急性心肌梗死大鼠心肌组织趋化因子及其受体mRNA表达的观察

目的:探讨急性心肌梗死大鼠心肌局部趋化因子和T细胞趋化因子受体的表达,揭示AMI后T细胞浸润心肌组织的机制。方法:结扎冠脉左前降支建立AMI大鼠模型,用半定量RT-PCR方法分析心肌梗死区和非梗死区趋化因子的表达,包括γ干扰素诱导的单核因子(MIG),正常T细胞表达和分泌、活化时表达下降的因子(RANTES),巨噬细胞炎性蛋白-1α(MIP-1α),以及T细胞趋化因子受体的表达(包括CXCR3、CCR3、CCR5)。HE染色切片进行心肌梗死区和非梗死区淋巴细胞计数分析。结果:心肌梗死区和非梗死区趋化因子RANTES、MIP-1α、MIG的mRNA表达于术后3天开始升高,1周达峰值,然后开始下降,8周降至正常,而趋化因子受体的表达没有明显改变。AMI大鼠心脏梗死区和非梗死区均可见淋巴细胞浸润,梗死区1周达高峰(81.0±10.3vs2.6±1.1,P<0.05),非梗死区2周达高峰(19.0±8.0vs3.2±0.8,P<0.05)。RANTES和MIP-1α的表达与淋巴细胞浸润显著相关。结论:AMI后心肌局部趋化因子表达增高,可能是诱导T细胞浸润心肌组织的始动因子。     

气道给rhSOD对胎粪诱导肺损伤中NF-κB及MIP-1α表达的影响

目的：观察早期经气道给予重组人超氧化物歧化酶（rhSOD）对胎粪诱导大鼠肺NF-κB和炎症因子MIP-1α表达的影响，以探讨其在胎粪诱导肺损伤中的作用及其机制。 方法： 24只雄性SD大鼠，随机分为：（1）对照组（control）,经气管插管注入生理盐水1 mL/kg；（2）胎粪+生理盐水处理组（Mec/saline）；（3）胎粪+ rhSOD治疗组(Mec/rhSOD)。后两者先由气管插管注入20%新生儿胎粪生理盐水混悬液1 mL/kg建立急性肺损伤模型，再分别经气管插管注入生理盐水1 mL/kg或rhSOD 20 g·L-1·kg-1。24 h后取材， RT-PCR法测定肺组织MIP-1α mRNA、Western blotting法测定NF-κB蛋白表达改变，同时行支气管肺泡灌洗液（BAL）细胞计数。 结果： Mec/saline组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达均明显高于control组［(4.68±1.40)×109 cells/L vs (0.53±0.19)×109 cells/L, 3.60±0.75 vs 1.56±0.33， 0.72±0.31 vs 0.23±0.21］，（均P<0.01）； Mec/rhSOD组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达分别为(3.13±0.77)×109cells/L、2.20±0.39和0.44±0.21，均显著低于Mec/saline组（均P<0.01），但仍显著高于control组（均P<0.01）。 结论： 早期经气道给rhSOD可能通过抑制肺MIP-1α和NF-κB表达而减轻胎粪诱导的肺炎症反应。     

亚砷酸对类风湿性关节炎大鼠治疗作用的研究

目的： 探讨类风湿性关节炎大鼠发病机制并观察亚砷酸对AP-1和MIP-1α表达的影响。方法：随机将32只大鼠分成4组:对照组(C组)、关节炎组（A组）、LSA组（腹腔注射亚砷酸0.5 mg·kg^-1·d^-1）、HSA组（腹腔注射亚砷酸1.0 mg·kg^-1·d^-1）。免疫组织化学检测各组AP-1、MIP-1α表达；采用HE法观察滑膜病理改变。结果： C组未见AP-1和MIP-1α表达，A组AP-1及MIP-1α表达明显高于C组（P<0.05）； LSA组及HSA组AP-1、MIP-1α表达低于A组（P<0.05），且HSA组更明显。结论： AP-1和MIP-1α可能参与大鼠佐剂性关节炎发生、发展；亚砷酸能下调AP-1和MIP-1α表达,可能对RA有一定治疗作用。     

脂多糖活化的大鼠肺泡巨噬细胞TNF-α产生的新机制

目的：探讨脂多糖（LPS）活化的肺泡巨噬细胞中低氧诱导因子－1α（HIF-1α）的表达及其在肺泡巨噬细胞产生肿瘤坏死因子α（TNF-α）中的作用。 方法： 应用HIF-1α 诱骗法（HIF-1α decoy）抑制其作用，并用Western blotting、半定量RT-PCR、酶联免疫吸附法（ELISA）分别检测HIF-1α蛋白、mRNA的表达和TNF-α的产生。 结果： HIF-1α蛋白含量在LPS组（1.95±0.57）和HIF-1α decoy组（1.89±0.59）均明显高于对照组（0.41±0.14，P＜0.05）；HIF-1α mRNA的表达在对照组（0.7838±0.3183）、LPS组（0.7622±0.3387）和HIF-1α decoy组（0.8155±0.3594）之间无显著差异（P>0.05）；LPS刺激24 h后，大鼠肺泡巨噬细胞TNF-α的产生明显高于对照组（61 ng/L vs 156 ng/L, P<0.05），抑制HIF-1α后TNF-α的产生明显低于LPS刺激组（90 ng/L vs 156 ng/L, P<0.05），但 HIF-1α decoy组TNF-α的产生仍然高于对照组（61 ng/L vs 94 ng/L, P<0.05）。 结论： 大鼠肺泡巨噬细胞在LPS的刺激下HIF-1α蛋白的稳定性增强使其表达明显上调，并且促进TNF-α的产生，提示HIF-1α在肺部慢性炎症性疾病如COPD的发病机制中可能有重要作用。     

心肌营养素-1在心肌成纤维细胞增殖中的作用

目的：探讨心肌营养素-1（CT-1）在高血压心室重塑中的作用。方法：3-4代心肌成纤维细胞用于实验，分为对照组、助溶剂（二甲亚砜，DMSO）组、CT-1反义寡核苷酸组（ASODN）、正义寡核苷酸对照组（SODN）、PD98059组、AG490组、LY294002组。利用自制压力培养装置，将各组细胞置于160 mmHg压力下培养8 h。 STAT3、ERK1/2和PI3-K的活性通过Western blotting分析测定；MTT测定心肌成纤维细胞增殖。结果：高静水压明显促进心肌成纤维增殖，CT-1表达上调，CT-1ASODN干预后，CT-1ASODN能抑制高静水压所致的细胞增殖（0.132±0.013 vs 0.154±0.011，P<0.05），STAT3、ERK1/2和 PI3-K蛋白表达水平明显低于对照组（2.09±0.25 vs 2.47±0.28,P<0.05)、(1.13±0.19 vs 1.61±0.22,P<0.05)、（1.25±0.23 vs1.71±0.25,P<0.05)。AG490组明显减弱高静水压的促增殖作用（0.118±0.018 vs 0.155±0.010，P<0.05）并且增加ERK1蛋白磷酸化（1.85±0.18 vs 1.45±0.23，P<0.05）;PD98059增强高静水压的促增殖（0.185±0.011 vs 0.155±0.010，P<0.05）并且增加STAT3蛋白磷酸化（1.83±0.23 vs 1.58±0.22，P<0.05）, PI3/K阻断剂LY294002干预后对高静水压的促增殖作用无影响（0.157±0.015 vs 0.155±0.010，P>0.05）；SOND (0.151±0.010 vs 0.154±0.011, P>0.05) 和DMSO组(0.141±0.017 vs 0.155±0.010, P>0.05)与对照组相比对心肌成纤维细胞增殖无明显差别。结论：高静水压下，心肌成纤维细胞增殖主要通过STAT3通路；ERK1/2通路通过抑制STAT3的活性起负向调节作用，可能在防止心肌成纤维细胞过度增殖起重要的作用；PI3-K没有参与这一作用。上述STAT3通路与ERK1/2通路之间的相互作用可能有助于防止诱导成纤维细胞过度增殖。     

病毒感染大鼠心室肌细胞钙通道基因表达及功能改变的研究

目的：研究大鼠心室肌细胞感染柯萨奇病毒B3（CVB3）后L型钙通道mRNA表达量及其电生理特性的变化。 方法: 用CVB3感染培养的SD大鼠心室肌细胞，采用半定量逆转录-聚合酶链式反应技术，检测病毒感染心室肌细胞L型钙通道各亚单位mRNA表达量的变化；用全细胞膜片钳技术，观察病毒感染前后心室肌细胞L型钙电流（ICa-L）的变化。结果: 病毒感染组心室肌细胞L型钙通道α1和β亚单位mRNA的表达量显著高于正常对照组（4.00±0.07 vs 2.21±0.41, P<0.01; 2.06±0.06 vs 1.22±0.30, P<0.05），而α2/δ亚单位mRNA表达量的改变不明显（4.12±0.19 vs 4.13±0.27, P>0.05）；感染组细胞ICa-L的平均电流密度明显大于正常组细胞［（-8.66±0.99) pA/pF vs (-6.97±1.75) pA/pF, P<0.01］，且前者的电流-电压曲线下移，峰电流密度增加25.74%（P<0.05）。结论: CVB3感染心室肌细胞后，使其L型钙通道α1和β亚单位mRNA的表达量增加，ICa-L增大，可能是病毒感染导致心肌出现异常电生理活动的细胞和分子机制之一。     

急性心肌梗死大鼠淋巴细胞体外增殖及杀伤效应的观察

目的：观察急性心肌梗死（AMI）大鼠的淋巴细胞体外增殖及对心肌细胞的杀伤效应。 方法： 在体结扎SD大鼠冠状动脉左前降支（LAD），建立AMI大鼠模型和假手术对照。手术后第1周、2周和4周分别分离大鼠脾脏淋巴细胞，与乳鼠心肌细胞共培养，5-溴脱氧尿嘧啶（BrdU）标记ELISA方法测定淋巴细胞增殖指数（PI），结晶紫法测定淋巴细胞对心肌细胞的杀伤效应。 结果： AMI后2周和4周大鼠淋巴细胞增殖指数（32.5±4.4，29.8±5.8）显著大于假手术组（18.4±3.7，17.9±3.2）和正常大鼠组（13.6±2.5，13.4±2.1），淋巴细胞对培养心肌细胞的杀伤效应［(36.4±7.2)%,(68.2±7.1)％］显著强于假手术组［（22.5±4.5）％,（34.7±6.3）％］和正常大鼠组［(16.7±3.2)％,（17.6±2.7）％］，且在AMI后4周时达高峰。 结论： AMI后大鼠的淋巴细胞能够识别并杀伤正常的心肌细胞，该机制可能参与AMI后免疫机制介导的心肌损伤和心室重塑过程。     

凝血酶敏感蛋白-1在2型糖尿病心肌病大鼠心肌中的表达及意义

目的： 探讨凝血酶敏感蛋白-1（TSP-1）在2型糖尿病心肌病（DCM）发病中的作用。方法： 采用高脂高热量饮食诱导出胰岛素抵抗，加小剂量链脲佐菌素注射建立DCM动物模型，12周后采用Masson染色、免疫组织化学染色、实时定量逆转录－聚合酶链反应、Western blotting技术，检测左室心肌胶原含量、TSP-1 mRNA和蛋白质表达水平的变化。结果： DCM大鼠左室心肌组织胶原含量明显高于对照组（11.01±3.05 vs 16.92±3.18，P<0.01），TSP-1 mRNA和蛋白表达水平均明显高于对照组（0.0089±0.0034 vs 0.0141±0.0037，P<0.05；96.38±16.80 vs 129.98±16.96，P<0.05）；TSP-1 mRNA水平与血糖、心肌组织胶原含量、LVEDP均呈正相关（r=0.762，P<0.01；r=0.717，P<0.05；r=0.658，P<0.05）；与LVSP、-dp/dtmax均呈负相关（r=-0.605，P<0.05；r=-0.694，P<0.05）；TSP-1蛋白质表达水平与血糖、心肌组织胶原含量、LVEDP均呈正相关（r=0.735，P<0.01；r=0.750，P<0.01；r=0.716，P<0.05）；与LVSP、-dp/dtmax均呈负相关（r=-0.633，P<0.05；r=-0.669，P<0.05）。结论： 心肌组织TSP-1高表达在DCM心肌间质纤维化的发生中起着重要的作用。     

大鼠缺血再灌注心肌过氧化物酶体增殖物激活受体α的表达及血清游离脂肪酸含量的变化

目的：研究缺血再灌注后大鼠心肌过氧化物酶体增殖物激活受体α(PPAR α)表达及血清游离脂肪酸含量的变化情况。 方法： Wistar大鼠66只随机分为3组：正常对照组（n=18），假手术组（n=24），缺血再灌注组（n=24）。采用大鼠心冠状动脉左前降支结扎法复制在体缺血再灌注模型。运用半定量RT-PCR方法对心肌PPARα mRNA的表达程度进行分析，运用Western blotting方法检测PPARα蛋白表达水平。并测定各组血清游离脂肪酸含量。 结果： 缺血再灌注组心肌PPARα mRNA 0.374±0.115显著少于正常对照组及假手术组（分别为1.071±0.140、 1.012±0.127）（P<0.01）；缺血再灌注组心肌PPARα蛋白表达为42.32±13.06，显著少于正常对照组及假手术组（114.09±23.15、101.25±21.20）（P<0.01）。缺血再灌注组游离脂肪酸水平于再灌注后4 h、6 h显著上升。 结论： 在实验性大鼠缺血再灌注心肌中PPARα表达减少同时伴有大鼠血清中游离脂肪酸增多。     

西酞普兰对慢性应激大鼠额叶皮质神经细胞Bcl-2、Bax表达及凋亡的影响

目的： 探讨西酞普兰对慢性应激大鼠额叶皮质神经细胞Bcl-2、Bax表达及凋亡的影响。方法: 将24只雄性SD大鼠随机分为对照组、慢性应激组、西酞普兰+慢性应激组，每组8只，采用免疫组化检测Bcl-2、Bax表达水平，TUNEL法检测细胞凋亡,尼康图像分析（NIS DR）软件测量分析Bcl-2、Bax、TUNEL阳性细胞数量及灰度值(gray value)。结果: 各组大鼠每周体重基本呈自然增长趋势，差异无统计学意义（P>0.05）。组内额叶皮质的阳性细胞数和灰度值比较（除Bcl-2灰度值外），差异均显著（P<0.05）。慢性应激组与对照组比较：额叶皮质神经细胞Bcl-2阳性细胞数量减少（30.63±10.75 vs 11.50±4.24），Bax阳性细胞数量增多（48.88±6.55 vs 65.13±15.05）、表达增强（155.21±8.55 vs 148.91±4.47），TUNEL检测阳性细胞增多（16.94±6.46 vs 31.69±19.89）、表达增强（152.56±5.28 vs 141.91±10.38），差异显著（P<0.05）；西酞普兰+慢性应激组与应激组比较：Bcl-2阳性细胞数量增多（27.00±9.89 vs 11.50±4.24），Bax阳性细胞数量减少（50.56±12.70 vs 65.13±15.05），TUNEL检测阳性细胞减少（17.31±5.41 vs 31.69±19.89），差异有统计学意义（P<0.05）。结论: 慢性应激影响大鼠额叶皮质神经细胞Bcl-2、Bax表达水平，促进细胞凋亡；西酞普兰可调节慢性应激大鼠额叶皮质神经细胞Bcl-2、Bax表达水平，拮抗细胞凋亡。     

Serum profiles of C-C chemokines in acute myocardial infarction: possible implication in postinfarction left ventricular remodeling.

C-C chemokines are essential factors in the recruitment and activation of leukocytes from the circulation into inflamed tissue and may play a role in ischemia-induced myocardial injury and left ventricular remodeling after acute myocardial infarction (AMI). We investigated the kinetics of three major C-C chemokines, macrophage chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1 alpha), and regulated on activation normally T cell expressed and secreted (RANTES), in the sera of AMI patients and correlated the findings with the severity of the disease. Serum levels of C-C chemokines were determined in 35 AMI patients by ELISA assays serially during the first week of hospitalization and 1 month after hospital admission. Patients (n = 18) with uncomplicated AMI (Killip class I) were classified as group A, patients (n = 17) with AMI complicated by heart failure manifestations (Killip classes II and III) were classified as group B, and 15 age-matched and sex-matched volunteers were used as healthy controls. A sustained increase in serum C-C chemokines was observed in both AMI groups during the 7-day hospitalization period. Peaks of these inflammatory factors were significantly higher in group B than in group A (MCP-1, 295 +/- 11 vs. 203 +/- 9 pg/ml, p < 0.01; MIP-1 alpha, 30 +/- 1 vs. 24 +/- 2 pg/ml, p < 0.05; RANTES, 32 +/- 2 vs. 16 +/- 1 ng/ml, p < 0.01) and healthy controls (MCP-1, 125 +/- 7 pg/ml, p < 0.001; MIP-1 alpha, 14 +/- 1 pg/ml, p < 0.001; RANTES, 12 +/- 1 ng/ml, p < 0.001). In group B, significant correlations were found between the peak of MCP-1 and the peak of C-reactive protein levels (r = 0.55, p < 0.02) as well as wedge pressure (r = 0.40, p < 0.05). In the same group, the peak of MIP-1 alpha levels was also significantly correlated with the peak of serum creatine kinase-myocardial band (MB) (r = 0.51, p < 0.04) and left ventricular ejection fraction (LVEF) (r = -0.45, p < 0.05). After 1 month, AMI patients (n = 14) with severe left ventricular dysfunction (LVEF < or = 35%) exhibited significantly higher levels of C-C chemokines (all p < 0.05) than the other AMI patients (n = 21) (LVEF > 35%). A significant correlation was found between MIP-1 alpha levels and left ventricular end-diastolic diameter (r = 0.47, p < 0.03) in this patient population. In conclusion, we have detected a significant elevation of major C-C chemokines during the course of AMI, with the highest levels in patients with AMI complicated by heart failure manifestations and severe left ventricular dysfunction. The elevation of these chemotactic inflammatory factors may actively contribute to the pathophysiology of the disease and the subsequent left ventricular remodeling.     

Characterization of chemokines and chemokine receptors in two murine models of inflammatory bowel disease: IL-10-/- mice and Rag-2-/- mice reconstituted with CD4+CD45RBhigh T cells

We used quantitative PCR to investigate the expression of chemokines and chemokine receptors in two Th1-mediated murine models of inflammatory bowel disease (IBD). First, mRNA levels encoding the chemokines MIG, RANTES, lymphotactin, MIP-3alpha, TCA-3, TARC, MIP-3beta, LIX, MCP-1 and MIP-1beta and the receptors CCR4, CCR6 and CCR2 were significantly increased in chronically inflamed colons of IL-10-/- mice when compared with wildtype mice. Interestingly, reversal of colitis in IL-10-/- mice by anti-IL-12 mAb was accompanied by the inhibition in the expression of LIX, lymphotactin, MCP-1, MIG, MIP-3alpha, MIP-3beta, TCA-3, CCR2 and CCR4, whereas the increased mRNA levels of MIP-1beta, RANTES, TARC and CCR6 were unaffected. Second, to investigate which chemokines and receptors were up-regulated during the inductive phase of colitis, we employed the CD4+CD45RBhigh T cell transfer model. At 4 and 8 weeks after reconstitution of Rag-2-/- mice the mRNA levels of IP-10, MCP-1, MDC, MIG, TARC, RANTES, CCR4 and CCR5 were significantly increased prior to the appearance of macroscopic lesions. Other chemokines and chemokine receptors were clearly associated with the acute phase of the disease when lesions were evident. The sum of our studies with these two models identifies chemokines that are expressed at constant levels, irrespective of inflammatory responses, and those that are specifically associated with acute and/or chronic stages of Th1-driven colitis.     

C-C chemokines,but not the C-X-C chemokines interleukin-8 and interferon-γ inducible protein-10, stimulate transendothelial chemotaxis of T lymphocytes

Eight chemokines were tested for ability to elicit transendothelial chemotaxis of unstimulated peripheral blood T lymphocytes. The C-C chemokines monocyte chemotactic protein (MCP)-2, MCP-3, RANTES, macrophage inflammatory protein (MCP)-lα, MIP-1β, and, as previously described, MCP-1 induced significant, dose-dependent transendothelial chemotaxis of CD3⁺ T lymphocytes. In contrast, the C-X-C chemokines interleukin-8 (IL-8) and interferon-γ inducible protein-10 (IP-10) failed to induce transendothelial chemotaxis of CD3⁺ T lymphocytes or T lymphocyte subsets. RANTES, MIP-1α, and MIP-1β induced significant transendothelial chemotaxis of CD4⁺, CD8⁺, and CD45RO⁺ T lymphocyte subsets. Phenotyping of mononuclear cells that underwent transendothelial migration to MCP-2, MCP-3, RANTES, or MIP-1α showed both monocytes and activated (CD26 high), memory-type (CD45RO⁺) T cells. Both CD4⁺ and CD8⁺ T lymphocytes were recruited, but not natural killer cells or significant numbers of B cells. MCP-2 was the only C-C chemokine tested that attracted a significant number of naive-type (CD45RA⁺) T lymphocytes. In the absence of endothelium, IL-8 but not IP-10 promoted modest but significant chemotoxis of CD3⁺ T lymphocytes. Our data support the hypothesis that C-C, not the C-X-C chemokines IL-8 or IP-10, promote transendothelial chemotaxis of T lymphocytes.     

Actions of the chemotactic cytokines MCP-1, MCP-2, MCP-3, RANTES,MIP-1α and MIP-1β on human monocytes

The activities of six synthetic CC chemokines, MCP-1, MCP-2, MCP-3, RANTES, MIP-1α and MIP-1β on human blood monocytes were studied. All CC chemokines elicited a bimodal migration response in vitro. Highest numbers of migrating cells were obtained with the monocyte chemotactic proteins (MCP) and RANTES, somewhat lower numbers with MIP-1α, and only weak migration with MIP-1β. The most potent attractants were MCP-1 and MIP-1α which reached maximum efficacy at 0.1 to 1 nM. All CC chemokines also induced the release of N-acetyl-β-D-glucosaminidase from cytochalasin B-pretreated monocytes. The MCP were most effective (MCP-1 > MCP-3 > MCP-2), RANTES and MIP-1α showed moderate (1/3 of MCP-1 activity), and MIP-1β only minimal activity. Cytosolic free Ca²⁺ changes and exocytosis were used to monitor receptor desensitization. Marked cross-desensitization was observed among MCP-1, MCP-2 and MCP-3 on the one hand, and RANTES, MIP-1α and MIP-1β on the other, indicating receptor sharing within these two subgroups of CC chemokines. The responses to RANTES, MIP-1α and MIP-1β were also moderately to markedly desensitized by pretreatment with MCP-1, MCP-2 or MCP-3, while the responses to the MCP were virtually unaffected by pretreatment with RANTES, MIP-1α and MIP-1β. These results suggest that the MCP also interact with receptors recognized by RANTES, MIP-1α and MIP-1β, but not vice versa. Binding studies were performed with radiolabeled MCP-1 or MIP-1α. All MCP competed readily for labeled MCP-1 yielding a concentration-dependent sigmoidal displacement curve. Displacement with RANTES, MIP-1α and MIP-1β was observed at higher concentrations, but was not complete. Radiolabeled MIP-1α was displaced efficiently by MIP-1α or MIP-1β, but only partially by RANTES. Of the MCP, only MC-3 completely displaced MIP-1α, while only partial displacement was observed with MCP-1 and MCP-2.     

Differential expression of binding sites for chemokine RANTES on human T lymphocytes

The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3+ T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6–15 h incubation at 37°C, the binding of RANTES, but not of macrophage inflammatory protein-1α (MIP-1α) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RANTES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4⁺ T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-1α, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-1α.     

Transendothelial chemotaxis of human αβ and γδ T lymphocytes to chemokines

Two subpopulations of human T lymphocytes expressing different antigen receptors, α / β and γ / δ, emigrate into inflamed tissues in distinctive patterns. We compared the transmigration of α / β and γ / δ T cells to C-C and C-X-C chemokines using an in vitro transendothelial chemotaxis assay. The C-C chemokines monocyte chemoattractant protein (MCP)-1, RANTES, macrophage inflammatory protein (MIP)-1α and MIP-1β stimulated similar, dose-dependent chemotaxis of purified γ / δ T cells, whereas MCP-1, RANTES, and MIP-1α pro duced greater chemotaxis of purified α / β T cells than MIP-1β. In contrast, the C-X-C chemokines interleukin (IL)-8 and interferon-γ inducible protein-10 (IP-10) did not promote chemotaxis of either α / β or γ / δ T cells. Three γ / δ T cell clones with differing CD4 and CD8 phenotypes also migrated exclusively to C-C chemokines. Phenotypic analysis of mononuclear cells that transmigrated from an input population of unfractionated peripheral blood mono nuclear cells confirmed the results with purified γ / δ T cells. Our data demonstrate that human peripheral blood α / β and γ / δ T cells can transmigrate to MCP-1, RANTES, MIP-1α, and MIP-1β, and suggest that both T lymphocyte subpopulations share the capacity to emigrate in response to C-C chemokines during inflammation.     

A rapid chemokine response of macrophage inflammatory protein (MIP)-1α, MIP-1β and the regulated on activation,normal T expressed and secreted chemokine is associated with a sustained virological response in the treatment of chronic hepatitis C

The role of chemokines in chronic hepatitis C virus (HCV) infection is not fully understood. The present study aimed to characterize the baseline serum concentrations and the initial β-chemokine response to treatment with interferon-α and ribavirin with respect to the final clinical outcome of virological response to treatment. Serum concentrations of alanine aminotransferase (ALT) and of the CC subfamily chemokines [macrophage inflammatory protein (MIP)-1α, MIP-1β, monocyte chemoattractant protein (MCP)-1 and the regulated on activation, normal T expressed and secreted (RANTES) chemokine] were measured in patients with chronic HCV infection and in healthy individuals. Necroinflammation and fibrosis were scored in liver biopsies. Treatment outcomes were classified as with or without a sustained virological response after a full-course treatment according to the genotypes. The main treatment group consisted of 72 patients with chronic hepatitis C, whereas 24-h blood samples were available for 42 patients. Increased baseline levels of all CC chemokines were found in the two responder groups compared to the healthy controls, although significant levels were reached only for MIP-1α and MCP-1. No correlation was observed between chemokine levels and serum ALT levels, any histological necroinflammatory parameters, or the fibrosis grade. After 24 h of treatment, increases in MIP-1α, MIP-1β and RANTES levels were exclusively observed in the group with sustained virological response. MCP-1 was also significantly increased after 24 h in both responder groups, although no differences were observed between the two responder groups. In conclusion, an early MIP-1α, MIP-1β, and RANTES response may predict a sustained response to virological treatment.     

Expression of macrophage inflammatory protein (MIP)-1α, MIP-1β, and RANTES genes in lymph nodes from HIV+ individuals: correlation with a Th1-type cytokine response

The in vivo response of the immune system after HIV infection in regard to cytokine production and C-C chemokine synthesis is not well known. Here we have analysed cytokine and chemokine mRNA production in lymph nodes with follicular hyperplasia (FHLN) of HIV-infected patients by in situ hybridization using anti-sense mRNA probes. The synthesis of mRNAs for interferon-gamma (IFN-γ), IL-12p35, IL-12p40, IL-4, and for the C-C chemokines RANTES, MIP-1α, and MIP-1β was compared with that of lymph nodes from non-infected individuals to define HIV-specific events. Only few cells expressing IFN-γ, RANTES, MIP-1α, and MIP-1β mRNAs were detectable in the T-dependent area of lymph nodes from HIV-negatives. In contrast, in FHLN from HIV⁺ patients a high number of IFN-γ, RANTES, MIP-1α, and MIP-1β mRNA-containing cells were detectable. Remarkably, only single individual IL-12p35 mRNA-producing cells were present in the T-dependent area from both HIV⁺ and HIV^? lymph nodes. Furthermore, the low number of IL-12p40 mRNA-expressing cells did not differ between HIV⁺ and HIV^? lymph nodes. This indicates that IFN-γ is expressed independently of IL-12, possibly by a direct T cell-mediated reaction. IL-4 mRNA-producing cells were hardly detectable in infected and control lymph nodes. The same findings were made in a limited number of samples from patients with advanced disease. Thus, these results demonstrate that a high IFN-γ production is accompanied by a strong expression of MIP-1α, MIP-1β, and RANTES in the lymph node after HIV infection. This favours the idea that a Th1-type immune response correlates with a preferential production of C-C chemokines in FHLN of HIV⁺ patients.     

Campylobacter jejuni-mediated induction of CC and CXC chemokines and chemokine receptors in human dendritic cells

Campylobacter jejuni is a leading worldwide bacterial cause of human diarrheal disease. Although the specific molecular mechanisms of C. jejuni pathogenesis have not been characterized in detail, host inflammatory responses are thought to be major contributing factors to the resulting typical acute colitis. The intestinal mucosal chemokine response is particularly important in the initial stages of bacterium-induced gut inflammation. Chemokines attract blood phagocytes and lymphocytes to the site of infection and regulate immune cell maturation and the development of localized lymphoid tissues. The production of chemokines by dendritic cells (DCs) following Campylobacter infection has not yet been analyzed. In the current study, we infected human monocyte-derived DCs with C. jejuni to examine the production of key proinflammatory chemokines and chemokine receptors. The chemokines, including CC families (macrophage inflammatory protein 1α [MIP-1α], MIP-1β, RANTES) and CXC families (growth-related oncogene α [GRO-α], IP-10, and monokine induced by gamma interferon [MIG]), were upregulated in Campylobacter-infected DCs. Chemokine receptors CCR6 and CCR7, with roles in DC trafficking, were also induced in Campylobacter-infected DCs. Further, Campylobacter infection stimulated the phosphorylation of P38, P44/42, and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) mitogen-activated protein kinases (MAPKs) in DCs. NF-κB activation was specifically involved in chemokine induction in DCs infected with C. jejuni. Additionally, STAT3 was significantly increased in Campylobacter-infected DCs compared to that in uninfected DCs. These results suggest that DCs play a significant role in the initiation and modulation of the inflammatory response by enlisting monocytes, neutrophils, and T lymphocytes during human intestinal infection with Campylobacter.     

急性心肌梗死大鼠钙调蛋白的改变及卡维地洛的干预作用

目的：研究急性心肌梗死（AMI）后心力衰竭大鼠心肌钙调蛋白肌质网Ca2+-ATP酶（SERCA）和受磷蛋白（PLB)的变化及卡维地洛对其干预作用。 方法： 选取AMI术后成活的雄性SD大鼠随机分为AMI组、卡维地洛组两组。给药6周后观察血流动力学参数、心室重构指标及钙调蛋白SERCA、PLB的蛋白和mRNA表达。另设正常对照组及假手术组。 结果： AMI组左室舒张末压（LVEDP）、各心室重量均显著大于假手术组，左室内压最大收缩和舒张速率（±dp/dt）显著低于假手术组；SERCA蛋白和mRNA表达显著低于假手术组（P<0.01），PLB蛋白和mRNA表达高于假手术组（P<0.01）。卡维地洛组的LVEDP、心室重量均显著低于AMI组，±dp/dt显著高于AMI组；卡维地洛治疗使SERCA蛋白和mRNA表达明显升高（P<0.05），但未能改变PLB蛋白和mRNA水平(P>0.05）。 结论： 急性心肌梗死后心力衰竭中钙调蛋白SERCA和PLB的变化可能是心肌收缩功能失调的重要机制；卡维地洛能有效地抑制大鼠AMI后心室重构并改善血流动力学，其分子机制可能与钙调蛋白SERCA含量正常化有关。