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Abstract
BACKGROUND The cardiac nitric oxide and endothelin-1 (ET-1) systems are closely linked and play a critical role in cardiac physiology. The balance between both systems is often disturbed in cardiovascular diseases. To define the cardiac effect of excessive ET-1 in a status of nitric oxide deficiency, we compared left ventricular function and morphology in wild-type mice, ET-1 transgenic (ET(+/+)) mice, endothelial nitric oxide synthase knockout (eNOS(-/-)) mice, and ET(+/+)eNOS(-/-) mice. METHODS AND RESULTS eNOS(-/-) and ET(+/+)eNOS(-/-) mice developed high blood pressure compared with wild-type and ET(+/+) mice. Left ventricular catheterization showed that eNOS(-/-) mice, but not ET(+/+)eNOS(-/-) , developed diastolic dysfunction characterized by increased end-diastolic pressure and relaxation constant tau. To elucidate the causal molecular mechanisms driving the rescue of diastolic function in ET(+/+)eNOS(-/-) mice, the cardiac proteome was analyzed. Two-dimensional gel electrophoresis coupled to mass spectrometry offers an appropriate hypothesis-free approach. ET-1 overexpression on an eNOS(-/-) background led to an elevated abundance and change in posttranslational state of antioxidant enzymes (e.g., peroxiredoxin-6, glutathione S-transferase mu 2, and heat shock protein beta 7). In contrast to ET(+/+)eNOS(-/-) mice, eNOS(-/-) mice showed an elevated abundance of proteins responsible for sarcomere disassembly (e.g., cofilin-1 and cofilin-2). In ET(+/+)eNOS(-/-) mice, glycolysis was favored at the expense of fatty acid oxidation. CONCLUSION eNOS(-/-) mice developed diastolic dysfunction; this was rescued by ET-1 transgenic overexpression. This study furthermore suggests that cardiac ET-1 overexpression in case of eNOS deficiency causes specifically the regulation of proteins playing a role in oxidative stress, myocytes contractility, and energy metabolism.
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52
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Kimura A. Contribution of genetic factors to the pathogenesis of dilated cardiomyopathy: the cause of dilated cardiomyopathy: genetic or acquired? (genetic-side). Circ J 2011; 75:1756-65; discussion 1765. [PMID: 21617319 DOI: 10.1253/circj.cj-11-0368] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dilated cardiomyopathy (DCM) is characterized by dilated ventricles and systolic dysfunction. Its etiology is not fully unraveled, but both extrinsic and intrinsic factors are considered to be involved. The intrinsic factors include genetic variations in the genes (ie, disease-causing mutations and disease-associated polymorphisms), which play key roles in controlling the susceptibility to the disease by affecting the performance, regulation, and/or maintenance of cardiac function. DCM can be classified into 2 types: hereditary and non-hereditary. The genetic variations, or disease-causing mutations, contributing to the pathogenesis of hereditary DCM can be found in various genes, especially those for sarcolemma elements, contractile elements, Z-disc elements, sarcoplasmic elements, and nuclear lamina elements of cardiomyocytes. On the other hand, disease-associated polymorphisms, which control the susceptibility to non-hereditary DCM, may be found in genes expressing not only in cardiomyocytes but also other non-cardiac cells involved in the immune system. Because functional alterations caused by these genetic variations can be classified into several categories, it is necessary to understand the pathogenesis and hence to develop diagnostic and therapeutic strategies for both hereditary and non-hereditary DCM from the viewpoint of genetic factors.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, and Laboratory of Genome Diversity, Graduate School of Biomedical Science, Tokyo Medical and Dental University
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53
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Abstract
Costameres are sub-membranous, Z-line associated structures found in striated muscle. They have been shown to have important roles in transmission of force from the sarcomere to the sarcolemma and extracellular matrix, maintaining mechanical integrity of the sarcolemma, and orchestrating mechanically related signaling. The costamere is akin to the more well-known focal adhesion complex present in most cells. The Z-line is a critical structural anchor for the sarcomere, but it is also a hot-spot for muscle cell signaling. Therefore functionally, the costamere represents a two-way signaling highway tethered between the Z-line and the extracellular matrix, relaying mechanical stress signals from outside the cell to intracellular signaling networks. In this role it can modulate myofibril growth and contraction. The major force generated by sarcomeres is transduced in the lateral direction from the sarcomere to the extracellular matrix through the costamere. Two major protein complexes have been described at the costamere: the dystrophin-glycoprotein complex and the integrin-vinculin-talin complex. The importance of these two protein complexes in striated muscle function has between demonstrated both in human disease and mouse models. Members of the dystrophin glycoprotein complex and integrins have both been reported to interact directly with filamin-C, thus linking costameric complexes with those present at the Z-line. Moreover, studies from our labs and others have shown that the Z-line proteins belonging to the PDZ-LIM domain protein family, enigma homolog (ENH) and cypher, may directly or indirectly be involved in this linkage. The following review will focus on the protein components of this linkage, their function in force transmission, and how the dysfunction or loss of proteins within these complexes contributes to muscular disease.
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Cheng H, Zheng M, Peter AK, Kimura K, Li X, Ouyang K, Shen T, Cui L, Frank D, Dalton ND, Gu Y, Frey N, Peterson KL, Evans SM, Knowlton KU, Sheikh F, Chen J. Selective deletion of long but not short Cypher isoforms leads to late-onset dilated cardiomyopathy. Hum Mol Genet 2011; 20:1751-62. [PMID: 21303826 DOI: 10.1093/hmg/ddr050] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cypher long (CypherL) and short (CypherS) isoforms are distinguished from each other by the presence and absence of three C-terminal LIM domains, respectively. Cypher isoforms are developmentally regulated, and mutations affecting both long and short isoforms are linked to muscle disease in humans. Given these data, we hypothesized that various Cypher isoforms play overlapping and unique roles in striated muscle. To determine the specific role of Cypher isoforms in striated muscle, we generated two mouse lines in which either CypherS or CypherL isoforms were specifically deleted. Mice specifically, deficient in CypherS isoforms had no detectable muscle phenotype. In contrast, selective loss of CypherL isoforms resulted in partial neonatal lethality. Surviving mutants exhibited growth retardation and late-onset dilated cardiomyopathy, which was associated with cardiac fibrosis and calcification, leading to premature adult mortality. At a young age, preceding development of cardiomyopathy, hearts from these mutants exhibited defects in both Z-line ultrastructure and specific aberrations in calcineurin-NFAT and protein kinase C pathways. Earlier onset of cardiac dilation relative to control wild-type mice was observed in young CypherL isoform knockout mice consequent to pressure overload, suggesting a greater susceptibility to the disease. In summary, we have identified unique roles for CypherL isoforms in maintaining Z-line ultrastructure and signaling that are distinct from the roles of CypherS isoforms, while highlighting the contribution of mutations in the long isoforms to the development of dilated cardiomyopathy.
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Affiliation(s)
- Hongqiang Cheng
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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55
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LIM domains regulate protein kinase C activity: a novel molecular function. Cell Signal 2011; 23:928-34. [PMID: 21266195 DOI: 10.1016/j.cellsig.2011.01.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 01/19/2011] [Indexed: 11/23/2022]
Abstract
Enigma homolog protein 1 (ENH1) acts as a scaffold that selectively associates protein kinases and transcription factors with cytoskeletal elements. ENH1 comprises an N-terminal PDZ domain and three C-terminal LIM domains. Through the LIM domains ENH1 interacts with the N-terminal region of protein kinase C βI (PKCβI). Here, we show that when ENH1 is co-expressed, PKCβI is translocated from the cytoplasm to the plasma membrane in the absence of any other stimulation. Moreover expression of ENH1 markedly increases PKCβI activity in the absence of PKC activators. A similar activation of PKCβI was observed with co-expression of Cypher1 or Enigma, but not other LIM proteins. The region including the three LIM domains of ENH1 (residues 415-591) appears to be sufficient for this PKCβI activation. Finally, interaction with ENH1 also increases the activity of PKCα and PKCγ, whereas it reduces PKCζ activity. These findings provide strong evidence that ENH1 activates conventional PKCs by directly binding through its LIM domains. Thus, LIM domains have a novel molecular function: the regulation of PKC activities in a PKC isoform-specific manner.
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Abstract
During the last 15 years, the perception of the cardiac z-disc has undergone substantial changes. Initially viewed as a structural component at the lateral boundaries of the sarcomere, the cardiac z-disc has increasingly become recognized as a nodal point in cardiomyocyte signal transduction and disease. This minireview thus focuses on novel components and recent developments in z-disc biology and their role in cardiac signaling and disease.
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Affiliation(s)
- Derk Frank
- Internal Medicine III/Cardiology, University of Kiel, 24105 Kiel, Germany
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57
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Selcen D. Myofibrillar myopathies. Neuromuscul Disord 2011; 21:161-71. [PMID: 21256014 DOI: 10.1016/j.nmd.2010.12.007] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Revised: 12/15/2010] [Accepted: 12/17/2010] [Indexed: 12/18/2022]
Abstract
Myofibrillar myopathies represent a group of muscular dystrophies with a similar morphologic phenotype. They are characterized by a distinct pathologic pattern of myofibrillar dissolution associated with disintegration of the Z-disk, accumulation of myofibrillar degradation products, and ectopic expression of multiple proteins and sometimes congophilic material. The clinical features of myofibrillar myopathies are more variable. These include progressive muscle weakness, that often involves or begins in distal muscles but limb-girdle or scapuloperoneal distributions can also occur. Cardiomyopathy and peripheral neuropathy are frequent associated features. EMG of the affected muscles reveals myopathic motor unit potentials and abnormal irritability often with myotonic discharges. Rarely, neurogenic motor unit potentials or slow nerve conductions are present. The generic diagnosis of myofibrillar myopathies is based on muscle biopsy findings in frozen sections. To date, all myofibrillar myopathy mutations have been traced to Z-disk-associated proteins, namely, desmin, αB-crystallin, myotilin, ZASP, filamin C and Bag3. However, in the majority of the myofibrillar myopathy patients the disease gene awaits discovery.
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Affiliation(s)
- Duygu Selcen
- Department of Neurology, Division of Child Neurology and Neuromuscular Disease Research Laboratory, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA.
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58
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Abstract
Myofibrillar myopathies (MFMs) represent a group of muscular dystrophies with a similar morphological phenotype. The diagnosis is established by muscle biopsy. The MFMs are characterized by a distinct pathological pattern of myofibrillar dissolution associated with disintegration of the Z-disk, accumulation of myofibrillar degradation products, and ectopic expression of multiple proteins that include desmin, αB-crystallin, dystrophin, and sometimes congophilic material. The clinical features of MFMs are more variable. These include progressive muscle weakness that often involves or begins in distal muscles, but limb-girdle or scapuloperoneal distributions can also occur. Cardiomyopathy and peripheral neuropathy are frequent associated features. Electromyography of the affected muscles reveals myopathic motor unit potentials and abnormal irritability, often with myotonic discharges. Rarely, neurogenic motor unit potentials or slowing of nerve conduction velocities are present. To date, all MFM mutations have appeared in Z-disk-associated proteins: namely, desmin, αB-crystallin, myotilin, ZASP, filamin C, and Bag3. However, in the majority of patients with MFM, the disease gene awaits discovery.
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Affiliation(s)
- Duygu Selcen
- Department of Neurology and Neuromuscular Disease Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
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Griggs RC, Udd BA. Markesbery disease: autosomal dominant late-onset distal myopathy: from phenotype to ZASP gene identification. Neuromolecular Med 2010; 13:27-30. [PMID: 20809097 DOI: 10.1007/s12017-010-8134-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 08/13/2010] [Indexed: 11/27/2022]
Abstract
In 1974, Markesbery et al. thoroughly characterized and reported a large kindred with distal muscle weakness of late adult-onset that was autosomal dominantly inherited. Clinical evidence supported myopathy rather than the usual neuropathy expected with distal weakness. Postmortem examination of two patients documented myopathy and excluded anterior horn cell disease or peripheral neuropathy as the cause. Distinctive morphologic changes were present in muscle. Widely accepted as a distinct disease entity, this disorder has recently been characterized as one of a group of myofibrillar myopathies resulting from mutations in several muscle proteins. Studies of members of the original family have now identified the molecular defect to be a mutation in ZASP, Z-band alternatively spliced PDZ-motif-containing protein. The specific mutation, A165V, was identified in all clinical affected family members by direct sequencing. Thus, Markesbery disease is a zaspopathy. Other families have been identified with the same mutation and a shared haplotype indicating a founder effect.
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Affiliation(s)
- Robert C Griggs
- Department of Neurology, University of Rochester School of Medicine and Dentistry, 1351 Mt. Hope Avenue, Suite 203, Rochester, NY 14620, USA.
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60
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Gasanov AG, Bershova TV, Basargina EN, Bakanov MI. [Molecular mechanisms of genetic damages of the myocardium in cardiomyopathy]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2010; 56:319-28. [PMID: 20695211 DOI: 10.18097/pbmc20105603319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The review highlighted problems of reorganization of myocardical contractile and cytoskeletal proteins in cardiomyopathy (CM). The role of the genetic factors coding contractile proteins, proteins of thin and thick filaments, and also extracellular matrix proteins in processes of formation and development of hypertrophic (HCM) and dilated (DCM) cardiomyopathy are analyzed. The mechanisms responsible for the changes in cardiac proteins on regulation involved into force generation, its transfer, recycling ATP, impairments in transmembranal signals, that finally lead to cardiac cell dysfunction determining various manifestations of CM are considered.
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Abstract
PURPOSE Genetic tests for the most commonly mutated genes in dilated cardiomyopathy (DCM) can confirm a clinical diagnosis in the proband and inform family management. Presymptomatic family members can be identified, allowing for targeted clinical monitoring to minimize adverse outcomes. However, the marked locus and allelic heterogeneity associated with DCM have made clinical genetic testing challenging. Novel sequencing platforms have now opened up avenues for more comprehensive diagnostic testing while simultaneously decreasing test cost and turn around time. METHODS By using a custom design based on triplicate resequencing and separate genotyping of known disease-causing variants, we developed the DCM CardioChip for efficient analysis of 19 genes previously implicated in causing DCM. RESULTS The chip's analytical sensitivity for known and novel substitution variants is 100% and 98%, respectively. In screening 73 previously tested DCM patients who did not carry clinically significant variants in 10 genes, 7 variants of likely clinical significance were identified in the remaining 9 genes included on the chip. Compared with traditional Sanger-based sequencing, test cost and turn around time were reduced by approximately 50%. CONCLUSIONS The DCM CardioChip is a highly efficient screening test with a projected clinical sensitivity of 26-29%.
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62
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Abstract
Dilated cardiomyopathy (DCM) is a myocardial disorder defined by ventricular chamber enlargement and systolic dysfunction. DCM can result in progressive heart failure, arrhythmias, thromboembolism, and premature death, and contributes significantly to health care costs. In many cases, DCM results from acquired factors that affect cardiomyocyte function or survival. Inherited genetic variants are also now recognized to have an important role in the etiology of DCM. Despite substantial progress over the past decade, our understanding of familial DCM remains incomplete. Current concepts of the molecular pathogenesis, clinical presentation, natural history, and management of familial DCM are outlined in this review.
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Affiliation(s)
- Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW 2010, Australia.
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63
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Cheng H, Kimura K, Peter AK, Cui L, Ouyang K, Shen T, Liu Y, Gu Y, Dalton ND, Evans SM, Knowlton KU, Peterson KL, Chen J. Loss of enigma homolog protein results in dilated cardiomyopathy. Circ Res 2010; 107:348-56. [PMID: 20538684 DOI: 10.1161/circresaha.110.218735] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE The Z-line, alternatively termed the Z-band or Z-disc, is a highly ordered structure at the border between 2 sarcomeres. Enigma subfamily proteins (Enigma, Enigma homolog protein, and Cypher) of the PDZ-LIM domain protein family are Z-line proteins. Among the Enigma subfamily, Cypher has been demonstrated to play a pivotal role in the structure and function of striated muscle, whereas the role of Enigma homolog protein (ENH) in muscle remains largely unknown. OBJECTIVE We studied the role of Enigma homolog protein in the heart using global and cardiac-specific ENH knockout mouse models. METHODS AND RESULTS We identified new exons and splice isoforms for ENH in the mouse heart. Impaired cardiac contraction and dilated cardiomyopathy were observed in ENH null mice. Mice with cardiac specific ENH deletion developed a similar dilated cardiomyopathy. Like Cypher, ENH interacted with Calsarcin-1, another Z-line protein. Moreover, biochemical studies showed that ENH, Cypher short isoform and Calsarcin-1 are within the same protein complex at the Z-line. Cypher short isoform and Calsarcin-1 proteins are specifically downregulated in ENH null hearts. CONCLUSIONS We have identified an ENH-CypherS-Calsarcin protein complex at the Z-line. Ablation of ENH leads to destabilization of this protein complex and dilated cardiomyopathy.
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Affiliation(s)
- Hongqiang Cheng
- Department of Medicine, University of California San Diego, La Jolla, 92093, USA
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Beqqali A, Monshouwer-Kloots J, Monteiro R, Welling M, Bakkers J, Ehler E, Verkleij A, Mummery C, Passier R. CHAP is a newly identified Z-disc protein essential for heart and skeletal muscle function. J Cell Sci 2010; 123:1141-50. [PMID: 20215401 DOI: 10.1242/jcs.063859] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In recent years, the perception of Z-disc function has changed from a passive anchor for myofilaments that allows transmission of force, to a dynamic multicomplex structure, capable of sensing and transducing extracellular signals. Here, we describe a new Z-disc protein, which we named CHAP (cytoskeletal heart-enriched actin-associated protein), expressed in differentiating heart and skeletal muscle in vitro and in vivo. Interestingly, in addition to its sarcomeric localization, CHAP was also able to translocate to the nucleus. CHAP was associated with filamentous actin in the cytoplasm and the nucleus when expressed ectopically in vitro, but in rat neonatal cardiomyocytes, CHAP disrupted the subcellular localization of alpha-actinin, another Z-disc protein. More importantly, knockdown of CHAP in zebrafish resulted in aberrant cardiac and skeletal muscle development and function. These findings suggest that CHAP is a critical component of the sarcomere with an important role in muscle development.
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Affiliation(s)
- Abdelaziz Beqqali
- Hubrecht Institute, Developmental Biology and Stem Cell Research, 3584 CT, Utrecht, The Netherlands
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65
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Kimura A. Molecular basis of hereditary cardiomyopathy: abnormalities in calcium sensitivity, stretch response, stress response and beyond. J Hum Genet 2010; 55:81-90. [PMID: 20075948 DOI: 10.1038/jhg.2009.138] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiomyopathy is caused by functional abnormality of cardiac muscle. The functional abnormality involved in its etiology includes both extrinsic and intrinsic factors, and cardiomyopathy caused by the intrinsic factors is called as idiopathic or primary cardiomyopathy. There are several clinical types of primary cardiomyopathy including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Linkage studies and candidate gene approaches have explored the disease genes for hereditary primary cardiomyopathy. The most notable finding was that mutations in the same disease gene can be found in different clinical types of cardiomyopathy. Functional analyses of disease-related mutations have revealed that characteristic functional alterations are associated with the clinical types, such that increased and decreased Ca(2+) sensitivity due to sarcomere mutations are associated with HCM and DCM, respectively. In addition, our recent studies have suggested that mutations in the Z-disc components found in HCM and DCM may result in increased and decreased stiffness of sarcomere; that is, stiff sarcomere and loose sarcomere, respectively, and hence altered stretch response. More recently, mutations in the components of I region were found in hereditary cardiomyopathy and the functional analyses of the mutations suggested that the altered stress response was associated with cardiomyopathy, further complicating the etiology and pathogenesis. However, elucidation of genetic etiology and functional alterations caused by the mutations shed lights on the new therapeutic approaches to hereditary cardiomyopathy, such that treatment of DCM with a Ca(2+) sensitizer prevented the disease in a mouse model.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, Japan.
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66
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Marín-García J. Basic Mechanisms Mediating Cardiomyopathy and Heart Failure in Aging. HEART FAILURE 2010. [PMCID: PMC7121883 DOI: 10.1007/978-1-60761-147-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Biological aging represents the major risk factor for the development of heart failure (HF), malignancies, and neurodegenerative diseases. While risk factors such as lifestyle patterns, genetic traits, blood lipid levels, and diabetes can contribute to its development, advancing age remains the most determinant predictor of cardiac disease. Several parameters of left ventricular function may be affected with aging, including increased duration of systole, decreased sympathetic stimulation, and increased left ventricle ejection time, while compliance decreases. In addition, changes in cardiac phenotype with diastolic dysfunction, reduced contractility, left ventricular hypertrophy, and HF, all increase in incidence with age. Given the limited capacity that the heart has for regeneration, reversing or slowing the progression of these abnormalities poses a major challenge. In this chapter, we present a discussion on the molecular and cellular mechanisms involved in the pathogenesis of cardiomyopathies and HF in aging and the potential involvement of specific genes identified as primary mediators of these diseases.
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Zheng M, Cheng H, Banerjee I, Chen J. ALP/Enigma PDZ-LIM domain proteins in the heart. J Mol Cell Biol 2009; 2:96-102. [PMID: 20042479 DOI: 10.1093/jmcb/mjp038] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Actinin-associated LIM protein (ALP) and Enigma are two subfamilies of Postsynaptic density 95, discs large and zonula occludens-1 (PDZ)-Lin-11, Isl1 and Mec-3 (LIM) domain containing proteins. ALP family members have one PDZ and one LIM domain, whereas Enigma proteins contain one PDZ and three LIM domains. Four ALP and three Enigma proteins have been identified in mammals, each having multiple splice variants and unique expression patterns. Functionally, these proteins bind through their PDZ domains to alpha-actinin and bind through their LIM domains or other internal protein interaction domains to other proteins, including signaling molecules. ALP and Enigma proteins have been implicated in cardiac and skeletal muscle structure, function and disease, neuronal function, bipolar disorder, tumor growth, platelet and epithelial cell motility and bone formation. This review will focus on recent advances in the biological roles of ALP/Enigma PDZ-LIM domain proteins in cardiac muscle and provide insights into mechanisms by which mutations in these proteins are related to human cardiac disease.
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Affiliation(s)
- Ming Zheng
- Institute of Molecular Medicine, Peking University, Beijing 100871, China
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68
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Post-transcriptional silencing of the Drosophila homolog of human ZASP: a molecular and functional analysis. Cell Tissue Res 2009; 337:463-76. [PMID: 19603185 DOI: 10.1007/s00441-009-0813-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 04/22/2009] [Indexed: 11/27/2022]
Abstract
In humans, mutations in ZASP (the gene for Z-band alternatively spliced PDZ-motif protein) are associated with dilated cardiomyopathy and left ventricular non-compaction. In particular, mutations in or around the Zasp motif seem to be related to myofibrillar myopathy. Thus, "zaspopathies" include symptoms such as Z-line disgregation, proximal and distal muscle weakness, cardiomyopathies, and peripheral neuropathies. In order to understand the role of ZASP in muscle structure and function, we have performed a molecular characterization of the Drosophila ortholog of human ZASP and a functional analysis following the post-transcriptional silencing of the Drosophila gene. Transcriptional analysis of dzasp has revealed six additional exons, with respect to the known 16, and multiple splice variants. We have produced transgenic lines harboring constructs that, through the use of the UAS/Gal4 binary system, have enabled us to drive dsRNA interference of dzasp in a tissue-specific manner. Knockdown individuals show locomotor defects associated with alterations of muscle structure and ultrastructure, consistent with a role of dzasp specifically in the maintenance of muscular integrity.
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69
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Finsterer J. Cardiogenetics, neurogenetics, and pathogenetics of left ventricular hypertrabeculation/noncompaction. Pediatr Cardiol 2009; 30:659-81. [PMID: 19184181 DOI: 10.1007/s00246-008-9359-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 11/15/2008] [Indexed: 01/28/2023]
Abstract
BACKGROUND Left ventricular hypertrabeculation (LVHT), also known as noncompaction or spongy myocardium, is a cardiac abnormality of unknown etiology and pathogenesis frequently associated with genetic cardiac and noncardiac disorders, particularly genetic neuromuscular disease. This study aimed to review the current knowledge about the genetic or pathogenetic background of LVHT. METHODS A literature review of all human studies dealing with the association of LVHT with genetic cardiac and noncardiac disorders, particularly neuromuscular disorders, was conducted. RESULTS Most frequently, LVHT is associated with mitochondrial disorders (mtDNA, nDNA mutations), Barth syndrome (G4.5, TAZ mutations), hypertrophic cardiomyopathy (MYH7, ACTC mutations), zaspopathy (ZASP/LDB3 mutations), myotonic dystrophy 1 (DMPK mutations), and dystrobrevinopathy (DTNA mutations). More rarely, LVHT is associated with mutations in the DMD, SCNA5, MYBPC3, FNLA1, PTPN11, LMNA, ZNF9, AMPD1, PMP22, TNNT2, fibrillin2, SHP2, MMACHC, LMX1B, HCCS, or NR0B1 genes. Additionally, LVHT occurs with a number of chromosomal disorders, polymorphisms, and not yet identified genes, as well in a familial context. The broad heterogeneity of LVHT's genetic background suggests that the uniform morphology of LVHT not only is attributable to embryonic noncompaction but also may result from induction of hypertrabeculation as a compensatory reaction of an impaired myocardium. CONCLUSIONS Most frequently, LVHT is associated with mutations in genes causing muscle or cardiac disease, or with chromosomal disorders. These associations require comprehensive cardiac, neurologic, and cytogenetic investigations.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Postfach 20, 1180 Vienna, Austria, Europe.
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70
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Arimura T, Bos JM, Sato A, Kubo T, Okamoto H, Nishi H, Harada H, Koga Y, Moulik M, Doi YL, Towbin JA, Ackerman MJ, Kimura A. Cardiac Ankyrin Repeat Protein Gene (ANKRD1) Mutations in Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2009; 54:334-42. [DOI: 10.1016/j.jacc.2008.12.082] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 11/20/2008] [Accepted: 12/03/2008] [Indexed: 01/07/2023]
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71
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Jani K, Schöck F. Molecular mechanisms of mechanosensing in muscle development. Dev Dyn 2009; 238:1526-34. [DOI: 10.1002/dvdy.21972] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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72
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Arimura T, Inagaki N, Hayashi T, Shichi D, Sato A, Hinohara K, Vatta M, Towbin JA, Chikamori T, Yamashina A, Kimura A. Impaired binding of ZASP/Cypher with phosphoglucomutase 1 is associated with dilated cardiomyopathy. Cardiovasc Res 2009; 83:80-8. [PMID: 19377068 DOI: 10.1093/cvr/cvp119] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Z-band alternatively spliced PDZ-motif protein (ZASP)/Cypher is a Z-disc component of which several dilated cardiomyopathy (DCM)-associated mutations have been reported. Most of the mutations were found in exons 4 and 10 of ZASP/Cypher gene LDB3 and both exons were expressed preferentially in the heart. The aim of this study was to investigate the functional alteration of ZASP/Cypher caused by the DCM-associated mutations. METHODS AND RESULTS The yeast-two-hybrid method was used to identify the protein bound to a domain encoded by exon 4 of LDB3. Interaction of ZASP/Cypher with the binding protein was investigated in relation to the functional alterations caused by LDB3 mutations. Localization of the ZASP/Cypher-binding protein was examined at the cellular level in rat cardiomyocytes. Phosphoglucomutase 1 (PGM1), a metabolic enzyme involved in glycolysis and gluconeogenesis, was identified as a protein interacting with ZASP/Cypher. PGM1 bound to ZASP/Cypher at the domains encoded by exons 4 and 10. Two LDB3 mutations in exon 4 (Ser189Leu and Thr206Ile) and another mutation in exon 10 (Ile345Met) reduced the binding to PGM1. PGM1 showed diffuse localization in the cytoplasm of rat cardiomyocytes under standard culture conditions, and distribution at the Z-discs was observed under stressed culture conditions. Binding of endogenous PGM1 and ZASP/Cypher was found to be enhanced by stress in rat cardiomyocytes. CONCLUSION ZASP/Cypher anchors PGM1 to Z-disc under conditions of stress. The impaired binding of PGM1 to ZASP/Cypher might be involved in the pathogenesis of DCM.
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Affiliation(s)
- Takuro Arimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Bunkyo-Ku, Tokyo, Japan
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73
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Han HF, Beckerle MC. The ALP-Enigma protein ALP-1 functions in actin filament organization to promote muscle structural integrity in Caenorhabditis elegans. Mol Biol Cell 2009; 20:2361-70. [PMID: 19261811 DOI: 10.1091/mbc.e08-06-0584] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Mutations that affect the Z-disk-associated ALP-Enigma proteins have been linked to human muscular and cardiac diseases. Despite their clear physiological significance for human health, the mechanism of action of ALP-Enigma proteins is largely unknown. In Caenorhabditis elegans, the ALP-Enigma protein family is encoded by a single gene, alp-1; thus C. elegans provides an excellent model to study ALP-Enigma function. Here we present a molecular and genetic analysis of ALP-Enigma function in C. elegans. We show that ALP-1 and alpha-actinin colocalize at dense bodies where actin filaments are anchored and that the proper localization of ALP-1 at dense bodies is dependent on alpha-actinin. Our analysis of alp-1 mutants demonstrates that ALP-1 functions to maintain actin filament organization and participates in muscle stabilization during contraction. Reducing alpha-actinin activity enhances the actin filament phenotype of the alp-1 mutants, suggesting that ALP-1 and alpha-actinin function in the same cellular process. Like alpha-actinin, alp-1 also interacts genetically with a connectin/titin family member, ketn-1, to provide mechanical stability for supporting body wall muscle contraction. Taken together, our data demonstrate that ALP-1 and alpha-actinin function together to stabilize actin filaments and promote muscle structural integrity.
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74
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Arimura T, Hayashi YK, Murakami T, Oya Y, Funabe S, Arikawa-Hirasawa E, Hattori N, Nishino I, Kimura A. Mutational Analysis of Fukutin Gene in Dilated Cardiomyopathy and Hypertrophic Cardiomyopathy. Circ J 2009; 73:158-61. [DOI: 10.1253/circj.cj-08-0722] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Takuro Arimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University
| | - Yukiko K. Hayashi
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP)
| | - Terumi Murakami
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP)
| | - Yasushi Oya
- Department of Neurology, National Center Hospital of Neurology and Psychiatry, National Center of Neurology and Psychiatry (NCNP)
| | - Sayaka Funabe
- Department of Neurology, Juntendo University School of Medicine
| | | | | | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP)
| | - Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University
- Laboratory of Genome Diversity, School of Biomedical Science, Tokyo Medical and Dental University
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Zheng M, Cheng H, Li X, Zhang J, Cui L, Ouyang K, Han L, Zhao T, Gu Y, Dalton ND, Bang ML, Peterson KL, Chen J. Cardiac-specific ablation of Cypher leads to a severe form of dilated cardiomyopathy with premature death. Hum Mol Genet 2008; 18:701-13. [PMID: 19028670 DOI: 10.1093/hmg/ddn400] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Accumulating data suggest a link between alterations/deficiencies in cytoskeletal proteins and the progression of cardiomyopathy and heart failure, although the molecular basis for this link remains unclear. Cypher/ZASP is a cytoskeletal protein localized in the sarcomeric Z-line. Mutations in its encoding gene have been identified in patients with isolated non-compaction of the left ventricular myocardium, dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy. To explore the role of Cypher in myocardium and to better understand molecular mechanisms by which mutations in cypher cause cardiomyopathy, we utilized a conditional approach to knockout Cypher, specially in either developing or adult myocardium. Cardiac-specific Cypher knockout (CKO) mice developed a severe form of DCM with disrupted cardiomyocyte ultrastructure and decreased cardiac function, which eventually led to death before 23 weeks of age. A similar phenotype was observed in inducible cardiac-specific CKO mice in which Cypher was specifically ablated in adult myocardium. In both cardiac-specific CKO models, ERK and Stat3 signaling pathways were augmented. Finally, we demonstrate the specific binding of Cypher's PDZ domain to the C-terminal region of both calsarcin-1 and myotilin within the Z-line. In conclusion, our studies suggest that (i) Cypher plays a pivotal role in maintaining adult cardiac structure and cardiac function through protein-protein interactions with other Z-line proteins, (ii) myocardial ablation of Cypher results in DCM with premature death and (iii) specific signaling pathways participate in Cypher mutant-mediated dysfunction of the heart, and may in concert facilitate the progression to heart failure.
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Affiliation(s)
- Ming Zheng
- Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA
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76
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Sheikh F, Raskin A, Chu PH, Lange S, Domenighetti AA, Zheng M, Liang X, Zhang T, Yajima T, Gu Y, Dalton ND, Mahata SK, Dorn GW, Brown JH, Heller-Brown J, Peterson KL, Omens JH, McCulloch AD, Chen J. An FHL1-containing complex within the cardiomyocyte sarcomere mediates hypertrophic biomechanical stress responses in mice. J Clin Invest 2008; 118:3870-80. [PMID: 19033658 DOI: 10.1172/jci34472] [Citation(s) in RCA: 184] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 09/24/2008] [Indexed: 11/17/2022] Open
Abstract
The response of cardiomyocytes to biomechanical stress can determine the pathophysiology of hypertrophic cardiac disease, and targeting the pathways regulating these responses is a therapeutic goal. However, little is known about how biomechanical stress is sensed by the cardiomyocyte sarcomere to transduce intracellular hypertrophic signals or how the dysfunction of these pathways may lead to disease. Here, we found that four-and-a-half LIM domains 1 (FHL1) is part of a complex within the cardiomyocyte sarcomere that senses the biomechanical stress-induced responses important for cardiac hypertrophy. Mice lacking Fhl1 displayed a blunted hypertrophic response and a beneficial functional response to pressure overload induced by transverse aortic constriction. A link to the Galphaq (Gq) signaling pathway was also observed, as Fhl1 deficiency prevented the cardiomyopathy observed in Gq transgenic mice. Mechanistic studies demonstrated that FHL1 plays an important role in the mechanism of pathological hypertrophy by sensing biomechanical stress responses via the N2B stretch sensor domain of titin and initiating changes in the titin- and MAPK-mediated responses important for sarcomere extensibility and intracellular signaling. These studies shed light on the physiological regulation of the sarcomere in response to hypertrophic stress.
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Affiliation(s)
- Farah Sheikh
- Department of Medicine, UCSD, La Jolla, California 92093, USA
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Abstract
Cardiomyopathy is defined as a cardiac disease caused by functional abnormality of cardiac muscle, and the etiology of the functional abnormality includes both extrinsic and intrinsic factors. Cardiomyopathy caused by the intrinsic factors is defined as idiopathic or primary cardiomyopathy, and there are several clinical phenotypes, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). The major intrinsic factor is gene mutations, and linkage studies, as well as candidate gene approaches, have deciphered multiple disease genes for hereditary primary cardiomyopathy. Of note is that mutations in the same disease gene can be found in different clinical phenotypes of cardiomyopathy. Functional analyses of disease-related mutations have revealed that characteristic functional alterations are associated with the clinical phenotypes, such that increased and decreased Ca(2+) sensitivity because of sarcomere mutations are associated with HCM and DCM, respectively. In addition, recent data have suggested that mutations in the Z-disc components found in HCM and DCM may result in increased and decreased stiffness of the sarcomere (ie, stiff sarcomere and loose sarcomere, respectively). More recently, mutations in the components of the I region can be found in hereditary cardiomyopathy, further complicating the etiology of primary cardiomyopathy.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
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78
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Abstract
Myofibrillar myopathies (MFMs) are clinically and genetically heterogeneous muscle disorders that are defined morphologically by the presence of foci of myofibril dissolution, accumulation of myofibrillar degradation products, and ectopic expression of multiple proteins. MFMs are the paradigm of conformational protein diseases of the skeletal (and cardiac) muscles characterised by intracellular protein accumulation in muscle cells. Understanding of this group of disorders has advanced in recent years through the identification of causative mutations in various genes, most of which encode proteins of the sarcomeric Z-disc, including desmin, alphaB-crystallin, myotilin, ZASP and filamin C. This review focuses on the MFMs arising from defects in these proteins, summarising genetic and clinical features of the disorders and then discussing emerging understanding of the molecular pathogenic mechanisms leading to muscle fibre degeneration. Defective extralysosomal degradation of proteins is now recognised as an important element in this process. Several factors--including mutant proteins, a defective ubiquitin-proteasome system, aggresome formation, mutant ubiquitin, p62, oxidative stress and abnormal regulation of some transcription factors--are thought to participate in the cascade of events occurring in muscle fibres in MFMs.
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79
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Ajima R, Akazawa H, Kodama M, Takeshita F, Otsuka A, Kohno T, Komuro I, Ochiya T, Yokota J. Deficiency of Myo18B in mice results in embryonic lethality with cardiac myofibrillar aberrations. Genes Cells 2008; 13:987-99. [PMID: 18761673 DOI: 10.1111/j.1365-2443.2008.01226.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myo18B is an unconventional myosin family protein expressed predominantly in muscle cells. Although conventional myosins are known to be localized on the A-bands and function as a molecular motor for muscle contraction, Myo18B protein was localized on the Z-lines of myofibrils in striated muscles. Like Myo18A, another 18th class of myosin, the N-terminal unique domain of the protein and not the motor domain and the coiled-coil tail is critical for its localization to F-actin in myocytes. Myo18B expression was induced by myogenic differentiation through the binding of myocyte-specific enhancer factor-2 to its promoter. Deficiency of Myo18B caused an embryonic lethality in mice accompanied by disruption of myofibrillar structures in cardiac myocytes at embryonic day 10.5. Thus, Myo18B is a unique unconventional myosin that is predominantly expressed in myocytes and whose expression is essential for the development and/or maintenance of myofibrillar structure.
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Affiliation(s)
- Rieko Ajima
- Biology Division, National Cancer Center Research Institute, Tokyo 104-0045, Japan
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80
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Zhang L, Hu A, Yuan H, Cui L, Miao G, Yang X, Wang L, Liu J, Liu X, Wang S, Zhang Z, Liu L, Zhao R, Shen Y. A Missense Mutation in the CHRM2 Gene Is Associated With Familial Dilated Cardiomyopathy. Circ Res 2008; 102:1426-32. [DOI: 10.1161/circresaha.107.167783] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Lin Zhang
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Aihua Hu
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Haixin Yuan
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Liang Cui
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Guobin Miao
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Xinchun Yang
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Lefeng Wang
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Jinchun Liu
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Xiulan Liu
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Shuyan Wang
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Zhiyong Zhang
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Lisheng Liu
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Rongrui Zhao
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
| | - Yan Shen
- From the Heart Center (L.Z., H.Y., L.C., G.M., X.Y., L.W., J.L., X.L., S.W., Z.Z.), Department of Medicine, Capital Medical University, ChaoYang Hospital, Beijing; Fu Wai Hospital (A.H., L.L.), Chinese Academy of Sciences/Peking Union Medical College, Beijing; Department of Physiology (R.Z.), Shanxi Medical University, Taiyuan; and National Laboratory of Medical Molecular Biology (Y.S.), Institute of Basic Medical Sciences, Chinese Academy of Sciences/Peking Union Medical College, Beijing, China
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Jani K, Schöck F. Zasp is required for the assembly of functional integrin adhesion sites. ACTA ACUST UNITED AC 2008; 179:1583-97. [PMID: 18166658 PMCID: PMC2373490 DOI: 10.1083/jcb.200707045] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The integrin family of heterodimeric transmembrane receptors mediates cell–matrix adhesion. Integrins often localize in highly organized structures, such as focal adhesions in tissue culture and myotendinous junctions in muscles. Our RNA interference screen for genes that prevent integrin-dependent cell spreading identifies Z band alternatively spliced PDZ-motif protein (zasp), encoding the only known Drosophila melanogaster Alp/Enigma PDZ-LIM domain protein. Zasp localizes to integrin adhesion sites and its depletion disrupts integrin adhesion sites. In tissues, Zasp colocalizes with βPS integrin in myotendinous junctions and with α-actinin in muscle Z lines. Zasp also physically interacts with α-actinin. Fly larvae lacking Zasp do not form Z lines and fail to recruit α-actinin to the Z line. At the myotendinous junction, muscles detach in zasp mutants with the onset of contractility. Finally, Zasp interacts genetically with integrins, showing that it regulates integrin function. Our observations point to an important function for Zasp in the assembly of integrin adhesion sites both in cell culture and in tissues.
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Affiliation(s)
- Klodiana Jani
- Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada
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82
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Sheikh F, Bang ML, Lange S, Chen J. "Z"eroing in on the role of Cypher in striated muscle function, signaling, and human disease. Trends Cardiovasc Med 2008; 17:258-62. [PMID: 18021935 DOI: 10.1016/j.tcm.2007.09.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 09/10/2007] [Accepted: 09/13/2007] [Indexed: 11/24/2022]
Abstract
The striated muscle Z line, a multiprotein complex at the boundary between sarcomeres, plays an integral role in maintaining striated muscle structure and function. Multiple Z-line-associated proteins have been identified and shown to play an increasingly important role in the pathogenesis of human muscle disease. Cypher/Z-band alternatively spliced PDZ-motif protein, a PDZ-LIM protein in the Z line, binds to alpha-actinin (via its PDZ domain) and has been suggested to function as a linker-strut to maintain cytoskeletal structural integrity during contraction. Cypher may also participate in signaling pathways by binding to protein kinase C via its LIM domains. Analysis of Cypher-deficient mice has revealed that Cypher plays an integral role in Z-line maintenance/integrity of striated muscles and the pathogenesis of congenital myopathies, including cardiomyopathy. These studies have led to the subsequent discovery of Cypher mutations in human patients with dilated cardiomyopathy, hypertrophic cardiomyopathy, as well as skeletal muscle myopathies, which have been recently termed zaspopathies. The recent discovery of various alternatively spliced isoforms of Cypher with potentially distinct structural and signaling roles brings a different level of complexity to the mechanisms underlying Cypher-based human myopathies. This review will focus on recent developments on the role of Cypher and its isoforms in striated muscle structure, signaling, and disease to provide insights into the mechanisms involved in the pathogenesis of Z-line-associated human myopathies.
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Affiliation(s)
- Farah Sheikh
- Department of Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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83
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Kuhl A, Melberg A, Meinl E, Nürnberg G, Nürnberg P, Kehrer-Sawatzki H, Jenne DE. Myofibrillar myopathy with arrhythmogenic right ventricular cardiomyopathy 7: corroboration and narrowing of the critical region on 10q22.3. Eur J Hum Genet 2008; 16:367-73. [PMID: 18197198 DOI: 10.1038/sj.ejhg.5201980] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Several years ago, autosomal dominant myofibrillar myopathy (MFM) in combination with arrhythmogenic right ventricular cardiomyopathy (ARVC7) was tentatively mapped to a 10.6-Mbp (million base pairs) region on chromosome 10q22.3 between D10S605 (78.9 Mbp) and D10S215 (89.5 Mbp) in a Swedish family assuming that ARVC7 was allelic with cardiomyopathy, dilated 1C (CMD1C). To date, neither the genetic defect in ARVC7 nor CMD1C has been reported. In a comprehensive follow-up study we re-examined and confirmed the previous linkage data for ARVC7 using a high-density single nucleotide polymorphism marker panel from Affymetrix (Human Mapping 10K Array). No other regions with significant evidence for linkage were discovered. The critical interval was narrowed down to 4.27 Mbp between D10S1645 and D10S1786. This reduced the total number of candidate genes to 18 of which 17 (RAI17, PPIF, C10ORF56, SFTPA1, SFTPA2, SFTPA1B, SFTPA2B, SFTPD, C10ORF57, PLAC9, ANXA11, MAT1A, DYDC1, DYDC2, C10ORF58, TSPAN14 and SH2D4B) are shared with the CMD1C region. No disease-causing mutation was found in their coding regions. Moreover, metavinculin (VCL) and ZASP/cypher (LDB3) proximal and distal to this linked region were excluded by sequence analysis. To search for submicroscopic and intragenic deletions by PCR, we generated hybrid cell lines carrying only the affected or normal chromosome 10 homolog. All sequence tagged sites and exons were present on both homologs. We speculate that regulatory mutations in 1 of the 18 genes from 10q22.3 are responsible for a heterogenous spectrum of clinically distinct myodegenerative disorders, affecting both skeletal and cardiac muscles to variable degrees.
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Affiliation(s)
- Angelika Kuhl
- Department of Neuroimmunology, Max-Planck-Institute of Neurobiology, Martinsried, Germany
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84
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Dowling JJ, Gibbs E, Russell M, Goldman D, Minarcik J, Golden JA, Feldman EL. Kindlin-2 is an essential component of intercalated discs and is required for vertebrate cardiac structure and function. Circ Res 2008; 102:423-31. [PMID: 18174465 DOI: 10.1161/circresaha.107.161489] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Integrins and proteins that associate with integrins are implicated in normal cardiac muscle function and development. Unc-112 is a cytoplasmic adaptor protein required for the proper establishment of integrin junctions in Caenorhabditis elegans muscle. A vertebrate homolog of unc-112, kindlin-2, is an integrin-binding protein that is expressed in cardiac muscle, but its function is unknown. We sought to understand the role of kindlin-2 in the development and function of the mouse and zebrafish heart. In the mouse, we found that kindlin-2 is highly expressed in the heart and is enriched at intercalated discs and costameres. Targeted disruption of the murine kindlin-2 gene resulted in embryonic lethality before cardiogenesis. To better assess the role of kindlin-2 in cardiac muscle development, we used morpholinos to knockdown the kindlin-2 homolog in zebrafish (z-kindlin-2), which resulted in severe abnormalities of heart development. Morphant hearts were hypoplastic and dysmorphic and exhibited significantly reduced ventricular contractility. Ultrastructural analysis of these hearts revealed disrupted intercalated disc formation and a failure in the attachment of myofibrils to membrane complexes. We conclude that kindlin-2 is an essential component of the intercalated disc, is necessary for cytoskeletal organization at sites of membrane attachment, and is required for vertebrate myocardial formation and function. These findings provide the first characterization of the in vivo functions of this novel and critical regulator of cardiogenesis.
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Affiliation(s)
- James J Dowling
- Division of Pediatric Neurology, L3215 Women's Hospital, Ann Arbor, MI 48109-0203, USA.
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Walker JW. Protein scaffolds, lipid domains and substrate recognition in protein kinase C function: implications for rational drug design. Handb Exp Pharmacol 2008:185-203. [PMID: 18491053 DOI: 10.1007/978-3-540-72843-6_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein kinase C (PKC) represents a family of lipid-regulated protein kinases with ubiquitous expression throughout the animal kingdom. High fidelity in PKC phosphorylation of intended target substrates is crucial for normal cell and tissue function. Therefore, it is likely that multiple interdependent factors contribute to determining substrate specificity in vivo, including divalent cation binding, substrate recognition motifs, local lipid heterogeneity and protein scaffolds. This review provides an overview of targeting mechanisms for the three subclasses of PKC isoforms, conventional, novel and atypical, with an emphasis on how they bind to substrates, lipids/lipid microdomains and multifunctional protein scaffolds. The diversity of interactions between PKC isoforms and their immediate environment is extensive, suggesting that systems biology approaches including proteomics and network modeling may be important strategies for rational drug design in the future.
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Affiliation(s)
- J W Walker
- Department of Physiology, Director of Human Proteomics Program, University of Wisconsin, Madison, WI 53706, USA.
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86
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The Sarcomere and the Nucleus: Functional Links to Hypertrophy, Atrophy and Sarcopenia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 642:176-91. [DOI: 10.1007/978-0-387-84847-1_13] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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87
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Abstract
Over the last two decades, a large number of mutations have been identified in sarcomeric proteins as a cause of hypertrophic, dilated or restrictive cardiomyopathy. Functional analyses of mutant proteins in vitro have revealed several important functional changes in sarcomeric proteins that might be primarily involved in the pathogenesis of each cardiomyopathy. Creation of transgenic or knock-in animals expressing mutant proteins in their hearts confirmed that these mutations in genes for sarcomeric proteins induced distinct types of cardiomyopathies and provided useful animal models to explore the molecular pathogenic mechanisms and potential therapeutics of cardiomyopathy in vivo. In this review, I discuss the functional consequences of mutations in different sarcomeric proteins found in hypertrophic, dilated, and restrictive cardiomyopathies in conjunction with their effects on cardiac structure and function in vivo and their possible molecular and cellular mechanisms, which underlie the pathogenesis of these inherited cardiomyopathies.
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Affiliation(s)
- Sachio Morimoto
- Laboratory of Clinical Pharmacology, Kyushu University Graduate School of Medicine, Fukuoka, Japan.
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88
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Nakano N, Hori H, Abe M, Shibata H, Arimura T, Sasaoka T, Sawabe M, Chida K, Arai T, Nakahara KI, Kubo T, Sugimoto K, Katsuya T, Ogihara T, Doi Y, Izumi T, Kimura A. Interaction of BMP10 with Tcap may modulate the course of hypertensive cardiac hypertrophy. Am J Physiol Heart Circ Physiol 2007; 293:H3396-403. [DOI: 10.1152/ajpheart.00311.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Elevated wall stress by hypertension induces an adaptive myocardial hypertrophy via releasing prohypertrophic hormones such as angiotensin II. In this study, we investigated the involvement of bone morphogenetic protein-10 (BMP10) in hypertension-induced cardiac hypertrophy. Expression of BMP10 was increased in the hypertrophied ventricles from hypertensive rats. BMP10 localized on cell surface and at stretch-sensing Z disc of cardiomyocytes, where BMP10 interacted with a protein called titin-cap (Tcap). A rare variant of the human BMP10 gene, Thr326Ile, was found to be associated with hypertensive dilated cardiomyopathy. The variant BMP10 demonstrated decreased binding to Tcap and increased extracellular secretion. Conditioned medium from cells transfected with wild-type or variant BMP10 induced hypertrophy in rat neonatal cardiomyocytes, except that medium from variant BMP10-carrying cells showed an enhanced effect reflecting the increased secretion. These observations suggested that hypertension induced expression of prohypertrophic BMP10, and the hypertrophic effect of BMP10 was modulated, at least in part, by its binding to Tcap at the Z disc.
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Abstract
PURPOSE OF REVIEW Noncompaction of the left ventricle is a descriptive anatomical term and recently recognized primary cardiomyopathy. Cardiac imaging now allows for prompt detection. The specific etiology remains poorly understood, however, and the major genetic determinants are unknown. This review describes recent data showing the genetic heterogeneity and overlap with other cardiomyopathies. Understanding the genetics may depend on clarifying the distinctive diagnostic features and investigating the contribution of all known cardiomyopathy-causing genes with overlapping morphology. RECENT FINDINGS Adding to the known genes (TAZ, DTNA, LDB3 and LMNA), recent work has identified SCN5A, MYH7 and MYBPC3 as associated loci. LDB3 may also be a genetic modifier. Case reports and linkage studies suggest additional loci at 1p36, 1q43 and 11p15. Aside from Barth syndrome, other genetic and metabolic syndromes with noncompaction have been described. Despite this, large studies have failed to identify the etiology in the majority of patients. SUMMARY Despite advances in detection, comprehensive clinical, pathological, genetic, and family studies are necessary to define the phenotypic overlap with other cardiomyopathies. Without a more precise understanding of its etiology, the answers to the questions regarding the clinical relevance and management of patients with noncompaction of the left ventricle will remain elusive.
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90
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Frank D, Kuhn C, Katus HA, Frey N. Role of the sarcomeric Z-disc in the pathogenesis of cardiomyopathy. Future Cardiol 2007; 3:611-22. [DOI: 10.2217/14796678.3.6.611] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The Z-disc has traditionally been viewed as a structure required to maintain sarcomeric function and integrity. More recently, the sarcomeric Z-disc has also emerged as a nodal point in cardiomyocyte signaling and mechanotransduction. This notion is not only supported by several transgenic animal models, but also by the identification of mutations in various Z-disc proteins, resulting in dilated or hypertrophic cardiomyopathy in patients. This review will thus focus on the role of the sarcomeric Z-disc and its associated proteins in the pathogenesis of cardiomyopathy.
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Affiliation(s)
- Derk Frank
- University of Heidelberg, Department of Internal Medicine III, Germany
| | - Christian Kuhn
- University of Heidelberg, Department of Internal Medicine III, Germany
| | - Hugo A Katus
- University of Heidelberg, Department of Internal Medicine III, Germany
| | - Norbert Frey
- Im Neuenheimer Feld 350, D-69120 Heidelberg, Germany
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91
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92
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Wiersma AC, Leegwater PA, van Oost BA, Ollier WE, Dukes-McEwan J. Canine candidate genes for dilated cardiomyopathy: annotation of and polymorphic markers for 14 genes. BMC Vet Res 2007; 3:28. [PMID: 17949487 PMCID: PMC2194671 DOI: 10.1186/1746-6148-3-28] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Accepted: 10/19/2007] [Indexed: 12/19/2022] Open
Abstract
Background Dilated cardiomyopathy is a myocardial disease occurring in humans and domestic animals and is characterized by dilatation of the left ventricle, reduced systolic function and increased sphericity of the left ventricle. Dilated cardiomyopathy has been observed in several, mostly large and giant, dog breeds, such as the Dobermann and the Great Dane. A number of genes have been identified, which are associated with dilated cardiomyopathy in the human, mouse and hamster. These genes mainly encode structural proteins of the cardiac myocyte. Results We present the annotation of, and marker development for, 14 of these genes of the dog genome, i.e. α-cardiac actin, caveolin 1, cysteine-rich protein 3, desmin, lamin A/C, LIM-domain binding factor 3, myosin heavy polypeptide 7, phospholamban, sarcoglycan δ, titin cap, α-tropomyosin, troponin I, troponin T and vinculin. A total of 33 Single Nucleotide Polymorphisms were identified for these canine genes and 11 polymorphic microsatellite repeats were developed. Conclusion The presented polymorphisms provide a tool to investigate the role of the corresponding genes in canine Dilated Cardiomyopathy by linkage analysis or association studies.
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Affiliation(s)
- Anje C Wiersma
- Small Animal Teaching Hospital, University of Liverpool, Leahurst, Chester High Road, Neston, CH64 7TE, UK.
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93
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Arimura T, Matsumoto Y, Okazaki O, Hayashi T, Takahashi M, Inagaki N, Hinohara K, Ashizawa N, Yano K, Kimura A. Structural analysis of obscurin gene in hypertrophic cardiomyopathy. Biochem Biophys Res Commun 2007; 362:281-7. [PMID: 17716621 DOI: 10.1016/j.bbrc.2007.07.183] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 07/20/2007] [Indexed: 11/26/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac disease characterized by left ventricular hypertrophy with diastolic dysfunction. Molecular genetic studies have revealed that HCM is caused by mutations in genes for sarcomere/Z-band components including titin/connectin and its associate proteins. However, disease-causing mutations can be found in about half of the patients, suggesting that other disease-causing genes remain to be identified. To explore a novel disease gene, we searched for obscurin gene (OBSCN) mutations in HCM patients, because obscurin interacts with titin/connectin. Two linked variants, Arg4344Gln and Ala4484Thr, were identified in a patient and functional analyses demonstrated that Arg4344Gln affected binding of obscurin to Z9-Z10 domains of titin/connectin, whereas Ala4484Thr did not. Myc-tagged obscurin showed that Arg4344Gln impaired obscurin localization to Z-band. These observations suggest that the obscurin abnormality may be involved in the pathogenesis of HCM.
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MESH Headings
- Adult
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Cardiomyopathy, Hypertrophic/genetics
- Cardiomyopathy, Hypertrophic/pathology
- Cells, Cultured
- DNA Mutational Analysis
- Guanine Nucleotide Exchange Factors/chemistry
- Guanine Nucleotide Exchange Factors/genetics
- Guanine Nucleotide Exchange Factors/metabolism
- Humans
- Immunoprecipitation
- Models, Molecular
- Molecular Sequence Data
- Muscle Proteins/chemistry
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Mutation
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/metabolism
- Protein Binding
- Protein Serine-Threonine Kinases
- Protein Structure, Tertiary
- Rats
- Rats, Sprague-Dawley
- Rho Guanine Nucleotide Exchange Factors
- Sarcomeres/metabolism
- Sequence Homology, Amino Acid
- Transfection
- Two-Hybrid System Techniques
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Affiliation(s)
- Takuro Arimura
- Department of Molecular Pathogenesis, Medical Research Institute and Laboratory of Genome Diversity, School of Biomedical Science, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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94
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Arimura T, Hayashi T, Matsumoto Y, Shibata H, Hiroi S, Nakamura T, Inagaki N, Hinohara K, Takahashi M, Manatsu SI, Sasaoka T, Izumi T, Bonne G, Schwartz K, Kimura A. Structural analysis of four and half LIM protein-2 in dilated cardiomyopathy. Biochem Biophys Res Commun 2007; 357:162-7. [PMID: 17416352 DOI: 10.1016/j.bbrc.2007.03.128] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 03/19/2007] [Indexed: 10/23/2022]
Abstract
Dilated cardiomyopathy (DCM) is a cardiac disease characterized by dilated ventricle and systolic dysfunction. Most of the DCM patients are sporadic cases, but a certain population of DCM patients can be familial cases caused by mutations in genes for sarcomere/Z-disc components including titin/connectin. However, disease-causing mutations could be identified only in a part of the familial DCM patients, suggesting that there should be other disease causing genes for DCM. To explore a novel disease gene for DCM, we searched for mutations in FHL2, encoding for four and half LIM protein 2 (FHL2) in DCM patients, because FHL2 is known to associate with titin/connectin. A missense mutation, Gly48Ser, was identified in a patient with familial DCM. Functional analysis demonstrated that the FHL2 mutation affected the binding to titin/connectin. Because FHL2 protein is known to tether metabolic enzymes to titin/connectin, these observations suggest that the Gly48Ser mutation may be involved in the pathogenesis of DCM via impaired recruitment of metabolic enzymes to the sarcomere.
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Affiliation(s)
- Takuro Arimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 101-0062, Japan
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95
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Abstract
Dilated cardiomyopathy (DCM) is a myocardial disease characterized by dilatation and impaired systolic function of the left or both ventricles. The etiology of DCM is multifactorial, and many different clinical conditions can lead to the phenotype of DCM. During recent years it has become evident that genetic factors play an important role in the etiology and pathogenesis of idiopathic DCM. The genetics of DCM have been under intensive investigation lately, and thereby the knowledge on the genetic basis of DCM has increased rapidly. The genetic background of the disease seems to be relatively heterogeneous, and the disease-associated mutations concern mostly single families and only few affected patients. Disease-associated mutations have been detected e.g. in genes encoding sarcomere, cytoskeletal, and nuclear proteins, as well as proteins involved with regulation of Ca(2+) metabolism. The mechanisms, by which mutations eventually result in clinical heart failure, are complex and not yet totally resolved. DCM causes considerable morbidity and mortality. Better knowledge of the genetic background and disease-causing mechanisms would probably help us in focusing early treatment on right subjects and potentially also developing new treatment modalities and improving cardiac outcome in the affected patients. This review deals with DCM of genetic origin.
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Affiliation(s)
- Satu Kärkkäinen
- Kuopio University and Kuopio University Hospital, Kuopio, Finland.
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97
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Machuca-Tzili L, Thorpe H, Robinson TE, Sewry C, Brook JD. Flies deficient in Muscleblind protein model features of myotonic dystrophy with altered splice forms of Z-band associated transcripts. Hum Genet 2006; 120:487-99. [PMID: 16927100 DOI: 10.1007/s00439-006-0228-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 07/03/2006] [Indexed: 11/24/2022]
Abstract
Myotonic dystrophy (DM) is a dominantly inherited neuromuscular disorder characterised by muscle weakness and wasting. There are two forms of DM; both of which are caused by the expansion of repeated DNA sequences. DM1 is associated with a CTG repeat located in the 3' untranslated region of a gene, DMPK and DM2 with a tetranucleotide repeat expansion, CCTG, located in the first intron of a different gene, ZNF9. Recent data suggest a dominant RNA gain-of-function mechanism underlying DM, as transcripts containing either CUG or CCUG repeat expansions accumulate as foci in the nuclei of DM1 and DM2 cells respectively, where they exert a toxic effect, sequestering specific RNA binding proteins such as Muscleblind, which leads to splicing defects and the disruption of normal cellular functions. Z-band disruption is a well-known histological feature of DM1 muscle, which has also been reported in Muscleblind deficient flies. In order to determine whether there is a common molecular basis for this abnormality we have examined the alternative splicing pattern of transcripts that encode proteins associated with the Z-band in both organisms. Our results demonstrate that the missplicing of ZASP/LDB3 leads to the expression of an isoform in DM1 patient muscle, which is not present in normal controls, nor in other myopathies. Furthermore the Drosophila homologue, CG30084, is also misspliced, in Muscleblind deficient flies. Another Z-band transcript, alpha actinin, is misspliced in mbl mutant flies, but not in DM1 patient samples. These results point to similarities but subtle differences in the molecular breakdown of Z-band structures in flies and DM patients and emphasise the relevance of Muscleblind proteins in DM pathophysiology.
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Affiliation(s)
- Laura Machuca-Tzili
- Institute of Genetics, University of Nottingham, Queen's Medical Centre, Nottingham, UK
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98
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van der Meer DLM, Marques IJ, Leito JTD, Besser J, Bakkers J, Schoonheere E, Bagowski CP. Zebrafish cypher is important for somite formation and heart development. Dev Biol 2006; 299:356-72. [PMID: 16982050 DOI: 10.1016/j.ydbio.2006.07.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 05/25/2006] [Accepted: 07/26/2006] [Indexed: 11/26/2022]
Abstract
Mammalian CYPHER (Oracle, KIA0613), a member of the PDZ-LIM family of proteins (Enigma/LMP-1, ENH, ZASP/Cypher, RIL, ALP, and CLP-36), has been associated with cardiac and muscular myopathies. Targeted deletion of Cypher in mice is neonatal lethal possibly caused by myopathies. To further investigate the role of cypher in development, we have cloned the zebrafish orthologue. We present here the gene, domain structure, and expression pattern of zebrafish cypher during development. Cypher was not present as a maternal mRNA and was absent during early development. Cypher mRNA was first detected at the 3-somite stage in adaxial somites, and as somites matured, cypher expression gradually enveloped the whole somite. Later, cypher expression was also found in the heart, in head and jaw musculature, and in the brain. We further identified 13 alternative spliced forms of cypher from zebrafish heart and skeletal muscle tissue, among them a very short form containing the PDZ domain but lacking the ZM (ZASP-like) motif and the LIM domains. Targeted gene knock-down experiments using cypher antisense morpholinos led to severe defects, including truncation of the embryo, deformation of somites, dilatation of the pericardium, and thinning of the ventricular wall. The phenotype could be rescued by a cypher form, which contains the PDZ domain and the ZM motif, but lacks all three LIM domains. These findings indicate that a PDZ domain protein is important for normal somite formation and in normal heart development. Treatment of zebrafish embryos with cyclopamine, which disrupts hedgehog signaling, abolished cypher expression in 9 somite and 15-somite stage embryos. Taken together, our data suggest that cypher may play a role downstream of sonic hedgehog, in a late stage of somite development, when slow muscle fibers differentiate and migrate from the adaxial cells.
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Affiliation(s)
- David L M van der Meer
- Institute of Biology, Department of Integrative Zoology University of Leiden, Kaiserstraat 3, 2311 GN, The Netherlands
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99
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Affiliation(s)
- Jeffrey A Towbin
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Texas Children's Hospital, Houston, TX 77030, USA.
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100
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Delnatte C, Sanlaville D, Mougenot JF, Vermeesch JR, Houdayer C, Blois MCD, Genevieve D, Goulet O, Fryns JP, Jaubert F, Vekemans M, Lyonnet S, Romana S, Eng C, Stoppa-Lyonnet D. Contiguous gene deletion within chromosome arm 10q is associated with juvenile polyposis of infancy, reflecting cooperation between the BMPR1A and PTEN tumor-suppressor genes. Am J Hum Genet 2006; 78:1066-74. [PMID: 16685657 PMCID: PMC1474102 DOI: 10.1086/504301] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2005] [Accepted: 03/14/2006] [Indexed: 12/24/2022] Open
Abstract
We describe four unrelated children who were referred to two tertiary referral medical genetics units between 1991 and 2005 and who are affected with juvenile polyposis of infancy. We show that these children are heterozygous for a germline deletion encompassing two contiguous genes, PTEN and BMPR1A. We hypothesize that juvenile polyposis of infancy is caused by the deletion of these two genes and that the severity of the disease reflects cooperation between these two tumor-suppressor genes.
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Affiliation(s)
- Capucine Delnatte
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Damien Sanlaville
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Jean-François Mougenot
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Joris-Robert Vermeesch
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Claude Houdayer
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Marie-Christine de Blois
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - David Genevieve
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Olivier Goulet
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Jean-Pierre Fryns
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Francis Jaubert
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Michel Vekemans
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Stanislas Lyonnet
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Serge Romana
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Charis Eng
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
| | - Dominique Stoppa-Lyonnet
- Department of Genetics, Institut Curie, and Departments of Genetics, Pediatrics, and Pathology, Hôpital Necker-Enfants Malades, Assistance Publique–Hôpitaux de Paris, and INSERM Equipe Mixte INSERM E0210, Paris; Center of Human Genetics, Katholieke Universiteit Leuven, Leuven, Belgium; and Cleveland Clinic Genomic Medicine Institute and Department of Genetics, Case Western Reserve University School of Medicine, Cleveland
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