Identification of exosome protein panels as predictive biomarkers for non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related deaths worldwide, primarily due to its propensity for metastasis. Patients diagnosed with localized primary cancer have higher survival rates than those with metastasis. Thus, it is imperative to discover biomarkers for the early detection of NSCLC and the timely prediction of tumor metastasis to improve patient outcomes. METHODS: Here, we utilized an integrated approach to isolate and characterize plasma exosomes from NSCLC patients as well as healthy individuals. We then conducted proteomics analysis and parallel reaction monitoring to identify and validate the top-ranked proteins of plasma exosomes. RESULTS: Our study revealed that the proteome in exosomes from NSCLC patients with metastasis was distinctly different from that from healthy individuals. The former had larger diameters and lower concentrations of exosomes than the latter. Furthermore, among the 1220 identified exosomal proteins, we identified two distinct panels of biomarkers. The first panel of biomarkers (FGB, FGG, and VWF) showed potential for early NSCLC diagnosis and demonstrated a direct correlation with the survival duration of NSCLC patients. The second panel of biomarkers (CFHR5, C9, and MBL2) emerged as potential biomarkers for assessing NSCLC metastasis, of which CFHR5 alone was significantly associated with the overall survival of NSCLC patients. CONCLUSIONS: These findings underscore the potential of plasma exosomal biomarkers for early NSCLC diagnosis and metastasis prediction. Notably, CFHR5 stands out as a promising prognostic indicator for NSCLC patients. The clinical utility of exosomal biomarkers offers the potential to enhance the management of NSCLC.

Comprehensive Analysis of Fibroblast Growth Factor Receptor (FGFR) Family Genes in Breast Cancer by Integrating Online Databases and Bioinformatics.

BACKGROUND Fibroblast growth factor receptors (FGFRs) play vital roles in the development and progression of human cancers. This study aimed to comprehensively understand the prognostic performances of FGFR1-4 expression in breast cancer (BC) by mining databases. MATERIAL AND METHODS The levels of FGFR1-4 expression in BC were analyzed by online databases, GEPIA (Gene Expression Profiling Interactive Analysis) and UALCAN. Survival analysis of FGFR1-4 was carried out by Kaplan-Meier plotter. GSE74146 was downloaded from Gene Expression Omnibus (GEO) and analyzed by GEO2R to screen the differentially expressed genes (DEGs) between FGFR2-silenced BC cells and control. Over-presentation for DEGs were done by Enrichr tool. Networks of DEGs were obtained by using Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape software. Hub genes were identified by cytoHubba Cytoscape plugin. RESULTS The online databases showed that FGFR1 was significantly downregulated whereas FGFR3 was upregulated in BC. Kaplan-Meier plotter demonstrated the upregulation of both FGFR1 and FGFR3 indicated favorable relapse free survival (RFS) whereas FGFR4 overexpression predicted unfavorable overall survival (OS) in BC patients. Importantly, our results showed FGFR2 overexpression robustly predicted favorable OS and RFS in BC. Further bioinformatics analysis of GSE74146 suggested FGFR2 mainly participated in regulating degradation and organization of the extracellular matrix and signaling of retinoic acid. Moreover, CXCL8, CD44, MMP9, and BMP7 were identified as crucial FGFR2-related hub genes. CONCLUSIONS Our study comprehensively analyzed the prognostic values of FGFR1-4 expression in BC and proposed FGFR2 might serve as a promising biomarker. However, the underlying mechanisms remain to be elucidated.

iTRAQ-Based Proteomic Analysis reveals possible target-related proteins and signal networks in human osteoblasts overexpressing FGFR2.

BACKGROUND: Fibroblast growth factor receptor 2 (FGFR2) play a vital role in skeletogenesis. However, the molecular mechanisms triggered by FGFR2 in osteoblasts are still not fully understood. In this study, proteomics and bioinformatics analysis were performed to investigate changes in the protein profiles regulated by FGFR2, with the goal of characterizing the molecular mechanisms of FGFR2 function in osteoblasts. METHODS: In this study, FGFR2-overexpression cell line was established using the lentivirus-packaging vector in human osteoblasts (hFOB1.19). Next, the isobaric tags for relative and absolute quantitation (iTRAQ) in combination with the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to compare the proteomic changes between control and FGFR2-overexpression cells. Thresholds (fold-change of ≥ 1.5 and a P-value of < 0.05) were selected to determine differentially expressed proteins (DEPs). The bioinformatics analysis including GO and pathway analysis were done to identify the key pathways underlying the molecular mechanism. RESULTS: A Total of 149 DEPs was identified. The DEPs mainly located within organelles and involved in protein binding and extracellular regulation of signal transduction. ColI, TNC, FN1 and CDKN1A were strikingly downregulated while UBE2E3, ADNP2 and HSP70 were significantly upregulated in FGFR2-overexpression cells. KEEG analysis suggested the key pathways included cell death, PI3K-Akt signaling, focal adhesion and cell cycle. CONCLUSIONS: To our knowledge, this is the first protomic research to investigate alterations in protein levels and affected pathways in FGFR2-overexpression osteoblasts. Thus, this study not only provides a comprehensive dataset on overall protein changes regulated by FGFR2, but also shed light on its potential molecular mechanism in human osteoblasts.

Overexpression of Glypican 3 Promotes Proliferation, Regulates Cell Cycle Progression, and Inhibits Apoptosis of Human Fetal Osteoblastic Cell Line 1.19.

Craniosynostosis is a complex disease condition, which involves premature fusion of cranial vault sutures and lacks desirable treatment. Previous studies have demonstrated decreased proliferation rate of osteoblasts and downregulated expression of glypican 3 (GPC3) in syndromic craniosynostosis patients. In this study, quantitative and qualitative analysis were utilized to assess the effect of GPC3 in human fetal osteoblastic cell line, hFOB 1.19. Lentiviral transfection efficiency with green fluorescent protein images was obtained after 72 hours. Western Blot and quantitative real-time polymerase chain reaction analysis results indicated that GPC3 was overexpressed in hFOB 1.19 cells transfected with recombinant lentivirus LV-GPC3-GFP. Cell proliferation was assessed by CCK-8 assay and cell cycle progression and apoptosis were analyzed by flow cytometric assay. Results revealed that GPC3 promoted cell viability, induced cell cycle entry into S phase, and inhibited cell apoptosis. These findings provide novel ideas in understanding the pathogenesis of craniosynostosis. It also provides novel insights in the treatment of craniosynostosis by targeting GPC3.

Value of Osteoblast-Derived Exosomes in Bone Diseases.

PURPOSE: The authors' purpose is to reveal the value of osteoblast-derived exosomes in bone diseases. METHODS: Microvesicles from supernatants of mouse Mc3t3 were isolated by ultracentrifugation and then the authors presented the protein profile by proteomics analysis. RESULTS: The authors detected a total number of 1536 proteins by mass spectrometry and found 172 proteins overlap with bone database. The Ingenuity Pathway Analysis shows network of "Skeletal and Muscular System Development and Function, Developmental Disorder, Hereditary Disorder" and pathway about osteogenesis. EFNB1 and transforming growth factor beta receptor 3 in the network, LRP6, bone morphogenetic protein receptor type-1, and SMURF1 in the pathway seemed to be valuable in the exosome research of related bone disease. CONCLUSIONS: The authors' study unveiled the content of osteoblast-derived exosome and discussed valuable protein in it which might provide novel prospective in bone diseases research.

Identification and proteomic analysis of osteoblast-derived exosomes.

Exosomes are nanometer-sized vesicles with the function of intercellular communication, and they are released by various cell types. To reveal the knowledge about the exosomes from osteoblast, and explore the potential functions of osteogenesis, we isolated microvesicles from supernatants of mouse Mc3t3 by ultracentrifugation, characterized exosomes by electron microscopy and immunoblotting and presented the protein profile by proteomic analysis. The result demonstrated that microvesicles were between 30 and 100 nm in diameter, round shape with cup-like concavity and expressed exosomal marker tumor susceptibility gene (TSG) 101 and flotillin (Flot) 1. We identified a total number of 1069 proteins among which 786 proteins overlap with ExoCarta database. Gene Oncology analysis indicated that exosomes mostly derived from plasma membrane and mainly involved in protein localization and intracellular signaling. The Ingenuity Pathway Analysis showed pathways are mostly involved in exosome biogenesis, formation, uptake and osteogenesis. Among the pathways, eukaryotic initiation factor 2 pathways played an important role in osteogenesis. Our study identified osteoblast-derived exosomes, unveiled the content of them, presented potential osteogenesis-related proteins and pathways and provided a rich proteomics data resource that will be valuable for further studies of the functions of individual proteins in bone diseases.

The C342R mutation in FGFR2 causes Crouzon syndrome with elbow deformity.

Crouzon syndrome is an autosomal dominant craniosynostosis syndrome caused by mutation in the fibroblast growth factor receptor 2 (FGFR-2). Numerous findings from animal studies imply a critical role for FGFRs in the regulation of skeletal development. Here, we report 2 unrelated patients with Crouzon syndrome accompanied by elbow deformity. Subsequently, we analyzed the sequence of the FGFR2 gene and found that both of the patients carried the Cys342Arg mutation. The findings suggest that the C342R mutation in FGFR2 may cause Crouzon syndrome and elbow deformity in Chinese patients.

S267P mutation in FGFR2: first report in a patient with Crouzon syndrome.

It has been known for several years that mutations in the fibroblast growth factor receptor (FGFR2) result in syndromic craniosynostosis including Apert, Crouzon, or Pfeiffer syndromes. Here, we report on a child with a clinically diagnosed Crouzon syndrome that shows the missense point mutation S267P in FGFR2 gene. The mutation is firstly identified in Crouzon syndrome. Our observations expand the molecular spectrum of FGFR2 mutations in the syndrome.

Severe meningeal calcification in a Crouzon patient carrying a mutant C342W FGFR2.

Crouzon is an autosomal dominant craniosynostosis syndrome caused by mutation in the fibroblast growth factor receptor (FGFR)-2 gene. Recent findings from animal studies imply a critical role for FGFs in the regulation of mineralization. Here, we presented a 5-year-old girl with severe meningeal calcification. Subsequently, we analyzed FGFR2 mutation and identified a mutation of Cys342Tyr. The findings suggest that abnormal calcification was atypical phenotype of Crouzon patients with Cys342Tyr mutation in FGFR2.

Skeleton first in surgical treatment of facial disharmony.

PURPOSE: The aim of this study was to correct facial disharmony with or without occlusal dysfunction. METHODS: Based on computed tomography and presurgical design, restoration of normal skeleton relationship is a priority for selected facial deformities. Combination of different osteotomies for facial skeleton was chosen in 1-stage operation such as orthognathic surgery, zygomatic reduction, and mandibular angle reduction. Supplementary surgeries was considered in some cases as substitute implantation or autologous fat graft. RESULTS: All the 50 patients (hemifacial microsomia, Romberg syndrome, mandibular condyle hyperplasia, secondary cleft palate, and Crouzon syndrome) received surgeries, and their facial appearance improved significantly. Yearly follow-up shows that the symmetry and balance of the facial proportion approach normal, whereas most of their occlusal relationship has been significantly improved after the first stage of surgery. CONCLUSIONS: For most facial disharmony with or without occlusal dysfunction, skeleton-first surgery is a feasible strategy.

Decreased expression of LASS2 is associated with worse prognosis in meningiomas.

Homo sapiens longevity assurance homolog 2 of yeast LAG1 (LASS2) has been indicated to have a critical role in various tumors. In the study, we aimed to evaluate the LASS2 expression level in prognostic significance and compare it with commonly used biomarkers: Ki-67, p53 and progesterone receptor (PR) for patients with meningiomas. Firstly, 50 fresh tissues and 143 paraffin-embedded meningiomas samples were analyzed for LASS2 expression by quantitative PCR and immunohistochemistry (IHC), respectively. Subsequently, LASS2 immunostaining was evaluated for its clinical significance. Furthermore, Correlations of LASS2 expression with common biomarkers were assessed. Both PCR and IHC results showed LASS2 was downregulated in high-grade meningiomas in comparison with that of grade I or normal brain (all P < 0.01). IHC results demonstrated LASS2 intensity distribution (ID) score was significantly correlated with tumor size, brain invasion, tumor recurrence and clinical course (all P < 0.01), whereas no correlation of LASS2 ID score with sex or Simpson grade. Moreover, lower LASS2 ID score was strikingly associated with shorter overall and progression-free survival (P < 0.01). Pearson's analysis revealed the ID score was significantly reversely associated with Ki-67 and p53 but not with PR. More importantly,multivariate analyses revealed that LASS2 was an independent prognostic factor (P < 0.05). To our knowledge, it is the first time to investigate the expression of LASS2 and identify it as a potential biomarker for prognosis in meningiomas.

Expression of RACGAP1 in high grade meningiomas: a potential role in cancer progression.

Recently, Rac GTPase-activating protein 1 (RACGAP1) has been shown to have a critical role in various tumors. The aim of the present study was to investigate the expression of RACGAP1 in human meningiomas and to compare these results with the clinicopathological parameters. Thirty-two cases, classified as 13 World Health Organization grade I (40.6 %), 10 grade II (31.3 %) and 9 grade III (28.1 %) primary meningiomas, were selected from our pathological files. Clinico-pathological data, including survival data, were also available. RACGAP1 expression in the meningiomas was measured by real-time quantitative PCR and western blot. Our results showed the level of RACGAP1 expression in grade III meningioma is higher than that of grade I. Higher levels of RACGAP1 mRNA were significantly correlated with tumor size, higher Simpson grade, histological type and clinical course (P < 0.05). Furthermore, the level of RACGAP1 expression mRNA was positively correlated with MIB-1 labeling index in different meningiomas tissue (r(2) = 0.3237, P = 0.0007). Additionally, Kaplan-Meier curves demonstrated a significantly worse survival in patients with high levels of RACGAP1 mRNA (P = 0.008). In conclusion, these findings suggest that RACGAP1 may be used as a potential predictor for tumor proliferative and patient prognosis in meningiomas.

Association between laminin γ1 expression and meningioma grade, recurrence, and progression-free survival.

BACKGROUND: Laminins are central components of basement membranes and play important roles in cell adhesion, proliferation, and migration. However, the role of laminins in tumor progression has not been thoroughly investigated in meningiomas. OBJECTIVE: The aim of the present study is to evaluate the expression of laminin γ1 in various grades of meningiomas in Chinese patients. METHODS: In the current study, clinical and pathological data for 32 meningioma patients with various tumor grades were collected. The expression of laminin γ1 in each tumor was assessed by using quantitative real-time polymerase chain reaction (qPCR), Western blot and immunohistochemical analysis and was correlated with the meningioma grade, tumor recurrence and patient survival. Patient prognoses were attained and the progression-free survival was calculated based on the Kaplan-Meier method. A two-sided probability cutoff of 0.05 was chosen for statistical significance. RESULTS: A total of 32 meningioma patients with various pathological subtypes (WHO grade I: 13, grade II: 10 and grade III: 9) were enrolled in this study. The qPCR results showed that laminin γ1 mRNA expression was significantly higher in grade III meningiomas than in grade I meningiomas (p < 0.05), although there was no significant difference in laminin γ1 expression between grade II and grade I meningiomas (p > 0.05). Western blot and immunohistochemistry analysis confirmed that the expression of laminin γ1 protein was relatively higher in grade III meningiomas when compared with grade I meningiomas. Higher levels of laminin γ1 expression in meningiomas are associated with a significantly shorter tumor recurrence time (p < 0.05) and a decreased patient survival time (p < 0.05). CONCLUSIONS: Our results suggest that laminin γ1 is associated with meningioma grades and could play a role in enhancing tumor invasion. Laminin γ1 could be used as a predictor for meningioma recurrence and patient survival. Furthermore, laminin γ1 may represent a druggable molecular target for future therapies for tumors that overexpress this marker.

Polyphyllin VII induces CTC anoikis to inhibit lung cancer metastasis through EGFR pathway regulation.

Circulating tumor cells (CTCs) are cells that detach from the primary tumor and enter the bloodstream, playing a crucial role in the metastasis of lung cancer. Unfortunately, there is currently a lack of drugs specifically designed to target CTCs and prevent tumor metastasis. In this study, we present evidence that polyphyllin VII, a potent anticancer compound, effectively inhibits the metastasis of lung cancer by inducing a process called anoikis in CTCs. We observed that polyphyllin VII had significant cytotoxicity and inhibited colony formation, migration, and invasion in both our newly established cell line CTC-TJH-01 and a commercial lung cancer cell line H1975. Furthermore, we found that polyphyllin VII induced anoikis and downregulated the TrkB and EGFR-MEK/ERK signaling pathways. Moreover, activation of TrkB protein did not reverse the inhibitory effect of polyphyllin VII on CTCs, while upregulation of EGFR protein effectively reversed it. Furthermore, our immunodeficient mouse models recapitulated that polyphyllin VII inhibited lung metastasis, which was associated with downregulation of the EGFR protein, and reduced the number of CTCs disseminated into the lungs by inducing anoikis. Together, these results suggest that polyphyllin VII may be a promising compound for the treatment of lung cancer metastasis by targeting CTCs.

Gene Regulation Network of Prognostic Biomarker YAP1 in Human Cancers: An Integrated Bioinformatics Study.

Background: Yes-associated protein 1 (YAP1) is the main downstream effector of the Hippo signaling pathway, which is involved in tumorigenesis. This study aimed to comprehensively understand the prognostic performances of YAP1 expression and its potential mechanism in pan-cancers by mining databases. Methods: The YAP1 expression was evaluated by the Oncomine database and GEPIA tool. The clinical significance of YAP1 expression was analyzed by the UALCAN, GEPIA, and DriverDBv3 database. Then, the co-expressed genes with YAP1 were screened by the LinkedOmics, and annotated by the Metascape and DAVID database. Additionally, by the MitoMiner 4.0 v tool, the YAP1 co-expressed genes were screened to obtain the YAP1-associated mitochondrial genes that were further enriched by DAVID and analyzed by MCODE for the hub genes. Results: YAP1 was differentially expressed in human cancers. Higher YAP1 expression was significantly associated with poorer overall survival and disease-free survival in adrenocortical carcinoma (ACC), brain Lower Grade Glioma (LGG), and pancreatic adenocarcinoma (PAAD). The LinkedOmics analysis revealed 923 co-expressed genes with YAP1 in adrenocortical carcinoma, LGG and PAAD. The 923 genes mainly participated in mitochondrial functions including mitochondrial gene expression and mitochondrial respiratory chain complex I assembly. Of the 923 genes, 112 mitochondrial genes were identified by MitoMiner 4.0 v and significantly enriched in oxidative phosphorylation. The MCODE analysis identified three hub genes including CHCHD1, IDH3G and NDUFAF5. Conclusion: Our findings showed that the YAP1 overexpression could be a biomarker for poor prognosis in ACC, LGG and PAAD. Specifically, the YAP1 co-expression genes were mainly involved in the regulation of mitochondrial function especially in oxidative phosphorylation. Thus, our findings provided evidence of the carcinogenesis of YAP1 in human cancers and new insights into the mechanisms underlying the role of YAP1 in mitochondrial dysregulation.

RNA sequencing analysis of FGF2-responsive transcriptome in skin fibroblasts.

BACKGROUND: Fibroblast growth factor 2 (FGF2) is a highly pleiotropic cytokine with antifibrotic activity in wound healing. During the process of wound healing and fibrosis, fibroblasts are the key players. Although accumulating evidence has suggested the antagonistic effects of FGF2 in the activation process of fibroblasts, the mechanisms by which FGF2 hinders the fibroblast activation remains incompletely understood. This study aimed to identify the key genes and their regulatory networks in skin fibroblasts treated with FGF2. METHODS: RNA-seq was performed to identify the differentially expressed mRNA (DEGs) and lncRNA between FGF2-treated fibroblasts and control. DEGs were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Furthermore, the networks between mRNAs and lncRNAs were constructed by Pearson correlation analysis and the networkanalyst website. Finally, hub genes were validated by real time-PCR. RESULTS: Between FGF2-treated fibroblasts and control fibroblasts, a total of 1475 DEGs was obtained. These DEGs were mainly enriched in functions such as the ECM organization, cell adhesion, and cell migration. They were mainly involved in ECM-receptor interaction, PI3K-Akt signaling, and the Hippo pathway. The hub DEGs included COL3A1, COL4A1, LOX, PDGFA, TGFBI, and ITGA10. Subsequent real-time PCR, as well as bioinformatics analysis, consistently demonstrated that the expression of ITGA10 was significantly upregulated while the other five DEGs (COL3A1, COL4A1, LOX, PDGFA, TGFBI) were downregulated in FGF2-treated fibroblasts. Meanwhile, 213 differentially expressed lncRNAs were identified and three key lncRNAs (HOXA-AS2, H19, and SNHG8) were highlighted in FGF2-treated fibroblasts. CONCLUSION: The current study comprehensively analyzed the FGF2-responsive transcriptional profile and provided candidate mechanisms that may account for FGF2-mediated wound healing.

[LASS2 interacts with V-ATPase and inhibits cell growth of hepatocellular carcinoma].

Homo sapiens longevity assurance homologue 2 (LASS2) is a novel gene isolated from a human liver cDNA library by our laboratory, and it is a human homologue of the yeast longevity assurance gene LAG1 (Saccharomyces cerevisiae longevity assurance gene). According to our previous results, LASS2 could interact with subunit c of vacuolar type H(+)-ATPase (V-ATPase), and the overexpression of LASS2 could inhibit the cell growth of a human hepatocellular carcinoma (HCC) cell line, SMMC-7721. In order to understand the role of the interaction between LASS2 and V-ATPase in HCC cell growth, we transiently transfected plasmid pCMV-HA2-LASS2 into HCCLM3, a HCC cell line without the significant expression of endogenous LASS2. The pH-sensitive fluorescence probes, BCECF and BCECF-AM, were used to measure the intracellular and extracellular H(+) concentrations of HCCLM3 cells respectively. The effect of LASS2 gene on apoptosis was evaluated with Annexin-V/FITC and propidium iodide (PI) by flow cytometry. Western blot was used to detect cytochrome c (Cyt c) in the cytosol and mitochondria, as well as pro-caspase-3 in cytosol. The results showed that the cell growth of LASS2-transfected HCCLM3 cells was significantly inhibited compared with that of the mock control. LASS2 transfection increased intracellular H(+) concentration of HCCLM3 cells, while decreased extracellular H(+) concentration. Moreover, LASS2 transfection significantly enhanced the apoptosis of HCCLM3 cells. In LASS2-transfected cells, the amounts of Cyt c increased in the cytosol, while decreased in the mitochondria. Meanwhile, the expression of pro-caspase-3 in the cytosolic extracts was decreased. These results implicate that LASS2 gene might increase intracellular H(+) of HCC cells via the interaction with V-ATPase, thereby inducing cell apoptosis through mitochondrial pathway.

FOXE1 inhibits cell proliferation, migration and invasion of papillary thyroid cancer by regulating PDGFA.

PURPOSE: Forkhead box E1 (FOXE1) plays an important role in the development, proliferation and differentiation of thyroid cells. However, the biological functions of FOXE1 in papillary thyroid cancer (PTC) remain unclear. MATERIALS AND METHODS: In this study, the level of FOXE1 expression was examined in human PTC tissues and cells. Then, the high expression of FOXE1 was specifically silenced by RNA interference in vitro. Subsequently, FOXE1-shRNA was transfected into PTC cells (TPC-1 and K1). The effects on cell proliferation, migration and invasion were evaluated. In addition, FOXE1 targets were screened by cDNA microarray assays. The correlation between the expression of target gene platelet-derived growth factor A (PDGFA) and clinicopathological features of PTC patients was analysed. RESULTS: FOXE1 is highly expressed in PTC tissues and PTC cell lines. The silencing of FOXE1 significantly promotes PTC cell proliferation, migration and invasion in vitro. The cDNA microarray analyses show that PDGFA is a critical downstream target gene of FOXE1 in PTC cells. It was also observed that PDGFA is negatively regulated by FOXE1 in PTC. The clinical data indicate that the low expression level of PDGFA is correlated with the small size of PTC. CONCLUSION: Collectively, the results indicate for the first time that high expression of FOXE1 may function as a tumour suppressor in the early stage of PTC and restrain the proliferation, migration and invasion of PTC by negatively regulating PDGFA expression. Thus, FOXE1 could serve as a prognostic biomarker for PTC.

Differential proteomic analysis of serum exosomes reveals alterations in progression of Parkinson disease.

Exosomes are nanometer-sized vesicles with intercellular communication functions, and their encapsulated proteins may participate in the pathological process of neurodegenerative disorders. The aim of this study was to identify the protein changes of serum exosomes in Parkinson disease (PD) patients with different disease progress types, and to identify potential biomarkers. The exosomes of PD patients with different severity and healthy control group were isolated from serum. The exosome proteins were analyzed by mass spectrometry with label-free quantitative proteomics. A total of 429 proteins were identified, of which 14 were significantly different in mild and severe PD patients. The expression levels of 7 proteins, including pigmented epithelium-derived factor, afamin, apolipoprotein D and J, were significantly increased in PD patients. The expression levels of 7 proteins, including complement C1q and protein Immunoglobulin Lambda Variable 1-33 (IGLV1-33)Cluster -33, were decreased in PD patients. These differentially expressed proteins were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, which confirmed that the interaction between prion diseases and ECM receptors was the most significant pathways of enrichment. The changes of proteins and pathways may be related to the pathophysiological mechanism of PD. Therefore, some of these proteins could be considered as potential biomarkers for early PD diagnosis.