Tongxinluo Inhibits Cyclooxygenase-2, Inducible Nitric Oxide Synthase, Hypoxia-inducible Factor-2α/Vascular Endothelial Growth Factor to Antagonize Injury in Hypoxia-stimulated Cardiac Microvascular Endothelial Cells

Abstract

Background:Endothelial dysfunction is considered as the initiating process and pathological basis of cardiovascular disease. Cyclooxygenase-2 (COX-2) and prostacyclin synthase (PGIS), inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) are key enzymes with opposing actions in inflammation and oxidative stress, which are believed to be the major driver of endothelial dysfunction. And in hypoxia (Hx), Hx-inducible factor (HIF)-1α and HIF-2α are predominantly induced to activate vascular endothelial growth factor (VEGF), resulting in abnormal proliferation. Whether and how Tongxinluo (TXL) modulates COX-2, PGIS, iNOS, eNOS, HIF-1α, HIF-2α, and VEGF in Hx-stimulated human cardiac microvascular endothelial cells (HCMECs) have not been clarified.Methods:HCMEC were treated with CoCl2 to mimic Hx and the mRNA expressions of COX-2, PGIS, iNOS, eNOS, HIF-1α, HIF-2α, and VEGF were first confirmed, and then their mRNA expression and protein content as well as the cell pathological alterations were evaluated for TXL treatment with different concentrations. In addition, the effector molecular of inflammation prostaglandin E2 (PGE2) and the oxidative marker nitrotyrosine (NT) was adopted to reflect HCMEC injury.Results:Hx could induce time-dependent increase of COX-2, iNOS, HIF-2α, and VEGF in HCMEC. Based on the Hx-induced increase, TXL could mainly decrease COX-2, iNOS, HIF-2α, and VEGF in a concentration-dependent manner, with limited effect on the increase of PGIS and eNOS. Their protein contents verified the mRNA expression changes, which was consistent with the cell morphological alterations. Furthermore, high dose TXL could inhibit the Hx-induced increase of PGE2 and NT contents, attenuating the inflammatory and oxidative injury.Conclusions:TXL could inhibit inflammation-related COX-2, oxidative stress-related iNOS, and HIF-2α/VEGF to antagonize Hx-induced HCMEC injury.

Quantitative Proteomics Analysis of Ischemia/Reperfusion Injury-Modulated Proteins in Cardiac Microvascular Endothelial Cells and the Protective Role of Tongxinluo

“…TXL has been proved to effectively improve the cardiac microcirculation in previous studies [17, 18]. However, there is no explicit mechanism responsible for IR and the regulation by TXL.…”

“…In our analysis, we identified a complete network of proteins associated with I/R. In the case of ischemia and hypoxia, vascular and endothelial tissues may release inflammatory factors, including HIF [18], SOD1, NFκB [27, 28]. ECs normally regulate the release of vasoconstriction factors (ET1, TXA2) and diastolic factors (prostaglandins and adenosine oxidase) to maintain balance, which is disrupted in ischemia-reperfusion injury [29].…”

Tea polyphenols protect against ischemia/reperfusion-induced liver injury in mice through anti-oxidative and anti-apoptotic properties

“…However, no statistically significant difference in the GSH/GSSG ratio was detected between the saline + sham group and the TP + sham group. (16); therefore, the mRNA and protein expression of iNOS in each group was analyzed. As demonstrated in Fig.…”

A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Study of the Effects of Tongxinluo Capsules in Acute Coronary Syndrome Patients with High On-Treatment Platelet Reactivity

“…They have been treated for decades with demonstrated efficacy with Tongxinluo capsules (TCs). [ 9 10 ] Platelets are activated via multiple pathways, and the activation and aggregation of platelets does not influence ischemic events alone. Hence, a single-antiplatelet treatment strategy (e.g., high-dose clopidogrel) directed against a specific receptor cannot be expected to completely overcome HPR, or to reduce the risk of recurrent ischemic events.…”