齐康
中国医学科学院阜外医院 心血管内科
BACKGROUND:Traditional Chinese medicine Tongxinluo (TXL) has been widely used to treat coronary artery disease in China, since it could reduce myocardial infarct size and ischemia/reperfusion injury in both non-diabetic and diabetic conditions. It has been shown that TXL could regulate peroxisome proliferator activated receptor-α (PPAR-α), a positive modulator of angiopoietin-like 4 (Angptl4), in diabetic rats. Endothelial junction substructure components, such as VE-cadherin, are involved in the protection of reperfusion injury. Thus, we hypothesized cell-intrinsic and endothelial-specific Angptl4 mediated the protection of TXL on endothelial barrier under high glucose condition against ischemia/reperfusion-injury via PPAR-α pathway.METHODS:Incubated with high glucose medium, the human cardiac microvascular endothelial cells (HCMECs) were then exposed to oxygen-glucose-serum deprivation (2 hours) and restoration (2 hours) stimulation, with or without TXL, insulin, or rhAngptl4 pretreatment.RESULTS:TXL, insulin, and rhAngptl4 had similar protective effects on the endothelial barrier. TXL treatment reversed the endothelial barrier breakdown in HCMECs significantly as identified by decreasing endothelial permeability, upregulating the expression of JAM-A, VE-cadherin, and integrin-α5 and increasing the membrane location of VE-cadherin and integrin-α5, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with small interfering RNA (siRNA) interference and PPAR-α inhibitor MK886 partially abrogated these beneficial effects of TXL. Western blotting also revealed that similar with insulin, TXL upregulated the expression of Angptl4 in HCMECs, which could be inhibited by Angptl4 siRNA or MK886 exposure. TXL treatment increased PPAR-α activity, which could be diminished by MK886 but not by Angptl4 siRNA.CONCLUSION:These data suggest cell-intrinsic and endothelial-specific Angptl4 mediates the protection of TXL against endothelial barrier breakdown during oxygen-glucose-serum deprivation and restoration under high glucose condition partly via the PPAR-α/Angptl4 pathway.
Medicine 2020
The SDF-1/CXCR4 signaling plays a critical role in the trafficking of mesenchymal stem cells (MSCs) to the sites of tissue damage. Our recent study demonstrated that atorvastatin (ATV) treatment improved the survival of MSCs, and ATV pretreated MSCs (ATV-MSCs) exhibited enhanced engraftment to injured myocardium. In this study, we investigated whether combined treatment with ATV and ATV-MSCs enhances cardiac repair and regeneration by activating SDF-1/CXCR4 signaling in a rat model of acute myocardial infarction. Rats were randomized into eight groups: the Sham, AMI control and 6 other groups that were subjected to AMI followed by treatment with MSCs, ATV, ATV+MSCs, ATV-MSCs, ATV+ATV-MSCs, ATV+ATV-MSCs+AMD3100 (SDF-1/CXCR4 antagonist), respectively. ATV+ATV-MSCs significantly potentiated targeted recruitment of MSCs to peri-infarct myocardium and resulted in further improvements in cardiac function and reduction in scar size compared with MSCs treatment alone at 4-week after AMI. More importantly, the cardioprotective effects conferred by ATV+ATV-MSCs were almost completely abolished by AMD3100 treatment. Together, our study demonstrated that ATV+ATV-MSCs significantly enhanced the targeted recruitment and survival of transplanted MSCs, and resulted in subsequent cardiac function improvement by augmenting SDF-1/CXCR4 signaling.
American journal of translational research 2019
OBJECTIVE:Endothelial barrier function in the onset and Tongxinluo (TXL) protection of myocardial ischemia/reperfusion (I/R) injury, and TXL can induce the secretion of Angiopoietin-like 4 (Angptl4) in human cardiac microvascular endothelial cells during hypoxia/reoxygenation. We intend to demonstrate whether TXL can attenuate myocardial I/R injury in diabetes, characterized with microvascular endothelial barrier disruption, by induction of Angptl4-mediated protection of endothelial barrier integrity.METHODS AND RESULTS:I/R injury was created by coronary ligation in ZDF diabetic and non-diabetic control rats. The animals were anesthetized and randomized to sham operation or I/R injury with or without the exposure to insulin, rhAngptl4, TXL, Angptl4 siRNA, and the PPAR-α inhibitor MK886. Tongxinluo, insulin and rhAngptl4 have the similar protective effect on diabetic hearts against I/R injury. In I/R-injured diabetic hearts, TXL treatment remarkably reduced the infarct size, and protected endothelial barrier integrity demonstrated by decreased endothelial cells apoptosis, microvascular permeability, and myocardial hemorrhage, fortified tight junction, and upregulated expression of JAM-A, integrin-α5, and VE-cadherin, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with siRNA interference and inhibition of PPAR-α with MK886 partially diminished these beneficial effects of TXL and rhAngptl4. TXL induced the expression of Angptl4 in I/R-injured diabetic hearts, and was canceled by Angptl4 siRNA and MK886. TXL treatment increased myocardial PPAR-α activity, and was abolished by MK886 but not by Angptl4 siRNA.CONCLUSIONS:TXL protects diabetic hearts against I/R injury by activating Angptl4-mediated restoration of endothelial barrier integrity via the PPAR-α pathway.
PloS one 2018
Cardiac microvascular endothelial cells (CMECs) extensively secrete cytokines during myocardial ischemia/reperfusion injury (MIRI). Tongxinluo (TXL) has been demonstrated to preserve the function of the endothelium and myocardium against MIRI. This study was designed to identify alterations in the paracrine function of CMECs under hypoxia/reoxygenation (H/R) conditions and assess its modulation by TXL. CMECs were exposed to different concentrations of TXL for 30 min and then subjected to hypoxia and reoxygenation for 12 and 2 h, respectively. Apoptosis was measured to determine the optimal TXL concentration. Protein antibody arrays were used to assess changes in cytokines secreted into conditioned medium by CMECs. A Gene Ontology (GO) analysis was applied to interpret the functional implications of changes in cytokines. TXL inhibited CMEC apoptosis in a concentration-dependent manner after H/R, reaching peak efficacy at a concentration of 800 μg/ml. H/R significantly altered 33 cytokines, and TXL (800 μg/ml) changed the levels of 121 different cytokines compared with the H/R group. Among these cytokines, 10 that were increased by H/R were decreased by TXL, five that were decreased by H/R were increased by TXL, and eight that were attenuated by H/R were further decreased by TXL. Insulin-like growth factor binding protein-1 was up-regulated by H/R and was further increased by TXL. Significantly altered factors were found to be involved in cell proliferation, growth and differentiation, as well as chemotaxis and transport. TXL inhibited the apoptosis of CMECs and modulated their paracrine function in MIRI.
American journal of translational research 2016
OBJECTIVE:Tongxinluo (TXL) has been shown to decrease myocardial necrosis after ischemia/reperfusion (I/R) by simulating ischemia preconditioning (IPC). However, the core mechanism of TXL remains unclear. This study was designed to investigate the key targets of TXL against I/R injury (IRI) among the cardiac structure-function network.MATERIALS AND METHODS:To evaluate the severity of lethal IRI, a mathematical model was established according to the relationship between myocardial no-reflow size and necrosis size. A total of 168 mini-swine were employed in myocardial I/R experiment. IRI severity among different interventions was compared and IPC and CCB groups were identified as the mildest and severest groups, respectively. Principal component analysis was applied to further determine 9 key targets of IPC in cardioprotection. Then, the key targets of TXL in cardioprotection were confirmed.RESULTS:Necrosis size and no-reflow size fit well with the Sigmoid Emax model. Necrosis reduction space (NRS) positively correlates with I/R injury severity and necrosis size (R2=0.92, R2=0.57, P<0.01, respectively). Functional and structural indices correlate positively with NRS (R2=0.64, R2=0.62, P<0.01, respectively). TXL recovers SUR2, iNOS activity, eNOS activity, VE-cadherin, β-catenin, γ-catenin and P-selectin with a trend toward the sham group. Moreover, TXL increases PKA activity and eNOS expression with a trend away from the sham group. Among the above nine indices, eNOS activity, eNOS, VE-cadherin, β-catenin and γ-catenin expression were significantly up-regulated by TXL compared with IPC (P>0.05) or CCB (P<0.05) and these five microvascular barrier-related indices may be the key targets of TXL in minimizing IRI.CONCLUSIONS:Our study underlines the lethal IRI as one of the causes of myocardial necrosis. Pretreatment with TXL ameliorates myocardial IRI through promoting cardiac microvascular endothelial barrier function by simulating IPC.
PloS one 2015
: In contrast to cardiomyocytes, autophagy in cardiac microvascular endothelial cells (CMECs) during ischemia/reperfusion (I/R) injury has not been fully investigated. Tongxinluo (TXL), a traditional Chinese medicine, was shown to be vascular protective. We aimed to elucidate the role of autophagy and its regulatory mechanisms by TXL in CMECs subjected to I/R injury. CMECs were exposed to different treatments for 30 minutes and subjected to hypoxia/reoxygenation each for 2 hours. The results indicated that hypoxia/reoxygenation significantly induced autophagy, as identified by an increased number of monodansylcadaverine-positive CMECs, increased autophagosome formation, and a higher type II/type I of light chain 3 ratio, but not Beclin-1 expression. Autophagy inhibition using 3-methyladenine was proapoptotic, but rapamycin-induced autophagy was antiapoptotic. TXL enhanced autophagy and decreased apoptosis in a dose-dependent manner, reaching its largest effect at 800 μg/mL. 3-methyladenine attenuated the TXL-promoted autophagy and antiapoptotic effects, whereas rapamycin had no additional effects compared with TXL alone. TXL upregulated mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK) phosphorylation; however, PD98059 abrogated ERK phosphorylation and decreased autophagy and increased apoptosis compared with TXL alone. These results suggest that autophagy is a protective mechanism in CMECs subjected to I/R injury and that TXL can promote autophagy through activation of the mitogen-activated protein kinase/ERK pathway.
Journal of cardiovascular pharmacology 2014
