Identification of a novel cardiac-specific transcript critical for cardiac myocyte differentiation

Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2779-2789 ◽  
Author(s):  
Y. Wei ◽  
D. Bader ◽  
J. Litvin
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Cardiac Myocyte ◽  
Heart Tube ◽  
Myogenic Cells ◽  
Chicken Heart ◽  
Reading Frame ◽  
Cardiac Myogenesis ◽  
Myocyte Differentiation ◽  
Heart Formation

A novel cDNA, pCMF1, which is expressed exclusively and transiently in the myogenic cells of the differentiating chicken heart was isolated and characterized. The full-length cDNA of pCMF1 has one open reading frame encoding 1538 predicted amino acids. While computer analysis predicts the presence of specific structural motifs, the overall sequence of pCMF1 is unique. The pattern of pCMF1 gene expression during heart formation was determined by whole-mount in situ hybridization. pCMF1 is transiently expressed within the myogenic cells of the primitive heart tube from stages 9 to 18 and is not detected in the heart or any other tissue thereafter. A replication-deficient retrovirus was used to mediate pCMF1 antisense expression in cardiogenic mesoderm. These analyses determined that the presence of pCMF1 antisense sequences disrupted myosin heavy chain expression during cardiac mesoderm differentiation. pCMF1 antisense had no effect on myosin heavy chain expression in differentiated cardiac myocytes. These data suggest a potential function for pCMF1 during cardiac myogenesis.

Expression of the atrial-specific myosin heavy chain AMHC1 and the establishment of anteroposterior polarity in the developing chicken heart

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 871-883 ◽  
Author(s):  
K.E. Yutzey ◽  
J.T. Rhee ◽  
D. Bader
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Cardiac Myocyte ◽  
Anterior Segment ◽  
Heart Cells ◽  
Heart Tube ◽  
Expression Domain ◽  
Chicken Heart

A unique myosin heavy chain cDNA (AMHC1), which is expressed exclusively in the atria of the developing chicken heart, was isolated and used to study the generation of diversified cardiac myocyte cell lineages. The pattern of AMHC1 gene expression during heart formation was determined by whole-mount in situ hybridization. AMHC1 is first activated in the posterior segment of the heart when these myocytes initially differentiate (Hamburger and Hamilton stage 9+). The anterior segment of the heart at this stage does not express AMHC1 although the ventricular myosin heavy chain isoform is strongly expressed beginning at stage 8+. Throughout chicken development, AMHC1 continues to be expressed in the posterior heart tube as it develops into the diversified atria. The early activation of AMHC1 expression in the posterior cardiac myocytes suggests that the heart cells are diversified when they differentiate initially and that the anterior heart progenitors differ from the posterior heart progenitors in their myosin isoform gene expression. The expression domain of AMHC1 can be expanded anteriorly within the heart tube by treating embryos with retinoic acid as the heart primordia fuse. Embryos treated with retinoic acid prior to the initiation of fusion of the heart primordia express AMHC1 throughout the entire heart-forming region and fusion of the heart primordia is inhibited. These data indicate that retinoic acid treatment produces an expansion of the posterior (atrial) domain of the heart and suggests that diversified fates of cardiomyogenic progenitors can be altered.

scholarly journals Tissue-Restricted Expression of the Cardiac α-Myosin Heavy Chain Gene Is Controlled by a Downstream Repressor Element Containing a Palindrome of Two Ets-Binding Sites

1998 ◽  
Vol 18 (12) ◽  
pp. 7243-7258 ◽  
Author(s):  
Madhu Gupta ◽  
Radovan Zak ◽  
Towia A. Libermann ◽  
Mahesh P. Gupta
Keyword(s):  
Gene Regulation ◽  
Myosin Heavy Chain ◽  
Cardiac Myocytes ◽  
Heavy Chain ◽  
Binding Sites ◽  
Cardiac Myocyte ◽  
Specific Expression ◽  
Tissue Specific Expression ◽  
Nonmuscle Cells ◽  
Muscle Gene

ABSTRACT The expression of the α-myosin heavy chain (MHC) gene is restricted primarily to cardiac myocytes. To date, several positive regulatory elements and their binding factors involved in α-MHC gene regulation have been identified; however, the mechanism restricting the expression of this gene to cardiac myocytes has yet to be elucidated. In this study, we have identified by using sequential deletion mutants of the rat cardiac α-MHC gene a 30-bp purine-rich negative regulatory (PNR) element located in the first intronic region that appeared to be essential for the tissue-specific expression of the α-MHC gene. Removal of this element alone elevated (20- to 30-fold) the expression of the α-MHC gene in cardiac myocyte cultures and in heart muscle directly injected with plasmid DNA. Surprisingly, this deletion also allowed a significant expression of the α-MHC gene in HeLa and other nonmuscle cells, where it is normally inactive. The PNR element required upstream sequences of the α-MHC gene for negative gene regulation. By DNase I footprint analysis of the PNR element, a palindrome of two high-affinity Ets-binding sites (CTTCCCTGGAAG) was identified. Furthermore, by analyses of site-specific base-pair mutation, mobility gel shift competition, and UV cross-linking, two different Ets-like proteins from cardiac and HeLa cell nuclear extracts were found to bind to the PNR motif. Moreover, the activity of the PNR-binding factor was found to be increased two- to threefold in adult rat hearts subjected to pressure overload hypertrophy, where the α-MHC gene is usually suppressed. These data demonstrate that the PNR element plays a dual role, both downregulating the expression of the α-MHC gene in cardiac myocytes and silencing the muscle gene activity in nonmuscle cells. Similar palindromic Ets-binding motifs are found conserved in the α-MHC genes from different species and in other cardiac myocyte-restricted genes. These results are the first to reveal a role of the Ets class of proteins in controlling the tissue-specific expression of a cardiac muscle gene.

scholarly journals Detection of a ventricular-specific myosin heavy chain in adult and developing chicken heart.

1986 ◽  
Vol 102 (4) ◽  
pp. 1480-1484 ◽  
Author(s):  
Y Zhang ◽  
S A Shafiq ◽  
D Bader
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Heart Development ◽  
In Ovo ◽  
Specific Expression ◽  
Adult Chicken ◽  
Chicken Heart ◽  
Developing Heart ◽  
Caudal Portion ◽  
Atrial Myosin

In the present study, a monoclonal antibody (McAb), ALD19, generated against myosin of slow tonic muscle, was shown to react with the heavy chain of ventricular myosin in the adult chicken heart. With this antibody, it was possible to detect a ventricular-specific myosin during myocardial differentiation and to show that the epitope recognized by ALD19 was present from the earliest stages of ventricular differentiation and maintained throughout development only in the ventricle. A second McAb, specific for atrial myosin heavy chain (MHC) (Gonzalez-Sanchez, A., and D. Bader, 1984, Dev. Biol., 103:151-158), was used as a control to detect an atrial-specific myosin in the caudal portion of the developing heart at Hamburger-Hamilton stage 15. It was found that the appearance of ventricular MHC predated the expression of atrial MHC by approximately 1 d in ovo and that specific MHCs were always differentially distributed. While a common primordial MHC may be present in the early heart, this study showed the tissue-specific expression of a ventricular MHC during the initial stages of heart development and its differential accumulation throughout development.

Role of USF1 phosphorylation on cardiac α-myosin heavy chain promoter activity

2002 ◽  
Vol 283 (1) ◽  
pp. H213-H219 ◽  
Author(s):  
Qianxun Xiao ◽  
Agnes Kenessey ◽  
Kaie Ojamaa
Keyword(s):  
Protein Kinase ◽  
Myosin Heavy Chain ◽  
Molecular Mechanism ◽  
Heavy Chain ◽  
Promoter Activity ◽  
Cardiac Myocyte ◽  
Contractile Function ◽  
Contractile Activity ◽  
Cell Mass ◽  
Two Dimensional Gel Electrophoresis

Contractile activity of the cardiac myocyte is required for maintaining cell mass and phenotype, including expression of the cardiac-specific α-myosin heavy chain (α-MHC) gene. An E-box hemodynamic response element (HME) located at position −47 within the α-MHC promoter is both necessary and sufficient to confer contractile responsiveness to the gene and has been shown to bind upstream stimulatory factor-1 (USF1). When studied in spontaneously contracting cardiac myocytes, there is enhanced binding of USF1 to the HME compared with quiescent cells, which correlates with a threefold increase in α-MHC promoter activity. A molecular mechanism by which contractile function modulates α-MHC transcriptional activity may involve signaling via phosphorylation of USF1. The present studies showed that purified rat USF1 was phosphorylated in vitro by protein kinase C (PKC) and cAMP-dependent protein kinase (PKA) but not casein kinase II. Phosphorylated USF1 by either PKC or PKA had increased DNA binding activity to the HME. PKC-mediated phosphorylation also leads to the formation of USF1 multimers as assessed by gel shift assay. Analysis of in vivo phosphorylated nuclear proteins from cultured ventricular myocytes showed that USF1 was phosphorylated, and resolution by two-dimensional gel electrophoresis identified at least two distinct phosphorylated USF1 molecules. These results suggest that endogenous kinases can covalently modify USF1 and provide a potential molecular mechanism by which the contractile stimulus mediates changes in myocyte gene transcription.

Myogenic cell migration from somites is induced by tissue contact with medial region of the presumptive limb mesoderm in chick embryos

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 661-669 ◽  
Author(s):  
K. Hayashi ◽  
E. Ozawa
Keyword(s):  
Cell Migration ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Flank Region ◽  
Myogenic Cell ◽  
Chick Embryos ◽  
Medial Region ◽  
Myogenic Cells ◽  
Limb Buds ◽  
Lateral Region

It is known that myogenic cells in limb buds are derived from somites. In order to examine the potential of the limb primordium (presumptive limb somatopleure) to induce myogenic cell migration, we transplanted chick presumptive limb somatopleure to the flank region of an embryo, a region that does not normally contribute myogenic cells to the limb. Somitic cell migration was examined using a vital labeling technique. When the presumptive limb somatopleure was transplanted and was in contact with the host flank somite, somitic-cell migration toward the graft was observed. The labeled somitic cells within the graft were identified as myogenic cells in two ways: first, we found that N-cadherin-expressing cells appeared in the graft. Second, after 3 further days of incubation, the somitic cells formed dorsal and ventral masses and expressed sarcomeric myosin heavy chain within the graft. Cell migration occurred only when the somite was in contact with the medial region of the presumptive limb somatopleure. When the somite was not in contact with the limb somatopleure, or when the somite was in contact with the lateral region of the limb somatopleure, migration did not occur. These observations indicate that the potential to induce myogenic cell migration is restricted to the medial region of the presumptive limb somatopleure and that tissue contact is required.

scholarly journals A Calcineurin-NFATc3-Dependent Pathway Regulates Skeletal Muscle Differentiation and Slow Myosin Heavy-Chain Expression

2000 ◽  
Vol 20 (17) ◽  
pp. 6600-6611 ◽  
Author(s):  
Ulrike Delling ◽  
Jolana Tureckova ◽  
Hae W. Lim ◽  
Leon J. De Windt ◽  
Peter Rotwein ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Signal Transduction ◽  
Gene Transfer ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myogenic Differentiation ◽  
Fiber Type ◽  
Slow Myosin ◽  
Slow Myosin Heavy Chain ◽  
Myocyte Differentiation

ABSTRACT The differentiation and maturation of skeletal muscle cells into functional fibers is coordinated largely by inductive signals which act through discrete intracellular signal transduction pathways. Recently, the calcium-activated phosphatase calcineurin (PP2B) and the family of transcription factors known as NFAT have been implicated in the regulation of myocyte hypertrophy and fiber type specificity. Here we present an analysis of the intracellular mechanisms which underlie myocyte differentiation and fiber type specificity due to an insulinlike growth factor 1 (IGF-1)–calcineurin–NFAT signal transduction pathway. We demonstrate that calcineurin enzymatic activity is transiently increased during the initiation of myogenic differentiation in cultured C2C12 cells and that this increase is associated with NFATc3 nuclear translocation. Adenovirus-mediated gene transfer of an activated calcineurin protein (AdCnA) potentiates C2C12 and Sol8 myocyte differentiation, while adenovirus-mediated gene transfer of noncompetitive calcineurin-inhibitory peptides (cain or ΔAKAP79) attenuates differentiation. AdCnA infection was also sufficient to rescue myocyte differentiation in an IGF-depleted myoblast cell line. Using 10T1/2 cells, we demonstrate that MyoD-directed myogenesis is dramatically enhanced by either calcineurin or NFATc3 cotransfection, while a calcineurin inhibitory peptide (cain) blocks differentiation. Enhanced myogenic differentiation directed by calcineurin, but not NFATc3, preferentially specifies slow myosin heavy-chain expression, while enhanced differentiation through mitogen-activated protein kinase kinase 6 (MKK6) promotes fast myosin heavy-chain expression. These data indicate that a signaling pathway involving IGF-calcineurin-NFATc3 enhances myogenic differentiation whereas calcineurin acts through other factors to promote the slow fiber type program.

scholarly journals Atrial and Ventricular Myosin Heavy-chain Expression in the Developing Chicken Heart: Strengths and Limitations of Non-radioactive In Situ Hybridization

2006 ◽  
Vol 54 (6) ◽  
pp. 649-664 ◽  
Author(s):  
Semir Somi ◽  
André T. J. Klein ◽  
Arjan C. Houweling ◽  
Jan M. Ruijter ◽  
Anita A.M. Buffing ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Chicken Heart ◽  
Ventricular Myosin

scholarly journals Turnover of the creatine kinase subunits in chicken myogenic cell cultures and in fibroblasts

1981 ◽  
Vol 196 (2) ◽  
pp. 377-382 ◽  
Author(s):  
M Caravatti ◽  
J C Perriard
Keyword(s):  
Creatine Kinase ◽  
Myosin Heavy Chain ◽  
Cell Cultures ◽  
Heavy Chain ◽  
Half Life ◽  
Regulatory Mechanism ◽  
Total Acid ◽  
Myogenic Cells ◽  
Creatine Kinase Isoenzyme ◽  
The Stability

The rates of degradation of creatine kinase subunits, M-CK and B-CK subunits, were measured in cultured myogenic cells and in subcultured fibroblasts. In differentiated myogenic cells, the myotubes, both M-CK and B-CK subunits are synthesized. Their rates of degradation were compared. The M-CK subunits is slightly more stable and is degraded with an average apparent half-life of 75 h, whereas that of the B-CK subunit was shorter with 63 h. The turnover properties of M-CK subunit from soluble and of myofibril-bound MM-CK homodimeric creatine kinase isoenzyme isolated from breast muscle of young chickens were identical. The apparent half-life of the B-CK subunit was also determined in subcultured fibroblasts and 5-bromo-2′-deoxyuridine-treated cells, and found to be shorter than in myotubes (46 h and 37 h respectively). Similar observations were made for myosin heavy chain, actin and total acid-precipitable material. It appears therefore that proteins are in general degraded more slowly in differentiated myogenic cells. The differences in the stability of M-CK and B-CK subunits in myotubes probably do not reflect a major regulatory mechanism of the creatine kinase isoenzyme transition.

scholarly journals MyoD, myogenin independent differentiation of primordial myoblasts in mouse somites.

1992 ◽  
Vol 116 (5) ◽  
pp. 1243-1255 ◽  
Author(s):  
M G Cusella-De Angelis ◽  
G Lyons ◽  
C Sonnino ◽  
L De Angelis ◽  
E Vivarelli ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Posttranscriptional Regulation ◽  
Proximal Region ◽  
Limb Bud ◽  
Northern Analysis ◽  
Myogenic Cells

The accumulation of two myogenic regulatory proteins, MyoD and myogenin, was investigated by double-immunocytochemistry and correlated with myosin heavy chain expression in different classes of myoblasts in culture and during early myogenesis in vivo. During in vitro differentiation of fetal myoblasts, MyoD-positive cells were detected first, followed by the appearance of cells positive for both MyoD and myogenin and finally by the appearance of differentiated myocytes and myotubes expressing myosin heavy chain (MHC). A similar pattern of expression was observed in cultures of embryonic and satellite cells. In contrast, most myogenic cells isolated from newly formed somites, expressed MHC in the absence of detectable levels of myogenin or MyoD. In vivo, the appearance of both myogenin and MyoD proteins was only detected at 10.5 d postcoitum (d.p.c.), when terminally differentiated muscle cells could already be identified in the myotome. Parasagittal sections of the caudal myotomes of 10.5-d-old embryos showed that expression of contractile proteins preceded the expression of myogenin or MyoD and, when coexpressed, MHC and myogenin did not co-localize within all the cells of the myotome. In the limb bud, however, many myogenin (or MyoD) positive/MHC negative cells could be observed in the proximal region at day 11. During further embryonic development the expression of these proteins remained constant in all the muscle anlagens examined, decreasing to a low level during the late fetal period. Western and Northern analysis confirmed that the myogenin protein could only be detected after 10.5 d.p.c. while the corresponding message was clearly present at 9.5 d.p.c., strongly suggesting a posttranscriptional regulation of myogenin during this stage of embryonic development. These data show that the first myogenic cells which appear in the mouse myotome, and can be cultured from it, accumulate muscle structural proteins in their cytoplasm without expressing detectable levels of myogenin protein (although the message is clearly accumulated). Neither MyoD message or protein are detectable in these cells, which may represent a distinct myogenic population whose role in development remains to be established.

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