炭疽水肿因子在大肠杆菌中高效表达及一步法纯化

【目的】本研究旨在建立一种简单快捷的炭疽水肿因子(EF)重组表达及纯化方法。【方法】构建GST-EF融合表达载体,基于EF基因的密码子使用偏好,选择菌株Escherichia coli BL21-Codon Plus(DE3)-RIL为表达宿主,对EF进行诱导表达;细胞透性技术分离粗蛋白,进而利用亲和层析一步法纯化EF;Native-PAGE、竞争性抑制实验及c AMP浓度分析用于鉴定EF的生物活性。【结果】实现了EF可溶性高效表达,透性化处理可有效抽提可溶性重组蛋白;利用亲和层析一步法纯化得到了纯度达96%的EF;EF可与保护性抗原(PA)结合形成水肿毒素,该毒素能够急剧提高CHO-K1细胞中c AMP的浓度。【结论】本研究建立了一种高效快速制备具有生物活性的炭疽水肿因子的方法,为炭疽相关研究工作提供了新的选择。     

Ghrelin治疗脑出血大鼠脑水肿及MMP-9表达的影响

目的:研究Ghrelin对大鼠脑出血后脑水肿及脑组织中基质金属蛋白酶-9(MMP-9)表达的影响。方法:选取雄性SD大鼠80只,随机分为对照组(NC组)20只、假手术组(SHAM组)20只、脑出血组(ICH组)20只、Ghrelin治疗组(Ghrelin组)20只。利用自体动脉血注入法建立大鼠脑出血模型;Ghrelin组于建立脑出血模型后经股静脉注射Ghrelin 10 nmol/Kg·d。分别于12 h、24 h、3d、5 d、7 d时间点根据Berderson评分法评估各组大鼠神经系统功能;利用干湿重法测定各组大鼠脑组织含水量;利用蛋白质免疫印迹法(WB)检测脑组织中MMP-9表达情况。结果:在12 h、24 h、3 d、5 d、7 d,ICH组、Ghrelin组大鼠Berderson评分及脑组织含水量高于NC组、SHAM组(P0.05);在5 d、7 d,ICH组大鼠Berderson评分及脑组织含水量高于Ghrelin组(P0.05)。WB结果表明在12 h、24 h、3 d、5 d、7 d,ICH组大鼠脑组织中MMP-9的表达均高于NC组、SHAM组(P0.05);Ghrelin组MMP-9的表达在12 h、24 h、3 d高于NC组、SHAM组(P0.05),在5 d、7 d,与NC组、SHAM组无明显差异(P0.05);在5 d、7 d,ICH组MMP-9表达高于Ghrelin组(P0.05)。结论:在本研究中,Ghrelin可以在5 d后降低脑出血大鼠脑组织中MMP-9的表达程度,从而减轻脑水肿,改善脑出血大鼠神经功能。     

糖尿病白内障术后黄斑水肿与房水细胞因子的关系

为了探讨2型糖尿病白内障术后黄斑水肿与房水中细胞因子的关系,本研究选取2016年2月至2017年7月在我院治疗的2型糖尿病白内障患者117例117眼,均行超声乳化白内障摘除术,观察术后4周黄斑水肿发生情况以及房水中多种细胞因子水平。研究结果显示:术后4周,有37眼发生黄斑水肿(观察组),未发生黄斑水肿80眼(对照组);观察组术后4周黄斑区视网膜厚度为(247.28±18.37)μm,明显高于对照组(p<0.05),且明显高于术前水平(p<0.05);观察组术后4周干扰素诱导蛋白-10 (IP-10)、巨噬细胞趋化蛋白(MCP-1)、血管内皮生长因子(VEGF)和细胞因子转化生长因子-β2 (TGF-β2)水平分别为(6.01±0.89) pg/mL、(340.03±45.39) pg/mL、(812.28±40.06) pg/mL和(40.05±10.03) pg/mL,明显高于对照组(p<0.05),且高于术前水平(p<0.05);观察组和对照组手术前后粒细胞-巨噬细胞集落刺激因子(GM-CSF)和碱性成纤维细胞生长因子(b-FGF)比较差异无统计学意义(p>0.05);术后4周IP-10、MCP-1、VEGF和TGF-β2水平与黄斑区视网膜厚度呈正相关(r=0.452, 0.501, 0.466和0.470, p<0.05)。本研究的结果初步说明,房水中IP-10、MCP-1、VEGF和TGF-2水平与2型糖尿病白内障术后黄斑水肿有一定关系,有可能成为黄斑水肿的特异性评价指标,值得进一步研究。     

Late‐onset retinal degeneration pathology due to mutations in CTRP5 is mediated through HTRA1

Late‐onset retinal degeneration (L‐ORD) is an autosomal dominant macular degeneration characterized by the formation of sub‐retinal pigment epithelium (RPE) deposits and neuroretinal atrophy. L‐ORD results from mutations in the C1q‐tumor necrosis factor‐5 protein (CTRP5), encoded by the CTRP5/C1QTNF5 gene. To understand the mechanism underlying L‐ORD pathology, we used a human cDNA library yeast two‐hybrid screen to identify interacting partners of CTRP5. Additionally, we analyzed the Bruch's membrane/choroid (BM‐Ch) from wild‐type (Wt), heterozygous S163R Ctrp5 mutation knock‐in (Ctrp5^S163R/wt), and homozygous knock‐in (Ctrp5^S163R/S163R) mice using mass spectrometry. Both approaches showed an association between CTRP5 and HTRA1 via its C‐terminal PDZ‐binding motif, stimulation of the HTRA1 protease activity by CTRP5, and CTRP5 serving as an HTRA1 substrate. The S163R‐CTRP5 protein also binds to HTRA1 but is resistant to HTRA1‐mediated cleavage. Immunohistochemistry and proteomic analysis showed significant accumulation of CTRP5 and HTRA1 in BM‐Ch of Ctrp5^S163R/S163R and Ctrp5^S163R/wt mice compared with Wt. Additional extracellular matrix (ECM) components that are HTRA1 substrates also accumulated in these mice. These results implicate HTRA1 and its interaction with CTRP5 in L‐ORD pathology.     

Protective effects of cynaroside on oxidative stress in retinal pigment epithelial cells

Cynaroside is a flavonoid compound proved to possess antioxidant activity, but its protective effect on age‐related macular degeneration still remains unclear. In this study, the protective effects of cynaroside on oxidative stress and apoptosis in retinal pigment epithelial (RPE) cells induced by hydrogen peroxide (H₂O₂) were investigated. Results showed that cynaroside effectively attenuated the decrease of cell activity induced by H₂O₂. The total reactive oxygen species can be remitted by decreasing malondialdehyde level, as well as increasing glutathione level, and superoxide dismutase and catalase activities. In addition, Western blot analysis indicated that cynaroside protected ARPE‐19 cells from apoptosis through downregulation of caspase‐3 protein activation which was controlled by the upstream proteins Bcl‐2 and Bax. It was finally proved that cynaroside could enhance the antioxidant and antiapoptotic ability in ARPE‐19 cells by promoting the expression of p‐Akt.     

Expression of adiponectin in choroidal tissue and inhibition of laser induced choroidal neovascularization by adiponectin

The aim of this study was to investigate the role of adiponectin (APN) in a mouse model of laser induced choroidal neovascularization (CNV). We have shown by immunohistochemistry that the expression of APN, adiponectin receptor 1, adiponectin receptor 2 and T cadherin gradually increased from day 1 to day 7 post-laser in laser treated mice compared to controls. Recombinant APN (rAPN) was injected intraperitoneally (i.p., 25 microg/mouse) or intravitreally (2 microg/eye) in lasered mice. Another set of lasered mice received APN peptide via i.p. (75 microg/mouse) or intravitreal (30 microg/eye) route. Control mice received a similar treatment with PBS, control protein or control peptide after laser treatment. We found that in the i.p. and intravitreal injection of rAPN resulted in 78% and 68% inhibition respectively in the size of CNV complex compared to control mice. Similar results were observed when APN peptide was injected intravitreally or i.p. Treatment with rAPN or the peptide resulted in decreased levels of vascular endothelial growth factor. Thus, APN inhibited choroidal angiogenesis and may have therapeutic implications in the treatment of wet age related macular degeneration.     

雷珠单抗联合复方血栓通胶囊对年龄相关性黄斑变性患者血液流变学和血清VEGF、PDGF的影响

摘要 目的：观察雷珠单抗联合复方血栓通胶囊对年龄相关性黄斑变性（AMD）患者血液流变学和血清血管内皮生长因子（VEGF）、血小板衍生生长因子（PDGF）的影响。方法：选取我院2019年6月~2021年1月收治的AMD患者60例（96眼）,按照随机数字表法分别为对照组（n=30,46眼）和实验组（n=30,50眼）,对照组给予雷珠单抗治疗,实验组给予雷珠单抗联合复方血栓通胶囊治疗,对比两组眼部相关指标、血液流变学指标和血清VEGF、PDGF水平变化情况,观察两组治疗期间不良反应发生情况。结果：实验组治疗3个月后眼内压（IOP）、黄斑中央区厚度（CMT）、脉络新生血管（CNV）面积低于对照组,视力高于对照组（P<0.05）。实验组治疗3个月后全血低切/中切/高切黏度、血浆黏度低于对照组（P<0.05）。实验组治疗3个月后血清VEGF、PDGF水平低于对照组（P<0.05）。两组不良反应发生率对比无差异（P>0.05）。结论：雷珠单抗联合复方血栓通胶囊可改善AMD临床症状,促进视力恢复,其作用机制可能与调节机体血液流变学、血清VEGF、PDGF水平有关。     

新生血管性年龄相关性黄斑变性对抗VEGF治疗的耐药性危险因素分析

摘要 目的：探究新生血管性年龄相关性黄斑变性对抗血管内皮生长因子（VEGF）治疗的耐药性危险因素。方法：选取2019年5月至2021年5月于我院接受治疗的90例nAMD患者作为研究对象,进行VEGF治疗,根据患者的耐药情况将其分为耐药组（n=19）和非耐药组（n=71）,统计患者资料,对比分析产生耐药性的危险因素。结果：危险因素与AMD类型、PED、椭圆体带完整性、积液、出血、BCVA、眼压、CRT异常有关（P<0.05）,危险因素与性别和平均年龄无关（P>0.05）;Ⅰ型CNV患者在VEGF治疗前后CRT水平未出现显著变化（P>0.05）,II型CNV患者和混合型CNV患者治疗前后CRT水平均显著降低（P<0.05）。Logistic回归分析显示：最终进入主效应模型的因素即抗VEGF治疗的耐药性发生的多因素为积液、PED、出血、AMD类型。结论：新生血管性年龄相关性黄斑变性（nAMD）对抗VEGF治疗出现耐药性与积液、出血和AMD类型有关。     

Interleukin-2 induces extracellular matrix synthesis and TGF-β2 expression in retinal pigment epithelial cells

Macular fibrosis is a vital obstacle of vision acuity improvement of age-related macular degeneration patients. This study was to investigate the effects of interleukin 2 (IL-2) on epithelial-mesenchymal transition (EMT), extracellular matrix (ECM) synthesis and transforming growth factor β2 (TGF-β2) expression in retinal pigment epithelial (RPE) cells. 10 μg/L IL-2 was used to induce fibrosis in RPE cells for various times. Western blot was used to detect the EMT marker α-smooth muscle actin (α-SMA), ECM markers fibronectin (Fn) and type 1 collagen (COL-1), TGF-β2, and the activation of the JAK/STAT3 and NF-κB signaling pathway. Furthermore, JAK/STAT3 and NF-κB signaling pathways were specifically blocked by WP1066 or BAY11-7082, respectively, and the expression of α-SMA, COL-1, Fn and TGF-β2 protein were detected. Wound healing and Transwell assays were used to measure cell migration ability of IL-2 with or without WP1066 or BAY11-7082. After induction of IL-2, the expressions of Fn, COL-1, TGF-β2 protein were significantly increased, and this effect was correlated with IL-2 treatment duration, while α-SMA protein expression did not change significantly. Both WP1066 and BAY11-7082 could effectively downregulate the expression of Fn, COL-1 and TGF-β2 induced by IL-2. What's more, both NF-κB and JAK/STAT3 inhibitors could suppress the activation of the other signaling pathway. Additionally, JAK/STAT3 inhibitor WP1066 and NF-κB inhibitor BAY 11-7082 could obviously decrease RPE cells migration capability induced by IL-2. IL-2 promotes cell migration, ECM synthesis and TGF-β2 expression in RPE cells via JAK/STAT3 and NF-κB signaling pathways, which may play an important role in proliferative vitreoretinopathy.     

Unexpected intracellular localization of the AMD-associated cystatin C variant

Cystatin C is abundantly expressed by the retinal pigment epithelium (RPE) of the eye. Targeting of cystatin C to the Golgi apparatus and processing through the secretory pathway of RPE cells are dependent upon a 26-amino acid signal sequence of precursor cystatin C. A variant with an alanine (A) to threonine (T) mutation in the penultimate amino acid of the signal sequence (A25T) was recently correlated with increased risk of developing exudative age-related macular degeneration. The biochemical consequence of the A25T mutation upon targeting of the protein is reported here. Targeting and trafficking of full-length mutant (A25T) precursor cystatin C-enhanced green fluorescent protein fusion protein were studied in living, cultured retinal pigment epithelial and HeLa cells. Confocal microscopy studies were substantiated by immunodetection. In striking contrast to wild-type precursor cystatin C fusion protein conspicuously targeted to the Golgi apparatus, the threonine variant was associated principally with mitochondria. Some diffuse fluorescence was also observed throughout the cytoplasm and nucleus (but not nucleoli). Secretion of fusion protein derived from the threonine variant was reduced by approximately 50% compared with that of the wild-type cystatin C fusion protein. Expression of the variant fusion protein did not appear to impair expression or secretion of endogenous cystatin C.