足细胞病与相关循环因子的表达

肾小球足细胞的损伤不仅是遗传性肾小球病的发病基础,还在很多后天的肾小球疾病中发挥重要作用。常见的足细胞病以微小病变性肾病(Minimal Change Disease,MCD)和局灶阶段性肾小管硬化(Focal Segmental glomerulosclerosis,FSGS)为主,有实验证明,足细胞损伤同时参与了各种不同类型的肾小球疾病,比如糖尿病肾病,HIV相关肾病,膜性肾病及其他获得性肾小球病等,因此,了解足细胞病损伤的机制尤为重要。临床观察提出局灶节段行肾小球硬化患者体内可能存在一种与大量蛋白尿发生有关的循环因子,相关的动物实验和体外观察同时也证实了循环因子的存在。越来越多的研究支持T细胞功能不全,细胞因子异常释放可能是循环因子的来源之一。如果能对患者循环因子进行检测,借助它来指导治疗方案的选择(免疫抑制剂、血浆置换),可能成为局灶节段行肾小球硬化诊断和治疗中的一个突破。本文以国内外研究文献为基础,对文献资料进行分析、归纳和总结,综述了足细胞病中相关循环因子的表达,探讨足细胞病发生及复发的机理,为足细胞病的定向治疗提供帮助。     

Mechanisms underlying modulation of podocyte TRPC6 channels by suPAR: Role of NADPH oxidases and Src family tyrosine kinases

The soluble urokinase receptor (suPAR) has been implicated in the pathogenesis of chronic kidney diseases (CKD) and may function as a circulating “permeability factor” driving primary focal and segmental glomerulosclerosis (FSGS). Here we examined the mechanisms whereby suPAR causes mobilization and increased activation of Ca²⁺-permeable TRPC6 channels, which are also implicated in FSGS. Treatment of immortalized mouse podocytes with recombinant suPAR for 24?h caused a marked increase in cytosolic reactive oxygen species (ROS) that required signaling through integrins. This effect was associated with increased assembly of active cell surface NADPH oxidase 2 (Nox2) complexes and was blocked by the Nox2 inhibitor apoycynin. Treatment with suPAR also evoked a functionally measurable increase in TRPC6 channels that was blocked by concurrent treatment with the ROS-quencher TEMPOL as well as by inhibition of Rac1, an essential component of active Nox2 complexes. Elevated ROS evoked by exposing cells to suPAR or H₂O₂ caused a marked increase in the abundance of tyrosine-phosphorylated proteins including Src, and suPAR-evoked Src activation was blocked by TEMPOL. Moreover, mobilization and increased activation of TRPC6 by suPAR or H₂O₂ was blocked by concurrent exposure to PP2, an inhibitor of Src family tyrosine kinases. These data suggest that suPAR induces oxidative stress in podocytes that in turn drives signaling through Src family kinases to upregulate TRPC6 channels. The combination of oxidative stress and altered Ca²⁺ signaling may contribute to loss of podocytes and progression of various forms of CKD.     

老年慢性心力衰竭患者血清sST2、CTGF、suPAR与心功能的关系及其联合检测对心血管事件的预测价值

摘要 目的：探讨老年慢性心力衰竭（CHF）患者血清可溶性肿瘤生成抑制因子2（sST2）、可溶性尿激酶纤溶酶原激活物受体（suPAR）、结缔组织生长因子（CTGF）与心功能的关系及其联合检测对心血管事件（CVE）的预测价值。方法：选取2019年1月～2022年1月我院收治的150例老年CHF患者（CHF组）,其中纽约心脏病协会（NYHA）分级Ⅱ级49例、Ⅲ级72例、Ⅳ级29例,根据随访6个月是否发生CVE分为CVE组（n=34）和非CVE组（n=116）,另选取同期在我院进行体检的110例健康体检志愿者作为对照组。通过超声心动图检查左室收缩末期内径（LVESD）、左室射血分数（LVEF）、左心室舒张末期内径（LVEDD）,酶联免疫吸附试验法检测血清sST2、CTGF、suPAR水平。多因素Logistic回归分析老年CHF患者发生CVE的影响因素,Pearson或Spearman相关性分析老年CHF患者血清sST2、CTGF、suPAR水平与超声心功能指标和NYHA分级的相关性,受试者工作特征（ROC）曲线分析血清sST2、CTGF、suPAR对老年CHF患者发生CVE的预测价值。结果：CHF组血清sST2、CTGF、suPAR水平和LVESD、LVEDD高于对照组,LVEF低于对照组（P＜0.05）。NYHA分级Ⅱ级、Ⅲ级、Ⅳ级老年CHF患者血清sST2、CTGF、suPAR水平均依次升高（P＜0.05）。 老年CHF患者血清sST2、CTGF、suPAR水平与LVEF呈负相关,与LVESD、LVEDD、NYHA分级呈正相关（P均＜0.05）。NYHA分级≥Ⅲ级（OR=2.318）、N末端B型钠尿肽前体（NT-proBNP）升高（OR=1.104）、sST2升高（OR=1.641）、CTGF升高（OR=1.644）、suPAR升高（OR=1.892）为老年CHF患者CVE发生的独立危险因素,LVEF升高（OR=0.839）为其独立保护因素,差异均有统计学意义（P＜0.05）。血清sST2、CTGF、suPAR单独与联合预测老年CHF患者发生CVE的曲线下面积分别为0.788、0.782、0.771、0.936。结论：老年CHF患者血清sST2、CTGF、suPAR水平升高与心功能异常和CVE发生密切相关,联合检测血清sST2、CTGF、suPAR水平对老年CHF患者发生CVE的预测价值较高。     

血清Copeptin、suPAR、SIRT1与慢性心力衰竭患者心功能及短期预后的关系研究

摘要 目的：研究血清和肽素（Copeptin）、可溶性尿激酶型纤溶酶原激活物受体（suPAR）、沉默信息调节因子2相关酶1（SIRT1）与慢性心力衰竭（CHF）患者心功能及短期预后的关系。方法：选取我院2018年2月～2020年2月收治的175例CHF患者,将其按照美国纽约心功能（NYHA）分级的差异分作Ⅱ级组56例,Ⅲ级组62例,Ⅳ级组57例。另取我院同期健康体检人员50例作为对照组。比较各组血清Copeptin、suPAR、SIRT1水平及心功能指标,并进行相关性分析。此外,对所有CHF患者进行为期1年的随访,按照预后差异分作预后不良组61例及预后良好组114例。以单因素、多因素Logistic回归分析CHF患者预后的影响因素。结果：与对照组相比,CHF患者的血清Copeptin、suPAR水平及左心室舒张末期内径（LVEDD）升高,而SIRT1水平及左心室射血分数（LVEF）降低（P＜0.05）;不同心功能等级的CHF患者间比较,随着心衰程度的加重,血清Copeptin、suPAR水平及LVEDD升高,而SIRT1水平及LVEF降低（P＜0.05）。Pearson相关性分析结果显示,CHF患者血清Copeptin、suPAR水平与LVEDD均呈正相关,而与LVEF呈负相关（P＜0.05）;血清SIRT1水平与LVEDD呈负相关,而与LVEF呈正相关（P＜0.05）。单因素分析结果显示,预后不良组年龄、LVEDD、血清Copeptin、suPAR水平均高于预后良好组,而LVEF和SIRT1水平低于预后良好组（P＜0.05）。多因素Logistic回归分析结果显示,年龄偏大、LVEDD偏高、LVEF偏低、血清Copeptin、suPAR水平过高以及血清SIRT1水平过低均是CHF患者短期预后不良的危险因素（P＜0.05）。结论：血清Copeptin、suPAR、SIRT1与CHF患者的心功能及短期预后密切相关。     

无创正压通气治疗重症社区获得性肺炎临床疗效和预后影响

摘要 目的：考察无创正压机械通气(noninvasive positive-presure ventilation,NIPPV)对重症社区获得性肺炎(Severe community acquired Pneumonia,SCAP)的治疗效果和预后的影响。方法：以2018年7月-2020年2月我院收治的80例SCAP患者为研究对象,采用随机数字法分为无创组和常规组,各40例。两组患者均在在入院后均接受常规治疗,无创组在常规治疗的基础上进行NIPPV治疗。详细记录患者治疗前和治疗后1 h、24 h的体温、呼吸、血压、心率、血二氧化碳分压(arterial partial pressure of CO₂,PaCO₂)、氧合指数(PaO₂/FIO₂)、气管插管率、病死率、ICU住院天数,对患者入院的第1、3、7 d的血清可溶性尿激酶型纤溶酶原激活物受体(soluble urokinase-plasminogen activator receptor,suPAR)、降钙素原(procalcitonin,PCT)及C反应蛋白(C-reactive protein,CRP)的水平进行检测。结果：治疗后1 h和24 h,无创组患者呼吸、心率、PaCO₂、PaO₂/FIO₂和PH均显著的改善（P＜0.05）,显示NIPPV可明显改善患者肺部气体交换,减慢呼吸频率、提高氧和指数,降低二氧化碳分压;第1 d两组患者的PCT、CRP和suPAR的水平无明显差异（P＞0.05）,相对于第1 d,两组患者第3 d和第7 d的PCT、CRP和suPAR水平均明显的降低（P＜0.05）;相对于常规组,第3 d和第7 d无创组患者的PCT、CRP和suPAR水平有显著的降低（P＜0.05）;与常规组相比,无创组患者的插管率、ICU住院天数和死亡率统计学上无显著差异（P＞0.05）,但均有一定程度上的降低。结论：NIPPV能显著改善SCAP患者的呼气情况,降低血清PCT、CRP和suPAR水平,对降低气管插管率、缩短ICU住院天数,降低患者死亡率有一定的效果。     

重症肺炎患儿suPAR水平对比分析及与影像学表现的相关性

摘要 目的：探讨重症肺炎患儿可溶性尿激酶型纤溶酶原激活物受体（soluble urokinase-type plasminogen activator receptor,suPAR）水平并对比分析及与影像学表现的相关性。方法：选取贵阳市第二人民医院及贵阳市儿童医院2020年1月到2020年12月共收治的70例肺炎患儿作为研究对象,其中重症肺炎患儿35例,男22例、女13例,将其分为重症组,轻症肺炎患儿35例,男20例、女15例,将其分为轻症组。对比两组患儿的suPAR水平、心肌酶水平以及肺部影像学结果,了解suPAR在重症肺炎中是否具有敏感性及特异性,并分析重症肺炎suPAR水平与心肌酶、肺部影像学结果是否存在相关性。结果：重症组suPAR水平较轻症组明显升高,差异具有统计学意义（P＜0.05）,重症组患儿肌酸激酶同工酶（creatine kinase isoenzymes-MB,CK-MB）、肌酸激酶（creatine kinase,CK）、乳酸脱氢酶（lactate dehydrogenase,LDH）、谷草转氨酶（Aspartate aminotransferase,AST）心肌酶相关指标明显高于轻症组,差异具有显著性（P＜0.05）;两组患儿密度增高影、带片絮状影、节段性实变、斑片状影人数对比无明显差异（P＞0.05）,两组患儿肺不张、大片状影、双肺纹增多人数对比差异显著（P＜0.05）;suPAR水平与CK-MB、CK、LDH、AST以及影像学特征呈正相关（P＜0.05）。血清suPAR水平对重症肺炎病情危重程度ROC的AUC为0.897（95%CI：0.819~0.975）,最佳cutoff值为1.9 ng/mL,此时特异度、灵敏度为82.86 %、85.71 %。结论：重症肺炎组suPAR的值与心肌酶呈正相关;suPAR水平与影像学表现具有相关性;suPAR水平越高提示病情越危重,在重症肺炎评估中其敏感性及特异性增高。     

Novel protein interactors of urokinase-type plasminogen activator receptor

The urokinase-type plasminogen activator receptor (uPAR) has been implicated in tumor growth and metastasis. The crystal structure of uPAR revealed that the external surface is largely free to interact with a number of proteins. Additionally, due to absence of an intracellular cytoplasmic protein domain, many of the biological functions of uPAR necessitate interactions with other proteins. Here, we used yeast two-hybrid screening of breast cancer cDNA library to identify hSpry1 and HAX1 proteins as putative candidate proteins that interact with uPAR bait constructs. Interaction between these two candidates and uPAR was confirmed by GST-pull down, co-immunoprecipitation assays and confocal microscopy. These novel interactions that have been identified may also provide further evidence that uPAR can interact with a number of other proteins which may influence a range of biological functions.     

Soluble urokinase plasminogen activator receptor informs on the progression course after multiple injuries

Purpose: The purpose of this study is to study the use of soluble urokinase plasminogen activator receptor (suPAR) for the prognosis of multiple organ dysfunction (MOF) after multiple traumas.

Methods: Serum suPAR was measured within the first 24?h after multiple injuries in 85 patients. Measurements were repeated after 4 d or at sepsis onset.

Results: Odds ratio for trauma-associated MOF was 4.09 (p: 0.026) with admission suPAR greater than 8?ng/ml. More than 40% increases of suPAR were associated with odds ratio 9.33 (p: 0.047) for severe sepsis.

Conclusions: suPAR is a useful surrogate biomarker for development of MOF and severe sepsis after multiple traumas.     

Multi-biomarker analysis in patients after transcatheter aortic valve implantation (TAVI)

Abstract

Background: In this study we sought to examine whether transcatheter aortic valve implantation (TAVI) is followed by a change in the plasma levels of novel cardiovascular biomarkers.

Methods: We collected blood samples of 79 patients with severe aortic valve stenosis undergoing TAVI before and at 7 days, 1 month, 3 months and 6 months post TAVI and analyzed the plasma concentrations of GDF-15, H-FABP, fetuin-A, galectin 3, sST2 and suPAR by means of ELISA.

Results: There was a significant increase in the concentration of fetuin-A (median: 52.44 mg/ml to 113.2 mg/ml, p?<?0.001) and a significant decrease of H–FABP after TAVI (median: 4.835 ng/ml to 2.534 ng/ml, p?<?0.001). The concentrations of suPAR and sST2 showed an initial increase (suPAR median: 2755 pg/ml 3489 pg/ml, p?<?0.001; sST2 median: 5832 pg/ml to 7137 pq/ml, p?<?0.001) and subsequently decreased significantly.

Conclusion: We hypothesize that the decrease of H-FABP and the increase of fetuin-A could be due to a hemodynamic improvement after valve replacement. The initial increase of suPAR could indicate an inflammatory stimulus and the significant increase in sST2 could be due to the mechanical strain caused by implantation of the valve.     

An anti-urokinase plasminogen activator receptor (uPAR) antibody: crystal structure and binding epitope

Human urokinase-type plasminogen activator receptor (uPAR/CD87) is expressed at the invasive interface of the tumor-stromal microenvironment in many human cancers and interacts with a wide array of extracellular molecules. An anti-uPAR antibody (ATN615) was prepared using hybridoma technology. This antibody binds to uPAR in vitro with high affinity (K(d) approximately 1 nM) and does not interfere with uPA binding to uPAR. Here we report the crystal structure of the Fab fragment of ATN615 at 1.77 A and the analysis of ATN615-suPAR-ATF structure that was previously determined, emphasizing the ATN615-suPAR interaction. The complementarity determining regions (CDRs) of ATN615 consist of a high percentage of aromatic residues, and form a relatively flat and undulating surface. The ATN615 Fab fragment recognizes domain 3 of suPAR. The antibody-antigen recognition involves 11 suPAR residues and 12 Fab residues from five CDRs. Structural data suggest that Pro188, Asn190, Gly191, and Arg192 residues of uPAR are the key residues for the antibody recognition, while Pro189 and Arg192 render specificity of ATN615 for human uPAR. Interestingly, this antibody-antigen interface has a small contact area, mainly polar interaction with little hydrophobic character, yet has high binding strength. Furthermore, several solvent molecules (assigned as polyethylene glycols) were clearly visible in the binding interface between antibody and antigen, suggesting that solvent molecules may be important for the maximal binding between suPAR and ATN615 Fab. ATN615 undergoes small but noticeable changes in its CDR region upon antigen binding.