PI3K/Akt在肺炎衣原体感染诱导血管平滑肌细胞迁移中的作用

目的研究PI3K/Akt在肺炎衣原体(Chlamydia pneumoniae,C.pn)感染诱导血管平滑肌细胞(vascularsmooth muscle cell,VSMC)迁移中的作用。方法利用透射电镜鉴定C.pn成功感染VSMC;采用PI3K特异性抑制剂LY294002预处理VSMC后,wound-healing实验和Transwell实验分别观察VSMC迁移能力的改变;Western blot实验检测VSMC内Akt的磷酸化水平。结果透射电镜可观察到感染的VSMC内出现典型的C.pn原体;C.pn感染VSMC 24 h后,细胞迁移实验结果显示C.pn感染组VSMC的迁移能力增强且明显高于正常对照组(P<0.05);Western blot结果显示C.pn感染组Akt的磷酸化表达水平明显上调且高于正常对照组(P<0.05);PI3K特异性抑制剂LY294002可有效抑制C.pn感染诱导的VSMC迁移及Akt的磷酸化。结论 C.pn感染通过激活PI3K/Akt促进VSMC迁移。     

黄连素通过PI3K抑制肺炎衣原体感染诱导的血管内皮细胞迁移

目的 观察肺炎衣原体感染对人血管内皮细胞迁移的影响,探讨黄连素对其干预作用及作用机制.方法 体外成功培养肺炎衣原体AR-39株后,感染不同浓度黄连素(0、100、150及200 mmol/L)预处理的内皮细胞,在感染后24、48及72 h,创伤修复实验、Transwell实验观察内皮细胞迁移的变化,逆转录聚合酶链反应和酶联免疫吸附法检测内皮细胞中信号蛋白PI3K mRNA表达水平和酶活性.结果 与正常对照组比较,肺炎衣原体感染组内皮细胞于24、48及72 h迁移量均明显增加(P<0.01),且PI3K mRNA表达水平显著升高,酶活性亦明显增强(P<0.01);与肺炎衣原体感染组比较,PI3K抑制剂Lγ294002组内皮细胞迁移量明显减少(P<0.01),PI3K mRNA表达水平明显降低,酶活性也明显减弱(P<0.01);与肺炎衣原体感染组比较,黄连素中剂量组和高剂量组内皮细胞迁移量均明显下降(P<0.01),PI3K mRNA表达水平和酶活性均明显降低(P<0.01),且PI3K mRNA表达水平和酶活性均与细胞迁移抑制程度呈正相关(r分别为0.841和0.832,P<0.01).结论 肺炎衣原体感染可能是通过激活PI3K诱导内皮细胞迁移;黄连素可拮抗肺炎衣原体感染诱导的内皮细胞迁移,其机制可能与黄连素下调PI3K表达及抑制PI3K活化有关.     

紫杉醇对大鼠血管平滑肌细胞G_1-S检查点作用的研究

目的:探讨紫杉醇对大鼠血管平滑肌细胞(VSMC)和血管内皮细胞(VEC)G1-S检查点的作用。方法:将大鼠VSMC与VEC进行原代培养,50 nmol/L紫杉醇干预72 h后进行免疫荧光染色和蛋白印迹法检测。结果:同VEC相比,紫杉醇干预的VSMC中BrdU表达明显增加(均P0.05)。紫杉醇干预的VSMC中cyclin D1、P27表达高于VEC,P21表达较低(均P0.05)。结论:紫杉醇干预的VSMC同VEC相比,在增殖率与细胞周期调节因子表达方面具有明显差异,紫杉醇对VSMC G1-S检查点有特异性调节作用。     

CXCL8/PI3K-Akt信号通路在缺氧诱导的人脑胶质瘤细胞血管生成拟态中的作用

目的探讨CXCL8/PI3K-Akt信号转导通路在缺氧诱导的人脑胶质瘤细胞株U87MG和U251血管生成拟态中的作用。方法用氯化钴(Co Cl2)模拟缺氧环境,将人脑胶质瘤细胞株U87MG和U251置中培养。分别加入PI3K-Akt信号通路激动剂CXCL8及PI3K-Akt信号通路抑制剂LY294002干预48 h,体外成管实验检测各组细胞成管能力;Western印迹检测各组Akt、P-Akt蛋白的表达情况。结果缺氧可导致U87MG细胞和U251细胞形成的管腔样结构明显增加,Akt蛋白的磷酸化活化表达显著增加(P0.05)。加入CXCL8干预可使管腔样结构直径进一步增长,而加入LY294002干预48 h则可使其管腔样结构在数量和直径上显著少于缺氧组(P0.05)。CXCL8能够有效激活Akt磷酸化,LY294002则显著抑制其磷酸化活化(P0.05),而总Akt蛋白表达无差异(P0.05)。结论 CXCL8/PI3K-Akt信号转导通路在缺氧诱导的人脑胶质瘤细胞株U87MG和U251血管生成拟态中发挥重要的促进作用,可望成为胶质瘤治疗有效靶点。     

血管紧张素Ⅱ引起心肌微血管内皮细胞功能障碍及其可能机制的研究

目的心肌内血管紧张素系统的激活是心力衰竭发生发展的重要因素之一,而其具体作用机制尚有许多不明之处。近年来心肌微血管新生障碍在心力衰竭发病中的作用逐渐得到认识。本研究观察了血管紧张素Ⅱ对心肌微血管内皮细胞功能的直接影响,为进一步明确血管紧张素Ⅱ引起心力衰竭的机制提供参考。方法（1）植块法分离成年Wistar雄性大鼠的心肌微血管内皮细胞,免疫荧光鉴定细胞种类并传代培养;（2）血管紧张素Ⅱ（10^-7-10^-6M）干预培养心肌微血管内皮细胞后,分别采用Western blot方法以及PT—PCR的方法,检测不同干预时间点细胞增殖相关蛋白激酶（ERK）的活性变化和细胞死亡相关分子p53的表达变化;（3）血管形成实验检测心肌微血管内皮细胞的功能：血管紧张素Ⅱ干预培养在Matrigel上的微血管内皮细胞后,显微镜下观察形成管腔样结构的能力。结果（1）植块法培养原代心肌微血管内皮细胞,细胞纯度达95％左右,且具有形成管腔样结构的能力;（2）在血管紧张素Ⅱ干预心肌微血管内皮细胞10分钟时,ERK的磷酸化水平明显升高,与非干预组相比具有统计学差异（P〈0．05）;（3）血管紧张素Ⅱ干预心肌微血管内皮细胞30min,虽然与非干预组相比没有统计学差异,但p53 mRNA表达增加;（4）用血管紧张素Ⅱ持续干预18h,心肌微血管内皮细胞形成管腔样结构的数量明显减少,与非干预组相比具有统计学差异（P〈0．01）;单纯血管紧张素Ⅱ持续干预18小时组与前处置10分钟后再干预18小时组相比,心肌微血管内皮细胞形成管腔样结构的数量明显减少、或基本上不形成管腔样结构,两组相比具有统计学差异（P〈0．05）。结论持续血管紧张素Ⅱ干预明显降低培养心肌微血管内皮细胞形成管腔样结构的完整性及其数量,其机制可能与增加p53的表达有关;短期血管紧张素Ⅱ前处置培养心肌微血管内皮细胞明显改善持续血管紧张素Ⅱ干预后细胞形成管腔样结构能力的下降,其机制可能与短期升高细胞内蛋白激酶ERK的活性进而起到细胞保护作用有关。     

高尿酸对血管内皮细胞eNOS基因表达的调节作用及其对血管新生的影响

目的探讨高尿酸对血管内皮细胞内皮型一氧化氮合酶(eNOS)基因表达调节作用及其对血管新生的影响。方法人脐静脉血管内皮细胞(HUVECs)在600μmol/L尿酸溶液中培养,应用RT-PCR和Western印迹分别检测各组细胞eNOS mRNA和蛋白表达,应用硝酸还原法检测各组细胞上清液中一氧化氮(NO)含量,应用人工基底膜检测细胞的管腔形成能力,应用鸡胚尿囊膜试验检测细胞的血管新生能力,应用四甲基偶氮唑蓝(MTT)法检测各组HUVECs的增殖,应用划痕试验检测各组HUVECs的迁移能力。结果与对照组比较,600μmol/L的高尿酸培养HUVECs 48 h后,细胞eNOS mRNA转录水平、蛋白表达量、NO浓度显著下降(P0.01);HUVECs有聚集倾向,但未能形成管腔样网络结构;CAM的血管新生面积比率降低49.78%(P0.01);同时,细胞的增殖能力降低63.68%(P0.05),细胞的迁移能力下降38.70%(P0.01)。结论高尿酸抑制血管内皮细胞eNOS基因表达和NO含量;高尿酸抑制细胞的血管新生能力,同时抑制细胞增殖与迁移,其抑制的可能机制与高尿酸下调eNOS的表达有关。     

缺血预处理对大鼠血管生长物质表达及新生动脉形成的影响

目的 观察缺血预处理(IPC)对促进血管新生的血管内皮生长因子(VEGF)、联合血小板源生长因子B(PDGF-B)和抑制血管新生的ADAMTS-1表达及对有功能的新生动脉形成的影响.方法 建立大鼠心脏IPC模型,通过免疫组织化学方法观察IPC后6、12、24 h VEGF、PDGF-B和ADAMTS-1的表达.在IPC后24 h建立大鼠心肌梗死模型,14 d后处死动物,通过免疫组织化学方法标记血管平滑肌细胞,观察IPC对心脏梗死区边缘成熟的新生小动脉形成的影响.对照组不进行缺血预处理,仅开胸手术24 h后取心脏组织行免疫组织化学检测或建立心肌梗死模型观察新生小动脉形成情况.结果 IPC后6、12、24 h,心肌的缺血区可见促进血管新生的VEGF和PDGF-B表达显著升高(P均<0.05),与对照组和非缺血区比较差异均有统计学意义,抑制血管生长的ADAMTS-1表达在各时间点亦可见显著升高(P均<0.05),且表达区域与VEGF和PDGF-B一致.IPC后心肌梗死14 d,可见梗死边缘区新生动脉数显著高于对照组(P<0.05).结论 IPC可以促进梗死边缘区成熟的新生动脉的形成,促血管生长的VEGF、PDGF-B和抑制血管生长的ADAMTS-1的相互调节作用可能促进了成熟的新生小动脉的形成.     

胰岛素经VEGF-A/VEGFR2途径促进恒河猴视网膜血管内皮细胞的血管新生

用人胰岛素处理恒河猴视网膜血管内皮细胞系RF/6A,测定其增殖、迁移、管腔形成情况和血管内皮生长因子A(VEGF-A)及其受体(VEGFR)的表达与磷酸化.与空白对照组相比,胰岛素促进RF/6A细胞增殖、迁移和管腔形成(均P＜0.01)、促进VEGF-A mRNA的表达和蛋白的活性(均P＜0.05);促进VEGFR2 mRNA的表达和蛋白的磷酸化(均P＜0.01),而对VEGFR1 mRNA的表达影响无统计学意义(P＞0.05)     

组织蛋白酶S对小鼠主动脉环微管腔形成的影响

目的:探讨组织蛋白酶S(Cat S)对小鼠主动脉环微管腔形成的影响。方法:分别在C57BL6野生型雄性小鼠(Cat~(S+/+)组)和CatS基因敲除雄性小鼠(Cat~(S-/-)组)建立下肢缺血模型,每组8只,分别测定术前、术后即刻、1天、4天、7天、14天、21天血流进行比较分析。再将Cat~(S+/+)组小鼠,分为正常对照亚组、选择性CatS抑制剂(LHVS)亚组、非选择性CatS抑制剂(E64d)亚组和基质金属蛋白酶(MMP)抑制剂(GM6001)亚组,每组2只,观察小鼠主动脉环微管腔形成情况。用免疫荧光法异硫氰酸荧光素(FITC)-CD31标记微管腔形成情况。结果:(1)Cat~(S-/-)组小鼠明显抑制下肢血流的恢复。用激光多普勒超声血流仪检测下肢血流,缺血与非缺血下肢血流比值统计结果显示:Cat~(S-/-)组小鼠术后第7、14、21天缺血下肢血流恢复均明显慢于Cat~(S+/+)组(P均0.05)。(2)Cat~(S-/-)组小鼠的主动脉环中生长出来的微管腔与Cat~(S+/+)组小鼠比较明显减少,两者有统计学差异(P0.001)。(3)LHVS、E64d以及GM6001亚组分别与正常对照亚组比较,均明显抑制主动脉环微管腔的形成,两者差异均有统计学意义(P均0.05)。(4)主动脉环培养形成的微管腔由内皮细胞组成。结论:Cat S在缺血性血管再生中发挥有益的作用,不但增加了主动脉环微管腔形成的数量,并且促进了缺血下肢的血流恢复。这些结果为寻找下肢缺血性血管再生提供了理论依据。     

血管生成素1通过NF-κB传导通路影响内皮祖细胞炎症反应中黏附分子的表达

目的研究脉管关联迁移细胞蛋白(angio-associated migratory cell protein,AAMP)对血管新生的调控作用,并试图揭示AAMP参与血管新生的调控机制。方法通过细胞免疫荧光和构建AAMP-GFP融合蛋白研究AAMP的亚细胞定位,单层细胞创面愈合实验研究AAMP对细胞迁移的影响,通过体外内皮细胞管腔形成、大鼠胸腹主动脉血管环实验和Western blot分析并结合PPARγ激动剂罗格列酮和抑制剂GW9662来研究AAMP对血管新生的调控及其机制。结果对内源性和外源性的AAMP分析发现,AAMP主要分布于内皮细胞的胞浆和细胞膜上。过表达AAMP后细胞迁移能力和管腔形成与对照相比显著增强,而干扰AAMP的表达后细胞迁移能力和管腔形成与对照相比显著减弱,并且AAMP抗体亦能减弱内皮细胞的管腔形成和主动脉血管环血管新生。罗格列酮能减弱AAMP过表达的内皮细胞的迁移能力、管腔形成,并且能够抑制主动脉血管环血管新生;而GW9662能显著抑制罗格列酮的这种作用。但GW9662不能显著增强内皮细胞的管腔形成和主动脉血管环血管新生。Western blot分析发现,罗格列酮显著降低内皮细胞AAMP...     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.