Serum levels of heat shock protein 27 in patients with acute ischemic stroke

Expression of intracellular heat shock protein 27 (Hsp27) rises in the brain of animal models of cerebral ischemia and stroke. Hsp27 is also released into the circulation and the aim of the present study was to investigated if serum Hsp27 (sHsp27) levels are altered in patients with acute ischemic stroke. sHsp27 was measured in 15 patients with acute ischemic stroke and in 14 control subjects comparable for age, sex, and cardiovascular risk factors. In patients, measurements were performed at admission and 1, 2, and 30 days thereafter. At admission, mean sHsp27 values were threefold higher in patients than in controls. In patients, sHsp27 values dropped after 24 h, rose again at 48 h, and markedly declined at 30 days, indicating the presence of a temporal trend of sHsp27 values following acute ischemic stroke.     

Development of multiplexed protein profiling and detection using near infrared detection of reverse-phase protein microarrays

Protein microarrays have been recently employed for signal pathway profiling and high-throughput protein expression analysis. Reversephase arrays, where the array consists of immobilized analytes and lysates has especially shown promise in low abundance analyte detection and signal pathway profiling using phospho-specific antibodies. A limitation to current reverse phase array methodology is the inability to multiplex proteomic-based endpoints as each array can only report one analyte endpoint. In this study, we report on the use of a dual dye based approach that can effectively double the number of endpoints observed per array allowing, for example, both phosphospecific and total protein levels to be measured and analyzed at once. The method utilizes antibody bound dyes that emit in the infrared spectral region as a means of sensitive and specific detection.     

A review of visualisations of protein fold networks and their relationship with sequence and function

Proteins form arguably the most significant link between genotype and phenotype. Understanding the relationship between protein sequence and structure, and applying this knowledge to predict function, is difficult. One way to investigate these relationships is by considering the space of protein folds and how one might move from fold to fold through similarity, or potential evolutionary relationships. The many individual characterisations of fold space presented in the literature can tell us a lot about how well the current Protein Data Bank represents protein fold space, how convergence and divergence may affect protein evolution, how proteins affect the whole of which they are part, and how proteins themselves function. A synthesis of these different approaches and viewpoints seems the most likely way to further our knowledge of protein structure evolution and thus, facilitate improved protein structure design and prediction.     

HSP90 and HSP70 proteins are essential for stabilization and activation of WASF3 metastasis-promoting protein

Inactivation of HSP90 and HSP70 leads to loss of invasion in a variety of cancer cell types, presumably as a result of destabilization of, as yet, undefined clients of these molecular chaperones that influence this phenotype. The WASF3 gene has been shown to be up-regulated in high-grade tumors and its down-regulation leads to loss of invasion and metastasis. WASF3 phosphorylation by ABL kinase is essential for its ability to regulate invasion. Mass spectroscopy analysis now shows that HSP90 is present in the WASF3 immunocomplex from prostate cancer cells. Inactivation of HSP90 in these and other cell types does not affect WASF3 stability but prevents its phosphoactivation as a result of destabilization of ABL. HSP70 was also found in the WASF3 immunocomplex and inactivation of HSP70 results in destabilization of WASF3 through proteasome degradation. Knockdown of WASF3, HSP90, and HSP70 individually, all lead to loss of invasion but as knockdown of WASF3 in the presence of robust expression of HSP90/70 has the same effect, it seems that the influence these chaperone proteins have on invasion is mediated, at least in part, by their control over the critical invasion promoting capacity of the WASF3 protein. Overexpression of HSP70 in WASF3 null cells does not enhance invasion. These observations suggest that targeting HSP90/70 may have efficacy in reducing cancer cell invasion.     

Proteomic signatures of serum albumin-bound proteins from stroke patients with and without endovascular closure of PFO are significantly different and suggest a novel mechanism for cholesterol efflux

Background

The anatomy of PFO suggests that it can allow thrombi and potentially harmful circulatory factors to travel directly from the venous to the arterial circulation – altering circulatory phenotype. Our previous publication using high-resolution LC-MS/MS to profile protein and peptide expression patterns in plasma showed that albumin was relatively increased in donor samples from PFO-related than other types of ischemic strokes. Since albumin binds a host of molecules and acts as a carrier for lipoproteins, small molecules and drugs, we decided to investigate the albumin-bound proteins (in a similar sample cohort) in an effort to unravel biological changes and potentially discover biomarkers related to PFO-related stroke and PFO endovascular closure.

Methods

The method used in this study combined albumin immuno-enrichment with high resolution LC-MS in order to specifically capture and quantify the albumin-bound proteins. Subsequently, we measured cholesterol and HDL in a larger, separate cohort of PFO stroke patients, pre and post closure.

Results

The results demonstrated that a number of proteins were specifically associated with albumin in samples with and without endovascular closure of the PFO, and that the protein profiles were very different. Eight proteins, typically associated with HDL were common to both sample sets and quantitatively differently abundant. Pathway analysis of the MS results suggested that enhanced cholesterol efflux and reduced lipid oxidation were associated with PFO closure. Measurement of total cholesterol and HDL in a larger cohort of PFO closure samples using a colorimetric assay was consistent with the proteomic predictions.

Conclusions

The collective data presented in this study demonstrate that analysis of albumin-bound proteins could provide a valuable tool for biomarker discovery on the effects of PFO endovascular closure. In addition, the results suggest that PFO endovascular closure can potentially have effects on HDL, cholesterol and albumin-bound ApoA-I abundance, therefore possibly providing benefits in cardioprotective functions.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-12-2) contains supplementary material, which is available to authorized users.     

Plasma prion protein concentration and progression of Alzheimer disease

Background/Objective: Recently, PrP^c has been linked to AD pathogenesis. Second, a relation of PrP^c plasma levels with cognitive status and decline of healthy elderly subjects has been reported. Therefore, we hypothesized baseline plasma levels of PrP^c to be associated with AD progression in cognitive and functional domains.Materials and Methods: AD patients (n = 84) were included into an observational study at time of diagnosis. Baseline plasma PrP^c levels were determined. Decline was assessed annually (mean follow-up time 3 years) with the aid of different standardized tests (MMSE, iADL, bADL, GDS, UPDRSIII). Multiple regression analyses were used to uncover potential associations between decline and PrP^c levels.Results: No association of PrP^c and decline could be established. Presence of diabetes mellitus was linked to slower deterioration. Intake of neuroleptic drugs or memantine was associated with faster progression.Conclusion: Plasma PrP^c at baseline could not be shown to be related to AD progression in this study. An interesting association of diabetes mellitus and decline warrants further investigation.     

Interaction interfaces of protein domains are not topologically equivalent across families within superfamilies: Implications for metabolic and signaling pathways

Using a data set of aligned protein domain superfamilies of known three-dimensional structure, we compared the location of interdomain interfaces on the tertiary folds between members of distantly related protein domain superfamilies. The data set analyzed is comprised of interdomain interfaces, with domains occurring within a polypeptide chain and those between two polypeptide chains. We observe that, in general, the interfaces between protein domains are formed entirely in different locations on the tertiary folds in such pairs. This variation in the location of interface happens in protein domains involved in a wide range of functions, such as enzymes, adapters, and domains that bind protein ligands, or cofactors. While basic biochemical functionality is preserved at the domain superfamily level, the effect of biochemical function on protein assemblies is different in these protein domains related by superfamily. The divergence between proteins, in most cases, is coupled with domain recruitment, with different modes of interaction with the recruited domain. This is in complete contrast to the observation that in closely related homologous protein domains, almost always the interaction interfaces are topologically equivalent. In a small subset of interacting domains within proteins related by remote homology, we observe that the relative positioning of domains with respect to one another is preserved. Based on the analysis of multidomain proteins of known or unknown structure, we suggest that variation in protein-protein interactions in members within a superfamily could serve as diverging points in otherwise parallel metabolic or signaling pathways. We discuss a few representative cases of diverging pathways involving domains in a superfamily.     

Heat shock protein 70 and AMP‐activated protein kinase contribute to 17‐DMAG‐dependent protection against heat stroke

Heat shock protein 70 (Hsp70) preconditioning induces thermotolerance, and adenosine monophosphate (AMP)‐activated protein kinase (AMPK) plays a role in the process of autophagy. Here, we investigated whether 17‐dimethylaminoethylamino‐17‐demethoxy‐geldanamycin (17‐DMAG) protected against heat stroke (HS) in rats by up‐regulation of Hsp70 and phosphorylated AMPK (pAMPK). To produce HS, male Sprague–Dawley rats were placed in a chamber with an ambient temperature of 42°C. Physiological function (mean arterial pressure, heart rate and core temperature), hepatic and intestinal injury, inflammatory mediators and levels of Hsp70, pAMPK and light chain 3 (LC3B) in hepatic tissue were measured in HS rats or/and rats pre‐treated with 17‐DMAG. 17‐DMAG pre‐treatment significantly attenuated hypotension and organ dysfunction induced by HS in rats. The survival time during HS was also prolonged by 17‐DMAG treatment. Hsp70 expression was increased, whereas pAMPK levels in the liver were significantly decreased in HS rats. Following pre‐treatment with 17‐DMAG, Hsp70 protein levels increased further, and pAMPK levels were enhanced. Treatment with an AMPK activator significantly increased the LC3BII/LC3BI ratio as a marker of autophagy in HS rats. Treatment with quercetin significantly suppressed Hsp70 and pAMPK levels and reduced the protective effects of 17‐DMAG in HS rats. Both of Hsp70 and AMPK are involved in the 17‐DMAG‐mediated protection against HS. 17‐DMAG may be a promising candidate drug in the clinical setting.     

Circadian rhythms may not influence the outcomes of thrombolysis in patients with ischemic stroke: A study from China

ABSTRACT

Circadian rhythms can affect physical or mental activities as well as the time of stroke onset. The impact of circadian rhythms on acute ischemic stroke (AIS) patients treated by recombinant alteplase (rt-PA) is still incongruent. This study aims to consider whether the outcomes of thrombolysis differ depending on stroke onset time and rt-PA infusion time in patients with AIS. A total of 447 AIS patients, who underwent rt-PA intravenous infusion within 4.5 hours after stroke onset, were enrolled in this study consecutively from June 2010 through December 2016. All of the patients were grouped based on the stroke onset time and rt-PA infusion time into two exact 12-hour intervals as daytime (06:01–18:00) and nighttime (18:01–06:00) and further divided into four subgroups at 6-hour time intervals (00:01–06:00, 06:01–12:00, 12:01–18:00 and 18:01–24:00). Major neurological improvement at 1 hour, 24 hours and 7 days, 7-day mortality rate and 24-hour hemorrhage transformation was recorded. The results showed that a total of 295 patients (66.4%) appeared with AIS and 252 (56.4%) were treated during daytime. Higher NIHSS at admission was observed when stroke occurred in nighttime, especially during 00:01–06:00. Patients with stroke onset in nighttime especially during 18:01–24:00 had a significant shorter onset-door time and onset-needle time. No differences of the major neurological improvement at 1 hour, 24 hours and 7 days, 24-hour hemorrhagic transformation and 7-day fatality rate were found among either 12-hour time frames or 6-hour time frames according to the time of stroke onset or rt-PA infusion. In conclusion, there was no evidence to predict that circadian rhythms could influence the outcomes of AIS patients treated with rt-PA in China, although stroke onset during nighttime might aggravate neurological impairment before treatment. Further, multicenter and prospective clinical trials with larger number of subjects are still needed to draw more reliable conclusions.     

An association study of cyclase-associated protein 2 and frailty

Frailty is a geriatric syndrome that results from multisystem impairment caused by age-associated accumulation of deficits. The frailty index is used to define the level of frailty. Several studies have searched for molecular biomarkers associated with frailty, to meet the needs for personalized care. Cyclase-associated protein 2 (CAP2) is a multifunctional actin-binding protein involved in various physiological and pathological processes, that might reflect frailty's intrinsic complexity. This study aimed to investigate the association between frailty index and circulating CAP2 concentration in 467 community-dwelling older adults (median age: 79; range: 65–92 years) from Milan, Italy. The selected robust regression model showed that circulating CAP2 concentration was not associated with chronological age, as well as sex and education. However, circulating CAP2 concentration was significantly and inversely associated with the frailty index: a 0.1-unit increase in frailty index leads to ~0.5-point mean decrease in CAP2 concentration. Furthermore, mean CAP2 concentration was significantly lower in frail participants (i.e., frailty index ≥0.25) than in non-frail participants. This study shows the association between serum CAP2 concentration and frailty status for the first time, highlighting the potential of CAP2 as a biomarker for age-associated accumulation of deficits.     

Role of JAK/STAT signaling in neuroepithelial stem cell maintenance and proliferation in the Drosophila optic lobe

Human urine contains a large number of proteins and peptides (the urinary proteome). Global analysis of the human urinary proteome is important for understanding urinary tract diseases. Bladder cancer is the most common urological cancer with higher incidence rates in endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to use the proteomic approach to establish urinary protein biomarkers of bladder cancer. ADAM28, identified by proteomic approaches and confirmed by Western blotting, showed significant differences compared with normal individuals, so it may be a biomarker of bladder cancer.     

日本血吸虫重组信号蛋白14—3—3的纯化及单克隆抗体的制备

纯化日本血吸虫（中国大陆株）重组信号蛋白（rSj14—3—3）,并制备其单克隆抗体。以纯化后的rsj14-3—3蛋白为抗原免疫Balb／c小鼠,用杂交瘤技术制备抗rSj14-3-3的单克隆抗体,并通过ELISA方法和Westernblotting测定抗体的效价与特异性。获得了大量高纯度的rSj14-3-3蛋白：筛选出了能够稳定分泌抗rSj14．3．3单抗的杂交瘤细胞株3H6。单抗亚型为IgG1。实验依靠大肠杆菌表达系统高效表达了rSj14—3—3蛋白,并利用该蛋白制备了单克隆抗体．可用于今后血吸虫病免疫诊断的实验研究。     

Dopaminergic and adrenergic toxicities on SK-N-MC human neuroblastoma cells are mediated through G protein signaling and oxidative stress

Dopamine and norepinephrine are neurotransmitters which participate in various regulatory functions of the human brain. These functions are lost in neurodegenerative diseases including Parkinson’s disease and Alzheimer’s disease. In this study, we used SK-N-MC neuroblastoma cells to investigate the cytotoxicities of high concentrations of dopamine and norepinephrine on neuronal cells. Dopamine, norepinephrine, as well as their corresponding synthetic agonists (SKF38393 and isoproterenol, respectively) triggered SK-N-MC cell death when applied at 50–100 μM persistently for 2 days. This catecholamine-induced cell death appears to be neuronal specific, as demonstrated by their inabilities of triggering apoptosis of A549 lung carcinoma cells and Cos-7 kidney fibroblasts. By pretreating SK-N-MC cells with target-specific inhibitors before administration of catecholamine, components of G protein signaling (i.e. G _s /cAMP/PKA), monoamine oxidases, nitric oxide synthase, c-Jun N-terminal kinase and oxidative stress were found to be involved in this dopamine/norepinephrine-induced cytotoxicity, which subsequently led to caspase-dependent and -independent apoptotic responses as well as DNA degradation. In contrast, agonists of G _i -coupled dopamine receptors and adrenergic receptors (quinpirole and UK14,304, respectively) were incapable of triggering apoptosis of SK-N-MC cells. Our results suggest that both G protein (G _s )-mediated signaling cascade and oxidative stress participate in the dopamine/norepinephrine-induced neuronal apoptosis. Anthony Chan and Ng Contributed equally to this work.     

Critical analysis of protein signaling networks involved in the regulation of plant secondary metabolism: focus on anthocyanins

Anthocyanin biosynthesis in Arabidopsis is a convenient and relatively simple model for investigating the basic principles of secondary metabolism regulation. In recent years, many publications have described links between anthocyanin biosynthesis and general defense reactions in plants as well as photomorphogenesis and hormonal signaling. These relationships are complex, and they cannot be understood intuitively. Upon observing the lacuna in the Arabidopsis interactome (an interaction map of the factors involved in the regulation of Arabidopsis secondary metabolism is not available), we attempted to connect various cellular processes that affect anthocyanin biosynthesis. In this review, we revealed the main signaling protein modules that regulate anthocyanin biosynthesis. To our knowledge, this is the first reconstruction of a network of proteins involved in plant secondary metabolism.     

Antimicrobial peptide HI-3 from Hermetia illucens alleviates inflammation in lipopolysaccharide-stimulated RAW264.7 cells via suppression of the nuclear factor kappa-B signaling pathway

Hermetia illucens-3 (HI-3), an active insect antimicrobial peptide extracted from H. illucens larvae, exerts antibacterial and anticancer activity. However, the inflammatory effects and their relative molecular mechanisms remain unclear. To explore the inflammatory effects of HI-3, an inflammatory model was induced using 1 ng/mL LPS in RAW264.7 cells. The cell viability and phagocytosis of LPS-stimulated RAW264.7 cells were then detected after HI-3 treatment. Furthermore, the antioxidant activity, the levels of proinflammatory cytokines, and the expression levels of both p65 and inhibitor of nuclear factor kappa B (IκB) were measured. Results showed that HI-3 could inhibit the differentiation, proliferation, phagocytosis, and antioxidant ability, as well as the secretion and messenger RNA expression levels of IL-6, TNF-α, and IL-1β of LPS-induced RAW264.7 cells in a dose-dependent manner. At the same time, the level of the anti-inflammatory cytokine IL-10 was increased after HI-3 treatment. Western blotting results showed that HI-3 suppressed LPS-induced p65 and IκB activation in a dose-dependent manner. Therefore, HI-3 exerts its anti-inflammatory effect by inhibiting the expression of proinflammatory cytokines and the activation of p65 and IκB, which indicated that HI-3 could be a promising therapeutic medicine for inflammation.     

基于人类蛋白质图集的蛋白质表达的总论

新的人类蛋白质图集4.0版本上已经含有了对应5000个人类基因的6000多种抗体。这个版本里已经拥有500多万张高分辨率的免疫组化和激光共聚焦图片。每张图片都是经过优秀的病理学家的注释,从而为功能研究提供知识储备,也可以进行正常和病理组织中蛋白质表达谱的查询和文献检索。一个新的结构实现了,它包括了所有预测的基因(大约20400个),并且带有可视化的所有编码蛋白质基因的特征。一个新的搜索工具也已经启动了,它可以执行高级检索功能,包括染色体定位、蛋白质分级和(或)组织特异性的检索。蛋白质图集作为一种搜索工具可以发现癌症诊断学的潜在生物标志物。