Elevated 20-HETE impairs coronary collateral growth in metabolic syndrome via endothelial dysfunction

Abstract

Coronary collateral growth (CCG) is impaired in metabolic syndrome (MetS). microRNA-145 (miR-145-Adv) delivery to our rat model of MetS (JCR) completely restored and neutrophil depletion significantly improved CCG. We determined whether low endogenous levels of miR-145 in MetS allowed for elevated production of 20-hydroxyeicosatetraenoic acid (20-HETE), which, in turn, resulted in excessive neutrophil accumulation and endothelial dysfunction leading to impaired CCG. Rats underwent 0-9 days of repetitive ischemia (RI). RI-induced cardiac CYP4F (neutrophil-specific 20-HETE synthase) expression and 20-HETE levels were increased (4-fold) in JCR vs. normal rats. miR-145-Adv and 20-HETE antagonists abolished and neutrophil depletion (blocking antibodies) reduced (~60%) RI-induced increases in CYP4F expression and 20-HETE production in JCR rats. Impaired CCG in JCR rats (collateral-dependent blood flow using microspheres) was completely restored by 20-HETE antagonists [collateral-dependent zone (CZ)/normal zone (NZ) flow ratio was 0.76 ± 0.07 in JCR + 20-SOLA, 0.84 ± 0.05 in JCR + 20-HEDGE vs. 0.11 ± 0.02 in JCR vs. 0.84 ± 0.03 in normal rats]. In JCR rats, elevated 20-HETE was associated with excessive expression of endothelial adhesion molecules and neutrophil infiltration, which were reversed by miR-145-Adv. Endothelium-dependent vasodilation of coronary arteries, endothelial nitric oxide synthase (eNOS) Ser1179 phosphorylation, eNOS-dependent NO production and endothelial cell survival were compromised in JCR rats. These parameters of endothelial dysfunction were completely reversed by 20-HETE antagonism or miR-145-Adv delivery, whereas neutrophil depletion resulted in partial reversal (~70%). We conclude that low miR-145 in MetS allows for increased 20-HETE, mainly from neutrophils, which compromises endothelial cell survival and function leading to impaired CCG. 20-HETE antagonists could provide viable therapy for restoration of CCG in MetS. Elevated 20-hydroxyeicosatetraenoic acid (20-HETE) impairs coronary collateral growth (CCG) in metabolic syndrome by eliciting endothelial dysfunction and apoptosis via excessive neutrophil infiltration. 20-HETE antagonists completely restore coronary collateral growth in metabolic syndrome. microRNA-145 (miR-145) is an upstream regulator of 20-HETE production in metabolic syndrome; low expression of miR-145 in metabolic syndrome promotes elevated production of 20-HETE.

20-HETE in the regulation of vascular and cardiac function

“…In humans, there are two major 20-HETE synthases, CYP4A11 and CYP4F2 (Capdevila, Falck, & Harris, 2000; Lasker et al, 2000; Powell, Wolf, Jin, & Lasker, 1998; Roman, 2002), but others, including CYP4F11 and CYP4F3 have some capacity to produce 20-HETE (Edson & Rettie, 2013). In mice, the primary 20-HETE synthase is Cyp4a12a (Muller et al, 2007) and in the rat the major 20-HETE synthases are CYP4A1, 2 and 3 (Hardwick, 2008; Nguyen, Wang, Reddy, Falck, & Schwartzman, 1999) as well as CYP4F1 and 4 (Imaoka, Hashizume, & Funae, 2005; Joseph et al, 2017; Soler et al, 2018; Xu, Falck, Ortiz de Montellano, & Kroetz, 2004). These enzymes are expressed in different tissues and cell types and are subjected to transcriptional regulation by nuclear receptor and transcriptional factors, which are activated by hormones such as androgens and by xenobiotics.…”

“…MicroRNAs (miR), endogenous 22-nucleotide non-coding RNAs that regulate gene expression via translational repression and degradation of RNAs, have also been shown to regulate CYP enzymes (Nakano & Nakajima, 2018; Shahabi, Siest, Meyer, & Visvikis-Siest, 2014). As for 20-HETE-producing CYPs, a recent study implicated miR-145 as an upstream regulator of cardiac 20-HETE production in metabolic syndrome rats; administration of adenoviral vector carrying miR-145 effectively lowered levels of CYP4F protein and 20-HETE in the ischemic zone of metabolic syndrome rats undergoing transient, repetitive ischemia (Joseph et al, 2017). The existence of several pathways by which the expression and the activity of 20-HETE-producing enzymes can be regulated implies that individual variations in CYP4A/F may not only be due to SNPs but also may arise from post transcriptional modifications.…”

“…20-HETE formation has been identified in the liver, kidney, heart, lung, conductive and resistant arterial vessels, brain, small intestine and pancreas (Capdevila, Falck, & Estabrook, 1992; Joseph et al, 2017; Macica, Balazy, Falck, Mioskowski, & Carroll, 1993; Schwartzman et al, 1990; Tunaru et al, 2018; Yousif, Benter, & Roman, 2009; Zhu, Zhang, Medhora, & Jacobs, 1985). One of the major sites of 20-HETE biosynthesis within many of these tissues is the blood vessel wall.…”

“…However, there are reports that demonstrate significant CYP4A/F expression in the vascular endothelium, especially under ischemic or hypoxic conditions, suggesting that the endothelium has the capacity to produce 20-HETE (L. Chen et al, 2016; Joseph et al, 2017; Zhu et al, 1985). In addition, peripheral blood myeloid and bone marrow-derived cells such as neurtrophils, platelets and endothelial progenitor cells (EPC) are also sources of 20-HETE that may contribute to circulatory levels of 20-HETE and to its levels in inflamed and injured tissues (L.…”

“…Chen et al, 2014; L. Chen et al, 2016; Joseph et al, 2017). In cultured human endothelial cells, hypoxia (3% O 2 ) for 16 h increases 20-HETE levels by 10-fold (L.…”