尿液可溶性CD163对IgA肾病临床预后的预测价值研究

目的探讨尿液可溶性巨噬细胞生物标志物CD163（sCD163）对IgA肾病（IgAN）临床预后的预测价值。方法选取原发性IgAN患者78例,均行肾脏穿刺病理检查,检测尿液sCD163水平。根据病理检查肾小球中新月体的百分比将患者分为C0组（无新月体形成）、C1组（新月体百分比＜25%）、C2组（新月体百分比≥25%）,比较3组患者尿液sCD163水平;分析尿液sCD163水平与肾脏穿刺时的平均动脉压（MAP）、尿蛋白肌酐比、血肌酐、估算的肾小球滤过率（eGFR）及肾小球新月体百分比的相关性;以尿液sCD163水平＜1.03为尿液sCD163低水平组,尿液sCD163水平≥1.03为尿液sCD163高水平组,比较两组患者临床预后情况。结果C2组患者尿液sCD163水平高于C0、C1组患者（5.67±7.49vs0.69±0.76、0.57±0.67,均P＜0.05）。尿液sCD163水平与尿蛋白肌酐比、血肌酐、肾小球新月体百分比呈正相关（r=0.787、0.271、0.217,均P＜0.05）,与eGFR呈负相关（r=-0.299,P＜0.05）。尿液sCD163高水平组患者的肾脏生存率低于低水平组患者（84.35%vs98.18%,P＜0.05）。结论尿液sCD163可作为预测IgAN临床预后的一项无创性生物标志物。IgAN患者高尿液sCD163提示预后不良。     

赖型钩端螺旋体Loa22重组质粒的蛋白表达和对巨噬细胞的毒性作用

目的对赖型钩端螺旋体Loa22基因进行表达和功能研究。方法构建赖型钩端螺旋体Loa22成熟肽重组质粒,经异丙基-β-D-硫代半乳糖苷(IPTG)对重组质粒进行蛋白诱导表达,SDS-PAGE和Western Blotting检测目标蛋白表达情况。经亲和层析获得目标蛋白并作用于小鼠巨噬细胞ANA-1,检测细胞上清液中乳酸脱氢酶(LDH)活力、四氮唑复合物(XTT)吸光度值和细胞凋亡率以评价其细胞毒性。结果成功构建Loa22成熟肽原核表达质粒,通过鉴定并纯化得到Loa22成熟肽,该蛋白使培养ANA-1细胞上清液中LDH活力升高,XTT吸光度值下降,细胞凋亡率增加。结论Loa22对ANA-1具有明显的毒性效性,该基因可能是致病钩体的一个重要毒力相关基因。     

高迁移率族蛋白B1诱导小鼠腹腔巨噬细胞凋亡的受体机制

目的 了解高迁移率族蛋白B1(HMGB1)对小鼠腹腔巨噬细胞凋亡的影响及其受体机制.方法 分离培养小鼠腹腔巨噬细胞,在巨噬细胞中加入不同的刺激物,分为HMGB1组:加入10 μg/ml的HMGB1;HMGB1+抗晚期糖基化终末产物受体(RAGE)组:先加入RAGE多克隆抗体5μg/ml孵育2 h后,再加入HMGB1;HMGB1+重组鼠(rm)RAGE/Fc组:将10 μg/ml的HMGB1与10μg/ml的rmRAGE/Fc混合作用2 h后,再加入巨噬细胞;对照组:加入磷酸盐缓冲液.采用流式细胞仪检测细胞表面RAGE的表达强度.激光共聚焦显微镜观察细胞凋亡情况,流式细胞仪检测细胞凋亡率.结果 HMGB1组RAGE阳性细胞率(54±12)%明显高于对照组[(13±5)%,P＜0.01],其荧光强度(126±10)也显著高于对照组(34±8,P＜0.01).HMGB1+rmRAGE/Fc组、HMGB1+抗RAGE组凋亡细胞明显多于对照组,而HMGB1组晚期凋亡及坏死细胞明显多于其他3组.HMGB1组细胞凋亡率(39.5±2.3)%高于HMGB1+rmRAGE/Fc组[(17.3±3.6)%]、HMGB1+抗RAGE组[(14.8±4.8)%]及对照组[(5.4±2.3)%,P＜0.01].结论 HMGB1可诱导RAGE表达上调,RAGE是HMGB1诱导巨噬细胞凋亡的主要受体之一.     

Anti-atherosclerotic action of GW9508 – Free fatty acid receptors activator – In apoE-knockout mice

BackgroundIn the past two decades, enhanced understanding of the biology of G-protein-coupled receptors (GPRs) has led to the identification of several such receptors as novel targets for free fatty acids (FFAs). Two GPRs, FFAR1 and FFAR4, have received special attention in the context of chronic inflammatory diseases, thanks to their anti-inflammatory activities.MethodsThe present study investigates the influence of prolonged treatment with GW9508 – agonist of FFAR1 and FFAR4 – on the development of atherosclerosis plaque in apoE-knockout mice, using morphometric and molecular methods.ResultsGW9508 administration has led to the reduction of atheroscletoric plaque size in an apoE-knockout mice model. Moreover, a FFAR1/FFAR4 agonist reduced the content of macrophages by almost 20%, attributed by immunohistochemical phenotyping to the pro-inflammatory M1-like activation state macrophages.ConclusionsProlonged administration of GW9508 resulted in significant amelioration of atherogenesis, providing evidence that the strategy based on macrophage phenotype switching toward an M2-like activation state via stimulation of FFAR1/FFAR4 receptors holds promise for a new approach to the prevention or treatment of atherosclerosis.     

Outer membrane protein A (OmpA) from Shigella flexneri 2a: A promising subunit vaccine candidate

Shigellosis is the leading cause of childhood mortality and morbidity. Despite many years of extensive research a practical vaccine is not yet available against the disease. Recent studies illustrate that bacterial outer membrane proteins are budding target as vaccine antigen. Outer membrane proteins A (OmpA) are among the most immunodominant antigens in the outer membrane of gram negative bacteria and possess many characteristics desired of a vaccine candidate. We observe that OmpA of Shigella flexneri 2a is crossreactive and common antigen among Shigella spp. and the epitope is widely exposed on the cell surface as well as capable of evoking protective immunity in mice. The protective immunity involves participation of both the humoral and cellular immune responses, since OmpA boosts rapid induction of IgG and IgA in both the systemic and mucosal compartments and also activates Th1 cells. The immunopotentiating activity of OmpA is mediated by its ability to bind and stimulate macrophages and up-regulate the surface expression of MHCII, CD80 and CD40, leading to activation of CD4⁺ T cells to secrete cytokines and express chemokine receptor and IL-12Rβ2, thereby orchestrating the bridge between innate and adaptive immune responses. This ability is dependent on Toll-like receptor 2 (TLR2), as demonstrated by lack of response by TLR2 knockdown macrophages to OmpA. Hence this property of OmpA to link innate and adaptive immunity via TLR2 offers a novel vista to develop vaccine against shigellosis.     

Silymarin Inhibits Morphological Changes in LPS-Stimulated Macrophages by Blocking NF-κB Pathway

The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-κB), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-κB inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-κB activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-κB in mediating inflammatory responses in macrophages.     

One-hit wonder: Late after burn injury,granulocytes can clear one bacterial infection but cannot control a subsequent infection

ObjectiveBurn injury induces an acute hyperactive immune response followed by a chronic immune dysregulation that leaves those afflicted susceptible to multiple secondary infections. Many murine models are able to recapitulate the acute immune response to burn injury, yet few models are able to recapitulate long-term immune suppression and thus chronic susceptibility to bacterial infections seen in burn patients. This has hindered the field, making evaluation of the mechanisms responsible for these susceptibilities difficult to study. Herein we describe a novel mouse model of burn injury that promotes chronic immune suppression allowing for susceptibility to primary and secondary infections and thus allows for the evaluation of associated mechanisms.MethodsC57Bl/6 mice receiving a full-thickness contact burn were infected with Pseudomonas aeruginosa 14 days (primary infection) and/or 17 days (secondary infection) after burn or sham injury. The survival, pulmonary and systemic bacterial load as well as frequency and function of innate immune cells (neutrophils and macrophages) were evaluated.ResultsFollowing secondary infection, burn mice were less effective in clearance of bacteria compared to sham injured or burn mice following a primary infection. Following secondary infection both neutrophils and macrophages recruited to the airways exhibited reduced production of anti-bacterial reactive oxygen and nitrogen species and the pro-inflammatory cytokineIL-12 while macrophages demonstrated increased expression of the anti-inflammatory cytokine interleukin-10 compared to those from sham burned mice and/or burn mice receiving a primary infection. In addition the BALF from these mice contained significantly higher level so of the anti-inflammatory cytokine IL-4 compared to those from sham burned mice and/or burn mice receiving a primary infection.ConclusionsBurn-mediated protection from infection is transient, with a secondary infection inducing immune protection to collapse. Repeated infection leads to increased neutrophil and macrophage numbers in the lungs late after burn injury, with diminished innate immune cell function and an increased anti-inflammatory cytokine environment.     

Human apolipoprotein A-I Gly26Arg stimulation of inflammatory responses via NF-kB activation: Potential roles in amyloidosis?

The cascade of molecular events leading to Human apolipoprotein A–I (apoA–I) amyloidosis is not completely understood, not even the pathways that determine clinical manifestations associated to systemic protein deposition in organs such as liver, kidney and heart. About twenty natural variants of apoA–I were described as inducing amyloidosis, but the mechanisms driving their aggregation and deposition are still unclear. We previously identified that the mutant Gly26Arg but not Lys107-0 induced the release of cytokines and reactive oxygen species from cultured RAW 264.7 murine macrophages, suggesting that part of the pathogenic pathway could elicit of an inflammatory signal. In this work we gained deep insight into this mechanism and determined that Gly26Arg induced a specific pro-inflammatory cascade involving activation of NF-κB and its translocation into the nucleus. These findings suggest that some but not all apoA–I natural variants might promote a pro-oxidant microenvironment which could in turn result in oxidative processing of the variants into a misfolded conformation.     

Correlation between Profile of Circulating Mononuclear Cells and Clinical Manifestations in Patients with Pemphigus Vulgaris

Phenotypes of 38 samples of mononuclear (PBMC) cells from 11 different patients with pemphigus vulgaris (PV) at different stages of the disease were explored looking for a possible relationship between cell immunity, mucocutaneous or mucosal lesion intensity and capacity of serum autoantibodies to elicit the disease in mice. PBMC from 5 patients with mucocutaneous lesions and sera with IgG capable of inducing the disease in neonatal mice had a high proportion of mature monocytes with CD14^lowDR ^gh and co-expresing CD16 and CDllb. In addition, a high proportion of CD19⁺CD5⁺ activated B cells and a very low proportion of naive CD4⁺CD45RA⁺ and CD8⁺CDllb⁺ T lymphocytes was observed. Monocytes from these patients expressed inducible nitric oxide synthase (iNOS). In contrast, PBMC from 6 patients, with lesions restricted to mucosal membranes and IgG lacking the capacity to induce the disease in mice, contained a high proportion of CD14^hlg DR^low co-expressing CD16 circulating macrophages, CD8⁺CDllb⁺ T cells, and a low proportion of activated B lymphocytes. The results suggest a possible association between proportion of different antigen presenting cells (monocytes with high HLA-DR and low CD 14 expression and activated B lymphocytes, or differentiated monocytes/macrophages), type of PV and capacity of serum autoantibodies to elicit the disease in mice