Blood platelet and monocyte activations and relation to stages of liver cirrhosis

AIM: Blood platelets (pIt) and monocytes are the cells that play a crucial role in the pathogenesis of liver damage and liver cirrhosis (LC). In this paper, the analysis of mutual relationship between platelets and monocytes activation in LC was conducted. METHODS: Immunofluorescent flow cytometry was used to measure the percentage of activated platelet populations (CD62P, CD63), the percentage of plt-monocyte aggregates (pma) (CD41/CD45), and activated monocytes (CD11b, CD14, CD16) in the blood of 20 volunteers and 40 patients with LC. Platelet activation markers: sP-selectin, platelet factor 4 (PF4), beta-thromboglobulin (PTG) and monocyte chemotactic peptide-1 (MCP-1) were measured and compared in different stages of LC. RESULTS: Platelet activation with the increase in both βTG serum concentration and elevation of pIt population (CD62P and CD63 as well as MIF CD62P and CD63) is elevated as LC develops and thrombocytopenia rises. There is a positive correlation between medial intensity of fluorescence (MIF) CD62P and MIF CD63 in LC. We did not show any relationship between monocyte activation and pma level. SP-selectin concentration correlates positively with pIt count and pma, and negatively with stage of pIt activation and MIF CD62P and MIF CD63. There was no correlation between MCP-1 concentration and pIt, monocyte activation as well as pma level in LC. CD16 monocytes and MIF CD16 populations are significantly higher in the end stage of LC. A positive correlation occurs between the value of CDllb monocyte population and MIF CD14 and MIF CD16 on monocytes in LC. CONCLUSION: Platelet and monocyte activation plays an important role in LC. Platelet activation stage does not influence monocyte activation and production of pIt aggregates with monocytes in LC. With LC development, thrombocytopenia may be the result of pIt consumption in platelet-monocyte aggregates.

Effects of procainamide on 0morphological parameter of dense granule and a granule in blood platelet

Objective: To study the protective effect of procainamide (PA) on the ultrastructure of blood platelets.Methods:The stereology measurement was used to study the effects of PA on morphological parameters of dense granule and a granule. Results: 8. 5, 34. 0 and 136. 0 μmol· L-1 PA ascended morphological parameter values of dense granule and a granule significantly. The increasing percentages were 153. 6% ~ 256. 2% (SS ), 81. 6% ~188. 9% (Sv) and 96. 3% ~145. 4 % (St ) for surface parameter values; 144. 0% ~499. 7% (Vv) and 221. 3% ~1593. 4 % (Vt ) for volume parameter values in dense granule. In a granule, the increasing percentages were 68. 2 %~335. 9% (Nv) and 14. 8%~ 696. 0% (N) for number parameter values; 45. 4%~ 87. 5% (S), -(50.7% 57. 1 % ) (SS), 160. 3% -558. 0% (Sv ) and 181. 5%~395. 7% (St ) for surface parameter values ; 87. 8%~127. 7% (D). 81. 4 %~ 202. 3% (V), 410. 5% ~773. 6% (Vv) and 195. 8% ~297. 8% (Vt) for volume parameter values. Conclusion: PA protects dense granule and a granule from AA-stimulating changes of morphology.

Considerations on Blood Platelets: A Neuron’s Mirror for Mood Disorders?

This work aims to be a reflection concerning a remarkable similarity between platelet and neuron. Through a series of experimental tests which have affected the fatty acid composition of the membrane of platelets, it was possible to provide a contribution to the scientific literature, which had already reported strong similarities between platelet and neuron. The work performed could be of great interest to investigate, by studying the interactome of the platelet, the molecular behavior of the neuron.

Effects of Dan Wei Powder (胆胃散) Tea Bag on Aggregation of Blood Platelet in vivo and in vitro

Objective: To observe effects of Dan Wei Powder (胆胃散 Powder for treating the gall bladder and stomach) Tea Bag (DWSTB) on the aggregation rate of blood platelet in vivo and in vitro. Methods: Increase of the platelet aggregation rate in the rat in vivo was induced by carrageenin, and increase of the rabbit platelet aggregation rate in vitro was induced by adenosine diphosphate (ADP) and collagen, respectively. The effects of DWSTB on the platelet aggregation rate were investigated in vivo and in vitro, respectively. Results: The maximum in vivo platelet aggregation rate in the rat was significantly decreased after administration of 2.0 and 4.0 g·kg-1 DWSTB (P<0.05.P<0.01). The maximum rabbit platelet aggregation rate induced by ADP and collagen in vitro were suppressed significantly by 2.0-16.0 mg·mL-1 and 2.0-8.0 mg·mL-1 DWSTB, respectively (P<0.05.P<0.01). And the effect of DWSTB on platelet aggregation was raised with increase ofits dose. Conclusion: Dan Wei Powder Tea Bag can restrain the aggregation of platelet in vivo and in vitro.

BLOOD PLATELETS AND OXIDIZED LOW DENSITY LIPOPROTEIN

Functional morphological alterations of human blood platelets induced by oxidatively modified low density lipoprotein (LDL) were studied with an in vitro model by means of electron microscopy, reflection contrast microscopy and quantitative image analysis. The oxidized LDL (50-300 μg/ml) induced the disc-sphere transformation of platelets, the formation of pseudopodia, centralization of granules and degranulation. Platelet plasma membrane was damaged by oxidized LDL leading to a lower electron density of he cytoplasm compared to controls. In an incubation chamber, oxidized LDL-treated platelets sedimented onto the

Effect of the Esters of Gallic Acid on Model and Human Blood Platelet Membranes Studied by Fourier Transform Infrared Spectroscopy

Gallic acid is one of the components of Chinese herbal drug Radix paeoniae used for promoting blood circulation to remove blood stasis. This paper studied the effects of gallic acid and its esters (e.g. ethyl, propyl, isobutyl and butyl gallate) on model and human blood platelet membranes by FTIR which was used for monitoring the physical state of the acyl chain, interfacial and head group region of the membrane lipid bilayer. From the experimental results it can be seen that the gallic acid and its esters have the modifying function on the pure and cholesterol-containing DPPC model membranes, and have the quantity-effective and structural-effective relationships. In addition, it is discovered that these esters have the modifying effect on the structure of human blood platelet membrane and can reverse the effect of ADP. That the effect of the esters of gallic acid counteracts the effect of cholesterol and ADP on human blood platelet perhaps provides a new explanation of the mechanism of Chinese herbal drugs used for promoting blood circulation to remove blood stasis.

Red cell distribution width/platelet ratio estimates the 3-year risk of decompensation in Metabolic Dysfunction-Associated Steatotic Liver Disease-induced cirrhosis

BACKGROUND For compensated advanced chronic liver disease(cACLD)patients,the first decompensation represents a dramatically worsening prognostic event.Based on the first decompensation event(DE),the transition to decompensated advanced chronic liver disease(dACLD)can occur through two modalities referred to as acute decompensation(AD)and non-AD(NAD),respectively.Clinically Significant Portal Hypertension(CSPH)is considered the strongest predictor of decompensation in these patients.However,due to its invasiveness and costs,CSPH is almost never evaluated in clinical practice.Therefore,recognizing noninvasively predicting tools still have more appeal across healthcare systems.The red cell distribution width to platelet ratio(RPR)has been reported to be an indicator of hepatic fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD).However,its predictive role for the decompensation has never been explored.AIM In this observational study,we investigated the clinical usage of RPR in predicting DEs in MASLD-related cACLD patients.METHODS Fourty controls and 150 MASLD-cACLD patients were consecutively enrolled and followed up(FUP)semiannually for 3 years.At baseline,biochemical,clinical,and Liver Stiffness Measurement(LSM),Child-Pugh(CP),Model for End-Stage Liver Disease(MELD),aspartate aminotransferase/platelet count ratio index(APRI),Fibrosis-4(FIB-4),Albumin-Bilirubin(ALBI),ALBI-FIB-4,and RPR were collected.During FUP,DEs(timing and modaities)were recorded.CSPH was assessed at the baseline and on DE occurrence according to the available Clinical Practice Guidelines.RESULTS Of 150 MASLD-related cACLD patients,43(28.6%)progressed to dACLD at a median time of 28.9 months(29 NAD and 14 AD).Baseline RPR values were significantly higher in cACLD in comparison to controls,as well as MELD,CP,APRI,FIB-4,ALBI,ALBI-FIB-4,and LSM in dACLD-progressing compared to cACLD individuals[all P<0.0001,except for FIB-4(P:0.007)and ALBI(P:0.011)].Receiving operator curve analysis revealed RPR>0.472 and>0.894 as the best cut-offs in the prediction respectively of 3-year first DE,as well as its superiority compared to the other non-invasive tools examined.RPR(P:0.02)and the presence of baseline-CSPH(P:0.04)were significantly and independently associated with the DE.Patients presenting baseline-CSPH and RPR>0.472 showed higher risk of decompensation(P:0.0023).CONCLUSION Altogether these findings suggest the RPR as a valid and potentially applicable non-invasive tool in the prediction of timing and modalities of decompensation in MASLD-related cACLD patients.

Evaluation of Red Blood Cell Contribution to Platelet Activation in the Bulk Applying Red Blood Cell—Platelet Thrombus as a Point Source Model

In this study, a point source mathematical model is proposed to describe the diffusion of adenosine di-phosphate (ADP) from either damaged red blood cell (RBC) or activated platelet. The convective diffusion equation is reduced to describe the suggested problem. The final differential equation is solved using Laplace transforms and ADP concentration profiles around the source are obtained. Thrombi of 5 to 20 μm3 containing platelets and a range of red blood cells (RBCs) (0%, 25%, 50%, 75%, 100%) concentrations are used to apply the model. Reported ADP concentrations in the literature are used and its dynamic release from the point source is calculated. Results suggest that RBC chemical contribution to platelet aggregation in the bulk is much less than that of platelet (almost) negligible. However, the physical effect of RBCs is dominant in the bulk through augmentation of released ADP and platelets diffusivities. Moreover, the chemical contribution reported in previous studies is suggested to be as a result of interaction of RBC with the surface under the influence of shear stresses in the boundary region.

不同剂量替格瑞洛治疗ST段抬高型心肌梗死患者的有效性和安全性:基于倾向性评分匹配

背景双联抗血小板治疗是接受直接经皮冠状动脉介入治疗(PPCI)的ST段抬高型心肌梗死(STEMI)患者治疗的基础。阿司匹林联合替格瑞洛是STEMI患者抗血小板治疗的首选方案,与氯吡格雷相比,其能够更快、更有效地抑制血小板,并改善预后。但是尚缺乏在接受PPCI治疗的STEMI患者中应用减量替格瑞洛的研究。目的基于倾向性评分匹配(PSM)的方法,对比分析不同剂量替格瑞洛治疗STEMI患者的有效性和安全性。方法连续选取2019年6月—2021年5月在河北医科大学第二医院心血管内五科行PPCI并接受替格瑞洛治疗的STEMI患者为研究对象。根据应用替格瑞洛的维持剂量将患者分为减量组(60例:替格瑞洛60 mg/次,2次/d)和标准组(180例:替格瑞洛90 mg/次,2次/d)。采用PSM法对两组患者进行1∶1匹配,匹配变量包括性别、年龄、既往病史、入院时Killip分级和介入治疗相关参数等,最终减量组和标准组各纳入54例患者。分别于出院1、3、6个月时,对两组患者进行随访,记录和比较两组患者血小板功能相关参数和临床事件的发生情况。结果PSM后两组患者基线资料、介入治疗参数和住院期间主要不良心血管事件发生率比较,差异均无统计学意义(P>0.05)。基线时,两组患者血小板计数(PLT)、平均血小板体积(MPV)、血小板分布宽度(PDW)比较,差异均无统计学意义(P>0.05);减量组患者血小板聚集率(PAR)低于标准组(P<0.05)。出院时,减量组患者MPV高于标准组,PDW低于标准组(P<0.05)。出院1个月时,两组患者PLT、MPV、PDW、PAR比较,差异均无统计学意义(P>0.05)。出院3个月时,减量组患者PDW高于标准组(P<0.05)。出院6个月时,减量组患者MPV高于标准组(P<0.05)。减量组患者出院前后PLT、PAR比较,标准组患者出院前后PLT、PDW比较,差异均无统计学意义(P>0.05)。减量组、标准组患者出院时MPV高于基线,减量组患者出院时PDW低于基线,标准组患者出院时PAR低于基线(P<0.05)。减量组患者出院1、3、6个月MPV低于出院时,PDW高于出院时(P<0.05);标准组患者1、3、6个月PAR低于基线,高于出院时(P<0.05)。两组患者随访期间主要不良心血管事件、严重出血事件发生率比较,差异均无统计学意义(P>0.05)。结论在接受PPCI的STEMI患者中替格瑞洛60 mg治疗是安全有效的。

Effect of platelet activating factor on blood spinal cord barrier following cervical cord injury

Effect of platelet activating factor(PAF) on blood spinal cord barrier in cervical cord injury was investigated. Methods: Spinal cord injury at C6 segment was induced with Allen’s ’method in cats. PAF and PAF receptor antagonist BN52021 were administered by arachnoid space and intravenous injection respectively, and their effects on PAF levels, blood spinal cord barrier and cervical cord edema in the injuried zone and adjacent cervical cord tissue following cervical cord injury were investigated. Results: PAF levels, Evens content and water content in the injuried and adjacent cervical cord tissues significantly increased following trauma. PAF levels, Evens content and water content were evidently elevated with PAF by arachnoid space injection. PAF receptor antagonist BN52021 could inhibit the increase in PAF levels and reduce Evens and water content in the cervical cord tissue following trauma. Conclusion: PAF is an important contributing factor causing post-traumatic damage to the blood spinal cord barrier, while PAF receptor antagonist can effectively relieve post-traumatic damage to the blood spinal cord barrier.

Low preoperative platelet counts predict a high mortality after partial hepatectomy in patients with hepatocellular carcinoma

AIM： To assess the validity of our selection criteria for hepatectomy procedures based on indocyanine green disappearance rate （KICG）, and to unveil the factors affecting posthepatectomy mortality in patients with hepatocellular carcinoma （HCC）. METHODS： A retrospective analysis of 198 consecutive patients with HCC who underwent partial hepatectomies in the past 14 years was conducted. The selection criteria for hepatectomy procedures during the study period were KICG≥0.12 for hemihepatectomy, KICG≥0.10 for bisegmentectomy, KCG≥0.08 for monosegmentectomy, and KICG≥ 0.06 for nonanatomic hepatectomy. The hepatectomies were categorized into three types： major hepatectomy （hemihepatectomy or a more extensive procedure）, bisegmentectomy, and limited hepatectomy. Univariate （Fishers exact test） and multivariate （the logistic regression model） analyses were used. RESULTS： Postoperative mortality was 5% after major hepatectomy, 3% after bisegmentectomy, and 3% after limited hepatectomy. The bhree percentages were comparable （P = 0.876）. The platelet count of ≤ 10× 10^4/μL was the strongest independent factor for postoperative mortality on univariate （P = 0.001） and multivariate （risk ratio, 12.5; P= 0.029） analyses. No patient with a platelet count of 〉7.3× 10^4/μL died of postoperative morbidity, whereas 25% （6/24 patients） of patients with a platelet count of ≤7.3×10^4/μL died （P〈0.001）. CONCLUSION： The selection criteria for hepatectomy procedures based on KICG are generally considered valid, because of the acceptable morbidity and mortality with these criteria. The preoperative platelet count independently affects morbidity and mortality after hepatectomy, suggesting that a combination of KICG and platelet count would further reduce postoperative mortality.

Screening of active ingredients of Taohong Siwu Decoction on platelet membrane receptor

OBJECTIVE To screen the active ingredients preventing platelet aggregations from Taohong Siwu Decoction. METHODS Fresh blood from healthy adult volunteer was collected with vacuum tube for preparation of platelet suspension. Platelet suspension was incubated with Taohong Siwu Decoction for one hour at 37℃,then centrifuged. The precipitate was washed and desorbed with buffer solutions.The differences of chemical constituents between incubated and unincubated were identified with high performance liquid chromatography-diode array detector. RESULTS According to the chromatograph at 254 nm,at least three kinds of different components were detected in Taohong siwu decoction before and after incubated with platelet. CONCLUSION Platelet suspension can be used for screening active ingredients on platelet membrane receptor from the traditional Chinese medicine.

Significance of platelet count and platelet-based models for hepatocellular carcinoma recurrence

AIM:To explore the effects of platelet count(PLT)and11 platelet-based indices on postoperative recurrence of hepatocellular carcinoma(HCC).METHODS:We retrospectively analyzed 172 HCC patients who were treated by partial hepatectomy.Preoperative data,including laboratory biochemical results,were used to calculate the 11 indices included in the analysis.We performed receiver operating characteristic curve analysis to determine the optimal cut-off values for predicting recurrence.Cumulative rates of HCC recurrence were calculated using KaplanMeier survival curves and differences were analyzed by log-rank tests.Multivariate analyses were performed to identify independent predictors of recurrence,early recurrence(within one year after surgery),and late recurrence in HCC.To obtain better prognostic models,PLT-based indices were analyzed separately after being expressed as binary and continuous variables.Two platelet-unrelated,validated HCC prognostic models were included in the analyses as reference indices.Additional analyses were performed after patients were stratified based on hepatitis B virus infection status,cirrhosis,and tumor size to investigate the significance of platelets in different subgroups.RESULTS:In the study cohort,44.2%(76/172)of patients experienced HCC recurrence,and 50.6%(87/172)died during a median follow-up time of 46mo.PLT and five of the 11 platelet-related models were significant predisposing factors for recurrence(P<0.05).Multivariate analysis indicated that,among the clinical parameters,presence of ascites,PLT≥148×109/L,alkaline phosphatase≥116 U/L,and tumor size≥5 cm were independently associated with ahigher risk of HCC recurrence(P<0.05).Independent and significant models included the aspartate aminotransferase/PLT index,fibrosis index based on the four factors,fibro-quotient,aspartate aminotransferase/PLT/γ-glutamyl transpeptidase/alpha-fetoprotein index,and the PLT/age/alkaline phosphatase/alphafetoprotein/aspartate aminotransferase index.There were different risk factors between early and late recurrences,and PLT and these indices were more inclined to influence late recurrence.PLT was only predictive of recurrence in non-cirrhotic HCC patients,and was not influenced by tumor size,which was a critical confounder in our study.CONCLUSION:PLT and PLT-basednoninvasive models are effective tools for predicting postoperative recurrence,especially late recurrence.Larger cohorts are needed to validate our findings.

Assessment of platelet activation and phagocytic activity in gastric cancer patients

AIM:To assess the activation of platelets and their phagocytic activity in the course of gastric cancer.METHODS:Forty-three gastric cancer patients were recruited to the study.The patients were divided into 3 groups depending on tumor stage.Group E included 6 patients with early gastric cancer;group A 18 patients with locally advanced cancer;and group M-19 with metastatic cancer.The investigations were performed twice,prior to surgery and 12-14 d afterwards.RESULTS:The platelet count and the level of soluble platelet selectin(sP-selectin) were found to increase with the disease progression.The level of sP-selectin was lowest in early cancer and was observed to increase after surgery in all the study patients.Irrespective of tumor stage,a statistically significant decrease was noted in the percentage of phagocytizing platelets and in the phagocytic index in gastric cancer patients as compared to healthy subjects.Despite increasedplatelet count and stimulation of thrombocytopoiesis,the phagocytic functions of blood platelets were markedly impaired.Tumor development seems to impair metabolic processes.CONCLUSION:A decreasing phagocytic activity can promote both inflammatory processes and cancer growth.

Effect of Liangxuehuayu Recipe on hemorheology in rats with blood stasis syndrome

Objective:To investigate the effects of Uangxuehuayu Recipe on hemorheology in rats with blood stasis syndrome induced by mutifactor stimuli.Methods:SD rats were divided into control, model,Uangxuehuayu Recipe(high,middle and low dose,18,9,4.S g/kg accordingly).Except the control group,blood stasis model was established in the rest groups.The hemorheological parameters were measured and compared.Results:Blood viscosity at high,moderate and low level in rats with blood stasis significantly increased(P【0.05),but blood viscosity at high level and plasma viscosity was significantly decreased in rats induced by some stimuli after Uangxuehuayu Recipe were intra-gastrically administered for I weeks(P【0.01,P【0.05). Conclusions:Uangxuehuayu Recipe is effective in improving hemorheology,and has important application value in the prevention of occurrence and development of ischemic stroke.

Assessment of platelet activation and phagocytic activity in gastric cancer patients

AIM: To assess the activation of platelets and their phagocytic activity in the course of gastric cancer. METHODS: Forty-three gastric cancer patients were recruited to the study. The patients were divided into 3 groups depending on tumor stage. Group E included 6 patients with early gastric cancer; group A included 18 patients with locally advanced cancer; and group M included 19 patients with metastatic cancer. The investigations were performed twice, prior to surgery and 12-14 d afterwards. RESULTS: The platelet count and the level of sP-selectin were found to increase with the disease progression. The level of sP-selectin was lowest in early cancer and was observed to increase after surgery in all the study patients. Irrespective of tumor stage, a statistically significant decrease was noted in the percentage of phagocytizing platelets and in the phagocytic index in gastric cancer patients as compared to healthy subjects. Despite increased platelet count and stimulation of thrombocytopoiesis, the phagocytic functions of blood platelets were markedly impaired. Tumor development seems to impair metabolic processes. CONCLUSION: A decreasing phagocytic activity can promote both inflammatory processes and cancer growth.

延长氨甲环酸使用时间有助于减少老年股骨转子间骨折围术期隐性失血

背景:股骨转子间骨折好发于老年人,手术后会出现大量的隐性失血,减少隐性失血可以降低并发症和住院时间。目的:评估延长氨甲环酸的使用时间对股骨近端防旋髓内钉治疗转子间骨折围术期隐性失血的影响。方法:选择2022年1月至2023年5月自贡市第四人民医院经急诊收治入院的老年股骨转子间骨折患者共62例,均在牵引床上闭合牵引复位后置入股骨近端防旋髓内钉治疗。根据氨甲环酸的使用时间分为2组,对照组38例在切开皮肤前15-30 min给予氨甲环酸1 g静脉滴注,3 h后追加1 g;试验组24例在对照组的基础上,术后第1天再追加氨甲环酸1 g静脉滴注每12 h一次。术前、术后当天、术后第1,3,5天均复查血常规,统计血红蛋白量和红细胞压积,理论总失血量采用Gross方程计算,同时记录两组患者并发症发生情况。结果与结论:①通过统计学分析,两组患者术中显性出血量相差较小,差异无显著性意义(P>0.05);②试验组围术期血红蛋白下降量、总失血量、隐性失血量低于对照组,差异有显著性意义(P<0.05);③试验组术后第3天的血红蛋白值、术后第1,3天的红细胞压积值高于对照组,差异有显著性意义(P<0.05);④两组术后血红蛋白和血小板计数呈下降趋势,第3天的血红蛋白值为最低值,术后第1天的血小板值为最低值,然后开始回升;⑤两组患者术后并发症发生率相比差异无显著性意义(P>0.05);⑥结果表明,术后延迟氨甲环酸的使用时间,可能有助于减少股骨近端防旋髓内钉治疗股骨转子间骨折的隐性失血量,并不会增加并发症风险。

中华跌打丸活血化瘀作用的实验研究

目的:观察中华跌打丸对大鼠急性血瘀模型的体外血栓形成、血液黏度、血小板聚集率和对小鼠微循环障碍模型耳郭微循环的影响,评价中华跌打丸活血化瘀的作用。方法:通过注射肾上腺素加冰水刺激的方法建立大鼠急性血瘀模型,测定体外血栓形成和血液黏度;按照Born氏比浊法加入诱导剂诱导聚集测定大鼠血小板聚集率;尾静脉注射15%高分子右旋糖酐造成微循环障碍,观察小鼠耳郭各时段微动脉和微静脉管血液流速和血管管径的变化。结果:中华跌打丸可降低血瘀模型大鼠的血液黏度,在切变率150 S^(-1)、60 S^(-1)及5 S^(-1)下的全血黏度均显著降低(P<0.05),明显缩短血瘀模型大鼠血栓长度,减轻血栓湿重和干重(P<0.05,P<0.01);中华跌打丸具有抑制血小板聚集的作用,各剂量均能明显降低ADP诱导的大鼠血小板聚集率(P<0.05,P<0.01);中华跌打丸对高分子右旋糖酐所致小鼠耳郭微循环障碍有明显改善作用,于造模10 min、20 min、30 min时增加血液流速(P<0.05,P<0.01),扩大微动脉、微静脉管径(P<0.05,P<0.01),减轻红细胞聚集(P<0.05,P<0.01)。结论:中华跌打丸可明显改善血液黏度,抑制血小板聚集,改善微循环障碍,有较好的活血化瘀作用。

Vascular endothelial growth factor A promotes platelet adhesion to collagen Ⅳ and causes early brain injury after subarachnoid hemorrhage

The role of vascular endothelial growth factor A in platelet adhesion in cerebral microvessels in the early stage of subarachnoid hemorrhage remains unclear.In this study,the endovascular puncture method was used to produce a rat model of subarachnoid hemorrhage.Then,30 minutes later,vascular endothelial growth factor A antagonist anti-vascular endothelial growth factor receptor 2 antibody,10μg,was injected into the right ventricle.Immunohistochemistry and western blot assay were used to assess expression of vascular endothelial growth factor A,occludin and claudin-5.Immunohistochemical double labeling was conducted to examine co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen.TUNEL was used to detect apoptosis in the hippocampus.Neurological score was used to assess behavioral performance.After subarachnoid hemorrhage,the expression of vascular endothelial growth factor A increased in the hippocampus,while occludin and claudin-5 expression levels decreased.Co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen and the number of apoptotic cells increased,whereas behavioral performance was markedly impaired.After treatment with anti-vascular endothelial growth factor receptor 2 antibody,occludin and claudin-5 expression recovered,while co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen and the number of apoptotic cells decreased.Furthermore,behavioral performance improved notably.Our findings suggest that increased vascular endothelial growth factor A levels promote platelet adhesion and contribute to early brain injury after subarachnoid hemorrhage.This study was approved by the Biomedical Ethics Committee,Medical College of Xi’an Jiaotong University,China in December 2015.