Inhibition of IL-8–Mediated MAPK Activation in Human Neutrophils by β1 Integrin Ligands

Chemokine and integrin receptors must work in concert when circulating leukocytes mobilize toward a site of tissue inflammation or infection. In a previous study, we reported that ligation of the ₅₁ integrin with a 120-kDa cell-binding fibronectin fragment (120-kDa FN) in suspensions of human polymorphonuclear leukocytes (PMNLs) inhibited chemotaxis toward the chemokine called interleukin-8 (IL-8). Binding of chemokines to their receptors on leukocytes leads to the activation of heterotrimeric G proteins that initiate multiple signaling cascades, including p38 and p42/p44 mitogen-activated protein kinase (MAPK) pathways. In the present study, we examine the potential interaction of ₁ integrin ligation on chemokine-mediated MAPK signaling in human PMNLs. We demonstrate that blockade of the p42/p44 MAPK signaling pathway by the inhibitor PD98059 suppresses IL-8–mediated PMNL chemotaxis. Furthermore, when PMNLs are pretreated with 120-kDa FN or an activating antibody to ₁ integrins (TS2/16), IL-8–mediated phosphorylation of p42/p44 MAPK is also inhibited. In contrast, pretreating PMNL with a specific ligand (laminin-1) for the ₆₁ integrin does not suppress IL-8–mediated phosphorylation of p42/p44 MAPK. These observations demonstrate a desensitization of IL-8–mediated p42/p44 MAPK signaling in response to ligation of the ₅₁ integrin in PMNL. Also, they suggest an interplay between integrin and chemokine signaling during PMNL migration through the extracellular matrix.     

‘I Can’t Keep Up!’: an update on advances in soft tissue pathology occurring after the publication of the 2020 World Health Organization classification of soft tissue and bone tumours

Progress in our understanding of the pathogenesis and diagnosis of soft tissue neoplasia is exceptionally rapid. Although the most recent World Health Organization classification of soft tissue tumours contains many new entities and refinements of older ones, even this comprehensive document is by now incomplete or in need of modification. This review will attempt to summarise the developments in soft tissue pathology that have occurred since 2020, emphasising lesions for which morphology and genetics intersect in a complementary fashion. Novel entities discussed include KMT2A-rearranged sarcoma, PRRX::NCOAx fibroblastic tumours, EWSR1::PATZ1 sarcomas, BRAF-altered infantile fibrosarcoma-like lesions, NUTM1-rearranged colorectal sarcomas, and a variety of interesting giant cell-rich and matrix-producing lesions. In addition, recently described mimics of atypical lipomatous tumour/well-differentiated liposarcoma are covered, as is a wholly new, morphologically defined and genetically confirmed entity, pseudoendocrine sarcoma. Finally, exciting new developments in the use of immunohistochemistry as a surrogate for molecular genetic techniques are discussed.     

排斥性导向分子a抑制剂6FNⅢ对大鼠大脑皮质神经元缺血再灌注后自噬的作用

目的 探讨排斥性导向分子a(RGMa)特异性抑制剂6FNⅢ对大鼠大脑皮质神经元缺血再灌注引发的自噬及对神经功能恢复的影响。 方法 雄性成年SD大鼠立体定位侧脑室注射不同浓度6FNⅢ后建立大脑中动脉闭塞（MCAO）/再灌注模型,Western blotting检测RGMa下游分子脑衰反应调节蛋白-2（CRMP-2）蛋白表达水平,确定最佳6FNⅢ干预浓度。将72只雄性成年SD大鼠随机分成4组：假手术组（sham）、脑缺血再灌注组（I/R）、生理盐水干预组（I/R+NS）、6FNⅢ干预组（I/R+6FNⅢ）,每组18只。缺血2h再灌注后24h,采用神经功能缺损评分评估各组大鼠神经功能恢复情况;Western blotting检测自噬相关蛋白LC3Ⅱ/Ⅰ水平;免疫荧光双标检测LC3在神经元内的表达情况;透射电子显微镜观察自噬体的形成情况。 结果 根据各浓度6FNⅢ干预组CRMP-2表达,确定中浓度（0.5 g/L）为本实验的最适浓度。缺血再灌注后24h,I/R组较sham组神经功能评分降低(P＜0.05)、自噬相关蛋白LC3Ⅱ/Ⅰ水平升高(P＜0.05)、自噬体形成增多;I/R+6FNⅢ组较I/R组神经功能评分增高(P＜0.05)、自噬相关蛋白LC3Ⅱ/Ⅰ水平降低(P＜0.05)、自噬体形成减少;而I/R+NS组与I/R组以上各项均无统计学意义(P＞0.05)。 结论 RGMa特异性抑制剂6FNⅡ可在缺血再灌注急性期抑制自噬发生,促进神经功能恢复。     

褐藻多糖硫酸酯对阿霉素肾硬化大鼠肾组织FN、TGF-β、MMP-9的影响

目的 观察褐藻多糖硫酸酯(FPS)对阿霉素肾硬化大鼠肾脏的保护作用.方法 将40其SD大鼠分成正常组、模型组、海昆肾喜组(褐藻多糖硫酸酯组)、盐酸贝那普利组.建立阿霉素肾硬化大鼠模型,分别采用相应药物干预;8周后观察各组大鼠肾脏病理改变,PAS观察肾小球系膜基质,免疫组化观察肾脏组织纤连蛋白(FN),Western blot观察转化生长因子β(TGF-β)和金属蛋白酶-9(MMP-9)的表达.结果 FPS能减轻肾小球系膜基质增生,且能减少TGF-β、FN表达,上调肾皮质MMP-9的表达.相关性分析研究显示,TGF-β值与FN、系膜基质指数呈正相关;MMP-9值与FN、系膜基质指数呈负相关.结论 FPS可能通过调控TGF-β及MMP-9表达,减轻FN沉积,从而抑制肾小球硬化.     

大黄素对TGF-β1诱导的NRK-49F细胞增殖的影响

目的:研究大黄素对TGF-β1诱导的肾成纤维细胞株(NRK-49F)增殖以及降低FN(纤连蛋白),Col-I(I型胶原蛋白),Smad2/3蛋白及基因表达的机制。方法:采用CCK8法检测不同浓度大黄素对NRK-49F细胞增殖情况的影响;终浓度为20、40、80μmol/L的大黄素处理NRK-49F细胞30 min后,模型组和观察组均以TGF-β1以5 ng/m L的终浓度刺激24 h,并收集细胞,蛋白质免疫印迹技术(Western blot)检测FN,Col-I,Smad2/3蛋白表达水平,实时荧光定量PCR(Realtime PCR)检测FN,Col-I,Smad2/3 mRNA表达。结果:模型组FN,Col-I,Smad2/3蛋白和基因的表达明显增加,大黄素含药血清组能抑制NRK-49F细胞增殖,且抑制FN,Col-I,Smad2/3蛋白和的表达(P 0. 05)。大黄素浓度越高,抑制作用越明显,成一定的量效关系。结论:大黄素干预后,可改善肾纤维化程度,保护NRK-49F细胞模型损伤。