Ranolazine-mediated attenuation of mechanoelectric feedback in atrial myocyte monolayers

[EN] Background Mechanical stretch increases Na(+)inflow into myocytes, related to mechanisms including stretch-activated channels or Na+/H(+)exchanger activation, involving Ca(2+)increase that leads to changes in electrophysiological properties favoring arrhythmia induction. Ranolazine is an antianginal drug with confirmed beneficial effects against cardiac arrhythmias associated with the augmentation ofI(NaL)current and Ca(2+)overload. Objective This study investigates the effects of mechanical stretch on activation patterns in atrial cell monolayers and its pharmacological response to ranolazine. Methods Confluent HL-1 cells were cultured in silicone membrane plates and were stretched to 110% of original length. The characteristics ofin vitrofibrillation (dominant frequency, regularity index, density of phase singularities, rotor meandering, and rotor curvature) were analyzed using optical mapping in order to study the mechanoelectric response to stretch under control conditions and ranolazine action. Results HL-1 cell stretch increased fibrillatory dominant frequency (3.65 +/- 0.69 vs. 4.35 +/- 0.74 Hz,p< 0.01) and activation complexity (1.97 +/- 0.45 vs. 2.66 +/- 0.58 PS/cm(2),p< 0.01) under control conditions. These effects were related to stretch-induced changes affecting the reentrant patterns, comprising a decrease in rotor meandering (0.72 +/- 0.12 vs. 0.62 +/- 0.12 cm/s,p< 0.001) and an increase in wavefront curvature (4.90 +/- 0.42 vs. 5.68 +/- 0.40 rad/cm,p< 0.001). Ranolazine reduced stretch-induced effects, attenuating the activation rate increment (12.8% vs. 19.7%,p< 0.01) and maintaining activation complexity-both parameters being lower during stretch than under control conditions. Moreover, under baseline conditions, ranolazine slowed and regularized the activation patterns (3.04 +/- 0.61 vs. 3.65 +/- 0.69 Hz,p< 0.01). Conclusion Ranolazine attenuates the modifications of activation patterns induced by mechanical stretch in atrial myocyte monolayers.This work was supported by the Instituto de Salud Carlos III-FEDER (Fondo Europeo de Desarrollo Regional) (Grant Nos. CB16/11/00486, CB16/11/00292, PI16/01123, PI17/01059, PI17/01106, PI18/01620, and DTS16/0160) and the Generalitat Valenciana (Grant Nos. PROMETEO/2018/078 and APOSTD/2018/181).Del-Canto, I.; Gómez-Cid, L.; Hernández-Romero, I.; Guillem Sánchez, MS.; Fernández-Santos, ME.; Atienza, F.; Such, L.... (2020). Ranolazine-mediated attenuation of mechanoelectric feedback in atrial myocyte monolayers. Frontiers in Physiology. 11:1-13. https://doi.org/10.3389/fphys.2020.00922S11311Agladze, N. N., Halaidych, O. V., Tsvelaya, V. A., Bruegmann, T., Kilgus, C., Sasse, P., & Agladze, K. I. (2017). Synchronization of excitable cardiac cultures of different origin. Biomaterials Science, 5(9), 1777-1785. doi:10.1039/c7bm00171aAntzelevitch, C., Burashnikov, A., Sicouri, S., & Belardinelli, L. (2011). Electrophysiologic basis for the antiarrhythmic actions of ranolazine. Heart Rhythm, 8(8), 1281-1290. doi:10.1016/j.hrthm.2011.03.045Belardinelli, L., Giles, W. R., Rajamani, S., Karagueuzian, H. S., & Shryock, J. C. (2015). Cardiac late Na+ current: Proarrhythmic effects, roles in long QT syndromes, and pathological relationship to CaMKII and oxidative stress. Heart Rhythm, 12(2), 440-448. doi:10.1016/j.hrthm.2014.11.009BERENFELD, O., MANDAPATI, R., DIXIT, S., SKANES, A. C., CHEN, J., MANSOUR, M., & JALIFE, J. (2000). Spatially Distributed Dominant Excitation Frequencies Reveal Hidden Organization in Atrial Fibrillation in the Langendorff-Perfused Sheep Heart. Journal of Cardiovascular Electrophysiology, 11(8), 869-879. doi:10.1111/j.1540-8167.2000.tb00066.xBeyder, A., Strege, P. R., Reyes, S., Bernard, C. E., Terzic, A., Makielski, J., … Farrugia, G. (2012). Ranolazine Decreases Mechanosensitivity of the Voltage-Gated Sodium Ion Channel Na V 1.5. Circulation, 125(22), 2698-2706. doi:10.1161/circulationaha.112.094714Bray, M.-A., & Wikswo, J. P. (2002). Considerations in phase plane analysis for nonstationary reentrant cardiac behavior. Physical Review E, 65(5). doi:10.1103/physreve.65.051902Caves, R. E., Cheng, H., Choisy, S. C., Gadeberg, H. C., Bryant, S. M., Hancox, J. C., & James, A. F. (2017). Atrial-ventricular differences in rabbit cardiac voltage-gated Na + currents: Basis for atrial-selective block by ranolazine. Heart Rhythm, 14(11), 1657-1664. doi:10.1016/j.hrthm.2017.06.012Chorro, F. J., del Canto, I., Brines, L., Such-Miquel, L., Calvo, C., Soler, C., … Such, L. (2015). Ranolazine Attenuates the Electrophysiological Effects of Myocardial Stretch in Langendorff-Perfused Rabbit Hearts. Cardiovascular Drugs and Therapy, 29(3), 231-241. doi:10.1007/s10557-015-6587-4Claycomb, W. C., Lanson, N. A., Stallworth, B. S., Egeland, D. B., Delcarpio, J. B., Bahinski, A., & Izzo, N. J. (1998). HL-1 cells: A cardiac muscle cell line that contracts and retains phenotypic characteristics of the adult cardiomyocyte. Proceedings of the National Academy of Sciences, 95(6), 2979-2984. doi:10.1073/pnas.95.6.2979Climent, A. M., Guillem, M. S., Fuentes, L., Lee, P., Bollensdorff, C., Fernández-Santos, M. E., … Fernández-Avilés, F. (2015). Role of atrial tissue remodeling on rotor dynamics: an in vitro study. American Journal of Physiology-Heart and Circulatory Physiology, 309(11), H1964-H1973. doi:10.1152/ajpheart.00055.2015De Jong, A. M., Maass, A. H., Oberdorf-Maass, S. U., Van Veldhuisen, D. J., Van Gilst, W. H., & Van Gelder, I. C. (2010). Mechanisms of atrial structural changes caused by stretch occurring before and during early atrial fibrillation. Cardiovascular Research, 89(4), 754-765. doi:10.1093/cvr/cvq357Del-Canto, I., Gomez-Cid, L., Hernandez-Romero, I., Guillem, M. S., Fern�ndez-Santos, M. E., Such, L., … Climent, A. M. (2017). Ranolazine Attenuates Stretch-induced Modifications of Electrophysiological Characteristics in HL-1 Cells. 2017 Computing in Cardiology Conference (CinC). doi:10.22489/cinc.2017.311-412Del Canto, I., Santamaría, L., Genovés, P., Such-Miquel, L., Arias-Mutis, O., Zarzoso, M., … Chorro, F. J. (2018). Effects of the Inhibition of Late Sodium Current by GS967 on Stretch-Induced Changes in Cardiac Electrophysiology. Cardiovascular Drugs and Therapy, 32(5), 413-425. doi:10.1007/s10557-018-6822-xDias, P., Desplantez, T., El-Harasis, M. A., Chowdhury, R. A., Ullrich, N. D., Cabestrero de Diego, A., … Dupont, E. (2014). Characterisation of Connexin Expression and Electrophysiological Properties in Stable Clones of the HL-1 Myocyte Cell Line. PLoS ONE, 9(2), e90266. doi:10.1371/journal.pone.0090266Entcheva, E., & Bien, H. (2006). Macroscopic optical mapping of excitation in cardiac cell networks with ultra-high spatiotemporal resolution. Progress in Biophysics and Molecular Biology, 92(2), 232-257. doi:10.1016/j.pbiomolbio.2005.10.003Gong, M., Zhang, Z., Fragakis, N., Korantzopoulos, P., Letsas, K. P., Li, G., … Liu, T. (2017). Role of ranolazine in the prevention and treatment of atrial fibrillation: A meta-analysis of randomized clinical trials. Heart Rhythm, 14(1), 3-11. doi:10.1016/j.hrthm.2016.10.008Gutbrod, S. R., Walton, R., Gilbert, S., Meillet, V., Jaïs, P., Hocini, M., … Efimov, I. R. (2015). Quantification of the Transmural Dynamics of Atrial Fibrillation by Simultaneous Endocardial and Epicardial Optical Mapping in an Acute Sheep Model. Circulation: Arrhythmia and Electrophysiology, 8(2), 456-465. doi:10.1161/circep.114.002545Hong, J. H., Choi, J. H., Kim, T. Y., & Lee, K. J. (2008). Spiral reentry waves in confluent layer of HL-1 cardiomyocyte cell lines. Biochemical and Biophysical Research Communications, 377(4), 1269-1273. doi:10.1016/j.bbrc.2008.10.168Houston, C., Tzortzis, K. N., Roney, C., Saglietto, A., Pitcher, D. S., Cantwell, C. D., … Dupont, E. (2018). Characterisation of re-entrant circuit (or rotational activity) in vitro using the HL1-6 myocyte cell line. Journal of Molecular and Cellular Cardiology, 119, 155-164. doi:10.1016/j.yjmcc.2018.05.002Ishikawa, K., Watanabe, S., Lee, P., Akar, F. G., Lee, A., Bikou, O., … Hajjar, R. J. (2018). Acute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias. Journal of the American College of Cardiology, 72(7), 738-750. doi:10.1016/j.jacc.2018.05.059Jalife, J. (2010). Deja vu in the theories of atrial fibrillation dynamics. Cardiovascular Research, 89(4), 766-775. doi:10.1093/cvr/cvq364Jerling, M. (2006). Clinical Pharmacokinetics of Ranolazine. Clinical Pharmacokinetics, 45(5), 469-491. doi:10.2165/00003088-200645050-00003Karagueuzian, H. S., Pezhouman, A., Angelini, M., & Olcese, R. (2017). Enhanced Late Na and Ca Currents as Effective Antiarrhythmic Drug Targets. Frontiers in Pharmacology, 8. doi:10.3389/fphar.2017.00036Laughner, J. I., Ng, F. S., Sulkin, M. S., Arthur, R. M., & Efimov, I. R. (2012). Processing and analysis of cardiac optical mapping data obtained with potentiometric dyes. American Journal of Physiology-Heart and Circulatory Physiology, 303(7), H753-H765. doi:10.1152/ajpheart.00404.2012Ma, J., Luo, A., Wu, L., Wan, W., Zhang, P., Ren, Z., … Belardinelli, L. (2012). Calmodulin kinase II and protein kinase C mediate the effect of increased intracellular calcium to augment late sodium current in rabbit ventricular myocytes. American Journal of Physiology-Cell Physiology, 302(8), C1141-C1151. doi:10.1152/ajpcell.00374.2011Maltsev, V. A., & Undrovinas, A. (2008). Late sodium current in failing heart: Friend or foe? Progress in Biophysics and Molecular Biology, 96(1-3), 421-451. doi:10.1016/j.pbiomolbio.2007.07.010Meo, M., Pambrun, T., Derval, N., Dumas-Pomier, C., Puyo, S., Duchâteau, J., … Dubois, R. (2018). Noninvasive Assessment of Atrial Fibrillation Complexity in Relation to Ablation Characteristics and Outcome. Frontiers in Physiology, 9. doi:10.3389/fphys.2018.00929Nattel, S., & Dobrev, D. (2012). The multidimensional role of calcium in atrial fibrillation pathophysiology: mechanistic insights and therapeutic opportunities. European Heart Journal, 33(15), 1870-1877. doi:10.1093/eurheartj/ehs079Nesterenko, V. V., Zygmunt, A. C., Rajamani, S., Belardinelli, L., & Antzelevitch, C. (2011). Mechanisms of atrial-selective block of Na+ channels by ranolazine: II. Insights from a mathematical model. American Journal of Physiology-Heart and Circulatory Physiology, 301(4), H1615-H1624. doi:10.1152/ajpheart.00243.2011Neves, J. S., Leite-Moreira, A. M., Neiva-Sousa, M., Almeida-Coelho, J., Castro-Ferreira, R., & Leite-Moreira, A. F. (2016). Acute Myocardial Response to Stretch: What We (don’t) Know. Frontiers in Physiology, 6. doi:10.3389/fphys.2015.00408Pandit, S. V., Berenfeld, O., Anumonwo, J. M. B., Zaritski, R. M., Kneller, J., Nattel, S., & Jalife, J. (2005). Ionic Determinants of Functional Reentry in a 2-D Model of Human Atrial Cells During Simulated Chronic Atrial Fibrillation. Biophysical Journal, 88(6), 3806-3821. doi:10.1529/biophysj.105.060459Pandit, S. V., & Jalife, J. (2013). Rotors and the Dynamics of Cardiac Fibrillation. Circulation Research, 112(5), 849-862. doi:10.1161/circresaha.111.300158Patel, N., & Kluger, J. (2018). Ranolazine for Prevention of Atrial Fibrillation after Cardiac Surgery: A Systematic Review. Cureus. doi:10.7759/cureus.2584Peyronnet, R., Nerbonne, J. M., & Kohl, P. (2016). Cardiac Mechano-Gated Ion Channels and Arrhythmias. Circulation Research, 118(2), 311-329. doi:10.1161/circresaha.115.305043Prosser, B. L., Ward, C. W., & Lederer, W. J. (2013). X-ROS signalling is enhanced and graded by cyclic cardiomyocyte stretch. Cardiovascular Research, 98(2), 307-314. doi:10.1093/cvr/cvt066Quinn, T. A., & Kohl, P. (2016). Rabbit models of cardiac mechano-electric and mechano-mechanical coupling. Progress in Biophysics and Molecular Biology, 121(2), 110-122. doi:10.1016/j.pbiomolbio.2016.05.003Ravelli, F., & Allessie, M. (1997). Effects of Atrial Dilatation on Refractory Period and Vulnerability to Atrial Fibrillation in the Isolated Langendorff-Perfused Rabbit Heart. Circulation, 96(5), 1686-1695. doi:10.1161/01.cir.96.5.1686RAVELLI, F., MASÈ, M., DEL GRECO, M., MARINI, M., & DISERTORI, M. (2010). Acute Atrial Dilatation Slows Conduction and Increases AF Vulnerability in the Human Atrium. Journal of Cardiovascular Electrophysiology, 22(4), 394-401. doi:10.1111/j.1540-8167.2010.01939.xSalinet, J., Schlindwein, F. S., Stafford, P., Almeida, T. P., Li, X., Vanheusden, F. J., … Ng, G. A. (2017). Propagation of meandering rotors surrounded by areas of high dominant frequency in persistent atrial fibrillation. Heart Rhythm, 14(9), 1269-1278. doi:10.1016/j.hrthm.2017.04.031Seo, K., Inagaki, M., Hidaka, I., Fukano, H., Sugimachi, M., Hisada, T., … Sugiura, S. (2014). Relevance of cardiomyocyte mechano-electric coupling to stretch-induced arrhythmias: Optical voltage/calcium measurement in mechanically stimulated cells, tissues and organs. Progress in Biophysics and Molecular Biology, 115(2-3), 129-139. doi:10.1016/j.pbiomolbio.2014.07.008Shryock, J. C., Song, Y., Rajamani, S., Antzelevitch, C., & Belardinelli, L. (2013). The arrhythmogenic consequences of increasing late INa in the cardiomyocyte. Cardiovascular Research, 99(4), 600-611. doi:10.1093/cvr/cvt145Song, Y., Shryock, J. C., & Belardinelli, L. (2008). An increase of late sodium current induces delayed afterdepolarizations and sustained triggered activity in atrial myocytes. American Journal of Physiology-Heart and Circulatory Physiology, 294(5), H2031-H2039. doi:10.1152/ajpheart.01357.2007Sossalla, S., Kallmeyer, B., Wagner, S., Mazur, M., Maurer, U., Toischer, K., … Maier, L. S. (2010). Altered Na+Currents in Atrial Fibrillation. Journal of the American College of Cardiology, 55(21), 2330-2342. doi:10.1016/j.jacc.2009.12.055Strege, P., Beyder, A., Bernard, C., Crespo-Diaz, R., Behfar, A., Terzic, A., … Farrugia, G. (2012). Ranolazine inhibits shear sensitivity of endogenous Na+current and spontaneous action potentials in HL-1 cells. Channels, 6(6), 457-462. doi:10.4161/chan.22017Tsai, C.-T., Chiang, F.-T., Tseng, C.-D., Yu, C.-C., Wang, Y.-C., Lai, L.-P., … Lin, J.-L. (2011). Mechanical Stretch of Atrial Myocyte Monolayer Decreases Sarcoplasmic Reticulum Calcium Adenosine Triphosphatase Expression and Increases Susceptibility to Repolarization Alternans. Journal of the American College of Cardiology, 58(20), 2106-2115. doi:10.1016/j.jacc.2011.07.039White, S. M., Constantin, P. E., & Claycomb, W. C. (2004). Cardiac physiology at the cellular level: use of cultured HL-1 cardiomyocytes for studies of cardiac muscle cell structure and function. American Journal of Physiology-Heart and Circulatory Physiology, 286(3), H823-H829. doi:10.1152/ajpheart.00986.200

Phenomenology of Light Sneutrino Dark Matter in cMSSM/mSUGRA with Inverse Seesaw

We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singlet-pair sector to account for the non-zero neutrino masses by inverse seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed at high scale and the singlet neutrino sector at low scale, we find that, contrary to the case of the usual cMSSM where the neutralino DM cannot be very light, we can have a light sneutrino DM with mass below 100 GeV satisfying all the current experimental constraints from cosmology, collider as well as low-energy experiments. We also note that the supersymmetric inverse seesaw mechanism with sneutrino as the lightest supersymmetric partner can have enhanced same-sign dilepton final states with large missing transverse energy (mET) coming from the gluino- and squark-pair as well as the squark-gluino associated productions and their cascade decay through charginos. We present a collider study for the same-sign dilepton+jets+mET signal in this scenario and propose some distinctions with the usual cMSSM. We also comment on the implications of such a light DM scenario on the invisible decay width of an 125 GeV Higgs boson.Comment: 24 pages, 4 figures, 7 tables; matches published versio

Hydrophilic interaction liquid chromatography (HILIC)—a powerful separation technique

Hydrophilic interaction liquid chromatography (HILIC) provides an alternative approach to effectively separate small polar compounds on polar stationary phases. The purpose of this work was to review the options for the characterization of HILIC stationary phases and their applications for separations of polar compounds in complex matrices. The characteristics of the hydrophilic stationary phase may affect and in some cases limit the choices of mobile phase composition, ion strength or buffer pH value available, since mechanisms other than hydrophilic partitioning could potentially occur. Enhancing our understanding of retention behavior in HILIC increases the scope of possible applications of liquid chromatography. One interesting option may also be to use HILIC in orthogonal and/or two-dimensional separations. Bioapplications of HILIC systems are also presented

On Naturalness of the MSSM and NMSSM

With a bottom-up approach, we consider naturalness in the MSSM and NMSSM. Assuming the light stops, the LHC gluino search implies that the degree of fine tuning in both models is less than 2.5%. Taking the LHC hints for the SM-like Higgs boson mass m_h\sim125 GeV seriously, we find that naturalness will favor the NMSSM. We study the Higgs boson mass for several scenarios in the NMSSM: (1) A large \lambda and the doublet-singlet Higgs boson mixing effect pushing upward or pulling downward m_h. The former case can readily give the di-photon excess of the Higgs boson decay whereas the latter case can not. However, we point out that the former case has a new large fine-tuning related to strong \lambda-RGE running effect and vacuum stability. (2) A small \lambda and the mixing effect pushing m_h upward. Naturalness status becomes worse and no significant di-photon excess can be obtained. In these scenarios, the lightest supersymmetric particle (LSP) as a dark matter candidate is strongly disfavored by the XENON100 experiment. Even if the LSP can be a viable dark matter candidate, there does exist fine-tuning. The above naturalness evaluation is based on a high mediation scale for supersymmetry breaking, whereas for a low mediation scale, fine-tuning can be improved by about one order.Comment: JHEP version, adding some comments/references and improving Englis

Hydrophilic interaction liquid chromatography (HILIC) in proteomics

In proteomics, nanoflow multidimensional chromatography is now the gold standard for the separation of complex mixtures of peptides as generated by in-solution digestion of whole-cell lysates. Ideally, the different stationary phases used in multidimensional chromatography should provide orthogonal separation characteristics. For this reason, the combination of strong cation exchange chromatography (SCX) and reversed-phase (RP) chromatography is the most widely used combination for the separation of peptides. Here, we review the potential of hydrophilic interaction liquid chromatography (HILIC) as a separation tool in the multidimensional separation of peptides in proteomics applications. Recent work has revealed that HILIC may provide an excellent alternative to SCX, possessing several advantages in the area of separation power and targeted analysis of protein post-translational modifications

Dark matter interpretations of ATLAS searches for the electroweak production of supersymmetric particles in s√=8 s=8 TeV proton-proton collisions

A selection of searches by the ATLAS experiment at the LHC for the electroweak production of SUSY particles are used to study their impact on the constraints on dark matter candidates. The searches use 20 fb−1 of proton-proton collision data at s √ =8 s=8 TeV. A likelihood-driven scan of a five-dimensional effective model focusing on the gaugino-higgsino and Higgs sector of the phenomenological minimal supersymmetric Standard Model is performed. This scan uses data from direct dark matter detection experiments, the relic dark matter density and precision flavour physics results. Further constraints from the ATLAS Higgs mass measurement and SUSY searches at LEP are also applied. A subset of models selected from this scan are used to assess the impact of the selected ATLAS searches in this five-dimensional parameter space. These ATLAS searches substantially impact those models for which the mass m(χ ~ 0 1 ) m(χ~10) of the lightest neutralino is less than 65 GeV, excluding 86% of such models. The searches have limited impact on models with larger m(χ ~ 0 1 ) m(χ~10) due to either heavy electroweakinos or compressed mass spectra where the mass splittings between the produced particles and the lightest supersymmetric particle is small