Salivary exosomal PSMA7: a promising biomarker of inflammatory bowel disease

Abstract

Inflammatory bowel disease (IBD) is an intestinal immune-dysfunctional disease worldwide whose prevalence increasing in Asia including China. It is a chronic disease of the gastrointestinal tract with unknown cause. Exosomes are small vesicles in various body fluids. They have diameters of 40–120 nm, and one of their functions is long-distance transfer of various substances. In this study, we investigated the contents of salivary exosomes in patients with IBD and in healthy controls to explore a new biomarker in patients with IBD. In this study, whole saliva was obtained from patients with IBD (ulcerative colitis (UC), n = 37; Crohn’s disease (CD), n = 11) and apparently healthy individuals (HC, n = 10). Salivary exosomes were extracted from samples, and the proteins within the exosomes were identified by liquid chromatograph-mass spectrometer (LC-MS/MS). The results showed that more than 2000 proteins were detected in salivary exosomes from patients with IBD. Through gene ontology analysis, we found that proteasome subunit alpha type 7 (PSMA7) showed especially marked differences between patients with IBD and the healthy controls, in that its expression level was much higher in the CD and UC groups. This exosomal protein is related to proteasome activity and inflammatory responses. So we conclude that in this research, salivary exosomal PSMA7 was present at high levels in salivary exosomes from subjects with IBD. It can be a very promising biomarker to release the patients from the pain of colonoscopy.Electronic supplementary materialThe online version of this article (doi:10.1007/s13238-017-0413-7) contains supplementary material, which is available to authorized users.

Identification of differentially expressed genes between the colon and ileum of patients with inflammatory bowel disease by gene co-expression analysis

“…The pathogenesis of IBD is extremely complex, involving multiple pathways and cytokines. 22,23 The disease is unpredictable and incurable. 24 Therefore, understanding the mechanism underlying IBD would be helpful in finding the best treatment options as early as possible, which would improve long-term treatment results and quality of life in patients with IBD.…”

Extracellular Vesicles with Possible Roles in Gut Intestinal Tract Homeostasis and IBD

“…Circulating pathogenesis-related EVs have emerged as promising biomarkers to monitor disease development and as novel targets for future anti-inflammation therapies in IBD. In 2017, Zheng et al investigated the high sensibility of salivary exosomal PSMA7 on IBD diagnosis [121]. This study identified the proteins within EVs by using a liquid chromatograph-mass spectrometer, and PSMA7 was shown to be associated with inflammation and immune response as well as depressive disorder in many studies [122,123].…”

Exosomes in Inflammation and Inflammatory Disease

“…Because of the involvement of exosomes in modulation of immune cells and disease progression, differentially expressed exosomal proteins have been proposed as biomarkers for IBD. LC–MS and bioinformatic analysis of exosomes from saliva samples of IBD patients versus healthy controls identified proteasome subunit alpha type 7 (PSMA7), a protein related to proteasome activity and the inflammatory response, as significantly upregulated in IBD patients . The potential for IBD screening via bodily fluids such as saliva provides a much less invasive alternative to colonoscopy.…”