IGF-PLGA microspheres promote angiogenesis and accelerate skin flap repair and healing by inhibiting oxidative stress and regulating the Ang 1/Tie 2 signaling pathway

Random flaps are widely used in the treatment of injuries, tumors, congenital malformations, and other diseases. However, postoperative skin flaps are prone to ischemic necrosis, leading to surgical failure. Insulin-like growth factor- 1(IGF-1) belongs to the IGF family and exerts its growth-promoting effects in various tissues through autocrine or paracrine mechanisms. Its application in skin flaps and other traumatic diseases is relatively limited. Poly (lactic-co-glycolic acid) (PLGA) is a degradable high-molecular-weight organic compound commonly used in biomaterials. This study prepared IGF-PLGA sustained-release microspheres to explore their impact on the survival rate of flaps both in vitro and in vivo, as well as the mechanisms involved. The research results demonstrate that IGF-PLGA has a good sustained-release effect. At the cellular level, it can promote 3T3 cell proliferation by inhibiting oxidative stress, inhibit apoptosis, and enhance the tube formation ability of human umbilical vein endothelial cells (HUVEC) . At the animal level, it accelerates flap healing by promoting vascularization through the inhibition of oxidative stress. Furthermore, this study reveals the role of IGF-PLGA in activating the Angiopoietin-1(Ang1)/Tie2 signaling pathway in promoting flap vascularization, providing a strong theoretical basis and therapeutic target for the application of IGF-1 in flaps and other traumatic diseases.

A machine learning approach to predict cellular mechanical stresses in response to chemical perturbation

Mechanical stresses generated at the cell-cell level and cell-substrate level have been suggested to be important in a host of physiological and pathological processes. However, the influence various chemical compounds have on the mechanical stresses mentioned above is poorly understood, hindering the discovery of novel therapeutics, and representing a barrier in the field. To overcome this barrier, we implemented two approaches: 1) monolayer boundary predictor and 2) discretized window predictor utilizing either stepwise linear regression or quadratic support vector machine machine learning model to predict the dose-dependent response of tractions and intercellular stresses to chemical perturbation. We used experimental traction and intercellular stress data gathered from samples subject to 0.2 or 2 μg/mL drug concentrations along with cell morphological properties extracted from the bright-field images as predictors to train our model. To demonstrate the predictive capability of our machine learning models, we predicted tractions and intercellular stresses in response to 0 and 1 μg/mL drug concentrations which were not utilized in the training sets. Results revealed the discretized window predictor trained just with four samples (292 images) to best predict both intercellular stresses and tractions using the quadratic support vector machine and stepwise linear regression models, respectively, for the unseen sample images.

Hydrogels to Recapture Extracellular Matrix Cues That Regulate Vascularization

The ECM (extracellular matrix) is a 3-dimensional network that supports cellular responses and maintains structural tissue integrity in healthy and pathological conditions. The interactions between ECM and cells trigger signaling cascades that lead to phenotypic changes and structural and compositional turnover of the ECM, which in turn regulates vascular cell behavior. Hydrogel biomaterials are a powerful platform for basic and translational studies and clinical applications due to their high swelling capacity and exceptional versatility in compositions and properties. This review highlights recent developments and uses of engineered natural hydrogel platforms that mimic the ECM and present defined biochemical and mechanical cues for vascularization. Specifically, we focus on modulating vascular cell stimulation and cell-ECM/cell-cell interactions in the microvasculature that are the established biomimetic microenvironment.

Orychophragine D:A new 2-piperazinone fused 5-azacytosine type alkaloid with radioprotective activity from the seeds of Orychophragmus violaceus

A new alkaloid, Orychophragine D (1), together with three known alkaloids, were isolated from the seeds of Orychophragmus violaceus. Orychophragine D represented the first example of 2-piperazinone fused 5-azacytosine skeleton. Their structures and absolute configurations were determined by spectroscopic analyses and X-ray crystallography. Compared to Ex-RAD, compound 1 exhibited a significant radioprotective activity on cell survival of irradiated HUVEC. In vivo experiments showed that 1 not only remarkably enhanced the survival of irradiated mice in 30 days, but also significantly promoted the recovery of the blood system of irradiated mice. These results suggested that 1 was valuable for further research as promising radioprotectors.

The effect and mechanism of excessive iodine on the endothelial function of human umbilical vein endothelial cells

Iodine excess (IE) can cause thyroid dysfunction, thyroid diseases can adversely affect cardiovascular function. Accordingly, this study was to explore the direct and indirect effects of IE on endothelial function. Nthy-ori 3-1 and HUVECs cells were treated with potassium iodide (KI). CCK-8, LDH leakage, Elisa, RT-PCR and Western blotting were used to detect relevant indicators. Results showed that a certain level of KI can directly and indirectly reduce the viability of HUVECs and increase cytotoxicity. KI decreased the expression of ET-1 and VWF in HUVECs, inhibited the secretion of ET-1 in culture medium, and increased the expression of IL-6 and TNFα in HUVECs or Nthy-ori 3-1 cells alone. In the co-culture system, KI decreased the expression of ET-1 and THBD and increased the expression of TNFα and IL-6. Collectively, IE can directly and indirectly inhibit endothelial function of endothelial cells, which may be related to its induced inflammatory response.

Myristicin regulates proliferation and apoptosis in oxidized low-density lipoprotein-stimulated human vascular smooth muscle cells and human umbilical vein endothelial cells by regulating the PI3K/Akt/NF-κB signalling pathway

CONTEXT

Atherosclerosis (AS) is a chronic inflammatory disease. Human vascular smooth muscle cell (hVSMC) accumulation and human umbilical vein endothelial cell (HUVEC) dysfunction are associated with the pathogenesis of AS. This study explores whether myristicin plays a protective role in AS.

MATERIALS AND METHODS

hVSMCs and HUVECs were stimulated with 100 μg/mL oxidized low-density lipoprotein (ox-LDL) to establish a cellular model of AS. Cell viability, lactate dehydrogenase (LDH) release and cell apoptosis were evaluated using MTT, LDH and flow cytometry assays, respectively. Cell migration and inflammatory cytokine release were assessed using Transwell assay and ELISA.

RESULTS

Myristicin (5, 10, 25, and 50 μM) had no obvious effect on cell viability or the activity of LDH in hVSMCs, while 100 and 200 μM myristicin markedly suppressed hVSMCs viability and increased LDH release. Myristicin had no obvious effect on cell viability or the activity of LDH in HUVECs. Myristicin inhibited viability and increased apoptosis in ox-LDL-treated hVSMCs, but was associated with increased proliferation and inhibited apoptosis in HUVECs stimulated by ox-LDL. Additionally, myristicin markedly suppressed ox-LDL-induced hVSMCs migration and the release of inflammatory cytokines, including MCP-1, IL-6, VCAM-1 and ICAM-1, in HUVECs. Results also demonstrated that the promoting effects of ox-LDL on the PI3K/Akt and NF-κB signalling pathway in both hVSMCs and HUVECs were abolished by treatment with myristicin.

DISCUSSION AND CONCLUSIONS

Myristicin regulated proliferation and apoptosis by regulating the PI3K/Akt/NF-κB signalling pathway in ox-LDL-stimulated hVSMCs and HUVECs. Thus, myristicin may be used as a new potential drug for AS treatment.

Concanavalin A promotes angiogenesis and proliferation in endothelial cells through the Akt/ERK/Cyclin D1 axis

CONTEXT

Concanavalin A (Con A) exhibited multiple roles in cancer cells. However, the role of Con A in endothelial cells was not reported.

OBJECTIVE

Our present study investigated the potential angiogenic role of Con A in endothelial cells and ischaemic hind-limb mice.

MATERIALS AND METHODS

Human umbilical vein endothelial cells and Ea.hy926 cells were employed to determine the effect of Con A (0.3, 1, and 3 μg/mL) or vehicle on angiogenesis and cell proliferation with tube formation, ELISA, flow cytometry, EdU, and western blot. Hind-limb ischaemic mice were conducted to determine the pro-angiogenic effect of Con A (10 mg/kg) for 7 days.

RESULTS

Con A promoted tube formation to about three-fold higher than the control group and increased the secretion of VEGFa, PDGFaa, and bFGF in the medium. The cell viability was promoted to 1.3-fold by Con A 3 μg/mL, and cell cycle progression of G0G1 phase was decreased from 77% in the vehicle group to 70% in Con A 3 μg/mL, G2M was promoted from 15 to 19%, and S-phase was from 7 to 10%. Con A significantly stimulated phosphorylation of Akt and ERK1/2 and expression of cyclin D1 and decreased the expression of p27. These effects of Con A were antagonised by the PI3K inhibitor LY294002 (10 μM) and MEK pathway antagonist PD98059 (10 μM). Moreover, Con A (10 mg/kg) exhibited a repair effect in ischaemic hind-limb mice.

DISCUSSION AND CONCLUSIONS

This study will provide a new option for treating ischaemic disease by local injection with Con A.

Curcumin reduces blood-nerve barrier abnormalities and cytotoxicity to endothelial cells and pericytes induced by cisplatin

BACKGROUND

Cisplatin is a platinum-based antineoplastic agent used to treat cancers of solid organs. Neuropathy is one of its major side effects, necessitating dose reduction or cessation. Previous studies suggested that cisplatin causes microvascular toxicity, including pericyte detachment. This study aimed to clarify whether these alterations occurred in the blood-nerve barrier (BNB) of capillaries after cisplatin treatment.

MATERIALS AND METHODS AND RESULTS

Electron microscopic analysis of rat sciatic nerves with cisplatin neuropathy showed increased frequency and severity of pericyte detachment. Moreover, the vascular basement membrane did not tightly encircle around the endothelial cells and pericytes. Cultured human umbilical vein endothelial cells and human brain vascular pericytes showed reduced viability, increased caspase-3 activity and enhanced oxidative stress following cisplatin treatment. In addition, cisplatin decreased transendothelial electrical resistance (TEER) and the expression of the tight junction proteins occludin and zonula occludens-1. Curcumin, a polyphenol found in the root of Curcuma longa, had favourable effects on cisplatin neuropathy in previous work. Therefore, curcumin was tested to determine whether it had any effect on these abnormalities. Curcumin alleviated pericyte detachment, cytotoxicity, oxidative stress, TEER reduction and tight junction protein expression.

CONCLUSIONS

These data indicate that cisplatin causes BNB disruption in the nerves and might result in neuropathy. Curcumin might improve neuropathy via the restoration of BNB. Whether alterations in the BNB occur and curcumin is effective in patients with cisplatin neuropathy remain to be investigated.

Investigations on the Wound Healing Potential of Tilapia Piscidin (TP)2-5 and TP2-6

Wound healing is a highly orchestrated process involving many cell types, such as keratinocytes, fibroblasts and endothelial cells. This study aimed to evaluate the potential application of synthetic peptides derived from tilapia piscidin (TP)2, TP2-5 and TP2-6 in skin wound healing. The treatment of HaCaT keratinocytes with TP2-5 and TP2-6 did not cause cytotoxicity, but did enhance cell proliferation and migration, which could be attributed to the activation of epidermal growth factor receptor signaling. In CCD-966SK fibroblasts, although TP2-5 (31.25 μg/mL) and TP2-6 (125 μg/mL) showed cytotoxic effects, we observed the significant promotion of cell proliferation and migration at low concentrations. In addition, collagen I, collagen III, and keratinocyte growth factor were upregulated by the peptides. We further found that TP2-5 and TP2-6 showed pro-angiogenic properties, including the enhancement of human umbilical vein endothelial cell (HUVEC) migration and the promotion of neovascularization. In a murine model, wounds treated topically with TP2-5 and TP2-6 were reduced by day 2 post-injury and healed significantly faster than untreated wounds. Taken together, these findings demonstrate that both TP2-5 and TP2-6 have multifaceted effects when used as topical agents for accelerating wound healing.

MiR-221-3p targets HIPK2 to promote diabetic wound healing

Diabetic foot ulcer is a severe complication of diabetes and is prone to being a chronic non-healing wound. We previously demonstrated that endothelial progenitor cell-derived exosomes, which contain miR-221-3p, alleviate diabetic ulcers. Here, to explore the mechanisms underlying this wound healing, we investigated the potential angiogenic effects of miR-221-3p in vitro using cultured human umbilical vein endothelial cells (HUVECs) and in vivo using a streptozotocin-induced mouse model of diabetes. We found that miR-221-3p promoted HUVEC viability, migration, and capillary-like tube formation. HUVECs cultured in high glucose showed up-regulated expression of homeodomain-interacting protein kinase 2 (HIPK2), a predicted target of miR-221-3p that may decrease angiogenesis. Knockdown of HIPK2 enhanced high glucose-suppressed HUVEC viability, migration, and tube formation, counteracting the effects of high glucose. Using a dual luciferase reporter assay, we found that HIPK2 was indeed a direct target of miR-221-3p. Subcutaneous injection of miR-221-3p agomir into diabetic mice promoted wound healing and suppressed HIPK2 expression in wound margin tissue. These findings indicate that HIPK2, as a direct target of miR-221-3p, contributes to the regulatory role of miR-221-3p in diabetic wound healing and may be a novel therapeutic target for diabetic foot ulcer.

Preparation, Identification, Molecular Docking Study and Protective Function on HUVECs of Novel ACE Inhibitory Peptides from Protein Hydrolysate of Skipjack Tuna Muscle

To prepare bioactive peptides with high angiotensin-I-converting enzyme (ACE)-inhibitory (ACEi) activity, Alcalase was selected from five kinds of protease for hydrolyzing Skipjack tuna (Katsuwonus pelamis) muscle, and its best hydrolysis conditions were optimized using single factor and response surface experiments. Then, the high ACEi protein hydrolysate (TMPH) of skipjack tuna muscle was prepared using Alcalase under the optimum conditions of enzyme dose 2.3%, enzymolysis temperature 56.2 °C, and pH 9.4, and its ACEi activity reached 72.71% at 1.0 mg/mL. Subsequently, six novel ACEi peptides were prepared from TMPH using ultrafiltration and chromatography methods and were identified as Ser-Pro (SP), Val-Asp-Arg-Tyr-Phe (VDRYF), Val-His-Gly-Val-Val (VHGVV), Tyr-Glu (YE), Phe-Glu-Met (FEM), and Phe-Trp-Arg-Val (FWRV), with molecular weights of 202.3, 698.9, 509.7, 310.4, 425.6, and 606.8 Da, respectively. SP and VDRYF displayed noticeable ACEi activity, with IC₅₀ values of 0.06 ± 0.01 and 0.28 ± 0.03 mg/mL, respectively. Molecular docking analysis illustrated that the high ACEi activity of SP and VDRYF was attributed to effective interaction with the active sites/pockets of ACE by hydrogen bonding, electrostatic force, and hydrophobic interaction. Furthermore, SP and VDRYF could significantly up-regulate nitric oxide (NO) production and down-regulate endothelin-1 (ET-1) secretion in HUVECs after 24 h treatment, but also abolish the negative effect of 0.5 μM norepinephrine (NE) on the generation of NO and ET-1. Therefore, ACEi peptides derived from skipjack tuna (K. pelamis) muscle, especially SP and VDRYF, are beneficial components for functional food against hypertension and cardiovascular diseases.

The orphan receptor GPRC5B activates pro-inflammatory signaling in the vascular wall via Fyn and NFκB

BACKGROUND AND AIMS

Atherosclerosis is driven by an inflammatory process of the vascular wall. The novel orphan G-protein coupled receptor 5B of family C (GPRC5B) is involved in drosophila sugar and lipid metabolism as well as mice adipose tissue inflammation. Here, we investigated the role of GPRC5B in the pro-atherogenic mechanisms of hyperglycemia and vascular inflammation.

METHODS

Immortalized and primary endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) were used for stimulation with high glucose or different cytokines. Adenoviral- or plasmid-driven GPRC5B overexpression and siRNA-mediated knockdown were performed in these cells to analyze functional and mechanistic pathways of GPRC5B.

RESULTS

In ECs and VSMCs, stimulation with high glucose, TNFα or LPS induced a significant upregulation of endogenous GPRC5B mRNA and protein levels. GPRC5B overexpression and knockdown increased and attenuated, respectively, the expression of the pro-inflammatory cytokines TNFα, IL-1β, IL-6 as well as the pro-atherogenic vascular adhesion molecules ICAM-1 and VCAM-1. Furthermore, the expression and activity of the metalloproteinase MMP-9, a component of atherosclerotic plaque stabilization, were significantly enhanced by GPRC5B overexpression. Mechanistically, GPRC5B increased the phosphorylation of ERK1/2 and activated NFκB through a direct interaction with the tyrosine kinase Fyn.

CONCLUSIONS

Our findings demonstrate that GPRC5B is upregulated in response to high glucose and pro-inflammatory signaling. GPRC5B functionally modulates the inflammatory activity in cells of the vascular wall, suggesting a pro-atherogenic GPRC5B-dependent positive feedback loop via Fyn and NFκB. Thus, GPRC5B warrants further attention as a novel pharmacological target for the treatment of vascular inflammation and possibly atherogenesis.

Gut microbial metabolite TMAO increases peritoneal inflammation and peritonitis risk in peritoneal dialysis patients

Trimethylamine-N-oxide (TMAO), a gut microbiota-produced metabolite, is accumulated in chronic kidney disease (CKD) patients. It is well known to contribute to CKD-related cardiovascular complications. However, the effect of TMAO on peritoneal dialysis (PD)-related peritonitis remains largely unknown. Here, we demonstrate that serum concentrations of TMAO were positively correlated with C-reactive protein levels, and the appearance rate of dialysate IL-6 and PAI-1, in PD patients. During the follow-up period of 28.3 ± 8.0 months, patients with higher TMAO levels (≥50 μM) had a higher risk of new-onset peritonitis (HR, 3.60; 95%CI, 1.18-10.99; P=0.025) after adjusting for sex, age, diabetes, PD duration, BUN, rGFR, C-reactive protein, BMI and β2-M. In CKD rat models, TMAO significantly promoted peritoneal dialysate-induced inflammatory cell infiltration, inflammatory cytokines production in the peritoneum. In vitro study revealed that TMAO directly induced primary peritoneal mesothelial cell necrosis, together with increased production of pro-inflammatory cytokines including CCL2, TNF-α, IL-6, and IL-1β. In addition, TMAO significantly increased TNF-α-induced P-selectin production in mesothelial cells, as well as high glucose-induced TNF-α and CCL2 expression in endothelial cells. In conclusion, our data demonstrate that higher levels of TMAO exacerbate peritoneal inflammation and might be a risk factor of incidence of peritonitis in PD patients.

Cyclosporin-A reduced the cytotoxicity of propranolol in HUVECs via p38 MAPK signaling

Propranolol (PROP) is a nonselective β-adrenergic receptor antagonist used to treat hypertension and cardiac arrhythmias. Oral administration of PROP has recently emerged as a new treatment modality for hemangiomas. However, the side effects of PROP at the cellular level have not been adequately described.The present study investigates and highlights the mechanisms of coupling of the drugs cyclosporin-A (CyA) and PROP on cell proliferation and the occurrence of apoptosis. It also relays the antioxidant effect of PROP on human umbilical vein endothelial cells (HUVECs).HUVECs were treated with CyA and PROP. At 24 hours after treatment, the levels of reactive oxygen species (ROS), cell proliferation, and apoptosis were determined using the ROS kit, MTT assay, and Annexin V staining. In addition, the related proteins of phospho-p38 mitogen-activated protein kinase were determined by western blotting. Subsequently, HUVECs pretreated with CyA or PROP were treated with the p38 inhibitor (SB203580). Finally, the ROS level, cell proliferation, and apoptosis were measured again in both active HUVECs and HUVECs, in which the p38 proteins were inhibited.The combination of CyA and PROP reversed the effect of CyA on cell viability, reduced the ROS level and the cell apoptosis induced by PROP. Moreover, inhibition of p38 protein catalase activity immediately stopped the effect of CyA-propranolol in HUVECs.The effect of the CyA-propranolol combination on HUVECs is associated with the p38 pathway changes, which is proven to be a potential chemotherapeutic agent that minimizes the side effects of PROP in hemangioma therapy.

Dapagliflozin exerts anti-inflammatory effects via inhibition of LPS-induced TLR-4 overexpression and NF-κB activation in human endothelial cells and differentiated macrophages

Evidence has demonstrated that a new class of anti-diabetic drugs, sodium-glucose co-transporter 2 (SGLT2) inhibitors, could exert beneficial effects on atherosclerotic complications of diabetes. Atherosclerosis is widely accepted as an inflammatory disease. Therefore, we aimed to assess the direct anti-inflammatory effects of SGLT2 inhibitors dapagliflozin (DAPA) on two cell types involved in the process of atherogenesis. Human umbilical vein endothelial cells (HUVECs) and macrophages were exposed to DAPA and lipopolysaccharide (LPS 20 ng/mL) for 24 h under normal (5.5 mmol/L, NG) or high glucose (25 mmol/L, HG) conditions. Then, levels of TLR-4/p-NF-κB, inflammatory cytokines, inflammation-related miR-146a and miR-155 as well as alteration in the ratio of M1/M2 macrophage polarization was assessed. DAPA (0.5 μM) could significantly attenuate LPS-induced TLR-4 overexpression (23.9% and 33.1% under NG and HG conditions in HUVECs and 53.3% and 52.4% under NG and HG states in macrophages, respectively). NF-κB p65 phosphorylation was also significantly decreased to 30.1% under NG condition in HUVECs and 51.9% and 34.5% under NG and HG states in macrophages by 0.5 μM DAPA. Moreover, DAPA elevated expression levels of anti-inflammatory miR-146a, while values of miR-155 decreased in those cells. DAPA also caused a shift from inflammatory M1 macrophages toward M2-dominant macrophages. These data suggest that regardless of glucose concentrations, DAPA could exert direct anti-inflammatory effects, at least partly, by inhibiting the expression of TLR-4 and activation of NF-κB along with the secretion of pro-inflammatory mediators.

Transient Exposure of Endothelial Cells to Doxorubicin Leads to Long-Lasting Vascular Endothelial Growth Factor Receptor 2 Downregulation

Doxorubicin (Dox) is an effective antineoplastic drug with serious cardiotoxic side effects that persist after drug withdrawal and can lead to heart failure. Dysregulation of vascular endothelium has been linked to the development of Dox-induced cardiotoxicity, but it is unclear whether and how transient exposure to Dox leads to long-term downregulation of Endothelial Vascular Endothelial Growth Factor Receptor type2 (VEGFR2), essential for endothelial cells function. Using an in vitro model devised to study the long-lasting effects of brief endothelial cells exposure to Dox, we show that Dox leads to sustained protein synthesis inhibition and VEGFR2 downregulation. Transient Dox treatment led to the development of long-term senescence associated with a reduction in VEGFR2 levels that persisted days after drug withdrawal. By analyzing VEGFR2 turnover, we ruled out that its downregulation was depended on Dox-induced autophagy. Conversely, Dox induced p53 expression, reduced mTOR-dependent translation, and inhibited global protein synthesis. Our data contribute to a mechanistic basis to the permanent damage caused to endothelial cells by short-term Dox treatment.

Rutaecarpine Prevents High Glucose-Induced Endothelial Cell Senescence Through Transient Receptor Potential Vanilloid Subtype 1/ SIRT1 Pathway

ABSTRACT

SIRT1 functions as a longevity factor to counteract vascular aging induced by high glucose. Our previous study revealed that rutaecarpine, the natural agonist of transient receptor potential vanilloid subtype 1 (TRPV1), prevented high glucose-induced endothelial dysfunction. The present study aims to evaluate the effects of rutaecarpine on endothelial cell senescence induced by high glucose, and focus on the regulatory effect on SIRT1 expression. In cultured human umbilical vein endothelial cell (HUVEC), exposure to 33 mM high glucose for 72 hours induced cellular senescence, demonstrated as cell cycle arrest at G0/G1 phase, decreased cell viability, and increased number of senescence-associated β-galactosidase positive senescence cells and ROS production, which were effectively attenuated by treatment with rutaecarpine (0.3, 1, and 3 μM). Furthermore, rutaecarpine upregulated longevity protein SIRT1 expression in HUVECs, accompanied by decreased level of senescence marker p21. In addition, rutaecarpine increased intracellular calcium level in HUVECs, and pretreatment with TRPV1 antagonist capsazepine, intracellular Ca2+ chelator BAPTA-AM or CaM antagonist W-7 abolished the effects of rutaecarpine on SIRT1 expression. In summary, this study shows that rutaecarpine upregulates SIRT1 expression and prevents high glucose-induced endothelial cell senescence, which is related to activation of TRPV1/[Ca2+]i/CaM signal pathway. Our findings provide evidence that rutaecarpine may be a promising candidate with a novel mechanism in prevention vascular aging in diabetes.

Bioglass promotes wound healing by inhibiting endothelial cell pyroptosis through regulation of the connexin 43/reactive oxygen species (ROS) signaling pathway

Bioactive glass (BG) has recently shown great promise in soft tissue repair, especially in wound healing; however, the underlying mechanism remains unclear. Pyroptosis is a novel type of programmed cell death that is involved in various traumatic injury diseases. Here, we hypothesized that BG may promote wound healing through suppression of pyroptosis. To test this scenario, we investigated the possible effect of BG on pyroptosis in wound healing both in vivo and in vitro. This study showed that BG can accelerate wound closure, granulation formation, collagen deposition, and angiogenesis. Moreover, western blot analysis and immunofluorescence staining revealed that BG inhibited the expression of pyroptosis-related proteins in vivo and in vitro. In addition, while BG regulated the expression of connexin43 (Cx43), it inhibited reactive oxygen species (ROS) production. Cx43 activation and inhibition experiments further indicate that BG inhibited pyroptosis in endothelial cells by decreasing Cx43 expression and ROS levels. Taken together, these studies suggest that BG promotes wound healing by inhibiting pyroptosis via Cx43/ROS signaling pathway.

Inhibition of Src/STAT3 signaling-mediated angiogenesis is involved in the anti-melanoma effects of dioscin

Angiogenesis plays an important role in the growth and metastasis of solid tumors including melanoma. Inhibiting tumor-associated angiogenesis is a tactic in treating melanoma. Dioscin restrains angiogenesis in colon tumor and has anti-melanoma effects in cell and animal models. In a previous study, we found that dioscin inhibits Src/STAT3 signaling in melanoma cells. Activation of the Src/STAT3 pathway has been shown to promote tumor angiogenesis. This study aimed to determine whether dioscin's anti-melanoma effects is related to inhibiting Src/STAT3 signaling-mediated angiogenesis. In a B16F10 allograft mouse model, we found that dioscin inhibited melanoma growth and angiogenesis. To exclude the impact of tumor growth on angiogenesis, a chicken chorioallantoic membrane (CAM) model was used to verify the anti-angiogenic effect of dioscin. Results showed that dioscin suppressed vessel formation in CAM. To determine if tumor secreted pro-angiogenic cytokines are involved in the anti-angiogenic effect of dioscin, conditioned media from dioscin-treated A375 melanoma cells were used to culture human umbilical vein endothelial cells (HUVECs), and tube formation was monitored. It was observed that the tube formation of HUVECs was inhibited. Mechanistic studies revealed that dioscin inhibited the activation of Src and STAT3, and lowered mRNA and protein levels of STAT3 transcriptionally-regulated genes, in B16F10 melanomas. ELISA assays showed that dioscin decreased the secretion of MMP-2, MMP-9 and VEGF from A375 cells. Over-activation of STAT3 lessened the effects of dioscin in decreasing the secretion of pro-angiogenic cytokines from melanoma cells, and in inhibiting tube formation of HUVECs cultured with conditioned media from melanoma cell cultures. In summary, we for the first time demonstrated that inhibiting Src/STAT3 signaling-mediated angiogenesis is involved in the anti-melanoma effects of dioscin. This study provides further pharmacological groundwork for developing dioscin as an anti-melanoma agent.

Transdermal Delivery of a Hydrogen Sulphide Donor, ADT-OH Using Aqueous Gel Formulations for the Treatment of Impaired Vascular Function: an Ex Vivo Study

PURPOSE

Hydrogen sulphide (H₂S) is an important signalling molecule involved in the regulation of several physiological and pathophysiological processes. The objective of this study was to investigate the feasibility of transdermal delivery of ADT-OH, a H₂S donor, by investigating the transdermal flux of aqueous gels loaded with penetration enhancers or liposomes. Furthermore, we explored the ability of permeated ADT-OH to promote angiogenesis and mitochondrial bioenergetics in HUVEC cells.

METHODS

Aqueous hypromellose gels (5% w/v) were prepared with up to 10% v/v propylene glycol (PG) or deformable liposomes with 0.025% w/w ADT-OH. ADT-OH permeation from formulations across excised murine skin into PBS was quantified over 24 h using HPLC-UV detection. Media was collected and applied to HUVEC cells to evidence ADT-OH functionality following permeation. Tube formation assays were performed as indicative of angiogenesis and mitochondrial oxygen consumption was evaluated using a Seahorse XF24.

RESULTS

Increasing the loading of PG caused an increase in ADT-OH permeation rate across skin and a decrease in dermal drug retention whereas liposomal gels produced a slow-release profile. Treatment of HUVEC's using conditioned media collected from the ADT-OH loaded permeation studies enhanced tube formation and the basal oxygen consumption rates after 30 min of treatment.

CONCLUSIONS

These findings demonstrate that transdermal delivery of ADT-OH may provide a promising approach in the treatment of impaired vascular function. Gels prepared with 10% v/v PG have the potential for use in conditions requiring rapid H₂S release whereas liposomal loaded gels for treatment requiring sustained H₂S release.

Pharmacological inhibition of IRAK1 and IRAK4 prevents endothelial inflammation and atherosclerosis in ApoE-/- mice

Inflammation associated endothelial dysfunction represents a pivotal contributor to atherosclerosis. Increasingly, evidence has demonstrated that interleukin 1 receptor (IL1-R) / toll-like receptor (TLR) signaling participates in the development of atherosclerosis. Recent large-scale clinical trials have supported the therapeutic potential of anti-inflammatory therapies targeting IL-1β and IL-6 in reducing atherosclerosis. The present study examined the pharmacological effects of IL-1R-associated kinase 1 and 4 inhibitors (IRAK1/4i) in regulating inflammation of the endothelium and atherosclerosis. We demonstrate that dual pharmacological inhibition of IRAK1 and IRAK4 by an IRAK1/4i is more effective against LPS induced endothelial inflammation, compared with IRAK1 inhibitor or IRAK4 inhibitor monotherapy. IRAK1/4i showed little endothelial cell toxicity at concentrations from 1 μM up to 10 μM. Inhibition of IRAK1/4 reduced endothelial activation induced by LPS in vitro as evidenced by attenuated monocyte adhesion to the endothelium. Mechanistically, blockade of IRAK1/4 ameliorated the transcriptional activity of NF-κB. To assess the pharmacological effects of IRAK1/4i on atherosclerosis in vivo, ApoE-/- mice were orally administered IRAK1/4i (20 mg/kg/d) for 8 weeks. We show that IRAK1/4i reduced atherosclerotic lesion size in the aortic sinus and increased hepatic LDLR protein levels as well as lowered LDL-C level, without affecting other lipid parameters or glucose tolerance. Taken together, our findings demonstrate that dual pharmacological inhibition of IRAK1 and IRAK4 attenuates endothelial inflammation, lowers LDL-C levels and reduces atherosclerosis. Our study reinforces the evolving standing of anti-inflammatory approaches in cardiovascular therapeutics.

AICAR Protects Vascular Endothelial Cells from Oxidative Injury Induced by the Long-Term Palmitate Excess

Hyperlipidemia manifested by high blood levels of free fatty acids (FFA) and lipoprotein triglycerides is critical for the progression of type 2 diabetes (T2D) and its cardiovascular complications via vascular endothelial dysfunction. However, attempts to assess high FFA effects in endothelial culture often result in early cell apoptosis that poorly recapitulates a much slower pace of vascular deterioration in vivo and does not provide for the longer-term studies of endothelial lipotoxicity in vitro. Here, we report that palmitate (PA), a typical FFA, does not impair, by itself, endothelial barrier and insulin signaling in human umbilical vein endothelial cells (HUVEC), but increases NO release, reactive oxygen species (ROS) generation, and protein labeling by malondialdehyde (MDA) hallmarking oxidative stress and increased lipid peroxidation. This PA-induced stress eventually resulted in the loss of cell viability coincident with loss of insulin signaling. Supplementation with 5-aminoimidazole-4-carboxamide-riboside (AICAR) increased endothelial AMP-activated protein kinase (AMPK) activity, supported insulin signaling, and prevented the PA-induced increases in NO, ROS, and MDA, thus allowing to maintain HUVEC viability and barrier, and providing the means to study the long-term effects of high FFA levels in endothelial cultures. An upgraded cell-based model reproduces FFA-induced insulin resistance by demonstrating decreased NO production by vascular endothelium.

Resveratrol Promotes Angiogenesis in a FoxO1-Dependent Manner in Hind Limb Ischemia in Mice

Critical limb ischemia (CLI) is a severe form of peripheral artery diseases (PAD) and seriously endangers the health of people. Therapeutic angiogenesis represents an important treatment strategy for CLI; various methods have been applied to enhance collateral circulation. However, the current development drug therapy to promote angiogenesis is limited. Resveratrol (RSV), a polyphenol compound extracted from plants, has various properties such as anti-oxidative, anti-inflammatory and anti-cancer effects. Whether RSV exerts protective effects on CLI remains elusive. In the current study, we demonstrated that oral intake of RSV significantly improved hind limb ischemia in mice, and increased the expression of phosphorylated Forkhead box class-O1 (FoxO1). RSV treatment in human umbilical vein endothelial cells (HUVECs) could increase the phosphorylation of FoxO1 and its cytoplasmic re-localization to promote angiogenesis. Then we manipulated FoxO1 in HUVECs to further verify that the effect of RSV on angiogenesis is in a FoxO1-dependent manner. Furthermore, we performed metabolomics to screen the metabolic pathways altered upon RSV intervention. We found that the pathways of pyrimidine metabolism, purine metabolism, as well as alanine, aspartate and glutamate metabolism, were highly correlated with the beneficial effects of RSV on the ischemic muscle. This study provides a novel direction for the medical therapy to CLI.

Genistein alleviates H2O2-induced senescence of human umbilical vein endothelial cells via regulating the TXNIP/NLRP3 axis

CONTEXT

Genistein (Gen) has shown protective effects against ageing process.

OBJECTIVE

To explore the role of Gen on the senescence of H₂O₂-induced human umbilical vein endothelial cells (HUVECs) and investigate the possible mechanism.

MATERIALS AND METHODS

HUVECs were treated with different concentrations of H₂O₂ (50, 100, 200 and 400 μmol/L) for 1 h or Gen administration (20, 40, 80 and 160 μg/mL) for 24 h. Functional experiments (cell counting kit-8, β-galactosidase staining and flow cytometry) were used to detect the effect of Gen on H₂O₂-induced HUVECs. After HUVECs were transfected with TXNIP overexpression plasmids, the expression of p16, p21, thioredoxin-interacting protein (TXNIP), nucleotide-binding and oligomerization domain-like receptor 3 (NLRP3), cleaved caspase-3 and cleaved caspase-1 in HUVECs were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot.

RESULTS

H₂O₂ (200 and 400 μmol/L) inhibited the proliferation of HUVECs. At concentrations of >50 μmol/L, H₂O₂ induced the cell cycle progression arrests in G1 phase and promoted cell senescence of HUVECs. Gen had no obvious cytotoxicity to HUVECs below 160 µg/mL. H₂O₂-induced HUVEC senescence and the expression of TXNIP and NLRP3 in HUVECs were down-regulated by Gen (40 and 80 µg/mL). Expressions of TXNIP and NLRP3 in HUVECs were up-regulated by H₂O₂ but down-regulated by Gen. Overexpressed TXNIP partially reversed the suppressive effect of Gen on H₂O₂-induced senescence and apoptosis of HUVECs. Expressions of p16, p21, TXNIP, NLRP3, cleaved caspase-3 and cleaved caspase-1 in H₂O₂-treated HUVECs were inhibited by Gen, while the inhibition as such was partially reversed by overexpressed TXNIP.

DISCUSSION AND CONCLUSIONS

H₂O₂-induced HUVEC senescence was alleviated by Gen via suppressing the TXNIP/NLRP3 axis, which may offer a potential therapeutic approach for improving HUVEC senescence and provide a new direction for the treatment of cardiovascular disease.

The natural product vioprolide A exerts anti-inflammatory actions through inhibition of its cellular target NOP14 and downregulation of importin-dependent NF-ĸB p65 nuclear translocation

Chronic inflammation is characterized by persisting leukocyte infiltration of the affected tissue, which is enabled by activated endothelial cells (ECs). Chronic inflammatory diseases remain a major pharmacotherapeutic challenge, and thus the search for novel drugs and drug targets is an ongoing demand. We have identified the natural product vioprolide A (vioA) to exert anti-inflammatory actions in vivo and in ECs in vitro through inhibition of its cellular target nucleolar protein 14 (NOP14). VioA attenuated the infiltration of microglia and macrophages during laser-induced murine choroidal neovascularization and the leukocyte trafficking through the vascular endothelium in the murine cremaster muscle. Mechanistic studies revealed that vioA downregulates EC adhesion molecules and the tumor necrosis factor receptor (TNFR) 1 by decreasing the de novo protein synthesis in ECs. Most importantly, we found that inhibition of importin-dependent NF-ĸB p65 nuclear translocation is a crucial part of the action of vioA leading to reduced NF-ĸB promotor activity and inflammatory gene expression. Knockdown experiments revealed a causal link between the cellular target NOP14 and the anti-inflammatory action of vioA, classifying the natural product as unique drug lead for anti-inflammatory therapeutics.

Comparison of the antioxidant activities of nonfumigated and sulphur-fumigated Chrysanthemum morifolium cv. Hang-ju induced by oxidative stress

CONTEXT

The traditional drying method, sun drying, for Chrysanthemum morifolium Ramat. cv. Hang-ju (Compositae) (HJ) is widely replaced by sulphur fumigation (SF), which has an unknown effect on its efficacy.

OBJECTIVE

To investigate protective effects of nonfumigated HJ (NHJ) and sulphur-fumigated HJ (SHJ) water extracts against oxidative stress and lipid peroxidation.

MATERIALS AND METHODS

Sprague-Dawley rats were administered high-fat diet to induce hyperlipidaemia and randomly divided into eight groups (n = 6): control, fenofibrate, NHJ and SHJ extracts (1, 2 or 4 g crude drugs/kg/d; intragastric administration for 8 weeks). Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected. Human umbilical vein endothelial cells (HUVECs) were treated with NHJ and SHJ extracts (50, 100 or 200 μg/mL) for 24 h, followed by oxidized low-density lipoprotein (ox-LDL, 20 μg/mL) for 2 h in vitro. Cellular reactive oxygen species (ROS), SOD and MDA levels and apoptosis were evaluated.

RESULTS

NHJ was more effective than SHJ in decreasing serum TG, TC, LDL-C, LDL/HDL and MDA while increasing serum HDL-C and SOD levels at high doses. SHJ (IC₅₀=19.9 mg/mL) suppressed HUVEC growth stronger than NHJ (IC₅₀=186.7 mg/mL). At 200 μg/mL, NHJ was more effective than SHJ in downregulating ROS and MDA levels, reducing HUVECs apoptosis rate and elevating SOD activity in ox-LDL-treated HUVECs.

CONCLUSIONS

SF causes oxidative damage and attenuates antioxidative activity in ox-LDL-treated HUVECs, which promotes lipid peroxidation. SF is not recommended for processing HJ.

Gambogic amide inhibits angiogenesis by suppressing VEGF/VEGFR2 in endothelial cells in a TrkA-independent manner

CONTEXT

Gambogic amide (GA-amide) is a non-peptide molecule that has high affinity for tropomyosin receptor kinase A (TrkA) and possesses robust neurotrophic activity, but its effect on angiogenesis is unclear.

OBJECTIVE

The study investigates the antiangiogenic effect of GA-amide on endothelial cells (ECs).

MATERIALS AND METHODS

The viability of endothelial cells (ECs) treated with 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5 μM GA-amide for 48 h was detected by MTS assay. Wound healing and angiogenesis assays were performed on cells treated with 0.2 μM GA-amide. Chicken eggs at day 7 post-fertilization were divided into the dimethyl sulfoxide (DMSO), bevacizumab (40 μg), and GA-amide (18.8 and 62.8 ng) groups to assess the antiangiogenic effect for 3 days. mRNA and protein expression in cells treated with 0.1, 0.2, 0.4, 0.8, and 1.2 μM GA-amide for 6 h was detected by qRT-PCR and Western blots, respectively.

RESULTS

GA-amide inhibited HUVEC (IC₅₀ = 0.1269 μM) and NhEC (IC₅₀ = 0.1740 μM) proliferation, induced cell apoptosis, and inhibited the migration and angiogenesis at a relatively safe dose (0.2 μM) in vitro. GA-amide reduced the number of capillaries from 56 ± 14.67 (DMSO) to 20.3 ± 5.12 (62.8 ng) in chick chorioallantoic membrane (CAM) assay. However, inactivation of TrkA couldn't reverse the antiangiogenic effect of GA-amide. Moreover, GA-amide suppressed the expression of VEGF and VEGFR2, and decreased activation of the AKT/mTOR and PLCγ/Erk1/2 pathways.

CONCLUSIONS

Considering the antiangiogenic effect of GA-amide, it might be developed as a useful agent for use in clinical combination therapies.

Mechanism Analysis of Antiangiogenic d-Isofloridoside from Marine Edible Red algae Laurencia undulata in HUVEC and HT1080 cell

Laurencia undulata, as one of the most biologically active species in the genus Laurencia, is an edible folk herb red algae. Among them, d-isofloridoside (DIF, 940.68 Da) is isolated from Laurencia undulata, which has antioxidant and matrix metalloproteinases (MMP) inhibitory activities. However, its mechanism of action on tumor angiogenesis has not yet been reported. In this study, we have studied the mechanism of DIF on tumor metastasis and angiogenesis in HT1080 cell and human vascular endothelial cell (HUVEC). The results show that DIF can reduce the activity of MMP-2/9, and can inhibit the expression of hypoxia-inducible factor-1α (HIF-1α) by regulating the downstream PI3K/AKT and mitogen-activated protein kinases (MAPK) pathways, thereby down-regulating the production of vascular endothelial growth factor (VEGF) in CoCl₂-induced HT1080 cell. In addition, DIF can inhibit the activation of VEGF receptor (VEGFR-2), regulate downstream PI3K/AKT, MAPK, nuclear factor-kappa B (NF-κB) signal pathways, activate apoptosis, and thus down-regulate the production of platelet-derived growth factor (PDGF) in VEGF-induced HUVEC. In conclusion, our research shows that DIF has the potential to develop into a tumor-preventing functional food and tumor angiogenesis inhibitor, and it can provide theoretical guidance for the high-value comprehensive utilization of edible red algae Laurencia undulata.

ACE Inhibitory Peptide from Skin Collagen Hydrolysate of Takifugu bimaculatus as Potential for Protecting HUVECs Injury

Angiotensin-I-converting enzyme (ACE) is a crucial enzyme or receptor that catalyzes the generation of potent vasopressor angiotensin II (Ang II). ACE inhibitory peptides from fish showed effective ACE inhibitory activity. In this study, we reported an ACE inhibitory peptide from Takifugu bimaculatus (T. bimaculatus), which was obtained by molecular docking with acid-soluble collagen (ASC) hydrolysate of T. bimaculatus. The antihypertensive effects and potential mechanism were conducted using Ang-II-induced human umbilical vein endothelial cells (HUVECs) as a model. The results showed that FNLRMQ alleviated the viability and facilitated apoptosis of Ang-II-induced HUVECs. Further research suggested that FNLRMQ may protect Ang-II-induced endothelial injury by regulating Nrf2/HO-1 and PI3K/Akt/eNOS signaling pathways. This study, herein, reveals that collagen peptide FNLRMQ could be used as a potential candidate compound for antihypertensive treatment, and could provide scientific evidence for the high-value utilization of marine resources including T. bimaculatus.

Unraveling the Structured Solvation Shell of Zwitterion Nanoparticles for Controlled Release of Nitric Oxide

Zwitterions have been attracting emerging attention as an anti-fouling polymer. However, the relationship between structured solvation shells and controlled drug release induced by deceleration of water molecule's translational and vibrational motions of zwitterions is an uncharted territory. Herein, sulfobetaine zwitterion nanoparticles (ZWNPs) were designed as a stable nitric oxide (NO)-delivering carrier. The condensed water structure of the solvation shell at its isoelectric point (PI) and the loose structure of water under different pH conditions were investigated through rheological and thermodynamical analyses. The ZWNPs showed a sustained-release profile at the PI, which presented a structured solvation barrier. On the other hand, NO-loaded ZWNPs showed different release profiles with the burst release at pH 5.5. Notably, an increased cell proliferation rate and a decreased antibacterial effect were observed at the same concentration depending on solvation shell's characteristics.

Marine Bromophenol Bis(2,3,6-Tribromo-4,5-Dihydroxybenzyl)ether Inhibits Angiogenesis in Human Umbilical Vein Endothelial Cells and Reduces Vasculogenic Mimicry in Human Lung Cancer A549 Cells

Angiogenesis, including the growth of new capillary blood vessels from existing ones and the malignant tumors cells formed vasculogenic mimicry, is quite important for the tumor metastasis. Anti-angiogenesis is one of the significant therapies in tumor treatment, while the clinical angiogenesis inhibitors usually exhibit endothelial cells dysfunction and drug resistance. Bis(2,3,6-tribromo-4,5-dihydroxybenzyl)ether (BTDE), a marine algae-derived bromophenol compound, has shown various biological activities, however, its anti-angiogenesis function remains unknown. The present study illustrated that BTDE had anti-angiogenesis effect in vitro through inhibiting human umbilical vein endothelial cells migration, invasion, tube formation, and the activity of matrix metalloproteinases 9 (MMP9), and in vivo BTDE also blocked intersegmental vessel formation in zebrafish embryos. Moreover, BTDE inhibited the migration, invasion, and vasculogenic mimicry formation of lung cancer cell A549. All these results indicated that BTDE could be used as a potential candidate in anti-angiogenesis for the treatment of cancer.

Human Periodontal Ligament Stem Cell and Umbilical Vein Endothelial Cell Co-Culture to Prevascularize Scaffolds for Angiogenic and Osteogenic Tissue Engineering

(1) Background: Vascularization remains a critical challenge in bone tissue engineering. The objective of this study was to prevascularize calcium phosphate cement (CPC) scaffold by co-culturing human periodontal ligament stem cells (hPDLSCs) and human umbilical vein endothelial cells (hUVECs) for the first time; (2) Methods: hPDLSCs and/or hUVECs were seeded on CPC scaffolds. Three groups were tested: (i) hUVEC group (hUVECs on CPC); (ii) hPDLSC group (hPDLSCs on CPC); (iii) co-culture group (hPDLSCs + hUVECs on CPC). Osteogenic differentiation, bone mineral synthesis, and microcapillary-like structures were evaluated; (3) Results: Angiogenic gene expressions of co-culture group were 6–9 fold those of monoculture. vWF expression of co-culture group was 3 times lower than hUVEC-monoculture group. Osteogenic expressions of co-culture group were 2–3 folds those of the hPDLSC-monoculture group. ALP activity and bone mineral synthesis of co-culture were much higher than hPDLSC-monoculture group. Co-culture group formed capillary-like structures at 14–21 days. Vessel length and junction numbers increased with time; (4) Conclusions: The hUVECs + hPDLSCs co-culture on CPC scaffold achieved excellent osteogenic and angiogenic capability in vitro for the first time, generating prevascularized networks. The hPDLSCs + hUVECs co-culture had much better osteogenesis and angiogenesis than monoculture. CPC scaffolds prevacularized via hPDLSCs + hUVECs are promising for dental, craniofacial, and orthopedic applications.

Impact of aliphatic acyl and aromatic thioamide substituents on the anticancer activity of Ru(II)-p-cymene complexes with acylthiourea ligands-in vitro and in vivo studies

Six different acylthiourea ligands (L1-L6) and their corresponding Ru(II)-p-cymene complexes (P1-P6) were designed to explore the structure-activity relationship of the complexes upon aliphatic chain and aromatic conjugation on the C- and N-terminals, respectively. The compounds were synthesized and adequately characterized using various analytical and spectroscopic techniques. The structures of P2-P6, solved using single crystal X-ray diffraction (XRD), confirmed the neutral monodentate coordination of the S atoms of the acylthiourea ligands to Ru(II) ions. In silico studies showed an increase of lipophilicity for the ligands with an increase in alkyl chain length or aromatic conjugation at the C- or N-terminal, respectively. Subsequently, mitogen-activated protein kinases (MAPK) were predicted as one of the primary targets for the complexes, which showed good binding affinity towards extracellular signal-regulated kinases (ERK1, ERK2 and ERK5), c-Jun N-terminal kinase (JNK) and p38 of the MAPK pathway. Henceforth, the complexes were tested for their anticancer activity in lung carcinoma (A549) and cisplatin-resistant lung carcinoma (cisA549R) cells and human umbilical vein epithelial normal cells (HUVEC). Interestingly, an increase in chain length or aromatic conjugation led to an increase in the activity of the complexes, with P5 (7.73 and 13.04 μM) and P6 (6.52 and 14.45 μM) showing the highest activity in A549 and cisA549R cells, which is better than the positive control, cisplatin (8.72 and 44.28 μM). Remarkably, we report the highest activity yet observed for complexes of the type [(η6-p-cymene)RuIICl2(S-acylthiourea)] in the tested cell lines. Aqueous solution studies showed that complexes P5 and P6 are rapidly hydrolyzed to produce solely aquated species that remained stable for 24 h. Staining assays and flow cytometric analyses of P5 and P6 in A549 cells revealed that the complexes induced apoptosis and arrested the cell cycle predominantly in the S phase. In vivo studies demonstrated the higher toxicity of cisplatin and a comparatively higher survival rate of mice injected with the most active complex P6. Histological analyses revealed that treatment with P6 at high doses of up to 8 mg kg-1 did not cause any palpable damage to the tested organs.

Nutrigenomic Effect of Hydroxytyrosol in Vascular Endothelial Cells: A Transcriptomic Profile Analysis

Hydroxytyrosol (HT), a peculiar olive and olive oil phenolic antioxidant, plays a significant role in the endothelial and cardiovascular protection associated with olive oil consumption. However, studies examining the effects of HT on the whole-genome expression of endothelial cells, which are prominent targets for vasculo-protective effects of olive oil polyphenols, have been lacking. This study aims to comprehensively evaluate the genomic effects exerted by HT, at the transcriptional level, in endothelial cells under resting or proinflammatory conditions. Human umbilical vein endothelial cells (HUVECs) were treated with 10 µmol/L HT for 1 h and then stimulated with 5 ng/mL interleukin (IL)-1β for 3 h. Total RNA was extracted, and gene expression profile assessed with microarray analysis. Functional enrichment analysis and pathway analysis were performed by Ingenuity Pathways Analysis. Microarray data were validated by qRT-PCR. Fixing a significance threshold at 1.5-fold change, HT affected the expression of 708 and 599 genes, respectively, in HUVECs under resting and IL-1β-stimulated conditions; among these, 190 were common to both conditions. Unfolded protein response (UPR) and endoplasmic reticulum stress resulted from the two top canonical pathways common between HT and HT-IL-1β affected genes. IL-17F/A signaling was found in the top canonical pathways of HT modified genes under resting unstimulated conditions, whereas cardiac hypertrophy signaling was identified among the pathways affected by HT-IL-1β. The transcriptomic analysis allowed pinpointing immunological, inflammatory, proliferative, and metabolic-related pathways as the most affected by HT in endothelial cells. It also revealed previously unsuspected genes and related gene pathways affected by HT, thus broadening our knowledge of its biological properties. The unbiased identification of novel genes regulated by HT improves our understanding of mechanisms by which olive oil prevents or attenuates inflammatory diseases and identifies new genes to be enquired as potential contributors to the inter-individual variation in response to functional food consumption.

The effects of bathing in neutral bicarbonate ion water

Percutaneously absorbed carbon dioxide enhances blood flow. The mechanism by which it does so is unclear, but we hypothesized that it involves bicarbonate ions. BALB/c mice were bathed in neutral bicarbonate ionized water (NBIW) and showed increased blood bicarbonate levels and blood flow via phosphorylation of peripheral vascular endothelial nitric oxide synthase (eNOS) and production of nitric oxide (NO). Phosphorylation of eNOS and NO production were also increased in human umbilical vein endothelial cells cultured in medium containing NBIW, and NBIW showed reactive oxygen species scavenging activity. In a double-blind, randomized study in men and women aged 30 to 59 years with subjective cold intolerance, bathing in NBIW elevated body temperature faster than bathing in a control solution and improved chills and sleep quality. Taken together, our results show that percutaneously absorbed carbon dioxide changes to bicarbonate ions, which act directly on endothelial cells to increase NO production by phosphorylation of eNOS and thus improve blood flow.

PEDF is an endogenous inhibitor of VEGF-R2 angiogenesis signaling in endothelial cells

Pigment epithelium derived factor (PEDF), an endogenous inhibitor of angiogenesis, targets the growth of aberrant blood vessels in many tissues, including the eye. In this study we show that PEDF prevented early mitogenic signals of vascular endothelial growth factor (VEGF-A) in primate retinal endothelial cells, blocking proliferation, migration and tube formation. PEDF inhibited the phosphorylation and activation of five major downstream VEGF-A signaling partners, namely phosphoinositide-3-OH Kinase (PI3K), AKT, FAK, Src (Y416), and PLC-γ. It did so by binding to the extracellular domain of VEGF-R2, blocking VEGF-A-induced tyrosine phosphorylation (Tyr 951 and Tyr 1175), and inhibiting VEGF-R2 receptor kinase activity. PEDF had no effect on the transcription or translation of VEGF-R2 in cultured HUVECs. PEDF also bound to the extracellular domain of VEGF-R1. We conclude that PEDF blocks the growth of new blood vessels, in part, by reducing VEGF-A activation of its key mitogenic receptor, VEGF-R2, and by preventing its downstream signals in endothelial cells.

Long-Term Sustained Drug Delivery via 3D Printed Masks for the Development of a Heparin-Loaded Interlayer in Vascular Tissue Engineering Applications

Current approaches in small-diameter vascular grafts for coronary artery bypass surgeries fail to address physiological variations along the graft that contribute to thrombus formation and ultimately graft failure. We present an innovative interlayer drug delivery system that can be utilized for the sustained delivery of heparin through a graft with a high degree of temporal and spatial control. A heparin-loaded gelatin methacrylate (gelMA) interlayer sits within a biohybrid composed of decellularized bovine pericardium (dECM) and poly(propylene fumarate) (PPF), and its UV crosslinking is controlled via three-dimensional (3D) printed shadow masks. The masks can be readily designed to modulate the incident light intensity on the graft, enabling us to control the resultant gelMA crosslinking and properties. A high heparin loading efficiency was obtained in gelMA and was independent of crosslinking. We achieved sustained heparin release over the course of 2 weeks within the biohybrid material using the 3D printed mask patterns. High doses of heparin were observed to have detrimental effects on endothelial cell function. However, when exposed to heparin in a slower, more sustained manner consistent with the masks, endothelial cells behave similarly to untreated cells. Further, slower release profiles cause significantly more release of tissue factor pathway inhibitor, an anticoagulant, than a faster release profile. The heparin-loaded gelMA interlayer we have developed is a useful tool for the temporal and spatial control of heparin release that supports endothelial function and promotes an antithrombotic environment.

Morin hydrate inhibits atherosclerosis and LPS-induced endothelial cells inflammatory responses by modulating the NFκB signaling-mediated autophagy

Atherosclerosis (AS) is a chronic inflammatory disease involving blood vessels. Inflammation affects different cells and increases the expression of adhesion molecules. Morin hydrate (MO) is a naturally occurring bioflavonoid with anti-inflammatory and anti-oxidant effects. Although the exact mechanism has not been fully elucidated, MO possibly influences autophagy pathways in immunity and inflammation. In this study, MO showed the potential to inhibit atherosclerotic and promote vascular endothelial autophagy in apolipoprotein E (ApoE)-/- mice with a high-fat diet. Then, we aimed to explore the anti-inflammatory effects of MO in human umbilical vein endothelial cells (HUVECs) and its relationship with autophagy. We found that MO inhibited lipopolysaccharide (LPS)-induced monocyte adhesion and the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), cyclooxygenase-2 (COX-2), and matrix metallopeptidase 9 (MMP-9) in HUVECs. Moreover, MO reduced the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/nuclear factor kappa B (NFκB) signaling pathway. MO induced autophagy by inhibiting the NFκB signaling pathway in normal HUVECs and LPS-stimulated HUVECs. When autophagy was inhibited by 3-methyladenine (3-MA) or small interfering RNA (siRNA), the anti-inflammatory effect of MO was reduced. In conclusion, MO inhibits atherosclerosis in ApoE-/- mice and LPS-induced inflammatory responses by inhibiting the activation of the PI3K/Akt1/NFκB signaling pathway in a NFκB signaling-mediated autophagy way.

Human urinary kininogenase reduces the endothelial injury by inhibiting Pyk2/MCU pathway

The injury of endothelial cells is one of the initiating factors in restenosis after endovascular treatment. Human urinary kallidinogenase (HUK) is a tissue kallikrein which is used for ischemia-reperfusion injury treatment. Studies have shown that HUK may be a potential therapeutic agent to prevent stenosis after vascular injury, however, the precise mechanisms have not been fully established. This study is to investigate whether HUK can protect endothelial cells after balloon injury or H2O2-induced endothelial cell damage through the proline-rich tyrosine kinase 2 (Pyk2)/mitochondrial calcium uniporter (MCU) pathway. Intimal hyperplasia, a decrease of pinocytotic vesicles and cell apoptosis were found in the common carotid artery balloon injury and H2O2-induced endothelial cell damage, Pyk2/MCU was also up-regulated in such pathological process. HUK could prevent these injuries partially via the bradykinin B2 receptor by inhibiting Pyk2/MCU pathway, which prevented the mitochondrial damage, maintained calcium balance, and eventually inhibited cell apoptosis. Furthermore, MCU expression was not markedly increased if Pyk2 was suppressed by shRNA technique in the H2O2 treatment group, and cell viability was significantly better than H2O2-treated only. In short, our results indicate that the Pyk2/MCU pathway is involved in endothelial injury induced by balloon injury or H2O2-induced endothelial cell damage. HUK plays an protective role by inhibiting the Pyk2/MCU pathway in the endothelial injury.

Circ_USP36 Silencing Attenuates Oxidized Low-Density Lipoprotein-Induced Dysfunction in Endothelial Cells in Atherosclerosis Through Mediating miR-197-3p/ROBO1 Axis

ABSTRACT

Circular RNAs (circRNAs) are reported to play pivotal regulatory roles in atherosclerosis progression. In the present study, we explored the biological role of circRNA ubiquitin-specific peptidase 36 (circ_USP36; hsa_circ_0003204) in oxidized low-density lipoprotein (ox-LDL)-induced dysfunction of endothelial cells (ECs). RNA and protein levels were determined by reverse transcription-quantitative polymerase chain reaction and Western blot assay, respectively. Cell proliferation was analyzed by 5-ethynyl-2'-deoxyuridine assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry was conducted to analyze cell cycle progression and cell apoptosis. The release of tumor necrosis factor α in the supernatant was measured by enzyme linked immunosorbent assay. Cell death was evaluated by lactate dehydrogenase assay. Intermolecular interaction was verified by dual-luciferase reporter assay. Circ_USP36 expression was significantly up-regulated in the serum of atherosclerosis patients and ox-LDL-stimulated HUVECs than that in their corresponding controls. ox-LDL exposure inhibited the proliferation ability and cell cycle progression and triggered the apoptosis and inflammation of HUVECs, and these effects were largely overturned by the knockdown of circ_USP36. microRNA-197-3p (miR-197-3p) was a target of circ_USP36, and circ_USP36 knockdown-mediated protective role in ox-LDL-induced HUVECs was largely counteracted by the silence of miR-197-3p. miR-197-3p interacted with the 3' untranslated region of roundabout guidance receptor 1 (ROBO1). Circ_USP36 knockdown reduced ROBO1 expression partly by up-regulating miR-197-3p in HUVECs. ROBO1 overexpression reversed miR-197-3p accumulation-mediated effects in ox-LDL-induced HUVECs. In conclusion, circ_USP36 interference alleviated ox-LDL-induced dysfunction in HUVECs by targeting miR-197-3p/ROBO1 axis.

HMOX1 upregulation promotes ferroptosis in diabetic atherosclerosis

OBJECTIVE

Atherosclerotic vascular disease remains the principal cause of death and disability among patients with type 2 diabetes. Unfortunately, the problem is not adequately resolved by therapeutic strategies with currently available drugs or approaches that solely focus on optimal glycemic control. To identify the key contributors and better understand the mechanism of diabetic atherosclerotic vascular disease, we aimed to elucidate the key genetic characteristics and pathological pathways in atherosclerotic vascular disease through nonbiased bioinformatics analysis and subsequent experimental demonstration and exploration in diabetic atherosclerotic vascular disease.

METHODS AND RESULTS

Sixty-eight upregulated and 23 downregulated genes were identified from the analysis of gene expression profiles (GSE30169 and GSE6584). A comprehensive bioinformatic assay further identified that ferroptosis, a new type of programmed cell death and HMOX1 (a gene that encodes heme oxygenase), were vital factors in atherosclerotic vascular disease. We further demonstrated that diabetes significantly increased ferroptosis and HMOX1 levels compared to normal controls. Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated diabetic atherosclerosis, suggesting the causative role of ferroptosis in diabetic atherosclerosis development. At the cellular level, Fer-1 ameliorated high glucose high lipid-induced lipid peroxidation and downregulated ROS production. More importantly, HMOX1 knockdown attenuated Fe2+ overload, reduced iron content and ROS, and alleviated lipid peroxidation, which led to a reduction in ferroptosis in diabetic human endothelial cells.

CONCLUSIONS

We demonstrated that HMOX1 upregulation is responsible for the increased ferroptosis in diabetic atherosclerosis development, suggesting that HMOX1 may serve as a potential therapeutic or drug development target for diabetic atherosclerosis.

Quantification and cytotoxicity of degradation products (chloropropanols) in sucralose containing e-liquids with propylene glycol and glycerol as base

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

Astragaloside IV Inhibits Bleomycin-Induced Ferroptosis in Human Umbilical Vein Endothelial Cells by Mediating LPC

Ferroptosis, as an iron-dependent programmed cell death pathway, can induce a variety of cardiovascular diseases. Astragaloside IV (AS-IV), which is purified from Astragalus membranaceus, can protect endothelial function and promote vascular regeneration. However, the role played by AS-IV in ferroptosis remains unknown. In this study, the lipid metabolomics in HUVECs treated with/without bleomycin and/or AS-IV were explored using LC/MS. The most differential metabolite between groups was further identified via GO and pathway enrichment analyses. The effects of lysophosphatidylcholine (LPC), AS-IV, and FIN56 on cell viability were explored using the CCK-8 assay, their effects on cell senescence were examined by β-galactosidase staining, and their effects on ferroptosis were detected by a flow cytometric analysis of lipid ROS levels, transmission electron microscopy, and an assay for cellular iron levels. The related mechanisms were investigated by real-time PCR and Western blot assays. Our results showed that LPC, as the most differential metabolite, inhibited cell viability but promoted cell apoptosis and senescence as its concentration increased. Also, the decreased cell activity, increased iron ion and lipid ROS levels, and the enhanced cell senescence induced by LPC treatment were all significantly reversed by AS-IV but further enhanced by FIN56 treatment. The changes in mitochondrial morphology caused by the LPC treatment were significantly alleviated by the AS-IV treatment, while treatment with FIN56 reversed those phenomena. Moreover, AS-IV partially upregulated the levels of SLC7A11 and GPX4 expression which were reduced by LPC. However, those changes were prevented by FIN56 treatment. In conclusion, our data suggested that AS-IV could serve as a novel drug for treating ferroptosis-related diseases.

Activation of cannabinoid receptor 2 alleviates glucocorticoid-induced osteonecrosis of femoral head with osteogenesis and maintenance of blood supply

In glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH), downregulated osteogenic ability and damaged blood supply are two key pathogenic mechanisms. Studies suggested that cannabinoid receptor 2 (CB2) is expressed in bone tissue and it plays a positive role in osteogenesis. However, whether CB2 could enhance bone formation and blood supply in GC-induced ONFH remains unknown. In this study, we focused on the effect of CB2 in GC-induced ONFH and possible mechanisms in vitro and in vivo. By using GC-induced ONFH rat model, rat-bone mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) to address the interaction of CB2 in vitro and in vivo, we evaluate the osteogenic and angiogenic effect variation and possible mechanisms. Micro-CT, histological staining, angiography, calcein labeling, Alizarin red staining (ARS), alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) staining, TUNEL staining, migration assay, scratch assay, and tube formation were applied in this study. Our results showed that selective activation of CB2 alleviates GC-induced ONFH. The activation of CB2 strengthened the osteogenic activity of BMSCs under the influence of GCs by promotion of GSK-3β/β-catenin signaling pathway. Furthermore, CB2 promoted HUVECs migration and tube-forming capacities. Our findings indicated that CB2 may serve as a rational new treatment strategy against GC-induced ONFH by osteogenesis activation and maintenance of blood supply.

Composition of Algerian Propolis, Plant Origin, and Its Antiangiogenic Activity In Vitro

The antiangiogenic activity of the ethanol extract of propolis collected from different regions in western Algeria was investigated using in vitro human umbilical vein endothelial cells (HUVECs). The ethanol extract with the strongest activity, i.e., Algerian propolis 1 (EEPA1), inhibited the formation of capillary networks in a dose-dependent manner (6.25–50 μg/mL) within 12 h and induced cell fragmentation of HUVECs at 50 μg/mL after treatment for 24 h. To identify the active compounds in EEAP1, a high-performance liquid chromatography (HPLC) analysis was performed, revealing that EEAP1 contains two major compounds. Both compounds were isolated by repeated column chromatography and identified as ω-hydroxyferulenol (1) and ferulenol (2), which have a coumarin structure conjugated with a farnesyl group according to NMR, high-resolution electrospray ionization mass spectroscopy, and chemical modification. Compounds 1 and 2 inhibited the tube-forming activity of HUVECs, especially 2, which exhibited a stronger antiangiogenic effect even at a low concentration of 3.31 μg/mL. Moreover, 2 suppressed the elongation and induced cell fragmentation at the same dose. The molecular changes in tube-forming HUVECs induced by 2 were found to be related to the activation of the caspase signals. To confirm the plant origin of propolis, an HPLC comparative analysis of the ethanol extracts of some plants near beekeeping areas and that of Algerian propolis (EEAP1) was performed, and similar chromatographic patterns were observed. This result suggests that the plant origin of this Algerian propolis is the resin of Ferula communis.

Low Dose of IL-2 Normalizes Hypertension and Mitochondrial Function in the RUPP Rat Model of Placental Ischemia

IL-2 is a cytokine released from CD4+T cells with dual actions and can either potentiate the inflammatory response or quell a chronic inflammatory response depending on its circulating concentration. IL-2 is elevated in many chronic inflammatory conditions and is increased during preeclampsia (PE). PE is characterized by new-onset hypertension during pregnancy and organ dysfunction and increasing evidence indicates that proinflammatory cytokines cause hypertension and mitochondrial (mt) dysfunction during pregnancy. The reduced uterine perfusion pressure (RUPP) model of placental ischemia is a rat model of PE that we commonly use in our laboratory and we have previously shown that low doses of recombinant IL-2 can decrease blood pressure in RUPP rats. The objective of this study was to determine the effects of a low dose of recombinant IL-2 on multi-organ mt dysfunction in the RUPP rat model of PE. We tested our hypothesis by infusing recombinant IL-2 (0.05 ng/mL) into RUPP rats on GD14 and examined mean arterial pressure (MAP), renal, placental and endothelial cell mt function compared to control RUPP. MAP was elevated in RUPP rats (n = 6) compared to controls (n = 5) (122 ± 5 vs. 102 ± 3 mmHg, p < 0.05), but was reduced by administration of LD recombinant IL-2 (107 ± 1 vs. 122 ± 5 mmHg, n = 9, p < 0.05). Renal, placental and endothelial mt ROS were significantly increased in RUPP rats compared to RUPP+ IL-2 and controls. Placental and renal respiration rates were reduced in RUPP rats compared to control rats but were normalized with IL-2 administration to RUPPs. These data indicate that low-dose IL-2 normalized multi-organ mt function and hypertension in response to placental ischemia.

Systems pharmacological study based on UHPLC-Q-Orbitrap-HRMS, network pharmacology and experimental validation to explore the potential mechanisms of Danggui-Shaoyao-San against atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS) plays an important role in the pathogenesis of cardiovascular and cerebrovascular diseases. Danggui-Shaoyao-San (DSS) is not only a representative Chinese formula to treat gynecological disorder, but also found its use in AS-related diseases. However, the active ingredients and the anti-AS effects are vague yet.

AIM OF THE STUDY

An integrated strategy combined ultrahigh-performance liquid chromatography quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS), network pharmacology and experiments was carried out to investigate the potential materials and pharmacological mechanisms of DSS for AS.

MATERIALS AND METHODS

First, UHPLC-Q-Orbitrap-HRMS was applied to identify the active compositions of DSS. Then, the putative targets of DSS relevant to AS were predicted from TCMSP and BATMAN, which were further determined through bioinformatic analyses, including protein-protein interactions (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, Western blot, qPCR and ELISA were carried out for target validation in human umbilical vein endothelial cells (HUVECs).

RESULTS

A total of 37 active ingredients of DSS, connecting 47 key targets were identified. The functional enrichment showed that DSS may treat AS through regulating a series of signaling pathways which involving inflammatory responses, immune systems and metabolism. The in vitro experiment revealed that DSS ameliorated AS mainly through anti-inflammatory effects, by reducing the levels of vascular cell adhesion molecule-1 (VCAM1), intercellular adhesion molecule-1 (ICAM1), IL-6, TNF-α, cyclooxygenase-2 (Cox-2) and IL-1β. DSS also inhibited the phosphorylation of IκB-α, NF-κB (p65), p38 and JNK in lipopolysaccharide (LPS)-induced HUVEC injury model. Moreover, as the main bioactive compounds of DSS, paeoniflorin (PF), ferulic acid (FA) and pachymic acid (PA) inhibited IL-6 and TNF-α secretion as well as IκB-α, NF-κB (p65), p38 and JNK activation. All these findings were consistent with the predicted targets and pathways.

CONCLUSION

Collectively, the basic pharmacological effects and relevant mechanisms of DSS in the treatment of AS were revealed. The results suggest that DSS is a potential drug for AS treatment, and PF, FA, PA may be the core compositions contributing to the pharmacological function of this formula.

Circ-USP9X Inhibition Reduces Oxidized Low-density Lipoprotein-induced Endothelial Cell Injury via the microRNA 599/Chloride Intracellular Channel 4 Axis

ABSTRACT

Atherosclerosis (AS) is the common pathological basis of cardiovascular disease. Circular RNA circ-USP9X (hsa_circ_0090231) has been discovered to be upregulated in oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs), but the role of circ-USP9X in ox-LDL-induced endothelial cell injury is indistinct. The purpose of the research was to investigate the role and regulatory mechanism of circ-USP9X in ox-LDL--induced endothelial cell injury. Expression of circ-USP9X was examined by quantitative real-time polymerase chain reaction. Loss-of-function experiments were performed to assess the impacts of circ-USP9X inhibition on viability, cell cycle progression, apoptosis, and tube formation, inflammation, and oxidative stress of ox-LDL-induced HUVEC. The regulatory mechanism of circ-USP9X predicted by bioinformatics analysis and verified by dual-luciferase reporter or RNA immunoprecipitation assays. We observed that circ-USP9X was upregulated in AS patients' serum and ox-LDL-induced HUVEC. Inhibition of circ-USP9X elevated viability, promoted cell cycle progression and angiopoiesis, and decreased apoptosis, inflammation, and oxidative stress of ox-LDL-induced HUVEC. Mechanically, circ-USP9X regulated chloride intracellular channel 4 (CLIC4) messenger RNA expression by sponging microRNA (miR)-599. Furthermore, miR-599 inhibitor overturned circ-USP9X silencing-mediated influence on ox-LDL-induced HUVEC injury. Also, CLIC4 overexpression reversed miR-599 elevation-mediated effect on ox-LDL-induced HUVEC injury. In conclusion, circ-USP9X silencing decreased ox-LDL-induced endothelial cell injury via the miR-599/CLIC4 axis, which offered a novel molecular mechanism to comprehend the pathology of AS.

Effect of heparinization on promoting angiogenesis of decellularized kidney scaffolds

Native decellularized extracellular matrix provides an adequate platform for tissues and organs and promotes the development of organogenesis and tissue remodeling. However, thrombosis poses a great challenge that hinders the transplantation for a substantial organ in vivo. Therefore, anticoagulation and re-reendothelialization of organ biological scaffolds are the primary concerns to be addressed before orthotopic transplantation. Herein, a heparinized decellularized kidney scaffold (HEP-DKSs) was prepared using end-point attachment technology, followed by binding the vascular endothelial growth factor (VEGF) to greatly improve the hemocompatibility and angiogenesis of DKSs. Based on the anticoagulant, co-culture of human umbilical vein endothelial cells, and subcapsular transplantation of kidney experiments, HEP-VEGF-DKSs are shown to reduce platelet adhesion, which is crucial for subsequent vascularization and slow release of heparin and VEGF, suggesting its ability of improve neovascularization. Taken together, these data indicated an optimal anticoagulation function of HEP-VEGF-DKSs and the potential of vascularization for regeneration of whole decellularized kidney.

Omega-3 and omega-6 fatty acids have distinct effects on endothelial fatty acid content and nitric oxide bioavailability

Treatment with high dose icosapent ethyl (IPE), an ethyl ester of the omega-3 fatty acid eicosapentaenoic acid (EPA), significantly reduced ischemic events in patients with either cardiovascular disease (CV) or diabetes plus other risk factors (REDUCE-IT) but the mechanism is not well understood.  We compared the effects of EPA, docosahexaenoic acid (DHA), and the omega-6 fatty acid arachidonic acid (AA) on bioavailability of nitric oxide (NO) and fatty acid composition. Human umbilical vein endothelial cells (HUVECs) were pretreated with EPA, DHA, or AA (10 µM). Cells were stimulated with calcium ionophore and NO and peroxynitrite (ONOO^-) were measured using porphyrinic nanosensors. Levels of EPA, DHA, AA and other fatty acids were measured by gas chromatography (GC). EPA treatment caused the greatest NO release (18%, p < 0.001) and reduction in ONOO^- (13%, p < 0.05) compared to control; the [NO]/[ ONOO^-] ratio increased by 35% (p < 0.001). DHA treatment increased NO levels by 12% (p < 0.01) but had no effect on ONOO^- release. AA did not affect either NO or ONOO^- release.  Fatty acid treatments increased their respective levels in endothelial cells.  EPA levels increased 10-fold to 4.59 mg/g protein (p < 0.001) with EPA treatment and the EPA/AA ratio increased by 10-fold (p < 0.001) compared to vehicle.  Only EPA increased docosapentaenoic acid (DPA, omega-3) levels by 2-fold (p < 0.001). AA alone decreased the EPA/AA ratio 4-fold (p<0.001). These findings support a preferential benefit of EPA on endothelial function and omega-3 fatty acid content.