scholarly journals Cilostazol Improves Hyperglycemia-Induced Impairment of Angiogenesis by Stimulating Adiponectin/Adiponectin Receptor1/Sirtuin1

Author(s):  
Shih-Ya Tseng ◽  
Hsien-Yuan Chang ◽  
Yi-Heng Li ◽  
Ting-Hsing Chao

Abstract Background: Cilostazol is an antiplatelet agent with vasodilating effects that functions by increasing the intracellular concentration of cyclic adenosine monophosphate. However, the effect of cilostazol on adiponectin is still unclear. Purpose: We investigated the effects of cilostazol on adiponectin/adiponectin receptors and the Sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) signaling pathway to prevent high glucose (HG)-induced impairment of angiogenesis in vitro and in vivo. Methods and Results: Human umbilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs) were cocultured in HG conditions. Adiponectin concentrations in the supernatant were significantly increased when HASMCs were treated with cilostazol but not significantly changed when only HUVECs were treated with cilostazol. Cilostazol treatment restored the expression of the adipoR1 and SIRT1 proteins and upregulated the phosphorylation of AMPKa1 in the HUVECs treated with HG but not adipoR2. Cilostazol prevented apoptosis and stimulated proliferation, chemotactic motility and capillary-like tube formation in HG-treated HUVECs through the adipoR1/AMPK/SIRT1 signaling pathway. In cilostazol-treated mice, recovery of the blood flow ratio after hindlimb ischemia and circulating CD34+CD45dim cells were significantly attenuated by adipoR1 knockdown but not adipoR2 knockdown. The expression of SIRT1, phosphorylation of AMPKa1/acetyl-CoA carboxylase and Akt/endothelial nitric oxide synthase in ischemic muscles were significantly attenuated by gene knockdown of adipoR1. Conclusions: Cilostazol prevents HG-induced endothelial dysfunction in vascular endothelial cells and enhances angiogenesis in hyperglycemic mice by upregulating the expression of adiponectin/adipoR1 and its SIRT1/AMPK downstream signaling pathway.

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin

Abstract When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.


2018 ◽  
Vol 46 (2) ◽  
pp. 520-531 ◽  
Author(s):  
Yan Ding ◽  
Lanlan Shan ◽  
Wenqing Nai ◽  
Xiaojun Lin ◽  
Ling Zhou ◽  
...  

Background/Aims: The mechanistic target of rapamycin (mTOR) signaling pathway is essential for angiogenesis and embryonic development. DEP domain-containing mTOR-interacting protein (DEPTOR) is an mTOR binding protein that functions to inhibit the mTOR pathway In vitro experiments suggest that DEPTOR is crucial for vascular endothelial cell (EC) activation and angiogenic responses. However, knowledge of the effects of DEPTOR on angiogenesis in vivo is limited. This study aimed to determine the role of DEPTOR in tissue angiogenesis and to elucidate the molecular mechanisms. Methods: Cre/loxP conditional gene knockout strategy was used to delete the Deptor gene in mouse vascular ECs. The expression or distribution of cluster of differentiation 31 (CD31), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1 alpha (HIF-1α) were detected by immunohistochemical staining or western blot. Tube formation assay was used to measure angiogenesis in vitro. Results: Deptor knockdown led to increased expression of CD31, VEGF and HIF-1α in heart, liver, kidney and aorta. After treatment with rapamycin, their expression was significantly down regulated. In vitro, human umbilical vein endothelial cells (HUVECs) were transfected with DEPTOR-specific small interfering RNA (siRNA), which resulted in a significant increase in endothelial tube formation and migration rates. In contrast, DEPTOR overexpression markedly reduced the expression of CD31, VEGF and HIF-1α. Conclusions: Our findings demonstrated that deletion of the Deptor gene in vascular ECs resulted in upregulated expression of CD31 and HIF-1α, and further stimulated the expression of VEGF which promoted angiogenesis, indicating that disruption of normal angiogenic pathways may occur through hyperactivation of the mTORC1/HIF-1α/VEGF signaling pathway.


2003 ◽  
Vol 284 (6) ◽  
pp. H1978-H1984 ◽  
Author(s):  
M. Ursula Norman ◽  
Shane B. Reeve ◽  
Vincent Dive ◽  
A. Ian Smith ◽  
Rebecca A. Lew

The closely related metalloendopeptidases EC 3.4.24.15 (EP24.15; thimet oligopeptidase) and 24.16 (EP24.16; neurolysin) cleave a number of vasoactive peptides such as bradykinin and neurotensin in vitro. We have previously shown that hypotensive responses to bradykinin are potentiated by an inhibitor of EP24.15 and EP24.16 (26), suggesting a role for one or both enzymes in bradykinin metabolism in vivo. In this study, we have used selective inhibitors that can distinguish between EP24.15 and EP24.16 to determine their activity in cultured endothelial cells (the transformed human umbilical vein endothelial hybrid cell line EA.hy926 or ovine aortic endothelial cells). Endopeptidase activity was assessed using a specific quenched fluorescent substrate [7-methoxycoumarin-4-acetyl-Pro-Leu-Gly-d-Lys(2,4-dinitrophenyl)], as well as the peptide substrates bradykinin and neurotensin (assessed by high-performance liquid chromatography with mass spectroscopic detection). Our results indicate that both peptidases are present in endothelial cells; however, EP24.16 contributes significantly more to substrate cleavage by both cytosolic and membrane preparations, as well as intact cells, than EP24.15. These findings, when coupled with previous observations in vivo, suggest that EP24.16 activity in vascular endothelial cells may play an important role in the degradation of bradykinin and/or other peptides in the circulation.


2021 ◽  
Author(s):  
Ke Xu ◽  
Kai Fang ◽  
Yueping Zhan ◽  
Yuqian Wang ◽  
Chengqi Wu ◽  
...  

Abstract Background Anti-angiogenesis therapy has increasingly become an important strategy for the treatment of colorectal cancer. Recent studies have shown that tumor microenvironment (TME) promotes tumour angiogenesis. Bufalin is an active compound whose anti-tumor efficacy has been proven by previous studies. However, there are very few studies on the anti-angiogenic effects of bufalin. Methods Herein, human umbilical vein endothelial cells (HUVEC) tube formation, migration and adhesion test were used to assess angiogenesis in vitro. Western blot and quantitative PCR were used to detect relevant protein levels and the expressions of mRNAs. Subcutaneous xenograft tumor model and hepatic metastasis model in mice were established to investigate the influence of bufalin on angiogenesis-mediated by TME in vivo. Results We found that the angiogenesis mediated by tumor microenvironment cells was significantly inhibited in the present of bufalin. The results demonstrated that the pro-angiogenic gene in HUVEC such as VEGF, PDGFA, E-selectin and P-selectin were downregulated by bufalin, and the downregulation was regulated by inhibiting the STAT3 pathway. Overexpression STAT3 could reverse the inhibitory effect of bufalin on angiogenesis. What is more, few reduction of angiogenesis when bufalin directly acted on tumor microenvironment cells. Conclusion Our findings demonstrate that bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signaling pathway of vascular endothelial cells, which reveals that bufalin may be used as a new anti-angiogenic adjuvant therapy medicine in the treatment of colorectal cancer.


Author(s):  
Yuanyuan Li ◽  
Ying Shen ◽  
Yudan Zheng ◽  
Shundong Ji ◽  
Mengru Wang ◽  
...  

We previously demonstrated the immunostimulatory efficacy of Pseudomonas aeruginosa flagellar hook protein FlgE on epithelial cells, presumably via ectopic ATP synthases or subunits ATP5B on cell membranes. Here, by using recombinant wild-type FlgE, mutant FlgE (FlgEM; bearing mutations on two postulated critical epitopes B and F), and a FlgE analog in pull-down assay, Western blotting, flow cytometry, and ELISA, actual bindings of FlgE proteins or epitope B/F peptides with ATP5B were all confirmed. Upon treatment with FlgE proteins, human umbilical vein endothelial cells (HUVECs) and SV40-immortalized murine vascular endothelial cells manifested decreased proliferation, migration, tube formation, and surface ATP production and increased apoptosis. FlgE proteins increased the permeability of HUVEC monolayers to soluble large molecules like dextran as well as to neutrophils. Immunofluorescence showed that FlgE induced clustering and conjugation of F-actin in HUVECs. In Balb/c-nude mice bearing transplanted solid tumors, FlgE proteins induced a microvascular hyperpermeability in pinna, lungs, tumor mass, and abdominal cavity. All effects observed in FlgE proteins were partially or completely impaired in FlgEM proteins or blocked by pretreatment with anti-ATP5B antibodies. Upon coculture of bacteria with HUVECs, FlgE was detectable in the membrane and cytosol of HUVECs. It was concluded that FlgE posed a pathogenic ligand of ectopic ATP5B that, upon FlgE–ATP5B coupling on endothelial cells, modulated properties and increased permeability of endothelial layers both in vitro and in vivo. The FlgE-ectopic ATP5B duo might contribute to the pathogenesis of disorders associated with bacterial infection or ectopic ATP5B-positive cells.


Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin

When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.


2013 ◽  
Vol 110 (12) ◽  
pp. 2201-2206 ◽  
Author(s):  
Theertham Pradyumna Rao ◽  
Takayuki Okamoto ◽  
Nobuyuki Akita ◽  
Tatsuya Hayashi ◽  
Naomi Kato-Yasuda ◽  
...  

Amla (Emblica officinalisGaertn.) has been used for many centuries in traditional Indian Ayurvedic formulations for the prevention and treatment of many inflammatory diseases. The present study evaluated the anti-inflammatory and anticoagulant properties of amla fruit extract. The amla fruit extract potentially and significantly reduced lipopolysaccharide (LPS)-induced tissue factor expression and von Willebrand factor release in human umbilical vein endothelial cells (HUVEC)in vitroat clinically relevant concentrations (1–100 μg/ml). In a leucocyte adhesion model of inflammation, it also significantly decreased LPS-induced adhesion of human monocytic cells (THP-1) to the HUVEC, as well as reduced the expression of endothelial-leucocyte adhesion molecule-1 (E-selectin) in the target cells. In addition, thein vivoanti-inflammatory effects were evaluated in a LPS-induced endotoxaemia rat model. Oral administration of the amla fruit extract (50 mg/kg body weight) significantly decreased the concentrations of pro-inflammatory cytokines, TNF-α and IL-6 in serum. These results suggest that amla fruit extract may be an effective anticoagulant and anti-inflammatory agent.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831770164
Author(s):  
Guanying Wang ◽  
Na Yuan ◽  
Shangke Huang ◽  
Lu Feng ◽  
Rui Han ◽  
...  

Fibrinogen Asn-Gly-Arg motif can specifically recognize and bind to Aminopeptidase N (CD13) on vascular endothelial cells in newly formed tumor vessels. Adipose-derived stem cells can serve as ideal vectors for gene therapy because of their ability of migrating to tumor tissues. First, this study was aimed to design a new peptide (CNGRCLLII(KLAKLAK)2) named CNAK which contains cyclic Asn-Gly-Arg motif and test its biological activity against human umbilical vein endothelial cells. Second, we aimed to construct stably transfected adipose-derived stem cells which express the CNAK peptide and investigate their anti-angiogenic activity in vivo. Adipose-derived stem cells were employed to localize CNAK on vascular endothelial cells in tumors based on their homing property. First of all, the new peptide was synthesized, which effectively entered into CD13+ human umbilical vein endothelial cells and showed cytotoxicity against human umbilical vein endothelial cells. The peptide induced apoptosis of human umbilical vein endothelial cells in a time- and dose-dependent manner, inhibited the expression of Bcl-2, and promoted the expression of Caspase-3 in human umbilical vein endothelial cells. Furthermore, the migration and tube formation of human umbilical vein endothelial cells were inhibited by CNAK. Primary adipose-derived stem cells were then isolated and identified. Stably transfected adipose-derived stem cells which express CNAK peptide (CNAK-ASCs) were successfully established, and the migration of CNAK-ASCs was assessed. In vivo, CNAK-ASCs were found to inhibit the growth and angiogenesis of breast cancer xenografts. This effect may be through inhibiting the secretion of matrix metalloproteinase-2 and membrane type 1-matrix metalloproteinase in vivo. It was also found that CNAK-ASCs reduced the quantity of breast cancer stem cells in tumor tissues. Our data suggested that the new peptide CNAK containing Asn-Gly-Arg motif had anti-angiogenic activity in vitro and in vivo.


2012 ◽  
Vol 303 (1) ◽  
pp. H96-H105 ◽  
Author(s):  
Takayuki Koya ◽  
Takuro Miyazaki ◽  
Takuya Watanabe ◽  
Masayoshi Shichiri ◽  
Takashi Atsumi ◽  
...  

The bioactive peptide salusin-β is highly expressed in human atheromas; additionally, infusion of antiserum against salusin-β suppresses the development of atherosclerosis in atherogenic mice. This study examined the roles of salusin-β in vascular inflammation during atherogenesis. Infusion of antiserum against salusin-β attenuated the induction of VCAM-1, monocyte chemoattractant protein (MCP)-1, and IL-1β and as well as nuclear translocation of NF-κB in aortic endothelial cells (ECs) of LDL receptor-deficient mice, which led to the prevention of monocyte adhesion to aortic ECs. In vitro experiments indicated that salusin-β directly enhances the expression levels of proinflammatory molecules, including VCAM-1, MCP-1, IL-1β, and NADPH oxidase 2, as well as THP-1 monocyte adhesion to cultured human umbilical vein ECs (HUVECs). Both salusin-β-induced VCAM-1 induction and monocyte/HUVEC adhesion were suppressed by pharmacological inhibitors of NF-κB, e.g., Bay 11-7682 and curcumin. Furthermore, the VCAM-1 induction was significantly prevented by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, whereas it was accelerated by the ERK inhibitor, U-0126. Treatment of HUVECs with salusin-β, but not with salusin-α, accelerated oxidative stress and nuclear translocation of NF-κB as well as phosphorylation and degradation of IκB-α, an endogenous inhibitor of NF-κB. Thus, salusin-β enhanced monocyte adhesion to vascular ECs through NF-κB-mediated inflammatory responses in ECs, which can be modified by PI3K or ERK signals. These findings are suggestive of a novel role of salusin-β in atherogenesis.


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