1
|
Carrasco L, Cea P, Rocco P, Peña-Oyarzún D, Rivera-Mejias P, Sotomayor-Flores C, Quiroga C, Criollo A, Ibarra C, Chiong M, Lavandero S. Role of Heterotrimeric G Protein and Calcium in Cardiomyocyte Hypertrophy Induced by IGF-1. J Cell Biochem 2014; 115:712-20. [DOI: 10.1002/jcb.24712] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 11/05/2013] [Indexed: 01/09/2023]
Affiliation(s)
- Loreto Carrasco
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Paola Cea
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Paola Rocco
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Daniel Peña-Oyarzún
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Pablo Rivera-Mejias
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Cristian Sotomayor-Flores
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Clara Quiroga
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Alfredo Criollo
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Departamento Ciencias Básicas y Comunitarias; Facultad Odontología; Universidad de Chile; Santiago Chile
| | - Cristian Ibarra
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Department of Medical Biochemistry and Biophysics; Karolinska Institutet; Stockholm Sweden
| | - Mario Chiong
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
- Instituto de Ciencias Biomédicas; Facultad Medicina; Universidad de Chile; Santiago Chile
- Cardiology Division; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas Texas
| |
Collapse
|
2
|
Ibarra C, Vicencio JM, Estrada M, Lin Y, Rocco P, Rebellato P, Munoz JP, Garcia-Prieto J, Quest AFG, Chiong M, Davidson SM, Bulatovic I, Grinnemo KH, Larsson O, Szabadkai G, Uhlén P, Jaimovich E, Lavandero S. Local control of nuclear calcium signaling in cardiac myocytes by perinuclear microdomains of sarcolemmal insulin-like growth factor 1 receptors. Circ Res 2012; 112:236-45. [PMID: 23118311 DOI: 10.1161/circresaha.112.273839] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
RATIONALE The ability of a cell to independently regulate nuclear and cytosolic Ca(2+) signaling is currently attributed to the differential distribution of inositol 1,4,5-trisphosphate receptor channel isoforms in the nucleoplasmic versus the endoplasmic reticulum. In cardiac myocytes, T-tubules confer the necessary compartmentation of Ca(2+) signals, which allows sarcomere contraction in response to plasma membrane depolarization, but whether there is a similar structure tunneling extracellular stimulation to control nuclear Ca(2+) signals locally has not been explored. OBJECTIVE To study the role of perinuclear sarcolemma in selective nuclear Ca(2+) signaling. METHODS AND RESULTS We report here that insulin-like growth factor 1 triggers a fast and independent nuclear Ca(2+) signal in neonatal rat cardiac myocytes, human embryonic cardiac myocytes, and adult rat cardiac myocytes. This fast and localized response is achieved by activation of insulin-like growth factor 1 receptor signaling complexes present in perinuclear invaginations of the plasma membrane. The perinuclear insulin-like growth factor 1 receptor pool connects extracellular stimulation to local activation of nuclear Ca(2+) signaling and transcriptional upregulation through the perinuclear hydrolysis of phosphatidylinositol 4,5-biphosphate inositol 1,4,5-trisphosphate production, nuclear Ca(2+) release, and activation of the transcription factor myocyte-enhancing factor 2C. Genetically engineered Ca(2+) buffers--parvalbumin--with cytosolic or nuclear localization demonstrated that the nuclear Ca(2+) handling system is physically and functionally segregated from the cytosolic Ca(2+) signaling machinery. CONCLUSIONS These data reveal the existence of an inositol 1,4,5-trisphosphate-dependent nuclear Ca(2+) toolkit located in direct apposition to the cell surface, which allows the local control of rapid and independent activation of nuclear Ca(2+) signaling in response to an extracellular ligand.
Collapse
Affiliation(s)
- Cristian Ibarra
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago, Chile
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Wang KC, Brooks DA, Botting KJ, Morrison JL. IGF-2R-Mediated Signaling Results in Hypertrophy of Cultured Cardiomyocytes from Fetal Sheep1. Biol Reprod 2012; 86:183. [DOI: 10.1095/biolreprod.112.100388] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
|
4
|
Waite E, Lafont C, Carmignac D, Chauvet N, Coutry N, Christian H, Robinson I, Mollard P, Le Tissier P. Different degrees of somatotroph ablation compromise pituitary growth hormone cell network structure and other pituitary endocrine cell types. Endocrinology 2010; 151:234-43. [PMID: 19887571 DOI: 10.1210/en.2009-0539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have generated transgenic mice with somatotroph-specific expression of a modified influenza virus ion channel, (H37A)M2, leading to ablation of GH cells with three levels of severity, dependent on transgene copy number. GH-M2(low) mice grow normally and have normal-size pituitaries but 40-50% reduction in pituitary GH content in adult animals. GH-M2(med) mice have male-specific transient growth retardation and a reduction in pituitary GH content by 75% at 42 d and 97% by 100 d. GH-M2(high) mice are severely dwarfed with undetectable pituitary GH. The GH secretory response of GH-M2(low) and GH-M2(med) mice to GH-releasing peptide-6 and GHRH was markedly attenuated. The content of other pituitary hormones was affected depending on transgene copy number: no effect in GH-M2(low) mice, prolactin and TSH reduced in GH-M2(med) mice, and all hormones reduced in GH-M2(high) mice. The effect on non-GH hormone content was associated with increased macrophage invasion of the pituitary. Somatotroph ablation affected GH cell network organization with limited disruption in GH-M2(low) mice but more severe disruption in GH-M2(med) mice. The remaining somatotrophs formed tight clusters after puberty, which contrasts with GHRH-M2 mice with a secondary reduction in somatotrophs that do not form clusters. A reduction in pituitary beta-catenin staining was correlated with GH-M2 transgene copy number, suggesting M2 expression has an effect on cell-cell communication in somatotrophs and other pituitary cell types. GH-M2 transgenic mice demonstrate that differing degrees of somatotroph ablation lead to correlated secondary effects on cell populations and cellular network organization.
Collapse
Affiliation(s)
- Eleanor Waite
- Division of Molecular Neuroendocrinology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Hu BS, Landeen LK, Aroonsakool N, Giles WR. An analysis of the effects of stretch on IGF-I secretion from rat ventricular fibroblasts. Am J Physiol Heart Circ Physiol 2007; 293:H677-83. [PMID: 17400715 DOI: 10.1152/ajpheart.01413.2006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanical force can induce a number of fundamental short- and long-term responses in myocardium. These include alterations in ECM, activation of cell-signaling pathways, altered gene regulation, changes in cell proliferation and growth, and secretion of a number of peptides and growth factors. It is now known that a number of these autocrine/paracrine factors are secreted from both cardiomyocytes and ventricular cardiac fibroblasts (CFb) in response to stretch. One such substance is IGF-I. IGF-I is an important autocrine/paracrine factor that can regulate physiological or pathophysiological responses, such as hypertrophy. In this study, we addressed the possible effects of mechanical perturbation, biaxial strain, on IGF-I secretion from adult rat CFb. CFb were subjected to either static stretch (3-10%) or cyclic stretch (10%; 0.1-1 Hz) over a 24-h period. IGF-1 secretion from CFb in response to selected stretch paradigms was examined using ELISA to measure IGF-I concentrations in conditioned media. Static stretch did not result in any measurable modulation of IGF-I secretion from CFb. However, cyclic stretch significantly increased IGF-I secretion from CFb in a frequency- and time-dependent manner compared with nonstretched controls. This stretch-induced increase in secretion was relatively insensitive to changes in extracellular [Ca(2+)] or to block of L-type Ca(2+) channels. In contrast, thapsigargin, an inhibitor of sarco(endo)plasmic reticulum Ca(2+) ATPase, remarkably decreased stretch-induced IGF-I secretion from CFb. We further show that IGF-I can upregulate mRNA expression of atrial natriuretic peptide in myocytes. In summary, cyclic stretch can significantly increase IGF-I secretion from CFb, and this effect is dependent on a thapsigargin-sensitive pool of intracellular [Ca(2+)].
Collapse
Affiliation(s)
- Betty S Hu
- Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada
| | | | | | | |
Collapse
|
6
|
Tivesten A, Isgaard J. Cardiovascular and Respiratory Systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 567:149-66. [PMID: 16370139 DOI: 10.1007/0-387-26274-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Asa Tivesten
- Research Center for Endocrinology and Metabolism, Department of Internal Medicine, Sahlgrenska Academy at the University of Göteborg, Sweden
| | | |
Collapse
|
7
|
Dong F, Esberg LB, Roughead ZK, Ren J, Saari JT. Increased contractility of cardiomyocytes from copper-deficient rats is associated with upregulation of cardiac IGF-I receptor. Am J Physiol Heart Circ Physiol 2005; 289:H78-84. [PMID: 15734878 DOI: 10.1152/ajpheart.01093.2004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hearts from severely Cu-deficient rats show a variety of pathological defects, including hypertrophy and, in intact hearts, depression of contractile function. Paradoxically, isolated cardiomyocytes from these rats exhibit enhanced contractile properties. Because hypertrophy and enhanced contractility observed with other pathologies are associated with elevation of insulin-like growth factor-I (IGF)-I, this mechanism was examined for the case of dietary Cu deficiency. Male, weanling Sprague-Dawley rats were provided diets that were deficient (∼0.5 mg Cu/kg diet) or adequate (∼6 mg Cu/kg diet) in Cu for 5 wk. IGF-I was measured in serum and hearts by an ELISA method, cardiac IGF-I and IGF-II receptors and IGFBP-3 were measured by Western blotting analysis, and mRNAs for cardiac IGF-I and IGF-II were measured by RT-PCR. Contractility of isolated cardiomyocytes was assessed by a video-based edge-detection system. Cu deficiency depressed serum and heart IGF-I and heart IGFBP-3 protein levels and increased cardiac IGF-I receptor protein. Cardiac IGF-II protein and mRNA for cardiac IGF-I and IGF-II were unaffected by Cu deficiency. A Cu deficiency-induced increase in cardiomyocyte contractility, as indicated by increases in maximal velocities of shortening (−d L/d t) and relengthening (+d L/d t) and decrease in time to peak shortening (TPS), was confirmed. These changes were largely inhibited by use of H-1356, an IGF-I receptor blocker. We conclude that enhanced sensitivity to IGF-I, as indicated by an increase in IGF-I receptor protein, accounts for the increased contractility of Cu-deficient cardiomyocytes and may presage cardiac failure.
Collapse
Affiliation(s)
- Feng Dong
- Division of Pharmaceutical Sciences and Center for Cardiovascular Research and Alternative Medicine, University of Wyoming, Laramie, Wyoming, USA
| | | | | | | | | |
Collapse
|
8
|
Horio T, Maki T, Kishimoto I, Tokudome T, Okumura H, Yoshihara F, Suga SI, Takeo S, Kawano Y, Kangawa K. Production and autocrine/paracrine effects of endogenous insulin-like growth factor-1 in rat cardiac fibroblasts. ACTA ACUST UNITED AC 2005; 124:65-72. [PMID: 15544842 DOI: 10.1016/j.regpep.2004.06.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Revised: 06/29/2004] [Accepted: 06/30/2004] [Indexed: 11/30/2022]
Abstract
Insulin-like growth factor (IGF)-1 appears to play an important role in cardiac hypertrophy or remodeling. However, the role of endogenous IGF-1 in the growth of cardiac myocytes and fibroblasts remains unclear. This study investigated the major site of the production of cardiac IGF-1 and the local effects of endogenous IGF-1 secreted from cardiac cells. A significant expression of IGF-1 mRNA was found in cultured neonatal and adult rat cardiac fibroblasts, but not in myocytes. In addition, an in vivo examination by in situ hybridization histochemical analyses demonstrated the IGF-1 transcripts in the interstitial fibrotic tissue of the ventricle. Time-dependent secretion of IGF-1 protein was also observed in cultured cardiac fibroblasts. An antibody against IGF-1 decreased collagen synthesis in cardiac fibroblasts under basal conditions. Fibroblast-conditioned medium, as well as exogenous IGF-1, increased protein synthesis in cardiac myocytes, and this increase was inhibited by antibodies against IGF-1 and IGF-1 receptor, IGF binding protein-3, and IGF-1 receptor antagonist. These observations suggest that IGF-1 is produced and released mainly from cardiac fibroblasts and that endogenous IGF-1 promotes collagen synthesis by cardiac fibroblasts and hypertrophy of myocytes as an autocrine and a paracrine factor. Cardiac IGF-1 may function as an endogenous modulator of cardiac hypertrophy or remodeling.
Collapse
Affiliation(s)
- Takeshi Horio
- Division of Hypertension and Nephrology, Department of Medicine, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565-8565, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Lü L, Yao T, Zhu YZ, Huang GY, Cao YX, Zhu YC. Chronic all-trans retinoic acid treatment prevents medial thickening of intramyocardial and intrarenal arteries in spontaneously hypertensive rats. Am J Physiol Heart Circ Physiol 2003; 285:H1370-7. [PMID: 12775563 DOI: 10.1152/ajpheart.00260.2003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There are in vitro data linking all-trans retinoic acid (atRA) with inhibition of hypertrophy and hyperplasia in cardiomyocytes, vascular smooth muscle cells, and fibroblasts. In the present study, we tested the hypothesis that chronic treatment with atRA may blunt the process of myocardial remodeling in spontaneously hypertensive rats (SHR). Four-week-old male SHR were treated with atRA (5 or 10 mg.kg-1.day-1) given daily for 3 mo by gavage; age- and sex-matched Wistar-Kyoto rats (WKY) and placebo-treated SHR served as controls. At the end of the treatment period, cardiac geometry and function were assessed by Doppler echocardiography. Histological examination and RIA were performed to evaluate medial thickening of intramyocardial and renal arteries, perivascular and interstitial collagen content, and atrial natriuretic peptide (ANP) and IGF-I in the heart, respectively. The novel finding of the present study is that atRA prevented hypertrophy of intramyocardial and intrarenal arteries and ventricular fibrosis. However, atRA treatment did not lower blood pressure or left ventricular weight and left ventricular weight-to-body weight ratio in SHR. atRA did not change cardiac geometry and function as assessed by Doppler echocardiography. atRA showed no influence on either ANP or IGF-I levels. In conclusion, the present study suggests that chronic atRA treatment prevents medial thickening of intramyocardial and intrarenal arteries and ventricular fibrosis during the development of hypertension. Left ventricular hypertrophy and cardiac geometry and function are not changed by atRA treatment.
Collapse
Affiliation(s)
- Lei Lü
- Department of Physiology and Pathophysiology, Key Laboratory of Molecular Medicine of the Ministry of Education, Fudan University Shanghai Medical College, 138 Yi Xue Yuan Rd., Shanghai 200032, People's Republic of China
| | | | | | | | | | | |
Collapse
|
10
|
Huang CY, Buchanan DL, Gordon RL, Sherman MJ, Razzaq J, White K, Buetow DE. Increased insulin-like growth factor-I gene expression precedes left ventricular cardiomyocyte hypertrophy in a rapidly-hypertrophying rat model system. Cell Biochem Funct 2003; 21:355-61. [PMID: 14624474 DOI: 10.1002/cbf.1040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chronic pressure overload leads to an increase in the size, i.e. hypertrophy, of cardiomyocytes in the heart. However, the molecular mechanisms underlying this hypertrophy are not understood. Insulin-like growth factor-I (IGF-I) synthesized locally in the heart is known to be associated with the hypertrophic process. So far, however, cardiac IGF-I gene expression in the widely used rat model system has only been shown to be increased when the hypertrophy induced by pressure-overload was already established. Therefore, the question of whether IGF-I serves as an initiating or early-enhancing factor for the cardiac hypertrophy remains unanswered. Here, cardiac hypertension and hypertrophy were rapidly induced in the rat by complete constriction of the abdominal aorta between the origins of the renal arteries. Carotid arterial systolic blood pressure remained unchanged in sham rats but increased rapidly in the pressure-overloaded constricted rats with a sustained hypertension established by 3 days. Hypertrophy of left ventricular (LV) cardiomyocytes in constricted rats also occurred by 3 days. However, this hypertrophy was preceded by increases in LV IGF-I mRNA and protein which occurred within 1 day. These results support the hypothesis that cardiac-synthesized IGF-I is an initiating or early-enhancing factor for hypertrophy of LV cardiomyocytes.
Collapse
Affiliation(s)
- Chi-Yang Huang
- Department of Molecular and Integrative Physiology, University of Illinois, 524 Burrill Hall, 407 South Goodwin Avenue, Urbana, IL 61801, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Li G, Borger MA, Williams WG, Weisel RD, Mickle DAG, Wigle ED, Li RK. Regional overexpression of insulin-like growth factor-I and transforming growth factor-beta1 in the myocardium of patients with hypertrophic obstructive cardiomyopathy. J Thorac Cardiovasc Surg 2002; 123:89-95. [PMID: 11782760 DOI: 10.1067/mtc.2002.118275] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Hypertrophic obstructive cardiomyopathy has been proposed to be the result of gene mutations of contractile proteins. However, we have previously shown significant elevation of insulin-like growth factor-I (IGF-I) and transforming growth factor-beta1 (TGF-beta1) at the messenger RNA, protein, and receptor levels in patients with hypertrophic obstructive cardiomyopathy when compared with myocardium from patients without this disorder. We hypothesized that this growth factor overexpression is a regional phenomenon. To test this hypothesis, we compared levels of IGF-I and TGF-beta1 in hypertrophic and nonhypertrophic myocardium within the same group of patients with hypertrophic obstructive cardiomyopathy. METHODS Two biopsy specimens were obtained from each patient undergoing septal myectomy for severely symptomatic hypertrophic obstructive cardiomyopathy, from hypertrophied septum and from nonhypertrophied myocardium (8 patients in total). Clinical data were prospectively recorded. Messenger RNA levels for growth factor were quantified by means of multiplex reverse transcriptase-polymerase chain reaction, expressed as a densitometric ratio of growth factor/glyceraldehyde-3-phosphate dehydrogenase. Protein levels were quantified by means of chemiluminescent slot blot analysis. Growth factor proteins were used to generate a standard curve. RESULTS IGF-I messenger RNA and protein levels in hypertrophic myocardium were 2.6 and 2.9 times greater, respectively, than in nonhypertrophic myocardium of the same patients (both P <.01). TGF-beta 1 messenger RNA and protein levels in the hypertrophic myocardium were 2.5 and 2.8 times greater, respectively, than the levels in the nonhypertrophied myocardium (both P <.01). There was a significant correlation between the IGF-I protein ratio (hypertrophic/nonhypertrophic myocardium) and the inducible left ventricular outflow tract gradients measured at cardiac catheterization (r = 0.77, P =.025). CONCLUSIONS Myocardial overexpression of IGF-I and TGF-beta1 is a regional phenomenon in patients with hypertrophic obstructive cardiomyopathy and is likely involved in the pathogenesis of the disorder.
Collapse
Affiliation(s)
- Guangming Li
- Division of Cardiovascular Surgery, Toronto General Hospital and University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
12
|
Foncea R, Gálvez A, Pérez V, Morales MP, Calixto A, Meléndez J, González-Jara F, Díaz-Araya G, Sapag-Hagar M, Sugden PH, LeRoith D, Lavandero S. Extracellular regulated kinase, but not protein kinase C, is an antiapoptotic signal of insulin-like growth factor-1 on cultured cardiac myocytes. Biochem Biophys Res Commun 2000; 273:736-44. [PMID: 10873673 DOI: 10.1006/bbrc.2000.3008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study aims to elucidate the signaling pathway for insulin-like growth factor-1 (IGF-1) in cultured neonatal rat cardiomyocytes and particularly the role of IGF-1 in cardiac apoptosis. IGF-1 stimulated polyphosphoinositide turnover, translocation of protein kinase C (PKC) isoforms (alpha, epsilon, and delta) from the soluble to the particulate fraction, activation of phospholipid-dependent and Ca(2+)-, phospholipid-dependent PKC, and activation of the extracellular-regulated kinase (ERK). IGF-1 attenuated sorbitol-induced cardiomyocyte viability and nuclear DNA fragmentation. These antiapoptotic effects of IGF-1 were blocked by PD-098059 (an MEK inhibitor) but not by bisindolylmaleimide I (BIM, a specific PKC inhibitor). The ERK pathway may therefore be an important component in the mechanism whereby IGF-1 exerts its antiapoptotic effect on the cardiomyocyte.
Collapse
Affiliation(s)
- R Foncea
- Departamento de Bioquímica y Biología Molecular, Universidad de Chile, Santiago, 664 0750, Chile
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Morales MP, Gálvez A, Eltit JM, Ocaranza P, Díaz-Araya G, Lavandero S. IGF-1 regulates apoptosis of cardiac myocyte induced by osmotic-stress. Biochem Biophys Res Commun 2000; 270:1029-35. [PMID: 10772945 DOI: 10.1006/bbrc.2000.2550] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a natural protectant of cardiac myocytes that has been shown to improve cardiac function. The role of IGF-1 in attenuating apoptosis induced by osmotic stress (sorbitol, SOR) or by other known apoptotic stimuli (doxorubicin, angiotensin II, and serum withdrawal) was determined in cultured cardiac myocytes. After 6 h of exposure to SOR, apoptosis was initiated, concomitant with a decrease in cell survival and increases in poly-[ADP-ribose] polymerase (PARP) degradation and DNA fragmentation. These effects were maximal after 24 h. IGF-1 partially attenuated apoptosis induced by sorbitol but not that induced by angiotensin II, doxorubicin, or serum withdrawal. In cells preincubated with IGF-1 before the addition of SOR, we detected an increase in the number of viable cells, a decrease in the generation of DNA fragments on agarose gel electrophoresis and in the percentage of positive TUNEL cells, and a reduction on PARP levels. These results suggest that IGF-1 prevents apoptosis induced by osmotic stress in cardiac myocytes but not apoptosis induced by doxorubicin and angiotensin II.
Collapse
Affiliation(s)
- M P Morales
- Department of Biochemistry and Molecular Biology, University of Chile, Santiago, 6640750, Chile
| | | | | | | | | | | |
Collapse
|
14
|
Affiliation(s)
- W J Brickman
- Children's Memorial Hospital, Department of Pediatrics, Northwestern University Medical School, Chicago, IL 60614, USA
| | | |
Collapse
|
15
|
Bell D, McDermott BJ. Contribution of de novo protein synthesis to the hypertrophic effect of IGF-1 but not of thyroid hormones in adult ventricular cardiomyocytes. Mol Cell Biochem 2000; 206:113-24. [PMID: 10839201 DOI: 10.1023/a:1007014500965] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Enhanced expression of IGF-1 occurs in left ventricular hypertrophy (LVH) associated with systemic hypertension. Cardiac dysfunction accompanied by LVH is also observed in hyperthyroidism. OBJECTIVE to assess the relative contributions of de novo protein synthesis and attenuated protein degradation to increased protein mass associated with cardiomyocyte hypertrophy elicited by IGF-1 and thyroid hormones (tri-iodo thyronine T3, and l-thyroxine T4), respectively. METHODS total mass of protein, and both the incorporation, and removal of previously incorporated l-U-14C-phenylalanine, indices of protein synthesis and degradation, respectively, were assessed in quiescent adult rat ventricular cardiomyocytes maintained in short-term culture, and corrected for DNA content, as a index of cell number. RESULTS IGF-1 (1 pM-100 nM) increased cell protein significantly, maximally at 1 nM and by 38% above basal value after 24 h. T3 (10 pM-2 microM) and T4 (10 pM-2 microM) increased cell protein significantly maximally at 1 microM and by 33.2 and 30.5%, respectively, above basal value. IGF-1 (< or = 10 pM), T3 (10 pM-2 microM) and T4 (10 pM-2 microM) did not increase incorporation of l-U-14C-phenylalanine above basal values. IGF-1 (100 pM-100 nM) increased incorporation of radiolabel significantly maximally at 100 nM and by 56%. T4 (100 pM) and IGF-1 (10 pM), concentrations that did not stimulate de novo protein synthesis, attenuated the degradation of radiolabelled protein by 13.6 and 11.8%, respectively, compared to control values after 48 h. CONCLUSION These data indicate that the acute hypertrophic response to (i) thyroid hormones cannot be attributed to initiation of de novo protein synthesis; (ii) IGF- 1 comprises two components; the response elicited by IGF-1 (< 10 pM) is independent of, while the response elicited by IGF-1 (> 100 pM) is due to de novo protein synthesis.
Collapse
Affiliation(s)
- D Bell
- Department of Therapeutics and Pharmacology, The Cardiovascular Research Centre, The School of Medicine, The Queen's University of Belfast, Northern Ireland, UK
| | | |
Collapse
|
16
|
Jalil JE, Ebensperger R, Meléndez J, Acevedo E, Sapag-Hagar M, González-Jara F, Gálvez A, Pérez-Montes V, Lavandero S. Effects of antihypertensive treatment on cardiac IGF-1 during prevention of ventricular hypertrophy in the rat. Life Sci 1999; 64:1603-12. [PMID: 10328520 DOI: 10.1016/s0024-3205(99)00097-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
There is some evidence that cardiac rather than circulating insulin-like growth factor-1 (IGF-1) levels contribute to the development of renovascular hypertensive left ventricular hypertrophy (LVH), remaining unknown the effects of antihypertensive drugs on IGF-1 levels. We have assessed here the preventive effects of enalapril, losartan, propanolol and alpha-methyldopa on left ventricle (LV) and circulating IGF-1 levels in a rat model of hypertension and LVH (Goldblatt, GB). Our results show that relative LV mass and the LV content of IGF-1 were significantly lower with all antihypertensive drugs in GB rats (p<0.001). Serum concentrations of IGF-1 were lower in GB rats treated with enalapril, alpha-methyldopa and propanolol (p<0.01), but not in those treated with losartan. These results support the hypothesis that local rather than seric IGF-1 contributes to the development of left ventricular hypertrophy induced by pressure overload in the rat.
Collapse
Affiliation(s)
- J E Jalil
- Department of Cardiovascular Diseases, School of Medicine, P. Catholic University of Chile, Santiago
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Pauliks LB, Cole KE, Mergner WJ. Increased insulin-like growth factor-1 protein in human left ventricular hypertrophy. Exp Mol Pathol 1999; 66:53-8. [PMID: 10331964 DOI: 10.1006/exmp.1999.2245] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Animal models of cardiac hypertrophy demonstrated increased expression of insulin-like-growth factor-1 (IGF-1) in the heart. To study protein expression of insulin-like-growth factor 1 in left ventricular hypertrophy (LVH) in humans 11 hearts of autopsy cases with LVH were compared to 11 controls using immunohistochemical staining with anti-human IGF-1. LVH was defined as thickening of the left ventricular wall which ranged from 1.6 to 2.5 cm with hearts weights from 400 to 900 g. Immunohistochemical staining for IGF-1 was increased in the presence of LVH. In cases of LVH 37.9 +/- 3.5% of the cross-sectional myocardial area stained positively for IGF-1 compared to 6.8 +/- 2.9% in controls (P < 0.001). The findings support the hypothesis that IGF-1 has a role in the pathogenesis of LVH in humans. The increase of IGF-1 protein with LVH suggests reactivation of the cardiac IGF-1 genes in the hypertrophied adult cardiomyocyte.
Collapse
Affiliation(s)
- L B Pauliks
- Division of Pediatric Cardiology, Cornell University-New York Presbyterian Hospital, 436 East 69th Street, New York, New York 10021, USA
| | | | | |
Collapse
|