Galactosylation of N- and O-linked carbohydrate moieties of IgA1 and IgG in IgA nephropathy

The mechanism of IgA deposition in the kidneys in IgA nephropathy is unknown, Mesangial IgA is of the IgA I subclass, and since no consistent antigenic target for the IgA I has been described, we have investigated the glycosylation of the molecule, as a potential non-immunological abnormality which may contribute to its deposition. IgA 1 is rich in carbohydrate, carrying N-linked moieties in common with IgG, but also O-linked sugars, which are rare in serum proteins, and not expressed by IgG or lgA2, Lectin binding assays were designed to examine the expression of terminal galactose on the N-linked carbohydrate chains of purified serum IgG and IgAI, and the O-linked sugars of IgAI and C1 inhibitor (one of the very few other serum proteins with O-linked glycosylation). No evidence was found for abnormalities of N-linked glycosylation of either isotype in IgA nephropathy compared with matched controls. However, in IgA nephropathy, reduced terminal galactosylation of the hinge region O-linked moieties was demonstrated; this was not seen in C1 inhibitor, which showed normal or increased galactosylation of the O-linked sugars. This abnormality of IgA1 has considerable implications for the pathogenesis of IgA nephropathy, since the O-linked sugars lie in an important functional location within the IgA1 molecule, close to the ligand of Fc receptors. Changes in the carbohydrates in this site may therefore affect interactions with receptors and extracellular proteins, leading to anomalous handling of the IgA1 protein in this condition, including failure of normal clearance mechanisms, and mesangial deposition.     

Altered synthesis of interferon-γ and expression of interferon-γ receptor by peripheral blood mononuclear cells from patients with IgA nephropathy and non-IgA proliferative glomerulonephritis

Previously we reported disease-specific interaction between interferon- (IFN-) and interleukin-4 (IL-4) in patients with IgA nephropathy (IgAN), suggesting the existence of unusual T cell behavior in this disease. In the present study, we investigated characteristic synthesis of interferon- (IFN-) and expression of IFN- receptor (IFN-R) in the peripheral blood mononuclear cells (PBMC) from patients with IgAN and other chronic proliferative glomerulonephritis (PGN). Heparinized peripheral blood samples were obtained from 38 patients with chronic mesangial proliferative glomerulonephritis (CGN; including 24 with IgA nephropathy) and 20 healthy controls. PBMC were isolated by gradient centrifugation and fragments were cultured in Iscove's modified Dulbecco's medium (IMDM) supplemented with 10% fetal calf serum (FCS) for 72 hr. IFN- concentrations in supernatants were evaluated by the enzyme-linked immunosorbent assay (ELISA). Other parts of PBMC pellets were reacted with anti-human IFN-R monoclonal antibody and FITC-labeled anti-mouse second antibody for analysis of IFN-R expression on these cells by FACScan. The remaining PBMC were fractionated into CD4⁺ T cells, CD8⁺ T cells, B cells, NK, cells and macrophages using the MACS cell sorting system. The isolated cells were evaluated for IFN- or IFN-R mRNA expression by the semiquantitative RT-PCR method.In vitro IFN- synthesis was enhanced in patients with CGN, and NK cells were revealed to be responsible for such enhancement. On the other hand, the expression of IFN-R on macrophages was suppressed in CGN patients. These results suggest that impairment of regulation of the IFN- system might be involved in the development of CGN.     

慢性肾病患者细胞因子测定的临床意义

目的：探讨了慢性肾病患者血清IL-6、IL-8、IL-10和IL-18水平的变化及意义。方法：分别应用放射免疫分析和酶联法对32例慢性肾病患者进行了血清IL-6、IL-8、IL-10和IL-18测定,并与35名正常健康人作比较。结果：慢性肾病患者血清IL-6、IL-8、IL-10和IL-18水平显著地高于正常人组（P〈0.01）,经治疗6个月后与正常人组比较仍有差异（P〈0.05）。结论：检测慢性肾病患者血清IL-6、IL-8、IL-10和IL-18水平的变化对疾病的预后观察具有重要的临床价值。     

Aberrant T-regulation in rheumatoid arthritis and IgA nephropathy affects CD5+ and CD5- B lymphocytes equally.

T-suppressor function and T-helper function in healthy adults, elderly patients with non-immune diseases, and patients with rheumatoid arthritis (RA) and IgA nephropathy (IgAN) were titrated by adding graded concentrations of CD8+ cells to autologous CD8-depleted peripheral blood mononuclear cells (PBMC), or CD4+ cells to CD8- 4- PBMC, respectively. Following culture with pokeweed mitogen (PWM), numbers of CD5+ and CD5- immunoglobulin-secreting cells were determined using a combination of rosetting with anti-CD5-coated Dynabeads and reverse haemolytic plaque formation (Jones, 1990). Of 11 RA patients studied, eight had slightly reduced suppressor activity for CD5+ and CD5- IgM-secreting cells, and three with active disease and high serum levels of C-reactive protein, could not suppress IgG, IgA or IgM secretion by either B subset. Helper activity for both CD5+ and CD5- B cells was slightly but significantly increased in RA patients. One of eight patients with IgAN could not suppress IgG, IgA or IgM production by CD5+ or CD5- B cells, and all IgAN patients required strikingly fewer CD4+ cells for PWM-induced activation of CD5+ and CD5- B cells than controls. It was concluded that in two immunologically mediated diseases in which some patients have raised numbers of circulating CD5+ B cells, aberrant T-regulation affects CD5+ and conventional CD5- B cells equally.     

川芎嗪、山莨菪碱、蝮蛇抗栓酶及卡托普利对糖尿病大鼠肾脏的保护作用

目的　探讨川芎嗪、山莨菪碱、蝮蛇抗栓酶及卡托普利对实验大鼠糖尿病肾病 (DN)的预防作用。方法　SD大鼠 6 0只 ,分为正常对照组、糖尿病组及各糖尿病治疗组。以四氧嘧啶腹腔内注射制成糖尿病模型。各治疗组分别给予上述药物治疗 ,每周 5次 ,共 14周。取肾脏行光镜和电镜检查 ,并进行图像分析 ,同时测定蛋白糖基化产物 (GP)。结果　与糖尿病组比较 ,各治疗组肾组织中水平明显降低 (P <0 .0 1) ;除蝮蛇抗栓酶组外 ,其他治疗组大鼠肾小球截面积亦明显缩小 (P <0 .0 5 ) ;糖尿病组大鼠肾小球基底膜显著不均匀增厚 ,而各治疗组病变较轻 ,尤以卡托普利组疗效最为明显。结论　改善微循环、血液流变学及血流动力学治疗可减慢实验大鼠DN的进展。     

细胞凋亡在阿霉素大鼠肾病模型中的作用

目的：探讨细胞凋亡在阿霉素肾病中的作用及其机制。方法：将30只体重250－300g的Wistar雄性大白鼠随机分为3组,给模型组和SOD组一次性尾静脉注射阿霉素7．0mg/kg,SOD组于注射阿霉素30min后,每天尾静脉注射超氧化物歧化酶（SOD)1．8mg/kg,对照组注射等量生理盐水,于实验第7天,第14天,第28天分别用代谢笼留取24h尿液,测定尿蛋白,第28天末处死动物,取贤皮质做常规病理检查,电镜检查,并用原位末端标记法检测肾小球,肾小管细胞凋亡情况,肾皮质匀浆丙二醛（MDA）及谷胱甘肽过氧化物酶（GSH－Px)水平分别用硫代巴比妥酸比色法,还原型谷胱甘肽消耗法测定。结果：模型组肾小球,肾小管细胞凋亡数及肾皮质MDA水平明显高于对照组（P＜0．01）,GSH－Px水平则明显低于对照组（P＜0．01）,SOD组肾小球,肾小管,细胞凋亡数及肾皮质MDA水平明显低于模型组（P＜0．01）,GSH－Px水平则明显高于模型组（P＜0．01）,结论：阿霉素肾病鼠发病与病鼠肾小球,肾小管细胞亡有密切关系,而病鼠肾小球,肾小管细胞凋亡与氧自由基（OFR）有关。     

血管紧张素转换酶基因多态性对苯那普利治疗糖尿病肾病疗效的影响

按照血管紧张素转换酶 (ACE)基因插入 /缺失多态性不同 ,将 92例 2型糖尿病肾病患者分为II型组 31例 ,ID型组 30例及DD型组 31例。用苯那普利治疗 6个月后 ,观察治疗前后各组的尿白蛋白排泄率 (UAER)、平均动脉压 (MABP)、肌酐清除率 (Ccr)及ACE的变化。结果 :苯那普利治疗后 3组UAER、MABP、ACE均下降 ,以II型组下降幅度最大 (分别为 58.6%、2 .87kPa和 72 .3% ) ,DD型组下降幅度最小 (P <0 .0 5) ;而Ccr在DD型组下降幅度最大 ,II型组下降幅度最小 (P <0 .0 5) ;多元线性逐步回归分析显示 :ACE基因型对UAER下降率有显著回归效果(R2 =0 .72 ,P <0 .0 0 1 )。提示 :ACE基因型影响血管紧张素转换酶抑制剂 (ACEI)对糖尿病肾病的疗效 ,II基因型患者对ACEI治疗更为敏感。     

Tacrolimus versus cyclophosphamide for patients with idiopathic membranous nephropathy and treated with steroids: a systematic review and meta-analysis of randomized controlled trials

BackgroundThe therapeutic effects of tacrolimus (TAC) versus cyclophosphamide (CTX) were not fully illustrated for patients with idiopathic membranous nephropathy (IMN).MethodsThe PubMed, EmBase, Cochrane library, and CNKI were systematically searched throughout March 2020 for randomized controlled trials evaluating the therapeutic effects of TAC versus CTX for IMN patients treated with steroids. The pooled relative risks (RRs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using the random-effects model.ResultsTwelve trials recruited a total of 868 IMN patients were identified and contained in final meta-analysis. Patients in TAC group was associated with an increased incidence of overall remission (12 trials: 868 patients; RR: 1.21; 95% CI: 1.11–1.31; p < 0.001) and complete remission (12 trials: 868 patients; RR: 1.50; 95% CI: 1.25–1.80; p < 0.001). Moreover, we noted TAC therapy significantly reduced urinary protein excretion (9 trials: 567 patients; WMD: −1.06; 95%CI: −1.41 to −0.71; p < 0.001), and increased serum albumin (9 trials: 567 patients; WMD: 5.37; 95%CI: 2.97 to 7.77; p < 0.001) than CTX therapy. Furthermore, no significant difference between TAC and CTX for serum creatinine was detected (6 trials: 378 patients; WMD: 0.15; 95%CI: −3.46 to 3.75; p = 0.936). Finally, the risk of alopecia (p = 0.008), infection (p = 0.045), leukocytosis (p = 0.002), and elevated ALT/AST (p = 0.011) in TAC group was significantly lower than CTX group, whereas TAC was associated with an increased risk of tremor than CTX (p = 0.010).ConclusionsThis study found IMN patients treated with TAC combined with steroids provides a better therapeutic effect and less adverse events than those treated with CTX combined with steroids, with moderate-certainty evidence.     

膜肾1号方对大鼠肾脏病理及PI3K/Akt/mTOR信号通路表达的影响

[目的] 观察膜肾1号方对膜性肾病大鼠肾脏病理的改善作用及其对自噬通路磷脂肌醇3-激酶（PI3K）/蛋白激酶B（AKT）/雷帕霉素靶蛋白（mTOR）相关蛋白表达的影响。[方法] 将大鼠随机分为对照组、模型组、膜肾1号方高剂量组、中剂量组、低剂量组,盐酸贝那普利组。采用大鼠尾静脉注射阳离子化牛血清白蛋白（C-BSA）的方法建立MN大鼠模型,灌胃、取材。苏木精-伊红（HE ）染色法观察大鼠肾脏组织病理改变;免疫球蛋白G（IgG）免疫荧光染色观察大鼠IgG沉积;蛋白免疫印迹法（Western Blot）检测PI3K/Akt/mTOR 信号通路相关蛋白及自噬相关蛋白轻链3（LC3）表达。[结果] 药物干预后,膜肾1号方组大鼠24 h尿蛋白、三酰甘油、总胆固醇、低密度脂蛋白下降且低于模型组,并具有统计学差异（P＜0.05）。光镜下观察,HE染色示正常组肾组织整体结构基本正常,膜性肾病（MN）模型组肾小球毛细血管丛充血,系膜增生,基底膜出现增厚,部分肾小管细胞空泡变、组织内可见炎症细胞浸润,可见嗜复红蛋白及IgG沉积。经膜肾1号方和盐酸贝那普利干预后,大鼠肾脏病理学改变均有所减轻。各组大鼠IgG沉积显示,与对照组比较模型组IgG沉积明显,IgG荧光表达升高,差异具有统计学意义（P＜0.05）,盐酸贝那普利组和膜肾1号方组IgG荧光表达下降且低于模型组,具有统计学差异（P＜0.05）。Western Blot检测显示,药物干预后,盐酸贝那普利组和膜肾1号方组大鼠PI3K-Akt信号通路相关蛋白表达下降,LC3 表达增加,并具有统计学差异（P＜0.05）。[结论] 膜肾1号方可改善大鼠肾脏病理损伤,膜肾1号方干预后PI3K-Akt信号通路相关蛋白磷酸化磷酸肌醇3激酶（p-PI3K）,磷酸化Akt蛋白（p-Akt）,磷酸化雷帕霉素靶蛋白（p-mTOR）表达明显降低,自噬相关蛋白LC3表达升高,其分子机制与自噬信号通路的调控有关。     

中医药治疗糖尿病肾病实验研究进展

糖尿病肾病（DN）是糖尿病常见慢性并发症之一,白蛋白尿和肾小球滤过率下降是目前糖尿病肾病诊断的重要临床指征。DN严重影响着患者的生命质量,尽早地干预糖尿病肾病的危险因素,纠正胰岛素代谢障碍导致的长期高血糖因素影响下的肾脏损伤,是有效阻止其进展为终末期肾脏疾病的关键。中医药秉持其特色理论取得了独特的治疗优势,随着中医药对于DN的认识与研究的加深,实验研究方面也取得了一定的进展。本文总结了中医研究DN动物模型的常用构建方法,同时从中医药调节免疫炎症反应、降低氧化应激水平、改善肾脏血流动力学改变、纠正糖脂代谢紊乱等机制方面列举分析中医药辨治糖尿病实验研究进展,探讨中医药防治DN的机制,以期对临床有所裨益。