H2O2 Regulates Lung Epithelial Sodium Channel (ENaC) via Ubiquitin-like Protein Nedd8

Redundancies in both the ubiquitin and epithelial sodium transport pathways allude to their importance of proteolytic degradation and ion transport in maintaining normal cell function. The classical pathway implicated in ubiquitination of the epithelial sodium channel (ENaC) involves Nedd4-2 regulation of sodium channel subunit expression and has been studied extensively studied. However, less attention has been given to the role of the ubiquitin-like protein Nedd8. Here we show that Nedd8 plays an important role in the ubiquitination of ENaC in alveolar epithelial cells. We report that the Nedd8 pathway is redox-sensitive and that under oxidizing conditions Nedd8 conjugation to Cullin-1 is attenuated, resulting in greater surface expression of α-ENaC. This observation was confirmed in our electrophysiology studies in which we inhibited Nedd8-activating enzyme using MLN4924 (a specific Nedd8-activating enzyme inhibitor) and observed a marked increase in ENaC activity (measured as the product of the number of channels (N) and the open probability (Po) of a channel). These results suggest that ubiquitination of lung ENaC is redox-sensitive and may have significant implications for our understanding of the role of ENaC in pulmonary conditions where oxidative stress occurs, such as pulmonary edema and acute lung injury.     

光学椭偏成像技术在生物分子研究中的应用

光学椭偏显微成像是一种新型超薄膜及表面显示技术,是研究生物分子与固体表面吸附以及生物分子之间相互作用的一种简单、快速和可靠的手段。它不仅能够大面积精确显示超薄膜的厚度分布,而且能够用于表面实时吸附的动力学研究。在抗原抗体检测分析方面,它不需要像酶联免疫法、荧光免疫法和放射免疫法那样对待测物作标记,也不会对待测生物分子活性造成任何扰动和损伤,操作简单,费用低廉。另外,它还弥补了传统的椭偏法的不足之处,能够有效地区分非特异性吸附、脱吸附或表面污染带来的干扰。     

Integrative Metabolic Pathway Analysis Reveals Novel Therapeutic Targets in Osteoarthritis

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Highlights

• •SILAC-based protein quantification of OA hBMSCs undergoing chondrogenesis.
• •Spatially-resolved metabolomics by MSI of hBMSCs in chondrogenic differentiation.
• •Differential metabolic pathways involved in OA compared to control hBMSCs.
• •UDP-glucuronic acid/UDP-GlcNAc synthesis is decreased in chondrogenic OA hBMSCs.

     

RNA Protein Granules Modulate tau Isoform Expression and Induce Neuronal Sprouting

The neuronal microtubule-associated protein Tau is expressed in different variants, and changes in Tau isoform composition occur during development and disease. Here, we investigate a potential role of the multivalent tau mRNA-binding proteins G3BP1 and IMP1 in regulating neuronal tau expression. We demonstrate that G3BP1 and IMP1 expression induces the formation of structures, which qualify as neuronal ribonucleoprotein (RNP) granules and concentrate multivalent proteins and mRNA. We show that RNP granule formation leads to a >30-fold increase in the ratio of high molecular weight to low molecular weight tau mRNA and an ∼12-fold increase in high molecular weight to low molecular weight Tau protein. We report that RNP granule formation is associated with increased neurite formation and enhanced process growth. G3BP1 deletion constructs that do not induce granule formation are also deficient in inducing neuronal sprouting or changing the expression pattern of tau. The data indicate that granule formation driven by multivalent proteins modulates tau isoform expression and suggest a morphoregulatory function of RNP granules during health and disease.     

Single-molecule Study on the Decay Process of the Football-shaped GroEL-GroES Complex Using Zero-mode Waveguides

It has been widely believed that an asymmetric GroEL-GroES complex (termed the bullet-shaped complex) is formed solely throughout the chaperonin reaction cycle, whereas we have recently revealed that a symmetric GroEL-(GroES)₂ complex (the football-shaped complex) can form in the presence of denatured proteins. However, the dynamics of the GroEL-GroES interaction, including the football-shaped complex, is unclear. We investigated the decay process of the football-shaped complex at a single-molecule level. Because submicromolar concentrations of fluorescent GroES are required in solution to form saturated amounts of the football-shaped complex, single-molecule fluorescence imaging was carried out using zero-mode waveguides. The single-molecule study revealed two insights into the GroEL-GroES reaction. First, the first GroES to interact with GroEL does not always dissociate from the football-shaped complex prior to the dissociation of a second GroES. Second, there are two cycles, the “football cycle ” and the “bullet cycle,” in the chaperonin reaction, and the lifetimes of the football-shaped and the bullet-shaped complexes were determined to be 3–5 s and about 6 s, respectively. These findings shed new light on the molecular mechanism of protein folding mediated by the GroEL-GroES chaperonin system.     

A novel homozygous GALC mutation: Very early onset and rapidly progressive Krabbe disease

A clear cut genotype–phenotype correlation for Krabbe disease is not available. Therefore, it is important to identify new mutations and their associated phenotypes to predict the prognosis of the disease. The aim of this study is to identify the causative mutation(s) in a family with Krabbe disease. After a clinical evaluation and suspicion of Krabbe disease galactocerebrosidase activity was analyzed and GALC gene mutation analysis was performed. The galactocerebrosidase enzyme activity was 0.01 nmol/mg/h protein (normal range 0.8–4). For further investigation mutation screening was performed by Sanger sequencing across the 17 exons of GALC gene. A novel homozygous mutation c.727delT (p.S243QfsX7) was found. In this study we present the clinical findings along with a novel GALC mutation in a consanguineous Turkish family. Although the relationship between the various genotypes and phenotypes in Krabbe disease has not been fully elucidated an accurate genetic family study is helpful for genetic counseling follow-up and therapy of Krabbe disease. Also, it is important to identify new mutations in order to clarify their clinical importance, to assess the prognosis of the disease, and to suggest either prenatal diagnosis or preimplantation genetic diagnosis to the effected families.     

硫化铜纳米粒子应用于肿瘤诊断和治疗的研究进展

癌症是当今威胁人类健康的主要疾病之一。近年来提出的近红外光介导的光热治疗,能够对肿瘤组织进行定点清除并且对正常组织具有较低的毒副作用,为肿瘤的治疗提供了新的方法。开发具有良好生物相容性的高效光热偶联剂是发展光热治疗的首要条件。随着纳米技术的飞速发展,一些金属纳米结构由于具有独特的光学特性作为光热偶联剂被广泛应用到肿瘤的光热治疗中。然而,成本高昂、制备过程繁琐以及光热稳定性较差等不足,限制了这些纳米材料的进一步应用。最新报道的新型光热偶联剂半导体硫化铜纳米粒子(copper sulfide nanoparticles,CuS NPs),由于其具有制备工艺简单、成本低廉、突出的光热稳定性和良好的生物相容性等优势,成为了当今纳米医学领域研究的热点。本文主要综述了CuS纳米粒子在肿瘤光热治疗和影像诊断方面的应用研究,并对CuS纳米粒子在生物医学领域应用中存在的问题和未来的研究方向进行了展望。     

原发性骨恶性纤维组织细胞瘤24例临床特征及预后分析

摘要 目的：总结原发性骨恶性纤维组织细胞瘤（PBMFH）的临床特征和预后。方法：回顾性分析我院2000年10月至2011年1月收治的24例PBMFH患者的术前影像学资料、诊断依据、治疗方案和随访资料。结果：24例患者全部通过术后病理确诊,穿刺准确率为75.00%.胸部X线检查结果显示：2例发现肺部转移灶,22例未发现肺部转移灶。肿瘤局部X线检查结果显示：3例出现骨质溶解性破坏,1例出现肿块影,20例表现为骨膜反应。MRI检查结果显示：4例MRI检查肿瘤局部情况时发现3例T1WI等信号、T2WI稍高信号,1例T1WI低信号、T2WI低信号。本研究中行放化疗18例,有6例（33.33%）发生转移,转移时间为6~45个月,中位转移时间为（25.30±6.24）个月,单纯手术治疗6例中有5例发生转移（83.33%）,转移发生时间为3~6月,中位转移时间为（5.00±0.24）个月。结论：PBMFH患者单纯手术出现转移多发生于术后5月,根治性手术辅以放化疗出现转移多发生于术后25月。由此可见,术前穿刺活检病理有助于疾病诊断,术后辅助化疗有助于降低PBMFH的复发率和转移率。     

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。