Circulating proteomic biomarkers for diagnosing sporadic amyotrophic lateral sclerosis:a cross-sectional study

Biomarke rs are required for the early detection,prognosis prediction,and monitoring of amyotrophic lateral sclerosis,a progressive disease.Proteomics is an unbiased and quantitative method that can be used to detect neurochemical signatures to aid in the identification of candidate biomarke rs.In this study,we used a label-free quantitative proteomics approach to screen for substantially differentially regulated proteins in ten patients with sporadic amyotrophic lateral scle rosis compared with five healthy controls.Su bstantial upregulation of serum proteins related to multiple functional clusters was observed in patients with spo radic amyotrophic lateral sclerosis.Potential biomarke rs were selected based on functionality and expression specificity.To validate the proteomics profiles,blood samples from an additional cohort comprising 100 patients with sporadic amyotrophic lateral sclerosis and 100 healthy controls were subjected to enzyme-linked immunosorbent assay.Eight substantially upregulated serum proteins in patients with spora dic amyotrophic lateral sclerosis were selected,of which the cathelicidin-related antimicrobial peptide demonstrated the best discriminative ability between patients with sporadic amyotrophic lateral sclerosis and healthy controls(area under the curve[AUC]=0.713,P<0.0001).To further enhance diagnostic accuracy,a multi-protein combined discriminant algorithm was developed incorporating five proteins(hemoglobin beta,cathelicidin-related antimicrobial peptide,talin-1,zyxin,and translationally-controlled tumor protein).The algo rithm achieved an AUC of 0.811 and a P-value of<0.0001,resulting in 79%sensitivity and 71%specificity for the diagnosis of sporadic amyotrophic lateral scle rosis.Subsequently,the ability of candidate biomarkers to discriminate between early-stage amyotrophic lateral sclerosis patients and controls,as well as patients with different disease severities,was examined.A two-protein panel comprising talin-1 and translationally-controlled tumor protein effectively distinguished early-stage amyotrophic lateral sclerosis patients from controls(AUC=0.766,P<0.0001).Moreove r,the expression of three proteins(FK506 binding protein 1A,cathelicidin-related antimicrobial peptide,and hemoglobin beta-1)was found to increase with disease progression.The proteomic signatures developed in this study may help facilitate early diagnosis and monitor the progression of sporadic amyotrophic lateral sclerosis when used in co mbination with curre nt clinical-based parameters.

Proteomic Analysis of Chrysanthemum Lateral Buds after Removing Apical Dominance Based on Label-Free Technology

Studying the genetic basis and regulatory mechanism of chrysanthemum lateral bud outgrowth is of great significance for reduction the production cost of cut chrysanthemum.To clarify the molecular basis of lateral bud elongation after removal of apical dominance in chrysanthemum,label-free quantification analysis was used to analyze the proteome changes after apical bud removal.Quantitative real-time PCR(qPCR)was used to analyze the changes in the expression of three plant hormone-related genes.A total of 440 differentially expressed proteins were successfully identified at three time points during the lateral bud elongation.The number of differentially expressed proteins in the three stages(24 h/0 h,48 h/0 h,48 h/24 h)were 219,332,and 97,respectively.The difference in expressed proteins in the three comparison stages mainly involves RNA processing and modification;translation,ribosomal structure and biogenesis;Posttranslational modification,protein turnover,and chaperones.Path analysis showed that there was various physiological activities in the process of lateral bud dormancy breaking and elongation,which involved energy metabolism,biosynthesis,signal transduction and stress response in the growth process of lateral buds.qPCR indicated that the expression of cytokinin synthesis related gene was significantly increased after the removal of apical dominance,while the expression of strigolactones synthesis related gene experiences a dramatic fall to promote the development of the lateral buds.However,there was a drop before a slight increase in the expression of the auxin synthesis related gene,which was mainly due to the removal of apical dominance that led to the loss of indoleacetic acid in the main stem.However,with formation of the new apical source,indoleacetic acid can be released again.

Differential Proteomics Analysis on Fluoride-resistant Streptococcus mutans by Label-free Quantitation

To figure out the changed biological characteristics of a fluoride-resistant strain compared with those of the parent sensitive strain of Streptococcus mutans（S,mutans） with the help of differential proteomics analysis,sixtyseven proteins with obvious differential expression were identified in fluoride-resistant strain.Among them are the important virulence factors causing caries,including glucosyltransferase-S,glucosyltransferase-I,glucosyltransferase-Si,major cell-surface adhesin Pac,F-ATPase β-subunit,Fth,molecular chaperone DnaK,chaperonin GroEL,and the lactate dehydrogenase.We obtained the differential proteomics expression profiles of the fluoride-resistant strain（UA159-FR） and its parental strain（UA159） of S.mutans.Several important virulence factors bringing about caries were identified to have differential expressions,among which the expression of lactate dehydrogenase in fluoride-resistant strain was enhanced compared to that in its parent strain.The results could provide the basis for analvsing the functions of proteins encoded by caries-related genes from the fluoride-resistant S.mutans strain.

Label-free quantitative proteomics reveals fibrinopeptide B and heparin cofactorⅡas potential serum biomarkers in respiratory syncytial virus-infected mice treated with Qingfei oral liquid formula

Respiratory syncytial virus(RSV) is a leading cause of acute lower respiratory tract infections. Qingfei oral liquid(QFOL), a traditional Chinese medicine, is widely used in clinical treatment for RSV-induced pneumonia. The present study was designed to reveal the potential targets and mechanism of action for QFOL by exploring its influence on the host cellular network following RSV infection. We investigated the serum proteomic changes and potential biomarkers in an RSV-infected mouse pneumonia model treated with QFOL. Eighteen BALB/c mice were randomly divided into three groups: RSV pneumonia model group(M), QFOL-treated group(Q) and the control group(C). Serum proteomes were analyzed and compared using a label-free quantitative LC-MS/MS approach. A total of 172 protein groups, 1009 proteins, and 1073 unique peptides were successfully identified. 51 differentially expressed proteins(DEPs) were identified(15 DEPs when M/C and 43 DEPs when Q/M; 7 DEPs in common). Classification and interaction network showed that these proteins participated in various biological processes including immune response, blood coagulation, complement activation, and so forth. Particularly, fibrinopeptide B(FpB) and heparin cofactor Ⅱ(HCII) were evaluated as important nodes in the interaction network, which was closely involved in coagulation and inflammation. Further, the Fp B level was increased in Group M but decreased in Group Q, while the HCII level exhibited the opposite trend. These findings not only indicated FpB and HCII as potential biomarkers and targets of QFOL in the treatment of RSV pneumonia, but also suggested a regulatory role of QFOL in the RSV-induced disturbance of coagulation and inflammation-coagulation interactions.

Comparative proteomic analysis reveals the effects of different fatty acid forms on high-fat diet mice

Long-chain omega-3 polyunsaturated fatty acids(LC-PUFAs),known for having many health benefits,are usually present in three forms:triglycerides(TG),ethyl esters(EE),and phospholipid(PL).In this study,the effects of these three LC-PUFAs forms(fish oil for TG and EE,krill oil for PL)on the obese mice were compared,and the proteomic changes that focused on lipid metabolism were evaluated via label-free quantitative proteomics analysis.Compared with the model group,all three of the LC-PUFA form supplementations(labeled as the FO-TG group,FO-EE group and KO-PL groups)could significantly reduce body weight gain(P<0.01).Low-density lipoprotein cholesterol levels were significantly decreased,whereas high-density lipoprotein cholesterol levels were significantly increased in the FO-TG group and FO-EE group(P<0.01),and especially in the PL group(P<0.001).Furthermore,proteomics analysis results suggested that some differentially expressed genes involved in the fatty acid degradation and oxidation pathways had a higher expression fold in the KO-PL group than in the FO-TG or FO-EE groups.Our results showed that dietary LC-PUFAs can reduce fat deposition and inhibit lipogenesis in the liver by upregulating the expression of proteins that are involved in the fatty acid degradation and oxidation pathways.Additionally,KO-PL elicits stronger effects than FO-TG or FO-EE.

无标记定量方法在小鼠精子发生相关蛋白质组学研究中的应用

目的:利用无标记定量蛋白质组学技术筛选在3周龄及成年小鼠睾丸中差异表达的蛋白质。方法:分别抽提3周龄及成年小鼠睾丸蛋白,酶解后所得肽段经纳升液相色谱分离,并经LTQ Obitrap质谱鉴定,在获得蛋白鉴定信息的同时根据相应肽段离子质谱峰强度对蛋白进行相对定量。结果:在3周龄及成年小鼠睾丸中共鉴定到非冗余蛋白319种,其中30种蛋白在两者之间存在显著的表达差异,这些蛋白主要参与形态发生、收缩、胞吞、受精等细胞事件,与精子变形过程及精子功能相关。结论:无标记定量蛋白质组学技术,具有方法简便、通量大、成本低廉等优点,利用其寻找睾丸发育,精子发生/功能相关蛋白具有广阔的前景。

Xiao-Xu-Ming decoction extract regulates differentially expressed proteins in the hippocampus after chronic cerebral hypoperfusion

Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global protein profile and signaling conduction pathways regulated by Xiao-Xu-Ming decoction are still unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Rats were intragastrically administered 50 or 150 mg/kg Xiao-Xu-Ming decoction for 4 consecutive weeks. Learning and memory abilities were measured with Morris water maze. Motor ability was detected with prehensile test. Coordination ability was examined using the inclined screen test. Neuronal plasticity was observed by immunofluorescent staining. Differentially expressed proteins of rat hippocampus were analyzed by label-free quantitative proteomics. Real time-polymerase chain reaction and western blot assay were used to identify the changes in proteins. Results showed that Xiao-Xu-Ming decoction dramatically alleviated learning and memory deficits, and motor and coordination dysfunction, and increased the expression of microtubule-associated protein 2. Xiao-Xu-Ming decoction extract remarkably decreased 13 upregulated proteins and increased 39 downregulated proteins. The regulated proteins were mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process. The signaling pathways were mainly involved in ubiquitin mediated proteolysis and the phosphatidylinositol signaling system. Furthermore, there was an interaction among Rab2 a, Ptpn1, Ppm1 e, Cdk18, Gorasp2, Eps15, Capza2, Syngap1 and Mt-nd1. Protein analyses confirmed the changes in expression of MTND1. The current findings provide new insights into the molecular mechanisms of Xiao-Xu-Ming decoction extract's effects on chronic cerebral hypoperfusion.