Paeonol protects rat vascular endothelial cells from ox-LDL-induced injury in vitro via downregulating microRNA-21 expression and TNF-α release

Molecular mechanisms of PTEN in atherosclerosis: A comprehensive review

Atherosclerosis is a chronic inflammatory disease of the arterial wall caused by an imbalance of lipid metabolism and a maladaptive inflammatory response. A variety of harmful cellular changes associated with atherosclerosis include endothelial dysfunction, the migration of circulating inflammatory cells to the arterial wall, the production of proinflammatory cytokines, lipid buildup in the intima, local inflammatory responses in blood vessels, atherosclerosis-associated apoptosis, and autophagy. PTEN inhibits the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT)/mammalian target of rapamycin (mTOR) pathway through its lipid phosphatase activity. Previous studies have shown that PTEN is closely related to atherosclerosis. This article reviews the role of PTEN in atherosclerosis from the perspectives of autophagy, apoptosis, inflammation, proliferation, and angiogenesis.

Paeonol alleviates ox-LDL-induced endothelial cell injury by targeting the heme oxygenase-1/phosphoinositide 3-kinase/protein kinase B pathway

Atherosclerosis is a leading cause of vascular disease worldwide. Paeonol has been reported to have therapeutical potential in atherosclerosis. The aim of this study is to explore the effect of paeonol on oxidized low-density lipoprotein (ox-LDL)-induced endothelial cells injury and the underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were treated with ox-LDL (100 μg/ml) to mimic atherosclerosis in vitro. The cell viability, proliferation, and apoptosis were assessed by cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry, respectively. The angiogenesis was detected by tube formation assay. The levels of inflammatory factor were measured by enzyme-linked immunosorbent assay (ELISA). In addition, the levels of Fe2+, reactive oxygen species (ROS), and glutathione (GSH) were detected to assess ferroptosis. The western blot was used to detect the protein expression. Ox-LDL inhibited cell viability, proliferation, and angiogenesis, but induced apoptosis and inflammation in HUVECs, and paeonol (75 μM) relieves ox-LDL-induced HUVEC injury. Also, paeonol inhibited ox-LDL-induced ferroptosis of HUVECs. Interestingly, heme oxygenase-1 (HMOX1) knockdown alleviated ox-LDL-induced HUVECs injury and ferroptosis. Paeonol affected ox-LDL-induced HUVECs via regulating HMOX1. In addition, paeonol regulated PI3K/AKT pathway via HMOX1, and the inhibitor of phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway reversed the effects of HMOX1 knockdown on ox-LDL-induced HUVECs. Paeonol alleviated ox-LDL-induced HUVEC injury by regulating the PI3K/AKT pathway via targeting HMOX1.

Elucidating the crosstalk between endothelial-to-mesenchymal transition (EndoMT) and endothelial autophagy in the pathogenesis of atherosclerosis

Atherosclerosis, a chronic systemic inflammatory condition, is implicated in most cardiovascular ischemic events. The pathophysiology of atherosclerosis involves various cell types and associated processes, including endothelial cell activation, monocyte recruitment, smooth muscle cell migration, involvement of macrophages and foam cells, and instability of the extracellular matrix. The process of endothelial-to-mesenchymal transition (EndoMT) has recently emerged as a pivotal process in mediating vascular inflammation associated with atherosclerosis. This transition occurs gradually, with a significant portion of endothelial cells adopting an intermediate state, characterized by a partial loss of endothelial-specific gene expression and the acquisition of "mesenchymal" traits. Consequently, this shift disrupts endothelial cell junctions, increases vascular permeability, and exacerbates inflammation, creating a self-perpetuating cycle that drives atherosclerotic progression. While endothelial cell dysfunction initiates the development of atherosclerosis, autophagy, a cellular catabolic process designed to safeguard cells by recycling intracellular molecules, is believed to exert a significant role in plaque development. Identifying the pathological mechanisms and molecular mediators of EndoMT underpinning endothelial autophagy, may be of clinical relevance. Here, we offer new insights into the underlying biology of atherosclerosis and present potential molecular mechanisms of atherosclerotic resistance and highlight potential therapeutic targets.

Targeted intervention of natural medicinal active ingredients and traditional Chinese medicine on epigenetic modification: Possible strategies for prevention and treatment of atherosclerosis

BACKGROUND

Atherosclerosis is a deadly consequence of cardiovascular disease and has very high mortality rate worldwide. The epigenetic modifications can regulate the pervasiveness and progression of atherosclerosis through its involvement in regulation of inflammation, oxidative stress, lipid metabolism and several other factors. Specific non-coding RNAs, DNA methylation, and histone modifications are key regulatory factors of atherosclerosis. Natural products from traditional Chinese medicine have shown promising therapeutic potential against atherosclerosis by means of regulating the expression of specific genes, stabilizing arterial plaques and protecting vascular endothelial cells.

OBJECTIVE

Our study is focusing to explore the pathophysiology and probability of traditional Chinese medicine and natural medicinal active ingredients to treat atherosclerosis.

METHODS

Comprehensive literature review was conducted using PubMed, Web of Science, Google Scholar and China National Knowledge Infrastructure with a core focus on natural medicinal active ingredients and traditional Chinese medicine prying in epigenetic modification related to atherosclerosis.

RESULTS

Accumulated evidence demonstrated that natural medicinal active ingredients and traditional Chinese medicine have been widely studied as substances that can regulate epigenetic modification. They can participate in the occurrence and development of atherosclerosis through inflammation, oxidative stress, lipid metabolism, cell proliferation and migration, macrophage polarization and autophagy respectively.

CONCLUSION

The function of natural medicinal active ingredients and traditional Chinese medicine in regulating epigenetic modification may provide a new potential strategy for the prevention and treatment of atherosclerosis. However, more extensive research is essential to determine the potential of these natural medicinal active ingredients to treat atherosclerosis because of least clinical data.

Anti-atherosclerosis mechanisms associated with regulation of non-coding RNAs by active monomers of traditional Chinese medicine

Atherosclerosis is the leading cause of numerous cardiovascular diseases with a high mortality rate. Non-coding RNAs (ncRNAs), RNA molecules that do not encode proteins in human genome transcripts, are known to play crucial roles in various physiological and pathological processes. Recently, researches on the regulation of atherosclerosis by ncRNAs, mainly including microRNAs, long non-coding RNAs, and circular RNAs, have gradually become a hot topic. Traditional Chinese medicine has been proved to be effective in treating cardiovascular diseases in China for a long time, and its active monomers have been found to target a variety of atherosclerosis-related ncRNAs. These active monomers of traditional Chinese medicine hold great potential as drugs for the treatment of atherosclerosis. Here, we summarized current advancement of the molecular pathways by which ncRNAs regulate atherosclerosis and mainly highlighted the mechanisms of traditional Chinese medicine monomers in regulating atherosclerosis through targeting ncRNAs.

Review of the Protective Mechanism of Paeonol on Cardiovascular Disease

Cardiovascular disease (CVD) is one of the leading causes of death in the world. Paeonol(Pae) is a phenolic component extracted from peony bark, peony root and Xu Changqing. Studies have shown that Pae can protect cardiomyocytes by inhibiting oxidative stress, promoting mitochondrial fusion, regulating mitochondrial autophagy and inhibiting inflammation. In addition, Pae improves ventricular remodeling by inhibiting myocardial apoptosis, hypertrophy and fibrosis. Pae also has a good protective effect on blood vessels by inhibiting vascular inflammation, reducing the expression of adhesion molecules, inhibiting vascular proliferation, and inhibiting oxidative stress and endoplasmic reticulum stress(ERS). Pae also has the effect of anti-endothelial cell senescence, promoting thrombus recanalization and vasodilating. In conclusion, the molecular targets of Pae are very complex, and the relationship between different targets and signaling pathways cannot be clearly explained, which requires us to use systems biology methods to further study specific molecular targets of Pae. It has to be mentioned that the bioavailability of Pae is poor, and some nanotechnology-assisted drug delivery systems improve the therapeutic effect of Pae. We reviewed the protective mechanism of paeonol on the cardiovascular system, hoping to provide help for drug development in the treatment of CVD.

A review on therapeutical potential of paeonol in atherosclerosis

The morbidity and mortality of atherosclerotic cardiovascular disease (ASCVD) is increasing year by year. Cortex Moutan is a traditional Chinese medicinal herb that has been widely used for thousands of years to treat a wide variety of diseases in Eastern countries due to its heat-clearing and detoxifying effects. Paeonol is a bioactive monomer extracted from Cortex Moutan, which has anti-atherosclerotic effects. In this article, we reviewed the pharmacological effects of paeonol against experimental atherosclerosis, as well as its protective effects on vascular endothelial cells, smooth muscle cells, macrophages, platelets, and other important cell types. The pleiotropic effects of paeonol in atherosclerosis suggest that it can be a promising therapeutic agent for atherosclerosis and its complications. Large-scale randomized clinical trials are warranted to elucidate whether paeonol are effective in patients with ASCVD.

miR‑129‑5p inhibits oxidized low‑density lipoprotein‑induced A7r5 cell viability and migration by targeting HMGB1 and the PI3k/Akt signaling pathway

The mechanisms underlying gene therapy for the treatment of cardiovascular diseases remain to be elucidated. microRNAs (miRs) have been recognized as key regulators in vascular smooth muscle cells, which are involved in the formation of atherosclerosis. The present study aimed to explore the role of miR-129-5p in the regulation of high-mobility group box 1 protein (HMGB1) and the PI3k/Akt signaling pathway, and further explore the role of miR-129-5p in the viability and migration of A7r5 cells induced by oxidized low-density lipoprotein (ox-LDL). Cell viability, viability and migration were determined using Cell Counting Kit-8, colony formation, wound healing and Transwell assays. The expression levels of miR-129-5p and HMGB1 were detected using reverse transcription-quantitative PCR and western blotting. A dual-luciferase assay was used to confirm the association between miR-129-5p and HMGB1. RT-qPCR results in the present study demonstrated that the expression levels of miR-129-5p in A7r5 cells induced by ox-LDL were significantly decreased, compared with the control cells. Moreover, the viability and migration of A7r5 cells induced by ox-LDL were increased compared with control group. Western blot and RT-qPCR results showed that miR-129-5p decreased the expression of HMGB1 in A7r5 cells compared with control group. The present results demonstrated that miR-129-5p inhibited the viability, viability and migration of A7r5 cells induced by ox-LDL, and directly targeted HMGB1 to regulate the PI3k/Akt signaling pathway. In conclusion, miR-129-5p inhibited the PI3k/Akt signaling pathway by directly targeting HMGB1, and reduced the viability, viability and migration of A7r5 cells induced by ox-LDL.

Inhibition of miR-21 improves pulmonary vascular responses in bronchopulmonary dysplasia by targeting the DDAH1/ADMA/NO pathway

miR-21 has been confirmed to be overexpressed in neonatal rat lungs with hyperoxia-mediated bronchopulmonary dysplasia (BPD). The specific function of miR-21 in BPD is still unclear. We established the hyperoxia-induced BPD rat model in vivo and the hyperoxia-induced pulmonary microvascular endothelial cells (PMVECs) model in vitro. Transwell assay was utilized to detect the migratory capability of PMVECs. Tube formation assay was utilized to measure angiogenesis ability. ELISA was utilized to test nitric oxide (NO) production and the intracellular and extracellular Asymmetric Dimethylarginine (ADMA) concentration. Furthermore, the interaction between miR-21 and dimethylarginine dimethylaminohydrolase 1 (DDAH1) was evaluated using luciferase reporter assay. We found that miR-21 expression in PMVECs was increased by hyperoxia stimulation. Inhibition of miR-21 improved the migratory and angiogenic activities of PMVECs and overexpression of miR-21 exerted the opposite effects. Furthermore, knockdown of miR-21 increased NO production and decreased intracellular and extracellular ADMA concentration in hyperoxia-treated PMVECs. Next we proved that miR-21 could bind to DDAH1 and negatively regulate its expression. Rescues assays showed that DDAH1 knockdown reversed the effects of miR-21 depletion on hyperoxia-mediated PMVEC functions, NO production, and ADMA concentration. Importantly, miR-21 downregulation restored alveolarization and vascular density in BPD rats. This study demonstrates that inhibition of miR-21 improves pulmonary vascular responses in BPD by targeting the DDAH1/ADMA/NO pathway.

Paeonol suppresses lipid formation and promotes lipid degradation in adipocytes

Paeonol can regulate a variety of physiological and pathological processes such as thrombosis, oxidative stress, inflammation and atherosclerosis. However, its potential role and underlying mechanisms in obesity and lipid metabolism remain to be elucidated. In the present study, 3T3-L1 cells were differentiated and collected on days 4, 6 and 8. The expression levels of fatty-acid-binding protein 4 (FABP4) and microRNA (miR)-21 were detected using reverse transcription-quantitative PCR and western blot analyses. Cell viability was assessed using a Cell Counting Kit-8 assay. A miR-21 mimic was constructed and transfected into 3T3-L1 preadipocytes. Adipocyte differentiation was detected using Oil Red O staining. The proteins CD36, glucose transporter 4, peroxisome proliferator-activated receptor γ (PPAR-γ) and adipocyte protein 2 (Ap2) were detected using western blot analysis. The expression levels of FABP4 and miR-21 were increased in differentiated 3T3-L1 cells. Paeonol exhibited no effects on cell activity, whereas it inhibited the expression levels of miR-21 in the 3T3-L1 differentiated adipocytes. Paeonol suppressed the differentiation of 3T3-L1 adipocytes and its effect was partially reversed by the overexpression of miR-21. In addition, paeonol promoted the lipid degradation of 3T3-L1 adipocytes, increased the expression levels of PPAR-γ and Ap2, and suppressed triglyceride synthesis in these cells. These effects were partially reversed by the overexpression of miR-21. In conclusion, the findings of the present study indicated that paeonol may exert protective effects against lipid formation and promote lipid degradation in adipocytes. These data provide evidence of the regulatory effect of paeonol on adipocyte differentiation and highlight its pathological significance.

miRNA-576 Alleviates the Malignant Progression of Atherosclerosis through Downregulating KLF5

Objective

To elucidate the role of microRNA-576 (miRNA-576) in alleviating the deterioration of atherosclerosis (AS) through downregulating krüpple-like factor 5 (KLF5).

Materials and Methods

The AS model in mice was first constructed. Body weight, inflammation degrees, blood lipid, and relative levels of KLF5, miRNA-576, caspase-3, and bcl-2 in AS mice and control mice were compared. Dual-luciferase reporter gene assay was performed to evaluate the binding between miRNA-576 and KLF5. RAW264.7 cells were treated with 200 mg/L ox-LDL for establishing in vitro high-fat model. Regulatory effects of miRNA-576/KLF5 on relative levels of β-catenin and inflammatory factors in RAW264.7 cells were explored.

Results

Body weight was heavier in AS mice than in controls. Protein levels of KLF5 and caspase-3 were upregulated, while bcl-2 was downregulated in AS mice. In particular, protein level of KLF5 was highly expressed in aortic tissues of AS mice. TC and LDL increased, and HDL decreased in AS mice compared with controls. Inflammatory factor levels were markedly elevated in AS mice. KLF5 was verified to be the target gene binding miRNA-576. Overexpression of miRNA-576 downregulated KLF5, inflammatory factors, and β-catenin in ox-LDL-treated RAW264.7 cells. Regulatory effect of miRNA-576 on the release of inflammatory factors in RAW264.7 cells could be partially abolished by KLF5.

Conclusions

miRNA-576 alleviates malignant progression of AS via downregulating KLF5.

Biological Activities of Paeonol in Cardiovascular Diseases: A Review

Paeonol is a naturally existing bioactive compound found in the root bark of Paeonia suffruticosa and it is traditionally used in Chinese medicine for the prevention and management of cardiovascular diseases. To date, a great deal of studies has been reported on the pharmacological effects of paeonol and its mechanisms of action in various diseases and conditions. In this review, the underlying mechanism of action of paeonol in cardiovascular disease has been elucidated. Recent studies have revealed that paeonol treatment improved endothelium injury, demoted inflammation, ameliorated oxidative stress, suppressed vascular smooth muscle cell proliferation, and repressed platelet activation. Paeonol has been reported to effectively protect the cardiovascular system either employed alone or in combination with other traditional medicines, thus, signifying it could be a hypothetically alternative or complementary atherosclerosis treatment. This review summarizes the biological and pharmacological activities of paeonol in the treatment of cardiovascular diseases and its associated underlying mechanisms for a better insight for future clinical practices.

Paeonol Suppresses Vasculogenesis Through Regulating Vascular Smooth Muscle Phenotypic Switching

OBJECTIVE

Smooth muscle cell (SMC) phenotypic switching is associated with development of a variety of occlusive vascular diseases. Paeonol has been reported to be involved in suppressing SMC proliferation. However, it is still unknown whether paeonol can regulate SMC phenotypic switching, and which eventually result in suppressing vasculogenesis.

METHODS

Murine left common carotid artery was injured by completely ligation, and paeonol was administrated by intraperitoneal injection. Hematoxylin and eosin (H&E) staining was performed to visualize vascular neointima formation. Rat aortic SMCs were used to determine whether paeonol suppresses cell proliferation and migration. And murine hind limb ischemia model was performed to confirm the function role of paeonol in suppressing vasculogenesis.

RESULTS

Complete ligation of murine common carotid artery successfully induced neointima formation. Paeonol treatment dramatically reduced the size of injury-induced neointima. Using rat aortic primary SMC, we identified that paeonol strongly suppressed cell proliferation, migration, and decreased extracellular matrix deposition. And paeonol treatment dramatically suppressed vasculogenesis after hind limb ischemia injury.

CONCLUSION

Paeonol could regulate SMC phenotypic switching through inhibiting proliferation and migration of SMC, which results in inhibiting ischemia-induced vasculogenesis.

Paeonol for the Treatment of Atherosclerotic Cardiovascular Disease: A Pharmacological and Mechanistic Overview

With improvement in living standards and average life expectancy, atherosclerotic cardiovascular disease incidences and mortality have been increasing annually. Paeonia suffruticosa, a natural herb, has been used for the treatment of atherosclerotic cardiovascular disease for thousands of years in Eastern countries. Paeonol is an active ingredient extracted from Paeonia suffruticosa. Previous studies have extensively explored the clinical benefits of paeonol. However, comprehensive reviews on the cardiovascular protective effects of paeonol have not been conducted. The current review summarizes studies reporting on the protective effects of paeonol on the cardiovascular system. This study includes studies published in the last 10 years. The biological characteristics of Paeonia suffruticosa, pharmacological mechanisms of paeonol, and its toxicological and pharmacokinetic characteristics were explored. The findings of this study show that paeonol confers protection against atherosclerotic cardiovascular disease through various mechanisms, including inflammation, platelet aggregation, lipid metabolism, mitochondria damage, endoplasmic reticulum stress, autophagy, and non-coding RNA. Further studies should be conducted to elucidate the cardiovascular benefits of paeonol.

Paeonol suppresses the effect of ox-LDL on mice vascular endothelial cells by regulating miR-338-3p/TET2 axis in atherosclerosis

Atherosclerosis is the common vascular disease. Vascular smooth muscle cell proliferation and vascular endothelial cell (VEC) dysfunction are involved in the causes of atherosclerosis. And oxidized low-density lipoprotein (ox-LDL)-induced vascular endothelial cells (VECs) are suitable models for studying atherosclerosis development. Paeonol was reported to repress ox-LDL-induced VEC progression. However, its detailed mechanism was not fully reported. MicroRNAs (miRNAs) acted as regulators in multiple diseases. Previous findings found that microRNA-338-3p (miR-338-3p) was overexpressed in Atherosclerosis process. However, the function and underlying mechanism of miR-338-3p in ox-LDL-treated VECs needed to be elucidated. The purpose of this research was to reveal the role of miR-338-3p in paeonol-regulated ox-LDL-induced VEC progression. Cell counting kit-8 (CCK-8) and flow cytometry were employed to determine cell viability and apoptosis, respectively. Moreover, the levels of IL-6 and IL-1β were analyzed using enzyme-linked immunosorbent assay, as well as the contents of reactive oxygen species, lactate dehydrogenase, and malonic dialdehyde were investigated using related kits. Furthermore, quantitative real-time polymerase chain reaction was carried out to determine the expression of miR-338-3p. Western blot assay was conducted to detect the level of tet methylcytosine dioxygenase 2 (TET2). Besides, the interaction between miR-338-3p and TET2 was predicted by DIANA, and then confirmed by the dual-luciferase reporter assay and RNA immunoprecipitation assay. Ox-LDL repressed mice VEC viability, and promoted apoptosis, inflammatory response, and oxidative injury. Paeonol inhibited the effect of ox-LDL on the growth of the VECs. Furthermore, paeonol regulated VEC development via downregulating miR-338-3p expression. Interestingly, miR-338-3p targeted TET2 and inhibited TET2 expression. MiR-338-3p modulated ox-LDL-treated VEC growth through suppressing TET2 expression. We demonstrated that paeonol attenuated the effect of ox-LDL on the development of mice VECs via modulating miR-338-3p/TET2 axis, providing a theoretical basis for the treatment of AS.

Aspirin Enhances the Protection of Hsp90 from Heat-Stressed Injury in Cardiac Microvascular Endothelial Cells Through PI3K-Akt and PKM2 Pathways

Heat stress (HS) often causes sudden death of humans and animals due to heart failure, mainly resulting from the contraction of cardiac microvasculature followed by myocardial ischemia. Cardiac microvascular endothelial cells (CMVECs) play an important role in maintaining vasodilatation. Aspirin (ASA) is well known for its protective abilities of febrile animals. However, there is little knowledge about molecular resistance mechanisms of CMVECs and which role ASA may play in this context. Therefore, we used a heat stress model of rat cardiac microvascular endothelial cell cultures in vitro and investigated the cell injuries and molecular resistance mechanism of CMVECs caused by heat stress, and the effect of aspirin (ASA) on it. HS induced severe pathological damage of CMVECs and cellular oxidative stress and dysfunction of NO release. Hsp90 was proven to be indispensable for resisting HS-injury of CMVECs through PI3K-Akt and PKM2 signaling pathways. Meanwhile, PKM2 functioned in reducing Akt phosphorylation. ASA treatment of CMVECs induced a significant expression of Hsp90, which promoted both Akt and PKM2 signals, which are beneficial for relieving HS damage and maintaining the function of CMVECs. Akt activation also promoted HSF-1 that regulates the expression of Hsp70, which is known to assist Hsp90′s molecular chaperone function and when released to the extracellular liquid to protect myocardial cells from HS damage. To the best of our knowledge, this is the first study to show that HS damages CMVECs and the protection mechanism of Hsp90 on it, and that ASA provides a new potential strategy for regulating cardiac microcirculation preventing HS-induced heart failure.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Paeonol: pharmacological effects and mechanisms of action

Paeonia suffruticosa possesses various medicinal benefits and has been used extensively in traditional oriental medicine for thousands of years. Paeonol is the main component isolated from the root bark of Paeonia suffruticosa. The pharmacological effects of Paeonia suffruticosa are mostly attributed to paeonol. Paeonol injection has been successfully applied in China for nearly 50 years for inflammation/pain-related indications. Currently, the dosage forms of paeonol approved by China Food and Drug Administration include tablet, injection, and external preparations such as ointment and adhesive plaster. So far, the clinical applications of paeonol are mainly focusing on the anti-inflammatory activity. Studies of other pharmacological activities of paeonol are developing rapidly, and which may play an important role in the future. Besides, substantial mechanisms of pharmacological action of paeonol have been clarified in recent years. In this review, we summarize the pharmacological effects anti-inflammatory, neuroprotective, anti-tumor, anti-cardiovascular diseases and associated mechanisms of action of paeonol up to date.

Matrine attenuates high-fat diet-induced in vivo and ox-LDL-induced in vitro vascular injury by regulating the PKCα/eNOS and PI3K/Akt/eNOS pathways

Lipid metabolism disorders lead to vascular endothelial injury. Matrine is an alkaloid that has been used to improve obesity and diabetes and for the treatment of hepatitis B. However, its effect on lipid metabolism disorders and vascular injury is unclear. Here, we investigated the effect of matrine on high‐fat diet fed mice and oxidized low‐density lipoprotein (ox‐LDL)‐induced human umbilical vein endothelial cells (HUVECs). Computational virtual docking analyses, phosphoinositide 3‐kinase (PI3K) and protein kinase C‐α (PKCα) inhibitors were used to localize matrine in vascular injuries. The results showed that matrine‐treated mice were more resistant to abnormal lipid metabolism and inflammation than vehicle‐treated mice and exhibited significantly alleviated ox‐LDL‐stimulated dysfunction of HUVECs, restored diminished nitric oxide release, decreased reactive oxygen species generation and increased expression phosphorylation of AKT‐Ser473 and endothelial nitric oxide synthase (eNOS)‐Ser1177. Matrine not only up‐regulates eNOS‐Ser1177 but also down‐regulates eNOS‐Thr495, a PKCα‐controlled negative regulator of eNOS. Using computational virtual docking analyses and biochemical assays, matrine was also shown to influence eNOS/NO via PKCα inhibition. Moreover, the protective effects of matrine were significantly abolished by the simultaneous application of PKCα and the PI3K inhibitor. Matrine may thus be potentially employed as a novel therapeutic strategy against high‐fat diet‐induced vascular injury.

Paeonol Attenuated Inflammatory Response of Endothelial Cells via Stimulating Monocytes-Derived Exosomal MicroRNA-223

Introduction: Paeonol, an active compound isolated from the radix of Cortex Moutan, has been shown to have anti-atherosclerosis effects by regulating blood cells' function and protecting vascular cells injury. Besides, emerging evidences has proven that exosomes might play a pivotal role in intercellular communication by transmiting proteins and microRNAs from cell to cell. However, the relationship between monocytes-derived exosomal microRNA-223 and vascular inflammation injury along with paeonol' effects are still not clear. Objective: Our study aimed to explain whether paeonol's protective effect on inflammatory response is related to the regulation of exosomal microRNA-223 in the VECs. Methods: ApoE-/- mice were fed with high fat diet to replicate the AS model. HE staining and immunohistochemistry was used to detect inflammatory response of aorta. The expression of IL-1β and IL-6 were detected by ELISA. Western blot was used to detect the expression of STAT3, pSTAT3, ICAM-1 and VCAM-1. qRT-PCR was used to detect miR-223 expression. Exosomes were extracted from THP-1 cells by differential centrifugation and observed by transmission electron microscope. Observation of exosomes uptake into HUVECs was realized by laser microscopy. miR-223 target gene was detected by double luciferase gene report test. Results: In vivo experiments confirmed that paeonol restricted atherosclerosis development and increased miR-223 expression, inhibited STAT3 pathway in ApoE-/- mice. In vitro, miR-223 showed robust presence in THP-1 cells and undetectable in HUVECs. And we had observed that miR-223 could be internalized from THP-1 cells into HUVECs taking exosomes as a carrier. Paeonol obviously increased miR-223 expression in co-cultured HUVECs and exosomes in concentration dependent manner, compared to LPS group. In addition, paeonol relieved inflammatory secretion, adhesion and STAT3 expression in HUVECs, which could be inverted after miR-223 inhibitor transfection into THP-1 cells. Conclusion: Paeonol could increase the expression of miR-223 in THP-1 derived exosomes and in HUVECs after uptake of exosomes, whereas decrease the expression of STAT3, p-STAT3 in HUVECs. Ultimately paeonol decreased the expression of IL-1β, IL-6, ICAM-1, VCAM-1 in HUVECs and alleviated adhesion of THP-1 cells to HUVECs.

Beneficial Effects Exerted by Paeonol in the Management of Atherosclerosis

Atherosclerosis, a chronic luminal stenosis disorder occurred in large and medium arteries, is the principle pathological basis of cardiovascular diseases with the highest morbidity and mortality worldwide. In oriental countries, traditional Chinese medicine Cortex Moutan has been widely used for the treatment of atherosclerosis-related illnesses for thousands of years. Paeonol, a bioactive monomer extracted from Cortex Moutan, is an important pharmacological component responsible for the antiatherosclerotic effects. Numerous lines of findings have established that paeonol offers beneficial roles against the initiation and progression of atherosclerotic lesions through inhibiting proatherogenic processes, such as endothelium damage, chronic inflammation, disturbance of lipid metabolism, uncontrolled oxidative stress, excessive growth, and mobilization of vascular smooth muscle cells as well as abnormality of platelet activation. Investigations identifying the atheroprotective effects of paeonol present substantial evidence for potential clinical application of paeonol as a therapeutic agent in atherosclerosis management. In this review, we summarize the antiatherosclerotic actions by which paeonol suppresses atherogenesis and provide newly insights into its atheroprotective mechanisms and the future clinical practice.

Effect of microRNA-26a on vascular endothelial cell injury caused by lower extremity ischemia-reperfusion injury through the AMPK pathway by targeting PFKFB3

Vascular endothelial cell (VEC) dysfunction plays an important role in the ischemia-reperfusion injury (IRI)-related diseases, and microRNAs (miRNAs) are key factors during this process. We conducted this study to investigate whether miRNA-26a (miR-26a) has effect on the IRI-induced VEC injury via the AMPK pathway by targeting 6-phosphofructo-2-kinase-fructose-2,6-biphosphatase 3 (PFKFB3). IRI rat models were successfully constructed by an abdominal incision. Additionally, the cultured VECs were further treated with miR-26a mimic or inhibitor, and si-PFKFB3. Both the reverse-transcription quantitative polymerase chain reaction and the western blot assay method were carried out to examine the expressions of PFKFB3, endothelial nitric oxide synthase (eNOS), and 5'-adenosine monophosphate-activated protein kinase (AMPK) α1, as well as the extent of the AMPK α1 phosphorylation levels in vascular tissues. Circulating endothelial cell (CEC), von Willebrand factor (VWF), thrombomodulin (TM), superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and endothelin (ET) were all measured. In the rat model of an IRI, a poorly expressed miR-26a and contrarily highly expressed PFKFB3 were identified in vascular tissues. In response to an overexpression of miR-26a or to the PFKFB3 gene silencing, decreased CEC number, TM, VWF, MDA, and ET contents, increased AMPK α1, and eNOS levels, as well as the extent of AMPK α1 phosphorylation coordinate with both increased SOD and NO contents based on the restoration of the AMPK pathway. Overexpression of the miR-26a or si-PFKFB3 provides an elevation in cell proliferation. Our study suggests that the miR-26a RNA alleviates lower extremity IRI-induced VEC injury in rats through the activation of the AMPK pathway by inhibiting PFKFB3.

The Signaling Pathways Involved in the Antiatherosclerotic Effects Produced by Chinese Herbal Medicines

Cardiovascular diseases (CVDs) are considered to be the predominant cause of death in the world. Chinese herb medicines (CHMs) have been widely used for the treatment of CVDs in Asian countries for thousands of years. One reason of high efficacy of CHMs in treating CVDs is attributed to their inhibition in atherosclerosis (AS) development, a critical contributor to CVDs occurrence. Cumulative studies have demonstrated that CHMs alleviate atherogenesis via mediating pathophysiologic events involved in AS. However, there is deficiency in the summaries regarding antiatherogenic signal pathways regulated by CHMs. In this review, we focus on the signal cascades by which herb medicines and relevant extractives, derivatives, and patents improve proatherogenic processes including endothelium dysfunction, lipid accumulation, and inflammation. We mainly elaborate the CHMs-mediated signaling pathways in endothelial cells, macrophages, and vascular smooth muscle cells of each pathogenic event. Moreover, we briefly describe the other AS-related factors such as thrombosis, autophagy, immune response, and noncoding RNAs and effects of CHMs on them in the way of cascade regulation, which is helpful to further illustrate the molecular mechanisms of AS initiation and progression and discover newly effective agents for AS management.

Protective effects of icariin on human vascular endothelial cells induced by oxidized low-density lipoprotein via modulating caspase-3 and Bcl-2

Icariin belongs to the family of flavonoids that is extracted from Epimedium brevicornum Maxim, and exhibits antioxidative, antitumorigenic, antiosteoporotic, immunoregulatory and antiatherosclerotic properties. To understand the mechanisms underlying the antiatherosclerotic properties of icariin, the present study investigated the effects of icariin on human vascular endothelial cells (HUVECs) following treatment with oxidized low‑density lipoprotein (ox‑LDL). Thus, following pretreatment with icariin at four various concentrations (0, 10, 20 and 40 µM), HUVECs were stimulated with ox‑LDL (100 µg/ml). The viability of cells was evaluated via an MTT assay and flow cytometry was performed to assess apoptosis. Additionally, the protein and mRNA expression levels of apoptosis regulator Bcl‑2 (Bcl‑2) and caspase‑3 were determined by western blotting and reverse transcription‑quantitative polymerase chain reaction. The findings of the present study indicated that icariin prevented injury and apoptosis in HUVECs following ox‑LDL treatment, in particular via the regulation of protein and mRNA expression levels of Bcl-2 and caspase-3.

Dihydromyricetin Attenuates TNF-α-Induced Endothelial Dysfunction through miR-21-Mediated DDAH1/ADMA/NO Signal Pathway

Accumulating studies demonstrate that dihydromyricetin (DMY), a compound extracted from Chinese traditional herb, Ampelopsis grossedentata, attenuates atherosclerotic process by improvement of endothelial dysfunction. However, the underlying mechanism remains poorly understood. Thus, the aim of this study is to investigate the potential mechanism behind the attenuating effects of DMY on tumor necrosis factor alpha- (TNF-α-) induced endothelial dysfunction. In response to TNF-α, microRNA-21 (miR-21) expression was significantly increased in human umbilical vein endothelial cells (HUVECs), in line with impaired endothelial dysfunction as evidenced by decreased tube formation and migration, endothelial nitric oxide synthase (eNOS) (ser1177) phosphorylation, dimethylarginine dimethylaminohydrolases 1 (DDAH1) expression and metabolic activity, and nitric oxide (NO) concentration as well as increased asymmetric dimethylarginine (ADMA) levels. In contrast, DMY or blockade of miR-21 expression ameliorated endothelial dysfunction in HUVECs treated with TNF-α through downregulation of miR-21 expression, whereas these effects were abolished by overexpression of miR-21. In addition, using a nonspecific NOS inhibitor, L-NAME, also abrogated the attenuating effects of DMY on endothelial dysfunction. Taken together, these data demonstrated that miR-21-mediated DDAH1/ADMA/NO signal pathway plays an important role in TNF-α-induced endothelial dysfunction, and DMY attenuated endothelial dysfunction induced by TNF-α in a miR-21-dependent manner.

Protective effects of paeonol on subacute/chronic brain injury during cerebral ischemia in rats

Ischemic stroke is a highly complex pathological process that is divided into acute, subacute and chronic phases. Paeonol is a biologically active natural product with a variety of pharmacological effects, including those on neuronal activity. However, the effects of paeonol on subacute/chronic ischemic stroke have remained to be elucidated. The present study was designed to investigate the effects of paeonol against subacute and chronic cerebral ischemic injury and to explore the possible underlying mechanisms. Male adult Sprague Dawley rats were randomly divided into a sham group (treated with saline), a model group [subjected to middle cerebral artery occlusion (MCAO) and treated with saline] and a paeonol-treated group (MCAO + paeonol at 25 mg/kg). Behavioral impairment, infarct volume and ischemic/contralateral hemispheric ratios were assessed at 72 h and at 28 days after MCAO, respectively. Immunofluorescence was employed to determine the neuronal damage and glial responses after MCAO. Compared with the model group, paeonol treatment significantly attenuated behavioral impairment, ischemic infarct volume and moderate cerebral edema in the ischemic brain at 72 h, as well as brain atrophy at 28 days after reperfusion. Furthermore, paeonol treatment ameliorated neuronal damage in the ischemic core and boundary zone regions at 72 h after reperfusion and in the boundary zone at 28 days after reperfusion. In addition, paeonol treatment reduced the proliferation of astrocytes in the boundary zone, and inhibited microglial activation in the ischemic core and boundary zone regions at 72 h and 28 days after reperfusion. These results demonstrated the protective effects of paeonol against subacute/chronic cerebral ischemia, and the mechanism of action may include subacute/chronic microglial activation and astrocyte proliferation.

Paeonol Inhibits Oxidized Low-Density Lipoprotein-Induced Vascular Endothelial Cells Autophagy by Upregulating the Expression of miRNA-30a

Paeonol from Cortex Moutan root is a potential therapeutic agent for atherosclerosis (AS). However, its mechanisms of action are still not fully understood. Vascular endothelial cells (VECs) autophagy plays a vital role in the initiation and progression of AS. In this study, we aim to investigate whether the protective effect of paeonol on ox-LDL-induced VECs injury by regulating autophagy. To address this question, we used ox-LDL-induced rat VECs as a model system to elucidate the protective effect of paeonol on VECs injury. This study displayed that ox-LDL (100 mg/L) treatment inhibited VEC growth in dose- and time-dependent manners, paeonol (60 μM) shown potential in inhibiting ox-LDL-induced death. Furthermore, paeonol significantly reduced ox-LDL-induced the formation of autophagy vacuoles and the expression of LC3II in VECs. Further double-luciferase reporter assay shown that miR-30a specifically binds to the 3′-UTR of Beclin-1 mRNA in VECs. Moreover, we found that ox-LDL decreased miR-30a and increased Beclin-1 expression, pretreatment with paeonol could reverse the process of regulation in dose-dependent manners. In ox-LDL treated VECs, transfection with a miR-30a mimic significantly increased miR-30a expression and inhibited Beclin-1 and LC3II expression, thus enhanced the protective effects of paeonol. Whereas transfection with a miR-30a inhibitor significantly decreased miR-30a expression and increased Beclin-1 and LC3II expression, thus attenuated the protective effects of paeonol. In conclusion, this study has, for the ?rst time, highlighted that miR-30a might be a critical target of paeonol against ox-LDL-induced VECs injury by inhibiting excessive autophagy. Paeonol may be one of promising candidate drug for treatment of AS.

The Anti-atherosclerotic Effect of Paeonol against Vascular Smooth Muscle Cell Proliferation by Up-regulation of Autophagy via the AMPK/mTOR Signaling Pathway

Introduction: Paeonol (2′-hydroxy-4′-methoxyacetophenone), isolated from moutan cortex, is an active component and has been shown to have anti-atherosclerotic and anti-proliferation effects on vascular smooth muscle cells (VSMCs). However, the possible role of Paeonol in protecting against VSMC proliferation as related to autophagy has yet to be elucidated.

Materials and Methods: The athero-protective effects of Paeonol were evaluated in apoE^-/- mice. The effects of Paeonol on VSMC proliferation and autophagy were examined by staining α-SMA and LC3II spots in the media layer of apoE^-/- mice, respectively. CCK8 and BrdU assays were used to investigate the effects of Paeonol on cell proliferation in vitro. The autophagic levels in VSMCs were evaluated by detecting LC3II accumulation and p62 degradation by immunoblot analysis. To investigate if Paeonol could prevent VSMCs proliferation through autophagy induction, we tested the change in autophagy and cell proliferation by inhibition of autophagy. The levels of the AMPK/mTOR pathway in autophagy regulation were detected by immunoblot analysis. An AMPK inhibitor and si-AMPK transfection in VSMCs was used to confirm whether AMPK activity plays a key role in autophagy regulation of Paeonol.

Results:In vivo experiments confirmed that Paeonol restricted atherosclerosis development and decreased the amount of VSMCs in the media layer of apoE^-/- mice. Paeonol increased protein levels of LC3II and the presence of autophagosomes in the media layer of arteries, which implies that Paeonol may induce VSMCs autophagy in vivo. Paeonol showed potential in inhibiting ox-LDL-induced proliferation in vitro experiments. Paeonol dose-dependently enhanced the formation of acidic vesicular organelles and autophagosmomes, up-regulated the expression of LC3II and increased p62 degradation. The autophagy inhibitor CQ obviously attenuated Paeonol-induced autophagy and the anti-proliferation effect in VSMCs. In addition, Paeonol induced phosphorylation of AMPK and reduced phosphorylation of mTOR. An AMPK inhibitor reversed the Paeonol-induced p-mTOR/mTOR decrease. Paeonol induced LC3II conversion, increased p62 degradation and inhibited cell proliferation in VSMCs, the effects of which were abolished by si-AMPK.

Conclusion: These results imply that Paeonol inhibits proliferation of VSMCs by up-regulating autophagy, and activating the AMPK/mTOR signaling pathway, providing new insights into the anti-atherosclerosis activity of Paeonol.

MicroRNA-21 suppresses ox-LDL-induced human aortic endothelial cells injuries in atherosclerosis through enhancement of autophagic flux: Involvement in promotion of lysosomal function

Atherosclerosis is a common pathological basis of cardiovascular disease and remains the leading cause of mortality. Endothelial cell (EC) injury and autophagy dysfunction have been proved to contribute to the development of atherosclerosis. Recently, accumulating evidence confirms that microRNAs (miRNAs) have emerged as vital regulators and fine-tuners of various pathophysiological cellular impacts and molecular signaling pathways involved in atherosclerosis. Herein, the objective of the present study was to explore the biological function of miR-21 in oxidized low-density lipoprotein (ox-LDL)-induced human aortic endothelial cells (HAECs) injury and the underlying molecular mechanism. The results showed that ox-LDL treatment significantly decreased HAECs viability, increased caspase-3 activity, apoptosis ratio and Bax protein expression, and reduced Bcl-2 protein expression resulting in EC injuries. Simultaneously, ox-LDL treatment obviously reduced miR-21 level in a time-and dose-dependent manner. Notably, ox-LDL-induced EC injuries were abolished by miR-21 mimics transfection. In addition, miR-21 mimics alleviated ox-LDL-induced impaired autophagic flux as illustrated by the increases in LC3-II/LC3-I ratio and Beclin-1 protein expression, and the decrease in p62 protein expression in HAECs. Moreover, ox-LDL suppressed the expressions of lysosomal membrane protein (LAMP1) and cathepsin D proteins, and attenuated cathepsin D activity in HAECs, leading to lysosomal dysfunction, while these effects were also blocked by miR-21 mimics. These findings indicated that miR-21 restored impaired autophagic flux and lysosomal dysfunction, thereby attenuating ox-LDL-induced HAECs injuries.

Study on the physicochemical properties and anti-inflammatory effects of paeonol in rats with TNBS-induced ulcerative colitis

Paeonol, an active component from Paeonia suffruticosa Andr., has a variety of biological activities, such as vascular endothelial cell protection, anti-oxidation, and anti-inflammation. The aim of this study was to investigate the basic physicochemical properties of paeonol, including solubility, oil-water partition coefficient, and permeability. Then evaluated the anti-inflammatory effects of paeonol were evaluated on 2,4,6-trinitrobenzenesulfonic acid-induced ulcerative colitis in rats. The rats were divided randomly into 6 groups, namely, normal, model, paeonol-treated (100, 200, and 400mg/kg), and positive. Each group had 10 rats. Inhibition effects were evaluated by the disease activity index (DAI), colon weight/length ratio, as well as macroscopical and histological evaluations. Serum interleukin (IL)-17, IL-6 and transforming growth factor beta 1 (TGF-β1) levels were determined by enzyme-linked immunosorbent assay. The solubility and oil-water partition coefficient of paeonol in different phosphate buffer solutions were 284.06-598.23 and 461.97-981.17μg/mL, respectively. The effective passive permeability value Pe was 23.49×10^-6cm/s. In terms of anti-inflammatory results, compared with the model group, treatment with 200 and 400mg/kg doses of paeonol had significantly decreased DAI, colon weight/length ratio, and macroscopic and histopathological scores. Furthermore, the serum levels of IL-17 and IL-6 were significantly reduced, whereas the TGF-β1 level was increased in the two paeonol-treated groups (medium- and high-dose group). Therefore, paeonol had poor water solubility, but oral absorption was good. In addition, paeonol had therapeutic effects on ulcerative colitis, and the therapeutic efficacy was dose dependent. The results presented in this study provide evidence for the development of a novel therapeutic agent in the treatment of UC. However, whether this agent could have therapeutic benefit or adverse effects in human IBD remains to be fully explored.

Attenuating Oxidative Stress by Paeonol Protected against Acetaminophen-Induced Hepatotoxicity in Mice

Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. The purpose of this study was to investigate whether paeonol protected against APAP-induced hepatotoxicity. Mice treated with paeonol (25, 50, 100 mg/kg) received 400 mg/kg acetaminophen intraperitoneally (i.p.) and hepatotoxicity was assessed. Pre-treatment with paeonol for 6 and 24 h ameliorated APAP-induced hepatic necrosis and significantly reduced the serum alanine aminotransferase (ALT) and aspartate transaminase (AST) levels in a dose-dependent manner. Post-treatment with 100 mg/kg paeonol ameliorated APAP-induced hepatic necrosis and reduced AST and ALT levels in the serum after APAP administration for 24 h. Western blot revealed that paeonol inhibited APAP-induced phosphorylated JNK protein expression but not p38 and Erk1/2. Moreover, paeonol showed anti-oxidant activities with reducing hepatic MDA contents and increasing hepatic SOD, GSH-PX and GSH levels. Paeonol dose-dependently prevented against H2O2 or APAP-induced LDH releasing and ROS production in primary mouse hepatocytes. In addition, the mRNA levels of pro-inflammatory genes such as TNF-α, MCP-1, IL-1β and IL-6 in the liver were dose-dependently reduced by paeonol pre-treatment. Pre-treatment with paeonol significantly inhibited IKKα/β, IκBα and p65 phosphorylation which contributed to ameliorating APAP-induced hepatic inflammation. Collectively, the present study demonstrates paeonol has a protective ability against APAP-induced hepatotoxicity and might be an effective candidate compound against drug-induced acute liver failure.

MicroRNAs in oral lichen planus and potential miRNA-mRNA pathogenesis with essential cytokines: a review

Oral lichen planus (OLP) is a potentially premalignant condition with unknown pathogenesis. Immune and inflammatory factors are thought to play important roles in the development of OLP, and cytokines, such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, can act as critical players in the immunopathogenesis of OLP. MicroRNAs (miRNAs) are closely correlated with cytokines in various inflammation-related diseases. In patients with OLP, miRNA-146a and miRNA-155 are increased in peripheral blood mononuclear cells, and numerous miRNAs have been shown to exhibit altered expression profiles in lesions. Although the microRNA-messenger RNA (miRNA-mRNA) network is thought to be involved in the development of OLP, in-depth studies are lacking. Here, we summarize current data on the mechanisms of action of miRNAs regulating typical cytokines in OLP, including interleukin (IL)-10, IL-17, IL-22, IFN-γ, and TNF-α, to study the genetic basis of the pathogenesis of OLP and to provide prospects of therapy.

The roles of macrophage autophagy in atherosclerosis

Although various types of drugs and therapies are available to treat atherosclerosis, it remains a major cause of mortality throughout the world. Macrophages are the major source of foam cells, which are hallmarks of atherosclerotic lesions. Consequently, the roles of macrophages in the pathophysiology of atherosclerosis are increasingly investigated. Autophagy is a self-protecting cellular catabolic pathway. Since its discovery, autophagy has been found to be associated with a variety of diseases, including cardiovascular diseases, malignant tumors, neurodegenerative diseases, and immune system disorders. Accumulating evidence demonstrates that autophagy plays an important role in inhibiting inflammation and apoptosis, and in promoting efferocytosis and cholesterol efflux. These facts suggest the induction of autophagy may be exploited as a potential strategy for the treatment of atherosclerosis. In this review we mainly discuss the relationship between macrophage autophagy and atherosclerosis and the molecular mechanisms, as well as the recent advances in targeting the process of autophagy to treat atherosclerosis.

Low-dose paeonol derivatives alleviate lipid accumulation

Here, we present a series of novel paeonol derivatives that prevent lipid accumulation at lower doses.