Agmatine induces gastric protection against ischemic injury by reducing vascular permeability in rats

AIM:To investigate the effect of administration of agmatine(AGM) on gastric protection against ischemia reperfusion(I/R) injury.METHODS:Three groups of rats(6/group);sham,gastric I/R injury,and gastric I/R + AGM(100 mg/kg,i.p.given 15 min prior to gastric ischemia) were recruited.Gastric injury was conducted by ligating celiac artery for 30 min and reperfusion for another 30 min.Gastric tissues were histologically studied and immunostained with angiopoietin 1(Ang-1) and Ang-2.Vascular endothelial growth factor(VEGF) and monocyte chemoattractant protein-1(MCP-1) were measured in gastric tissue homogenate.To assess whether AKt/phosphatidyl inositol-3-kinase(PI3K) mediated the effect of AGM,an additional group was pretreated with Wortmannin(WM)(inhibitor of Akt/PI3K,15 μg/kg,i.p.),prior to ischemic injury and AGM treatment,and examined histologically and immunostained.Another set of experiments was run to study vascular permeability of the stomach using Evan's blue dye.RESULTS:AGM markedly reduced Evan's blue dye extravasation(3.58 ± 0.975 μg/stomach vs 1.175 ± 0.374 μg/stomach,P < 0.05),VEGF(36.87 ± 2.71 pg/100 mg protein vs 48.4 ± 6.53 pg/100 mg protein,P < 0.05) and MCP-1 tissue level(29.5 ± 7 pg/100 mg protein vs 41.17 ± 10.4 pg/100 mg protein,P < 0.01).It preserved gastric histology and reduced congestion.Ang-1 and Ang-2 immunostaining were reduced in stomach sections of AGM-treated animals.The administration of WM abolished the protective effects of AGM and extensive hemorrhage and ulcerations were seen.CONCLUSION:AGM protects the stomach against I/R injury by reducing vascular permeability and inflammation.This protection is possibly mediated by Akt/PI3K.

Triolein emulsion infusion into the hepatic artery increases vascular permeability to doxorubicin in rabbit liver

BACKGROUND The infusion of triolein emulsion(TE)induced increased vascular permeability and a negligible and temporary decrease in liver function without specific histopathological damage.AIM To assess changes in doxorubicin concentration according to the percentage of TE infused via a hepatic artery to study the vascular permeability in the rabbit liver.METHODS Thirty-nine healthy rabbits were divided into five groups according to the concentration of emulsified triolein infused into the hepatic arteries:Group 0,saline infusion(control group,n=5);group 1,0.3%TE(n=13);group 2,0.6%TE(n=6);group 3,0.9%TE(n=8);and group 4,1.5%TE(n=6).Doxorubicin(2.4 mg/kg)was infused immediately after TE injection via the hepatic arteries.After 2 h,the livers were harvested,and doxorubicin concentrations were calculated fluorometrically.The doxorubicin concentrations were compared between TE groups and the control group,and the optimal concentrations within the TE groups were calculated.Statistical analysis was performed using the nonparametric Mann-Whitney U test and Kruskal-Wallis test.P<0.05 were considered statistically significant.RESULTS In the liver,doxorubicin concentrations were 2.06,2.07,2.16 and 1.66 times higher in groups 1 through 4,respectively,and significantly higher in the TE groups than in the control group(all P<0.05).However,there were no significant differences in the mean doxorubicin concentrations between the four TE groups(P=0.642).In the lungs,the mean doxorubicin concentrations were not significantly different between the control and TE groups(P>0.05).CONCLUSION TE infusion into the hepatic arteries significantly increased the doxorubicin concentration approximately twofold but was not different between the TE groups.These findings suggest that TE infusion might be a useful adjuvant treatment of liver cancers.

AB039. BMP9 signaling maintains endothelial integrity and prevents hyperglycemia-induced retinal vascular permeability

Background:The maintenance of a quiescent retinal vascular endothelial barrier is paramount for tissue supply and homeostasis to ensure visual function.Chronic hyperglycemia in diabetes causes structural and functional alterations of the endothelium that are accelerated by the production of several mediators such as VEGF.The disturbance of interendothelial junction stability leading to retinal hyperpermeability is one of the changes leading to diabetic macular edema(DME)that can occur at any stage of diabetic retinopathy.Advances in our understanding of the pathophysiological mechanisms of DME have enabled effective new therapies such as anti-VEGF’s,which are however associated with non-negligible side effects.The discovery of endothelium-specific protective targets that could restore retinal endothelial quiescence could provide a therapeutic alternative.Signaling mediated by BMP9 circulating protein via its endothelium-specific receptor ALK1,is known for its role in the maintenance of vascular quiescence.However,its ability to protect the endothelium and prevent vascular permeability has not been tested in the context of diabetes.Methods:We investigated BMP9/ALK1 signalling pathway in the hyperglycemic endothelium and its effect on retinal permeability in a type 1 diabetes mouse model.Hyperglycemic endothelial cells and tissue were extracted to evaluate BMP9/ALK1 signaling.BMP9 overexpression was achieved using adenoviral vectors.Retinal permeability was measured using miles assay.Results:We found that BMP9/ALK1 signaling was inhibited in hyperglycemic endothelial cells and blood vessels of diabetic(DB)mice,and that this loss of function was directly associated with retinal hyperpermeability.Molecularly,inhibition of this pathway triggers the activation of the VEGFR2/SRC pathway reducing interendothelial adhesion junctions.Conversely,the activation of ALK1 by sustained BMP9 overexpression in DB mice enabled the restoration of physiological permeability by regulating the levels and localization of interendothelial junctions,in part by limiting the action of VEGF signalling.We also observed that BMP9 overexpression demonstrated a regulating effect of blood glucose levels in DB mice.Our results showed that BMP9 significantly ameliorates glucose control over a 4-week span in DB mice and that this regulation was mediated primarily via the ALK3 receptor inhibiting gluconeogenic gene expression and hepatic glucose production and hence hyperglycemia.Conclusions:Together,our data show that BMP9 acts on several levels to safeguard endothelial integrity preventing retinal hyperpermeability in DB mice.The effects are mediated by its endocrine effect by directly stabilizing the endothelial barrier through Alk1 and its hypoglycemic paracrine/autocrine action in the liver through Alk3.Thus,BMP9 could be used in the development of future therapeutic alternatives against several vascular diseases involving edematous complications.

AB004. Regulation of retinal angiogenesis and vascular permeability by bone morphogenetic protein signaling

The bone morphogenetic protein(BMP)family of proteins has a multitude of roles throughout the body.It plays important roles in development and in the adult vascular endothelium,by modulating the angiogenic response.The endothelial-specific receptor BMP receptor Alk1 is of particular importance in the proper remodeling of the vasculature and its ligand BMP9 has been shown to be a potent inhibitor of neovascularization.Dysregulated BMP signaling has been linked to multiple vascular diseases and can lead to the abnormal angiogenesis.We therefore investigated the role of BMP9/Alk1 signaling in retinal angiogenesis,and its therapeutic implications for vascular pathologies of the eye.

Pericytes protect rats and mice from sepsis-induced injuries by maintaining vascular reactivity and barrier function:implication of miRNAs and microvesicles

Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.

Knockdown of fibrillin-1 suppresses retina-blood barrier dysfunction by inhibiting vascular endothelial apoptosis under diabetic conditions

AIM:To investigate the effects of fibrillin-1(FBN1)deletion on the integrity of retina-blood barrier function and the apoptosis of vascular endothelial cells under diabetic conditions.METHODS:Streptozotocin(STZ)-induced diabetic mice were used to simulate the diabetic conditions of diabetic retinopathy(DR)patients,and FBN1 expression was detected in retinas from STZ-diabetic mice and controls.In the Gene Expression Omnibus(GEO)database,the GSE60436 dataset was selected to analyze FBN1 expressions in fibrovascular membranes from DR patients.Using lentivirus to knock down FBN1 levels,vascular leakage and endothelial barrier integrity were detected by Evans blue vascular permeability assay,fluorescein fundus angiography(FFA)and immunofluorescence labeled with tight junction marker in vivo.High glucose-induced monkey retinal vascular endothelial cells(RF/6A)were used to investigate effects of FBN1 on the cells in vitro.The vascular endothelial barrier integrity and apoptosis were detected by trans-endothelial electrical resistance(TEER)assay and flow cytometry,respectively.RESULTS:FBN1 mRNA expression was increased in retinas of STZ-induced diabetic mice and fibrovascular membranes of DR patients(GSE60436 datasets)using RNA-seq approach.Besides,knocking down of FBN1 by lentivirus intravitreal injection significantly inhibited the vascular leakage compared to STZ-DR group by Evans blue vascular permeability assay and FFA detection.Expressions of tight junction markers in STZ-DR mouse retinas were lower than those in the control group,and knocking down of FBN1 increased the tight junction levels.In vitro,30 mmol/L glucose could significantly inhibit viability of RF/6A cells,and FBN1 mRNA expression was increased under 30 mmol/L glucose stimulation.Down-regulation of FBN1 reduced high glucose(HG)-stimulated retinal microvascular endothelial cell permeability,increased TEER,and inhibited RF/6A cell apoptosis in vitro.CONCLUSION:The expression level of FBN1 increases in retinas and vascular endothelial cells under diabetic conditions.Down-regulation of FBN1 protects the retina of early diabetic rats from retina-blood barrier damage,reduce vascular leakage,cell apoptosis,and maintain vascular endothelial cell barrier function.

Fingolimod alters inflammatory mediators and vascular permeability in intracerebral hemorrhage

Intracerebral hemorrhage （ICH） leads to high rates of death and disability. The pronounced inflammatory reactions that rapidly follow ICH contribute to disease progression. Our recent clinical trial demonstrated that oral administration of an immune modulator fingolimod restrained secondary injury derived from initial hematoma, but the mechanisms remain unknown. In this study, we aim to investigate the effects of fingolimod on inflammatory mediators and vascular permeability in the clinical trial of oral fingolimod for intracerebral hemorrhage （ICH）. The results showed that fingolimod decreased the numbers of circulating CD4~ T, CD8~ T, CD19~ B, NK, and NKT cells and they recovered quickly after the drug＇ was stopped. The plasma ICAM level was decreased and IL-10 was increased by fingolimod. Interestingly, fingolimod protected vascular permeability as indicated by a decreased plasma level of MMP9 and the reduced rT1%. In conclusion, modulation of systemic inflammation by fingolimod demonstrates that it is an effective therapeutic agent for ICH. Fingolimod may prevent perihematomal edema enlargement by protecting vascular permeability.

VASOACTIVE INTESTINAL POLYPEPTIDE PREVENTS INJURY OF PULMONARY VASCULAR PERMEABILITY DUE TO XANTHINE WITH XANTHINE OXIDASE

Hyperpermeability is a crux of pathogenesis of sudden lung edema in many pulmonary disorders. especially in acute lung injury and adult respiratory distress syndrome(ARDS). Using our modified method for assessment of pulmonary vascular permeability. we observed the effects of xanthine with xanthine oxidase(X-XO) perfused in rat pulmonary artery and the protection of vasoactive intestinal polypeptide(VIP) against the injury of pulmonary vascular permeabilrty. After addition of xanthine oxidase in the perfusate reservoir containing xanthine￣(125) I-albumin leak index (￣(125)IALI)was remarkably increased while peak airway pressure(Paw) was not significantly increased, and perfusion pressure of pulmonary artery(Ppa)and lung wet/dry weight ratio(W/D) were only slightly increased. Xanthine plus xanthine oxidase also increased thromboxane B_2(TX B_2) and 6-keto-prostaglandin F_(1α)(6-keto -PGF_(1α)) in the perfusate. Treatment with VIP obviously reduced or totally prevented all signs of injury. Simultaneously, VIP also diminished or abolished the associated generation of arachidonate products. The results indicated that VIP has potent protective activity against injury of pulmonary vascular permeability and may be a physiological modulator of inflammatory damage to vascular endothelium associated with toxic oxygen metacolites.

Expression and significance of the vascular permeability factor in nasal polyps

目的 探讨血管通透性因子 (vascularpermeabilityfactor,VPF)在鼻息肉组织中的表达及意义。方法 将 9例鼻息肉标本及 8例下鼻甲粘膜标本行VPF及其受体flk 1的免疫组化染色 ,光镜观查。结果 VPF在鼻息肉组织的血管内皮细胞和腺体细胞的表达明显高于下鼻甲组织 (P <0 .0 1,P <0 .0 5 ) ,flk 1在血管内皮细胞的表达明显高于下鼻甲组织 (P <0 .0 1)。

Regulatory mechanisms,prophylaxis and treatment of vascular leakage following severe trauma and shock

Vascular leakage, or increased vascular permeability, is a common but important pathological process for various critical diseases, including severe trauma, shock, sepsis, and multiple organ dysfunction syndrome(MODS), and has become one of the most important causes of death for intensive care units(ICU) patients. Currently, although there has been some progress in knowledge of the pathogenesis of these vascular disorders, the detailed mechanisms remain unclear, and effective prophylaxis and treatment are still lacking. In this study, we aimed to provide a review of the literature regarding the regulatory mechanisms and prophylaxis as well as the treatment of vascular leakage in critical diseases such as severe trauma and shock, which could be beneficial for the overall clinical treatment of vascular leakage disorders.

Effect of High Frequency Oscillatory Ventilation on EVLW and Lung Capillary Permeability of Piglets with Acute Respiratory Distress Syndrome Caused by Pulmonary and Extrapulmonary Insults

The effect of high frequency oscillatory ventilation（HFOV） at early stage on hemodynamic parameters, extravascular lung water（EVLW）, lung capillary permeability, CC16 and s ICAM-1 in piglets with pulmonary or extrapulmonary acute respiratory distress syndrome（ARDS） was explored. Central vein pressure（CVP） and pulse indicator continuous cardiac output（Pi CCO） were monitored in 12 anesthetized and intubated healthy piglets. Pulmonary ARDS（ARDSp） and extrapulmonary ARDS（ARDSexp） models were respectively established by lung lavage of saline solution and intravenous injection of oleic acid. Then the piglets received HFOV for 4 h. EVLW index（EVLWI）, EVLW/intratroracic blood volume（ITBV） and pulmonary vascular permeability index（PVPI） were measured before and after modeling（T0 and T1）, and T2（1 h）, T3（2 h）, T4（3 h） and T5（4 h） after HFOV. CC16 and s ICAM-1 were also detected at T1 and T5. Results showed at T1, T3, T4 and T5, EVLWI was increased more significantly in ARDSp group than in ARDSexp group（P〈0.05）. The EVLWI in ARDSp group was increased at T1（P=0.008）, and sustained continuously within 2 h（P=0.679, P=0.216）, but decreased at T4（P=0.007） and T5（P=0.037）. The EVLWI in ARDSexp group was also increased at T1（P=0.003）, but significantly decreased at T3（P=0.002） and T4（P=0.019）. PVPI was increased after modeling in both two groups（P=0.004, P=0.012）, but there was no significant change within 4 h（T5） under HFOV in ARDSp group, while PVPI showed the increasing trends at first, then decreased in ARDSexp group after HFOV. The changes of EVLW/ITBV were similar to those of PVPI. No significant differences were found in ΔEVLWI（P=0.13）, ΔPVPI（P=0.28） and ΔEVLW/ITBV between the two groups（P=0.63）. The significant decreases in both CC16 and s ICAM-1 were found in both two groups 4 h after HFOV, but there was no significant difference between the two groups. It was concluded that EVLWI and lung capillary permeability were markedly increased in ARDSp and ARDSexp groups. EVLW could be decreased 4 h after the HFOV treatment. HFOV, EVLW/ITBV and PVPI were increased slightly at first, and then decreased in ARDSexp group, while in ARDSp group no significant difference was found after modeling. No significant differences were found in the decreases in EVLW and lung capillary permeability 4 h after HFOV.

Ginkgo biloba extract(EGb 761) attenuates lung injury induced by intestinal ischemia/reperfusion in rats:Roles of oxidative stress and nitric oxide

AIM： To investigate the effect of ginkgo biloba extract （EGb 761） on lung injury induced by intestinal ischemia/ reperfusion （ Ⅱ/R）. METHODS： The rat model of Ⅱ/R injury was produced by damping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The rats were randomly allocated into sham, Ⅱ/R, and EGb ＋Ⅱ/R groups. In EGb ＋Ⅱ/R group, EGb 761 （100 mg/kg per day） was given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761. Lung injury was assessed by light microscopy, wet-todry lung weight ratio （W/D） and pulmonary permeability index （PPT）. The levels of malondialdehyde （MDA） and nitrite/nitrate （NO2/NO3）, as well as the activities of superoxide dismutase （SOD） and myeloperoxidase （MPO） were examined. Western blot was used to determine the expression of inducible nitric oxide synthase （iNOS）. RESULTS： EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPT （P 〈 0.05 or 0.01）.Moreover, EGb 761 markedly increased SOD activity, reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression （P 〈 0.05 or 0.01）. CONCLUSION： The results indicate that EGb 761 has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOS- induced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.

Pretreatment with scutellaria baicalensis stem-leaf total flavonoid protects against cerebral ischemia/reperfusion injury in hippocampal neurons

Previous experimental studies have shown that cerebral infarction can be effectively reduced following treatment with scutellaria baicalensis stem-leaf total flavonoid （SSTF）. However, the mechanism of action of SSTF as a preventive drug to treat cerebral infarction remains unclear. In this study, Sprague-Dawley rats were pretreated with 50, 100, 200 mg/kg SSTF via intragastric ad- ministration for 1 week prior to the establishment of focal cerebral ischemia/reperfusion injury. The results showed that pretreatment with SSTF effectively improved neurological function, reduced brain water content and the permeability of blood vessels, ameliorated ischemia-induced morphology changes in hippocampal microvessels, down-regulated Fas and FasL protein expression, elevated the activity of superoxide dismutase and glutathione peroxidase, and decreased malondialdehyde content. In contrast to low-dose SSTF pretreatment, the above changes were most obvious after pretreatment with moderateand high-doses of SSTF. Experimental findings indicate that SSTF pretreatment can exert protective effects on the brain against cerebral ischemia/reperfusion injury. The underlying mechanisms may involve reducing brain water content, increasing microvascular recanalization, inhibiting the apoptosis of hippocampal neurons, and attenuating free radical damage.

Protective effects of dl-3n-butylphthalide against diffuse brain injury

DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this study, models of diffuse brain injury were established in Sprague-Dawley rats with the vertical impact method. DI-3n-butylphthalide at 80 and 160 mg/kg was given via intraperitoneal injection immediately after diffuse brain injury. Ultrastructural changes in the cerebral cortex were observed using electron microscopy. Cerebral blood flow was measured by laser Doppler flowmetry, vascular density was marked by tannic acid-ferric chloride staining, vascular permeability was es- timated by the Evans blue method, brain water content was measured using the dry-wet method, and rat behavior was measured by motor function and sensory function tests. At 6, 24, 48, and 72 hours after administration of dl-3n-butylphthalide, reduced cerebral ultrastructure damage, in- creased vascular density and cerebral blood flow, and improved motor and sensory functions were observed. Our findings demonstrate that dl-3n-butylphthalide may have protective effects against diffuse brain injury by ameliorating microcirculation disorder and reducing blood-brain barrier dam- age and cerebral edema.

Naringin ameliorates acetic acid induced colitis through modulation of endogenous oxido-nitrosative balance and DNA damage in rats

The aim of this study was to evaluate the effect of naringin on experimentally induced inflammatory bowel dis- ease in rats. Naringin （20, 40 and 80 mg/kg） was given orally for 7 days to Wistar rats before induction of colitis by intrarectal instillation of 2 mL of 4% （v/v） acetic acid solution. The degree of colonic mucosal damage was analyzed by examining mucosal damage, ulcer area, ulcer index and stool consistency. Intrarectal administration of 4% acetic acid resulted in significant modulation of serum alkaline phosphatase, lactate dehydrogenase, superoxide dismutase （SOD）, glutathione （GSH）, malondialdehyde （MDA） and myeloperoxidase （MPO） content along with colonic nitric oxide （NO）, xanthine oxidase （XO） level and protein carbonyl content in the colonic tissue as well as in blood. Naringin （40 and 80 mg/kg） exerted a dose dependent （P 〈 0.05） ameliorative effect, as it significantly increased hematological parameter as well as colonic SOD and GSH. There was a significant （P 〈 0.05） and dose dependant inhibition of macroscopical score, ulcer area along with colonic MDA, MPO activity by the 7 days of pretreatment of naringin （40 and 80 mg/kg）. Biochemical studies revealed a significant （P 〈 0.05） dose dependant inhibition in serum alkaline phosphatase （ALP） and lactate dehydrogenase （LDH） levels by pretreatment of naringin. Increased levels of colonic NO, XO, protein carbonyl content and DNA damage were also sig- nificantly decreased by naringin pretreatment. The findings of the present investigation propose that naringin has an anti-inflammatory, anti-oxidant and anti-apoptotic potential effect at colorectal sites as it modulates the production and expression of oxidative mediators such as MDA, MPO, NO and XO, thus reducing DNA damage.

Phospholipase A_2 and Its Relationship with Acute Lung Injury in Acute Pancreatitis in Dogs

Acute fulminant pancreatitis was produced in dogs by injection of autobile into the main pancreatic duct.After injection the phospholipase A_2(PLA_2)activities in serum,lung lymph and bronchoalveolar lavage fluid(BAL)were elevated significantly,lung lymph flow and pulmonary transvascular potein clearance increased progressively,protein content and cell numbers in BAL in the experimental animals were significantly higher than those in the control animals.Furthermore the lung index,wet to dry lung weight ratio,extravascular lung water to bloodless dry lung weight ra- tio,extravascuar lung water to bloodless dry lung weight ratio increased significantly as compared to control animals.Pretreatment with PLA_2 inhibitor,chloroquine,blocked the changes mentioned above.This experiment suggests:1.PLA_2 activity in lung lymph fluid as well as in serum and BAL is elevated in acute hemorrhagic pancreatitis.2.Elevated PLA_2 activity may increase the pulmonary vascular permeability.3.PLA_2 is the major factor leading to pulmonary edema in acute hemorrhagic pancreatitis.4.Phagocytes contribute to the lung injury induced by PLA_2 to some ex- tent.

Effect of Qinggan Huayu granule on H22 liver ascitic tumor mice

Objective:To evaluate the therapeutic effect of Qinggan Huayu granule on mice with H22 liver cancer ascites tumor.Methods:A H22 liver cancer ascites mouse model was established by intraperitoneally injecting H22 liver cancer cells.Mice were randomly divided into the model group,the Ganfule group(1.35 g/kg),the fluorouracil group(50 mg/kg i.p),the Qinggan Huayu granule groups at low(0.67 g/kg),medium(1.34 g/kg),and high(2.68 g/kg)doses.Then the mice were administered continuously for 10 days and body weight and abdominal circumference were monitored every 3 days.On day 11,eight rats in each group were randomly selected for dissection to detect the amount of peritoneal water,peritoneal permeability and histopathological changes.The remaining mice were observed for survival.In addition,the vascular endothelial growth factor A(VEGFA)and vascular endothelial growth factor receptor 2(VEGFR2)were determined by Western blotting.Results:Compared with the model group,the weight growth of mice in the fluorouracil group and the medium-dose and high-dose Qinggan Huayu granule groups was slower(P<0.05).Moreover,the abdominal circumference of mice in each treatment group was increased slowly.There were significant differences in abdominal circumference between the fluorouracil group,the medium-dose group and the control group from day 6(P<0.05)while the abdominal circumference of the high dose group was significantly smaller than that of the control group from day 12(P<0.05).Moreover,compared with the model group,the amount of ascites in the medium-and high-dose Qinggan Huayu granule groups was decreased significantly(P<0.05).The optical density value of ascites supernatant in medium-and high-dose Qinggan Huayu granule group and the fluorouracil group decreased significantly(P<0.05)and the survival period of the medium-dose Qinggan Huayu granule group and the fluorouracil group was prolonged prominently(P<0.05).There was no significant difference in the low-dose Qinggan Huayu granule group and the Ganfule group.Peritoneal histopathological assay showed more complete peritoneal structure,less edema and less angiogenesis of the peritoneum in the fluorouracil group and the medium-and high-dose Qinggan Huayu granule group,which was better than that of the Ganfule group and the low-dose group.Compared with the model group,the expressions of VEGFA and VEGFR2 in the medium-dose Qinggan Huayu granule group decreased significantly(P<0.05,P<0.01).Conclusion:Qinggan Huayu granule can inhibit ascites production in the mice model with H22 liver cancer ascites tumor,prolong the survival of mice,and reduce peritoneal permeability and suppress the increase of peritoneal neovascularization.The mechanism may be related to the inhibition of VEGF/VEGFR pathway.

AB010.Promotion of BMP9/ALK1 quiescence signaling for the prevention of diabetic macular edema(DME)

Background:Sight-threatening diabetic macular edema(DME)is caused by increased microvascular permeability.While few direct vascular targeting strategies are available,VEGF pathway inhibition has shown to be effective in reducing retinal vascular leakage but is associated with non-negligible side effects.Thus,more options are needed.Vascular specific Activin-like kinase receptor type I(ALK1)pathway and its circulating ligand Bone morphogenetic protein-9(BMP9)is known for its potent quiescent and stabilizing effect on the vasculature.However,little is known about this pathway in the context of microvascular permeability associated with diabetes.We hypothesize that BMP9/ALK1 pathway is inhibited in diabetic(DB)retinas leading to vascular destabilization and leakage and that its activation could re-establish proper vascular endothelial barrier functions(EBF).Methods:The effect of hyperglycemia(i.e.,HG>10 mM of D-glucose)on Alk1 signaling was evaluated in vitro by subjecting endothelial cells(EC)to increasing concentrations of D-glucose(5,11,25 mM)and in vivo using DB mice(Streptozotocin-induced diabetes).The contribution of Alk1 signaling on EBF was evaluated using Evans Blue permeation in inducible endothelial specific Alk1 KO mice.To evaluate the potential protective effects of BMP9/Alk1 signaling on EBF,BMP9 overexpression was achieved using adenoviral delivery in DB mice.Statistical-One-Way ANOVA or Student’s t-test was used.Results:Endothelial tissue from DB mice showed a significant inhibition of BMP9/ALK1-canonical Smad1,5,8 quiescence signaling(DB n=5;CTL n=4;P<0.01),which was associated with reduced expression of target genes(JAG1,Id1,3,Hey1,2&HES).Moreover,we showed that retinal hyperpermeability associated with diabetes was exacerbated in Alk1 heterozygote mice(n=4-9/group;P<0.0001).Finally,we demonstrated that activation of Alk1 signaling in ECs prevented vascular permeability induced by HG,both in vitro(n=3;P=0.009)and in vivo(n=4-9/group;P<0.0001).Conclusions:Consistent with our hypothesis,vascular stability and quiescence induced by BMP9-ALK1 signaling is inhibited in the DB/HG endothelium which could be an important factor in vascular leakage leading to DME.Our results show that activation of this pathway could offer a therapeutically interesting future option to slow down the onset of DME.

Low-power Helium-Neon laser irradiation enhances the expression of VEGF in murine myocardium

Background Low-power helium-neon (He-Ne) lasers have been increasingly widely applied in the treatment of cardiovascular diseases, and its vasodilation effect has been proven. The aim of this study was to determine the effects of low-power He-Ne laser irradiation directed at the precardial region of Wistar rats on capillary permeability in the myocardium and the expression of myocardial vascular endothelial growth factor (VEGF). Methods Sixteen rats were divided randomly into control and irradiated groups (n=8, each). A He-Ne laser (632.8 nm) was applied to the irradiated group with a dose of 60.5 J/cm2. Ferritin was perfused into the left femoral vein and capillary permeability was examined under an electron microscope. VEGF expression in the myocardium was investigated by immunohistochemical methods, RT-PCR, and image analysis. Results The ultrastructures of the myocardial capillaries were examined. Compared to the control group, more high-density granules (ferritin), which were present within the capillary endothelium and the mitochondrions of myocardial cells in the internal layer of the myocardium, were observed in the irradiated group. VEGF staining of the myocardium was stronger in the irradiated group than that in the control group. The optic density of the irradiated group (0.246±0.015) was significantly higher than that of the control group (0.218±0.012, P<0.05). Finally, the levels of RT-PCR products of VEGF165 mRNA were 2.79 times higher in irradiated rats than in the control rats.Conclusions Our study demonstrates that He-Ne laser irradiation (in doses of 60.5 J/cm2) increases myocardial capillary permeability and the production of VEGF in myocardial microvessels and in myocardium. Our study provides experimental morphological evidence that myocardial microcirculation can be improved using He-Ne laser irradiation.