Cardiac microvascular barrier function mediates the protection of Tongxinluo against myocardial ischemia/reperfusion injury

Tongxinluo capsule as a multi-functional traditional Chinese medicine in treating cardiovascular disease: A review of components, pharmacological mechanisms, and clinical applications

Cardiovascular diseases (CVDs) are one of the most significant diseases that pose a threat to human health. The innovative traditional Chinese medicine Tongxinluo Capsule, developed under the guidance of the theory of traditional Chinese medicine, has good clinical efficacy in various cardiovascular diseases, this medicine has effects such as blood protection, vascular protection, myocardial protection, stabilizing vulnerable plaques, and vasodilation. However, CVDs are a multifactorial disease, and their underlying mechanisms are not fully understood. Therefore, exploring the mechanism of action and clinical application of Tongxinluo Capsule in the treatment of various cardiovascular diseases is beneficial for exerting its therapeutic effect from multiple components, targets, and pathways. At the same time, it provides broader treatment ideas for other difficult to treat diseases in the cardiovascular event chain, and has significant theoretical and clinical significance for improving the treatment of cardiovascular diseases with traditional Chinese medicine.

Clinical effects and mechanisms of a Chinese patent medicine, Tongxinluo capsule, as an adjuvant treatment in coronary heart disease

Coronary heart disease (CHD) is the leading cause of death globally, posing a serious threat to human health. However, the current treatment approaches available for CHD fall short of the ideal results. Tongxinluo (TXL) is a traditional Chinese medicine (TCM) that has been employed in the clinical treatment of cardiovascular and cerebrovascular diseases (such as angina pectoris, stroke, etc.) in China for many years and holds great potential as a prospective treatment. TXL either as a standalone treatment or in combination with interventions recommended in CHD guidelines has been shown to be effective and well tolerated in clinical trials for CHD. Drawing on the evidence from clinical trials and experimental studies, this review will focus on the cardiovascular protective properties and related mechanisms of TXL. By searching 8 Chinese and English databases, more than 4000 articles were retrieved. These articles were categorized, then read, and finally written into this review. In this review, the pharmacological properties of TXL include regulation of blood lipids, improvement of endothelial function, anti-inflammatory, antioxidant, inhibition of apoptosis and regulation of autophagy, anti-fibrosis, promotion of angiogenesis, and modulation of exosome communication. The information provided in this review will help the reader to comprehend better the insights that TCM has developed over time in practice and provide new perspectives for the treatment of CHD.

Inhibiting leukocyte-endothelial cell interactions by Chinese medicine Tongxinluo capsule alleviates no-reflow after arterial recanalization in ischemic stroke

AIMS

Despite successful vascular recanalization in stroke, one-fourth of patients have an unfavorable outcome due to no-reflow. The pathogenesis of no-reflow is fully unclear, and therapeutic strategies are lacking. Upon traditional Chinese medicine, Tongxinluo capsule (TXL) is a potential therapeutic agent for no-reflow. Thus, this study is aimed to investigate the pathogenesis of no-reflow in stroke, and whether TXL could alleviate no-reflow as well as its potential mechanisms of action.

METHODS

Mice were orally administered with TXL (3.0 g/kg/d) after transient middle cerebral artery occlusion. We examined the following parameters: neurological function, no-reflow, leukocyte-endothelial cell interactions, HE staining, leukocyte subtypes, adhesion molecules, and chemokines.

RESULTS

Our results showed stroke caused neurological deficits, neuron death, and no-reflow. Adherent and aggregated leukocytes obstructed microvessels as well as leukocyte infiltration in ischemic brain. Leukocyte subtypes changed after stroke mainly including neutrophils, lymphocytes, regulatory T cells, suppressor T cells, helper T type 1 (Th1) cells, Th2 cells, B cells, macrophages, natural killer cells, and dendritic cells. Stroke resulted in upregulated expression of adhesion molecules (P-selectin, E-selectin, and ICAM-1) and chemokines (CC-chemokine ligand (CCL)-2, CCL-3, CCL-4, CCL-5, and chemokine C-X-C ligand 1 (CXCL-1)). Notably, TXL improved neurological deficits, protected neurons, alleviated no-reflow and leukocyte-endothelial cell interactions, regulated multiple leukocyte subtypes, and inhibited the expression of various inflammatory mediators.

CONCLUSION

Leukocyte-endothelial cell interactions mediated by multiple inflammatory factors are an important cause of no-reflow in stroke. Accordingly, TXL could alleviate no-reflow via suppressing the interactions through modulating various leukocyte subtypes and inhibiting the expression of multiple inflammatory mediators.

Intervention effects of traditional Chinese medicine on stem cell therapy of myocardial infarction

Cardiovascular diseases are the leading cause of global mortality, in which myocardial infarction accounts for 46% of total deaths. Although good progress has been achieved in medication and interventional techniques, a proven method to repair the damaged myocardium has not yet been determined. Stem cell therapy for damaged myocardial repair has evolved into a promising treatment for ischemic heart disease. However, low retention and poor survival of the injected stem cells are the major obstacles to achieving the intended therapeutic effects. Chinese botanical and other natural drug substances are a rich source of effective treatment for various diseases. As such, numerous studies have revealed the role of Chinese medicine in stem cell therapy for myocardial infarction treatment, including promoting proliferation, survival, migration, angiogenesis, and differentiation of stem cells. Here, we discuss the potential and limitations of stem cell therapy, as well as the regulatory mechanism of Chinese medicines underlying stem cell therapy. We focus on the evidence from pre-clinical trials and clinical practices, and based on traditional Chinese medicine theories, we further summarize the mechanisms of Chinese medicine treatment in stem cell therapy by the commonly used prescriptions. Despite the pre-clinical evidence showing that traditional Chinese medicine is helpful in stem cell therapy, there are still some limitations of traditional Chinese medicine therapy. We also systematically assess the detailed experimental design and reliability of included pharmacological research in our review. Strictly controlled animal models with multi-perspective pharmacokinetic profiles and high-grade clinical evidence with multi-disciplinary efforts are highly demanded in the future.

Tongxinluo prevents chronic obstructive pulmonary disease complicated with atherosclerosis by inhibiting ferroptosis and protecting against pulmonary microvascular barrier dysfunction

Cardiovascular comorbidities are pervasive in chronic obstructive pulmonary disease (COPD) and often result in serious adverse cardiovascular events. Tongxinluo (TXL) has been clinically verified to treat atherosclerosis (AS), improve lung function and alleviate dyspnoea. The present study aimed to explore the effect of lung microvascular barrier dysfunction on AS in COPD and the potential pulmonary protective mechanisms of TXL in COPD complicated with AS. COPD complicated with AS was induced in mice by cigarette smoke (CS) exposure and high-fat diet (HFD) feeding. The mice were treated with atorvastatin (ATO), TXL or combination therapy (ATO+TXL) for 20 weeks. Pulmonary function, lung pathology, serum lipid levels, atherosclerotic plaque area and indicators of barrier function, oxidative stress and ferroptosis in lung tissue were evaluated. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL for 4 h and then incubated with cigarette smoke extract (CSE) and homocysteine (Hcy) for 36 h to induce barrier dysfunction. Then the indicators of barrier function, oxidative stress and ferroptosis were measured. The results demonstrate that CS aggravated dyslipidaemia, atherosclerotic plaque formation, pulmonary function decline, pathological injury, barrier dysfunction, oxidative stress and ferroptosis in the HFD-fed mice. However, these abnormalities were partially reversed by ATO and TXL. Similar results were observed in vitro. In conclusion, pulmonary microvascular barrier dysfunction plays an important role by which COPD affects the progression of AS, and ferroptosis may be involved. Moreover, TXL delays the progression of AS and reduces cardiovascular events by protecting the pulmonary microvascular barrier and inhibiting ferroptosis.

China Tongxinluo Study for myocardial protection in patients with Acute Myocardial Infarction (CTS-AMI): Rationale and design of a randomized, double-blind, placebo-controlled, multicenter clinical trial

Acute ST-segment elevation myocardial infarction (STEMI) remains a serious life-threatening event. Despite coronary revascularization, patients might still suffer from poor outcomes caused by myocardial no-reflow and ischemic/reperfusion injury. Tongxinluo (TXL), a traditional Chinese medicine, has been preliminarily demonstrated to reduce myocardial no-reflow and ischemic/reperfusion injury. We further hypothesize that TXL treatment is also effective in reducing clinical end points for the patients with STEMI. METHODS AND RESULTS: The CTS-AMI trial is a prospective, randomized, double-blind, placebo-controlled, multicenter clinical study in China. An estimated 3,796 eligible patients with STEMI from about 120 centers are randomized 1:1 ratio to TXL or placebo groups. All enrolled patients are orally administrated a loading dose of 8 capsules of TXL or placebo together with dual antiplatelet agents on admission followed by 4 capsules 3 times a day until 12 months. The primary end point is 30-day major adverse cardiovascular and cerebrovascular events, a composite of cardiac death, myocardial reinfarction, emergency coronary revascularization, and stroke. Secondary end points include each component of the primary end point, 1-year major adverse cardiovascular and cerebrovascular events, and other efficacy and safety parameters. CONCLUSIONS: Results of CTS-AMI trial will determine the clinical efficacy and safety of traditional Chinese medicine TXL capsule in the treatment of STEMI patients in the reperfusion era.

Tongxinluo attenuates oxygen-glucose-serum deprivation/restoration-induced endothelial barrier breakdown via peroxisome proliferator activated receptor-α/angiopoietin-like 4 pathway in high glucose-incubated human cardiac microvascular endothelial cells

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.

Evaluating Novel Targets of Ischemia Reperfusion Injury in Pig Models

Coronary heart diseases are of high relevance for health care systems in developed countries regarding patient numbers and costs. Disappointingly, the enormous effort put into the development of innovative therapies and the high numbers of clinical studies conducted are counteracted by the low numbers of therapies that become clinically effective. Evidently, pre-clinical research in its present form does not appear informative of the performance of treatments in the clinic and, even more relevant, it appears that there is hardly any consent about how to improve the predictive capacity of pre-clinical experiments. According to the steadily increasing relevance that pig models have gained in biomedical research in the recent past, we anticipate that research in pigs can be highly predictive for ischemia-reperfusion injury (IRI) therapies as well. Thus, we here describe the significance of pig models in IRI, give an overview about recent developments in evaluating such models by clinically relevant methods and present the latest insight into therapies applied to pigs under IRI.

Tongxinluo Improves Apolipoprotein E-Deficient Mouse Heart Function

Background:

Our previous studies have shown that Tongxinluo (TXL), a compound Chinese medicine, can decrease myocardial ischemia-reperfusion injury, protect capillary endothelium function, and lessen cardiac ventricle reconstitution in animal models. The aim of this study was to illuminate whether TXL can improve hypercholesterolemia-impaired heart function by protecting artery endothelial function and increasing microvascular density (MVD) in heart. Furthermore, we will explore the underlying molecular mechanism of TXL cardiovascular protection.

Methods:

After intragastric administration of TXL (0.1 ml/10 g body weight) to C57BL/6J wild-type mice (n = 8) and ApoE-/- mice (n = 8), total cholesterol, high-density lipoprotein-cholesterol, very-low-density lipoprotein (VLDL)-cholesterol, triglyceride, and blood glucose levels in serum were measured. The parameters of heart rate (HR), left ventricular diastolic end diameter, and left ventricular systolic end diameter were harvested by ultrasonic cardiogram. The left ventricular ejection fraction, stroke volume, cardiac output, and left ventricular fractional shortening were calculated. Meanwhile, aorta peak systolic flow velocity (PSV), end diastolic flow velocity, and mean flow velocity (MFV) were measured. The pulsatility index (PI) and resistant index were calculated in order to evaluate the vascular elasticity and resistance. The endothelium-dependent vasodilatation was evaluated by relaxation of aortic rings in response to acetylcholine. Western blotting and real-time quantitative reverse transcription polymerase chain reaction were performed for protein and gene analyses of vascular endothelial growth factor (VEGF). Immunohistochemical detection was performed for myocardial CD34 expression. Data in this study were compared by one-way analysis of variance between groups. A value of P < 0.05 was considered statistically significant.

Results:

Although there was no significant decrease of cholesterol level (F = 2.300, P = 0.240), TXL inhibited the level of triglyceride and VLDL (F = 9.209, P = 0.024 and F = 9.786, P = 0.020, respectively) in ApoE-/- mice. TXL improved heart function of ApoE-/- mice owing to the elevations of LVEF, SV, CO, and LVFS (all P < 0.05). TXL enhanced aortic PSV and MFV (F = 10.774, P = 0.024 and F = 11.354, P = 0.020, respectively) and reduced PI of ApoE-/- mice (1.41 ± 0.17 vs. 1.60 ± 0.17; P = 0.037). After incubation with 10 μmol/L acetylcholine, the ApoE-/- mice treated with TXL aortic segment relaxed by 44% ± 3%, significantly higher than control group mice (F = 9.280, P = 0.040). TXL also restrain the angiogenesis of ApoE-/- mice aorta (F = 21.223, P = 0.010). Compared with C57BL/6J mice, the MVD was decreased in heart tissue of untreated ApoE-/- mice (54.0 ± 3.0/mm²vs. 75.0 ± 2.0/mm²; F = 16.054, P = 0.010). However, TXL could significantly enhance MVD (65.0 ± 5.0/mm²vs. 54.0 ± 3.0/mm²; F = 11.929, P = 0.020) in treated ApoE-/- mice. In addition, TXL obviously increased the expression of VEGF protein determined by Western blot (F = 20.247, P = 0.004).

Conclusions:

TXL obviously improves the ApoE-/- mouse heart function from different pathways, including reduces blood fat to lessen atherosclerosis; enhances aortic impulsivity, blood supply capacity, and vessel elasticity; improves endothelium-dependent vasodilatation; restraines angiogenesis of aorta-contained plaque; and enhances MVD of heart. The molecular mechanism of MVD enhancement maybe relate with increased VEGF expression.

Potential Effectiveness of Chinese Patent Medicine Tongxinluo Capsule for Secondary Prevention After Acute Myocardial Infarction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Chinese patent medicine Tongxinluo capsule (TXL) is commonly used for cardio-cerebrovascular diseases. Previous research had demonstrated that TXL exhibited great clinical effects on the treatment of acute myocardial infarction (AMI), however there is a lack of systematic review. The purpose of this study was to evaluate the potential effectiveness and safety of TXL for secondary prevention in patients with AMI. Method: We searched 6 databases to identify relevant randomized controlled trials (RCTs) from inceptions to December 30, 2017. Two review authors independently assessed the methodological quality and analyzed data by the RevMan 5.3 software. The publication bias was assessed through funnel plot and Begg's test. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used for evaluating the quality of evidence. Results: We included 19 RCTs in this review and performed a meta-analysis based on 16 studies. There were statistical differences of TXL treatment group in reducing primary cardiovascular events (cardiac death [RR = 0.27, 95%CI: 0.08~0.95, I2 = 0%], recurrent myocardial reinfarction [RR = 0.38, 95%CI: 0.20~0.74, I2 = 0%], arrhythmia [RR = 0.44, 95%CI: 0.30~0.66, I2 = 0%], recurrent angina pectoris [RR = 0.34, 95%CI: 0.17~0.69, I2 = 0%]). TXL could improve cardiac function (LVEF [MD = 4.10, 95%CI: 3.95~4.25, I2 = 0%]), regulate blood lipid TC [MD = -0.66, 95%CI: -0.94 ~ -0.37, I2 = 74%], TG [MD = -0.38, 95%CI: -0.62 ~ -0.14, I2 = 70%], LDL-C[-0.40, 95%CI: -0.65 ~ -0.16, I2 = 88%), decrease the level of hs-CRP (4-week: MD = -0.78, 95%CI: -0.97 ~ -0.60, I2 = 20%; Over 4-week: MD = -1.36, 95%CI: -1.55 ~ -1.17, I2 = 20%). However, TXL has little effects on revascularization [RR = 0.45, 95%CI: 0.13~1.56, I2 = 0%], recurrent heart failure (RR = 0.83, 95%CI: 0.27~2.57, I2 = 0%), and HDL-C (MD = 0.14, 95%CI: 0.00 ~0.29, I2 = 73%). Furthermore, TXL treatment group was more prone to suffer gastrointestinal discomfort. Conclusion: Chinese patent medicine TXL seemed beneficial for secondary prevention after AMI. This potential benefit needs to be further assessed through more rigorous RCTs. Systematic review registration number in the PROSPERO register: CRD42017068417.

Tongxinluo attenuates reperfusion injury in diabetic hearts by angiopoietin-like 4-mediated protection of endothelial barrier integrity via PPAR-α pathway

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.

Tongxinluo mitigates atherogenesis by regulating angiogenic factors and inhibiting vasa vasorum neovascularization in apolipoprotein E-deficient mice

Vasa vasorum (VV) neovascularization contributes to atherogenesis and its expansion and distribution is correlated with intraplaque expression of angiogenic factors. The present study investigated the roles of Tongxinluo (TXL), a traditional Chinese medication, on VV proliferation and atherogenesis. In vitro, TXL pre-treatment reversed the tumor necrosis factor-a (TNF-a) induced expression of vascular endothelial growth factor A (VEGF-A) and angiopoietin-1 (ANGPT-1) but not ANGPT-2, leading to increased ratio of ANGPT-1 to ANGPT-2. Consistently, TXL treatment (at a dosage of 0.38, 0.75, 1.5 g/kg/d, respectively) decreased the expression of VEGF-A while increased that of ANGPT-1 in early atherosclerotic lesions of apolipoprotein E deficient (apoE−/−) mice. On aortic ring assay, microvessels sprouting from aortas were significantly inhibited in TXL-treated mice. Moreover, VV neovascularization in plaques was markedly reduced with TXL treatment. Histological and morphological analysis demonstrated that TXL treatment reduced plaque burden, plaque size and changed the plaque composition. These data suggest that TXL inhibits early atherogenesis through regulating angiogenic factor expression and inhibiting VV proliferation in atherosclerotic plaque. Our study shed new light on the anti-atherosclerotic effect of TXL.

Inhibition of miR-128-3p by Tongxinluo Protects Human Cardiomyocytes from Ischemia/reperfusion Injury via Upregulation of p70s6k1/p-p70s6k1

Background and Aims: Tongxinluo (TXL) is a multifunctional traditional Chinese medicine that has been widely used to treat cardiovascular and cerebrovascular diseases. However, no studies have explored whether TXL can protect human cardiomyocytes (HCMs) from ischemia/reperfusion (I/R) injury. Reperfusion Injury Salvage Kinase (RISK) pathway activation was previously demonstrated to protect the hearts against I/R injury and it is generally activated via Akt or (and) Erk 1/2, and their common downstream protein, ribosomal protein S6 kinase (p70s6k). In addition, prior studies proved that TXL treatment of cells promoted secretion of VEGF, which could be stimulated by the increased phosphorylation of one p70s6k subtype, p70s6k1. Consequently, we hypothesized TXL could protect HCMs from I/R injury by activating p70s6k1 and investigated the underlying mechanism.

Methods and Results: HCMs were exposed to hypoxia (18 h) and reoxygenation (2 h) (H/R), with or without TXL pretreatment. H/R reduced mitochondrial membrane potential, increased bax/bcl-2 ratios and cytochrome C levels and induced HCM apoptosis. TXL preconditioning reversed these H/R-induced changes in a dose-dependent manner and was most effective at 400 μg/mL. The anti-apoptotic effect of TXL was abrogated by rapamycin, an inhibitor of p70s6k. However, inhibitors of Erk1/2 (U0126) or Akt (LY294002) failed to inhibit the protective effect of TXL. TXL increased p70s6k1 expression and, thus, enhanced its phosphorylation. Furthermore, transfection of cardiomyocytes with siRNA to p70s6k1 abolished the protective effects of TXL. Among the micro-RNAs (miR-145-5p, miR-128-3p and miR-497-5p) previously reported to target p70s6k1, TXL downregulated miR-128-3p in HCMs during H/R, but had no effects on miR-145-5p and miR-497-5p. An in vivo study confirmed the role of the p70s6k1 pathway in the infarct-sparing effect of TXL, demonstrating that TXL decreased miR-128-3p levels in the rat myocardium during I/R. Transfection of HCMs with a hsa-miR-128-3p mimic eliminated the protective effects of TXL.

Conclusions: The miR-128-3p/p70s6k1 signaling pathway is involved in protection by TXL against HCM apoptosis during H/R. Overexpression of p70s6k1 is, therefore, a potential new strategy for alleviating myocardial reperfusion injury.

Tongxinluo Regulates Expression of Tight Junction Proteins and Alleviates Endothelial Cell Monolayer Hyperpermeability via ERK-1/2 Signaling Pathway in Oxidized Low-Density Lipoprotein-Induced Human Umbilical Vein Endothelial Cells

Vascular hyperpermeability resulting from distortion of endothelial junctions is associated with a number of cardiovascular diseases. Endothelial tight junction regulates the paracellular permeability of macromolecules, a function of Human Umbilical Vein Endothelial Cells (HUVEC) monolayers that can be regulated by oxidized Low-density Lipoprotein (ox-LDL). However, the understanding of drug regulation of vascular hyperpermeability is so far limited. This study thus aimed to investigate the role of Tongxinluo (TXL) in the maintenance of the vascular endothelial paracellular permeability. Here, changes in permeability were determined by measuring the paracellular flux of FITC-dextran 40000 (FD40), while protein expression and intercellular distribution were examined by western blot and immunofluorescence assay, respectively. We found that TXL alleviated the ox-LDL-induced increase in flux of FD40 and then reduced the hyperpermeability. Moreover, ox-LDL-induced disruptions of ZO-1, occludin, and claudin1 were also restored. This is via the activation of ERK1/2 in the vascular endothelial cells. Our results provide insights into the molecular mechanism by which TXL alleviates ox-LDL-induced hyperpermeability and provide the basis for further investigations of TXL as regulators of vascular barrier function.

Protective effects of Tongxinluo on cerebral ischemia/reperfusion injury related to Connexin 43/Calpain II/Bax/Caspase-3 pathway in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Tongxinluo (TXL) is a multifunctional traditional Chinese medicine and has been widely used in the treatment of cardiovascular and cerebrovascular diseases. Numerous studies demonstrate that TXL is a novel neuroprotective drug, however, the mechanisms are largely unknown.

AIM OF THE STUDY

we aimed to demonstrate the protective effect of TXL on cerebral ischemia/reperfusion (I/R) injury and provide the evidence for the involvement of Connexin 43/Calpain II/ Bax/Caspase-3 pathway in TXL-mediated neuroprotection.

METHODS

Focal cerebral I/R injury were induced by transient middle cerebral artery occlusion (MCAO, for 90min) in adult male Sprague-Dawley rats. We estimated the effects of TXL on I/R injury including neurological deficit assessment and cerebral infarct volume measurement via TTC staining, and detected the protein expression of Connexin 43 (Cx43) by western blot. Furthermore, after the intracerebroventricular injection of carbenoxolone (CBX, the inhibitor of Cx43) at 30min before MCAO surgery, Calpain II, Bax and cleaved Caspased-3 immunoreactivity in ischemic penumbra region was detected by immunofluorescent staining, and cell apoptosis was detected by TUNEL staining.

RESULTS

TXL treatment greatly improved neurological deficit and reduced the infarction volume compared to MCAO with buffer treatment (P<0.05), and TXL pre-post treatment showed better results than TXL pre-treatment. TXL pre-post treatment significantly up-regulated Cx43 protein expression at 3d, 7d and 14d post-injury compared to MCAO with buffer treatment (P<0.05). Meanwhile, the immunoreactivity of Calpain II, Bax and cleaved Caspase-3 in ischemic penumbra region was obviously decreased by TXL pre-post treatment compared to MCAO group (P<0.05). However, with the treatment of the Cx43 inhibitor, CBX, the down-regulated effect of TXL on Calpain II, Bax and cleaved Caspase-3 immunoreactivity was abolished (P<0.05). Moreover, the protective effect of TXL against neuron apoptosis in penumbra region was conteracted by CBX (P<0.05).

CONCLUSIONS

TXL could effectively protect against I/R injury and reduced cell death via Cx43/Calpain II/Bax/Caspase-3 pathway, which contribute to I/R injury prevention and therapy.

Tongxinluo Reverses the Hypoxia-suppressed Claudin-9 in Cardiac Microvascular Endothelial Cells

Background:

Claudin-5, claudin-9, and claudin-11 are expressed in endothelial cells to constitute tight junctions, and their deficiency may lead to hyperpermeability, which is the initiating process and pathological basis of cardiovascular disease. Although tongxinluo (TXL) has satisfactory antianginal effects, whether and how it modulates claudin-5, claudin-9, and claudin-11 in hypoxia-stimulated human cardiac microvascular endothelial cells (HCMECs) have not been reported.

Methods:

In this study, HCMECs were stimulated with CoCl₂ to mimic hypoxia and treated with TXL. First, the messenger RNA (mRNA) expression of claudin-5, claudin-9, and claudin-11 was confirmed. Then, the protein content and distribution of claudin-9, as well as cell morphological changes were evaluated after TXL treatment. Furthermore, the distribution and content histone H3K9 acetylation (H3K9ac) in the claudin-9 gene promoter, which guarantees transcriptional activation, were examined to explore the underlying mechanism, by which TXL up-regulates claudin-9 in hypoxia-stimulated HCMECs.

Results:

We found that hypoxia-suppressed claudin-9 gene expression in HCMECs (F = 7.244; P = 0.011) and the hypoxia-suppressed claudin-9 could be reversed by TXL (F = 61.911; P = 0.000), which was verified by its protein content changes (F = 29.142; P = 0.000). Moreover, high-dose TXL promoted the cytomembrane localization of claudin-9 in hypoxia-stimulated HCMECs, with attenuation of cell injury. Furthermore, high-dose TXL elevated the hypoxia-inhibited H3K9ac in the claudin-9 gene promoter (F = 37.766; P = 0.000), activating claudin-9 transcription.

Conclusions:

The results manifested that TXL reversed the hypoxia-suppressed claudin-9 by elevating H3K9ac in its gene promoter, playing protective roles in HCMECs.

Clinical effect of preoperative high-dose atorvastatin against no-reflow after PCI

The aim of the present study was to evaluate the use of preoperative high-dose atorvastatin to prevent the no-reflow phenomenon after percutaneous coronary intervention (PCI). A total of 138 patients with ST-segment elevation myocardial infarction, admitted from March 2014 to January 2015, were enrolled and randomly divided into 3 groups of 46 individuals each. The groups included a control group in which patients were not treated with atorvastatin before PCI; a conventional-dose atorvastatin treatment group in which patients received a single dose of 20 mg at bedtime one day prior to PCI; and a high-dose atorvastatin treatment group in which patients were treated with 40 mg divided in two doses the day before PCI. The treatment effects were assessed by re-examining the echocardiography, high-sensitivity C-reactive protein and brain natriuretic peptide (BNP) levels after the PCI. The follow-up examinations included determinations of ultrasound imaging indicators and the contact with patients was maintained for a whole year. The CTFC (frame), pro-BNP, CK-MB peak and WMSI levels of the patients in the high-dose treatment group were significantly lower than those in the conventional dose or the control group. Trombolysis in myocardial infarction ≤2 and myocardial blush grade ≤1 levels were significantly lower than those in the conventional dose group (P=0.01) or those in the control group (P=0.01), although the echocardiographic indicators of the three groups were not significantly different (P<0.05). Nevertheless, it was found that there were significantly fewer adverse cardiovascular events in the high-dose group (P<0.05 in both cases). During the follow-up period, thromboembolism and restenosis were most infrequent in the high-dose atorvastatin group. Based on our findings the oral administration of high-dose atorvastatin before bedtime, one day before the procedure, can effectively prevent no-reflow cases, reduce adverse events and improve the long-term prognosis for acute coronary syndrome patients after PCI.