (MD-1), a secreted protein interacting with radioprotective 105 (RP105), plays an important role in Toll-like receptor 4 (TLR4) signalling pathway. Previous studies showed that MD-1 may be restricted in the immune system. In this study, we demonstrated for the first time that MD-1 was highly expressed in both human and animal hearts. We also discovered that cardiac-specific overexpression of MD-1 significantly attenuated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of MD-1 had the opposite effects. Similar results were observed for in vitro angiotensin II-induced neonatal rat cardiomyocyte hypertrophy. The antihypertrophic effects of MD-1 under hypertrophic stimuli were associated with the blockage of MEK-ERK 1/2 and NF-κB signalling. Blocking MEK-ERK 1/2 signalling with a pharmacological inhibitor (U0126) greatly attenuated the detrimental effects observed in MD-1 knockout cardiomyocytes exposed to angiotensin II stimuli. Similar results were observed by blocking NF-κB signalling with a pharmacological inhibitor (BAY11–7082). Our data indicate that MD-1 inhibits cardiac hypertrophy and suppresses cardiac dysfunction during the remodelling process, which is dependent on its modulation of the MEK-ERK 1/2 and NF-κB signalling pathways. Thus, MD-1 might be a novel target for the treatment of pathological cardiac hypertrophy. PMID:28165494

  4. Deletion of CXCR4 in cardiomyocytes exacerbates cardiac dysfunction following isoproterenol administration.

    PubMed

    Wang, E R; Jarrah, A A; Benard, L; Chen, J; Schwarzkopf, M; Hadri, L; Tarzami, S T

    2014-05-01

    Altered alpha- and beta-adrenergic receptor signaling is associated with cardiac hypertrophy and failure. Stromal cell-derived factor-1α (SDF-1α) and its cognate receptor CXCR4 have been reported to mediate cardioprotection after injury through the mobilization of stem cells into injured tissue. However, little is known regarding whether SDF-1/CXCR4 induces acute protection following pathological hypertrophy and if so, by what molecular mechanism. We have previously reported that CXCR4 physically interacts with the beta-2 adrenergic receptor and modulates its downstream signaling. Here we have shown that CXCR4 expression prevents beta-adrenergic receptor-induced hypertrophy. Cardiac beta-adrenergic receptors were stimulated with the implantation of a subcutaneous osmotic pump administrating isoproterenol and CXCR4 expression was selectively abrogated in cardiomyocytes using Cre-loxP-mediated gene recombination. CXCR4 knockout mice showed worsened fractional shortening and ejection fraction. CXCR4 ablation increased susceptibility to isoproterenol-induced heart failure, by upregulating apoptotic markers and reducing mitochondrial function; cardiac function decreases whereas fibrosis increases. In addition, CXCR4 expression was rescued with the use of cardiotropic adeno-associated viral-9 vectors. CXCR4 gene transfer reduced cardiac apoptotic signaling, improved mitochondrial function and resulted in a recovered cardiac function. Our results represent the first evidence that SDF-1/CXCR4 signaling mediates acute cardioprotection through modulating beta-adrenergic receptor signaling in vivo.

  5. Integrative Cardiac Health Project

    DTIC Science & Technology

    2014-10-01

    Integrative Cardiac Health Project” protocol. Status: Sub Task #3.4 Collaboration on “Assessing Risk Factors for Cardiovascular Disease in Individuals...Coronary Heart Disease Reversal and the Sub-Study for Subjects in the Dr. Dean Ornish Program and 2) Cardiovascular Risk Assessment and Prevention...Cardiovasc Nurs. Circ. Manuscripts-to be submitted: Conclusions Appendix A 151 Cardiovascular disease (CVD) remains the

  6. Kruppel-like Factor 4 Protein Regulates Isoproterenol-induced Cardiac Hypertrophy by Modulating Myocardin Expression and Activity*

    PubMed Central

    Yoshida, Tadashi; Yamashita, Maho; Horimai, Chihiro; Hayashi, Matsuhiko

    2014-01-01

    Kruppel-like factor 4 (KLF4) plays an important role in vascular diseases, including atherosclerosis and vascular injury. Although KLF4 is expressed in the heart in addition to vascular cells, the role of KLF4 in cardiac disease has not been fully determined. The goals of this study were to investigate the role of KLF4 in cardiac hypertrophy and to determine the underlying mechanisms. Cardiomyocyte-specific Klf4 knockout (CM Klf4 KO) mice were generated by the Cre/LoxP technique. Cardiac hypertrophy was induced by chronic infusion of the β-adrenoreceptor agonist isoproterenol (ISO). Results showed that ISO-induced cardiac hypertrophy was enhanced in CM Klf4 KO mice compared with control mice. Accelerated cardiac hypertrophy in CM Klf4 KO mice was accompanied by the augmented cellular enlargement of cardiomyocytes as well as the exaggerated expression of fetal cardiac genes, including atrial natriuretic factor (Nppa). Additionally, induction of myocardin, a transcriptional cofactor regulating fetal cardiac genes, was enhanced in CM Klf4 KO mice. Interestingly, KLF4 regulated Nppa expression by modulating the expression and activity of myocardin, providing a mechanical basis for accelerated cardiac hypertrophy in CM Klf4 KO mice. Moreover, we showed that KLF4 mediated the antihypertrophic effect of trichostatin A, a histone deacetylase inhibitor, because ISO-induced cardiac hypertrophy in CM Klf4 KO mice was attenuated by olmesartan, an angiotensin II type 1 antagonist, but not by trichostatin A. These results provide novel evidence that KLF4 is a regulator of cardiac hypertrophy by modulating the expression and the activity of myocardin. PMID:25100730

  7. The Role of Cardiac Side Population Cells in Cardiac Regeneration

    PubMed Central

    Yellamilli, Amritha; van Berlo, Jop H.

    2016-01-01

    The heart has a limited ability to regenerate. It is important to identify therapeutic strategies that enhance cardiac regeneration in order to replace cardiomyocytes lost during the progression of heart failure. Cardiac progenitor cells are interesting targets for new regenerative therapies because they are self-renewing, multipotent cells located in the heart. Cardiac side population cells (cSPCs), the first cardiac progenitor cells identified in the adult heart, have the ability to differentiate into cardiomyocytes, endothelial cells, smooth muscle cells, and fibroblasts. They become activated in response to cardiac injury and transplantation of cSPCs into the injured heart improves cardiac function. In this review, we will discuss the current literature on the progenitor cell properties and therapeutic potential of cSPCs. This body of work demonstrates the great promise cSPCs hold as targets for new regenerative strategies. PMID:27679798

  8. Cardiac Signatures of Personality

    PubMed Central

    Koelsch, Stefan; Enge, Juliane; Jentschke, Sebastian

    2012-01-01

    Background There are well-established relations between personality and the heart, as evidenced by associations between negative emotions on the one hand, and coronary heart disease or chronic heart failure on the other. However, there are substantial gaps in our knowledge about relations between the heart and personality in healthy individuals. Here, we investigated whether amplitude patterns of the electrocardiogram (ECG) correlate with neurotisicm, extraversion, agreeableness, warmth, positive emotion, and tender-mindedness as measured with the Neuroticism-Extraversion-Openness (NEO) personality inventory. Specifically, we investigated (a) whether a cardiac amplitude measure that was previously reported to be related to flattened affectivity (referred to as values) would explain variance of NEO scores, and (b) whether correlations can be found between NEO scores and amplitudes of the ECG. Methodology/Principal Findings NEO scores and rest ECGs were obtained from 425 healthy individuals. Neuroticism and positive emotion significantly differed between individuals with high and low values. In addition, stepwise cross-validated regressions indicated correlations between ECG amplitudes and (a) agreeableness, as well as (b) positive emotion. Conclusions/Significance These results are the first to demonstrate that ECG amplitude patterns provide information about the personality of an individual as measured with NEO personality scales and facets. These findings open new perspectives for a more efficient personality assessment using cardiac measures, as well as for more efficient risk-stratification and pre-clinical diagnosis of individuals at risk for cardiac, affective and psychosomatic disorders. PMID:22363649

  9. Ultrasound in cardiac trauma.

    PubMed

    Saranteas, Theodosios; Mavrogenis, Andreas F; Mandila, Christina; Poularas, John; Panou, Fotios

    2017-04-01

    In the perioperative period, the emergency department or the intensive care unit accurate assessment of variable chest pain requires meticulous knowledge, diagnostic skills, and suitable usage of various diagnostic modalities. In addition, in polytrauma patients, cardiac injury including aortic dissection, pulmonary embolism, acute myocardial infarction, and pericardial effusion should be immediately revealed and treated. In these patients, arrhythmias, mainly tachycardia, cardiac murmurs, or hypotension must alert physicians to suspect cardiovascular trauma, which would potentially be life threatening. Ultrasound of the heart using transthoracic and transesophageal echocardiography are valuable diagnostic tools that can be used interchangeably in conjunction with other modalities such as the electrocardiogram and computed tomography for the diagnosis of cardiovascular abnormalities in trauma patients. Although ultrasound of the heart is often underused in the setting of trauma, it does have the advantages of being easily accessible, noninvasive, and rapid bedside assessment tool. This review article aims to analyze the potential cardiac injuries in trauma patients, and to provide an elaborate description of the role of echocardiography for their accurate diagnosis.

  10. Cardiac outflow tract anomalies

    PubMed Central

    Neeb, Zachary; Lajiness, Jacquelyn D.; Bolanis, Esther; Conway, Simon J

    2014-01-01

    The mature outflow tract (OFT) is, in basic terms, a short conduit. It is a simple, although vital, connection situated between contracting muscular heart chambers and a vast embryonic vascular network. Unfortunately, it is also a focal point underlying many multifactorial congenital heart defects (CHDs). Through the use of various animal models combined with human genetic investigations, we are beginning to comprehend the molecular and cellular framework that controls OFT morphogenesis. Clear roles of neural crest cells (NCC) and second heart field (SHF) derivatives have been established during OFT formation and remodeling. The challenge now is to determine how the SHF and cardiac NCC interact, the complex reciprocal signaling that appears to be occurring at various stages of OFT morphogenesis, and finally how endocardial progenitors and primary heart field (PHF) communicate with both these colonizing extra-cardiac lineages. Although we are beginning to understand that this dance of progenitor populations is wonderfully intricate, the underlying pathogenesis and the spatiotemporal cell lineage interactions remain to be fully elucidated. What is now clear is that OFT alignment and septation are independent processes, invested via separate SHF and cardiac neural crest (CNC) lineages. This review will focus on our current understanding of the respective contributions of the SHF and CNC lineage during OFT development and pathogenesis. PMID:24014420

  11. Sudden cardiac death.

    PubMed

    Kuriachan, Vikas P; Sumner, Glen L; Mitchell, L Brent

    2015-04-01

    Sudden death accounts for 300,000-400,000 deaths annually in the United States. Most sudden deaths are cardiac, and most sudden cardiac deaths are related to arrhythmias secondary to structural heart disease or primary electrical abnormalities of the heart. The most common structural disease leading to sudden death is ischemic heart disease. Nonischemic cardiomyopathy and other structural abnormalities such as arrhythmogenic ventricular dysplasia and hypertrophic cardiomyopathy may also be causative. Patients without structural disease have a primary electrical abnormality, such as long-QT syndrome or Brugada syndrome. Severe left ventricular systolic dysfunction is the main marker for sudden death in patients with ischemic or nonischemic cardiomyopathy. In other conditions, other markers for structural heart disease and electrical abnormalities need to be considered. It is seen that β-blocker therapy is associated with a reduction in sudden cardiac death across a broad range of disorders. Nevertheless, the implantable cardioverter defibrillator remains the most effective treatment strategy in selected patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Mechanical cardiac assistance.

    PubMed

    Sezai, Y

    1998-08-01

    In our institute, we have intensively introduced both pulsatile and non-pulsatile mechanical cardiac assist devices, such as the pneumatic ventricular assist device (VAD) and percutaneous cardiopulmonary support (PCPS), using a centrifugal pump. From various kinds of clinical views, these cases were estimated and evaluated retrospectively according to the weaning results, long-term survival rate and cause of death. Based upon our experiences and clinical results, an alternate strategy of mechanical cardiac assistance for severe heart failure is suggested as follows. In the case of post-cardiotomy cardiogenic shock or low output syndrome, PCPS system should be applied firstly under intra-aortic balloon pumping (IABP) assist for a maximum of 2-3 days. If the native cardiac function does not recover and more long-term support is needed, several types of VAD, which are more powerful and durable devices should be introduced, according to end organ function and expected support duration. In order to obtain better clinical results, we have to select an appropriate device depending on the limited availability of supporting duration. Generally speaking, centrifugal pumps can support in short-term duration, while pulsatile devices cover the broad spectrum of the supporting period. Pneumatic VADs can cover short-term to long-term support up to a year, and electric VADs can cover over 1 year, and can be used as a bridge to heart transplantation.

  13. Biomechanics of Cardiac Function

    PubMed Central

    Voorhees, Andrew P.; Han, Hai-Chao

    2015-01-01

    The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments. PMID:26426462

  14. Cardiac surgery 2015 reviewed.

    PubMed

    Doenst, Torsten; Strüning, Constanze; Moschovas, Alexandros; Gonzalez-Lopez, David; Essa, Yasin; Kirov, Hristo; Diab, Mahmoud; Faerber, Gloria

    2016-10-01

    For the year 2015, almost 19,000 published references can be found in PubMed when entering the search term "cardiac surgery". The last year has been again characterized by lively discussions in the fields where classic cardiac surgery and modern interventional techniques overlap. Lacking evidence in the field of coronary revascularization with either percutaneous coronary intervention or bypass surgery has been added. As in the years before, CABG remains the gold standard for the revascularization of complex stable triple-vessel disease. Plenty of new information has been presented comparing the conventional to transcatheter aortic valve implantation (TAVI) demonstrating similar short- and mid-term outcomes at high and low risk, but even a survival advantage with transfemoral TAVI at intermediate risk. In addition, there were many relevant and interesting other contributions from the purely operative arena. This review article will summarize the most pertinent publications in the fields of coronary revascularization, surgical treatment of valve disease, heart failure (i.e., transplantation and ventricular assist devices), and aortic surgery. While the article does not have the expectation of being complete and cannot be free of individual interpretation, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.

  15. Cardiac assessment prior to non-cardiac surgery.

    PubMed

    Mooney, J F; Hillis, G S; Lee, V W; Halliwell, R; Vicaretti, M; Moncrieff, C; Chow, C K

    2016-08-01

    Increasingly, patients undergoing non-cardiac surgery are older and have more comorbidities yet preoperative cardiac assessment appears haphazard and unsystematic. We hypothesised that patients at high cardiac risk were not receiving adequate cardiac assessment, and patients with low-cardiac risk were being over-investigated. To compare in a representative sample of patients undergoing non-cardiac surgery the use of cardiac investigations in patients at high and low preoperative cardiac risk. We examined cardiac assessment patterns prior to elective non-cardiac surgery in a representative sample of patients. Cardiac risk was calculated using the Revised Cardiac Risk Index. Of 671 patients, 589 (88%) were low risk and 82 (12%) were high risk. We found that nearly 14% of low-risk and 45% of high-risk patients had investigations for coronary ischaemia prior to surgery. Vascular surgery had the highest rate of investigation (38%) and thoracic patients the lowest rate (14%). Whilst 78% of high-risk patients had coronary disease, only 46% were on beta-blockers, 49% on aspirin and 77% on statins. For current smokers (17.3% of cohort, n = 98), 60% were advised to quit pre-op. Practice patterns varied across surgical sub-types with low-risk patients tending to be over-investigated and high-risk patients under-investigated. A more systemised approach to this large group of patients could improve clinical outcomes, and more judicious use of investigations could lower healthcare costs and increase efficiency in managing this cohort. © 2016 Royal Australasian College of Physicians.

  16. Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

    PubMed Central

    Zhang, Xiaowei; Bearer, Elaine L.; Boulat, Benoit; Hall, F. Scott; Uhl, George R.; Jacobs, Russell E.

    2010-01-01

    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn2+ into the prefrontal cortex indicated that DAT KO mice have a truncated Mn2+ distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn2+ transport into more posterior midbrain nuclei and contralateral mesolimbic structures at

  17. TNF-α knockout mice have increased corpora cavernosa relaxation

    PubMed Central

    2010-01-01

    Introduction Erectile dysfunction (ED) is considered an early clinical manifestation of vascular disease and an independent risk factor for cardiovascular events associated with endothelial dysfunction and increased levels of pro-inflammatory cytokines. Tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, suppresses endothelial nitric oxide synthase (eNOS) expression. Aim Considering that nitric oxide (NO) is of critical importance in penile erection, we hypothesized that blockade of TNF-α actions would increase cavernosal smooth muscle relaxation through an increase in NOS expression. Methods In vitro organ bath studies were used to measure cavernosal reactivity in wild type and TNF-α knockout (TNF-α KO) mice and NOS expression was evaluated by western blot. In addition, spontaneous erections (in vivo) were evaluated by videomonitoring the animals (30 min.). Collagen and elastin expression were evaluated by Masson trichrome and Verhoff-van Gieson stain reaction, respectively. Main Outcome Measures Corpora cavernosa from TNF-α KO mice exhibited increased NO-dependent relaxation, which was associated with increased eNOS and neuronal NOS (nNOS) cavernosal expression. Results Cavernosal strips from TNF-α KO mice displayed increased endothelium-dependent [97.4±5.3 vs Control: 76.3±6.3, %] and nonadrenergic-noncholinergic (NANC) [93.3±3.0 vs Control: 67.5±16.0; 16 Hz] relaxation compared to control animals. These responses were associated with increased protein expression of eNOS and nNOS (p<0.05). Sympathetic-mediated [0.69±0.16 vs Control: 1.22±0.22; 16 Hz] as well as phenylephrine-induced contractile responses [1.6±0.1 vs Control: 2.5±0.1, mN] were attenuated in cavernosal strips from TNF-α KO mice. Additionally, corpora cavernosa from TNF-α KO mice displayed increased collagen and elastin expression. In vivo experiments demonstrated that TNF-α KO mice display increased number of spontaneous erections. Conclusion Corpora cavernosa from

  18. Aqueous Humor Outflow Physiology in NOS3 Knockout Mice.

    PubMed

    Lei, Yuan; Zhang, Xuejin; Song, Maomao; Wu, Jihong; Sun, Xinghuai

    2015-07-01

    To investigate the role of endothelial nitric oxide synthase (eNOS) on conventional outflow function using NOS3 knockout (KO) mice. Intraocular pressure was measured in both NOS3 KO and wild type (WT) by rebound tonometry. Outflow facility was measured by perfusing enucleated mouse eyes at multiple pressure steps. A subset of eyes was sectioned and stained for histology. Mock aqueous humor ± the nitric oxide (NO) donors nitroprusside dihydrate (SNP) or S-Nitroso-N-Acetyl-D,L-Penicillamine (SNAP) was perfused into enucleated eyes. SNP and SNAP was administered topically at 0, 1, 2, and 3 hours while the contralateral eyes served as vehicle controls. Intraocular pressure was measured in both eyes before and after the last drug treatment. Intraocular pressure was higher in KO mice (18.2 ± 0.7 mm Hg vs. 13.9 ± 0.5 mm Hg, mean ± SEM, n = 30, P < 0.05), and pressure-dependent conventional drainage was significantly lower (0.0058 ± 0.0005 μL/min/mm Hg, mean ± SEM, n = 21) compared with WT mice (0.0082 ± 0.0013 μL/min/mm Hg, n = 23, P < 0.05). No obvious morphological differences in iridiocorneal angle tissues were observed in hematoxylin and eosin (H&E)-stained sections. SNP and SNAP significantly increased pressure-dependent drainage in KO animals (n = 12, P < 0.05). In WT mice, SNP and SNAP caused a significant increase in pressure dependent drainage (n = 12, P < 0.05) to a similar degree as in KO mice. Topical application of SNP significantly reduced IOP in WT and KO mice (n = 12, P < 0.05), but SNAP did not change IOP significantly (n = 19). NOS3 KO mice have elevated IOP, which is likely the result of reduced pressure-dependent drainage. These findings are consistent with human data showing polymorphisms in the NOS3 gene associate with ocular hypertension and the development of glaucoma.

  19. The Alberta Cardiac Access Collaborative: improving the cardiac patient journey.

    PubMed

    Blackadar, Robyn; Houle, Mishaela

    2009-01-01

    The Alberta Cardiac Access Collaborative (ACAC) is a joint initiative of Alberta's health system to improve access to adult cardiac services across the patient journey. ACAC has created new care delivery models and implemented best practices across Alberta in four streams across the continuum: heart attack, patient navigation, heart failure and arrhythmia. Emergency medical providers, nurses, primary care physicians, hospitals, cardiac specialists and clinicians are all working together to integrate services, bridge jurisdictions and geography with one aim--improving the patient journey for adults in need of cardiac care.

  20. Cardiac Emergencies in Neurosurgical Patients

    PubMed Central

    Petropolis, Andrea; Cappellani, Ronald B.

    2015-01-01

    Perioperative safety concerns are a major area of interest in recent years. Severe cardiac perturbation such as cardiac arrest is one of the most dreaded complications in the intraoperative period; however, little is known about the management of these events in the patients undergoing elective neurosurgery. This special group needs further attention, as it is often neither feasible nor appropriate to apply conventional advanced cardiac life support algorithms in patients undergoing neurosurgery. Factors such as neurosurgical procedure and positioning can also have a significant effect on the occurrence of cardiac arrest. Therefore, the aim of this paper is to describe the various causes and management of cardiac emergencies with special reference to cardiac arrest during elective neurosurgical procedures, including discussion of position-related factors and resuscitative considerations in these situations. This will help to formulate possible guidelines for management of such events. PMID:25692145

  1. Sudden cardiac death and obesity.

    PubMed

    Plourde, Benoit; Sarrazin, Jean-François; Nault, Isabelle; Poirier, Paul

    2014-09-01

    For individuals and the society as a whole, the increased risk of sudden cardiac death in obese patients is becoming a major challenge, especially since obesity prevalence has been increasing steadily around the globe. Traditional risk factors and obesity often coexist. Hypertension, diabetes, obstructive sleep apnea and metabolic syndrome are well-known risk factors for CV disease and are often present in the obese patient. Although the bulk of evidence is circumstantial, sudden cardiac death and obesity share common traditional CV risk factors. Structural, functional and metabolic factors modulate and influence the risk of sudden cardiac death in the obese population. Other risk factors such as left ventricular hypertrophy, increased number of premature ventricular complexes, altered QT interval and reduced heart rate variability are all documented in both obese and sudden cardiac death populations. The present review focuses on out-of-hospital sudden cardiac death and potential mechanisms leading to sudden cardiac death in this population.

  2. Phenotypic assessment of THC discriminative stimulus properties in fatty acid amide hydrolase knockout and wildtype mice.

    PubMed

    Walentiny, D Matthew; Vann, Robert E; Wiley, Jenny L

    2015-06-01

    A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ(9)-tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC discrimination procedure. THC (5.6 mg/kg) served as a discriminative stimulus in both genotypes, with similar THC dose-response curves between groups. Anandamide fully substituted for THC in FAAH knockout, but not wildtype, mice. Conversely, the metabolically stable anandamide analog O-1812 fully substituted in both groups, but was more potent in knockouts. The CB1 receptor antagonist rimonabant dose-dependently attenuated THC generalization in both groups and anandamide substitution in FAAH knockouts. Pharmacological inhibition of monoacylglycerol lipase (MAGL), the primary catabolic enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG), with JZL184 resulted in full substitution for THC in FAAH knockout mice and nearly full substitution in wildtypes. Quantification of brain endocannabinoid levels revealed expected elevations in anandamide in FAAH knockout mice compared to wildtypes and equipotent dose-dependent elevations in 2-AG following JZL184 administration. Dual inhibition of FAAH and MAGL with JZL195 resulted in roughly equipotent increases in THC-appropriate responding in both groups. While the notable similarity in THC's discriminative stimulus effects across genotype suggests that the increased baseline brain anandamide levels (as seen in FAAH knockout mice) do not alter THC's subjective effects, FAAH knockout mice are more sensitive to the THC-like effects of pharmacologically induced increases in anandamide and MAGL inhibition (e.g., JZL184).

  3. Knockout of Endothelial Cell-Derived Endothelin-1 Attenuates Skin Fibrosis but Accelerates Cutaneous Wound Healing

    PubMed Central

    Makino, Katsunari; Jinnin, Masatoshi; Aoi, Jun; Kajihara, Ikko; Makino, Takamitsu; Fukushima, Satoshi; Sakai, Keisuke; Nakayama, Kazuhiko; Emoto, Noriaki; Yanagisawa, Masashi; Ihn, Hironobu

    2014-01-01

    Endothelin (ET)-1 is known for the most potent vasoconstrictive peptide that is released mainly from endothelial cells. Several studies have reported ET-1 signaling is involved in the process of wound healing or fibrosis as well as vasodilation. However, little is known about the role of ET-1 in these processes. To clarify its mechanism, we compared skin fibrogenesis and wound repair between vascular endothelial cell-specific ET-1 knockout mice and their wild-type littermates. Bleomycin-injected fibrotic skin of the knockout mice showed significantly decreased skin thickness and collagen content compared to that of wild-type mice, indicating that bleomycin-induced skin fibrosis is attenuated in the knockout mice. The mRNA levels of transforming growth factor (TGF)-β were decreased in the bleomycin-treated skin of ET-1 knockout mice. On the other hand, skin wound healing was accelerated in ET-1 knockout mice, which was indicated by earlier granulation tissue reduction and re-epithelialization in these mice. The mRNA levels of TGF-β, tumor necrosis factor (TNF)-α and connective tissue growth factor (CTGF) were reduced in the wound of ET-1 knockout mice. In endothelial ET-1 knockout mouse, the expression of TNF-α, CTGF and TGF-β was down-regulated. Bosentan, an antagonist of dual ET receptors, is known to attenuate skin fibrosis and accelerate wound healing in systemic sclerosis, and such contradictory effect may be mediated by above molecules. The endothelial cell-derived ET-1 is the potent therapeutic target in fibrosis or wound healing, and investigations of the overall regulatory mechanisms of these pathological conditions by ET-1 may lead to a new therapeutic approach. PMID:24853267

  4. Sudden Cardiac Death in Athletes

    PubMed Central

    Wasfy, Meagan M.; Hutter, Adolph M.; Weiner, Rory B.

    2016-01-01

    There are clear health benefits to exercise; even so, patients with cardiac conditions who engage in exercise and athletic competition may on rare occasion experience sudden cardiac death (SCD). This article reviews the epidemiology and common causes of SCD in specific athlete populations. There is ongoing debate about the optimal mechanism for SCD prevention, specifically regarding the inclusion of the ECG and/or cardiac imaging in routine preparticipation sports evaluation. This controversy and contemporary screening recommendations are also reviewed. PMID:27486488

  5. Cardiac surgery for Kartagener syndrome.

    PubMed

    Tkebuchava, T; von Segesser, L K; Niederhäuser, U; Bauersfeld, U; Turina, M

    1997-01-01

    Two patients (one girl, one boy) with Kartagener syndrome (situs inversus, bronchiectasis, sinusitis), despite pulmonary problems and associated congenital cardiac anomalies, were operated on at the ages of 4 years and 7 years, respectively. They had had previous palliative treatment at the age of 3 months and 1.3 years, respectively. Both postoperative periods after total correction were without significant complications. Long-term follow-up was available for 9 and 19 years, respectively, with no manifestations of heart insufficiency. Both patients are physically active, and neither requires cardiac medication. Patients with Kartagener syndrome and associated congenital cardiac anomalies can successfully undergo multiple cardiac operations with good long-term outcome.

  6. Cardiac Dysautonomia in Huntington's Disease.

    PubMed

    Abildtrup, Mads; Shattock, Michael

    2013-01-01

    Huntington's disease is a fatal, hereditary, neurodegenerative disorder best known for its clinical triad of progressive motor impairment, cognitive deficits and psychiatric disturbances. Although a disease of the central nervous system, mortality surveys indicate that heart disease is a leading cause of death. The nature of such cardiac abnormalities remains unknown. Clinical findings indicate a high prevalence of autonomic nervous system dysfunction - dysautonomia - which may be a result of pathology of the central autonomic network. Dysautonomia can have profound effects on cardiac health, and pronounced autonomic dysfunction can be associated with neurogenic arrhythmias and sudden cardiac death. Significant advances in the knowledge of neural mechanisms in cardiac disease have recently been made which further aid our understanding of cardiac mortality in Huntington's disease. Even so, despite the evidence of aberrant autonomic activity the potential cardiac consequences of autonomic dysfunction have been somewhat ignored. In fact, underlying cardiac abnormalities such as arrhythmias have been part of the exclusion criteria in clinical autonomic Huntington's disease research. A comprehensive analysis of cardiac function in Huntington's disease patients is warranted. Further experimental and clinical studies are needed to clarify how the autonomic nervous system is controlled and regulated in higher, central areas of the brain - and how these regions may be altered in neurological pathology, such as Huntington's disease. Ultimately, research will hopefully result in an improvement of management with the aim of preventing early death in Huntington's disease from cardiac causes.

  7. Cardiac risk stratification and protection.

    PubMed

    Halub, Meghan E; Sidwell, Richard A

    2015-04-01

    The goal of preoperative cardiac evaluation is to screen for undiagnosed cardiac disease or to find evidence of known conditions that are poorly controlled to allow management that reduces the risk of perioperative cardiac complications. A careful history and physical examination combined with the procedure-specific risk is the cornerstone of this assessment. This article reviews a brief history of prior cardiac risk stratification indexes, explores current practice guidelines by the American College of Cardiology and the American Heart Association Task Force, reviews current methods for preoperative evaluation, discusses revascularization options, and evaluates perioperative medication recommendations.

  8. Registry of Unexplained Cardiac Arrest

    ClinicalTrials.gov

    2016-05-16

    Cardiac Arrest; Long QT Syndrome; Brugada Syndrome; Catecholaminergi Polymorphic Ventricular Tachycardia; Idiopathic VentricularFibrillation; Early Repolarization Syndrome; Arrhythmogenic Right Ventricular Cardiomyopathy

  9. Thioredoxin-2 inhibits mitochondrial reactive oxygen species generation and apoptosis stress kinase-1 activity to maintain cardiac function.

    PubMed

    Huang, Qunhua; Zhou, Huanjiao Jenny; Zhang, Haifeng; Huang, Yan; Hinojosa-Kirschenbaum, Ford; Fan, Peidong; Yao, Lina; Belardinelli, Luiz; Tellides, George; Giordano, Frank J; Budas, Grant R; Min, Wang

    2015-03-24

    Thioredoxin 2 (Trx2) is a key mitochondrial protein that regulates cellular redox and survival by suppressing mitochondrial reactive oxygen species generation and by inhibiting apoptosis stress kinase-1 (ASK1)-dependent apoptotic signaling. To date, the role of the mitochondrial Trx2 system in heart failure pathogenesis has not been investigated. Western blot and histological analysis revealed that Trx2 protein expression levels were reduced in hearts from patients with dilated cardiomyopathy, with a concomitant increase in ASK1 phosphorylation/activity. Cardiac-specific Trx2 knockout mice develop spontaneous dilated cardiomyopathy at 1 month of age with increased heart size, reduced ventricular wall thickness, and a progressive decline in left ventricular contractile function, resulting in mortality due to heart failure by ≈4 months of age. The progressive decline in cardiac function observed in cardiac-specific Trx2 knockout mice was accompanied by the disruption of mitochondrial ultrastructure, mitochondrial membrane depolarization, increased mitochondrial reactive oxygen species generation, and reduced ATP production, correlating with increased ASK1 signaling and increased cardiomyocyte apoptosis. Chronic administration of a highly selective ASK1 inhibitor improved cardiac phenotype and reduced maladaptive left ventricular remodeling with significant reductions in oxidative stress, apoptosis, fibrosis, and cardiac failure. Cellular data from Trx2-deficient cardiomyocytes demonstrated that ASK1 inhibition reduced apoptosis and reduced mitochondrial reactive oxygen species generation. Our data support an essential role for mitochondrial Trx2 in preserving cardiac function by suppressing mitochondrial reactive oxygen species production and ASK1-dependent apoptosis. Inhibition of ASK1 represents a promising therapeutic strategy for the treatment of dilated cardiomyopathy and heart failure. © 2015 American Heart Association, Inc.

  10. Angiotensin II type 1a receptor signalling directly contributes to the increased arrhythmogenicity in cardiac hypertrophy

    PubMed Central

    Yasuno, Shinji; Kuwahara, Koichiro; Kinoshita, Hideyuki; Yamada, Chinatsu; Nakagawa, Yasuaki; Usami, Satoru; Kuwabara, Yoshihiro; Ueshima, Kenji; Harada, Masaki; Nishikimi, Toshio; Nakao, Kazuwa

    2013-01-01

    BACKGROUND AND PURPOSE Angiotensin II has been implicated in the development of various cardiovascular ailments, including cardiac hypertrophy and heart failure. The fact that inhibiting its signalling reduced the incidences of both sudden cardiac death and heart failure in several large-scale clinical trials suggests that angiotensin II is involved in increased cardiac arrhythmogenicity during the development of heart failure. However, because angiotensin II also promotes structural remodelling, including cardiomyocyte hypertrophy and cardiac fibrosis, it has been difficult to assess its direct contribution to cardiac arrhythmogenicity independently of the structural effects. EXPERIMENTAL APPROACH We induced cardiac hypertrophy in wild-type (WT) and angiotensin II type 1a receptor knockout (AT1aR-KO) mice by transverse aortic constriction (TAC). The susceptibility to ventricular tachycardia (VT) assessed in an in vivo electrophysiological study was compared in the two genotypes. The effect of acute pharmacological blockade of AT1R on the incidences of arrhythmias was also assessed. KEY RESULTS As described previously, WT and AT1aR-KO mice with TAC developed cardiac hypertrophy to the same degree, but the incidence of VT was much lower in the latter. Moreover, although TAC induced an increase in tyrosine phosphorylation of connexin 43, a critical component of gap junctional channels, and a reduction in ventricular levels of connexin 43 protein in both genotypes, the effect was significantly ameliorated in AT1aR-KO mice. Acute pharmacological blockade of AT1R also reduced the incidence of arrhythmias. CONCLUSIONS AND IMPLICATIONS Our findings demonstrate that AT1aR-mediated signalling makes a direct contribution to the increase in arrhythmogenicity in hypertrophied hearts independently of structural remodelling. PMID:23937445

  11. c-Cbl Inhibition Improves Cardiac function and Survival in Response to Myocardial Ischemia

    PubMed Central

    Rafiq, Khadija; Kolpakov, Mikhail A; Seqqat, Rachid; Guo, Jianfen; Guo, Xinji; Qi, Zhao; Yu, Daohai; Mohapatra, Bhopal; Zutshi, Neha; An, Wei; Band, Hamid; Sanjay, Archana; Houser, Steven R; Sabri, Abdelkarim

    2014-01-01

    Background The proto-oncogene Casitas b-lineage lymphoma (c-Cbl) is an adaptor protein with an intrinsic E3 ubiquitin ligase activity that targets receptor and non-receptor tyrosine kinases, resulting in their ubiquitination and down-regulation. However, the function of c-Cbl in the control of cardiac function is currently unknown. In this study, we examined the role of c-Cbl in myocyte death and cardiac function after myocardial ischemia. Methods and Results We show increased c-Cbl expression in human ischemic and dilated cardiomyopathy hearts and in response to pathological stress stimuli in mice. c-Cbl deficient mice demonstrated a more robust functional recovery after myocardial ischemia reperfusion injury, as well as significantly reduced myocyte apoptosis and improved cardiac function. Ubiquitination and downregulation of key survival c-Cbl targets, epidermal growth factor receptors and focal adhesion kinase, were significantly reduced in c-Cbl knockout mice. Inhibition of c-Cbl expression or its ubiquitin ligase activity in cardiac myocytes offered protection against H2O2 stress. Interestingly, c-Cbl deletion reduced the risk of death and increased cardiac functional recovery after chronic myocardial ischemia. This beneficial effect of c-Cbl deletion was associated with enhanced neoangiogenesis and increased expression of vascular endothelial growth factor (VEGF)-a and VEGF receptor type 2 in the infarcted region. Conclusions c-Cbl activation promotes myocyte apoptosis, inhibits angiogenesis and causes adverse cardiac remodeling after myocardial infarction. These findings point to c-Cbl as a potential therapeutic target for the maintenance of cardiac function and remodeling after myocardial ischemia. PMID:24583314

  12. Cardiac α-actin over-expression therapy in dominant ACTA1 disease.

    PubMed

    Ravenscroft, Gianina; McNamara, Elyshia; Griffiths, Lisa M; Papadimitriou, John M; Hardeman, Edna C; Bakker, Anthony J; Davies, Kay E; Laing, Nigel G; Nowak, Kristen J

    2013-10-01

    More than 200 mutations in the skeletal muscle α-actin gene (ACTA1) cause either dominant or recessive skeletal muscle disease. Currently, there are no specific therapies. Cardiac α-actin is 99% identical to skeletal muscle α-actin and the predominant actin isoform in fetal muscle. We previously showed cardiac α-actin can substitute for skeletal muscle α-actin, preventing the early postnatal death of Acta1 knock-out mice, which model recessive ACTA1 disease. Dominant ACTA1 disease is caused by the presence of 'poison' mutant actin protein. Experimental and anecdotal evidence nevertheless indicates that the severity of dominant ACTA1 disease is modulated by the relative amount of mutant skeletal muscle α-actin protein present. Thus, we investigated whether transgenic over-expression of cardiac α-actin in postnatal skeletal muscle could ameliorate the phenotype of mouse models of severe dominant ACTA1 disease. In one model, lethality of ACTA1(D286G). Acta1(+/-) mice was reduced from ∼59% before 30 days of age to ∼12%. In the other model, Acta1(H40Y), in which ∼80% of male mice die by 5 months of age, the cardiac α-actin transgene did not significantly improve survival. Hence cardiac α-actin over-expression is likely to be therapeutic for at least some dominant ACTA1 mutations. The reason cardiac α-actin was not effective in the Acta1(H40Y) mice is uncertain. We showed that the Acta1(H40Y) mice had endogenously elevated levels of cardiac α-actin in skeletal muscles, a finding not reported in dominant ACTA1 patients.

  13. Cardiac oxidative stress in a mouse model of neutral lipid storage disease☆

    PubMed Central

    Schrammel, Astrid; Mussbacher, Marion; Winkler, Sarah; Haemmerle, Guenter; Stessel, Heike; Wölkart, Gerald; Zechner, Rudolf; Mayer, Bernd

    2013-01-01

    Cardiac oxidative stress has been implicated in the pathogenesis of hypertrophy, cardiomyopathy and heart failure. Systemic deletion of the gene encoding adipose triglyceride lipase (ATGL), the enzyme that catalyzes the rate-limiting step of triglyceride lipolysis, results in a phenotype characterized by severe steatotic cardiac dysfunction. The objective of the present study was to investigate a potential role of oxidative stress in cardiac ATGL deficiency. Hearts of mice with global ATGL knockout were compared to those of mice with cardiomyocyte-restricted overexpression of ATGL and to those of wildtype littermates. Our results demonstrate that oxidative stress, measured as lucigenin chemiluminescence, was increased ~ 6-fold in ATGL-deficient hearts. In parallel, cytosolic NADPH oxidase subunits p67phox and p47phox were upregulated 4–5-fold at the protein level. Moreover, a prominent upregulation of different inflammatory markers (tumor necrosis factor α, monocyte chemotactant protein-1, interleukin 6, and galectin-3) was observed in those hearts. Both the oxidative and inflammatory responses were abolished upon cardiomyocyte-restricted overexpression of ATGL. Investigating the effect of oxidative and inflammatory stress on nitric oxide/cGMP signal transduction we observed a ~ 2.5-fold upregulation of soluble guanylate cyclase activity and a ~ 2-fold increase in cardiac tetrahydrobiopterin levels. Systemic treatment of ATGL-deficient mice with the superoxide dismutase mimetic Mn(III)tetrakis (4-benzoic acid) porphyrin did not ameliorate but rather aggravated cardiac oxidative stress. Our data suggest that oxidative and inflammatory stress seems involved in lipotoxic heart disease. Upregulation of soluble guanylate cyclase and cardiac tetrahydrobiopterin might be regarded as counterregulatory mechanisms in cardiac ATGL deficiency. PMID:23867907

  14. Pharyngeal mesoderm regulatory network controls cardiac and head muscle morphogenesis.

    PubMed

    Harel, Itamar; Maezawa, Yoshiro; Avraham, Roi; Rinon, Ariel; Ma, Hsiao-Yen; Cross, Joe W; Leviatan, Noam; Hegesh, Julius; Roy, Achira; Jacob-Hirsch, Jasmine; Rechavi, Gideon; Carvajal, Jaime; Tole, Shubha; Kioussi, Chrissa; Quaggin, Susan; Tzahor, Eldad

    2012-11-13

    The search for developmental mechanisms driving vertebrate organogenesis has paved the way toward a deeper understanding of birth defects. During embryogenesis, parts of the heart and craniofacial muscles arise from pharyngeal mesoderm (PM) progenitors. Here, we reveal a hierarchical regulatory network of a set of transcription factors expressed in the PM that initiates heart and craniofacial organogenesis. Genetic perturbation of this network in mice resulted in heart and craniofacial muscle defects, revealing robust cross-regulation between its members. We identified Lhx2 as a previously undescribed player during cardiac and pharyngeal muscle development. Lhx2 and Tcf21 genetically interact with Tbx1, the major determinant in the etiology of DiGeorge/velo-cardio-facial/22q11.2 deletion syndrome. Furthermore, knockout of these genes in the mouse recapitulates specific cardiac features of this syndrome. We suggest that PM-derived cardiogenesis and myogenesis are network properties rather than properties specific to individual PM members. These findings shed new light on the developmental underpinnings of congenital defects.

  15. Pharyngeal mesoderm regulatory network controls cardiac and head muscle morphogenesis

    PubMed Central

    Harel, Itamar; Maezawa, Yoshiro; Avraham, Roi; Rinon, Ariel; Ma, Hsiao-Yen; Cross, Joe W.; Leviatan, Noam; Hegesh, Julius; Roy, Achira; Jacob-Hirsch, Jasmine; Rechavi, Gideon; Carvajal, Jaime; Tole, Shubha; Kioussi, Chrissa; Quaggin, Susan; Tzahor, Eldad

    2012-01-01

    The search for developmental mechanisms driving vertebrate organogenesis has paved the way toward a deeper understanding of birth defects. During embryogenesis, parts of the heart and craniofacial muscles arise from pharyngeal mesoderm (PM) progenitors. Here, we reveal a hierarchical regulatory network of a set of transcription factors expressed in the PM that initiates heart and craniofacial organogenesis. Genetic perturbation of this network in mice resulted in heart and craniofacial muscle defects, revealing robust cross-regulation between its members. We identified Lhx2 as a previously undescribed player during cardiac and pharyngeal muscle development. Lhx2 and Tcf21 genetically interact with Tbx1, the major determinant in the etiology of DiGeorge/velo-cardio-facial/22q11.2 deletion syndrome. Furthermore, knockout of these genes in the mouse recapitulates specific cardiac features of this syndrome. We suggest that PM-derived cardiogenesis and myogenesis are network properties rather than properties specific to individual PM members. These findings shed new light on the developmental underpinnings of congenital defects. PMID:23112163

  16. [Cardiac rehabilitation in women].

    PubMed

    Ghannem, M; Ghannem, L; Lamouchi, S; Justin, K D; Meimoun, P; Ghannem, L

    2016-12-01

    Coronary artery disease (CAD) occurs later in life in women when compared to men (10 years later). The FAST-MI study has shown that the profile of women with CAD has changed in the past 15 years, they are younger, more obese, and usually smokers. Whatever the age at which CAD occurs in women, the prognosis tends to be worse than in men, despite a higher frequency of acute coronary syndrome (ACS) with angiographically normal coronary arteries in women. In women without significant lesion at coronary angiography, the WISE study has shown abnormalities of the coronary vasomotricy. Despite its beneficial effect on morbidity and mortality, cardiac rehabilitation is underused particularly in women. Indeed, several factors do not encourage a woman to follow a cardiac rehabilitation program, even after an ACS. These factors may be cultural, domestic, familial, orthopedic, or even the fear of exercising. Therefore, physicians have to be particularly convincing in women, in order to have them participating in rehabilitation programs. Physical capacity is lower in women when compared to men. However, the weaker the physical capacity, the better the benefit of cardiac rehabilitation. Physical endurance training continuously or in interval, associated to muscle strengthening can improve the physical capacity in women. Vascular risk factors correction is also an important step for the management of women with CAD. Therapeutic education and several available workshops help women to better understand their disease and to improve their self-management when they return home. Anxiety, depression, and sexual dysfunction frequently deteriorate the quality of life of our patients. Therefore, psychological management is also essential in our departments.

  17. Dipyridamole cardiac imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Askenase, A.; Segal, B.L.; Auerbach, N.

    1988-02-01

    Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

  18. Gene Knockout Identification Using an Extension of Bees Hill Flux Balance Analysis

    PubMed Central

    Choon, Yee Wen; Mohamad, Mohd Saberi; Deris, Safaai; Chong, Chuii Khim; Omatu, Sigeru; Corchado, Juan Manuel

    2015-01-01

    Microbial strain optimisation for the overproduction of a desired phenotype has been a popular topic in recent years. Gene knockout is a genetic engineering technique that can modify the metabolism of microbial cells to obtain desirable phenotypes. Optimisation algorithms have been developed to identify the effects of gene knockout. However, the complexities of metabolic networks have made the process of identifying the effects of genetic modification on desirable phenotypes challenging. Furthermore, a vast number of reactions in cellular metabolism often lead to a combinatorial problem in obtaining optimal gene knockout. The computational time increases exponentially as the size of the problem increases. This work reports an extension of Bees Hill Flux Balance Analysis (BHFBA) to identify optimal gene knockouts to maximise the production yield of desired phenotypes while sustaining the growth rate. This proposed method functions by integrating OptKnock into BHFBA for validating the results automatically. The results show that the extension of BHFBA is suitable, reliable, and applicable in predicting gene knockout. Through several experiments conducted on Escherichia coli, Bacillus subtilis, and Clostridium thermocellum as model organisms, extension of BHFBA has shown better performance in terms of computational time, stability, growth rate, and production yield of desired phenotypes. PMID:25874200

  19. Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis

    PubMed Central

    Sun, Xingshen; Sui, Hongshu; Fisher, John T.; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M.; Lei-Butters, Diana C.; Griffin, Michelle A.; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J.; Meyerholz, David K.; Engelhardt, John F.

    2010-01-01

    Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments. PMID:20739752

  20. A Protocol for Multiple Gene Knockout in Mouse Small Intestinal Organoids Using a CRISPR-concatemer

    PubMed Central

    Merenda, Alessandra; Andersson-Rolf, Amanda; Mustata, Roxana C.; Li, Taibo; Kim, Hyunki; Koo, Bon-Kyoung

    2017-01-01

    CRISPR/Cas9 technology has greatly improved the feasibility and speed of loss-of-function studies that are essential in understanding gene function. In higher eukaryotes, paralogous genes can mask a potential phenotype by compensating the loss of a gene, thus limiting the information that can be obtained from genetic studies relying on single gene knockouts. We have developed a novel, rapid cloning method for guide RNA (gRNA) concatemers in order to create multi-gene knockouts following a single round of transfection in mouse small intestinal organoids. Our strategy allows for the concatemerization of up to four individual gRNAs into a single vector by performing a single Golden Gate shuffling reaction with annealed gRNA oligos and a pre-designed retroviral vector. This allows either the simultaneous knockout of up to four different genes, or increased knockout efficiency following the targeting of one gene by multiple gRNAs. In this protocol, we show in detail how to efficiently clone multiple gRNAs into the retroviral CRISPR-concatemer vector and how to achieve highly efficient electroporation in intestinal organoids. As an example, we show that simultaneous knockout of two pairs of genes encoding negative regulators of the Wnt signaling pathway (Axin1/2 and Rnf43/Znrf3) renders intestinal organoids resistant to the withdrawal of key growth factors. PMID:28745625

  1. The knockout of secretin in cerebellar Purkinje cells impairs mouse motor coordination and motor learning.

    PubMed

    Zhang, Li; Chung, Sookja Kim; Chow, Billy Kwok Chong

    2014-05-01

    Secretin (SCT) was first considered to be a gut hormone regulating gastrointestinal functions when discovered. Recently, however, central actions of SCT have drawn intense research interest and are supported by the broad distribution of SCT in specific neuronal populations and by in vivo physiological studies regarding its role in water homeostasis and food intake. The direct action of SCT on a central neuron was first discovered in cerebellar Purkinje cells in which SCT from cerebellar Purkinje cells was found to potentiate GABAergic inhibitory transmission from presynaptic basket cells. Because Purkinje neurons have a major role in motor coordination and learning functions, we hypothesize a behavioral modulatory function for SCT. In this study, we successfully generated a mouse model in which the SCT gene was deleted specifically in Purkinje cells. This mouse line was tested together with SCT knockout and SCT receptor knockout mice in a full battery of behavioral tasks. We found that the knockout of SCT in Purkinje neurons did not affect general motor ability or the anxiety level in open field tests. However, knockout mice did exhibit impairments in neuromuscular strength, motor coordination, and motor learning abilities, as shown by wire hanging, vertical climbing, and rotarod tests. In addition, SCT knockout in Purkinje cells possibly led to the delayed development of motor neurons, as supported by the later occurrence of key neural reflexes. In summary, our data suggest a role in motor coordination and motor learning for SCT expressed in cerebellar Purkinje cells.

  2. Knockouts of high-ranking males have limited impact on baboon social networks.

    PubMed

    Franz, Mathias; Altmann, Jeanne; Alberts, Susan C

    Social network structures can crucially impact complex social processes such as collective behaviour or the transmission of information and diseases. However, currently it is poorly understood how social networks change over time. Previous studies on primates suggest that `knockouts' (due to death or dispersal) of high-ranking individuals might be important drivers for structural changes in animal social networks. Here we test this hypothesis using long-term data on a natural population of baboons, examining the effects of 29 natural knockouts of alpha or beta males on adult female social networks. We investigated whether and how knockouts affected (1) changes in grooming and association rates among adult females, and (2) changes in mean degree and global clustering coefficient in these networks. The only significant effect that we found was a decrease in mean degree in grooming networks in the first month after knockouts, but this decrease was rather small, and grooming networks rebounded to baseline levels by the second month after knockouts. Taken together our results indicate that the removal of high-ranking males has only limited or no lasting effects on social networks of adult female baboons. This finding calls into question the hypothesis that the removal of high-ranking individuals has a destabilizing effect on social network structures in social animals.

  3. Glutamate transporter type 3 knockout leads to decreased heart rate possibly via parasympathetic mechanism.

    PubMed

    Deng, Jiao; Li, Jiejie; Li, Liaoliao; Feng, Chenzhuo; Xiong, Lize; Zuo, Zhiyi

    2013-08-01

    Parasympathetic tone is a dominant neural regulator for basal heart rate. Glutamate transporters (EAAT) via their glutamate uptake functions regulate glutamate neurotransmission in the central nervous system. We showed that EAAT type 3 (EAAT3) knockout mice had a slower heart rate than wild-type mice when they were anesthetized. We design this study to determine whether non-anesthetized EAAT3 knockout mice have a slower heart rate and, if so, what may be the mechanism for this effect. Young adult EAAT3 knockout mice had slower heart rates than those of their littermate wild-type mice no matter whether they were awake or anesthetized. This difference was abolished by atropine, a parasympatholytic drug. Carbamylcholine chloride, a parasympathomimetic drug, equally effectively reduced the heart rates of wild-type and EAAT3 knockout mice. Positive immunostaining for EAAT3 was found in the area of nuclei deriving fibers for vagus nerve. There was no positive staining for the EAATs in the sinoatrial node. These results suggest that EAAT3 knockout mice have a slower heart rate at rest. This effect may be caused by an increased parasympathetic tone possibly due to increased glutamate neurotransmission in the central nervous system. These findings indicate that regulation of heart rate, a vital sign, is one of the EAAT biological functions.

  4. Stabilization of tooth movement by administration of reveromycin A to osteoprotegerin-deficient knockout mice.

    PubMed

    Yabumoto, Takahiro; Miyazawa, Ken; Tabuchi, Masako; Shoji, Satsuki; Tanaka, Miyuki; Kadota, Manami; Yoshizako, Mamoru; Kawatani, Makoto; Osada, Hiroyuki; Maeda, Hatsuhiko; Goto, Shigemi

    2013-09-01

    In this study, mechanical stress in the form of tooth movement was applied to osteoprotegerin-deficient knockout mice, which served as an animal model for juvenile Paget's disease. To compare and evaluate bone turnover and response of the surrounding bony tissue, we administered reveromycin A. We also investigated the ability of reveromycin A to control osteoclastic activity in juvenile Paget's disease. Eight-week-old male osteoprotegerin-deficient knockout and wild-type mice were injected with reveromycin A (15 mg/kg of body weight) intraperitoneally twice daily. An elastic module was inserted interproximally between the maxillary left first and second molars. Administration of reveromycin A to osteoprotegerin-deficient knockout mice reduced tooth movement distances, increased bone volumes at the interradicular septum, decreased osteoclast counts, and reduced serum alkaline phosphatase and tartrate resistant acid phosphatase. Reveromycin A administration also caused a temporal shift in peak Runx2 staining in osteoprotegerin-deficient knockout mice so that the overall staining time course was similar to that observed for wild-type mice. Reveromycin A administration in osteoprotegerin-deficient knockout mice inhibited bone resorption and normalized bone formation. As a result, normal bone turnover was obtained. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  5. Effects of morphine on pentobarbital-induced responses in mu-opioid receptor knockout mice.

    PubMed

    Park, Y; Ho, I K; Jang, C G; Tanaka, S; Ma, T; Loh, H H; Ko, K H

    2001-03-15

    Effects of morphine on the potentiation of pentobarbital-induced responses were investigated using mu-opioid receptor knockout mice. The duration of loss of righting reflex, hypothermia, and loss of motor coordination induced by pentobarbital were measured after pretreatment with either morphine or saline. Morphine pretreatment failed to show potentiation of both pentobarbital-induced loss of righting reflex and hypothermia in mu-opioid receptor knockout mice, while it significantly potentiated these responses in the wild-type controls. For motor incoordination test, morphine potentiated pentobarbital-induced motor incoordination in the wild-type mice. However, morphine may have opposite effects in the mu-opioid receptor knockout mice. These results demonstrate that synergism between morphine and pentobarbital is not detected in mu-opioid receptor knockout mice and that potentiation of pentobarbital-induced loss of righting reflex and hypothermia by morphine is mediated through mu-opioid receptor. It was interesting to note that pentobarbital-induced decrease in body temperature was less severe in mu-opioid receptor knockout mice than in wild-type mice.

  6. Postnatal handling reverses social anxiety in serotonin receptor 1A knockout mice.

    PubMed

    Zanettini, C; Carola, V; Lo Iacono, L; Moles, A; Gross, C; D'Amato, F R

    2010-02-01

    Mice lacking the serotonin receptor 1A (Htr1a knockout, Htr1a(KO)) show increased innate and conditioned anxiety. This phenotype depends on functional receptor activity during the third through fifth weeks of life and thus appears to be the result of long-term changes in brain function as a consequence of an early deficit in serotonin signaling. To evaluate whether this phenotype can be influenced by early environmental factors, we subjected Htr1a knockout mice to postnatal handling, a procedure known to reduce anxiety-like behavior and stress responses in adulthood. Offspring of heterozygous Htr1a knockout mice were separated from their mother and exposed 15 min each day from postnatal day 1 (PD1) to PD14 to clean bedding. Control animals were left undisturbed. Maternal behavior was observed during the first 13 days of life. Adult male offspring were tested in the open field, social approach and resident-intruder tests and assessed for corticosterone response to restraint stress. Knockout mice showed increased anxiety in the open field and in the social approach test as well as an enhanced corticosterone response to stress. However, while no effect of postnatal handling was seen in wild-type mice, handling reduced anxiety-like behavior in the social interaction test and the corticosterone response to stress in knockout mice. These findings extend the anxiety phenotype of Htr1a(KO) mice to include social anxiety and demonstrate that this phenotype can be moderated by early environmental factors.

  7. Cardiac Rehabilitation: MedlinePlus Health Topic

    MedlinePlus

    ... exercising are other risk factors. NIH: National Heart, Lung, and Blood Institute Start Here Cardiac Rehabilitation (Mayo Foundation for Medical Education and Research) Cardiac Rehabilitation (National Heart, Lung, and Blood Institute) What Is Cardiac Rehabilitation? (American Heart Association) - ...

  8. Single ventricle cardiac defect.

    PubMed

    Eren, Bulent; Turkmen, Nursel; Turkmen, Nurset; Fedakar, Recep; Senel, Berna; Cetin, Volkan; Cetin, Volkn

    2010-05-01

    Single ventricle heart is defined as a rare cardiac abnormality with a single ventricle chamber involving diverse functional and physiological defects. Our case is of a ten month-old baby boy who died shortly after admission to the hospital due to vomiting and diarrhoea. Autopsy findings revealed cyanosis of finger nails and ears. Internal examination revealed; large heart, weighing 60 grams, single ventricle, without a septum and upper membranous part. Single ventricle is a rare pathology, hence, this paper aims to discuss this case from a medico-legal point of view.

  9. The broken mouse: the role of development, plasticity and environment in the interpretation of phenotypic changes in knockout mice.

    PubMed

    Gingrich, J A; Hen, R

    2000-02-01

    With the advent of gene knockout technology has arisen the problem of how to interpret the resulting phenotypic changes in mice lacking specific genes. This problem is especially relevant when applied to behavioral phenotypes of knockout mice, which are difficult to interpret. Of particular interest are the roles of development and compensatory changes, as well as other factors, such as the influence of the gene knockout on nearby genes, the effect of the genetic background strain, maternal behavioral influences, and pleiotrophy.

  10. Geranylgeranylacetone and volatile anesthetic-induced cardiac protection synergism is dependent on caveolae and caveolin-3.

    PubMed

    Tsutsumi, Yasuo M; Tsutsumi, Rie; Horikawa, Yousuke T; Sakai, Yoko; Hamaguchi, Eisuke; Kitahata, Hiroshi; Kasai, Asuka; Kambe, Noriko; Tanaka, Katsuya

    2014-10-01

    Pharmacological preconditioning, including that with geranylgeranylacetone (GGA) and volatile anesthetics, has been shown to confer cardiac protection from ischemia/reperfusion injury although the mechanisms for this protection are poorly understood. Caveolins, integral membrane proteins that act as scaffolding proteins in caveolar membranes, localize molecules involved in cardiac protection. We have tested the hypothesis that caveolin-3 (Cav-3), the predominant isoform in cardiac myocytes, is essential for the synergistic effect observed between GGA and volatile anesthetics. Mice were randomly assigned to receive GGA, isoflurane [0.5 and 1.0 minimum alveolar concentration (MAC)], or GGA + isoflurane (0.5 MAC). An in vivo mouse model of ischemia/reperfusion injury was tested in wild-type and Cav-3 knockout mice, and the infarct size was determined. Biochemical assays were also performed in excised hearts. Geranylgeranylacetone and therapeutic isoflurane (1.0 MAC) independently reduced infarct size (31.6 ± 6.1 and 28.0 ± 5.0% of the area at risk, respectively; n = 10) as compared to the controls (45.8 ± 9.4%; n = 10). The combination GGA + sub-therapeutic isoflurane (0.5 MAC) further decreased the infarct size to 19.3 ± 5.1% (n = 10). Preconditioning [GGA, isoflurane (1.0 MAC), and GGA + isoflurane] increased the amount of Cav-3 protein in the discontinuous sucrose-gradient buoyant fractions. Additionally, cardiac protection was not observed in Cav-3 knockout mice following the administration of GGA, isoflurane, and GGA + isoflurane. Combined administration of GGA + isoflurane had a synergistic effect, enhancing the protection against myocardial infarction to a greater extent than either drug alone. This beneficial effect is mediated by Cav-3 expression.

  11. Control of Pathological Cardiac Hypertrophy by Transcriptional Corepressor IRF2BP2 (Interferon Regulatory Factor-2 Binding Protein 2).

    PubMed

    Fang, Jing; Li, Tianyu; Zhu, Xuehai; Deng, Ke-Qiong; Ji, Yan-Xiao; Fang, Chun; Zhang, Xiao-Jing; Guo, Jun-Hong; Zhang, Peng; Li, Hongliang; Wei, Xiang

    2017-09-01

    The transcription factor NFAT1 (nuclear factor of activated T-cells 1), with the aid of transcriptional coactivators, has been recognized for its necessity and sufficiency to drive pathological cardiac hypertrophy. However, how the transcriptional activity of NFAT1 in terms of cardiac hypertrophy is controlled at the transcriptional level has not been well defined. Herein, we showed that a cardiac-enriched protein IRF2BP2 (interferon regulatory factor-2 binding protein 2) was further upregulated in both human and mouse hypertrophied myocardium and negatively regulated cardiomyocyte hypertrophic response in vitro. By generating cardiomyocyte-specific Irf2bp2 knockout and Irf2bp2-transgenic mouse strains, our in vivo experiments showed that, whereas IRF2BP2 loss-of-function exacerbated both aortic banding- and angiotensin II infusion-induced cardiac hypertrophic response, IRF2BP2 overexpression exerted a strong protective effect against these maladaptive processes. Particularly, IRF2BP2 directly interacted with the C-terminal transactivation domain of NFAT1 by competing with myocyte enhancer factor-2C and disturbing their transcriptional synergism, thereby impeding NFAT1-transactivated hypertrophic transcriptome. As a result, the devastating effect of Irf2bp2 deficiency on cardiac hypertrophy was largely rescued by NFAT1 blockage. Our study, thus, defined IRF2BP2 as a novel negative regulator in controlling pathological cardiac hypertrophy at the transcriptional level. © 2017 American Heart Association, Inc.

  12. Exacerbated cardiac fibrosis induced by β-adrenergic activation in old mice due to decreased AMPK activity.

    PubMed

    Wang, Jingjing; Song, Yao; Li, Hao; Shen, Qiang; Shen, Jing; An, Xiangbo; Wu, Jimin; Zhang, Jianshu; Wu, Yunong; Xiao, Han; Zhang, Youyi

    2016-11-01

    Senescent hearts exhibit defective responses to β-adrenergic receptor (β-AR) over-activation upon stress, leading to more severe pathological cardiac remodelling. However, the underlying mechanisms remain unclear. Here, we investigated the role of adenosine monophosphate-activated protein kinase (AMPK) in protecting against ageing-associated cardiac remodelling in mice upon β-AR over-activation. 10-week-old (young) and 18-month-old (old) mice were subcutaneously injected with the β-AR agonist isoproterenol (ISO; 5 mg/kg). More extensive cardiac fibrosis was found in old mice upon ISO exposure than in young mice. Meanwhile, ISO treatment decreased AMPK activity and increased β-arrestin 1, but not β-arrestin 2, expression, and the effects of ISO on AMPK and β-arrestin 1 were greater in old mice than in young mice. Similarly, young AMPKα2-knockout (KO) mice showed more extensive cardiac fibrosis upon ISO exposure than that was observed in age-matched wild-type (WT) littermates. The extent of cardiac fibrosis in WT old mice was similar to that in young KO mice. Additionally, AMPK activities were decreased and β-arrestin 1 expression increased in KO mice. In contrast, the AMPK activator metformin decreased β-arrestin 1 expression and attenuated cardiac fibrosis in both young and old mice upon ISO exposure. In conclusion, more severe cardiac fibrosis is induced by ISO in old mice than in young mice. A decrease in AMPK activity, which further increases β-arrestin 1 expression, is the central mechanism underlying the ageing-related cardiac fibrosis induced by ISO. The AMPK activator metformin is a promising therapeutic agent for treating ageing-related cardiac remodelling upon β-AR over-activation.

  13. Lrrc10 is a novel cardiac-specific target gene of Nkx2-5 and GATA4

    PubMed Central

    Brody, Matthew J.; Cho, Eunjin; Mysliwiec, Matthew R.; Kim, Tae-gyun; Carlson, Clayton D.; Lee, Kyu-Ho; Lee, Youngsook

    2013-01-01

    Cardiac gene expression is precisely regulated and its perturbation causes developmental defects and heart disease. Leucine-rich repeat containing 10 (Lrrc10) is a cardiac-specific factor that is crucial for proper cardiac development and deletion of Lrrc10 in mice results in dilated cardiomyopathy. However, the mechanisms regulating Lrrc10 expression in cardiomyocytes remain unknown. Therefore, we set out to determine trans-acting factors and cis-elements critical for mediating Lrrc10 expression. We identify Lrrc10 as a transcriptional target of Nkx2-5 and GATA4. The Lrrc10 promoter region contains two highly conserved cardiac regulatory elements, which are functional in cardiomyocytes but not in fibroblasts. In vivo, Nkx2-5 and GATA4 endogenously occupy the proximal and distal cardiac regulatory elements of Lrrc10 in the heart. Moreover, embryonic hearts of Nkx2-5 knockout mice have dramatically reduced expression of Lrrc10. These data demonstrate the importance of Nkx2-5 and GATA4 in regulation of Lrrc10 expression in vivo. The proximal cardiac regulatory element located at around −200 bp is synergistically activated by Nkx2-5 and GATA4 while the distal cardiac regulatory element present around −3 Kb requires SRF in addition to Nkx2-5 and GATA4 for synergistic activation. Mutational analyses identify a pair of adjacent Nkx2-5 and GATA binding sites within the proximal cardiac regulatory element that are necessary to induce expression of Lrrc10. In contrast, only the GATA site is functional in the distal regulatory element. Taken together, our data demonstrate that the transcription factors Nkx2-5 and GATA4 cooperatively regulate cardiac-specific expression of Lrrc10. PMID:23751912

  14. MG53 is dispensable for T-tubule maturation but critical for maintaining T-tubule integrity following cardiac stress.

    PubMed

    Zhang, Caimei; Chen, Biyi; Wang, Yihui; Guo, Ang; Tang, Yiqun; Khataei, Tahsin; Shi, Yun; Kutschke, William J; Zimmerman, Kathy; Weiss, Robert M; Liu, Jie; Benson, Christopher J; Hong, Jiang; Ma, Jianjie; Song, Long-Sheng

    2017-08-16

    The cardiac transverse (T)-tubule membrane system is the safeguard for cardiac function and undergoes dramatic remodeling in response to cardiac stress. However, the mechanism by which cardiomyocytes repair damaged T-tubule network remains unclear. In the present study, we tested the hypothesis that MG53, a muscle-specific membrane repair protein, antagonizes T-tubule damage to protect against maladaptive remodeling and thereby loss of excitation-contraction coupling and cardiac function. Using MG53-knockout (MG53-KO) mice, we first established that deficiency of MG53 had no impact on maturation of the T-tubule network in developing hearts. Additionally, MG53 ablation did not influence T-tubule integrity in unstressed adult hearts as late as 10months of age. Following left ventricular pressure overload-induced cardiac stress, MG53 protein levels were increased by approximately three-fold in wild-type mice, indicating that pathological stress induces a significant upregulation of MG53. MG53-deficient mice had worsened T-tubule disruption and pronounced dysregulation of Ca(2+) handling properties, including decreased Ca(2+) transient amplitude and prolonged time to peak and decay. Moreover, MG53 deficiency exacerbated cardiac hypertrophy and dysfunction and decreased survival following cardiac stress. Our data suggest MG53 is not required for T-tubule development and maintenance in normal physiology. However, MG53 is essential to preserve T-tubule integrity and thereby Ca(2+) handling properties and cardiac function under pathological cardiac stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Curvature Analysis of Cardiac Excitation Wavefronts

    DTIC Science & Technology

    2013-04-01

    computational cardiac-cell network accurately reproduces a particular kind of cardiac arrhythmia , such as ventricular fibrillation. Curvature Analysis of Cardiac...network accurately reproduces a particular kind of cardiac arrhythmia , such as ventricular fibrillation. Index Terms Cardiac excitation waves...isopotentials, Bézier curves, curvature, cardiac arrhythmia and fibrillation Ç 1 INTRODUCTION AN estimated 81,000,000 American adults, more than onein three

  16. Cardiac rehabilitation in Germany.

    PubMed

    Cantwell, J D

    1976-09-01

    The concept of cardiac reconditioning centers for the prevention and rehabilitation of coronary patients has been tremendously successful in Germany over the past 20 years. At least 40 such centers are located throughout the country. Physicians, nurses, and physical therapists work closely together in the various facets of the rehabilitation process. The financial backing for these facilities is primarily through governmental and regional insurance companies, whose officials are apparently convinced that in the long run supporting preventive measures is financially sound. Objective data supporting their convictions come from studies such as that of Brusis, who showed that such as that of 1,500 employees was diminished by nearly 70 percent during a two-year period after cardiac reconditioning, as compared to a similar time period before the rehabilitation experience. Subjective benefits, which are extremely difficult to quantitate in meaningful terms, were nonetheless expressed by nearly all the patients with whom I conversed. Perhaps they have experienced the same feelings that Mark Twain did when he observed that "all frets and worries and chafings sank to sleep in the presence of the benignant serenity of the Alps; the Great Spirit of the Mountains breathed his own peace upon their hurt minds and sore hearts and healed them."

  17. Decoding the Cardiac Message

    PubMed Central

    Dorn, Gerald W

    2012-01-01

    This review reflects and expands upon the contents of the author’s presentation at The Thomas W. Smith Memorial Lecture at AHA Scientific Sessions, 2011. “Decoding the cardiac message” refers to accumulating results from ongoing microRNA research that is altering longstanding concepts of the mechanisms for, and consequences of, messenger RNA (mRNA) regulation in the heart. First, I provide a brief historical perspective of the field of molecular genetics, touching upon seminal research that paved the way for modern molecular cardiovascular research and helped establish the foundation for current concepts of mRNA regulation in the heart. I follow with some interesting details about the specific research that led to the discovery and appreciation of microRNAs as highly conserved pivotal regulators of RNA expression and translation. Finally, I provide a personal viewpoint as to how agnostic genome-wide techniques for measuring microRNAs, their mRNA targets, and their protein products can be applied in an integrated multi-systems approach to uncover direct and indirect effects of microRNAs. Experimental designs integrating next-generation sequencing and global proteomics have the potential to address unanswered questions regarding microRNA-mRNA interactions in cardiac disease, how disease alters mRNA targeting by specific microRNAs, and how mutational and polymorphic nucleotide variation in microRNAs can affect end-organ function and stress-response. PMID:22383710

  18. Anaesthesia for cardiac surgery.

    PubMed

    Rooney, P

    1996-09-01

    Perhaps no form of surgery is as emotive as that on the heart. From ancient times, seen as the seat of the emotions, the heart has been recognised as a vital if, at times, mysterious organ. Its grip on the imagination of primitive peoples is exemplified in the extreme by the climax of the human sacrificial ceremonies carried out by the Aztec and Inca peoples of Mexico and Peru: the holding aloft by the priest of the victim's still-beating heart. Nowadays, although we might congratulate ourselves on the heights of civilization which we have attained, it is salutary to consider that such cultural achievements are but a veneer through which primordial emotions frequently burst. As professional nurses, however, while appreciating the emotions of our patients and relatives with regard to cardiac surgery, we need to exercise sufficient detachment so that effective care may be delivered. This article will discuss cardiac anaesthesia generally, but will not touch on the specialised subjects of transplantation. It also accepts that techniques and drug regimes vary from centre to centre.

  19. Leadership in cardiac surgery.

    PubMed

    Rao, Christopher; Patel, Vanash; Ibrahim, Michael; Ahmed, Kamran; Wong, Kathie A; Darzi, Ara; von Segesser, Ludwig K; Athanasiou, Thanos

    2011-06-01

    Despite the efficacy of cardiac surgery, less invasive interventions with more uncertain long-term outcomes are increasingly challenging surgery as first-line treatment for several congenital, degenerative and ischemic cardiac diseases. The specialty must evolve if it is to ensure its future relevance. More importantly, it must evolve to ensure that future patients have access to treatments with proven long-term effectiveness. This cannot be achieved without dynamic leadership; however, our contention is that this is not enough. The demands of a modern surgical career and the importance of the task at hand are such that the serendipitous emergence of traditional charismatic leadership cannot be relied upon to deliver necessary change. We advocate systematic analysis and strategic leadership at a local, national and international level in four key areas: Clinical Care, Research, Education and Training, and Stakeholder Engagement. While we anticipate that exceptional individuals will continue to shape the future of our specialty, the creation of robust structures to deliver collective leadership in these key areas is of paramount importance.

  20. Cardiac Remodeling in Obesity

    PubMed Central

    ABEL, E. DALE; LITWIN, SHELDON E.; SWEENEY, GARY

    2010-01-01

    The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic. PMID:18391168

  1. Redox Control of Cardiac Excitability

    PubMed Central

    Aggarwal, Nitin T.

    2013-01-01

    Abstract Reactive oxygen species (ROS) have been associated with various human diseases, and considerable attention has been paid to investigate their physiological effects. Various ROS are synthesized in the mitochondria and accumulate in the cytoplasm if the cellular antioxidant defense mechanism fails. The critical balance of this ROS synthesis and antioxidant defense systems is termed the redox system of the cell. Various cardiovascular diseases have also been affected by redox to different degrees. ROS have been indicated as both detrimental and protective, via different cellular pathways, for cardiac myocyte functions, electrophysiology, and pharmacology. Mostly, the ROS functions depend on the type and amount of ROS synthesized. While the literature clearly indicates ROS effects on cardiac contractility, their effects on cardiac excitability are relatively under appreciated. Cardiac excitability depends on the functions of various cardiac sarcolemal or mitochondrial ion channels carrying various depolarizing or repolarizing currents that also maintain cellular ionic homeostasis. ROS alter the functions of these ion channels to various degrees to determine excitability by affecting the cellular resting potential and the morphology of the cardiac action potential. Thus, redox balance regulates cardiac excitability, and under pathological regulation, may alter action potential propagation to cause arrhythmia. Understanding how redox affects cellular excitability may lead to potential prophylaxis or treatment for various arrhythmias. This review will focus on the studies of redox and cardiac excitation. Antioxid. Redox Signal. 18, 432–468. PMID:22897788

  2. Health Instruction Packages: Cardiac Anatomy.

    ERIC Educational Resources Information Center

    Phillips, Gwen; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

  3. Health Instruction Packages: Cardiac Anatomy.

    ERIC Educational Resources Information Center

    Phillips, Gwen; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

  4. New Developments in Cardiac Regeneration.

    PubMed

    Le, Thi Yen Loan; Thavapalachandran, Sujitha; Kizana, Eddy; Chong, James Jh

    2017-04-01

    Numerous pharmacological and device therapies have improved adverse cardiac remodelling and mortality in heart failure. However, none are able to regenerate damaged cardiac tissue. Stem cell based therapies using multipotent (adult) stem cells and pluripotent stem cells are new approaches that could potentially achieve the elusive goal of true cardiac regeneration. Over the past two decades, various stem cell based approaches have been shown to improve left ventricular function in pre-clinical animal models. Promising results rapidly led to clinical trials, initially using bone marrow-derived mononuclear cells, then mesenchymal stromal cell populations and, more recently, progenitor cells from the adult heart itself. These have been shown to be safe and have advanced our understanding of potential suitable recipients, cell delivery routes, and possible mechanisms of action. However, efficacy in these trials has been inconsistent. Human pluripotent stem cells (hPSCs) are another potential source of stem cells for cardiac regeneration. They could theoretically provide an unlimited source of cardiomyocytes or cardiac progenitors. Pre-clinical studies in both small and large animal models have shown robust engraftment and improvements in cardiac function. The first clinical trial using hPSC-derived cardiac derivatives has now commenced and others are imminent. In this brief review article, we summarise recent developments in stem cell therapies aimed at cardiac regeneration, including discussion of types of cell and non-cell-based strategies being explored.

  5. Mitochondrial biogenesis in cardiac pathophysiology.

    PubMed

    Rimbaud, Stéphanie; Garnier, Anne; Ventura-Clapier, Renée

    2009-01-01

    Cardiac performance depends on a fine balance between the work the heart has to perform to satisfy the needs of the body and the energy that it is able to produce. Thus, energy production by oxidative metabolism, the main energy source of the cardiac muscle, has to be strictly regulated to adapt to cardiac work. Mitochondrial biogenesis is the mechanism responsible for mitochondrial component synthesis and assembly. This process controls mitochondrial content and thus correlates with energy production that, in turn, sustains cardiac contractility. Mitochondrial biogenesis should be finely controlled to match cardiac growth and cardiac work. When the heart is subjected to an increase in work in response to physiological and pathological challenges, it adapts by increasing its mass and expressing a new genetic program. In response to physiological stimuli such as endurance training, mitochondrial biogenesis seems to follow a program involving increased cardiac mass. But in the context of pathological hypertrophy, the modifications of this mechanism remain unclear. What appears clear is that mitochondrial biogenesis is altered in heart failure, and the imbalance between cardiac work demand and energy production represents a major factor in the development of heart failure.

  6. GPCR signaling and cardiac function.

    PubMed

    Capote, Leany A; Mendez Perez, Roberto; Lymperopoulos, Anastasios

    2015-09-15

    G protein-coupled receptors (GPCRs), such as β-adrenergic and angiotensin II receptors, located in the membranes of all three major cardiac cell types, i.e. myocytes, fibroblasts and endothelial cells, play crucial roles in regulating cardiac function and morphology. Their importance in cardiac physiology and disease is reflected by the fact that, collectively, they represent the direct targets of over a third of the currently approved cardiovascular drugs used in clinical practice. Over the past few decades, advances in elucidation of their structure, function and the signaling pathways they elicit, specifically in the heart, have led to identification of an increasing number of new molecular targets for heart disease therapy. Here, we review these signaling modalities employed by GPCRs known to be expressed in the cardiac myocyte membranes and to directly modulate cardiac contractility. We also highlight drugs and drug classes that directly target these GPCRs to modulate cardiac function, as well as molecules involved in cardiac GPCR signaling that have the potential of becoming novel drug targets for modulation of cardiac function in the future.

  7. Signaling pathway factors expression in renal tissue of apoE-knockout mice.

    PubMed

    Zhou, Tian-Biao

    2015-01-01

    Apolipoprotein E (apoE) is regarded as one of the major plasma lipoproteins, and it plays an important role in the transport and metabolism of lipids. apoE can be found in multiple tissues, such as liver, kidney, jejunum, urinary bladder, ileum, colon, brain, adrenal glands, lung, ovary, spleen, pancreas, and testis, etc. As a secreted protein, it plays an important role in the systemic lipoprotein metabolism and vascular wall homeostasis and in the pathogenesis of renal diseases. apoE-knockout (apoE(-/-)) mice is a classic model of atherosclerosis and renal diseases. However, no review summed up the signaling pathway factors expression in renal tissue of apoE-knockout mice. The literatures were searched extensively and this review was performed to review the signaling pathway factors expression in renal tissue of apoE-knockout mice.

  8. Generating gene knockout rats by homologous recombination in embryonic stem cells

    PubMed Central

    Tong, Chang; Huang, Guanyi; Ashton, Charles; Li, Ping; Ying, Qi-Long

    2013-01-01

    We describe here a detailed protocol for generating gene knockout rats by homologous recombination in embryonic stem (ES) cells. This protocol comprises the following procedures: derivation and expansion of rat ES cells, construction of gene-targeting vectors, generation of gene-targeted rat ES cells and, finally, production of gene-targeted rats. The major differences between this protocol and the classical mouse gene-targeting protocol include ES cell culture methods, drug selection scheme, colony picking and screening strategies. This ES cell–based gene-targeting technique allows sophisticated genetic modifications to be performed in the rat, as many laboratories have been doing in the mouse for the past two decades. Recently we used this protocol to generate Tp53 (also known as p53) gene knockout rats. The entire process requires ~1 year to complete, from derivation of ES cells to generation of knockout rats. PMID:21637202

  9. MR histology of advanced atherosclerotic lesions of ApoE- knockout mice

    NASA Astrophysics Data System (ADS)

    Naumova, A.; Yarnykh, V.; Ferguson, M.; Rosenfeld, M.; Yuan, C.

    2016-02-01

    The purposes of this study were to examine the feasibility of determining the composition of advanced atherosclerotic plaques in fixed ApoE-knockout mice and to develop a time-efficient microimaging protocol for MR histological imaging on mice. Five formalin-fixed transgenic ApoE-knockout mice were imaged at the 9.4T Bruker BioSpec MR scanner using 3D spoiled gradient-echo sequence with an isotropic field of view of 24 mm3; TR 20.8 ms; TE 2.6 ms; flip angle 20°, resulted voxel size 47 × 63 × 94 pm3. MRI examination has shown that advanced atherosclerotic lesions of aorta, innominate and carotid arteries in ApoE-knockout mice are characterized by high calcification and presence of the large fibrofatty nodules. MRI quantification of atherosclerotic lesion components corresponded to histological assessment of plaque composition with a correlation coefficient of 0.98.

  10. [Chronic surplus of Japanese cardiac surgeon--ideal nurse practitioner for cardiac surgery, cardiac surgeon's attitude toward the future].

    PubMed

    Ikegami, Hirohisa

    2014-03-01

    It is chronically surplus of doctors in the world of cardiac surgery. There are too many cardiac surgeons because cardiac surgery requires a large amount of manpower resources to provide adequate medical services. Many Japanese cardiac surgeons do not have enough opportunity to perform cardiac surgery operations, and many Japanese cardiac surgery residents do not have enough opportunity to learn cardiac surgery operations. There are physician assistants and nurse practitioners in the US. Because they provide a part of medical care to cardiac surgery patients, American cardiac surgeons can focus more energy on operative procedures. Introduction of cardiac surgery specialized nurse practitioner is essential to deliver a high quality medical service as well as to solve chronic problems that Japanese cardiac surgery has had for a long time.

  11. THE CHEMOTHERAPY OF CARDIAC ARREST.

    PubMed

    MINUCK, M

    1965-01-02

    Direct-air ventilation, external cardiac compression, and external defibrillation are established techniques for patients who unexpectedly develop cardiac arrest. The proper use of drugs can increase the incidence of successful resuscitation. Intracardiac adrenaline (epinephrine) acts as a powerful stimulant during cardiac standstill and, in addition, converts fine ventricular fibrillation to a coarser type, more responsive to electrical defibrillation. Routine use of intravenous sodium bicarbonate is recommended to combat the severe metabolic acidosis accompanying cardiac arrest. Lidocaine is particularly useful when ventricular fibrillation or ventricular tachycardia tends to recur. Analeptics are contraindicated, since they invariably increase oxygen requirements of already hypoxic cerebral tissues. The following acrostic is a useful mnemonic for recalling the details of the management of cardiac arrest in their proper order: A (Airway), B (Breathing), C (Circulation), D (Diagnosis of underlying cause), E (Epinephrine), F (Fibrillation), G (Glucose intravenously), pH (Sodium bicarbonate), I (Intensive care).

  12. Challenges in cardiac tissue engineering.

    PubMed

    Vunjak-Novakovic, Gordana; Tandon, Nina; Godier, Amandine; Maidhof, Robert; Marsano, Anna; Martens, Timothy P; Radisic, Milica

    2010-04-01

    Cardiac tissue engineering aims to create functional tissue constructs that can reestablish the structure and function of injured myocardium. Engineered constructs can also serve as high-fidelity models for studies of cardiac development and disease. In a general case, the biological potential of the cell-the actual "tissue engineer"-is mobilized by providing highly controllable three-dimensional environments that can mediate cell differentiation and functional assembly. For cardiac regeneration, some of the key requirements that need to be met are the selection of a human cell source, establishment of cardiac tissue matrix, electromechanical cell coupling, robust and stable contractile function, and functional vascularization. We review here the potential and challenges of cardiac tissue engineering for developing therapies that could prevent or reverse heart failure.

  13. Challenges in Cardiac Tissue Engineering

    PubMed Central

    Tandon, Nina; Godier, Amandine; Maidhof, Robert; Marsano, Anna; Martens, Timothy P.; Radisic, Milica

    2010-01-01

    Cardiac tissue engineering aims to create functional tissue constructs that can reestablish the structure and function of injured myocardium. Engineered constructs can also serve as high-fidelity models for studies of cardiac development and disease. In a general case, the biological potential of the cell—the actual “tissue engineer”—is mobilized by providing highly controllable three-dimensional environments that can mediate cell differentiation and functional assembly. For cardiac regeneration, some of the key requirements that need to be met are the selection of a human cell source, establishment of cardiac tissue matrix, electromechanical cell coupling, robust and stable contractile function, and functional vascularization. We review here the potential and challenges of cardiac tissue engineering for developing therapies that could prevent or reverse heart failure. PMID:19698068

  14. Pediatric cardiac surgery in Indonesia.

    PubMed

    Asou, T; Rachmat, J

    1998-10-01

    Pediatric cardiac surgery in Indonesia first developed thanks to the cooperation of various cardiac centers abroad. The establishment of the 'Harapan Kita' National Cardiac Center in 1985 was one of the most important initial steps. Thereafter, the discipline advanced remarkably in terms of the number of the operations performed and the variety of the diseases treated and, as a result, the surgical outcome also improved. Numerous problems remain to be solved. Only 1% of the children with congenital heart disease are today properly treated in Indonesia. Some of the underlying problems responsible for this situation include a shortage of pediatric cardiac professionals, the lack of the information and education on the part of the patients, and a shortage of funding, both privately and publicly. It would thus be welcome for pediatric cardiac surgeons, cardiologists and nurses in Indonesia to learn about congenital heart disease from doctors and nurses in advanced countries in order to improve the outlook at home.

  15. Mechanisms of sudden cardiac death.

    PubMed

    McElwee, Samuel K; Velasco, Alejandro; Doppalapudi, Harish

    2016-12-01

    Sudden cardiac death (SCD) continues to be a major public health problem and is thought to account for almost half of all cardiac deaths. Cardiac arrest and SCD are most commonly due to ventricular arrhythmias. Most patients who suffer cardiac arrest have underlying structural heart disease, with coronary artery disease (CAD) being the most common. In the setting of CAD, ventricular arrhythmias can result due to acute ischemia in the absence of preexisting myocardial scarring or in the presence of established scar from prior infarction without clinically significant ischemia. LV systolic dysfunction is an important predictor of risk for SCD in ischemic heart disease and in most nonischemic disorders, although other factors such as ventricular hypertrophy also play a role. Cardiac arrest and SCD can also occur due to primary electrical disorders in the absence of major structural abnormalities.

  16. Effect of knockout of α2δ-1 on action potentials in mouse sensory neurons

    PubMed Central

    Margas, Wojciech; Ferron, Laurent; Nieto-Rostro, Manuela; Schwartz, Arnold; Dolphin, Annette C.

    2016-01-01

    Gene deletion of the voltage-gated calcium channel auxiliary subunit α2δ-1 has been shown previously to have a cardiovascular phenotype, and a reduction in mechano- and cold sensitivity, coupled with delayed development of neuropathic allodynia. We have also previously shown that dorsal root ganglion (DRG) neuron calcium channel currents were significantly reduced in α2δ-1 knockout mice. To extend our findings in these sensory neurons, we have examined here the properties of action potentials (APs) in DRG neurons from α2δ-1 knockout mice in comparison to their wild-type (WT) littermates, in order to dissect how the calcium channels that are affected by α2δ-1 knockout are involved in setting the duration of individual APs and their firing frequency. Our main findings are that there is reduced Ca2+ entry on single AP stimulation, particularly in the axon proximal segment, reduced AP duration and reduced firing frequency to a 400 ms stimulation in α2δ-1 knockout neurons, consistent with the expected role of voltage-gated calcium channels in these events. Furthermore, lower intracellular Ca2+ buffering also resulted in reduced AP duration, and a lower frequency of AP firing in WT neurons, mimicking the effect of α2δ-1 knockout. By contrast, we did not obtain any consistent evidence for the involvement of Ca2+-activation of large conductance calcium-activated potassium (BK) and small conductance calcium-activated potassium (SK) channels in these events. In conclusion, the reduced Ca2+ elevation as a result of single AP stimulation is likely to result from the reduced duration of the AP in α2δ-1 knockout sensory neurons. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’. PMID:27377724

  17. Distortion effects on the neutron knockout from exotic nuclei in the collision with a proton target

    NASA Astrophysics Data System (ADS)

    Cravo, E.; Crespo, R.; Deltuva, A.

    2016-05-01

    Background: Reaction theory plays a major role in the interpretation of experimental data and one needs to identify and include accurately all the relevant dynamical effects in order to extract reliable structure information. The knockout of a nucleon (neutron/proton) from a high energy exotic nucleus projectile colliding with a proton target allows to get insight on the structure of its valence and inner shells. Purpose: We aim to clarify the role of the distortion on the calculated observables for nucleon knockout, in particular, the dependence of the calculated observables on the binding energy ɛb and angular momentum L of the knockout particle, and on the mass of the projectile core, Ac. We consider mainly the knockout of a neutron that may be either in the valence or in the inner shell of the projectile nucleus. Method: Exact three-body Faddeev/Alt-Grassberger-Sandhas (Faddeev/AGS) calculations are performed for the nucleon knockout from stable and exotic nuclei in the collision of 420 MeV/u projectile beams with a proton target. Results are compared with plane-wave impulse approximation (PWIA) calculations. Results: The Faddeev/AGS formalism accurately predicts: (i) a systematic nearly logarithmic dependence of the distortion parameter on the separation energy; (ii) roughly linear dependence of the ratio of the full to the PWIA cross section on the asymmetry parameter; (iii) a distinct behavior between the calculated transverse core momentum distribution from the PWIA and full Faddeev/AGS exact approach which indicates that distortion effects do not modify fully exclusive observables through a common renormalization factor. Conclusions: To extract structure information on deeper shells one needs to include distortion effects accurately. A systematic analysis enables to estimate the total cross section for knockout of a nucleon from a given shell of nuclei at/away the stability line of the nuclear landscape. The comparison with experimental results may

  18. Glutaminyl Cyclase Knock-out Mice Exhibit Slight Hypothyroidism but No Hypogonadism

    PubMed Central

    Schilling, Stephan; Kohlmann, Stephanie; Bäuscher, Christoph; Sedlmeier, Reinhard; Koch, Birgit; Eichentopf, Rico; Becker, Andreas; Cynis, Holger; Hoffmann, Torsten; Berg, Sabine; Freyse, Ernst-Joachim; von Hörsten, Stephan; Rossner, Steffen; Graubner, Sigrid; Demuth, Hans-Ulrich

    2011-01-01

    Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) residues at the N terminus of peptides and proteins. Hypothalamic pGlu hormones, such as thyrotropin-releasing hormone and gonadotropin-releasing hormone are essential for regulation of metabolism and fertility in the hypothalamic pituitary thyroid and gonadal axes, respectively. Here, we analyzed the consequences of constitutive genetic QC ablation on endocrine functions and on the behavior of adult mice. Adult homozygous QC knock-out mice are fertile and behave indistinguishably from wild type mice in tests of motor function, cognition, general activity, and ingestion behavior. The QC knock-out results in a dramatic drop of enzyme activity in the brain, especially in hypothalamus and in plasma. Other peripheral organs like liver and spleen still contain QC activity, which is most likely caused by its homolog isoQC. The serum gonadotropin-releasing hormone, TSH, and testosterone concentrations were not changed by QC depletion. The serum thyroxine was decreased by 24% in homozygous QC knock-out animals, suggesting a mild hypothyroidism. QC knock-out mice were indistinguishable from wild type with regard to blood glucose and glucose tolerance, thus differing from reports of thyrotropin-releasing hormone knock-out mice significantly. The results suggest a significant formation of the hypothalamic pGlu hormones by alternative mechanisms, like spontaneous cyclization or conversion by isoQC. The different effects of QC depletion on the hypothalamic pituitary thyroid and gonadal axes might indicate slightly different modes of substrate conversion of both enzymes. The absence of significant abnormalities in QC knock-out mice suggests the presence of a therapeutic window for suppression of QC activity in current drug development. PMID:21330373

  19. TRPV2 KNOCKOUT MICE ARE SUSCEPTIBLE TO PERINATAL LETHALITY BUT DISPLAY NORMAL THERMAL AND MECHANICAL NOCICEPTION

    PubMed Central

    Park, Una; Vastani, Nisha; Guan, Yun; Raja, Srinivasa N.; Koltzenburg, Martin; Caterina, Michael J.

    2011-01-01

    TRPV2 is a nonselective cation channel expressed prominently in medium- to large-diameter sensory neurons that can be activated by extreme heat (>52°C). These features suggest that TRPV2 might be a transducer of noxious heat in vivo. TRPV2 can also be activated by hypoosmolarity or cell stretch, suggesting potential roles in mechanotransduction. To address the physiological functions of TRPV2 in somatosensation, we generated TRPV2 knockout mice and examined their behavioral and electrophysiological responses to heat and mechanical stimuli. TRPV2 knockout mice showed reduced embryonic weight and perinatal viability. As adults, surviving knockout mice also exhibited a slightly reduced body weight. TRPV2 knockout mice showed normal behavioral responses to noxious heat over a broad range of temperatures and normal responses to punctate mechanical stimuli, both in the basal state and under hyperalgesic conditions such as peripheral inflammation and L5 spinal nerve ligation. Moreover, behavioral assays of TRPV1/TRPV2 double knockout mice or of TRPV2 knockout mice treated with resiniferatoxin to desensitize TRPV1-expressing afferents revealed no thermosensory consequences of TRPV2 absence. In line with behavioral findings, electrophysiological recordings from skin afferents showed that C-fiber responses to heat and C- and Aδ-fiber responses to noxious mechanical stimuli were unimpaired in the absence of TRPV2. The prevalence of thermosensitive Aδ-fibers was too low to permit comparison between genotypes. Thus, TRPV2 is important for perinatal viability but is not essential for heat or mechanical nociception or hypersensitivity in the adult mouse. PMID:21832173

  20. Evaluation and Design of Genome-Wide CRISPR/SpCas9 Knockout Screens.

    PubMed

    Hart, Traver; Tong, Amy Hin Yan; Chan, Katie; Van Leeuwen, Jolanda; Seetharaman, Ashwin; Aregger, Michael; Chandrashekhar, Megha; Hustedt, Nicole; Seth, Sahil; Noonan, Avery; Habsid, Andrea; Sizova, Olga; Nedyalkova, Lyudmila; Climie, Ryan; Tworzyanski, Leanne; Lawson, Keith; Sartori, Maria Augusta; Alibeh, Sabriyeh; Tieu, David; Masud, Sanna; Mero, Patricia; Weiss, Alexander; Brown, Kevin R; Usaj, Matej; Billmann, Maximilian; Rahman, Mahfuzur; Constanzo, Michael; Myers, Chad L; Andrews, Brenda J; Boone, Charles; Durocher, Daniel; Moffat, Jason

    2017-08-07

    The adaptation of CRISPR/SpCas9 technology to mammalian cell lines is transforming the study of human functional genomics. Pooled libraries of CRISPR guide RNAs (gRNAs) targeting human protein-coding genes and encoded in viral vectors have been used to systematically create gene knockouts in a variety of human cancer and immortalized cell lines, in an effort to identify whether these knockouts cause cellular fitness defects. Previous work has shown that CRISPR screens are more sensitive and specific than pooled-library shRNA screens in similar assays, but currently there exists significant variability across CRISPR library designs and experimental protocols. In this study, we reanalyze 17 genome-scale knockout screens in human cell lines from three research groups, using three different genome-scale gRNA libraries. Using the Bayesian Analysis of Gene Essentiality algorithm to identify essential genes, we refine and expand our previously defined set of human core essential genes from 360 to 684 genes. We use this expanded set of reference core essential genes, CEG2, plus empirical data from six CRISPR knockout screens to guide the design of a sequence-optimized gRNA library, the Toronto KnockOut version 3.0 (TKOv3) library. We then demonstrate the high effectiveness of the library relative to reference sets of essential and nonessential genes, as well as other screens using similar approaches. The optimized TKOv3 library, combined with the CEG2 reference set, provide an efficient, highly optimized platform for performing and assessing gene knockout screens in human cell lines. Copyright © 2017 Hart et al.

  1. Evaluation and Design of Genome-Wide CRISPR/SpCas9 Knockout Screens

    PubMed Central

    Hart, Traver; Tong, Amy Hin Yan; Chan, Katie; Van Leeuwen, Jolanda; Seetharaman, Ashwin; Aregger, Michael; Chandrashekhar, Megha; Hustedt, Nicole; Seth, Sahil; Noonan, Avery; Habsid, Andrea; Sizova, Olga; Nedyalkova, Lyudmila; Climie, Ryan; Tworzyanski, Leanne; Lawson, Keith; Sartori, Maria Augusta; Alibeh, Sabriyeh; Tieu, David; Masud, Sanna; Mero, Patricia; Weiss, Alexander; Brown, Kevin R.; Usaj, Matej; Billmann, Maximilian; Rahman, Mahfuzur; Constanzo, Michael; Myers, Chad L.; Andrews, Brenda J.; Boone, Charles; Durocher, Daniel; Moffat, Jason

    2017-01-01

    The adaptation of CRISPR/SpCas9 technology to mammalian cell lines is transforming the study of human functional genomics. Pooled libraries of CRISPR guide RNAs (gRNAs) targeting human protein-coding genes and encoded in viral vectors have been used to systematically create gene knockouts in a variety of human cancer and immortalized cell lines, in an effort to identify whether these knockouts cause cellular fitness defects. Previous work has shown that CRISPR screens are more sensitive and specific than pooled-library shRNA screens in similar assays, but currently there exists significant variability across CRISPR library designs and experimental protocols. In this study, we reanalyze 17 genome-scale knockout screens in human cell lines from three research groups, using three different genome-scale gRNA libraries. Using the Bayesian Analysis of Gene Essentiality algorithm to identify essential genes, we refine and expand our previously defined set of human core essential genes from 360 to 684 genes. We use this expanded set of reference core essential genes, CEG2, plus empirical data from six CRISPR knockout screens to guide the design of a sequence-optimized gRNA library, the Toronto KnockOut version 3.0 (TKOv3) library. We then demonstrate the high effectiveness of the library relative to reference sets of essential and nonessential genes, as well as other screens using similar approaches. The optimized TKOv3 library, combined with the CEG2 reference set, provide an efficient, highly optimized platform for performing and assessing gene knockout screens in human cell lines. PMID:28655737

  2. Hyperactivity of Newborn Pten Knock-out Neurons Results from Increased Excitatory Synaptic Drive

    PubMed Central

    Williams, Michael R.; DeSpenza, Tyrone; Li, Meijie; Gulledge, Allan T.

    2015-01-01

    Developing neurons must regulate morphology, intrinsic excitability, and synaptogenesis to form neural circuits. When these processes go awry, disorders, including autism spectrum disorder (ASD) or epilepsy, may result. The phosphatase Pten is mutated in some patients having ASD and seizures, suggesting that its mutation disrupts neurological function in part through increasing neuronal activity. Supporting this idea, neuronal knock-out of Pten in mice can cause macrocephaly, behavioral changes similar to ASD, and seizures. However, the mechanisms through which excitability is enhanced following Pten depletion are unclear. Previous studies have separately shown that Pten-depleted neurons can drive seizures, receive elevated excitatory synaptic input, and have abnormal dendrites. We therefore tested the hypothesis that developing Pten-depleted neurons are hyperactive due to increased excitatory synaptogenesis using electrophysiology, calcium imaging, morphological analyses, and modeling. This was accomplished by coinjecting retroviruses to either “birthdate” or birthdate and knock-out Pten in granule neurons of the murine neonatal dentate gyrus. We found that Pten knock-out neurons, despite a rapid onset of hypertrophy, were more active in vivo. Pten knock-out neurons fired at more hyperpolarized membrane potentials, displayed greater peak spike rates, and were more sensitive to depolarizing synaptic input. The increased sensitivity of Pten knock-out neurons was due, in part, to a higher density of synapses located more proximal to the soma. We determined that increased synaptic drive was sufficient to drive hypertrophic Pten knock-out neurons beyond their altered action potential threshold. Thus, our work contributes a developmental mechanism for the increased activity of Pten-depleted neurons. PMID:25609613

  3. Knockout of the vascular endothelial glucocorticoid receptor abrogates dexamethasone-induced hypertension

    PubMed Central

    GOODWIN, Julie E.; ZHANG, Junhui; GONZALEZ, David; ALBINSSON, Sebastian; GELLER, David S.

    2012-01-01

    Glucocorticoid-mediated hypertension is incompletely understood. Recent studies have suggested the primary mechanism of this form of hypertension may be through the effects of glucocorticoids on vascular tissues and not to excess sodium and water reabsorption as traditionally believed. Objective The goal of this study was to better understand the role of the vasculature in the generation and maintenance of glucocorticoid-mediated hypertension. Methods We created a mouse model with a tissue-specific knockout of the glucocorticoid receptor in the vascular endothelium. Results We show that these mice are relatively resistant to dexamethasone-induced hypertension. After one week of dexamethasone treatment, control animals have a mean blood pressure increase of 13.1 mm Hg while knockout animals have only a 2.7 mm Hg increase (p<0.001). Interestingly, the knockout mice have slightly elevated baseline BP compared to the controls (112.2 ± 2.5 mm Hg vs. 104.6 ± 1.2 mm Hg, p = 0.04), a finding which is not entirely explained by our data. Furthermore, we demonstrate that the knockout resistance arterioles have a decreased contractile response to dexamethasone with only 6.6% contraction in knockout vessels compared to 13.4% contraction in control vessels (p=0.034). Finally, we show that in contrast to control animals, the knockout animals are able to recover a significant portion of their normal circadian blood pressure rhythm suggesting that the vascular endothelial glucocorticoid receptor may function as a peripheral circadian clock. Conclusions Our study highlights the importance of the vascular endothelial GR in several fundamental physiologic processes, namely blood pressure homeostasis and circadian rhythm. PMID:21659825

  4. Altered Sleep and Affect in the Neurotensin Receptor 1 Knockout Mouse

    PubMed Central

    Fitzpatrick, Karrie; Winrow, Christopher J.; Gotter, Anthony L.; Millstein, Joshua; Arbuzova, Janna; Brunner, Joseph; Kasarskis, Andrew; Vitaterna, Martha H.; Renger, John J.; Turek, Fred W.

    2012-01-01

    Study Objective: Sleep and mood disorders have long been understood to have strong genetic components, and there is considerable comorbidity of sleep abnormalities and mood disorders, suggesting the involvement of common genetic pathways. Here, we examine a candidate gene implicated in the regulation of both sleep and affective behavior using a knockout mouse model. Design: Previously, we identified a quantitative trait locus (QTL) for REM sleep amount, REM sleep bout number, and wake amount in a genetically segregating population of mice. Here, we show that traits mapping to this QTL correlated with an expression QTL for neurotensin receptor 1 (Ntsr1), a receptor for neurotensin, a ligand known to be involved in several psychiatric disorders. We examined sleep as well as behaviors indicative of anxiety and depression in the NTSR1 knockout mouse. Measurements and Results: NTSR1 knockouts had a lower percentage of sleep time spent in REM sleep in the dark phase and a larger diurnal variation in REM sleep duration than wild types under baseline conditions. Following sleep deprivation, NTSR1 knockouts exhibited more wake and less NREM rebound sleep. NTSR1 knockouts also showed increased anxious and despair behaviors. Conclusions: Here we illustrate a link between expression of the Ntsr1 gene and sleep traits previously associated with a particular QTL. We also demonstrate a relationship between Ntsr1 and anxiety and despair behaviors. Given the considerable evidence that anxiety and depression are closely linked with abnormalities in sleep, the data presented here provide further evidence that neurotensin and Ntsr1 may be a component of a pathway involved in both sleep and mood disorders. Citation: Fitzpatrick K; Winrow CJ; Gotter AL; Millstein J; Arbuzova J; Brunner J; Kasarskis A; Vitaterna MH; Renger JJ; Turek FW. Altered sleep and affect in the neurotensin receptor 1 knockout mouse. SLEEP 2012;35(7):949-956. PMID:22754041

  5. Effects of HAb18G/CD147 knockout on hepatocellular carcinoma cells in vitro using a novel zinc-finger nuclease-targeted gene knockout approach.

    PubMed

    Li, Hong-Wei; Yang, Xiang-Min; Tang, Juan; Wang, Shi-Jie; Chen, Zhi-Nan; Jiang, Jian-Li

    2015-03-01

    HAb18G/CD147 belongs to the immunoglobulin superfamily and predominantly functions as an inducer of matrix metalloproteinase secretion for tumor invasion and metastasis. This study was designed to investigate the effects of HAb18G/CD147 knockout on hepatocellular carcinoma cells using zinc-finger nuclease (ZFNs)-targeted gene knockout approach. The HCC cell line SMMC-7721 was used for ZFNs-targeted cleavage of the HAb18G/CD147 gene. RT-PCR and Western blot assays were used to detect HAb18G/CD147 expression. HAb18G phenotypic changes following HAb18G/CD147 knockout in SMMC-K7721 cells were assessed using tumor cell adhesion, invasion, migration and colony formation and flow cytometric assays. These data demonstrated that tumor cell adhesion, invasion, migration, and colony formation capabilities of SMMC-K7721 were significantly reduced compared to parental cells or SMMC-7721 with re-expression of HAb18G/CD147 protein transfected with HAb18G/CD147 cDNA. Moreover, knockout of HAb18G/CD147 expression also induced SMMC-K7721 cells to undergo apoptosis compared to SMMC-7721 and SMMC-R7721 (P < 0.01). Molecularly, protein expression of p53 was induced in these cells, but re-expression of HAb18G/CD147 reduced p53 levels in SMMC-R7721 cells, possibly through inhibition of the PI3K-Akt-MDM2 signaling pathway. The findings provide a novel insight into the mechanisms underlying HAb18G/CD147-induced progression of HCC cells.

  6. Cardiac rehabilitation after myocardial infarction.

    PubMed

    Contractor, Aashish S

    2011-12-01

    Cardiac rehabilitation/secondary prevention programs are recognized as integral to the comprehensive care of patients with coronary heart disease (CHD), and as such are recommended as useful and effective (Class I) by the American Heart Association and the American College of Cardiology in the treatment of patients with CHD. The term cardiac rehabilitation refers to coordinated, multifaceted interventions designed to optimize a cardiac patient's physical, psychological, and social functioning, in addition to stabilizing, slowing, or even reversing the progression of the underlying atherosclerotic processes, thereby reducing morbidity and mortality. Cardiac rehabilitation, aims at returning the patient back to normal functioning in a safe and effective manner and to enhance the psychosocial and vocational state of the patient. The program involves education, exercise, risk factor modification and counselling. A meta-analysis based on a review of 48 randomized trials that compared outcomes of exercise-based rehabilitation with usual medical care, showed a reduction of 20% in total mortality and 26% in cardiac mortality rates, with exercise-based rehabilitation compared with usual medical care. Risk stratification helps identify patients who are at increased risk for exercise-related cardiovascular events and who may require more intensive cardiac monitoring in addition to the medical supervision provided for all cardiac rehabilitation program participants. During exercise, the patients' ECG is continuously monitored through telemetry, which serves to optimize the exercise prescription and enhance safety. The safety of cardiac rehabilitation exercise programs is well established, and the occurrence of major cardiovascular events during supervised exercise is extremely low. As hospital stays decrease, cardiac rehabilitation is assuming an increasingly important role in secondary prevention. In contrast with its growing importance internationally, there are very few

  7. Invariant Mass Spectroscopy of 17C via One-Neutron Knockout Reaction of 18C

    NASA Astrophysics Data System (ADS)

    Kim, Sunji; Hwang, Jongwon; Satou, Yoshiteru; Orr, Nigel A.; Nakamura, Takashi; Kondo, Yosuke; Gibelin, Julien; Achouri, N. Lynda; Aumann, Thomas; Baba, Hidetada; Delaunay, Franck; Doornenbal, Pieter; Fukuda, Naoki; Inabe, Naohito; Isobe, Tadaaki; Kameda, Daisuke; Kanno, Daiki; Kobayashi, Nobuyuki; Kobayashi, Toshio; Kubo, Toshiyuki; Leblond, Sylvain; Lee, Jenny; Marqués, F. Miguel; Minakata, Ryogo; Motobayashi, Tohru; Murai, Daichi; Murakami, Tetsuya; Muto, Kotomi; Nakashima, Tomohiro; Nakatsuka, Noritsugu; Navin, Alahari; Nishi, Seijiro; Ogoshi, Shun; Otsu, Hideaki; Sato, Hiromi; Shimizu, Yohei; Suzuki, Hiroshi; Takahashi, Kento; Takeda, Hiroyuki; Takeuchi, Satoshi; Tanaka, Ryuki; Togano, Yasuhiro; Tuff, Adam G.; Vandebrouck, Marine; Yoneda, Ken-ichiro

    Unbound states in 17C were investigated via one-neutron knockout of 18C. The experiment was performed using SAMURAI spectrometer in RIBF at RIKEN. By invariant mass spectroscopy, three resonances were measured at excitation energies of 3.03(12), 2.74(3), and 4.03(6) MeV as preliminary results. For the excited state at 2.74(3) MeV, the parallel momentum distribution was satisfactorily described by the distribution calculated for p-wave knockout from 18C.

  8. Construction and Analysis of a MutL Knockout Strain of Vibrio cholerae

    DTIC Science & Technology

    2007-10-01

    8217 ................. 4-𔃼 4 aw / mAw X ± bapBNM XIN& i p od6K pCVD444I mobRPRP Figure 1. Construction and Cloning of AmutL, an Allele of mutL from V. cholerae...2,036bp 1,198bp-- - 1636bp Ladder . <- 1,0 18bp 3.4 Construction of Knockout V. cholerae Strain. Homologous recombination was set up with E. coil SM17,pir...EDGEWOOD CHEMICAL BIOLOGICAL CENTER U.S. ARMY RESEARCH, DEVELOPMENT AND ENGINEERING COMMAND ECBC-TR-563 CONSTRUCTION AND ANALYSIS OF A MUTL KNOCKOUT

  9. Differential cytokine expression in skin graft healing in inducible nitric oxide synthase knockout mice.

    PubMed

    Most, D; Efron, D T; Shi, H P; Tantry, U S; Barbul, A

    2001-10-01

    Inducible nitric oxide synthase (iNOS) and its product, nitric oxide, have been shown to play important roles in wound biology. The present study was performed to investigate the role of iNOS in modulating the cytokine cascade during the complex process of skin graft wound healing.Fifteen iNOS-knockout mice and 15 wild-type C57BL/6J mice were subjected to autogenous 1-cm2 intrascapular full-thickness skin grafts. Three animals in each group were killed on postoperative days 3, 5, 7, 10, and 14. Specimens were then analyzed using nonisotopic in situ hybridization versus mRNA of tumor growth factor-beta1, vascular endothelial growth factor, iNOS, endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha, and basic fibroblast growth factor, as well as positive and negative control probes. Positive cells in both grafts and wound beds were counted using a Leica microgrid. Scar thickness was measured with a Leica micrometer. Data were analyzed using the unpaired Student's t test. Expression of iNOS was 2- to 4-fold higher in knockout mice than in wild-type mice on postoperative days 5, 7, and 14. Expression of eNOS was 2- to 2.5-fold higher in knockout mice than in wild-type mice on postoperative days 5 and 7. Tumor necrosis factor-alpha expression was 2- to 7-fold higher in knockout mice than in wild-type mice on all postoperative days. In contrast, expression levels of angiogenic/fibrogenic cytokines (vascular endothelial growth factor, basis fibroblast growth factor, and tumor growth factor-beta1) were 2.5- to 4-fold higher in wild-type mice than in knockout mice. Scars were 1.5- to 2.5-fold thicker in knockout mice than in wild-type mice at all time points. All of the above results represent statistically significant differences (p < 0.05). Significantly different patterns of cytokine expression were seen in knockout and wild-type mice. Although the scar layer was thicker in knockout mice, it showed much greater infiltration with inflammatory cells. These

  10. Adaptive bi-level programming for optimal gene knockouts for targeted overproduction under phenotypic constraints

    PubMed Central

    2013-01-01

    Background Optimization procedures to identify gene knockouts for targeted biochemical overproduction have been widely in use in modern metabolic engineering. Flux balance analysis (FBA) framework has provided conceptual simplifications for genome-scale dynamic analysis at steady states. Based on FBA, many current optimization methods for targeted bio-productions have been developed under the maximum cell growth assumption. The optimization problem to derive gene knockout strategies recently has been formulated as a bi-level programming problem in OptKnock for maximum targeted bio-productions with maximum growth rates. However, it has been shown that knockout mutants in fact reach the steady states with the minimization of metabolic adjustment (MOMA) from the corresponding wild-type strains instead of having maximal growth rates after genetic or metabolic intervention. In this work, we propose a new bi-level computational framework--MOMAKnock--which can derive robust knockout strategies under the MOMA flux distribution approximation. Methods In this new bi-level optimization framework, we aim to maximize the production of targeted chemicals by identifying candidate knockout genes or reactions under phenotypic constraints approximated by the MOMA assumption. Hence, the targeted chemical production is the primary objective of MOMAKnock while the MOMA assumption is formulated as the inner problem of constraining the knockout metabolic flux to be as close as possible to the steady-state phenotypes of wide-type strains. As this new inner problem becomes a quadratic programming problem, a novel adaptive piecewise linearization algorithm is developed in this paper to obtain the exact optimal solution to this new bi-level integer quadratic programming problem for MOMAKnock. Results Our new MOMAKnock model and the adaptive piecewise linearization solution algorithm are tested with a small E. coli core metabolic network and a large-scale iAF1260 E. coli metabolic network

  11. [Non-cardiac surgery in patients with cardiac disease].

    PubMed

    Sellevold, Olav F Münter; Stenseth, Roar

    2010-03-25

    Patients with cardiac disease have a higher incidence of cardiovascular events after non-cardiac surgery than those without such disease. This paper provides an overview of perioperative examinations and treatment. Own experience and systematic literature search through work with European guidelines constitute the basis for recommendations given in this article. Beta-blockers should not be discontinued before surgery. High-risk patients may benefit from beta-blockers administered before major non-cardiac surgery. Slow dose titration is recommended. Echocardiography should be performed before preoperative beta-blockade to exclude latent heart failure. Statins should be considered before elective surgery and coronary intervention (stenting or surgery) before high-risk surgery. Otherwise, interventions should be evaluated irrespective of planned non-cardiac surgery. Patients with unstable coronary syndrome should only undergo non-cardiac surgery on vital indications. Neuraxial techniques are optimal for postoperative pain relief and thus for postoperative mobilization. Thromboprophylaxis is important, but increases the risk of epidural haematoma and requires systematic follow-up with respect to diagnostics and treatment. Little evidence supports the use of different anaesthetic methods in cardiac patients that undergo non-cardiac surgery than in other patients. Stable circulation, sufficient oxygenation, good pain relief, thromboprophylaxis, enteral nutrition and early mobilization are important factors for improving the perioperative course. Close cooperation between anaesthesiologist, surgeon and cardiologist improves logistics and treatment.

  12. The Scaffold Protein Muscle A-Kinase Anchoring Protein β Orchestrates Cardiac Myocyte Hypertrophic Signaling Required for the Development of Heart Failure

    PubMed Central

    Kritzer, Michael D.; Li, Jinliang; Passariello, Catherine L.; Gayanilo, Marjorie; Thakur, Hrishikesh; Dayan, Joseph; Dodge-Kafka, Kimberly; Kapiloff, Michael S.

    2014-01-01

    Background Cardiac myocyte hypertrophy is regulated by an extensive intracellular signal transduction network. In vitro evidence suggests that the scaffold protein muscle A-kinase anchoring protein β (mAKAPβ) serves as a nodal organizer of hypertrophic signaling. However, the relevance of mAKAPβ signalosomes to pathological remodeling and heart failure in vivo remains unknown. Methods and Results Using conditional, cardiac myocyte–specific gene deletion, we now demonstrate that mAKAPβ expression in mice is important for the cardiac hypertrophy induced by pressure overload and catecholamine toxicity. mAKAPβ targeting prevented the development of heart failure associated with long-term transverse aortic constriction, conferring a survival benefit. In contrast to 29% of control mice (n=24), only 6% of mAKAPβ knockout mice (n=31) died in the 16 weeks of pressure overload (P=0.02). Accordingly, mAKAPβ knockout inhibited myocardial apoptosis and the development of interstitial fibrosis, left atrial hypertrophy, and pulmonary edema. This improvement in cardiac status correlated with the attenuated activation of signaling pathways coordinated by the mAKAPβ scaffold, including the decreased phosphorylation of protein kinase D1 and histone deacetylase 4 that we reveal to participate in a new mAKAP signaling module. Furthermore, mAKAPβ knockout inhibited pathological gene expression directed by myocyte-enhancer factor-2 and nuclear factor of activated T-cell transcription factors that associate with the scaffold. Conclusions mAKAPβ orchestrates signaling that regulates pathological cardiac remodeling in mice. Targeting of the underlying physical architecture of signaling networks, including mAKAPβ signalosome formation, may constitute an effective therapeutic strategy for the prevention and treatment of pathological remodeling and heart failure. PMID:24812305

  13. Transient receptor potential vanilloid 2 function regulates cardiac hypertrophy via stretch-induced activation.

    PubMed

    Koch, Sheryl E; Mann, Adrien; Jones, Shannon; Robbins, Nathan; Alkhattabi, Abdullah; Worley, Mariah C; Gao, Xu; Lasko-Roiniotis, Valerie M; Karani, Rajiv; Fulford, Logan; Jiang, Min; Nieman, Michelle; Lorenz, John N; Rubinstein, Jack

    2017-03-01

    Hypertension (increased afterload) results in cardiomyocyte hypertrophy leading to left ventricular hypertrophy and subsequently, heart failure with preserved ejection fraction. This study was performed to test the hypothesis that transient receptor potential vanilloid 2 subtype (TRPV2) function regulates hypertrophy under increased afterload conditions. We used functional (pore specific) TRPV2 knockout mice to evaluate the effects of increased afterload-induced stretch on cardiac size and function via transverse aortic constriction (TAC) as well as hypertrophic stimuli including adrenergic and angiotensin stimulation via subcutaneous pumps. Wild-type animals served as control for all experiments. Expression and localization of TRPV2 was investigated in wild-type cardiac samples. Changes in cardiac function were measured in vivo via echocardiography and invasive catheterization. Molecular changes, including protein and real-time PCR markers of hypertrophy, were measured in addition to myocyte size. TRPV2 is significantly upregulated in wild-type mice after TAC, though not in response to beta-adrenergic or angiotensin stimulation. TAC-induced stretch stimulus caused an upregulation of TRPV2 in the sarcolemmal membrane. The absence of functional TRPV2 resulted in significantly reduced left ventricular hypertrophy after TAC, though not in response to beta-adrenergic or angiotensin stimulation. The decreased development of hypertrophy was not associated with significant deterioration of cardiac function. We conclude that TRPV2 function, as a stretch-activated channel, regulates the development of cardiomyocyte hypertrophy in response to increased afterload.

  14. Abnormal cardiac conduction and morphogenesis in connexin40 and connexin43 double-deficient mice.

    PubMed

    Kirchhoff, S; Kim, J S; Hagendorff, A; Thönnissen, E; Krüger, O; Lamers, W H; Willecke, K

    2000-09-01

    Connexin40-deficient (Cx40(-/-)/Cx43(+/+)) and connexin43-heterozygous knockout mice (Cx40(+/+)/Cx43(+/-)) are viable but show cardiac conduction abnormalities. The ECGs of adult double heterozygous animals (Cx40(+/-)/Cx43(+/-)) suggest additive effects of Cx40 and Cx43 haploinsufficiency on ventricular, but not on atrial, conduction. We also observed additive effects of both connexins on cardiac morphogenesis. Approximately half of the Cx40(-/-)/Cx43(+/+) embryos died during the septation period, and an additional 16% died after birth. The majority of the latter mice had cardiac hypertrophy in conjunction with common atrioventricular junction or a ventricular septal defect. All Cx40(-/-)/Cx43(+/-) progeny exhibited cardiac malformations and died neonatally. The most frequent defect was common atrioventricular junction with abnormal atrioventricular connection, which was more severe than that seen in Cx40(-/-)/Cx43(+/+) mice. Furthermore, muscular ventricular septal defects, premature closure of the ductus arteriosus, and subcutaneous edema were noticed in these embryos. Cx40(+/-)/Cx43(-/-) embryos showed the same phenotype (ie, obstructed right ventricular outflow tract) as reported for Cx40(+/+)/Cx43(-/-) mice. These findings demonstrate that Cx43 haploinsufficiency aggravates the abnormalities observed in the Cx40(-/-) phenotype, whereas Cx40 haploinsufficiency does not worsen the Cx43(-/-) phenotype. We conclude that the gap-junctional proteins Cx40 and Cx43 contribute to morphogenesis of the heart in an isotype-specific manner.

  15. Snf1-related kinase improves cardiac mitochondrial efficiency and decreases mitochondrial uncoupling

    PubMed Central

    Rines, Amy K.; Chang, Hsiang-Chun; Wu, Rongxue; Sato, Tatsuya; Khechaduri, Arineh; Kouzu, Hidemichi; Shapiro, Jason; Shang, Meng; Burke, Michael A.; Jiang, Xinghang; Chen, Chunlei; Rawlings, Tenley A.; Lopaschuk, Gary D.; Schumacker, Paul T.; Abel, E. Dale; Ardehali, Hossein

    2017-01-01

    Ischaemic heart disease limits oxygen and metabolic substrate availability to the heart, resulting in tissue death. Here, we demonstrate that the AMP-activated protein kinase (AMPK)-related protein Snf1-related kinase (SNRK) decreases cardiac metabolic substrate usage and mitochondrial uncoupling, and protects against ischaemia/reperfusion. Hearts from transgenic mice overexpressing SNRK have decreased glucose and palmitate metabolism and oxygen consumption, but maintained power and function. They also exhibit decreased uncoupling protein 3 (UCP3) and mitochondrial uncoupling. Conversely, Snrk knockout mouse hearts have increased glucose and palmitate oxidation and UCP3. SNRK knockdown in cardiac cells decreases mitochondrial efficiency, which is abolished with UCP3 knockdown. We show that Tribbles homologue 3 (Trib3) binds to SNRK, and downregulates UCP3 through PPARα. Finally, SNRK is increased in cardiomyopathy patients, and SNRK reduces infarct size after ischaemia/reperfusion. SNRK also decreases cardiac cell death in a UCP3-dependent manner. Our results suggest that SNRK improves cardiac mitochondrial efficiency and ischaemic protection. PMID:28117339

  16. Cardiac-specific VLCAD deficiency induces dilated cardiomyopathy and cold intolerance

    PubMed Central

    Xiong, Dingding; He, Huamei; James, Jeanne; Tokunaga, Chonan; Powers, Corey; Huang, Yan; Osinska, Hanna; Towbin, Jeffrey A.; Purevjav, Enkhsaikhan; Balschi, James A.; Javadov, Sabzali; McGowan, Francis X.; Strauss, Arnold W.

    2013-01-01

    The very long-chain acyl-CoA dehydrogenase (VLCAD) enzyme catalyzes the first step of mitochondrial β-oxidation. Patients with VLCAD deficiency present with hypoketotic hypoglycemia and cardiomyopathy, which can be exacerbated by fasting and/or cold stress. Global VLCAD knockout mice recapitulate these phenotypes: mice develop cardiomyopathy, and cold exposure leads to rapid hypothermia and death. However, the contribution of different tissues to development of these phenotypes has not been studied. We generated cardiac-specific VLCAD-deficient (cVLCAD−/−) mice by Cre-mediated ablation of the VLCAD in cardiomyocytes. By 6 mo of age, cVLCAD−/− mice demonstrated increased end-diastolic and end-systolic left ventricular dimensions and decreased fractional shortening. Surprisingly, selective VLCAD gene ablation in cardiomyocytes was sufficient to evoke severe cold intolerance in mice who rapidly developed severe hypothermia, bradycardia, and markedly depressed cardiac function in response to fasting and cold exposure (+5°C). We conclude that cardiac-specific VLCAD deficiency is sufficient to induce cold intolerance and cardiomyopathy and is associated with reduced ATP production. These results provide strong evidence that fatty acid oxidation in myocardium is essential for maintaining normal cardiac function under these stress conditions. PMID:24285112

  17. Deletion of peroxisome proliferator-activated receptor-alpha induces an alteration of cardiac functions.

    PubMed

    Loichot, Cécile; Jesel, Laurence; Tesse, Angela; Tabernero, Antonia; Schoonjans, Kristina; Roul, Gérard; Carpusca, Irina; Auwerx, Johan; Andriantsitohaina, Ramaroson

    2006-07-01

    The peroxisome proliferator-activated receptor-alpha (PPARalpha) plays a major role in the control of cardiac energy metabolism. The role of PPARalpha on cardiac functions was evaluated by using PPARalpha knockout (PPARalpha -/-) mice. Hemodynamic parameters by sphygmomanometric measurements show that deletion of PPARalpha did not affect systolic blood pressure and heart rate. Echocardiographic measurements demonstrated reduced systolic performance as shown by the decrease of left ventricular fractional shortening in PPARalpha -/- mice. Telemetric electrocardiography revealed neither atrio- nor intraventricular conduction defects in PPARalpha -/- mice. Also, heart rate, P-wave duration and amplitude, and QT interval were not affected. However, the amplitude of T wave from PPARalpha -/- mice was lower compared with wild-type (PPARalpha +/+) mice. When the myocardial function was measured by ex vivo Langendorff's heart preparation, basal and beta-adrenergic agonist-induced developed forces were significantly reduced in PPARalpha-null mice. In addition, Western blot analysis shows that the protein expression of beta1-adrenergic receptor is reduced in hearts from PPARalpha -/- mice. Histological analysis showed that hearts from PPARalpha -/- but not PPARalpha +/+ mice displayed myocardial fibrosis. These results suggest that PPARalpha-null mice have an alteration of cardiac contractile performance under basal and under stimulation of beta1-adrenergic receptors. These effects are associated with myocardial fibrosis. The data shed light on the role of PPARalpha in maintaining cardiac functions.

  18. Physics of Cardiac Arrhythmogenesis

    NASA Astrophysics Data System (ADS)

    Karma, Alain

    2013-04-01

    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  19. [Thrombolysis in cardiac arrest].

    PubMed

    Ruiz Bailén, M; Rucabado Aguilar, L; Morante Valle, A; Castillo Rivera, A

    2006-03-01

    Both acute myocardial infarction and pulmonary thromboembolism are responsible for a great number of cardiac arrests. Both present high rates of mortality. Thrombolysis has proved to be an effective treatment for acute myocardial infarction and pulmonary thromboembolism with shock. It would be worth considering whether thrombolysis could be effective and safe during or after cardiopulmonary resuscitation (CPR). Unfortunately, too few clinical studies presenting sufficient scientific data exist in order to respond adequately to this question. However, most studies they show that thrombolysis applied during and after CPR is a therapeutic option that is not associated with greater risk of serious hemorrhaging and could possibly have beneficial effects. On the other hand, experimental data exists which show that thrombolytics can attenuate neurological damage produced after CPR. Nevertheless, clinical trials would be necessary in order to adequately establish the effectiveness and safety of thrombolysis in patients who require CPR.

  20. Cardiac arrest and pregnancy

    PubMed Central

    Campbell, Tabitha A; Sanson, Tracy G

    2009-01-01

    Cardiopulmonary arrest in pregnancy is rare occurring in 1 in 30,000 pregnancies. When it does occur, it is important for a clinician to be familiar with the features peculiar to the pregnant state. Knowledge of the anatomic and physiologic changes of pregnancy is helpful in the treatment and diagnosis. Although the main focus should be on the mother, it should not be forgotten that there is another potential life at stake. Resuscitation of the mother is performed in the same manner as in any other patient, except for a few minor adjustments because of the changes of pregnancy. The specialties of obstetrics and neonatology should be involved early in the process to ensure appropriate treatment of both mother and the newborn. This article will explore the changes that occur in pregnancy and their impact on treatment. The common causes of maternal cardiac arrest will be discussed briefly. PMID:19561954

  1. Cardiac Rehabilitation Series: Canada

    PubMed Central

    Grace, Sherry L.; Bennett, Stephanie; Ardern, Chris I.; Clark, Alexander

    2015-01-01

    Cardiovascular disease is among the leading causes of mortality and morbidity in Canada. Cardiac rehabilitation (CR) has a long robust history here, and there are established clinical practice guidelines. While the effectiveness of CR in the Canadian context is clear, only 34% of eligible patients participate, and strategies to increase access for under-represented groups (e.g., women, ethnic minority groups) are not yet universally applied. Identified CR barriers include lack of referral and physician recommendation, travel and distance, and low perceived need. Indeed there is now a national policy position recommending systematic inpatient referral to CR in Canada. Recent development of 30 CR Quality Indicators and the burgeoning national CR registry will enable further measurement and improvement of the quality of CR care in Canada. Finally, the Canadian Association of CR is one of the founding members of the International Council of Cardiovascular Prevention and Rehabilitation, to promote CR globally. PMID:24607018

  2. Cardiac action potential imaging

    NASA Astrophysics Data System (ADS)

    Tian, Qinghai; Lipp, Peter; Kaestner, Lars

    2013-06-01

    Action potentials in cardiac myocytes have durations in the order of magnitude of 100 milliseconds. In biomedical investigations the documentation of the occurrence of action potentials is often not sufficient, but a recording of the shape of an action potential allows a functional estimation of several molecular players. Therefore a temporal resolution of around 500 images per second is compulsory. In the past such measurements have been performed with photometric approaches limiting the measurement to one cell at a time. In contrast, imaging allows reading out several cells at a time with additional spatial information. Recent developments in camera technologies allow the acquisition with the required speed and sensitivity. We performed action potential imaging on isolated adult cardiomyocytes of guinea pigs utilizing the fluorescent membrane potential sensor di-8-ANEPPS and latest electron-multiplication CCD as well as scientific CMOS cameras of several manufacturers. Furthermore, we characterized the signal to noise ratio of action potential signals of varying sets of cameras, dye concentrations and objective lenses. We ensured that di-8-ANEPPS itself did not alter action potentials by avoiding concentrations above 5 μM. Based on these results we can conclude that imaging is a reliable method to read out action potentials. Compared to conventional current-clamp experiments, this optical approach allows a much higher throughput and due to its contact free concept leaving the cell to a much higher degree undisturbed. Action potential imaging based on isolated adult cardiomyocytes can be utilized in pharmacological cardiac safety screens bearing numerous advantages over approaches based on heterologous expression of hERG channels in cell lines.

  3. Trends in Cardiac Pacemaker Batteries