Astragaloside IV improves the isoproterenol-induced vascular dysfunction via attenuating eNOS uncoupling-mediated oxidative stress and inhibiting ROS-NF-κB pathways

Review on the protective mechanism of astragaloside IV against cardiovascular diseases

Cardiovascular disease is a global health problem. Astragaloside IV (AS-IV) is a saponin compound extracted from the roots of the Chinese herb Astragalus. Over the past few decades, AS-IV has been shown to possess various pharmacological properties. It can protect the myocardium through antioxidative stress, anti-inflammatory effects, regulation of calcium homeostasis, improvement of myocardial energy metabolism, anti-apoptosis, anti-cardiomyocyte hypertrophy, anti-myocardial fibrosis, regulation of myocardial autophagy, and improvement of myocardial microcirculation. AS-IV exerts protective effects on blood vessels. For example, it can protect vascular endothelial cells through antioxidative stress and anti-inflammatory pathways, relax blood vessels, stabilize atherosclerotic plaques, and inhibit the proliferation and migration of vascular smooth muscle cells. Thus, the bioavailability of AS-IV is low. Toxicology indicates that AS-IV is safe, but should be used cautiously in pregnant women. In this paper, we review the mechanisms of AS-IV prevention and treatment of cardiovascular diseases in recent years to provide a reference for future research and drug development.

Magnesium ions improve vasomotor function in exhausted rats

To observe the effect of magnesium ion on vascular function in rats after long-term exhaustive exercise. Forty male SD rats were divided into two groups, the control group (CON group, n = 20) and the exhaustive exercise group (EEE group, n = 20). Exhausted rats performed 1W adaptive swimming exercise (6 times/W, 15min/time), and then followed by 3W formal exhaustive exercise intervention. Hematoxylin and eosin (HE) staining was used to detect the morphological changes of rat thoracic aorta. The contents of interleukin-1 β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum of rats were determined by enzyme-linked immunosorbent assay (ELISA), and the contents of malondialdehyde (MDA), reactive oxygen species (ROS), nitric oxide (NO) and endothelin 1 (ET-1) in serum of rats were determined by biochemical kit. Vascular ring test detects vascular function. Compared with the CON group, the smooth muscle layer of the EEE group became thicker, the cell arrangement was disordered, and the integrity of endothelial cells was destroyed; the serum Mg2+ in EEE group was decreased; the serum levels of IL-1β, TNF-α, MDA and ROS in EEE group were significantly higher than those in the CON group (P are all less than 0.05); the serum NO content in EEE group was significantly decreased, and the ratio of NO/ET-1 was significantly decreased. In the exhaustion group, the vasoconstriction response to KCl was increased, and the relaxation response to Ach was weakened, while 4.8mM Mg2+ could significantly improve this phenomenon (P are all less than 0.01). The damage of vascular morphology and function in rats after exhaustion exercise may be related to the significant increase of serum IL-1β, TNF-α, ROS, MDA and ET-1/NO ratio in rats after exhaustion exercise, while Mg2+ can significantly improve the vasomotor function of rats after exhaustion exercise.

A novel Nanocellulose-Gelatin-AS-IV external stent resists EndMT by activating autophagy to prevent restenosis of grafts

Vein grafts are widely used for coronary artery bypass grafting and hemodialysis access, but restenosis remains the "Achilles' heel" of these treatments. An extravascular stent is one wrapped around the vein graft and provides mechanical strength; it can buffer high arterial pressure and secondary vascular dilation of the vein to prevent restenosis. In this study, we developed a novel Nanocellulose-gelatin hydrogel, loaded with the drug Astragaloside IV (AS-IV) as an extravascular scaffold to investigate its ability to reduce restenosis. We found that the excellent physical and chemical properties of the drug AS-IV loaded Nanocellulose-gelatin hydrogel external stent limit graft vein expansion and make the stent biocompatible. We also found it can prevent restenosis by resisting endothelial-to-mesenchymal transition (EndMT) in vitro. It does so by activating autophagy, and AS-IV can enhance this effect both in vivo and in vitro. This study has added to existing research on the mechanism of extravascular stents in preventing restenosis of grafted veins. Furthermore, we have developed a novel extravascular stent for the prevention and treatment of restenosis. This will help optimize the clinical treatment plan of external stents and improve the prognosis in patients with vein grafts.

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The NC-Gelatin extravascular stent has suitable physicochemical properties to prevent restenosis of the grafted veins.

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The NC-Gelatin extravascular stent has excellent biocompatibility, which is critical for grafting veins.

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The NC-Gelatin extravascular stent prevents restenosis by activating autophagy against EndMT.

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AS-IV can enhance the effect of the stent to activate autophagy against EndMT.

Remodeling of the Neurovascular Unit Following Cerebral Ischemia and Hemorrhage

Formulated as a group effort of the stroke community, the transforming concept of the neurovascular unit (NVU) depicts the structural and functional relationship between brain cells and the vascular structure. Composed of both neural and vascular elements, the NVU forms the blood-brain barrier that regulates cerebral blood flow to meet the oxygen demand of the brain in normal physiology and maintain brain homeostasis. Conversely, the dysregulation and dysfunction of the NVU is an essential pathological feature that underlies neurological disorders spanning from chronic neurodegeneration to acute cerebrovascular events such as ischemic stroke and cerebral hemorrhage, which were the focus of this review. We also discussed how common vascular risk factors of stroke predispose the NVU to pathological changes. We synthesized existing literature and first provided an overview of the basic structure and function of NVU, followed by knowledge of how these components remodel in response to ischemic stroke and brain hemorrhage. A greater understanding of the NVU dysfunction and remodeling will enable the design of targeted therapies and provide a valuable foundation for relevant research in this area.

Astragalus Mongholicus: A review of its anti-fibrosis properties

Background: Fibrosis-related diseases (FRD) include cerebral fibrosis, pulmonary fibrosis, cardiac fibrosis, liver fibrosis, renal fibrosis, peritoneal fibrosis, etc. The effects of fibrosis can be severe, resulting in organ dysfunction, functional decline, and even organ failure, which can cause serious health problems.

Aim: Currently, there is no effective modern medicine for anti-fibrosis in the clinics; however, Chinese medicine has a certain beneficial effect on treating such diseases. Astragalus Mongholicus (AM) has rich medicinal value, and its anti-fibrosis effect has been recently investigated. In recent years, more and more experimental studies have been conducted on the intervention of astragaloside IV (AS-IV), astragalus polysaccharide (APS), astragalus flavone, cycloastragalus alcohol, astragalus water extract and other pharmacological components in fibrosis-related diseases, attracting the interest of researchers. We aim to provide ideas for future research by summarizing recent research advances of AM in treating fibrosis-related diseases.

Methods: A literature search was conducted from the core collections of electronic databases such as Baidu Literature, Sciencen.com, Google Scholar, PubMed, and Science Direct using the above keywords and the pharmacological and phytochemical details of the plant.

Results: AM can be used to intervene in fibrosis-disease progression by regulating inflammation, oxidative stress, the immune system, and metabolism.

Conclusion: AS-IV, APS, and astragalus flavone were studied and discussed in detail. These components have high potential anti-fibrosis activity. Overall, this review aims to gain insight into the AM’s role in treating fibro-related diseases.

Astragaloside IV promotes pharmacological effect of Descurainia sophia seeds on isoproterenol-induced cardiomyopathy in rats by synergistically modulating the myosin motor

Descurainia sophia seeds (DS), Astragalus mongholicus (AM), and their formulas are widely used to treat heart failure caused by various cardiac diseases in traditional Chinese medicine practice. However, the molecular mechanism of action of DS and AM has not been completely understood. Herein, we first used mass spectrometry coupled to UPLC to characterize the chemical components of DS and AM decoctions, then applied MS-based quantitative proteomic analysis to profile protein expression in the heart of rats with isoproterenol-induced cardiomyopathy (ISO-iCM) before and after treated with DS alone or combined with AM, astragaloside IV (AS4), calycosin-7-glucoside (C7G), and Astragalus polysaccharides (APS) from AM. We demonstrated for the first time that DS decoction alone could reverse the most of differentially expressed proteins in the heart of the rats with ISO-iCM, including the commonly recognized biomarkers natriuretic peptides (NPPA) of cardiomyopathy and sarcomeric myosin light chain 4 (MYL4), relieving ISO-iCM in rats, but AM did not pronouncedly improve the pharmacological efficiency of DS. Significantly, we revealed that AS4 remarkably promoted the pharmacological potency of DS by complementarily reversing myosin motor MYH6/7, and further downregulating NPPA and MYL4. In contrast, APS reduced the efficiency of DS due to upregulating NPPA and MYL4. These findings not only provide novel insights to better understanding in the combination principle of traditional Chinese medicine but also highlight the power of mass spectrometric proteomics strategy combined with conventional pathological approaches for the traditional medicine research.

Protein tyrosine nitration in atherosclerotic endothelial dysfunction

Accumulation of reactive oxygen species (ROS) can induce both protein tyrosine nitration and endothelial dysfunction in atherosclerosis. Endothelial dysfunction refers to impaired endothelium-dependent vasorelaxation that can be triggered by an imbalance in nitric oxide (NO) production and consumption. ROS reacts with NO to generate peroxynitrite, decreasing NO bioavailability. Peroxynitrite also promotes protein tyrosine nitration in vivo that can affect protein structure and function and further damage endothelial function. In this review, we discuss the process of protein tyrosine nitration, increased expression of nitrated proteins in cardiovascular disease and their association with endothelial dysfunction, and the interference of tyrosine nitration with antioxidants and the protective role in endothelial dysfunction. These may lead us to the conception that protein tyrosine nitration may be one of the causes of endothelial dysfunction, and help us gain information about the mechanism of endothelial dysfunction underlying atherosclerosis.

Polyphenols extracted from Shanxi-aged vinegar exert hypolipidemic effects on OA-induced HepG2 cells via the PPARα-LXRα-ABCA1 pathway

Hyperlipidemia is one of the key risk factors causing many chronic diseases, and lowering blood lipid levels can prevent many diseases. In this paper, a hyperlipidemic cell model of oleic acid (OA) induced hepatocellular carcinoma cells (HepG2) was established using polyphenols extracted from Shanxi-aged vinegar (SAVEP). The effects of SAVEP on nuclear damage, mitochondrial membrane potential, apoptosis, cellular lipid deposition, and lipid metabolism protein expression in HepG2 hyperlipidemic cells were examined to investigate the lipid-lowering mechanism of SAVEP at the cellular level. The results showed that SAVEP could reduce the content of TC/TG index, repair the nuclear damage, reduce lipid accumulation and finally decrease the rate of apoptosis by up-regulating the expression of key proteins such as PPARα, LXRα, and ABCA1 in the process of lipid metabolism. PRACTICAL APPLICATIONS: In this thesis, the hypolipidemic activity of polyphenol extracts from Shanxi-aged vinegar was analyzed on the level of HepG2 cells. The hypolipidemic mechanism of oxidative stress, lipid metabolism and inflammatory stress was also elucidated. It provided a theoretical basis for the in-depth understanding of the hypolipidemic health effects of Shanxi-aged vinegar.

The protective role of neuronal nitric oxide synthase in endothelial vasodilation in chronic β-adrenoceptor overstimulation

AIMS

Nitric oxide synthases (NOSs) are key enzymes regulating vascular function. Previously, we reported that β-adrenergic (β-AR) overstimulation, a common feature of cardiovascular diseases, did not impair endothelium-dependent vasodilation, although it resulted in endothelial NOS (eNOS) uncoupling and reduced NO bioavailability. In addition to NO, neuronal NOS (nNOS) produces H₂O₂, which contributes to vasodilation. However, there is limited information regarding vascular β-AR signaling and nNOS. In the present study, we assessed the possible role of nNOS-derived H₂O₂ and caveolins on endothelial vasodilation function following β-AR overstimulation.

MAIN METHODS

Male C57BL/6 wild-type and nNOS knockout mice (nNOS^-/-) were treated with the β-AR agonist isoproterenol (ISO, 15 mg·kg^-1·day^-1, s.c.) or vehicle (VHE) for seven days. Relaxation responses of aortic rings were evaluated using wire myograph and H₂O₂ by Amplex Red.

KEY FINDINGS

Acetylcholine- or calcium ionophore A23187-induced endothelium-dependent relaxation was similar in aortic rings from VHE and ISO. However, this relaxation was significantly reduced in aortas from ISO compared to VHE when (1) caveolae were disrupted, (2) nNOS was pharmacologically inhibited or genetically suppressed and (3) H₂O₂ was scavenged. NOS-derived H₂O₂ production was higher in the aortas of ISO mice than in those of VHE mice. Aortas from ISO-treated mice showed increased expression of caveolin-1, nNOS and catalase, while caveolin-3 expression did not change.

SIGNIFICANCE

The results suggest a role of caveolin-1 and the nNOS/H₂O₂ vasodilatory pathway in endothelium-dependent relaxation following β-AR overstimulation and reinforce the protective role of nNOS in cardiovascular diseases associated with high adrenergic tone.

Emerging medical therapies in crush syndrome - progress report from basic sciences and potential future avenues

Crush injury is a disease that is commonly found in victims of earthquakes, debris flows, mine disasters, explosions, terrorist attacks, local wars, and other accidents. The complications that arise due to the crush injury inflicted on victims give rise to crush syndrome (CS). If not treated in time, the mortality rate of CS is very high. The most important measure that can be taken to reduce mortality in such situations is to immediately start treatment. However, the traditional treatment methods such as fluid resuscitation, diuresis, and hemodialysis are not feasible enough to be carried out at the disaster scene. So there is a need for developing new treatments that are efficient and convenient. Because it is difficult to diagnose in the disaster area and reach the treatment equipment and treat on time. It has become a new research needs to be directed into identifying new medical treatment targets and methods using the etiology and pathophysiological mechanisms of CS. In recent years, a large number of new anti-oxidant and anti-inflammatory drug therapies have been shown to be highly efficacious in CS rat/mouse models. Some of them are expected to become specific drugs for the emergency treatment of a large number of patients who may develop CS in the aftermath of earthquakes, wars, and other disasters in the future. Hence, we have reviewed the latest research on the medical therapy of CS as a source for anyone wishing to pursue research in this direction.

Induction of autophagy via the TLR4/NF-κB signaling pathway by astragaloside Ⅳ contributes to the amelioration of inflammation in RAW264.7 cells

Cigarette smoking-related lung injury is one of the most common and fatal etiologies of many respiratory diseases, for which no effective interventions are available. Astragaloside Ⅳ (ASⅣ) is an active component extracted from Astragalus membranaceus. It is prescribed as a treatment for upper respiratory tract infections. Here, we report the potential anti-inflammatory effects and mechanisms of ASⅣ on cigarette smoking extract- (CSE)-exposed RAW264.7 cells. Murine macrophages were exposed to CSE, followed by administration of ASⅣ at 25-100 μg/mL for 24 h. ASⅣ significantly rescued CSE-induced cell death by inhibition of release pro-inflammatory cytokines. We measured autophagy as an intracellular scavenger by analyzing autophagic flux using tandem mRFP-GFP-LC3 fluorescence microscopy. Following administration with ASⅣ in CSE-exposed RAW264.7 cells, there was a notable increase in autophagosomes and a range of autophagic vacuoles were generated, as seen with transmission electron microscopy. Loss of autophagy following transfection siRNA aggravated inflammatory injury and release of inflammatory cytokines. Mechanistically, ASⅣ-triggered autophagy is mediated by the TLR4/NF-κB signaling pathway to reduce inflammation. Taken together, our findings suggest that ASⅣ acts stimulates autophagy, and that ASⅣ induces autophagy by inhibiting the TLR4/NF-κB signaling pathway, contributing to alleviation of inflammation.

Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels

Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.

Prenatal hypoxia predisposes vascular functional and structural changes associated with oxidative stress damage and depressive behavior in adult offspring male rats

Intrauterine hypoxia-ischemia (HI) provides a strong stimulus for a developmental origin of both the central nervous system and cardiovascular diseases. This study aimed to investigate vascular functional and structural changes, oxidative stress damage, and behavioral alterations in adult male offspring submitted to HI during pregnancy. The pregnant Wistar rats had a uterine artery clamped for 45 min on the 18th gestational day, submitting the offspring to hypoxic-ischemic conditions. The Sham group passed to the same surgical procedure as the HI rats, without occlusion of the maternal uterine artery, and the controls consisted of non-manipulated healthy animals. After weaning, the male pups were divided into three groups: control, sham, and HI, according to the maternal procedure. At postnatal day 90 (P90), the adult male offspring performed the open field and forced swim tests. In P119, the rats had their blood pressure checked and were euthanized. Prenatal HI induced a depressive behavior in adult male offspring associated with a reduced vasodilator response to acetylcholine in perfused mesenteric arterial bed, and reduced superoxide dismutase and glutathione peroxidase activities in the aorta compared to control and sham groups. Prenatal HI also increased the vasoconstrictor response to norepinephrine, the media thickness, collagen deposition, and the oxidative damage in the aorta from adult male offspring compared to control and sham groups. Our results suggest an association among prenatal HI and adult vascular structural and functional changes, oxidative stress damage, and depressive behavior.

Astragaloside IV: An Effective Drug for the Treatment of Cardiovascular Diseases

Cardiovascular disease (CVD), the number one cause of death worldwide, has always been the focus of clinical and scientific research. Due to the high number of deaths each year, it is essential to find alternative therapies that are safe and effective with minimal side effects. Traditional Chinese medicine (TCM) has a long history of significant impact on the treatment of CVDs. The mode of action of natural active ingredients of drugs and the development of new drugs are currently hot topics in research on TCM. Astragalus membranaceus is a commonly used Chinese medicinal herb. Previous studies have shown that Astragalus membranaceus has anti-tumor properties and can regulate metabolism, enhance immunity, and strengthen the heart. Astragaloside IV (AS-IV) is the active ingredient of Astragalus membranaceus, which has a prominent role in cardiovascular diseases. AS-IV can protect against ischemic and hypoxic myocardial cell injury, inhibit myocardial hypertrophy and myocardial fibrosis, enhance myocardial contractility, improve diastolic dysfunction, alleviate vascular endothelial dysfunction, and promote angiogenesis. It can also regulate blood glucose and blood lipid levels and reduce the risk of cardiovascular diseases. In this paper, the mechanism of AS-IV intervention in cardiovascular diseases in recent years is reviewed in order to provide a reference for future research and new drug development.

Structural and Functional Remodeling of the Brain Vasculature Following Stroke

Maintenance of cerebral blood vessel integrity and regulation of cerebral blood flow ensure proper brain function. The adult human brain represents only a small portion of the body mass, yet about a quarter of the cardiac output is dedicated to energy consumption by brain cells at rest. Due to a low capacity to store energy, brain health is heavily reliant on a steady supply of oxygen and nutrients from the bloodstream, and is thus particularly vulnerable to stroke. Stroke is a leading cause of disability and mortality worldwide. By transiently or permanently limiting tissue perfusion, stroke alters vascular integrity and function, compromising brain homeostasis and leading to widespread consequences from early-onset motor deficits to long-term cognitive decline. While numerous lines of investigation have been undertaken to develop new pharmacological therapies for stroke, only few advances have been made and most clinical trials have failed. Overall, our understanding of the acute and chronic vascular responses to stroke is insufficient, yet a better comprehension of cerebrovascular remodeling following stroke is an essential prerequisite for developing novel therapeutic options. In this review, we present a comprehensive update on post-stroke cerebrovascular remodeling, an important and growing field in neuroscience, by discussing cellular and molecular mechanisms involved, sex differences, limitations of preclinical research design and future directions.

The detailed biological investigations about combined effects of novel polyphenolic and photo-plasmonic nanoparticles loaded graphene nanosheets on coronary endothelial cells and isolated rat aortic rings

In this study, the effect of Polyp-Au-GO nanocomposite on VSMC proliferation, cell cycle proteins, down-regulation of mRNA in the rat was tested. Briefly, Polyp-Au-GO composite material was synthesized and characterized by UV-Vis spectra, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Polyp-Au-GO composite exhibited the absorbance peak at 530 nm. XRD analysis confirmed the crystalline particle with size ranging between 16.5 and 32.6 nm. The crystallinity differences of the nanocomposite were examined by Raman spectroscopy analysis. The presence of a strong band (1500 cm^-1) and the absence of other lower frequency bands confirmed that the absence of crystallinity of Polyp-Au-GO nanocomposite. The thermal properties of Polyp-Au-GO nanocomposite were determined by TGA analysis. The results revealed that 15% of its weight loss has occurred at 300 °C. Further, the growth of VSMCs was inhibited by the treatment of Polyp-Au-GO composite at 72 h. The IC₅₀ value was registered at 0.57 μg/mL. Additionally, the Polyp-Au-GO composite arrest G1 cell cycle and down-regulated cell cycle proteins. These Polyp-Au-GO composite also reduced the extracellular ERK1/2 phosphorylation. Furthermore, Polyp-Au-GO composite inhibited TNF-R-evoked inflammatory responses. Moreover, Polyp-Au-GO composite inhibited of CEC proliferation. These results suggest that Polyp-Au-GO composite inhibits VSMC proliferation and TNF-R-mediated inflammatory responses. This study suggested the therapeutic role of Polyp-Au-GO composite in cardiovascular disease.

Astragaloside IV alleviates myocardial damage induced by type 2 diabetes via improving energy metabolism

The aim of the present study was to evaluate the protective effect and mechanism of Astragaloside IV (ASIV) on myocardial injury induced by type 2 diabetes, with a focus on energy metabolism. Blood glucose, the hemodynamic index, left ventricular weight/heart weight (LVW/HW), the left ventricular systolic pressure (LVSP), the left ventricular end diastolic pressure (LVEDP) and cell survival rate were measured in streptozotocin‑induced diabetes model rats. Western blot analysis, PCR, hematoxylin‑eosin and TUNEL staining, flow cytometry and ELISA were used to detect: i) Cardiomyocyte damage indicators such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), cytochrome c (Cyt C), caspase‑3, cleaved caspase‑3 and the apoptotic rate; ii) energy metabolism indicators such as ATP/AMP and ADP/AMP; and iii) energy metabolism associated pathway proteins such as peroxisome proliferator‑activated receptor γ coactivator 1‑α (PGC‑1α) and nuclear respiratory factor 1 (NRF1). The present demonstrated increased blood glucose, LVW/HW, LVSP, LVEDP and the cardiomyocyte damage indicators (ANP, BNP, Cyt C and caspase‑3), in the diabetic and high glucose‑treated groups, which were decreased by ASIV. The expression of NRF‑1 and PGC‑1α significantly changed in the model group and was markedly improved following ASIV treatment. Furthermore, the abnormal energy metabolism in the model group was reversed by ASIV. According to the results, ASIV can regulate energy metabolism by regulating the release of PGC‑1α and NRF1 to rescue the abnormal energy metabolism caused by diabetes mellitus, thus decreasing the myocardial damage caused by diabetic cardiomyopathy.

Lycium barbarum polysaccharide attenuates cardiac hypertrophy, inhibits calpain-1 expression and inhibits NF-κB activation in streptozotocin-induced diabetic rats

Cardiac hypertrophy is one of the key structural changes that occurs in diabetic cardiomyopathy. Previous studies have indicated that the activation of NF-κB by calpain-1, a Ca²⁺-dependent cysteine protease, serves an important role in cardiac hypertrophy. The aim of the present study was to assess the effect of 30 and 60 mg/kg Lycium barbarum polysaccharide (LBP) treatment, the major active ingredient extracted from Lycium barbarum, on cardiac hypertrophy in streptozotocin (STZ) induced diabetic rats. In addition, the present study examined the possible underlying mechanisms of this effect by assessing calpain-1 expression and the NF-κB pathway. The mRNA expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was determined by reverse transcription-quantitative PCR. Western blotting was used to detect the protein expressions of calpain-1, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1) and toll-like receptor-4 (TLR-4) in the heart tissue. The results revealed that compared with non-diabetic rats, diabetic rats exhibited cardiac hypertrophy. Cardiac hypertrophy was defined by the following: Dysfunction of the cardiac hemodynamics, an increase in the ratios of left ventricular weight/body weight and heart weight/body weight and the increased expressions of ANP and BNP, which serve as hypertrophic markers in cardiac tissue. However, all of these changes were attenuated in diabetic rats treated with LBP. In addition, the protein expression of calpain-1 was increased in the heart tissue of diabetic rats compared with that of non-diabetic rats, where it was inhibited by LBP. LBP also decreased the protein expression of certain inflammatory mediators, IL-6, TNF-α, ICAM-1, VCAM-1 and TLR-4 in diabetic heart tissue. Furthermore, LBP treatment reduced the production of reactive oxygen species, upregulated the protein expression of endothelial nitric oxide synthase and downregulated the protein expression of inducible nitric-oxide synthase. Additionally, LBP increased the protein expression of p65, the subunit of NF-κB and inhibitory protein кB-α in the cytoplasm and reduced p65 expression in the nucleus. In conclusion, LBP improves cardiac hypertrophy, inhibits the expression of calpain-1 and inhibits the activation of NF-κB in diabetic rats.

PG201 protects mice from experimental autoimmune encephalomyelitis via suppression of effector T cell activation

BACKGROUND

PG201 is a botanical formulation, approved as an ethical drug (ETC) phytomedicine for treatment of patients with osteoarthritis in Korea, following satisfactory phase II and phase III studies. This phytomedicine was previously been shown to possess significant anti-inflammatory activities, presumably via the control of Th1 and Th17 cells in animal models and in vitro cell culture systems.

PURPOSE

In this study, the possibility of using PG201 to treat multiple sclerosis was explored.

METHODS

In vitro, the effect of PG201 on the differentiation of CD4⁺ T cells was investigated. To test the effects of PG201 in vivo, a mouse experimental autoimmune encephalomyelitis (EAE) model was used.

RESULTS

It was found that PG201 treatment decreased the frequency of both CD4⁺T-bet⁺ and CD4⁺RORγt⁺T cells. In addition, the production of interferon- gamma (IFN-γ) and interleukin-17 (IL-17) from respective Th cells was highly reduced. The data from western blots showed that the amount of phosphorylated c-Jun, but not that of p65, was decreased by PG201. Consistently, the level of luciferase activity was downregulated by PG201 in activator protein 1 (AP-1) reporter plasmid assays. In mice pretreated with PG201, the day of onset was delayed and clinical symptoms of EAE were significantly improved in a dose-dependent manner. Consistent with these results, the number of infiltrated cells and the expression level of pro-inflammatory molecules were decreased.

CONCLUSION

These findings indicate that PG201 may exert strong immunomodulatory effects in the EAE model via suppression of T cell activation, and that PG201 is a therapeutic reagent for the treatment of multiple sclerosis.

Age-, Gender-, and in Vivo Different Doses of Isoproterenol Modify in Vitro Aortic Vasoreactivity and Circulating VCAM-1

Different human-like cardiomyopathies associated to β-adrenergic stimulation are experimentally modeled in animals through variations in dose, route, and duration of administration of different cardiotoxic drugs. However, associated changes in the vasculature and their relation to systemic inflammation, and the influence of cardiovascular diseases risk factors (gender and age) upon them are seldom analyzed. Here we studied the effect of age and gender on the vasoreactivity of aortas from mice subjected to in vivo repeated β-adrenergic stimulation with different doses of isoproterenol (ISO) in association with circulating inflammatory cytokines. Young (2 months) and old (18 months) male and female mice received 0 (control), 5, 40, 80 or 160 μg/g/d of ISO (7 days, s.c.). IL-1α, IL-4 and vascular cell adhesion molecule-1 (VCAM-1) were quantified in plasma. In vitro, norepinephrine-induced vasoconstriction and acetylcholine-induced relaxation were measured in aortas. No differences in contraction, relaxation, IL-1α, and IL-4 were found between control young males and females. Age decreased contraction in males and relaxation was lower in females and abolished in males. VCAM-1 was higher in young males than in females and increased in old mice. Vasoconstriction in ISO-treated mice results as a bell-shaped curve on contraction in young and old males, with lower values in the latter. In females, ISO-160 increased contraction in young females but decreased it in old females. Vasorelaxation was reduced in ISO-treated young males and females. ISO-80 and 160 reduced vasorelaxation in old females, and intermediate doses relaxed aortas from old males. VCAM-1 was higher in young and old males with ISO-80 and 160; while VCAM-1 was higher only with ISO-160 in old females. Our results demonstrate that repeated β-adrenergic stimulation modifies vascular reactivity depending on gender, age, and dose. Females were less sensitive to alterations in vasoreactivity, and young females required a higher amount of the adrenergic stimuli than old females to show vascular alterations. Changes were independent of IL-1α and IL-4. VCAM-1 only changed in old females stimulated with ISO 160. Our results highlight the relevance of considering and comparing in the same study females and aged organisms to improve the accuracy of applications to clinical studies.

Astragaloside IV protects blood-brain barrier integrity from LPS-induced disruption via activating Nrf2 antioxidant signaling pathway in mice

Endothelial cells of cerebral microvessels are one of the components of blood-brain-barrier (BBB), which are connected by tight junctions (TJs). BBB disruption in cerebral diseases such as ischemic stroke, Alzhemer's disease, multiple sclerosis and traumatic brain injury is implicated to exacerbate the disease progression. Astragaloside IV (ASIV) isolated from Astragalus membranaceus prevents BBB breakdown in rodents induced with cerebral edema and experimental autoimmune encephalomyelitis. However, its underlying molecular mechanism has not been elucidated yet. In present study, ASIV was found to prevent the leakage of BBB in LPS-induced mice, which was accompanied with increased zo-1 and occludin but reduced VCAM-1 in brain microvessels. Similarly, in brain endothelial cell line bEnd.3 cells, ASIV mitigated the increased permeability induced by LPS, as evidenced by increased TEER and reduced sodium fluorescein extravasation. ASIV also enhanced the expression of TJ proteins such as zo-1, occludin and claudin-5 in LPS stimulated bEnd.3 cells. Meanwhile, it inhibited the inflammatory responses and prevented the monocyte adhesion onto bEnd.3 cells upon LPS stimulation. Further study disclosed that ASIV could alleviate ROS level and activate Nrf2 antioxidant pathway in bEnd.3 cells. When Nrf2 was silenced, the protective effect of ASIV was abolished. In brain microvessels of LPS-induced mice, ASIV also enhanced the expression of Nrf2 antioxidant pathway related proteins. Collectively, our results demonstrated that ASIV protected the integrity of BBB in LPS-induced mice, the mechanism of which might be mediated via activating Nrf2 signaling pathway. The findings suggested that ASIV might be a potential neuroprotective drug acting on BBB.

Rosmarinic Acid Alleviates the Endothelial Dysfunction Induced by Hydrogen Peroxide in Rat Aortic Rings via Activation of AMPK

Endothelial dysfunction is the key player in the development and progression of vascular events. Oxidative stress is involved in endothelial injury. Rosmarinic acid (RA) is a natural polyphenol with antioxidative, antiapoptotic, and anti-inflammatory properties. The present study investigates the protective effect of RA on endothelial dysfunction induced by hydrogen peroxide (H2O2). Compared with endothelium-denuded aortic rings, the endothelium significantly alleviated the decrease of vasoconstrictive reactivity to PE and KCl induced by H2O2. H2O2 pretreatment significantly injured the vasodilative reactivity to ACh in endothelium-intact aortic rings in a concentration-dependent manner. RA individual pretreatment had no obvious effect on the vasoconstrictive reaction to PE and KCl, while its cotreatment obviously mitigated the endothelium-dependent relaxation impairments and the oxidative stress induced by H2O2. The RA cotreatment reversed the downregulation of AMPK and eNOS phosphorylation induced by H2O2 in HAEC cells. The pretreatment with the inhibitors of AMPK (compound C) and eNOS (L-NAME) wiped off RA's beneficial effects. All these results demonstrated that RA attenuated the endothelial dysfunction induced by oxidative stress by activating the AMPK/eNOS pathway.

Context-dependent function of ROS in the vascular endothelium: The role of the Notch pathway and shear stress

Reactive oxygen species (ROS) act as signal molecules in several biological processes whereas excessive, unregulated, ROS production contributes to the development of pathological conditions including endothelial dysfunction and atherosclerosis. The maintenance of a healthy endothelium depends on many factors and on their reciprocal interactions; in this framework, the Notch pathway and shear stress (SS) play two lead roles. Recently, evidence of a crosstalk between ROS, Notch, and SS, is emerging. The aim of this review is to describe the way ROS interact with the Notch pathway and SS protecting from-or promoting-the development of endothelial dysfunction. © 2017 BioFactors, 43(4):475-485, 2017.

Fermented Chinese Formula Shuan-Tong-Ling Protects Brain Microvascular Endothelial Cells against Oxidative Stress Injury

Fermented Chinese formula Shuan-Tong-Ling (STL), composed of fourteen medicinal herbs, was an experiential formula by Dr. Zhigang Mei for treating vascular encephalopathy, but the underlying mechanisms remained unknown. In this study, we aimed to investigate the protective effects of fermented STL on hydrogen peroxide- (H₂O₂-) induced injury in rat brain microvascular endothelial cells (BMECs) and the possible mechanisms. Cultured BMECs were treated with H₂O₂, STL, or nicotinamide (NAM, a SIRT1 inhibitor). Then, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was employed to detect cell proliferation and senescence-associated beta-galactosidase (SA-β-gal) was used to examine cell senescence. Cell nuclei were observed by 4',6-diamidino-2-phenylindole. Additionally, changes in reactive oxygen species (ROS), superoxide dismutase (SOD), and glutathione (GSH) levels were measured. Expression of SIRT1, p21, and PGC-1α was determined by western blot. Cell proliferation significantly increased with STL treatment in a dose-dependent manner. H₂O₂ treatment could intensify cell senescence and nuclei splitting or pyknosis. With STL treatment, the reduced ROS level was accompanied by increased SOD and GSH activity. Further assays showed upregulation of SIRT1 and PGC-1α and downregulation of p21 after STL treatment. The results revealed that STL could protect BMECs against oxidative stress injury at least partially through the SIRT1 pathway.

Genome-Wide Transcriptional Analysis Reveals the Protection against Hypoxia-Induced Oxidative Injury in the Intestine of Tibetans via the Inhibition of GRB2/EGFR/PTPN11 Pathways

The molecular mechanisms for hypoxic environment causing the injury of intestinal mucosal barrier (IMB) are widely unknown. To address the issue, Han Chinese from 100 m altitude and Tibetans from high altitude (more than 3650 m) were recruited. Histological and transcriptome analyses were performed. The results showed intestinal villi were reduced and appeared irregular, and glandular epithelium was destroyed in the IMB of Tibetans when compared with Han Chinese. Transcriptome analysis revealed 2573 genes with altered expression. The levels of 1137 genes increased and 1436 genes decreased in Tibetans when compared with Han Chinese. Gene ontology (GO) analysis indicated most immunological responses were reduced in the IMB of Tibetans when compared with Han Chinese. Gene microarray showed that there were 25-, 22-, and 18-fold downregulation for growth factor receptor-bound protein 2 (GRB2), epidermal growth factor receptor (EGFR), and tyrosine-protein phosphatase nonreceptor type 11 (PTPN11) in the IMB of Tibetans when compared with Han Chinese. The downregulation of EGFR, GRB2, and PTPN11 will reduce the production of reactive oxygen species and protect against oxidative stress-induced injury for intestine. Thus, the transcriptome analysis showed the protecting functions of IMB patients against hypoxia-induced oxidative injury in the intestine of Tibetans via affecting GRB2/EGFR/PTPN11 pathways.