Angiotensin II binding and extracellular matrix remodelling in a rat model of myocardial infarction

Abstract Aims Left ventricular (LV) remodelling after myocardial infarction (MI) is promoted by an intense fibrotic response, which could be targeted by an anti-fibrotic drug such as pirfenidone. Methods and results We explored the relationship between protein modulation by pirfenidone and post-MI remodelling, based on publicly available molecular information and transcriptomic data from a swine model of MI. We also compared the effects of pirfenidone and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARB), mineralocorticoid receptor blockers (MRA) and beta-blockers. We identified six causative motives of post-MI remodelling (cardiomyocyte cell death, impaired myocyte contractility, extracellular matrix remodelling and fibrosis, hypertrophy, renin–angiotensin–aldosterone system activation, and inflammation), 4 pirfenidone targets and 21 bioflags (indirect effectors). When considering both targets and bioflags, pirfenidone showed a broad relationship encompassing all six motives. p38γ-MAPK12 blockade inhibits cardiomyocyte apoptosis, cardiomyocyte hypertrophy and inflammation. Furthermore, pirfenidone can modulate extracellular matrix remodelling and cardiac fibrosis by targeting the TGFβ1-SMAD2/3 pathway and other effector proteins such as matrix metalloproteases 2 and 14, PDGFA/B, and IGF1, which promote myocardial fibrosis, cardiomyocyte hypertrophy and impaired contractility. All the gold standard drugs were found to be important for specific clinical motives, but pirfenidone had a more widespread action on the molecular pathways active in the post-MI setting. Conclusions A bioinformatic approach allowed to identify several possible mechanisms of action of pirfenidone with beneficial effects in the post-MI LV remodelling, and suggests additional effects over guideline-recommended therapies. These findings support clinical studies evaluating the beneficial effects of pirfenidone in patients with MI.

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Cardiac-Restricted IGF-1Ea Overexpression Reduces the Early Accumulation of Inflammatory Myeloid Cells and Mediates Expression of Extracellular Matrix Remodelling Genes after Myocardial Infarction

Mediators of Inflammation ◽

10.1155/2015/484357 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 17

Author(s):

Enrique Gallego-Colon ◽

Robert D. Sampson ◽

Susanne Sattler ◽

Michael D. Schneider ◽

Nadia Rosenthal ◽

...

Keyword(s):

Myocardial Infarction ◽

Extracellular Matrix ◽

Cardiac Function ◽

Immune Cell ◽

Myocardial Infarct ◽

Myeloid Cells ◽

Constitutive Expression ◽

Functional Restoration ◽

Cellular Mechanisms ◽

Extracellular Matrix Remodelling

Strategies to limit damage and improve repair after myocardial infarct remain a major therapeutic goal in cardiology. Our previous studies have shown that constitutive expression of a locally acting insulin-like growth factor-1 Ea (IGF-1Ea) propeptide promotes functional restoration after cardiac injury associated with decreased scar formation. In the current study, we investigated the underlying molecular and cellular mechanisms behind the enhanced functional recovery. We observed improved cardiac function in mice overexpressing cardiac-specific IGF-1Ea as early as day 7 after myocardial infarction. Analysis of gene transcription revealed that supplemental IGF-1Ea regulated expression of key metalloproteinases (MMP-2 and MMP-9), their inhibitors (TIMP-1 and TIMP-2), and collagen types (Col 1α1 and Col 1α3) in the first week after injury. Infiltration of inflammatory cells, which direct the remodelling process, was also altered; in particular there was a notable reduction in inflammatory Ly6C+ monocytes at day 3 and an increase in anti-inflammatory CD206+ macrophages at day 7. Taken together, these results indicate that the IGF-1Ea transgene shifts the balance of innate immune cell populations early after infarction, favouring a reduction in inflammatory myeloid cells. This correlates with reduced extracellular matrix remodelling and changes in collagen composition that may confer enhanced scar elasticity and improved cardiac function.

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