Expression and Complex Formation of MMP9, MMP2, NGAL, and TIMP1 in Porcine Myocardium but Not in Skeletal Muscles in Male Pigs with Tachycardia-Induced Systolic Heart Failure

Liliana Kiczak,Piotr Skrzypczak,Urszula Paslawska,Maciej Zacharski,Ewa A Jankowska,Hossein Ardehali,Jacek Bania,Piotr Ponikowski,Adrian Janiszewski,Agnieszka Noszczyk-Nowak,Alicja Tomaszek

doi:10.1155/2013/283856

Abstract

Matrix metalloproteinases (MMPs) are involved in the remodeling of extracellular matrix in various tissues. Their functioning could be related to the formation of complexes, containing MMP9, MMP2, tissue inhibitor of metalloproteinases type 1 (TIMP1), and neutrophil gelatinase-associated lipocalin (NGAL). Such complexes have not been investigated in either myocardial or skeletal muscles. We examined 20 male pigs with heart failure (HF), and 5 sham-operated animals. There were no differences in the mRNA expression of MMP9, MMP2, TIMP1, and NGAL between diseased and healthy animals, in either left ventricle (LV) myocardium or skeletal muscles. In LV from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we demonstrated the presence of high molecular weight (HMW) complexes (130, 170, and 220 kDa) containing MMP9, TIMP1, and NGAL (also MMP2 in 220 kDa complex) without proteolytic activity, and a proteolytically active 115 kDa MMP9 form together with 72 and 68 kDa bands (proMMP2 and MMP2). Proteolytically active bands were also spontaneously released from HMW complexes. In skeletal muscles from both diseased and healthy animals, in nonreducing and nondenaturing conditions, we found no HMW complexes, and proteolytic activity was associated with the presence of 72 and 68 kDa bands (proMMP2 and MMP2).

Highlights

Matrix metalloproteinases (MMPs) are the key enzymes orchestrating the turnover of extracellular matrix (ECM) of virtually all tissues [1]
The proteolytic activity of MMPs is critical for the ongoing processes of tissue remodeling and repair [7], and it is tightly controlled through different mechanisms including interaction with inhibitors or stabilizers of active enzymes [8]
Echocardiography performed directly before euthanasia revealed that right ventricular (RV) pacing-induced progressive development of left ventricle (LV) systolic and diastolic dysfunction along with LV dilatation with the most marked echocardiography abnormalities seen in pigs with severe symptoms of heart failure (HF) (Table 2)

Summary

Introduction

Matrix metalloproteinases (MMPs) are the key enzymes orchestrating the turnover of extracellular matrix (ECM) of virtually all tissues [1]. The proteolytic activity of MMPs is critical for the ongoing processes of tissue remodeling and repair [7], and it is tightly controlled through different mechanisms including interaction with inhibitors (tissue inhibitors of metalloproteinases, TIMP1-4) or stabilizers of active enzymes (neutrophil gelatinase-associated lipocalin, NGAL) [8]. Both pro-MMPs and MMPs can form the noncovalent high molecular weight (HMW) complexes, which may contain different molecules, such as TIMPs [7] or/and NGAL [9, 10]. HMW complex composed of MMP9, MMP2, MMP3, TIMP1, and TIMP2 found in rat chorioallantoid membranes has been shown to be stabile and latent at high physiological calcium concentrations, dissociating at low calcium concentration and releasing active enzymes [11]

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