ABSTRACT
@#[摘 要] 目的：以磷酸化蛋白质组学技术分析抗菌肽merecidin处理人肺腺癌A549细胞后细胞内磷酸化蛋白质表达的差异，探究merecidin对肺腺癌A549细胞蛋白质活性、功能的影响以及涉及的信号通路。方法：采用9 μmol/L merecidin处理肺腺癌A549细胞6 h，收集并提取总蛋白，SDS-PAGE检验全蛋白提取效果，加入胰酶来对蛋白质进行酶解。酶解所获肽段用TMT标记、采用HPLC分级分离、经IMAC磷酸化修饰富集以及液相色谱-质谱联用（HPLC-MS/MS）分离肽段。使用localization probability>0.75的标准对鉴定数据进行过滤，利用GO（Gene Ontology）数据库、KEGG（KyotoEncyclopedia of Genes and Genomes）数据库和STRING数据库对磷酸化蛋白组学数据进行分析。结果：SDS-PAGE 结果显示，经9 μmol/L merecidin处理后的A549细胞全蛋白分离效果清晰、无明显降解，且实验组与对照组条带差异明显；质谱共鉴定出位于3 089个蛋白上的10 320个磷酸化修饰位点，以|Fold change|>或<1.5且P<0.05为阈值从中筛选出差异明显的753个蛋白质及其1 172个磷酸化位点。蛋白质功能富集显示，磷酸化水平显著变化的蛋白质功能主要集中在蛋白质分子结合、代谢活性、分子功能调节、细胞进程、生物功能调节等方面；整合通路生物信息学分析结果显示，差异蛋白与Ras、PI3K/AKT、mTOR、AMPK等多条通路相关联；经过COG数据库筛选，发现差异性磷酸化蛋白主要集中在细胞信号转导、RNA转录、翻译后加工和修饰、核糖体合成蛋白质、细胞骨架蛋白形成及细胞内的物质转运和分泌、囊泡运输等多个方面；蛋白质互相作用层面分析结果显示，merecidin处理后的A549细胞中形成以MAPK1、RPL23A、SRSF3H、NCBP1等为关键蛋白的相互作用网，其中ATG2B、ULK1等蛋白显著上调，MAPK1、AKT1等蛋白显著下调。结论：磷酸化蛋白组学分析结果显示，抗菌肽merecidin可能通过MAPK、RPL23A、SRSF3H和AKT1等关键蛋白质在多方面生物功能和多条信号通路中发挥作用，促进肺腺癌A549细胞凋亡和自噬，从而抑制细胞的增殖。
ABSTRACT
@# Objective: To investigate the effects of antimicrobial peptides merecidin on the biological functions of human lung adenocarcinomaA549 cells and the potential signaling pathways and targets that involved in promoting apoptosis, by studying the changes of phosphorylation levels of proteins in A549 cells after merecidin treatment. Methods: The antibacterial peptide mericidin (9 μmol/L) was applied to treat A549 cells for 6 h, and the total protein was collected and extracted. The peptide was digested by trypsin and labeled with TMT, and then fractionated by HPLC. The phosphorylated peptides were enriched with IMAC-Fe, and finally subjected to mass spectrometry analysis. Library identification and quantification of phosphorylated peptides obtained by mass spectrometry were processed using MaxQuant software, to further analyze the functions and pathways of differentially expressed phosphorylated proteins by combining with bioinformatic analysis. Results: Through IPA analysis of phosphorylated proteins in the normal control group and the antibacterial peptide merecidin treatment group, 753 differentially phosphorylated proteins in mericidin treatment group were screened out under the conditions of |Fold Change|≥2 and P<0.05, including 229 significantly up-regulated genes and 417 down-regulated genes. Among them, the differentially expressed proteins related to apoptosis included RB1, MAPK1, ARAF, PTK2, FOXO, MARCKSandsoon.Theresultsofbiologicalprocessanalysisshowedthatdifferentiallyexpressed phosphorylated proteins were mainly concentrated in cell signal transduction, degradation and transport of nucleic acid, and cellular energy metabolism, protein translation and synthesis, and cytoskeleton formation etc. The enrichment results showed that the differentially expressed phosphorylated proteins were mainly involved in apoptosis-related MAPK, ErbB, PI3K-Akt, and Ras signaling pathways. Protein-protein interaction analysis indicated the associations among apoptosis-related proteins PTK2, PRKCA, MA2PK2, MAPK1, and LMNA. Conclusion: The antibacterial peptide merecidin may induce apoptosis and alteration of other cell functions by affecting a variety of genes and signaling pathways such as RB1, MAPK1,ARAF, PTK2, FOXO and MARCKS etc.
ABSTRACT
Objective@#To analyze the prevalence and influencing factors of suicidal behaviors among middle school students in minority areas of Guizhou Province, and to provide the reference for targetedly preventing suicidal behavior among middle school students.@*Methods@#Questionnaire survey including adolescent health information, Depression Self-rating Scale for Children(DSR-SC), Childhood Trauma Questionnaire-Short Form (CTQ-SF) and the Pittsburgh Sleep Quality Index survey were conducted among 6 139 middle school students in minority areas of Guizhou Province, Logistic regression was used to analyze the influencing factors of suicidal behavior of middle school students.@*Results@#A total of 1 241(20.2%) had suicidal ideation in the past 12 months, and 250 (4.1%) of middle school students had committed suicide in the past 12 months. Suicidal ideation among middle school students was positively associated with: female, non-residence, being only child, smoking, having poor relationship with teachers, poor relationship with classmates, school violence victimization, physical abused, sexual abuse, emotionally neglected, having depression, having sleeping disorders(OR=1.67, 1.64, 0.84, 0.72, 0.67, 0.58, 2.06, 2.45, 2.12, 1.68, 2.82, 1.62). While being women(OR=1.52), non-residence(OR=2.25), smoking(OR=0.52), poor relationship with teachers(OR=0.49), poor relationship with classmates(OR=0.47), school violence victimization (OR=1.79) and physically abused(OR=2.17), sexual abused(OR=1.97), physically neglected(OR=1.94), depressive symptoms(OR=3.14), sleep disorders (OR=1.66) were associated positively with the risk of suicide attempt.@*Conclusion@#Suicide-related behaviors are more common in minority areas of Guizhou Province. Teachers and parents should attach great importance to it, and their suicidal risk should be early recognized to reduce suicide-related behaviors.