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(Circulation. 2004;109:262-268.)
© 2004 American Heart Association, Inc.
Basic Science Reports |
From the Winters Center for Heart Failure Research (A.D., Z.D., N.S., D.L.M.), Medical Service Care Line (S.N., G.D., B.A.C.), Houston VAMC, Baylor College of Medicine and the Methodist Hospital, Houston, Tex; and Department of Surgery (E.M.W., F.G.S.), Cardiothoracic Research, Medical University of South Carolina, Charleston, SC.
Correspondence to Douglas L. Mann, MD, Winters Center for Heart Failure Research, MS 524, 6565 Fannin, Houston, TX 77030. E-mail dmann{at}bcm.tmc.edu
Received July 21, 2003; revision received September 11, 2003; accepted September 22, 2003.
| Abstract |
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converting enzyme (TACE) may contribute to the left ventricular (LV) remodeling that occurs in the failing human heart. Methods and Results To address the functional significance of TNF shedding, we generated lines of transgenic mice with targeted overexpression of secreted wild-type (MHCsTNF2) TNF and overexpression of a mutated noncleavable transmembrane form of TNF (MHCmTNF). Both lines of mice had overlapping levels of myocardial TNF protein; however, the phenotypes of the MHCsTNF2 and MHCmTNF mice were strikingly disparate. Whereas the MHCmTNF mice developed a concentric LV hypertrophy phenotype, the MHCsTNF2 mice developed a dilated LV phenotype. The fibrillar collagen weave in MHCmTNF mice with concentric hypertrophy was characterized by thick collagen fibrils and increased collagen content, whereas the fibrillar collagen weave in the MHCsTNF2 mice with LV dilation was characterized by a diminished collagen content. Inhibition of matrix metalloproteinases with a broad-based matrix metalloproteinase inhibitor prevented LV dilation in the MHCsTNF2 mice.
Conclusions These findings suggest that posttranslational processing of TNF, as opposed to TNF expression per se, is responsible for the adverse cardiac remodeling that occurs after sustained TNF overexpression.
Key Words: hypertrophy remodeling metalloproteinases
| Introduction |
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converting enzyme (TACE).3 The resultant 17-kDa TNF monomer that is "shed" from the cell-surface membrane subsequently assembles as a biologically active homotrimer that initiates cell signaling.3 Noting that the membrane-bound and secreted forms of TNF have distinctly different biological actions4 and that TACE is upregulated in the heart in pathophysiological contexts wherein LV dilation and dysfunction occur,5 we questioned whether posttranslation processing of TNF (ie, secretion) might contribute to the adverse cardiac remodeling that is observed after sustained TNF expression. In the present report, we compared a line of transgenic mice with targeted cardiac overexpression of a mutated form of TNF that lacks the TACE recognition site, and hence cannot be secreted, with a second line of mice with targeted cardiac overexpression of wild-type secreted TNF. | Methods |
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-myosin heavy chain (MHC) promoter (a gift from Jeff Robbins, University of Cincinnati, Cincinnati, Ohio) to target TNF expression to the cardiac myocyte, as described previously.6 The TNF transgene that encoded wild-type secretable TNF contained an intact TACE recognition site, whereas the transgene coding for the noncleavable transmembrane form of TNF lacked the TACE recognition site (see Data Supplement). The generation and preliminary characterization of the MHCmTNF has been reported previously.7 Both the MHCmTNF and MHCsTNF2 mice were generated on an FVB background to facilitate comparison between lines of transgenic mice.
Characterization of Cardiac Phenotype in MHCmTNF and MHCsTNF2 Mice
Cardiac Phenotype and Morphology
Perfusion fixation and histological analysis of the hearts were performed as described (see Data Supplement).8 Myocyte length was measured on fixed isolated cardiac myocytes according to the method of Gerdes et al.9
Cardiac Structure and Hemodynamics
We used 2D-targeted M-mode echocardiography and simultaneous hemodynamic catheterization to characterize LV structure and hemodynamics, respectively, in male wild-type, MHCmTNF, and MHCsTNF2 mice.10 LV end-systolic and end-diastolic pressure were assessed with a 1.4F microtipped Millar catheter. LV end-systolic and end-diastolic wall stress were calculated with hemodynamic data and the assessments of end-systolic and end-diastolic LV wall thickness that were obtained from M-mode echocardiography.10
Myocardial Fibrillar Collagen
Scanning electron microscopy and picrosirius red staining were performed to examine myocardial fibrillar collagen, as described previously.6
Matrix Metalloproteinase Activity and Abundance
Matrix metalloproteinase (MMP) zymographic activity was measured in myocardial protein extracts (16 µg) with gelatin zymography.6 Purified gelatinase (MMP9; 0.125 mg/mL) and MMP2 (0.125 mg/mL) were used as standards. To measure MMP2 abundance (ie, the sum of latent and activated MMP2 species), the cardiac protein extracts were treated with p-aminophenylmercuric acetate (APMA), an organomercurial compound that activates MMPs. MMP2 abundance was then measured with an ELISA that measures levels of total activated MMP2 species (#RPN 2631, Amersham).
Expression of Tissue Inhibitor of Metalloproteinases Type 1
Tissue inhibitor of metalloproteinases type 1 (TIMP-1) levels were measured in myocardial extracts by ELISA (#RPN 2611, Amersham), as described previously.6
MMP Inhibition
To determine the effects of MMP inhibition on LV structure in MHCsTNF2 mice, we treated MHCsTNF2 mice with an MMP inhibitor (MMPi), PD 166793 (30 mg · kg-1 · d-1 PO in chow), from 3 to 6 weeks of age (n=13/group). Six-week-old wild-type mice (n=13) and 6 week-old MHCsTNF2 mice (n=11) fed normal chow were used as the appropriate controls. In preliminary dosing studies in this strain of mice, this dosing strategy resulted in steady state plasma levels of 33±2 µg/mL. This plasma level of PD 166793 exceeds the concentration necessary to inhibit all of the classes of MMPs. Importantly, PD 166973 has no effect on other metalloproteinases such as TACE. After the 3-week treatment period, the mice were anesthetized, and a precalibrated 4-electrode pressure sensor catheter (1.4F, Millar Instruments) was positioned in the LV. The catheter was interfaced to a Millar volumetric-conductance unit to compute absolute LV volumes in vivo, as described previously.11
Statistical Analysis
All values are expressed as mean±SEM. Two-way ANOVA was used to detect differences between MHCmTNF, MHCsTNF2, and wild-type mice for all parameters at the ages studied. Where appropriate, post hoc testing was performed with a Tukey test to detect differences between groups. Significant differences were said to exist at P<0.05.
| Results |
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Phenotypic Characterization of MHCmTNF and MHCsTNF2 Mice (6 Weeks)
Figure 2 shows that at 6 weeks of age, the MHCmTNF mice developed a concentric cardiac hypertrophic phenotype (Figures 2E and 2H), whereas the MHCsTNF2 mice developed a dilated cardiac phenotype (Figures 2F and 2I). Histological examination of hearts from the MHCmTNF (Figure 2K) and MHCsTNF2 (Figure 2L) mice showed a normal linear arrangement of myofibrils compared with wild-type mice (Figure 2J). There was no obvious myofibrillar disarray nor prominent interstitial infiltrating cells in any of the sections that were examined from the MHCmTNF and MHCsTNF2 mice.
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Longitudinal Characterization of Cardiac Phenotype in MHCmTNF and MHCsTNF2 Mice (6 to 24 Weeks)
Figure 3 summarizes the longitudinal assessment of cardiac structure in the wild-type, MHCmTNF, and MHCsTNF2 mice. The heart-weighttobody-weight ratios were significantly greater (P=0.002) in the MHCmTNF and MHCsTNF2 mice than in the wild-type mice at 6 and 24 weeks of age (Figure 3A). This increase in heart-weighttobody-weight ratio in the MHCmTNF mice and the MHCsTNF2 mice was due, at least in part, to a significant (P<0.006) increase in LV mass-tobody-weight ratio in the MHCmTNF and MHCsTNF2 mice compared with the wild-type control mice (Figure 3B). However, the pattern of cardiac hypertrophy was different in the MHCmTNF and MHCsTNF2 mice. Consistent with the phenotypic appearance of the hearts presented in Figure 2, MHCmTNF mice developed a hypertrophic phenotype that was characterized by a significant (P<0.001) increase in LV wall thickness (ie, concentric hypertrophy) compared with wild-type mice (Figure 3C), whereas MHCsTNF2 mice developed a cardiac phenotype characterized by a significant (P<0.001) increase in LV volume compared with wild-type mice (Figure 3D). Importantly, the concentric hypertrophic phenotype of the MHCmTNF mice persisted from 6 to 24 weeks, as shown by the preserved increase in LV wall thickness, with no increase in LV end-diastolic volume (Figures 3C and 3D). Similarly, the dilated cardiac phenotype of the MHCsTNF2 mice was maintained, as demonstrated by the persistent (P<0.001) increase in LV volume at 6 to 24 weeks in the MHCsTNF2 mice compared with the wild-type and the MHCmTNF mice (Figure 3D).
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Longitudinal Characterization of Myocardial Structure in MHCmTNF and MHCsTNF2 Mice (6 and 24 Weeks)
Cardiac Myocyte Hypertrophy
The cross-sectional area of myocytes from the hearts of MHCmTNF mice was significantly (P<0.05) greater in MHCmTNF mice at 6 and 24 weeks than in wild-type and MHCsTNF2 mice, whereas myocyte cross-sectional area was not significantly different (P>0.05) between MHCsTNF2 and wild-type control mice (Table 1). In contrast, myocyte cell length was significantly increased (P<0.05) in MHCsTNF2 mice at 6 and 24 weeks compared with both wild-type and MHCmTNF mice, whereas myocyte cell length was not significantly different (P=0.67) between MHCmTNF and wild-type mice (Table 1).
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Myocardial Fibrillar Collagen
Figures 4B and 4E show that there was a loss of myocardial fibrillar collagen in the MHCsTNF2 mice at 6 and 24 weeks of age compared with age-matched wild-type controls. In contrast, myocardial sections taken from the MHCmTNF mice revealed a dense fibrillar collagen weave and a thickening of the fibrillar struts between myocytes (Figures 4C and 4F). To further characterize the time-dependent changes in fibrillar collagen content, we performed picrosirius red staining in the MHCsTNF2, MHCmTNF, and wild-type mice (n=5 to 6 hearts per time point). There was a significant (P=0.002)
25% to 35% decrease in myocardial fibrillar collagen content in MHCsTNF mice compared with MHCmTNF and wild-type control mice (Figure 4G), which coincided with the qualitative changes in fibrillar collagen weave observed in the MHCsTNF2 mice (Figures 4B and 4E), whereas there was a significant (P<0.001)
35% to 40% increase in collagen content in the MHCmTNF mice at 6 and 24 weeks of age (compared with age-matched control mice), consistent with the qualitative assessment of fibrillar collagen in the MHCmTNF mice (Figures 4B and 4E).
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Mechanism for the Disparate Cardiac Phenotypes in MHCmTNF and MHCsTNF2 Mice
Hemodynamic Assessment of MHCmTNF and MHCsTNF2 Mice
Peak LV systolic pressure was not significantly different between the MHCmTNF, MHCsTNF2, and wild-type mice (Table 2). Moreover, end-systolic wall stress was significantly less (P<0.05) in the MHCmTNF mice (25.99±1.5 g/cm2) than in either the MHCsTNF2 mice (31.10±1.2 g/cm2) or the wild-type mice (37.75±1.0 g/cm2). LV end-diastolic pressure was significantly (P<0.05) elevated in MHCsTNF2 compared with MHCmTNF and wild-type mice.
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MMP Activity
As shown in the representative gelatin zymograms in Figure 5A, we observed lytic bands at
65 kDa (arrow) in all 3 lines of mice, suggestive of MMP2 activity. However, relative to wild-type mice and MHCmTNF mice, MMP activity was significantly greater (P<0.001 and P<0.02, respectively) in MHCsTNF2 mice at 6 weeks of age, coinciding with the decrease in fibrillar collagen content observed in these mice at this time point. There was, however, no significant (P=0.11) overall difference in MMP activity between wild-type and MHCmTNF mice. In addition, there was a striking decrease in MMP activity in MHCsTNF2 mice at 24 weeks of age (P=0.007 for 6 weeks versus 24 weeks), whereas MMP activity was not significantly different (P=0.32) in MHCmTNF mice from 6 to 24 weeks of age. To determine whether the changes in MMP activity observed in MHCsTNF2 mice were the result of changes in MMP2 abundance, we measured MMP2 abundance at 6 and 24 weeks of age. Figure 5C shows that there was a significant increase (P<0.001) in MMP2 abundance in both the MHCsTNF2 mice and the MHCmTNF mice compared with wild-type mice at 6 weeks of age. However, whereas MMP2 abundance decreased in MHCsTNF2 mice and was not significantly (P>0.4) different from wild-type mice at 24 weeks of age, MMP2 abundance remained increased in MHCmTNF mice and was significantly (P<0.001) greater than in wild-type mice at 24 weeks of age. Insofar as there was no significant difference in total MMP2 abundance between MHCmTNF and MHCsTNF2 hearts at 6 weeks (P=0.94), the increase in MMP2 zymographic activity in MHCsTNF2 mice suggests there was increased activation of MMP in these mice.
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TIMP Levels
We next examined changes in TIMP-1 levels as a possible mechanism for the observed differences in MMP activity in the MHCmTNF and MHCsTNF2 mice. Figure 5D shows that relative to levels in wild-type mice, TIMP-1 levels were significantly lower in MHCsTNF2 and MHCmTNF mice at 6 weeks of age (P=0.04 and P=0.002, respectively). However, at 24 weeks of age, there was a significant (P=0.90) difference in TIMP-1 levels between MHCsTNF2, MHCmTNF, and wild-type mice.
MMP Inhibition
As shown in Table 3, treatment of MHCsTNF2 (n=13) mice with an MMPi from 3 to 6 weeks of age significantly (P<0.05) attenuated the degree of LV dilation compared with untreated MHCsTNF2 mice (n=13). Furthermore, attenuation of LV dilation was not the result of a decrease in afterload, insofar as the peak LV systolic pressures were not significantly different (P=0.27) in wild-type, MMPi, and MHCsTNF2 mice.
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| Discussion |
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To delineate the mechanisms that were responsible for the different patterns of extracellular matrix remodeling in the MHCmTNF and MHCsTNF2 mice, we asked whether there were differences in MMP activity and TIMP levels in the 2 lines of mice, insofar as previous observations from this and other laboratories have implicated time-dependent changes in the balance between MMP activity and TIMP activity as an important determinant of LV dilation.6,12 Consistent with our previous observations, we observed increased MMP abundance, increased MMP activity (Figures 5A and 5B), and decreased TIMP levels in the MHCsTNF2 mice at 6 weeks of age. Collectively, the increased levels of active MMP-2 determined by zymography coupled with the reduction in TIMP-1 levels would favor increased MMP activation within the myocardium and thereby accelerate degradation of the extracellular matrix in the MHCsTNF2 mice. Notably, the most remarkable change in MMP-2/TIMP-1 stoichiometry occurred at 6 weeks, which coincided with the significant increase in LV dilation in the MHCsTNF2 mice at this time point. Given the MMP2 abundance and that TIMP levels were not significantly different in the MHCmTNF and MHCsTNF2 mice, the increased MMP-2 activational state in the MHCsTNF2 mice was likely due to increased activation of 1 or more upstream proteases (eg, plasmin) or local MMP activational systems (eg, membrane-bound MMPs) that are known to activate MMPs. Although the potential reasons for this differential activation are not known, one plausible explanation is that transmembrane TNF is spatially constrained, whereas secretable TNF lacks spatial constraint and is able to activate upstream proteases in endothelial cells, smooth muscle cells, and fibroblasts, which in turn are capable of activating MMPs in a paracrine manner. The importance of MMP activation as a mechanism for LV dilation in the MHCsTNF2 mice was shown by studies in which an MMPi was sufficient to attenuate LV dilation in MHCsTNF2 mice (Table 3), consistent with previous reports that have shown that MMPi attenuates LV dilation in different heart failure models.1315
| Conclusions |
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| Acknowledgments |
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| Footnotes |
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Guest Editor for this article was Wilson S. Colucci, MD, Boston University Medical Center, Boston, Mass.
| References |
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2. Mann DL. Inflammatory mediators and the failing heart: past, present, and the foreseeable future. Circ Res. 2002; 91: 988998.
3. Black RA, Rauch CT, Kozlosky CJ, et al. A metalloproteinase disintegrin that releases tumour-necrosis factor-
from cells. Nature. 1997; 385: 729733.[CrossRef][Medline]
[Order article via Infotrieve]
4. Grell M, Douni E, Wajant H, et al. The transmembrane form of tumor necrosis factor is the prime activating ligand of the 80 kDa tumor necrosis factor receptor. Cell. 1995; 83: 793802.[CrossRef][Medline] [Order article via Infotrieve]
5. Satoh M, Nakamura M, Saitoh H, et al. Tumor necrosis factor-alpha-converting enzyme and tumor necrosis factor-alpha in human dilated cardiomyopathy. Circulation. 1999; 99: 32603265.
6. Sivasubramanian N, Coker ML, Kurrelmeyer K, et al. Left ventricular remodeling in transgenic mice with cardiac restricted overexpression of tumor necrosis factor. Circulation. 2001; 2001: 826831.
7. Dibbs ZI, Diwan A, Nemoto S, et al. Targeted overexpression of transmembrane tumor necrosis factor provokes a concentric cardiac hypertrophic phenotype. Circulation. 2003; 108: 10021008.
8. Bozkurt B, Kribbs S, Clubb FJ Jr, et al. Pathophysiologically relevant concentrations of tumor necrosis factor-
promote progressive left ventricular dysfunction and remodeling in rats. Circulation. 1998; 97: 13821391.
9. Gerdes AM, Onodera T, Tamura T, et al. New method to evaluate myocyte remodeling from formalin-fixed biopsy and autopsy material. J Card Fail. 1998; 4: 343348.[CrossRef][Medline] [Order article via Infotrieve]
10. Nemoto S, Vallejo JG, Knuefermann P, et al. Escherichia coli lipopolysaccharide-induced left ventricular dysfunction: the role of toll-like receptor-4 in the adult mammalian heart. Am J Physiol. 2002; 282: H2316H2323.
11. Roten L, Nemoto S, Simsic J, et al. Effects of gene deletion of the tissue inhibitor of the matrix metalloproteinase-type 1 (TIMP-1) on left ventricular geometry and function in mice. J Mol Cell Cardiol. 2000; 32: 109120.[CrossRef][Medline] [Order article via Infotrieve]
12. Li YY, Feng YQ, Kadokami T, et al. Myocardial extracellular matrix remodeling in transgenic mice overexpressing tumor necrosis factor alpha can be modulated by anti-tumor necrosis factor alpha therapy. Proc Natl Acad Sci U S A. 2000; 97: 1274612751.
13. Spinale FG, Coker ML, Krombach SR, et al. Matrix metalloproteinase inhibition during the development of congestive heart failure : effects on left ventricular dimensions and function. Circ Res. 1999; 85: 364376.
14. Li YY, Kadokami T, Wang P, et al. MMP inhibition modulates TNF-alpha transgenic mouse phenotype early in the development of heart failure. Am J Physiol Heart Circ Physiol. 2002; 282: H983H989.
15. McElmurray JH III, Mukherjee R, New RB, et al. Angiotensin-converting enzyme and matrix metalloproteinase inhibition with developing heart failure: comparative effects on left ventricular function and geometry. J Pharmacol Exp Ther. 1999; 291: 799811.
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