Osthole alleviates oxidized low-density lipoprotein-induced vascular endothelial injury through suppression of transforming growth factor-β1/Smad pathway

Fabrication of a biochar-doped monolithic adsorbent and its application for the extraction and determination of coumarins from Angelicae Pubescentis Radix

A monolithic adsorbent was designed aiming to the structure of osthole and columbianadin, and fabricated using diallyl phthalate as the monomer and ethylene dimethacrylate as the crosslinker with the addition of bamboo biochar, via polymerization reaction in a stainless-steel tube. The prepared composite adsorbent packed in the tube was used as a solid-phase extraction column for the extraction and determination of two coumarins (osthole and columbianadin) in Angelicae Pubescentis Radix, combing with a C18 analytical column through an HPLC instrument, which show excellent matrix-removal ability and good selectivity to osthole and columbianadin. Furthermore, the present adsorbent shows good applicability, which was used for the extraction of osthole from Duhuo Jisheng Pill. Compared to the commercial C18 and phenyl adsorbent, the present adsorbent own better selectivity and higher resolution. These results attributed to the enhanced specific surface area (141 m2/g) and enriched interaction sites of the resulting composite adsorbent, due to the doping of bamboo biochar, which can produce hydrogen bond, dipole-dipole, π-π and hydrophobic force interactions with the osthole and columbianadin. The methodology validation indicated that the present method showed good precision and good accuracy, and the composite adsorbent showed good preparative repeatability, which can be reused for no less than 100 times with the relative standard deviation ≤4.6 % (n = 100). The present work provided a simple and efficient method for the extraction and determination osthole and columbianadin from Angelicae Pubescentis Radix.

miR-125a-3p aggravates ox-LDL-induced HUVEC injury through BAMBI

Atherosclerosis (AS) is a chronic inflammatory disease characterized by the formation of atherosclerotic plaque in the intima of arteries. Among the known regulators of atherosclerosis, microRNAs (miRNAs) have been reported to play critical roles in lipoprotein homeostasis and plaque formation. But the roles of microRNA-125a-3p (miR-125a-3p) in the pathogenesis of AS remain unknown. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to construct the vascular injury model of AS pathogenesis in vitro. miR-125a-3p and BMP and activin membrane-bound inhibitor (BAMBI) expression levels in HUVECs were then measured by quantitative real-time polymerase chain reaction and western blot. The viability and apoptosis of HUVECs were analyzed by Cell Counting Kit-8 assay, TUNEL assay, and flow cytometry, respectively. The relationship between BAMBI 3'-untranslated region and miR-125a-3p was validated by dual luciferase reporter gene assay. miR-125a-3p expression was raised in HUVECs induced with ox-LDL. In HUVECs, miR-125a-3p enhanced the effects of ox-LDL treatment on repressing the viability and promoting the apoptosis of cells. Additionally, BAMBI was confirmed as a direct target of miR-125a-3p and BAMBI overexpression reversed the effects of miR-125a-3p on HUVECs. miR-125a-3p aggravates the dysfunction of HUVECs induced by ox-LDL via BAMBI, which implies that miR-125a-3p is involved in the pathogenesis of AS.

Galangin reduces vascular endothelial cell dysfunction via Heme oxygenase-1 signaling

OBJECTIVE

As one of the independent risk factors for atherosclerosis (AS), oxidized low-density lipoprotein (ox-LDL) can trigger damage to the vascular intima and induce the expression of various adhesion molecules. This study aimed to explore the effects of galangin, an extract of galangal, on ox-LDL-induced vascular endothelial cells.

METHODS

The effects of different concentrations of galangin or ox-LDL on the metabolic activity of vascular endothelial cells were determined using the CCK8 assay. Afterward, the role of galangin in the expression levels of inflammatory factors was assessed using RT-qPCR and Western blotting. In addition, the influences of galangin on apoptosis and endothelial-mesenchymal transition (EndMT) were also evaluated. Through molecular docking, the Heme oxygenase-1 (HO-1) signaling pathway was proposed, and then the effects of the HO-1 signaling pathway on the regulatory roles of galangin were evaluated.

RESULTS

In this study, galangin was found to effectively increase the metabolic activity of ox-LDL-induced cells in a concentration-dependent manner. In addition, galangin was found to reduce ox-LDL-induced cell inflammation, apoptosis, and EndMT. Moreover, galangin could combine with HO-1 and regulate the HO-1 signaling pathway. The effects of galangin on cells were shown to be through the HO-1 signaling pathway.

CONCLUSION

To sum up, galangin reduced ox-LDL-induced inflammation, apoptosis, and EndMT of vascular endothelial cells via regulating the HO-1 signaling pathway.

Astaxanthin suppresses End MT by LOX-1 pathway in ox-LDL-induced HUVECs

Introduction

Astaxanthin (ASX) is carotenoid with the highest antioxidant activity in various cell types and reverse atherosclerosis. However, the roles and detailed mechanisms of ASX in atherosclerosis associated endothelial injury remains unclear.

Methods

In vitro atherosclerosis model was established in HUVECs by incubation with oxidized low-density lipoprotein (ox-LDL). Cell viability and oxidative stress were measured. The mRNA and protein expressions of lectin-like ox-LDL receptor (LOX-1) and other related genes were determined.

Results

ox-LDL reduced cell viability of HUVECs, and induced oxidative stress, as evidenced by elevated cellular malondialdehyde (MDA) and decreased superoxide dismutase (SOD). Pretreatment with ASX (50, 100, 200, and 400 μM) markedly reversed the reduction in cell viability and an increase in migration of HUVECs induced by ox-LDL (50 μg/mL). ASX attenuated the increase in the endothelial-to-mesenchymal transition (EndMT) process, as evidenced by increased CD31 and decreased α-SMA and vimentin proteins by ASX treatment in HUVECs. Furthermore, ASX attenuated the increase in MDA and decrease in SOD induced by ox-LDL, increased supernatant NO production, attenuated the increase in iNOS and decrease in eNOS in HUVECs with ox-LDL. ASX enhanced mRNA and protein expressions of the lectin-like ox-LDL receptor (LOX-1), which was dependent on ASX’s antioxidant activity. The inhibitory effect of ASX on EndMT could be abolished by overexpression of LOX-1 in HUVECs induced by ox-LDL.

Conclusions

Our data speculate that ASX prevents ox-LDL-induced endothelial cell injury and EndMT by inducing antioxidant property (SOD and NO) and decreasing LOX-1 expression.

Metformin alleviates bevacizumab-induced vascular endothelial injury by up-regulating GDF15 and activating the PI3K/AKT/FOXO/PPARγ signaling pathway

Background

Previous studies have reported that the combination of metformin and bevacizumab exhibit favorable efficacy in the treatment of cancer patients, and metformin possesses effects on relieving vascular injury in multiple diseases. Nonetheless, the effect of metformin in alleviating bevacizumab-induced vascular injury remains unknown. Therefore, the present study aimed to investigate the impact of metformin on apoptosis, vascular endothelial injury marker expressions, and inflammation in human umbilical vein endothelial cells (HUVECs), as well as its possible molecular mechanism.

Methods

HUVECs were treated with bevacizumab, metformin or both, and subsequently treated with growth differentiation factor 15 (GDF15) overexpression plasmid, negative control (NC) plasmid, GDF15 small interfering ribonucleic acid (siRNA), NC siRNA, and the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, respectively. After treatment, apoptosis, levels of endothelial injury biomarkers and the potential downstream proteins were detected.

Results

Bevacizumab increased the levels of apoptosis, vascular endothelial injury marker expressions and pro-inflammatory cytokine expressions in HUVECs, while metformin alleviated these effects in bevacizumab-treated HUVECs. Furthermore, GDF15 overexpression reduced the apoptosis, vascular endothelial injury marker expressions, pro-inflammatory cytokine expressions, and activated the PI3K/protein kinase B (AKT)/forkhead box O (FOXO)/peroxisome proliferator-activated receptor γ (PPARγ) signaling pathway in bevacizumab-treated HUVECs. Subsequently, GDF15 siRNA reduced the effects of metformin on the bevacizumab-induced vascular endothelial injury (as described above) in HUEVCs. Lastly, the PI3K inhibitor exhibited similar effects to those of GDF15 siRNA in bevacizumab-treated HUVECs.

Conclusions

Metformin protected against bevacizumab-induced vascular endothelial injury via activation of GDF15 and the PI3K/AKT/FOXO/PPARγ signaling pathway.

Simvastatin inhibits POVPC-mediated induction of endothelial-to-mesenchymal cell transition

Endothelial-to-mesenchymal transition (EndMT), the process by which an endothelial cell (EC) undergoes a series of molecular events that result in a mesenchymal cell phenotype, plays an important role in atherosclerosis. 1-Palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), derived from the oxidation of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine, is a proinflammatory lipid found in atherosclerotic lesions. Whether POVPC promotes EndMT and how simvastatin influences POVPC-mediated EndMT remains unclear. Here, we treated human umbilical vein ECs with POVPC, simvastatin, or both, and determined their effect on EC viability, morphology, tube formation, proliferation, and generation of NO and superoxide anion (O2•-). Expression of specific endothelial and mesenchymal markers was detected by immunofluorescence and immunoblotting. POVPC did not affect EC viability but altered cellular morphology from cobblestone-like ECs to a spindle-like mesenchymal cell morphology. POVPC increased O2- generation and expression of alpha-smooth muscle actin, vimentin, Snail-1, Twist-1, transforming growth factor-beta (TGF-β), TGF-β receptor II, p-Smad2/3, and Smad2/3. POVPC also decreased NO production and expression of CD31 and endothelial NO synthase. Simvastatin inhibited POVPC-mediated effects on cellular morphology, production of O2•- and NO, and expression of specific endothelial and mesenchymal markers. These data demonstrate that POVPC induces EndMT by increasing oxidative stress, which stimulates TGF-β/Smad signaling, leading to Snail-1 and Twist-1 activation. Simvastatin inhibited POVPC-induced EndMT by decreasing oxidative stress, suppressing TGF-β/Smad signaling, and inactivating Snail-1 and Twist-1. Our findings reveal a novel mechanism of atherosclerosis that can be inhibited by simvastatin.

miR-4286/TGF-β1/Smad3-Negative Feedback Loop Ameliorated Vascular Endothelial Cell Damage by Attenuating Apoptosis and Inflammatory Response

Atherosclerosis (AS), known as the chronic inflammatory disease, results from the dysfunction of vascular endothelial cells (VECs). Transforming growth factor-β1 (TGF-β1) has been reported to be induced by oxidized low-density lipoprotein (ox-LDL) and contribute to AS-related vascular endothelial cell damage. This work planned to study the mechanism of TGF-β1 in vascular endothelial cell damage. We found that TGF-β1 was activated by ox-LDL in human umbilical vascular endothelial cells (HUVECs). Silence of TGF-β1 reversed the inductive effect of ox-LDL on apoptosis and inflammatory response of HUVECs. Mechanistically, microRNA-4286 (miR-4286) targeted and inhibited TGF-β1 to inhibit Smad3, and Smad3 bound to the promoter of miR-4286 to repress its transcription. Rescue assays indicated that miR-4286 ameliorated the ox-LDL-induced apoptosis and inflammatory response through inhibiting TGF-β1. In conclusion, our study first demonstrated that miR-4286/TGF-β1/Smad3-negative feedback loop ameliorated vascular endothelial cell damage by attenuating apoptosis and inflammatory response, providing new thoughts for promoting the treatment of AS.

Endothelial epithelial sodium channel involves in high-fat diet-induced atherosclerosis in low-density lipoprotein receptor-deficient mice

We previously showed that increased epithelial sodium channel (ENaC) activity in endothelial cells induced by oxidized low-density lipoprotein (ox-LDL) contributes to vasculature dysfunction. Here, we investigated whether ENaC participates in the pathological process of atherosclerosis using LDL receptor-deficient (LDLr^-/-) mice. Male C57BL/6 and LDLr^-/- mice were fed a normal diet (ND) or high fat diet (HFD) for 10 weeks. Our data show that treatment of LDLr^-/- mice with a specific ENaC blocker, benzamil, significantly decreased atherosclerotic lesion formation and expression of matrix metalloproteinase 2 (MMP2) and metalloproteinase 9 (MMP9) in aortic arteries. Furthermore, benzamil ameliorated HFD-induced impairment of aortic endothelium-dependent dilation by reducing expression of proinflammatory cytokines, including TNF-α, IL-1β, and IL-6 and production of adhesion molecules including VCAM-1 and ICAM-1 in both C57BL/6 and LDLr^-/- mice fed with HFD. In addition, HFD significantly increased ENaC activity and the levels of serum lipids, including ox-LDL. Our in vitro data further demonstrated that exogenous ox-LDL significantly increased the production of TNF-α, IL-1β, IL-6, VCAM-1 and ICAM-1. This ox-LDL-induced increase in inflammatory cytokines and adhesion molecules was reversed by γ-ENaC silencing or by treatment with the cyclooxygenase-2 (COX-2) antagonist celecoxib. Benzamil inhibited HFD-induced increase in COX-2 expression in aortic tissue in both C57BL/6 and LDLr^-/- mice, and γ-ENaC gene silencing attenuated ox-LDL-induced COX-2 expression in HUVECs. These data together suggest that HFD-induced activation of ENaC stimulates inflammatory signaling, thereby contributes to HFD-induced endothelial dysfunction and atherosclerotic lesion formation. Thus, targeting endothelial ENaC may be a promising strategy to halt atherogenesis.

Anti-Tumor Effects of Osthole on Different Malignant Tissues: A Review of Molecular Mechanisms

Cancer management and/or treatment require a comprehensive understanding of the molecular and signaling pathways involved. Recently, much attention has been directed to these molecular and signaling pathways, and it has been suggested that a number of biomolecules/players involved in such pathways, such as PI3K/Akt, NF-kB, STAT, and Nrf2 contribute to the progression, invasion, proliferation, and metastasis of malignant cells. Synthetic anti-tumor agents and chemotherapeutic drugs have been a mainstay in cancer therapy and are widely used to suppress the progression and, hopefully, halt the proliferation of malignant cells. However, these agents have some undesirable side-effects and, therefore, naturally-occurring compounds with high potency and fewer side-effects are now of great interest. Osthole is a plant-derived chemical compound that can inhibit the proliferation of malignant cells and provide potent anti-cancer effects in various tissues. Therefore, in this review, we presented the main findings concerning the potential anti-tumor effects of osthole and its derivatives and described possible molecular mechanisms by which osthole may suppress malignant cell proliferation in different tissues.

Systems Approach to Study Associations between OxLDL and Abdominal Aortic Aneurysms

Although abdominal aortic aneurysm (AAA) is a common vascular disease and is associated with high mortality, the full pathogenesis of AAA remains unknown to researchers. Abdominal aortic aneurysms and atherosclerosis are strongly related. Currently, it is more often suggested that development of AAA is not a result of atherosclerosis, however, individual factors can act independently or synergistically with atherosclerosis. One of such factors is low-density lipoprotein (LDL) and its oxidized form (oxLDL). It is known that oxLDL plays an important role in the pathogenesis of atherosclerosis, thus, we decided to examine oxLDL impact on the development of AAA by creating two models using Petri-nets. The first, full model, contains subprocess of LDL oxidation and all subprocesses in which it participates, while the second, reduced model, does not contain them. The analysis of such models can be based on t-invariants. They correspond to subprocesses which do not change the state of the modeled system. Moreover, the knockout analysis has been used to estimate how crucial a selected transition (representing elementary subprocess) is, based on the number of excluded subprocesses as a result of its knockout. The results of the analysis of our models show that oxLDL affects 55.84% of subprocesses related to AAA development, but the analysis of the nets based on knockouts and simulation has shown that the influence of oxLDL on enlargement and rupture of AAA is negligible.

Chromones with lipoprotein oxidation inhibitory activity from an endophytic fungus Alternaria brassicae JS959 derived from Vitex rotundifolia

Chemical investigation of the ethyl acetate extract of an endophytic fungus, Alternaria brassicae JS959 derived from a halophyte, Vitex rotundifolia, led to the isolation of a new chromone, (2'S)-2-(2-acetoxypropyl)-7-hydroxy-5-methylchromone (1), along with sixteen known compounds: a chromone (2), twelve benzopyranones (3-14) and three perylenequinones (15-17). The chemical structures of the isolated compounds were identified by extensive spectroscopic data analysis including 1D, 2D NMR, HRESIMS, and optical rotation. Of these compounds, 1 and 2 showed inhibitory activity on Cu²⁺‒induced low density lipoprotein (LDL) and high density lipoprotein (HDL) oxidation in human blood plasma. The results suggest that metabolites of endophytic microbes could provide the basis for developing treatments for heart disease.

The in vitro and in vivo anti-inflammatory effect of osthole, the major natural coumarin from Cnidium monnieri (L.) Cuss, via the blocking of the activation of the NF-κB and MAPK/p38 pathways

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory condition of the intestines and is difficult to cure once diagnosed. The efficacy of the current clinical treatment for UC is limited. Common anti-inflammatory drugs are prone to adverse effects, while novel biological agents are expensive, although tolerated by patients. Therefore, an urgency exists to find more safe and effective drugs to treat UC. Osthole is an active constituent isolated from the fruit of Cnidium monnieri (L.) Cuss. Osthole has anti-inflammatory activities and offers certain intestinal protection. These characteristics indicate that osthole has the potential to inhibit UC.

PURPOSE

The study was conducted to investigate the anti-inflammatory potential of osthole in LPS-induced RAW 264.7 cells and dextran sulphate sodium (DSS)-induced ulcerative colitis in mice.

METHODS

In in vitro experiments, mouse monocyte-macrophage RAW 264.7 cells were stimulated by 1 μg/ml LPS to produce inflammatory mediators. Griess reagent was used to determine Nitric Oxide (NO) production, and ELISA kits were used to determine the levels of PGE_2, TNF-α, and IL-6. The anti-inflammatory mechanisms of osthole were detected using western blot. In in vivo experiments, UC was induced via the intragastric administration of 3.5% DSS to BALB/C mice for 7 days. During the experiment, clinical signs and body weight were monitored and recorded daily to calculate the DAI score. At the end of the experiment, the colon lengths were measured. The colonic histopathological lesions were evaluated. MPO activity and TNF-α levels were determined using the corresponding kits. The protein expression of TNF-α and NF-κB pathways were analysed using western blot.

RESULTS

In an in vitro study, osthole inhibited the production of NO, PGE2, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells. The results of western blot showed that osthole inhibited the expression of iNOS, COX-2, p38 MAPK and IκB α in RAW 264.7 cells. On this basis, in DSS-induced UC mice, it was found that osthole relieved the symptoms of UC by inhibiting weight loss, colon shortening and the DAI score, and simultaneously alleviating colon tissue lesions. It was also found that osthole reduced the levels of TNF-α in serum and colon tissues and effectively inhibited the activity of MPO. The western blot results showed that osthole reduced the expression of NF-κB p65 and p-IκB α and increased the content of IκB α in colon tissues.

CONCLUSION

Osthole exerted anti-inflammatory effects by blocking the activation of the NF-κB and MAPK/p38 pathways. Additionally, osthole possesses therapeutic potential in the treatment of UC.