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Sharma B, Koren DT, Ghosh S. Nitric oxide modulates NMDA receptor through a negative feedback mechanism and regulates the dynamical behavior of neuronal postsynaptic components. Biophys Chem 2023; 303:107114. [PMID: 37832215 DOI: 10.1016/j.bpc.2023.107114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/22/2023] [Accepted: 09/24/2023] [Indexed: 10/15/2023]
Abstract
Nitric oxide (NO) is known to be an important regulator of neurological processes in the central nervous system which acts directly on the presynaptic neuron and enhances the release of neurotransmitters like glutamate into the synaptic cleft. Calcium influx activates a cascade of biochemical reactions to influence the production of nitric oxide in the postsynaptic neuron. This has been modeled in the present work as a system of ordinary differential equations, to explore the dynamics of the interacting components and predict the dynamical behavior of the postsynaptic neuron. It has been hypothesized that nitric oxide modulates the NMDA receptor via a feedback mechanism and regulates the dynamic behavior of postsynaptic components. Results obtained by numerical analyses indicate that the biochemical system is stimulus-dependent and shows oscillations of calcium and other components within a limited range of concentration. Some of the parameters such as stimulus strength, extracellular calcium concentration, and rate of nitric oxide feedback are crucial for the dynamics of the components in the postsynaptic neuron.
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Affiliation(s)
- Bhanu Sharma
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India
| | | | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India.
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Cai K, Chen H. MiR-625-5p Inhibits Cardiac Hypertrophy Through Targeting STAT3 and CaMKII. HUM GENE THER CL DEV 2020; 30:182-191. [PMID: 31617427 DOI: 10.1089/humc.2019.087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cardiac hypertrophy is an adaptive cardiac response to heart stress. Sustained cardiac hypertrophy indicates higher risk of heart failure. Ca2+/calmodulin-dependent protein kinase II (CaMKII) has been proved to be a key regulator of cardiac hypertrophy, but its mechanism remains largely unknown. Our study proposed to explore the regulatory mechanism of CaMKII in cardiac hypertrophy. We validated that CaMKII was upregulated in cardiac hypertrophy models in vivo and in vitro and that knockdown of CaMKII attenuated Ang II-induced cardiac hypertrophy in vitro. Furthermore, we demonstrated that signal transducer and activator of transcription 3 (STAT3) was highly expressed in cardiac hypertrophy and could stimulate the transactivation of CaMKII. Moreover, we predicted through TargetScan and confirmed that miR-625-5p targeted and inhibited STAT3 so as to reduce the expression of CaMKII. Interestingly, we also found that miR-625-5p directly targeted CaMKII and inhibited its expression. Rescue assays suggested that miR-625-5p attenuated Ang II-induced cardiac hypertrophy through CaMKII/STAT3. Consequently, this study elucidated that miR-625-5p inhibited cardiac hypertrophy through targeting STAT3 and CaMKII, suggesting miR-625-5p as a novel negative regulator of cardiac hypertrophy. Graphical abstract [Figure: see text].
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Affiliation(s)
- Kefeng Cai
- Cardiovascular Department, The Second Affiliated Hospital of Fujian Medical University, Quanzhou City, China
| | - Huiqin Chen
- Department of Basic Medical, Quanzhou Medical College, Quanzhou City, China
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3
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Yu L, Ma X, Sun J, Tong J, Shi L, Sun L, Zhang J. Fluid shear stress induces osteoblast differentiation and arrests the cell cycle at the G0 phase via the ERK1/2 pathway. Mol Med Rep 2017; 16:8699-8708. [PMID: 28990082 PMCID: PMC5779962 DOI: 10.3892/mmr.2017.7720] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 08/10/2017] [Indexed: 11/05/2022] Open
Abstract
Numerous studies have demonstrated that fluid shear stress (FSS) may promote the proliferation and differentiation of osteoblast cells. However, proliferation and differentiation are mutually exclusive processes and are unlikely to be promoted by FSS simultaneously. Cell proliferation and differentiation induced by FSS has rarely been reported. In order to provide an insight into this process, the present study investigated the effects of FSS on osteoblast‑like MC3T3 cells in the G0/G1 phase, the period during which the fate of a cell is determined. The results of the present study demonstrated that FSS promoted alkaline phosphatase (ALP) activity, and the mRNA expression and protein expression of osteocalcin, collagen type I and runt‑related transcription factor 2 (Runx2), while inhibiting DNA synthesis and arresting the cell cycle at the G0/G1 phase. The increase in Runx2 and ALP activity was accompanied by the activation of calcium/calmodulin‑dependent protein kinase type II (CaMK II) and extracellular signal‑regulated kinases 1/2 (ERK1/2), which was completely abolished by treatment with KN93 and U0126, respectively. In addition, the inhibition of ERK1/2, although not CaMK II, decreased p21Cip/Kip activity, resulting in an increase in cell number and S phase re‑entry. The results of the present study indicated that in the G0/G1 phase, FSS promoted osteoblast differentiation via the CaMK II and ERK1/2 signaling pathways, and blocked the cell cycle at the G0/G1 phase via the ERK1/2 pathway only. The present findings provided an increased understanding of osteoblastic mechanobiology.
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Affiliation(s)
- Liyin Yu
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Xingfeng Ma
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Junqin Sun
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Jie Tong
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Liang Shi
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Lijun Sun
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, Shaanxi 710119, P.R. China
| | - Jianbao Zhang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
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Yang X, Chen Y, Li Y, Ren X, Xing Y, Shang H. Effects of Wenxin Keli on Cardiac Hypertrophy and Arrhythmia via Regulation of the Calcium/Calmodulin Dependent Kinase II Signaling Pathway. BIOMED RESEARCH INTERNATIONAL 2017; 2017:1569235. [PMID: 28573136 PMCID: PMC5440795 DOI: 10.1155/2017/1569235] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/05/2017] [Indexed: 12/19/2022]
Abstract
We investigated the effects of Wenxin Keli (WXKL) on the Calcium/Calmodulin dependent kinase II (CaMK II) signal transduction pathway with transverse aortic constriction (TAC) rats. Echocardiographic measurements were obtained 3 and 9 weeks after the surgery. Meanwhile, the action potentials (APDs) were recorded using the whole-cell patch clamp technique, and western blotting was used to assess components of the CaMK II signal transduction pathway. At both 3 and 9 weeks after treatment, the fractional shortening (FS%) increased in the WXKL group compared with the TAC group. The APD90 of the TAC group was longer than that of the Sham group and was markedly shortened by WXKL treatment. Western blotting results showed that the protein expressions of CaMK II, phospholamban (PLB), and ryanodine receptor 2 (RYR2) were not statistically significant among the different groups at both treatment time points. However, WXKL treatment decreased the protein level and phosphorylation of CaMK II (Thr-286) and increased the protein level and phosphorylation of PLB (Thr-17) and the phosphorylation of RYR2 (Ser-2814). WXKL also decreased the accumulation of type III collagen fibers. In conclusion, WXKL may improve cardiac function and inhibit the arrhythmia by regulating the CaMK II signal transduction pathway.
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Affiliation(s)
- Xinyu Yang
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Yu Chen
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
- Fujian Health College, Fuzhou 350101, China
| | - Yanda Li
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Xiaomeng Ren
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Yanwei Xing
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
| | - Hongcai Shang
- The Key Laboratory of Chinese Internal Medicine of the Ministry of Education, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing 100700, China
- Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing 100053, China
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Targeting the CaMKII/ERK Interaction in the Heart Prevents Cardiac Hypertrophy. PLoS One 2015; 10:e0130477. [PMID: 26110816 PMCID: PMC4481531 DOI: 10.1371/journal.pone.0130477] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/20/2015] [Indexed: 11/25/2022] Open
Abstract
Aims Activation of Ca2+/Calmodulin protein kinase II (CaMKII) is an important step in signaling of cardiac hypertrophy. The molecular mechanisms by which CaMKII integrates with other pathways in the heart are incompletely understood. We hypothesize that CaMKII association with extracellular regulated kinase (ERK), promotes cardiac hypertrophy through ERK nuclear localization. Methods and Results In H9C2 cardiomyoblasts, the selective CaMKII peptide inhibitor AntCaNtide, its penetratin conjugated minimal inhibitory sequence analog tat-CN17β, and the MEK/ERK inhibitor UO126 all reduce phenylephrine (PE)-mediated ERK and CaMKII activation and their interaction. Moreover, AntCaNtide or tat-CN17β pretreatment prevented PE induced CaMKII and ERK nuclear accumulation in H9C2s and reduced the hypertrophy responses. To determine the role of CaMKII in cardiac hypertrophy in vivo, spontaneously hypertensive rats were subjected to intramyocardial injections of AntCaNtide or tat-CN17β. Left ventricular hypertrophy was evaluated weekly for 3 weeks by cardiac ultrasounds. We observed that the treatment with CaMKII inhibitors induced similar but significant reduction of cardiac size, left ventricular mass, and thickness of cardiac wall. The treatment with CaMKII inhibitors caused a significant reduction of CaMKII and ERK phosphorylation levels and their nuclear localization in the heart. Conclusion These results indicate that CaMKII and ERK interact to promote activation in hypertrophy; the inhibition of CaMKII-ERK interaction offers a novel therapeutic approach to limit cardiac hypertrophy.
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6
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Aberrant interaction of calmodulin with the ryanodine receptor develops hypertrophy in the neonatal cardiomyocyte. Biochem J 2011; 438:379-87. [PMID: 21649588 DOI: 10.1042/bj20110203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have shown previously that the inter-domain interaction between the two domains of RyR (ryanodine receptor), CaMBD [CaM (calmodulin)-binding domain] and CaMLD (CaM-like domain), activates the Ca(2+) channel, and this process is called activation-link formation [Gangopadhyay and Ikemoto (2008) Biochem. J. 411, 415-423]. Thus CaM that is bound to CaMBD is expected to interfere the activation-link formation, thereby stabilizing the closed state of the channel under normal conditions. In the present paper, we report that, upon stimulation of neonatal cardiomyocytes with the pro-hypertrophy agonist ET-1 (endothelin-1), CaM dissociates from the RyR, which induces a series of intracellular events: increased frequency of Ca(2+) transients, translocation of the signalling molecules CaM, CaMKII (CaM kinase II) and the transcription factor NFAT (nuclear factor of activated T-cells) to the nucleus. These events then lead to the development of hypertrophy. Importantly, an anti-CaMBD antibody that interferes with activation-link formation prevented all of these intracellular events triggered by ET-1 and prevented the development of hypertrophy. These results indicate that the aberrant formation of the activation link between CaMBD and CaMLD of RyR is a key step in the development of hypertrophy in cultured cardiomyocytes.
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Erickson JR, He BJ, Grumbach IM, Anderson ME. CaMKII in the cardiovascular system: sensing redox states. Physiol Rev 2011; 91:889-915. [PMID: 21742790 DOI: 10.1152/physrev.00018.2010] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The multifunctional Ca(2+)- and calmodulin-dependent protein kinase II (CaMKII) is now recognized to play a central role in pathological events in the cardiovascular system. CaMKII has diverse downstream targets that promote vascular disease, heart failure, and arrhythmias, so improved understanding of CaMKII signaling has the potential to lead to new therapies for cardiovascular disease. CaMKII is a multimeric serine-threonine kinase that is initially activated by binding calcified calmodulin (Ca(2+)/CaM). Under conditions of sustained exposure to elevated Ca(2+)/CaM, CaMKII transitions into a Ca(2+)/CaM-autonomous enzyme by two distinct but parallel processes. Autophosphorylation of threonine-287 in the CaMKII regulatory domain "traps" CaMKII into an open configuration even after Ca(2+)/CaM unbinding. More recently, our group identified a pair of methionines (281/282) in the CaMKII regulatory domain that undergo a partially reversible oxidation which, like autophosphorylation, prevents CaMKII from inactivating after Ca(2+)/CaM unbinding. Here we review roles of CaMKII in cardiovascular disease with an eye to understanding how CaMKII may act as a transduction signal to connect pro-oxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of cardiovascular disease.
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Affiliation(s)
- Jeffrey R Erickson
- Department of Pharmacology, University of California at Davis, Davis, California 95616, USA.
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8
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Unraveling the secrets of a double life: contractile versus signaling Ca2+ in a cardiac myocyte. J Mol Cell Cardiol 2011; 52:317-22. [PMID: 21600216 DOI: 10.1016/j.yjmcc.2011.05.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 04/27/2011] [Accepted: 05/03/2011] [Indexed: 11/21/2022]
Abstract
No other inorganic molecule known in biology is considered as versatile as Ca(2+). In a vast majority of cell types, Ca(2+) acts as a universal second messenger underlying critical cellular processes varying from gene transcription to cell death. Although the role of Ca(2+) in myocyte contraction has been known for over a century, it was only more recently that this divalent cation has been implicated in mediating reactive signal transduction to promote cardiac hypertrophy. However, it remains unclear how Ca(2+)-dependent signaling pathways are regulated/activated in a cardiac myocyte given the prevailing conditions throughout the cytosol where Ca(2+) concentration oscillates between 100 nM and upwards of 1-2 μM during each contractile cycle. In this review we will examine three hypotheses put forward to explain how Ca(2+) might still function as a hypertrophic signaling molecule in cardiac myocytes and discuss the current literature that supports each of these views. This article is part of a special issue entitled "Local Signaling in Myocytes."
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9
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Usui T, Okada M, Hara Y, Yamawaki H. Exploring calmodulin-related proteins, which mediate development of hypertension, in vascular tissues of spontaneous hypertensive rats. Biochem Biophys Res Commun 2011; 405:47-51. [DOI: 10.1016/j.bbrc.2010.12.120] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 12/23/2010] [Indexed: 10/18/2022]
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10
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Colomer J, Schmitt AA, Toone EJ, Means AR. Identification and inhibitory properties of a novel Ca(2+)/calmodulin antagonist. Biochemistry 2010; 49:4244-54. [PMID: 20392081 DOI: 10.1021/bi1001213] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We developed a high-throughput yeast-based assay to screen for chemical inhibitors of Ca(2+)/calmodulin-dependent kinase pathways. After screening two small libraries, we identified the novel antagonist 125-C9, a substituted ethyleneamine. In vitro kinase assays confirmed that 125-C9 inhibited several calmodulin-dependent kinases (CaMKs) competitively with Ca(2+)/calmodulin (Ca(2+)/CaM). This suggested that 125-C9 acted as an antagonist for Ca(2+)/CaM rather than for CaMKs. We confirmed this hypothesis by showing that 125-C9 binds directly to Ca(2+)/CaM using isothermal titration calorimetry. We further characterized binding of 125-C9 to Ca(2+)/CaM and compared its properties with those of two well-studied CaM antagonists: trifluoperazine (TFP) and W-13. Isothermal titration calorimetry revealed that binding of 125-C9 to CaM is absolutely Ca(2+)-dependent, likely occurs with a stoichiometry of five 125-C9 molecules to one CaM molecule, and involves an exchange of two protons at pH 7.0. Binding of 125-C9 is driven overall by entropy and appears to be competitive with TFP and W-13, which is consistent with occupation of similar binding sites. To test the effects of 125-C9 in living cells, we evaluated mitogen-stimulated re-entry of quiescent cells into proliferation and found similar, although slightly better, levels of inhibition by 125-C9 than by TFP and W-13. Our results not only define a novel Ca(2+)/CaM inhibitor but also reveal that chemically unique CaM antagonists can bind CaM by distinct mechanisms but similarly inhibit cellular actions of CaM.
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Affiliation(s)
- Josep Colomer
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, P.O. Box 3813, Durham, North Carolina 27710, USA
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Lu YM, Shioda N, Han F, Kamata A, Shirasaki Y, Qin ZH, Fukunaga K. DY-9760e Inhibits Endothelin-1-induced Cardiomyocyte Hypertrophy Through Inhibition of CaMKII and ERK Activities. Cardiovasc Ther 2009; 27:17-27. [DOI: 10.1111/j.1755-5922.2008.00068.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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12
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Enayetul Babar SM, Song EJ, Yoo YS. Analysis of calcineurin activity by capillary electrophoresis with laser-induced fluorescence detection using peptide substrate. J Sep Sci 2008; 31:579-87. [DOI: 10.1002/jssc.200700326] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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13
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Bossuyt J, Helmstadter K, Wu X, Clements-Jewery H, Haworth RS, Avkiran M, Martin JL, Pogwizd SM, Bers DM. Ca2+/calmodulin-dependent protein kinase IIdelta and protein kinase D overexpression reinforce the histone deacetylase 5 redistribution in heart failure. Circ Res 2008; 102:695-702. [PMID: 18218981 DOI: 10.1161/circresaha.107.169755] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac hypertrophy and heart failure (HF) are associated with reactivation of fetal cardiac genes, and class II histone deacetylases (HDACs) (eg, HDAC5) have been strongly implicated in this process. We have shown previously that inositol trisphosphate, Ca2+/calmodulin-dependent protein kinase II (CaMKII), and protein kinase (PK)D are involved in HDAC5 phosphorylation and nuclear export in normal adult ventricular myocytes and also that CaMKIIdelta and inositol trisphosphate receptors are upregulated in HF. Here we tested whether, in our rabbit HF model, nucleocytoplasmic shuttling of HDAC5 was altered either at baseline or in response to endothelin-1, which would indicate HDAC5 phosphorylation and transcription effects. The fusion protein HDAC5-green fluorescent protein (HDAC5-GFP) was more cytosolic in HF myocytes (F(nuc)/F(cyto) 3.3+/-0.3 vs 7.2+/-0.4 in control), and HDAC5 was more phosphorylated. Despite this baseline cytosolic HDAC5 shift, endothelin-1 produced more rapid HDAC5-GFP nuclear export in HF versus control myocytes. We also find that PKD and CaMKIIdelta(C) expression and activation state are increased in both rabbit and human HF. Inhibition of either CaMKII or PKD in HF myocytes partially restored the HDAC5-GFP F(nuc)/F(cyto) toward control, and simultaneous inhibition restored F(nuc)/F(cyto) to that in control myocytes. Moreover, adenovirus-mediated overexpression of PKD, CaMKIIdelta(B), or CaMKIIdelta(C) reduced baseline HDAC5 F(nuc)/F(cyto) in control myocytes (3.4+/-0.5, 3.8+/-0.5, and 5.2+/-0.5, respectively), approaching that seen in HF. We conclude that chronic upregulation and activation of inositol trisphosphate receptors, CaMKII, and PKD in HF shifts HDAC5 out of the nucleus, derepressing transcription of hypertrophic genes. This may directly contribute to the development and/or maintenance of HF.
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Affiliation(s)
- Julie Bossuyt
- Department of Physiology, Loyola University Chicago, Maywood, IL 60153, USA
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14
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Zhang T, Kohlhaas M, Backs J, Mishra S, Phillips W, Dybkova N, Chang S, Ling H, Bers DM, Maier LS, Olson EN, Brown JH. CaMKIIdelta isoforms differentially affect calcium handling but similarly regulate HDAC/MEF2 transcriptional responses. J Biol Chem 2007; 282:35078-87. [PMID: 17923476 DOI: 10.1074/jbc.m707083200] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The delta(B) and delta(C) splice variants of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), which differ by the presence of a nuclear localization sequence, are both expressed in cardiomyocytes. We used transgenic (TG) mice and CaMKII expression in cardiomyocytes to test the hypothesis that the CaMKIIdelta(C) isoform regulates cytosolic Ca(2+) handling and the delta(B) isoform, which localizes to the nucleus, regulates gene transcription. Phosphorylation of CaMKII sites on the ryanodine receptor (RyR) and on phospholamban (PLB) were increased in CaMKIIdelta(C) TG. This was associated with markedly enhanced sarcoplasmic reticulum (SR) Ca(2+) spark frequency and decreased SR Ca(2+) content in cardiomyocytes. None of these parameters were altered in TG mice expressing the nuclear-targeted CaMKIIdelta(B). In contrast, cardiac expression of either CaMKIIdelta(B) or delta(C) induced transactivation of myocyte enhancer factor 2 (MEF2) gene expression and up-regulated hypertrophic marker genes. Studies using rat ventricular cardiomyocytes confirmed that CaMKIIdelta(B) and delta(C) both regulate MEF2-luciferase gene expression, increase histone deacetylase 4 (HDAC4) association with 14-3-3, and induce HDAC4 translocation from nucleus to cytoplasm, indicating that either isoform can stimulate HDAC4 phosphorylation. Finally, HDAC4 kinase activity was shown to be increased in cardiac homogenates from either CaMKIIdelta(B) or delta(C) TG mice. Thus CaMKIIdelta isoforms have similar effects on hypertrophic gene expression but disparate effects on Ca(2+) handling, suggesting distinct roles for CaMKIIdelta isoform activation in the pathogenesis of cardiac hypertrophy versus heart failure.
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Affiliation(s)
- Tong Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0636, USA.
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15
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Kirchhefer U, Klimas J, Baba HA, Buchwalow IB, Fabritz L, Hüls M, Matus M, Müller FU, Schmitz W, Neumann J. Triadin is a critical determinant of cellular Ca cycling and contractility in the heart. Am J Physiol Heart Circ Physiol 2007; 293:H3165-74. [PMID: 17890426 DOI: 10.1152/ajpheart.00799.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Triadin is involved in the regulation of cardiac excitation-contraction coupling. However, the extent of its contribution to the regulation of sarcoplasmic reticulum (SR) Ca release remains unclear, because overexpression of triadin in single-transgenic mice was associated with the downregulation of its homologous protein, junctin. In the present study, this problem was circumvented by cross-breeding of mice with heart-directed overexpression of triadin and junctin (JxT). This resulted in a stable approximately threefold expression of total triadin but unchanged junctin protein. Transgenic mice exhibited cardiac hypertrophy and structural abnormalities of myofibrils. Measurement of cardiac function by echocardiography and edge detection in myocytes revealed an impaired relaxation in JxT mice. The stimulation of beta-adrenergic receptors resulted in a depressed contractility and an impaired relaxation in catheterized hearts and myocytes of JxT mice. The use of a maximum stimulation frequency (5 Hz) was associated with both a lower shortening and relengthening in isolated myocytes of JxT mice. The contractile effects in JxT myocytes were paralleled by similar changes of the intracellular Ca concentration ([Ca](i)) peak amplitude and Ca transient decay kinetics at basal conditions, under administration of isoproterenol, and with high-frequency stimulation. Finally, we found a higher caffeine-induced [Ca](i) peak amplitude in JxT myocytes. Our data show that the stable expression of triadin, independent of junctin expression, resulted in cardiac hypertrophy, prolonged basal relaxation, a depressed response to beta-adrenergic agonists, and altered Ca transients. Thus the maintenance of triadin expression is essential for normal SR Ca cycling and contractile function.
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Affiliation(s)
- Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Münster, Germany.
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16
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Colomer JM, Illario M, Means AR. The Roles of CaMKII in the Genesis of Cardiac Hypertrophy. High Blood Press Cardiovasc Prev 2007. [DOI: 10.2165/00151642-200714010-00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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17
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Grueter CE, Colbran RJ, Anderson ME. CaMKII, an emerging molecular driver for calcium homeostasis, arrhythmias, and cardiac dysfunction. J Mol Med (Berl) 2006; 85:5-14. [PMID: 17119905 DOI: 10.1007/s00109-006-0125-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 10/04/2006] [Accepted: 10/10/2006] [Indexed: 01/11/2023]
Abstract
Maintenance of cytoplasmic calcium homeostasis is critical for all cells. An exciting field has emerged in elucidating the multiple roles that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) plays in regulating Ca(2+) cycling in normal cardiac myocytes and in pathophysiological states. Moreover, CaMKII was recently identified as a potential drug target in cardiac disease. This work has given us a closer view of the complexity and therapeutic possibilities of CaMKII regulation of Ca(2+) signaling in cardiac myocytes.
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Affiliation(s)
- Chad E Grueter
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
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18
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Wu X, Bers DM. Free and bound intracellular calmodulin measurements in cardiac myocytes. Cell Calcium 2006; 41:353-64. [PMID: 16999996 PMCID: PMC1868497 DOI: 10.1016/j.ceca.2006.07.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Revised: 07/12/2006] [Accepted: 07/17/2006] [Indexed: 10/24/2022]
Abstract
Calmodulin (CaM) is a ubiquitous Ca2+ binding protein and Ca2+-CaM activates many cellular targets and functions. While much of CaM is thought to be protein bound, quantitative data in cardiac myocytes is lacking regarding CaM location, [CaM]free and CaM redistribution during changes in [Ca2+]i. Here, we demonstrated that in adult rabbit cardiac myocytes, CaM is highly concentrated at Z-lines (confirmed by Di-8-ANEPPS staining of transverse tubules) using three different approaches: immunocytochemistry (endogenous CaM), Alexa Fluor 488 conjugate CaM (F-CaM) in both permeabilized cells (exogenous CaM) and in patch clamped intact cells (via pipette dialysis). Using 100 nM [CaM]free we washed F-CaM into permeabilized myocytes and saw a two-phase (fast and slow) CaM binding curve with a plateau after 40 min of F-CaM wash-in. We also measured myocyte [CaM]free using two modified null-point titration methods, finding [CaM]free to be 50-75 nM (which is only 1% of total [CaM]). Higher [Ca2+]i increased CaM binding especially in the nucleus and at Z-lines and significantly slowed F-CaM dissociation rate when F-CaM was washed out of permeabilized myocytes. Additionally, in both permeabilized and intact myocytes, CaM moved into the nucleus when [Ca2+]i was elevated, and this was reversible. We conclude that [CaM]free is very low in myocytes even at resting [Ca2+]i, indicating intense competition of CaM targets for free CaM. Bound CaM is relatively concentrated at Z-lines at rest but translocates significantly to the nucleus upon elevation of [Ca2+]i, which may influence activation of different targets and cellular functions.
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Affiliation(s)
- Xu Wu
- Department of Physiology, Loyola University Chicago, 2160 S First Ave., Maywood, IL 60153, United States
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19
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Backs J, Song K, Bezprozvannaya S, Chang S, Olson EN. CaM kinase II selectively signals to histone deacetylase 4 during cardiomyocyte hypertrophy. J Clin Invest 2006; 116:1853-64. [PMID: 16767219 PMCID: PMC1474817 DOI: 10.1172/jci27438] [Citation(s) in RCA: 393] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 04/18/2006] [Indexed: 01/05/2023] Open
Abstract
Class IIa histone deacetylases (HDACs) regulate a variety of cellular processes, including cardiac growth, bone development, and specification of skeletal muscle fiber type. Multiple serine/threonine kinases control the subcellular localization of these HDACs by phosphorylation of common serine residues, but whether certain class IIa HDACs respond selectively to specific kinases has not been determined. Here we show that calcium/calmodulin-dependent kinase II (CaMKII) signals specifically to HDAC4 by binding to a unique docking site that is absent in other class IIa HDACs. Phosphorylation of HDAC4 by CaMKII promotes nuclear export and prevents nuclear import of HDAC4, with consequent derepression of HDAC target genes. In cardiomyocytes, CaMKII phosphorylation of HDAC4 results in hypertrophic growth, which can be blocked by a signal-resistant HDAC4 mutant. These findings reveal a central role for HDAC4 in CaMKII signaling pathways and have implications for the control of gene expression by calcium signaling in a variety of cell types.
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Affiliation(s)
- Johannes Backs
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA
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20
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Wu X, Zhang T, Bossuyt J, Li X, McKinsey TA, Dedman JR, Olson EN, Chen J, Brown JH, Bers DM. Local InsP3-dependent perinuclear Ca2+ signaling in cardiac myocyte excitation-transcription coupling. J Clin Invest 2006; 116:675-82. [PMID: 16511602 PMCID: PMC1386110 DOI: 10.1172/jci27374] [Citation(s) in RCA: 369] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Accepted: 01/03/2006] [Indexed: 11/17/2022] Open
Abstract
Previous work showed that calmodulin (CaM) and Ca2+-CaM-dependent protein kinase II (CaMKII) are somehow involved in cardiac hypertrophic signaling, that inositol 1,4,5-trisphosphate receptors (InsP3Rs) in ventricular myocytes are mainly in the nuclear envelope, where they associate with CaMKII, and that class II histone deacetylases (e.g., HDAC5) suppress hypertrophic gene transcription. Furthermore, HDAC phosphorylation in response to neurohumoral stimuli that induce hypertrophy, such as endothelin-1 (ET-1), activates HDAC nuclear export, thereby regulating cardiac myocyte transcription. Here we demonstrate a detailed mechanistic convergence of these 3 issues in adult ventricular myocytes. We show that ET-1, which activates plasmalemmal G protein-coupled receptors and InsP3 production, elicits local nuclear envelope Ca2+ release via InsP3R. This local Ca2+ release activates nuclear CaMKII, which triggers HDAC5 phosphorylation and nuclear export (derepressing transcription). Remarkably, this Ca2+-dependent pathway cannot be activated by the global Ca2+ transients that cause contraction at each heartbeat. This novel local Ca2+ signaling in excitation-transcription coupling is analogous to but separate (and insulated) from that involved in excitation-contraction coupling. Thus, myocytes can distinguish simultaneous local and global Ca2+ signals involved in contractile activation from those targeting gene expression.
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MESH Headings
- Active Transport, Cell Nucleus/physiology
- Animals
- Calcium Channels/deficiency
- Calcium Channels/genetics
- Calcium Signaling/physiology
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors
- Calmodulin/metabolism
- Cells, Cultured
- Endothelin-1/physiology
- Histone Deacetylases/metabolism
- Inositol 1,4,5-Trisphosphate/physiology
- Inositol 1,4,5-Trisphosphate Receptors
- Mice
- Mice, Knockout
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/physiology
- Nuclear Envelope/enzymology
- Nuclear Envelope/metabolism
- Nuclear Envelope/physiology
- Rabbits
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Transcription, Genetic/physiology
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Affiliation(s)
- Xu Wu
- Loyola University Chicago, Chicago, Illinois 60153, USA
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21
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Obata K, Nagata K, Iwase M, Odashima M, Nagasaka T, Izawa H, Murohara T, Yamada Y, Yokota M. Overexpression of calmodulin induces cardiac hypertrophy by a calcineurin-dependent pathway. Biochem Biophys Res Commun 2005; 338:1299-305. [PMID: 16256941 DOI: 10.1016/j.bbrc.2005.10.083] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 10/09/2005] [Indexed: 11/23/2022]
Abstract
The possible role of calcineurin in cardiac hypertrophy induced by calmodulin (CaM) overexpression in the heart was investigated. CaM transgenic (CaM-TG) mice developed marked cardiac hypertrophy and exhibited up-regulation of atrial natriuretic factor (ANF) and beta-myosin heavy chain gene expression in the heart during the first 2 weeks after birth. The activity of calcineurin in the heart was also significantly increased in CaM-TG mice compared with wild-type littermates. Treatment of CaM-TG mice with the calcineurin inhibitor FK506 (1mg/kg per day) prevented the increase in the heart-to-body weight ratio as well as that in cardiomyocyte width. FK506 also inhibited the induction of fetal-type cardiac gene expression in CaM-TG mice. Overexpression of CaM in cultured rat cardiomyocytes activated the ANF gene promoter in a manner sensitive to FK506. Activation of a calcineurin-dependent pathway thus contributes to the development of cardiac hypertrophy induced by CaM overexpression in the heart.
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Affiliation(s)
- Koji Obata
- Department of Cardiovascular Genome Science, Nagoya University School of Medicine, Nagoya, Japan
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22
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Maier LS. CaMKIIdelta overexpression in hypertrophy and heart failure: cellular consequences for excitation-contraction coupling. Braz J Med Biol Res 2005; 38:1293-302. [PMID: 16138211 DOI: 10.1590/s0100-879x2005000900002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ca/calmodulin-dependent protein kinase IIdelta (CaMKIIdelta) is the predominant isoform in the heart. During excitation-contraction coupling (ECC) CaMKII phosphorylates several Ca-handling proteins including ryanodine receptors (RyR), phospholamban, and L-type Ca channels. CaMKII expression and activity have been shown to correlate positively with impaired ejection fraction in the myocardium of patients with heart failure and CaMKII has been proposed to be a possible compensatory mechanism to keep hearts from complete failure. However, in addition to these acute effects on ECC, CaMKII was shown to be involved in hypertrophic signaling, termed excitation-transcription coupling (ETC). Thus, animal models have shown that overexpression of nuclear isoform CaMKIIdeltaB can induce myocyte hypertrophy. Recent study from our laboratory has suggested that transgenic overexpression of the cytosolic isoform CaMKIIdeltaC in mice causes severe heart failure with altered intracellular Ca handling and protein expression leading to reduced sarcoplasmic reticulum (SR) Ca content. Interestingly, the frequency of diastolic spontaneous SR Ca release events (or opening of RyR) was greatly enhanced, demonstrating increased diastolic SR Ca leak. This was attributed to increased CaMKII-dependent RyR phosphorylation, resulting in increased and prolonged openings of RyR since Ca spark frequency could be reduced back to normal levels by CaMKII inhibition. This review focuses on acute and chronic effects of CaMKII in ECC and ETC. In summary, CaMKII overexpression can lead to heart failure and CaMKII-dependent RyR hyperphosphorylation seems to be a novel and important mechanism in ECC due to SR Ca leak which may be important in the pathogenesis of heart failure.
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Affiliation(s)
- L S Maier
- Abteilung Kardiologie and Pneumologie, Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany.
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23
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Zayzafoon M, Fulzele K, McDonald JM. Calmodulin and Calmodulin-dependent Kinase IIα Regulate Osteoblast Differentiation by Controlling c-fos Expression. J Biol Chem 2005; 280:7049-59. [PMID: 15590632 DOI: 10.1074/jbc.m412680200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Ca(2+)/calmodulin-dependent protein kinase IIalpha (alpha-CaMKII) was once thought to be exclusively expressed in neuronal tissue, but it is becoming increasingly evident that CaMKII is also expressed in various extraneural cells. CaMKII plays a critical role in regulating various signaling pathways leading to modulation of several aspects of cellular functions, including proliferation, differentiation, cytoskeletal structure, and gene expression. The purpose of this study was to examine the expression of CaMKII in osteoblast-like cells (MC4) and to elucidate its role in osteoblast differentiation. We demonstrated that CaMKII, specifically the alpha isoform, is expressed in osteoblasts both in vitro and in vivo. Inhibition of CaMKII by the calmodulin antagonist trifluoperazine or the CaMKII antagonist KN93 reduces alkaline phosphatase activity and mineralization, as well as causes 85 and 56% decreases in alkaline phosphatase and osteocalcin gene expression, respectively. CaM and CaMKII antagonists, using the newborn mouse calvaria in vivo model, cause a 50% decrease in osteoblast number (N.Ob-BS) and a 32% decrease in mineralization (BV/TV). Pharmacologic and genetic inhibition of alpha-CaMKII by using trifluoperazine, KN93, and alpha-CaMKII small interfering RNA decreases the phosphorylation of ERK and of cAMP-response element-binding protein, leading to a significant decrease in the transactivation of serum response element and cAMP-response element. Inhibition of alpha-CaMKII decreases the expression of c-fos, AP-1 transactivation, and AP-1 DNA binding activity. Our findings demonstrated that alpha-CaMKII is expressed in osteoblasts and is involved in c-fos expression via regulation of serum response element and cAMP-response element. Inhibition of alpha-CaMKII results in a decrease in c-fos expression and AP-1 activation, leading to inhibition of osteoblast differentiation.
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Affiliation(s)
- Majd Zayzafoon
- Department of Pathology, University of Alabama at Birmingham, USA
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24
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Colomer JM, Terasawa M, Means AR. Targeted expression of calmodulin increases ventricular cardiomyocyte proliferation and deoxyribonucleic acid synthesis during mouse development. Endocrinology 2004; 145:1356-66. [PMID: 14670993 DOI: 10.1210/en.2003-1119] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cell signaling pathways that control ventricular cardiomyocyte proliferation during development are poorly understood. Here we show that increasing levels of the ubiquitous Ca(2+) receptor calmodulin (CaM) can regulate cardiomyocyte proliferation in vivo. Targeted overexpression of calmodulin in the heart during embryonic development leads to a 37% or a 79% increase in the number of ventricular myocytes present at embryonic d 17 in mice heterozygous or homozygous for the transgene, respectively. Whereas all homozygous mice die within 10 d after birth, most of the heterozygous mice survive even though they contain 40% more ventricular myocytes relative to the wild-type mice throughout development and into adulthood. The CaM transgene continues to be overexpressed postnatally and, although cell proliferation ceases soon after birth, the elevated levels of CaM lead to an increase in DNA synthesis, which correlates with an increase in the degree of ventricular myocyte polyploidy. Only after proliferation has ceased and polyploidy has become maximal does the continued presence of overexpressed CaM lead to ventricular hypertrophy. However, unlike the case for myocyte number, turning off expression of the CaM transgene results in regression of the hypertrophic response. Together, our results reveal that excess CaM enhances the extent of cell proliferation and DNA synthesis as well as development of hypertrophy of ventricular myocytes in vivo, in a manner consistent with the normal timing of these events during heart development.
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Affiliation(s)
- Josep M Colomer
- Department of Pharmacology and Cancer Biology, Box 3813, Durham, North Carolina 27710, USA
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25
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Illario M, Cavallo AL, Bayer KU, Di Matola T, Fenzi G, Rossi G, Vitale M. Calcium/calmodulin-dependent protein kinase II binds to Raf-1 and modulates integrin-stimulated ERK activation. J Biol Chem 2003; 278:45101-8. [PMID: 12954639 DOI: 10.1074/jbc.m305355200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrin activation generates different signalings in a cell type-dependent manner and stimulates cell proliferation through the Ras/Raf-1/Mek/Erk pathway. In this study, we demonstrate that integrin stimulation by fibronectin (FN), besides activating the Ras/Erk pathway, generates an auxiliary calcium signal that activates calmodulin and the Ca2+/calmodulin-dependent protein kinase II (CaMKII). This signal regulates Raf-1 activation by Ras and modulates the FN-stimulated extracellular signal-regulated kinase (Erk-1/2). The binding of soluble FN to integrins induced increase of intracellular calcium concentration associated with phosphorylation and activation of CaMKII. In two different cell lines, inhibition of CaMKII activity by specific inhibitors inhibited Erk-1/2 phosphorylation. Whereas CaMK inhibition affected neither integrin-stimulated Akt phosphorylation nor p21Ras or Mek-1 activity, it was necessary for Raf-1 activity. FN-induced Raf-1 activity was abrogated by the CaMKII specific inhibitory peptide ant-CaNtide. Integrin activation by FN induced the formation of a Raf-1/CaMKII complex, abrogated by inhibition of CaMKII. Active CaMKII phosphorylated Raf-1 in vitro. This is the first demonstration that CaMKII interplays with Raf-1 and regulates Erk activation induced by Ras-stimulated Raf-1. These findings also provide evidence supporting the possible existence of cross-talk between other intracellular pathways involving CaMKII and Raf-1.
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Affiliation(s)
- Maddalena Illario
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico II, Napoli, 80131 Italy
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26
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Zhang T, Maier LS, Dalton ND, Miyamoto S, Ross J, Bers DM, Brown JH. The deltaC isoform of CaMKII is activated in cardiac hypertrophy and induces dilated cardiomyopathy and heart failure. Circ Res 2003; 92:912-9. [PMID: 12676814 DOI: 10.1161/01.res.0000069686.31472.c5] [Citation(s) in RCA: 439] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recent studies have demonstrated that transgenic (TG) expression of either Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) or CaMKIIdeltaB, both of which localize to the nucleus, induces cardiac hypertrophy. However, CaMKIV is not present in heart, and cardiomyocytes express not only the nuclear CaMKIIdeltaB but also a cytoplasmic isoform, CaMKIIdeltaC. In the present study, we demonstrate that expression of the deltaC isoform of CaMKII is selectively increased and its phosphorylation elevated as early as 2 days and continuously for up to 7 days after pressure overload. To determine whether enhanced activity of this cytoplasmic deltaC isoform of CaMKII can lead to phosphorylation of Ca2+ regulatory proteins and induce hypertrophy, we generated TG mice that expressed the deltaC isoform of CaMKII. Immunocytochemical staining demonstrated that the expressed transgene is confined to the cytoplasm of cardiomyocytes isolated from these mice. These mice develop a dilated cardiomyopathy with up to a 65% decrease in fractional shortening and die prematurely. Isolated myocytes are enlarged and exhibit reduced contractility and altered Ca2+ handling. Phosphorylation of the ryanodine receptor (RyR) at a CaMKII site is increased even before development of heart failure, and CaMKII is found associated with the RyR in immunoprecipitates from the CaMKII TG mice. Phosphorylation of phospholamban is also increased specifically at the CaMKII but not at the PKA phosphorylation site. These findings are the first to demonstrate that CaMKIIdeltaC can mediate phosphorylation of Ca2+ regulatory proteins in vivo and provide evidence for the involvement of CaMKIIdeltaC activation in the pathogenesis of dilated cardiomyopathy and heart failure.
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MESH Headings
- Animals
- Blotting, Western
- Calcium/metabolism
- Calcium-Binding Proteins/metabolism
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Calcium-Calmodulin-Dependent Protein Kinases/genetics
- Calcium-Calmodulin-Dependent Protein Kinases/metabolism
- Cardiomegaly/enzymology
- Cardiomegaly/mortality
- Cardiomegaly/pathology
- Cardiomyopathy, Dilated/enzymology
- Cardiomyopathy, Dilated/pathology
- Cell Size/physiology
- Cells, Cultured
- Constriction, Pathologic/physiopathology
- Enzyme Activation
- Female
- Gene Expression Regulation, Enzymologic
- Heart Failure/enzymology
- Heart Failure/pathology
- Heart Ventricles/pathology
- Heart Ventricles/physiopathology
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Myocardium/enzymology
- Myocardium/pathology
- Phosphorylation
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Ryanodine Receptor Calcium Release Channel/metabolism
- Survival Rate
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Affiliation(s)
- Tong Zhang
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Dr, La Jolla, Calif 92093-0636, USA
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27
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Abstract
Calcium (Ca) is the key regulator of cardiac contraction during excitation-contraction (E-C) coupling. However, differences exist between the amount of Ca being transported into the myocytes upon electrical stimulation as compared to Ca released from the sarcoplasmic reticulum (SR). Moreover, alterations in E-C coupling occur in cardiac hypertrophy and heart failure. In addition to the direct effects of Ca on the myofilaments, Ca plays a pivotal role in activation of a number of Ca-dependent proteins or second messengers, which can modulate E-C coupling. Of these proteins, calmodulin (CaM) and Ca-CaM-dependent kinase II (CaMKII) are of special interest in the heart because of their role of modulating Ca influx, SR Ca release, and SR Ca uptake during E-C coupling. Indeed, CaM and CaMKII may be associated with some ion channels and Ca transporters and both can modulate acute cellular Ca handling. In addition to the changes in Ca, CaM and CaMKII signals from beat-to-beat, changes may occur on a longer time scale. These may occur over seconds to minutes involving phosphorylation/dephosphorylation reactions, and even a longer time frame in altering gene transcription (excitation-transcription (E-T) coupling) in hypertrophic signaling and heart failure. Here we review the classical role of Ca in E-C coupling and extend this view to the role of the Ca-dependent proteins CaM and CaMKII in modulating E-C coupling and their contribution to E-T coupling.
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Affiliation(s)
- Lars S Maier
- Department of Physiology, Stritch School of Medicine, Loyola University-Chicago, 2160 South First Avenue, Chicago, IL 60153, USA
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28
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Li J, Pucéat M, Perez-Terzic C, Mery A, Nakamura K, Michalak M, Krause KH, Jaconi ME. Calreticulin reveals a critical Ca(2+) checkpoint in cardiac myofibrillogenesis. J Cell Biol 2002; 158:103-13. [PMID: 12105184 PMCID: PMC2173019 DOI: 10.1083/jcb.200204092] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2002] [Revised: 05/30/2002] [Accepted: 05/30/2002] [Indexed: 11/22/2022] Open
Abstract
Calreticulin (crt) is an ubiquitously expressed and multifunctional Ca(2+)-binding protein that regulates diverse vital cell functions, including Ca(2+) storage in the ER and protein folding. Calreticulin deficiency in mice is lethal in utero due to defects in heart development and function. Herein, we used crt(-/-) embryonic stem (ES) cells differentiated in vitro into cardiac cells to investigate the molecular mechanisms underlying heart failure of knockout embryos. After 8 d of differentiation, beating areas were prominent in ES-derived wild-type (wt) embryoid bodies (EBs), but not in ES-derived crt(-/-) EBs, despite normal expression levels of cardiac transcription factors. Crt(-/-) EBs exhibited a severe decrease in expression and a lack of phosphorylation of ventricular myosin light chain 2 (MLC2v), resulting in an impaired organization of myofibrils. Crt(-/-) phenotype could be recreated in wt cells by chelating extracellular or cytoplasmic Ca(2+) with EGTA or BAPTA, or by inhibiting Ca(2+)/calmodulin-dependent kinases (CaMKs). An imposed ionomycin-triggered cystolic-free Ca(2+) concentration ([Ca(2+)](c)) elevation restored the expression, phosphorylation, and insertion of MLC2v into sarcomeric structures and in turn the myofibrillogenesis. The transcription factor myocyte enhancer factor C2 failed to accumulate into nuclei of crt(-/-) cardiac cells in the absence of ionomycin-triggered [Ca(2+)](c) increase. We conclude that the absence of calreticulin interferes with myofibril formation. Most importantly, calreticulin deficiency revealed the importance of a Ca(2+)-dependent checkpoint critical for early events during cardiac myofibrillogenesis.
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Affiliation(s)
- Jian Li
- Biology of Aging Laboratory, Department of Geriatrics, Geneva University Hospitals, Geneva 1225, Switzerland
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29
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Zhang T, Johnson EN, Gu Y, Morissette MR, Sah VP, Gigena MS, Belke DD, Dillmann WH, Rogers TB, Schulman H, Ross J, Brown JH. The cardiac-specific nuclear delta(B) isoform of Ca2+/calmodulin-dependent protein kinase II induces hypertrophy and dilated cardiomyopathy associated with increased protein phosphatase 2A activity. J Biol Chem 2002; 277:1261-7. [PMID: 11694533 DOI: 10.1074/jbc.m108525200] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The delta isoform of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) predominates in the heart. To investigate the role of CaMKII in cardiac function, we made transgenic (TG) mice that express the nuclear delta(B) isoform of CaMKII. The expressed CaMKIIdelta(B) transgene was restricted to the myocardium and highly concentrated in the nucleus. Cardiac hypertrophy was evidenced by an increased left ventricle to body weight ratio and up-regulation of embryonic and contractile protein genes including atrial natriuretic factor, beta-myosin heavy chain, and alpha-skeletal actin. Echocardiography revealed ventricular dilation and decreased cardiac function, which was also observed in hemodynamic measurements from CaMKIIdelta(B) TG mice. Surprisingly, phosphorylation of phospholamban at both Thr(17) and Ser(16) was significantly decreased in the basal state as well as upon adrenergic stimulation. This was associated with diminished sarcoplasmic reticulum Ca(2+) uptake in vitro and altered relaxation properties in vivo. The activity and expression of protein phosphatase 2A were both found to be increased in CaMKII TG mice, and immunoprecipitation studies indicated that protein phosphatase 2A directly associates with CaMKII. Our findings are the first to demonstrate that CaMKII can induce hypertrophy and dilation in vivo and indicate that compensatory increases in phosphatase activity contribute to the resultant phenotype.
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Affiliation(s)
- Tong Zhang
- Department of Pharmacology and Medicine, University of California, San Diego, La Jolla, California 92093, USA
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30
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Frey N, McKinsey TA, Olson EN. Decoding calcium signals involved in cardiac growth and function. Nat Med 2000; 6:1221-7. [PMID: 11062532 DOI: 10.1038/81321] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Calcium is central in the regulation of cardiac contractility, growth and gene expression. Variations in the amplitude, frequency and compartmentalization of calcium signals are decoded by calcium/calmodulin-dependent enzymes, ion channels and transcription factors. Understanding the circuitry for calcium signaling creates opportunities for pharmacological modification of cardiac function.
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Affiliation(s)
- N Frey
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, Texas 75390-9148, USA
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