GATA-4 Is a Nuclear Mediator of Mechanical Stretch-activated Hypertrophic Program

In overloaded heart the cardiomyocytes adapt to increased mechanical and neurohumoral stress by activation of hypertrophic program, resulting in morphological changes of individual cells and specific changes in gene expression. Accumulating evidence suggests an important role for the zinc finger transcription factor GATA-4 in hypertrophic agonist-induced cardiac hypertrophy. However, its role in stretch-induced cardiomyocyte hypertrophy is not known. We employed an in vitro mechanical stretch model of cultured cardiomyocytes and used rat B-type natriuretic peptide promoter as stretch-sensitive reporter gene. Stretch transiently increased GATA-4 DNA binding activity and transcript levels, which was followed by increases in the expression of B-type natriuretic peptide as well as atrial natriuretic peptide and skeletal α-actin genes. The stretch inducibility mapped primarily to the proximal 520 bp of the B-type natriuretic peptide promoter. Mutational studies showed that the tandem GATA consensus sites of the proximal promoter in combination with an Nkx-2.5 binding element are critical for stretch-activated B-type natriuretic peptide transcription. Inhibition of GATA-4 protein production by adenovirus-mediated transfer of GATA-4 antisense cDNA blocked stretch-induced increases in B-type natriuretic peptide transcript levels and the sarcomere reorganization. The proportion of myocytes with assembled sarcomeres in control adenovirus-infected cultures increased from 14 to 59% in response to stretch, whereas the values for GATA-4 antisense-treated cells were 6 and 13%, respectively. These results show that activation of GATA-4, in cooperation with a factor binding on Nkx-2.5 binding element, is essential for mechanical stretch-induced cardiomyocyte hypertrophy. In overloaded heart the cardiomyocytes adapt to increased mechanical and neurohumoral stress by activation of hypertrophic program, resulting in morphological changes of individual cells and specific changes in gene expression. Accumulating evidence suggests an important role for the zinc finger transcription factor GATA-4 in hypertrophic agonist-induced cardiac hypertrophy. However, its role in stretch-induced cardiomyocyte hypertrophy is not known. We employed an in vitro mechanical stretch model of cultured cardiomyocytes and used rat B-type natriuretic peptide promoter as stretch-sensitive reporter gene. Stretch transiently increased GATA-4 DNA binding activity and transcript levels, which was followed by increases in the expression of B-type natriuretic peptide as well as atrial natriuretic peptide and skeletal α-actin genes. The stretch inducibility mapped primarily to the proximal 520 bp of the B-type natriuretic peptide promoter. Mutational studies showed that the tandem GATA consensus sites of the proximal promoter in combination with an Nkx-2.5 binding element are critical for stretch-activated B-type natriuretic peptide transcription. Inhibition of GATA-4 protein production by adenovirus-mediated transfer of GATA-4 antisense cDNA blocked stretch-induced increases in B-type natriuretic peptide transcript levels and the sarcomere reorganization. The proportion of myocytes with assembled sarcomeres in control adenovirus-infected cultures increased from 14 to 59% in response to stretch, whereas the values for GATA-4 antisense-treated cells were 6 and 13%, respectively. These results show that activation of GATA-4, in cooperation with a factor binding on Nkx-2.5 binding element, is essential for mechanical stretch-induced cardiomyocyte hypertrophy. Cardiac hypertrophy is the primary adaptive mechanism for terminally differentiated cardiac myocytes to increased hemodynamic load. In addition to mechanical stretch, a number of humoral factors, such as G-protein-coupled receptor agonists angiotensin II and endothelin-1 (ET-1) 1The abbreviations used are: ET-1, endothelin-1; ANP, atrial natriuretic peptide; AP-1, activator protein-1; BNP, B-type natriuretic peptide; rBNP, rat BNP; ds, double-stranded; EMSA, electrophoretic mobility shift assay; NF-AT, nuclear factor of activated T-cells; NKE, Nkx-2.5 binding element; skαA, skeletal muscle α-actin; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum. as well as adrenergic receptor agonists released by the activated symphatic nervous system participate in the adaptive process and modify the growth of cardiac myocytes in vivo (for review, see Refs. 1Lorell B.H. Carabello B.A. Circulation. 2000; 102: 470-479Google Scholar and 2Swynghedauw B. Physiol. Rev. 1999; 79: 215-262Google Scholar). When the cardiac overload is sustained, this initially compensatory mechanism fails, and the contractile function is impaired, leading to congestive heart failure (1Lorell B.H. Carabello B.A. Circulation. 2000; 102: 470-479Google Scholar). The hypertrophic response in cardiac myocytes is characterized by morphologic changes that include increase in cell size and protein synthesis and enhanced sarcomere reorganization as well as specific changes in cardiac gene expression (2Swynghedauw B. Physiol. Rev. 1999; 79: 215-262Google Scholar, 3Sugden P.H. Clerk A. J. Mol. Med. 1998; 76: 725-746Google Scholar). The early genetic response to hemodynamic overload is the activation of immediate early response genes such as c-fos and c-jun, components of the activator protein-1 (AP-1) transcription factor complex. This is followed by up-regulation of B-type natriuretic peptide (BNP) and reactivation of fetal genes such as atrial natriuretic peptide (ANP), β-myosin heavy chain, and skeletal muscle α-actin (skαA) (2Swynghedauw B. Physiol. Rev. 1999; 79: 215-262Google Scholar, 4Chien K.R. Knowlton K.U. Zhu H. Chien S. FASEB J. 1991; 5: 3037-3046Google Scholar, 5Magga J. Marttila M. Mäntymaa P. Vuolteenaho O. Ruskoaho H. Endocrinology. 1994; 134: 2505-2515Google Scholar, 6Ruskoaho H. Pharmacol. Rev. 1992; 44: 479-602Google Scholar). The mechanisms regulating the genetic reprogramming in cardiac overload has been the subject of intensive research. GATA-4 was originally shown to be a crucial regulator of cardiogenesis and cardiac-specific genes such as ANP and BNP (for review, see Refs. 7Charron F. Nemer M. Semin. Cell Dev. Biol. 1999; 10: 85-91Google Scholar and 8Molkentin J.D. J. Biol. Chem. 2000; 275: 38949-38952Google Scholar). Several lines of evidence suggest the involvement of GATA-4 in the development of cardiac hypertrophy. First, hemodynamic overload caused by aortic banding, Arg8 vasopressin infusion, or nephrectomy in vivo (9Hasegawa K. Lee S.J. Jobe S.M. Markham B.E. Kitsis R.N. Circulation. 1997; 96: 3943-3953Google Scholar, 10Hautala N. Tokola H. Luodonpää M. Puhakka J. Romppanen H. Vuolteenaho O. Ruskoaho H. Circulation. 2001; 103: 730-735Google Scholar, 11Marttila M. Hautala N. Paradis P. Toth M. Vuolteenaho O. Nemer M. Ruskoaho H. Endocrinology. 2001; 142: 4693-4700Google Scholar) as well as in vitro treatment of cultured neonatal rat cardiac myocytes with α1-adrenergic agonist phenylephrine, β-adrenergic agonist isoprenaline, or ET-1 (10Hautala N. Tokola H. Luodonpää M. Puhakka J. Romppanen H. Vuolteenaho O. Ruskoaho H. Circulation. 2001; 103: 730-735Google Scholar, 12Morimoto T. Hasegawa K. Kaburagi S. Kakita T. Wada H. Yanazume T. Sasayama S. J. Biol. Chem. 2000; 275: 13721-13726Google Scholar, 13Liang Q. De Windt L.J. Witt S.A. Kimball T.R. Markham B.E. Molkentin J.D. J. Biol. Chem. 2001; 276: 30245-30253Google Scholar, 14Morimoto T. Hasegawa K. Wada H. Kakita T. Kaburagi S. Yanazume T. Sasayama S. J. Biol. Chem. 2001; 276: 34983-34989Google Scholar, 15He Q. Mendez M. LaPointe M.C. Am. J. Physiol. Endocrinol. Metab. 2002; 283: 50-57Google Scholar, 16Morisco C. Seta K. Hardt S.E. Lee Y. Vatner S.F. Sadoshima J. J. Biol. Chem. 2001; 276: 28586-28597Google Scholar, 17Pikkarainen S. Kerkelä R. Pöntinen J. Majalahti-Palviainen T. Tokola H. Eskelinen S. Vuolteenaho O. Ruskoaho H. J. Mol. Med. 2002; 80: 51-60Google Scholar, 18Kerkelä R. Pikkarainen S. Majalahti-Palviainen T. Tokola H. Ruskoaho H. J. Biol. Chem. 2002; 277: 13752-13760Google Scholar, 19Morin S. Paradis P. Aries A. Nemer M. Mol. Cell. Biol. 2001; 21: 1036-1044Google Scholar) activate GATA-4 binding on cis-acting elements of target genes. Second, hemodynamic overload in vivo induces transcription via GATA binding elements present in the regulatory region of the angiotensin type 1A receptor, β-myosin heavy chain, and BNP genes (9Hasegawa K. Lee S.J. Jobe S.M. Markham B.E. Kitsis R.N. Circulation. 1997; 96: 3943-3953Google Scholar, 11Marttila M. Hautala N. Paradis P. Toth M. Vuolteenaho O. Nemer M. Ruskoaho H. Endocrinology. 2001; 142: 4693-4700Google Scholar, 20Herzig T.C. Jobe S.M. Aoki H. Molkentin J.D. Cowley Jr., A.W. Izumo S. Markham B.E. Proc. Natl. S. A. 1997; Scholar). hypertrophic agonists and activate transcription of ET-1, BNP, and ANP in vitro T. Hasegawa K. Kaburagi S. Kakita T. Wada H. Yanazume T. Sasayama S. J. Biol. Chem. 2000; 275: 13721-13726Google T. Hasegawa K. Wada H. Kakita T. Kaburagi S. Yanazume T. Sasayama S. J. Biol. Chem. 2001; 276: 34983-34989Google Scholar, 15He Q. Mendez M. LaPointe M.C. Am. J. Physiol. Endocrinol. Metab. 2002; 283: 50-57Google Scholar, 16Morisco C. Seta K. Hardt S.E. Lee Y. Vatner S.F. Sadoshima J. J. Biol. Chem. 2001; 276: 28586-28597Google J. Biol. Chem. 1997; Scholar). of GATA-4 in cultured neonatal cardiomyocytes by gene transfer or in the of was shown to be to cardiomyocyte hypertrophy Q. De Windt L.J. Witt S.A. Kimball T.R. Markham B.E. Molkentin J.D. J. Biol. Chem. 2001; 276: 30245-30253Google Scholar, F. M. Q. Molkentin J.D. S. Nemer M. Dev. 2001; Scholar). expression of GATA-4 or antisense GATA-4 cDNA blocked and of cardiomyocyte hypertrophy by and ET-1 Q. De Windt L.J. Witt S.A. Kimball T.R. Markham B.E. Molkentin J.D. J. Biol. Chem. 2001; 276: 30245-30253Google Scholar, F. M. Q. Molkentin J.D. S. Nemer M. Dev. 2001; Scholar). GATA-4 as in the of hypertrophic agonist-induced a of the hypertrophic is not mechanical stretch the hypertrophic via the role of GATA-4 and its in mechanical stretch-activated hypertrophic program, employed an in vitro mechanical stretch model of The model the to the mechanical from the humoral and components of hemodynamic which are present in the Stretch of cultured neonatal rat cardiomyocytes has been shown to BNP transcription F. J. M. J. Biol. Chem. 1997; a target gene to the mechanisms of stretch-induced gene expression in cardiac present show that GATA-4 is a critical regulator of and morphological changes by mechanical of GATA-4 and components of or and Nkx-2.5 were from and to was from 6 was from and system were from The BNP and as well as a of rat BNP cDNA J. Vuolteenaho O. Marttila M. Ruskoaho H. Circulation. 1997; 96: Scholar) were from of ANP cDNA H. K. Vuolteenaho O. Ruskoaho H. J. 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Pharmacol. 1994; Scholar). the of of were with type and in The cells were and in a of with fetal bovine The cells were for in with to the number of not to the were on or a of The myocytes were with 6 in for The of 6 and DNA were 6 and control the reporter were with the of The was with The of was to that H. K. Vuolteenaho O. Ruskoaho H. J. Pharmacol. 1994; that the of was In were to myocytes to a of of by the to the The were the cells were with and The reporter gene were by the system and the II with cells were in Dulbecco's modified Eagle's were and with of or control with 6 cells were and to nuclear protein of was to myocytes in by a the with The in a to of the cardiomyocytes the of of the cells were with and with and in for and with was with for of were by The number of cardiomyocytes from of the cell to the was and by the number of cardiomyocytes in the These were were in by and to The were blocked in and with GATA-4 a in in binding was with an a and as by the and of was the Scholar). the were by and to The cDNA to rat ANP, BNP, skαA, and GATA-4 or were with II for and GATA-4 were by and by to of rat and of rat GATA-4 and The were and as H. K. Vuolteenaho O. Ruskoaho H. J. Pharmacol. 1994; Scholar). the were with which were with and cDNA of The of specific were to that of in and DNA were from cells as by P. Scholar). were and with cells were in of with 6 and 6 by and to on for were by of and for followed by for was as the were in of and with to in and for The were for The was as the nuclear The was were by of the of and with of nuclear protein and of in a and of and of When were by nuclear with of for the binding a of the was and binding was to for The were by on in the were and as the of ANP and of ANP and BNP were as J. Marttila M. Mäntymaa P. Vuolteenaho O. Ruskoaho H. Endocrinology. 1994; 134: 2505-2515Google Scholar, O. O. N. Scholar). The of the BNP and ANP were and respectively. of the and The and were and respectively. results are as the S.E. were with of followed by a of for was of was Stretch a the system the of mechanical stretch on the gene expression of BNP, ANP, and skαA, which genetic of the stretch-induced cardiac hypertrophic F. J. M. J. Biol. Chem. 1997; Scholar, Y. T. Y. M. F. Y. J. Biol. Chem. 1991; Scholar, H. Am. J. Physiol. 1992; Scholar, J. Izumo S. Rev. Physiol. 1997; Scholar). mechanical stretch BNP levels mechanical stretch caused increases in ANP and levels, and natriuretic peptide levels were by increased peptide from cardiomyocytes the and of response the of and the peptide BNP a target gene to the 520 bp of to Stretch the rat BNP promoter region that the activation by mechanical stretch, cardiomyocytes with reporter by of the of of the to in a in reporter activity to increased promoter in with the of elements from J. Biol. Chem. 1997; Scholar). of the region from to not the inducibility of the promoter in response to mechanical to the as well as mechanical stretch-induced promoter activity by with to the stretch The of promoter GATA-4 and by tandem GATA elements the BNP promoter are well and C. T. Nemer M. Mol. Cell. Biol. 1994; Scholar). elements been shown to the activation of promoter in response to hemodynamic overload in vivo M. Hautala N. Paradis P. Toth M. Vuolteenaho O. Nemer M. Ruskoaho H. Endocrinology. 2001; 142: 4693-4700Google an important role in stretch-activated BNP transcription. used the GATA sites of as the in to mechanical stretch nuclear protein binding on shown in stretch transiently increased GATA DNA binding activity binding activity by stretch on nuclear the of GATA binding were The of with the GATA was by the not by the BNP GATA the specific showed of the GATA-4 not or the of mechanical stretch on GATA-4 gene rat GATA-4 cDNA was The activation of GATA-4 binding was by a increase in GATA-4 levels showed that the levels of GATA-4 protein were in the In the nuclear of cardiomyocytes GATA-4 protein to this was not studies suggest cooperation GATA-4 and in hypertrophy T.C. Jobe S.M. Aoki H. Molkentin J.D. Cowley Jr., A.W. Izumo S. Markham B.E. Proc. Natl. S. A. 1997; nuclear protein binding on the by the rat Stretch increased binding and for of the which was by the not by the BNP the components of the and shown in were with and was the of or not in the complex. were with and stretch not the with nuclear of cardiomyocytes BNP by of GATA the activation of GATA-4 on BNP transcription. We to the reporter the proximal promoter that is to stretch inducibility of the tandem GATA sites in in the stretch-induced reporter activity with which was activated by the that stretch-induced transcription be by cooperation of GATA-4 with as in angiotensin type 1A receptor transcription in vivo T.C. Jobe S.M. Aoki H. Molkentin J.D. Cowley Jr., A.W. Izumo S. Markham B.E. Proc. Natl. S. A. 1997; the of increased of cardiac nuclear with of this or in combination with the tandem GATA sites not modify stretch-induced transcription of with GATA-4 in BNP addition to AP-1, GATA-4 has been shown to with transcription Nkx-2.5 in of cardiac-specific gene expression F. R. Nemer M. J. 1997; Scholar, Y. T. H. Jobe S.M. Markham B.E. Izumo S. Mol. Cell. Biol. 1998; Scholar, T. Y. T. K. R. H. T. S. Y. J. Biol. Chem. 1999; Scholar). a for cis-acting elements in a promoter and with to and elements are binding sites for nuclear from cells with Nkx-2.5 expression The nuclear were with DNA to and sites of BNP and a from the rat ANP gene Y. T. H. Jobe S.M. Markham B.E. Izumo S. Mol. Cell. Biol. 1998; Scholar, T. Y. T. K. R. H. T. S. Y. J. Biol. Chem. 1999; Scholar). shown in 6 shift that the and the ANP that were by an the of the element for Nkx-2.5 was that of the ANP the the of BNP was not to in with that this the transcription factor S. Tokola H. Kerkelä R. Majalahti-Palviainen T. Vuolteenaho O. Ruskoaho H. J. Biol. Chem. used in in a that the element to be the binding target for Nkx-2.5 as with GATA element in stretch-induced transcription of BNP in of on stretch-induced promoter the inducibility by stretch was of the was with the of the tandem GATA the of in the stretch-induced BNP transcription was the tandem GATA sites were that Nkx-2.5 in cooperation with In of this of which is to Nkx-2.5 to NKE, not modify stretch-induced transcription of with or GATA sites GATA-4 for addition to changes in gene the hypertrophic of cultured cardiomyocytes is characterized by morphologic changes increased reorganization of sarcomeres P.H. Clerk A. J. Mol. Med. 1998; 76: 725-746Google Scholar). the activation of GATA-4 is in the morphologic changes with stretch-induced the production of GATA-4 protein by an antisense GATA-4 cDNA In with studies F. M. Q. Molkentin J.D. S. Nemer M. Dev. 2001; Scholar, F. Paradis P. O. Nemer Nemer M. Mol. Cell. Biol. 1999; GATA-4 protein levels in cells with with cells with control a nuclear cDNA of GATA-4 in cardiomyocytes blocked a stretch-induced increase in BNP levels and sarcomere reorganization of cardiomyocytes showed that stretch increased the number of cardiomyocytes that sarcomere reorganization in cultures by and that this was in cells treatment the sarcomere in cells with cells with the an essential role for GATA-4 in the genetic and morphologic response of cardiomyocytes to mechanical of the in vitro stretch model for cultured neonatal rat has an for the of the mechanisms in stretch-activated changes in cardiomyocyte hypertrophy. These changes of cardiac hypertrophy in vivo (for review, see J. Izumo S. Rev. Physiol. 1997; Scholar). this model to of the to In the present show for the that mechanical stretch GATA-4 binding on the well proximal GATA element of BNP promoter. This element with the activation of the gene. We evidence that GATA-4 mechanical stretch-activated enhanced sarcomere a of cardiac hypertrophy in vitro P.H. Clerk A. J. Mol. Med. 1998; 76: 725-746Google Scholar). has been nuclear mechanisms that activate the genetic reprogramming in response to was that activation of BNP promoter by mechanical stretch was via nuclear binding on the stress response elements present in the BNP promoter F. J. 1999; Scholar). the is not with be that stress response elements are not in the rat BNP whereas the GATA element is C. T. Nemer M. Mol. Cell. Biol. 1994; Scholar). The activity of GATA-4 is by specific with transcription that with GATA-4 in of cardiac-specific gene expression. These include Nkx-2.5 F. R. Nemer M. J. 1997; Scholar, Y. T. H. Jobe S.M. Markham B.E. Izumo S. Mol. Cell. Biol. 1998; Scholar, T. Y. T. K. R. H. T. S. Y. J. Biol. Chem. 1999; nuclear factor of activated J.D. Markham B. J. J. Cell. 1998; F. Paradis P. O. Nemer Nemer M. Mol. Cell. Biol. 1999; of GATA Proc. Natl. S. A. 1999; 96: response factor F. Nemer M. Mol. Cell. Biol. 2000; factor S. F. Nemer M. J. 2000; Nemer M. J. Biol. Chem. 2001; 276: Markham B.E. J. Biol. Chem. 2001; 276: Scholar, P. Markham B.E. Molkentin J.D. J. Biol. Chem. 2002; 277: and P. Markham B.E. Molkentin J.D. J. Biol. Chem. 2002; 277: Scholar). of and response been with genetic to of cardiac hypertrophy S. Paradis P. Aries A. Nemer M. Mol. Cell. Biol. 2001; 21: 1036-1044Google Scholar, J.D. Markham B. J. J. Cell. 1998; Scholar, Y. A. M. Zhu J. Biol. Chem. 2000; 275: the role of GATA-4 in hypertrophic has not been in the present of GATA-4 production by was to the stretch-induced increase in BNP the the of the GATA sites in the of in a in the stretch response whereas the stretch response of rBNP, GATA was was to stretch suggest that which bp and bp of are with GATA in stretch-activated transcription. the results of GATA-4 in stretch response and be to the of GATA-4 with of GATA-4 protein the GATA-4 and its whereas of GATA-4 DNA binding not an on the with that the on the promoter. Y. A. M. Zhu J. Biol. Chem. 2000; 275: Scholar) that and factor elements were for activation of gene in hypertrophy of cardiomyocytes Y. A. M. Zhu J. Biol. Chem. 2000; 275: Scholar). The binding element for in activation of BNP is in the promoter J.D. Markham B. J. J. Cell. 1998; Scholar) and not to be for stretch were not to specific binding activity on sites and of not In bp of region of rat BNP gene factor response factor binding and the element to of the Nemer M. J. Biol. Chem. 2001; 276: that not with GATA-4 in stretch-activated BNP transcription. The expression of angiotensin type 1A receptor by overload in vivo has been to be by cooperation of GATA and in rat heart T.C. Jobe S.M. Aoki H. Molkentin J.D. Cowley Jr., A.W. Izumo S. Markham B.E. Proc. Natl. S. A. 1997; Scholar). However, the of of to modify stretch-induced reporter activity of with tandem GATA sites that not with GATA-4 or that the cooperation not binding on the in mechanical stretch-induced activation of of this was that of the tandem GATA sites in combination with of the the stretch inducibility of whereas of on This suggests that is by stretch-induced GATA-4 Nkx-2.5 on promoter via GATA sites Nkx-2.5 binding on its binding is by stretch the involvement of Nkx-2.5 in stretch-induced transcription is and its on promoter is blocked by of the tandem GATA resulting in in stretch inducibility with in GATA sites the has been shown to be by and the early of cardiogenesis Dev. 1997; Scholar, K. Y. S. T. T. A. T. T. Y. Mol. Cell. Biol. 1999; Scholar). results the of the to cardiomyocytes and in the response of cardiomyocytes to mechanical In the studies hypertrophic response has been with a increase in GATA-4 DNA binding activity in GATA-4 protein levels, that GATA-4 activity is by mechanisms T. Hasegawa K. Kaburagi S. Kakita T. Wada H. Yanazume T. Sasayama S. J. Biol. Chem. 2000; 275: 13721-13726Google Scholar, 13Liang Q. De Windt L.J. Witt S.A. Kimball T.R. Markham B.E. Molkentin J.D. J. Biol. Chem. 2001; 276: 30245-30253Google Scholar, 15He Q. Mendez M. LaPointe M.C. Am. J. Physiol. Endocrinol. Metab. 2002; 283: 50-57Google Scholar, 20Herzig T.C. Jobe S.M. Aoki H. Molkentin J.D. Cowley Jr., A.W. Izumo S. Markham B.E. Proc. Natl. S. A. 1997; Scholar). is evidence that changes in gene expression and cell are not by with by of GATA-4 by specific protein C. Seta K. Hardt S.E. Lee Y. Vatner S.F. Sadoshima J. J. Biol. Chem. 2001; 276: 28586-28597Google Scholar, F. M. Q. Molkentin J.D. S. Nemer M. Dev. 2001; Scholar, Q. Markham B.E. Molkentin J.D. Mol. Cell. Biol. 2001; 21: Scholar). ET-1 and activate shown to activate sarcomere reorganization in cardiac myocytes M. Y. Chien K.R. J. Biol. Chem. 1998; Scholar). in GATA-4 via protein on leading to genetic reprogramming and of sarcomere reorganization R. Pikkarainen S. Majalahti-Palviainen T. Tokola H. Ruskoaho H. J. Biol. Chem. 2002; 277: 13752-13760Google Scholar, F. M. Q. Molkentin J.D. S. Nemer M. Dev. 2001; Scholar). In addition to protein been shown to GATA-4 followed by enhanced binding and activity of GATA-4 T. Hasegawa K. Kaburagi S. Kakita T. Wada H. Yanazume T. Sasayama S. J. Biol. Chem. 2000; 275: 13721-13726Google Scholar, Q. Markham B.E. Molkentin J.D. Mol. Cell. Biol. 2001; 21: Scholar). mechanical stretch has been shown to activate of protein J. Izumo S. Rev. Physiol. 1997; Scholar, F. J. 1999; Scholar, T. S. Y. T. H. Y. K. K. J. 96: Scholar). been shown to a critical role in mechanical stretch-induced activation of and protein in cultured cardiomyocytes R. T. M. Y. T. H. Hasegawa H. H. M. R. 2001; Scholar, R. T. Y. S. Zhu T. Y. 1999; a mechanical stretch and the enhanced sarcomere as well as BNP transcription in the present C. Seta K. Hardt S.E. Lee Y. Vatner S.F. Sadoshima J. J. Biol. Chem. 2001; 276: 28586-28597Google Scholar) that of cardiac myocytes with β-adrenergic agonists increased nuclear GATA-4 protein levels C. Seta K. Hardt S.E. Lee Y. Vatner S.F. Sadoshima J. J. Biol. Chem. 2001; 276: 28586-28597Google Scholar). The suggest that activation of protein by to of which the of GATA-4, resulting to increased from the has been shown to be activated by mechanical in the of to 2002; Scholar). the that increased GATA-4 protein in the nuclear of cells from via activation of the to be studies shown that a role in the development of cardiac hypertrophy. stretch is with the of angiotensin II and ET-1, which as of stretch-induced hypertrophy in cultured rat cardiomyocytes J. Izumo S. Rev. Physiol. 1997; Scholar, T. S. Y. Y. T. K. H. R. H. Y. J. Biol. Chem. Scholar). and F. J. Biol. Chem. 1998; Scholar) that of angiotensin II of ET-1, which for of the stretch-induced BNP gene transcription F. J. Biol. Chem. 1998; Scholar). In ET-1 GATA-4 binding activity (10Hautala N. Tokola H. Luodonpää M. Puhakka J. Romppanen H. Vuolteenaho O. Ruskoaho H. Circulation. 2001; 103: 730-735Google Scholar, 17Pikkarainen S. Kerkelä R. Pöntinen J. Majalahti-Palviainen T. Tokola H. Eskelinen S. Vuolteenaho O. Ruskoaho H. J. Mol. Med. 2002; 80: 51-60Google Scholar, 18Kerkelä R. Pikkarainen S. Majalahti-Palviainen T. Tokola H. Ruskoaho H. J. Biol. Chem. 2002; 277: 13752-13760Google Scholar, 19Morin S. Paradis P. Aries A. Nemer M. Mol. Cell. Biol. 2001; 21: 1036-1044Google the of of the tandem GATA sites the activation of promoter of shown that of the tandem GATA sites of the promoter not activation by ET-1 or angiotensin II S. Kerkelä R. Pöntinen J. Majalahti-Palviainen T. Tokola H. Eskelinen S. Vuolteenaho O. Ruskoaho H. J. Mol. Med. 2002; 80: 51-60Google Scholar). of the that is a target for was shown to BNP transcription S. Tokola H. Kerkelä R. Majalahti-Palviainen T. Vuolteenaho O. Ruskoaho H. J. Biol. Chem. whereas on stretch-induced promoter activity in the present suggest that the role of GATA-4 in the stretch-induced response is In results that stretch, a of hemodynamic a hypertrophic response in cultured neonatal cardiac as by enhanced sarcomere and activation of BNP transcription. via that GATA-4 is a nuclear of mechanical stretch-activated hypertrophic results suggests that the is by stretch-induced the for to cardiomyocytes and its role in the response of cardiomyocytes to We and for