Inhibition of MMP-2 Expression with siRNA Increases Baseline Cardiomyocyte Contractility and Protects against Simulated Ischemic Reperfusion Injury

Abstract

Matrix metalloproteinases (MMPs) significantly contribute to ischemia reperfusion (I/R) injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s) involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2) in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological) conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

Subthreshold nitric oxide synthase inhibition improves synergistic effects of subthreshold MMP‐2/MLCK‐mediated cardiomyocyte protection from hypoxic injury

“…The optimal duration of ischaemia, 3 min., was established in previous studies . Three‐minute ischaemia caused approximately 50% loss in cell contractility, and viability of cells was maintained at the level of 70% or higher . After 3 min.…”

“…Recently, we demonstrated that in addition to the pathological role of MMP‐2 in I/R, MMP‐2 also regulates MLC levels under physiological conditions . We showed that the complete inhibition of intracellular MMP‐2 in aerobically perfused cardiomyocytes increases MLC levels and increases cardiomyocyte contractility above normal .…”

“…Recently, we demonstrated that in addition to the pathological role of MMP-2 in I/R, MMP-2 also regulates MLC levels under physiological conditions [15,19]. We showed that the complete inhibition of intracellular MMP-2 in aerobically perfused cardiomyocytes increases MLC levels and increases cardiomyocyte contractility above normal [19]. Aside from increased phosphorylation and nitration/nitrosylation of MLC and its degradation by MMP-2 in pathological conditions, other researchers showed that these modifications of MLC are important for its physiological roles [20][21][22][23][24].…”

Impact of corvitin and alpha-ketoglutarate on heart morphology, expression and activity of matrix metalloproteinases 2/9 in the heart of rats with doxorubicin-induced cardiomyopathy

“…MMP2 and MMP9 also exhibit proteolytic activity against elastin and proteoglycans. It was shown that the level of circulating gelatinases can serve as indicators of dilated cardiomyopathy (Pytliak et al, 2017), heart failure under doxorubicin treatment (Ivanova et al, 2012, Gordiienko et al, 2014, poor output of acute coronary syndrome (Lindsey et al, 2016) and efficiency of the therapy provided to heart failure patients (Radosinska et al, 2017). At the same time, the changes in expression and intracellular localization of these enzymes in heart tissue are poorly understood and discussed mostly as markers of post-infarction complications (Mayer et al, 2018).…”

LncRNA260-specific siRNA targeting IL28RA gene inhibit cardiomyocytes hypoxic/reoxygenation injury

“…RNA interference (RNAi) is a common biological phenomenon, where siRNA binding with its complementary messenger RNA (mRNA) results in the degradation of the mRNA molecule, thus inhibiting its translation. RNAimediated gene expression is easier than conventional gene knockouts approaches and also possesses a high specificity and efficiency compared with antisense oligonucleotides, RNA enzymes, and DNA enzymes (13)(14)(15)(16).…”