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Sample records for mybp-c knockout cardiac

  1. Cathepsin K knockout alleviates aging-induced cardiac dysfunction.

    PubMed

    Hua, Yinan; Robinson, Timothy J; Cao, Yongtao; Shi, Guo-Ping; Ren, Jun; Nair, Sreejayan

    2015-06-01

    Aging is a major risk factor for cardiovascular disease. It has previously been shown that protein levels of cathepsin K, a lysosomal cysteine protease, are elevated in the failing heart and that genetic ablation of cathepsin K protects against pressure overload-induced cardiac hypertrophy and contractile dysfunction. Here we test the hypothesis that cathepsin K knockout alleviates age-dependent decline in cardiac function. Cardiac geometry, contractile function, intracellular Ca(2+) properties, and cardiomyocyte apoptosis were evaluated using echocardiography, fura-2 technique, immunohistochemistry, Western blot and TUNEL staining, respectively. Aged (24-month-old) mice exhibited significant cardiac remodeling (enlarged chamber size, wall thickness, myocyte cross-sectional area, and fibrosis), decreased cardiac contractility, prolonged relengthening along with compromised intracellular Ca(2+) release compared to young (6-month-old) mice, which were attenuated in the cathepsin K knockout mice. Cellular markers of senescence, including cardiac lipofuscin, p21 and p16, were lower in the aged-cathepsin K knockout mice compared to their wild-type counterpart. Mechanistically, cathepsin K knockout mice attenuated an age-induced increase in cardiomyocyte apoptosis and nuclear translocation of mitochondrial apoptosis-inducing factor (AIF). In cultured H9c2 cells, doxorubicin stimulated premature senescence and apoptosis. Silencing of cathepsin K blocked the doxorubicin-induced translocation of AIF from the mitochondria to the nuclei. Collectively, these results suggest that cathepsin K knockout attenuates age-related decline in cardiac function via suppressing caspase-dependent and caspase-independent apoptosis. PMID:25692548

  2. Cathepsin K knockout alleviates aging-induced cardiac dysfunction

    PubMed Central

    Hua, Yinan; Robinson, Timothy J; Cao, Yongtao; Shi, Guo-Ping; Ren, Jun; Nair, Sreejayan

    2015-01-01

    Aging is a major risk factor for cardiovascular disease. It has previously been shown that protein levels of cathepsin K, a lysosomal cysteine protease, are elevated in the failing heart and that genetic ablation of cathepsin K protects against pressure overload-induced cardiac hypertrophy and contractile dysfunction. Here we test the hypothesis that cathepsin K knockout alleviates age-dependent decline in cardiac function. Cardiac geometry, contractile function, intracellular Ca2+ properties, and cardiomyocyte apoptosis were evaluated using echocardiography, fura-2 technique, immunohistochemistry, Western blot and TUNEL staining, respectively. Aged (24-month-old) mice exhibited significant cardiac remodeling (enlarged chamber size, wall thickness, myocyte cross-sectional area, and fibrosis), decreased cardiac contractility, prolonged relengthening along with compromised intracellular Ca2+ release compared to young (6-month-old) mice, which were attenuated in the cathepsin K knockout mice. Cellular markers of senescence, including cardiac lipofuscin, p21 and p16, were lower in the aged-cathepsin K knockout mice compared to their wild-type counterpart. Mechanistically, cathepsin K knockout mice attenuated an age-induced increase in cardiomyocyte apoptosis and nuclear translocation of mitochondrial apoptosis-inducing factor (AIF). In cultured H9c2 cells, doxorubicin stimulated premature senescence and apoptosis. Silencing of cathepsin K blocked the doxorubicin-induced translocation of AIF from the mitochondria to the nuclei. Collectively, these results suggest that cathepsin K knockout attenuates age-related decline in cardiac function via suppressing caspase-dependent and caspase-independent apoptosis. PMID:25692548

  3. Cathepsin K knockout alleviates aging-induced cardiac dysfunction.

    PubMed

    Hua, Yinan; Robinson, Timothy J; Cao, Yongtao; Shi, Guo-Ping; Ren, Jun; Nair, Sreejayan

    2015-06-01

    Aging is a major risk factor for cardiovascular disease. It has previously been shown that protein levels of cathepsin K, a lysosomal cysteine protease, are elevated in the failing heart and that genetic ablation of cathepsin K protects against pressure overload-induced cardiac hypertrophy and contractile dysfunction. Here we test the hypothesis that cathepsin K knockout alleviates age-dependent decline in cardiac function. Cardiac geometry, contractile function, intracellular Ca(2+) properties, and cardiomyocyte apoptosis were evaluated using echocardiography, fura-2 technique, immunohistochemistry, Western blot and TUNEL staining, respectively. Aged (24-month-old) mice exhibited significant cardiac remodeling (enlarged chamber size, wall thickness, myocyte cross-sectional area, and fibrosis), decreased cardiac contractility, prolonged relengthening along with compromised intracellular Ca(2+) release compared to young (6-month-old) mice, which were attenuated in the cathepsin K knockout mice. Cellular markers of senescence, including cardiac lipofuscin, p21 and p16, were lower in the aged-cathepsin K knockout mice compared to their wild-type counterpart. Mechanistically, cathepsin K knockout mice attenuated an age-induced increase in cardiomyocyte apoptosis and nuclear translocation of mitochondrial apoptosis-inducing factor (AIF). In cultured H9c2 cells, doxorubicin stimulated premature senescence and apoptosis. Silencing of cathepsin K blocked the doxorubicin-induced translocation of AIF from the mitochondria to the nuclei. Collectively, these results suggest that cathepsin K knockout attenuates age-related decline in cardiac function via suppressing caspase-dependent and caspase-independent apoptosis.

  4. Akt2 Knockout Alleviates Prolonged Caloric Restriction-Induced Change in Cardiac Contractile Function through Regulation of Autophagy

    PubMed Central

    Zhang, Yingmei; Han, Xuefeng; Hu, Nan; Huff, Anna F.; Gao, Feng; Ren, Jun

    2014-01-01

    Caloric restriction leads to changes in heart geometry and function although the underlying mechanism remains elusive. Autophagy, a conserved pathway for degradation of intracellular proteins and organelles, preserves energy and nutrient in the face of caloric insufficiency. This study was designed to examine the role of Akt2 in prolonged caloric restriction-induced change in cardiac homeostasis and the underlying mechanism(s) involved. Wild-type (WT) and Akt2 knockout mice were caloric restricted (by 40%) for 30 weeks. Echocardiographic, cardiomyocyte contractile and intracellular Ca2+ properties, autophagy and its regulatory proteins were evaluated. Caloric restriction compromised echocardiographic indices (decreased left ventricular mass, left ventricular diameters and cardiac output), cardiomyocyte contractile and intracellular Ca2+ properties associated with dampened SERCA2a phosphorylation, upregulated phospholamban and autophagy (Beclin-1, Atg7, LC3BII-to-LC3BI ratio), increased autophagy adaptor protein p62, elevated phosphorylation of AMPK, Akt2 and the Akt downstream signal molecule TSC2, the effects of which with the exception of autophagy protein markers (Beclin-1, Atg7, LC3B) and AMPK were mitigated or significantly alleviated by Akt2 knockout. Lysosomal inhibition using bafilomycin A1 negated Akt2 knockout-induced protective effect on p62. Evaluation of downstream signaling molecules of Akt and AMPK including mTOR and ULK1 revealed that caloric restriction suppressed and promoted phosphorylation of mTOR and ULK1, respectively, without affecting total mTOR and ULK1 expression. Akt2 knockout significantly augmented caloric restriction-induced responses on mTOR and ULK1. Taken together, these data suggest a beneficial role of Akt2 knockout in preservation of cardiac homeostasis against prolonged caloric restriction-induced pathological changes possibly through facilitating autophagy. PMID:24368095

  5. Aldehyde Dehydrogenase 2 Knockout Accentuates Ethanol-Induced Cardiac Depression: Role of Protein Phosphatases

    PubMed Central

    Ma, Heng; Byra, Emily A.; Yu, Lu; Hu, Nan; Kitagawa, Kyoko; Nakayama, Keiichi I.; Kawamoto, Toshihiro; Ren, Jun

    2010-01-01

    Alcohol consumption leads to myocardial contractile dysfunction possibly due to the toxicity of ethanol and its major metabolite acetaldehyde. This study was designed to examine the influence of mitochondrial aldehyde dehydrogenase-2 (ALDH2) knockout (KO) on acute ethanol exposure-induced cardiomyocyte dysfunction. Wild-type (WT) and ALDH2 KO mice were subjected to acute ethanol (3 g/kg, i.p.) challenge and cardiomyocyte contractile function was assessed 24 hrs later using an IonOptix® edge-detection system. Western blot analysis was performed to evaluate ALDH2, protein phosphatase 2A (PP2A), phosphorylation of Akt and glycogen synthase kinase-3β (GSK-3β). ALDH2 KO accentuated ethanol-induced elevation in cardiac acetaldehyde levels. Ethanol exposure depressed cardiomyocyte contractile function including decreased cell shortening amplitude and maximal velocity of shortening/relengthening as well as prolonged relengthening duration and a greater decline in peak shortening in response to increasing stimulus frequency, the effect of which was significantly exaggerated by ALDH2 KO. ALDH2 KO also unmasked an ethanol-induced prolongation of shortening duration. In addition, short-term in vitro incubation of ethanol-induced cardiomyocyte mechanical defects were exacerbated by the ALDH inhibitor cyanamide. Ethanol treatment dampened phosphorylation of Akt and GSK-3β associated with up-regulated PP2A, which was accentuated by ALDH2 KO. ALDH2 KO aggravated ethanol-induced decrease in mitochondrial membrane potential. These results suggested that ALDH2 deficiency led to worsened ethanol-induced cardiomyocyte function, possibly due to upregulated expression of protein phosphatase, depressed Akt activation and subsequently impaired mitochondrial function. These findings depict a critical role of ALDH2 in the pathogenesis of alcoholic cardiomyopathy. PMID:20362583

  6. Interleukin 10 knockout frail mice develop cardiac and vascular dysfunction with increased age☆

    PubMed Central

    Sikka, Gautam; Miller, Karen L.; Steppan, Jochen; Pandey, Deepesh; Jung, Sung M.; Fraser, Charles D.; Ellis, Carla; Ross, Daniel; Vandegaer, Koenraad; Bedja, Djahida; Gabrielson, Kathleen; Walston, Jeremy D.; Berkowitz, Dan E.; Barouch, Lili A.

    2013-01-01

    Cardiovascular dysfunction is a primary independent predictor of age-related morbidity and mortality. Frailty is associated with activation of inflammatory pathways and fatigue that commonly presents and progresses with age. Interleukin 10 (IL-10), the cytokine synthesis inhibitory factor, is an anti-inflammatory cytokine produced by immune and non-immune cells. Homozygous deletion of IL-10 in mice yields a phenotype that is consistent with human frailty, including age-related increases in serum inflammatory mediators, muscular weakness, higher levels of IGF-1 at midlife, and early mortality. While emerging evidence suggests a role for IL-10 in vascular protection, a clear mechanism has not yet been elucidated. Methods In order to evaluate the role of IL-10 in maintenance of vascular function, force tension myography was utilized to access ex-vivo endothelium dependent vasorelaxation in vessels isolated from IL-10 knockout IL-10(tm/tm) and control mice. Pulse wave velocity ((PWV), index of stiffness) of vasculature was measured using ultrasound and blood pressure was measured using the tail cuff method. Echocardiography was used to elucidated structure and functional changes in the heart. Results Mean arterial pressures were significantly higher in IL-10(tm/tm) mice as compared to C57BL6/wild type (WT) controls. PWV was increased in IL-10(tm/tm) indicating stiffer vasculature. Endothelial intact aortic rings isolated from IL-10(tm/tm) mice demonstrated impaired vasodilation at low acetylcholine doses and vasoconstriction at higher doses whereas vasorelaxation responses were preserved in rings from WT mice. Cyclo-oxygenase (COX-2)/thromboxane A2 inhibitors improved endothelial dependent vasorelaxation and reversed vasoconstriction. Left ventricular end systolic diameter, left ventricular mass, isovolumic relaxation time, fractional shortening and ejection fraction were all significantly different in the aged IL-10(tm/tm) mice compared to WT mice. Conclusion Aged IL

  7. 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

  8. 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

  9. High-fat feeding in cardiomyocyte-restricted PPARdelta knockout mice leads to cardiac overexpression of lipid metabolic genes but fails to rescue cardiac phenotypes.

    PubMed

    Li, Yuquan; Cheng, Lihong; Qin, Qianhong; Liu, Jian; Lo, Woo-kuen; Brako, Lowrence A; Yang, Qinglin

    2009-10-01

    Peroxisome proliferator-activated receptor delta (PPARdelta) is an essential determinant of basal myocardial fatty acid oxidation (FAO) and bioenergetics. We wished to determine whether increased lipid loading affects the PPARdelta deficient heart in transcriptional regulation of FAO and in the development of cardiac pathology. Cardiomyocyte-restricted PPARdelta knockout (CR-PPARdelta(-/-)) and control (alpha-MyHC-Cre) mice were subjected to 48 h of fasting and to a long-term maintenance on a (28 weeks) high-fat diet (HFD). The expression of key FAO proteins in heart was examined. Serum lipid profiles, cardiac pathology, and changes of various transduction signaling pathways were also examined. Mice subjected to fasting exhibited upregulated transcript expression of FAO genes in the CR-PPARdelta(-/-) hearts. Moreover, long-term HFD in CR-PPARdelta(-/-) mice induced a strikingly greater transcriptional response. After HFD, genes encoding key FAO enzymes were expressed remarkably more in CR-PPARdelta(-/-) hearts than in those of control mice. Despite the marked rise of FAO gene expression, corresponding protein expression remained low in the CR-PPARdelta(-/-) heart, accompanied by abnormalities in sarcomere structures and mitochondria that were similar to those of CR-PPARdelta(-/-) hearts with regular chow feeding. The CR-PPARdelta(-/-) mice displayed increased expression of PPARgamma co-activator-1alpha (PGC-1alpha) and PPARalpha in the heart with deactivated Akt and p42/44 MAPK signaling in response to HFD. We conclude that PPARdelta is an essential determinant of myocardial FAO. Increased lipid intake activates cardiac expression of FAO genes via PPARalpha/PGC-1alpha pathway, albeit it is not sufficient to improve cardiac pathology due to PPARdelta deficiency.

  10. 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

  11. 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. PMID:14734644

  12. 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.

  13. Hydrogen sulfide alleviates cardiac contractile dysfunction in an Akt2-knockout murine model of insulin resistance: role of mitochondrial injury and apoptosis

    PubMed Central

    Hu, Nan; Dong, Maolong

    2014-01-01

    Hydrogen sulfide (H2S) is a toxic gas now being recognized as an endogenous signaling molecule in multiple organ systems, in particular, the cardiovascular system. H2S is known to regulate cardiac function and protect against ischemic injury. However, little information is available regarding the effect of H2S on cardiac function in insulin resistance. This study was designed to examine the impact of H2S supplementation on cardiac function using an Akt2 knockout model of insulin resistance. Wild-type and Akt2 knockout mice were treated with NaHS (50 μM·kg−1·day−1 ip for 10 days) prior to evaluation of echocardiographic, cardiomyocyte contractile, and intracellular Ca2+ properties, apoptosis, and mitochondrial damage. Our results revealed that Akt2 ablation led to overtly enlarged ventricular end-systolic diameter, reduced myocardial and cardiomyocyte contractile function, and disrupted intracellular Ca2+ homeostasis and apoptosis, the effects of which were ameliorated by H2S. Furthermore, Akt2 knockout displayed upregulated apoptotic protein markers (Bax, caspase-3, caspase-9, and caspace-12) and mitochondrial damage (reduced aconitase activity and NAD+, elevated cytochrome-c release from mitochondria) along with reduced phosphorylation of PTEN, Akt, and GSK3β in the absence of changes in pan protein expression, the effects of which were abolished or significantly ameliorated by H2S treatment. In vitro data revealed that H2S-induced beneficial effect against Akt2 ablation was obliterated by mitochondrial uncoupling. Taken together, our findings suggest the H2S may reconcile Akt2 knockout-induced myocardial contractile defect and intracellular Ca2+ mishandling, possibly via attenuation of mitochondrial injury and apoptosis. PMID:24622975

  14. 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.

  15. Rejection of Cardiac Xenografts Transplanted from α 1,3-Galactosyltransferase Gene-Knockout (GalT-KO) Pigs to Baboons

    PubMed Central

    Hisashi, Y.; Yamada, K.; Kuwaki, K.; Tseng, Y.-L; Dor, F. J. M. F.; Houser, S. L; Robson, S. C.; Schuurman, H.-J.; Cooper, D. K. C.; Sachs, D. H.; Colvin, R. B.; Shimizu, A.

    2010-01-01

    The use of α 1,3-galactosyltransferase gene-knockout (GalT-KO) swine donors in discordant xenotransplantation has extended the survival of cardiac xenografts in baboons following transplantation. Eight baboons received heterotopic cardiac xenografts from GalT-KO swine and were treated with a chronic immunosuppressive regimen. The pathologic features of acute humoral xenograft rejection (AHXR), acute cellular xenograft rejection (ACXR) and chronic rejection were assessed in the grafts. No hyperacute rejection developed and one graft survived up to 6 months after transplantation. However, all GalT-KO heart grafts underwent graft failure with AHXR, ACXR and/or chronic rejection. AHXR was characterized by interstitial hemorrhage and multiple thrombi in vessels of various sizes. ACXR was characterized by TUNEL+ graft cell injury with the infiltration of T cells (including CD3 and TIA-1+ cytotoxic T cells), CD4+ cells, CD8+ cells, macrophages and a small number of B and NK cells. Chronic xenograft vasculopathy, a manifestation of chronic rejection, was characterized by arterial intimal thickening with TUNEL+ dead cells, antibody and complement deposition, and/or cytotoxic T-cell infiltration. In conclusion, despite the absence of the Gal epitope, acute and chronic antibody and cell-mediated rejection developed in grafts, maintained by chronic immunosupression, presumably due to de novo responses to non-Gal antigens. PMID:19032222

  16. Nebulette knockout mice have normal cardiac function, but show Z-line widening and up-regulation of cardiac stress markers

    PubMed Central

    Mastrototaro, Giuseppina; Liang, Xingqun; Li, Xiaodong; Carullo, Pierluigi; Piroddi, Nicoletta; Tesi, Chiara; Gu, Yusu; Dalton, Nancy D.; Peterson, Kirk L.; Poggesi, Corrado; Sheikh, Farah; Chen, Ju; Bang, Marie-Louise

    2015-01-01

    Aims Nebulette is a 109 kDa modular protein localized in the sarcomeric Z-line of the heart. In vitro studies have suggested a role of nebulette in stabilizing the thin filament, and missense mutations in the nebulette gene were recently shown to be causative for dilated cardiomyopathy and endocardial fibroelastosis in human and mice. However, the role of nebulette in vivo has remained elusive. To provide insights into the function of nebulette in vivo, we generated and studied nebulette-deficient (nebl−/−) mice. Methods and results Nebl−/− mice were generated by replacement of exon 1 by Cre under the control of the endogenous nebulette promoter, allowing for lineage analysis using the ROSA26 Cre reporter strain. This revealed specific expression of nebulette in the heart, consistent with in situ hybridization results. Nebl−/− mice exhibited normal cardiac function both under basal conditions and in response to transaortic constriction as assessed by echocardiography and haemodynamic analyses. Furthermore, histological, IF, and western blot analysis showed no cardiac abnormalities in nebl−/− mice up to 8 months of age. In contrast, transmission electron microscopy showed Z-line widening starting from 5 months of age, suggesting that nebulette is important for the integrity of the Z-line. Furthermore, up-regulation of cardiac stress responsive genes suggests the presence of chronic cardiac stress in nebl−/− mice. Conclusion Nebulette is dispensable for normal cardiac function, although Z-line widening and up-regulation of cardiac stress markers were found in nebl−/− heart. These results suggest that the nebulette disease causing mutations have dominant gain-of-function effects. PMID:25987543

  17. 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

  18. Cardiac catheterization

    MedlinePlus

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

  19. Knockout beyond the dripline

    SciTech Connect

    Bonaccorso, A.; Charity, R. J.; Kumar, R.; Salvioni, G.

    2015-02-24

    In this contribution, we will describe neutron and proton removal from {sup 9}C and {sup 7}Be which are two particularly interesting nuclei entering the nucleo-synthesis pp-chain [1, 2]. Neutron and proton removal reactions have been used in the past twenty years to probe the single-particle structure of exotic nuclei. The core parallel-momentum distribution can give information on the angular momentum and spin of the nucleon initial state while the total removal cross section is sensitive to the asymptotic part of the initial wave function and also to the reaction mechanism. Because knockout is a peripheral reaction from which the Asymptotic Normalization Constant (ANC) of the single-particle wave function can be extracted, it has been used as an indirect method to obtain the rate of reactions like {sup 8}B(p,γ){sup 9}C or {sup 7}Be(p,γ){sup 8}B. Nucleon removal has recently been applied by the HiRA collaboration [3] to situations in which the remaining “core” is beyond the drip line, such as {sup 8}C and {sup 6}Be, unbound by one or more protons, and whose excitation-energy spectrum can be obtained by the invariant-mass method. By gating on the ground-state peak, “core” parallel-momentum distributions and total knockout cross sections have been obtained similar to previous studies with well-bound “cores”. In addition for each projectile, knock out to final bound states has also been obtained in several cases. We will report on the theoretical description and comparison to this experimental data for a few cases for which advances in the accuracy of the transfer-to-the continuum model [4, 5] have been made [6]. These include the use, when available, of “ab-initio” overlaps for the initial state [7] and in particular their ANC values [8]. Also, the construction of a nucleus-target folding potential for the treatment of the core-target S-matrix [9] using for the cores “ab-initio” densities [10] and state-of-the-art n−{sup 9}Be optical

  20. Cardiac Rehabilitation

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Cardiac Rehabilitation? Cardiac rehabilitation (rehab) is a medically supervised program ... be designed to meet your needs. The Cardiac Rehabilitation Team Cardiac rehab involves a long-term commitment ...

  1. 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.

  2. Cardiac rehabilitation

    MedlinePlus

    ... Coronary artery disease - cardiac rehab; Angina - cardiac rehab; Heart failure - cardiac rehab ... have had: Heart attack Coronary heart disease (CHD) Heart failure Angina (chest pain) Heart or heart valve surgery ...

  3. 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.

  4. 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

  5. Knockout of the neural and heart expressed gene HF-1b results in apical deficits of ventricular structure and activation

    PubMed Central

    Hewett, Kenneth W.; Norman, Lisa W.; Sedmera, David; Barker, Ralph J.; Justus, Charles; Zhang, Jing; Kubalak, Steven W.; Gourdie, Robert G.

    2011-01-01

    Objective Knockout of the neural and cardiac expressed transcription factor HF-1b causes electrophysiological abnormalities including fatal ventricular arrhythmias that occur with increasing frequency around the 4th week of postnatal life. This study addresses factors that may contribute to conduction disturbance in the ventricle of the HF-1b knockout mouse. Disruptions to gap junctional connexin40 (Cx40) have been reported in distal (i.e., apically located), but not proximal His–Purkinje conduction tissues of the HF-1b knockout mouse. This abnormality in myocardial Cx40 led us to address whether 4-week-old HF-1b knockout postnates display other disruptions to ventricular structure and function. Methods Western blotting and immunoconfocal quantification of Cx43 and coronary arteriole density and function were undertaken in the ventricle. Electrical activation was described by optical mapping. Results Western blotting and immunoconfocal microscopy indicated that overall levels of Cx43 (p <0.001) and percent of Cx43 localized in intercalated disks (p <0.001) were significantly decreased in the ventricular myocardium of knockouts relative to wildtype littermate controls. Analysis of the reduction in Cx43 level by basal and apical territories revealed that the decrease was most pronounced in the lower, apical half of the ventricle of knockouts relative to controls (p <0.001). Myocyte size also showed a significant decrease in the knockout, that was more marked within the apical half of the ventricle (p <0.05). Optical recordings of ventricular activation indicated apically localized sectors of slowed conduction in knockout ventricles not occurring in controls that could be correlated directly to tissues showing reduced Cx43. These discrete sectors of abnormal conduction in the knockout heart were resolved following point stimulation of the ventricular epicardium and thus were not explained by dysfunction of the His–Purkinje system. To further probe base

  6. Cardiac arrest

    MedlinePlus

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  7. Adaptation of the myoglobin knockout mouse to hypoxic stress.

    PubMed

    Schlieper, Georg; Kim, Jie-Hoon; Molojavyi, Andrei; Jacoby, Christoph; Laussmann, Tim; Flögel, Ulrich; Gödecke, Axel; Schrader, Jürgen

    2004-04-01

    Myoglobin knockout (myo-/-) mice were previously reported to show no obvious phenotype but revealed several compensatory mechanisms that include increases in cardiac capillary density, coronary flow, and hemoglobin. The aim of this study was to investigate whether severe hypoxic stress can exhaust these compensatory mechanisms and whether this can be monitored on the gene and protein level. Myo-/- and wild-type (WT) mice we e exposed to hypoxia (10% O(2)) fo 2 wk. Thereafter hemodynamic parameters were investigated by invasive measurement combined with magnetic resonance imaging. Cardiac gene and protein expression were analyzed using cDNA arrays and two-dimensional gel electrophoresis plus mass spectrometry, respectively. Hematocrit levels increased from 44% (WT) and 48% (myo-/-) to 72% in both groups. Similar to WT controls, hypoxic myo-/- animals maintained stable cardiovascular function (mean arterial blood pressure 82.4 mmHg, ejection fraction 72.5%). Cardiac gene expression of hypoxic myo-/- mice differed significantly from WT controls in 17 genes (e.g., keratinocyte lipid binding protein +202%, cytochrome c oxidase Vb +41%). Interestingly, hypoxia inducible factor-1alpha remained unchanged in both groups. Proteome analysis revealed reduced levels of heart fatty acid-binding protein and heat shock protein 27 both in hypoxic myo-/- and WT mice. Our data thus demonstrate that myo-/- mice do not decompensate du ing hypoxic st ess but a e surprisingly well adapted. Changes in ene gy metabolism of fatty acids may contribute to the robustness of myoglobin-deficient mice. PMID:14656764

  8. Adaptation of the myoglobin knockout mouse to hypoxic stress.

    PubMed

    Schlieper, Georg; Kim, Jie-Hoon; Molojavyi, Andrei; Jacoby, Christoph; Laussmann, Tim; Flögel, Ulrich; Gödecke, Axel; Schrader, Jürgen

    2004-04-01

    Myoglobin knockout (myo-/-) mice were previously reported to show no obvious phenotype but revealed several compensatory mechanisms that include increases in cardiac capillary density, coronary flow, and hemoglobin. The aim of this study was to investigate whether severe hypoxic stress can exhaust these compensatory mechanisms and whether this can be monitored on the gene and protein level. Myo-/- and wild-type (WT) mice we e exposed to hypoxia (10% O(2)) fo 2 wk. Thereafter hemodynamic parameters were investigated by invasive measurement combined with magnetic resonance imaging. Cardiac gene and protein expression were analyzed using cDNA arrays and two-dimensional gel electrophoresis plus mass spectrometry, respectively. Hematocrit levels increased from 44% (WT) and 48% (myo-/-) to 72% in both groups. Similar to WT controls, hypoxic myo-/- animals maintained stable cardiovascular function (mean arterial blood pressure 82.4 mmHg, ejection fraction 72.5%). Cardiac gene expression of hypoxic myo-/- mice differed significantly from WT controls in 17 genes (e.g., keratinocyte lipid binding protein +202%, cytochrome c oxidase Vb +41%). Interestingly, hypoxia inducible factor-1alpha remained unchanged in both groups. Proteome analysis revealed reduced levels of heart fatty acid-binding protein and heat shock protein 27 both in hypoxic myo-/- and WT mice. Our data thus demonstrate that myo-/- mice do not decompensate du ing hypoxic st ess but a e surprisingly well adapted. Changes in ene gy metabolism of fatty acids may contribute to the robustness of myoglobin-deficient mice.

  9. Pathway knockout and redundancy in metabolic networks.

    PubMed

    Min, Yong; Jin, Xiaogang; Chen, Ming; Pan, Zhengzheng; Ge, Ying; Chang, Jie

    2011-02-01

    The robustness and stability of complex cellular networks is often attributed to the redundancy of components, including genes, enzymes and pathways. Estimation of redundancy is still an open question in systems biology. Current theoretical tools to measure redundancy have various strengths and shortcomings in providing a comprehensive description of metabolic networks. Specially, there is a lack of effective measures to cover different perturbation situations. Here we present a pathway knockout algorithm to improve quantitative measure of redundancy in metabolic networks grounded on the elementary flux mode (EFM) analysis. The proposed redundancy measure is based on the average ratio of remaining EFMs after knockout of one EFM in the unperturbed state. We demonstrated with four example systems that our algorithm overcomes limits of previous measures, and provides additional information about redundancy in the situation of targeted attacks. Additionally, we compare existing enzyme knockout and our pathway knockout algorithm by the mean-field analysis, which provides mathematical expression for the average ratio of remaining EFMs after both types of knockout. Our results prove that multiple-enzymes knockout does not always yield more information than single-enzyme knockout for evaluating redundancy. Indeed, pathway knockout considers additional effects of structural asymmetry. In the metabolic networks of amino acid anabolism in Escherichia coli and human hepatocytes, and the central metabolism in human erythrocytes, we validate our mean-field solutions and prove the capacity of pathway knockout algorithm. Moreover, in the E. coli model the two sub-networks synthesizing amino acids that are essential and those that are non-essential for humans are studied separately. In contrast to previous studies, we find that redundancy of two sub-networks is similar with each other, and even sub-networks synthesizing essential amino acids can be more redundant.

  10. 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.

  11. Cardiac transplantation.

    PubMed

    Shanewise, Jack

    2004-12-01

    Cardiac transplantation is a proven, accepted mode of therapy for selected patients with end-stage heart failure, but the inadequate number of suitable donor hearts available ultimately limits its application. This chapter reviews adult cardiac transplantation, with an emphasis on the anesthetic considerations of the heart transplant operation itself.

  12. 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

  13. UPDATE: CARDIAC XENOTRANSPLANTATION

    PubMed Central

    Ekser, Burcin; Cooper, David K.C.

    2009-01-01

    Purpose of review To review the latest development in cardiac xenotransplantation in small and large animal models and related in vitro studies. Recent findings With the recent introduction of α1,3-galactosyltransferase gene-knockout (GT-KO) pig organs for xenotransplantation, improved cardiac graft survival has been obtained. However, this experience has demonstrated the importance of pig antigens other than Galα1,3Gal (Gal) antigens (so-called nonGal antigens) as targets for primate anti-pig antibodies. Several in vitro studies have confirmed that, although the incidence and levels of anti-nonGal antibodies in non-human primates and humans are significantly less when compared with total anti-pig antibodies (i.e., anti-Gal + anti-nonGal), they can result in complement-mediated lysis of GT-KO pig cells. More recently, it has been demonstrated that regulatory T cells (Treg) suppress the cellular xenogeneic response, thus potentially preventing or reducing T cell-mediated rejection. The importance of thrombotic microangiopathy as a feature of the immune/inflammatory response and incompatibilities between the coagulation-anticoagulation systems of pig and primate are receiving increasing attention. Development of GT-KO pigs transgenic for one or more ‘anti-thrombotic’ genes, e.g., CD39 or tissue factor pathway inhibitor, may contribute to overcoming these problems. Summary Although GT-KO pigs have provided an advance over wild-type pigs as a source of Organs for transplantation into primates, further genetic modification of GT-KO pigs is required to overcome the remaining immune barriers before a clinical trial of cardiac xenotransplantation can be contemplated. PMID:19060538

  14. Cardiomyocyte specific deletion of PP2A causes cardiac hypertrophy

    PubMed Central

    Li, Lei; Fang, Chao; Xu, Di; Xu, Yidan; Fu, Heling; Li, Jianmin

    2016-01-01

    Cardiac hypertrophy is a common pathological alteration in heart disease, which has been reported to be connected with serine/threonine protein phosphatases that control the dephosphorylation of a variety of cardiac proteins. Herein, we generated protein phosphatase type 2A knockout expressing a tamoxifen-inducible Cre recombinase protein fused to two mutant estrogen-receptor ligand-binding domains (MerCreMer) under the control of the a-myosin heavy chain promoter. Cardiac function of mice was determined by echocardiography. Decrease in PP2A activity leads to increased cardiomyocyte hypertrophy and fibrosis. Loss of PP2ACα leads to the heart failure, including the changes of EF, FS, LV, ANP and BNP. On the molecular level, knockout mice shows increased expression of B55a and B56e at 60 days after tamoxifen injection. Additionally, the regulation of the Akt/GSK3β/β-catenin pathway is severely disturbed in knockout mice. In conclusion, cardiomyocyte specific deletion of PP2A gene causes the cardiac hypertrophy. We will use the knockout mice to generate a type of cardiomyocyte hypertrophy mouse model with myocardial fibrosis. PMID:27186301

  15. Leukemogenesis in heterozygous PU.1 knockout mice.

    PubMed

    Genik, Paula C; Vyazunova, Irina; Steffen, Leta S; Bacher, Jeffery W; Bielefeldt-Ohmann, Helle; McKercher, Scott; Ullrich, Robert L; Fallgren, Christina M; Weil, Michael M; Ray, F Andrew

    2014-09-01

    Most murine radiation-induced acute myeloid leukemias involve biallelic inactivation of the PU.1 gene, with one allele being lost through a radiation-induced chromosomal deletion and the other allele affected by a recurrent point mutation in codon 235 that is likely to be spontaneous. The short latencies of acute myeloid leukemias occurring in nonirradiated mice engineered with PU.1 conditional knockout or knockdown alleles suggest that once both copies of PU.1 have been lost any other steps involved in leukemogenesis occur rapidly. Yet, spontaneous acute myeloid leukemias have not been reported in mice heterozygous for a PU.1 knockout allele, an observation that conflicts with the understanding that the PU.1 codon 235 mutation is spontaneous. Here we describe experiments that show that the lack of spontaneous leukemia in PU.1 heterozygous knockout mice is not due to insufficient monitoring times or mouse numbers or the genetic background of the knockout mice. The results reveal that spontaneous leukemias that develop in mice of the mixed 129S2/SvPas and C57BL/6 background of knockout mice arise by a pathway that does not involve biallelic PU.1 mutation. In addition, the latency of radiation-induced leukemia in PU.1 heterozygous mice on a genetic background susceptible to radiation-induced leukemia indicates that the codon 235 mutation is not a rate-limiting step in radiation leukemogenesis driven by PU.1 loss.

  16. Phenomics of Cardiac Chloride Channels

    PubMed Central

    Duan, Dayue Darrel

    2014-01-01

    Forward genetic studies have identified several chloride (Cl−) channel genes, including CFTR, ClC-2, ClC-3, CLCA, Bestrophin, and Ano1, in the heart. Recent reverse genetic studies using gene targeting and transgenic techniques to delineate the functional role of cardiac Cl− channels have shown that Cl− channels may contribute to cardiac arrhythmogenesis, myocardial hypertrophy and heart failure, and cardioprotection against ischemia reperfusion. The study of physiological or pathophysiological phenotypes of cardiac Cl− channels, however, is complicated by the compensatory changes in the animals in response to the targeted genetic manipulation. Alternatively, tissue-specific conditional or inducible knockout or knockin animal models may be more valuable in the phenotypic studies of specific Cl− channels by limiting the effect of compensation on the phenotype. The integrated function of Cl− channels may involve multiprotein complexes of the Cl− channel subproteome. Similar phenotypes can be attained from alternative protein pathways within cellular networks, which are influenced by genetic and environmental factors. The phenomics approach, which characterizes phenotypes as a whole phenome and systematically studies the molecular changes that give rise to particular phenotypes achieved by modifying the genotype under the scope of genome/proteome/phenome, may provide more complete understanding of the integrated function of each cardiac Cl− channel in the context of health and disease. PMID:23720326

  17. Cardiac amyloidosis

    MedlinePlus

    ... the way electrical signals move through the heart (conduction system). This can lead to abnormal heartbeats ( arrhythmias ) ... due to medicine) Sick sinus syndrome Symptomatic cardiac conduction system disease (arrhythmias related to abnormal conduction of ...

  18. Cardiac Sarcoidosis

    MedlinePlus

    ... is Cardiac Sarcoidosis? Sarcoidosis is a poorly understood disease that commonly affects the lungs. It can also involve the lymph nodes, liver, spleen, eyes, skin, bones, salivary glands and heart. ...

  19. Rescue of heart lipoprotein lipase-knockout mice confirms a role for triglyceride in optimal heart metabolism and function.

    PubMed

    Khan, Raffay S; Lin, Yan; Hu, Yunying; Son, Ni-Huiping; Bharadwaj, Kalyani G; Palacios, Carla; Chokshi, Aalap; Ji, Ruiping; Yu, Shuiqing; Homma, Sunichi; Schulze, P Christian; Tian, Rong; Goldberg, Ira J

    2013-12-01

    Hearts utilize fatty acids as a primary source of energy. The sources of those lipids include free fatty acids and lipoprotein triglycerides. Deletion of the primary triglyceride-hydrolyzing enzyme lipoprotein lipase (LPL) leads to cardiac dysfunction. Whether heart LPL-knockout (hLPL0) mice are compromised due a deficiency in energetic substrates is unknown. To test whether alternative sources of energy will prevent cardiac dysfunction in hLPL0 mice, two different models were used to supply nonlipid energy. 1) hLPL0 mice were crossed with mice transgenically expressing GLUT1 in cardiomyocytes to increase glucose uptake into the heart; this cross-corrected cardiac dysfunction, reduced cardiac hypertrophy, and increased myocardial ATP. 2) Mice were randomly assigned to a sedentary or training group (swimming) at 3 mo of age, which leads to increased skeletal muscle production of lactate. hLPL0 mice had greater expression of the lactate transporter monocarboxylate transporter-1 (MCT-1) and increased cardiac lactate uptake. Compared with hearts from sedentary hLPL0 mice, hearts from trained hLPL0 mice had adaptive hypertrophy and improved cardiac function. We conclude that defective energy intake and not the reduced uptake of fat-soluble vitamins or cholesterol is responsible for cardiac dysfunction in hLPL0 mice. In addition, our studies suggest that adaptations in cardiac metabolism contribute to the beneficial effects of exercise on the myocardium of patients with heart failure. PMID:24085031

  20. 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

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

    PubMed

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

    2016-07-01

    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.

  2. 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

  3. 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

  4. 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

  5. [Cardiac amyloidosis].

    PubMed

    Hoyer, Caroline; Angermann, Christiane E; Knop, Stefan; Ertl, Georg; Störk, Stefan

    2008-03-15

    Amyloidoses are a heterogeneous group of multisystem disorders, which are characterized by an extracellular deposition of amyloid fibrils. Typically affected are the heart, liver, kidneys, and nervous system. More than half of the patients die due to cardiac involvement. Clinical signs of cardiac amyloidosis are edema of the lower limbs, hepatomegaly, ascites and elevated jugular vein pressure, frequently in combination with dyspnea. There can also be chest pain, probably due to microvessel disease. Dysfunction of the autonomous nervous system or arrhythmias may cause low blood pressure, dizziness, or recurrent syncope. The AL amyloidosis caused by the deposition of immunoglobulin light chains is the most common form. It can be performed by monoclonal gammopathy. The desirable treatment therapy consists of high-dose melphalan therapy twice followed by autologous stem cell transplantation. Due to the high peritransplantation mortality, selection of appropriate patients is mandatory. The ATTR amyloidosis is an autosomal dominant disorder caused by the amyloidogenic form of transthyretin, a plasmaprotein that is synthesized in the liver. Therefore, liver transplantation is the only curative therapy. The symptomatic treatment of cardiac amyloidosis is based on the current guidelines for chronic heart failure according to the patient's New York Heart Association (NYHA) state. Further types of amyloidosis with possible cardiac involvement comprise the senile systemic amyloidosis caused by the wild-type transthyretin, secondary amyloidosis after chronic systemic inflammation, and the beta(2)-microglobulin amyloidosis after long-term dialysis treatment. PMID:18344065

  6. Lingual deficits in neurotrophin double knockout mice.

    PubMed

    Nosrat, Irina V; Agerman, Karin; Marinescu, Andrea; Ernfors, Patrik; Nosrat, Christopher A

    2004-12-01

    Brain-derived neurotrophic factor (BDNF) and Neurotrophin 3 (NT-3) are members of the neurotrophin family and are expressed in the developing and adult tongue papillae. BDNF null-mutated mice exhibit specific impairments related to innervation and development of the gustatory system while NT-3 null mice have deficits in their lingual somatosensory innervation. To further evaluate the functional specificity of these neurotrophins in the peripheral gustatory system, we generated double BDNF/NT-3 knockout mice and compared the phenotype to BDNF(-/-) and wild-type mice. Taste papillae morphology was severely distorted in BDNF(-/-) xNT-3(-/-) mice compared to single BDNF(-/-) and wild-type mice. The deficits were found throughout the tongue and all gustatory papillae. There was a significant loss of fungiform papillae and the papillae were smaller in size compared to BDNF(-/-) and wild-type mice. Circumvallate papillae in the double knockouts were smaller and did not contain any intraepithelial nerve fibers. BDNF(-/-) xNT-3(-/-) mice exhibited additive losses in both somatosensory and gustatory innervation indicating that BDNF and NT-3 exert specific roles in the innervation of the tongue. However, the additional loss of fungiform papillae and taste buds in BDNF(-/-) xNT-3(-/-) mice compared to single BDNF knockout mice indicate a synergistic functional role for both BDNF-dependent gustatory and NT-3-dependent somatosensory innervations in taste bud and taste papillae innervation and development. PMID:16217617

  7. Differential role of PKA catalytic subunits in mediating phenotypes caused by knockout of the Carney complex gene Prkar1a.

    PubMed

    Yin, Zhirong; Pringle, Daphne R; Jones, Georgette N; Kelly, Kimberly M; Kirschner, Lawrence S

    2011-10-01

    The Carney complex is an inherited tumor predisposition caused by activation of the cAMP-dependent protein kinase [protein kinase A (PKA)] resulting from mutation of the PKA-regulatory subunit gene PRKAR1A. Myxomas and tumors in cAMP-responsive tissues are cardinal features of this syndrome, which is unsurprising given the important role played by PKA in modulating cell growth and function. Previous studies demonstrated that cardiac-specific knockout of Prkar1a causes embryonic heart failure and myxomatous degeneration in the heart, whereas limited Schwann cell-specific knockout of the gene causes schwannoma formation. In this study, we sought to determine the role of PKA activation in this phenotype by using genetic means to reduce PKA enzymatic activity. To accomplish this goal, we introduced null alleles of the PKA catalytic subunits Prkaca (Ca) or Prkacb (Cb) into the Prkar1a-cardiac knockout (R1a-CKO) or limited Schwann cell knockout (R1a-TEC3KO) line. Heterozygosity for Prkaca rescued the embryonic lethality of the R1a-CKO, although mice had a shorter than normal lifespan and died from cardiac failure with atrial thrombosis. In contrast, heterozygosity for Prkacb only enabled the mice to survive 1 extra day during embryogenesis. Biochemical analysis indicated that reduction of Ca markedly reduced PKA activity in embryonic hearts, whereas reduction of Cb had minimal effects. In R1a-TEC3KO mice, tumorigenesis was completely suppressed by a heterozygosity for Prkaca, and by more than 80% by heterozygosity for Prkacb. These data suggest that both developmental and tumor phenotypes caused by Prkar1a mutation result from excess PKA activity due to PKA-Ca. PMID:21852354

  8. 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

  9. 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. PMID:25064116

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Altered reward circuitry in the norepinephrine transporter knockout mouse.

    PubMed

    Gallagher, Joseph J; Zhang, Xiaowei; 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 Mn(2+) 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

  16. Cardiac conduction system

    MedlinePlus

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals ... to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle ...

  17. Urea Transporter Physiology Studied in Knockout Mice

    PubMed Central

    Li, Xuechen; Chen, Guangping; Yang, Baoxue

    2012-01-01

    In mammals, there are two types of urea transporters; urea transporter (UT)-A and UT-B. The UT-A transporters are mainly expressed in kidney epithelial cells while UT-B demonstrates a broader distribution in kidney, heart, brain, testis, urinary tract, and other tissues. Over the past few years, multiple urea transporter knockout mouse models have been generated enabling us to explore the physiological roles of the different urea transporters. In the kidney, deletion of UT-A1/UT-A3 results in polyuria and a severe urine concentrating defect, indicating that intrarenal recycling of urea plays a crucial role in the overall capacity to concentrate urine. Since UT-B has a wide tissue distribution, multiple phenotypic abnormalities have been found in UT-B null mice, such as defective urine concentration, exacerbated heart blockage with aging, depression-like behavior, and earlier male sexual maturation. This review summarizes the new insights of urea transporter functions in different organs, gleaned from studies of urea transporter knockout mice, and explores some of the potential pharmacological prospects of urea transporters. PMID:22745630

  18. 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

    2016-08-01

    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. PMID:27418529

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

    PubMed

    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 ([Formula: see text]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 [Formula: see text]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 [Formula: see text]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 [Formula: see text]O2,max is identical in normoxia and hypoxia indicates moreover that the limitation of [Formula: see text]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 [Formula: see text]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 [Formula: see text]O2,max, which constitutes a new phenotype of these mice. PMID:27559317

  20. 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

  1. Substrate uptake and metabolism are preserved in hypertrophic caveolin-3 knockout hearts

    PubMed Central

    Augustus, Ayanna S.; Buchanan, Jonathan; Addya, Sankar; Rengo, Giuseppe; Pestell, Richard G.; Fortina, Paolo; Koch, Walter J.; Bensadoun, Andre; Abel, E. Dale; Lisanti, Michael P.

    2008-01-01

    Caveolin-3 (Cav3), the primary protein component of caveolae in muscle cells, regulates numerous signaling pathways including insulin receptor signaling and facilitates free fatty acid (FA) uptake by interacting with several FA transport proteins. We previously reported that Cav3 knockout mice (Cav3KO) develop cardiac hypertrophy with diminished contractile function; however, the effects of Cav3 gene ablation on cardiac substrate utilization are unknown. The present study revealed that the uptake and oxidation of FAs and glucose were normal in hypertrophic Cav3KO hearts. Real-time PCR analysis revealed normal expression of lipid metabolism genes including FA translocase (CD36) and carnitine palmitoyl transferase-1 in Cav3KO hearts. Interestingly, myocardial cAMP content was significantly increased by 42%; however, this had no effect on PKA activity in Cav3KO hearts. Microarray expression analysis revealed a marked increase in the expression of genes involved in receptor trafficking to the plasma membrane, including Rab4a and the expression of WD repeat/FYVE domain containing proteins. We observed a fourfold increase in the expression of cellular retinol binding protein-III and a 3.5-fold increase in 17β-hydroxysteroid dehydrogenase type 11, a member of the short-chain dehydrogenase/reductase family involved in the biosynthesis and inactivation of steroid hormones. In summary, a loss of Cav3 in the heart leads to cardiac hypertrophy with normal substrate utilization. Moreover, a loss of Cav3 mRNA altered the expression of several genes not previously linked to cardiac growth and function. Thus we have identified a number of new target genes associated with the pathogenesis of cardiac hypertrophy. PMID:18552160

  2. 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.

  3. 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

  4. Universal statistics of the knockout tournament.

    PubMed

    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

  5. 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

  6. Imaging of cardiac sarcoidosis.

    PubMed

    Erthal, Fernanda; Juneau, Daniel; Lim, Siok P; Dwivedi, Girish; Nery, Pablo B; Birnie, David; Beanlands, Rob S

    2016-09-01

    Sarcoidosis is a multisystem inflammatory disease. Cardiac involvement is described in up to 50% of the cases. The disease spectrum is wide and cardiac manifestations ranges from being asymptomatic to heart failure, arrhythmias and sudden cardiac death. The diagnosis of cardiac sarcoidosis can be challenging due to its non-specific nature and the focal involvement of the heart. In this review, we discuss the utility of a stepwise approach with multimodality cardiac imaging in the diagnosis and management of CS. PMID:27225318

  7. Cardiomyocyte-specific conditional knockout of the histone chaperone HIRA in mice results in hypertrophy, sarcolemmal damage and focal replacement fibrosis

    PubMed Central

    Valenzuela, Nicolas; Fan, Qiying; Fa'ak, Faisal; Soibam, Benjamin; Nagandla, Harika; Liu, Yu; Schwartz, Robert J.; McConnell, Bradley K.; Stewart, M. David

    2016-01-01

    ABSTRACT HIRA is the histone chaperone responsible for replication-independent incorporation of histone variant H3.3 within gene bodies and regulatory regions of actively transcribed genes, and within the bivalent promoter regions of developmentally regulated genes. The HIRA gene lies within the 22q11.2 deletion syndrome critical region; individuals with this syndrome have multiple congenital heart defects. Because terminally differentiated cardiomyocytes have exited the cell cycle, histone variants should be utilized for the bulk of chromatin remodeling. Thus, HIRA is likely to play an important role in epigenetically defining the cardiac gene expression program. In this study, we determined the consequence of HIRA deficiency in cardiomyocytes in vivo by studying the phenotype of cardiomyocyte-specific Hira conditional-knockout mice. Loss of HIRA did not perturb heart development, but instead resulted in cardiomyocyte hypertrophy and susceptibility to sarcolemmal damage. Cardiomyocyte degeneration gave way to focal replacement fibrosis and impaired cardiac function. Gene expression was widely altered in Hira conditional-knockout hearts. Significantly affected pathways included responses to cellular stress, DNA repair and transcription. Consistent with heart failure, fetal cardiac genes were re-expressed in the Hira conditional knockout. Our results suggest that transcriptional regulation by HIRA is crucial for cardiomyocyte homeostasis. PMID:26935106

  8. CARDIAC MUSCLE

    PubMed Central

    Sommer, Joachim R.; Johnson, Edward A.

    1968-01-01

    With light and electron microscopy a comparison has been made of the morphology of ventricular (V) and Purkinje (P) fibers of the hearts of guinea pig, rabbit, cat, dog, goat, and sheep. The criteria, previously established for the rabbit heart, that V fibers are distinguished from P fibers by the respective presence and absence of transverse tubules is shown to be true for all animals studied. No evidence was found of a permanent connection between the sarcoplasmic reticulum and the extracellular space. The sarcoplasmic reticulum (SR) of V fibers formed couplings with the sarcolemma of a transverse tubule (interior coupling) and with the peripheral sarcolemma (peripheral coupling), whereas in P fibers the SR formed only peripheral couplings. The forms of the couplings were identical. The significance, with respect to excitation-contraction coupling, of the difference in the form of the couplings in cardiac versus skeletal muscle is discussed together with the electrophysiological implications of the differing geometries of bundles of P fibers from different animals. PMID:5645545

  9. 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.

  10. Development of a Markerless Knockout Method for Actinobacillus succinogenes

    PubMed Central

    Joshi, Rajasi V.; Schindler, Bryan D.; McPherson, Nikolas R.; Tiwari, Kanupriya

    2014-01-01

    Actinobacillus succinogenes is one of the best natural succinate-producing organisms, but it still needs engineering to further increase succinate yield and productivity. In this study, we developed a markerless knockout method for A. succinogenes using natural transformation or electroporation. The Escherichia coli isocitrate dehydrogenase gene with flanking flippase recognition target sites was used as the positive selection marker, making use of A. succinogenes's auxotrophy for glutamate to select for growth on isocitrate. The Saccharomyces cerevisiae flippase recombinase (Flp) was used to remove the selection marker, allowing its reuse. Finally, the plasmid expressing flp was cured using acridine orange. We demonstrate that at least two consecutive deletions can be introduced into the same strain using this approach, that no more than a total of 1 kb of DNA is needed on each side of the selection cassette to protect from exonuclease activity during transformation, and that no more than 200 bp of homologous DNA is needed on each side for efficient recombination. We also demonstrate that electroporation can be used as an alternative transformation method to obtain knockout mutants and that an enriched defined medium can be used for direct selection of knockout mutants on agar plates with high efficiency. Single-knockout mutants of the fumarate reductase and of the pyruvate formate lyase-encoding genes were obtained using this knockout strategy. Double-knockout mutants were also obtained by deleting the citrate lyase-, β-galactosidase-, and aconitase-encoding genes in the pyruvate formate lyase knockout mutant strain. PMID:24610845

  11. 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

  12. 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

  13. Generation of knockout mice using engineered nucleases.

    PubMed

    Sung, Young Hoon; Jin, Young; Kim, Seokjoong; Lee, Han-Woong

    2014-08-15

    The use of engineered nucleases in one-cell stage mouse embryos is emerging as an efficient alternative to conventional gene targeting in mouse embryonic stem (ES) cells. These nucleases are designed or reprogrammed to specifically induce double strand breaks (DSBs) at a desired genomic locus, and efficiently introduce mutations by both error-prone and error-free DNA repair mechanisms. Since these mutations frequently result in the loss or alteration of gene function by inserting, deleting, or substituting nucleotide sequences, engineered nucleases are enabling us to efficiently generate gene knockout and knockin mice. Three kinds of engineered endonucleases have been developed and successfully applied to the generation of mutant mice: zinc-finger nuclease (ZFNs), transcription activator-like effector nucleases (TALENs) and RNA-guided endonucleases (RGENs). Based on recent advances, here we provide experimentally validated, detailed guidelines for generating non-homologous end-joining (NHEJ)-mediated mutant mice by microinjecting TALENs and RGENs into the cytoplasm or the pronucleus of one-cell stage mouse embryos.

  14. 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.

  15. What Is Cardiac Rehabilitation?

    MedlinePlus

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  16. 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

  17. Exercise, Nrf2 and Antioxidant Signaling in Cardiac Aging.

    PubMed

    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

  18. Cardiac-specific ablation of G-protein receptor kinase 2 redefines its roles in heart development and beta-adrenergic signaling.

    PubMed

    Matkovich, Scot J; Diwan, Abhinav; Klanke, Justin L; Hammer, Daniel J; Marreez, Yehia; Odley, Amy M; Brunskill, Eric W; Koch, Walter J; Schwartz, Robert J; Dorn, Gerald W

    2006-10-27

    G-protein receptor kinase 2 (GRK2) is 1 of 7 mammalian GRKs that phosphorylate ligand-bound 7-transmembrane receptors, causing receptor uncoupling from G proteins and potentially activating non-G-protein signaling pathways. GRK2 is unique among members of the GRK family in that its genetic ablation causes embryonic lethality. Cardiac abnormalities in GRK2 null embryos implicated GRK2 in cardiac development but prevented studies of the knockout phenotype in adult hearts. Here, we created GRK2-loxP-targeted mice and used Cre recombination to generate germline and cardiac-specific GRK2 knockouts. GRK2 deletion in the preimplantation embryo with EIIa-Cre (germline null) resulted in developmental retardation and embryonic lethality between embryonic day 10.5 (E10.5) and E11.5. At E9.5, cardiac myocyte specification and cardiac looping were normal, but ventricular development was delayed. Cardiomyocyte-specific ablation of GRK2 in the embryo with Nkx2.5-driven Cre (cardiac-specific GRK2 knockout) produced viable mice with normal heart structure, function, and cardiac gene expression. Cardiac-specific GRK2 knockout mice exhibited enhanced inotropic sensitivity to the beta-adrenergic receptor agonist isoproterenol, with impairment of normal inotropic and lusitropic tachyphylaxis, and exhibited accelerated development of catecholamine toxicity with chronic isoproterenol treatment. These findings show that cardiomyocyte autonomous GRK2 is not essential for myocardial development after cardiac specification, suggesting that embryonic developmental abnormalities may be attributable to extracardiac effects of GRK2 ablation. In the adult heart, cardiac GRK2 is a major factor regulating inotropic and lusitropic tachyphylaxis to beta-adrenergic agonist, which likely contributes to its protective effects in catecholamine cardiomyopathy. PMID:17008600

  19. Mesenchymal stem cells promote matrix metalloproteinase secretion by cardiac fibroblasts and reduce cardiac ventricular fibrosis after myocardial infarction.

    PubMed

    Mias, Céline; Lairez, Olivier; Trouche, Elodie; Roncalli, Jérome; Calise, Denis; Seguelas, Marie-Hélène; Ordener, Catherine; Piercecchi-Marti, Marie-Dominique; Auge, Nathalie; Salvayre, Anne Negre; Bourin, Philippe; Parini, Angelo; Cussac, Daniel

    2009-11-01

    Recent studies showed that mesenchymal stem cells (MSCs) transplantation significantly decreased cardiac fibrosis; however, the mechanisms involved in these effects are still poorly understood. In this work, we investigated whether the antifibrotic properties of MSCs involve the regulation of matrix metalloproteinases (MMPs) and matrix metalloproteinase endogenous inhibitor (TIMP) production by cardiac fibroblasts. In vitro experiments showed that conditioned medium from MSCs decreased viability, alpha-smooth muscle actin expression, and collagen secretion of cardiac fibroblasts. These effects were concomitant with the stimulation of MMP-2/MMP-9 activities and membrane type 1 MMP expression. Experiments performed with fibroblasts from MMP2-knockout mice demonstrated that MMP-2 plays a preponderant role in preventing collagen accumulation upon incubation with conditioned medium from MSCs. We found that MSC-conditioned medium also decreased the expression of TIMP2 in cardiac fibroblasts. In vivo studies showed that intracardiac injection of MSCs in a rat model of postischemic heart failure induced a significant decrease in ventricular fibrosis. This effect was associated with the improvement of morphological and functional cardiac parameters. In conclusion, we showed that MSCs modulate the phenotype of cardiac fibroblasts and their ability to degrade extracellular matrix. These properties of MSCs open new perspectives for understanding the mechanisms of action of MSCs and anticipate their potential therapeutic or side effects.

  20. Altered calcium regulation in isolated cardiomyocytes from Egr-1 knock-out mice.

    PubMed

    Pacini, Luca; Suffredini, Silvia; Ponti, Donatella; Coppini, Raffaele; Frati, Giacomo; Ragona, Giuseppe; Cerbai, Elisabetta; Calogero, Antonella

    2013-12-01

    Early growth response-1 one gene (Egr-1), one of the immediate early response genes, plays an important role in the adaptive response of the myocardium to hypertrophic stimuli. We aimed to investigate the effects of Egr-1 deletion on cardiac function. Egr-1 knock-out (Egr-1(-/-)) homozygous mice were employed to evaluate the electrophysiological and molecular properties of left ventricular cardiomyocytes (VCM) by using patch-clamp technique, intracellular calcium measurements, real-time PCR, and Western blot. Action potential was prolonged and diastolic potential was positive-shifted in VCMs isolated from Egr-1(-/-) mice, in comparison with those from their wild-type (WT) littermates. The calcium content of the sarcoplasmic reticulum was reduced and the decay time for steady-state calcium transient slowed down. Serca2, Ryr, L-type Ca(2+)-channel, and PLB mRNA expression were reduced in Egr-1(-/-) mice compared with the controls. Moreover, Serca2 protein was reduced, while the amount of Ncx1 protein was increased in Egr-1(-/-) hearts compared with those of the WT littermates. Furthermore, genes involved in heart development (GATA-4, TGF-β) and in Egr-1 regulation (Nab1, Nab2) were down regulated in Egr-1(-/-) mice. These results suggest that Egr-1 plays a pivotal role in regulating excitation-contraction coupling in cardiac myocytes.

  1. 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.

  2. 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

  3. Nrf2-Mediated Cardiac Maladaptive Remodeling and Dysfunction in a Setting of Autophagy Insufficiency.

    PubMed

    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 and switching on Nrf2-mediated cardiac dysfunction. In a murine model of pressure overload-induced cardiac remodeling and dysfunction via transverse aortic arch constriction, 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. Transverse aortic arch constriction -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 the upregulation of angiotensinogen (Agt) only in the autophagy-impaired heart after transverse aortic arch constriction. 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 and 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

  4. 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.

  5. 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.

  6. Cardiac gated ventilation

    NASA Astrophysics Data System (ADS)

    Hanson, C. William, III; Hoffman, Eric A.

    1995-05-01

    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. We 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 50msec scan aperture. Multislice, 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. We observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a nonfailing model of the heart.

  7. Induction of functional Brm protein from Brm knockout mice

    PubMed Central

    Thompson, Kenneth W.; Marquez, Stefanie B.; Lu, Li; Reisman, David

    2015-01-01

    Once the knockout of the Brm gene was found to be nontumorigenic in mice, the study of BRM's involvement in cancer seemed less important compared with that of its homolog, Brg1. This has likely contributed to the disparity that has been observed in the publication ratio between BRG1 and BRM. We show that a previously published Brm knockout mouse is an incomplete knockout whereby a truncated isoform of Brm is detected in normal tissue and in tumors. We show that this truncated Brm isoform has functionality comparable to wild type Brm. By immunohistochemistry (IHC), this truncated Brm is undetectable in normal lung tissue and is minimal to very low in Brmnull tumors. However, it is significant in a subset (~40%) of Brg1/Brm double knockout (DKO) tumors that robustly express this truncated BRM, which in part stems from an increase in Brm mRNA levels. Thus, it is likely that this mutant mouse model does not accurately reflect the role that Brm plays in cancer development. We suggest that the construction of a completely new mouse Brm knockout, where Brm is functionally absent, is needed to determine whether or not Brm is actually tumorigenic and if Brm might be a tumor suppressor. PMID:26097869

  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. 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

  10. Marketing cardiac CT programs.

    PubMed

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  11. Aromatase knockout mice reveal an impact of estrogen on drug-induced alternation of murine electrocardiography parameters.

    PubMed

    Kurokawa, Junko; Sasano, Tetsuo; Kodama, Masami; Li, Min; Ebana, Yusuke; Harada, Nobuhiro; Honda, Shin-ichiro; Nakaya, Haruaki; Furukawa, Tetsushi

    2015-06-01

    Our in vitro characterization showed that physiological concentrations of estrogen partially suppressed the I(Kr) channel current in guinea pig ventricular myocytes and the human ether-a-go-go-related gene (hERG) channel currents in CHO-K1 cells regardless of estrogen receptor signaling and revealed that the partially suppressed hERG currents enhanced the sensitivity to the hERG blocker E-4031. To obtain in vivo proof-of-concept data to support the effects of estrogen on cardiac electrophysiology, we here employed an aromatase knockout mouse as an in vivo estrogen-null model and compared the acute effects of E-4031 on cardiac electrophysiological parameters with those in wild-type mice (C57/BL6J) by recording surface electrocardiogram (ECG). The ablation of circulating estrogens blunted the effects of E-4031 on heart rate and QT interval in mice under a denervation condition. Our result provides in vivo proof of principle and demonstrates that endogenous estrogens increase the sensitivity of E-4031 to cardiac electrophysiology. PMID:25972195

  12. Aromatase knockout mice reveal an impact of estrogen on drug-induced alternation of murine electrocardiography parameters.

    PubMed

    Kurokawa, Junko; Sasano, Tetsuo; Kodama, Masami; Li, Min; Ebana, Yusuke; Harada, Nobuhiro; Honda, Shin-ichiro; Nakaya, Haruaki; Furukawa, Tetsushi

    2015-06-01

    Our in vitro characterization showed that physiological concentrations of estrogen partially suppressed the I(Kr) channel current in guinea pig ventricular myocytes and the human ether-a-go-go-related gene (hERG) channel currents in CHO-K1 cells regardless of estrogen receptor signaling and revealed that the partially suppressed hERG currents enhanced the sensitivity to the hERG blocker E-4031. To obtain in vivo proof-of-concept data to support the effects of estrogen on cardiac electrophysiology, we here employed an aromatase knockout mouse as an in vivo estrogen-null model and compared the acute effects of E-4031 on cardiac electrophysiological parameters with those in wild-type mice (C57/BL6J) by recording surface electrocardiogram (ECG). The ablation of circulating estrogens blunted the effects of E-4031 on heart rate and QT interval in mice under a denervation condition. Our result provides in vivo proof of principle and demonstrates that endogenous estrogens increase the sensitivity of E-4031 to cardiac electrophysiology.

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

    PubMed

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

    2009-03-01

    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.

  14. Characteristics of aldehyde dehydrogenase 2 (Aldh2) knockout mice.

    PubMed

    Yu, Hsu-Sheng; Oyama, Tsunehiro; Isse, Toyohi; Kitakawa, Kyoko; Ogawa, Masanori; Pham, Thi-Thu-Phuong; Kawamoto, Toshihiro

    2009-11-01

    Acetaldehyde is an intermediate of ethanol oxidation. It covalently binds to DNA, and is known as a carcinogen. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme that oxidizes acetaldehyde. Approximately 45% of Chinese and Japanese individuals have the inactive ALDH2 genotypes (ALDH2*2/*2 and ALDH2*1/*2), and Aldh2 knockout mice appear to be a valid animal model for humans with inactive ALDH2. This review gives an overview of published studies on Aldh2 knockout mice, which were treated with ethanol or acetaldehyde. According to these studies, it was found that Aldh2 -/- mice (Aldh2 knockout mice) are more susceptible to ethanol and acetaldehyde-induced toxicity than Aldh2 +/+ mice (wild type mice). When mice were fed with ethanol, the mortality was increased. When they were exposed to atmospheres containing acetaldehyde, the Aldh2 -/- mice showed more severe toxic symptoms, like weight loss and higher blood acetaldehyde levels, as compared with the Aldh2 +/+ mice. Thus, ethanol and acetaldehyde treatment affects Aldh2 knockout mice more than wild type mice. Based on these findings, it is suggested that ethanol consumption and acetaldehyde inhalation are inferred to pose a higher risk to ALDH2-inactive humans. These results also support that ALDH2-deficient humans who habitually consume alcohol have a higher rate of cancer than humans with functional ALDH2. PMID:19874182

  15. The time-of-day of myocardial infarction onset affects healing through oscillations in cardiac neutrophil recruitment.

    PubMed

    Schloss, Maximilian J; Horckmans, Michael; Nitz, Katrin; Duchene, Johan; Drechsler, Maik; Bidzhekov, Kiril; Scheiermann, Christoph; Weber, Christian; Soehnlein, Oliver; Steffens, Sabine

    2016-01-01

    Myocardial infarction (MI) is the leading cause of death in Western countries. Epidemiological studies show acute MI to be more prevalent in the morning and to be associated with a poorer outcome in terms of mortality and recovery. The mechanisms behind this association are not fully understood. Here, we report that circadian oscillations of neutrophil recruitment to the heart determine infarct size, healing, and cardiac function after MI Preferential cardiac neutrophil recruitment during the active phase (Zeitgeber time, ZT13) was paralleled by enhanced myeloid progenitor production, increased circulating numbers of CXCR2(hi) neutrophils as well as upregulated cardiac adhesion molecule and chemokine expression. MI at ZT13 resulted in significantly higher cardiac neutrophil infiltration compared to ZT5, which was inhibited by CXCR2 antagonism or neutrophil-specific CXCR2 knockout. Limiting exaggerated neutrophilic inflammation at this time point significantly reduced the infarct size and improved cardiac function. PMID:27226028

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  17. Measurement of cardiac troponins.

    PubMed

    Collinson, P O; Boa, F G; Gaze, D C

    2001-09-01

    The cardiac troponins form part of the regulatory mechanism for muscle contraction. Specific cardiac isoforms of cardiac troponin T and cardiac troponin I exist and commercially available immunoassay systems have been developed for their measurement. A large number of clinical and analytical studies have been performed and the measurement of cardiac troponins is now considered the 'gold standard' biochemical test for diagnosis of myocardial damage. There have been advances in understanding the development and structure of troponins and their degradation following myocardial cell necrosis. This has contributed to the understanding of the problems with current assays. Greater clinical use has also highlighted areas of analytical and clinical confusion. The assays are reviewed based on manufacturers' information, current published material as well as the authors' in-house experience.

  18. 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

  19. 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

  20. Query cardiac pain.

    PubMed

    Todd, J W

    1983-08-01

    Query cardiac pain is a common problem, and immense efforts are made to solve it. No test can prove that a patient has not had a cardiac infarct, though in the recent past eminent authorities wrongly stated that a normal ECG supplied this proof. This history is by far the most important means of interpreting recurrent pain. Coronary arteriography is only useful in diagnosis when the pain is certainly due to myocardial ischaemia but it is uncertain whether this is caused by coronary artery disease or some other cardiac lesion. In practice, much pain is not diagnosed. This need be no cause for concern, and patients who in fact have had a small cardiac infarct gain rather than lose if wrongly reassured of its non-existence. The history of cardiology is a depressing catalogue of error. Bogus cardiac diseases have been diagnosed on an enormous scale, mainly because attention has been concentrated on the cardiac manifestations, while the patient was ignored. Much "excluding" is fatuous. Because treatment was derived from theory, treatment for patients who had had cardiac infarcts was disastrous. The great error at present is to overvalue technology.

  1. Disruption of calpain reduces lipotoxicity-induced cardiac injury by preventing endoplasmic reticulum stress

    PubMed Central

    Li, Shengcun; Zhang, Lulu; Ni, Rui; Cao, Ting; Zheng, Dong; Xiong, Sidong; Greer, Peter A.; Fan, Guo-Chang; Peng, Tianqing

    2016-01-01

    Diabetes and obesity are prevalent in westernized countries. In both conditions, excessive fatty acid uptake by cardiomyocytes induces cardiac lipotoxicity, an important mechanism contributing to diabetic cardiomyopathy. This study investigated the effect of calpain disruption on cardiac lipotoxicity. Cardiac-specific capns1 knockout mice and their wild-type littermates (male, age of 4 weeks) were fed a high fat diet (HFD) or normal diet for 20 weeks. HFD increased body weight, altered blood lipid profiles and impaired glucose tolerance comparably in both capns1 knockout mice and their wild-type littermates. Calpain activity, cardiomyocyte cross-sectional areas, collagen deposition and triglyceride were significantly increased in HFD-fed mouse hearts, and these were accompanied by myocardial dysfunction and up-regulation of hypertrophic and fibrotic collagen genes as well as pro-inflammatory cytokines. These effects of HFD were attenuated by disruption of calpain in capns1 knockout mice. Mechanistically, deletion of capns1 in HFD-fed mouse hearts and disruption of calpain with calpain inhibitor-III, silencing of capn1, or deletion of capns1 in palmitate-stimulated cardiomyocytes prevented endoplasmic reticulum stress, apoptosis, cleavage of caspase-12 and junctophilin-2, and pro-inflammatory cytokine expression. Pharmacological inhibition of endoplasmic reticulum stress diminished palmitate-induced apoptosis and pro-inflammatory cytokine expression in cardiomyocytes. In summary, disruption of calpain prevents lipotoxicity-induced apoptosis in cardiomyocytes and cardiac injury in mice fed a HFD. The role of calpain is mediated, at least partially, through endoplasmic reticulum stress. Thus, calpain/endoplasmic reticulum stress may represent a new mechanism and potential therapeutic targets for cardiac lipotoxicity. PMID:27523632

  2. Hmga1/Hmga2 double knock-out mice display a “superpygmy” phenotype

    PubMed Central

    Federico, Antonella; Forzati, Floriana; Esposito, Francesco; Arra, Claudio; Palma, Giuseppe; Barbieri, Antonio; Palmieri, Dario; Fedele, Monica; Pierantoni, Giovanna Maria; De Martino, Ivana; Fusco, Alfredo

    2014-01-01

    ABSTRACT The HMGA1 and HMGA2 genes code for proteins belonging to the High Mobility Group A family. Several genes are negatively or positively regulated by both these proteins, but a number of genes are specifically regulated by only one of them. Indeed, knock-out of the Hmga1 and Hmga2 genes leads to different phenotypes: cardiac hypertrophy and type 2 diabetes in the former case, and a large reduction in body size and amount of fat tissue in the latter case. Therefore, to better elucidate the functions of the Hmga genes, we crossed Hmga1-null mice with mice null for Hmga2. The Hmga1−/−/Hmga2−/− mice showed reduced vitality and a very small size (75% smaller than the wild-type mice); they were even smaller than pygmy Hmga2-null mice. The drastic reduction in E2F1 activity, and consequently in the expression of the E2F-dependent genes involved in cell cycle regulation, likely accounts for some phenotypic features of the Hmga1−/−/Hmga2−/− mice. PMID:24728959

  3. Hmga1/Hmga2 double knock-out mice display a "superpygmy" phenotype.

    PubMed

    Federico, Antonella; Forzati, Floriana; Esposito, Francesco; Arra, Claudio; Palma, Giuseppe; Barbieri, Antonio; Palmieri, Dario; Fedele, Monica; Pierantoni, Giovanna Maria; De Martino, Ivana; Fusco, Alfredo

    2014-04-11

    The HMGA1 and HMGA2 genes code for proteins belonging to the High Mobility Group A family. Several genes are negatively or positively regulated by both these proteins, but a number of genes are specifically regulated by only one of them. Indeed, knock-out of the Hmga1 and Hmga2 genes leads to different phenotypes: cardiac hypertrophy and type 2 diabetes in the former case, and a large reduction in body size and amount of fat tissue in the latter case. Therefore, to better elucidate the functions of the Hmga genes, we crossed Hmga1-null mice with mice null for Hmga2. The Hmga1(-/-)/Hmga2(-/-) mice showed reduced vitality and a very small size (75% smaller than the wild-type mice); they were even smaller than pygmy Hmga2-null mice. The drastic reduction in E2F1 activity, and consequently in the expression of the E2F-dependent genes involved in cell cycle regulation, likely accounts for some phenotypic features of the Hmga1(-/-)/Hmga2(-/-) mice.

  4. Knockout of Lmod2 results in shorter thin filaments followed by dilated cardiomyopathy and juvenile lethality

    PubMed Central

    Pappas, Christopher T.; Mayfield, Rachel M.; Henderson, Christine; Jamilpour, Nima; Cover, Cathleen; Hernandez, Zachary; Hutchinson, Kirk R.; Chu, Miensheng; Nam, Ki-Hwan; Valdez, Jose M.; Wong, Pak Kin; Granzier, Henk L.; Gregorio, Carol C.

    2015-01-01

    Leiomodin 2 (Lmod2) is an actin-binding protein that has been implicated in the regulation of striated muscle thin filament assembly; its physiological function has yet to be studied. We found that knockout of Lmod2 in mice results in abnormally short thin filaments in the heart. We also discovered that Lmod2 functions to elongate thin filaments by promoting actin assembly and dynamics at thin filament pointed ends. Lmod2-KO mice die as juveniles with hearts displaying contractile dysfunction and ventricular chamber enlargement consistent with dilated cardiomyopathy. Lmod2-null cardiomyocytes produce less contractile force than wild type when plated on micropillar arrays. Introduction of GFP-Lmod2 via adeno-associated viral transduction elongates thin filaments and rescues structural and functional defects observed in Lmod2-KO mice, extending their lifespan to adulthood. Thus, to our knowledge, Lmod2 is the first identified mammalian protein that functions to elongate actin filaments in the heart; it is essential for cardiac thin filaments to reach a mature length and is required for efficient contractile force and proper heart function during development. PMID:26487682

  5. Cardiac Arrest Resuscitation.

    PubMed

    Guyette, Francis X; Reynolds, Joshua C; Frisch, Adam

    2015-08-01

    Cardiac arrest is a dynamic disease that tests the multitasking and leadership abilities of emergency physicians. Providers must simultaneously manage the logistics of resuscitation while searching for the cause of cardiac arrest. The astute clinician will also realize that he or she is orchestrating only one portion of a larger series of events, each of which directly affects patient outcomes. Resuscitation science is rapidly evolving, and emergency providers must be familiar with the latest evidence and controversies surrounding resuscitative techniques. This article reviews evidence, discusses controversies, and offers strategies to provide quality cardiac arrest resuscitation.

  6. [Cardiac Rehabilitation 2015].

    PubMed

    Hoffmann, Andreas

    2015-11-25

    The goals of cardiac rehabilitation are (re-)conditioning and secondary prevention in patients with heart disease or an elevated cardiovascular risk profile. Rehabilitation is based on motivation through education, on adapted physical activity, instruction of relaxation techniques, psychological support and optimized medication. It is performed preferably in groups either in outpatient or inpatient settings. The Swiss working group on cardiac rehabilitation provides a network of institutions with regular quality auditing. Positive effects of rehabilitation programs on mortality and morbidity have been established by numerous studies. Although a majority of patients after cardiac surgery are being referred to rehabilitation, these services are notoriously underused after catheter procedures. PMID:26602848

  7. 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.

  8. Neurologic complications of cardiac tumors.

    PubMed

    Roeltgen, David; Kidwell, Chelsea S

    2014-01-01

    Cardiac tumors are an uncommon cause for neurologic disease, but if undiagnosed can be associated with devastating neurologic consequences. Primary cardiac tumors, both benign and neoplastic, and metastatic tumors occur. Primary cardiac tumors are more likely to be associated with neurologic embolic complications. Metastatic cardiac tumors are more likely to be associated with valvular distraction, arrhythmia, diminished cardiac output and indirect neurological dysfunction. Primary and metastatic cardiac tumors may result in cerebral metastatic disease. Atrial myxoma, a benign primary cardiac tumor, is the most common cardiac tumor associated with neurologic disease, and most commonly causes cerebral embolization and stroke. The use of thrombolytic therapy for these strokes is controversial. Additionally, delayed manifestations, including aneurysm formation and intracranial hemorrhage, are possible. Aneurysm formation has been described as occurring after removal of the primary tumor. The availability of noninvasive cardiac imaging has significantly helped decrease the neurologic morbidity of cardiac tumors and has led to frequent successful intervention. PMID:24365298

  9. Molecular Basis of Cardiac Myxomas

    PubMed Central

    Singhal, Pooja; Luk, Adriana; Rao, Vivek; Butany, Jagdish

    2014-01-01

    Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis. PMID:24447924

  10. 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

  11. Pauli blocking and medium effects in nucleon knockout reactions

    SciTech Connect

    Bertulani, C. A.; De Conti, C.

    2010-06-15

    We study medium modifications of the nucleon-nucleon (NN) cross sections and their influence on the nucleon knockout reactions. Using the eikonal approximation, we compare the results obtained with free NN cross sections with those obtained with a purely geometrical treatment of Pauli blocking and with NN obtained with more elaborated Dirac-Bruecker methods. The medium effects are parametrized in terms of the baryon density. We focus on symmetric nuclear matter, although the geometrical Pauli blocking also allows for the treatment of asymmetric nuclear matter. It is shown that medium effects can change the nucleon knockout cross sections and momentum distributions up to 10% in the energy range E{sub lab}=50-300 MeV/nucleon. The effect is more evident in reactions involving halo nuclei.

  12. Targeted gene knockout in chickens mediated by TALENs.

    PubMed

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

    2014-09-01

    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

  13. 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.

  14. 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

  15. 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 ...

  16. Knock-out models reveal new aquaporin functions.

    PubMed

    Verkman, Alan S

    2009-01-01

    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

  17. 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

  18. Neuroprotection during cardiac surgery.

    PubMed

    Grocott, Hilary P; Yoshitani, Kenji

    2007-01-01

    Cerebral injury following cardiac surgery continues to be a significant source of morbidity and mortality after cardiac surgery. A spectrum of injuries ranging from subtle neurocognitive dysfunction to fatal strokes are caused by a complex series of multifactorial mechanisms. Protecting the brain from these injuries has focused on intervening on each of the various etiologic factors. Although numerous studies have focused on a pharmacologic solution, more success has been found with nonpharmacologic strategies, including optimal temperature management and reducing emboli generation. PMID:17680190

  19. Ranolazine in Cardiac Arrhythmia.

    PubMed

    Saad, Marwan; Mahmoud, Ahmed; Elgendy, Islam Y; Richard Conti, C

    2016-03-01

    Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias.

  20. Cardiac rehabilitation in Germany.

    PubMed

    Karoff, Marthin; Held, Klaus; Bjarnason-Wehrens, Birna

    2007-02-01

    The purpose of this review is to give an overview of the rehabilitation measures provided for cardiac patients in Germany and to outline its legal basis and outcomes. In Germany the cardiac rehabilitation system is different from rehabilitation measures in other European countries. Cardiac rehabilitation in Germany since 1885 is based on specific laws and the regulations of insurance providers. Cardiac rehabilitation has predominantly been offered as an inpatient service, but has recently been complemented by outpatient services. A general agreement on the different indications for offering these two services has yet to be reached. Cardiac rehabilitation is mainly offered after an acute cardiac event and bypass surgery. It is also indicated in severe heart failure and special cases of percutaneous coronary intervention. Most patients are men (>65%) and the age at which events occur is increasing. The benefits obtained during the 3-4 weeks after an acute event, and confirmed in numerous studies, are often later lost under 'usual care' conditions. Many attempts have been made by rehabilitation institutions to improve this deficit by providing intensive aftercare. One instrument set up to achieve this is the nationwide institution currently comprising more than 6000 heart groups with approximately 120000 outpatients. After coronary artery bypass grafting or acute coronary syndrome cardiac rehabilitation can usually be started within 10 days. The multidisciplinary rehabilitation team consists of cardiologists, psychologists, exercise therapists, social workers, nutritionists and nurses. The positive effects of cardiac rehabilitation are also important economically, for example, for the improvement of secondary prevention and vocational integration. PMID:17301623

  1. Ranolazine in Cardiac Arrhythmia.

    PubMed

    Saad, Marwan; Mahmoud, Ahmed; Elgendy, Islam Y; Richard Conti, C

    2016-03-01

    Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias. PMID:26459200

  2. Cardiac Munchausen's syndrome.

    PubMed Central

    Dickinson, E J; Evans, T R

    1987-01-01

    Ten years' experience of cardiac Munchausen's syndrome in the Cardiac Care Unit of an Inner London teaching hospital is reported. Thirty-six admissions in this category were identified and analysed, and 4 typical cases are described. The common presenting complaints, recurring features and the relationship with other forms of Munchausen's syndrome are discussed, as are possible strategies available to deal with this clinical entity. PMID:3694601

  3. 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.

  4. 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

  5. Trends in cardiac metastasis.

    PubMed

    Karwinski, B; Svendsen, E

    1989-11-01

    A review of 8571 autopsies disclosed 2833 patients with malignant tumours from 1975 to 1984 at the Department of Pathology, The Gade Institute. Cardiac metastases were found in 130 cases. An increase of cardiac involvement was shown in the autopsy material from 1.2% in 1975-1979 to 1.8% in 1980-1984. The same trend was seen if cardiac metastases were related to malignant tumours. Numerically, lung cancer accounted for most of the metastases seen, but the increase was made up by other tumours than lung cancer. especially malignant melanoma, mesothelioma, breast cancer and sarcomas. These tumours have a high frequency of heart metastases and the increased incidence of these cancers in the material explains the rise of cardiac metastases. Cardiac metastases increased with rising number of distant metastases. This study shows that mesotheliomas have the highest percentage of cardiac spread. The importance of autopsy for detecting metastatic spread in sites that are difficult to detect clinically is emphasized.

  6. 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.

  7. Direct Cardiac Reprogramming: Advances in Cardiac Regeneration

    PubMed Central

    Chen, Olivia; Qian, Li

    2015-01-01

    Heart disease is one of the lead causes of death worldwide. Many forms of heart disease, including myocardial infarction and pressure-loading cardiomyopathies, result in irreversible cardiomyocyte death. Activated fibroblasts respond to cardiac injury by forming scar tissue, but ultimately this response fails to restore cardiac function. Unfortunately, the human heart has little regenerative ability and long-term outcomes following acute coronary events often include chronic and end-stage heart failure. Building upon years of research aimed at restoring functional cardiomyocytes, recent advances have been made in the direct reprogramming of fibroblasts toward a cardiomyocyte cell fate both in vitro and in vivo. Several experiments show functional improvements in mouse models of myocardial infarction following in situ generation of cardiomyocyte-like cells from endogenous fibroblasts. Though many of these studies are in an early stage, this nascent technology holds promise for future applications in regenerative medicine. In this review, we discuss the history, progress, methods, challenges, and future directions of direct cardiac reprogramming. PMID:26176012

  8. [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.

  9. Cardiac applications of PET.

    PubMed

    Sarikaya, Ismet

    2015-10-01

    Routine use of cardiac positron emission tomography (PET) applications has been increasing but has not replaced cardiac single-photon emission computerized tomography (SPECT) studies yet. The majority of cardiac PET tracers, with the exception of fluorine-18 fluorodeoxyglucose (18F-FDG), are not widely available, as they require either an onsite cyclotron or a costly generator for their production. 18F-FDG PET imaging has high sensitivity for the detection of hibernating/viable myocardium and has replaced Tl-201 SPECT imaging in centers equipped with a PET/CT camera. PET myocardial perfusion imaging with various tracers such as Rb-82, N-13 ammonia, and O-15 H2O has higher sensitivity and specificity than myocardial perfusion SPECT for the detection of coronary artery disease (CAD). In particular, quantitative PET measurements of myocardial perfusion help identify subclinical coronary stenosis, better define the extent and severity of CAD, and detect ischemia when there is balanced reduction in myocardial perfusion due to three-vessel or main stem CAD. Fusion images of PET perfusion and CT coronary artery calcium scoring or CT coronary angiography provide additional complementary information and improve the detection of CAD. PET studies with novel 18F-labeled perfusion tracers such as 18F-flurpiridaz and 18F-FBnTP have yielded high sensitivity and specificity in the diagnosis of CAD. These tracers are still being tested in humans, and, if approved for clinical use, they will be commercially and widely available. In addition to viability studies, 18F-FDG PET can also be utilized to detect inflammation/infection in various conditions such as endocarditis, sarcoidosis, and atherosclerosis. Some recent series have obtained encouraging results for the detection of endocarditis in patients with intracardiac devices and prosthetic valves. PET tracers for cardiac neuronal imaging, such as C-11 HED, help assess the severity of heart failure and post-transplant cardiac

  10. Cardiac involvement in hemochromatosis.

    PubMed

    Gulati, Vinay; Harikrishnan, Prakash; Palaniswamy, Chandrasekar; Aronow, Wilbert S; Jain, Diwakar; Frishman, William H

    2014-01-01

    Cardiac hemochromatosis or primary iron-overload cardiomyopathy is an important and potentially preventable cause of heart failure. This is initially characterized by diastolic dysfunction and arrhythmias and in later stages by dilated cardiomyopathy. Diagnosis of iron overload is established by elevated transferrin saturation (>55%) and elevated serum ferritin (>300 ng/mL). Genetic testing for mutations in the HFE (high iron) gene and other proteins, such as hemojuvelin, transferrin receptor, and ferroportin, should be performed if secondary causes of iron overload are ruled out. Patients should undergo comprehensive 2D and Doppler echocardiography to evaluate their systolic and diastolic function. Newer modalities like strain imaging and speckle-tracking echocardiography hold promise for earlier detection of cardiac involvement. Cardiac magnetic resonance imaging with measurement of T2* relaxation times can help quantify myocardial iron overload. In addition to its value in diagnosis of cardiac iron overload, response to iron reduction therapy can be assessed by serial imaging. Therapeutic phlebotomy and iron chelation are the cornerstones of therapy. The average survival is less than a year in untreated patients with severe cardiac impairment. However, if treated early and aggressively, the survival rate approaches that of the regular heart failure population.

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

    PubMed Central

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

    2011-01-01

    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. PMID:21335464

  12. [Preoperative cardiac assessment before non-cardiac surgery: cardiac risk stratification].

    PubMed

    Iglesias, J F; Sierro, C; Aebischer, N; Vogt, P; Eeckhout, E

    2010-06-01

    Perioperative cardiac events occurring in patients undergoing non-cardiac surgery are a common cause of morbidity and mortality. Current guidelines recommend an individualized approach to preoperative cardiac risk stratification prior to non-cardiac surgery, integrating risk factors both for the patient (active cardiac conditions, clinical risk factors, functional capacity) and for the planned surgery. Preoperative cardiac investigations are currently limited to high-risk patients in whom they may contribute to modify the perioperative management. A multidisciplinary approach to such patients, integrating the general practitioner, is recommended in order to define an individualized peri-operative strategy.

  13. Cardiac Imaging In Athletes.

    PubMed

    Khan, Asaad A; Safi, Lucy; Wood, Malissa

    2016-01-01

    Athletic heart syndrome refers to the physiological and morphological changes that occur in a human heart after repetitive strenuous physical exercise. Examples of exercise-induced changes in the heart include increases in heart cavity dimensions, augmentation of cardiac output, and increases in heart muscle mass. These cardiac adaptations vary based on the type of exercise performed and are often referred to as sport-specific cardiac remodeling. The hemodynamic effects of endurance and strength training exercise lead to these adaptations. Any abnormalities in chamber dilatation and left ventricular function usually normalize with cessation of exercise. Athletic heart syndrome is rare and should be differentiated from pathologic conditions such as hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia when assessing a patient for athletic heart syndrome. This paper describes specific adaptations that occur in athletic heart syndrome and tools to distinguish between healthy alterations versus underlying pathology. PMID:27486490

  14. Cardiac Imaging In Athletes

    PubMed Central

    Khan, Asaad A.; Safi, Lucy; Wood, Malissa

    2016-01-01

    Athletic heart syndrome refers to the physiological and morphological changes that occur in a human heart after repetitive strenuous physical exercise. Examples of exercise-induced changes in the heart include increases in heart cavity dimensions, augmentation of cardiac output, and increases in heart muscle mass. These cardiac adaptations vary based on the type of exercise performed and are often referred to as sport-specific cardiac remodeling. The hemodynamic effects of endurance and strength training exercise lead to these adaptations. Any abnormalities in chamber dilatation and left ventricular function usually normalize with cessation of exercise. Athletic heart syndrome is rare and should be differentiated from pathologic conditions such as hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia when assessing a patient for athletic heart syndrome. This paper describes specific adaptations that occur in athletic heart syndrome and tools to distinguish between healthy alterations versus underlying pathology. PMID:27486490

  15. mRNA regulation of cardiac iron transporters and ferritin subunits in a mouse model of iron overload.

    PubMed

    Brewer, Casey J; Wood, Ruth I; Wood, John C

    2014-12-01

    Iron cardiomyopathy is the leading cause of death in iron overload. Men have twice the mortality rate of women, though the cause is unknown. In hemojuvelin-knockout mice, a model of the disease, males load more cardiac iron than females. We postulated that sex differences in cardiac iron import cause differences in cardiac iron concentration. Reverse transcription polymerase chain reaction was used to measure mRNA of cardiac iron transporters in hemojuvelin-knockout mice. No sex differences were discovered among putative importers of nontransferrin-bound iron (L-type and T-type calcium channels, ZRT/IRT-like protein 14 zinc channels). Transferrin-bound iron transporters were also analyzed; these are controlled by the iron regulatory element/iron regulatory protein (IRE/IRP) system. There was a positive relationship between cardiac iron and ferroportin mRNA in both sexes, but it was significantly steeper in females (p < 0.05). Transferrin receptor 1 and divalent metal transporter 1 were more highly expressed in females than males (p < 0.01 and p < 0.0001, respectively), consistent with their lower cardiac iron levels, as predicted by IRE/IRP regulatory pathways. Light-chain ferritin showed a positive correlation with cardiac iron that was nearly identical in males and females (R(2) = 0.41, p < 0.01; R(2) = 0.56, p < 0.05, respectively), whereas heavy-chain ferritin was constitutively expressed in both sexes. This represents the first report of IRE/IRP regulatory pathways in the heart. Transcriptional regulation of ferroportin was suggested in both sexes, creating a potential mechanism for differential set points for iron export. Constitutive heavy-chain-ferritin expression suggests a logical limit to cardiac iron buffering capacity at levels known to produce heart failure in humans. PMID:25220979

  16. Akap1 Deficiency Promotes Mitochondrial Aberrations and Exacerbates Cardiac Injury Following Permanent Coronary Ligation via Enhanced Mitophagy and Apoptosis

    PubMed Central

    Schiattarella, Gabriele Giacomo; Cattaneo, Fabio; Pironti, Gianluigi; Magliulo, Fabio; Carotenuto, Giuseppe; Pirozzi, Marinella; Polishchuk, Roman; Borzacchiello, Domenica; Paolillo, Roberta; Oliveti, Marco; Boccella, Nicola; Avvedimento, Marisa; Sepe, Maria; Lombardi, Assunta; Busiello, Rosa Anna; Trimarco, Bruno; Esposito, Giovanni; Feliciello, Antonio; Perrino, Cinzia

    2016-01-01

    A-kinase anchoring proteins (AKAPs) transmit signals cues from seven-transmembrane receptors to specific sub-cellular locations. Mitochondrial AKAPs encoded by the Akap1 gene have been shown to modulate mitochondrial function and reactive oxygen species (ROS) production in the heart. Under conditions of hypoxia, mitochondrial AKAP121 undergoes proteolytic degradation mediated, at least in part, by the E3 ubiquitin ligase Seven In-Absentia Homolog 2 (Siah2). In the present study we hypothesized that Akap1 might be crucial to preserve mitochondrial function and structure, and cardiac responses to myocardial ischemia. To test this, eight-week-old Akap1 knockout mice (Akap1-/-), Siah2 knockout mice (Siah2-/-) or their wild-type (wt) littermates underwent myocardial infarction (MI) by permanent left coronary artery ligation. Age and gender matched mice of either genotype underwent a left thoracotomy without coronary ligation and were used as controls (sham). Twenty-four hours after coronary ligation, Akap1-/- mice displayed larger infarct size compared to Siah2-/- or wt mice. One week after MI, cardiac function and survival were also significantly reduced in Akap1-/- mice, while cardiac fibrosis was significantly increased. Akap1 deletion was associated with remarkable mitochondrial structural abnormalities at electron microscopy, increased ROS production and reduced mitochondrial function after MI. These alterations were associated with enhanced cardiac mitophagy and apoptosis. Autophagy inhibition by 3-methyladenine significantly reduced apoptosis and ameliorated cardiac dysfunction following MI in Akap1-/- mice. These results demonstrate that Akap1 deficiency promotes cardiac mitochondrial aberrations and mitophagy, enhancing infarct size, pathological cardiac remodeling and mortality under ischemic conditions. Thus, mitochondrial AKAPs might represent important players in the development of post-ischemic cardiac remodeling and novel therapeutic targets. PMID

  17. Normal Taste Acceptance and Preference of PANX1 Knockout Mice.

    PubMed

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

    2015-09-01

    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.

  18. 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.

  19. Electron-Induced Neutron Knockout from 4He

    NASA Astrophysics Data System (ADS)

    Misiejuk, A.; Papandreou, Z.; Voutier, E.; Bauer, Th. S.; Blok, H. P.; Boersma, D. J.; den Bok, H. W.; Bruins, E. E.; Farzanpay, F.; Grüner, K.; Hesselink, W. H.; Huber, G. M.; Jans, E.; Kalantar-Nayestanaki, N.; Kasdorp, W.-J.; Konijn, J.; Laget, J.-M.; Lapikás, L.; Lolos, G. J.; Onderwater, G. J.; Pellegrino, A.; Schroevers, R.; Spaltro, C. M.; Starink, R.; van der Steenhoven, G.; Steiger, J. J.; Visschers, J. L.; Willering, H. W.; Yeomans, D. M.

    2002-10-01

    The differential cross section for electron-induced neutron knockout in the reaction 4He(e,e'n)3He has been measured for the first time with a statistical accuracy of 11%. The experiment was performed in quasielastic kinematics at a momentum transfer of 300 MeV/c and in the missing-momentum range of 25-70 MeV/c. The comparison of the data with theoretical calculations shows an impressive increase of the cross section resulting from final state interaction effects. Specifically , the p-n charge-exchange process dominates the cross section in this kinematical regime.

  20. Cardiac arrest in the skies.

    PubMed

    Charles, R A

    2011-08-01

    Cardiac arrest occurring on board aeroplanes is rare, but remains a common cause of inflight incidents. This review examines some of the management problems unique to inflight cardiac arrests, and emphasises the use of cardiopulmonary resuscitation and automated external defibrillators.

  1. [Cardiac failure in endocrine diseases].

    PubMed

    Hashizume, K

    1993-05-01

    Several endocrine diseases show the symptoms of cardiac failure. Among them, patients with acromegaly show a specific cardiomyopathy which results in a severe left-sided cardiac failure. Hypoparathyroidism also induces cardiac failure, which is resulted from hypocalcemia and low levels of serum parathyroid hormone. In the cases of hypothyroidism, the patients with myxedemal coma show a severe cardiac failure, which is characterized by disturbance of central nervous system, renal function, and cardiac function. In the patients with thyroid crisis (storm), the cardiac failure comes from the great reduction of cardiac output with dehydration. The reduction of circulation volume, observed in the patients with pheochromocytoma easily induces cardiac failure (shock) just after the removal of adrenal tumor. In patients with malignant carcinoid syndrome, right-sided ventricular failure which may be occurred through the actions of biogenic amines is observed. PMID:8331806

  2. 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

  3. 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. PMID:27649573

  4. 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

  5. Perioperative management of cardiac disease.

    PubMed

    Aresti, N A; Malik, A A; Ihsan, K M; Aftab, S M E; Khan, W S

    2014-01-01

    Pre-existing cardiac disease contributes significantly to morbidity and mortality amongst patients undergoing non cardiac surgery. Patients with pre-existing cardiac disease or with risk factors for it, have as much as a 3.9% risk of suffering a major perioperative cardiac event (Lee et al 1999, Devereaux 2005). Furthermore, the incidence of perioperative myocardial infarction (MI) is increased 10 to 50 fold in patients with previous coronary events (Jassal 2008).

  6. Mildly impaired water maze performance in male Fmr1 knockout mice.

    PubMed

    D'Hooge, R; Nagels, G; Franck, F; Bakker, C E; Reyniers, E; Storm, K; Kooy, R F; Oostra, B A; Willems, P J; De Deyn, P P

    1997-01-01

    Fmr1 knockout mice constitute a putative model of fragile X syndrome, the most common form of heritable mental disability in humans. We have compared the performance of transgenic mice with an Fmr1 knockout with that of normal littermates in hidden- and visible-platform water maze learning, and showed that knockouts exhibit subnormal spatial learning abilities and marginal motor performance deficits. During 12 training trials of the hidden-platform task, escape latency and path length decreased significantly in knockouts and control littermates, and no effect of genotype was found. During four ensuing reversal trials, however, significant differences were found between knockouts and control littermates both in escape latency and path length. During the visible-platform condition, the reversal trials also revealed a difference between knockouts and normal littermates in escape latency, but not in path length. Possibly due to marginal motor incapacity, knockouts swam significantly slower than controls during these latter trials. During both probe trials of the hidden-platform task, knockouts as well as normal littermates spent more time in the target quadrant than in the other quadrants, and percent of time spent in the target quadrant was the same in both groups; swimming velocity was not significantly different between knockouts and normal littermates during these trials. Entries in the target area during the probe trials did show a significant effect of genotype on number of entries. The present results largely confirm and extend our previous findings. Impaired spatial abilities in Fmr1 knockouts might have been due to relatively low response flexibility or high memory interference in Fmr1 knockouts. It remains unclear, however, which brain region or neurochemical system might be involved in these disabilities. We conclude that Fmr1 knockout mice might be a valid model of fragile X mental retardation.

  7. Penetrating Cardiac Injury: A Review

    PubMed Central

    Lateef Wani, Mohd; Ahangar, Ab Gani; Wani, Shadab Nabi; Irshad, Ifat; Ul-Hassan, Nayeem

    2012-01-01

    Cardiac injury presents a great challenge to the emergency resident because these injuries require urgent intervention to prevent death. Sometimes serious cardiac injury may manifest only subtle or occult symptoms or signs. As there is an epidemic of cardiac injuries in Kashmir valley due to problems of law and order, we herein present a review on management of such injuries. PMID:24829887

  8. 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.

  9. Studying TGF-beta superfamily signaling by knockouts and knockins.

    PubMed

    Chang, H; Lau, A L; Matzuk, M M

    2001-06-30

    The transforming growth factor beta (TGF-beta) superfamily has profound effects on many aspects of animal development. In the last decade, our laboratory and others have performed in vivo functional studies on multiple components of the TGF-beta superfamily signal transduction pathway, including upstream ligands, transmembrane receptors, receptor-associated proteins and downstream Smad proteins. We have taken gene knockout approaches to generate null alleles of the genes of interest, as well as a gene knockin approach to replace the mature region of one TGF-beta superfamily ligand with another. We found that activin betaB, expressed in the spatiotemporal pattern of activin betaA, can function as a hypomorphic allele of activin betaA and rescue the craniofacial defects and neonatal lethal phenotype of activin betaA-deficient mice. With the knockout approach, we have shown that the expression pattern of a component in the TGF-beta superfamily signal transduction cascade does not necessarily predict its in vivo function. Two liver-specific activins, activin betaC and activin betaE are dispensable for liver development, regeneration and function, whereas ubiquitously expressed Smad5 has specific roles in the development of multiple embryonic and extraembryonic tissues. PMID:11451570

  10. Immunoglobulin treatment reduces atherosclerosis in apo E knockout mice.

    PubMed Central

    Nicoletti, A; Kaveri, S; Caligiuri, G; Bariéty, J; Hansson, G K

    1998-01-01

    Atherosclerosis is associated with immune activation. T cells and macrophages infiltrate atherosclerotic plaques and disease progression is associated with formation of autoantibodies to oxidized lipoproteins. In the apo E knockout mouse, a genetic model of cholesterol-induced atherosclerosis, congenital deficiency of macrophages, lymphocytes, or interferon-gamma receptors result in reduced lesion formation. We have now evaluated whether immune modulation in the adult animal affects disease development. Injections of 7-wk-old male apo E knockout mice with polyclonal immunoglobulin preparations (ivIg) during a 5-d period reduced fatty streak formation over a 2-mo period on cholesterol diet by 35%. Fibrofatty lesions induced by diet treatment for 4 mo were reduced by 50% in mice receiving ivIg after 2 mo on the diet. ivIg treatment also reduced IgM antibodies to oxidized LDL and led to inactivation of spleen and lymph node T cells. These data indicate that ivIg inhibits atherosclerosis, that it is effective both during the fatty streak and plaque phases, and that it may act by modulating T cell activity and/or antibody production. Therefore, immunomodulation may be an effective way to prevent and/or treat atherosclerosis. PMID:9727059

  11. 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.

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

    PubMed

    Wu, Xudong; Indzhykulian, Artur A; 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.

  13. 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.

  14. Conditional knockout of fibronectin abrogates mouse mammary gland lobuloalveolar differentiation

    PubMed Central

    Liu, Keyi; Cheng, Le; Flesken-Nikitin, Andrea; Huang, Lynn; Nikitin, Alexander Y.; Pauli, Bendicht U.

    2010-01-01

    Fibronectin (Fn) plays an important part in the branching morphogenesis of salivary gland, lung, and kidney. Here, we examine the effect of the conditional knockout of Fn in the mammary epithelium [FnMEp−/−] on postnatal mammary gland development, using Cre-loxP mediated gene knockout technology. Our data show that Fn deletion causes a moderate retardation in outgrowth and branching of the ductal tree in 5-week old mice. These defects are partially compensated in virgin 16-week old mice. However, mammary glands consisting of Fn-deficient epithelial cells fail to undergo normal lobuloalveolar differentiation during pregnancy. The severity of lobuloalveolar impairment ranged from lobular hypoplasia to aplasia in some cases and was associated with the amount of Fn protein recovered from these glands. Decreased rates of mammary epithelial cell proliferation accounted for delayed ductal outgrowth in virgin and lack of alveologenesis in pregnant FnMEp−/− mice. Concomitant decreased expression of integrin β1 (Itgb1) and lack of autophosphorylation of focal adhesion kinase (Fak) suggest that this pathology might, at least in part, be mediated by disruption of the Fn/Itgb1/Fak signaling pathway. PMID:20624380

  15. Evidence for increased tissue androgen sensitivity in neurturin knockout mice.

    PubMed

    Simanainen, Ulla; Gao, Yan Ru Ellen; Desai, Reena; Jimenez, Mark; Spaliviero, Jennifer; Keast, Janet R; Handelsman, David J

    2013-01-01

    Neurturin (NTN) is a member of the glial cell line-derived neurotrophic factor (GDNF) family and signals through GDNF family receptor alpha 2 (GFRα2). We hypothesised that epithelial atrophy reported in the reproductive organs of Ntn (Nrtn)- and Gfrα2 (Gfra2)-deficient mice could be due to NTN affecting the hormonal environment. To investigate this, we compared the reproductive organs of Ntn- and Gfrα2-deficient male mice in parallel with an analysis of their circulating reproductive hormone levels. There were no significant structural changes within the organs of the knockout mice; however, serum and intratesticular testosterone and serum LH levels were very low. To reconcile these observations, we tested androgen sensitivity by creating a dihydrotestosterone (DHT) clamp (castration plus DHT implant) to create fixed circulating levels of androgens, allowing the evaluation of androgen-sensitive endpoints. At the same serum DHT levels, serum LH levels were lower and prostate and seminal vesicle weights were higher in the Ntn knockout (NTNKO) mice than in the wild-type mice, suggesting an increased response to androgens in the accessory glands and hypothalamus and pituitary of the NTNKO mice. Testicular and pituitary responsiveness was unaffected in the NTNKO males, as determined by the response to the human chorionic gonadotrophin or GNRH analogue, leuprolide, respectively. In conclusion, our results suggest that NTN inactivation enhances androgen sensitivity in reproductive and neuroendocrine tissues, revealing a novel mechanism to influence reproductive function and the activity of other androgen-dependent tissues.

  16. 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

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

    PubMed

    Wu, Xudong; Indzhykulian, Artur A; 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

  18. Behavioral Analysis of Ste20 Kinase SPAK Knockout Mice

    PubMed Central

    Geng, Yang; Byun, Nellie; Delpire, Eric

    2009-01-01

    SPAK/STK39 is a mammalian protein kinase involved in the regulation of inorganic ion transport mechanisms known to modulate GABAergic neurotransmission in the both central and the peripheral nervous systems. We have previously shown that disruption of the gene encoding SPAK by homologous recombination in mouse embryonic stem cells results in viable mice that lack expression of the kinase [16]. With the exception of reduced fertility, these mice do not exhibit an overt adverse phenotype. In the present study, we examine the neurological phenotype of these mice by subjecting them to an array of behavioral tests. We show that SPAK knockout mice displayed a higher nociceptive threshold than their wild-type counterparts on the hot plate and tail flick assays. SPAK knockout mice also exhibited a strong locomotor phenotype evidenced by significant deficits on the rotarod and decreased activity in open field tests. In contrast, balance and proprioception was not affected. Finally, they demonstrated an increased anxiety-like phenotype, spending significantly longer periods of time in the dark area of the light/dark box and increased thigmotaxis in the open field chamber. These results suggest that the kinase plays an important role in CNS function, consistent with SPAK regulating ion transport mechanisms directly involved in inhibitory neurotransmission. PMID:20006650

  19. BDNF restricted knockout mice as an animal model for aggression

    PubMed Central

    Ito, Wataru; Chehab, Mahmoud; Thakur, Siddarth; Li, Jiayang; Morozov, Alexei

    2011-01-01

    Mice with global deletion of one BDNF allele, or with forebrain-restricted deletion of both alleles show elevated aggression, but this phenotype is accompanied by other behavioral changes, including increases in anxiety and deficits in cognition. Here, we performed behavioral characterization of conditional BDNF knockout mice generated using a Cre recombinase driver line, KA1-Cre, which expresses Cre in few areas of brain: highly at hippocampal area CA3, moderately in dentate gyrus, cerebellum and facial nerve nucleus. The mutant animals exhibited elevated conspecific aggression and social dominance, but did not show changes in anxiety-like behaviors assessed using the elevated plus maze and open field test. There were no changes in depression like behaviors tested in the forced swim test, but small increase in immobility in the tail suspension test. In cognitive tasks, mutants showed normal social recognition and normal spatial and fear memory, but exhibited a deficit in object recognition. Thus, this knockout can serve as a robust model of BDNF-dependent aggression and object recognition deficiency. PMID:21255268

  20. 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. PMID:24973446

  1. Evaluation of high efficiency gene knockout strategies for Trypanosoma cruzi

    PubMed Central

    2009-01-01

    Background Trypanosoma cruzi, a kinetoplastid protozoan parasite that causes Chagas disease, infects approximately 15 million people in Central and South America. In contrast to the substantial in silico studies of the T. cruzi genome, transcriptome, and proteome, only a few genes have been experimentally characterized and validated, mainly due to the lack of facile methods for gene manipulation needed for reverse genetic studies. Current strategies for gene disruption in T. cruzi are tedious and time consuming. In this study we have compared the conventional multi-step cloning technique with two knockout strategies that have been proven to work in other organisms, one-step-PCR- and Multisite Gateway-based systems. Results While the one-step-PCR strategy was found to be the fastest method for production of knockout constructs, it does not efficiently target genes of interest using gene-specific sequences of less than 80 nucleotides. Alternatively, the Multisite Gateway based approach is less time-consuming than conventional methods and is able to efficiently and reproducibly delete target genes. Conclusion Using the Multisite Gateway strategy, we have rapidly produced constructs that successfully produce specific gene deletions in epimastigotes of T. cruzi. This methodology should greatly facilitate reverse genetic studies in T. cruzi. PMID:19432966

  2. 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

  3. 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.

  4. 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

  5. Cardiac Physiology of Pregnancy.

    PubMed

    May, Linda

    2015-07-01

    Although the physiology of the heart and vascular system has not changed, there are many things we have learned and are still learning today. Research related to heart adaptations during pregnancy has been performed since the 1930s. Since the mid-1950s, researchers began to look at changes in the maternal cardiovascular system during exercise while pregnant. Research related to exercise during pregnancy and offspring heart development began and has continued since the 1970s. We will review the normal female cardiovascular system adaptations to pregnancy in general. Additionally, topics related to maternal cardiac adaptations to pregnancy during acute exercise, as well as the chronic conditioning response from exercise training will be explored. Since physical activity during pregnancy influences fetal development, the fetal cardiac development will be discussed in regards to acute and chronic maternal exercise. Similarly, the influence of various types of maternal exercise on acute and chronic fetal heart responses will be described. Briefly, the topics related to how and if there is maternal-fetal synchrony will be explained. Lastly, the developmental changes of the fetal cardiovascular system that persist after birth will be explored. Overall, the article will discuss maternal cardiac physiology related to changes with normal pregnancy, and exercise during pregnancy, as well as fetal cardiac physiology related to changes with normal development, and exercise during pregnancy as well as developmental changes in offspring after birth.

  6. The cardiac malpositions.

    PubMed

    Perloff, Joseph K

    2011-11-01

    Dextrocardia was known in the 17th century and was 1 of the first congenital malformations of the heart to be recognized. Fifty years elapsed before Matthew Baillie published his account of complete transposition in a human of the thoracic and abdominal viscera to the opposite side from what is natural. In 1858, Thomas Peacock stated that "the heart may be congenitally misplaced in various ways, occupying either an unusual position within the thorax, or being situated external to that cavity." In 1915, Maude Abbott described ectopia cordis, and Richard Paltauf's remarkable illustrations distinguished the various types of dextrocardia. In 1928, the first useful classification of the cardiac malpositions was proposed, and in 1966, Elliott et al's radiologic classification set the stage for clinical recognition. The first section of this review deals with the 3 basic cardiac malpositions in the presence of bilateral asymmetry. The second section deals with cardiac malpositions in the presence of bilateral left-sidedness or right-sidedness. Previous publications on cardiac malpositions are replete with an arcane vocabulary that confounds rather than clarifies. Even if the terms themselves are understood, inherent complexity weighs against clarity. This review was designed as a guided tour of an unfamiliar subject.

  7. 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…

  8. Comparative cardiac imaging

    SciTech Connect

    Brundage, B.H.

    1990-01-01

    This book is designed to compare all major cardiac imaging techniques. All major imaging techniques - including conventional angiography, digital angiography, echocardiography and Doppler imaging, conventional radioisotope techniques, computed tomography, and magnetic resonance imaging - are covered in this text as they apply to the major cardiovascular disorders. There is brief coverage of positron emission tomography and an extensive presentation of ultrafast computed tomography.

  9. 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

  10. 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

  11. Generation of mice carrying a knockout-first and conditional-ready allele of transforming growth factor beta2 gene.

    PubMed

    Ishtiaq Ahmed, A S; Bose, Gracelyn C; Huang, Li; Azhar, Mohamad

    2014-09-01

    Transforming growth factor beta2 (TGFβ2) is a multifunctional protein which is expressed in several embryonic and adult organs. TGFB2 mutations can cause Loeys Dietz syndrome, and its dysregulation is involved in cardiovascular, skeletal, ocular, and neuromuscular diseases, osteoarthritis, tissue fibrosis, and various forms of cancer. TGFβ2 is involved in cell growth, apoptosis, cell migration, cell differentiation, cell-matrix remodeling, epithelial-mesenchymal transition, and wound healing in a highly context-dependent and tissue-specific manner. Tgfb2(-/-) mice die perinatally from congenital heart disease, precluding functional studies in adults. Here, we have generated mice harboring Tgfb2(βgeo) (knockout-first lacZ-tagged insertion) gene-trap allele and Tgfb2(flox) conditional allele. Tgfb2(βgeo/βgeo) or Tgfb2(βgeo/-) mice died at perinatal stage from the same congenital heart defects as Tgfb2(-/-) mice. β-galactosidase staining successfully detected Tgfb2 expression in the heterozygous Tgfb2(βgeo) fetal tissue sections. Tgfb2(flox) mice were produced by crossing the Tgfb2(+/βgeo) mice with the FLPeR mice. Tgfb2(flox/-) mice were viable. Tgfb2 conditional knockout (Tgfb2(cko/-) ) fetuses were generated by crossing of Tgfb2(flox/-) mice with Tgfb2(+/-) ; EIIaCre mice. Systemic Tgfb2(cko/-) embryos developed cardiac defects which resembled the Tgfb2(βgeo/βgeo) , Tgfb2(βgeo/-) , and Tgfb2(-/-) fetuses. In conclusion, Tgfb2(βgeo) and Tgfb2(flox) mice are novel mouse strains which will be useful for investigating the tissue specific expression and function of TGFβ2 in embryonic development, adult organs, and disease pathogenesis and cancer. genesis

  12. 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.

  13. Symmetry of cardiac function assessment.

    PubMed

    Bai, Xu-Fang; Ma, Amy X

    2016-09-01

    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.

  14. Symmetry of cardiac function assessment.

    PubMed

    Bai, Xu-Fang; Ma, Amy X

    2016-09-01

    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

  15. 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

  16. 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

  17. 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.

  18. SGK1-dependent cardiac CTGF formation and fibrosis following DOCA treatment.

    PubMed

    Vallon, Volker; Wyatt, Amanda W; Klingel, Karin; Huang, Dan Yang; Hussain, Azeemudeen; Berchtold, Susanne; Friedrich, Björn; Grahammer, Florian; Belaiba, Rachida S; Görlach, Agnes; Wulff, Peer; Daut, Jürgen; Dalton, Nancy D; Ross, John; Flögel, Ulrich; Schrader, Jürgen; Osswald, Hartmut; Kandolf, Reinhard; Kuhl, Dietmar; Lang, Florian

    2006-05-01

    The mineralocorticoids aldosterone and deoxycorticosterone acetate (DOCA) stimulate renal tubular salt reabsorption, increase salt appetite, induce extracellular volume expansion, and elevate blood pressure. Cardiac effects of mineralocorticoids include stimulation of matrix protein deposition leading to cardiac fibrosis, which is at least partially due to the direct action of the hormones on cardiac cells. The signaling mechanisms mediating mineralocorticoid-induced cardiac fibrosis have so far remained elusive. Mineralocorticoids have been shown to upregulate the serum- and glucocorticoid-inducible kinase 1 (SGK1), which participates in the effects of mineralocorticoids on renal tubular Na+ reabsorption and salt appetite. To explore the involvement of SGK1 in the pathogenesis of mineralocorticoid-induced cardiac fibrosis, SGK1 knockout mice (sgk1-/-) and wild-type littermates (sgk1+/+) were implanted a 21-day-release 50-mg DOCA pellet and supplied with 1% NaCl in drinking water for 18 days. This DOCA/high-salt treatment increased blood pressure in both genotypes but led to significant cardiac fibrosis only in sgk1+/+ but not in sgk1-/- mice. According to real-time polymerase chain reaction and Western blotting, DOCA/high-salt treatment enhanced transcript levels and protein expression of cardiac connective tissue growth factor (CTGF) only in sgk1+/+ but not in sgk1-/- mice. Furthermore, DOCA (10 microM) upregulated CTGF expression and enhanced CTGF promoter activity in lung fibroblasts isolated from sgk1+/+ but not from sgk1-/- mice, an effect involving spironolactone-sensitive mineralocorticoid receptors and activation of nuclear factor-kappaB (NFkappaB). Our results suggest that SGK1 plays a decisive role in mineralocorticoid-induced CTGF expression and cardiac fibrosis. PMID:16604333

  19. Influence of natriuretic peptide receptor-1 on survival and cardiac hypertrophy during development

    PubMed Central

    Scott, Nicola J.A.; Ellmers, Leigh. J.; Lainchbury, John G.; Maeda, Nobuyo; Smithies, Oliver; Richards, A. Mark; Cameron, Vicky A.

    2010-01-01

    The heart adapts to an increased workload through the activation of a hypertrophic response within the cardiac ventricles. This response is characterized by both an increase in the size of the individual cardiomyocytes and an induction of a panel of genes normally expressed in the embryonic and neonatal ventricle, such as atrial natriuretic peptide (ANP). ANP and brain natriuretic peptide (BNP) exert their biological actions through activation of the natriuretic peptide receptor-1 (Npr1). The current study examined mice lacking Npr1 (Npr1−/−) activity and investigated the effects of the absence of Npr1 signaling during cardiac development on embryo viability, cardiac structure and gene and protein expression. Npr1−/−embryos were collected at embryonic day (ED) 12.5, 15.5 and neonatal day 1 (ND 1). Npr1−/−embryos occurred at the expected Mendelian frequency at ED 12.5, but knockout numbers were significantly decreased at ED 15.5 and ND 1. There was no indication of cardiac structural abnormalities in surviving embryos. However, Npr1−/−embryos exhibited cardiac enlargement (without fibrosis) from ED 15.5 as well as significantly increased ANP mRNA and protein expression compared to wild-type (WT) mice, but no concomitant increase in expression of the hypertrophy-related transcription factors, Mef2A, Mef2C, GATA-4, GATA-6 or serum response factor (SRF). However, there was a significant decrease in Connexin-43 (Cx43) gene and protein expression at mid-gestation in Npr1−/−embryos. Our findings suggest that the mechanism by which natriuretic peptide signaling influences cardiac development in Npr1−/− mice is distinct from that seen during the development of pathological cardiac hypertrophy and fibrosis. The decreased viability of Npr1−/−embryos may result from a combination of cardiomegaly and dysregulated Cx43 protein affecting cardiac contractility. PMID:19782130

  20. SGK1-dependent cardiac CTGF formation and fibrosis following DOCA treatment.

    PubMed

    Vallon, Volker; Wyatt, Amanda W; Klingel, Karin; Huang, Dan Yang; Hussain, Azeemudeen; Berchtold, Susanne; Friedrich, Björn; Grahammer, Florian; Belaiba, Rachida S; Görlach, Agnes; Wulff, Peer; Daut, Jürgen; Dalton, Nancy D; Ross, John; Flögel, Ulrich; Schrader, Jürgen; Osswald, Hartmut; Kandolf, Reinhard; Kuhl, Dietmar; Lang, Florian

    2006-05-01

    The mineralocorticoids aldosterone and deoxycorticosterone acetate (DOCA) stimulate renal tubular salt reabsorption, increase salt appetite, induce extracellular volume expansion, and elevate blood pressure. Cardiac effects of mineralocorticoids include stimulation of matrix protein deposition leading to cardiac fibrosis, which is at least partially due to the direct action of the hormones on cardiac cells. The signaling mechanisms mediating mineralocorticoid-induced cardiac fibrosis have so far remained elusive. Mineralocorticoids have been shown to upregulate the serum- and glucocorticoid-inducible kinase 1 (SGK1), which participates in the effects of mineralocorticoids on renal tubular Na+ reabsorption and salt appetite. To explore the involvement of SGK1 in the pathogenesis of mineralocorticoid-induced cardiac fibrosis, SGK1 knockout mice (sgk1-/-) and wild-type littermates (sgk1+/+) were implanted a 21-day-release 50-mg DOCA pellet and supplied with 1% NaCl in drinking water for 18 days. This DOCA/high-salt treatment increased blood pressure in both genotypes but led to significant cardiac fibrosis only in sgk1+/+ but not in sgk1-/- mice. According to real-time polymerase chain reaction and Western blotting, DOCA/high-salt treatment enhanced transcript levels and protein expression of cardiac connective tissue growth factor (CTGF) only in sgk1+/+ but not in sgk1-/- mice. Furthermore, DOCA (10 microM) upregulated CTGF expression and enhanced CTGF promoter activity in lung fibroblasts isolated from sgk1+/+ but not from sgk1-/- mice, an effect involving spironolactone-sensitive mineralocorticoid receptors and activation of nuclear factor-kappaB (NFkappaB). Our results suggest that SGK1 plays a decisive role in mineralocorticoid-induced CTGF expression and cardiac fibrosis.

  1. Erbb2 Is Required for Cardiac Atrial Electrical Activity during Development

    PubMed Central

    Tenin, Gennadiy; Clowes, Christopher; Wolton, Kathryn; Krejci, Eliska; Wright, Jayne A.; Lovell, Simon C.; Sedmera, David; Hentges, Kathryn E.

    2014-01-01

    The heart is the first organ required to function during embryonic development and is absolutely necessary for embryo survival. Cardiac activity is dependent on both the sinoatrial node (SAN), which is the pacemaker of heart's electrical activity, and the cardiac conduction system which transduces the electrical signal though the heart tissue, leading to heart muscle contractions. Defects in the development of cardiac electrical function may lead to severe heart disorders. The Erbb2 (Epidermal Growth Factor Receptor 2) gene encodes a member of the EGF receptor family of receptor tyrosine kinases. The Erbb2 receptor lacks ligand-binding activity but forms heterodimers with other EGF receptors, stabilising their ligand binding and enhancing kinase-mediated activation of downstream signalling pathways. Erbb2 is absolutely necessary in normal embryonic development and homozygous mouse knock-out Erbb2 embryos die at embryonic day (E)10.5 due to severe cardiac defects. We have isolated a mouse line, l11Jus8, from a random chemical mutagenesis screen, which carries a hypomorphic missense mutation in the Erbb2 gene. Homozygous mutant embryos exhibit embryonic lethality by E12.5-13. The l11Jus8 mutants display cardiac haemorrhage and a failure of atrial function due to defects in atrial electrical signal propagation, leading to an atrial-specific conduction block, which does not affect ventricular conduction. The l11Jus8 mutant phenotype is distinct from those reported for Erbb2 knockout mouse mutants. Thus, the l11Jus8 mouse reveals a novel function of Erbb2 during atrial conduction system development, which when disrupted causes death at mid-gestation. PMID:25269082

  2. Deficiency of adipocyte fatty-acid-binding protein alleviates myocardial ischaemia/reperfusion injury and diabetes-induced cardiac dysfunction.

    PubMed

    Zhou, Mi; Bao, Yuqian; Li, Haobo; Pan, Yong; Shu, Lingling; Xia, Zhengyuan; Wu, Donghai; Lam, Karen S L; Vanhoutte, Paul M; Xu, Aimin; Jia, Weiping; Hoo, Ruby L-C

    2015-10-01

    Clinical evidence shows that circulating levels of adipocyte fatty-acid-binding protein (A-FABP) are elevated in patients with diabetes and closely associated with ischaemic heart disease. Patients with diabetes are more susceptible to myocardial ischaemia/reperfusion (MI/R) injury. The experiments in the present study investigated the role of A-FABP in MI/R injury with or without diabetes. Non-diabetic and diabetic (streptozotocin-induced) A-FABP knockout and wild-type mice were subjected to MI/R or sham intervention. After MI/R, A-FABP knockout mice exhibited reductions in myocardial infarct size, apoptotic index, oxidative and nitrative stress, and inflammation. These reductions were accompanied by an improved left ventricular function compared with the relative controls under non-diabetic or diabetic conditions. After diabetes induction, A-FABP knockout mice exhibited a preserved cardiac function compared with that in wild-type mice. Endothelial cells, but not cardiomyocytes, were identified as the most likely source of cardiac A-FABP. Cardiac and circulating A-FABP levels were significantly increased in mice with diabetes or MI/R. Diabetes-induced superoxide anion production was significantly elevated in wild-type mice, but diminished in A-FABP knockout mice, and this elevation contributed to the exaggeration of MI/R-induced cardiac injury. Phosphorylation of endothelial nitric oxide synthase (eNOS) and production of nitric oxide (NO) were enhanced in both diabetic and non-diabetic A-FABP knockout mice after MI/R injury, but diminished in wild-type mice. The beneficial effects of A-FABP deficiency on MI/R injury were abolished by the NOS inhibitor N(G)-nitro-L-arginine methyl ester. Thus, A-FABP deficiency protects mice against MI/R-induced and/or diabetes-induced cardiac injury at least partially through activation of the eNOS/NO pathway and reduction in superoxide anion production.

  3. Neuregulin 3 Knockout Mice Exhibit Behaviors Consistent with Psychotic Disorders.

    PubMed

    Hayes, Lindsay N; Shevelkin, Alexey; Zeledon, Mariela; Steel, Gary; Chen, Pei-Lung; Obie, Cassandra; Pulver, Ann; Avramopoulos, Dimitrios; Valle, David; Sawa, Akira; Pletnikov, Mikhail V

    2016-07-01

    Neuregulin 3 (NRG3) is a paralog of NRG1. Genetic studies in schizophrenia demonstrate that risk variants in NRG3 are associated with cognitive and psychotic symptom severity, and several intronic single nucleotide polymorphisms in NRG3 are associated with delusions in patients with schizophrenia. In order to gain insights into the biological function of the gene, we generated a novel Nrg3 knockout (KO) mouse model and tested for neurobehavioral phenotypes relevant to psychotic disorders. KO mice displayed novelty-induced hyperactivity, impaired prepulse inhibition of the acoustic startle response, and deficient fear conditioning. No gross cytoarchitectonic or layer abnormalities were noted in the brain of KO mice. Our findings suggest that deletion of the Nrg3 gene leads to alterations consistent with aspects of schizophrenia. We propose that KO mice will provide a valuable animal model to determine the role of the NRG3 in the molecular pathogenesis of schizophrenia and other psychotic disorders. PMID:27606322

  4. 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.

  5. Knockout of Foxp2 disrupts vocal development in mice.

    PubMed

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

    2016-03-16

    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.

  6. Complex, multimodal behavioral profile of the Homer1 knockout mouse.

    PubMed

    Jaubert, P J; Golub, M S; Lo, Y Y; Germann, S L; Dehoff, M H; Worley, P F; Kang, S H; Schwarz, M K; Seeburg, P H; Berman, R F

    2007-03-01

    Proteins of the Homer1 immediate early gene family have been associated with synaptogenesis and synaptic plasticity suggesting broad behavioral consequences of loss of function. This study examined the behavior of male Homer1 knockout (KO) mice compared with wild-type (WT) and heterozygous mice using a battery of 10 behavioral tests probing sensory, motor, social, emotional and learning/memory functions. KO mice showed mild somatic growth retardation, poor motor coordination, enhanced sensory reactivity and learning deficits. Heterozygous mice showed increased aggression in social interactions with conspecifics. The distribution of mGluR5 and N-methyl-D-aspartate receptors (NMDA) receptors appeared to be unaltered in the hippocampus (HIP) of Homer1 KO mice. The results indicate an extensive range of disrupted behaviors that should contribute to the understanding of the Homer1 gene in brain development and behavior.

  7. SNARE function analyzed in synaptobrevin/VAMP knockout mice.

    PubMed

    Schoch, S; Deák, F; Königstorfer, A; Mozhayeva, M; Sara, Y; Südhof, T C; Kavalali, E T

    2001-11-01

    SNAREs (soluble NSF-attachment protein receptors) are generally acknowledged as central components of membrane fusion reactions, but their precise function has remained enigmatic. Competing hypotheses suggest roles for SNAREs in mediating the specificity of fusion, catalyzing fusion, or actually executing fusion. We generated knockout mice lacking synaptobrevin/VAMP 2, the vesicular SNARE protein responsible for synaptic vesicle fusion in forebrain synapses, to make use of the exquisite temporal resolution of electrophysiology in measuring fusion. In the absence of synaptobrevin 2, spontaneous synaptic vesicle fusion and fusion induced by hypertonic sucrose were decreased approximately 10-fold, but fast Ca2+-triggered fusion was decreased more than 100-fold. Thus, synaptobrevin 2 may function in catalyzing fusion reactions and stabilizing fusion intermediates but is not absolutely required for synaptic fusion.

  8. 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…

  9. Modulation of cardiac gap junction expression and arrhythmic susceptibility.

    PubMed

    Danik, Stephan B; Liu, Fangyu; Zhang, Jie; Suk, H Jacqueline; Morley, Gregory E; Fishman, Glenn I; Gutstein, David E

    2004-11-12

    Connexin43 (Cx43), the predominant ventricular gap junction protein, is critical for maintaining normal cardiac electrical conduction, and its absence in the mouse heart results in sudden arrhythmic death. The mechanisms linking reduced Cx43 abundance in the heart and inducibility of malignant ventricular arrhythmias have yet to be established. In this report, we investigate arrhythmic susceptibility in a murine model genetically engineered to express progressively decreasing levels of Cx43. Progressively older cardiac-restricted Cx43 conditional knockout (CKO) mice were selectively bred to produce a heart-specific Cx43-deficient subline ("O-CKO" mice) in which the loss of Cx43 in the heart occurs more gradually. O-CKO mice lived significantly longer than the initial series of CKO mice but still died suddenly and prematurely. At 25 days of age, cardiac Cx43 protein levels decreased to 59% of control values (P<0.01), but conduction velocity was not significantly decreased and no O-CKO mice were inducible into sustained ventricular tachyarrhythmias. By 45 days of age, cardiac Cx43 abundance had decreased in a heterogeneous fashion to 18% of control levels, conduction velocity had slowed to half of that observed in control hearts, and 80% of O-CKO mice were inducible into lethal tachyarrhythmias. Enhanced susceptibility to induced arrhythmias was not associated with altered invasive hemodynamic measurements or changes in ventricular effective refractory period. Thus, moderately severe reductions in Cx43 abundance are associated with slowing of impulse propagation and a dramatic increase in the susceptibility to inducible ventricular arrhythmias. PMID:15499029

  10. Modulation of Cardiac Gap Junction Expression and Arrhythmic Susceptibility

    PubMed Central

    Danik, Stephan B.; Liu, Fangyu; Zhang, Jie; Suk, H. Jacqueline; Morley, Gregory E.; Fishman, Glenn I.; Gutstein, David E.

    2010-01-01

    Connexin43 (Cx43), the predominant ventricular gap junction protein, is critical for maintaining normal cardiac electrical conduction, and its absence in the mouse heart results in sudden arrhythmic death. The mechanisms linking reduced Cx43 abundance in the heart and inducibility of malignant ventricular arrhythmias have yet to be established. In this report, we investigate arrhythmic susceptibility in a murine model genetically engineered to express progressively decreasing levels of Cx43. Progressively older cardiac-restricted Cx43 conditional knockout (CKO) mice were selectively bred to produce a heart-specific Cx43-deficient subline (“O-CKO” mice) in which the loss of Cx43 in the heart occurs more gradually. O-CKO mice lived significantly longer than the initial series of CKO mice but still died suddenly and prematurely. At 25 days of age, cardiac Cx43 protein levels decreased to 59% of control values (P<0.01), but conduction velocity was not significantly decreased and no O-CKO mice were inducible into sustained ventricular tachyarrhythmias. By 45 days of age, cardiac Cx43 abundance had decreased in a heterogeneous fashion to 18% of control levels, conduction velocity had slowed to half of that observed in control hearts, and 80% of O-CKO mice were inducible into lethal tachyarrhythmias. Enhanced susceptibility to induced arrhythmias was not associated with altered invasive hemodynamic measurements or changes in ventricular effective refractory period. Thus, moderately severe reductions in Cx43 abundance are associated with slowing of impulse propagation and a dramatic increase in the susceptibility to inducible ventricular arrhythmias. PMID:15499029

  11. Vulnerability to mild predator stress in serotonin transporter knockout mice.

    PubMed

    Adamec, Robert; Burton, Paul; Blundell, Jacqueline; Murphy, Dennis L; Holmes, Andrew

    2006-06-01

    Effect of predator stress on rat and mouse anxiety-like behavior may model aspects of post traumatic stress disorder (PTSD). A single cat exposure of wild type (C57, CFW) mice can produce lasting anxiety-like effects in the elevated plus maze, light/dark box tests and startle. In addition, female but not male C57 mice are made more anxious in the plus maze by exposure to predator odors alone, suggesting differential vulnerability to predator stressors of differing intensity. There is a link between genetic variation in the serotonin (5-HT) transporter (SERT) and anxiety in humans. This prompted the generation of SERT knockout mice [see Holmes A, Murphy DL, Crawley, JN. Biol Psychiatry 2003;54(10):953-9]. Present work used these mice to determine if there was a link between vulnerability to the anxiogenic effects of predator odors and abnormalities of 5-HT transmission induced by a life long reduction in 5-HT reuptake. Wild type (WT, C57 background), heterozygous (SERT +/-, HET) mice and homozygous knockout (SERT -/-, KO) were assigned to handled control groups or groups exposed for 10 min to a large testing room rich in cat odor. One week after handling or room exposure, anxiety testing took place in the dark phase of the light/dark cycle, in red light. Predator odor exposure was selectively anxiogenic in the plus maze and light/dark box tests in SERT -/- mice. Exposure to predator odor did not potentiate startle. Findings suggest a role for abnormalities in 5-HT transmission in vulnerability to some of the lasting anxiogenic effects of species relevant stressors and possibly in vulnerability to PTSD. PMID:16546269

  12. Transcriptional control of behavior: Engrailed knockout changes cockroach escape trajectories

    PubMed Central

    Booth, David; Marie, Bruno; Domenici, Paolo; Blagburn, Jonathan M; Bacon, Jonathan P

    2009-01-01

    The cerci of the cockroach are covered with identified sensory hairs, which detect air movements. The sensory neurons which innervate these hairs synapse with giant interneurons (GIs) in the terminal ganglion which in turn synapse with interneurons and leg motorneurons in thoracic ganglia. This neural circuit mediates the animal's escape behavior. The transcription factor Engrailed (En) is expressed only in the medially born sensory neurons, which suggested it could work as a positional determinant of sensory neuron identity. Previously, we used dsRNA interference to abolish En expression, and found that the axonal arborization and synaptic outputs of an identified En-positive sensory neuron changed so that it came to resemble a nearby En-negative cell, which was itself unaffected. We thus demonstrated directly that En controls synaptic choice, as well as axon projections. Is escape behavior affected as a result of this mis-wiring? We recently showed that adult cockroaches keep each escape unpredictable by running along one of a set of preferred escape trajectories (ETs) at fixed angles from the direction of the threatening stimulus. The probability of selecting a particular ET is influenced by wind direction. In this present study we show that early instar juvenile cockroaches also use those same ETs. En knockout significantly perturbs the animals' perception of posterior wind, altering the choice of ETs to one more appropriate for anterior wind. This is the first time that it has been shown that knockout of a transcription factor controlling synaptic connectivity can alter the perception of a directional stimulus. PMID:19494140

  13. Bioelectric Characterization of Epithelia from Neonatal CFTR Knockout Ferrets

    PubMed Central

    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.

    2013-01-01

    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. PMID:23782101

  14. 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.

  15. 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.

  16. 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.

  17. Recovery after cardiac events.

    PubMed

    Davidson, D M; Maloney, C A

    1985-12-01

    This article describes an interdisciplinary program of cardiac rehabilitation that integrates physical therapy with medical, nursing, nutritional, and psychological assessment and treatment. Hospitalized patients recovering from myocardial infarction or cardiac surgery progress through a seven-level program of physical activity, education, and emotional support. These components of the program continue during their early home period and again are integrated during the active training period. In the active training period, patients participate in support groups and receive nutritional, exercise, and medical education and engage in one hour of exercise three times weekly. In all phases, considerable attention is given to the development of behavioral skills necessary for long-term adherence to healthy life style habits.

  18. 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.

  19. 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

  20. The Role of Cardiac Side Population Cells in Cardiac Regeneration.

    PubMed

    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.

  1. The Role of Cardiac Side Population Cells in Cardiac Regeneration.

    PubMed

    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

  2. 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

  3. 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

  4. 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

  5. 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

  6. Deletion of PDK1 Causes Cardiac Sodium Current Reduction in Mice

    PubMed Central

    Han, Zhonglin; Jiang, Yu; Yang, Yuqing; Li, Xuehan; Yang, Zhongzhou; Cao, Kejiang; Wang, Dao W.

    2015-01-01

    Background The AGC protein kinase family regulates multiple cellular functions. 3-phosphoinositide-dependent protein kinase-1 (PDK1) is involved in the pathogenesis of arrhythmia, and its downstream factor, Forkhead box O1 (Foxo1), negatively regulates the expression of the cardiac sodium channel, Nav1.5. Mice are known to die suddenly after PDK1 deletion within 11 weeks, but the underlying electrophysiological bases are unclear. Thus, the aim of this study was to investigate the potential mechanisms between PDK1 signaling pathway and cardiac sodium current. Methods and Results Using patch clamp and western blotting techniques, we investigated the role of the PDK1-Foxo1 pathway in PDK1 knockout mice and cultured cardiomyocytes. We found that PDK1 knockout mice undergo slower heart rate, prolonged QRS and QTc intervals and abnormal conduction within the first few weeks of birth. Furthermore, the peak sodium current is decreased by 33% in cells lacking PDK1. The phosphorylation of Akt (308T) and Foxo1 (24T) and the expression of Nav1.5 in the myocardium of PDK1-knockout mice are decreased, while the nuclear localization of Foxo1 is increased. The role of the PDK1-Foxo1 pathway in regulating Nav1.5 levels and sodium current density was verified using selective PDK1, Akt and Foxo1 inhibitors and isolated neonatal rat cardiomyocytes. Conclusion These results indicate that PDK1 participates in the dysregulation of electrophysiological basis by regulating the PDK1-Foxo1 pathway, which in turn regulates the expression of Nav1.5 and cardiac sodium channel function. PMID:25781322

  7. An unauthorized biography of the second heart field and a pioneer/scaffold model for cardiac development.

    PubMed

    Xavier-Neto, José; Trueba, Sylvia Sura; Stolfi, Alberto; Souza, Henrique Marques; Sobreira, Tiago José Pascoal; Schubert, Michael; Castillo, Hozana Andrade

    2012-01-01

    The identification of subpharyngeal cardiac precursors has had a strong influence on the way we think about early cardiac development. From this discovery was born the concept of multiple heart fields. Early support for the concept came from gene expression, genetic retrospective fate mapping, and gene targeting studies, which collectively suggested the existence of a second heart field (SHF) on the basis of specific Islet-1 (Isl-1) expression, presence of two cardiac ancestral lineages, and compatible cardiac knockout phenotypes, respectively. A decade after the original studies, support for the SHF concept is dwindling. This is because in all bilaterian models studied, Isl expression in heart progenitors is not SHF-specific, because lineage data are best explained by alternative models including an older, truly ancestral, lineage of cardiac pioneers with unrestricted contribution to all cardiac segments and, finally, because the inflow-to-outflow segmental nature of the early vertebrate peristaltic heart has been reaffirmed with novel, less invasive, methodologies. Altogether, the paradigms derived from the discovery of subpharyngeal cardiac progenitors helped us shift from relatively simple models, which rely predominantly either on patterning, gene expression patterns or lineages, to a much more sophisticated body of knowledge in which all these parameters must be accounted. Thus, it is well possible that due consideration of the key elements contained in the inflow/outflow, pioneer/scaffold, ballooning, and SHF hypotheses may provide us with a unified framework of the early stages of cardiac development. Here, we advance into this direction by suggesting an intuitive model of early heart development based on the concept of an inflow/outflow scaffold erected by cardiac pioneers, one that is required to assemble all the subsequent cell contribution that emigrates from cardiac progenitor areas.

  8. 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. PMID:24646609

  9. β-Arrestin-biased AT1R stimulation promotes cell survival during acute cardiac injury.

    PubMed

    Kim, Ki-Seok; Abraham, Dennis; Williams, Barbara; Violin, Jonathan D; Mao, Lan; Rockman, Howard A

    2012-10-15

    Pharmacological blockade of the ANG II type 1 receptor (AT1R) is a common therapy for treatment of congestive heart failure and hypertension. Increasing evidence suggests that selective engagement of β-arrestin-mediated AT1R signaling, referred to as biased signaling, promotes cardioprotective signaling. Here, we tested the hypothesis that a β-arrestin-biased AT1R ligand TRV120023 would confer cardioprotection in response to acute cardiac injury compared with the traditional AT1R blocker (ARB), losartan. TRV120023 promotes cardiac contractility, assessed by pressure-volume loop analyses, while blocking the effects of endogenous ANG II. Compared with losartan, TRV120023 significantly activates MAPK and Akt signaling pathways. These hemodynamic and biochemical effects were lost in β-arrestin-2 knockout (KO) mice. In response to cardiac injury induced by ischemia reperfusion injury or mechanical stretch, pretreatment with TRV120023 significantly diminishes cell death compared with losartan, which did not appear to be cardioprotective. This cytoprotective effect was lost in β-arrestin-2 KO mice. The β-arrestin-biased AT1R ligand, TRV120023, has cardioprotective and functional properties in vivo, which are distinct from losartan. Our data suggest that this novel class of drugs may provide an advantage over conventional ARBs by supporting cardiac function and reducing cellular injury during acute cardiac injury.

  10. Deletion of CXCR4 in cardiomyocytes exacerbates cardiac dysfunction following isoproterenol administration

    PubMed Central

    Wang, ER; Jarrah, AA; Benard, L; Chen, J; Schwarzkopf, M; Hadri, L; Tarzami, ST

    2014-01-01

    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 down stream 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 while fibrosis increases. Additionally, CXCR4 expression was rescued with the use of cardiotropic Adeno-associated viral-9 (AAV9) 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. PMID:24646609

  11. UCP3 Regulates Single-Channel Activity of the Cardiac mCa1.

    PubMed

    Motloch, Lukas J; Gebing, Tina; Reda, Sara; Schwaiger, Astrid; Wolny, Martin; Hoppe, Uta C

    2016-08-01

    Mitochondrial Ca(2+) uptake (mCa(2+) uptake) is thought to be mediated by the mitochondrial Ca(2+) uniporter (MCU). UCP2 and UCP3 belong to a superfamily of mitochondrial ion transporters. Both proteins are expressed in the inner mitochondrial membrane of the heart. Recently, UCP2 was reported to modulate the function of the cardiac MCU related channel mCa1. However, the possible role of UCP3 in modulating cardiac mCa(2+) uptake via the MCU remains inconclusive. To understand the role of UCP3, we analyzed cardiac mCa1 single-channel activity in mitoplast-attached single-channel recordings from isolated murine cardiac mitoplasts, from adult wild-type controls (WT), and from UCP3 knockout mice (UCP3(-/-)). Single-channel registrations in UCP3(-/-) confirmed a murine voltage-gated Ca(2+) channel, i.e., mCa1, which was inhibited by Ru360. Compared to WT, mCa1 in UCP3(-/-) revealed similar single-channel characteristics. However, in UCP3(-/-) the channel exhibited decreased single-channel activity, which was insensitive to adenosine triphosphate (ATP) inhibition. Our results suggest that beyond UCP2, UCP3 also exhibits regulatory effects on cardiac mCa1/MCU function. Furthermore, we speculate that UCP3 might modulate previously described inhibitory effects of ATP on mCa1/MCU activity as well.

  12. Renal and Cardiac Endothelial Heterogeneity Impact Acute Vascular Rejection in Pig-to-Baboon Xenotransplantation

    PubMed Central

    Knosalla, C.; Yazawa, K.; Behdad, A.; Bodyak, N.; Shang, H.; Bühler, L.; Houser, S.; Gollackner, B.; Griesemer, A.; Schmitt-Knosalla, I.; Schuurman, H.-J.; Awwad, M.; Sachs, D. H.; Cooper, D. K. C.; Yamada, K.; Usheva, A.; Robson, S. C.

    2010-01-01

    Xenograft outcomes are dictated by xenoantigen expression, for example, Gal α 1, 3Gal (Gal), but might also depend on differing vascular responses. We investigated whether differential vascular gene expression in kidney and cardiac xenografts correlate with development of thrombotic microangiopathy (TM) and consumptive coagulation (CC). Immunosuppressed baboons underwent miniswine or hDAF pig kidney (n = 6) or heart (n = 7), or Gal-transferase gene-knockout (GalT-KO) (thymo)kidney transplantation (n = 14). Porcine cDNA miniarrays determined donor proinflammatory, apoptosis-related and vascular coagulant/fibrinolytic gene expression at defined time points; validated by mRNA, protein levels and immunopathology. hDAF-transgenic and GalT-KO xenografts, (particularly thymokidneys) exhibited prolonged survival. CC was seen with Gal-expressing porcine kidneys (3 of 6), only 1 of 7 baboons post-cardiac xenotransplantation and was infrequent following GalT-KO grafts (1 of 14). Protective-type genes (heme oxygenase-I, superoxide dismutases and CD39) together with von Willebrand factor and P-selectin were upregulated in all renal grafts. Transcriptional responses in Gal-expressing xenografts were comparable to those seen in the infrequent GalT-KO rejection. In cardiac xenografts, fibrin deposition was associated with increased plasminogen activator inhibitor-1 expression establishing that gene expression profiles in renal and cardiac xenografts differ in a quantitative manner. These findings suggest that therapeutic targets may differ for renal and cardiac xenotransplants. PMID:19422330

  13. Diuretics Prevent Thiazolidinedione-Induced Cardiac Hypertrophy without Compromising Insulin-Sensitizing Effects in Mice

    PubMed Central

    Chang, Cherng-Shyang; Tsai, Pei-Jane; Sung, Junne-Ming; Chen, Ju-Yi; Ho, Li-Chun; Pandya, Kumar; Maeda, Nobuyo; Tsai, Yau-Sheng

    2015-01-01

    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 (PpargP465L/+). 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. PMID:24287404

  14. An overview of cardiac morphogenesis.

    PubMed

    Schleich, Jean-Marc; Abdulla, Tariq; Summers, Ron; Houyel, Lucile

    2013-11-01

    Accurate knowledge of normal cardiac development is essential for properly understanding the morphogenesis of congenital cardiac malformations that represent the most common congenital anomaly in newborns. The heart is the first organ to function during embryonic development and is fully formed at 8 weeks of gestation. Recent studies stemming from molecular genetics have allowed specification of the role of cellular precursors in the field of heart development. In this article we review the different steps of heart development, focusing on the processes of alignment and septation. We also show, as often as possible, the links between abnormalities of cardiac development and the main congenital heart defects. The development of animal models has permitted the unraveling of many mechanisms that potentially lead to cardiac malformations. A next step towards a better knowledge of cardiac development could be multiscale cardiac modelling. PMID:24138816

  15. 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

  16. Sudden Cardiac Death in Athletes.

    PubMed

    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

  17. 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

  18. Cardiac size during prenatal development.

    PubMed

    Jordaan, H V

    1987-06-01

    In this study, the cardiac circumference as measured in a four-chamber view was analyzed to determine its relationship to three linear, sonar measurements--biparietal diameter, femoral length, and abdominal circumference--and two sonographically derived fetal parameters--gestational age and estimated fetal weight. The results showed that the cardiac circumference correlates significantly with these direct and derived variables. It is recommended that the magnitude of the cardiac circumference as a function of any or all of these variables be used as an index of organ size when assessing fetuses at risk for anomalous cardiac development.

  19. 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

  20. Developmental Divergence of Sleep-Wake Patterns in Orexin Knockout and Wild-Type Mice

    PubMed Central

    Coleman, Cassandra M.; Johnson, Eric D.; Shaw, Cynthia

    2008-01-01

    Narcolepsy, a disorder characterized by fragmented bouts of sleep and wakefulness during the day and night as well as cataplexy, has been linked in humans and non-human animals to the functional integrity of the orexinergic system. Adult orexin knockout mice and dogs with a mutation of the orexin receptor exhibit symptoms that mirror those seen in narcoleptic humans. As with narcolepsy, infant sleep-wake cycles in humans and rats are highly fragmented, with consolidated bouts of sleep and wakefulness developing gradually. Based on these common features of narcoleptics and infants, we hypothesized that the development of sleep-wake fragmentation in orexin knockout mice would be expressed as a developmental divergence between knockouts and wild-types, with the knockouts lagging behind the wild-types. We tested this hypothesis by recording the sleep-wake patterns of infant orexin knockout and wild-type mice across the first three postnatal weeks. Both knockouts and wild-types exhibited age-dependent, and therefore orexin-independent, quantitative and qualitative changes in sleep-wake patterning. At 3 weeks of age, however, by which time the sleep and wake bouts of the wild-types had consolidated further, the knockouts lagged behind the wild-types and exhibited significantly more bout fragmentation. These findings suggest the possibility that the fragmentation of behavioral states that characterizes narcolepsy in adults reflects reversion back toward the more fragmented sleep-wake patterns that characterize infancy. PMID:17284193

  1. [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.

  2. 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

  3. 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

  4. Mouse ataxin-3 functional knock-out model.

    PubMed

    Switonski, Pawel M; Fiszer, Agnieszka; Kazmierska, Katarzyna; Kurpisz, Maciej; Krzyzosiak, Wlodzimierz J; Figiel, Maciej

    2011-03-01

    Spinocerebellar ataxia 3 (SCA3) is a genetic disorder resulting from the expansion of the CAG repeats in the ATXN3 gene. The pathogenesis of SCA3 is based on the toxic function of the mutant ataxin-3 protein, but the exact mechanism of the disease remains elusive. Various types of transgenic mouse models explore different aspects of SCA3 pathogenesis, but a knock-in humanized mouse has not yet been created. The initial aim of this study was to generate an ataxin-3 humanized mouse model using a knock-in strategy. The human cDNA for ataxin-3 containing 69 CAG repeats was cloned from SCA3 patient and introduced into the mouse ataxin-3 locus at exon 2, deleting it along with exon 3 and intron 2. Although the human transgene was inserted correctly, the resulting mice acquired the knock-out properties and did not express ataxin-3 protein in any analyzed tissues, as confirmed by western blot and immunohistochemistry. Analyses of RNA expression revealed that the entire locus consisting of human and mouse exons was expressed and alternatively spliced. We detected mRNA isoforms composed of exon 1 spliced with mouse exon 4 or with human exon 7. After applying 37 PCR cycles, we also detected a very low level of the correct exon 1/exon 2 isoform. Additionally, we confirmed by bioinformatic analysis that the structure and power of the splicing site between mouse intron 1 and human exon 2 (the targeted locus) was not changed compared with the native mouse locus. We hypothesized that these splicing aberrations result from the deletion of further splicing sites and the presence of a strong splicing site in exon 4, which was confirmed by bioinformatic analysis. In summary, we created a functional ataxin-3 knock-out mouse model that is viable and fertile and does not present a reduced life span. Our work provides new insights into the splicing characteristics of the Atxn3 gene and provides useful information for future attempts to create knock-in SCA3 models.

  5. 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

  6. Cardiac oxidative stress in a mouse model of neutral lipid storage disease.

    PubMed

    Schrammel, Astrid; Mussbacher, Marion; Winkler, Sarah; Haemmerle, Guenter; Stessel, Heike; Wölkart, Gerald; Zechner, Rudolf; Mayer, Bernd

    2013-11-01

    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

  7. 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

  8. The tight junction protein CAR regulates cardiac conduction and cell-cell communication.

    PubMed

    Lisewski, Ulrike; Shi, Yu; Wrackmeyer, Uta; Fischer, Robert; Chen, Chen; Schirdewan, Alexander; Jüttner, Rene; Rathjen, Fritz; Poller, Wolfgang; Radke, Michael H; Gotthardt, Michael

    2008-09-29

    The Coxsackievirus-adenovirus receptor (CAR) is known for its role in virus uptake and as a protein of the tight junction. It is predominantly expressed in the developing brain and heart and reinduced upon cardiac remodeling in heart disease. So far, the physiological functions of CAR in the adult heart are largely unknown. We have generated a heart-specific inducible CAR knockout (KO) and found impaired electrical conduction between atrium and ventricle that increased with progressive loss of CAR. The underlying mechanism relates to the cross talk of tight and gap junctions with altered expression and localization of connexins that affect communication between CAR KO cardiomyocytes. Our results indicate that CAR is not only relevant for virus uptake and cardiac remodeling but also has a previously unknown function in the propagation of excitation from the atrium to the ventricle that could explain the association of arrhythmia and Coxsackievirus infection of the heart.

  9. Myocardial Galectin-3 Expression Is Associated with Remodeling of the Pressure-Overloaded Heart and May Delay the Hypertrophic Response without Affecting Survival, Dysfunction, and Cardiac Fibrosis.

    PubMed

    Frunza, Olga; Russo, Ilaria; Saxena, Amit; Shinde, Arti V; Humeres, Claudio; Hanif, Waqas; Rai, Vikrant; Su, Ya; Frangogiannis, Nikolaos G

    2016-05-01

    The β-galactoside-binding animal lectin galectin-3 is predominantly expressed by activated macrophages and is a promising biomarker for patients with heart failure. Galectin-3 regulates inflammatory and fibrotic responses; however, its role in cardiac remodeling remains unclear. We hypothesized that galectin-3 may be up-regulated in the pressure-overloaded myocardium and regulate hypertrophy and fibrosis. In normal mouse myocardium, galectin-3 was constitutively expressed in macrophages and was localized in atrial but not ventricular cardiomyocytes. In a mouse model of transverse aortic constriction, galectin-3 expression was markedly up-regulated in the pressure-overloaded myocardium. Early up-regulation of galectin-3 was localized in subpopulations of macrophages and myofibroblasts; however, after 7 to 28 days of transverse aortic constriction, a subset of cardiomyocytes in fibrotic areas contained large amounts of galectin-3. In vitro, cytokine stimulation suppressed galectin-3 synthesis by macrophages and cardiac fibroblasts. Correlation studies revealed that cardiomyocyte- but not macrophage-specific galectin-3 localization was associated with adverse remodeling and dysfunction. Galectin-3 knockout mice exhibited accelerated cardiac hypertrophy after 7 days of pressure overload, whereas female galectin-3 knockouts had delayed dilation after 28 days of transverse aortic constriction. However, galectin-3 loss did not affect survival, systolic and diastolic dysfunction, cardiac fibrosis, and cardiomyocyte hypertrophy in the pressure-overloaded heart. Despite its potential role as a prognostic biomarker, galectin-3 is not a critical modulator of cardiac fibrosis but may delay the hypertrophic response. PMID:26948424

  10. Modeling fragile X syndrome in the Fmr1 knockout mouse

    PubMed Central

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

    2014-01-01

    Summary 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. PMID:25606362

  11. Generation and Behavior Characterization of CaMKIIβ Knockout Mice

    PubMed Central

    Tu, Tao; Goulding, Danielle S.; Haiech, Jacques; Watterson, D. Martin; Van Eldik, Linda J.

    2014-01-01

    The calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain, where it makes important contributions to synaptic organization and homeostasis, including playing an essential role in synaptic plasticity and memory. Four genes encode isoforms of CaMKII (α, β, δ, γ), with CaMKIIα and CaMKIIβ highly expressed in the brain. Decades of molecular and cellular research, as well as the use of a large number of CaMKIIα mutant mouse lines, have provided insight into the pivotal roles of CaMKIIα in brain plasticity and cognition. However, less is known about the CaMKIIβ isoform. We report the development and extensive behavioral and phenotypic characterization of a CaMKIIβ knockout (KO) mouse. The CaMKIIβ KO mouse was found to be smaller at weaning, with an altered body mass composition. The CaMKIIβ KO mouse showed ataxia, impaired forelimb grip strength, and deficits in the rotorod, balance beam and running wheel tasks. Interestingly, the CaMKIIβ KO mouse exhibited reduced anxiety in the elevated plus maze and open field tests. The CaMKIIβ KO mouse also showed cognitive impairment in the novel object recognition task. Our results provide a comprehensive behavioral characterization of mice deficient in the β isoform of CaMKII. The neurologic phenotypes and the construction of the genotype suggest the utility of this KO mouse strain for future studies of CaMKIIβ in brain structure, function and development. PMID:25127391

  12. NELF knockout is associated with impaired pubertal development and subfertility.

    PubMed

    Quaynor, Samuel D; Ko, Eun Kyung; Chorich, Lynn P; Sullivan, Megan E; Demir, Durkadin; Waller, Jennifer L; Kim, Hyung-Goo; Cameron, Richard S; Layman, Lawrence C

    2015-05-15

    Puberty and reproduction require proper signaling of the hypothalamic-pituitary-gonadal axis controlled by gonadotropin-releasing hormone (GnRH) neurons, which arise in the olfactory placode region and migrate along olfactory axons to the hypothalamus. Factors adversely affecting GnRH neuron specification, migration, and function lead to delayed puberty and infertility. Nasal embryonic luteinizing hormone-releasing factor (NELF) is a predominantly nuclear protein. NELF mutations have been demonstrated in patients with hypogonadotropic hypogonadism, but biallelic mutations are rare and heterozygous NELF mutations typically co-exist with mutations in another gene. Our previous studies in immortalized GnRH neurons supported a role for NELF in GnRH neuron migration. To better understand the physiology of NELF, a homozygous Nelf knockout (KO) mouse model was generated. Our findings indicate that female Nelf KO mice have delayed vaginal opening but no delay in time to first estrus, decreased uterine weight, and reduced GnRH neuron number. In contrast, male mice were normal at puberty. Both sexes of mice had impaired fertility manifested as reduced mean litter size. These data support that NELF has important reproductive functions. The milder than expected phenotype of KO mice also recapitulates the human phenotype since heterozygous NELF mutations usually require an additional mutation in a second gene to result in hypogonadotropic hypogonadism.

  13. Tissue-specific knockouts of steroidogenic factor 1.

    PubMed

    Zhao, Liping; Bakke, Marit; Hanley, Neil A; Majdic, Gregor; Stallings, Nancy R; Jeyasuria, Pancharatnam; Parker, Keith L

    2004-02-27

    Targeted gene disruption has produced knockout (KO) mice globally deficient in the orphan nuclear receptor steroidogenic factor 1 (SF-1). These SF-1 KO mice lacked adrenal glands and gonads, and also had impaired expression of gonadotropins in pituitary gonadotropes and marked structural abnormalities of the ventromedial hypothalamic nucleus (VMH). To define the roles of SF-1 within discrete sites of the hypothalamic-pituitary-steroidogenic organ axis, we have sought to make tissue-specific SF-1 KO mice (as reviewed here). We first used adrenal transplants to restore adrenal function in global SF-1 KO mice, providing a physiological form of a "VMH-specific" KO to study the roles of SF-1 in weight regulation. These adrenal-transplanted SF-1 KO mice became obese due to decreased locomotor activity, providing a novel model of hypothalamic obesity. Mice with a pituitary-specific KO of SF-1 mediated by the Cre-loxP recombination strategy exhibited hypogonadotropic hypogonadism, revealing essential roles of SF-1 in pituitary function in vivo. Ongoing studies seek to inactivate SF-1 in the brain or specific gonadal cell types, thereby defining its roles in development and function at these sites. In addition, we review our use of bacterial artificial chromosome transgenesis to develop a fluorescent marker for cells that express SF-1.

  14. 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

  15. 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

    2008-03-01

    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.

  16. Bone Growth and Turnover in Progesterone Receptor Knockout Mice

    PubMed Central

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

    2008-01-01

    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 microcomputed tomography analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 wk 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 were normal in PRKO mice. In contrast, total, cancellous, and cortical bone mass were increased in the humerus of 12-wk-old PRKO mice, whereas cortical and cancellous bone mass in the tibia was normal. At 26 wk of age, cancellous bone area in the proximal tibia metaphysis of PRKO mice was 153% greater than age matched wild-type mice. The improved cancellous bone balance in 6-month-old 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 is not essential for bone growth and turnover. However, at some skeletal sites, PR signaling attenuates the accumulation of cortical and cancellous bone mass during adolescence. PMID:18276762

  17. 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

  18. 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.

  19. 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.

  20. Delayed Wound Healing in CXCR2 Knockout Mice

    PubMed Central

    Devalaraja, Radhika M.; Nanney, Lillian B.; Qian, Qinghua; Du, Jianguo; Yu, Yingchun; Devalaraja, Madhav N.; Richmond, Ann

    2009-01-01

    Previous studies demonstrated that the CXC chemokine, MGSA/GRO-α and its receptor, CXCR2, are expressed during wound healing by keratinocytes and endothelial cells at areas where epithelialization and neovascularization occur. The process of wound healing is dependent on leukocyte recruitment, keratinocyte proliferation and migration, and angiogenesis. These processes may be mediated in part by CXC chemokines, such as interleukin-8 and MGSA/GRO-α. To examine further the significance of CXC chemokines in wound healing, full excisional wounds were created on CXCR2 wild-type (+/+), heterozygous (+/−), or knockout (−/−) mice. Wounds were histologically analyzed for neutrophil and monocyte infiltration, neovascularization and epithelialization at days 3, 5, 7, and 10 postwounding. The CXCR2−/− mice exhibited defective neutrophil recruitment, an altered temporal pattern of monocyte recruitment, and altered secretion of interleukin-1β. Significant delays in wound healing parameters, including epithelialization and decreased neovascularization, were also observed in CXCR2−/− mice. In vitro wounding experiments with cultures of keratinocytes established from −/− and +/+ mice revealed a retardation in wound closure in CXCR2−/− keratinocytes, suggesting a role for this receptor on keratinocytes in epithelial resurfacing that is independent of neutrophil recruitment. These in vitro and in vivo studies further establish a pathophysiologic role for CXCR2 during cutaneous wound repair. PMID:10951241

  1. The peripheral cannabinoid receptor knockout mice: an update

    PubMed Central

    Buckley, N E

    2007-01-01

    This review gives an overview of the CB2 receptor (CB2R) knockout (CB2R−/−) mice phenotype and the work that has been carried out using this mutant mouse. Using the CB2R−/− mice, investigators have discovered the involvement of CB2R on immune cell function and development, infection, embryonic development, bone loss, liver disorders, pain, autoimmune inflammation, allergic dermatitis, atherosclerosis, apoptosis and chemotaxis. Using the CB2R−/− mice, investigators have also found that this receptor is not involved in cannabinoid-induced hypotension. In addition, the CB2R−/− mice have been used to determine specific tissue CB2R expression. The specificity of synthetic cannabinoid agonists, antagonists and anti-CB2R antibodies has been screened using tissues from CB2R−/− mice. Thus, the use of this mouse model has greatly helped reveal the diverse events involving the CB2R, and has aided in drug and antibody screening. PMID:17965741

  2. 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

  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 and label…

  4. 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

  5. Psychological aspects of cardiac arrhythmia.

    PubMed

    Lynch, J J; Paskewitz, D A; Gimbel, K S; Thomas, S A

    1977-05-01

    A review of data from a wide spectrum of research studies suggests that psychological-emotional factors can significantly influence and alter the incidence of cardiac arrhythmia. While the existing data are, in many cases, difficult to interpret because of theoretical and methodological problems, sufficient evidence does exist to warrant a concerted investigation into the total involvement of psychological factors in cardiac arrhythmia.

  6. Ictal Cardiac Ryhthym Abnormalities

    PubMed Central

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic–clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  7. Ictal Cardiac Ryhthym Abnormalities.

    PubMed

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic-clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  8. 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." PMID:959329

  9. Interventional cardiac catheterization.

    PubMed

    Pihkala, J; Nykanen, D; Freedom, R M; Benson, L N

    1999-04-01

    Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

  10. 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.

  11. 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

  12. Conditional Knockout of Myocyte Focal Adhesion Kinase Abrogates Ischemic Preconditioning in Adult Murine Hearts

    PubMed Central

    Perricone, Adam J.; Bivona, Benjamin J.; Jackson, Fannie R.; Vander Heide, Richard S.

    2013-01-01

    Background Our laboratory has previously demonstrated the importance of a cytoskeletal‐based survival signaling pathway using in vitro models of ischemia/reperfusion (IR). However, the importance of this pathway in mediating stress‐elicited survival signaling in vivo is unknown. Methods and Results The essential cytoskeletal signaling pathway member focal adhesion kinase (FAK) was selectively deleted in adult cardiac myocytes using a tamoxifen‐inducible Cre‐Lox system (α‐MHC‐MerCreMer). Polymerase chain reaction (PCR) and Western blot were performed to confirm FAK knockout (KO). All mice were subjected to a 40‐minute coronary occlusion followed by 24 hours of reperfusion. Ischemic preconditioning (IP) was performed using a standard protocol. Control groups included wild‐type (WT) and tamoxifen‐treated α‐MHC‐MerCreMer+/−/FAKWT/WT (experimental control) mice. Infarct size was expressed as a percentage of the risk region. In WT mice IP significantly enhanced the expression of activated/phosphorylated FAK by 36.3% compared to WT mice subjected to a sham experimental protocol (P≤0.05; n=6 hearts [sham], n=4 hearts [IP]). IP significantly reduced infarct size in both WT and experimental control mice (43.7% versus 19.8%; P≤0.001; 44.7% versus 17.5%; P≤0.001, respectively). No difference in infarct size was observed between preconditioned FAK KO and nonpreconditioned controls (37.1% versus 43.7% versus 44.7%; FAK KO versus WT versus experimental control; P=NS). IP elicited a 67.2%/88.8% increase in activated phosphatidylinositol‐3‐kinase (PI3K) p85/activated Akt expression in WT mice, but failed to enhance the expression of either in preconditioned FAK KO mice. Conclusions Our results indicate that FAK is an essential mediator of IP‐elicited cardioprotection and provide further support for the hypothesis that cytoskeletal‐based signaling is an important component of stress‐elicited survival signaling. PMID:24080910

  13. Metabolomic Characterization of Knockout Mutants in Arabidopsis: Development of a Metabolite Profiling Database for Knockout Mutants in Arabidopsis.

    PubMed

    Fukushima, Atsushi; Kusano, Miyako; Mejia, Ramon Francisco; Iwasa, Mami; Kobayashi, Makoto; Hayashi, Naomi; Watanabe-Takahashi, Akiko; Narisawa, Tomoko; Tohge, Takayuki; Hur, Manhoi; Wurtele, Eve Syrkin; Nikolau, Basil J; Saito, Kazuki

    2014-05-14

    Despite recent intensive research efforts in functional genomics, the functions of only a limited number of Arabidopsis (Arabidopsis thaliana) genes have been determined experimentally, and improving gene annotation remains a major challenge in plant science. As metabolite profiling can characterize the metabolomic phenotype of a genetic perturbation in the plant metabolism, it provides clues to the function(s) of genes of interest. We chose 50 Arabidopsis mutants, including a set of characterized and uncharacterized mutants, that resemble wild-type plants. We performed metabolite profiling of the plants using gas chromatography-mass spectrometry. To make the data set available as an efficient public functional genomics tool for hypothesis generation, we developed the Metabolite Profiling Database for Knock-Out Mutants in Arabidopsis (MeKO). It allows the evaluation of whether a mutation affects metabolism during normal plant growth and contains images of mutants, data on differences in metabolite accumulation, and interactive analysis tools. Nonprocessed data, including chromatograms, mass spectra, and experimental metadata, follow the guidelines set by the Metabolomics Standards Initiative and are freely downloadable. Proof-of-concept analysis suggests that MeKO is highly useful for the generation of hypotheses for genes of interest and for improving gene annotation. MeKO is publicly available at http://prime.psc.riken.jp/meko/.

  14. 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)

  15. 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...

  16. Cardiac Biomarkers and Acute Kidney Injury After Cardiac Surgery

    PubMed Central

    Bucholz, Emily M.; Whitlock, Richard P.; Zappitelli, Michael; Devarajan, Prasad; Eikelboom, John; Garg, Amit X.; Philbrook, Heather Thiessen; Devereaux, Philip J.; Krawczeski, Catherine D.; Kavsak, Peter; Shortt, Colleen

    2015-01-01

    OBJECTIVES: To examine the relationship of cardiac biomarkers with postoperative acute kidney injury (AKI) among pediatric patients undergoing cardiac surgery. METHODS: Data from TRIBE-AKI, a prospective study of children undergoing cardiac surgery, were used to examine the association of cardiac biomarkers (N-type pro–B-type natriuretic peptide, creatine kinase-MB [CK-MB], heart-type fatty acid binding protein [h-FABP], and troponins I and T) with the development of postoperative AKI. Cardiac biomarkers were collected before and 0 to 6 hours after surgery. AKI was defined as a ≥50% or 0.3 mg/dL increase in serum creatinine, within 7 days of surgery. RESULTS: Of the 106 patients included in this study, 55 (52%) developed AKI after cardiac surgery. Patients who developed AKI had higher median levels of pre- and postoperative cardiac biomarkers compared with patients without AKI (all P < .01). Preoperatively, higher levels of CK-MB and h-FABP were associated with increased odds of developing AKI (CK-MB: adjusted odds ratio 4.58, 95% confidence interval [CI] 1.56–13.41; h-FABP: adjusted odds ratio 2.76, 95% CI 1.27–6.03). When combined with clinical models, both preoperative CK-MB and h-FABP provided good discrimination (area under the curve 0.77, 95% CI 0.68–0.87, and 0.78, 95% CI 0.68–0.87, respectively) and improved reclassification indices. Cardiac biomarkers collected postoperatively did not significantly improve the prediction of AKI beyond clinical models. CONCLUSIONS: Preoperative CK-MB and h-FABP are associated with increased risk of postoperative AKI and provide good discrimination of patients who develop AKI. These biomarkers may be useful for risk stratifying patients undergoing cardiac surgery. PMID:25755241

  17. 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.

  18. Feeding-elicited cataplexy in orexin knockout mice

    PubMed Central

    Clark, Erika L.; Baumann, Christian R.; Cano, Georgina; Scammell, Thomas E.; Mochizuki, Takatoshi

    2009-01-01

    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 lib regular chow. Mice were then placed on a scheduled feeding protocol in which they received 60% of their normal amount of chow 3 hr 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. PMID:19362119

  19. Targeting cancer using KAT inhibitors to mimic lethal knockouts.

    PubMed

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

    2016-08-15

    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

  20. 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

  1. Spontaneous sleep and homeostatic sleep regulation in ghrelin knockout mice.

    PubMed

    Szentirmai, Eva; Kapás, Levente; Sun, Yuxiang; Smith, Roy G; Krueger, James M

    2007-07-01

    Ghrelin is well known for its feeding and growth hormone-releasing actions. It may also be involved in sleep regulation; intracerebroventricular administration and hypothalamic microinjections of ghrelin stimulate wakefulness in rats. Hypothalamic ghrelin, together with neuropeptide Y and orexin form a food intake-regulatory circuit. We hypothesized that this circuit also promotes arousal. To further investigate the role of ghrelin in the regulation of sleep-wakefulness, we characterized spontaneous and homeostatic sleep regulation in ghrelin knockout (KO) and wild-type (WT) mice. Both groups of mice exhibited similar diurnal rhythms with more sleep and less wakefulness during the light period. In ghrelin KO mice, spontaneous wakefulness and rapid-eye-movement sleep (REMS) were slightly elevated, and non-rapid-eye-movement sleep (NREMS) was reduced. KO mice had more fragmented NREMS than WT mice, as indicated by the shorter and greater number of NREMS episodes. Six hours of sleep deprivation induced rebound increases in NREMS and REMS and biphasic changes in electroencephalographic slow-wave activity (EEG SWA) in both genotypes. Ghrelin KO mice recovered from NREMS and REMS loss faster, and the delayed reduction in EEG SWA, occurring after sleep loss-enhanced increases in EEG SWA, was shorter-lasting compared with WT mice. These findings suggest that the basic sleep-wake regulatory mechanisms in ghrelin KO mice are not impaired and they are able to mount adequate rebound sleep in response to a homeostatic challenge. It is possible that redundancy in the arousal systems of the brain or activation of compensatory mechanisms during development allow for normal sleep-wake regulation in ghrelin KO mice. PMID:17409264

  2. Salty taste deficits in CALHM1 knockout mice.

    PubMed

    Tordoff, Michael G; Ellis, Hillary T; Aleman, Tiffany R; Downing, Arnelle; Marambaud, Philippe; Foskett, J Kevin; Dana, Rachel M; McCaughey, Stuart A

    2014-07-01

    Genetic ablation of calcium homeostasis modulator 1 (CALHM1), which releases adenosine triphosphate from Type 2 taste cells, severely compromises the behavioral and electrophysiological responses to tastes detected by G protein-coupled receptors, such as sweet and bitter. However, the contribution of CALHM1 to salty taste perception is less clear. Here, we evaluated several salty taste-related phenotypes of CALHM1 knockout (KO) mice and their wild-type (WT) controls: 1) In a conditioned aversion test, CALHM1 WT and KO mice had similar NaCl avoidance thresholds. 2) In two-bottle choice tests, CALHM1 WT mice showed the classic inverted U-shaped NaCl concentration-preference function but CALHM1 KO mice had a blunted peak response. 3) In brief-access tests, CALHM1 KO mice showed less avoidance than did WT mice of high concentrations of NaCl, KCl, NH(4)Cl, and sodium lactate (NaLac). Amiloride further ameliorated the NaCl avoidance of CALHM1 KO mice, so that lick rates to a mixture of 1000 mM NaCl + 10 µM amiloride were statistically indistinguishable from those to water. 4) Relative to WT mice, CALHM1 KO mice had reduced chorda tympani nerve activity elicited by oral application of NaCl, NaLac, and sucrose but normal responses to HCl and NH(4)Cl. Chorda tympani responses to NaCl and NaLac were amiloride sensitive in WT but not KO mice. These results reinforce others demonstrating that multiple transduction pathways make complex, concentration-dependent contributions to salty taste perception. One of these pathways depends on CALHM1 to detect hypertonic NaCl in the mouth and signal the aversive taste of concentrated salt.

  3. 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

  4. Comprehensive Behavioral Analysis of Cluster of Differentiation 47 Knockout Mice

    PubMed Central

    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. PMID:24586890

  5. Salty taste deficits in CALHM1 knockout mice.

    PubMed

    Tordoff, Michael G; Ellis, Hillary T; Aleman, Tiffany R; Downing, Arnelle; Marambaud, Philippe; Foskett, J Kevin; Dana, Rachel M; McCaughey, Stuart A

    2014-07-01

    Genetic ablation of calcium homeostasis modulator 1 (CALHM1), which releases adenosine triphosphate from Type 2 taste cells, severely compromises the behavioral and electrophysiological responses to tastes detected by G protein-coupled receptors, such as sweet and bitter. However, the contribution of CALHM1 to salty taste perception is less clear. Here, we evaluated several salty taste-related phenotypes of CALHM1 knockout (KO) mice and their wild-type (WT) controls: 1) In a conditioned aversion test, CALHM1 WT and KO mice had similar NaCl avoidance thresholds. 2) In two-bottle choice tests, CALHM1 WT mice showed the classic inverted U-shaped NaCl concentration-preference function but CALHM1 KO mice had a blunted peak response. 3) In brief-access tests, CALHM1 KO mice showed less avoidance than did WT mice of high concentrations of NaCl, KCl, NH(4)Cl, and sodium lactate (NaLac). Amiloride further ameliorated the NaCl avoidance of CALHM1 KO mice, so that lick rates to a mixture of 1000 mM NaCl + 10 µM amiloride were statistically indistinguishable from those to water. 4) Relative to WT mice, CALHM1 KO mice had reduced chorda tympani nerve activity elicited by oral application of NaCl, NaLac, and sucrose but normal responses to HCl and NH(4)Cl. Chorda tympani responses to NaCl and NaLac were amiloride sensitive in WT but not KO mice. These results reinforce others demonstrating that multiple transduction pathways make complex, concentration-dependent contributions to salty taste perception. One of these pathways depends on CALHM1 to detect hypertonic NaCl in the mouth and signal the aversive taste of concentrated salt. PMID:24846212

  6. 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.

  7. 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.

  8. FastPros: screening of reaction knockout strategies for metabolic engineering

    PubMed Central

    Ohno, Satoshi; Shimizu, Hiroshi; Furusawa, Chikara

    2014-01-01

    Motivation: Although constraint-based flux analysis of knockout strains has facilitated the production of desirable metabolites in microbes, current screening methods have placed a limitation on the number knockouts that can be simultaneously analyzed. Results: Here, we propose a novel screening method named FastPros. In this method, the potential of a given reaction knockout for production of a specific metabolite is evaluated by shadow pricing of the constraint in the flux balance analysis, which generates a screening score to obtain candidate knockout sets. To evaluate the performance of FastPros, we screened knockout sets to produce each metabolite in the entire Escherichia coli metabolic network. We found that 75% of these metabolites could be produced under biomass maximization conditions by adding up to 25 reaction knockouts. Furthermore, we demonstrated that using FastPros in tandem with another screening method, OptKnock, could further improve target metabolite productivity. Availability and implementation: Source code is freely available at http://www-shimizu.ist.osaka-u.ac.jp/shimizu_lab/FastPros/, implemented in MATLAB and COBRA toolbox. Contact: chikara.furusawa@riken.jp or shimizu@ist.osaka-u.ac.jp Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24257186

  9. Trends in Cardiac Pacemaker Batteries

    PubMed Central

    Mallela, Venkateswara Sarma; Ilankumaran, V; Rao, N.Srinivasa

    2004-01-01

    Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future. PMID:16943934

  10. Trends in cardiac pacemaker batteries.

    PubMed

    Mallela, Venkateswara Sarma; Ilankumaran, V; Rao, N Srinivasa

    2004-01-01

    Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future. PMID:16943934

  11. The Pathogenesis of Cardiac Fibrosis

    PubMed Central

    Kong, Ping; Christia, Panagiota; Frangogiannis, Nikolaos G

    2013-01-01

    Cardiac fibrosis is characterized by net accumulation of extracellular matrix proteins in the cardiac interstitium and contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. This review manuscript discusses the cellular effectors and molecular pathways implicated in the pathogenesis of cardiac fibrosis. Although activated myofibroblasts are the main effector cells in the fibrotic heart, monocytes/macrophages, lymphocytes, mast cells, vascular cells and cardiomyocytes may also contribute to the fibrotic response by secreting key fibrogenic mediators. Inflammatory cytokines and chemokines, reactive oxygen species, mast cell-derived proteases, endothelin-1, the renin/angiotensin/aldosterone system, matricellular proteins and growth factors (such as TGF-β and PDGF) are some of the best-studied mediators implicated in cardiac fibrosis. Both experimental and clinical evidence suggests that cardiac fibrotic alterations may be reversible. Understanding the mechanisms responsible for initiation, progression and resolution of cardiac fibrosis is crucial to design anti-fibrotic treatment strategies for patients with heart disease. PMID:23649149

  12. 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.

  13. Acceleration of crossbridge kinetics by protein kinase A phosphorylation of cardiac myosin binding protein C modulates cardiac function

    PubMed Central

    Tong, Carl W.; Stelzer, Julian E.; Greaser, Marion L.; Powers, Patricia A.; Moss, Richard L.

    2009-01-01

    Normal cardiac function requires dynamic modulation of contraction. β1 adrenergic-induced protein kinase A (PKA) phosphorylation of cardiac myosin binding protein C (cMyBP-C) may regulate crossbridge kinetics to modulate contraction. We tested this idea with mechanical measurements and echocardiography in a mouse model lacking three PKA sites on cMyBP-C, i.e., cMyBP-C(t3SA). We developed the model by transgenic expression of mutant cMyBP-C with Ser to Ala mutations on the cMyBP-C knock-out (KO) background. Western blots, immunofluorescence, and in vitro phosphorylation combined to show that non-PKA-phosphorylatable cMyBP-C expressed at 74% compared to normal wild type (WT) and was correctly positioned in the sarcomeres. Similar expression of WT cMyBP-C at 72% served as control, i.e., cMyBP-C(tWT). Skinned myocardium responded to stretch with an immediate increase in force, followed by a transient relaxation of force, and finally a delayed development of force, i.e., stretch activation. The rate constants of relaxation, krel (s−1), and delayed force development, kdf (s−1), in the stretch activation response are indicators of crossbridge cycling kinetics. cMyBP-C(t3SA) myocardium had baseline krel and kdf similar to WT myocardium, but unlike WT, krel and kdf were not accelerated by PKA treatment. Reduced dobutamine augmentation of systolic function in cMyBP-C(t3SA) hearts during echocardiography corroborated the stretch activation findings. Furthermore, cMyBP-C(t3SA) hearts exhibited basal echocardiagraphic findings of systolic dysfunction, diastolic dysfunction, and hypertrophy. Conversely, cMyBP-C(tWT) hearts performed similar to WT. Thus, PKA phosphorylation of cMyBP-C accelerates crossbridge kinetics and loss of this regulation leads to cardiac dysfunction. PMID:18802026

  14. 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

  15. Cardiac-specific VLCAD deficiency induces dilated cardiomyopathy and cold intolerance.

    PubMed

    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; Khuchua, Zaza

    2014-02-01

    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.

  16. Recent advances in animal and human pluripotent stem cell modeling of cardiac laminopathy.

    PubMed

    Lee, Yee-Ki; Jiang, Yu; Ran, Xin-Ru; Lau, Yee-Man; Ng, Kwong-Man; Lai, Wing-Hon Kevin; Siu, Chung-Wah; Tse, Hung-Fat

    2016-01-01

    Laminopathy is a disease closely related to deficiency of the nuclear matrix protein lamin A/C or failure in prelamin A processing, and leads to accumulation of the misfold protein causing progeria. The resultant disrupted lamin function is highly associated with abnormal nuclear architecture, cell senescence, apoptosis, and unstable genome integrity. To date, the effects of loss in nuclear integrity on the susceptible organ, striated muscle, have been commonly associated with muscular dystrophy, dilated cardiac myopathy (DCM), and conduction defeats, but have not been studied intensively. In this review, we aim to summarize recent breakthroughs in an in vivo laminopathy model and in vitro study using patient-specific human induced pluripotent stem cells (iPSCs) that reproduce the pathophysiological phenotype for further drug screening. We describe several in-vivo transgenic mouse models to elucidate the effects of Lmna H222P, N195K mutations, and LMNA knockout on cardiac function, in terms of hemodynamic and electrical signal propagation; certain strategies targeted on stress-related MAPK are mentioned. We will also discuss human iPSC cardiomyocytes serving as a platform to reveal the underlying mechanisms, such as the altered mechanical sensation in electrical coupling of the heart conduction system and ion channel alternation in relation to altered nuclear architecture, and furthermore to enable screening of drugs that can attenuate this cardiac premature aging phenotype by inhibition of prelamin misfolding and oxidative stress, and also enhancement of autophagy protein clearance and cardiac-protective microRNA. PMID:27649756

  17. Myeloid Mineralocorticoid Receptor Deficiency Inhibits Aortic Constriction-Induced Cardiac Hypertrophy in Mice

    PubMed Central

    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. PMID:25354087

  18. Recent advances in animal and human pluripotent stem cell modeling of cardiac laminopathy.

    PubMed

    Lee, Yee-Ki; Jiang, Yu; Ran, Xin-Ru; Lau, Yee-Man; Ng, Kwong-Man; Lai, Wing-Hon Kevin; Siu, Chung-Wah; Tse, Hung-Fat

    2016-09-20

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

  19. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert . E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  20. 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

  1. Cardiac Involvement in Ankylosing Spondylitis

    PubMed Central

    Ozkan, Yasemin

    2016-01-01

    Ankylosing spondylitis is one of the subgroup of diseases called “seronegative spondyloarthropathy”. Frequently, it affects the vertebral colon and sacroiliac joint primarily and affects the peripheral joints less often. This chronic, inflammatory and rheumatic disease can also affect the extraarticular regions of the body. The extraarticular affections can be ophthalmologic, cardiac, pulmonary or neurologic. The cardiac affection can be 2-10% in all patients. Cardiac complications such as left ventricular dysfunction, aortitis, aortic regurgitation, pericarditis and cardiomegaly are reviewed. PMID:27222669

  2. Acupuncture therapy related cardiac injury.

    PubMed

    Li, Xue-feng; Wang, Xian

    2013-12-01

    Cardiac injury is the most serious adverse event in acupuncture therapy. The causes include needling chest points near the heart, the cardiac enlargement and pericardial effusion that will enlarge the projected area on the body surface and make the proper depth of needling shorter, and the incorrect needling method of the points. Therefore, acupuncture practitioners must be familiar with the points of the heart projected area on the chest and the correct needling methods in order to reduce the risk of acupuncture therapy related cardiac injury.

  3. Videoscope-assisted cardiac surgery

    PubMed Central

    Chen, Robert Jeen-Chen

    2014-01-01

    Videoscope-assisted cardiac surgery (VACS) offers a minimally invasive platform for most cardiac operations such as coronary and valve procedures. It includes robotic and thoracoscopic approaches and each has strengths and weaknesses. The success depends on appropriate hardware setup, staff training, and troubleshooting efficiency. In our institution, we often use VACS for robotic left-internal-mammary-artery takedown, mitral valve repair, and various intra-cardiac operations such as tricuspid valve repair, combined Maze procedure, atrial septal defect repair, ventricular septal defect repair, etc. Hands-on reminders and updated references are provided for reader’s further understanding of the topic. PMID:24455172

  4. Dual gated nuclear cardiac images

    SciTech Connect

    Zubal, I.G.; Bennett, G.W.; Bizais, Y.; Brill, A.B.

    1984-02-01

    A data acquisition system has been developed to collect camera events simultaneously with continually digitized electrocardiograph signals and respiratory flow measurements. Software processing of the list mode data creates more precisely gated cardiac frames. Additionally, motion blur due to heart movement during breathing is reduced by selecting events within a specific respiratory phase. Thallium myocardium images of a healthy volunteer show increased definition. This technique of combined cardiac and respiratory gating has the potential of improving the detectability of small lesions, and the characterization of cardiac wall motion.

  5. A novel conditional mouse model for Nkx2-5 reveals transcriptional regulation of cardiac ion channels.

    PubMed

    Furtado, Milena B; Wilmanns, Julia C; Chandran, Anjana; Tonta, Mary; Biben, Christine; Eichenlaub, Michael; Coleman, Harold A; Berger, Silke; Bouveret, Romaric; Singh, Reena; Harvey, Richard P; Ramialison, Mirana; Pearson, James T; Parkington, Helena C; Rosenthal, Nadia A; Costa, Mauro W

    2016-01-01

    Nkx2-5 is one of the master regulators of cardiac development, homeostasis and disease. This transcription factor has been previously associated with a suite of cardiac congenital malformations and impairment of electrical activity. When disease causative mutations in transcription factors are considered, NKX2-5 gene dysfunction is the most common abnormality found in patients. Here we describe a novel mouse model and subsequent implications of Nkx2-5 loss for aspects of myocardial electrical activity. In this work we have engineered a new Nkx2-5 conditional knockout mouse in which flox sites flank the entire Nkx2-5 locus, and validated this line for the study of heart development, differentiation and disease using a full deletion strategy. While our homozygous knockout mice show typical embryonic malformations previously described for the lack of the Nkx2-5 gene, hearts of heterozygous adult mice show moderate morphological and functional abnormalities that are sufficient to sustain blood supply demands under homeostatic conditions. This study further reveals intriguing aspects of Nkx2-5 function in the control of cardiac electrical activity. Using a combination of mouse genetics, biochemistry, molecular and cell biology, we demonstrate that Nkx2-5 regulates the gene encoding Kcnh2 channel and others, shedding light on potential mechanisms generating electrical abnormalities observed in patients bearing NKX2-5 dysfunction and opening opportunities to the study of novel therapeutic targets for anti-arrhythmogenic therapies. PMID:26897459

  6. Cardiac Gab1 deletion leads to dilated cardiomyopathy associated with mitochondrial damage and cardiomyocyte apoptosis.

    PubMed

    Zhao, J; Yin, M; Deng, H; Jin, F Q; Xu, S; Lu, Y; Mastrangelo, M A; Luo, H; Jin, Z G

    2016-04-01

    A vital step in the development of heart failure is the transition from compensatory cardiac hypertrophy to decompensated dilated cardiomyopathy (DCM) during cardiac remodeling under mechanical or pathological stress. However, the molecular mechanisms underlying the development of DCM and heart failure remain incompletely understood. In the present study, we investigate whether Gab1, a scaffolding adaptor protein, protects against hemodynamic stress-induced DCM and heat failure. We first observed that the protein levels of Gab1 were markedly reduced in hearts from human patients with DCM and from mice with experimental viral myocarditis in which DCM developed. Next, we generated cardiac-specific Gab1 knockout mice (Gab1-cKO) and found that Gab-cKO mice developed DCM in hemodynamic stress-dependent and age-dependent manners. Under transverse aorta constriction (TAC), Gab1-cKO mice rapidly developed decompensated DCM and heart failure, whereas Gab1 wild-type littermates exhibited adaptive left ventricular hypertrophy without changes in cardiac function. Mechanistically, we showed that Gab1-cKO mouse hearts displayed severe mitochondrial damages and increased cardiomyocyte apoptosis. Loss of cardiac Gab1 in mice impaired Gab1 downstream MAPK signaling pathways in the heart under TAC. Gene profiles further revealed that ablation of Gab1 in heart disrupts the balance of anti- and pro-apoptotic genes in cardiomyocytes. These results demonstrate that cardiomyocyte Gab1 is a critical regulator of the compensatory cardiac response to aging and hemodynamic stress. These findings may provide new mechanistic insights and potential therapeutic target for DCM and heart failure.

  7. Targeted deletion of PTEN in cardiomyocytes renders cardiac contractile dysfunction through interruption of Pink1-AMPK signaling and autophagy.

    PubMed

    Roe, Nathan D; Xu, Xihui; Kandadi, Machender R; Hu, Nan; Pang, Jiaojiao; Weiser-Evans, Mary C M; Ren, Jun

    2015-02-01

    Phosphatase and tensin homolog (PTEN) deleted from chromosome 10 has been implicated in the maintenance of cardiac homeostasis although the underlying mechanism(s) remains elusive. We generated a murine model of cardiomyocyte-specific knockout of PTEN to evaluate cardiac geometry and contractile function, as well as the effect of metformin on PTEN deficiency-induced cardiac anomalies, if any. Cardiac histology, autophagy and related signaling molecules were evaluated. Cardiomyocyte-specific PTEN deletion elicited cardiac hypertrophy and contractile anomalies (echocardiographic and cardiomyocyte contractile dysfunction) associated with compromised intracellular Ca(2+) handling. PTEN deletion-induced cardiac hypertrophy and contractile anomalies were associated with dampened phosphorylation of PTEN-inducible kinase 1 (Pink1) and AMPK. Interestingly, administration of AMPK activator metformin (200mg/kg/d, in drinking H2O for 4weeks) rescued against PTEN deletion-induced geometric and functional defects as well as interrupted autophagy and autophagic flux in the heart. Moreover, metformin administration partially although significantly attenuated PTEN deletion-induced accumulation of superoxide. RNA interference against Pink1 in H9C2 myoblasts overtly increased intracellular ATP levels and suppressed AMPK phosphorylation, confirming the role of AMPK as a downstream target for PTEN-Pink1. Further scrutiny revealed that activation of AMPK and autophagy using metformin and rapamycin, respectively, rescued against PTEN deletion-induced mechanical anomalies with little additive effect. These data demonstrated that cardiomyocyte-specific deletion of PTEN leads to the loss of Pink1-AMPK signaling, development of cardiac hypertrophy and contractile defect. Activation of AMPK rescued against PTEN deletion-induced cardiac anomalies associated with restoration of autophagy and autophagic flux. This article is part of a Special Issue entitled: Autophagy and protein quality control

  8. Recent developments in cardiac pacing.

    PubMed

    Rodak, D J

    1995-10-01

    Indications for cardiac pacing continue to expand. Pacing to improve functional capacity, which is now common, relies on careful patient selection and technical improvements, such as complex software algorithms and diagnostic capabilities.

  9. Robot-Assisted Cardiac Surgery

    PubMed Central

    Watanabe, Go

    2015-01-01

    Recognition of the significant advantages of minimizing surgical trauma has resulted in the development of minimally invasive surgical procedures. Endoscopic surgery offers patients the benefits of minimally invasive surgery, and surgical robots have enhanced the ability and precision of surgeons. Consequently, technological advances have facilitated totally endoscopic robotic cardiac surgery, which has allowed surgeons to operate endoscopically rather than through a median sternotomy during cardiac surgery. Thus, repairs for structural heart conditions, including mitral valve plasty, atrial septal defect closure, multivessel minimally invasive direct coronary artery bypass grafting (MIDCAB), and totally endoscopic coronary artery bypass graft surgery (CABG), can be totally endoscopic. Robot-assisted cardiac surgery as minimally invasive cardiac surgery is reviewed. PMID:26134073

  10. Cardiac Rehabilitation: Then and Now.

    ERIC Educational Resources Information Center

    Wilson, Philip K.

    1988-01-01

    As more and more patients survive a coronary event, the need for cardiac rehabilitation will increase. The author reviews the history and current status of this field and predicts what lies ahead. (JD)

  11. Robot-assisted cardiac surgery.

    PubMed

    Ishikawa, Norihiko; Watanabe, Go

    2015-01-01

    Recognition of the significant advantages of minimizing surgical trauma has resulted in the development of minimally invasive surgical procedures. Endoscopic surgery offers patients the benefits of minimally invasive surgery, and surgical robots have enhanced the ability and precision of surgeons. Consequently, technological advances have facilitated totally endoscopic robotic cardiac surgery, which has allowed surgeons to operate endoscopically rather than through a median sternotomy during cardiac surgery. Thus, repairs for structural heart conditions, including mitral valve plasty, atrial septal defect closure, multivessel minimally invasive direct coronary artery bypass grafting (MIDCAB), and totally endoscopic coronary artery bypass graft surgery (CABG), can be totally endoscopic. Robot-assisted cardiac surgery as minimally invasive cardiac surgery is reviewed. PMID:26134073

  12. MedlinePlus: Cardiac Rehabilitation

    MedlinePlus

    ... available Research Clinical Trials Journal Articles Resources Reference Desk Find an Expert For You Patient Handouts Summary Cardiac rehabilitation (rehab) is a medically supervised program to help people who have A heart attack Angioplasty or ...

  13. Rescue of the mineralocorticoid receptor knock-out mouse.

    PubMed

    Bleich, M; Warth, R; Schmidt-Hieber, M; Schulz-Baldes, A; Hasselblatt, P; Fisch, D; Berger, S; Kunzelmann, K; Kriz, W; Schütz, G; Greger, R

    1999-08-01

    The mineralocorticoid receptor knock-out mouse (MR-/-), resembling inborn pseudohypoaldosteronism, dies 8-12 days after birth in circulatory failure with all the signs of terminal volume contraction. The present study aimed to examine the functional defects in the kidney and colon in detail and to attempt to rescue these mice. In neonatal (nn) MR-/- the amiloride-sensitive short-circuit current in the colon was reduced to approximately one-third compared to controls (MR+/+ and MR+/-). In isolated in vitro perfused collecting ducts the amiloride-induced hyperpolarization of the basolateral membrane (Vbl) of nn MR-/- was similar to that of controls, but urinary Na+ excretion was markedly increased to 4.3 micromol/day.g (BW). Based on this measured urinary Na+ loss we tried to rescue nn MR-/- mice by injecting NaCl twice daily (3.85 micromol/g BW), corresponding to 22 microliter of isotonic saline/g BW subcutaneously. This regimen was continued until the animals had reached a body mass of 8.5 g. Thereafter, in addition to normal chow and tap water, NaCl drinking water (333 mmol/l) and pellets soaked in 333 mmol/l NaCl were offered. Unlike the untreated nn MR-/- most of these mice survived. The adult animals were examined between days 27 and 41, some were used for breeding. When compared to age-matched controls the growth of MR-/- was delayed until day 20. Then their growth curve increased in slope and reached that of controls. MR-/- retained their Na+-losing defect. Amiloride's effect on urinary Na+ excretion was not significant in MR-/- mice and the effect on Vbl in isolated cortical collecting ducts was attenuated. The renin-producing cells were hypertrophic and hyperplastic. Plasma renin and aldosterone concentrations were significantly elevated in MR-/- mice. These data indicate that MR-/- can be rescued by timely and matched NaCl substitutions. This enables the animals to develop through a critical phase of life, after which they adapt their oral salt and water

  14. 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

  15. Behavioral and electrophysiological characterization of Dyt1 heterozygous knockout mice.

    PubMed

    Yokoi, Fumiaki; Chen, Huan-Xin; Dang, Mai Tu; Cheetham, Chad C; Campbell, Susan L; Roper, Steven N; Sweatt, J David; Li, Yuqing

    2015-01-01

    DYT1 dystonia is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most of the patients have a trinucleotide deletion (ΔGAG) corresponding to a glutamic acid in the C-terminal region (torsinA(ΔE)). Dyt1 ΔGAG heterozygous knock-in (KI) mice, which mimic ΔGAG mutation in the endogenous gene, exhibit motor deficits and deceased frequency of spontaneous excitatory post-synaptic currents (sEPSCs) and normal theta-burst-induced long-term potentiation (LTP) in the hippocampal CA1 region. Although Dyt1 KI mice show decreased hippocampal torsinA levels, it is not clear whether the decreased torsinA level itself affects the synaptic plasticity or torsinA(ΔE) does it. To analyze the effect of partial torsinA loss on motor behaviors and synaptic transmission, Dyt1 heterozygous knock-out (KO) mice were examined as a model of a frame-shift DYT1 mutation in patients. Consistent with Dyt1 KI mice, Dyt1 heterozygous KO mice showed motor deficits in the beam-walking test. Dyt1 heterozygous KO mice showed decreased hippocampal torsinA levels lower than those in Dyt1 KI mice. Reduced sEPSCs and normal miniature excitatory post-synaptic currents (mEPSCs) were also observed in the acute hippocampal brain slices from Dyt1 heterozygous KO mice, suggesting that the partial loss of torsinA function in Dyt1 KI mice causes action potential-dependent neurotransmitter release deficits. On the other hand, Dyt1 heterozygous KO mice showed enhanced hippocampal LTP, normal input-output relations and paired pulse ratios in the extracellular field recordings. The results suggest that maintaining an appropriate torsinA level is important to sustain normal motor performance, synaptic transmission and plasticity. Developing therapeutics to restore a normal torsinA level may help to prevent and treat the symptoms in DYT1 dystonia. PMID:25799505

  16. Cardiac effects of noncardiac neoplasms

    SciTech Connect

    Schoen, F.J.; Berger, B.M.; Guerina, N.G.

    1984-11-01

    Clinically significant cardiovascular abnormalities may occur as secondary manifestations of noncardiac neoplasms. The principal cardiac effects of noncardiac tumors include the direct results of metastases to the heart or lungs, the indirect effects of circulating tumor products (causing nonbacterial thrombotic endocarditis, myeloma-associated amyloidosis, pheochromocytoma-associated cardiac hypertrophy and myofibrillar degeneration, and carcinoid heart disease), and the undesired cardiotoxicities of chemotherapy and radiotherapy. 89 references.

  17. Gene Transfer into Cardiac Myocytes

    PubMed Central

    Lang, Sarah E.; Westfall, Margaret V.

    2016-01-01

    Traditional methods for DNA transfection are often inefficient and toxic for terminally differentiated cells, such as cardiac myocytes. Vector-based gene transfer is an efficient approach for introducing exogenous cDNA into these types of primary cell cultures. In this chapter, separate protocols for adult rat cardiac myocyte isolation and gene transfer with recombinant adenovirus are provided and are routinely utilized for studying the effects of sarcomeric proteins on myofilament function. PMID:25836585

  18. Cardiac anatomy revisited

    PubMed Central

    Anderson, Robert H; Razavi, Reza; Taylor, Andrew M

    2004-01-01

    In tomorrow's world of clinical medicine, students will increasingly be confronted by anatomic displays reconstructed from tomographically derived images. These images all display the structure of the various organs in anatomical orientation, this being determined in time-honoured fashion by describing the individual in the ‘anatomical position’, standing upright and facing the observer. It follows from this approach that all adjectives used to describe the organs should be related to the three orthogonal planes of the body. Unfortunately, at present this convention is not followed for the heart, even though most students are taught that the so-called ‘right chambers’ are, in reality, in front of their ‘left’ counterparts. Rigorous analysis of the tomographic images already available, along with comparison with dissected hearts displayed in attitudinally correct orientation, calls into question this continuing tendency to describe the heart in terms of its own orthogonal axes, but with the organ positioned on its apex, so that the chambers can artefactually be visualized with the right atrium and right ventricle in right-sided position. Although adequate for describing functional aspects, such as ‘right-to-left’ shunting across intracardiac communications, this convention falls short when used to describe the position of the artery that supplies the diaphragmatic surface of the heart. Currently known as the ‘posterior descending artery’, in reality it is positioned inferiorly, and its blockage produces inferior myocardial infarction. In this review, we extend the concept of describing cardiac structure in attitudinally correct orientation, showing also how access to tomographic images clarifies many aspects of cardiac structure previously considered mysterious and arcane. We use images prepared using new techniques such as magnetic resonance imaging and computerized tomography, and compare them with dissection of the heart made in time

  19. 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).

  20. Drosophila Models of Cardiac Disease

    PubMed Central

    Piazza, Nicole; Wessells, R.J.

    2013-01-01

    The fruit fly Drosophila melanogaster has emerged as a useful model for cardiac diseases, both developmental abnormalities and adult functional impairment. Using the tools of both classical and molecular genetics, the study of the developing fly heart has been instrumental in identifying the major signaling events of cardiac field formation, cardiomyocyte specification, and the formation of the functioning heart tube. The larval stage of fly cardiac development has become an important model system for testing isolated preparations of living hearts for the effects of biological and pharmacological compounds on cardiac activity. Meanwhile, the recent development of effective techniques to study adult cardiac performance in the fly has opened new uses for the Drosophila model system. The fly system is now being used to study long-term alterations in adult performance caused by factors such as diet, exercise, and normal aging. The fly is a unique and valuable system for the study of such complex, long-term interactions, as it is the only invertebrate genetic model system with a working heart developmentally homologous to the vertebrate heart. Thus, the fly model combines the advantages of invertebrate genetics (such as large populations, facile molecular genetic techniques, and short lifespan) with physiological measurement techniques that allow meaningful comparisons with data from vertebrate model systems. As such, the fly model is well situated to make important contributions to the understanding of complicated interactions between environmental factors and genetics in the long-term regulation of cardiac performance. PMID:21377627

  1. [Stem cells and cardiac regeneration].

    PubMed

    Perez Millan, Maria Ines; Lorenti, Alicia

    2006-01-01

    Stem cells are defined by virtue of their functional attributes: absence of tissue specific differentitated markers, capable of proliferation, able to self-maintain the population, able to produce a large number of differentiated, functional progeny, able to regenerate the tissue after injury. Cell therapy is an alternative for the treatment of several diseases, like cardiac diseases (cell cardiomyoplasty). A variety of stem cells could be used for cardiac repair: from cardiac and extracardiac sources. Each cell type has its own profile of advantages, limitations, and practicability issues in specific clinical settings. Differentiation of bone marrow stem cells to cardiomyocyte-like cells have been observed under different culture conditions. The presence of resident cardiac stem cell population capable of differentiation into cardiomyocyte or vascular lineage suggests that these cells could be used for cardiac tissue repair, and represent a great promise for clinical application. Stem cells mobilization by cytokines may also offer a strategy for cardiac regeneration. The use of stem cells (embryonic and adult) may hold the key to replacing cells lost in many devastating diseases. This potential benefit is a major focus for stem cell research.

  2. Cardiac Regeneration and Stem Cells.

    PubMed

    Zhang, Yiqiang; Mignone, John; MacLellan, W Robb

    2015-10-01

    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world.

  3. Global availability of cardiac rehabilitation.

    PubMed

    Turk-Adawi, Karam; Sarrafzadegan, Nizal; Grace, Sherry L

    2014-10-01

    Cardiovascular disease (CVD) is the most-prevalent noncommunicable disease and leading cause of death globally. Over 80% of deaths from CVD occur in low-income and middle-income countries (LMICs). To limit the socioeconomic impact of CVD, a comprehensive approach to health care is needed. Cardiac rehabilitation delivers a cost-effective and structured exercise, education, and risk reduction programme, which can reduce mortality by up to 25% in addition to improving a patient's functional capacity and lowering rehospitalization rates. Despite these benefits and recommendations in clinical practice guidelines, cardiac rehabilitation programmes are grossly under-used compared with revascularization or medical therapy for patients with CVD. Worldwide, only 38.8% of countries have cardiac rehabilitation programmes. Specifically, 68.0% of high-income and 23% of LMICs (8.3% for low-income and 28.2% for middle-income countries) offer cardiac rehabilitation programmes to patients with CVD. Cardiac rehabilitation density estimates range from one programme per 0.1 to 6.4 million inhabitants. Multilevel strategies to augment cardiac rehabilitation capacity and availability at national and international levels, such as supportive public health policies, systematic referral strategies, and alternative models of delivery are needed. PMID:25027487

  4. Cardiac Regeneration and Stem Cells

    PubMed Central

    Zhang, Yiqiang; Mignone, John; MacLellan, W. Robb

    2015-01-01

    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world. PMID:26269526

  5. Cardiac Imaging System

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Although not available to all patients with narrowed arteries, balloon angioplasty has expanded dramatically since its introduction with an estimated further growth to 562,000 procedures in the U.S. alone by 1992. Growth has fueled demand for higher quality imaging systems that allow the cardiologist to be more accurate and increase the chances of a successful procedure. A major advance is the Digital Cardiac Imaging (DCI) System designed by Philips Medical Systems International, Best, The Netherlands and marketed in the U.S. by Philips Medical Systems North America Company. The key benefit is significantly improved real-time imaging and the ability to employ image enhancement techniques to bring out added details. Using a cordless control unit, the cardiologist can manipulate images to make immediate assessment, compare live x-ray and roadmap images by placing them side-by-side on monitor screens, or compare pre-procedure and post procedure conditions. The Philips DCI improves the cardiologist's precision by expanding the information available to him.

  6. The Implantable Cardiac Pacemaker

    PubMed Central

    Trimble, A. S.; Heimbecker, R. O.; Bigelow, W. G.

    1964-01-01

    The transistorized implanted pacemaker is proving to be an effective and reliable method for long-term pacing of the heart. All patients suffering from Stokes-Adams seizures were first given a trial period of conservative therapy, including isoproterenol (Isuprel), ephedrine, atropine and steroids. Twenty-four pacemaker implants were performed on 23 patients over a 21-month period. The preoperative insertion of a pacemaker cardiac catheter was a very valuable safety precaution. In this way the heart could be safely and reliably paced during the period of preoperative assessment and during the critical periods of anesthetic induction and thoracotomy. Infection did not occur, probably because of careful gas sterilization of the units. Various models of pacemakers are compared, and the reasons for two pacemaker failures are presented. There were two early deaths and one late death in the series. The relationship of progressive coronary disease to recent infarction is stressed. Patients having intermittent heart block frequently showed the picture of “competing pacemakers” postoperatively, but without deleterious effect. Twenty patients, between 54 and 88 years of age, are alive and well at the time of reporting, with excellent pacemaker response and no further Stokes-Adams attacks. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:14118681

  7. Exploring cardiac biophysical properties

    PubMed Central

    Mou, Younss Ait; Bollensdorff, Christian; Cazorla, Olivier; Magdi, Yacoub; de Tombe, Pieter P.

    2015-01-01

    The heart is subject to multiple sources of stress. To maintain its normal function, and successfully overcome these stresses, heart muscle is equipped with fine-tuned regulatory mechanisms. Some of these mechanisms are inherent within the myocardium itself and are known as intrinsic mechanisms. Over a century ago, Otto Frank and Ernest Starling described an intrinsic mechanism by which the heart, even ex vivo, regulates its function on a beat-to-beat basis. According to this phenomenon, the higher the ventricular filling is, the bigger the stroke volume. Thus, the Frank-Starling law establishes a direct relationship between the diastolic and systolic function of the heart. To observe this biophysical phenomenon and to investigate it, technologic development has been a pre-requisite to scientific knowledge. It allowed for example to observe, at the cellular level, a Frank-Starling like mechanism and has been termed: Length Dependent Activation (LDA). In this review, we summarize some experimental systems that have been developed and are currently still in use to investigate cardiac biophysical properties from the whole heart down to the single myofibril. As a scientific support, investigation of the Frank-Starling mechanism will be used as a case study. PMID:26779498

  8. [Pharmaca Induced Cardiac Injury].

    PubMed

    Haen, Ekkehard

    2016-01-01

    Many drugs influence vital functions via the sympathetic and the parasympathetic system. Besides that hypersensitivity reactions and reactions by chemical radicals that arise in drug metabolism may directly harm the heart muscle cell. Cardiac adverse drug reactions (ADR) result in disturbances of the heart rhythm, negative inotropic effects, direct damage to the heart muscle cell, and reduced perfusion of heart tissue. Their importance is often neglected because pharmacologically similar drugs are licensed for completely different indications. This is of particular interest if more drugs are prescribed in combination. Now these effects may add up to pharmacodynamic drug-drug-interactions. Data banks like PSIAConline (www.psiac.de), individualization of drug prescription by therapeutic drug monitoring (TDM) combined with a clinical pharmacological report (www.konbest.de), as well as drug information systems such as AGATE (www.amuep-agate.de) are today of help not just to recognize such drug risks, but also to find professional and evidence based solutions for it. PMID:26800070

  9. Cardiac achalasia in childhood

    PubMed Central

    Singh, Harjit; Sethi, R. S.; Gupta, H. L.; Khetarpal, S. K.

    1969-01-01

    Cardiac achalasia is a disorder not unknown in the paediatric age-group and may occur even in the neonatal period. This disorder should, therefore, be considered in all cases presenting with persistent vomiting, as well as in those with chronic respiratory disease in whom more common causes have been excluded. It is almost universally accepted that the disorder results from a disturbed function of ganglion cells in the distal oesophagus, as the disease has been reproduced in laboratory animals by denervation of the distal oesophagus. The exact pathogenesis of this degenerative change is not well understood. However, in at least some of the cases congenital absence of the ganglion cells may be responsible for this functional disturbance. This is inferred from the fact that the disease may be found in association with Hirschsprung disease, in which there is a congenital absence of ganglion cells in the terminal colon. Moreover, the occurrence of the disease in the neonatal period itself favours a congenital lesion. Surgery was preferred to other forms of treatment in the paediatric age-group in view of the reported equivocal response to mechanical dilatation and pre-disposition of children to respiratory complications. The results of surgery were satisfactory. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8 PMID:5790932

  10. Gender and cardiac surgery.

    PubMed

    Koch, Colleen Gorman; Nussmeier, Nancy A

    2003-09-01

    The increased operative mortality and morbidity of women compared with men undergoing CABG surgery results from multiple differences in presentation, preoperative risk profile, and surgical factors. Investigators have found consistently that women present with a different preoperative risk profile than do men. Women more commonly have factors associated with increased short- and long-term mortality, such as less frequent use of IMA grafts. Differences in study design and patient population may contribute to variability in short- and long-term mortality among the various studies. The lack of representation of women in older clinical trials has hindered our understanding of the management of CAD in women; this situation must be remedied in future studies, [95]. Known physiologic and anatomic differences must be evaluated for their effects on outcomes. Further studies are needed to evaluate gender-related differences in autonomic responses to acute coronary occlusion, complications related to cardiopulmonary bypass, susceptibility to abnormalities in coagulation, and other factors that might account for discrepant outcomes in men versus women undergoing CABG [96]. Beyond these factors, specific pharmacologic and therapeutic considerations, such as the role of estrogen replacement therapy, need to be clarified. As further knowledge accumulates, it is hoped that gender-specific risk factors can be mitigated and protective factors exploited, thereby improving the outcomes for all cardiac surgery patients.

  11. Interleukin-10 Deficiency Increases Atherosclerosis, Thrombosis, and Low-density Lipoproteins in Apolipoprotein E Knockout Mice

    PubMed Central

    Caligiuri, Giuseppina; Rudling, Mats; Ollivier, Véronique; Jacob, Marie-Paule; Michel, Jean-Baptiste; Hansson, Göran K; Nicoletti, Antonino

    2003-01-01

    Interleukin (IL)-10 is an anti-inflammatory cytokine that may play a protective role in atherosclerosis. The aim of this study was to assess the effect of IL-10 deficiency in the apolipoprotein E knockout mouse. Apolipoprotein E deficient (E−/−) and IL-10 deficient (−/−) mice were crossed to generate E−/− × IL-10−/− double knockout mice. By 16 wk, cholesterol and triglycerides were similar in double and single knockouts but the lack of IL-10 led to increased low-density lipoprotein cholesterol whereas very-low-density lipoprotein was reduced. In parallel, T-helper 1 responses and lesion size were dramatically increased in double knockout compared with E−/− controls. At 48 wk, matrix metalloproteinases and tissue factor activities were increased in lesions of double-knockout mice. Furthermore, markers of systemic coagulation were increased, and vascular thrombosis in response to i.v. thrombin occurred more frequently in E−/− × IL-10−/− than in E−/− mice. Our findings suggest that IL-10 deficiency plays a deleterious role in atherosclerosis. The early phase of lesion development was increased, and the proteolytic and procoagulant activity was elevated in advanced lesions. These data show that IL-10 may reduce atherogenesis and improve the stability of plaques. PMID:12765335

  12. Effects of D1 receptor knockout on fear and reward learning.

    PubMed

    Abraham, Antony D; Neve, Kim A; Lattal, K Matthew

    2016-09-01

    Dopamine signaling is involved in a variety of neurobiological processes that contribute to learning and memory. D1-like dopamine receptors (including D1 and D5 receptors) are thought to be involved in memory and reward processes, but pharmacological approaches have been limited in their ability to distinguish between D1 and D5 receptors. Here, we examine the effects of a specific knockout of D1 receptors in associative learning tasks involving aversive (shock) or appetitive (cocaine) unconditioned stimuli. We find that D1 knockout mice show similar levels of cued and contextual fear conditioning to WT controls following conditioning protocols involving one, two, or four shocks. D1 knockout mice show increased generalization of fear conditioning and extinction across contexts, revealed as increased freezing to a novel context following conditioning and decreased freezing to an extinguished cue during a contextual renewal test. Further, D1 knockout mice show mild enhancements in extinction following an injection of SKF81297, a D1/D5 receptor agonist, suggesting a role for D5 receptors in extinction enhancements induced by nonspecific pharmacological agonists. Finally, although D1 knockout mice show decreased locomotion induced by cocaine, they are able to form a cocaine-induced conditioned place preference. We discuss these findings in terms of the role of dopamine D1 receptors in general learning and memory processes. PMID:27423521

  13. [Genetic knockout--the first steps and outlook for a neurophysiology of behavior].

    PubMed

    Popova, N K

    2000-01-01

    A review of modern data on genetic knockout strategy application to study the brain neurotransmitters and their role in the regulation of behavior. Advantages and shortcomings of genetic knockout of receptors and the enzymes of neurotransmitters metabolism models in comparison to other methods are discussed. Data on the effect of genetic knockout of various types of opioid, dopamine, serotonin and adrenoreceptors as well as enzymes in biosynthesis of catecholamines and serotonin on physiology and behavior is adduced. The data provide evidence that genetic knockout reproduces a principal effects of the lack of receptors and enzymes and allows to find new yet unknown properties. Mouse strains with genetic knockout represent unique models of hereditary neuropathology. At the same time the data presented clearly demonstrated that the lack of a single type of receptor or enzyme does not lead usually to disorganization of regulated by them physiological functions and behavior. The data witness to the complexity and multifactoriality of their regulations and evidenced the great compensatory potentials of organism.

  14. Tendon fascicle gliding in wild type, heterozygous, and lubricin knockout mice.

    PubMed

    Kohrs, Ross T; Zhao, Chunfeng; Sun, Yu-Long; Jay, Gregory D; Zhang, Ling; Warman, Matthew L; An, Kai-Nan; Amadio, Peter C

    2011-03-01

    The objective of this study was to investigate the role of lubricin in the lubrication of tendon fascicles. Lubricin, a glycoprotein, lubricates cartilage and tendon surfaces, but the function of lubricin within the tendon fascicle is unclear. We developed a novel method to assess the gliding resistance of a single fascicle in a mouse tail model and used it to test the hypothesis that gliding resistance would be increased in lubricin knockout mice. Thirty-six mouse tails were used from 12 wild type, 12 heterozygous, and 12 lubricin knockout mice. A 15 mm long fascicle segment was pulled proximally after being divided distally. The peak resistance during fascicle pullout and the fascicle perimeter were measured. Lubricin expression was evaluated by immunohistochemistry. The peak gliding resistance in the lubricin knockout mice was significantly higher than in the wild type (p < 0.05). Fascicles from heterozygous mice were intermediate in value, but not significantly different from either wild type or lubricin knockout fascicles in peak gliding resistance. No significant difference was found in fascicle perimeter among the three groups. No correlation was observed between fascicle perimeter and gliding resistance. While lubricin was detected by immunostaining on the fascicle surface in wild type and heterozygous mice, lubricin was not detectable in the tendons of knockout mice. We conclude that the absence of lubricin is associated with increased interfascicular friction and that lubricin may play an important role in interfascicular lubrication.

  15. Molecular mechanisms of cocaine reward: Combined dopamine and serotonin transporter knockouts eliminate cocaine place preference

    PubMed Central

    Sora, Ichiro; Hall, F. Scott; Andrews, Anne M.; Itokawa, Masanari; Li, Xiao-Fei; Wei, Hong-Bing; Wichems, Christine; Lesch, Klaus-Peter; Murphy, Dennis L.; Uhl, George R.

    2001-01-01

    Cocaine blocks uptake by neuronal plasma membrane transporters for dopamine (DAT), serotonin (SERT), and norepinephrine (NET). Cocaine reward/reinforcement has been linked to actions at DAT or to blockade of SERT. However, knockouts of neither DAT, SERT, or NET reduce cocaine reward/reinforcement, leaving substantial uncertainty about cocaine's molecular mechanisms for reward. Conceivably, the molecular bases of cocaine reward might display sufficient redundancy that either DAT or SERT might be able to mediate cocaine reward in the other's absence. To test this hypothesis, we examined double knockout mice with deletions of one or both copies of both the DAT and SERT genes. These mice display viability, weight gain, histologic features, neurochemical parameters, and baseline behavioral features that allow tests of cocaine influences. Mice with even a single wild-type DAT gene copy and no SERT copies retain cocaine reward/reinforcement, as measured by conditioned place-preference testing. However, mice with no DAT and either no or one SERT gene copy display no preference for places where they have previously received cocaine. The serotonin dependence of cocaine reward in DAT knockout mice is thus confirmed by the elimination of cocaine place preference in DAT/SERT double knockout mice. These results provide insights into the brain molecular targets necessary for cocaine reward in knockout mice that develop in their absence and suggest novel strategies for anticocaine medication development. PMID:11320258

  16. Cardiac pacing and aviation.

    PubMed

    Toff, W D; Edhag, O K; Camm, A J

    1992-12-01

    Certain applicants with stable disturbances of rhythm or conduction requiring cardiac pacing, in whom no other disqualifying condition is present, may be considered fit for medical certification restricted to multi-crew operations. The reliability of modern pacing systems appears adequate to permit restricted certification even in pacemaker dependent subjects except for certain models of pacemakers and leads known to be at increased risk of failure. These are to be avoided. There is little evidence to suggest that newer devices are any more reliable than their predecessors. Single and dual chamber systems appear to have similar reliability up to 4 years, after which time significant attrition of dual chamber devices occurs, principally due to battery depletion. All devices require increased scrutiny as they approach their end of life as predicted from longevity data and pacing characteristics. Unipolar and bipolar leads are of similar reliability, apart from a number of specific bipolar polyurethane leads which have been identified. Atrial leads, particularly those without active fixation, are less secure than ventricular leads and applicants who are dependent on atrial sensing or pacing should be denied certification. Bipolar leads are to be preferred due to the lower risk of myopotential and exogenous EMI. Sensor-driven adaptive-rate pacing systems using active sensors may have reduced longevity and require close scrutiny. Activity-sensing devices using piezoelectric crystal sensors may be subject to significant rate rises in rotary wing aircraft. The impracticality of restricted certification in helicopters will, in any event, preclude certification. Such devices would best be avoided in hovercraft (air cushioned vehicle) pilots. Only minor rate rises are likely in fixed-wing aircraft which are unlikely to be of significance. Anti-tachycardia devices and implanted defibrillators are inconsistent with any form of certification to fly. PMID:1493823

  17. Women's compliance with cardiac rehabilitation programs.

    PubMed

    Ginzel, A R

    1996-01-01

    As the incidence of cardiovascular disease in women increases, the process of cardiac rehabilitation in women is becoming increasingly important to nurses. Specifically, the issue of women's compliance with cardiac rehabilitation needs to be addressed by nurses. Most past and current research on cardiac rehabilitation and compliance with rehabilitation programs has been conducted on male subjects and cannot be accurately generalized to the female population. This article reviews current literature which addresses the issues of heart disease in women, cardiac rehabilitation and compliance in the general population, gender differences in cardiac rehabilitation, and compliance of women in cardiac rehabilitation. PMID:8657707

  18. Direct Cardiac Reprogramming: From Developmental Biology to Cardiac Regeneration

    PubMed Central

    Qian, Li; Srivastava, Deepak

    2013-01-01

    Heart disease affects millions worldwide and is a progressive condition involving loss of cardiomyocytes. The human heart has limited endogenous regenerative capacity and is thus an important target for novel regenerative medicine approaches. While cell-based regenerative therapies hold promise, cellular reprogramming of endogenous cardiac fibroblasts, which represent more than half of the cells in the mammalian heart, may be an attractive alternative strategy for regenerating cardiac muscle. Recent advances leveraging years of developmental biology point to the feasibility of generating de novo cardiomyocyte-like cells from terminally differentiated non-myocytes in the heart in situ after ischemic damage. Here, we review the progress in cardiac reprogramming methods and consider the opportunities and challenges that lie ahead in refining this technology for regenerative medicine. PMID:24030021

  19. 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.

  20. Type IX collagen knock-out mouse shows progressive hearing loss.

    PubMed

    Suzuki, Nobuyoshi; Asamura, Kenji; Kikuchi, Yasutake; Takumi, Yutaka; Abe, Satoko; Imamura, Yasutada; Hayashi, Toshihiko; Aszodi, Attila; Fässler, Reinhard; Usami, Shin-ichi

    2005-03-01

    Type IX collagen is one of the important components, together with type II, V, and XI collagens, in the tectorial membrane of the organ of Corti. To confirm the significance of type IX collagen for normal hearing, we assessed the detailed morphological and electrophysiological features of type IX collagen knock-out mice, which have recently been reported as a deafness model. Through assessment by auditory brainstem response (ABR), knock-out mice were shown to have progressive hearing loss. At the light microscopic level, the tectorial membrane of knock-out mice was found to be abnormal in shape. These morphological changes started in the basal turn and were progressive toward the apical turn. Electron microscopy confirmed disturbance of organization of the collagen fibrils. These results suggest that mutations in type IX collagen genes may lead to abnormal integrity of collagen fibers in the tectorial membrane.

  1. A simplified method to prepare PCR template DNA for screening of transgenic and knockout mice.

    PubMed

    Ren, S; Li, M; Cai, H; Hudgins, S; Furth, P A

    2001-03-01

    Polymerase chain reaction (PCR) amplification of DNA is the most widely used technique for screening of large numbers of genetically engineered transgenic or knockout mice (Mus musculus). In this report, we present a new DNA preparation procedure for running diagnostic PCR. In this procedure, mouse ear tissue was used directly for PCR after the tissue underwent brief digestion in a solution containing only proteinase K. Using this method, we have successfully screened several lines of single, double, and triple transgenic and knockout mice. The results are reliable and reproducible. The advantage of this new method is that DNA purification by organic extraction or isolation kit was omitted. DNA purification is the limiting factor in terms of time and money when screening transgenic and knockout mice by PCR. In addition, using ear instead of tail tissue can reduce distress of animals because the samples can be obtained when the mice are labeled by ear punch.

  2. Cardiac injury complicating traumatic asphyxia.

    PubMed

    Rosato, R M; Shapiro, M J; Keegan, M J; Connors, R H; Minor, C B

    1991-10-01

    During a 3-year period (1986-1989), 8 patients were seen at St. Louis University Medical Center exhibiting the stigmata of traumatic asphyxia. Fewer than 200 cases of traumatic asphyxia have been reported and there is only a single report of a cardiac injury. In this series, 3 of 8 (37.5%) patients were found to have an injury to the heart: two cardiac contusions and a ventricular rupture. Five patients were crushed in motor vehicle collisions, one by an elevator counterweight, and two patients by river barges. Injuries associated with these patients include pulmonary contusion, hemopneumothorax, traumatic pneumatocele, traumatic retinopathy, bone fractures, mental confusion, and liver contusion. There was one death in the series, a patient with rupture of the right ventricle and severe splenic and liver injuries. The cardiac status of the patients was evaluated by serial serum cardiac enzyme determinations, electrocardiograms, and echocardiography. This report illustrates the importance of complete cardiac evaluation in patients with traumatic asphyxia. PMID:1942148

  3. Cardiac complications in thalassemia major.

    PubMed

    Auger, Dominique; Pennell, Dudley J

    2016-03-01

    The myocardium is particularly susceptible to complications from iron loading in thalassemia major. In the first years of life, severe anemia leads to high-output cardiac failure and death if not treated. The necessary supportive blood transfusions create loading of iron that cannot be naturally excreted, and this iron accumulates within tissues, including the heart. Free unbound iron catalyzes the formation of toxic hydroxyl radicals, which damage cells and cause cardiac dysfunction. Significant cardiac siderosis may present by the age of 10 and may lead to acute clinical heart failure, which must be treated urgently. Atrial fibrillation is the most frequently encountered iron-related arrhythmia. Iron chelation is effective at removing iron from the myocardium, at the expense of side effects that hamper compliance to therapy. Monitoring of myocardial iron content is mandatory for clinical management of cardiac risk. T2* cardiac magnetic resonance measures myocardial iron and is the strongest biomarker for prediction of heart failure and arrhythmic events. It has been calibrated to human myocardial tissue iron concentration and is highly reproducible across all magnetic resonance scanner vendors. As survival and patient age increases, endothelial dysfunction and diabetes may become new factors in the cardiovascular health of thalassemia patients. Promising new imaging technology and therapies could ameliorate the long-term prognosis.

  4. Animal models of cardiac cachexia.

    PubMed

    Molinari, Francesca; Malara, Natalia; Mollace, Vincenzo; Rosano, Giuseppe; Ferraro, Elisabetta

    2016-09-15

    Cachexia is the loss of body weight associated with several chronic diseases including chronic heart failure (CHF). The cachectic condition is mainly due to loss of skeletal muscle mass and adipose tissue depletion. The majority of experimental in vivo studies on cachexia rely on animal models of cancer cachexia while a reliable and appropriate model for cardiac cachexia has not yet been established. A critical issue in generating a cardiac cachexia model is that genetic modifications or pharmacological treatments impairing the heart functionality and used to obtain the heart failure model might likely impair the skeletal muscle, this also being a striated muscle and sharing with the myocardium several molecular and physiological mechanisms. On the other hand, often, the induction of heart damage in the several existing models of heart failure does not necessarily lead to skeletal muscle loss and cachexia. Here we describe the main features of cardiac cachexia and illustrate some animal models proposed for cardiac cachexia studies; they include the genetic calsequestrin and Dahl salt-sensitive models, the monocrotaline model and the surgical models obtained by left anterior descending (LAD) ligation, transverse aortic constriction (TAC) and ascending aortic banding. The availability of a specific animal model for cardiac cachexia is a crucial issue since, besides the common aspects of cachexia in the different syndromes, each disease has some peculiarities in its etiology and pathophysiology leading to cachexia. Such peculiarities need to be unraveled in order to find new targets for effective therapies. PMID:27317993

  5. Animal models of cardiac cachexia.

    PubMed

    Molinari, Francesca; Malara, Natalia; Mollace, Vincenzo; Rosano, Giuseppe; Ferraro, Elisabetta

    2016-09-15

    Cachexia is the loss of body weight associated with several chronic diseases including chronic heart failure (CHF). The cachectic condition is mainly due to loss of skeletal muscle mass and adipose tissue depletion. The majority of experimental in vivo studies on cachexia rely on animal models of cancer cachexia while a reliable and appropriate model for cardiac cachexia has not yet been established. A critical issue in generating a cardiac cachexia model is that genetic modifications or pharmacological treatments impairing the heart functionality and used to obtain the heart failure model might likely impair the skeletal muscle, this also being a striated muscle and sharing with the myocardium several molecular and physiological mechanisms. On the other hand, often, the induction of heart damage in the several existing models of heart failure does not necessarily lead to skeletal muscle loss and cachexia. Here we describe the main features of cardiac cachexia and illustrate some animal models proposed for cardiac cachexia studies; they include the genetic calsequestrin and Dahl salt-sensitive models, the monocrotaline model and the surgical models obtained by left anterior descending (LAD) ligation, transverse aortic constriction (TAC) and ascending aortic banding. The availability of a specific animal model for cardiac cachexia is a crucial issue since, besides the common aspects of cachexia in the different syndromes, each disease has some peculiarities in its etiology and pathophysiology leading to cachexia. Such peculiarities need to be unraveled in order to find new targets for effective therapies.

  6. Neurological prognostication after cardiac arrest

    PubMed Central

    Sandroni, Claudio; Geocadin, Romergryko G.

    2016-01-01

    Purpose of review Prediction of neurological prognosis in patients who are comatose after successful resuscitation from cardiac arrest remains difficult. Previous guidelines recommended ocular reflexes, somatosensory evoked potentials and serum biomarkers for predicting poor outcome within 72h from cardiac arrest. However, these guidelines were based on patients not treated with targeted temperature management and did not appropriately address important biases in literature. Recent findings Recent evidence reviews detected important limitations in prognostication studies, such as low precision and, most importantly, lack of blinding, which may have caused a self-fulfilling prophecy and overestimated the specificity of index tests. Maintenance of targeted temperature using sedatives and muscle relaxants may interfere with clinical examination, making assessment of neurological status before 72 h or more after cardiac arrest unreliable. Summary No index predicts poor neurological outcome after cardiac arrest with absolute certainty. Prognostic evaluation should start not earlier than 72 h after ROSC and only after major confounders have been excluded so that reliable clinical examination can be made. Multimodality appears to be the most reasonable approach for prognostication after cardiac arrest. PMID:25922894

  7. 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

  8. 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

  9. Effect of knockout of α2δ-1 on action potentials in mouse sensory neurons.

    PubMed

    Margas, Wojciech; Ferron, Laurent; Nieto-Rostro, Manuela; Schwartz, Arnold; Dolphin, Annette C

    2016-08-01

    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 Ca(2+) 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 Ca(2+) 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 Ca(2+)-activation of large conductance calcium-activated potassium (BK) and small conductance calcium-activated potassium (SK) channels in these events. In conclusion, the reduced Ca(2+) 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 Ca(2+) and ATP together to control life and death'. PMID:27377724

  10. Cardiomyocyte-Specific Deletion of Endothelin Receptor A Rescues Ageing-Associated Cardiac Hypertrophy and Contractile Dysfunction: Role of Autophagy

    PubMed Central

    Ceylan-Isik, Asli F.; Dong, Maolong; Zhang, Yingmei; Dong, Feng; Turdi, Subat; Nair, Sreejayan; Yanagisawa, Masashi; Ren, Jun

    2013-01-01

    Cardiac ageing is manifested as cardiac remodeling and contractile dysfunction although precise mechanisms remain elusive. This study was designed to examine the role of endothelin-1 (ET-1) in ageing-associated myocardial morphological and contractile defects. Echocardiographic and cardiomyocyte contractile properties were evaluated in young (5–6 mo) and old (26–28 mo) C57BL/6 wild-type and cardiomyocyte-specific ETA receptor knockout (ETAKO) mice. Cardiac ROS production and histology were examined. Our data revealed that ETAKO mice displayed an improved survival. Ageing increased plasma levels of ET-1 and Ang II, compromised cardiac function (fractional shortening, cardiomyocyte peak shortening, maximal velocity of shortening/ relengthening and prolonged relengthening) and intracellular Ca2+ handling (reduced intracellular Ca2+ release and decay), the effects of which with the exception of ET-1 and Ang II levels was improved by ETAKO. Histological examination displayed cardiomyocyte hypertrophy and interstitial fibrosis associated with cardiac remodeling in aged C57 mice, which were alleviated in ETAKO mice. Ageing promoted ROS generation, protein damage, ER stress, upregulated GATA4, ANP, NFATc3, and the autophagosome cargo protein p62, downregulated intracellular Ca2+ regulatory proteins SERCA2a and phospholamban as well as the autophagic markers Beclin-1, Atg7, Atg5 and LC3BII, which were ablated by ETAKO. ET-1 triggered a decrease in autophagy and increased hypertrophic markers in vitrothe effect of which were reversed by the ETA receptor antagonist BQ123 and the autophagy inducer rapamycin. Antagonism of ETA but not ETB receptor rescued cardiac ageing, which was negated by autophagy inhibition. Taken together, our data suggest that cardiac ETA receptor ablation protects against ageing-associated myocardial remodeling and contractile dysfunction possibly through autophagy regulation. PMID:23381122

  11. Deficiency of Smad7 Enhances Cardiac Remodeling Induced by Angiotensin II Infusion in a Mouse Model of Hypertension

    PubMed Central

    Wei, Li Hua; Huang, Xiao Ru; Zhang, Yang; Li, You Qi; Chen, Hai-yong; Heuchel, Rainer; Yan, Bryan P.; Yu, Cheuk-Man; Lan, Hui Yao

    2013-01-01

    Smad7 has been shown to negatively regulate fibrosis and inflammation, but its role in angiotensin II (Ang II)-induced hypertensive cardiac remodeling remains unknown. Therefore, the present study investigated the role of Smad7 in hypertensive cardiopathy induced by angiotensin II infusion. Hypertensive cardiac disease was induced in Smad7 gene knockout (KO) and wild-type (WT) mice by subcutaneous infusion of Ang II (1.46 mg/kg/day) for 28 days. Although equal levels of high blood pressure were developed in both Smad7 KO and WT mice, Smad7 KO mice developed more severe cardiac injury as demonstrated by impairing cardiac function including a significant increase in left ventricular (LV) mass (P<0.01),reduction of LV ejection fraction(P<0.001) and fractional shortening(P<0.001). Real-time PCR, Western blot and immunohistochemistry detected that deletion of Smad7 significantly enhanced Ang II-induced cardiac fibrosis and inflammation, including upregulation of collagen I, α-SMA, interleukin-1β, TNF-α, and infiltration of CD3+ T cells and F4/80+ macrophages. Further studies revealed that enhanced activation of the Sp1-TGFβ/Smad3-NF-κB pathways and downregulation of miR-29 were mechanisms though which deletion of Smad7 promoted Ang II-mediated cardiac remodeling. In conclusions, Smad7 plays a protective role in AngII-mediated cardiac remodeling via mechanisms involving the Sp1-TGF-β/Smad3-NF.κB-miR-29 regulatory network. PMID:23894614

  12. PROXIMAL GUT MUCOSAL EPITHELIAL HOMEOSTASIS IN AGED IL-1 TYPE I RECEPTOR KNOCKOUT MICE AFTER STARVATION

    PubMed Central

    Song, Juquan; Wolf, Steven E.; Wu, Xiao-Wu; Finnerty, Celeste C.; Herndon, David N.; Jeschke, Marc G.

    2010-01-01

    Background Previous studies have shown that starvation induces small bowel atrophy, and that atrophy diminishes with aging. In this experiment, we assessed whether starvation-induced atrophy of proximal gut mucosa is associated with the Interleukin-1 receptor (IL-1R) signaling pathway in aged mice. Materials and Methods Thirty 26-month-old IL-1R knockout mice and age-matched wild-type C57BL/6 mice were randomly divided into two groups: ad libitum fed and fasted. Mice were euthanized 12 or 48 hours after starvation. The proximal small bowel was harvested for morphologic analysis. Gut epithelial cell proliferation was detected using immunohistochemical staining for proliferating cell nuclear antigen (PCNA), and apoptosis was identified using terminal deoxyuridine nick-end labeling (TUNEL) staining. Results Aged IL-1R knockout mice were larger than aged-matched wild-type mice (p<0.05). Proximal gut mucosal height and mucosal cell number were not different between aged IL-1R knockout and wild-type groups. The apoptosis index in gut epithelial cells was higher in fed IL-1R knockout versus wild-type mice (p<0.05), while no significant difference in cell proliferation between both groups. Mucosal atrophy was induced in both aged IL-1R knockout and wild-type groups by starvation (p<0.05), however, aged IL-1R knockout mice experienced greater losses in proximal gut weight, mucosal length, and corresponding cell number than did wild-type mice at the 12-hour time point (p<0.05). The apoptosis index in gut epithelial cells significantly increased in both groups after starvation (p<0.05). Starvation decreased cell proliferation in IL-1R knockout mice (p<0.05), but not in wild-type mice. Conclusions The response in aged IL-1R knockout mice differs from wild-type mice in that starvation increases atrophy and is associated with decreased cell proliferation rather than increased apoptosis. PMID:20605606

  13. Population of positive-parity states in {sup 53}Sc through one-proton knockout.

    SciTech Connect

    McDaniel, S.; Gade, A.; Janssens, R. V. F.; Bazin, D.; Brown, B. A.; Campbell, C. M.; Carpenter, M. P.; Cook, J. M.; Deacon, A. N.; Dinca, D.-C.; Freeman, S. J.; Glasmacher, T.; Hansen, P. G.; Kay, B. P.; Mantica, P. F.; Mueller, W. F.; Terry, J. R.; Tostevin, J. A.; Zhu, S.; Physics; Michigan State Univ.; Univ. of Manchester; Univ. of Surrey

    2010-02-01

    The one-proton knockout reaction {sup 9}Be({sup 54}Ti,{sup 53}Sc+{gamma})X at 72 MeV/nucleon has been measured. The location of the first 3/2{sup -} state at 2110(3) keV was confirmed, and new {gamma}-ray transitions were observed at 1111(2), 1273(2), 1539(4), and 2495(5) keV. Large spectroscopic strength to excited states in {sup 53}Sc was found and attributed to the knockout of sd-shell protons.

  14. Population of positive-parity states in {sup 53}Sc through one-proton knockout

    SciTech Connect

    McDaniel, S.; Gade, A.; Brown, B. A.; Campbell, C. M.; Cook, J. M.; Dinca, D.-C.; Glasmacher, T.; Hansen, P. G.; Terry, J. R.; Janssens, R. V. F.; Carpenter, M. P.; Zhu, S.; Bazin, D.; Mueller, W. F.; Deacon, A. N.; Freeman, S. J.; Kay, B. P.; Mantica, P. F.; Tostevin, J. A.

    2010-02-15

    The one-proton knockout reaction {sup 9}Be({sup 54}Ti,{sup 53}Sc+{gamma})X at 72 MeV/nucleon has been measured. The location of the first 3/2{sup -} state at 2110(3) keV was confirmed, and new {gamma}-ray transitions were observed at 1111(2), 1273(2), 1539(4), and 2495(5) keV. Large spectroscopic strength to excited states in {sup 53}Sc was found and attributed to the knockout of sd-shell protons.

  15. 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

  16. Neutron knockout of Be12 populating neutron-unbound states in Be11

    NASA Astrophysics Data System (ADS)

    Peters, W. A.; Baumann, T.; Brown, B. A.; Brown, J.; Deyoung, P. A.; Finck, J. E.; Frank, N.; Jones, K. L.; Lecouey, J.-L.; Luther, B.; Peaslee, G. F.; Rogers, W. F.; Schiller, A.; Thoennessen, M.; Tostevin, J. A.; Yoneda, K.

    2011-05-01

    Neutron-unbound resonant states of Be11 were populated in neutron knockout reactions from Be12 and identified by Be10-n coincidence measurements. A resonance in the decay-energy spectrum at 80(2) keV was attributed to a highly excited unbound state in Be11 at 3.949(2) MeV decaying to the 2+ excited state in Be10. A knockout cross section of 15(3) mb was inferred for this 3.949(2) MeV state, suggesting a spectroscopic factor near unity for this 0p3/2- level, consistent with the detailed shell model calculations.

  17. Thioredoxin-2 Inhibits Mitochondrial ROS Generation and ASK1 Activity to Maintain Cardiac Function

    PubMed Central

    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

    2015-01-01

    Background Thioredoxin 2 (Trx2) is a key mitochondrial protein which regulates cellular redox and survival by suppressing mitochondrial ROS 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. Methods and Results Western blot and histological analysis revealed that Trx2 protein expression levels were reduced in hearts from patients with dilated cardiomyopathy (DCM), with a concomitant increase in increased ASK1 phosphorylation/activity. Cardiac-specific Trx2 knockout mice (Trx2-cKO). Trx2-cKO mice develop spontaneous DCM at 1 month of age with increased heart size, reduced ventricular wall thickness, and a progressive decline in left ventricular (LV) contractile function, resulting in mortality due to heart failure by ~4 months of age. The progressive decline in cardiac function observed in Trx2-cKO mice was accompanied by disruption of mitochondrial ultrastructure, mitochondrial membrane depolarization, increased mitochondrial ROS 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 LV 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 ROS generation. Conclusions Our data support an essential role for mitochondrial Trx2 in preserving cardiac function by suppressing mitochondrial ROS production and ASK1-dependent apoptosis. Inhibition of ASK1 represents a promising therapeutic strategy for the treatment of dilated cardiomyopathy and heart failure. PMID:25628390

  18. Stochastic Aspects of Cardiac Arrhythmias

    NASA Astrophysics Data System (ADS)

    Lerma, Claudia; Krogh-Madsen, Trine; Guevara, Michael; Glass, Leon

    2007-07-01

    Abnormal cardiac rhythms (cardiac arrhythmias) often display complex changes over time that can have a random or haphazard appearance. Mathematically, these changes can on occasion be identified with bifurcations in difference or differential equation models of the arrhythmias. One source for the variability of these rhythms is the fluctuating environment. However, in the neighborhood of bifurcation points, the fluctuations induced by the stochastic opening and closing of individual ion channels in the cell membrane, which results in membrane noise, may lead to randomness in the observed dynamics. To illustrate this, we consider the effects of stochastic properties of ion channels on the resetting of pacemaker oscillations and on the generation of early afterdepolarizations. The comparison of the statistical properties of long records showing arrhythmias with the predictions from theoretical models should help in the identification of different mechanisms underlying cardiac arrhythmias.

  19. Cardiac myofilaments: mechanics and regulation

    NASA Technical Reports Server (NTRS)

    de Tombe, Pieter P.; Bers, D. M. (Principal Investigator)

    2003-01-01

    The mechanical properties of the cardiac myofilament are an important determinant of pump function of the heart. This report is focused on the regulation of myofilament function in cardiac muscle. Calcium ions form the trigger that induces activation of the thin filament which, in turn, allows for cross-bridge formation, ATP hydrolysis, and force development. The structure and protein-protein interactions of the cardiac sarcomere that are responsible for these processes will be reviewed. The molecular mechanism that underlies myofilament activation is incompletely understood. Recent experimental approaches have been employed to unravel the mechanism and regulation of myofilament mechanics and energetics by activator calcium and sarcomere length, as well as contractile protein phosphorylation mediated by protein kinase A. Central to these studies is the question whether such factors impact on muscle function simply by altering thin filament activation state, or whether modulation of cross-bridge cycling also plays a part in the responses of muscle to these stimuli.

  20. Mechanical regulation of cardiac development

    PubMed Central

    Lindsey, Stephanie E.; Butcher, Jonathan T.; Yalcin, Huseyin C.

    2014-01-01

    Mechanical forces are essential contributors to and unavoidable components of cardiac formation, both inducing and orchestrating local and global molecular and cellular changes. Experimental animal studies have contributed substantially to understanding the mechanobiology of heart development. More recent integration of high-resolution imaging modalities with computational modeling has greatly improved our quantitative understanding of hemodynamic flow in heart development. Merging these latest experimental technologies with molecular and genetic signaling analysis will accelerate our understanding of the relationships integrating mechanical and biological signaling for proper cardiac formation. These advances will likely be essential for clinically translatable guidance for targeted interventions to rescue malforming hearts and/or reconfigure malformed circulations for optimal performance. This review summarizes our current understanding on the levels of mechanical signaling in the heart and their roles in orchestrating cardiac development. PMID:25191277

  1. Cardiac Regenerative Capacity and Mechanisms

    PubMed Central

    Kikuchi, Kazu; Poss, Kenneth D.

    2013-01-01

    The heart holds the monumental yet monotonous task of maintaining circulation. Although cardiac function is critical to other organs and to life itself, mammals are not equipped with significant natural capacity to replace heart muscle that has been lost by injury. This deficiency plays a role in leaving millions worldwide each year vulnerable to heart failure. By contrast, certain other vertebrate species like zebrafish are strikingly good at heart regeneration. A cellular and molecular understanding of endogenous regenerative mechanisms, combined with advances in methodology to transplant cells, together project a future in which cardiac muscle regeneration can be therapeutically stimulated in injured human hearts. This review will focus on what has been discovered recently about cardiac regenerative capacity and how natural mechanisms of heart regeneration in model systems are stimulated and maintained. PMID:23057748

  2. Cardiac output during human sleep.

    PubMed

    Miller, J C; Horvath, S M

    1976-10-01

    Impedance cardiogram and sleep EEG were recorded from four male and four female subjects, aged 21 to 22 years, during one night in the laboratory following one adaptation night. Cardiac output fell approximately 26% during the night as a consequence of diminished stroke volume, the lowest values of both occurring during the latter portion of the night, dominated by SREM (rapid-eye-movement stage). Intracycle comparisons between SREM and SWS (slow wave sleep) or between eye movement burst and non-burst SREM showed no significant differences in stroke volume or cardiac output. Pre-ejection period and systolic ejection period were measured and discussed. The non-coincidence of the nadir of metabolic activity, expressed as cardiac output, and the apex of slow-wave sleep activity supported the concept of slow-wave sleep as a period of physiological restoration.

  3. Electrophysiological Cardiac Modeling: A Review.

    PubMed

    Beheshti, Mohammadali; Umapathy, Karthikeyan; Krishnan, Sridhar

    2016-01-01

    Cardiac electrophysiological modeling in conjunction with experimental and clinical findings has contributed to better understanding of electrophysiological phenomena in various species. As our knowledge on underlying electrical, mechanical, and chemical processes has improved over time, mathematical models of the cardiac electrophysiology have become more realistic and detailed. These models have provided a testbed for various hypotheses and conditions that may not be easy to implement experimentally. In addition to the limitations in experimentally validating various scenarios implemented by the models, one of the major obstacles for these models is computational complexity. However, the ever-increasing computational power of supercomputers facilitates the clinical application of cardiac electrophysiological models. The potential clinical applications include testing and predicting effects of pharmaceutical agents and performing patient-specific ablation and defibrillation. A review of studies involving these models and their major findings are provided.

  4. Multimodality treatment for cardiac angiosarcoma.

    PubMed

    Wang, Meng; Fu, Ganglan; Jiang, Huiqi; Zeng, Kuan; Hua, Ping

    2014-01-01

    Primary cardiac angiosarcoma is a rare and highly malignant condition. Besides performing complete surgical excision, it remains controversial as to whether survival can be improved with additional treatment. We herein describe a 30-year-old man with a right atrial angiosarcoma. He underwent two operations for the resection of the primary lesion, and the patient's metastatic lesions involved an intestinal segment. With chemotherapy, radiotherapy, and molecular targeted therapy, he survived for 33 months. The literature describing adjuvant therapy for cardiac angiosarcoma, which is mostly case reports, is also reviewed. In conclusion, the limited evidence suggests that multimodality treatment for cardiac angiosarcoma is a beacon of hope to improve the survival of such patients.

  5. Electrophysiological Cardiac Modeling: A Review.

    PubMed

    Beheshti, Mohammadali; Umapathy, Karthikeyan; Krishnan, Sridhar

    2016-01-01

    Cardiac electrophysiological modeling in conjunction with experimental and clinical findings has contributed to better understanding of electrophysiological phenomena in various species. As our knowledge on underlying electrical, mechanical, and chemical processes has improved over time, mathematical models of the cardiac electrophysiology have become more realistic and detailed. These models have provided a testbed for various hypotheses and conditions that may not be easy to implement experimentally. In addition to the limitations in experimentally validating various scenarios implemented by the models, one of the major obstacles for these models is computational complexity. However, the ever-increasing computational power of supercomputers facilitates the clinical application of cardiac electrophysiological models. The potential clinical applications include testing and predicting effects of pharmaceutical agents and performing patient-specific ablation and defibrillation. A review of studies involving these models and their major findings are provided. PMID:27652454

  6. [Risk management in cardiac anesthesia].

    PubMed

    Inada, Eiichi

    2008-05-01

    Cardiac anesthesia carries high risk because of the patient's cardiac and coexisting diseases and rapid and complex hemodynamic changes during surgery. We should be ready to treat hemodynamic changes which may rapidly deteriorate into a vicious cycle. Many potent drugs and life-support devices are used. The drugs should be properly labeled to avoid drug error. Prefilled drug syringes and ready-to-use bags are helpful to avoid mixture error. Syringe and infusion pumps should be properly set. All the infusion systems should be checked in a systematical way. Blood management including blood transfusion and coagulation is important. Heparin-induced thrombocytopenia (HIT) may cause thrombosis. Heparin and heparin-coated catheter should be avoided in patients with HIT. Causes of bleeding tendency should be sort out and treated accordingly. Protamine reactions including hypotension and pulmonary hypertension can be catastrophic. Lastly, intimate communication between surgeons, anesthesiologists, medical engineers, and nurses is essential to perform cardiac surgery safely.

  7. Sudden Cardiac Arrest in Pediatrics.

    PubMed

    Scheller, RoseAnn L; Johnson, Laurie; Lorts, Angela; Ryan, Thomas D

    2016-09-01

    Sudden cardiac arrest (SCA) in the pediatric population is a rare and potentially devastating occurrence. An understanding of the differential diagnosis for the etiology of the cardiac arrest allows for the most effective emergency care and provides the patient with the best possible outcome. Pediatric SCA can occur with or without prodromal symptoms and may occur during exercise or rest. The most common cause is arrhythmia secondary to an underlying channelopathy, cardiomyopathy, or myocarditis. After stabilization, evaluation should include electrocardiogram, chest radiograph, and echocardiogram. Management should focus on decreasing the potential for recurring arrhythmia, maintaining cardiac preload, and thoughtful medication use to prevent exacerbation of the underlying condition. The purpose of this review was to provide the emergency physician with a concise and current review of the incidence, differential diagnosis, and management of pediatric patients presenting with SCA. PMID:27585126

  8. Myocardial injection of apelin-overexpressing bone marrow cells improves cardiac repair via upregulation of Sirt3 after myocardial infarction.

    PubMed

    Li, Lanfang; Zeng, Heng; Hou, Xuwei; He, Xiaochen; Chen, Jian-Xiong

    2013-01-01

    Our previous study shows that treatment with apelin increases bone marrow cells (BMCs) recruitment and promotes cardiac repair after myocardial infarction (MI). The objective of this study was to investigate whether overexpression of apelin in BMCs improved cell therapy and accelerated cardiac repair and functional recovery in post-MI mice. Mouse myocardial infarction was achieved by coronary artery ligation and BMCs overexpressing apelin (apelin-BMCs) or GFP (GFP-BMCs) were injected into ischemic area immediately after surgery. In vitro, exposure of cultured BMCs to apelin led to a gradual increase in SDF-1á and CXCR4 expression. Intramyocardial delivery of apelin-BMCs in post-MI mice resulted in a significant increase number of APJ⁺/c-kit⁺/Sca1⁺ cells in the injected area compared to GFP-BMCs treated post-MI mice. Treatment with apelin-BMCs increased expression of VEGF, Ang-1 and Tie-2 in post-MI mice. Apelin-BMCs treatment also significantly increased angiogenesis and attenuated cardiac fibrosis formation in post-MI mice. Most importantly, treatment with apelin-BMCs significantly improved left ventricular (LV) systolic function in post-MI mice. Mechanistically, Apelin-BMCs treatment led to a significant increase in Sirtuin3 (Sirt3) expression and reduction of reactive oxygen species (ROS) formation. Treatment of cultured BMCs with apelin also increased Notch3 expression and Akt phosphorylation. Apelin treatment further attenuated stress-induced apoptosis whereas knockout of Sirt3 abolished anti-apoptotic effect of apelin in cultured BMCs. Moreover, knockout of Sirt3 significantly attenuated apelin-BMCs-induced VEGF expression and angiogenesis in post-MI mice. Knockout of Sirt3 further blunted apelin-BMCs-mediated improvement of cardiac repair and systolic functional recovery in post-MI mice. These data suggest that apelin improves BMCs therapy on cardiac repair and systolic function in post-MI mice. Upregulation of Sirt3 may contribute to the protective

  9. MR and CT appearance of cardiac hemangioma

    SciTech Connect

    Kemp, J.L.; Kessler, R.M.; Raizada, V.; Williamson, M.R.

    1996-05-01

    We present a case of cardiac hemangioma in a symptomatic patient. MR and CT each have specific characteristics that should make one consider including or excluding this in the differential diagnosis of a cardiac tumor. 7 refs., 3 figs.

  10. Sudden Cardiac Arrest (SCA) Risk Assessment

    MedlinePlus

    ... Find a Specialist Share Twitter Facebook SCA Risk Assessment Sudden Cardiac Arrest (SCA) occurs abruptly and without ... of all ages and health conditions. Start Risk Assessment The Sudden Cardiac Arrest (SCA) Risk Assessment Tool ...

  11. [Cardiac arrhythmias: Diagnosis and management].

    PubMed

    Waldmann, V; Marijon, E

    2016-09-01

    Cardiac arrhythmias, with, on top of the list, atrial fibrillation, are frequent conditions and any physician might have to get involved at any stage of patient care (from diagnosis to treatment), without always having the opportunity to immediately refer to the cardiologist. The aim of this review is to present a summary of pathophysiology, clinical and electrocardiographic presentations, as well as diagnostic and therapeutic strategies for the main cardiac arrhythmias. Supra-ventricular tachycardias (atrial fibrillation and flutter, atrioventricular reciprocating tachycardias) and ventricular tachycardias will be consecutively presented and discussed.

  12. Cardiac 4D Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    D'hooge, Jan

    Volumetric cardiac ultrasound imaging has steadily evolved over the last 20 years from an electrocardiography (ECC) gated imaging technique to a true real-time imaging modality. Although the clinical use of echocardiography is still to a large extent based on conventional 2D ultrasound imaging it can be anticipated that the further developments in image quality, data visualization and interaction and image quantification of three-dimensional cardiac ultrasound will gradually make volumetric ultrasound the modality of choice. In this chapter, an overview is given of the technological developments that allow for volumetric imaging of the beating heart by ultrasound.

  13. Benign cardiac tumours, malignant arrhythmias

    PubMed Central

    Myers, Kimberley A; Wong, Kenny K; Tipple, Marion; Sanatani, Shubhayan

    2010-01-01

    Four cases of pediatric cardiac tumours (PCTs) associated with ventricular arrhythmias are reported. Sudden cardiac death attributable to the tumour occurred in two children. A third child received an implantable cardioverter defibrillator and the fourth had persistent ventricular arrhythmia despite medical therapy. Most PCTs are considered benign; however, the development of malignant arrhythmias may complicate the management of these tumours in some patients. The literature regarding the arrhythmogenic potential of PCTs and the use of implantable cardioverter defibrillators in these patients is reviewed. The series highlights the deficiency of prognostic information for this cohort. PMID:20151061

  14. Cardiac Metastasis from Invasive Thymoma Via the Superior Vena Cava: Cardiac MRI Findings

    SciTech Connect

    Dursun, Memduh Sarvar, Sadik; Cekrezi, Bledi; Kaba, Erkan; Bakir, Baris; Toker, Alper

    2008-07-15

    Cardiac tumors are rare, and metastatic deposits are more common than primary cardiac tumors. We present cardiac magnetic resonance imaging (MRI) findings of a 50-year-old woman with invasive thymoma. Cardiac MRI revealed a heterogeneous, lobulated anterior mediastinal mass invading the superior vena cava and extending to the right atrium. In cine images there was no invasion to the right atrial wall.

  15. [Cardiac output monitoring by impedance cardiography in cardiac surgery].

    PubMed

    Shimizu, H; Seki, S; Mizuguchi, A; Tsuchida, H; Watanabe, H; Namiki, A

    1990-04-01

    The cardiac output monitoring by impedance cardiography, NCCOM3, was evaluated in adult patients (n = 12) who were subjected to coronary artery bypass grafting. Values of cardiac output measured by impedance cardiography were compared to those by the thermodilution method. Changes of base impedance level used as an index of thoracic fluid volume were also investigated before and after cardiopulmonary bypass (CPB). Correlation coefficient (r) of the values obtained by thermodilution with impedance cardiography was 0.79 and the mean difference was 1.29 +/- 16.9 (SD)% during induction of anesthesia. During the operation, r was 0.83 and the mean difference was -14.6 +/- 18.7%. The measurement by impedance cardiography could be carried out through the operation except when electro-cautery was used. Base impedance level before CPB was significantly lower as compared with that after CPB. There was a negative correlation between the base impedance level and central venous pressure (CVP). No patients showed any signs suggesting lung edema and all the values of CVP, pulmonary artery pressure and blood gas analysis were within normal ranges. From the result of this study, it was concluded that cardiac output monitoring by impedance cardiography was useful in cardiac surgery, but further detailed examinations will be necessary on the relationship between the numerical values of base impedance and the clinical state of the patients. PMID:2362347

  16. Health Literacy Predicts Cardiac Knowledge Gains in Cardiac Rehabilitation Participants

    ERIC Educational Resources Information Center

    Mattson, Colleen C.; Rawson, Katherine; Hughes, Joel W.; Waechter, Donna; Rosneck, James

    2015-01-01

    Objective: Health literacy is increasingly recognised as a potentially important patient characteristic related to patient education efforts. We evaluated whether health literacy would predict gains in knowledge after completion of patient education in cardiac rehabilitation. Method: This was a re-post observational analysis study design based on…

  17. Cardiac torsion and electromagnetic fields: the cardiac bioinformation hypothesis.

    PubMed

    Burleson, Katharine O; Schwartz, Gary E

    2005-01-01

    Although in physiology the heart is often referred to as a simple piston pump, there are in fact two additional features that are integral to cardiac physiology and function. First, the heart as it contracts in systole, also rotates and produces torsion due to the structure of the myocardium. Second, the heart produces a significant electromagnetic field with each contraction due to the coordinated depolarization of myocytes producing a current flow. Unlike the electrocardiogram, the magnetic field is not limited to volume conduction and extends outside the body. The therapeutic potential for interaction of this cardioelectromagnetic field both within and outside the body is largely unexplored. It is our hypothesis that the heart functions as a generator of bioinformation that is central to normative functioning of body. The source of this bioinformation is based on: (1) vortex blood flow in the left ventricle; (2) a cardiac electromagnetic field and both; (3) heart sounds; and (4) pulse pressure which produce frequency and amplitude information. Thus, there is a multidimensional role for the heart in physiology and biopsychosocial dynamics. Recognition of these cardiac properties may result in significant implications for new therapies for cardiovascular disease based on increasing cardiac energy efficiency (coherence) and bioinformation from the cardioelectromagnetic field. Research studies to test this hypothesis are suggested.

  18. Ah Receptor Signaling Controls the Expression of Cardiac Development and Homeostasis Genes.

    PubMed

    Carreira, Vinicius S; Fan, Yunxia; Wang, Qing; Zhang, Xiang; Kurita, Hisaka; Ko, Chia-I; Naticchioni, Mindi; Jiang, Min; Koch, Sheryl; Medvedovic, Mario; Xia, Ying; Rubinstein, Jack; Puga, Alvaro

    2015-10-01

    Congenital heart disease (CHD) is the most common congenital abnormality and one of the leading causes of newborn death throughout the world. Despite much emerging scientific information, the precise etiology of this disease remains elusive. Here, we show that the aryl hydrocarbon receptor (AHR) regulates the expression of crucial cardiogenesis genes and that interference with endogenous AHR functions, either by gene ablation or by agonist exposure during early development, causes overlapping structural and functional cardiac abnormalities that lead to altered fetal heart physiology, including higher heart rates, right and left ventricle dilation, higher stroke volume, and reduced ejection fraction. With striking similarity between AHR knockout (Ahr(-/-)) and agonist-exposed wild type (Ahr(+/+)) embryos, in utero disruption of endogenous AHR functions converge into dysregulation of molecular mechanisms needed for attainment and maintenance of cardiac differentiation, including the pivotal signals regulated by the cardiogenic transcription factor NKH2.5, energy balance via oxidative phosphorylation and TCA cycle and global mitochondrial function and homeostasis. Our findings suggest that AHR signaling in the developing mammalian heart is central to the regulation of pathways crucial for cellular metabolism, cardiogenesis, and cardiac function, which are potential targets of environmental factors associated with CHD.

  19. Gestational hypertension and the developmental origins of cardiac hypertrophy and diastolic dysfunction.

    PubMed

    Armstrong, David W J; Tse, M Yat; Wong, Philip G; Ventura, Nicole M; Meens, Jalna A; Johri, Amer M; Matangi, Murray F; Pang, Stephen C

    2014-06-01

    The developmental origins of health and disease refer to the theory that adverse maternal environments influence fetal development and the risk of cardiovascular disease in adulthood. We used the chronically hypertensive atrial natriuretic peptide knockout (ANP-/-) mouse as a model of gestational hypertension, and attempted to determine the effect of gestational hypertension on left ventricular (LV) structure and function in adult offspring. We crossed normotensive ANP+/+ females with ANP-/- males (yielding ANP+/-(WT) offspring) and hypertensive ANP-/- females with ANP+/+ males (yielding ANP+/-(KO) offspring). Cardiac gene expression was measured using real-time quantitative PCR. Cardiac function was assessed using echocardiography. Daily injections of isoproterenol (ISO) were used to induce cardiac stress. Collagen deposition was assessed using picrosirius red staining. All mice were 10 weeks of age. Gestational hypertension resulted in significant LV hypertrophy in offspring, with no change in LV function. Treatment with ISO resulted in significant LV diastolic dysfunction with a restrictive filling pattern (increased E/A ratio and E/e') and interstitial myocardial fibrosis only in ANP+/-(KO) and not ANP+/-(WT) offspring. Gestational hypertension programs adverse LV structural and functional remodeling in offspring. These data suggest that adverse maternal environments may increase the risk of heart failure in offspring later in life.

  20. Neonatal cardiac dysfunction and transcriptome changes caused by the absence of Celf1

    PubMed Central

    Giudice, Jimena; Xia, Zheng; Li, Wei; Cooper, Thomas A.

    2016-01-01

    The RNA binding protein Celf1 regulates alternative splicing in the nucleus and mRNA stability and translation in the cytoplasm. Celf1 is strongly down-regulated during mouse postnatal heart development. Its re-induction in adults induced severe heart failure and reversion to fetal splicing and gene expression patterns. However, the impact of Celf1 depletion on cardiac transcriptional and posttranscriptional dynamics in neonates has not been addressed. We found that homozygous Celf1 knock-out neonates exhibited cardiac dysfunction not observed in older homozygous animals, although homozygous mice are smaller than wild type littermates throughout development. RNA-sequencing of mRNA from homozygous neonatal hearts identified a network of cell cycle genes significantly up-regulated and down-regulation of ion transport and circadian genes. Cell cycle genes are enriched for Celf1 binding sites supporting a regulatory role in mRNA stability of these transcripts. We also identified a cardiac splicing network coordinated by Celf1 depletion. Target events contain multiple Celf1 binding sites and enrichment in GU-rich motifs. Identification of direct Celf1 targets will advance our knowledge in the mechanisms behind developmental networks regulated by Celf1 and diseases where Celf1 is mis-regulated. PMID:27759042

  1. Cardiac tamponade: an unusual clinical presentation.

    PubMed

    Eakle, J F; Goodin, R R

    2001-02-01

    Pericardial effusion with cardiac tamponade is an unusual presentation of lymphoma, although cardiac involvement is often a late finding in widespread malignancy. Clinical identification can be difficult ante-mortem. New cardiac symptoms or classic findings of cardiac tamponade should prompt aggressive investigation. We present a case of B-cell lymphoma that initially presented as pericardial effusion with tamponade and discuss the characteristic physical findings and radiographic data that assist in diagnosis. PMID:11441582

  2. Pituitary gonadotrophic hormone synthesis, secretion, subunit gene expression and cell structure in normal and follicle-stimulating hormone β knockout, follicle-stimulating hormone receptor knockout, luteinising hormone receptor knockout, hypogonadal and ovariectomised female mice.

    PubMed

    Abel, M H; Widen, A; Wang, X; Huhtaniemi, I; Pakarinen, P; Kumar, T R; Christian, H C

    2014-11-01

    To investigate the relationship between gonadotroph function and ultrastructure, we have compared, in parallel in female mice, the effects of several different mutations that perturb the hypothalamic-pituitary-gonadal axis. Specifically, serum and pituitary gonadotrophin concentrations, gonadotrophin gene expression, gonadotroph structure and number were measured. Follicle-stimulating hormone β knockout (FSHβKO), follicle-stimulating hormone receptor knockout (FSHRKO), luteinising hormone receptor knockout (LuRKO), hypogonadal (hpg) and ovariectomised mice were compared with control wild-type or heterozygote female mice. Serum levels of LH were elevated in FSHβKO and FSHRKO compared to heterozygote females, reflecting the likely decreased oestrogen production in KO females, as demonstrated by the threadlike uteri and acyclicity. As expected, there was no detectable FSH in the serum or pituitary and an absence of expression of the FSHβ subunit gene in FSHβKO mice. However, there was a significant increase in expression of the FSHβ and LHβ subunit genes in FSHRKO female mice. The morphology of FSHβKO and FSHRKO gonadotrophs was not significantly different from the control, except that secretory granules in FSHRKO gonadotrophs were larger in diameter. In LuRKO and ovariectomised mice, stimulation of LHβ and FSHβ mRNA, as well as serum protein concentrations, were reflected in subcellular changes in gonadotroph morphology, including more dilated rough endoplasmic reticula and fewer, larger secretory granules. In the gonadotophin-releasing hormone deficient hpg mouse, gonadotrophin mRNA and protein levels were significantly lower than in control mice and gonadotrophs were correspondingly smaller with less abundant endoplasmic reticula and reduced numbers of secretory granules. In summary, major differences in pituitary content and serum concentrations of the gonadotrophins LH and FSH were found between control and mutant female mice. These changes were

  3. Cardiac transplantation in Becker muscular dystrophy.

    PubMed

    Quinlivan, R M; Dubowitz, V

    1992-01-01

    Becker muscular dystrophy is associated with abnormal cardiac features in about 75% of cases; up to one-third will develop ventricular dilatation leading to congestive cardiac failure. As this form of muscular dystrophy is relatively benign, failure to respond to medical treatment warrants assessment for cardiac transplantation.

  4. Telocytes in exercise-induced cardiac growth.

    PubMed

    Xiao, Junjie; Chen, Ping; Qu, Yi; Yu, Pujiao; Yao, Jianhua; Wang, Hongbao; Fu, Siyi; Bei, Yihua; Chen, Yan; Che, Lin; Xu, Jiahong

    2016-05-01

    Exercise can induce physiological cardiac growth, which is featured by enlarged cardiomyocyte cell size and formation of new cardiomyocytes. Telocytes (TCs) are a recently identified distinct interstitial cell type, existing in many tissues and organs including heart. TCs have been shown to form a tandem with cardiac stem/progenitor cells in cardiac stem cell niches, participating in cardiac regeneration and repair. Although exercise-induced cardiac growth has been confirmed as an important way to promote cardiac regeneration and repair, the response of cardiac TCs to exercise is still unclear. In this study, 4 weeks of swimming training was used to induce robust healthy cardiac growth. Exercise can induce an increase in cardiomyocyte cell size and formation of new cardiomyocytes as determined by Wheat Germ Lectin and EdU staining respectively. TCs were identified by three immunofluorescence stainings including double labelling for CD34/vimentin, CD34/platelet-derived growth factor (PDGF) receptor-α and CD34/PDGF receptor-β. We found that cardiac TCs were significantly increased in exercised heart, suggesting that TCs might help control the activity of cardiac stem/progenitor cells, cardiomyocytes or endothelial cells. Adding cardiac TCs might help promote cardiac regeneration and renewal. PMID:26987685

  5. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of…

  6. Cardiac ablation of Rheb1 induces impaired heart growth, endoplasmic reticulum-associated apoptosis and heart failure in infant mice.

    PubMed

    Cao, Yunshan; Tao, Lichan; Shen, Shutong; Xiao, Junjie; Wu, Hang; Li, Beibei; Wu, Xiangqi; Luo, Wen; Xiao, Qi; Hu, Xiaoshan; Liu, Hailang; Nie, Junwei; Lu, Shuangshuang; Yuan, Baiyin; Han, Zhonglin; Xiao, Bo; Yang, Zhongzhou; Li, Xinli

    2013-12-13

    Ras homologue enriched in brain 1 (Rheb1) plays an important role in a variety of cellular processes. In this study, we investigate the role of Rheb1 in the post-natal heart. We found that deletion of the gene responsible for production of Rheb1 from cardiomyocytes of post-natal mice resulted in malignant arrhythmias, heart failure, and premature death of these mice. In addition, heart growth impairment, aberrant metabolism relative gene expression, and increased cardiomyocyte apoptosis were observed in Rheb1-knockout mice prior to the development of heart failure and arrhythmias. Also, protein kinase B (PKB/Akt) signaling was enhanced in Rheb1-knockout mice, and removal of phosphatase and tensin homolog (Pten) significantly prolonged the survival of Rheb1-knockouts. Furthermore, signaling via the mammalian target of rapamycin complex 1 (mTORC1) was abolished and C/EBP homologous protein (CHOP) and phosphorylation levels of c-Jun N-terminal kinase (JNK) were increased in Rheb1 mutant mice. In conclusion, this study demonstrates that Rheb1 is important for maintaining cardiac function in post-natal mice via regulation of mTORC1 activity and stress on the endoplasmic reticulum. Moreover, activation of Akt signaling helps to improve the survival of mice with advanced heart failure. Thus, this study provides direct evidence that Rheb1 performs multiple important functions in the heart of the post-natal mouse. Enhancing Akt activity improves the survival of infant mice with advanced heart failure.

  7. Effects of ptb knockout on butyric acid fermentation by Clostridium tyrobutyricum.

    PubMed

    Zhang, Yali; Yu, Mingrui; Yang, Shang-Tian

    2012-01-01

    Clostridium tyrobutyricum ATCC 25755 is an anaerobic, rod-shaped, gram-positive bacterium that produces butyrate, acetate, hydrogen, and carbon dioxide from various saccharides, including glucose and xylose. Phosphotransbutyrylase (PTB) is a key enzyme in the butyric acid synthesis pathway. In this work, effects of ptb knockout by homologous recombination on metabolic flux and product distribution were investigated. When compared with the wild type, the activities of PTB and butyrate kinase in ptb knockout mutant decreased 76 and 42%, respectively; meanwhile, phosphotransacetylase and acetate kinase increased 7 and 29%, respectively. However, ptb knockout did not significantly reduce butyric acid production from glucose or xylose in batch fermentations. Instead, it increased acetic acid and hydrogen production 33.3-53.8% and ≈ 11%, respectively. Thus, the ptb knockout did increase the carbon flux toward acetate synthesis, resulting in a significant decrease (28-35% reduction) in the butyrate/acetate ratio in ptb mutant fermentations. In addition, the mutant displayed a higher specific growth rate (0.20 h(-1) vs. 0.15 h(-1) on glucose and 0.14 h(-1) vs. 0.10 h(-1) on xylose) and tolerance to butyric acid. Consequently, batch fermentation with the mutant gave higher fermentation rate and productivities (26-48% increase for butyrate, 81-100% increase for acetate, and 38-46% increase for hydrogen). This mutant thus can be used more efficiently than the parental strain in fermentations to produce butyrate, acetate, and hydrogen from glucose and xylose.

  8. Serotonin Transporter Knockout Rats Show Improved Strategy Set-Shifting and Reduced Latent Inhibition

    ERIC Educational Resources Information Center

    Nonkes, Lourens J. P.; van de Vondervoort, Ilse I. G. M.; de Leeuw, Mark J. C.; Wijlaars, Linda P.; Maes, Joseph H. R.; Homberg, Judith R.

    2012-01-01

    Behavioral flexibility is a cognitive process depending on prefrontal areas allowing adaptive responses to environmental changes. Serotonin transporter knockout (5-HTT[superscript -/-]) rodents show improved reversal learning in addition to orbitofrontal cortex changes. Another form of behavioral flexibility, extradimensional strategy set-shifting…

  9. Reproductive toxicity of ethylene glycol monoethyl ether in Aldh2 knockout mice.

    PubMed

    Wang, Rui-Sheng; Ohtani, Katsumi; Suda, Megumi; Kitagawa, Kyoko; Nakayama, Keiichi; Kawamoto, Toshihiro; Nakajima, Tamie

    2007-08-01

    Ethylene glycol monoethyl ether (EGEE) can cause damage to testes and sperm, and its metabolites are believed to play an important role in its toxicity. Aldehyde dehydrogenase 2 (ALDH2) is involved in the metabolism of this chemical. To investigate whether and how the enzyme affects the toxicity of EGEE, we conducted experiments comparing Aldh2 knockout mice with wild-type mice. Administration of EGEE at 100 and 600 mg/kg/day for one week did not induce any significant change in the weight and body weight ratios of testes, prostate and epididymides in either Aldh2 knockout or wild-type mice. However, motion of sperm from the spermaduct, as analyzed with a Hamilton-Thorne Sperm analyzer, was slightly decreased in the low dose group, and significantly lower in the high dose group; and the percentage of progressive sperm was also reduced in the two EGEE groups. This effect of EGEE treatment was observed in the wild-type, but not in the Aldh2 knockout mice. Sperm motion from the cauda epididymides was not affected. On the other hand, the concentration of ethoxyacetic acid, a metabolite of EGEE, in 24 h pooled urine of EGEE-treated Aldh2 knockout mice was not significantly lower than that of the wild-type mice on most days of urine sampling. These results suggest that inactivation of the ALDH2 enzyme due to gene mutation may be linked to differences in the susceptibility to EGEE-induced sperm toxicity. PMID:17878629

  10. Generation and behavioral characterization of beta-catenin forebrain-specific conditional knock-out mice.

    PubMed

    Gould, Todd D; O'Donnell, Kelley C; Picchini, Alyssa M; Dow, Eliot R; Chen, Guang; Manji, Husseini K

    2008-05-16

    The canonical Wnt pathway and beta-catenin have been implicated in the pathophysiology of mood disorders. We generated forebrain-specific CRE-mediated conditional beta-catenin knock-out mice to begin exploring the behavioral implications of decreased Wnt pathway signaling in the central nervous system. In situ hybridization revealed a progressive knock-out of beta-catenin that began between 2 and 4 weeks of age, and by 12 weeks resulted in considerably decreased beta-catenin expression in regions of the forebrain, including the frontal cortex, hippocampus, and striatum. A significant decrease in protein levels of beta-catenin in these brain regions was observed by Western blot. Behavioral characterization of these mice in several tests (including the forced swim test, tail suspension test (TST), learned helplessness, response and sensitization to stimulants, and light/dark box among other tests) revealed relatively circumscribed alterations. In the TST, knock-out mice spent significantly less time struggling (a depression-like phenotype). However, knock-out mice did not differ from their wild-type littermates in the other behavioral tests of mood-related or anxiety-related behaviors. These results suggest that a 60-70% beta-catenin reduction in circumscribed brain regions is only capable of inducing subtle behavioral changes. Alternatively, regulating beta-catenin may modulate drug effects rather than being a model of mood disorder pathophysiology per se.

  11. Simultaneous generation of fra-2 conditional and fra-2 knock-out mice.

    PubMed

    Eferl, Robert; Zenz, Rainer; Theussl, Hans-Christian; Wagner, Erwin F

    2007-07-01

    Loss of function mouse models comprise knock-out mice, where a gene is deleted in the germline, and conditional knock-out mice with somatic deletion of a floxed allele in defined tissues. Both types of mice are used for comprehensive studies of gene functions in vivo. Here, we describe a simple method for simultaneous generation of mice with conditional or knock-out alleles for the transcription factor fra-2 (Fos-related antigen 2) using a single embryonic stem (ES) cell clone. ES cells with a floxed fra-2 allele were transiently transfected with a Cre-recombinase expression plasmid and plated at low density. Most of the resulting ES cell colonies consisted of a mixture of cells that have either retained or lost the conditional allele. We demonstrate that these mixed ES cell clones can be directly used for generation of chimeras that give rise to offspring with conditional or knock-out alleles simultaneously. This strategy shortens the time and reduces the number of germline transmission events to generate genetically modified mice.

  12. Uncovering the gene knockout landscape for improved lycopene production in E. coli.

    PubMed

    Alper, Hal; Stephanopoulos, Gregory

    2008-04-01

    Systematic and combinatorial genetic approaches for the identification of gene knockout and overexpression targets have been effectively employed in the improvement of cellular phenotypes. Previously, we demonstrated how two of these tools, metabolic modeling and transposon mutagenesis, can be combined to identify strains of interest spanning the metabolic landscape of recombinant lycopene production in Escherichia coli. However, it is unknown how to best select multiple-gene knockout targets. Hence, this study seeks to understand how the overall order of gene selection, or search trajectory, biases the exploration and topology of the metabolic landscape. In particular, transposon mutagenesis and selection were employed in the background of eight different knockout genotypes. Collectively, 800,000 mutants were analyzed in hopes of exhaustively identifying all advantageous gene knockout targets. Several interesting observations, including clusters of gene functions, recurrence, and divergent genotypes, demonstrate the complexity of mapping only one genotype to one phenotype. One particularly interesting mutant, the DeltahnrDeltayliE genotype, exhibited a drastically improved lycopene production capacity in basic minimal medium in comparison to the best strains identified in previous studies.

  13. Brief Report: Altered Social Behavior in Isolation-Reared "Fmr1" Knockout Mice

    ERIC Educational Resources Information Center

    Heitzer, Andrew M.; Roth, Alexandra K.; Nawrocki, Lauren; Wrenn, Craige C.; Valdovinos, Maria G.

    2013-01-01

    Social behavior abnormalities in Fragile X syndrome (FXS) are characterized by social withdrawal, anxiety, and deficits in social cognition. To assess these deficits, a model of FXS, the "Fmr1" knockout mouse ("Fmr1" KO), has been utilized. This mouse model has a null mutation in the fragile X mental retardation 1 gene ("Fmr1") and displays…

  14. Fasting induces ketoacidosis and hypothermia in PDHK2/PDHK4-double-knockout mice

    PubMed Central

    Jeoung, Nam Ho; Rahimi, Yasmeen; Wu, Pengfei; Lee, W. N. Paul; Harris, Robert A.

    2015-01-01

    The importance of PDHK (pyruvate dehydrogenase kinase) 2 and 4 in regulation of the PDH complex (pyruvate dehydrogenase complex) was assessed in single- and double-knockout mice. PDHK2 deficiency caused higher PDH complex activity and lower blood glucose levels in the fed, but not the fasted, state. PDHK4 deficiency caused similar effects, but only after fasting. Double deficiency intensified these effects in both the fed and fasted states. PDHK2 deficiency had no effect on glucose tolerance, PDHK4 deficiency produced only a modest effect, but double deficiency caused a marked improvement and also induced lower insulin levels and increased insulin sensitivity. In spite of these beneficial effects, the double-knockout mice were more sensitive than wild-type and single-knockout mice to long-term fasting, succumbing to hypoglycaemia, ketoacidosis and hypothermia. Stable isotope flux analysis indicated that hypoglycaemia was due to a reduced rate of gluconeogenesis and that slightly more glucose was converted into ketone bodies in the double-knockout mice. The findings establish that PDHK2 is more important in the fed state, PDHK4 is more important in the fasted state, and survival during long-term fasting depends upon regulation of the PDH complex by both PDHK2 and PDHK4. PMID:22360721

  15. Histidine decarboxylase knockout mice, a genetic model of Tourette syndrome, show repetitive grooming after induced fear.

    PubMed

    Xu, Meiyu; Li, Lina; Ohtsu, Hiroshi; Pittenger, Christopher

    2015-05-19

    Tics, such as are seen in Tourette syndrome (TS), are common and can cause profound morbidity, but they are poorly understood. Tics are potentiated by psychostimulants, stress, and sleep deprivation. Mutations in the gene histidine decarboxylase (Hdc) have been implicated as a rare genetic cause of TS, and Hdc knockout mice have been validated as a genetic model that recapitulates phenomenological and pathophysiological aspects of the disorder. Tic-like stereotypies in this model have not been observed at baseline but emerge after acute challenge with the psychostimulant d-amphetamine. We tested the ability of an acute stressor to stimulate stereotypies in this model, using tone fear conditioning. Hdc knockout mice acquired conditioned fear normally, as manifested by freezing during the presentation of a tone 48h after it had been paired with a shock. During the 30min following tone presentation, knockout mice showed increased grooming. Heterozygotes exhibited normal freezing and intermediate grooming. These data validate a new paradigm for the examination of tic-like stereotypies in animals without pharmacological challenge and enhance the face validity of the Hdc knockout mouse as a pathophysiologically grounded model of tic disorders.

  16. IdealKnock: A framework for efficiently identifying knockout strategies leading to targeted overproduction.

    PubMed

    Gu, Deqing; Zhang, Cheng; Zhou, Shengguo; Wei, Liujing; Hua, Qiang

    2016-04-01

    In recent years, computer aided redesigning methods based on genome-scale metabolic network models (GEMs) have played important roles in metabolic engineering studies; however, most of these methods are hindered by intractable computing times. In particular, methods that predict knockout strategies leading to overproduction of desired biochemical are generally unable to do high level prediction because the computational time will increase exponentially. In this study, we propose a new framework named IdealKnock, which is able to efficiently evaluate potentials of the production for different biochemical in a system by merely knocking out pathways. In addition, it is also capable of searching knockout strategies when combined with the OptKnock or OptGene framework. Furthermore, unlike other methods, IdealKnock suggests a series of mutants with targeted overproduction, which enables researchers to select the one of greatest interest for experimental validation. By testing the overproduction of a large number of native metabolites, IdealKnock showed its advantage in successfully breaking through the limitation of maximum knockout number in reasonable time and suggesting knockout strategies with better performance than other methods. In addition, gene-reaction relationship is well considered in the proposed framework. PMID:26948338

  17. A baculovirus alkaline nuclease knockout construct produces fragmented DNA and aberrant capsids

    SciTech Connect

    Okano, Kazuhiro; Vanarsdall, Adam L.; Rohrmann, George F. . E-mail: rohrmanng@orst.edu

    2007-03-01

    DNA replication of bacmid-derived constructs of the Autographa californica multiple nucleocapsid nucleopolyhedrovirus (AcMNPV) was analyzed by field inversion gel electrophoresis (FIGE) in combination with digestion at a unique Eco81I restriction enzyme site. Three constructs were characterized: a parental bacmid, a bacmid deleted for the alkaline nuclease gene, and a bacmid from which the gp64 gene had been deleted. The latter was employed as a control for comparison with the alkaline nuclease knockout because neither yields infectious virus and their replication is limited to the initially transfected cells. The major difference between DNA replicated by the different constructs was the presence in the alkaline nuclease knockout of high concentrations of relatively small, subgenome length DNA in preparations not treated with Eco81I. Furthermore, upon Eco81I digestion, the alkaline nuclease knockout bacmid also yielded substantially more subgenome size DNA than the other constructs. Electron microscopic examination of cells transfected with the alkaline nuclease knockout indicated that, in addition to a limited number of normal-appearing electron-dense nucleocapsids, numerous aberrant capsid-like structures were observed indicating a defect in nucleocapsid maturation or in a DNA processing step that is necessary for encapsidation. Because of the documented role of the baculovirus alkaline nuclease and its homologs from other viruses in homologous recombination, these data suggest that DNA recombination may play a major role in the production of baculovirus genomes.

  18. CRISPR-Cas9-Based Knockout of the Prion Protein and Its Effect on the Proteome

    PubMed Central

    Mehrabian, Mohadeseh; Brethour, Dylan; MacIsaac, Sarah; Kim, Jin Kyu; Gunawardana, C . Geeth; Wang, Hansen; Schmitt-Ulms, Gerold

    2014-01-01

    The molecular function of the cellular prion protein (PrPC) and the mechanism by which it may contribute to neurotoxicity in prion diseases and Alzheimer's disease are only partially understood. Mouse neuroblastoma Neuro2a cells and, more recently, C2C12 myocytes and myotubes have emerged as popular models for investigating the cellular biology of PrP. Mouse epithelial NMuMG cells might become attractive models for studying the possible involvement of PrP in a morphogenetic program underlying epithelial-to-mesenchymal transitions. Here we describe the generation of PrP knockout clones from these cell lines using CRISPR-Cas9 knockout technology. More specifically, knockout clones were generated with two separate guide RNAs targeting recognition sites on opposite strands within the first hundred nucleotides of the Prnp coding sequence. Several PrP knockout clones were isolated and genomic insertions and deletions near the CRISPR-target sites were characterized. Subsequently, deep quantitative global proteome analyses that recorded the relative abundance of>3000 proteins (data deposited to ProteomeXchange Consortium) were undertaken to begin to characterize the molecular consequences of PrP deficiency. The levels of ∼120 proteins were shown to reproducibly correlate with the presence or absence of PrP, with most of these proteins belonging to extracellular components, cell junctions or the cytoskeleton. PMID:25490046

  19. SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS

    EPA Science Inventory

    SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS. L.F. Strader*, S.D. Perreault, J.C. Luft*, and D.J. Dix*. US EPA/ORD, Reproductive Toxicology Div., Research Triangle Park, NC
    Heat shock proteins (HSPs) protect cells from environm...

  20. Cardiac sarcoidosis: diagnosis and management.

    PubMed

    Dubrey, S W; Sharma, R; Underwood, R; Mittal, T

    2015-07-01

    Cardiac sarcoidosis is one of the most serious and unpredictable aspects of this disease state. Heart involvement frequently presents with arrhythmias or conduction disease, although myocardial infiltration resulting in congestive heart failure may also occur. The prognosis in cardiac sarcoidosis is highly variable, which relates to the heterogeneous nature of heart involvement and marked differences between racial groups. Electrocardiography and echocardiography often provide the first clue to the diagnosis, but advanced imaging studies using positron emission tomography and MRI, in combination with nuclear isotope perfusion scanning are now essential to the diagnosis and management of this condition. The identification of clinically occult cardiac sarcoidosis and the management of isolated and/or asymptomatic heart involvement remain both challenging and contentious. Corticosteroids remain the first treatment choice with the later substitution of immunosuppressive and steroid-sparing therapies. Heart transplantation is an unusual outcome, but when performed, the results are comparable or better than heart transplantation for other disease states. We review the epidemiology, developments in diagnostic techniques and the management of cardiac sarcoidosis.

  1. Primary Cardiac Solitary Fibrous Tumors

    PubMed Central

    2015-01-01

    Primary cardiac solitary fibrous tumors were reviewed. They are classified as pericardial tumors. Their incidences are very rare. Only 16 cases were reported in the literature. Basically, surgical treatments are performed. Their prognoses are generally good, although malignant cases are also reported. PMID:26156195

  2. Real time cardiac radionuclide imaging

    SciTech Connect

    Jarkewicz, G.G.

    1986-04-29

    A data acquisition system is described for use in radionuclide cardiac imaging of a patient having been administered a myocardium specific radionuclide, comprising: (a) means for monitoring the electrical activity of the heart; (b) first temporary storage means for accumulating respective pages of data corresponding to nuclear events during each cardiac cycle; (c) means, responsive to the means for monitoring, for determining the time duration of each successive cardiac cycle; (d) means for comparing each determined duration of a cardiac cycle with a preselected time duration range; (e) second temporary storage means; and (f) means for conditionally transferring pages of data from the first temporary storage means to the second temporary storage means if the measured duration associated with each page has predetermined correspondence with the preselected duration range, whereby pages of data having the predetermined correspondence may be collated into a quasi-real time study, while pages of data having different correspondence with the preselected time duration range are discarded from the study.

  3. Cardiac R-wave detector

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.

    1968-01-01

    Cardiac R wave detector obtains the systolic contraction signal of the human heart and uses it as a reference signal for the heart-assist pump cycle. It processes the electrocardiac signal /QRS wave complex/ of the natural heart in a sequence of operations which essentially elimates all components from the input signal except the R wave.

  4. The cardiac patient in Ramadan

    PubMed Central

    Chamsi-Pasha, Majed; Chamsi-Pasha, Hassan

    2016-01-01

    Ramadan is one of the five fundamental pillars of Islam. During this month, the majority of the 1.6 billion Muslims worldwide observe an absolute fast from dawn to sunset without any drink or food. Our review shows that the impact of fasting during Ramadan on patients with stable cardiac disease is minimal and does not lead to any increase in acute events. Most patients with the stable cardiac disease can fast safely. Most of the drug doses and their regimen are easily manageable during this month and may need not to be changed. Ramadan fasting is a healthy nonpharmacological means for improving cardiovascular risk factors. Most of the Muslims, who suffer from chronic diseases, insist on fasting Ramadan despite being exempted by religion. The Holy Quran specifically exempts the sick from fasting. This is particularly relevant if fasting worsens one's illness or delays recovery. Patients with unstable angina, recent myocardial infarction, uncontrolled hypertension, decompensated heart failure, recent cardiac intervention or cardiac surgery or any debilitating diseases should avoid fasting. PMID:27144139

  5. Bifurcation theory and cardiac arrhythmias.

    PubMed

    Karagueuzian, Hrayr S; Stepanyan, Hayk; Mandel, William J

    2013-01-01

    In this paper we review two types of dynamic behaviors defined by the bifurcation theory that are found to be particularly useful in describing two forms of cardiac electrical instabilities that are of considerable importance in cardiac arrhythmogenesis. The first is action potential duration (APD) alternans with an underlying dynamics consistent with the period doubling bifurcation theory. This form of electrical instability could lead to spatially discordant APD alternans leading to wavebreak and reentrant form of tachyarrhythmias. Factors that modulate the APD alternans are discussed. The second form of bifurcation of importance to cardiac arrhythmogenesis is the Hopf-homoclinic bifurcation that adequately describes the dynamics of the onset of early afterdepolarization (EAD)-mediated triggered activity (Hopf) that may cause ventricular tachycardia and ventricular fibrillation (VT/VF respectively). The self-termination of the triggered activity is compatible with the homoclinic bifurcation. Ionic and intracellular calcium dynamics underlying these dynamics are discussed using available experimental and simulation data. The dynamic analysis provides novel insights into the mechanisms of VT/VF, a major cause of sudden cardiac death in the US.

  6. Device Assists Cardiac Chest Compression

    NASA Technical Reports Server (NTRS)

    Eichstadt, Frank T.

    1995-01-01

    Portable device facilitates effective and prolonged cardiac resuscitation by chest compression. Developed originally for use in absence of gravitation, also useful in terrestrial environments and situations (confined spaces, water rescue, medical transport) not conducive to standard manual cardiopulmonary resuscitation (CPR) techniques.

  7. The Cardiac Complications of Methamphetamines.

    PubMed

    Paratz, Elizabeth D; Cunningham, Neil J; MacIsaac, Andrew I

    2016-04-01

    Methamphetamines are increasingly popular drugs of abuse in Australia, and are rising in purity. The rising popularity and purity of methamphetamines has notably increased demands upon Australian medical services. Methamphetamines are sympathomimetic amines with a range of adverse effects upon multiple organ systems. Cardiovascular complications are the second leading cause of death in methamphetamine abusers, and there appears to be a high prevalence of cardiac pathology. Cardiovascular pathology frequently seen in methamphetamine abusers includes hypertension, aortic dissection, acute coronary syndromes, pulmonary arterial hypertension and methamphetamine-associated cardiomyopathy. The rising prevalence of methamphetamine abuse is likely to increase the burden of cardiovascular pathology in Australians. A National Parliamentary Enquiry was opened in March 2015 to address concerns regarding the medical and social impacts of methamphetamine abuse. From April 2015, a National 'Ice Taskforce' was also created in parallel. Reversal of cardiac pathology appears to be achievable with abstinence from methamphetamines and initiation of appropriate treatment. It is key to appreciate that the pathogenesis of methamphetamine-induced cardiac complications arises as a result of the specific toxic effects of methamphetamines. Clinical management is hence individualised; suggested management approaches for methamphetamine-induced cardiac complications are detailed within this article.

  8. Cardiac arrest during dipyridamole imaging

    SciTech Connect

    Blumenthal, M.S.; McCauley, C.S.

    1988-05-01

    A case of cardiac arrest and subsequent acute myocardial infarction occurring during thallium-201 imaging with oral dipyridamole augmentation is presented. Previous reports emphasizing the safety of this procedure are briefly reviewed and a recommendation for close hemodynamic and arrhythmia monitoring during the study is made. Large doses of oral dipyridamole may be contraindicated in patients with unstable angina.

  9. Dermatoglyphic's in Congenital Cardiac Disease.

    PubMed

    Brijendra, Singh; Renu, Gupta; Dushyant, Agrawal; Rajneesh, Garg; Sunil, Katri

    2016-02-01

    Various dermatoglyphic parameters like finger print pattern, atd angle, absolute ridge count & ab, bc ,cd, and ad ridge counts were observed in 150 cases of congenital cardiac disease, comprising of 72 cases of Ventricular Septal Defects (VSD), 60 cases of Atrial Septal Defects (ASD), 9 cases of Coarctation of Aorta (COA) & 9 cases of Tetralogy of Fallot's (TOF). Same dermatoglyphic parameters were also studied in 300 controls and statistical comparison of cases and controls was done. In our study it was observed that the congenital cardiac disease cases exhibited preponderance of whorls (55.8%) with decrease in loop pattern (36.2%) as compared to those of controls and the difference was highly significant (P<0.001). The difference in the mean total finger ridge count (TFRC) of the controls and of the cases of Congenital Cardiac Diseases (CCD) was found to be highly significant (P<0.001), while the  mean atd angle in the cases of Congenital Cardiac Disease (CCD) was widen up and was statistically significant too. The mean ab, the mean bc ridge, the mean cd ridge and the mean ad ridge counts were also higher in the various type of CCD as compared to that controls and on statistical comparison, the difference was found to be highly significant.

  10. [Long-term cardiac rehabilitation].

    PubMed

    Tormo Alfonso, V

    1995-01-01

    Cardiac rehabilitation for life-time in a patient who has suffered coronary pathology is considered as appropriate. The reasons for such an opinion are given, as well as the two most indicated courses of action, being this rehabilitation at home and coronary clubs.

  11. MedlinePlus: Cardiac Arrest

    MedlinePlus

    ... Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine) Article: A Prospective Study of Sudden Cardiac Death ... Players MedlinePlus Connect for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department ...

  12. MR imaging of cardiac tumors.

    PubMed

    Sparrow, Patrick J; Kurian, John B; Jones, Tim R; Sivananthan, Mohan U

    2005-01-01

    Magnetic resonance (MR) imaging is an important tool in the evaluation of cardiac neoplasms. T1-weighted, T2-weighted, and gadolinium-enhanced sequences are used for anatomic definition and tissue characterization, whereas cine gradient-echo imaging is used to assess functional effects. Recent improvements in pulse sequences for cardiac MR imaging have led to superior image quality, with reduced motion artifact and improved signal-to-noise ratio and tissue contrast. Although there is some overlap in the MR imaging appearances of cardiac tumors, particularly of primary malignancies, differences in characteristic locations and features should allow confident differentiation between benign and malignant tumors. Indicators of malignancy at MR imaging are invasive behavior, involvement of the right side of the heart or the pericardium, tissue inhomogeneity, diameter greater than 5 cm, and enhancement after administration of gadolinium contrast material (as a result of higher tissue vascularity). Concomitant pericardial or pleural effusions are rare in benign processes but occur in about 50% of cases of malignant tumors. MR imaging offers improved resolution, a larger field of view, and superior soft-tissue contrast compared with those of echocardiography, suggesting that knowledge of the MR imaging features of cardiac neoplasms is important for accurate diagnosis and management. PMID:16160110

  13. Quantification of beta adrenergic receptor subtypes in beta-arrestin knockout mouse airways.

    PubMed

    Hegde, Akhil; Strachan, Ryan T; Walker, Julia K L

    2015-01-01

    In allergic asthma Beta 2 adrenergic receptors (β2ARs) are important mediators of bronchorelaxation and, paradoxically, asthma development. This contradiction is likely due to the activation of dual signaling pathways that are downstream of G proteins or β-arrestins. Our group has recently shown that β-arrestin-2 acts in its classical role to desensitize and constrain β2AR-induced relaxation of both human and murine airway smooth muscle. To assess the role of β-arrestins in regulating β2AR function in asthma, we and others have utilized β-arrestin-1 and -2 knockout mice. However, it is unknown if genetic deletion of β-arrestins in these mice influences β2AR expression in the airways. Furthermore, there is lack of data on compensatory expression of βAR subtypes when either of the β-arrestins is genetically deleted, thus necessitating a detailed βAR subtype expression study in these β-arrestin knockout mice. Here we standardized a radioligand binding methodology to characterize and quantitate βAR subtype distribution in the airway smooth muscle of wild-type C57BL/6J and β-arrestin-1 and β-arrestin-2 knockout mice. Using complementary competition and single-point saturation binding assays we found that β2ARs predominate over β1ARs in the whole lung and epithelium-denuded tracheobronchial smooth muscle of C57BL/6J mice. Quantification of βAR subtypes in β-arrestin-1 and β-arrestin-2 knockout mouse lung and epithelium-denuded tracheobronchial tissue showed that, similar to the C57BL/6J mice, both knockouts display a predominance of β2AR expression. These data provide further evidence that β2ARs are expressed in greater abundance than β1ARs in the tracheobronchial smooth muscle and that loss of either β-arrestin does not significantly affect the expression or relative proportions of βAR subtypes. As β-arrestins are known to modulate β2AR function, our analysis of βAR subtype expression in β-arrestin knockout mice airways sets a reference

  14. Molecular Modeling of Cardiac Troponin

    NASA Astrophysics Data System (ADS)

    Manning, Edward P.

    The cardiac thin filament regulates interactions of actin and myosin, the force-generating elements of muscular contraction. Over the past several decades many details have been discovered regarding the structure and function of the cardiac thin filament and its components, including cardiac troponin (cTn). My hypothesis is that signal propagation occurs between distant ends of the cardiac troponin complex through calcium-dependent alterations in the dynamics of cTn and tropomyosin (Tm). I propose a model of the thin filament that encompasses known structures of cTn, Tm and actin to gain insight into cardiac troponin's allosteric regulation of thin filament dynamics. By performing molecular dynamics simulations of cTn in conjunction with overlapping Tm in two conditions, with and without calcium bound to site II of cardiac troponin C (cTnC), I found a combination of calcium-dependent changes in secondary structure and dynamics throughout the cTn-Tm complex. I then applied this model to investigate familial hypertrophic cardiomyopathy (FHC), a disease of the sarcomere that is one of the most commonly occurring genetic causes of heart disease. Approximately 15% of known FHC-related mutations are found in cardiac troponin T (cTnT), most of which are in or flank the alpha-helical N-tail domain TNT1. TNT1 directly interacts with overlapping Tm coiled coils. Using this model I identified effects of TNT1 mutations that propagate to the cTn core where site II of cTnC, the regulatory site of calcium binding in the thin filament, is located. Specifically, I found that mutations in TNT1 alter the flexibility of TNT1 and that the flexibility of TNT1 is inversely proportional to the cooperativity of calcium activation of the thin filament. Further, I identified a pathway of propagation of structural and dynamic changes linking TNT1 to site II of cTnC. Mutation-induced changes at site II cTnC alter calcium coordination which corresponds to biophysical measurements of calcium

  15. Knockout mutations of insulin-like peptide genes enhance sexual receptivity in Drosophila virgin females.

    PubMed

    Watanabe, Kazuki; Sakai, Takaomi

    2016-01-01

    In the fruitfly Drosophila melanogaster, females take the initiative to mate successfully because they decide whether to mate or not. However, little is known about the molecular and neuronal mechanisms regulating sexual receptivity in virgin females. Genetic tools available in Drosophila are useful for identifying molecules and neural circuits involved in the regulation of sexual receptivity. We previously demonstrated that insulin-producing cells (IPCs) in the female brain are critical to the regulation of female sexual receptivity. Ablation and inactivation of IPCs enhance female sexual receptivity, suggesting that neurosecretion from IPCs inhibits female sexual receptivity. IPCs produce and release insulin-like peptides (Ilps) that modulate various biological processes such as metabolism, growth, lifespan and behaviors. Here, we report a novel role of the Ilps in sexual behavior in Drosophila virgin females. Compared with wild-type females, females with knockout mutations of Ilps showed a high mating success rate toward wild-type males, whereas wild-type males courted wild-type and Ilp-knockout females to the same extent. Wild-type receptive females retard their movement during male courtship and this reduced female mobility allows males to copulate. Thus, it was anticipated that knockout mutations of Ilps would reduce general locomotion. However, the locomotor activity in Ilp-knockout females was significantly higher than that in wild-type females. Thus, our findings indicate that the high mating success rate in Ilp-knockout females is caused by their enhanced sexual receptivity, but not by improvement of their sex appeal or by general sluggishness.

  16. Global Nav1.7 Knockout Mice Recapitulate the Phenotype of Human Congenital Indifference to Pain

    PubMed Central

    Gingras, Jacinthe; Smith, Sarah; Matson, David J.; Johnson, Danielle; Nye, Kim; Couture, Lauren; Feric, Elma; Yin, Ruoyuan; Moyer, Bryan D.; Peterson, Matthew L.; Rottman, James B.; Beiler, Rudolph J.; Malmberg, Annika B.; McDonough, Stefan I.

    2014-01-01

    Clinical genetic studies have shown that loss of Nav1.7 function leads to the complete loss of acute pain perception. The global deletion is reported lethal in mice, however, and studies of mice with promoter-specific deletions of Nav1.7 have suggested that the role of Nav1.7 in pain transduction depends on the precise form of pain. We developed genetic and animal husbandry strategies that overcame the neonatal-lethal phenotype and enabled construction of a global Nav1.7 knockout mouse. Knockouts were anatomically normal, reached adulthood, and had phenotype wholly analogous to human congenital indifference to pain (CIP): compared to littermates, knockouts showed no defects in mechanical sensitivity or overall movement yet were completely insensitive to painful tactile, thermal, and chemical stimuli and were anosmic. Knockouts also showed no painful behaviors resulting from peripheral injection of nonselective sodium channel activators, did not develop complete Freund’s adjuvant-induced thermal hyperalgesia, and were insensitive to intra-dermal histamine injection. Tetrodotoxin-sensitive sodium current recorded from cell bodies of isolated sensory neurons and the mechanically-evoked spiking of C-fibers in a skin-nerve preparation each were reduced but not eliminated in tissue from knockouts compared to littermates. Results support a role for Nav1.7 that is conserved between rodents and humans and suggest several possibly translatable biomarkers for the study of Nav1.7-targeted therapeutics. Results further suggest that Nav1.7 may retain its key role in persistent as well as acute forms of pain. PMID:25188265

  17. Knockout Mice Reveal a Major Role for Alveolar Epithelial Type I Cells in Alveolar Fluid Clearance.

    PubMed

    Flodby, Per; Kim, Yong Ho; Beard, LaMonta L; Gao, Danping; Ji, Yanbin; Kage, Hidenori; Liebler, Janice M; Minoo, Parviz; Kim, Kwang-Jin; Borok, Zea; Crandall, Edward D

    2016-09-01

    Active ion transport by basolateral Na-K-ATPase (Na pump) creates an Na(+) gradient that drives fluid absorption across lung alveolar epithelium. The α1 and β1 subunits are the most highly expressed Na pump subunits in alveolar epithelial cells (AEC). The specific contribution of the β1 subunit and the relative contributions of alveolar epithelial type II (AT2) versus type I (AT1) cells to alveolar fluid clearance (AFC) were investigated using two cell type-specific mouse knockout lines in which the β1 subunit was knocked out in either AT1 cells or both AT1 and AT2 cells. AFC was markedly decreased in both knockout lines, revealing, we believe for the first time, that AT1 cells play a major role in AFC and providing insights into AEC-specific roles in alveolar homeostasis. AEC monolayers derived from knockout mice demonstrated decreased short-circuit current and active Na(+) absorption, consistent with in vivo observations. Neither hyperoxia nor ventilator-induced lung injury increased wet-to-dry lung weight ratios in knockout lungs relative to control lungs. Knockout mice showed increases in Na pump β3 subunit expression and β2-adrenergic receptor expression. These results demonstrate a crucial role for the Na pump β1 subunit in alveolar ion and fluid transport and indicate that both AT1 and AT2 cells make major contributions to these processes and to AFC. Furthermore, they support the feasibility of a general approach to altering alveolar epithelial function in a cell-specific manner that allows direct insights into AT1 versus AT2 cell-specific roles in the lung. PMID:27064541

  18. Gonadotropin Signaling in Zebrafish Ovary and Testis Development: Insights From Gene Knockout Study.

    PubMed

    Chu, Lianhe; Li, Jianzhen; Liu, Yun; Cheng, Christopher H K

    2015-12-01

    Using the transcription activator-like effectors nucleases-mediated gene knockout technology, we have previously demonstrated that LH signaling is required for oocyte maturation and ovulation but is dispensable for testis development in zebrafish. Here, we have further established the fshb and fshr knockout zebrafish lines. In females, fshb mutant is subfertile, whereas fshr mutant is infertile. Folliculogenesis is partially affected in the fshb mutant but is completely arrested at the primary growth stage in the fshr mutant. In males, fshb and fshr mutant are fertile. The fertilization rate and histological structure of the testis is not affected. However, double knockout of fshb;lhb or fshr;lhr leads to all infertile male offspring. The key steroid hormones and steroidogenic genes are dramatically decreased in double knockout mutant (fshb;lhb and fshr;lhr) but not in single knockout mutant (fshb, lhb, fshr, and lhr) males. Furthermore, we have also demonstrated the constitutive activities of both FSH receptor (FSHR) and LH receptor in zebrafish and the compensatory role of LH by cross-reacting with FSHR in the fshb;lhr double mutant, thus explaining the phenotypic discrepancy observed among the ligand/receptor mutant lines. Taken together, our data established the following models on the roles of gonadotropin signaling in zebrafish gonad development. In females, FSH signaling is mainly responsible for promoting follicular growth, whereas LH signaling is mainly responsible for stimulating oocyte maturation and ovulation. In males, the functions of FSH and LH signaling overlap, and only disruption of both FSH and LH signaling could lead to the infertile phenotype. In the absence of FSH, LH could play a compensatory role by cross-reacting with FSHR in both male and female.

  19. Carney complex with biatrial cardiac myxoma.

    PubMed

    Havrankova, Eniko; Stenova, Emoke; Olejarova, Ingrid; Sollarova, Katarina; Kinova, Sona

    2014-01-01

    Cardiac myxomas make up approximately 50% of all benign cardiac tumors and represented 86% of all surgically treated cardiac tumors. Most of them originated from the left atrium, in some cases from both of atria. We report a case of male patient with biatrial myxomas and other extra-cardiac involvement: hypophyseal adenoma, enlargement of thyroid gland, tubular adenoma polyp of colon and bilateral large cell calcifying Sertoli cell tumor (LCCSCT) of testis. These findings led to the diagnosis of Carney's complex, which is a syndrome with multiple neoplasias, cardiac myxomas, lentigines, and endocrine abnormalities. A genetic test confirm this diagnosis. PMID:24088910

  20. Bioactive scaffolds for engineering vascularized cardiac tissues

    PubMed Central

    Chiu, Loraine; Radisic, Milica; Vunjak-Novakovic, Gordana

    2013-01-01

    Functional vascularization is a key requirement for the development and function of most tissues, and most critically cardiac muscle. Rapid and irreversible loss of cardiomyocytes during cardiac infarction directly results from the lack of blood supply. Contractile cardiac grafts, engineered using cardiovascular cells in conjunction with biomaterial scaffolds, are an actively studied method for cardiac repair. In this article, we focus on biomaterial scaffolds designed to mediate the development and maturation of vascular networks, by immobilized growth factors. The interactive effects of multiple vasculogenic factors are discussed in the context of cardiac tissue engineering. PMID:20857391

  1. Cardiac Function and Dysfunction in Sepsis.

    PubMed

    Fenton, Kimberly E; Parker, Margaret M

    2016-06-01

    Cardiac function and dysfunction are important in the clinical outcomes of sepsis and septic shock. Cardiac dysfunction is not a single entity, but is a broad spectrum of syndromes that result in biventricular cardiac dysfunction manifested by both systolic and diastolic dysfunction and is influenced by cardiac loading conditions (ie, preload and afterload). Elucidating the underlying pathophysiology has proved to be complex. This article emphasizes the underlying pathophysiology of cardiac dysfunction and explores recent evidence related to diagnosis, including the utility of biomarkers, the role of echocardiography, and management goals and treatment. PMID:27229645

  2. Loss of CEACAM1, a Tumor-Associated Factor, Attenuates Post-infarction Cardiac Remodeling by Inhibiting Apoptosis

    PubMed Central

    Wang, Yan; Chen, Yanmei; Yan, Yi; Li, Xinzhong; Chen, Guojun; He, Nvqin; Shen, Shuxin; Chen, Gangbin; Zhang, Chuanxi; Liao, Wangjun; Liao, Yulin; Bin, Jianping

    2016-01-01

    Carcinoembryonic antigen-related cell adhesion molecule1 (CEACAM1) is a tumor-associated factor that is known to be involved in apoptosis, but the role of CEACAM1 in cardiovascular disease is unclear. We aims to investigate whether CEACAM1 influences cardiac remodeling in mice with myocardial infarction (MI) and hypoxia-induced cardiomyocyte injury. Both serum in patients and myocardial CEACAM1 levels in mice were significantly increased in response to MI, while levels were elevated in neonatal rat cardiomyocytes (NRCs) exposed to hypoxia. Eight weeks after MI, a lower mortality rate, improved cardiac function, and less cardiac remodeling in CEACAM1 knock-out (KO) mice than in their wild-type (WT) littermates were observed. Moreover, myocardial expression of mitochondrial Bax, cytosolic cytochrome C, and cleaved caspase-3 was significantly lower in CEACAM1 KO mice than in WT mice. In cultured NRCs exposed to hypoxia, recombinant human CEACAM1 (rhCEACAM1) reduced mitochondrial membrane potential, upregulated mitochondrial Bax, increased cytosolic cytochrome C and cleaved caspase-3, and consequently increased apoptosis. RhCEACAM1 also increased the levels of GRP78 and CHOP in NRCs with hypoxia. All of these effects were abolished by silencing CEACAM1. Our study indicates that CEACAM1 exacerbates hypoxic cardiomyocyte injury and post-infarction cardiac remodeling by enhancing cardiomyocyte mitochondrial dysfunction and endoplasmic reticulum stress-induced apoptosis. PMID:26911181

  3. Cardiac deficiency of single cytochrome oxidase assembly factor scox induces p53-dependent apoptosis in a Drosophila cardiomyopathy model

    PubMed Central

    Martínez-Morentin, Leticia; Martínez, Lidia; Piloto, Sarah; Yang, Hua; Schon, Eric A.; Garesse, Rafael; Bodmer, Rolf; Ocorr, Karen; Cervera, Margarita; Arredondo, Juan J.

    2015-01-01

    The heart is a muscle with high energy demands. Hence, most patients with mitochondrial disease produced by defects in the oxidative phosphorylation (OXPHOS) system are susceptible to cardiac involvement. The presentation of mitochondrial cardiomyopathy includes hypertrophic, dilated and left ventricular noncompaction, but the molecular mechanisms involved in cardiac impairment are unknown. One of the most frequent OXPHOS defects in humans frequently associated with cardiomyopathy is cytochrome c oxidase (COX) deficiency caused by mutations in COX assembly factors such as Sco1 and Sco2. To investigate the molecular mechanisms that underlie the cardiomyopathy associated with Sco deficiency, we have heart specifically interfered scox expression, the single Drosophila Sco orthologue. Cardiac-specific knockdown of scox reduces fly lifespan, and it severely compromises heart function and structure, producing dilated cardiomyopathy. Cardiomyocytes with low levels of scox have a significant reduction in COX activity and they undergo a metabolic switch from OXPHOS to glycolysis, mimicking the clinical features found in patients harbouring Sco mutations. The major cardiac defects observed are produced by a significant increase in apoptosis, which is dp53-dependent. Genetic and molecular evidence strongly suggest that dp53 is directly involved in the development of the cardiomyopathy induced by scox deficiency. Remarkably, apoptosis is enhanced in the muscle and liver of Sco2 knock-out mice, clearly suggesting that cell death is a key feature of the COX deficiencies produced by mutations in Sco genes in humans. PMID:25792727

  4. Cardiac deficiency of single cytochrome oxidase assembly factor scox induces p53-dependent apoptosis in a Drosophila cardiomyopathy model.

    PubMed

    Martínez-Morentin, Leticia; Martínez, Lidia; Piloto, Sarah; Yang, Hua; Schon, Eric A; Garesse, Rafael; Bodmer, Rolf; Ocorr, Karen; Cervera, Margarita; Arredondo, Juan J

    2015-07-01

    The heart is a muscle with high energy demands. Hence, most patients with mitochondrial disease produced by defects in the oxidative phosphorylation (OXPHOS) system are susceptible to cardiac involvement. The presentation of mitochondrial cardiomyopathy includes hypertrophic, dilated and left ventricular noncompaction, but the molecular mechanisms involved in cardiac impairment are unknown. One of the most frequent OXPHOS defects in humans frequently associated with cardiomyopathy is cytochrome c oxidase (COX) deficiency caused by mutations in COX assembly factors such as Sco1 and Sco2. To investigate the molecular mechanisms that underlie the cardiomyopathy associated with Sco deficiency, we have heart specifically interfered scox expression, the single Drosophila Sco orthologue. Cardiac-specific knockdown of scox reduces fly lifespan, and it severely compromises heart function and structure, producing dilated cardiomyopathy. Cardiomyocytes with low levels of scox have a significant reduction in COX activity and they undergo a metabolic switch from OXPHOS to glycolysis, mimicking the clinical features found in patients harbouring Sco mutations. The major cardiac defects observed are produced by a significant increase in apoptosis, which is dp53-dependent. Genetic and molecular evidence strongly suggest that dp53 is directly involved in the development of the cardiomyopathy induced by scox deficiency. Remarkably, apoptosis is enhanced in the muscle and liver of Sco2 knock-out mice, clearly suggesting that cell death is a key feature of the COX deficiencies produced by mutations in Sco genes in humans.

  5. Clinically applicable gated cardiac computed tomography

    SciTech Connect

    Cipriano, P.R.; Nassi, M.; Brody, W.R.

    1983-03-01

    Several attempts have been made to improve cardiac images obtained with x-ray transmission computed tomography (CT) by stopping cardiac motion through electrocardiographic gating. These methods reconstruct images that correspond to time intervals of the cardiac cycle identified by electrocardiography using either a pulsed x-ray beam at a selected time in the cardiac cycle or selected measurements in retrospect from regularly pulsed measurements made over several cardiac cycles. Missing CT angles of view (line integrals) have been a major problem contributing to degradation of such gated cardiac CT images. A new method for CT reconstruction from an incomplete set of projection data is presented that can be used clinically with a standard fan-beam reconstruction algorithm to improve gated cardiac CT images.

  6. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) and Cyclic ADP-Ribose (cADPR) Mediate Ca2+ Signaling in Cardiac Hypertrophy Induced by β-Adrenergic Stimulation

    PubMed Central

    Shawl, Asif Iqbal; Im, Soo-Yeul; Nam, Tae-Sik; Lee, Sun-Hwa; Ko, Jae-Ki; Jang, Kyu Yoon; Kim, Donghee; Kim, Uh-Hyun

    2016-01-01

    Ca2+ signaling plays a fundamental role in cardiac hypertrophic remodeling, but the underlying mechanisms remain poorly understood. We investigated the role of Ca2+-mobilizing second messengers, NAADP and cADPR, in the cardiac hypertrophy induced by β-adrenergic stimulation by isoproterenol. Isoproterenol induced an initial Ca2+ transients followed by sustained Ca2+ rises. Inhibition of the cADPR pathway with 8-Br-cADPR abolished only the sustained Ca2+ increase, whereas inhibition of the NAADP pathway with bafilomycin-A1 abolished both rapid and sustained phases of the isoproterenol-mediated signal, indicating that the Ca2+ signal is mediated by a sequential action of NAADP and cADPR. The sequential production of NAADP and cADPR was confirmed biochemically. The isoproterenol-mediated Ca2+ increase and cADPR production, but not NAADP production, were markedly reduced in cardiomyocytes obtained from CD38 knockout mice. CD38 knockout mice were rescued from chronic isoproterenol infusion-induced myocardial hypertrophy, interstitial fibrosis, and decrease in fractional shortening and ejection fraction. Thus, our findings indicate that β-adrenergic stimulation contributes to the development of maladaptive cardiac hypertrophy via Ca2+ signaling mediated by NAADP-synthesizing enzyme and CD38 that produce NAADP and cADPR, respectively. PMID:26959359

  7. ABSENCE OF THE SP/SP RECEPTOR CIRCUITRY IN THE SP PRECURSOR KNOCKOUT MICE OR SP-RECEPTOR, NEUROKININ (NK1) KNOCKOUT MICE LEADS TO AN INHIBITED CYTOKINE RESPONSE IN GRANULOMAS ASSOCIATED WITH MURINE TAENIA CRASSICEPS INFECTION

    PubMed Central

    Garza, Armandina; Weinstock, Joel; Robinson, Prema

    2008-01-01

    Neurocysticercosis, caused by the cestode Taenia solium, is the most common parasitic infection of the human central nervous system that leads to seizures. Taenia crassiceps cysticercosis in mice is an experimental model for Taenia solium cysticercosis. Similar to the human infection, live parasites cause little or no granulomatous inflammation. Dying parasites initiate a granulomatous reaction. The neuropeptide, Substance P (SP), stimulates Th1 cytokine production. In the current studies, we determined if absence of SP/SP receptor circuitry in the SP precursor, preprotachykinin knockout or SP-receptor, neurokinin (NK1) knockout mice, affected granuloma cytokine production. We hence compared the levels of Th1 cytokines, IL-2 and IFN-γ, and levels of Th2/immunoregulatory cytokines, IL-4 and IL-10, by ELISA in T. crassiceps-induced granulomas derived from infected C57BL/6 wild type (WT) versus SP-Precursor knockout and NK1 knockout mice. We found that mean levels of IL-2, IFN-γ, IL-4, and IL-10 in infected, WT-derived granulomas were significantly higher than those of granulomas derived from infected SP-Precursor knockout or the NK1 receptor knockout mice. Levels of Th2/immunoregulatory cytokines, IL-4 and IL-10, were higher in early stage granulomas (histologically-staged on basis of evidence of parasite remnants) versus late stage granulomas (no parasite-remnants) of both knockouts, whereas the reverse was noted in WT-derived granulomas. These studies established that the absence of an SP/SP receptor circuitry in the SP precursor knockout mice or NK1 receptor knockout led to an inhibited cytokine response. PMID:18576810

  8. Resveratrol, an activator of SIRT1, upregulates sarcoplasmic calcium ATPase and improves cardiac function in diabetic cardiomyopathy

    PubMed Central

    Sulaiman, M.; Matta, M. J.; Sunderesan, N. R.; Periasamy, M.; Gupta, M.

    2010-01-01

    Reduced sarcoplasmic calcium ATPase (SERCA2a) expression has been shown to play a significant role in the cardiac dysfunction in diabetic cardiomyopathy. The mechanism of SERCA2a repression is, however, not known. This study was designed to examine the effect of resveratrol (RSV), a potent activator of SIRT1, on cardiac function and SERCA2a expression in chronic type 1 diabetes. Adult male mice were injected with streptozotocin (STZ) and fed with either a regular diet or a diet enriched with RSV. STZ administration produced progressive decline in cardiac function, associated with markedly reduced SERCA2a and SIRT1 protein levels and increased collagen deposition; RSV treatment to these mice had a tremendous beneficial effect both in terms of improving SERCA2a expression and on cardiac function. In cultured cardiomyocytes, RSV restored SERCA2 promoter activity, which was otherwise highly repressed in high-glucose media. Protective effects of RSV were found to be dependent on its ability to activate Silent information regulator (SIRT) 1. In cardiomyocytes, overexpression of SIRT1 was found sufficient to activate SERCA2 promoter in a dose-dependent manner. In contrast, pretreatment of cardiomyocytes with SIRT1 antagonist, splitomycin, blocked these beneficial effects of RSV. In addition, SIRT1 knockout (+/−) mice were also found to be more sensitive to STZ-induced decline in SERCA2a mRNA. The data demonstrate that, in chronic diabetes, 1) the enzymatic activity of cardiac SIRT1 is reduced, which contributes to reduced expression of SERCA2a and 2) through activation of SIRT1, RSV enhances expression of SERCA2a and improves cardiac function. PMID:20008278

  9. Carnitine Palmitoyltransferase-1b (CPT1b) Deficiency Aggravates Pressure-Overload-Induced Cardiac Hypertrophy due to Lipotoxicity

    PubMed Central

    He, Lan; Kim, Teayoun; Long, Qinqiang; Liu, Jian; Wang, Peiyong; Zhou, Yiqun; Ding, Yishu; Prasain, Jeevan; Wood, Philip A.; Yang, Qinglin

    2012-01-01

    Background Carnitine palmitoyltransferase 1(CPT1) is a rate-limiting step of mitochondrial β-oxidation by controlling the mitochondrial uptake of long-chain acyl-CoAs. The muscle isoform, CPT1b, is the predominant isoform expressed in the heart. It has been suggested that inhibiting CPT-1 activity by specific CPT-1 inhibitors exerts protective effects against cardiac hypertrophy and heart failure. However, clinical and animal studies have shown mixed results, thereby posting concerns on the safety of this class of drugs. Preclinical studies using genetically modified animal models should provide a better understanding of targeting CPT1 in order to evaluate it as a safe and effective therapeutic approach. Methods and Results Heterozygous CPT1b knockout mice (CPT1b+/−) were subjected to transverse aorta constriction (TAC)-induced pressure-overload. These mice showed overtly normal cardiac structure/function under the basal condition. Under a severe pressure-overload condition induced by two weeks of transverse aorta constriction (TAC), CPT1b+/− mice were susceptible to premature death with congestive heart failure. Under a milder pressure-overload condition, CPT1b+/− mice exhibited exacerbated cardiac hypertrophy and remodeling compared with that in wild-type littermates. There were more pronounced impairments of cardiac contraction with greater eccentric cardiac hypertrophy in CPT1b+/− than in controlled mice. Moreover, the CPT1b+/− heart exhibited exacerbated mitochondrial abnormalities and myocardial lipid accumulation with elevated triglycerides and ceramide content, leading to greater cardiomyocytes apoptosis. Conclusions We conclude that CPT1b deficiency can cause lipotoxicity in the heart under pathological stress, leading to exacerbation of cardiac pathology. Therefore, caution should be applied in the clinical use of CPT-1 inhibitors. PMID:22932257

  10. Cyclosporine A Treatment Inhibits Abcc6-Dependent Cardiac Necrosis and Calcification following Coxsackievirus B3 Infection in Mice

    PubMed Central

    Marton, Jennifer; Albert, Danica; Wiltshire, Sean A.; Park, Robin; Bergen, Arthur; Qureshi, Salman; Malo, Danielle; Burelle, Yan; Vidal, Silvia M.

    2015-01-01

    Coxsackievirus type B3 (CVB3) is a cardiotropic enterovirus. Infection causes cardiomyocyte necrosis and myocardial inflammation. The damaged tissue that results is replaced with fibrotic or calcified tissue, which can lead to permanently altered cardiac function. The extent of pathogenesis among individuals exposed to CVB3 is dictated by a combination of host genetics, viral virulence, and the environment. Here, we aimed to identify genes that modulate cardiopathology following CVB3 infection. 129S1 mice infected with CVB3 developed increased cardiac pathology compared to 129X1 substrain mice despite no difference in viral burden. Linkage analysis identified a major locus on chromosome 7 (LOD: 8.307, P<0.0001) that controlled the severity of cardiac calcification and necrosis following infection. Sub-phenotyping and genetic complementation assays identified Abcc6 as the underlying gene. Microarray expression profiling identified genotype-dependent regulation of genes associated with mitochondria. Electron microscopy examination showed elevated deposition of hydroxyapatite-like material in the mitochondrial matrices of infected Abcc6 knockout (Abcc6-/-) mice but not in wildtype littermates. Cyclosporine A (CsA) inhibits mitochondrial permeability transition pore opening by inhibiting cyclophilin D (CypD). Treatment of Abcc6 -/- mice with CsA reduced cardiac necrosis and calcification by more than half. Furthermore, CsA had no effect on the CVB3-induced phenotype of doubly deficient CypD-/-Abcc6-/- mice. Altogether, our work demonstrates that mutations in Abcc6 render mice more susceptible to cardiac calcification following CVB3 infection. Moreover, we implicate CypD in the control of cardiac necrosis and calcification in Abcc6-deficient mice, whereby CypD inhibition is required for cardioprotection. PMID:26375467

  11. Stem cells in cardiac repair.

    PubMed

    Henning, Robert J

    2011-01-01

    Myocardial infarction is the leading cause of death among people in industrialized nations. Although the heart has some ability to regenerate after infarction, myocardial restoration is inadequate. Consequently, investigators are currently exploring the use of human embryonic stem cells (hESCs), skeletal myoblasts and adult bone marrow stem cells to limit infarct size. hESCs are pluripotent cells that can regenerate myocardium in infarcted hearts, attenuate heart remodeling and contribute to left ventricle (LV) systolic force development. Since hESCs can form heart teratomas, investigators are differentiating hESCs toward cardiac progenitor cells prior to transplantation into hearts. Large quantities of hESCs cardiac progenitor cells, however, must be generated, immune rejection must be prevented and grafts must survive over the long term to significantly improve myocardial performance. Transplanted autologous skeletal myoblasts can survive in infarcted myocardium in small numbers, proliferate, differentiate into skeletal myofibers and increase the LV ejection fraction. These cells, however, do not form electromechanical connections with host cardiomyocytes. Consequently, electrical re-entry can occur and cause cardiac arrhythmias. Autologous bone marrow mononuclear cells contain hematopoietic and mesenchymal stem cells. In several meta-analyses, patients with coronary disease who received autologous bone marrow cells by intracoronary injection show significant 3.7% (range: 1.9-5.4%) increases in LV ejection fraction, decreases in LV end-systolic volume of -4.8 ml (range: -1.4 to -8.2 ml) and reductions in infarct size of 5.5% (-1.9 to -9.1%), without experiencing arrhythmias. Bone marrow cells appear to release biologically active factors that limit myocardial damage. Unfortunately, bone marrow cells from patients with chronic diseases propagate poorly and can die prematurely. Substantial challenges must be addressed and resolved to advance the use of stem cells

  12. Risk stratification for major adverse cardiac events and ventricular tachyarrhythmias by cardiac MRI in patients with cardiac sarcoidosis

    PubMed Central

    Yasuda, Masakazu; Iwanaga, Yoshitaka; Kato, Takao; Izumi, Toshiaki; Inuzuka, Yasutaka; Nakamura, Takashi; Miyaji, Yuki; Kawamura, Takayuki; Ikeguchi, Shigeru; Inoko, Moriaki; Kurita, Takashi; Miyazaki, Shunichi

    2016-01-01

    Background The presence of myocardial fibrosis by cardiac MRI has prognostic value in cardiac sarcoidosis, and localisation may be equally relevant to clinical outcomes. Objective We aimed to analyse cardiac damage and function in detail and explore the relationship with clinical outcomes in patients with cardiac sarcoidosis using cardiac MRI. Methods We included 81 consecutive patients with cardiac sarcoidosis undergoing cardiac MR. Left ventricular mass and fibrosis mass were calculated, and localisation was analysed using a 17-segment model. Participants underwent follow-up through 2015, and the development of major adverse cardiac events including ventricular tachyarrhythmias was recorded. Results Increased left ventricular fibrosis mass was associated with increased prevalence of ventricular tachyarrhythmias (p<0.001). When localisation was defined as the sum of late gadolinium enhancement in the left ventricular basal anterior and basal anteroseptal areas, or the right ventricular area, it was associated with ventricular tachyarrhythmias (p<0.001). Kaplan-Meier analysis during a median follow-up of 22.1 months showed that both the mass and localisation groupings for fibrosis were significantly associated with major adverse cardiac events or ventricular tachyarrhythmias and that when combined, the risk stratification was better than for each variable alone (p<0.001, respectively). By Cox-proportional hazard risk analysis, the localisation grouping was an independent predictor for the both. Conclusions In patients with cardiac sarcoidosis, both fibrosis mass and its localisation to the basal anterior/anteroseptal left ventricle, or right ventricle was associated with the development of major adverse cardiac events or ventricular tachyarrhythmias. Cardiac MR with late gadolinium enhancement may be useful for improving risk stratification in patients with cardiac sarcoidosis. PMID:27547432

  13. Maltodextrin and fat preference deficits in "taste-blind" P2X2/P2X3 knockout mice.

    PubMed

    Sclafani, Anthony; Ackroff, Karen

    2014-07-01

    Adenosine triphosphate is a critical neurotransmitter in the gustatory response to the 5 primary tastes in mice. Genetic deletion of the purinergic P2X2/P2X3 receptor greatly reduces the neural and behavioral response to prototypical primary taste stimuli. In this study, we examined the behavioral response of P2X double knockout mice to maltodextrin and fat stimuli, which appear to activate additional taste channels. P2X double knockout and wild-type mice were given 24-h choice tests (vs. water) with ascending concentrations of Polycose and Intralipid. In Experiment 1, naive double knockout mice, unlike wild-type mice, were indifferent to dilute (0.5-4%) Polycose solutions but preferred concentrated (8-32%) Polycose to water. In a retest, the Polycose-experienced double knockout mice, like wild-type mice, preferred all Polycose concentrations. In Experiment 2, naive double knockout mice, unlike wild-type mice, were indifferent to dilute (0.313-2.5%) Intralipid emulsions but preferred concentrated (5-20%) Intralipid to water. In a retest, the fat-experienced double knockout mice, like wild-type mice, strongly preferred 0.313-5% Intralipid to water. These results indicate that the inherent preferences of mice for maltodextrin and fat are dependent upon adenosine triphosphate taste cell signaling. With experience, however, P2X double knockout mice develop strong preferences for the nontaste flavor qualities of maltodextrin and fat conditioned by the postoral actions of these nutrients.

  14. Cardiac Arrest in a Heart Transplant Patient Receiving Dexmedetomidine During Cardiac Catheterization.

    PubMed

    Schwartz, Lawrence Israel; Miyamoto, Shelley D; Stenquist, Scott; Twite, Mark David

    2016-06-01

    Dexmedetomidine is an α-2 agonist with a sedative and cardiopulmonary profile that makes it an attractive anesthetic in pediatric cardiac patients. Cardiac transplant patients may suffer from acute cellular rejection of the cardiac conduction system and, therefore, are at an increased risk of the electrophysiological effect of dexmedetomidine. We present such a patient who had a cardiac arrest while receiving dexmedetomidine during cardiac catheterization. Because acute cellular rejection of the cardiac conduction system is difficult to diagnose, dexmedetomidine should be used with caution in pediatric heart transplant patients. PMID:26721807

  15. HMGB1-RAGE Axis Makes No Contribution to Cardiac Remodeling Induced by Pressure-Overload

    PubMed Central

    Xie, Jiahe; Hao, Huixin; Zhang, Yingxue; Chen, Zhenhuan; Yamamoto, Hiroshi; Liao, Wangjun; Bin, Jianping; Cao, Shiping; Huang, Xiaobo

    2016-01-01

    High-mobility group box1 (HMGB1) exerts effects on inflammation by binding to receptor for advanced glycation end products (RAGE) or Toll-like receptor 4. Considering that inflammation is involved in pressure overload-induced cardiac hypertrophy, we herein attempted to investigate whether HMGB1 plays a role in myocardial hypertrophy in RAGE knockout mice as well as in the growth and apoptosis of cardiomyocytes. The myocardial expression of RAGE was not significantly changed while TLR4 mRNA was upregulated in response to transverse aortic constriction (TAC) for 1 week. The myocardial expression of HMGB1 protein was markedly increased in TAC group when compared to the sham group. Heart weight to body weight ratio (HW/BW) and lung weight to body weight ratio (LW/BW) were evaluated in RAGE knockout (KO) and wild-type (WT) mice 1 week after TAC. Significant larger HW/BW and LW/BW ratios were found in TAC groups than the corresponding sham groups, but no significant difference was found between KO and WT TAC mice. Similar results were also found when TAC duration was extended to 4 weeks. Cultured neonatal rat cardiomyocytes were treated with different concentrations of recombinant HMGB1, then cell viability was determined using MTT and CCK8 assays and cell apoptosis was determined by Hoechst staining and TUNEL assay. The results came out that HMGB1 exerted no influence on viability or apoptosis of cardiomyocytes. Besides, the protein expression levels of Bax and Bcl2 in response to different concentrations of HMGB1 were similar. These findings indicate that HMGB1 neither exerts influence on cardiac remodeling by binding to RAGE nor induces apoptosis of cardiomyocytes under physiological condition. PMID:27355349

  16. Charge-to-Mass Dispersion Methods in Knockout-Ablation Fragmentation Models

    NASA Astrophysics Data System (ADS)

    Townsend, Lawrence; Burton, Krista; de Wet, Wouter

    2014-09-01

    Breakup of high-energy heavy ions in nuclear collisions is an important process in space radiation transport, shielding and risk assessment since the secondary particles produced by these collisions have ranges greater than their parent nucleus, and are damaging to humans and spacecraft components. This work uses a quantum-mechanical optical potential knockout-ablation model to estimate these collision cross sections in order to investigate differences in isotope and element production cross sections as a result of utilizing two different models of charge-to mass ratios for the projectile prefragments produced by the abrasion/knockout process. One model commonly used, a hypergeometric model, assumes that the distribution of abraded nucleons is completely uncorrelated. However, it permits some unrealistic distributions, such as removing all neutrons in the knockout stage, while leaving all protons intact. Another model, developed for use with a classical geometric, clean-cut abrasion model, is based upon the zero point vibrations of the giant dipole resonance of the fragmenting nucleus. In this work we compare fragment production cross section predictions using the two charge dispersion models with published experimental data. Breakup of high-energy heavy ions in nuclear collisions is an important process in space radiation transport, shielding and risk assessment since the secondary particles produced by these collisions have ranges greater than their parent nucleus, and are damaging to humans and spacecraft components. This work uses a quantum-mechanical optical potential knockout-ablation model to estimate these collision cross sections in order to investigate differences in isotope and element production cross sections as a result of utilizing two different models of charge-to mass ratios for the projectile prefragments produced by the abrasion/knockout process. One model commonly used, a hypergeometric model, assumes that the distribution of abraded nucleons is

  17. Phenotypes Associated with Knockouts of Eight Dense Granule Gene Loci (GRA2-9) in Virulent Toxoplasma gondii.

    PubMed

    Rommereim, Leah M; Bellini, Valeria; Fox, Barbara A; Pètre, Graciane; Rak, Camille; Touquet, Bastien; Aldebert, Delphine; Dubremetz, Jean-François; Cesbron-Delauw, Marie-France; Mercier, Corinne; Bzik, David J

    2016-01-01

    Toxoplasma gondii actively invades host cells and establishes a parasitophorous vacuole (PV) that accumulates many proteins secreted by the dense granules (GRA proteins). To date, at least 23 GRA proteins have been reported, though the function(s) of most of these proteins still remains unknown. We targeted gene knockouts at ten GRA gene loci (GRA1-10) to investigate the cellular roles and essentiality of these classical GRA proteins during acute infection in the virulent type I RH strain. While eight of these genes (GRA2-9) were successfully knocked out, targeted knockouts at the GRA1 and GRA10 loci were not obtained, suggesting these GRA proteins may be essential. As expected, the Δgra2 and Δgra6 knockouts failed to form an intravacuolar network (IVN). Surprisingly, Δgra7 exhibited hyper-formation of the IVN in both normal and lipid-free growth conditions. No morphological alterations were identified in parasite or PV structures in the Δgra3, Δgra4, Δgra5, Δgra8, or Δgra9 knockouts. With the exception of the Δgra3 and Δgra8 knockouts, all of the GRA knockouts exhibited defects in their infection rate in vitro. While the single GRA knockouts did not exhibit reduced replication rates in vitro, replication rate defects were observed in three double GRA knockout strains (Δgra4Δgra6, Δgra3Δgra5 and Δgra3Δgra7). However, the virulence of single or double GRA knockout strains in CD1 mice was not affected. Collectively, our results suggest that while the eight individual GRA proteins investigated in this study (GRA2-9) are not essential, several GRA proteins may provide redundant and potentially important functions during acute infection. PMID:27458822

  18. Phenotypes Associated with Knockouts of Eight Dense Granule Gene Loci (GRA2-9) in Virulent Toxoplasma gondii

    PubMed Central

    Fox, Barbara A.; Pètre, Graciane; Rak, Camille; Touquet, Bastien; Aldebert, Delphine; Dubremetz, Jean-François; Cesbron-Delauw, Marie-France; Mercier, Corinne; Bzik, David J.

    2016-01-01

    Toxoplasma gondii actively invades host cells and establishes a parasitophorous vacuole (PV) that accumulates many proteins secreted by the dense granules (GRA proteins). To date, at least 23 GRA proteins have been reported, though the function(s) of most of these proteins still remains unknown. We targeted gene knockouts at ten GRA gene loci (GRA1-10) to investigate the cellular roles and essentiality of these classical GRA proteins during acute infection in the virulent type I RH strain. While eight of these genes (GRA2-9) were successfully knocked out, targeted knockouts at the GRA1 and GRA10 loci were not obtained, suggesting these GRA proteins may be essential. As expected, the Δgra2 and Δgra6 knockouts failed to form an intravacuolar network (IVN). Surprisingly, Δgra7 exhibited hyper-formation of the IVN in both normal and lipid-free growth conditions. No morphological alterations were identified in parasite or PV structures in the Δgra3, Δgra4, Δgra5, Δgra8, or Δgra9 knockouts. With the exception of the Δgra3 and Δgra8 knockouts, all of the GRA knockouts exhibited defects in their infection rate in vitro. While the single GRA knockouts did not exhibit reduced replication rates in vitro, replication rate defects were observed in three double GRA knockout strains (Δgra4Δgra6, Δgra3Δgra5 and Δgra3Δgra7). However, the virulence of single or double GRA knockout strains in CD1 mice was not affected. Collectively, our results suggest that while the eight individual GRA proteins investigated in this study (GRA2-9) are not essential, several GRA proteins may provide redundant and potentially important functions during acute infection. PMID:27458822

  19. Endothelial Mineralocorticoid Receptor Deletion Prevents Diet-Induced Cardiac Diastolic Dysfunction in Females.

    PubMed

    Jia, Guanghong; Habibi, Javad; DeMarco, Vincent G; Martinez-Lemus, Luis A; Ma, Lixin; Whaley-Connell, Adam T; Aroor, Annayya R; Domeier, Timothy L; Zhu, Yi; Meininger, Gerald A; Barrett Mueller, Katelee; Jaffe, Iris Z; Sowers, James R

    2015-12-01

    Overnutrition and insulin resistance are especially prominent risk factors for the development of cardiac diastolic dysfunction in females. We recently reported that consumption of a Western diet (WD) containing excess fat (46%), sucrose (17.5%), and high fructose corn syrup (17.5%) for 16 weeks resulted in cardiac diastolic dysfunction and aortic stiffening in young female mice and that these abnormalities were prevented by mineralocorticoid receptor blockade. Herein, we extend those studies by testing whether WD-induced diastolic dysfunction and factors contributing to diastolic impairment, such as cardiac fibrosis, hypertrophy, inflammation, and impaired insulin signaling, are modulated by excess endothelial cell mineralocorticoid receptor signaling. Four-week-old female endothelial cell mineralocorticoid receptor knockout and wild-type mice were fed mouse chow or WD for 4 months. WD feeding resulted in prolonged relaxation time, impaired diastolic septal wall motion, and increased left ventricular filling pressure indicative of diastolic dysfunction. This occurred in concert with myocardial interstitial fibrosis and cardiomyocyte hypertrophy that were associated with enhanced profibrotic (transforming growth factor β1/Smad) and progrowth (S6 kinase-1) signaling, as well as myocardial oxidative stress and a proinflammatory immune response. WD also induced cardiomyocyte stiffening, assessed ex vivo using atomic force microscopy. Conversely, endothelial cell mineralocorticoid receptor deficiency prevented WD-induced diastolic dysfunction, profibrotic, and progrowth signaling, in conjunction with reductions in macrophage proinflammatory polarization and improvements in insulin metabolic signaling. Therefore, our findings indicate that increased endothelial cell mineralocorticoid receptor signaling associated with consumption of a WD plays a key role in the activation of cardiac profibrotic, inflammatory, and growth pathways that lead to diastolic dysfunction in

  20. Progressive troponin I loss impairs cardiac relaxation and causes heart failure in mice.

    PubMed

    Liu, Jing; Du, Jianfeng; Zhang, Chi; Walker, Jeffery W; Huang, Xupei

    2007-08-01

    Cardiac troponin I (TnI) knockout mice exhibit a phenotype of sudden death at 17-18 days after birth due to a progressive loss of TnI. The objective of this study was to gain insight into the physiological consequences of TnI depletion and the cause of death in these mice. Cardiac function was monitored serially between 12 and 17 days of age by using high-resolution ultrasonic imaging and Doppler echocardiography. Two-dimensional B-mode and anatomical M-mode imaging and Doppler echocardiography were performed using a high-frequency ( approximately 20-45 MHz) ultrasound imaging system on homozygous cardiac TnI mutant mice (cTnI(-/-)) and wild-type littermates. On day 12, cTnI(-/-) mice were indistinguishable from wild-type mice in terms of heart rate, atrial and LV (LV) chamber dimensions, LV posterior wall thickness, and body weight. By days 16 through 17, wild-type mice showed up to a 40% increase in chamber dimensions due to normal growth, whereas cTnI(-/-) mice showed increases in atrial dimensions of up to 97% but decreases in ventricular dimensions of up to 70%. Mitral Doppler analysis revealed prolonged isovolumic relaxation time and pronounced inversion of the mitral E/A ratio (early ventricular filling wave-to-late atrial contraction filling wave) only in cTnI(-/-) mice indicative of impaired LV relaxation. cTnI(-/-) mouse hearts showed clear signs of failure on day 17, characterized by >50% declines in cardiac output, ejection fraction, and fractional shortening. B-mode echocardiography showed a profoundly narrowed tube-like LV and enlarged atria at this time. Our data are consistent with TnI deficiency causing impaired LV relaxation, which leads to diastolic heart failure in this model.

  1. Depletion of T lymphocytes ameliorates cardiac fibrosis in streptozotocin-induced diabetic cardiomyopathy.

    PubMed

    Abdullah, Chowdhury S; Li, Zhao; Wang, Xiuqing; Jin, Zhu-Qiu

    2016-10-01

    T cell infiltration has been associated with increased coronary heart disease risk in patients with diabetes mellitus. Effect of modulation of T cell trafficking on diabetes-induced cardiac fibrosis has yet to be determined. Therefore, our aim was to investigate the circulatory T cell depletion-mediated cardioprotection in streptozotocin-induced diabetic cardiomyopathy. Fingolimod (FTY720), an immunomodulatory drug, was tested in wild-type (WT) C57BL/6 and recombination activating gene 1 (Rag1) knockout (KO) mice without mature lymphocytes in streptozotocin-induced type 1 diabetic model. FTY720 (0.3mg/kg/day) was administered intraperitoneally daily for the first 4weeks with interim 3weeks then resumed for another 4weeks in 11weeks study period. T lymphocyte counts, cardiac histology, function, and fibrosis were examined in diabetic both WT and KO mice. FTY720 reduced both CD4(+) and CD8(+) T cells in diabetic WT mice. FTY720-treated diabetic WT mouse myocardium showed reduction in CD3 T cell infiltration and decreased expression of S1P1 and TGF-β1 in cardiac tissue. Fibrosis was reduced after FTY720 treatment in diabetic WT mice. Rag1 KO mice exhibited no CD4(+) and CD8(+) T cells in the blood and CD3 T cells in the heart. Diabetic Rag1 KO mouse hearts appeared no fibrosis and exhibited preserved myocardial contractility. FTY720-induced antifibrosis was abolished in diabetic Rag1 KO mice. These findings demonstrate that chronic administration with FTY720 induces lymphopenia and protects diabetic hearts in WT mice whereas FTY720 increases cardiac fibrosis and myocardial dysfunction in diabetic Rag1 KO mice without mature lymphocytes. PMID:27494688

  2. Systems biology and cardiac arrhythmias

    PubMed Central

    Grace, Andrew A; Roden, Dan M

    2013-01-01

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence. PMID:23101717

  3. [Cardiac support and replacement therapies].

    PubMed

    Lotz, Christopher; Roewer, Norbert; Muellenbach, Ralf M

    2016-09-01

    Circulatory support represents an integral part within the treatment of the critically ill patient. Sophisticated pharmacologic regimens help to maintain systemic perfusion pressure by increasing vascular tone as well as mediating positive inotropic effects. Besides the administration of catecholamines and phosphodiesterase-III-inhibitors, in particular the administration of levosimendan represents a promising alternative during low-cardiac-output. Nevertheless, sufficient evidence demonstrating a survival benefit for any pharmacologic regimen is nonexistent. In case pharmacological measures do not suffice mechanical cardiopulmonary support (MCS) may be used. MCS may be used during cardiopulmonary resuscitation or a "low-cardiac-output-syndrome" as bridging towards decision, recovery or long-term support. Venoarterial extracorporeal membrane oxygenation (vaECMO) may take over cardiopulmonary function and may improve survival as well as neurological outcome after cardiogenic shock or cardiopulmonary resuscitation. PMID:27631451

  4. Heart fields and cardiac morphogenesis.

    PubMed

    Kelly, Robert G; Buckingham, Margaret E; Moorman, Antoon F

    2014-10-01

    In this review, we focus on two important steps in the formation of the embryonic heart: (i) the progressive addition of late differentiating progenitor cells from the second heart field that drives heart tube extension during looping morphogenesis, and (ii) the emergence of patterned proliferation within the embryonic myocardium that generates distinct cardiac chambers. During the transition between these steps, the major site of proliferation switches from progenitor cells outside the early heart to proliferation within the embryonic myocardium. The second heart field and ballooning morphogenesis concepts have major repercussions on our understanding of human heart development and disease. In particular, they provide a framework to dissect the origin of congenital heart defects and the regulation of myocardial proliferation and differentiation of relevance for cardiac repair.

  5. Cardiac regeneration: epicardial mediated repair

    PubMed Central

    2015-01-01

    The hearts of lower vertebrates such as fish and salamanders display scarless regeneration following injury, although this feature is lost in adult mammals. The remarkable capacity of the neonatal mammalian heart to regenerate suggests that the underlying machinery required for the regenerative process is evolutionarily retained. Recent studies highlight the epicardial covering of the heart as an important source of the signalling factors required for the repair process. The developing epicardium is also a major source of cardiac fibroblasts, smooth muscle, endothelial cells and stem cells. Here, we examine animal models that are capable of scarless regeneration, the role of the epicardium as a source of cells, signalling mechanisms implicated in the regenerative process and how these mechanisms influence cardiomyocyte proliferation. We also discuss recent advances in cardiac stem cell research and potential therapeutic targets arising from these studies. PMID:26702046

  6. Nutritional status and cardiac autophagy.

    PubMed

    Ahn, Jihyun; Kim, Jaetaek

    2013-02-01

    Autophagy is necessary for the degradation of long-lasting proteins and nonfunctional organelles, and is activated to promote cellular survival. However, overactivation of autophagy may deplete essential molecules and organelles responsible for cellular survival. Lifelong calorie restriction by 40% has been shown to increase the cardiac expression of autophagic markers, which suggests that it may have a cardioprotective effect by decreasing oxidative damage brought on by aging and cardiovascular diseases. Although cardiac autophagy is critical to regulating protein quality and maintaining cellular function and survival, increased or excessive autophagy may have deleterious effects on the heart under some circumstances, including pressure overload-induced heart failure. The importance of autophagy has been shown in nutrient supply and preservation of energy in times of limitation, such as ischemia. Some studies have suggested that a transition from obesity to metabolic syndrome may involve progressive changes in myocardial inflammation, mitochondrial dysfunction, fibrosis, apoptosis, and myocardial autophagy.

  7. Systems biology and cardiac arrhythmias.

    PubMed

    Grace, Andrew A; Roden, Dan M

    2012-10-27

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence.

  8. Monitoring chaos of cardiac rhythms

    SciTech Connect

    Mayer-Kress, G.

    1989-01-01

    Chaos theory provides a new paradigm in monitoring complexity changes in heart rate variability. Even in cases where the spectral analysis only shows broad band characteristics estimations of dimensional complexity parameters can show quantitative changes in the degree of chaos present in the interbeat interval dynamics. We introduce the concept of dimensional complexity as dynamical monitoring parameter and discuss its properties in connection with control data and data taken during cardiac arrest. Whereas dimensional complexity provides a quantitative indicator of overall chaotic behavior, recurrence plots allow direct visualization of recurrences in arbitrary high dimensional pattern-space. In combination these two methods from non-linear dynamics exemplify a new approach in the problem of heart rate monitoring and identification of precursors of cardiac arrest. Finally we mention a new method of chaotic control, by which selective and highly effective perturbations of nonlinear dynamical systems could be used for improved pacing patterns. 11 refs., 6 figs.

  9. Administration of exogenous 1,25(OH)2D3 normalizes overactivation of the central renin-angiotensin system in 1α(OH)ase knockout mice.

    PubMed

    Zhang, Wei; Chen, Lulu; Zhang, Luqing; Xiao, Ming; Ding, Jiong; Goltzman, David; Miao, Dengshun

    2015-02-19

    Previously, we reported that active vitamin D deficiency in mice causes secondary hypertension and cardiac dysfunction, but the underlying mechanism remains largely unknown. To clarify whether exogenous active vitamin D rescues hypertension by normalizing the altered central renin-angiotensin system (RAS) via an antioxidative stress mechanism, 1-alpha-hydroxylase [1α(OH)ase] knockout mice [1α(OH)ase(-/-)] and their wild-type littermates were fed a normal diet alone or with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], or a high-calcium, high-phosphorus "rescue" diet with or without antioxidant N-acetyl-l-cysteine (NAC) supplementation for 4 weeks. Compared with their wild-type littermates, 1α(OH)ase(-/-)mice had high mean arterial pressure, increased levels of renin, angiotensin II (Ang II), and Ang II type 1 receptor, and increased malondialdehyde levels, but decreased anti-peroxiredoxin I and IV proteins and the antioxidative genes glutathione reductase (Gsr) and glutathione peroxidase 4 (Gpx4) in the brain samples. Except Ang II type 1 receptor, these pathophysiological changes were rescued by exogenous 1,25(OH)2D3 or NAC plus rescue diet, but not by rescue diet alone. We conclude that 1,25(OH)2D3 normalizes the altered central RAS in 1α(OH)ase(-/-)mice, at least partially, through a central antioxidative mechanism.

  10. Investigation of long chain omega-3 PUFAs on arterial blood pressure, vascular reactivity and survival in angiotensin II-infused Apolipoprotein E-knockout mice.

    PubMed

    Bürgin-Maunder, Corinna S; Nataatmadja, Maria; Vella, Rebecca K; Fenning, Andrew S; Brooks, Peter R; Russell, Fraser D

    2016-02-01

    Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease. Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) decrease inflammation and oxidative stress in an angiotensin II-infused apolipoprotein E-knockout (ApoE(-/-)) mouse model of AAA. This study investigated the effects of LC n-3 PUFAs on blood pressure and vascular reactivity in fourteen angiotensin II-infused ApoE(-/-) male mice. Blood pressure was obtained using a non-invasive tail cuff method and whole blood was collected by cardiac puncture. Vascular reactivity of the thoracic aorta was assessed using wire myography and activation of endothelial nitric oxide synthase (eNOS) was determined by immunohistochemistry. A high LC n-3 PUFA diet increased the omega-3 index and reduced the n-6 to n-3 PUFA ratio. At day 10 post-infusion with angiotensin II, there was no difference in systolic blood pressure or diastolic blood pressure in mice fed the high or low n-3 PUFA diets. The high LC n-3 PUFA diet resulted in a non-significant trend for delay in time to death from abdominal aortic rupture. Vascular reactivity and eNOS activation remained unchanged in mice fed the high compared to the low LC n-3 PUFA diet. This study argues against direct improvement in vascular reactivity in ApoE(-/-) mice that were supplemented with n-3 PUFA for 8 weeks prior to infusion with angiotensin II.

  11. Pathophysiology and clinical management of cardiac sarcoidosis.

    PubMed

    Hamzeh, Nabeel; Steckman, David A; Sauer, William H; Judson, Marc A

    2015-05-01

    Cardiac sarcoidosis is a potentially life-threatening condition characterized by formation of granulomas in the heart, resulting in conduction disturbances, atrial and ventricular arrhythmias, and ventricular dysfunction. The presentation of cardiac sarcoidosis ranges from asymptomatic with an abnormal imaging scan, to palpitations, syncope, symptoms of congestive heart failure, and sudden cardiac death. Screening for cardiac sarcoidosis has not been standardized, but the presence of cardiac symptoms on medical history and physical examination, and an abnormal electrocardiogram (ECG), Holter monitoring, or echocardiogram has been shown to be highly sensitive for detecting cardiac sarcoidosis. A signal-averaged ECG might also have a role in screening for cardiac sarcoidosis in asymptomatic patients. Although endomyocardial biopsies are highly specific for the diagnosis of cardiac sarcoidosis, procedural yield is very low and appropriate findings on cardiac MRI or PET are, therefore, often used as diagnostic surrogates. Treatment for cardiac sarcoidosis usually involves immunosuppressive therapy, particularly corticosteroids. Additional therapy might be required, depending on the clinical presentation, including implantation of an internal defibrillator, antiarrhythmic agents, and catheter ablation.

  12. Cardiac arrhythmias misdiagnosed as epilepsy.

    PubMed Central

    Rutter, N; Southall, D P

    1985-01-01

    A mother and three children presenting with syncope induced by exercise and emotion were diagnosed as epileptic. They, and three symptom free children, showed frequent ventricular and supraventricular tachyarrhythmias on ambulatory electrocardiographic monitoring. Three died before the correct diagnosis of disordered sympathetic innervation of the heart was made, but episodes of syncope and cardiac arrhythmias in the survivors have been successfully treated by propranolol. Images Fig. 2 PMID:3970569

  13. Intensive Hemodialysis Preserved Cardiac injury.

    PubMed

    Chan, Christopher T; Li, Guo Hua; Valaperti, Alan; Liu, Peter

    2015-01-01

    Cardiac injury triggers cellular responses involving both cardiomyocytes and nonmuscle cells to process cardiac structural remodeling. End-stage renal disease (ESRD), despite conventional dialysis, is associated with adverse cardiac remodeling and increased cardiovascular events. Intensification of hemodialysis with nocturnal home hemodialysis (NHD; five sessions per week; 6-8 hours per treatment) was associated with regression of left ventricular hypertrophy and downregulation of genes in apoptosis and fibrosis. In this pilot study, we hypothesize that NHD achieves its cardiac effects in part through attenuation of innate immune activation resulting in amelioration of cardiomyocytes apoptosis and fibrosis. Eight patients (4M:4F; age, 59 ± 9 years) with ESRD were studied. Half of the cohort was converted to NHD, whereas the rest of the patients were maintained on conventional hemodialysis (CHD). At baseline, CHD was associated with an increase in cardiomyocyte apoptosis detected by flow cytometry using Annexin V (mean fluorescence index in CHD and in normal control is 1.00 ± 0.05 vs. 0.66 ± 0.01, p < 0.05). After conversion to NHD, cardiomyocyte apoptosis was reduced compared with baseline CHD situation (p < 0.05) and approached that of normal control (0.59 ± 0.09 vs. 0.66 ± 0.01, p > 0.05). The CHD serum was associated with a coordinated augmentation innate immunity pathway, significantly increasing myeloid differentiation factor-88 and interleukin-1 receptor-associated kinase-4; NHD was able to reduce their levels. Heat shock protein 60 was augmented during CHD condition and fell after NHD. In addition, CHD increased fibroblast proliferation and myofibroblast transformation. Uremia is associated with activation of common innate immune signaling pathways leading to fibrosis and apoptosis. Amelioration of uremic clearance by NHD may attenuate this pathological signaling cascade. PMID:26164598

  14. Inherited arrhythmias: The cardiac channelopathies.

    PubMed

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms "Long QT Syndrome" (MeSH) and "Short QT Syndrome" (MeSH) and "Brugada Syndrome" (MeSH) and "Catecholaminergic Polymorphic Ventricular Tachycardia" (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full. PMID:26556967

  15. Sudden cardiac death risk stratification.

    PubMed

    Deyell, Marc W; Krahn, Andrew D; Goldberger, Jeffrey J

    2015-06-01

    Arrhythmic sudden cardiac death (SCD) may be caused by ventricular tachycardia/fibrillation or pulseless electric activity/asystole. Effective risk stratification to identify patients at risk of arrhythmic SCD is essential for targeting our healthcare and research resources to tackle this important public health issue. Although our understanding of SCD because of pulseless electric activity/asystole is growing, the overwhelming majority of research in risk stratification has focused on SCD-ventricular tachycardia/ventricular fibrillation. This review focuses on existing and novel risk stratification tools for SCD-ventricular tachycardia/ventricular fibrillation. For patients with left ventricular dysfunction or myocardial infarction, advances in imaging, measures of cardiac autonomic function, and measures of repolarization have shown considerable promise in refining risk. Yet the majority of SCD-ventricular tachycardia/ventricular fibrillation occurs in patients without known cardiac disease. Biomarkers and novel imaging techniques may provide further risk stratification in the general population beyond traditional risk stratification for coronary artery disease alone. Despite these advances, significant challenges in risk stratification remain that must be overcome before a meaningful impact on SCD can be realized.

  16. Sudden Cardiac Death Risk Stratification

    PubMed Central

    Deyell, Marc W.; Krahn, Andrew D.; Goldberger, Jeffrey J.

    2015-01-01

    Arrhythmic sudden cardiac death (SCD) may be due to ventricular tachycardia/fibrillation (SCD-VT/VF) or pulseless electrical activity/asystole. Effective risk stratification to identify patients at risk of arrhythmic SCD is essential for targeting our health care and research resources to tackle this important public health issue. Although our understanding of SCD due to pulseless electrical activity/asystole is growing, the overwhelming majority of research in risk stratification has focused on SCD-VT/VF. This review focuses on existing and novel risk stratification tools for SCD-VT/VF. For patients with left ventricular dysfunction and/or myocardial infarction, advances in imaging, measures of cardiac autonomic function, and measures of repolarization have shown considerable promise in refining risk. Yet the majority of SCD-VT/VF occurs in patients without known cardiac disease. Biomarkers and novel imaging techniques may provide further risk stratification in the general population beyond traditional risk stratification for coronary artery disease alone. Despite these advances, significant challenges in risk stratification remain that must be overcome before a meaningful impact on SCD can be realized. PMID:26044247

  17. The history of cardiac catheterization.

    PubMed

    Bourassa, Martial G

    2005-10-01

    The evolution of cardiac catheterization has occurred over at least four centuries. One of the first major steps was the description of the circulation of the blood by William Harvey in 1628. The next milestone was the measurement of arterial pressure by Stephen Hales, one century later. However, the 19th century represented the golden age of cardiovascular physiology, highlighted by the achievements of Carl Ludwig, Etienne-Jules Marey and Claude Bernard, among others. Human cardiac catheterization developed during the 20th century. The first right heart catheterization in a human was performed by Werner Forssmann on himself in 1929. Diagnostic cardiac catheterization was introduced by André Cournand and Dickinson Richards in the early 1940s, and selective coronary angiography was described by Mason Sones in the early 1960s. More recently, with the advent of catheter-based interventions, pioneered by Andreas Gruentzig in the late 1970s, there has been considerable progress in the refinement and expansion of these techniques. Currently, the Sones technique is used only infrequently, and coronary angiography and percutaneous coronary intervention rely mainly on percutaneous femoral and percutaneous radial artery approaches. On the occasion of the 50th anniversary of the Montreal Heart Institute, it seems appropriate to highlight the contribution of this institution in these two areas. PMID:16234881

  18. Inherited arrhythmias: The cardiac channelopathies

    PubMed Central

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms “Long QT Syndrome” (MeSH) and “Short QT Syndrome” (MeSH) and “Brugada Syndrome” (MeSH) and “Catecholaminergic Polymorphic Ventricular Tachycardia” (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full. PMID:26556967

  19. Inherited arrhythmias: The cardiac channelopathies.

    PubMed

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms "Long QT Syndrome" (MeSH) and "Short QT Syndrome" (MeSH) and "Brugada Syndrome" (MeSH) and "Catecholaminergic Polymorphic Ventricular Tachycardia" (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full.

  20. Nox/Duox Family of NADPH Oxidases: Lessons from Knockout Mouse Models.

    PubMed

    Sirokmány, Gábor; Donkó, Ágnes; Geiszt, Miklós

    2016-04-01

    Nox/Duox NADPH oxidases are now considered the primary, regulated sources of reactive oxygen species (ROS). These enzymes are expressed in diverse cells and tissues, and their products are essential in several physiological settings. Knockout mouse models are instrumental in identifying the physiological functions of Nox/Duox enzymes as well as in exploring the impact of their pharmacological targeting on disease progression. The currently available data from experiments on knockout animals suggest that the lack of non-phagocytic Nox/Duox enzymes often modifies the course and phenotype in many disease models. Nevertheless, as illustrated by studies on Nox4-deficient animals, the absence of Nox-derived ROS can also lead to aggravated disease manifestation, reinforcing the need for a more balanced view on the role of ROS in health and disease.

  1. A high-throughput gene knockout procedure for Neurospora reveals functions for multiple transcription factors

    PubMed Central

    Colot, Hildur V.; Park, Gyungsoon; Turner, Gloria E.; Ringelberg, Carol; Crew, Christopher M.; Litvinkova, Liubov; Weiss, Richard L.; Borkovich, Katherine A.; Dunlap, Jay C.

    2006-01-01

    The low rate of homologous recombination exhibited by wild-type strains of filamentous fungi has hindered development of high-throughput gene knockout procedures for this group of organisms. In this study, we describe a method for rapidly creating knockout mutants in which we make use of yeast recombinational cloning, Neurospora mutant strains deficient in nonhomologous end-joining DNA repair, custom-written software tools, and robotics. To illustrate our approach, we have created strains bearing deletions of 103 Neurospora genes encoding transcription factors. Characterization of strains during growth and both asexual and sexual development revealed phenotypes for 43% of the deletion mutants, with more than half of these strains possessing multiple defects. Overall, the methodology, which achieves high-throughput gene disruption at an efficiency >90% in this filamentous fungus, promises to be applicable to other eukaryotic organisms that have a low frequency of homologous recombination. PMID:16801547

  2. Efficient Gene Knockout in Goats Using CRISPR/Cas9 System

    PubMed Central

    Ni, Wei; Qiao, Jun; Hu, Shengwei; Zhao, Xinxia; Regouski, Misha; Yang, Min; Polejaeva, Irina A.; Chen, Chuangfu

    2014-01-01

    The CRISPR/Cas9 system has been adapted as an efficient genome editing tool in laboratory animals such as mice, rats, zebrafish and pigs. Here, we report that CRISPR/Cas9 mediated approach can efficiently induce monoallelic and biallelic gene knockout in goat primary fibroblasts. Four genes were disrupted simultaneously in goat fibroblasts by CRISPR/Cas9-mediated genome editing. The single-gene knockout fibroblasts were successfully used for somatic cell nuclear transfer (SCNT) and resulted in live-born goats harboring biallelic mutations. The CRISPR/Cas9 system represents a highly effective and facile platform for targeted editing of large animal genomes, which can be broadly applied to both biomedical and agricultural applications. PMID:25188313

  3. Rapid phenotyping of knockout mice to identify genetic determinants of bone strength

    PubMed Central

    Freudenthal, Bernard; Logan, John; Croucher, Peter I

    2016-01-01

    The genetic determinants of osteoporosis remain poorly understood, and there is a large unmet need for new treatments in our ageing society. Thus, new approaches for gene discovery in skeletal disease are required to complement the current genome-wide association studies in human populations. The International Knockout Mouse Consortium (IKMC) and the International Mouse Phenotyping Consortium (IMPC) provide such an opportunity. The IKMC generates knockout mice representing each of the known protein-coding genes in C57BL/6 mice and, as part of the IMPC initiative, the Origins of Bone and Cartilage Disease project identifies mutants with significant outlier skeletal phenotypes. This initiative will add value to data from large human cohorts and provide a new understanding of bone and cartilage pathophysiology, ultimately leading to the identification of novel drug targets for the treatment of skeletal disease. PMID:27535945

  4. Simple knockout by electroporation of engineered endonucleases into intact rat embryos

    PubMed Central

    Kaneko, Takehito; Sakuma, Tetsushi; Yamamoto, Takashi; Mashimo, Tomoji

    2014-01-01

    Engineered endonucleases, such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system, provide a powerful approach for genome editing in animals. However, the microinjection of endonucleases into embryos requires a high skill level, is time consuming, and may cause damage to embryos. Here, we demonstrate that the electroporation of endonuclease mRNAs into intact embryos can induce editing at targeted loci and efficiently produce knockout rats. It is noteworthy that the electroporation of ZFNs resulted in an embryonic survival rate (91%) and a genome-editing rate (73%) that were more than 2-fold higher than the corresponding rates from conventional microinjection. Electroporation technology provides a simple and effective method to produce knockout animals. PMID:25269785

  5. K Basins floor sludge retrieval system knockout pot basket fuel burn accident

    SciTech Connect

    HUNT, J.W.

    1998-11-11

    The K Basins Sludge Retrieval System Preliminary Hazard Analysis Report (HNF-2676) identified and categorized a series of potential accidents associated with K Basins Sludge Retrieval System design and operation. The fuel burn accident was of concern with respect to the potential release of contamination resulting from a runaway chemical reaction of the uranium fuel in a knockout pot basket suspended in the air. The unmitigated radiological dose to an offsite receptor from this fuel burn accident is calculated to be much less than the offsite risk evaluation guidelines for anticipated events. However, because of potential radiation exposure to the facility worker, this accident is precluded with a safety significant lifting device that will prevent the monorail hoist from lifting the knockout pot basket out of the K Basin water pool.

  6. Rapid phenotyping of knockout mice to identify genetic determinants of bone strength.

    PubMed

    Freudenthal, Bernard; Logan, John; Croucher, Peter I; Williams, Graham R; Bassett, J H Duncan

    2016-10-01

    The genetic determinants of osteoporosis remain poorly understood, and there is a large unmet need for new treatments in our ageing society. Thus, new approaches for gene discovery in skeletal disease are required to complement the current genome-wide association studies in human populations. The International Knockout Mouse Consortium (IKMC) and the International Mouse Phenotyping Consortium (IMPC) provide such an opportunity. The IKMC generates knockout mice representing each of the known protein-coding genes in C57BL/6 mice and, as part of the IMPC initiative, the Origins of Bone and Cartilage Disease project identifies mutants with significant outlier skeletal phenotypes. This initiative will add value to data from large human cohorts and provide a new understanding of bone and cartilage pathophysiology, ultimately leading to the identification of novel drug targets for the treatment of skeletal disease. PMID:27535945

  7. Axonal and Periaxonal Swelling Precede Peripheral Neurodegeneration in KCC3 Knockout Mice

    PubMed Central

    Byun, Nellie; Delpire, Eric

    2007-01-01

    We have previously reported CNS and locomotor deficits in KCC3 knockout mice, an animal model of agenesis of the corpus callosum associated with peripheral neuropathy (ACCPN) (Howard, et al., 2002)). To assess the role of KCC3 in peripheral axon and/or myelin development and maintenance, we determined its expression and performed a detailed morphometric analysis of sciatic nerves. Sciatic nerves of juvenile wild-type mice, but not in adult, express KCC3. In the knockout, Schwann cell/myelin development appears normal at P3, but axons are swollen. At P8 and into P30, some fibers accumulate fluid periaxonally. These initial swelling pathologies are followed by myelin degeneration in adult nerves, leading to reduction in nerve conduction velocity. Mutant mice also exhibit decreased sensitivity to noxious pain. This evidence for swollen axons and fluid-related axonopathy, which ultimately result in neurodegeneration, implicates cell volume regulation as a critical component of peripheral nerve maintenance. PMID:17659877

  8. Protein Production with a Pichia pastoris OCH1 Knockout Strain in Fed-Batch Mode.

    PubMed

    Gmeiner, Christoph; Spadiut, Oliver

    2015-01-01

    The methylotrophic yeast Pichia pastoris is a widely used host organism for recombinant protein production in biotechnology and pharmaceutical industry. However, if the target product describes a glycoprotein, an α-1,6-mannosyltransferase located in the Golgi apparatus of P. pastoris, called OCH1, triggers hypermannosylation of the recombinant protein which significantly impedes following unit operations and hampers biopharmaceutical product applications. A knockout of the och1 gene allows the production of less-glycosylated proteins-however, morphology and physiology of P. pastoris also change, complicating the upstream process. Here, we describe a controlled and efficient bioprocess based on the specific substrate uptake rate (q s) for a recombinant P. pastoris OCH1 knockout strain expressing a peroxidase as model protein. PMID:26082217

  9. Sudden cardiac death in athletes.

    PubMed

    Schmied, C; Borjesson, M

    2014-02-01

    A 'paradox of sport' is that in addition to the undisputed health benefits of physical activity, vigorous exertion may transiently increase the risk of acute cardiac events. In general, the risk of sudden cardiac death (SCD) approximately doubles during physical activity and is 2- to 3-fold higher in athletes compared to nonathletes. The incidence of SCD in young athletes is in fact very low, at around 1-3 per 100,000, but attracts much public attention. Variations in incidence figures may be explained by the methodology used for data collection and more importantly by differences between subpopulations of athletes. The incidence of SCD in older (≥ 35 years) athletes is higher and may be expected to rise, as more and older individuals take part in organized sports. SCD is often the first clinical manifestation of a potentially fatal underlying cardiovascular disorder and usually occurs in previously asymptomatic athletes. In the young (<35 years), SCD is mainly due to congenital/inherited cardiac abnormalities, whilst coronary artery disease (CAD) is the most common cause in older athletes. Cardiac screening including family/personal history, physical examination and resting electrocardiogram (ECG) may identify individuals at risk and has the potential to decrease the risk of SCD in young athletes. Screening including the ECG has a high sensitivity for underlying disease in young athletes, but the specificity needs to be improved, whereas the sensitivity of screening without the use of ECG is very low. The screening modality recommended for young athletes is of limited value in older athletes, who should receive individualized screening with cardiac stress testing for patients with high risk of underlying CAD. As cardiovascular screening will never be able to identify all athletes at risk, adequate preparedness is vital in case of a potentially fatal event at the sporting arena/facility. Firstly, we will review the magnitude of the problem of SCD in athletes of

  10. Kv4.2 Knockout Mice Have Hippocampal-Dependent Learning and Memory Deficits

    ERIC Educational Resources Information Center

    Lugo, Joaquin N.; Brewster, Amy L.; Spencer, Corinne M.; Anderson, Anne E.

    2012-01-01

    Kv4.2 channels contribute to the transient, outward K[superscript +] current (A-type current) in hippocampal dendrites, and modulation of this current substantially alters dendritic excitability. Using Kv4.2 knockout (KO) mice, we examined the role of Kv4.2 in hippocampal-dependent learning and memory. We found that Kv4.2 KO mice showed a deficit…

  11. Lack of self-administration of cocaine in dopamine D1 receptor knock-out mice.

    PubMed

    Caine, S Barak; Thomsen, Morgane; Gabriel, Kara I; Berkowitz, Jill S; Gold, Lisa H; Koob, George F; Tonegawa, Susumu; Zhang, Jianhua; Xu, Ming

    2007-11-28

    Evidence suggests a critical role for dopamine in the reinforcing effects of cocaine in rats and primates. However, self-administration has been less often studied in the mouse species, and, to date, "knock-out" of individual dopamine-related genes in mice has not been reported to reduce the reinforcing effects of cocaine. We studied the dopamine D1 receptor and cocaine self-administration in mice using a combination of gene-targeted mutation and pharmacological tools. Two cohorts with varied breeding and experimental histories were tested, and, in both cohorts, there was a significant decrease in the number of D1 receptor knock-out mice that met criteria for acquisition of cocaine self-administration (2 of 23) relative to wild-type mice (27 of 32). After extinction of responding with saline self-administration, dose-response studies showed that cocaine reliably and dose dependently maintained responding greater than saline in all wild-type mice but in none of the D1 receptor knock-out mice. The D1-like agonist SKF 82958 (2,3,4,5,-tetrahydro-6-chloro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine hydrobromide) and the D2-like agonist quinelorane both functioned as positive reinforcers in wild-type mice but not in D1 receptor mutant mice, whereas food and intravenous injections of the opioid agonist remifentanil functioned as positive reinforcers in both genotypes. Finally, pretreatment with the D1-like antagonist SCH 23390 [R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-01] produced surmountable antagonism of the reinforcing effects of cocaine in the commonly used strain C57BL/6J. We conclude that D1 receptor knock-out mice do not reliably self-administer cocaine and that the D1 receptor is critical for the reinforcing effects of cocaine and other dopamine agonists, but not food or opioids, in mice.

  12. Selection-Independent Generation of Gene Knockout Mouse Embryonic Stem Cells Using Zinc-Finger Nucleases

    PubMed Central

    Osiak, Anna; Radecke, Frank; Guhl, Eva; Radecke, Sarah; Dannemann, Nadine; Lütge, Fabienne; Glage, Silke; Rudolph, Cornelia; Cantz, Tobias; Schwarz, Klaus; Heilbronn, Regine; Cathomen, Toni

    2011-01-01

    Gene knockout in murine embryonic stem cells (ESCs) has been an invaluable tool to study gene function in vitro or to generate animal models with altered phenotypes. Gene targeting using standard techniques, however, is rather inefficient and typically does not exceed frequencies of 10−6. In consequence, the usage of complex positive/negative selection strategies to isolate targeted clones has been necessary. Here, we present a rapid single-step approach to generate a gene knockout in mouse ESCs using engineered zinc-finger nucleases (ZFNs). Upon transient expression of ZFNs, the target gene is cleaved by the designer nucleases and then repaired by non-homologous end-joining, an error-prone DNA repair process that introduces insertions/deletions at the break site and therefore leads to functional null mutations. To explore and quantify the potential of ZFNs to generate a gene knockout in pluripotent stem cells, we generated a mouse ESC line containing an X-chromosomally integrated EGFP marker gene. Applying optimized conditions, the EGFP locus was disrupted in up to 8% of ESCs after transfection of the ZFN expression vectors, thus obviating the need of selection markers to identify targeted cells, which may impede or complicate downstream applications. Both activity and ZFN-associated cytotoxicity was dependent on vector dose and the architecture of the nuclease domain. Importantly, teratoma formation assays of selected ESC clones confirmed that ZFN-treated ESCs maintained pluripotency. In conclusion, the described ZFN-based approach represents a fast strategy for generating gene knockouts in ESCs in a selection-independent fashion that should be easily transferrable to other pluripotent stem cells. PMID:22194948

  13. Transgenic knockout mice with exclusively human sickle hemoglobinand sickle cell disease

    SciTech Connect

    Paszty, C.; Brion, C.; Manci, E.; Witkowska, E.; Stevens, M.; Narla, M.; Rubin, E.

    1997-06-13

    To create mice expressing exclusively human sicklehemoglobin (HbS), transgenic mice expressing human alpha-, gamma-, andbeta[S]-globin were generated and bred with knockout mice that haddeletions of the murine alpha- and beta-globin genes. These sickle cellmice have the major features (irreversibly sickled red cells, anemia,multiorgan pathology) found in humans with sickle cell disease and, assuch, represent a useful in vivo system to accelerate the development ofimproved therapies for this common genetic disease.

  14. Generating Targeted Gene Knockout Lines in Physcomitrella patens to Study Evolution of Stress-Responsive Mechanisms.

    PubMed

    Maronova, Monika; Kalyna, Maria

    2016-01-01

    The moss Physcomitrella patens possesses highly efficient homologous recombination allowing targeted gene manipulations and displays many features of the early land plants including high tolerance to abiotic stresses. It is therefore an invaluable model organism for studies of gene functions and comparative studies of evolution of stress responses in plants. Here, we describe a method for generating targeted gene knockout lines in P. patens using a polyethylene glycol-mediated transformation of protoplasts including basic in vitro growth, propagation, and maintenance techniques.

  15. Evaluation of Known or Suspected Cardiac Sarcoidosis.

    PubMed

    Blankstein, Ron; Waller, Alfonso H

    2016-03-01

    Sarcoidosis is a multisystem disorder of unknown cause, and cardiac sarcoidosis affects at least 25% of patients and accounts for substantial mortality and morbidity from this disease. Cardiac sarcoidosis may present with heart failure, left ventricular systolic dysfunction, AV block, atrial or ventricular arrhythmias, and sudden cardiac death. Cardiac involvement can be challenging to detect and diagnose because of the focal nature of the disease, as well as the fact that clinical criteria have limited diagnostic accuracy. Nevertheless, the diagnosis of cardiac sarcoidosis can be enhanced by integrating both clinical and imaging findings. This article reviews the various roles that different imaging modalities provide in the evaluation and management of patients with known or suspected cardiac sarcoidosis.

  16. Quality Control Systems in Cardiac Aging

    PubMed Central

    Quarles, Ellen K; Dai, Dao-Fu; Tocchi, Autumn; Basisty, Nathan; Gitari, Lemuel; Rabinovitch, Peter S

    2015-01-01

    Cardiac aging is an intrinsic process that results in impaired cardiac function, along with cellular and molecular changes. These degenerative changes are intimately associated with quality control mechanisms. This review provides a general overview of the clinical and cellular changes which manifest in cardiac aging, and the quality control mechanisms involved in maintaining homeostasis and retarding aging. These mechanisms include autophagy, ubiquitin-mediated turnover, apoptosis, mitochondrial quality control and cardiac matrix homeostasis. Finally, we discuss aging interventions that have been observed to impact cardiac health outcomes. These include caloric restriction, rapamycin, resveratrol, GDF11, mitochondrial antioxidants and cardiolipin-targeted therapeutics. A greater understanding of the quality control mechanisms that promote cardiac homeostasis will help to understand the benefits of these interventions, and hopefully lead to further improved therapeutic modalities. PMID:25702865

  17. Evaluation of Known or Suspected Cardiac Sarcoidosis.

    PubMed

    Blankstein, Ron; Waller, Alfonso H

    2016-03-01

    Sarcoidosis is a multisystem disorder of unknown cause, and cardiac sarcoidosis affects at least 25% of patients and accounts for substantial mortality and morbidity from this disease. Cardiac sarcoidosis may present with heart failure, left ventricular systolic dysfunction, AV block, atrial or ventricular arrhythmias, and sudden cardiac death. Cardiac involvement can be challenging to detect and diagnose because of the focal nature of the disease, as well as the fact that clinical criteria have limited diagnostic accuracy. Nevertheless, the diagnosis of cardiac sarcoidosis can be enhanced by integrating both clinical and imaging findings. This article reviews the various roles that different imaging modalities provide in the evaluation and management of patients with known or suspected cardiac sarcoidosis. PMID:26926267

  18. Cardiac mechanics: Physiological, clinical, and mathematical considerations

    NASA Technical Reports Server (NTRS)

    Mirsky, I. (Editor); Ghista, D. N.; Sandler, H.

    1974-01-01

    Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

  19. Acute secondhand smoke-induced pulmonary inflammation is diminished in RAGE knockout mice.

    PubMed

    Wood, Tyler T; Winden, Duane R; Marlor, Derek R; Wright, Alex J; Jones, Cameron M; Chavarria, Michael; Rogers, Geraldine D; Reynolds, Paul R

    2014-11-15

    The receptor for advanced glycation end-products (RAGE) has increasingly been demonstrated to be an important modulator of inflammation in cases of pulmonary disease. Published reports involving tobacco smoke exposure have demonstrated increased expression of RAGE, its participation in proinflammatory signaling, and its role in irreversible pulmonary remodeling. The current research evaluated the in vivo effects of short-term secondhand smoke (SHS) exposure in RAGE knockout and control mice compared with identical animals exposed to room air only. Quantitative PCR, immunoblotting, and immunohistochemistry revealed elevated RAGE expression in controls after 4 wk of SHS exposure and an anticipated absence of RAGE expression in RAGE knockout mice regardless of smoke exposure. Ras activation, NF-κB activity, and cytokine elaboration were assessed to characterize the molecular basis of SHS-induced inflammation in the mouse lung. Furthermore, bronchoalveolar lavage fluid was procured from RAGE knockout and control animals for the assessment of inflammatory cells and molecules. As a general theme, inflammation coincident with leukocyte recruitment was induced by SHS exposure and significantly influenced by the availability of RAGE. These data reveal captivating information suggesting a role for RAGE signaling in lungs exposed to SHS. However, ongoing research is still warranted to fully explain roles for RAGE and other receptors in cells coping with involuntary smoke exposure for prolonged periods of time.

  20. Behavioral characterization of striatal-enriched protein tyrosine phosphatase (STEP) knockout mice.

    PubMed

    Sukoff Rizzo, S J; Lotarski, S M; Stolyar, P; McNally, T; Arturi, C; Roos, M; Finley, J E; Reinhart, V; Lanz, T A

    2014-09-01

    Striatal-enriched protein tyrosine phosphatase (STEP) has been described as a regulator of multiple kinases and glutamate receptor subunits critical for synaptic plasticity. Published behavioral and biochemical characterization from the founder line of STEP knockout (KO) mice revealed superior cognitive performance, with enhanced phosphorylation of substrates such as ERK, Fyn and GluN2B; suggesting that inhibitors of STEP may have potential as therapeutic agents for the treatment of neuropsychiatric disorders. The objectives of this work aimed to replicate and extend the previously reported behavioral consequences of STEP knockout. Consistent with previous reported data, STEP KO mice demonstrated exploratory activity levels and similar motor coordination relative to WT littermate controls as well as intact memory in a Y-maze spatial novelty test. Interestingly, KO mice demonstrated deficits in pre-pulse inhibition as well as reduced seizure threshold relative to WT controls. Immunohistochemical staining of brains revealed the expected gene-dependent reduction in STEP protein confirming knockout in the mice. The present data confirm expression and localization of STEP and the absence in KO mice, and describe functional downstream implications of reducing STEP levels in vivo.

  1. Knockout Mice Challenge our Concepts of Glucose Homeostasis and the Pathogenesis of Diabetes

    PubMed Central

    2003-01-01

    A central component of type 2 diabetes and the metabolic syndrome is insulin resistance. Insulin exerts a multifaceted and highly integrated series of actions via its intracellular signaling systems. Generation of mice carrying null mutations of the genes encoding proteins in the insulin signaling pathway provides a unique approach to determining the role of individual proteins in the molecular mechanism of insulin action and the pathogenesis of insulin resistance and diabetes. The role of the four major insulin receptor substrates (IRS1-4) in insulin and IGF-1 signaling have been examined by creating mice with targeted gene knockouts. Each produces a unique phenotype, indicating the complementary role of these signaling components. Combined heterozygous defects often produce synergistic or epistatic effects, although the final severity of the phenotype depends on the genetic background of the mice. Conditional knockouts of the insulin receptor have also been created using the Cre-lox system. These tissue specific knockouts have provide unique insights into the control of glucose homeostasis and the pathogenesis of type 2 diabetes, and have led to development of new hypotheses about the nature of the insulin action and development of diabetes. PMID:15061645

  2. Oestrogen receptor knockout mice: roles for oestrogen receptors alpha and beta in reproductive tissues.

    PubMed

    Hewitt, Sylvia Curtis; Korach, Kenneth S

    2003-02-01

    Oestrogen is an essential component of female reproduction, with well-characterized functions in the uterus, ovaries, mammary gland and hypothalamic-pituitary axis. The mechanism of oestrogen action involves mediation of the rate of transcription by nuclear-localized oestrogen receptor molecules. Two oestrogen receptors are present in mouse tissues, oestrogen receptors alpha and beta. Each receptor exhibits differential tissue expression patterns. Mouse models with genetically engineered disruption or 'knockout' of the oestrogen receptors have been developed. Characterization of the resulting defects in reproductive tissues as well as alterations in physiological and genomic responses has given insight into the receptor-mediated effects of oestrogen in reproduction. Oestrogen receptor alpha knockout females are infertile because they are anovulatory, have disruption in LH regulation and have uteri that are insensitive to oestrogen. In contrast, oestrogen receptor beta knockout females are sub-fertile and primarily lack efficient ovulatory function. Mice with deletion of both oestrogen receptors alpha and beta are similar to those lacking oestrogen receptor alpha only, but exhibit a unique ovarian pathology. These observed phenotypes elucidate the relative roles of the oestrogen receptors in reproductive functions of female rodents.

  3. Generation of Recombinant Capripoxvirus Vectors for Vaccines and Gene Knockout Function Studies.

    PubMed

    Boshra, Hani; Cao, Jingxin; Babiuk, Shawn

    2016-01-01

    The ability to manipulate capripoxvirus through gene knockouts and gene insertions has become an increasingly valuable research tool in elucidating the function of individual genes of capripoxvirus, as well as in the development of capripoxvirus-based recombinant vaccines. The homologous recombination technique is used to generate capripoxvirus knockout viruses (KO), and is based on the targeting a particular viral gene of interest. This technique can also be used to insert a gene of interest. A protocol for the generation of a viral gene knockout is described. This technique involves the use of a plasmid which encodes the flanking sequences of the regions where the homologous recombination will occur, and will result in the insertion of an EGFP reporter gene for visualization of recombinant virus, as well as the E. coli gpt gene as a positive selection marker. If an additional gene is to be incorporated, this can be achieved by inserting a gene of interest for expression under a poxvirus promoter into the plasmid between the flanking regions for insertion. This chapter describes a protocol for generating such recombinant capripoxviruses.

  4. Positron emission tomography and functional characterization of a complete PBR/TSPO knockout.

    PubMed

    Banati, Richard B; Middleton, Ryan J; Chan, Ronald; Hatty, Claire R; Kam, Winnie Wai-Ying; Quin, Candice; Graeber, Manuel B; Parmar, Arvind; Zahra, David; Callaghan, Paul; Fok, Sandra; Howell, Nicholas R; Gregoire, Marie; Szabo, Alexander; Pham, Tien; Davis, Emma; Liu, Guo-Jun

    2014-11-19

    The evolutionarily conserved peripheral benzodiazepine receptor (PBR), or 18-kDa translocator protein (TSPO), is thought to be essential for cholesterol transport and steroidogenesis, and thus life. TSPO has been proposed as a biomarker of neuroinflammation and a new drug target in neurological diseases ranging from Alzheimer's disease to anxiety. Here we show that global C57BL/6-Tspo(tm1GuWu(GuwiyangWurra))-knockout mice are viable with normal growth, lifespan, cholesterol transport, blood pregnenolone concentration, protoporphyrin IX metabolism, fertility and behaviour. However, while the activation of microglia after neuronal injury appears to be unimpaired, microglia from (GuwiyangWurra)TSPO knockouts produce significantly less ATP, suggesting reduced metabolic activity. Using the isoquinoline PK11195, the ligand originally used for the pharmacological and structural characterization of the PBR/TSPO, and the imidazopyridines CLINDE and PBR111, we demonstrate the utility of (GuwiyangWurra)TSPO knockouts to provide robust data on drug specificity and selectivity, both in vitro and in vivo, as well as the mechanism of action of putative TSPO-targeting drugs.

  5. Bioinformatic analysis of miRNA expression patterns in TFF2 knock-out mice.

    PubMed

    Yin, Y; Shan, H Q; Huang, W; Wu, Y M; Lu, H; Jin, Y

    2014-10-20

    Trefoil factors, which bear a unique 3-loop trefoil domain, are a family of small secretory protease-resistant peptides (7-12 kDa) discovered in the 1980s. Trefoil factor 2 (TFF2) is a unique member of trefoil factors family that plays important roles in gastrointestinal mucosal defense and repair. However, few studies have characterized the miRNA expression patterns in TFF2 knock-out mice. In this study, we investigated the regulatory role of miRNAs in TFF2 knock-out mice. Whole miRNome profiling for TFF2 knock-out mice and wild-type mice were downloaded from the Gene Expression Omnibus database. A total of 14 differentially expressed miRNAs were identified using the limma package. Target genes for 2 differentially expressed miRNAs were retrieved from 2 databases. After mapping these target genes into STRING, an interaction network was constructed. Gene Ontology analysis suggested that the differentially expressed miRNAs are involved in cyclic AMP metabolism and the growth process. Additionally, dysregulated miRNAs target pathways of transforming growth factor-beta signaling pathway and cytokine-cytokine receptor interaction. Our results suggest that miRNAs may play important regulatory roles in processes involving TFF2, particularly in the regulation of signal transduction pathways. However, further validation of our results is needed.

  6. Histidine decarboxylase knockout mice, a genetic model of Tourette syndrome, show repetitive grooming after induced fear

    PubMed Central

    Xu, Meiyu; Li, Lina; Ohtsu, Hiroshi; Pittenger, Christopher

    2015-01-01

    Tics, such as are seen in Tourette syndrome (TS), are common and can cause profound morbidity, but they are poorly understood. Tics are potentiated by psychostimulants, stress, and sleep deprivation. Mutations in the gene histidine decarboxylase (Hdc) have been implicated as a rare genetic cause of TS, and Hdc knockout mice have been validated as a genetic model that recapitulates phenomenological and pathophysiological aspects of the disorder. Tic-like stereotypies in this model have not been observed at baseline but emerge after acute challenge with the psychostimulant D-amphetamine. We tested the ability of an acute stressor to stimulate stereotypies in this model, using tone fear conditioning. Hdc knockout mice acquired conditioned fear normally, as manifest by freezing during the presentation of a tone 48 hours after it had been paired with a shock. During the 30 minutes following tone presentation they showed increased grooming. Heterozygotes exhibited normal freezing and intermediate grooming. These data validate a new paradigm for the examination of tic-like stereotypies in animals without pharmacological challenge and enhance the face validity of the Hdc knockout mouse as a pathophysiologically grounded model of tic disorders. PMID:25841792

  7. Systemic inflammation and insulin sensitivity in obese IFN-γ knockout mice

    PubMed Central

    O’Rourke, Robert W.; White, Ashley E.; Metcalf, Monja D.; Winters, Brian R.; Diggs, Brian S.; Zhu, Xinxia; Marks, Daniel L.

    2012-01-01

    Adipose tissue macrophages are important mediators of inflammation and insulin resistance in obesity. IFN-γ is a central regulator of macrophage function. The role of IFN-γ in regulating systemic inflammation and insulin resistance in obesity is unknown. We studied obese IFN-γ knockout mice to identify the role of IFN-γ in regulating inflammation and insulin sensitivity in obesity. IFN-γ-knockout C57Bl/6 mice and wild-type control litter mates were maintained on normal chow or a high fat diet for 13 weeks and then underwent insulin sensitivity testing then sacrifice and tissue collection. Flow cytometry, intracellular cytokine staining, and QRTPCR were used to define tissue lymphocyte phenotype and cytokine expression profiles. Adipocyte size was determined from whole adipose tissue explants examined under immunofluorescence microscopy. Diet-induced obesity induced systemic inflammation and insulin resistance, along with a pan-leukocyte adipose tissue infiltrate that includes macrophages, T-cells, and NK cells. Obese IFN-γ-knockout animals, compared with obese wild-type control animals, demonstrate modest improvements in insulin sensitivity, decreased adipocyte size, and an M2-shift in ATM phenotype and cytokine expression. These data suggest a role for IFN-γ in the regulation of inflammation and glucose homeostasis in obesity though multiple potential mechanisms, including effects on adipogenesis, cytokine expression, and macrophage phenotype. PMID:22386937

  8. Generation of Recombinant Capripoxvirus Vectors for Vaccines and Gene Knockout Function Studies.

    PubMed

    Boshra, Hani; Cao, Jingxin; Babiuk, Shawn

    2016-01-01

    The ability to manipulate capripoxvirus through gene knockouts and gene insertions has become an increasingly valuable research tool in elucidating the function of individual genes of capripoxvirus, as well as in the development of capripoxvirus-based recombinant vaccines. The homologous recombination technique is used to generate capripoxvirus knockout viruses (KO), and is based on the targeting a particular viral gene of interest. This technique can also be used to insert a gene of interest. A protocol for the generation of a viral gene knockout is described. This technique involves the use of a plasmid which encodes the flanking sequences of the regions where the homologous recombination will occur, and will result in the insertion of an EGFP reporter gene for visualization of recombinant virus, as well as the E. coli gpt gene as a positive selection marker. If an additional gene is to be incorporated, this can be achieved by inserting a gene of interest for expression under a poxvirus promoter into the plasmid between the flanking regions for insertion. This chapter describes a protocol for generating such recombinant capripoxviruses. PMID:26458835

  9. Abolished synthesis of cholic acid reduces atherosclerotic development in apolipoprotein E knockout mice.

    PubMed

    Slätis, Katharina; Gåfvels, Mats; Kannisto, Kristina; Ovchinnikova, Olga; Paulsson-Berne, Gabrielle; Parini, Paolo; Jiang, Zhao-Yan; Eggertsen, Gösta

    2010-11-01

    To investigate the effects of abolished cholic acid (CA) synthesis in the ApoE knockout model [apolipoprotein E (apoE) KO],a double-knockout (DKO) mouse model was created by crossbreeding Cyp8b1 knockout mice (Cyp8b1 KO), unable to synthesize the primary bile acid CA, with apoE KO mice. After 5 months of cholesterol feeding, the development of atherosclerotic plaques in the proximal aorta was 50% less in the DKO mice compared with the apoE KO mice. This effect was associated with reduced intestinal cholesterol absorption, decreased levels of apoB-containing lipoproteins in the plasma, enhanced bile acid synthesis, reduced hepatic cholesteryl esters, and decreased hepatic activity of ACAT2. The upregulation of Cyp7a1 in DKO mice seemed primarily caused by reduced expression of the intestinal peptide FGF15. Treatment of DKO mice with the farnesoid X receptor (FXR) agonist GW4064 did not alter the intestinal cholesterol absorption, suggesting that the action of CA in this process is confined mainly to formation of intraluminal micelles and less to its ability to activate the nuclear receptor FXR. Inhibition of CA synthesis may offer a therapeutic strategy for the treatment of hyperlipidemic conditions that lead to atherosclerosis.

  10. Myo5b knockout mice as a model of microvillus inclusion disease

    PubMed Central

    Cartón-García, Fernando; Overeem, Arend W.; Nieto, Rocio; Bazzocco, Sarah; Dopeso, Higinio; Macaya, Irati; Bilic, Josipa; Landolfi, Stefania; Hernandez-Losa, Javier; Schwartz, Simo; Ramon y Cajal, Santiago; van Ijzendoorn, Sven C. D.; Arango, Diego

    2015-01-01

    Inherited MYO5B mutations have recently been associated with microvillus inclusion disease (MVID), an autosomal recessive syndrome characterized by intractable, life-threatening, watery diarrhea appearing shortly after birth. Characterization of the molecular mechanisms underlying this disease and development of novel therapeutic approaches is hampered by the lack of animal models. In this study we describe the phenotype of a novel mouse model with targeted inactivation of Myo5b. Myo5b knockout mice show perinatal mortality, diarrhea and the characteristic mislocalization of apical and basolateral plasma membrane markers in enterocytes. Moreover, in transmission electron preparations, we observed microvillus atrophy and the presence of microvillus inclusion bodies. Importantly, Myo5b knockout embryos at day 20 of gestation already display all these structural defects, indicating that they are tissue autonomous rather than secondary to environmental cues, such as the long-term absence of nutrients in the intestine. Myo5b knockout mice closely resemble the phenotype of MVID patients and constitute a useful model to further investigate the underlying molecular mechanism of this disease and to preclinically assess the efficacy of novel therapeutic approaches. PMID:26201991

  11. Memory formation and retention are affected in adult miR-132/212 knockout mice.

    PubMed

    Hernandez-Rapp, Julia; Smith, Pascal Y; Filali, Mohammed; Goupil, Claudia; Planel, Emmanuel; Magill, Stephen T; Goodman, Richard H; Hébert, Sébastien S

    2015-01-01

    The miR-132/212 family is thought to play an important role in neural function and plasticity, while its misregulation has been observed in various neurodegenerative disorders. In this study, we analyzed 6-month-old miR-132/212 knockout mice in a battery of cognitive and non-cognitive behavioral tests. No significant changes were observed in reflexes and basic sensorimotor functions as determined by the SHIRPA primary screen. Accordingly, miR-132/212 knockout mice did not differ from wild-type controls in general locomotor activity in an open-field test. Furthermore, no significant changes of anxiety were measured in an elevated plus maze task. However, the mutant mice showed retention phase defects in a novel object recognition test and in the T-water maze. Moreover, the learning and probe phases in the Barnes maze were clearly altered in knockout mice when compared to controls. Finally, changes in BDNF, CREB, and MeCP2 were identified in the miR-132/212-deficient mice, providing a potential mechanism for promoting memory loss. Taken together, these results further strengthen the role of miR-132/212 in memory formation and retention, and shed light on the potential consequences of its deregulation in neurodegenerative diseases.

  12. TFF3 knockout in human pituitary adenoma cell HP75 facilitates cell apoptosis via mitochondrial pathway

    PubMed Central

    Gao, Feng; Pan, Suxia; Liu, Bing; Zhang, Huanzhi

    2015-01-01

    Trefoil factor 3 (TFF3), a regulatory protein composed of 59 amino acids, has been suggested to be involved in pathogenesis, proliferation, differentiation, invasion, migration and apoptosis in multiple malignant tumors. This study thus investigated the effect of TFF3 knockout in human pituitary adenoma cell line HP75 on cell apoptosis and related pathways. RNA interference approach was used to knock down the expression of TFF3 protein. The gene silencing was validated by RNA denaturing gel electrophoresis and Western blotting. The effect of TFF3 knockout on cell apoptosis was analyzed by Western blotting and flow cytometry. TFF3 protein level in pituitary adenoma was about 3.61 ± 0.48 folds of that in normal tissues (P < 0.01). After transfecting with small interference RNA (siRNA) against TFF3, the apoptotic ration was significantly elevated (P < 0.01). Apoptosis related protein Bcl-2 and caspase-3 levels were remarkably depressed after siRNA transfection, while Bax and cleaved caspase-3 levels were elevated. TFF3 protein knockout can facilitate apoptosis of human pituitary adenoma HP75 cells via mitochondrial pathway. PMID:26823779

  13. TFF3 knockout in human pituitary adenoma cell HP75 facilitates cell apoptosis via mitochondrial pathway.

    PubMed

    Gao, Feng; Pan, Suxia; Liu, Bing; Zhang, Huanzhi

    2015-01-01

    Trefoil factor 3 (TFF3), a regulatory protein composed of 59 amino acids, has been suggested to be involved in pathogenesis, proliferation, differentiation, invasion, migration and apoptosis in multiple malignant tumors. This study thus investigated the effect of TFF3 knockout in human pituitary adenoma cell line HP75 on cell apoptosis and related pathways. RNA interference approach was used to knock down the expression of TFF3 protein. The gene silencing was validated by RNA denaturing gel electrophoresis and Western blotting. The effect of TFF3 knockout on cell apoptosis was analyzed by Western blotting and flow cytometry. TFF3 protein level in pituitary adenoma was about 3.61 ± 0.48 folds of that in normal tissues (P < 0.01). After transfecting with small interference RNA (siRNA) against TFF3, the apoptotic ration was significantly elevated (P < 0.01). Apoptosis related protein Bcl-2 and caspase-3 levels were remarkably depressed after siRNA transfection, while Bax and cleaved caspase-3 levels were elevated. TFF3 protein knockout can facilitate apoptosis of human pituitary adenoma HP75 cells via mitochondrial pathway.

  14. Impact of Temporal Variation on Design and Analysis of Mouse Knockout Phenotyping Studies

    PubMed Central

    Karp, Natasha A.; Speak, Anneliese O.; White, Jacqueline K.; Adams, David J.; Hrabé de Angelis, Martin; Hérault, Yann; Mott, Richard F.

    2014-01-01

    A significant challenge facing high-throughput phenotyping of in-vivo knockout mice is ensuring phenotype calls are robust and reliable. Central to this problem is selecting an appropriate statistical analysis that models both the experimental design (the workflow and the way control mice are selected for comparison with knockout animals) and the sources of variation. Recently we proposed a mixed model suitable for small batch-oriented studies, where controls are not phenotyped concurrently with mutants. Here we evaluate this method both for its sensitivity to detect phenotypic effects and to control false positives, across a range of workflows used at mouse phenotyping centers. We found the sensitivity and control of false positives depend on the workflow. We show that the phenotypes in control mice fluctuate unexpectedly between batches and this can cause the false positive rate of phenotype calls to be inflated when only a small number of batches are tested, when the effect of knockout becomes confounded with temporal fluctuations in control mice. This effect was observed in both behavioural and physiological assays. Based on this analysis, we recommend two approaches (workflow and accompanying control strategy) and associated analyses, which would be robust, for use in high-throughput phenotyping pipelines. Our results show the importance in modelling all sources of variability in high-throughput phenotyping studies. PMID:25343444

  15. Positron emission tomography and functional characterization of a complete PBR/TSPO knockout

    PubMed Central

    Banati, Richard B.; Middleton, Ryan J.; Chan, Ronald; Hatty, Claire R.; Wai-Ying Kam, Winnie; Quin, Candice; Graeber, Manuel B.; Parmar, Arvind; Zahra, David; Callaghan, Paul; Fok, Sandra; Howell, Nicholas R.; Gregoire, Marie; Szabo, Alexander; Pham, Tien; Davis, Emma; Liu, Guo-Jun

    2014-01-01

    The evolutionarily conserved peripheral benzodiazepine receptor (PBR), or 18-kDa translocator protein (TSPO), is thought to be essential for cholesterol transport and steroidogenesis, and thus life. TSPO has been proposed as a biomarker of neuroinflammation and a new drug target in neurological diseases ranging from Alzheimer’s disease to anxiety. Here we show that global C57BL/6-Tspotm1GuWu(GuwiyangWurra)-knockout mice are viable with normal growth, lifespan, cholesterol transport, blood pregnenolone concentration, protoporphyrin IX metabolism, fertility and behaviour. However, while the activation of microglia after neuronal injury appears to be unimpaired, microglia from GuwiyangWurraTSPO knockouts produce significantly less ATP, suggesting reduced metabolic activity. Using the isoquinoline PK11195, the ligand originally used for the pharmacological and structural characterization of the PBR/TSPO, and the imidazopyridines CLINDE and PBR111, we demonstrate the utility of GuwiyangWurraTSPO knockouts to provide robust data on drug specificity and selectivity, both in vitro and in vivo, as well as the mechanism of action of putative TSPO-targeting drugs. PMID:25406832

  16. A triad: cardiac rhabdomyosarcoma, stroke and tamponade.

    PubMed

    Ashraf, Tazeen; Day, Thomas George; Marek, Jan; Hughes, Marina; Giardini, Alessandro

    2013-03-01

    The case report describes a 9-year-old boy who presented with an acute cerebrovascular accident and was found to have cardiac tamponade caused by cardiac rhabdomyosarcoma. Symptoms of rhabdomyosarcoma can be indolent and nonspecific, even with metastatic disease. Echocardiography and cardiac magnetic resonance imaging are explored as adjuncts to diagnosis. The radiologic features that helped with the diagnosis of this rare condition are described.

  17. Sudden cardiac death – Historical perspectives

    PubMed Central

    Abhilash, S.P.; Namboodiri, Narayanan

    2014-01-01

    Sudden cardiac death (SCD) is an unexpected death due to cardiac causes that occurs in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease. It is believed to be involved in nearly a quarter of human deaths, with ventricular fibrillation being the most common mechanism. It is estimated that more than 7 million lives per year are lost to SCD worldwide. Historical perspectives of SCD are analyzed with a brief description on how the developments in the management of sudden cardiac arrest evolved over time. PMID:24568828

  18. New electrical plethysmograph monitors cardiac output

    NASA Technical Reports Server (NTRS)

    Kubicek, W. B.; Patterson, R. P.; Witsoe, D. A.

    1968-01-01

    Four-electrode impedance plethysmograph measures ventricular stroke volume of cardiac output of humans. The instrument is automatic, operates with only one recording channel, and minimizes patient discomfort.

  19. Cardiac Arrhythmias: Diagnosis, Symptoms, and Treatments.

    PubMed

    Fu, Du-Guan

    2015-11-01

    The cardiac arrhythmia is characterized by irregular rhythm of heartbeat which could be either too slow (<60 beats/min) or too fast (>100 beats/min) and can happen at any age. The use of pacemaker and defibrillators devices has been suggested for heart arrhythmias patients. The antiarrhythmic medications have been reported for the treatment of cardiac arrhythmias or irregular heartbeats. The diagnosis, symptoms, and treatments of cardiac arrhythmias as well as the radiofrequency ablation, tachycardia, Brugada syndrome, arterial fibrillation, and recent research on the genetics of cardiac arrhythmias have been described here.

  20. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage. 410.49 Section 410.49 Public Health CENTERS FOR... MEDICAL INSURANCE (SMI) BENEFITS Medical and Other Health Services § 410.49 Cardiac rehabilitation...

  1. [Thoracic lavage and open cardiac massage as treatment of hypothermic cardiac arrest--case report].

    PubMed

    Koponen, Timo; Vänni, Ville; Kettunen, Minna; Reinikainen, Matti; Hakala, Tapio

    2016-01-01

    Cardiopulmonary bypass is the treatment of choice for a severely hypothermic patient with cardiac arrest. However, the treatment is not always available. We describe a successful three-and-a-half hour resuscitation of a hypothermic cardiac arrest patient with manual chest compressions followed by open cardiac massage and rewarming with thoracic lavage. PMID:27188092

  2. Horses and Zebras: complex cardiac anatomy in a patient with out-of-hospital cardiac arrest.

    PubMed

    Brown, Samuel M; Miller, Dylan V; Vezina, Daniel; Dean, Nathan C; Grissom, Colin K

    2011-04-01

    This case report describes a woman presenting after out-of-hospital cardiac arrest with several cardiac anomalies, including a form fruste of Ebstein's anomaly complicated by a large tricuspid valve vegetation. On autopsy, she proved to have unstable plaques in epicardial vessels that likely caused arrhythmic sudden cardiac death, a reminder that even in the presence of rare anomalies, common things are common.

  3. An In Silico Knockout Model for Gastrointestinal Absorption Using a Systems Pharmacology Approach - Development and Application for Ketones

    PubMed Central

    Shivva, Vittal; Tucker, Ian G.; Duffull, Stephen B.

    2016-01-01

    Gastrointestinal absorption and disposition of ketones is complex. Recent work describing the pharmacokinetics (PK) of d-β-hydroxybutyrate (BHB) following oral ingestion of a ketone monoester ((R)-3-hydroxybutyl (R)-3-hydroxybutyrate) found multiple input sites, nonlinear disposition and feedback on endogenous production. In the current work, a human systems pharmacology model for gastrointestinal absorption and subsequent disposition of small molecules (monocarboxylic acids with molecular weight < 200 Da) was developed with an application to a ketone monoester. The systems model was developed by collating the information from the literature and knowledge gained from empirical population modelling of the clinical data. In silico knockout variants of this systems model were used to explore the mechanism of gastrointestinal absorption of ketones. The knockouts included active absorption across different regions in the gut and also a passive diffusion knockout, giving 10 gut knockouts in total. Exploration of knockout variants has suggested that there are at least three distinct regions in the gut that contribute to absorption of ketones. Passive diffusion predominates in the proximal gut and active processes contribute to the absorption of ketones in the distal gut. Low doses are predominantly absorbed from the proximal gut by passive diffusion whereas high doses are absorbed across all sites in the gut. This work has provided mechanistic insight into the absorption process of ketones, in the form of unique in silico knockouts that have potential for application with other therapeutics. Future studies on absorption process of ketones are suggested to substantiate findings in this study. PMID:27685985

  4. Gender-specific alteration of adrenergic responses in small femoral arteries from estrogen receptor-beta knockout mice.

    PubMed

    Luksha, Leonid; Poston, Lucilla; Gustafsson, Jan-Ake; Aghajanova, Lusine; Kublickiene, Karolina

    2005-11-01

    Estrogen receptor-beta knockout mice become hypertensive as they age, and males have a higher blood pressure than females. We hypothesized that the absence of estrogen receptor-beta may contribute to development of cardiovascular dysfunction by modification of adrenergic responsiveness in the peripheral vasculature. Small femoral arteries (internal diameter <200 microm) were isolated from estrogen receptor-beta knockout and wild-type mice and mounted on a wire myograph. Concentration-response curves to phenylephrine and norepinephrine were compared and the contribution of adrenoceptor subtypes established using specific agonists and antagonists. The involvement of endothelial factors in the modulation of resting tone was also investigated and immunohistochemical analysis used to confirm the presence or absence of estrogen receptor expression. Compared with wild type, arteries from estrogen receptor-beta knockout male, but not female, mice demonstrated gender-specific enhancement of the response to phenylephrine (alpha1-adrenoceptor agonist), which was accompanied by elevated basal tension attributable to endothelial factors. Contractile responses to the mixed adrenoceptor agonist norepinephrine did not differ significantly between estrogen receptor-beta knockout and wild type; however, beta-adrenoceptor inhibition unmasked an enhanced underlying alpha1-adrenoceptor responsiveness in estrogen receptor-beta knockout males. beta-adrenoceptor-mediated dilatation was also enhanced in estrogen receptor-beta knockout versus wild-type males. We suggest that estrogen receptor-beta modifies the adrenergic control of small artery tone in males but not in females.

  5. ECLS in Pediatric Cardiac Patients

    PubMed Central

    Di Nardo, Matteo; MacLaren, Graeme; Marano, Marco; Cecchetti, Corrado; Bernaschi, Paola; Amodeo, Antonio

    2016-01-01

    Extracorporeal life support (ECLS) is an important device in the management of children with severe refractory cardiac and or pulmonary failure. Actually, two forms of ECLS are available for neonates and children: extracorporeal membrane oxygenation (ECMO) and use of a ventricular assist device (VAD). Both these techniques have their own advantages and disadvantages. The intra-aortic balloon pump is another ECLS device that has been successfully used in larger children, adolescents, and adults, but has found limited applicability in smaller children. In this review, we will present the “state of art” of ECMO in neonate and children with heart failure. ECMO is commonly used in a variety of settings to provide support to critically ill patients with cardiac disease. However, a strict selection of patients and timing of intervention should be performed to avoid the increase in mortality and morbidity of these patients. Therefore, every attempt should be done to start ECLS “urgently” rather than “emergently,” before the presence of dysfunction of end organs or circulatory collapse. Even though exciting progress is being made in the development of VADs for long-term mechanical support in children, ECMO remains the mainstay of mechanical circulatory support in children with complex anatomy, particularly those needing rapid resuscitation and those with a functionally univentricular circulation. With the increase in familiarity with ECMO, new indications have been added, such as extracorporeal cardiopulmonary resuscitation (ECPR). The literature supporting ECPR is increasing in children. Reasonable survival rates have been achieved after initiation of support during active compressions of the chest following in-hospital cardiac arrest. Contraindications to ECLS have reduced in the last 5 years and many centers support patients with functionally univentricular circulations. Improved results have been recently achieved in this complex subset of patients. PMID

  6. Neuroprognostication After Pediatric Cardiac Arrest

    PubMed Central

    Kirschen, Matthew P.; Topjian, Alexis A.; Hammond, Rachel; Illes, Judy; Abend, Nicholas S.

    2014-01-01

    BACKGROUND Management decisions and parental counseling after pediatric cardiac arrest depend on the ability of physicians to make accurate and timely predictions regarding neurological recovery. We evaluated neurologists and intensivists performing neuroprognostication after cardiac arrest to determine prediction agreement, accuracy, and confidence. METHODS Pediatric neurologists (n = 10) and intensivists (n = 9) reviewed 18 cases of children successfully resuscitated from a cardiac arrest and managed in the pediatric intensive care unit. Cases were sequentially presented (after arrest day 1, days 2–4, and days 5–7), with updated examinations, neurophysiologic data, and neuroimaging data. At each time period, physicians predicted outcome by Pediatric Cerebral Performance Category and specified prediction confidence. RESULTS Predicted discharge Pediatric Cerebral Performance Category versus actual hospital discharge Pediatric Cerebral Performance Category outcomes were compared. Exact (Predicted Pediatric Cerebral Performance Category – Actual Pediatric Cerebral Performance Category = 0) and close (Predicted Pediatric Cerebral Performance Category – Actual Pediatric Cerebral Performance Category = ±1) outcome prediction accuracies for all physicians improved over successive periods (P < 0.05). Prediction accuracy did not differ significantly between physician groups at any period or overall. Agreement improved over time among neurologists (day 1 Kappa [κ], 0.28; days 2–4 κ, 0.43; days 5–7 κ, 0.68) and among intensivists (day 1 κ, 0.30; days 2–4 κ, 0.44; days 5–7 κ, 0.57). Prediction confidence increased over time (P < 0.001) and did not differ between physician groups. CONCLUSIONS Inter-rater agreement among neurologists and among intensivists improved over time and reached moderate levels. For all physicians, prediction accuracy and confidence improved over time. Further prospective research is needed to better characterize how physicians

  7. Slow Conduction in Cardiac Muscle

    PubMed Central

    Lieberman, Melvyn; Kootsey, J. Mailen; Johnson, Edward A.; Sawanobori, Tohru

    1973-01-01

    Mechanisms of slow conduction in cardiac muscle are categorized and the most likely identified. Propagating action potentials were obtained experimentally from a synthetically grown strand of cardiac muscle (around 50 μm by 30 mm) and theoretically from a one-dimensional cable model that incorporated varying axial resistance and membrane properties along its length. Action potentials propagated at about 0.3 m/s, but in some synthetic strands there were regions (approximately 100 μm in length) where the velocity decreased to 0.002 m/s. The electrophysiological behavior associated with this slow conduction was similar to that associated with slow conduction in naturally occurring cardiac muscle (notches, Wenckebach phenomena, and block). Theoretically, reasonable changes in specific membrane capacitance, membrane activity, and various changes in geometry were insufficient to account for the observed slow conduction velocities. Conduction velocities as low as 0.009 m/s, however, could be obtained by increasing the resistance (ri) of connections between the cells in the cable; velocities as low as 0.0005 m/s could be obtained by a further increase in ri made possible by a reduction in membrane activity by one-fourth, which in itself decreased conduction velocity by only a factor of 1/1.4. As a result of these findings, several of the mechanisms that have been postulated, previously, are shown to be incapable of accounting for delays such as those which occur in the synthetic strand as well as in the atrioventricular (VA) node. ImagesFIGURE 1FIGURE 2FIGURE 3FIGURE 4 PMID:4709519

  8. Demography of penetrating cardiac trauma.

    PubMed Central

    Naughton, M J; Brissie, R M; Bessey, P Q; McEachern, M M; Donald, J M; Laws, H L

    1989-01-01

    All cases of penetrating cardiac trauma in 1985 and 1986 in Jefferson County, Alabama, where patients dying of penetrating trauma received autopsies, were retrospectively reviewed. All hospitals in the county plus the single coroner's office provided the records of the 72 patients comprising this study. Incidents occurred most often in the home or residence (70%) by a known assailant (83%) due to domestic/social disputes (73%). Frequency was greatest in the evening hours (73% between 6:00 PM and 3:00 AM), on weekends in spring and summer. Victims tended to be male (86%), black (72%), married (46%), blue collar workers (62%). There were 41 (57%) gunshot wounds, 3 (4%) shotgun wounds, and 28 (39%) stab wounds with an associated mortality rate of 97%, 100%, and 68%, respectively. Prehospital mortality rate (dead at the scene) was 54.2% (39/72), and death on arrival was 26.4% (19/72), for a combined pretreatment mortality rate of 80.6%. All patients who arrived with no vital signs died. Mortality appeared to be related to mechanism of injury, age, race, sex, vital signs on arrival, number and specific cardiac chambers injured, associated major vascular injury, hematocrit, and mode of transportation. Mortality was not related to caliber of weapon, ethanol level, transport time, time from arrival to operation, or transfusion requirements. There were only ten survivors (1 gunshot wound and 9 stab wounds), all of whom had ventricular injuries and no associated major vascular injuries. The ten survivors represented a 71.4% (10/14) salvage rate for those victims arriving with vital signs. Complications occurred in three patients. Hospitalization averaged 7.3 days in the survivors. Penetrating cardiac trauma remains a serious, socially linked disease with a high rate of mortality. Rapid transport, aggressive resuscitation and cardiorrhaphy remain the best treatment. PMID:2730180

  9. Cellular Encapsulation Enhances Cardiac Repair

    PubMed Central

    Levit, Rebecca D.; Landázuri, Natalia; Phelps, Edward A.; Brown, Milton E.; García, Andrés J.; Davis, Michael E.; Joseph, Giji; Long, Robert; Safley, Susan A.; Suever, Jonathan D.; Lyle, Alicia N.; Weber, Collin J.; Taylor, W. Robert

    2013-01-01

    Background Stem cells for cardiac repair have shown promise in preclinical trials, but lower than expected retention, viability, and efficacy. Encapsulation is one potential strategy to increase viable cell retention while facilitating paracrine effects. Methods and Results Human mesenchymal stem cells (hMSC) were encapsulated in alginate and attached to the heart with a hydrogel patch in a rat myocardial infarction (MI) model. Cells were tracked using bioluminescence (BLI) and cardiac function measured by transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR). Microvasculature was quantified using von Willebrand factor staining and scar measured by Masson's Trichrome. Post‐MI ejection fraction by CMR was greatly improved in encapsulated hMSC‐treated animals (MI: 34±3%, MI+Gel: 35±3%, MI+Gel+hMSC: 39±2%, MI+Gel+encapsulated hMSC: 56±1%; n=4 per group; P<0.01). Data represent mean±SEM. By TTE, encapsulated hMSC‐treated animals had improved fractional shortening. Longitudinal BLI showed greatest hMSC retention when the cells were encapsulated (P<0.05). Scar size at 28 days was significantly reduced in encapsulated hMSC‐treated animals (MI: 12±1%, n=8; MI+Gel: 14±2%, n=7; MI+Gel+hMSC: 14±1%, n=7; MI+Gel+encapsulated hMSC: 7±1%, n=6; P<0.05). There was a large increase in microvascular density in the peri‐infarct area (MI: 121±10, n=7; MI+Gel: 153±26, n=5; MI+Gel+hMSC: 198±18, n=7; MI+Gel+encapsulated hMSC: 828±56 vessels/mm2, n=6; P<0.01). Conclusions Alginate encapsulation improved retention of hMSCs and facilitated paracrine effects such as increased peri‐infarct microvasculature and decreased scar. Encapsulation of MSCs improved cardiac function post‐MI and represents a new, translatable strategy for optimization of regenerative therapies for cardiovascular diseases. PMID:24113327

  10. Echocardiographic assessment of cardiac disease

    NASA Technical Reports Server (NTRS)

    Popp, R. L.

    1976-01-01

    The physical principles and current applications of echocardiography in assessment of heart diseases are reviewed. Technical considerations and unresolved points relative to the use of echocardiography in various disease states are stressed. The discussion covers normal mitral valve motion, mitral stenosis, aortic regurgitation, atrial masses, mitral valve prolapse, and idiopathic hypertrophic subaortic stenosis. Other topics concern tricuspic valve abnormalities, aortic valve disease, pulmonic valve, pericardial effusion, intraventricular septal motion, and left ventricular function. The application of echocardiography to congenital heart disease diagnosis is discussed along with promising ultrasonic imaging systems. The utility of echocardiography in quantitative evaluation of cardiac disease is demonstrated.

  11. Antithrombotic Therapy in Cardiac Embolism

    PubMed Central

    Cervera, Álvaro; Chamorro, Ángel

    2010-01-01

    Anticoagulation is indicated in most cardioembolic ischemic strokes for secondary prevention. In many cardiac conditions, anticoagulation is also indication for primary stroke prevention, mainly when associated to vascular risk factors. Anticoagulation should be started as soon as possible, as it is safe even in moderate acute strokes. The efficacy of early anticoagulation after cardioembolic stroke in relation to outcome has not been assessed adequately, but there is evidence from animal models and clinical studies that anticoagulation with unfractionated heparin is associated with a better outcome mediated in part by its anti-inflammatory properties. PMID:21804782

  12. CARDIAC OPERATIONS WITH EXTRACORPOREAL CIRCULATION

    PubMed Central

    Kay, Jerome Harold; Anderson, Robert M.; Lewis, Reuben R.; Meihaus, John; Magidson, Oscar; Snyder, Edward N.; Bennett, Louis C.; Bernstein, Sol; Amsden, Neal

    1959-01-01

    In a series of 50 patients for whom a heart-lung machine was used for periods as long as 70 minutes during operations to correct structural defects of the heart, there were no deaths attributable to the machine. Seven patients died. Two of them had high pressure ventricular septal defects with bidirectional shunts; a third patient with the same lesion recovered after repair. One patient died of cardiac tamponade when a large blood clot formed about the entire heart in a loosely closed pericardial sac. Others died of various causes. The development of subacute bacterial endocarditis in one patient led to a change in sterilization of apparatus. PMID:13662856

  13. Cardiac imaging: does radiation matter?

    PubMed Central

    Einstein, Andrew J.; Knuuti, Juhani

    2012-01-01

    The use of ionizing radiation in cardiovascular imaging has generated considerable discussion. Radiation should not be considered in isolation, but rather in the context of a careful examination of the benefits, risks, and costs of cardiovascular imaging. Such consideration requires an understanding of some fundamental aspects of the biology, physics, epidemiology, and terminology germane to radiation, as well as principles of radiological protection. This paper offers a concise, contemporary perspective on these areas by addressing pertinent questions relating to radiation and its application to cardiac imaging. PMID:21828062

  14. Thymosin-β4 prevents cardiac rupture and improves cardiac function in mice with myocardial infarction.

    PubMed

    Peng, Hongmei; Xu, Jiang; Yang, Xiao-Ping; Dai, Xiangguo; Peterson, Edward L; Carretero, Oscar A; Rhaleb, Nour-Eddine

    2014-09-01

    Thymosin-β4 (Tβ4) promotes cell survival, angiogenesis, and tissue regeneration and reduces inflammation. Cardiac rupture after myocardial infarction (MI) is mainly the consequence of excessive regional inflammation, whereas cardiac dysfunction after MI results from a massive cardiomyocyte loss and cardiac fibrosis. It is possible that Tβ4 reduces the incidence of cardiac rupture post-MI via anti-inflammatory actions and that it decreases adverse cardiac remodeling and improves cardiac function by promoting cardiac cell survival and cardiac repair. C57BL/6 mice were subjected to MI and treated with either vehicle or Tβ4 (1.6 mg·kg(-1)·day(-1) ip via osmotic minipump) for 7 days or 5 wk. Mice were assessed for 1) cardiac remodeling and function by echocardiography; 2) inflammatory cell infiltration, capillary density, myocyte apoptosis, and interstitial collagen fraction histopathologically; 3) gelatinolytic activity by in situ zymography; and 4) expression of ICAM-1 and p53 by immunoblot analysis. Tβ4 reduced cardiac rupture that was associated with a decrease in the numbers of infiltrating inflammatory cells and apoptotic myocytes, a decrease in gelatinolytic activity and ICAM-1 and p53 expression, and an increase in the numbers of CD31-positive cells. Five-week treatment with Tβ4 ameliorated left ventricular dilation, improved cardiac function, markedly reduced interstitial collagen fraction, and increased capillary density. In a murine model of acute MI, Tβ4 not only decreased mortality rate as a result of cardiac rupture but also significantly improved cardiac function after MI. Thus, the use of Tβ4 could be explored as an alternative therapy in preventing cardiac rupture and restoring cardiac function in patients with MI.

  15. Role of A2B Adenosine Receptors in Regulation of Paracrine Functions of Stem Cell Antigen 1-Positive Cardiac Stromal Cells

    PubMed Central

    Ryzhov, Sergey; Goldstein, Anna E.; Novitskiy, Sergey V.; Blackburn, Michael R.; Biaggioni, Italo

    2012-01-01

    The existence of multipotent cardiac stromal cells expressing stem cell antigen (Sca)-1 has been reported, and their proangiogenic properties have been demonstrated in myocardial infarction models. In this study, we tested the hypothesis that stimulation of adenosine receptors on cardiac Sca-1+ cells up-regulates their secretion of proangiogenic factors. We found that Sca-1 is expressed in subsets of mouse cardiac stromal CD31− and endothelial CD31+ cells. The population of Sca-1+CD31+ endothelial cells was significantly reduced, whereas the population of Sca-1+CD31− stromal cells was increased 1 week after myocardial infarction, indicating their relative functional importance in this pathophysiological process. An increase in adenosine levels in adenosine deaminase-deficient mice in vivo significantly augmented vascular endothelial growth factor (VEGF) production in cardiac Sca-1+CD31− stromal cells but not in Sca-1+CD31+ endothelial cells. We found that mouse cardiac Sca-1+CD31− stromal cells predominantly express mRNA encoding A2B adenosine receptors. Stimulation of adenosine receptors significantly increased interleukin (IL)-6, CXCL1 (a mouse ortholog of human IL-8), and VEGF release from these cells. Using conditionally immortalized Sca-1+CD31− stromal cells obtained from wild-type and A2B receptor knockout mouse hearts, we demonstrated that A2B receptors are essential for adenosine-dependent up-regulation of their paracrine functions. We found that the human heart also harbors a population of stromal cells similar to the mouse cardiac Sca-1+CD31− stromal cells that increase release of IL-6, IL-8, and VEGF in response to A2B receptor stimulation. Thus, our study identified A2B adenosine receptors on cardiac stromal cells as potential targets for up-regulation of proangiogenic factors in the ischemic heart. PMID:22431204

  16. CXCR6 deficiency attenuates pressure overload-induced monocytes migration and cardiac fibrosis through downregulating TNF-α-dependent MMP9 pathway

    PubMed Central

    Wang, Jia-Hong; Su, Feng; Wang, Shijun; Lu, Xian-Cheng; Zhang, Shao-Heng; Chen, De; Chen, Nan-Nan; Zhong, Jing-Quan

    2014-01-01

    An immerging role of TNF-α in collagen synthesis and cardiac fibrosis implies the significance of TNF-α production in the development of myocardial remodeling. Our previous study showed a reduction of TNF-α and attenuated cardiac remodeling in CXCR6 knockout (KO) mice after ischemia/reperfusion injury. However, the potential mechanism of TNF-α-mediated cardiac fibrosis with pressure overload has not been well elucidated. In the present study, we aim to investigate the role of CXCR6 in TNF-α release and myocardial remodeling in response to pressure overload. Pressure overload was performed by constriction of transverse aorta (TAC) surgery on CXCR6 KO mice and C57 wild-type (WT) counterparts. At 6 weeks after TAC, cardiac remodeling was assessed by echocardiography, cardiac TNF-α release and its type I receptor (TNFRI), were detected by ELISA and western blot, collagen genes Col1a1 (type I) and Col3a1 (type III) were examined by real-time PCR. Compared with CXCR6 WT mice, CXCR6 KO mice exhibited less cardiac dysfunction, reduced expression of TNFRI, Col1a1 and Col3a. In vitro, we confirmed that CXCR6 deficiency led to reduced homing and infiltration of CD11b+ monocytes, which contributed to attenuated TNF-α release in myocardium. Furthermore, TNFRI antagonist pretreatment blocked AT1 receptor signaling and NOX4 expression, reduced collagen synthesis, and blunted the activity of MMP9 in CXCR6 WT mice after TAC, but these were not observed in CXCR6 KO mice. In the present work, we propose a mechanism that CXCR6 is essential for pressure overload-mediated myocardial recruitment of monocytes, which contributes to cardiac fibrosis through TNF-α-dependent MMP9 activation and collagen synthesis. PMID:25400729

  17. CXCR6 deficiency attenuates pressure overload-induced monocytes migration and cardiac fibrosis through downregulating TNF-α-dependent MMP9 pathway.

    PubMed

    Wang, Jia-Hong; Su, Feng; Wang, Shijun; Lu, Xian-Cheng; Zhang, Shao-Heng; Chen, De; Chen, Nan-Nan; Zhong, Jing-Quan

    2014-01-01

    An immerging role of TNF-α in collagen synthesis and cardiac fibrosis implies the significance of TNF-α production in the development of myocardial remodeling. Our previous study showed a reduction of TNF-α and attenuated cardiac remodeling in CXCR6 knockout (KO) mice after ischemia/reperfusion injury. However, the potential mechanism of TNF-α-mediated cardiac fibrosis with pressure overload has not been well elucidated. In the present study, we aim to investigate the role of CXCR6 in TNF-α release and myocardial remodeling in response to pressure overload. Pressure overload was performed by constriction of transverse aorta (TAC) surgery on CXCR6 KO mice and C57 wild-type (WT) counterparts. At 6 weeks after TAC, cardiac remodeling was assessed by echocardiography, cardiac TNF-α release and its type I receptor (TNFRI), were detected by ELISA and western blot, collagen genes Col1a1 (type I) and Col3a1 (type III) were examined by real-time PCR. Compared with CXCR6 WT mice, CXCR6 KO mice exhibited less cardiac dysfunction, reduced expression of TNFRI, Col1a1 and Col3a. In vitro, we confirmed that CXCR6 deficiency led to reduced homing and infiltration of CD11b(+) monocytes, which contributed to attenuated TNF-α release in myocardium. Furthermore, TNFRI antagonist pretreatment blocked AT1 receptor signaling and NOX4 expression, reduced collagen synthesis, and blunted the activity of MMP9 in CXCR6 WT mice after TAC, but these were not observed in CXCR6 KO mice. In the present work, we propose a mechanism that CXCR6 is essential for pressure overload-mediated myocardial recruitment of monocytes, which contributes to cardiac fibrosis through TNF-α-dependent MMP9 activation and collagen synthesis. PMID:25400729

  18. Embryonic caffeine exposure acts via A1 adenosine receptors to alter adult cardiac function and DNA methylation in mice.

    PubMed

    Buscariollo, Daniela L; Fang, Xiefan; Greenwood, Victoria; Xue, Huiling; Rivkees, Scott A; Wendler, Christopher C

    2014-01-01

    Evidence indicates that disruption of normal prenatal development influences an individual's risk of developing obesity and cardiovascular disease as an adult. Thus, understanding how in utero exposure to chemical agents leads to increased susceptibility to adult diseases is a critical health related issue. Our aim was to determine whether adenosine A1 receptors (A1ARs) mediate the long-term effects of in utero caffeine exposure on cardiac function and whether these long-term effects are the result of changes in DNA methylation patterns in adult hearts. Pregnant A1AR knockout mice were treated with caffeine (20 mg/kg) or vehicle (0.09% NaCl) i.p. at embryonic day 8.5. This caffeine treatment results in serum levels equivalent to the consumption of 2-4 cups of coffee in humans. After dams gave birth, offspring were examined at 8-10 weeks of age. A1AR+/+ offspring treated in utero with caffeine were 10% heavier than vehicle controls. Using echocardiography, we observed altered cardiac function and morphology in adult mice exposed to caffeine in utero. Caffeine treatment decreased cardiac output by 11% and increased left ventricular wall thickness by 29% during diastole. Using DNA methylation arrays, we identified altered DNA methylation patterns in A1AR+/+ caffeine treated hearts, including 7719 differentially methylated regions (DMRs) within the genome and an overall decrease in DNA methylation of 26%. Analysis of genes associated with DMRs revealed that many are associated with cardiac hypertrophy. These data demonstrate that A1ARs mediate in utero caffeine effects on cardiac function and growth and that caffeine exposure leads to changes in DNA methylation.

  19. Deletion of thioredoxin-interacting protein improves cardiac inotropic reserve in the streptozotocin-induced diabetic heart.

    PubMed

    Myers, Ronald B; Fomovsky, Gregory M; Lee, Samuel; Tan, Max; Wang, Bing F; Patwari, Parth; Yoshioka, Jun

    2016-06-01

    Although the precise pathogenesis of diabetic cardiac damage remains unclear, potential mechanisms include increased oxidative stress, autonomic nervous dysfunction, and altered cardiac metabolism. Thioredoxin-interacting protein (Txnip) was initially identified as an inhibitor of the antioxidant thioredoxin but is now recognized as a member of the arrestin superfamily of adaptor proteins that classically regulate G protein-coupled receptor signaling. Here we show that Txnip plays a key role in diabetic cardiomyopathy. High glucose levels induced Txnip expression in rat cardiomyocytes in vitro and in the myocardium of streptozotocin-induced diabetic mice in vivo. While hyperglycemia did not induce cardiac dysfunction at baseline, β-adrenergic challenge revealed a blunted myocardial inotropic response in diabetic animals (24-wk-old male and female C57BL/6;129Sv mice). Interestingly, diabetic mice with cardiomyocyte-specific deletion of Txnip retained a greater cardiac response to β-adrenergic stimulation than wild-type mice. This benefit in Txnip-knockout hearts was not related to the level of thioredoxin activity or oxidative stress. Unlike the β-arrestins, Txnip did not interact with β-adrenergic receptors to desensitize downstream signaling. However, our proteomic and functional analyses demonstrated that Txnip inhibits glucose transport through direct binding to glucose transporter 1 (GLUT1). An ex vivo analysis of perfused hearts further demonstrated that the enhanced functional reserve afforded by deletion of Txnip was associated with myocardial glucose utilization during β-adrenergic stimulation. These data provide novel evidence that hyperglycemia-induced Txnip is responsible for impaired cardiac inotropic reserve by direct regulation of insulin-independent glucose uptake through GLUT1 and plays a role in the development of diabetic cardiomyopathy. PMID:27037370

  20. Cardiac-Specific Deletion of the Pdha1 Gene Sensitizes Heart to Toxicological Actions of Ischemic Stress.

    PubMed

    Sun, Wanqing; Quan, Nanhu; Wang, Lin; Yang, Hui; Chu, Dongyang; Liu, Quan; Zhao, Xuezhong; Leng, Jiyan; Li, Ji

    2016-05-01

    Pyruvate dehydrogenase (PDH) plays a key role in aerobic energy metabolism and occupies a central crossroad between glycolysis and the tricarboxylic acid cycle. We generated inducible cardiac-specific PDH E1α knockout (CreER(T2)-PDH(flox/flox)) mice that demonstrated a high mortality rate. It was hypothesized that PDH modulating cardiac glucose metabolism is crucial for heart functions under normal physiological and/or stress conditions. The myocardial infarction was conducted by a ligation of the left anterior descending coronary arteries. Cardiac PDH E1α deficiency caused large myocardial infarcts size and macrophage infiltration in the hearts (P < .01 vs wild-type [WT]). Wheat germ agglutinin and Masson trichrome staining revealed significantly increased hypertrophy and fibrosis in PDH E1α-deficient hearts (P < .05 vs WT). Measurements of heart substrate metabolism in an ex vivo working heart perfusion system demonstrated a significant impairment of glucose oxidation in PDH E1α-deficient hearts during ischemia/reperfusion (P < .05 vs WT). Dichloroacetate, a PDH activator, increased glucose oxidation in WT hearts during ischemia/reperfusion and reduced myocardial infarct size in WT, but not in PDH E1α-deficient hearts. Immunoblotting results demonstrated that cardiac PDH E1α deficiency leads to an impaired ischemic AMP-activated protein kinase activation through Sestrin2-liver kinase B1 interaction which is responsible for an increased susceptibility of PDH E1α-deficient heart to ischemic insults. Thus, cardiac PDH E1α deficiency impairs ischemic AMP-activated protein kinase signaling and sensitizes hearts to the toxicological actions of ischemic stress.