Human umbilical vein endothelial cells and human dermal microvascular endothelial cells offer new insights into the relationship between lipid metabolism and angiogenesis

E-selectin-targeted Sialic Acid-PEG-dexamethasone Micelles for Enhanced Anti-Inflammatory Efficacy for Acute Kidney Injury

The effective treatment for acute kidney injury (AKI) is currently limited, and care is primarily supportive. Sialic acid (SA) is main component of Sialyl Lewisx antigen on the mammalian cell surface, which participates in E-selectin binding. Therefore, dexamethasone(DXM)-loaded E-selectin-targeting sialic acid-polyethylene glycol-dexamethasone (SA-PEG-DXM/DXM) conjugate micelles are designed for ameliorating AKI. The conjugates are synthesized via the esterification reaction between PEG and SA or DXM, and can spontaneously form micelles in an aqueous solution with a 65.6 µg/mL critical micelle concentration. Free DXM is incorporated into the micelles with 6.28 ± 0.21% drug loading content. In vitro DXM release from SA-PEG-DXM/DXM micelles can be prolonged to 48h. Much more SA-PEG-DXM micelles can be internalized by lipopolysaccharide (LPS)-activated human umbilical vein endothelial cells (HUVECs) in comparison to PEG-DXM micelles due to specific interaction between SA and E-selectin expressed on HUVECs, and consequently more SA-PEG-DXM micelles are accumulated in the kidney of AKI murine model. Furthermore, SA in SA-PEG-DXM conjugates can significantly ameliorate LPS-induced production of pro-inflammatory cytokines via suppressing LPS-activated Beclin-1/Atg5-Atg12-mediated autophagy to attenuate toxicity. Compared with free DXM and PEG-DXM/DXM micelles, SA-PEG-DXM/DXM micelles show better therapeutical effects, as reflected by the improved renal function, histopathological changes, pro-inflammatory cytokines, oxidative stress and expression of apoptotic related proteins.

Mechanisms of Tanshinone II a inhibits malignant melanoma development through blocking autophagy signal transduction in A375 cell

Background

Malignant melanoma (MM) is one of the high degree of malignancy and early prone to blood and lymph node metastasis. There is not cured for MM. Tan II A has been reported to reduce cancer cell proliferation. But the mechanism by which Tan II A inhibited melanoma growth are not well characterized. We sought to explore the possible mechanism by which Tan II A regulated cell proliferation through autophagy signaling pathway in A375 cells.

Methods

We tested the effects of Tan II A on melanoma A375, MV3, M14, and other human cell lines including Hacat and HUVEC cells in cell culture model. Cell proliferation was assessed by using methyl thiazol tetrazolium (MTT) assay. Cell migration ability melanoma A375 was monitored by using cell scratch assay. Transwell chamber experimental was performed to assess the effect of Tan II A on A375 melanoma cell invasion ability. The autophagy body was examined by using flow cytometry. The expression of autophagy-associated protein beclin-1 and microtubule-associated protein 1 light chain 3(LC3)-II, as well as phosphatidylinositol 3-kinase(PI3K)、protein kinase B (Akt)、mammalian target of rapamycin (mTOR)、p70S6K1 signaling pathways were detected by using Western blotting. The effects of Tan II A on tumor progression was also examined in melanoma A375 induced tumor in mouse model.

Results

We found that Tan IIA inhibited melanoma A375, MV3, and M14 cell proliferation in dose and time dependent manner. Tan II A reduced CXCL12-induced A375 cell invasive ability and migration in a dose dependent manner. Tan IIA promoted autophagic body production and increased autophagy-associated protein beclin-1 and LC3-II expression in A375 cells. However, Tan IIA reduced the phosphorylation of PI3K, P-AKT, P-mTOR, and P-p7036k1. We also confirmed that Tan II A reduced melanoma A375 induced tumor volume and weight in mouse model.

Conclusions

We concluded that Tan II A reduced A375 cells proliferation by activation of autophagy production, blocked PI3K- Akt – mTOR - p70S6K1 signaling pathway, increased autophagic related gene beclin-1, LC3-II protein expressions and induced autophagocytosis. Tan II A inhibited melanoma A375 induced tumor development in mouse model.

Ginsenoside Rd regulates the Akt/mTOR/p70S6K signaling cascade and suppresses angiogenesis and breast tumor growth

Blockade of angiogenesis is an important approach for cancer treatment and prevention. In the present study, we investigated the effect of ginsenoside Rd (Rd) on angiogenesis in vitro and in vivo. Our results demonstrated that Rd inhibited vascular endothelial growth factor (VEGF)-induced migration, tube formation and proliferation of primary cultured human umbilical vascular endothelial cells (HUVECs) dose‑dependently. Furthermore, Rd abrogated VEGF-induced sprouting of the vessels from aortic rings, and inhibited vascular formation in the Matrigel plug assay in vivo. Under normoxic or hypoxic conditions, Rd suppressed VEGF‑induced activation of Akt/mammalian target of rapamycin (mTOR) signaling transduction cascades in HUVECs. When intraperitoneally administered to mice bearing human breast cancer (MDA‑MB-231) cell xenografts, Rd significantly decreased the volume and the weight of solid tumors in a dose-dependent manner, and decreased tumor angiogenesis as less Ki67- and CD31-positive cells were found. Additionally, we found that Rd inhibited proliferation and induced apoptosis as well as the inhibition of Akt/mTOR/P70S6 kinase signaling in breast cancer cells. Collectively, our findings revealed that Rd may be a promising anti-angiogenic drug with significant antitumor activity in human breast cancer.

Regulation of angiogenic behaviors by oxytocin receptor through Gli1-indcued transcription of HIF-1α in human umbilical vein endothelial cells

Angiogenesis is a dynamic hypoxia-stimulated process playing a key role in tissue growth and repair under various pathophysiological circumstances. Abnormal angiogenesis contributes to the pathogenesis of many human diseases. Oxytocin receptor is a classical G-protein-coupled receptor expressed on endothelial cells. The present study was aimed to investigate how oxytocin receptor regulated the angiogenic behaviors of human umbilical vein endothelial cells (HUVECs). We found that oxytocin at 0.1μM significantly increased cell proliferation, upregulated the mRNA and protein expression of CD31 and vWF (two important endothelial markers), and enhanced the tuber formation capacity in HUVECs. However, oxytocin receptor inhibitor atosiban at 10μM significantly suppressed these angiogenic properties of HUVECs. Additionally, hypoxia-inducible factor-1α (HIF-1α) inhibitor PX-478 at 20μM also remarkably inhibited the angiogenic properties of HUVECs. We further found that atosiban at 10μM significantly repressed the promoter activity of HIF-1α and reduced the mRNA and protein expression of HIF-1α in HUVECs. Moreover, pharmacological inhibition of HIF-1α by PX-478 at 20μM abolished oxytocin-enhanced angiogenic properties of HUVECs. Finally, transcription factor Gli1 inhibitor GANT-58 at 5μM significantly abolished oxytocin-induced mRNA and protein expression of HIF-1α, while the nuclear abundance of Gli1 was significantly reduced by atosiban at 10μM, but was increased by oxytocin at 0.1μM in HUVECs. GANT-58 at 5μM also significantly abolished oxytocin-enhanced angiogenic properties of HUVECs. Altogether, these discoveries suggested that oxytocin receptor signaling promoted the angiogenic behaviors of HUVECs via Gli1-indcued transcription of HIF-1α. We provided novel molecular insights into endothelial cell-mediated angiogenesis.

Curcumin induces G2/M cell cycle arrest and apoptosis of head and neck squamous cell carcinoma in vitro and in vivo through ATM/Chk2/p53-dependent pathway

Studies have demonstrated that curcumin (CUR) exerts its tumor suppressor function in a variety of human cancers including head and neck squamous cell carcinoma (HNSCC). However, the exact underlying molecular mechanisms remain obscure. Here, we aim to test whether CUR affects ATM/Chk2/p53 signaling pathway, leading to the induction of cell cycle arrest, inhibition of angiogenesis of HNSCC in vitro and in vivo. To this end, we conducted multiple methods such as MTT assay, Invasion assay, Flow cytometry, Western blotting, RT-PCR, and transfection to explore the functions and molecular insights of CUR in HNSCC. We observed that CUR significantly induced apoptosis and cell cycle arrest, inhibited angiogenesis in HNSCC. Mechanistically, we demonstrated that CUR markedly up-regulated ATM expression and subsequently down-regulated HIF-1α expression. Blockage of ATM production totally reversed CUR induced cell cycle arrest as well as anti-angiogenesis in HNSCC. Moreover, our results demonstrated that CUR exerts its antitumor activity through targeting ATM/Chk2/p53 signal pathway. In addition, the results of xenograft experiments in mice were highly consistent with in vitro studies. Collectively, our findings suggest that targeting ATM/Chk2/p53 signal pathway by CUR could be a promising therapeutic approach for HNSCC prevention and therapy.

ZLM-7 exhibits anti-angiogenic effects via impaired endothelial cell function and blockade of VEGF/VEGFR-2 signaling

Inhibition of angiogenesis is a promising therapeutic strategy against cancer. In this study, we reported that ZLM-7, a combretastain A-4 (CA-4) derivative, exhibited anti-angiogenic activity in vitro and in vivo. In vitro, ZLM-7 induced microtubule cytoskeletal disassembly. It decreased VEGF-induced proliferation, migration, invasion and tube formation in endothelial cells, which are critical steps in angiogenesis. In vivo, ZLM-7 significantly inhibited neovascularization in a chicken chorioallantoic membrane (CAM) model and reduced the microvessel density in tumor tissues of MCF-7 xenograft mouse model. ZLM-7 also displayed comparable antiangiogenic and anti-tumor activities associated with the lead compound CA-4, but exhibited lower toxicity compared with CA-4. The anti-angiogenic effect of ZLM-7 was exerted via blockade of VEGF/VEGFR-2 signaling. ZLM-7 treatment suppressed the expression and secretion of VEGF in endothelial cells and MCF-7 cells under hypoxia. Further, ZLM-7 suppressed the VEGF-induced phosphorylation of VEGFR-2 and its downstream signaling mediators including activated AKT, MEK and ERK in endothelial cells. Overall, these results demonstrate that ZLM-7 exhibits anti-angiogenic activities by impairing endothelial cell function and blocking VEGF/VEGFR-2 signaling, suggesting that ZLM-7 might be a potential angiogenesis inhibitor.

Delivery of curcumin by directed self-assembled micelles enhances therapeutic treatment of non-small-cell lung cancer

BACKGROUND

It has been widely reported that curcumin (CUR) exhibits anticancer activity and triggers the apoptosis of human A549 non-small-cell lung cancer (NSCLC) cells. However, its application is limited owing to its poor solubility and bioavailability. Therefore, there is an urgent need to develop a new CUR formulation with higher water solubility and better biocompatibility for clinical application in the future.

MATERIALS AND METHODS

In this study, CUR-loaded methoxy polyethylene glycol-polylactide (CUR/mPEG-PLA) polymeric micelles were prepared by a thin-film hydration method. Their characteristics and antitumor effects were evaluated subsequently.

RESULTS

The average size of CUR/mPEG-PLA micelles was 34.9±2.1 nm with its polydispersity index (PDI) in the range of 0.067-0.168. The encapsulation efficiency and drug loading were 90.2%±0.78% and 9.1%±0.07%, respectively. CUR was constantly released from the CUR/mPEG-PLA micelles, and its cellular uptake in A549 cells was significantly increased. It was also found that CUR/mPEG-PLA micelles inhibited A549 cell proliferation, increased the cell cytotoxicity, induced G2/M stage arrest and promoted cell apoptosis. Moreover, the CUR/mPEG-PLA micelles suppressed the migration and invasion of A549 cells more obviously than free CUR. Additionally, CUR/mPEG-PLA micelles inhibited human umbilical vein endothelial cells migration, invasion and corresponding tube formation, implying the antiangiogenesis ability. Its enhanced antitumor mechanism may be related to the reduced expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, MMP-9 and Bcl-2 as well as the increased expression of Bax.

CONCLUSION

The mPEG-PLA copolymer micelles can serve as an efficient carrier for CUR. The CUR/mPEG-PLA micelles have promising clinical potential in treating NSCLC.

6-Gingerol prevents MEHP-induced DNA damage in human umbilical vein endothelia cells

Mono (2-ethylhexyl) phthalate (MEHP) is the principal metabolite of di (2-etylhexyl) phthalate, which is widely used as a plasticizer, especially in medical devices. MEHP has toxic effects on cardiovascular system. The aim of this study was to investigate the possibility that 6-gingerol may inhibit the oxidative DNA damage of MEHP in human umbilical vein endothelial cells (HUVECs) and the potential mechanism. The comet assay was used to monitor DNA strand breaks. We have shown that 6-gingerol significantly reduced the DNA strand breaks caused by MEHP. MEHP increased the levels of reactive oxygen species and malondialdehyde, decreased the level of glutathione and activity of superoxide dismutase, and altered the mitochondrial membrane potential. In addition, DNA damage-associated proteins (p53 and p-Chk2 (T68)) were significantly increased by the treatment of MEHP. Those effects can all be protected by 6-gingerol. The results firmly indicate that 6-gingerol may have a strong protective ability against the DNA damage caused by MEHP in HUVECs, and the mechanism may relate to the antioxidant activity.

Cellular uptake and dynamics of unlabeled freestanding silicon nanowires

The ability to seamlessly merge electronic devices with biological systems at the cellular length scale is an exciting prospect for exploring new fundamental cell biology and in designing next-generation therapeutic devices. Semiconductor nanowires are well suited for achieving this goal because of their intrinsic size and wide range of possible configurations. However, current studies have focused primarily on delivering substrate-bound nanowire devices through mechanical abrasion or electroporation, with these bulkier substrates negating many of the inherent benefits of using nanoscale materials. To improve on this, an important next step is learning how to distribute these devices in a drug-like fashion, where cells can naturally uptake and incorporate these electronic components, allowing for truly noninvasive device integration. We show that silicon nanowires (SiNWs) can potentially be used as such a system, demonstrating that label-free SiNWs can be internalized in multiple cell lines (96% uptake rate), undergoing an active "burst-like" transport process. Our results show that, rather than through exogenous manipulation, SiNWs are internalized primarily through an endogenous phagocytosis pathway, allowing cellular integration of these materials. To study this behavior, we have developed a robust set of methodologies for quantitatively examining high-aspect ratio nanowire-cell interactions in a time-dependent manner on both single-cell and ensemble levels. This approach represents one of the first dynamic studies of semiconductor nanowire internalization and offers valuable insight into designing devices for biomolecule delivery, intracellular sensing, and photoresponsive therapies.

Calycosin and Formononetin Induce Endothelium-Dependent Vasodilation by the Activation of Large-Conductance Ca2+-Activated K+ Channels (BKCa)

Calycosin and formononetin are two structurally similar isoflavonoids that have been shown to induce vasodilation in aorta and conduit arteries, but study of their actions on endothelial functions is lacking. Here, we demonstrated that both isoflavonoids relaxed rat mesenteric resistance arteries in a concentration-dependent manner, which was reduced by endothelial disruption and nitric oxide synthase (NOS) inhibition, indicating the involvement of both endothelium and vascular smooth muscle. In addition, the endothelium-dependent vasodilation, but not the endothelium-independent vasodilation, was blocked by BK_Ca inhibitor iberiotoxin (IbTX). Using human umbilical vein endothelial cells (HUVECs) as a model, we showed calycosin and formononetin induced dose-dependent outwardly rectifying K⁺ currents using whole cell patch clamp. These currents were blocked by tetraethylammonium chloride (TEACl), charybdotoxin (ChTX), or IbTX, but not apamin. We further demonstrated that both isoflavonoids significantly increased nitric oxide (NO) production and upregulated the activities and expressions of endothelial NOS (eNOS) and neuronal NOS (nNOS). These results suggested that calycosin and formononetin act as endothelial BK_Ca activators for mediating endothelium-dependent vasodilation through enhancing endothelium hyperpolarization and NO production. Since activation of BK_Ca plays a role in improving behavioral and cognitive disorders, we suggested that these two isoflavonoids could provide beneficial effects to cognitive disorders through vascular regulation.

Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products

The increasing incidence of autism suggests a major environmental influence. Epidemiology has implicated many candidates and genetics many susceptibility genes. Gene/environment interactions in autism were analysed using 206 autism susceptibility genes (ASG's) from the Autworks database to interrogate ∼1 million chemical/gene interactions in the comparative toxicogenomics database. Any bias towards ASG's was statistically determined for each chemical. Many suspect compounds identified in epidemiology, including tetrachlorodibenzodioxin, pesticides, particulate matter, benzo(a)pyrene, heavy metals, valproate, acetaminophen, SSRI's, cocaine, bisphenol A, phthalates, polyhalogenated biphenyls, flame retardants, diesel constituents, terbutaline and oxytocin, inter alia showed a significant degree of bias towards ASG's, as did relevant endogenous agents (retinoids, sex steroids, thyroxine, melatonin, folate, dopamine, serotonin). Numerous other suspected endocrine disruptors (over 100) selectively targeted ASG's including paraquat, atrazine and other pesticides not yet studied in autism and many compounds used in food, cosmetics or household products, including tretinoin, soy phytoestrogens, aspartame, titanium dioxide and sodium fluoride. Autism polymorphisms influence the sensitivity to some of these chemicals and these same genes play an important role in barrier function and control of respiratory cilia sweeping particulate matter from the airways. Pesticides, heavy metals and pollutants also disrupt barrier and/or ciliary function, which is regulated by sex steroids and by bitter/sweet taste receptors. Further epidemiological studies and neurodevelopmental and behavioural research is warranted to determine the relevance of large number of suspect candidates whose addition to the environment, household, food and cosmetics might be fuelling the autism epidemic in a gene-dependent manner.

Oxalomalate reduces expression and secretion of vascular endothelial growth factor in the retinal pigment epithelium and inhibits angiogenesis: Implications for age-related macular degeneration

Clinical and experimental observations indicate a critical role for vascular endothelial growth factor (VEGF), secreted by the retinal pigment epithelium (RPE), in pathological angiogenesis and the development of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RPE-mediated VEGF expression, leading to angiogenesis, is a major signaling mechanism underlying ocular neovascular disease. Inhibiting this signaling pathway with a therapeutic molecule is a promising anti-angiogenic strategy to treat this disease with potentially fewer side effects. Oxalomalate (OMA) is a competitive inhibitor of NADP⁺-dependent isocitrate dehydrogenase (IDH), which plays an important role in cellular signaling pathways regulated by reactive oxygen species (ROS). Here, we have investigated the inhibitory effect of OMA on the expression of VEGF, and the associated underlying mechanism of action, using in vitro and in vivo RPE cell models of AMD. We found that OMA reduced the expression and secretion of VEGF in RPE cells, and consequently inhibited CNV formation. This function of OMA was linked to its capacity to activate the pVHL-mediated HIF-1α degradation in these cells, partly via a ROS-dependent ATM signaling axis, through inhibition of IDH enzymes. These findings reveal a novel role for OMA in inhibiting RPE-derived VEGF expression and angiogenesis, and suggest unique therapeutic strategies for treating pathological angiogenesis and AMD development.

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Oxalomalate reduces VEGF expression in RPE cells by promoting HIF-1α degradation.

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Oxalomalate activates pVHL-mediated HIF-1α degradation by regulation of ATM-Chk2-E2F1 axis.

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Inhibition of IDH enzymes by oxalomalate activates ROS-mediated ATM signaling axis.

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Oxalomalate inhibits CNV-related angiogenesis in in vivo mouse model of AMD.

Real-time monitoring of cytotoxic effects of electroporation on breast and colon cancer cell lines

PURPOSE

To study the effects of electroporation on different cell lines.

MATERIAL

The effects of electroporation on human breast cancer (MDA-MB-231), human colon cancer (SW-480 and HCT-116), human fibroblast cell line (MRC-5), primary human aortic smooth muscle cells (hAoSMC) and human umbilical vein endothelial cells (HUVEC) were studied. Real-time technology was used for cell viability monitoring. Acridine orange/ethidium bromide assay was applied for cell death type determination. A numerical model of electroporation has been proposed.

RESULTS

Electroporation induced inhibition of cell viability on dose (voltage) dependent way. The electroporation treatment 375-437.5Vcm-1 caused irreversible electroporation of cancer cells and reversible electroporation of healthy cells. The application of lower voltage rating (250Vcm-1) led to apoptosis as the predominant type of cell death, whereas the use of higher voltage (500Vcm-1) mainly caused necrosis.

CONCLUSION

Electroporation represents a promising method in cancer treatment. Different cancer cell lines had different response to the identical electroporation treatment. Electroporation 375-437.5Vcm-1 selectively caused permanent damage of cancer cells (SW-480), while healthy cells (MRC-5, hAoSM and HUVEC) recovered after 72h. The type of cell death is dependent of electroporation conditions. The proposed numerical model is useful for the analysis of phenomena related to electroporation treatment.

Angiotensin II-Induced Apoptosis of Human Umbilical Vein Endothelial Cells was Inhibited by Blueberry Anthocyanin Through Bax- and Caspase 3-Dependent Pathways

Background

This study aimed to investigate the inhibitory effect of blueberry anthocyanin (BBA) on Angiotensin II (Ang II)-induced apoptosis of human umbilical vein endothelial cells (HUVECs), and its regulation mechanisms involving Bax and Caspase 3.

Material/Methods

HUVECs were first treated by different concentrations of Ang II (10⁻⁹, 10⁻⁸, 10⁻⁷, 10⁻⁶, 10⁻⁵, and 10⁻⁴ mol/L) and BBA (80, 40, 20, 10, 5, and 2.5 μg/ml). After 24 h and 48 h of treatment, MTT was performed to detect the viability of HUVECs. Then, HUVECs were randomly divided into the Ang II group (10⁻⁶ mol/L Ang II) and Ang II + BBA group (10⁻⁶ mol/L Ang II and 20 μg/ml BBA), and the apoptosis rate was detected by flow cytometry. Western blot analysis was performed to detect the expression of Bax and Caspase 3 in these 2 groups. During the whole process, HUVECs without any treatments served as the control group.

Results

The cell viability of HUVECs was significantly reduced by Ang II in a time- and concentration-dependent manner (P<0.05), while BBA significantly elevated the cell viability of HUVECs until a peak of 20.0 μg/ml. The apoptosis rate of HUVECs was significantly increased by Ang II (P<0.01) and reduced by the BBA intervention (P<0.05). Ang II significantly elevated the expression of Bax and Caspase 3 in HUVECs, but their expression was significantly inhibited by BBA.

Conclusions

BBA increased cell viability and reduced apoptosis rate of HUVECs induced by Ang II through Bax- and Caspase 3-dependent pathways.

Strategic Endothelial Cell Tube Formation Assay: Comparing Extracellular Matrix and Growth Factor Reduced Extracellular Matrix

Malignant tumors require a blood supply in order to survive and spread. These tumors obtain their needed blood from the patient's blood stream by hijacking the process of angiogenesis, in which new blood vessels are formed from existing blood vessels. The CXCR2 (chemokine (C-X-C motif) receptor 2) receptor is a transmembrane G-protein-linked molecule found in many cells that is closely associated with angiogenesis(1). Specific blockade of the CXCR2 receptor inhibits angiogenesis, as measured by several assays such as the endothelial tube formation assay. The tube formation assay is useful for studying angiogenesis because it is an excellent method of studying the effects that any given compound or environmental condition may have on angiogenesis. It is a simple and quick in vitro assay that generates quantifiable data and requires relatively few components. Unlike in vivo assays, it does not require animals and can be carried out in less than two days. This protocol describes a variation of the extracellular matrix supporting endothelial tube formation assay, which tests the CXCR2 receptor.

Plasma angiopoietin-2 is persistently elevated after non-small cell lung cancer surgery and stimulates angiogenesis in vitro

Angiopoietin-2 (Ang2) is a key proangiogenic factor, but its role in surgery-induced angiogenesis, a possible cause of cancer recurrence, is still elusive.We measured the plasma Ang2 levels in healthy controls (n = 42) and stage I-IV perioperative nonsmall cell lung cancer (NSCLC) patients (n = 227) with enzyme-linked immunosorbent assay, and examined the impact of Ang2 in the plasmas on in vitro angiogenesis and proliferation of human umbilical vein endothelial cells and human microvascular endothelial cells.Ang2 plasma levels are significantly increased in untreated NSCLC patients (2697 ± 1354 pg/mL) compared to control (1473 ± 560.6 pg/mL) and positively associated with disease stage but not with histology. Ang2 plasma levels in stage I-IIIA NSCLC patients (n = 154) are elevated after the standard open thoracic surgery, following an approximate pattern to increase quickly in the 1st postoperative days (PODs, from preoperative 2342 ± 1084 to POD1: 4485 ± 1617 and POD3: 5370 ± 1879 pg/mL), reach the peak about 2 weeks later (POD14: 6099 ± 2280 pg/mL), drop slowly thereafter (POD28: 3877 ± 1388 and POD42: 3365 ± 1189 pg/mL), and remain significantly higher than preoperative 8 weeks after the procedure (POD56: 2937 ± 943.3 pg/mL). The postoperative plasmas enhance in vitro angiogenesis and Ang2 removal from the plasmas can counteract the effect. The postoperative plasmas stimulate endothelial proliferation independently of Ang2.These results suggest that plasma Ang2 increases after NSCLC surgery and contributes to the proangiogenic property of the postoperative plasmas, thus supporting the possible administration of anti-Ang2 therapy for NSCLC in postoperative adjuvant setting.

Insights into the anti-angiogenic properties of phosphaplatins

Phosphaplatins are platinum-based antitumor compounds that, unlike other clinically utilized platinum drugs (i.e. cisplatin, carboplatin, and oxaliplatin), appear to target proteins rather than DNA. Because of their unique mode of action, phosphaplatins are promising drug candidates for cisplatin-resistant cancers. In this study, we discovered that Pt(II) and Pt(IV) phosphaplatins possess diverse antitumor properties. In addition to targeting apoptosis antigen (FAS) and proapoptotic gene products as described previously, phosphaplatins also target angiogenesis. We demonstrate that phosphaplatins inhibit human umbilical vein endothelial cell (HUVEC) migration and tube formation in vitro and suppress tumor angiogenesis and growth in immunodeficient mice that were inoculated with A2780 ovarian cancer cells in vivo. To provide insight into this novel antitumor mechanism, phosphaplatin-treated HUVECs were found to exhibit lower gene expression levels of vascular endothelial growth factors (VEGFs) and the VEGFR-2 receptor compared to untreated cells. Kinase inhibition studies suggest that phosphaplatins are inhibitors of VEGFR-2. In ligand exchange experiments using both Pt atomic absorption and ³¹P NMR spectroscopies, we show that phosphaplatins most likely bind to VEGFR-2 through metal-ligand coordination rather than electrostatic interactions. These studies enhance our understanding of the diverse and novel mechanisms of action of the phosphaplatin antitumor agents, which could potentially be used as chemotherapeutic agents against cisplatin-resistant cancers.

Autophagic effects of Hibiscus sabdariffa leaf polyphenols and epicatechin gallate (ECG) against oxidized LDL-induced injury of human endothelial cells

PURPOSE

Oxidized low-density lipoprotein (ox-LDL) contributes to the pathogenesis of atherosclerosis by promoting vascular endothelial cell injury. Hibiscus sabdariffa leaf polyphenols (HLP), rich in flavonoids, have been shown to possess antioxidant and antiatherosclerotic activities. In this study, we examined the protective role of HLP and its main compound (-)-epicatechin gallate (ECG) in human umbilical vein endothelial cells (HUVECs) exposed to ox-LDL in vitro.

METHODS

In a model of ox-LDL-impaired HUVECs, assessments of cell viability, cytotoxicity, cell proliferation, apoptosis, and autophagy were detected. To highlight the mechanisms of the antiapoptotic effects of HLP and ECG, the expressions of molecular proteins were measured by Western blotting, real-time PCR, and so on.

RESULTS

HLP or ECG improved the survival of HUVECs from ox-LDL-induced viability loss. In addition, HLP or ECG showed potential in reducing ox-LDL-dependent apoptosis. Next, the ox-LDL-induced formation of acidic vesicular organelles and upregulation of the autophagy-related genes were increased by HLP or ECG. The HLP-triggered autophagic flux was further confirmed by increasing the LC3-II level under the pretreatment of an autophagy inhibitor chloroquine. Molecular data indicated the autophagic effect of HLP or ECG might be mediated via class III PI3K/Beclin-1 and PTEN/class I PI3K/Akt cascade signaling, as demonstrated by the usage of a class III PI3K inhibitor 3-methyladenine (3-MA) and a PTEN inhibitor SF1670.

CONCLUSIONS

Our data imply that ECG-enriched HLP upregulates the autophagic pathway, which in turn led to reduce ox-LDL-induced HUVECs injury and apoptosis and provide a new mechanism for its antiatherosclerotic activity.

Coadministration of VDR and RXR agonists synergistically alleviates atherosclerosis through inhibition of oxidative stress: An in vivo and in vitro study

BACKGROUND AND AIMS

Diabetes contributes to atherosclerosis partially through induction of oxidative stress. Both vitamin D receptor (VDR) and retinoid X receptor (RXR) agonists exhibit anti-atherogenic effects.

METHODS

We explored the effects of combination treatment with VDR and RXR agonists (represented by calcitriol and bexarotene, respectively) on atherosclerosis progression and the mechanisms involved, using a diabetes model of mice. The animals were intragastrically fed calcitriol (200 ng/kg, twice-a-week), bexarotene (10 mg/kg, once-daily) either alone or in combination for 12 weeks.

RESULTS

VDR and RXR agonists delayed atherosclerosis progression independent of serum lipid and glucose levels, and significantly reduced the protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit gp91phox and nuclear factor-kappa B (NF-κB) subunit p65, as well as plasma biomarkers of oxidative stress and inflammation. Combination therapy alleviated atherosclerosis and inhibited indexes of oxidative stress and inflammation to a greater extent than either monotherapy. In the in vitro study, naturally occurring VDR ligand 1α,25-dihydroxyvitamin D3 (1,25[OH]2D3) and RXR ligand 9-cis retinoic acid (9-cis-RA), both significantly inhibited high-glucose-induced endothelial cell apoptosis. Co-administration of VDR and RXR ligands produced synergistic protection against endothelial apoptosis by antagonizing the protein kinase C /NADPH oxidase/reactive oxygen species pathway. The inhibitory effects of 9-cis-RA on oxidative stress was attenuated when VDR was downregulated by VDR siRNA; however, downregulation of RXR by RXR siRNA imposed no influence on the effects of 1,25(OH)2D3.

CONCLUSIONS

Combination treatment with VDR and RXR agonists synergistically alleviated diabetic atherosclerosis through inhibition of oxidative stress, and the preventive effects of RXR agonist may partially depend on VDR activation.

Curcumin inhibits angiogenesis and improves defective hematopoiesis induced by tumor-derived VEGF in tumor model through modulating VEGF-VEGFR2 signaling pathway

Curcumin, a natural polyphenol compound from the perennial herb Curcuma longa, has been proved to be beneficial for tumor-bearing animals through inhibiting tumor neovasculature formation, but the underlying mechanisms are unclear. Here, we aim to test whether curcumin affects VEGF-VEGFR2 signaling pathway and attenuates defective hematopoiesis induced by VEGF in tumor model. We demonstrated that curcumin inhibited proliferation, migration of HUVEC under VEGF stimulation and caused HUVEC apoptosis, and blocked VEGFR2 activation and its downstream signaling pathways in vitro. Furthermore, in VEGF over-expressing tumor model, curcumin significantly inhibited the tumor growth accelerated by VEGF in a dose-dependent manner and improved anemia and extramedullary hematopoiesis in livers and spleens of tumor-bearing mice induced by tumor-derived VEGF. Immunohistochemical analysis showed that curcumin normalized vasculature structures of livers and reduced tumor microvessel density. ELISA revealed that curcumin suppressed VEGF secretion from tumor cells both in vitro and in vivo. Survival analysis showed that curcumin significantly improved survival ability of VEGF tumor-bearing mice. Taken together, these findings establish curcumin as a modulator of VEGF and VEGF-VEGFR2 signaling pathway, with potential implication for improving the quality of life of cancer patients.

MicroRNA: a connecting road between apoptosis and cholesterol metabolism

Resistance to apoptosis leads to tumorigenesis and failure of anti-cancer therapy. Recent studies also highlight abrogated lipid/cholesterol metabolism as one of the root causes of cancer that can lead to metastatic transformations. Cancer cells are dependent on tremendous supply of cellular cholesterol for the formation of new membranes and continuation of cell signaling. Cholesterol homeostasis network tightly regulates this metabolic need of cancer cells on cholesterol and other lipids. Genetic landscape is also shared between apoptosis and cholesterol metabolism. MicroRNAs (miRNAs) are the new fine tuners of signaling pathways and cellular processes and are known for their ability to post-transcriptionally repress gene expression in a targeted manner. This review summarizes the current knowledge about the cross talk between apoptosis and cholesterol metabolism via miRNAs. In addition, we also emphasize herein recent therapeutic modulations of specific miRNAs and their promising potential for the treatment of deadly diseases including cancer and cholesterol related pathologies. Understanding of the impact of miRNA-based regulation of apoptosis and metabolic processes is still at its dawn and needs further research for the development of future miRNA-based therapies. As both these physiological processes affect cellular homeostasis, we believe that this comprehensive summary of miRNAs modulating both apoptosis and cholesterol metabolism will open uncharted territory for scientific exploration and will provide the foundation for discovering novel drug targets for cancer and metabolic diseases.

Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In this study, a series of novel furo[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine based-derivatives were designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The synthesized compounds were evaluated for their ability to in vitro inhibit VEGFR-2 kinase enzyme. Seven compounds (15b, 16c, 16e, 21a, 21b, 21c and 21e) demonstrated highly potent dose-related VEGFR-2 inhibition with IC₅₀ values in nanomolar range, of which the thieno[2,3-d]pyrimidine based-derivatives (21b, 21c and 21e) exhibited IC₅₀ values of 33.4, 47.0 and 21 nM respectively. Moreover, furo[2,3-d]pyrimidine-based derivative (15b) showed the strongest inhibition of human umbilical vein endothelial cells (HUVEC) proliferation with 99.5% inhibition at 10 μM concentration. Consistent with our in vitro findings, compounds (21b and 21e) orally administered at 5 and 10 mg/kg/day for 8 consecutive days demonstrated potent anticancer activity in Erhlich ascites carcinoma (EAC) solid tumor murine model. Such compounds blunted angiogenesis in EAC as evidenced by reduced percent microvessel via decreasing VEGFR-2 phosphorylation with subsequent induction of apoptotic machinery. Furthermore, Miles vascular permeability assay confirmed their antiangiogenic effects in vivo. Intriguingly, such compounds showed no obvious toxicity.

Effect of novel blend nanofibrous scaffolds on diabetic wounds healing

Chitosan-poly (vinyl alcohol) (Cs: PVA) (2:3) and poly (caprolactone)-chitosan-poly (vinyl alcohol) (PCL: Cs: PVA) (2:1:1.5) nanofibrous blend scaffolds were fabricated using the electrospinning technique in the authors' previous studies. The results of the previous studies confirmed the high biological properties of the scaffolds and their ability in healing of burn and excision wounds on rat model. In the present study, the biological scaffolds were applied on diabetic dorsum skin wounds and diabetic foot wound on rat models (n = 16). Macroscopic and microscopic investigations were carried out using digital images and haematoxylin and eosin (H&E) staining respectively, to measure the wound areas and to track wound healing rate. It was found that at all time points the areas of wounds treated with nanofibrous scaffolds were smaller compared with the controls. Pathological results showed much better healing efficacy for the test samples compared with the control ones. Pathological investigations proved the presence of more pronounced granulation tissues in the scaffold-treated wounds compared with the control ones. At 20 days post excision, the scaffold-treated groups achieved complete repair. The results indicated that Cs: PVA and PCL: Cs: PVA nanofibrous webs could be considered to be promising materials for burn, excision and diabetic wounds healing.

Maggot debridement therapy promotes diabetic foot wound healing by up-regulating endothelial cell activity

To determine the role of maggot debridement therapy (MDT) on diabetic foot wound healing, we compared growth related factors in wounds before and after treatment. Furthermore, we utilized human umbilical vein endothelial cells (HUVECs) to explore responses to maggot excretions/secretions on markers of angiogenesis and proliferation. The results showed that there was neo-granulation and angiogenesis in diabetic foot wounds after MDT. Moreover, significant elevation in CD34 and CD68 levels was also observed in treated wounds. In vitro, ES increased HUVEC proliferation, improved tube formation, and increased expression of vascular endothelial growth factor receptor 2 in a dose dependent manner. These results demonstrate that MDT and maggot ES can promote diabetic foot wound healing by up-regulating endothelial cell activity.

Effect of an EDA-A1 gene mutant on the proliferation and cell cycle distribution of cultured human umbilical vein endothelial cells

Ectodysplasin (EDA) gene mutation is associated with hypohidrotic ectodermal dysplasia (HED). The aim of this study was to investigate the effect of ectodysplasin, transcript variant 1 (EDA-A1) on the proliferation and cell cycle of ECV304 human umbilical vein endothelial cells (HUVECs). Recombinant eukaryotic expression vectors containing mutant (M) and wild-type (W) EDA-A1 coding sequences, pcDNA3.1 (-)-EDA-A1-M and pcDNA3.1 (-)-EDA-A1-W, respectively, were transfected into ECV304 cells. The EDA-A1 gene was amplified by reverse transcription polymerase chain reaction (RT-PCR), and the protein was detected by western blotting. The EDA-A1 gene and protein were detected in ECV304 cells transfected with pcDNA3.1 (-)-EDA-A1-M and pcDNA3.1 (-)-EDA-A1-W, but not in ECV304 cells transfected with empty plasmid or cells that had not undergone transfection. Compared with the control group, the EDA-A1 gene mutant significantly decreased the proliferation of ECV304 cells and its inhibition rate was 45.70% (P<0.01), whereas the wild-type EDA-A1 gene did not cause such growth inhibition (P>0.05). A significant increase of the fraction of cells in the G0/G1 phase of the cell cycle was observed in the ECV304 cells of the mutant group compared with wild type group, with an increase in the S phase population and a concomitant reduction in the G2/M phase population (P<0.05). These results indicate that compared with the wild-type gene, transfection with a mutant EDA-A1 gene inhibited the proliferation and cell cycle of cultured HUVECs.

Downregulation of ERRα inhibits angiogenesis in human umbilical vein endothelial cells through regulating VEGF production and PI3K/Akt/STAT3 signaling pathway

The human estrogen related receptor α (ERRα) is a pivotal regulator involved in energy homeostasis and mitochondrial biogenesis. It has been demonstrated that activation of ERRα in various breast cancer cells results in a significant increase of vascular endothelial growth factor (VEGF) mRNA and protein secretion. However, little is known about the relationship between ERRα and angiogenesis. Thus, the present study is aimed to investigate the effects and mechanism of ERRα suppression on the angiogenesis in human umbilical vein endothelial cells (HUVECs). Here we show that ERRα suppression powerfully inhibits proliferation, migration and capillary-like structures formation of HUVECs. Importantly, we demonstrate that these inhibitory effects are associated with the significantly reduced expression and production of VEGF. Results from further experiments using western blot and luciferase reporter assay exhibit that ERRα suppression inhibits hypoxia-inducible factor 1α (HIF-1α) expression, and phosphorylation of protein kinase B (Akt) and signal transducer and activator of transcription (STAT3) which up-regulated VEGF expression. In summary, we show that ERRα suppression inhibits angiogenesis in HUVECs and deserves further studies for application of rationale therapeutic target for patient with diseases related with aberrant angiogenesis.

Notoginsenoside Ft1 Promotes Fibroblast Proliferation via PI3K/Akt/mTOR Signaling Pathway and Benefits Wound Healing in Genetically Diabetic Mice

Wound healing requires the essential participation of fibroblasts, which is impaired in diabetic foot ulcers (DFU). Notoginsenoside Ft1 (Ft1), a saponin from Panax notoginseng, can enhance platelet aggregation by activating signaling network mediated through P2Y12 and induce proliferation, migration, and tube formation in cultured human umbilical vein endothelial cells. However, whether it can accelerate fibroblast proliferation and benefit wound healing, especially DFU, has not been elucidated. In the present study on human dermal fibroblast HDF-a, Ft1 increased cell proliferation and collagen production via PI3K/Akt/mTOR signaling pathway. On the excisional wound splinting model established on db/db diabetic mouse, topical application of Ft1 significantly shortened the wound closure time by 5.1 days in contrast with phosphate-buffered saline (PBS) treatment (15.8 versus 20.9 days). Meanwhile, Ft1 increased the rate of re-epithelialization and the amount of granulation tissue at day 7 and day 14. The molecule also enhanced mRNA expressions of COL1A1, COL3A1, transforming growth factor (TGF)-β1 and TGF-β3 and fibronectin, the genes that contributed to collagen expression, fibroblast proliferation, and consequent scar formation. Moreover, Ft1 facilitated the neovascularization accompanied with elevated vascular endothelial growth factor, platelet-derived growth factor, and fibroblast growth factor at either mRNA or protein levels and alleviated the inflammation of infiltrated monocytes indicated by reduced tumor necrosis factor-α and interleukin-6 mRNA expressions in the diabetic wounds. Altogether, these results indicated that Ft1 might accelerate diabetic wound healing by orchestrating multiple processes, including promoting fibroblast proliferation, enhancing angiogenesis, and attenuating inflammatory response, which provided a great potential application of it in clinics for patients with DFU.

A comprehensive 1,000 Genomes-based genome-wide association meta-analysis of coronary artery disease

Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association studies (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of 185 thousand CAD cases and controls, interrogating 6.7 million common (MAF>0.05) as well as 2.7 million low frequency (0.005<MAF<0.05) variants. In addition to confirmation of most known CAD loci, we identified 10 novel loci, eight additive and two recessive, that contain candidate genes that newly implicate biological processes in vessel walls. We observed intra-locus allelic heterogeneity but little evidence of low frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect size.

A Highly Elastic and Rapidly Crosslinkable Elastin-Like Polypeptide-Based Hydrogel for Biomedical Applications

Elastin-like polypeptides (ELPs) are promising for biomedical applications due to their unique thermoresponsive and elastic properties. ELP-based hydrogels have been produced through chemical and enzymatic crosslinking or photocrosslinking of modified ELPs. Herein, a photocrosslinked ELP gel using only canonical amino acids is presented. The inclusion of thiols from a pair of cysteine residues in the ELP sequence allows disulfide bond formation upon exposure to UV light, leading to the formation of a highly elastic hydrogel. The physical properties of the resulting hydrogel such as mechanical properties and swelling behavior can be easily tuned by controlling ELP concentrations. The biocompatibility of the engineered ELP hydrogels is shown in vitro as well as corroborated in vivo with subcutaneous implantation of hydrogels in rats. ELP constructs demonstrate long-term structural stability in vivo, and early and progressive host integration with no immune response, suggesting their potential for supporting wound repair. Ultimately, functionalized ELPs demonstrate the ability to function as an in vivo hemostatic material over bleeding wounds.

Nanoemulsion-templated polylelectrolyte multifunctional nanocapsules for DNA entrapment and bioimaging

The emerging field of bionanotechnology aims at advancing colloidal and biomedical research via introduction of multifunctional nanoparticle-based containers intended for both gene therapy and bioimaging. In the present contribution we entrapped the model genetic material (herring testes DNA) in the newly-designed non-viral vectors, i.e., multifunctional nanocapsules obtained by layer-by-layer (LbL) adsorption of DNA and oppositely charged polysaccharide-based chitosan (CHIT) on the nanoemulsion core, loaded by IR-780 indocyanine (used as the fluorescent marker) and stabilized by gemini-type ammonium salts: N,N,N',N'-tetramethyl-N,N'-di(dodecyl)-ethylenediammonium bromide, d(DDA)PBr and N,N,N',N'-tetramethyl-N,N'-di(dodecyl)-butylenediammonium d(DDA)BBr. Ternary phase diagrams of the surfactant-oil-water systems were determined by titration method. Then, the stability of the nanoemulsions obtained with IR-780 solubilized in the oleic acid (OA) or isopropyl myristate (IPM) phase was evaluated by backscattering (BS) profiles and ζ-potential measurements. In the next step, CHIT and DNA layers were subsequently deposited on the kinetically stable nanoemulsion cores. The IR-780-loaded nanocarriers covered by (DNA/CHIT)4 bilayers shown the high ζ-potential value (about +43mV provided by Doppler electrophoresis), the size <120nm and the spherical shape as analyzed by dynamic light scattering (DLS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Finally, the long-lasting nanosystems were subjected to in vitro biological studies on human cancer cell lines - doxorubicin-sensitive breast (MCF-7/WT), epithelial lung adenocarcinoma (A549) and skin melanoma (MEWO). Biological response of the cell culture was expressed as cytotoxic activity evaluated by MTT-based proliferation assay as well as bioimaging of intracellular localization of IR-780 molecules loaded in the multilayer DNA-deposited nanocontainers - provided by confocal laser scanning microscopy (CLSM) and total internal reflection fluorescence microscopy (TIRFM). Our results demonstrate that the fabricated oil-core CHIT-coated nanocapsules stabilized by both d(DDA)PBr and d(DDA)BBr surfactants are promising as multifunctional nanocarriers for DNA delivery and cancer diagnostics.

Resveratrol alters human endothelial cells redox state and causes mitochondrial-dependent cell death

Studies analyzing the impact of natural antioxidants (NA) on Endothelial Cells (ECs) have dramatically increased during the last years, since a deregulated ECs redox state is at the base of the onset and progression of several cardiovascular diseases. However, whether NA can provide cardiovascular benefits is still a controversial area of debate. Resveratrol (RES), a natural polyphenol found in grapes, is believed to provide cardiovascular benefits by virtue of its antioxidant effect on the endothelium. Here, we report that tissue-attainable doses of resveratrol increased the intracellular oxidative state, thus affecting mitochondrial membrane depolarization and inducing EC death. Cyclosporine A, a mitochondrial permeability transition pore inhibitor, prevented oxidative-mediated cell death, thus implicating mitochondria in resveratrol-induced EC impairment. The specific cytochrome P450 (CYP) 2C9 inhibitor, sulfaphenazole, counteracted both oxidative stress and mitochondrial membrane depolarization, providing EC protection against resveratrol-elicited pro-oxidant effects. Our findings strongly suggest that CYP2C9 mediates resveratrol-induced oxidative stress leading to mitochondria impairment and EC death.

Engineering a vascularized collagen-β-tricalcium phosphate graft using an electrochemical approach

Vascularization of three-dimensional large synthetic grafts for tissue regeneration remains a significant challenge. Here we demonstrate an electrochemical approach, named the cell electrochemical detachment (CED) technique, to form an integral endothelium and use it to prevascularize a collagen-β-tricalcium phosphate (β-TCP) graft. The CED technique electrochemically detached an integral endothelium from a gold-coated glass rod to a collagen-infiltrated, channeled, macroporous β-TCP scaffold, forming an endothelium-lined microchannel containing graft upon removal of the rod. The in vitro results from static and perfusion culture showed that the endothelium robustly emanated microvascular sprouting and prevascularized the entire collagen/β-TCP integrated graft. The in vivo subcutaneous implantation studies showed that the prevascularized collagen/β-TCP grafts established blood flow originating from the endothelium-lined microchannel within a week, and the blood flow covered more areas in the graft over time. In addition, many blood vessels invaded the prevascularized collagen/β-TCP graft and the in vitro preformed microvascular networks anastomosed with the host vasculature, while collagen alone without the support of rigid ceramic scaffold showed less blood vessel invasion and anastomosis. These results suggest a promising strategy for effectively vascularizing large tissue-engineered grafts by integrating multiple hydrogel-based CED-engineered endothelium-lined microchannels into a rigid channeled macroporous scaffold.

Anti-inflammatory effects of vinpocetine in atherosclerosis and ischemic stroke: a review of the literature

Immune responses play an important role in the pathophysiology of atherosclerosis and ischemic stroke. Atherosclerosis is a common condition that increases the risk of stroke. Hyperlipidemia damages endothelial cells, thus initiating chemokine pathways and the release of inflammatory cytokines—this represents the first step in the inflammatory response to atherosclerosis. Blocking blood flow in the brain leads to ischemic stroke, and deprives neurons of oxygen and energy. Damaged neurons release danger-associated molecular patterns, which promote the activation of innate immune cells and the release of inflammatory cytokines. The nuclear factor κ-light-chain-enhancer of activated B cells κB (NF-κB) pathway plays a key role in the pathogenesis of atherosclerosis and ischemic stroke. Vinpocetine is believed to be a potent anti-inflammatory agent and has been used to treat cerebrovascular disorders. Vinpocetine improves neuronal plasticity and reduces the release of inflammatory cytokines and chemokines from endothelial cells, vascular smooth muscle cells, macrophages, and microglia, by inhibiting the inhibitor of the NF-κB pathway. This review clarifies the anti-inflammatory role of vinpocetine in atherosclerosis and ischemic stroke.

An engineered dimeric fragment of hepatocyte growth factor is a potent c-MET agonist

Hepatocyte growth factor (HGF), through activation of the c-MET receptor, mediates biological processes critical for tissue regeneration; however, its clinical application is limited by protein instability and poor recombinant expression. We previously engineered an HGF fragment (eNK1) that possesses increased stability and expression yield and developed a c-MET agonist by coupling eNK1 through an introduced cysteine residue. Here, we further characterize this eNK1 dimer and show it elicits significantly greater c-MET activation, cell migration, and proliferation than the eNK1 monomer. The efficacy of the eNK1 dimer was similar to HGF, suggesting its promise as a c-MET agonist.

Facile solid phase peptide synthesis with a Re-lysine conjugate generated via a one-pot procedure

We have synthesized a Re(CO)3-modified lysine via a one-pot Schiff base formation reaction that can be used in the solid phase peptide synthesis. To demonstrate its potential use, we have attached it to a neurotensin fragment and observed uptake into human umbilical vascular endothelial cells.

Differential roles of the mevalonate pathway in the development and survival of mouse Purkinje cells in culture

The cerebellum is an important locus for motor learning and higher cognitive functions, and Purkinje cells constitute a key component of its circuit. Biochemically, significant turnover of cholesterol occurs in Purkinje cells, causing the activation of the mevalonate pathway. The mevalonate pathway has important roles in cell survival and development. In this study, we investigated the outcomes of mevalonate inhibition in immature and mature mouse cerebellar Purkinje cells in culture. Specifically, we found that the inhibition of the mevalonate pathway by mevastatin resulted in cell death, and geranylgeranylpyrophosphate (GGPP) supplementation significantly enhanced neuronal survival. The surviving immature Purkinje cells, however, exhibited dendritic developmental deficits. The morphology of mature cells was not affected. The inhibition of squalene synthase by zaragozic acid caused impaired dendritic development, similar to that seen in the GGPP-rescued Purkinje cells. Our results indicate GGPP is required for cell survival and squalene synthase for the cell development of Purkinje cells. Abnormalities in Purkinje cells are linked to motor-behavioral learning disorders such as cerebellar ataxia. Thus, serious caution should be taken when using drugs that inhibit geranylgeranylation or the squalene-cholesterol branch of the pathway in the developing stage.

Rho-kinase: regulation, (dys)function, and inhibition

In a variety of normal and pathological cell types, Rho-kinases I and II (ROCKI/II) play a pivotal role in the organization of the nonmuscle and smooth muscle cytoskeleton and adhesion plaques as well as in the regulation of transcription factors. Thus, ROCKI/II activity regulates cellular contraction, motility, morphology, polarity, cell division, and gene expression. Emerging evidence suggests that dysregulation of the Rho-ROCK pathways at different stages is linked to cardiovascular, metabolic, and neurodegenerative diseases as well as cancer. This review focuses on the current status of understanding the multiple functions of Rho-ROCK signaling pathways and various modes of regulation of Rho-ROCK activity, thereby orchestrating a concerted functional response.

Manipulating the pH response of 2,3-diaminopropionic acid rich peptides to mediate highly effective gene silencing with low-toxicity

Cationic amphipathic pH responsive peptides possess high in vitro and in vivo nucleic acid delivery capabilities and function by forming a non-covalent complex with cargo, protecting it from nucleases, facilitating uptake via endocytosis and responding to endosomal acidification by being released from the complex and inserting into and disordering endosomal membranes. We have designed and synthesised peptides to show how Coulombic interactions between ionizable 2,3-diaminopropionic acid (Dap) side chains can be manipulated to tune the functional pH response of the peptides to afford optimal nucleic acid transfer and have modified the hydrogen bonding capabilities of the Dap side chains in order to reduce cytotoxicity. When compared with benchmark delivery compounds, the peptides are shown to have low toxicity and are highly effective at mediating gene silencing in adherent MCF-7 and A549 cell lines, primary human umbilical vein endothelial cells and both differentiated macrophage-like and suspension monocyte-like THP-1 cells.

Cytotoxic activities of [Ser⁴⁹]phospholipase A₂ from the venom of the saw-scaled vipers Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus

Fractionation by reversed-phase HPLC of venom from four species of saw-scaled viper: Echis ocellatus, Echis pyramidum leakeyi, Echis carinatus sochureki, and Echis coloratus led to identification in each sample of an abundant protein with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells. The active component in each case was identified by MALDI-TOF mass fingerprinting of tryptic digests as [Ser⁴⁹]phospholipase A₂ ([Ser⁴⁹]PLA₂). An isoform of [Ser⁴⁹]PLA₂ containing the single Ala¹⁸→ Val substitution and a partially characterized [Asp⁴⁹]PLA₂ were also present in the E. coloratus venom. LC₅₀ values against A549 cells for the purified [Ser⁴⁹]PLA₂ proteins from the four species are in the range 2.9-8.5 μM. This range is not significantly different from the range of LC₅₀ values against human umbilical vein endothelial HUVEC cells (2.5-12.2 μM) indicating that the [Ser⁴⁹]PLA₂ proteins show no differential anti-tumor activity. The LC₅₀ value for [Ser⁴⁹]PLA₂ from E. ocellatus against human erythrocytes is >100 μM and the MIC values against Escherichia coli and Staphylococcus aureus are >100 μM. It is suggested that the [Ser⁴⁹]PLA₂ proteins play a major role in producing local tissue necrosis and hemorrhage at the site of envenomation.

Advanced glycation end product Nε-carboxymethyllysine induces endothelial cell injury: the involvement of SHP-1-regulated VEGFR-2 dephosphorylation

N(ε)-carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes-induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML-related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)-mediated SH2 domain-containing tyrosine phosphatase-1 (SHP-1) activation by CML inhibits the VEGF receptor-2 (VEGFR-2, KDR/Flk-1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR-2 activation in parallel with the increased SHP-1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP-1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP-1 with VEGFR-2. Consistently, SHP-1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [(3)H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML-increased SHP-1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP-1 and CML was increased, but phospho-VEGFR-2 staining was decreased in the aortic endothelium of streptozotocin-induced and high-fat diet-induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP-1-regulated VEGFR-2 dephosphorylation through NADPH oxidase-derived ROS is involved in the CML-triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications.

Pearl extract enhances the migratory ability of fibroblasts in a wound healing model

CONTEXT

For 2000 years, traditional Chinese medicine has been used as a remedy for general health improvement, including the fight against aging. Pearl powder has recently been used as a health food that has antioxidant, antiaging, antiradioactive, and tonic activities for cells; it is also applied to cure aphthous ulcer, gastric ulcer, and duodenal ulcer on clinical therapy. In addition, the mother of pearl, nacre, could enhance the cell adhesion and tissue regeneration of skin fibroblasts.

OBJECTIVE

Fibroblast is regarded as indispensable in the processes of wound healing. Therefore, the effect of pearl extract (PL) on fibroblasts is investigated in this study.

MATERIALS AND METHODS

PL is produced by a room temperature super extraction system (Taiwan patent no. I271 220). DMEM medium containing PL (300 μg/mL) was used to examine the effect of migration-promoting potential on human fibroblast cell line or human primary fibroblast cells in a wound healing model in vitro.

RESULTS

Medium containing PL (300 μg/mL) demonstrated that the migratory cell numbers of fibroblasts were three times more than that without PL, and mRNA expression of collagen type III was higher than in collagen type I in fibroblasts. It revealed a migration-promoting potential of human fibroblasts in a wound healing model in vitro.

DISCUSSION AND CONCLUSION

The present study found that the migration-promoting effect in PL, which could be a supplement in cell culture. These data suggest PL could be useful for enhancing the wound healing of fibroblasts.