Abstract 198: Angiotensin II Inhibits Cardiac Angiogenesis via the Cooperation of p53 and Jagged 1

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Aili Guan ◽  
Hui Gong ◽  
Yong Ye ◽  
Jianguo Jia ◽  
Guoping Zhang ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Tube Formation ◽  
Ang Ii ◽  
Capillary Formation ◽  
Angiogenic Effect ◽  
Endothelial Growth Factor

It is well established that angiotension II (Ang II) is an important regulator in vascular homeostasis. Under certain conditions, Ang II could exert anti-angiogenic effects in cardiovascular system. However, the potential mechanism is unclear. P53 has been reported to suppress angiogenesis by promoting hypoxia-inducible factor-1 (Hif-1α) degradation. This study was conducted to determine the contribution of P53 and the underlying mechanism to the anti-angiogenic effect of Ang II. Angiogenesis was determined by tube formation from the cardiac microvascular endothelial cells (ECs). Microvessel density and cardiac function were analyzed in mice subjected to Ang II infusion (200 ng/kg/min ) or vehicle for 2 weeks. Ang II (1μM) greatly inhibited tube formation and stimulated phosphorylation and upregulation of P53 in cultured cardiac ECs. P53 inhibitor, pifithrin-α (PFT-α,3.0mg/kg), significantly reversed the inhibitory effect of Ang II on tube formation. Vascular endothelial growth factor (VEGF ) and Hif-1α has been reported as important pro-angiogenetic factors. The present study indicated that Ang II decreased VEGF concentration in cultured medium and downregulated Hif-1α expression in cultured ECs. Interestingly, Ang II also stimulated the upregulation of Jagged 1, a ligand of Notch, but it didn't affect the Delta-like 4 (Dll 4) , another ligand of Notch, expression in cardiac ECs. However, PFT-α partly abolished these effects of Ang II. These results were consistent with the study in vivo. Further research revealed that siRNA-Jagged 1 transfection in cultured ECs dramatically abolished the phosphorylation of P53 and the downregulation of Hif-1α induced by Ang II. Additionally, Ang II- induced inhibitory effect on capillary formation was blocked by siRNA-Jagged 1 transfection in cultured cardiac ECs. In conclusion, Ang II promoted the phosphorylation and upregulation of P53, and increased Jagged 1 expression, the upregulation of Jagged 1 in turn stimulated the phosphorylation of P53, which resulted in the downregulation of Hif-1α and VEGF, then induced the inhibitory effects of Ang II on capillary formation. The present data suggest that Ang II exerts anti-angiogenesis via the cooperation of P53 and Jagged 1 in vitro and in vivo.

scholarly journals Canstatin represses glioma growth by inhibiting formation of VM-like structures

2021 ◽  
Vol 12 (1) ◽  
pp. 309-319
Author(s):  
Yuqiang Ma ◽  
Tao Wu ◽  
Houjie Zhou ◽  
Guilu He ◽  
Yifei Li ◽  
...  
Keyword(s):  
Vasculogenic Mimicry ◽  
Angiogenesis Inhibitor ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Tube Formation ◽  
Vascular Endothelial ◽  
Glioma Growth ◽  
Endothelial Growth Factor

Abstract Vasculogenic mimicry (VM) is different from classical tumor angiogenesis and does not depend on endothelial cells. VM is closely related to the prognosis of various cancers. Canstatin was first identified as an endogenous angiogenesis inhibitor. In the present study, the inhibitory effect of canstatin on VM formation was evaluated. Human glioblastoma cell lines U87 and U251 were letivirally transduced to overexpress canstatin gene or GFP as control. In vitro assays showed that canstatin overexpression reduced the tube formation of U87 and U251 cells in Matrigel. A xenograft glioma model was created by subcutaneous injection of lentivirally modified U87 cells into nude mice. The results of in vivo experiments showed that canstatin gene introduction inhibited the growth of glioma xenografts. In tumor xenografts overexpressing canstatin, U87-mediated formation of VM-like structures and VM-related VEGF (vascular endothelial growth factor) expression were remarkably reduced. Canstatin overexpression also decreased the phosphorylation of Akt and reduced the expression of Survivin in vitro. In addition, HIF-1α production and MMP-2 secretion were decreased by canstatin overexpression. Therefore, these results suggested a protective role of canstatin during VM-like structure formation of glioma probably via inhibiting signaling pathways inducing vasculogenic mimicry.

scholarly journals miR-138-5p Inhibits Vascular Mimicry by Targeting the HIF-1α/VEGFA Pathway in Hepatocellular Carcinoma

2021 ◽  
Author(s):  
Hongwei Liu ◽  
Xiujin Hu ◽  
Weihe Tan ◽  
Peng Zhou ◽  
Yanmei Liu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Progression ◽  
Periodic Acid ◽  
Hypoxia Inducible Factor ◽  
Underlying Mechanism ◽  
Tube Formation ◽  
Periodic Acid Schiff ◽  
Vascular Mimicry ◽  
Endothelial Growth Factor

Abstract Tumor vascular mimicry (VM) is the process of new blood vessels formed by tumor cells rather than endothelial cells. An increasing number of researches have revealed that VM process is associated with cancer progression and metastasis. miR-138-5p has been reported to act as a tumor suppressor in many cancers. However, the role and underlying mechanism of miR-138-5p in hepatocellular carcinoma (HCC) VM remain unclear. In this study, VM density was detected by CD31/periodic acid-Schiff double staining in HCC clinical specimens. We found that miR-138-5p expression correlated strongly negatively with microvessel density. Additionally, miR-138-5p mimic or inhibitor decreased or increased, respectively, tube formation capacity in HepG2 and Hep3B cells. Consistent with this, miR-138-5p repressed vessel density in vivo. Moreover, miR-138-5p targeted hypoxia-inducible factor 1α (HIF-1α) and regulated expression of HIF-1α and vascular endothelial growth factor A (VEGFA), which are established classical markers of angiogenesis. Consistent with these findings, the HIF-1α inhibitor CAY10585 effectively blocked HCC cell VM and VEGFA expression. In conclusion, miR-138-5p inhibits HepG2 and Hep3B cell VM by blocking the HIF-1α/VEGFA pathway. Therefore, miR-138-5p may serve as a useful therapeutic target for miRNA-based HCC therapy.

A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

2012 ◽  
Vol 123 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Ting-Hsing Chao ◽  
Shih-Ya Tseng ◽  
Yi-Heng Li ◽  
Ping-Yen Liu ◽  
Chung-Lung Cho ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Umbilical Vein ◽  
Tube Formation ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
No Production ◽  
Angiogenic Effect

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

scholarly journals Novel Nargenicin A1 Analog Inhibits Angiogenesis by Downregulating the Endothelial VEGF/VEGFR2 Signaling and Tumoral HIF-1α/VEGF Pathway

Biomedicines ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 252
Author(s):  
Jang Mi Han ◽  
Ye Seul Choi ◽  
Dipesh Dhakal ◽  
Jae Kyung Sohng ◽  
Hye Jin Jung
Keyword(s):  
Capillary Tube ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Chorioallantoic Membrane ◽  
Tube Formation ◽  
Ags Cells ◽  
Vegf Pathway ◽  
Vegfr2 Signaling

Targeting angiogenesis is an attractive strategy for the treatment of angiogenesis-related diseases, including cancer. We previously identified 23-demethyl 8,13-deoxynargenicin (compound 9) as a novel nargenicin A1 analog with potential anticancer activity. In this study, we investigated the antiangiogenic activity and mode of action of compound 9. This compound was found to effectively inhibit in vitro angiogenic characteristics, including the proliferation, invasion, capillary tube formation, and adhesion of human umbilical vein endothelial cells (HUVECs) stimulated by vascular endothelial growth factor (VEGF). Furthermore, compound 9 suppressed the neovascularization of the chorioallantoic membrane of growing chick embryos in vivo. Notably, the antiangiogenic properties of compound 9 were related to the downregulation of VEGF/VEGFR2-mediated downstream signaling pathways, as well as matrix metalloproteinase (MMP)-2 and MMP-9 expression in HUVECs. In addition, compound 9 was found to decrease the in vitro AGS gastric cancer cell-induced angiogenesis of HUVECs by blocking hypoxia-inducible factor-1α (HIF-1α) and VEGF expression in AGS cells. Collectively, our findings demonstrate for the first time that compound 9 is a promising antiangiogenic agent targeting both VEGF/VEGFR2 signaling in ECs and HIF-1α/VEGF pathway in tumor cells.

IMB-BZ as an Inhibitor Targeting ESX-1 Secretion System to Control Mycobacterial Infection

2021 ◽  
Author(s):  
Pingping Jia ◽  
Yi Zhang ◽  
Jian Xu ◽  
Mei Zhu ◽  
Shize Peng ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterial Infection ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
New Drugs ◽  
Dependent Manner ◽  
High Potency ◽  
Resistance Development

Abstract Background Resistance to anti-tuberculosis (TB) drug is a major issue in TB control, and demands the discovery of new drugs targeting virulence factor ESX-1. Methods We first established a high-throughput screen (HTS) assay for the discovery of ESX-1 secretion inhibitors. The positive hits were then evaluated for the potency of diminishing the survival of virulent mycobacterium and reducing bacterial virulence. We further investigated the probability of inducing drug-resistance and the underlying mechanism using M-PFC. Results A robust HTS assay was developed to identify small molecules that inhibit ESX-1 secretion without impairing bacterial growth in vitro. A hit named IMB-BZ specifically inhibits the secretion of CFP-10 and reduces virulence in an ESX-1-dependent manner, therefore resulting in significant reduction in intracellular and in vivo survival of mycobacteria. Blocking the CFP-10-EccCb1 interaction directly or indirectly underlies the inhibitory effect of IMB-BZ on the secretion of CFP-10. Importantly, our finding shows that the ESX-1 inhibitors pose low risk of drug resistance development by mycobacteria in vitro as compared with traditional anti-TB drug, and exhibit high potency against chronic mycobacterial infection. Conclusion Targeting ESX-1 may lead to the development of novel therapeutics for tuberculosis. IMB-BZ holds the potential for future development into a new anti-TB drug.

Effect of CO2/pH on the aldosterone response to hypoxia in bovine adrenal cells in vitro

1993 ◽  
Vol 265 (4) ◽  
pp. R820-R825
Author(s):  
H. Raff ◽  
B. Jankowski
Keyword(s):  
Respiratory Acidosis ◽  
Inhibitory Effect ◽  
Zona Glomerulosa ◽  
Ang Ii ◽  
Adrenal Cells ◽  
Aldosterone Production ◽  
Per Se ◽  
Air Control

Acidosis increases and hypoxia decreases aldosterone production from the adrenal zona glomulerosa in vivo, in situ, and in vitro. These effects appear to be located at different steps in the steroidogenic process. Because respiratory acidosis and hypoxemia are common sequelae of chronic lung disease, the present experiments evaluated the interaction of hypoxia and CO2 (with uncompensated or compensated extracellular pH) on aldosteronogenesis in vitro. Bovine adrenal zona glomerulosa cells were stimulated with angiotensin II (ANG II) or adenosine 3',5'-cyclic monophosphate under room air control (21% O2-0% CO2), CO2 per se (21% O2-10% CO2), hypoxia per se (10% O2-0% CO2), and the combination of CO2 and hypoxia (10% O2-10% CO2). Furthermore, under CO2, pH was either allowed to decrease from 7.2 to 6.8 (uncompensated) or its decrease was minimized (> 7.05) with NaOH (compensated). CO2 without pH compensation led to a significant increase in ANG II-stimulated aldosterone release; when the decrease in pH was minimized, CO2 inhibited ANG II-stimulated aldosterone release. Hypoxia inhibited aldosterone release; the inhibitory effect of hypoxia predominated when combined with CO2. In the presence of cyanoketone, pregnenolone production from endogenous precursors (early pathway) was unaffected. However, the conversion of corticosterone to aldosterone (late pathway) was inhibited by low O2 but unaffected by CO2. It is concluded that the inhibitory effect of low O2 on the late pathway predominates over the effects of uncompensated or compensated simulated respiratory acidosis on aldosteronogenesis.

scholarly journals HIF-1α contributes to Ang II-induced inflammatory cytokine production in podocytes

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hao Huang ◽  
Yanqin Fan ◽  
Zhao Gao ◽  
Wei Wang ◽  
Ning Shao ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Renin Angiotensin System ◽  
Inflammatory Factors ◽  
Ang Ii ◽  
Angiotensin System ◽  
Inflammatory Injury ◽  
Tnf Α

Abstract Background Studies have indicated that changed expression of hypoxia-inducible factor-1α (HIF-1α) in epithelial cells from the kidney could affect the renal function in chronic kidney disease (CKD). As Angiotensin II (Ang II) is a critical active effector in the renin-angiotensin system (RAS) and was proved to be closely related to the inflammatory injury. Meanwhile, researchers found that Ang II could alter the expression of HIF-1α in the kidney. However, whether HIF-1α is involved in mediating Ang II-induced inflammatory injury in podocytes is not clear. Methods Ang II perfusion animal model were established to assess the potential role of HIF-1α in renal injury in vivo. Ang II stimulated podocytes to observe the corresponding between HIF-1α and inflammatory factors in vitro. Results The expression of inflammatory cytokines such as MCP-1 and TNF-α was increased in the glomeruli from rats treated with Ang II infusion compared with control rats. Increased HIF-1α expression in the glomeruli was also observed in Ang II-infused rats. In vitro, Ang II upregulated the expression of HIF-1α in podocytes. Furthermore, knockdown of HIF-1α by siRNA decreased the expression of MCP-1 and TNF-α. Moreover, HIF-1α siRNA significantly diminished the Ang II-induced overexpression of HIF-1α. Conclusion Collectively, our results suggest that HIF-1α participates in the inflammatory response process caused by Ang II and that downregulation of HIF-1α may be able to partially protect or reverse inflammatory injury in podocytes.

scholarly journals The Antitumor Effect of Gekko Sulfated Glycopeptide by Inhibiting bFGF-Induced Lymphangiogenesis

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Xiu-Li Ding ◽  
Ya-Nan Man ◽  
Jian Hao ◽  
Cui-Hong Zhu ◽  
Chang Liu ◽  
...  
Keyword(s):  
Immunohistochemical Staining ◽  
Antitumor Effect ◽  
Inhibitory Effect ◽  
Tube Formation ◽  
Fibroblast Growth ◽  
Lymphatic Endothelial Cells ◽  
Tumor Lymphangiogenesis ◽  
Extracellular Signal

Objective. To study the antilymphangiogenesis effect of Gekko Sulfated Glycopeptide (GSPP) on human lymphatic endothelial cells (hLECs).Methods. MTS was conducted to confirm the antiproliferation effect of GSPP on hLECs; flow cytometry was employed to detect hLECs cycle distribution; the antimigration effect of GSPP on hLECs was investigated by wound healing experiment and transwell experiment; tube formation assay was used to examine its inhibitory effect on the lymphangiogenesis; western blotting was conducted to detect the expression of extracellular signal-regulated kinase1/2 (Erk1/2) and p-Erk1/2 after GSPP and basic fibroblast growth factor (bFGF) treatment. Nude mice models were established to investigate the antitumor effect of GSPP in vivo. Decreased lymphangiogenesis caused by GSPP in vivo was verified by immunohistochemical staining.Results. In vitro, GSPP (10 μg/mL, 100 μg/mL) significantly inhibited bFGF-induced hLECs proliferation, migration, and tube-like structure formation (P<0.05) and antagonized the phosphorylation activation of Erk1/2 induced by bFGF. In vivo, GSPP treatment (200 mg/kg/d) not only inhibited the growth of colon carcinoma, but also inhibited the tumor lymphangiogenesis.Conclusion. GSPP possesses the antitumor ability by inhibiting bFGF-inducing lymphangiogenesis in vitro and in vivo, which may further inhibit tumor lymphatic metastasis.

scholarly journals MiRNA let-7b promotes the development of hypoxic pulmonary hypertension by targeting ACE2

2019 ◽  
Vol 316 (3) ◽  
pp. L547-L557 ◽  
Author(s):  
Ruifeng Zhang ◽  
Hua Su ◽  
Xiuqing Ma ◽  
Xiaoling Xu ◽  
Li Liang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Hypoxia Inducible Factor ◽  
Underlying Mechanism ◽  
Pulmonary Vessel ◽  
Hypoxic Pulmonary Hypertension ◽  
And Migration ◽  
Ventricle Hypertrophy ◽  
Proliferation And Migration

Angiotensin-converting enzyme 2 (ACE2) protects against hypoxic pulmonary hypertension (HPH) by inhibiting the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). Under hypoxia, the hypoxia-inducible factor 1α (HIF-1α) inhibits ACE2 indirectly; however, the underlying mechanism is unclear. In the present study, we found that exposure to chronic hypoxia stimulated microRNA (miRNA) let-7b expression in rat lung via a HIF-1α-dependent pathway. Let-7b downregulated ACE2 expression by directly targeting the coding sequence of ACE2. Our in vitro and in vivo results revealed that let-7b contributed to the pathogenesis of HPH by inducing PASMCs proliferation and migration. Let-7b knockout mitigated right ventricle hypertrophy and pulmonary vessel remodeling in HPH by restoring ACE2 expression. Overall, we demonstrated that HIF-1α inhibited ACE2 expression via the HIF-1α-let-7b-ACE2 axis, which contributed to the pathogenesis of HPH by stimulating PASMCs proliferation and migration. Since let-7b knockout alleviated the development of HPH, let-7b may serve as a potential clinical target for the treatment of HPH.

scholarly journals HIF-1α Protects Granulosa Cells From Hypoxia-Induced Apoptosis During Follicular Development by Inducing Autophagy

2021 ◽  
Vol 9 ◽  
Author(s):  
Zonghao Tang ◽  
Renfeng Xu ◽  
Zhenghong Zhang ◽  
Congjian Shi ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Mammalian Cells ◽  
Caspase 3 ◽  
Ovarian Follicle ◽  
Hypoxia Inducible Factor ◽  
Follicular Development ◽  
B Cell Lymphoma ◽  
Underlying Mechanism

Owing to the avascular structure of the ovarian follicle, proliferation of granulosa cells (GCs) and development of follicles occur under hypoxia, which is obviously different from the cell survival requirements of most mammalian cells. We hypothesized that autophagy may exert an inhibitory effect on GC apoptosis. To decipher the underlying mechanism, we constructed a rat follicular development model using pregnant mare serum gonadotropin and a cell culture experiment in hypoxic conditions (3% O2). The present results showed that the autophagy level was obviously increased and was accompanied by the concomitant elevation of hypoxia inducible factor (HIF)-1α and BNIP3 (Bcl-2/adenovirus E1B 19kDa-interacting protein 3) in GCs during follicular development. The levels of Bax (Bcl2-associated X) and Bcl-2 (B-cell lymphoma-2) were increased, while the activation of caspase-3 exhibited no obvious changes during follicular development. However, inhibition of HIF-1α attenuated the increase in Bcl-2 and promoted the increase in Bax and cleaved caspase-3. Furthermore, we observed the downregulation of BNIP3 and the decrease in autophagy after treatment with a specific HIF-1α activity inhibitor (echinomycin), indicating that HIF-1α/BNIP3 was involved in autophagy regulation in GCs in vivo. In an in vitro study, we also found that hypoxia did not obviously promote GC apoptosis, while it significantly enhanced the activation of HIF-1α/BNIP3 and the induction of autophagy. Expectedly, this effect could be reversed by 3-methyladenine (3-MA) treatment. Taken together, these findings demonstrated that hypoxia drives the activation of HIF-1α/BNIP3 signaling, which induces an increase in autophagy, protecting GC from apoptosis during follicular development.

Sign in / Sign up

Export Citation Format

Share Document