P-704 Distinctive proteomic profiling and pathway analysis of plasma extracellular vesicles provided clues for their regulatory roles in the pathogenesis of polycystic ovarian syndrome
Authors: Huang C  C , Yang J  H , Chen M  J 
Published: July 2024

Abstract

Study question
To elucidate the distinctive proteomic profiling of plasma extracellular vesicles (EVs) and the pathogenic contributions in polycystic ovarian syndrome (PCOS).

Summary answer
In PCOS, differentially expressed proteins in the circulatory exosomes are associated with the several characteristic signaling pathways related to cardiovascular and metabolism risks.

What is known already
EVs from various tissues or body fluids have been shown to be involved in the pathogenesis of PCOS and might serve as potential biomarkers for the diagnosis and prognostic prediction. Most of previous studies focus on the miRNAs expression of EVs isolated from blood, endometrium and follicular fluid. However, a comprehensive quantitative protein analysis of circulatory EVs has seldom been conducted in PCOS. Whether and how the proteomic profiling of circulatory EVs is related to the characteristic phenotypic expression is also unclear.

Study design, size, duration
This is a case-control study conducted at the reproductive endocrinologic department of the tertiary medical center from 2019 to 2022. Blood samples were collected from sixty PCOS and thirty non-PCOS control subjects.

Participants/materials, setting, methods
Plasma EVs were isolated by sucrose gradient-based ultracentrifugation. Quantitative proteomic analysis was performed by tandem mass tag labeling and liquid chromatography tandem mass spectrometry (TMT) to identify differentially expressed proteins. The functions and pathways of identified proteins were analyzed with Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The correlation between the identified proteins and the clinical, hormonal, and biochemical parameters were also analyzed.

Main results and the role of chance
Nanoparticle tracking analysis suggested the majority of EVs were 70-190 nm in diameter, which were corresponsive to the size of exosome. Differential expressed protein (DEP) analysis revealed distinctive upregulated proteins in the circulatory exosomes of PCOS patients, includes IGF-1, HIST1H1E, PF4, HBA1, HBB, SNC73, which were enriched in nitric oxide transport and negative regulation of extrinsic apoptotic signaling pathway. Proteins which were downregulated in PCOS patients, including RAA1, RARRES2, CFHR1, LBP, IGFBP3, TPI1, SERPINA5, SNC73, were enriched in lipid transport and complement and coagulation cascades. There is significant correlation between the differentially expressed exosome proteins and several clinical phenotypes, including hypertension, hyperandrogenism and iron metabolism. The enriched pathways and characterized phenotypes have been shown to be closely related to cardiovascular and metabolic aberrations of PCOS, which could provide pathogenic clues for how the circulatory EVs proteins contribute to the disease development and progression.

Limitations, reasons for caution
PCOS is highly heterogeneous and the case number of our study might not be large enough to differentiate distinctive patterns among different subtypes of PCOS. The enrolled population is limited to reproductive-age Asian patients and might not be generalized to other age or ethnic groups.

Wider implications of the findings
Our results could be apply to further studies for biomarker identification and mechanistic researches, and to elucidate whether and how the proteomic biology of circulatory EVs is related to the pathogenesis of PCOS.

Trial registration number
not applicable