Protective effects of Danzhi jiangtang capsule on vascular endothelial damages induced by high-fat diet and palmitic acid

Physcion prevents high-fat diet-induced endothelial dysfunction by inhibiting oxidative stress and endoplasmic reticulum stress pathways

High-fat diet (HFD)-induced obesity leads endothelial dysfunction and contributes to cardiovascular diseases. Palmitic acid (PA), a free fatty acid, is the main component of dietary saturated fat. Physcion, a chemical ingredient from Rhubarb, has been shown anti-hypertensive, anti-bacteria, and anti-tumor properties. However, the effects of physcion on endothelial dysfunction under HFD-induced obesity have not been reported. The purpose of the present study was to define the protective effect of physcion on HFD-induced endothelial dysfunction and its mechanisms involved. Obesity rat model was induced by HFD for 12 weeks. A rat thoracic aortic ring model was used to investigate the effects of physcion on HFD-induced impairment of vasorelaxation. Endothelial cell injury model was constructed in human umbilical vein endothelial cells (HUVECs) by treating with PA (0.25 mM) for 24 h. The results revealed that physcion reduced body weight and the levels of plasma TG, prevented impairment of endothelium-dependent relaxation in HFD-fed rats. In PA-injured HUVECs, physcion inhibited impaired viability, apoptosis and inflammation. Physcion also suppressed PA-induced both oxidative stress and ER stress in HUVECs. Furthermore, physcion increased PA-induced decrease in the activation of eNOS/Nrf2 signaling in HUVECs. These findings suggest that physcion has a significant beneficial effect on regulating HFD-induced endothelial dysfunction, which may be related to the inhibition of oxidative stress and ER stress through activation of eNOS/Nrf2 signaling pathway.

Physiological Doses of Oleic and Palmitic Acids Protect Human Endothelial Cells from Oxidative Stress

Oxidative stress has been proposed to be a pathogenic mechanism to induce endothelial dysfunction and the onset of cardiovascular disease. Elevated levels of free fatty acids can cause oxidative stress by increasing mitochondrial uncoupling but, at physiological concentrations, they are essential for cell and tissue function and olive oil free fatty acids have proved to exhibit beneficial effects on risk factors for cardiovascular disease. We hypothesize that realistic concentrations within the physiological range of oleic (OA) and palmitic (PA) acids could be beneficial in the prevention of oxidative stress in vascular endothelium. Hence, pre-treatment and co-treatment with realistic physiological doses of palmitic and oleic acids were tested on cultured endothelial cells submitted to a chemically induced oxidative stress to investigate their potential chemo-protective effect. Cell viability and markers of oxidative status: reactive oxygen species (ROS), reduced glutathione (GSH), malondialdehyde (MDA), glutathione peroxidase (GPx) and glutathione reductase (GR) were evaluated. As a conclusion, the increased ROS generation induced by stress was significantly prevented by a pre- and co-treatment with PA or OA. Moreover, pre- and co-treatment of cells with FFAs recovered the stress-induced MDA concentration to control values and significantly recovered depleted GSH and normalized GPx and GR activities. Finally, pre- and co-treatment of cells with physiological concentrations of PA or OA in the low micromolar range conferred a substantial protection of cell viability against an oxidative insult.

In vivo and in vitro studies of Danzhi Jiangtang capsules against diabetic cardiomyopathy via TLR4/MyD88/NF-κB signaling pathway

Objectives

Danzhi Jiangtang capsule (DJC) is widely used for preventing and treating diabetic cardiomyopathy (DCM). However, the underlying mechanisms of the anti-inflammatory and antiapoptotic activities are unclear.

Methods

In the in vivo diabetic cardiomyopathy rat model, cardiac function was measured through echocardiography, histological changes in the myocardium were visualized using HE staining, and cardiomyocyte apoptosis was detected using TUNEL. The serum levels of anti-inflammatory cytokines were detected using ELISA. Finally, TLR4, MyD88, and NF-κB mRNA expressions were analyzed using RT-qPCR. In the in vitro experiments, the apoptosis rate of the H9c2 cells was detected using FCM; moreover, TLR4, MyD88 and NF-κB mRNA expressions were measured using RT-qPCR and related protein levels were investigated using Western blotting.

Results

In vivo, DJC effectively improved cardiac function, alleviated the pathological changes, and reduced the apoptosis rate. Moreover, DJC reduced TNF-α, IL-1β, and IL-6 activities, with significant inhibition of the TLR4, MyD88 and NF-κB p65 mRNA expression. Moreover, in vitro, DJC effectively inhibited high-glucose-induced H9c2 apoptosis-an effect similar to that for TAK242. Finally, both the DJC and TAK242 considerably reduced TLR4, MyD88, NF-κB, Bax, and caspase-3 protein expression but increased that of BCL-2.

Conclusions

DJC prevented the overactivation of the TLR4/MyD88/NF-κB signaling pathway and regulate cardiomyocyte apoptosis against DCM.

Cordycepin Attenuates Palmitic Acid-Induced Inflammation and Apoptosis of Vascular Endothelial Cells through Mediating PI3K/Akt/eNOS Signaling Pathway

A well-known medicinal mushroom in the field of traditional Chinese medicine, Cordyceps sinensis, is a rare natural-occurring entomopathogenic fungus, and it typically grows at high altitudes on the plateau of the Himalayan. Previous studies indicated that cordycepin, the main bioactive chemical of Cordyceps sinensis, has very potent anticancer, anti-oxidant and anti-inflammatory activities. However, its protective effects against atherosclerotic changes in vascular endothelial cells have not been fully elucidated. In this study, we showed that pretreatment with cordycepin significantly attenuated palmitic acid (PA)-induced cytotoxicity, reactive oxygen species (ROS) generation, and inflammatory responses. We found that PA decreased phosphorylation of Akt, eNOS, and bioavailability of nitric oxide (NO), which in turn activated NF-[Formula: see text]B and the downstream inflammatory responses. All these detrimental events were markedly blocked by pretreatment with cordycepin. Moreover, cordycepin ameliorated destabilization of mitochondrial permeability, cytosolic calcium rises, and apoptotic features caused by PA. In addition, all these anti-inflammatory and anti-apoptosis effects of cordycepin were found to be inhibited by the PI3K and eNOS inhibitor, suggesting that its anti-atherosclerotic effects may partially be mediated by the PI3K/Akt/eNOS signaling pathway.

Medium-, long- and medium-chain-type structured lipids ameliorate high-fat diet-induced atherosclerosis by regulating inflammation, adipogenesis, and gut microbiota in ApoE-/- mice

Accumulating evidence has suggested that medium-, long-, and medium-chain (MLM) structured lipids have anti-obesity effects, but whether they can alleviate the development of atherosclerosis (AS) and affect the composition of the gut microbiota in high-fat diet-fed ApoE-/- mice has not been elucidated. The present study found that MLM structured lipid supplementation could significantly decrease obesity-related parameters compared with high-fat diet alone in ApoE-/- mice. Additionally, MLM structured lipids could significantly decrease the blood glucose and increase the serum total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) levels. Additionally, high-dose MLM structured lipids supplementation could reduce the area of atherosclerotic lesions and decrease the expression of VCAM-1, MCP-1 and CD68, which are related to inflammation in aortic tissue. Further analysis showed that MLM structured lipids could significantly reduce lipid accumulation in the adipose tissue of high-fat diet-fed ApoE-/- mice. The relative protein expression of SREBP-1, ACC, FAS, C/EBPα and PPARγ was decreased and the ratio of p-AMPK/AMPK was increased in epididymis white adipose tissue (eWAT) after MLM structured lipids treatment. Additionally, MLM structured lipids supplementation regulated the bacterial composition, including reducing the Firmicutes/Bacteroidetes ratio, increasing the relative abundance of short-chain fatty acid-producing bacteria (Blautia and Anaerotruncus), decreasing the relative abundance of [Ruminococcus] torques group, Ruminiclostridium 9, Catenibacterium and [Eubacterium] fissicatena group. Spearman's correlation analysis revealed significant correlations between changes in the gut microbiota and atherosclerosis-related indices. The results demonstrated that the alleviating effects of MLM structured lipids supplementation on AS in high-fat diet-fed ApoE-/- mice were closely related to reshaping the composition of the gut microbiota.

Targeting the epigenome in in-stent restenosis: from mechanisms to therapy

Coronary artery disease (CAD) is one of the most common causes of death worldwide. The introduction of percutaneous revascularization has revolutionized the therapy of patients with CAD. Despite the advent of drug-eluting stents, restenosis remains the main challenge in treating patients with CAD. In-stent restenosis (ISR) indicates the reduction in lumen diameter after percutaneous coronary intervention, in which the vessel's lumen re-narrowing is attributed to the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) and dysregulation of endothelial cells (ECs). Increasing evidence has demonstrated that epigenetics is involved in the occurrence and progression of ISR. In this review, we provide the latest and comprehensive analysis of three separate but related epigenetic mechanisms regulating ISR, namely, DNA methylation, histone modification, and non-coding RNAs. Initially, we discuss the mechanism of restenosis. Furthermore, we discuss the biological mechanism underlying the diverse epigenetic modifications modulating gene expression and functions of VSMCs, as well as ECs in ISR. Finally, we discuss potential therapeutic targets of the small molecule inhibitors of cardiovascular epigenetic factors. A more detailed understanding of epigenetic regulation is essential for elucidating this complex biological process, which will assist in developing and improving ISR therapy.

Interaction of TPPP3 with VDAC1 Promotes Endothelial Injury through Activation of Reactive Oxygen Species

Endothelial injury plays a critical role in the pathogenesis of cardiovascular disorders and metabolic-associated vascular complications which are the leading cause of death worldwide. However, the mechanism underlying endothelial dysfunction is not completely understood. The study is aimed at investigating the role of tubulin polymerization-promoting protein family member 3 (TPPP3) in palmitic acid- (PA-) induced endothelial injury. The effect of TPPP3 on human umbilical vein endothelial cells (HUVECs) was determined by evaluating apoptosis, tube formation, and reactive oxygen species (ROS) production. TPPP3 silencing inhibited PA overload-induced apoptosis and production of ROS, along with the alteration of apoptosis-related key proteins such as BCL-2 and Bax. Mechanically, voltage-dependent anion channel 1 (VDAC1) was identified as a novel functional binding partner of TPPP3, and TPPP3 promoted VDAC1 protein stability and its activity. Further studies indicated that TPPP3 could promote apoptosis, ROS production, tube formation, and proapoptotic protein expression and reduce antiapoptotic protein expression through increasing VDAC1 expression under mildly elevated levels of PA. Collectively, these results demonstrated that TPPP3 could promote PA-induced oxidative damage in HUVECs via a VDAC1-dependent pathway, suggesting that TPPP3 might be considered as a potential therapeutic target in vascular disease.

Radix pseudostellariae of Danzhi Jiangtang capsule relieves oxidative stress of vascular endothelium in diabetic macroangiopathy

Aim

Medicinal plants act as an alternative source of anti-diabetic agents. Recently, Danzhi Jiangtang capsule (DJC) has been clinically used for treatment of diabetes, but the effect of DJC on diabetic macroangiopathy remained unclear. The present study investigates the therapeutic role of DJC in diabetic macroangiopathy and elucidates the underlying mechanisms.

Methods

Diabetes patients were treated with DJC for 20 weeks. Blood glucose and serum parameters (insulin, FFA, SOD, GSH-Px, MDA, NO) were determined before and after treatment. Streptozotocin -induced diabetic rat model and human HUVECs cells were applied to assess the anti-oxidative capacity of DJC and its bioactive constituents. The expression levels of eNOS, JNK, GRP78, CHOP, Bcl2, and BAX were measured by qPCR and/or immunoblotting.

Results

Diabetic macroangiopathy were ameliorated by DJC administration. Radix pseudostellariae (RP) mediated the anti-oxidative stress capacity of DJC, which improved insulin resistance (p < 0.01) and relieved oxidative stress (p < 0.01) of vascular endothelium through oxidative stress signaling and apoptosis pathway. The ability of DJC to ameliorate diabetic macroangiopathy and relieve oxidative stress was mainly mediated by its bioactive constituent RP.

Conclusion

This study would provide experimental evidence for DJC in the prevention and treatment of diabetes and diabetic macroangiopathy.

Sirtuins family as a target in endothelial cell dysfunction: implications for vascular ageing

The vascular endothelium is a protective barrier between the bloodstream and the vasculature that may be disrupted by different factors such as the presence of diseased states. Diseases like diabetes and obesity pose a great risk toward endothelial cell inflammation and oxidative stress, leading to endothelial cell dysfunction and thereby cardiovascular complications such as atherosclerosis. Sirtuins are NAD⁺-dependent histone deacetylases that are implicated in the pathophysiology of cardiovascular diseases, and they have been identified to be important regulators of endothelial cell function. A handful of recent studies suggest that disbalance in the regulation of endothelial sirtuins, mainly sirtuin 1 (SIRT1), contributes to endothelial cell dysfunction. Herein, we summarize how SIRT1 and other sirtuins may contribute to endothelial cell function and how presence of diseased conditions may alter their expressions to cause endothelial dysfunction. Moreover, we discuss how the beneficial effects of exercise on the endothelium are dependent on SIRT1. These mainly include regulation of signaling pathways related to endothelial nitric oxide synthase phosphorylation and nitric oxide production, mitochondrial biogenesis and mitochondria-mediated apoptotic pathways, oxidative stress and inflammatory pathways. Sirtuins as modulators of the adverse conditions in the endothelium hold a promising therapeutic potential for health conditions related to endothelial dysfunction and vascular ageing.

[Effect of traditional Chinese medicine for replenishing qi, nourishing yin and activating blood on renal Notch/Hes1 signaling in rats with diabetic nephropathy]

OBJECTIVE

To observe the effects of a traditional Chinese medicine (TCM) capsule for replenishing qi, nourishing yin and activating blood on Notch/Hes1 signaling pathway in the renal tissue and vascular endothelial CD34 and CD144 expressions in a rat model of diabetic nephropathy.

METHODS

Rat models of early-stage diabetic nephropathy were established by left nephrectomy and high- fat and high- sugar feeding combined with intraperitoneal injection of STZ. The rats were randomized into model group, benazepril group, and high-, moderate-, and low-dose TCM capsule groups for corresponding treatments, with 6 normal rats as the control group. After 8 weeks of drug treatment, blood glucose and 24-h urinary albumin of the rats were measured, and the renal histopathology was observed with HE staining; Hes1 expression in the renal tissue was detected with immunohistochemical staining, and the renal expressions of CD34 and CD144 were detected using Western blotting.

RESULTS

Compared with the normal control group, the rat models of diabetic nephropathy showed obvious abnormalities in 24- h urinary albumin and expressions of Hes1, CD34 and CD144d. The TCM capsule at both the high and moderate doses significantly reduced 24-h urinary albumin in the rats; the renal expressions of Hes1 and CD34 was significantly reduced in all the dose groups, and the expression of CD144 was significantly reduced in the high- dose group. Compared with benazepril group, the TCM capsule obviously reduced CD34 expression at all the 3 doses and lowered CD144 expression at the low dose. Histopathologically, the rats in the model group showed glomerular hypertrophy, increased mesenteric matrix, thickening and widening of the mesenteric membrane, and nodular hyperplasia. These pathologies were obviously alleviated by treatment with the TCM capsule at the high and moderate doses.

CONCLUSIONS

The Traditional Chinese medicine (TCM) capsule for replenishing qi, nourishing yin and activating blood can reduce Hes1, CD34 and CD144 in kidney tissue of model rats, play a protective role on kidney function and delay the development of DN.

Exosomes derived from mangiferin‑stimulated perivascular adipose tissue ameliorate endothelial dysfunction

Perivascular adipose tissue (PVAT) is considered to serve a vital role during the development of endothelial dysfunction. The current study investigated the effect of exosomes derived from mangiferin-stimulated PVAT on endothelial function, including regeneration, migration, apoptosis and inflammation. The number of exosomes secreted by PVAT was increased by stimulation with mangiferin (0.1, 1 or 10 µM), and uptake of these exosomes by endothelial cells was observed. Exosomes produced by stimulation of PVAT with mangiferin reversed the effects of inflammation-induced endothelial dysfunction following palmitic acid (PA) treatment. Furthermore, nuclear factor (NF)-κB signaling in endothelial cells was significantly increased when treated with PA-induced PVAT-derived exosomes, whereas exosomes from the supernatant of PVAT stimulated with mangiferin reduced p65 and p50 phosphorylation levels in the cells, and inhibited p65 transportation to the nucleus. Taken together, the present study demonstrated that exosomes derived from mangiferin-stimulated PVAT supernatant inhibited inflammation-induced endothelial dysfunction via modulation of NF-κB signaling.

Chronic stress: a crucial promoter of cell apoptosis in atherosclerosis

Objective

Chronic stress may lead to augmented incidence rates of coronary and cerebrovascular diseases associated with atherosclerosis. However, few studies have focused on the effect of chronic stress on atherosclerosis plaque formation. Therefore, this study was designed to directly evaluate how chronic stress affects atherosclerosis.

Methods

Thirty rabbits were divided into three groups: the control group, balloon-injury operation + high-fat diet model group, and chronic stress + balloon-injury operation + high-fat diet model group. Physical and social stress were induced, and proteomic methods were applied to identify specific markers.

Results

After protein determination, the chronic stress + balloon-injury operation + high-fat diet model group exhibited significant upregulation of the following apoptosis-related proteins: UBE2K, caspase 3, caspase 9, BAX, P53, and FAS. In particular, real-time polymerase chain reaction showed that the protein expression of caspase 9 was significantly downregulated in the stress group compared with the non-stress groups. However, the other proteins showed significantly increased expression in the stress group.

Conclusion

Chronic stress may promote cell apoptosis in the physiopathologic process of atherosclerosis.