1
|
Gao WD. One size does not fit all: Perioperative management of patients with heart failure with preserved ejection fraction. J Clin Anesth 2024; 94:111409. [PMID: 38340679 DOI: 10.1016/j.jclinane.2024.111409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/18/2023] [Accepted: 02/03/2024] [Indexed: 02/12/2024]
Abstract
Heart failure with preserved ejection fraction (HFpEF) is recognized as an important risk factor for perioperative complications. However, anesthesia management of HFpEF patients remains a considerable challenge without clear guidance. HFpEF is heterogeneous in its pathophysiological processes, diverse clinical presentations, adverse remodeling of cardiovascular and other organs, and clinical outcomes. It is difficult to manage the disease with one fixed approach because of this. This review phenotypes HFpEF patients by combining their clinical features and anesthesia care issues. Five phenotypes of HFpEF patients are identified: A, O, P, C, and Y. The clinical features, anesthesia implications, and anesthesia management for each phenotype are highlighted and discussed. Such an approach to HFpEF patients in the operating room could deliver safe, high-quality perioperative care.
Collapse
|
2
|
Lin Q, Kumar S, Kariyawasam U, Yang X, Yang W, Skinner JT, Gao WD, Johns RA. Human Resistin Induces Cardiac Dysfunction in Pulmonary Hypertension. J Am Heart Assoc 2023; 12:e027621. [PMID: 36927008 PMCID: PMC10111547 DOI: 10.1161/jaha.122.027621] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 03/18/2023]
Abstract
Background Cardiac failure is the primary cause of death in most patients with pulmonary arterial hypertension (PH). As pleiotropic cytokines, human resistin (Hresistin) and its rodent homolog, resistin-like molecule α, are mechanistically critical to pulmonary vascular remodeling in PH. However, it is still unclear whether activation of these resistin-like molecules can directly cause PH-associated cardiac dysfunction and remodeling. Methods and Results In this study, we detected Hresistin protein in right ventricular (RV) tissue of patients with PH and elevated resistin-like molecule expression in RV tissues of rodents with RV hypertrophy and failure. In a humanized mouse model, cardiac-specific Hresistin overexpression was sufficient to cause cardiac dysfunction and remodeling. Dilated hearts exhibited reduced force development and decreased intracellular Ca2+ transients. In the RV tissues overexpressing Hresistin, the impaired contractility was associated with the suppression of protein kinase A and AMP-activated protein kinase. Mechanistically, Hresistin activation triggered the inflammation mediated by signaling of the key damage-associated molecular pattern molecule high-mobility group box 1, and subsequently induced pro-proliferative Ki67 in RV tissues of the transgenic mice. Intriguingly, an anti-Hresistin human antibody that we generated protected the myocardium from hypertrophy and failure in the rodent PH models. Conclusions Our data indicate that Hresistin is expressed in heart tissues and plays a role in the development of RV dysfunction and maladaptive remodeling through its immunoregulatory activities. Targeting this signaling to modulate cardiac inflammation may offer a promising strategy to treat PH-associated RV hypertrophy and failure in humans.
Collapse
Affiliation(s)
- Qing Lin
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Santosh Kumar
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Udeshika Kariyawasam
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Xiaomei Yang
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
- Department of AnesthesiologyQilu Hospital, Cheeloo College of Medicine, Shandong UniversityJinanChina
| | - Wei Yang
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
- Department of Cardiovascular MedicineXiangya Hospital, Central South UniversityChangshaChina
| | - John T. Skinner
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Roger A. Johns
- Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| |
Collapse
|
3
|
Suffredini G, Slowey C, Sun J, Gao WD, Choi CDW, Aziz H, Kilic A, Schena S, Lawton J, Hamilton JP, Dodd-O JM. Preoperative Liver Stiffness is Associated With Hospital Length of Stay After Cardiac Surgery. J Cardiothorac Vasc Anesth 2022; 36:4093-4099. [PMID: 35915004 DOI: 10.1053/j.jvca.2022.06.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVES Risk assessment models for cardiac surgery do not account for the degrees of liver dysfunction. Ultrasound shear-wave elastography measures liver stiffness (LSM), a quantitative measurement related to fibrosis, congestion, and inflammation. The authors hypothesized that preoperative liver stiffness would be associated with hospital length of stay after cardiac surgery. DESIGN Prospective observational study. SETTING University hospital, single center. PARTICIPANTS One hundred five adult patients undergoing nonemergent cardiac surgery. INTERVENTIONS Preoperative liver stiffness measured by ultrasound elastography. MEASUREMENTS AND MAIN RESULTS The associations were analyzed using linear mixed models, with adjustments for preoperative variables, duration of cardiopulmonary bypass, and type of surgery. Median liver stiffness was 6.4 kPa (range, 4.1-18.6 kPa). The median length of hospital stay was 6 days (range, 3-18 d). Each unit increase in liver stiffness, treated as a continuous variable, was associated with an increase of 0.32 ± 0.10 days in the hospital (p = 0.002). When treated as a categorical variable (<6 kPa, 6-9.4 kPa, and ≥9.5 kPa), LSM ≥9.5 kPa v LSM <6 kPa was associated strongly with an increase in hospital length of stay of 3.25 ± 0.87 days (p = 0.0003). CONCLUSIONS A preoperative LSM ≥9.5 kPa was associated with a significantly longer postoperative hospital length of stay. This association appeared independent of preoperative comorbidities commonly associated with coronary disease. Preoperative liver stiffness is a novel risk metric that is associated with the postoperative hospital length of stay after cardiac surgery.
Collapse
Affiliation(s)
- Giancarlo Suffredini
- Department of Anesthesiology and Critical Care Medicine, Division of Cardiac Anesthesia Johns Hopkins University School of Medicine, Baltimore, MD.
| | - Charlie Slowey
- Department of Anesthesiology and Critical Care Medicine, Division of Cardiac Anesthesia Johns Hopkins University School of Medicine, Baltimore, MD
| | - Junfeng Sun
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Division of Cardiac Anesthesia Johns Hopkins University School of Medicine, Baltimore, MD
| | - Chun Dan W Choi
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore MD
| | - Hamza Aziz
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore MD
| | - Ahmet Kilic
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore MD
| | - Stefano Schena
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore MD
| | - Jennifer Lawton
- Department of Surgery, Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore MD
| | - James Peter Hamilton
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Jeffrey M Dodd-O
- Department of Anesthesiology and Critical Care Medicine, Division of Cardiac Anesthesia Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
4
|
Mondal S, Faraday N, Gao WD, Singh S, Hebbar S, Hollander KN, Metkus TS, Goeddel LA, Bauer M, Bush B, Cho B, Cha S, Ibekwe SO, Mladinov D, Rolleri NS, Lester L, Steppan J, Sheinberg R, Hensley NB, Kapoor A, Dodd-o JM. Selected Transesophageal Echocardiographic Parameters of Left Ventricular Diastolic Function Predict Length of Stay Following Coronary Artery Bypass Graft-A Prospective Observational Study. J Clin Med 2022; 11:jcm11143980. [PMID: 35887745 PMCID: PMC9319456 DOI: 10.3390/jcm11143980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/02/2022] [Accepted: 07/04/2022] [Indexed: 02/05/2023] Open
Abstract
(1) Importance: Abnormal left ventricular (LV) diastolic function, with or without a diagnosis of heart failure, is a common finding that can be easily diagnosed by intra-operative transesophageal echocardiography (TEE). The association of diastolic function with duration of hospital stay after coronary artery bypass (CAB) is unknown. (2) Objective: To determine if selected TEE parameters of diastolic dysfunction are associated with length of hospital stay after coronary artery bypass surgery (CAB). (3) Design: Prospective observational study. (4) Setting: A single tertiary academic medical center. (5) Participants: Patients with normal systolic function undergoing isolated CAB from September 2017 through June 2018. (6) Exposures: LV function during diastole, as assessed by intra-operative TEE prior to coronary revascularization. (7) Main Outcomes and Measures: The primary outcome was duration of postoperative hospital stay. Secondary intermediate outcomes included common postoperative cardiac, respiratory, and renal complications. (8) Results: The study included 176 participants (mean age 65.2 ± 9.2 years, 73% male); 105 (60.2%) had LV diastolic dysfunction based on selected TEE parameters. Median time to hospital discharge was significantly longer for subjects with selected parameters of diastolic dysfunction (9.1/IQR 6.6−13.5 days) than those with normal LV diastolic function (6.5/IAR 5.3−9.7 days) (p < 0.001). The probability of hospital discharge was 34% lower (HR 0.66/95% CI 0.47−0.93) for subjects with diastolic dysfunction based on selected TEE parameters, independent of potential confounders, including a baseline diagnosis of heart failure. There was a dose−response relation between severity of diastolic dysfunction and probability of discharge. LV diastolic dysfunction based on those selected TEE parameters was also associated with postoperative cardio-respiratory complications; however, these complications did not fully account for the relation between LV diastolic dysfunction and prolonged length of hospital stay. (9) Conclusions and Relevance: In patients with normal systolic function undergoing CAB, diastolic dysfunction based on selected TEE parameters is associated with prolonged duration of postoperative hospital stay. This association cannot be explained by baseline comorbidities or common post-operative complications. The diagnosis of diastolic dysfunction can be made by TEE.
Collapse
Affiliation(s)
- Samhati Mondal
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
- Correspondence: ; Tel.: +1-410-328-1748
| | - Nauder Faraday
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | | | - Sachidanand Hebbar
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Kimberly N. Hollander
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Thomas S. Metkus
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA;
| | - Lee A. Goeddel
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Maria Bauer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Brian Bush
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Brian Cho
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Stephanie Cha
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Stephanie O. Ibekwe
- Department of Anesthesiology, Cardiovascular Division, BTGH, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Domagoj Mladinov
- Department of Anesthesiology and Critical Care Medicine, University of Alabama, Birmingham, AL 35233, USA;
| | - Noah S. Rolleri
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA;
| | - Laeben Lester
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Jochen Steppan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Rosanne Sheinberg
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Nadia B. Hensley
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| | - Anubhav Kapoor
- Department of Anesthesiology, Mercy General Hospital, Sacramento, CA 95819, USA;
| | - Jeffrey M. Dodd-o
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA; (N.F.); (W.D.G.); (S.H.); (L.A.G.); (M.B.); (B.B.); (B.C.); (S.C.); (L.L.); (J.S.); (R.S.); (N.B.H.); (J.M.D.-o.)
| |
Collapse
|
5
|
Lai W, Li S, Du Z, Ma X, Lu J, Gao WD, Abbott GW, Hu Z, Kang Y. Severe Patients With ARDS With COVID-19 Treated With Extracorporeal Membrane Oxygenation in China: A Retrospective Study. Front Med (Lausanne) 2021; 8:699227. [PMID: 34746170 PMCID: PMC8563993 DOI: 10.3389/fmed.2021.699227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/17/2021] [Indexed: 02/05/2023] Open
Abstract
Background: The novel coronavirus disease 2019 (COVID-19) pandemic has become a global health crisis affecting over 200 countries worldwide. Extracorporeal membrane oxygenation (ECMO) has been increasingly used in the management of COVID-19-associated end-stage respiratory failure. However, the exact effect of ECMO in the management of these patients, especially with regards to complications and mortality, is unclear. Methods: This is the largest retrospective study of ECMO treated COVID-19 patients in China. A total of 50 ECMO-treated COVID-19 patients were recruited. We describe the main characteristics, the clinical features, ventilator parameters, ECMO-related variables and management details, and complications and outcomes of COVID-19 patients with severe acute respiratory distress syndrome (ARDS) that required ECMO support. Results: For those patients with ECMO support, 21 patients survived and 29 died (mortality rate: 58.0%). Among those who survived, PaO2 (66.3 mmHg [59.5–74.0 mmHg] and PaO2/FiO2 (68.0 mmHg [61.0–76.0 mmHg]) were higher in the survivors than those of non-survivors (PaO2: 56.8 mmHg (49.0–65.0 mmHg), PaO2/FiO2 (58.2 mmHg (49.0–68.0 mmHg), all P < 0.01) prior to ECMO. Patients who achieved negative fluid balance in the early resuscitation phase (within 3 days) had a higher survival rate than those who did not (P = 0.0003). Conclusions: In this study of 50 cases of ECMO-treated COVID-19 patients, a low PO2/FIO2 ratio before ECMO commencement may indicate a poor prognosis. Negative fluid balance in the early resuscitation phase during ECMO treatment was a predictor of increased survival post-ECMO treatment.
Collapse
Affiliation(s)
- Wei Lai
- Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Shuanglei Li
- Division of Adult Cardiac Surgery, Department of Cardiology, The Sixth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Zhongtao Du
- Center for Cardiac Intensive Care, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xinhua Ma
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Junyu Lu
- Intensive Care Unit, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Zhaoyang Hu
- Laboratory of Anesthesiology & Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yan Kang
- Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
6
|
Gao WD, Nuuttila OP, Fang HB, Chen Q, Chen X. A New Fitness Test of Estimating VO 2max in Well-Trained Rowing Athletes. Front Physiol 2021; 12:701541. [PMID: 34276423 PMCID: PMC8283806 DOI: 10.3389/fphys.2021.701541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/10/2021] [Indexed: 11/22/2022] Open
Abstract
Background This study was designed to investigate the validity of maximal oxygen consumption (VO2max) estimation through the Firstbeat fitness test (FFT) method when using submaximal rowing and running programs for well-trained athletes. Methods Well-trained flatwater rowers (n = 45, 19.8 ± 3.0 years, 184 ± 8.7 cm, 76 ± 12.9 kg, and 58.7 ± 6.0 mL⋅kg–1⋅min–1) and paddlers (n = 45, 19.0 ± 2.5 years, 180 ± 7.7 cm, 74 ± 9.4 kg, and 59.9 ± 4.8 mL⋅kg–1⋅min–1) completed the FFT and maximal graded exercise test (GXT) programs of rowing and running, respectively. The estimated VO2max was calculated using the FFT system, and the measured VO2max was obtained from the GXT programs. Differences between the estimated and measured VO2max values were analyzed to assess the accuracy and agreement of the predictions. Equations from the previous study were also used to predict the VO2max in the submaximal programs to compare the accuracy of prediction with the FFT method. Results The FFT method was in good agreement with the measured VO2max in both groups based on the intraclass correlation coefficients (>0.8). Additionally, the FFT method had considerable accuracy in VO2max estimation as the mean absolute percentage error (≤5.0%) and mean absolute error (<3.0 mL⋅kg–1⋅min–1) were fairly low. Furthermore, the FFT method seemed more accurate in the estimation of VO2max than previously reported equations, especially in the rowing test program. Conclusion This study revealed that the FFT method provides a considerably accurate estimation of VO2max in well-trained athletes.
Collapse
Affiliation(s)
- Wei Dong Gao
- Zhejiang Institute of Sports Science, Hangzhou, China.,School of Sports Science, Wenzhou Medical University, Wenzhou, China
| | - Olli-Pekka Nuuttila
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Hai Bo Fang
- Zhejiang Institute of Sports Science, Hangzhou, China
| | - Qian Chen
- Zhejiang Institute of Sports Science, Hangzhou, China
| | - Xi Chen
- School of Sports Science, Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
7
|
Abstract
Right ventricular diastolic dysfunction and failure (RVDDF) has been increasingly identified in patients with cardiovascular diseases, including heart failure and other diseases with cardiac involvement. It is unknown whether RVDDF exists as a distinct clinical entity; however, its presence and degree have been shown to be a sensitive marker of end-organ dysfunction related to multiple disease processes including systemic hypertension, pulmonary hypertension, heart failure, and endocrine disease. In this manuscript, we review issues pertaining to RVDDF including anatomic features of the right ventricle, physiologic measurements, RVDDF diagnosis, underlying mechanisms, clinical impact, and clinical management. Several unique features of RVDDF are also discussed.
Collapse
Affiliation(s)
- Youn-Hoa Jung
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China
| | - Giancarlo Suffredini
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Jeffery M Dodd-O
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA.
| |
Collapse
|
8
|
Tao B, Kumar S, Gomez-Arroyo J, Fan C, Zhang A, Skinner J, Hunter E, Yamaji-Kegan K, Samad I, Hillel AT, Lin Q, Zhai W, Gao WD, Johns RA. Resistin-Like Molecule α Dysregulates Cardiac Bioenergetics in Neonatal Rat Cardiomyocytes. Front Cardiovasc Med 2021; 8:574708. [PMID: 33981729 PMCID: PMC8107692 DOI: 10.3389/fcvm.2021.574708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 03/30/2021] [Indexed: 11/13/2022] Open
Abstract
Heart (right) failure is the most frequent cause of death in patients with pulmonary arterial hypertension. Although historically, increased right ventricular afterload has been considered the main contributor to right heart failure in such patients, recent evidence has suggested a potential role of load-independent factors. Here, we tested the hypothesis that resistin-like molecule α (RELMα), which has been implicated in the pathogenesis of vascular remodeling in pulmonary artery hypertension, also contributes to cardiac metabolic remodeling, leading to heart failure. Recombinant RELMα (rRELMα) was generated via a Tet-On expression system in the T-REx 293 cell line. Cultured neonatal rat cardiomyocytes were treated with purified rRELMα for 24 h at a dose of 50 nM. Treated cardiomyocytes exhibited decreased mRNA and protein expression of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) and transcription factors PPARα and ERRα, which regulate mitochondrial fatty acid metabolism, whereas genes that encode for glycolysis-related proteins were significantly upregulated. Cardiomyocytes treated with rRELMα also exhibited a decreased basal respiration, maximal respiration, spare respiratory capacity, ATP-linked OCR, and increased glycolysis, as assessed with a microplate-based cellular respirometry apparatus. Transmission electron microscopy revealed abnormal mitochondrial ultrastructure in cardiomyocytes treated with rRELMα. Our data indicate that RELMα affects cardiac energy metabolism and mitochondrial structure, biogenesis, and function by downregulating the expression of the PGC-1α/PPARα/ERRα axis.
Collapse
Affiliation(s)
- Bingdong Tao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
- Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Santosh Kumar
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Jose Gomez-Arroyo
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Chunling Fan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Ailan Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - John Skinner
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Elizabeth Hunter
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Kazuyo Yamaji-Kegan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
- Department of Anesthesiology, Maryland University, School of Medicine, Baltimore, MD, United States
| | - Idris Samad
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Alexander T. Hillel
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Qing Lin
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Wenqian Zhai
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
- Department of Anesthesiology, Tianjin Chest Hospital, Tianjin, China
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Roger A. Johns
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| |
Collapse
|
9
|
Drzymalski DM, Guo JC, Qi XQ, Tsen LC, Sun Y, Ouanes JPP, Xia Y, Gao WD, Ruthazer R, Hu F, Hu LQ. The Effect of the No Pain Labor & Delivery-Global Health Initiative on Cesarean Delivery and Neonatal Outcomes in China: An Interrupted Time-Series Analysis. Anesth Analg 2021; 132:698-706. [PMID: 32332290 DOI: 10.1213/ane.0000000000004805] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The proportion of live births by cesarean delivery (CD) in China is significant, with some, particularly rural, provinces reporting up to 62.5%. The No Pain Labor & Delivery-Global Health Initiative (NPLD-GHI) was established to improve obstetric and neonatal outcomes in China, including through a reduction of CD through educational efforts. The purpose of this study was to determine whether a reduction in CD at a rural Chinese hospital occurred after NPLD-GHI. We hypothesized that a reduction in CD trend would be observed. METHODS The NPLD-GHI program visited the Weixian Renmin Hospital, Hebei Province, China, from June 15 to 21, 2014. The educational intervention included problem-based learning, bedside teaching, simulation drill training, and multidisciplinary debriefings. An interrupted time-series analysis using segmented logistic regression models was performed on data collected between June 1, 2013 and May 31, 2015 to assess whether the level and/or trend over time in the proportion of CD births would decline after the program intervention. The primary outcome was monthly proportion of CD births. Secondary outcomes included neonatal intensive care unit (NICU) admissions and extended NICU length of stay, neonatal antibiotic and intubation use, and labor epidural analgesia use. RESULTS Following NPLD-GHI, there was a level decrease in CD with an estimated odds ratio (95% confidence interval [CI]) of 0.87 (0.78-0.98), P = .017, with odds (95% CI) of monthly CD reduction an estimated 3% (1-5; P < .001), more in the post- versus preintervention periods. For labor epidural analgesia, there was a level increase (estimated odds ratio [95% CI] of 1.76 [1.48-2.09]; P < .001) and a slope decrease (estimated odds ratio [95% CI] of 0.94 [0.92-0.97]; P < .001). NICU admissions did not have a level change (estimated odds ratio [95% CI] of 0.99 [0.87-1.12]; P = .835), but the odds (95% CI) of monthly reduction in NICU admission was estimated 9% (7-11; P < .001), greater in post- versus preintervention. Neonatal intubation level and slope changes were not statistically significant. For neonatal antibiotic administration, while the level change was not statistically significant, there was a decrease in the slope with an odds (95% CI) of monthly reduction estimated 6% (3-9; P < .001), greater post- versus preintervention. CONCLUSIONS In a large, rural Chinese hospital, live births by CD were lower following NPLD-GHI and associated with increased use of labor epidural analgesia. We also found decreasing NICU admissions. International-based educational programs can significantly alter practices associated with maternal and neonatal outcomes.
Collapse
Affiliation(s)
- Dan M Drzymalski
- From the Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | | | - Xue-Qin Qi
- Anesthesiology, Weixian Renmin Hospital, Weixian, Hebei Province, People's Republic of China
| | - Lawrence C Tsen
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yingyong Sun
- Weixian Renmin Hospital, Weixian, Hebei Province, People's Republic of China
| | - Jean-Pierre P Ouanes
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Bayview Medical Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yun Xia
- Department of Anesthesiology, Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Wei Dong Gao
- Department of Anesthesiology, Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Robin Ruthazer
- Biostatistics, Epidemiology, and Research Design Center at the Tufts Clinical and Translational Research Institute, Tufts Medical Center, Boston, Massachusetts
| | - Fengling Hu
- The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ling-Qun Hu
- Department of Anesthesiology, Wexner Medical Center at The Ohio State University, Columbus, Ohio
| |
Collapse
|
10
|
Huang Y, Lu H, Ren X, Li F, Bu W, Liu W, Dailey WP, Saeki H, Gabrielson K, Abraham R, Eckenhoff R, Gao WD. Fropofol prevents disease progression in mice with hypertrophic cardiomyopathy. Cardiovasc Res 2021; 116:1175-1185. [PMID: 31424496 DOI: 10.1093/cvr/cvz218] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/12/2019] [Accepted: 08/15/2019] [Indexed: 01/12/2023] Open
Abstract
AIMS Increased myofilament contractility is recognized as a crucial factor in the pathogenesis of hypertrophic cardiomyopathy (HCM). Direct myofilament desensitization might be beneficial in preventing HCM disease progression. Here, we tested whether the small molecule fropofol prevents HCM phenotype expression and disease progression by directly depressing myofilament force development. METHODS AND RESULTS Force, intracellular Ca2+, and steady-state activation were determined in isolated trabecular muscles from wild-type (WT) and transgenic HCM mice with heterozygous human α-myosin heavy chain R403Q mutation (αMHC 403/+). αMHC 403/+ HCM mice were treated continuously with fropofol by intraperitoneal infusion for 12 weeks. Heart tissue was analysed with histology and real-time PCR of prohypertrophic and profibrotic genes. Fropofol decreased force in a concentration-dependent manner without significantly altering [Ca2+]i in isolated muscles from both WT and αMHC 403/+ HCM mouse hearts. Fropofol also depressed maximal Ca2+-activated force and increased the [Ca2+]i required for 50% activation during steady-state activation. In whole-animal studies, chronic intra-abdominal administration of fropofol prevented hypertrophy development and diastolic dysfunction. Chronic fropofol treatment also led to attenuation of prohypertrophic and profibrotic gene expression, reductions in cell size, and decreases in tissue fibrosis. CONCLUSIONS Direct inhibition of myofilament contraction by fropofol prevents HCM disease phenotypic expression and progression, suggesting that increased myofilament contractile force is the primary trigger for hypertrophy development and HCM disease progression.
Collapse
Affiliation(s)
- Yiyuan Huang
- Department of Cardiology, 2nd Xiangya Hospital Central South University, 139 Renmin Middle Road, Changsha, Hunan 410011, China
| | - Haisong Lu
- Department of Anesthesiology, Peking Union Hospital, Peking Union Medical College and Chinese Academy of Medical Science, 1 Shuaifuyuan, Wangfujin, Dongcheng District, Beijing 100730, China
| | - Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, 2 Yinghuanyuan East Street, Chaoying District, Beijing 100029, China
| | - Fazhao Li
- Department of General Surgery, 2nd Xiangya Hospital, 139 Renmin Middle Road, Central South University, Changsha, Hunan 410011, China
| | - Weiming Bu
- Department of Anesthesiology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Wenjie Liu
- Department of Anesthesiology, South China University School of Medicine, 69 Chuanshan Road, Shigu District, Hengyang, Hunan 421001, China
| | - William P Dailey
- Department of Chemistry, University of Pennsylvania School of Arts and Sciences, 231 S. 34 Street, Philadelphia, PA 19104, USA
| | - Harumi Saeki
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, 733 N. Broadway, MRB 807, Baltimore, MD 21205, USA
| | - Kathleen Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, 733 N. Broadway, MRB 807, Baltimore, MD 21205, USA
| | - Roselle Abraham
- Division of Cardiology, Department of Medicine, University of California San Francisco, 555 Mission Bay Blvd South, Smith Cardiovascular Research Building, 452K, San Francisco, CA 94158, USA
| | - Roderic Eckenhoff
- Department of Anesthesiology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 1800 Orleans Street, Zayed Tower 6208, Baltimore, MD 21287, USA
| |
Collapse
|
11
|
Liu X, Chen H, Yan Z, Du L, Huang D, Gao WD, Hu Z. Remote liver ischemic preconditioning attenuates myocardial ischemia/reperfusion injury in streptozotocin-induced diabetic rats. Sci Rep 2021; 11:1903. [PMID: 33479330 PMCID: PMC7820418 DOI: 10.1038/s41598-021-81422-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 01/06/2021] [Indexed: 02/08/2023] Open
Abstract
Diabetes mellitus (DM) exhibits a higher sensitivity to myocardial ischemia/reperfusion (I/R) injury and may compromise the effectiveness of cardioprotective interventions, including ischemic preconditioning. We previously found that liver ischemic preconditioning (RLIPC) could limit infarct size post I/R in non-diabetic rat hearts and further exerted anti-arrhythmic effects in diabetic or non-diabetic rats after myocardial I/R, however, little is known regarding the effect of RLIPC on infarct-sparing in diabetic hearts. In this study, we evaluated the protective effects of RLIPC on I/R injury in streptozotocin-induced type 1 diabetic rats. Type 1 diabetes mellitus was induced by one-time intraperitoneal injection of streptozotocin in Sprague-Dawley rats. Rats were exposed to 45 min of left anterior descend in (LAD) coronary artery occlusion, followed by 3 h of reperfusion. For liver ischemic preconditioning, four cycles of 5 min of liver I/R stimuli were performed before LAD occlusion. The cardioprotective effect of RLIPC was determined in diabetic rats. Compared to non-RLIPC treated DM rats, RLIPC treatment significantly reduced infarct size and cardiac tissue damage, inhibited apoptosis in diabetic hearts post I/R. RLIPC also improved cardiac functions including LVESP, LVEDP, dp/dtmax, and - dp/dtmax. In addition, RLIPC preserved cardiac morphology by reducing the pathological score post I/R in diabetic hearts. Finally, Westernblotting showed that RLIPC stimulated phosphorylation of ventricular GSK-3β and STAT-5, which are key components of RISK and SAFE signaling pathways. Our study showed that liver ischemic preconditioning retains strong cardioprotective properties in diabetic hearts against myocardial I/R injury via GSK-3β/STAT5 signaling pathway.
Collapse
Affiliation(s)
- Xinhao Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hui Chen
- Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhibing Yan
- Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lei Du
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Dou Huang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Zhaoyang Hu
- Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| |
Collapse
|
12
|
Poll BG, Xu J, Jun S, Sanchez J, Zaidman NA, He X, Lester L, Berkowitz DE, Paolocci N, Gao WD, Pluznick JL. Acetate, a Short-Chain Fatty Acid, Acutely Lowers Heart Rate and Cardiac Contractility Along with Blood Pressure. J Pharmacol Exp Ther 2021; 377:39-50. [PMID: 33414131 DOI: 10.1124/jpet.120.000187] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 01/04/2021] [Indexed: 12/14/2022] Open
Abstract
Short-chain fatty acids (SCFAs) are metabolites produced almost exclusively by the gut microbiota and are an essential mechanism by which gut microbes influence host physiology. Given that SCFAs induce vasodilation, we hypothesized that they might have additional cardiovascular effects. In this study, novel mechanisms of SCFA action were uncovered by examining the acute effects of SCFAs on cardiovascular physiology in vivo and ex vivo. Acute delivery of SCFAs in conscious radiotelemetry-implanted mice results in a simultaneous decrease in both mean arterial pressure and heart rate (HR). Inhibition of sympathetic tone by the selective β-1 adrenergic receptor antagonist atenolol blocks the acute drop in HR seen with acetate administration, yet the decrease in mean arterial pressure persists. Treatment with tyramine, an indirect sympathomimetic, also blocks the acetate-induced acute drop in HR. Langendorff preparations show that acetate lowers HR only after long-term exposure and at a smaller magnitude than seen in vivo. Pressure-volume loops after acetate injection show a decrease in load-independent measures of cardiac contractility. Isolated trabecular muscle preparations also show a reduction in force generation upon SCFA treatment, though only at supraphysiological concentrations. These experiments demonstrate a direct cardiac component of the SCFA cardiovascular response. These data show that acetate affects blood pressure and cardiac function through parallel mechanisms and establish a role for SCFAs in modulating sympathetic tone and cardiac contractility, further advancing our understanding of the role of SCFAs in blood pressure regulation. SIGNIFICANCE STATEMENT: Acetate, a short-chain fatty acid, acutely lowers heart rate (HR) as well as mean arterial pressure in vivo in radiotelemetry-implanted mice. Acetate is acting in a sympatholytic manner on HR and exerts negative inotropic effects in vivo. This work has implications for potential short-chain fatty acid therapeutics as well as gut dysbiosis-related disease states.
Collapse
Affiliation(s)
- Brian G Poll
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Jiaojiao Xu
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Seungho Jun
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Jason Sanchez
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Nathan A Zaidman
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Xiaojun He
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Laeben Lester
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Dan E Berkowitz
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Nazareno Paolocci
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Wei Dong Gao
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Jennifer L Pluznick
- Department of Physiology (B.G.P., J.X., J.S., N.Z., J.L.P.), Division of Cardiology (S.J., N.P.), Department of Anesthesiology and Critical Care Medicine (X.H., L.L., W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Anesthesiology and Perioperative Medicine, The University of Alabama at Birmingham (D.B.); and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| |
Collapse
|
13
|
Meng T, Ren X, Chen X, Yu J, Agrimi J, Paolocci N, Gao WD. Anesthetic Agents Isoflurane and Propofol Decrease Maximal Ca 2+-Activated Force and Thus Contractility in the Failing Myocardium. J Pharmacol Exp Ther 2019; 371:615-623. [PMID: 31515443 DOI: 10.1124/jpet.119.259556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 09/11/2019] [Indexed: 01/16/2023] Open
Abstract
In the normal heart, frequently used anesthetics such as isoflurane and propofol can reduce inotropy. However, the impact of these agents on the failing myocardium is unclear. Here, we examined whether and how isoflurane and propofol influence cardiac contractility in intact cardiac muscles from rats treated with monocrotaline to induce heart failure. We measured force and intracellular Ca2+ ([Ca2 +]i) in trabeculae from the right ventricles of the rats in the absence or presence of propofol or isoflurane. At low to moderate concentrations, both propofol and isoflurane dose-dependently depressed cardiac force generation in failing trabeculae without altering [Ca2+]i At high doses, propofol (but not isoflurane) also decreased amplitude of [Ca2+]i transients. During steady-state activation, both propofol and isoflurane impaired maximal Ca2+-activated force (Fmax) while increasing the amount of [Ca2+]i required for 50% of maximal activation (Ca50). These events occurred without apparent change in the Hill coefficient, suggesting no impairment of cooperativity. Exposing these same muscles to the anesthetics after fiber skinning resulted in a similar decrement in Fmax and rise in Ca50 but no change in the myofibrillar ATPase-Ca2+ relationship. Thus, our study demonstrates that challenging the failing myocardium with commonly used anesthetic agents such as propofol and isoflurane leads to reduced force development as a result of lowered myofilament responsiveness to Ca2+ SIGNIFICANCE STATEMENT: Commonly used anesthetics such as isoflurane and propofol can impair myocardial contractility in subjects with heart failure by lowering myofilament responsiveness to Ca2+. High doses of propofol can also reduce the overall amplitude of the intracellular Ca2+ transient. These findings may have important implications for the safety and quality of intra- and perioperative care of patients with heart failure and other cardiac disorders.
Collapse
Affiliation(s)
- Tao Meng
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Xianfeng Ren
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Xinzhong Chen
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Jingui Yu
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Jacopo Agrimi
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Nazareno Paolocci
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| | - Wei Dong Gao
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shangdong, China (T.M., J.Y.); Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China (X.R.); Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China (X.C.); Division of Cardiology (J.A., N.P.) and Department of Anesthesiology and Critical Care Medicine (W.D.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and Department of Biomedical Sciences, University of Padova, Padova, Italy (N.P.)
| |
Collapse
|
14
|
Gao WD, Xu YB, Li SS, Fu YJ, Zheng DY, She YJ. Obstructive sleep apnea syndrome detection based on ballistocardiogram via machine learning approach. Math Biosci Eng 2019; 16:5672-5686. [PMID: 31499731 DOI: 10.3934/mbe.2019282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Obstructive sleep apnea (OSA) is a common sleep-related respiratory disease that affects people's health, especially in the elderly. In the traditional PSG-based OSA detection, people's sleep may be disturbed, meanwhile the electrode slices are easily to fall off. In this paper, we study a sleep apnea detection method based on non-contact mattress, which can detect OSA accurately without disturbing sleep. Piezoelectric ceramics sensors are used to capture pressure changes in the chest and abdomen of the human body. Then heart rate and respiratory rate are extracted from impulse waveforms and respiratory waveforms that converted by filtering and processing of the pressure signals. Finally, the Heart Rate Variability (HRV) is obtained by processing the obtained heartbeat signals. The features of the heartbeat interval signal and the respiratory signal are extracted over a fixed length of time, wherein a classification model is used to predict whether sleep apnea will occur during this time interval. Model fusion technology is adopted to improve the detection accuracy of sleep apnea. Results show that the proposed algorithm can be used as an effective method to detect OSA.
Collapse
Affiliation(s)
- Wei Dong Gao
- School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, No.10 Xitucheng Road, Haidian District, Beijing 100876, China
| | - Yi Bin Xu
- School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, No.10 Xitucheng Road, Haidian District, Beijing 100876, China
| | | | - Yu Jun Fu
- Hainan Hospital of PLA General Hospital, China
| | | | | |
Collapse
|
15
|
Abstract
Right ventricular (RV) failure (RVF) has garnered significant attention in recent years because of its negative impact on clinical outcomes in patients with pulmonary hypertension (PH). PH triggers a series of events, including activation of several signaling pathways that regulate cell growth, metabolism, extracellular matrix remodeling, and energy production. These processes render the RV adaptive to PH. However, RVF develops when PH persists, accompanied by RV ischemia, alterations in substrate and mitochondrial energy metabolism, increased free oxygen radicals, increased cell loss, downregulation of adrenergic receptors, increased inflammation and fibrosis, and pathologic microRNAs. Diastolic dysfunction is also an integral part of RVF. Emerging non-invasive technologies such as molecular or metallic imaging, cardiac MRI, and ultrafast Doppler coronary flow mapping will be valuable tools to monitor RVF, especially the transition to RVF. Most PH therapies cannot treat RVF once it has occurred. A variety of therapies are available to treat acute and chronic RVF, but they are mainly supportive, and no effective therapy directly targets the failing RV. Therapies that target cell growth, cellular metabolism, oxidative stress, and myocyte regeneration are being tested preclinically. Future research should include establishing novel RVF models based on existing models, increasing use of human samples, creating human stem cell-based in vitro models, and characterizing alterations in cardiac excitation–contraction coupling during transition from adaptive RV to RVF. More successful strategies to manage RVF will likely be developed as we learn more about the transition from adaptive remodeling to maladaptive RVF in the future.
Collapse
Affiliation(s)
- Xianfeng Ren
- Department of Anesthesiology,
China-Japan
Friendship Hospital, Beijing, China
| | - Roger A. Johns
- Department of Anesthesiology and
Critical Care Medicine,
Johns
Hopkins University School of Medicine,
Baltimore, MD, USA
| | - Wei Dong Gao
- Department of Anesthesiology and
Critical Care Medicine,
Johns
Hopkins University School of Medicine,
Baltimore, MD, USA
| |
Collapse
|
16
|
Abstract
Supranormal contractile properties are frequently associated with cardiac diseases. Anesthetic agents, including propofol, can depress myocardial contraction. We tested the hypothesis that fropofol, a propofol derivative, reduces force development in cardiac muscles via inhibition of cross-bridge cycling and may therefore have therapeutic potential. Force and intracellular Ca2+ concentration ([Ca2+]i) transients of rat trabecular muscles were determined. Myofilament ATPase, actin-activated myosin ATPase, and velocity of actin filaments propelled by myosin were also measured. Fropofol dose dependently decreased force without altering [Ca2+]i in normal and pressure-induced hypertrophied-hypercontractile muscles. Similarly, fropofol depressed maximum Ca2+-activated force ( Fmax) and increased the [Ca2+]i required for 50% of Fmax (Ca50) at steady state without affecting the Hill coefficient in both intact and skinned cardiac fibers. The drug also depressed cardiac myofibrillar and actin-activated myosin ATPase activity. In vitro actin sliding velocity was significantly reduced when fropofol was introduced during rigor binding of cross-bridges. The data suggest that the depressing effects of fropofol on cardiac contractility are likely to be related to direct targeting of actomyosin interactions. From a clinical standpoint, these findings are particularly significant, given that fropofol is a nonanesthetic small molecule that decreases myocardial contractility specifically and thus may be useful in the treatment of hypercontractile cardiac disorders.-Ren, X., Schmidt, W., Huang, Y., Lu, H., Liu, W., Bu, W., Eckenhoff, R., Cammarato, A., Gao, W. D. Fropofol decreases force development in cardiac muscle.
Collapse
Affiliation(s)
- Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China
| | - William Schmidt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yiyuan Huang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Haisong Lu
- Department of Anesthesiology, Fuwai Hospital, Beijing, China
| | - Wenjie Liu
- Department of Anesthesiology, South China University School of Medicine, China
| | - Weiming Bu
- Department of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Roderic Eckenhoff
- Department of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
17
|
Ren X, Hensley N, Brady MB, Gao WD. The Genetic and Molecular Bases for Hypertrophic Cardiomyopathy: The Role for Calcium Sensitization. J Cardiothorac Vasc Anesth 2017; 32:478-487. [PMID: 29203298 DOI: 10.1053/j.jvca.2017.05.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 11/11/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) affects millions of people around the world as one of the most common genetic heart disorders and leads to cardiac ischemia, heart failure, dysfunction of other organ systems, and increased risk for sudden unexpected cardiac deaths. HCM can be caused by single-point mutations, insertion or deletion mutations, or truncation of cardiac myofilament proteins. The molecular mechanism that leads to disease progression and presentation is still poorly understood, despite decades of investigations. However, recent research has made dramatic advances in the understanding of HCM disease development. Studies have shown that increased calcium sensitivity is a universal feature in HCM. At the molecular level, increased crossbridge force (or power) generation resulting in hypercontractility is the prominent feature. Thus, calcium sensitization/hypercontractility is emerging as the primary stimulus for HCM disease development and phenotypic expression. Cross-bridge inhibition has been shown to halt HCM presentation, and myofilament desensitization appears to reduce lethal arrhythmias in animal models of HCM. These advances in basic research will continue to deepen the knowledge of HCM pathogenesis and are beginning to revolutionize the management of HCM.
Collapse
Affiliation(s)
- Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China
| | - Nadia Hensley
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mary Beth Brady
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
| |
Collapse
|
18
|
Li Z, Singh S, Suryavanshi SV, Ding W, Shen X, Wijaya CS, Gao WD, McConnell BK. Force development and intracellular Ca 2+ in intact cardiac muscles from gravin mutant mice. Eur J Pharmacol 2017; 807:117-126. [PMID: 28428008 DOI: 10.1016/j.ejphar.2017.04.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 02/08/2023]
Abstract
Gravin (AKAP12) is an A-kinase-anchoring-protein that scaffolds protein kinase A (PKA), β2-adrenergic receptor (β2-AR), protein phosphatase 2B and protein kinase C. Gravin facilitates β2-AR-dependent signal transduction through PKA to modulate cardiac excitation-contraction coupling and its removal positively affects cardiac contraction. Trabeculae from the right ventricles of gravin mutant (gravin-t/t) mice were employed for force determination. Simultaneously, corresponding intracellular Ca2+ transient ([Ca2+]i) were measured. Twitch force (Tf)-interval relationship, [Ca2+]i-interval relationship, and the rate of decay of post-extrasysolic potentiation (Rf) were also obtained. Western blot analysis were performed to correlate sarcomeric protein expression with alterations in calcium cycling between the WT and gravin-t/t hearts. Gravin-t/t muscles had similar developed force compared to WT muscles despite having lower [Ca2+]i at any given external Ca2+ concentration ([Ca2+]o). The time to peak force and peak [Ca2+]i were slower and the time to 75% relaxation was significantly prolonged in gravin-t/t muscles. Both Tf-interval and [Ca2+]i-interval relations were depressed in gravin-t/t muscles. Rf, however, did not change. Furthermore, Western blot analysis revealed decreased ryanodine receptor (RyR2) phosphorylation in gravin-t/t hearts. Gravin-t/t cardiac muscle exhibits increased force development in responsiveness to Ca2+. The Ca2+ cycling across the SR appears to be unaltered in gravin-t/t muscle. Our study suggests that gravin is an important component of cardiac contraction regulation via increasing myofilament sensitivity to calcium. Further elucidation of the mechanism can provide insights to role of gravin if any in the pathophysiology of impaired contractility.
Collapse
Affiliation(s)
- Zhitao Li
- Department of Pathophysiology, Harbin Medical University, Heilongjiang, China
| | - Sonal Singh
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Santosh V Suryavanshi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center, Houston, TX, USA
| | - Wengang Ding
- Department of Anesthesiology of 2nd Affiliated Hospital, Harbin Medical University, Heilongjiang, China
| | - Xiaoxu Shen
- Cardiology Department, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Cori S Wijaya
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center, Houston, TX, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 1800 Orleans Street, Zaye Tower 6208, Baltimore, MD 21287, USA.
| | - Bradley K McConnell
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center, Houston, TX, USA.
| |
Collapse
|
19
|
Yang S, Abbott GW, Gao WD, Liu J, Luo C, Hu Z. Involvement of glycogen synthase kinase-3β in liver ischemic conditioning induced cardioprotection against myocardial ischemia and reperfusion injury in rats. J Appl Physiol (1985) 2017; 122:1095-1105. [PMID: 28153944 PMCID: PMC5451530 DOI: 10.1152/japplphysiol.00862.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/23/2017] [Accepted: 01/27/2017] [Indexed: 02/05/2023] Open
Abstract
Remote ischemic conditioning has been convincingly shown to render the myocardium resistant to a subsequent more severe sustained episode of ischemia. Compared with other organs, little is known regarding the effect of transient liver ischemic conditioning. We proposed the existence of cardioprotection induced by remote liver conditioning. Male Sprague-Dawley rats were divided into sham-operated control (no further hepatic intervention) and remote liver ischemic conditioning groups. For liver ischemic conditioning, three cycles of 5 min of liver ischemia-reperfusion stimuli were conducted before-(liver preconditioning), post-myocardial ischemia (liver postconditioning), or in combination of both (liver preconditioning + liver postconditioning). Rats were exposed to 45 min of left anterior descending coronary artery occlusion, followed by 3 h of reperfusion thereafter. ECG and hemodynamics were measured throughout the experiment. The coronary artery was reoccluded at the end of reperfusion for infarct size determination. Blood samples were taken for serum lactate dehydrogenase and creatine kinase-MB test. Heart tissues were taken for apoptosis measurements and Western blotting. Our data demonstrate that liver ischemic preconditioning, postconditioning, or a combination of both, offered strong cardioprotection, as evidenced by reduction in infarct size and cardiac tissue damage, recovery of cardiac function, and inhibition of apoptosis after ischemia-reperfusion. Moreover, liver ischemic conditioning increased cardiac (not hepatic) glycogen synthase kinase-3β (GSK-3β) phosphorylation. Accordingly, inhibition of GSK-3β mimicked the cardioprotective action of liver conditioning. These results demonstrate that remote liver ischemic conditioning protected the heart against ischemia and reperfusion injury via GSK-3β-dependent cell-survival signaling pathway.NEW & NOTEWORTHY Remote ischemic conditioning protects hearts against ischemia and reperfusion (I/R) injury. However, it is unclear whether ischemic conditioning of visceral organs such as the liver, the largest metabolic organ in the body, can produce cardioprotection. This is the first study to show the cardioprotective effect of remote liver ischemic conditioning in a rat model of myocardial I/R injury. We also, for the first time, demonstrated these protective properties are associated with glycogen synthase kinase-3β-dependent cell-survival signaling pathway.
Collapse
Affiliation(s)
- Shuai Yang
- Laboratory of Anesthesiology & Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Pharmacology, and Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, California
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Jin Liu
- Laboratory of Anesthesiology & Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Chaozhi Luo
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhaoyang Hu
- Laboratory of Anesthesiology & Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China;
| |
Collapse
|
20
|
Meng T, Bu W, Ren X, Chen X, Yu J, Eckenhoff RG, Gao WD. Molecular mechanism of anesthetic-induced depression of myocardial contraction. FASEB J 2016; 30:2915-25. [PMID: 27170289 DOI: 10.1096/fj.201600290rr] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/26/2016] [Indexed: 01/22/2023]
Abstract
Isoflurane and propofol are known to depress cardiac contraction, but the molecular mechanisms involved are not known. In this study, we determined whether decreasing myofilament Ca(2+) responsiveness underlies anesthesia-induced depression of contraction and uncovered the molecular targets of isoflurane and propofol. Force and intracellular Ca(2+) ([Ca(2+)]i) were measured in rat trabeculae superfused with Krebs-Henseleit solution, with or without propofol or isoflurane. Photoaffinity labeling of myofilament proteins with meta-Azi-propofol (AziPm) and Azi-isoflurane (Azi-iso) and molecular docking were also used. Both propofol and isoflurane dose dependently depressed force from low doses (propofol, 27 ± 6 μM; isoflurane, 1.0 ± 0.1%) to moderate doses (propofol, 87 ± 4 μM; isoflurane, 3.0 ± 0.25%), without significant alteration [Ca(2+)]i During steady-state activations in both intact and skinned preparations, propofol and isoflurane depressed maximum Ca(2+)-activated force and increased the [Ca(2+)]i required for 50% of activation. Myofibrils photolabeled with AziPm and Azi-iso identified myosin, actin, and myosin light chain as targets of the anesthetics. Several adducted residues in those proteins were located in conformationally sensitive regions that underlie contractile function. Thus, propofol and isoflurane decrease force development by directly depressing myofilament Ca(2+) responsiveness and have binding sites in key regions for contraction in both actin and myosin.-Meng, T., Bu, W., Ren, X., Chen, X., Yu, J., Eckenhoff, R. G., Gao, W. D. Molecular mechanism of anesthetic-induced depression of myocardial contraction.
Collapse
Affiliation(s)
- Tao Meng
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Weiming Bu
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xianfeng Ren
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, China
| | - Xinzhong Chen
- Department of Cardiac Surgery, Tongji University Medical Center, Wuhan, China; and
| | - Jingui Yu
- Department of Anesthesiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Roderic G Eckenhoff
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
21
|
Sysa-Shah P, Tocchetti CG, Gupta M, Rainer PP, Shen X, Kang BH, Belmonte F, Li J, Xu Y, Guo X, Bedja D, Gao WD, Paolocci N, Rath R, Sawyer DB, Naga Prasad SV, Gabrielson K. Bidirectional cross-regulation between ErbB2 and β-adrenergic signalling pathways. Cardiovasc Res 2015; 109:358-73. [PMID: 26692570 DOI: 10.1093/cvr/cvv274] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 12/01/2015] [Indexed: 12/31/2022] Open
Abstract
AIMS Despite the observation that ErbB2 regulates sensitivity of the heart to doxorubicin or ErbB2-targeted cancer therapies, mechanisms that regulate ErbB2 expression and activity have not been studied. Since isoproterenol up-regulates ErbB2 in kidney and salivary glands and β2AR and ErbB2 complex in brain and heart, we hypothesized that β-adrenergic receptors (AR) modulate ErbB2 signalling status. METHODS AND RESULTS ErbB2 transfection of HEK293 cells up-regulates β2AR, and β2AR transfection of HEK293 up-regulates ErbB2. Interestingly, cardiomyocytes isolated from myocyte-specific ErbB2-overexpressing (ErbB2(tg)) mice have amplified response to selective β2-agonist zinterol, and right ventricular trabeculae baseline force generation is markedly reduced with β2-antagonist ICI-118 551. Consistently, receptor binding assays and western blotting demonstrate that β2ARs levels are markedly increased in ErbB2(tg) myocardium and reduced by EGFR/ErbB2 inhibitor, lapatinib. Intriguingly, acute treatment of mice with β1- and β2-AR agonist isoproterenol resulted in myocardial ErbB2 increase, while inhibition with either β1- or β2-AR antagonist did not completely prevent isoproterenol-induced ErbB2 expression. Furthermore, inhibition of ErbB2 kinase predisposed mice hearts to injury from chronic isoproterenol treatment while significantly reducing isoproterenol-induced pAKT and pERK levels, suggesting ErbB2's role in transactivation in the heart. CONCLUSION Our studies show that myocardial ErbB2 and βAR signalling are linked in a feedback loop with βAR activation leading to increased ErbB2 expression and activity, and increased ErbB2 activity regulating β2AR expression. Most importantly, ErbB2 kinase activity is crucial for cardioprotection in the setting of β-adrenergic stress, suggesting that this mechanism is important in the pathophysiology and treatment of cardiomyopathy induced by ErbB2-targeting antineoplastic drugs.
Collapse
Affiliation(s)
- Polina Sysa-Shah
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Carlo G Tocchetti
- Division of Internal Medicine, Department of Translational Medical Sciences, Federico II University, Naples, Italy
| | - Manveen Gupta
- Department of Molecular Cardiology, Cleveland Clinic, Lerner Research Institute, Cleveland, OH, USA
| | - Peter P Rainer
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Byung-Hak Kang
- Department of Oncology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Frances Belmonte
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Jian Li
- Clinical Laboratory, Chinese PLA General Hospital, Beijing, China
| | - Yi Xu
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Xin Guo
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Djahida Bedja
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Rutwik Rath
- Cardiovascular Services, Maine Medical Center, Portland, ME, USA
| | - Douglas B Sawyer
- Cardiovascular Services, Maine Medical Center, Portland, ME, USA
| | | | - Kathleen Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, MRB 807, 733 N. Broadway, Baltimore, MD 21205, USA
| |
Collapse
|
22
|
Ramirez-Correa GA, Ma J, Slawson C, Zeidan Q, Lugo-Fagundo NS, Xu M, Shen X, Gao WD, Caceres V, Chakir K, DeVine L, Cole RN, Marchionni L, Paolocci N, Hart GW, Murphy AM. Removal of Abnormal Myofilament O-GlcNAcylation Restores Ca2+ Sensitivity in Diabetic Cardiac Muscle. Diabetes 2015; 64:3573-87. [PMID: 26109417 PMCID: PMC4587639 DOI: 10.2337/db14-1107] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 05/14/2015] [Indexed: 11/13/2022]
Abstract
Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)-labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca(2+) sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca(2+) in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.
Collapse
Affiliation(s)
- Genaro A Ramirez-Correa
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Junfeng Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS
| | - Quira Zeidan
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nahyr S Lugo-Fagundo
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mingguo Xu
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Viviane Caceres
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Khalid Chakir
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Lauren DeVine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Robert N Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luigi Marchionni
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anne M Murphy
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
23
|
Li QL, Gao WD, Zhang C, Zhou PH, Zhong YS, Chen WF, Zhang YQ, Yao LQ, Xu MD. Is endoscopic sphincterotomy plus large-balloon dilation a better option than endoscopic large-balloon dilation alone in removal of large bile duct stones? A retrospective comparison study. Indian J Cancer 2015; 51 Suppl 2:e13-7. [PMID: 25712833 DOI: 10.4103/0019-509x.152000] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Several comparison studies have demonstrated that endoscopic sphincterotomy (EST) combined with large-balloon dilation (LBD) may be a better option than EST alone to manage large bile duct stones. However, limited data were available to compare this combination method with LBD alone in removal of large bile duct stones. OBJECTIVE To compare EST plus LBD and LBD alone for the management of large bile duct stones, and analyze the outcomes of each method. PATIENTS AND METHODS Sixty-one patients were included in the EST plus LBD group, and 48 patients were included in the LBD alone group retrospectively. The therapeutic success, clinical characteristics, procedure-related parameters and adverse events were compared. RESULTS Compared with EST plus LBD, LBD alone was more frequently performed in patients with potential bleeding diathesis or anatomical changes (P = 0.021). The procedure time from successful cannulating to complete stone removal was shorter in the LBD alone group significantly (21.5 vs. 17.3 min, P = 0.041). The EST plus LBD group and the LBD alone group had similar outcomes in terms of overall complete stone removal (90.2% vs. 91.7%, P = 1.000) and complete stone removal without the need for mechanical lithotripsy (78.7% vs. 83.3%, P = 0.542). Massive bleeding occurred in one patient of the EST plus LBD group, and successfully coagulated. Postoperative pancreatitis did not differ significantly between the EST plus LBD group and the LBD alone group (4.9% vs. 6.3%; P = 1.000). CONCLUSION Endoscopic sphincterotomy combined with LBD offers no significant advantage over LBD alone for the removal of large bile duct stones. LBD can simplify the procedure compared with EST plus LBD in terms of shorten the procedure time.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - M D Xu
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
24
|
Woll KA, Weiser BP, Liang Q, Meng T, McKinstry-Wu A, Pinch B, Dailey WP, Gao WD, Covarrubias M, Eckenhoff RG. Role for the propofol hydroxyl in anesthetic protein target molecular recognition. ACS Chem Neurosci 2015; 6:927-35. [PMID: 25799399 DOI: 10.1021/acschemneuro.5b00078] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Propofol is a widely used intravenous general anesthetic. We synthesized 2-fluoro-1,3-diisopropylbenzene, a compound that we call "fropofol", to directly assess the significance of the propofol 1-hydroxyl for pharmacologically relevant molecular recognition in vitro and for anesthetic efficacy in vivo. Compared to propofol, fropofol had a similar molecular volume and only a small increase in hydrophobicity. Isothermal titration calorimetry and competition assays revealed that fropofol had higher affinity for a protein site governed largely by van der Waals interactions. Within another protein model containing hydrogen bond interactions, propofol demonstrated higher affinity. In vivo, fropofol demonstrated no anesthetic efficacy, but at high concentrations produced excitatory activity in tadpoles and mice; fropofol also antagonized propofol-induced hypnosis. In a propofol protein target that contributes to hypnosis, α1β2γ2L GABAA receptors, fropofol demonstrated no significant effect alone or on propofol positive allosteric modulation of the ion channel, suggesting an additional requirement for the 1-hydroxyl within synaptic GABAA receptor site(s). However, fropofol caused similar adverse cardiovascular effects as propofol by a dose-dependent depression of myocardial contractility. Our results directly implicate the propofol 1-hydroxyl as contributing to molecular recognition within protein targets leading to hypnosis, but not necessarily within protein targets leading to side effects of the drug.
Collapse
Affiliation(s)
| | | | - Qiansheng Liang
- Department
of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, 900 Walnut Street, JHN 417, Philadelphia, Pennsylvania 19107, United States
| | - Tao Meng
- Department of Anesthesiology, Qilu Hospital, Shandong University, 107 Wenhua Xi Road, Jinan, 250012 P. R. China
- Department of Anesthesiology
and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, Maryland 21287, United States
| | | | - Benika Pinch
- Department of Chemistry, University of Pennsylvania School of Arts and Sciences, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - William P. Dailey
- Department of Chemistry, University of Pennsylvania School of Arts and Sciences, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Wei Dong Gao
- Department of Anesthesiology
and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, Maryland 21287, United States
| | - Manuel Covarrubias
- Department
of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, 900 Walnut Street, JHN 417, Philadelphia, Pennsylvania 19107, United States
| | | |
Collapse
|
25
|
Liu K, Liu H, Gao WD, Meng L. Cerebral circulation and ischemia: How to monitor it during surgery? Transl Perioper Pain Med 2015; 2:2-8. [PMID: 26065012 PMCID: PMC4459737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | | | | | - Lingzhong Meng
- University of California San Francisco,Corresponding author: Lingzhong Meng, MD, Associate Professor, Department of Anesthesia and Perioperative Care, UCSF School of Medicine. 521 Parnassus Ave, Clinic Sci, San Francisco CA 94143.
| |
Collapse
|
26
|
Bhatt NM, Aon MA, Tocchetti CG, Shen X, Dey S, Ramirez-Correa G, O'Rourke B, Gao WD, Cortassa S. Restoring redox balance enhances contractility in heart trabeculae from type 2 diabetic rats exposed to high glucose. Am J Physiol Heart Circ Physiol 2014; 308:H291-302. [PMID: 25485897 DOI: 10.1152/ajpheart.00378.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hearts from type 2 diabetic (T2DM) subjects are chronically subjected to hyperglycemia and hyperlipidemia, both thought to contribute to oxidizing conditions and contractile dysfunction. How redox alterations and contractility interrelate, ultimately diminishing T2DM heart function, remains poorly understood. Herein we tested whether the fatty acid palmitate (Palm), in addition to its energetic contribution, rescues function by improving redox [glutathione (GSH), NAD(P)H, less oxidative stress] in T2DM rat heart trabeculae subjected to high glucose. Using cardiac trabeculae from Zucker Diabetic Fatty (ZDF) rats, we assessed the impact of low glucose (EG) and high glucose (HG), in absence or presence of Palm or insulin, on force development, energetics, and redox responses. We found that in EG ZDF and lean trabeculae displayed similar contractile work, yield of contractile work (Ycw), representing the ratio of force time integral over rate of O2 consumption. Conversely, HG had a negative impact on Ycw, whereas Palm, but not insulin, completely prevented contractile loss. This effect was associated with higher GSH, less oxidative stress, and augmented matrix GSH/thioredoxin (Trx) in ZDF mitochondria. Restoration of myocardial redox with GSH ethyl ester also rescued ZDF contractile function in HG, independently from Palm. These results support the idea that maintained redox balance, via increased GSH and Trx antioxidant activities to resist oxidative stress, is an essential protective response of the diabetic heart to keep contractile function.
Collapse
Affiliation(s)
- Niraj M Bhatt
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Miguel A Aon
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Carlo G Tocchetti
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Swati Dey
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Genaro Ramirez-Correa
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sonia Cortassa
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| |
Collapse
|
27
|
Ramirez-Correa GA, Frazier AH, Zhu G, Zhang P, Rappold T, Kooij V, Bedja D, Snyder GA, Lugo-Fagundo NS, Hariharan R, Li Y, Shen X, Gao WD, Cingolani OH, Takimoto E, Foster DB, Murphy AM. Cardiac troponin I Pro82Ser variant induces diastolic dysfunction, blunts β-adrenergic response, and impairs myofilament cooperativity. J Appl Physiol (1985) 2014; 118:212-23. [PMID: 25324519 DOI: 10.1152/japplphysiol.00463.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Troponin I (TnI) variant Pro82Ser (cTnIP82S) was initially considered a disease-causing mutation; however, later studies suggested the contrary. We tested the hypothesis of whether a causal link exists between cTnIP82S and cardiac structural and functional remodeling, such as during aging or chronic pressure overload. A cardiac-specific transgenic (Tg) mouse model of cTnIP82S was created to test this hypothesis. During aging, Tg cTnIP82S displayed diastolic dysfunction, characterized by longer isovolumetric relaxation time, and impaired ejection and relaxation time. In young, Tg mice in vivo pressure-volume loops and intact trabecular preparations revealed normal cardiac contractility at baseline. However, upon β-adrenergic stimulation, a blunted contractile reserve and no hastening in left ventricle relaxation were evident in vivo, whereas, in isolated muscles, Ca(2+) transient amplitude isoproterenol dose-response was blunted. In addition, when exposed to chronic pressure overload, Tg mice show exacerbated hypertrophy and decreased contractility compared with age-matched non-Tg littermates. At the molecular level, this mutation significantly impairs myofilament cooperative activation. Importantly, this occurs in the absence of alterations in TnI or myosin-binding protein C phosphorylation. The cTnIP82S variant occurs near a region of interactions with troponin T; therefore, structural changes in this region could explain its meaningful effects on myofilament cooperativity. Our data indicate that cTnIP82S mutation modifies age-dependent diastolic dysfunction and impairs overall contractility after β-adrenergic stimulation or chronic pressure overload. Thus cTnIP82S variant should be regarded as a disease-modifying factor for dysfunction and adverse remodeling with aging and chronic pressure overload.
Collapse
Affiliation(s)
- Genaro A Ramirez-Correa
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Aisha H Frazier
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Guangshuo Zhu
- Department of Medicine and Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Pingbo Zhang
- The Hopkins Bayview Proteomics Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Thomas Rappold
- The Hopkins Bayview Proteomics Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Viola Kooij
- The Hopkins Bayview Proteomics Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Djahida Bedja
- Department of Comparative Medicine and Comparative Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Greg A Snyder
- Institute of Human Virology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Nahyr S Lugo-Fagundo
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Raena Hariharan
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Yuejin Li
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Oscar H Cingolani
- Department of Medicine and Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Eiki Takimoto
- Department of Medicine and Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - D Brian Foster
- Department of Medicine and Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anne M Murphy
- Department of Pediatrics and Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland;
| |
Collapse
|
28
|
Kirk JA, Holewinski RJ, Kooij V, Agnetti G, Tunin RS, Witayavanitkul N, de Tombe PP, Gao WD, Van Eyk J, Kass DA. Cardiac resynchronization sensitizes the sarcomere to calcium by reactivating GSK-3β. J Clin Invest 2014; 124:129-38. [PMID: 24292707 DOI: 10.1172/jci69253] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 09/19/2013] [Indexed: 01/10/2023] Open
Abstract
Cardiac resynchronization therapy (CRT), the application of biventricular stimulation to correct discoordinate contraction, is the only heart failure treatment that enhances acute and chronic systolic function, increases cardiac work, and reduces mortality. Resting myocyte function also increases after CRT despite only modest improvement in calcium transients, suggesting that CRT may enhance myofilament calcium responsiveness. To test this hypothesis, we examined adult dogs subjected to tachypacing-induced heart failure for 6 weeks, concurrent with ventricular dyssynchrony (HF(dys)) or CRT. Myofilament force-calcium relationships were measured in skinned trabeculae and/or myocytes. Compared with control, maximal calcium-activated force and calcium sensitivity declined globally in HF(dys); however, CRT restored both. Phosphatase PP1 induced calcium desensitization in control and CRT-treated cells, while HF(dys) cells were unaffected, implying that CRT enhances myofilament phosphorylation. Proteomics revealed phosphorylation sites on Z-disk and M-band proteins, which were predicted to be targets of glycogen synthase kinase-3β (GSK-3β). We found that GSK-3β was deactivated in HF(dys) and reactivated by CRT. Mass spectrometry of myofilament proteins from HF(dys) animals incubated with GSK-3β confirmed GSK-3β–dependent phosphorylation at many of the same sites observed with CRT. GSK-3β restored calcium sensitivity in HF(dys), but did not affect control or CRT cells. These data indicate that CRT improves calcium responsiveness of myofilaments following HF(dys) through GSK-3β reactivation, identifying a therapeutic approach to enhancing contractile function
Collapse
|
29
|
Shen X, Bhatt N, Xu J, Meng T, Aon MA, O'Rourke B, Berkowitz DE, Cortassa S, Gao WD. Effect of isoflurane on myocardial energetic and oxidative stress in cardiac muscle from Zucker diabetic fatty rat. J Pharmacol Exp Ther 2014; 349:21-8. [PMID: 24431470 DOI: 10.1124/jpet.113.211144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effect of inhalational anesthetics on myocardial contraction and energetics in type 2 diabetes mellitus is unknown. We investigated the effect of isoflurane (ISO) on force and intracellular Ca(2+) transient (iCa), myocardial oxygen consumption (MVo(2)), and energetics/redox behavior in trabecular muscles from Zucker diabetic fatty (ZDF) rats. At baseline, force and corresponding iCa were lower in ZDF trabeculae than in controls. ISO decreased force in both groups in a dose-dependent manner. ISO did not affect iCa amplitude in controls, but ISO > 1.5% significantly reduced iCa amplitude in ZDF trabeculae. ISO-induced force depression fully recovered as a result of increased iCa when external Ca(2+) was raised in controls. However, both force and iCa remained low in ZDF muscle at elevated external Ca(2+). In controls, force, iCa, and MVo(2) increased when stimulation frequency was increased from 0.5 to 1.5 Hz. ZDF muscles, however, exhibited blunted responses in force and iCa and decreased MVo(2). Oxidative stress levels were unchanged in control muscles but increased significantly in ZDF muscles after exposure to ISO. Finally, the depressive effect of ISO was prevented by 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (Tempol) in ZDF muscles. These findings suggest that ISO dose-dependently attenuates force in control and ZDF muscles with differential effect on iCa. The mechanism of force depression by ISO in controls is mainly decreased myofilament Ca(2+) sensitivity, whereas in ZDF muscles the ISO-induced decrease in contraction is due to worsening oxidative stress, which inhibits iCa and force development.
Collapse
Affiliation(s)
- Xiaoxu Shen
- Cardiology Department, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China (X.S.); Division of Cardiology, Department of Medicine (N.B., M.A.A., B.O., S.C.), and Department of Anesthesiology and Critical Care Medicine (T.M., D.E.B., W.D.G.), The Johns Hopkins University School of Medicine, Baltimore, Maryland; and Department of Anesthesiology, 1st Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China (J.X.)
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Shen X, Tan Z, Zhong X, Tian Y, Wang X, Yu B, Ramirez-Correa G, Murphy A, Gabrielson K, Paolocci N, Gao WD. Endocardial endothelium is a key determinant of force-frequency relationship in rat ventricular myocardium. J Appl Physiol (1985) 2013; 115:383-93. [PMID: 23703113 DOI: 10.1152/japplphysiol.01415.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We tested the hypothesis that removing endocardial endothelium (EE) negatively impacts the force-frequency relationship (FFR) of ventricular myocardium and dissected the signaling that underlies this phenomenon. EE of rat trabeculae was selectively damaged by brief (<1 s) exposure to 0.1% Triton X-100. Force, intracellular Ca(2+) transient (iCa(2+)), and activity of protein kinase A (PKA) and protein kinase C (PKC) were determined. In control muscles, force and iCa(2+) increased as the stimulation frequency increased in steps of 0.5 Hz up to 3.0 Hz. However, EE-denuded (EED) muscles exhibited a markedly blunted FFR. Neither isoproterenol (ISO; 0.1-5 nmol/l) nor endothelin-1 (ET-1; 10-100 nmol/l) alone restored the slope of FFR in EED muscles. Intriguingly, however, a positive FFR was restored in EED preparations by combining low concentrations of ISO (0.1 nmol/l) and ET-1 (20 nmol/l). In intact muscles, PKA and PKC activity increased proportionally with the increase in frequency. This effect was completely lost in EED muscles. Again, combining ISO and ET-1 fully restored the frequency-dependent rise in PKA and PKC activity in EED muscles. In conclusion, selective damage of EE leads to significantly blunted FFR. A combination of low concentrations of ISO and ET-1 successfully restores FFR in EED muscles. The interdependence of ISO and ET-1 in this process indicates cross-talk between the β1-PKA and ET-1-PKC pathways for a normal (positive) FFR. The results also imply that dysfunction of EE and/or EE-myocyte coupling may contribute to flat (or even negative) FFR in heart failure.
Collapse
Affiliation(s)
- Xiaoxu Shen
- Cardiology Department, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Bhatt NM, Aon MA, Shen X, O'Rourke B, Dong Gao W, Cortassa S. Redox-Dependent Differential Optimization of Contractile Work in Cardiac Muscle from Diabetic Rat under Hyperglycemia. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.1685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
32
|
Gao WD, Murray CI, Tian Y, Zhong X, DuMond JF, Shen X, Stanley BA, Foster DB, Wink DA, King SB, Van Eyk JE, Paolocci N. Nitroxyl-mediated disulfide bond formation between cardiac myofilament cysteines enhances contractile function. Circ Res 2012; 111:1002-11. [PMID: 22851540 DOI: 10.1161/circresaha.112.270827] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE In the myocardium, redox/cysteine modification of proteins regulating Ca(2+) cycling can affect contraction and may have therapeutic value. Nitroxyl (HNO), the one-electron-reduced form of nitric oxide, enhances cardiac function in a manner that suggests reversible cysteine modifications of the contractile machinery. OBJECTIVE To determine the effects of HNO modification in cardiac myofilament proteins. METHODS AND RESULTS The HNO-donor, 1-nitrosocyclohexyl acetate, was found to act directly on the myofilament proteins, increasing maximum force (F(max)) and reducing the concentration of Ca(2+) for 50% activation (Ca(50)) in intact and skinned cardiac muscles. The effects of 1-nitrosocyclohexyl acetate are reversible by reducing agents and distinct from those of another HNO donor, Angeli salt, which was previously reported to increase F(max) without affecting Ca50. Using a new mass spectrometry capture technique based on the biotin switch assay, we identified and characterized the formation by HNO of a disulfide-linked actin-tropomyosin and myosin heavy chain-myosin light chain 1. Comparison of the 1-nitrosocyclohexyl acetate and Angeli salt effects with the modifications induced by each donor indicated the actin-tropomyosin and myosin heavy chain-myosin light chain 1 interactions independently correlated with increased Ca(2+) sensitivity and force generation, respectively. CONCLUSIONS HNO exerts a direct effect on cardiac myofilament proteins increasing myofilament Ca(2+) responsiveness by promoting disulfide bond formation between critical cysteine residues. These findings indicate a novel, redox-based modulation of the contractile apparatus, which positively impacts myocardial function, providing further mechanistic insight for HNO as a therapeutic agent.
Collapse
Affiliation(s)
- Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Sheinberg R, Gao WD, Wand G, Abraham S, Schulick R, Roy R, Mitter N. Case 1—2012 A Perfect Storm: Fatality Resulting From Metoclopramide Unmasking A Pheochromocytoma and Its Management. J Cardiothorac Vasc Anesth 2012; 26:161-5. [DOI: 10.1053/j.jvca.2011.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Indexed: 01/08/2023]
|
34
|
Frazier A, Ramirez-Correa GA, Bedja D, Shen X, Gao WD, Zhu G, Cingolani OH, Takimoto E, Murphy AM. Abstract P249: Cardiac Troponin I Pro82Ser Variant Impairs Myofilament Cooperativity, Induces Diastolic Dysfunction, and Blunts β-Adrenergic Response. Circ Res 2011. [DOI: 10.1161/res.109.suppl_1.ap249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac troponin I is a key regulatory protein for muscle contraction and necessary for an adequate β-adrenergic response. The Proline 82 Serine (P82S) sequence variant of troponin I gene (
TNNI3
) is associated with late onset hypertrophic cardiomyopathy (HCM). Our preliminary data has shown that cTnIP82S is heterozygous in 3% of African Americans and is associated with increased LV mass in hypertensive black men. We hypothesize that cTnIP82S variant could influence the hypertrophic response to hypertension and/or the malignancy of the phenotypic expression when combined with known HCM disease causing myofilament mutations. We created a transgenic cTnIP82S mouse model. Echocardiography at baseline in older Tg and NTg mice (64-65 wks) showed impaired ejection time and relaxation, Tg display longer isovolumetric relaxation time (IVRT) (Tg 29.7±0.26 vs NTg 23± 0.23 msec, n=8 vs n=7 p<0.05) and a significantly higher TEI index. In the young NTg and Tg (17 wks) there were no echocardiographic differences. However, preliminary data suggest that 1 wk after transverse aortic coarctation (TAC), diastolic dysfunction was evident in Tg, and 10 weeks after TAC LV mass was also increased compared to NTg. Skinned fibers studies showed in the Tg mice borderline lower maximal Force (F
max
) and myofilament calcium sensitivity, whereas
n
Hill showed a marked depression (Tg 1.72±0.17 vs NTg 3.09±0.44, n=7 vs n=5, p<0.05), this effect was not due to the global myofilament phosphorylation pattern. In addition, intact twitching cardiac muscle studies in Tg mice revealed an impaired dose-dependent β-adrenergic acceleration of relaxation, evidenced by a failure to increase relaxation ([-dF/dt min]/[+dF/dt max]) and accelerate calcium transients decay after isoproterenol. Pressure-volume (PV) loop studies confirm that Tg mice fail to increase: Δ change in dP/dt max (NTg 4,928.3±7.7 vs Tg 843.3±10.7, n=4 vs n=4 p<0.05) in response to isoproterenol. TnIP82S variant is near a region of TnI-TnT interaction; this could explain its dramatic effects on myofilament cooperativity. Overall these studies suggest that the expression of cTnIP82S variant in the mice heart induces diastolic dysfunction, impairs relaxation at baseline and after β-adrenergic stimulation.
Collapse
Affiliation(s)
| | | | | | - Xiaoxu Shen
- Johns Hopkins Univ Sch of Med, Baltimore, MD
| | | | | | | | | | | |
Collapse
|
35
|
Ding W, Li Z, Shen X, Martin J, King SB, Sivakumaran V, Paolocci N, Gao WD. Reversal of isoflurane-induced depression of myocardial contraction by nitroxyl via myofilament sensitization to Ca2+. J Pharmacol Exp Ther 2011; 339:825-31. [PMID: 21865439 DOI: 10.1124/jpet.111.185272] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Isoflurane (ISO) is known to depress cardiac contraction. Here, we hypothesized that decreasing myofilament Ca(2+) responsiveness is central to ISO-induced reduction in cardiac force development. Moreover, we also tested whether the nitroxyl (HNO) donor 1-nitrosocyclohexyl acetate (NCA), acting as a myofilament Ca(2+) sensitizer, restores force in the presence of ISO. Trabeculae from the right ventricles of LBN/F1 rats were superfused with Krebs-Henseleit solution at room temperature, and force and intracellular Ca(2+) ([Ca(2+)](i)) were measured. Steady-state activations were achieved by stimulating the muscles at 10 Hz in the presence of ryanodine. The same muscles were chemically skinned with 1% Triton X-100, and the force-Ca(2+) relation measurements were repeated. ISO depressed force in a dose-dependent manner without significantly altering [Ca(2+)](i). At 1.5%, force was reduced over 50%, whereas [Ca(2+)](i) remained unaffected. At 3%, contraction was decreased by ∼75% with [Ca(2+)](i) reduced by only 15%. During steady-state activation, 1.5% ISO depressed maximal Ca(2+)-activated force (F(max)) and increased the [Ca(2+)](i) required for 50% activation (Ca(50)) without affecting the Hill coefficient. After skinning, the same muscles showed similar decreases in F(max) and increases in Ca(50) in the presence of ISO. NCA restored force in the presence of ISO without affecting [Ca(2+)](i). These results show that 1) ISO depresses cardiac force development by decreasing myofilament Ca(2+) responsiveness, and 2) myofilament Ca(2+) sensitization by NCA can effectively restore force development without further increases in [Ca(2+)](i). The present findings have potential translational value because of the efficiency and efficacy of HNO on ISO-induced myocardial contractile dysfunction.
Collapse
Affiliation(s)
- Wengang Ding
- Department of Anesthesiology, 2nd Affiliated Hospital, Harbin Medical University, Heilongjiang, China
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Tocchetti CG, Stanley BA, Murray CI, Sivakumaran V, Donzelli S, Mancardi D, Pagliaro P, Gao WD, van Eyk J, Kass DA, Wink DA, Paolocci N. Playing with cardiac "redox switches": the "HNO way" to modulate cardiac function. Antioxid Redox Signal 2011; 14:1687-98. [PMID: 21235349 PMCID: PMC3066693 DOI: 10.1089/ars.2010.3859] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nitric oxide (NO(•)) sibling, nitroxyl or nitrosyl hydride (HNO), is emerging as a molecule whose pharmacological properties include providing functional support to failing hearts. HNO also preconditions myocardial tissue, protecting it against ischemia-reperfusion injury while exerting vascular antiproliferative actions. In this review, HNO's peculiar cardiovascular assets are discussed in light of its unique chemistry that distinguish HNO from NO(•) as well as from reactive oxygen and nitrogen species such as the hydroxyl radical and peroxynitrite. Included here is a discussion of the possible routes of HNO formation in the myocardium and its chemical targets in the heart. HNO has been shown to have positive inotropic/lusitropic effects under normal and congestive heart failure conditions in animal models. The mechanistic intricacies of the beneficial cardiac effects of HNO are examined in cellular models. In contrast to β-receptor/cyclic adenosine monophosphate/protein kinase A-dependent enhancers of myocardial performance, HNO uses its "thiophylic" nature as a vehicle to interact with redox switches such as cysteines, which are located in key components of the cardiac electromechanical machinery ruling myocardial function. Here, we will briefly review new features of HNO's cardiovascular effects that when combined with its positive inotropic/lusitropic action may render HNO donors an attractive addition to the current therapeutic armamentarium for treating patients with acutely decompensated congestive heart failure.
Collapse
Affiliation(s)
- Carlo G Tocchetti
- Division of Cardiology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Gao WD, Li Z, Wijaya C, McConnell BK. Altered Force Development in Response to Calcium and Isopreterenol in Cardiac Muscle from Gravin Knock-Out (AKAP12) Mice. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.1807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
38
|
Ramirez-Correa GA, Cortassa S, Stanley B, Gao WD, Murphy AM. Calcium sensitivity, force frequency relationship and cardiac troponin I: critical role of PKA and PKC phosphorylation sites. J Mol Cell Cardiol 2010; 48:943-53. [PMID: 20083117 DOI: 10.1016/j.yjmcc.2010.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 01/06/2010] [Accepted: 01/07/2010] [Indexed: 11/18/2022]
Abstract
Transgenic models with pseudo phosphorylation mutants of troponin I, PKA sites at Ser 22 and 23 (cTnIDD(22,23) mice) or PKC sites at Ser 42 and 44 (cTnIAD(22,23)DD(42,44)) displayed differential force-frequency relationships and afterload relaxation delay in vivo. We hypothesized that cTnI PKA and PKC phosphomimics impact cardiac muscle rate-related developed twitch force and relaxation kinetics in opposite directions. cTnIDD(22,23) transgenic mice produce a force frequency relationship (FFR) equivalent to control NTG albeit at lower peak [Ca(2+)](i), while cTnIAD(22,23)DD(42,44) TG mice had a flat FFR with normal peak systolic [Ca(2+)](i), thus suggestive of diminished responsiveness to [Ca(2+)](i) at higher frequencies. Force-[Ca(2+)](i) hysteresis analysis revealed that cTnIDD(22,23) mice have a combined enhanced myofilament calcium peak response with an enhanced slope of force development and decline per unit of [Ca(2+)](i), whereas cTnIAD(22,23)DD(42,44) transgenic mice showed the opposite. The computational ECME model predicts that the TG lines may be distinct from each other due to different rate constants for association/dissociation of Ca(2+) at the regulatory site of cTnC. Our data indicate that cTnI phosphorylation at PKA sites plays a critical role in the FFR by increasing relative myofilament responsiveness, and results in a distinctive transition between activation and relaxation, as displayed by force-[Ca(2+)](i) hysteresis loops. These findings may have important implications for understanding the specific contribution of cTnI to beta-adrenergic inotropy and lusitropy and to adverse contractile effects of PKC activation, which is relevant during heart failure development.
Collapse
Affiliation(s)
- Genaro A Ramirez-Correa
- Department of Pediatrics/Division of Cardiology, Johns Hopkins University School of Medicine, Ross Bldg 1144/720 Rutland Avenue, Baltimore, MD 21205, USA
| | | | | | | | | |
Collapse
|
39
|
Ramirez-Correa GA, Cortassa S, Stanley B, Gao WD, Murphy AM. Calcium Sensitivity, Force Frequency Relation and Cardiac Troponin I: Critical Role of PKA and PKC Phosphorylation Sites. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.1924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
40
|
Kohr MJ, Kaludercic N, Tocchetti CG, Dong Gao W, Kass DA, Janssen PML, Paolocci N, Ziolo MT. Nitroxyl enhances myocyte Ca2+ transients by exclusively targeting SR Ca2+-cycling. Front Biosci (Elite Ed) 2010; 2:614-26. [PMID: 20036906 DOI: 10.2741/e118] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Nitroxyl (HNO), the 1-electron reduction product of nitric oxide, improves myocardial contraction in normal and failing hearts. Here we test whether the HNO donor Angeli's salt (AS) will change myocyte action potential (AP) waveform by altering the L-type Ca2+ current (ICa) and contrast the contractile effects of HNO with that of the hydroxyl radical (.OH) and nitrite (NO2-), two potential breakdown products of AS. We confirmed the positive effect of AS/HNO on basal cardiomyocyte function, as opposed to the detrimental effect of .OH and the negligible effect of NO2-. Upon examination of the myocyte AP, we observed no change in resting membrane potential or AP duration to 20 per cent repolarization with AS/HNO, whereas AP duration to 90 per cent repolarization was slightly prolonged. However, perfusion with AS/HNO did not elicit a change in basal ICa, but did hasten ICa inactivation. Upon further examination of the SR, the AS/HNO-induced increase in cardiomyocyte Ca2+ transients was abolished with inhibition of SR Ca2+-cycling. Therefore, the HNO-induced increase in Ca2+ transients results exclusively from changes in SR Ca2+-cycling, and not from ICa.
Collapse
Affiliation(s)
- Mark J Kohr
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Paolocci N, Tocchetti CG, Mahaney JE, Keceli G, Lee DI, Ballin JD, Farrance IK, Kranias E, Gao WD, Wilson GM, Kass DA, Toscano JP. Nitroxyl and “Forbidden Disulfides”: Phospholamban Cysteines are Targeted to Enhance SERCA2a Activity. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.4189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
42
|
Ramirez-Correa GA, Jin W, Wang Z, Zhong X, Gao WD, Dias WB, Vecoli C, Hart GW, Murphy AM. O-linked GlcNAc modification of cardiac myofilament proteins: a novel regulator of myocardial contractile function. Circ Res 2008; 103:1354-8. [PMID: 18988896 DOI: 10.1161/circresaha.108.184978] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In addition to O-phosphorylation, O-linked modifications of serine and threonine by beta-N-acetyl-D-glucosamine (GlcNAc) may regulate muscle contractile function. This study assessed the potential role of O-GlcNAcylation in cardiac muscle contractile activation. To identify specific sites of O-GlcNAcylation in cardiac myofilament proteins, a recently developed methodology based on GalNAz-biotin labeling followed by dithiothreitol replacement and light chromatography/tandem mass spectrometry site mapping was adopted. Thirty-two O-GlcNAcylated peptides from cardiac myofilaments were identified on cardiac myosin heavy chain, actin, myosin light chains, and troponin I. To assess the potential physiological role of the GlcNAc, force-[Ca(2+)] relationships were studied in skinned rat trabeculae. Exposure to GlcNAc significantly decreased calcium sensitivity (pCa50), whereas maximal force (F(max)) and Hill coefficient (n) were not modified. Using a pan-specific O-GlcNAc antibody, it was determined that acute exposure of myofilaments to GlcNAc induced a significant increase in actin O-GlcNAcylation. This study provides the first identification of O-GlcNAcylation sites in cardiac myofilament proteins and demonstrates their potential role in regulating myocardial contractile function.
Collapse
|
43
|
Gao WD, Murphy AM. Local control in thin filament activation of cardiac muscle. J Physiol 2007; 580:358. [PMID: 17347259 PMCID: PMC2075562 DOI: 10.1113/jphysiol.2007.131672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Wei Dong Gao
- Department of Anaesthesia and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | | |
Collapse
|
44
|
Abstract
Donors of nitroxyl (HNO), the reduced congener of nitric oxide (NO), exert positive cardiac inotropy/lusitropy in vivo and in vitro, due in part to their enhancement of Ca(2+) cycling into and out of the sarcoplasmic reticulum. Here we tested whether the cardiac action of HNO further involves changes in myofilament-calcium interaction. Intact rat trabeculae from the right ventricle were mounted between a force transducer and a motor arm, superfused with Krebs-Henseleit (K-H) solution (pH 7.4, room temperature) and loaded iontophoretically with fura-2 to determine [Ca(2+)](i). Sarcomere length was set at 2.2-2.3 microm. HNO donated by Angeli's salt (AS; Na(2)N(2)O(3)) dose-dependently increased both twitch force and [Ca(2+)](i) transients (from 50 to 1000 microm). Force increased more than [Ca(2+)](i) transients, especially at higher doses (332 +/- 33% versus 221 +/- 27%, P < 0.01 at 1000 microm). AS/HNO (250 microm) increased developed force without changing Ca(2+) transients at any given [Ca(2+)](o) (0.5-2.0 mm). During steady-state activation, AS/HNO (250 microm) increased maximal Ca(2+)-activated force (F(max), 106.8 +/- 4.3 versus 86.7 +/- 4.2 mN mm(-2), n = 7-8, P < 0.01) without affecting Ca(2+) required for 50% activation (Ca(50), 0.44 +/- 0.04 versus 0.52 +/- 0.04 microm, not significant) or the Hill coefficient (4.75 +/- 0.67 versus 5.02 +/- 1.1, not significant). AS/HNO did not alter myofibrillar Mg-ATPase activity, supporting an effect on the myofilaments themselves. The thiol reducing agent dithiothreitol (DTT, 5.0 mm) both prevented and reversed HNO action, confirming AS/HNO redox sensitivity. Lastly, NO (from DEA/NO) did not mimic AS/HNO cardiac effects. Thus, in addition to reported changes in Ca(2+) cycling, HNO also acts as a cardiac Ca(2+) sensitizer, augmenting maximal force without altering actomyosin ATPase activity. This is likely to be due to modulation of myofilament proteins that harbour reactive thiolate groups that are targets of HNO.
Collapse
Affiliation(s)
- Tieying Dai
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Tower 711, 600 N Wolfe Street, Baltimore, MD 21287, USA
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Bilchick KC, Duncan JG, Ravi R, Takimoto E, Champion HC, Gao WD, Stull LB, Kass DA, Murphy AM. Heart failure-associated alterations in troponin I phosphorylation impair ventricular relaxation-afterload and force-frequency responses and systolic function. Am J Physiol Heart Circ Physiol 2007; 292:H318-25. [PMID: 16936010 DOI: 10.1152/ajpheart.00283.2006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have found that selective stimulation of troponin (Tn)I protein kinase A (PKA) phosphorylation enhances heart rate-dependent inotropy and blunts relaxation delay coupled to increased afterload. However, in failing hearts, TnI phosphorylation by PKA declines while protein kinase C (PKC) activity is enhanced, potentially augmenting TnI PKC phosphorylation. Accordingly, we hypothesized that these site-specific changes deleteriously affect both rate-responsive cardiac function and afterload dependence of relaxation, both prominent phenotypic features of the failing heart. A transgenic (TG) mouse model was generated in which PKA-TnI sites were mutated to mimic partial dephosphorylation (Ser22 to Ala; Ser23 to Asp) and dominant PKC sites were mutated to mimic constitutive phosphorylation (Ser42 and Ser44 to Asp). The two highest-expressing lines were further characterized. TG mice had reduced fractional shortening of 34.7 ± 1.4% vs. 41.3 ± 2.0% ( P = 0.018) and slight chamber dilation on echocardiography. In vivo cardiac pressure-volume studies revealed near doubling of isovolumic relaxation prolongation with increasing afterload in TG animals ( P < 0.001), and this remained elevated despite isoproterenol infusion (PKA stimulation). Increasing heart rate from 400 to 700 beats/min elevated contractility 13% in TG hearts, nearly half the response observed in nontransgenic animals ( P = 0.005). This blunted frequency response was normalized by isoproterenol infusion. Abnormal TnI phosphorylation observed in cardiac failure may explain exacerbated relaxation delay in response to increased afterload and contribute to blunted chronotropic reserve.
Collapse
Affiliation(s)
- Kenneth C Bilchick
- Dept. of Pediatrics, Johns Hopkins Univ. School of Medicine, 720 Rutland Ave., Ross Bldg. 1144, Baltimore, MD 21205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Tocchetti CG, Wang W, Froehlich JP, Huke S, Aon MA, Wilson GM, Di Benedetto G, O'Rourke B, Gao WD, Wink DA, Toscano JP, Zaccolo M, Bers DM, Valdivia HH, Cheng H, Kass DA, Paolocci N. Nitroxyl improves cellular heart function by directly enhancing cardiac sarcoplasmic reticulum Ca2+ cycling. Circ Res 2006; 100:96-104. [PMID: 17138943 PMCID: PMC2769513 DOI: 10.1161/01.res.0000253904.53601.c9] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Heart failure remains a leading cause of morbidity and mortality worldwide. Although depressed pump function is common, development of effective therapies to stimulate contraction has proven difficult. This is thought to be attributable to their frequent reliance on cAMP stimulation to increase activator Ca(2+). A potential alternative is nitroxyl (HNO), the 1-electron reduction product of nitric oxide (NO) that improves contraction and relaxation in normal and failing hearts in vivo. The mechanism for myocyte effects remains unknown. Here, we show that this activity results from a direct interaction of HNO with the sarcoplasmic reticulum Ca(2+) pump and the ryanodine receptor 2, leading to increased Ca(2+) uptake and release from the sarcoplasmic reticulum. HNO increases the open probability of isolated ryanodine-sensitive Ca(2+)-release channels and accelerates Ca(2+) reuptake into isolated sarcoplasmic reticulum by stimulating ATP-dependent Ca(2+) transport. Contraction improves with no net rise in diastolic calcium. These changes are not induced by NO, are fully reversible by addition of reducing agents (redox sensitive), and independent of both cAMP/protein kinase A and cGMP/protein kinase G signaling. Rather, the data support HNO/thiolate interactions that enhance the activity of intracellular Ca(2+) cycling proteins. These findings suggest HNO donors are attractive candidates for the pharmacological treatment of heart failure.
Collapse
Affiliation(s)
- Carlo G Tocchetti
- Cardiology Division, Johns Hopkins Medical Institutions, 720 Rutland Ave, Baltimore, MD 21205, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Dai T, Ramirez-Correa G, Gao WD. Apelin increases contractility in failing cardiac muscle. Eur J Pharmacol 2006; 553:222-8. [PMID: 17055480 PMCID: PMC1815301 DOI: 10.1016/j.ejphar.2006.09.034] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2006] [Revised: 09/07/2006] [Accepted: 09/11/2006] [Indexed: 11/20/2022]
Abstract
Apelin, a ligand for apelin-angiotension receptor-like 1 (APJ), has recently been shown to be a potent positive inotropic agent in normal hearts. In humans, levels of apelin have been shown to rise in early-stage heart failure and to fall in late-stage heart failure. In this study, we tested the hypothesis that apelin augments contraction directly in failing rat cardiac muscle. Right ventricular heart failure secondary to pulmonary hypertension was induced by exposing the rats to hypoxia (10% O(2) inhaled air) for 14-16 weeks. Trabeculae were dissected and mounted between a force transducer and a motor arm, superfused with Krebs-Henseleit (K-H) solution (pH 7.4, 22 degrees C), and loaded with fura-2. Both force development and [Ca(2+)](i) transient amplitude increased in a dose-dependent manner in the presence of Apelin-12 (10 approximately 70 nM, [Ca(2+)](o)=0.5 mM) in failing muscles as compared to control (36+/-7% vs. 7.4+/-5% at 70 nM, P<0.05). Also, [Ca(2+)](i) transients increased up to 18.4+/-9.5% as compared to control (4.5+/-1.9%, P<0.05). The increases in contraction in the presence of apelin were also maintained over a range of external Ca(2+) (0.5-2.0 mM). Steady-state force-[Ca(2+)](i) relation of the failing muscles reveals decreased maximal Ca(2+)-activated force (F(max)) (51.45+/-5.3 vs. 98.5+/-11.5 mN/mm(2), P<0.001), with no changes in Ca(2+) required for 50% of maximal activation (Ca(50)) (0.45+/-0.07 vs. 0.30+/-0.04 muM, P>0.05) and Hill coefficient (4.60+/-0.73 vs. 3.17+/-0.92, P>0.05). Apelin (70 nM) had no effect on the steady-state force-[Ca(2+)](i) relation in failing muscles (F(max): 63.03+/-3.5 mN/mm(2); Ca(50): 0.50+/-0.08 microM; Hill coefficient: 4.73+/-0.89). These results indicate that apelin exerts a selective positive inotropic action in failing myocardium. The increased force development is the result of increased [Ca(2+)](i) transients rather than changes in myofilament calcium responsiveness.
Collapse
Affiliation(s)
- Tieying Dai
- Department of Anesthesiology and Critical Care Medicine, and
| | - Genaro Ramirez-Correa
- Institute of Cardiobiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, and
- To whom correspondence should be addressed at: Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Tower 711, 600 N Wolfe Street, Baltimore, MD 21287, Tel: 410-955-7519, Fax: 410-955-0994, E-mail:
| |
Collapse
|
48
|
Abstract
Decreased Ca2+ responsiveness of the myofilaments underlies myocardial stunning. Given that cross-bridge cycling is a major determinant of myofilament behavior, we quantified cross-bridge cycling rate in stunned myocardium. After stabilization, rat hearts were subjected to 20 min of no-flow global ischemia and 30 min of reperfusion at 37 degrees C. Control hearts were perfused continuously at 37 degrees C for 60 min. Trabeculae were dissected and chemically skinned with 1% Triton X-100. The muscles were then activated with solutions of varied Ca2+ concentration ([Ca2+]). Force-[Ca2+] relations, rate of force redevelopment after release (k(tr)), muscle stiffness (k(m)), and myofilament ATP consumption were determined. Maximal Ca2+-activated force (Fmax) was depressed in stunned myocardium (49 +/- 5 vs. 82 +/- 5 mN/mm2, P < 0.01). Western immunoblotting showed degradation of troponin I in stunned myocardium. The k(tr) at Fmax was significantly increased in stunned muscles (19.82 +/- 2.74 vs. 13.19 +/- 0.96 s(-1), 22 degrees C, P < 0.01; 7.49 +/- 0.52 vs. 5.81 +/- 0.54 s(-1), 10 degrees C, P < 0.05). The ratio of k(m) measured at 100 Hz over that at 1 Hz, during Fmax, is lower in stunned muscles (8.22 +/- 1.56 vs. 12.94 +/- 0.71, P < 0.05). In comparison with k(m) at rigor, k(m) at Fmax is significantly lower in the stunned group (78.82 +/- 6.11 vs. 93.27 +/- 3.03%, P < 0.05). Myofilament ATP consumption at Fmax did not change in stunned muscles (5,901 +/- 952 vs. 5,596 +/- 972 pmol x microl(-1) x min(-1), P = 0.49). These results show that cross-bridge cycling is increased in stunned myocardium. Such increases are likely the result of increased transition rate from force-generating states to non-force-generating states. Thus stunned myocardium still maintains ATP consumption in spite of lower force development, rationalizing the long-standing paradox of decreased force but unchanged oxygen consumption in the postischemic heart.
Collapse
Affiliation(s)
- Wei Dong Gao
- Dept. of Anesthesiology and Critical Care Medicine, Johns Hopkins Univ. School of Medicine, Tower 711, 600 N. Wolfe St., Baltimore, MD 21287, USA.
| | | | | |
Collapse
|
49
|
Abstract
Oxidative stress is a hallmark of systemic illnesses, including heart failure. Nevertheless, the overall importance of radical production in the heart remains conjectural; is it merely a marker of illness, or can intervention alter the progression of disease? This question was addressed by blocking xanthine oxidase (XO), a superoxide-generating enzyme that is upregulated in animal models of heart failure. In a randomized prospective trial design, we administered the XO inhibitor allopurinol orally to mice that had undergone massive myocardial infarction (MI). Cardiac XO activity was elevated in untreated mice after MI; allopurinol suppressed the XO activity to levels comparable to those in sham-operated mice. Eighty-one percent of untreated mice died of advanced heart failure over 2 to 4 weeks of follow-up. Survival doubled in the allopurinol-treated mice, whereas cardiac contractile function (both in vivo and in isolated muscle) was markedly improved. Response to isoproterenol was restored to near-normal levels in the allopurinol group but was attenuated in untreated mice. Oxidative modifications to proteins were prevented in the allopurinol-treated mice. Our findings indicate that targeted blockade of just one source of oxidants, XO, impacts dramatically on the progression of postischemic cardiomyopathy in mice and prevents oxidative protein modifications.
Collapse
Affiliation(s)
- Linda B Stull
- Institute of Molecular Cardiobiology, Johns Hopkins University School of Medicine, Baltimore, Md, USA
| | | | | | | | | |
Collapse
|
50
|
Gao WD, Pérez NG, Seidman CE, Seidman JG, Marbán E. Altered cardiac excitation-contraction coupling in mutant mice with familial hypertrophic cardiomyopathy. J Clin Invest 1999; 103:661-6. [PMID: 10074482 PMCID: PMC408123 DOI: 10.1172/jci5220] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Excitation-contraction coupling in cardiac muscle of familial hypertrophic cardiomyopathy (FHC) remains poorly understood, despite the fact that the genetic alterations are well defined. We characterized calcium cycling and contractile activation in trabeculae from a mutant mouse model of FHC (Arg403Gln knockin, alpha-myosin heavy chain). Wild-type mice of the same strain and age ( approximately 20 weeks old) served as controls. During twitch contractions, peak intracellular Ca2+ ([Ca2+]i) was higher in mutant muscles than in the wild-type (P < 0.05), but force development was equivalent in the two groups. Ca2+ transient amplitude increased dramatically in both groups as stimulation rate increased from 0.2 to 4 Hz. Nevertheless, developed force fell at the higher stimulation rates in the mutants but not in controls (P < 0.05). The steady-state force-[Ca2+]i relationship was less steep in mutants (Hill coefficient, 2.94 +/- 0.27 vs. 5.28 +/- 0.64; P > 0.003), with no changes in the [Ca2+]i required for 50% activation or maximal Ca2+-activated force. Thus, calcium cycling and myofilament properties are both altered in FHC mutant mice: more Ca2+ is mobilized to generate force, but this does not suffice to maintain contractility at high stimulation rates.
Collapse
Affiliation(s)
- W D Gao
- Section of Molecular and Cellular Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | |
Collapse
|