Engeletin protects against cerebral ischemia/reperfusion injury by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways

Engeletin is a natural derivative of Smilax glabra rhizomilax that exhibits anti-inflammatory activity and suppresses lipid peroxidation. In the present study, we sought to elucidate the mechanistic basis for the neuroprotective and pro-angiogenic activity of engeltin in a human umbilical vein endothelial cells (HUVECs) oxygen-glucose deprivation and reoxygenation (OGD/R) model system and a middle cerebral artery occlusion (MCAO) rat model of cerebral ischemia and reperfusion injury. These analyses revealed that engeletin (10, 20, or 40 mg/kg) was able to reduce the infarct volume, increase cerebral blood flow, improve neurological function, and bolster the expression of vascular endothelial growth factor (VEGF), vasohibin-2 (Vash-2), angiopoietin-1 (Ang-1), phosphorylated human angiopoietin receptor tyrosine kinase 2 (p-Tie2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in MCAO rats. Similarly, engeletin (100, 200, or 400 nM) markedly enhanced the migration, tube formation, and VEGF expression of HUVECs in an OGD/R model system, while the VEGF receptor (R) inhibitor axitinib reversed the observed changes in HUVEC tube formation activity and Vash-2, VEGF, and CD31 expression. These data suggested that engeletin exhibited significant neuroprotective effects against cerebral ischemia and reperfusion injury in rats, and improved cerebrovascular angiogenesis by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways.

Vascular endothelial growth factor association with angiopoietin 1 promotes improvement in ventricular function after ischemic cardiomyopathy induced in mini pigs

Abstract Purpose: To investigate the safety and clinical, hemodynamic and tissue improvement ability in mini pigs undergoing cell and gene therapy for the treatment of acute myocardial infarction. Methods: Thirty-two mini pigs Br1 lineage, 12 months old, undergoing induction of acute myocardial infarction by occlusion of the diagonal branch of the paraconal coronary. They were divided into 4 groups: one control group and 3 treatment groups (cell therapy and gene cell therapy). Echocardiography reviews were performed on three occasions and histopathological analysis was performed after 4 weeks. Analysis of variance (ANOVA), Tukey and Wilcoxon tests, were performed. Results: Association of vascular endothelial growth factor (VEGF) with angiopoietin1 (Ang1) presented satisfactory results in the improvement of ventricular function following ischemic cardiomyopathy in mini pigs when compared to the results of the other treated groups. Conclusion: The therapy with VEGF and the combination of VEGF with Ang1, promoted recovered function of the myocardium, characterized by reduced akinetic area and induction of neovascularization.

Angiopoietin-1 and -2 and vascular endothelial growth factor expression in ovarian grafts after cryopreservation using two methods / 대한생식의학회지

OBJECTIVE: The favored method of preserving fertility in young female cancer survivors is cryopreservation and autotransplantation of ovarian tissue. Reducing hypoxia until angiogenesis takes place is essential for the survival of transplanted ovarian tissue. The aim of this study was to investigate the role of angiopoietin-1 (Angpt-1), angiopoietin-2 (Angpt-2), and vascular endothelial growth factor (VEGF) in ovarian tissue grafts that were cryopreserved using two methods. METHODS: Ovarian tissues harvested from ICR mice were divided into three groups: group I (control), no cryopreservation; group II, vitrification in EFS (ethylene-glycol, ficoll, and sucrose solution)-40; and group III, slow freezing in dimethyl sulfoxide. We extracted mRNA for VEGF, Angpt-1, and Angpt-2 from ovarian tissue 1 week following cryopreservation and again 2 weeks after autotransplantation. We used reverse transcriptase-polymerase chain reaction to quantify the levels of VEGF, Angpt-1, and Angpt-2 in the tissue. RESULTS: Angpt-1 and Angpt-2 expression decreased after cryopreservation in groups II and III. After autotransplantation, Angpt-1 and Angpt-2 expression in ovarian tissue showed different trends. Angpt-1 expression in groups II and III was lower than in group I, but Angpt-2 in groups II and III showed no significant difference from group I. The vitrified ovarian tissues had higher expression of VEGF and Angpt-2 than the slowfrozen ovarian tissues, but the difference was not statistically significant. CONCLUSION: Our results indicate that Angpt-2 may play an important role in ovarian tissue transplantation after cryopreservation although further studies are needed to understand its exact function.

Combination of stromal vascular fraction and Ad-COMP-Ang1 gene therapy improves long-term therapeutic efficacy for diabetes-induced erectile dysfunction / 亚洲男科学杂志(英文版)

Men with diabetic erectile dysfunction (ED) respond poorly to the currently available oral phosphodiesterase-5 inhibitors. Therefore, functional therapies for diabetic ED are needed. Stromal vascular fraction (SVF) and the adenovirus-mediated cartilage oligomeric matrix angiopoietin-1 (Ad-COMP-Ang1) gene are known to play critical roles in penile erection. We previously reported that SVF and Ad-COMP-Ang1 have only a short-term effect in restoring erectile function. Further improvements to ED therapy are needed for long-lasting effects. In the present study, we aimed to test if the combination of SVF and Ad-COMP-Ang1 could extend the erection effect in diabetic ED. We found that the combination therapy showed a long-term effect in restoring erectile function through enhanced penile endothelial and neural cell regeneration. Combination therapy with SVF and Ad-COMP-Ang1 notably restored cavernous endothelial cell numbers, pericyte numbers, endothelial cell-cell junctions, decreased cavernous endothelial cell permeability, and promoted neural regeneration for at least 4 weeks in diabetic mice. In summary, this is an initial description of the long-term effect of combination therapy with SVF and Ad-COMP-Ang1 in restoring erectile function through a dual effect on endothelial and neural cell regeneration. Such combination therapy may have therapeutic potential for the treatment of diabetic ED.

Angiopoietin-1 Modified Human Umbilical Cord Mesenchymal Stem Cell Therapy for Endotoxin-Induced Acute Lung Injury in Rats

PURPOSE: Angiopoietin-1 (Ang1) is a critical factor for vascular stabilization and endothelial survival via inhibition of endothelial permeability and leukocyte- endothelium interactions. Hence, we hypothesized that treatment with umbilical cord mesenchymal stem cells (UCMSCs) carrying the Ang1 gene (UCMSCs-Ang1) might be a potential approach for acute lung injury (ALI) induced by lipopolysaccharide (LPS). MATERIALS AND METHODS: UCMSCs with or without transfection with the human Ang1 gene were delivered intravenously into rats one hour after intra-abdominal instillation of LPS to induce ALI. After the rats were sacrificed at 6 hours, 24 hours, 48 hours, 8 days, and 15 days post-injection of LPS, the serum, the lung tissues, and bronchoalveolar lavage fluid (BALF) were harvested for analysis, respectively. RESULTS: Administration of fluorescence microscope confirmed the increased presence of UCMSCs in the injured lungs. The evaluation of UCMSCs and UCMSCs-Ang1 actions revealed that Ang1 overexpression further decreased the levels of the pro-inflammatory cytokines TNF-α, TGF-β1, and IL-6 and increased the expression of the anti-inflammatory cytokine IL-10 in the injured lungs. This synergy caused a substantial decrease in lung airspace inflammation and vascular leakage, characterized by significant reductions in wet/dry ratio, differential neutrophil counts, myeloperoxidase activity, and BALF. The rats treated by UCMSCs-Ang1 showed improved survival and lower ALI scores. CONCLUSION: UCMSCs-Ang1 could improve both systemic inflammation and alveolar permeability in ALI. UC-derived MSCs-based Ang1 gene therapy may be developed as a potential novel strategy for the treatment of ALI.

Expressions and Clinical Significances of Angiopoietin-1, Angiopoietin-2, and Tie-2 Receptor in Patients With Colorectal Cancer

PURPOSE: Angiopoietin-1 (Ang-1) plays a crucial role in vascular and hematopoietic development, mainly through its cognate receptor, Tie-2. Increased levels of Ang-2 have been shown to be correlated with abnormal tumor angiogenesis in several malignancies. Hence, we estimated the increased expression of Ang-2 relative to Ang-1 in patients with colorectal cancer and correlated our finding with prognosis in order to investigate the relationships between the expressions of Ang-1/Ang-2/Tie-2 receptor and the clinical parameters or overall survival of such patients. METHODS: We retrospectively analyzed 114 tissue samples from patients with colorectal cancer by using immunohistochemistry (IHC) to examine Ang-1, Ang-2, and Tie-2 expressions and to investigate the relationship between those expressions and clinical parameters or overall survival of such patients. A Western blot analysis was used for Ang-2 expression. RESULTS: IHC staining showed a link between Ang-1 and Tie-2 (P = 0.018), as well as meaningful correlations between Ang-2 and Tie-2 receptor (P = 0.022) and between lymph-node metastasis and Ang-2 (P = 0.025). The stronger the IHC staining for Ang-2 expression was, the shorter the cumulative survival was (P = 0.016). CONCLUSION: A relationship was found to exist between Ang-2 and Tie-2 expressions. The Ang-2 was correlated with lymph-node metastasis, and high expression of Ang-2 was indicative of poor overall survival. These findings suggest that Ang-2 is a useful prognostic marker in the management of patients with colorectal cancer. In addition, we suggest that Ang/Tie-2 signaling plays an important role in the progression of colorectal cancer.

Angiopoietin-1 and Angiopoietin-2 Expression Imbalance Influence in Early Period After Subarachnoid Hemorrhage / 대한배뇨장애요실금학회지

PURPOSE: Microvascular endothelial integrity is important for maintaining the blood-brain barrier (BBB). However, subarachnoid hemorrhage (SAH) disrupts this integrity, making the BBB dysfunctional—an important pathophysiological change after SAH. Angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) regulate microvascular permeability by balancing each other’s expression. METHODS: This study investigated the dynamics of Ang-1 and Ang-2 expression after SAH and the protective effect of Ang-1 on BBB functioning using an endovascular puncture model of rat SAH. The Ang-1 and Ang-2 expression in brain tissue was determined by immunohistochemistry. In addition, Western blotting was used to estimate Ang-1 and Ang-2 concentration and to compare them at 6–72 hours post-SAH cortex and hippocampus. Evans blue viability assay was used to evaluate BBB permeability, and neurological testing was implemented to evaluate neurological impairment during SAH. RESULTS: It was found that following SAH, Ang-1 expression decreases and Ang-2 expression increases in the cortex, hippocampus, and microvessels. The Ang-1/Ang-2 ratio decreased as quickly as 6 hours after SAH and reached its lowest 1 day after SAH. Finally, it was found that exogenous Ang-1 reduces SAH-associated BBB leakage and improves neurological function in post-SAH rats. CONCLUSIONS: Our findings suggest that the equilibrium between Ang-1 and Ang-2 is broken in a period shortly after SAH, and the treatment of exogenous Ang-1 injection alleviates neurological dysfunctions through decreasing BBB destruction.

Angiogenic factors are associated with development of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation / 华中科技大学学报（医学）（英德文版）

Acute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-β in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-β promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.

Midtrimester maternal plasma concentrations of angiopoietin 1, angiopoietin 2, and placental growth factor in pregnant women who subsequently develop preeclampsia

OBJECTIVE: The aim of this study was to compare midtrimester maternal plasma concentrations of angiopoietin 1, angiopoietin 2, and placental growth factor between pregnant women who subsequently developed preeclampsia and those who did not. METHODS: Midtrimester maternal plasma was collected and stored at -70degrees C when genetic amniocentesis was performed. Cases included 37 samples of individual who subsequently developed preeclampsia, and matched controls were from individuals who did not develop preeclampsia. Angiopoietin 1, angiopoietin 2, and placental growth factor concentrations were measured by the enzyme-linked immunosorbent assay method and were compared using the Mann-Whitney U-test. A P-value <0.05 was considered significant. RESULTS: In pregnant women who subsequently developed preeclampsia, midtrimester maternal plasma concentrations of angiopoietin 1 and angiopoietin 2 were significantly higher and placental growth factor concentrations were significantly lower than in women who did not develop preeclampsia (angiopoietin 1: 10.6 [3.1-19.7] vs. 7.8 [0.9-24.4] ng/mL, P=0.031; angiopoietin 2: 31.0 [4.7-81.2] vs. 18.4 [4.2-49.7] ng/mL, P<0.001; placental growth factor: 87.1 [14.2-774.3] vs. 148.8 [57.2-425.6] pg/mL, P<0.001). Within the case group who subsequently developed preeclampsia, the placental growth factor was significantly lower in those who had fetal growth restrictions than in those who did not (placental growth factor: 72.5 [14.2-774.3] vs. 140.9 [44.2-257.5] pg/mL, P=0.003). CONCLUSION: Midtrimester maternal plasma concentrations of angiopoietin 1, angiopoietin 2, and placental growth factor may be associated with the subsequent development of preeclampsia.

Maternal Plasma Angiopoietin-1 and Angiopoietin-2 in Pregnant Women with Chronic Hypertension / 대한주산의학회잡지

PURPOSE: The aim of this study was to investigate whether plasma angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) concentrations in pregnant women with chronic hypertension are different from those of normotensive pregnant women. METHODS: This hospital-based case-control study consisted of 35 pregnant women with chronic hypertension who delivered at Seoul National University Hospital. Normotensive pregnant women (n=70) were selected as controls, matched with maternal age, gestational age at delivery and birthweight. Maternal blood was drawn at the time of admission for delivery and plasma was separated and stored. The plasma Ang-1 and Ang-2 levels were measured by ELISA. Statistical analysis was done with Mann-Whitney U test, Fisher's exact test and Spearman rank correlation test using SPSS. RESULTS: Median (range) maternal age, gestational age and birthweight were 33 years (24-42), 38 weeks (32-41), and 3.08 kg (1.13-4.01). Pregnant women with chronic hypertension had significantly higher median Ang-1 and Ang-2 levels than normotensive pregnant women (for Ang-1 : median 4,111 pg/mL, range 1,415-30,172 vs. median 2,824 pg/mL range 662-14,512, P=0.015, for Ang-2 : median 5,637 pg/mL, range 1,131-29,327 vs. median 3,345 pg/mL, range 609-24,467, P=0.039). CONCLUSION: Maternal plasma Ang-1 and Ang-2 levels were elevated in pregnant women with chronic hypertension compared with normotensive pregnant women. Further study is needed to determine if this change is a cause or a compensatory mechanism to chronic hypertension.

Research advances on anti-ANGPT2 antibody in acute myeloid leukemia / 中国实验血液学杂志

Angiopoietin2( ANGPT2 ) plays an important role in tumor angiopoiesis. ANGPT2 antagonises ANGPT1 resulting in an effect on the stability of blood vessels, which promotes tumor growth, invasion, proliferation as well as relating to tumor vascular density. A lot of researches published papers about anti-ANGPT2 for the treatment of tumor, and have made some progresses. In this review, the role of ANGPT2 in the pathogenesis of acute myelogenous leukemia (AML), including its effects on proliferation of leukemia cells, bone marrow angiopoiesis, tumor invasion and metastasis are briefly summarised in order to provide the basis for targeted ANGPT2 in treatment of AML.

Effects of adenovirus-delivered angiopoietin-1 siRNA on expression of matrix metalloproteinases in rats with acute lung injury induced by phosgene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of adenovirus-delivered angiopoietin-1 siRNA (Ad. Ang-1siRNA) on the expression of matrix metalloproteinase-2, 9 (MMP-2, 9) and tissue inhibitor of metallopro-teinase-1 (TIMP-1) in rats with acute lung injury (ALI) induced by phosgene (Psg).</p><p><b>METHODS</b>We first established a rat model of Psg-induced acute lung injury (ALI). The rats were randomly divided into 6 groups: air control group with exposure to air, air+adenovirus (air+Ad) group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after air exposure, air+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after air exposure, Psg group with exposure to 8.33 mg/L Psg (purity 100%, of the same volume as the inhaled air in the air control group) for 5 min, Psg+Ad group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after exposure to the same dose of Psg, and Psg+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after exposure to the same dose of Psg. Serum, bronchoalveolar lavage fluid (BALF), and lung tissue were collected 36 h after exposure. The protein expression of Ang-1, MMP-2, 9, and TIMP-1 in serum and BALF was determined by double-antibody sandwich ELISA. RT-PCR was used to determine the mRNA levels of Ang-1, MMP-2, 9, and TIMP-1 in lung tissue. The protein expression of MMP-2, 9 and TIMP-1 in lung tissue was determined by Western blot.</p><p><b>RESULTS</b>A rat model of Psg-induced ALI was successfully established. The levels of MMP-2, 9 in serum, BALF, and lung tissue were significantly increased in the Psg group and Psg+Ad/Ang1 group as compared with the control group (P<0.01); no significant change was observed in serum TIMP-1 protein expression (P>0.05); interestingly, TIMP-1 protein expression in BALF and lung tissue was significantly increased (P<0.01). Compared with the Psg group, the Psg+Ad/Ang1 group showed a significant decrease in MMP-2, 9 expression in BALF, serum, and lung tissue (P<0.05), but no significant change in protein expression of TIMP-1 was discovered (P>0.05).</p><p><b>CONCLUSION</b>Ad.Ang-1siRNA has a potential beneficial effect in rats with Psg-induced ALI through inhibition of MMP-2, 9 expression, but has no significant effect on the expression of TIMP-1.</p>

Microvascular protective role of pericytes in melatonin-treated spinal cord injury in the C57BL/6 mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Pericytes, located on microvessels, help to maintain vascular stability and blood-brain barrier integrity. The influence of pericytes on microvessels after spinal cord injury (SCI) is less clear. Therefore, the aim of this study was to investigate whether pericytes took a protective effect on microvessels in melatonin-treated SCI.</p><p><b>METHODS</b>C57BL/6 mice were randomly divided into three groups: sham group, SCI group, and melatonin group (n = 27 per group). Functional recovery was evaluated using the Basso Mouse Scale. Motor neurons were observed using hematoxylin and eosin staining. Pericyte coverage was analyzed using immunofluorescence. Permeability of blood-spinal cord barrier (BSCB) was assessed by administration of Evan's Blue. Protein levels of occludin, aquaporin-4 (AQP4), angiopoietin-1 (Ang1), intercellular cell adhesion molecule-1 (ICAM-1), Bcl-2, and Bax were determined using Western blotting. Mimicking the pathological conditions of SCI, melatonin-treated primary pericytes were subjected to oxygen-glucose deprivation/reperfusion (OGD/R). Secretion of Ang1 was analyzed using an enzyme-linked immunosorbent assay, and the expression of ICAM-1 was detected by immunofluorescence.</p><p><b>RESULTS</b>Melatonin treatment improved locomotor functional outcome and rescued motor neurons. Pericyte coverage was significantly reduced after SCI; melatonin treatment alleviated the loss of pericyte coverage and rescued perfused microvessels 7 days after injury. The permeability of BSCB and loss of occludin were attenuated, and edema formation and upregulation of AQP4 were inhibited, after melatonin treatment. The expression of Ang1 and Bcl-2 was improved, while the expression of ICAM-1 and Bax was inhibited, in melatonin-treated SCI mice. Furthermore, the secretion of Ang1 was increased and the expression of ICAM-1 was inhibited in melatonin-treated pericytes after OGD/R.</p><p><b>CONCLUSIONS</b>Melatonin ameliorated the loss of blood vessels and disruption of BSCB to exert a protective effect on SCI, which might be mediated by increased pericyte coverage. The upregulation of Ang1 in pericytes could inhibit inflammation and apoptosis to protect the microvessels.</p>

The influence of rhAng-1 on endothelial junctions of BBB after focal cerebral ischemia/reperfusion in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>This study was performed to determine whether recombinant human angiopoietin-1 (rhAng-1) decreases the permeability of the blood-brain barrier (BBB) in focal cerebral ischemia and reperfusion rats, whether RhAng-1 opens the BBB by affecting tight junction associated proteins zonnula occludin-1 (ZO-1), occludin and adherens junction protein vascular endothelial (VE)-cadherin.</p><p><b>METHODS</b>The rats were divided into eight groups randomly( n = 10): (1) sham-operated group; (2) ischemia group; (3)-(5) ischemia/reperfusion (middle cerebral artery occlusion and reperfusion (MCAO/R) 12 h, 48 h, and 7 days) and 0.9% saline groups; (6)-(8) ischemia/reperfusion (MCAO/R 12 h, 48 h, and 7 days) and rhAng-1 groups. The Bee permeability was assessed by Evans blue extravasation. The messenger RNA and protein expressions of ZO-1, occludin, and VE-cadherin were determined by reverse transcription-polymerase chain reaction, Western blot, and immunohistochemistry assays.</p><p><b>RESULTS</b>The BBB permeability and the brain infarct volume were significantly decreased after rhAng-1 injection. The expressions of ZO-1, occludin, and VE-cadherin were increased after rhAng-1 injection.</p><p><b>CONCLUSION</b>rhAng-1 may decrease the permeability of BBB in MCAO/R rats by upregulation of ZO-1, occludin, and VE-cadherin.</p>

Effect of Taohong Siwu decoction on angiogenesis of medicine-induced incomplete-abortion in early pregnancy rats and expressions of Ang-1, Ang-2 and Tie-2 / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Taohong Siwu decoction (THSWD) on micro-vascular density (MVD) in rat uterus, the content of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) in serum, and the expression of tyrosine kinasa receptor (Tie-2) in uterus.</p><p><b>METHOD</b>Early pregnancy rats were intragastrically administrated with misoprostol (100 microg x kg(-1)) and mifepristong (8.3 mg x kg(-1)) to established the incomplete-abortion model. The incomplete-abortion rats were randomly divided into the model group (the same volume of distilled water), the positive control group (at the daily dose of 4.3 g x kg(-1) Motherwort Particles), and THSWD-treated groups (at the daily dose of 18.0, 9.0 and 4.5 g x kg(-1)). Pregnant rats were taken as the control group (the same volume of distilled water). After the successive oral administration for 7 days, blood was collected from aorta abdominalis, and rat uterine tissues were collected. The content of serum Ang-1 and Ang-2 were detected by ELISA; And the levels of Tie-2 and MVD in uterine tissues were detected by SP immunohistochemistry.</p><p><b>RESULT</b>THSWD remarkably increased the levels of MVD in uterus of medicine-induced abortion rats, the content of Ang-1 and Ang-2 in serum, and the expression of Tie-2 in uterine tissues.</p><p><b>CONCLUSION</b>THSWD has the effect in markedly promoting angiogenesis in incomplete-abortion rats. Its mechanism may be related to the regulation of concentrations of Ang-1 and Ang-2 in serum and Tie-2 in uterine tissues.</p>

Treatment with EGCG in NSCLC leads to decreasing interstitial fluid pressure and hypoxia to improve chemotherapy efficacy through rebalance of Ang-1 and Ang-2 / 中国天然药物

AIM@#Microvasculature and microenvironment play important roles in proliferation, invasion, metastasis and prognosis in non-small cell lung cancer (NSCLC), which might be altered by many anti-angiogenic drugs. Epigallocatechin-3-gallate (EGCG), a natural anti-angiogenesis agent refined from green tea, was defined to have multiple effects on angiogenesis factors, such as endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and angiopoietins (ANGs). Hypothesizing that EGCG might regulate microvasculature and microenvironment in NSCLC, the effects of EGCG on microvessel density (MVD), expression of Ang-1 and Ang-2, interstitial fluid pressure (IFP), tumor hypoxia, and chemotherapy sensitivity were examined.@*METHODS AND RESULTS@#EGCG treatment of A549 cells in mice bearing xenografts in vivo led to a significant decrease of MVD detected by CD31, and of Ang-2 expression detected by quantum dots double-label immunofluorescence assessment, while Ang-1 decreased with no significance. Decreased IFP was measured by the Wink-in-needle method, while hypoxia was assessed by polarographic electrode and pimonidazole (PIMO) immunohistochemistry. Assuming that these changes would increase response to chemotherapy, tumor growth studies were p[erformed in nude mice with xenografts, which were then treated with EGCG and the chemotherapeutic agent cisplatin. EGCG therapy combined with cisplatin led to synergistic inhibition of tumor growth, compared with administration of each treatment separately (P < 0.001). According to linear regression analysis, IFP was positively correlated with PIMO staining (R(2) = 0.618, P = 0.002), Ang-2 was correlated with MVD (R(2) = 0.423, P = 0.022), IFP (R(2) = 0.663, P = 0.01) and PIMO staining (R(2) = 0.694, P = 0.01).@*CONCLUSION@#IFP and delivery of oxygen might be improved by rebalance of Ang-1/Ang-2 under the treatment of EGCG in NSCLC, which also acts as a sensitizer of chemotherapy. These studies established a new mechanism for using EGCG as an adjuvant chemotherapy agent through modifying microvasculature and microenvironment.

Potential protective effect of angiopoietin-1 on the leakage of rat choroidal neovascularization

To observe the potential protective effect of angiopoietin-1 [Ang-1] on rat choroidal neovascularization [CNV] leakage. The study was conducted at the Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China from June 2012 to June 2013. Thirty CNV model rats were induced by laser. In vivo, fluorescein fundus angiography and pathological techniques were applied to detect the effect of vascular endothelial growth factor [VEGF] and Ang-1 intravitreous injection. In vitro, 3-[4, 5-dimethylthiazole-2-yl]-2, 5-biphenyl tetrazolium bromide [MTT] assay was applied to detect the proliferation of cultured bovine retinal endothelial cells [BRECs] after treatment with VEGF and Ang-1. Transmission electron microscopy [TEM] was used to detect the morphological changes under VEGF and Ang-1. In the CNV rat model, less late leakage was found in the Ang-1 group than the vehicle control or the VEGF group. The MTT assay showed Ang-1 administration inhibited the proliferation of BRECs. The VEGF promoted proliferation at low concentrations and inhibited the proliferation when its concentration reached 50 ng/ml. The administration of VEGF+Ang-1 rescued the inhibition effect of Ang-1 alone. The TEM results showed that there were less intercellular junctions in the VEGF group compared with the vehicle control. In the VEGF + Ang-1 group, the intercellular junctions were nearly normal. The Ang-1 can induce intercellular junction formation and decrease the CNV leakage

Effect of alendronate on bone remodeling around implant in the rat

PURPOSE: The purpose of this study was to evaluate the effect of alendronates on bone remodeling around titanium implant in the maxilla of rats. MATERIALS AND METHODS: The maxillary first molars were extracted and customized-titanium implants were placed immediately in thirty male Sprague-Dawley rats. The rats were divided into experimental (bisphosphonate) group and control group. At 4 weeks after implantation, the rats in the bisphosphonate group were subcutaneously injected with alendronate three times a week for 6 weeks where as the rats in control group were injected with saline. The rats were sacrificed at 1, 2, 3, 4, or 6 weeks after starting of injection and maxillary bones were collected subsequently. Alveolar bone remodeling around the implants were evaluated by radiographic and histologic analysis. Microarray analysis and immunohistomorphologic analysis were also performed on one rat, sacrificed at 6 weeks after starting of injection, from each group. Statistical analysis was performed using repeated measures analysis of variance and independent t test at a significance level of 5%. RESULTS: There was no statistically significant difference in the bone area (%) around implant between the bisphosphonate group and the control group. However, the amount of empty lacuna was significantly increased in the bisphosphonate group, especially in the rats sacrificed at 4 weeks after starting of injection compared to that of the corresponding control group. The bisphosphonate group showed the same level of TRAP positive cell count, osteocalcin and angiopoietin 1 as the control group. CONCLUSION: Alendronate may not decrease the amount of osteoclast. However, the significantly increased amount of empty lacuna in the bisphosphonate group may explain the suppression of bone remodeling in the bisphosphonate group.

COMP-Angiopoietin-1 Promotes Cavernous Angiogenesis in a Type 2 Diabetic Rat Model

Cartilage oligomeric matrix protein-angiopoietin-1 (COMP-Ang1) is an angiogenic factor for vascular angiogenesis. The aim was to investigate the effect of an intracavernosal injection of COMP-Ang1 on cavernosal angiogenesis in a diabetic rat model. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats made up the experimental group (1 yr old) and Long-Evans Tokushima Otsuka (LETO) rats made up the control group. The experimental group was divided into vehicle only, 10 microg COMP-Ang1, and 20 microg COMP-Ang1. COMP-Ang1 was injected into the corpus cavernosum of the penis. After 4 weeks, the penile tissues of the rats were obtained for immunohistochemistry and Western blot analysis. The immunoreactivity of PECAM-1 and VEGF was increased in the COMP-Ang1 group compared with the vehicle only group. Moreover, the expression of PECAM-1 and VEGF was notably augmented in the 20 microg Comp Ang-1 group. In the immunoblotting study, the expression of PECAM-1 and VEGF protein was significantly less in the OLEFT rats than in the control LETO rats. However, this expression was restored to control level after intracavernosal injection of COMP-Ang1. These results show that an intracavernosal injection of COMP-Ang1 enhances cavernous angiogenesis by structurally reinforcing the cavernosal endothelium.

Influence of negative pressure wound therapy on the angiogenesis of wounds in diabetic rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the influence of negative pressure wound therapy on the angiogenesis of wounds in diabetic rats.</p><p><b>METHODS</b>Diabetes model was reproduced by intraperitoneal injection of 20 g/L streptozotocin in the dosage of 65 mg/kg in 40 SD rats. Two weeks later, rats were divided into control group (C) and negative pressure group (NP) according to the random number table, with 20 rats in each group. A piece of full-thickness skin in the center of the back of each rat in the size of 2 cm×2 cm was excised to produce a wound. Immediately after injury, wounds in group C were given conventional dressing change; wounds in group NP were treated with continuous negative pressure (-16.0 kPa) therapy for four hours a day, which lasted for seven days. (1) Blood glucose and body weight of rats in two groups were respectively measured by glucose meter and electronic scale before treatment, and 1 and 2 week (s) after. (2) Wound blood flow was detected by laser Doppler perfusion imager before treatment and on post treatment day (PTD) 1, 3, 7, with 5 rats at each time point. (3) On PTD 3 and 7, respectively, five rats from each group were sacrificed. The wound tissue was excised and divided into two parts. The angiogenesis in the left part tissue was observed with immunohistochemical staining. The microvessel density was calculated. (4) The full-thickness skin excised before treatment and the right part tissue freeze on PTD 3 and 7 were collected. On PTD 1 and 14, wound tissue was excised in the above-mentioned method. The mRNA levels of the vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 1 (Fit-1), angiopoietin 1 (Ang-1), Ang-2, and tyrosine kinase receptor 2 (Tie-2) were determined with real-time fluorescence quantification PCR. Data were processed with two-way analysis of variance or LSD-t test.</p><p><b>RESULTS</b>(1) No significant difference was observed between two groups in blood glucose level and body weight as a whole or at each time point (with F values respectively 0.667, 0.176, t values from 0.311 to 0.707, P values all above 0.05). (2) The difference in the overall wound blood flow of rats between two groups was significant (F = 24.66, P < 0.05). On PTD 1, 3, 7, values of wound blood flow of rats in group NP were (179 ± 24), (219 ± 12), (192 ± 30) perfusion unit, significantly higher than those of rats in group C[(127 ± 16), (179 ± 8), (144 ± 17) perfusion unit, with t values respectively 3.71, 5.57, 2.77, P < 0.05 or P < 0.01]. (3) The difference in the overall microvessel density in the wound of rats between two groups was significant (F = 33.25, P < 0.05). On PTD 3, the microvessel density in the wound of rats in group NP was (80 ± 12) per 100-time visual field, which was significantly higher than that of group C[(38 ± 4) per 100-time visual field, t = 9.257, P < 0.05]. On PTD 7, the microvessel density in the wound of rats in two groups were close (t = 1.159, P > 0.05), but the vessels in group NP were regularly arranged with spacious lumen, while the vessels in group C were disorderly arranged with narrow lumen. (4) On PTD 1, 3, mRNA expression levels of VEGF, Fit-1, and Ang-1 in group NP were obviously higher than those in group C (with t values from 1.28 to 11.60, P values all below 0.01). On PTD 7, the mRNA expression level of Ang-1 (27.59 ± 3.55) in group NP was obviously higher than that in group C (19.87 ± 1.86, t = 7.23, P < 0.001), while the mRNA level of its antagonist Ang-2 (5.79 ± 0.61) in group NP was obviously lower than that in group C (17.62 ± 0.85, t = 19.88, P < 0.001). On PTD 3, 7, 14, mRNA levels of Tie-2 in group NP were obviously lower than those in group C (with t values from 8.92 to 15.60, P values all below 0.01).</p><p><b>CONCLUSIONS</b>Negative pressure wound therapy may promote wound angiogenesis by enhancing the expression of Ang-1 and lowering the expression of Ang-2 in diabetic rats.</p>