Stability of human salivary extracellular vesicles containing dipeptidyl peptidase IV under simulated gastrointestinal tract conditions.
Background
Extracellular vesicles (EVs) have been isolated from various sources, including primary and cultured cell lines and body fluids. Previous studies, including those conducted in our laboratory, have reported the stability of EVs under various storage conditions.


Methods
EVs from human whole saliva were separated via size-exclusion chromatography. To simulate the effects of gastric or intestinal fluids on the stability of EVs, pepsin or pancreatin was added to the samples. Additionally, to determine the effect of bile acids, sodium cholate was added. The samples were then subjected to western blotting, dynamic light scattering, and transmission electron microscopy analyses. In addition, the activity of dipeptidyl peptidase (DPP) IV retained in the samples was examined to monitor the stability of EVs.


Results
Under acidic conditions, with pepsin mimicking the milieu of the stomach, the EVs remained stable. However, they partially lost their membrane integrity in the presence of pancreatin and sodium cholate, indicating that they may be destabilized after passing through the duodenum. Although several associated proteins, such as mucin 5B and CD9 were degraded, DPP IV was stable, and its activity was retained under the simulated gastrointestinal conditions.


Conclusion
Our data indicate that although EVs can pass through the stomach without undergoing significant damage, they may be disrupted in the intestine to release their contents. The consistent delivery of active components such as DPP IV from EVs into the intestine might play a role in the efficient modulation of homeostasis of the signal transduction pathways occurring in the gastrointestinal tract.
['Ogawa|Yuko|Y|', 'Akimoto|Yoshihiro|Y|', 'Ikemoto|Mamoru|M|', 'Goto|Yoshikuni|Y|', 'Ishikawa|Anna|A|', 'Ohta|Sakura|S|', 'Takase|Yumi|Y|', 'Kawakami|Hayato|H|', 'Tsujimoto|Masafumi|M|', 'Yanoshita|Ryohei|R|']
Stability Extracellular vesicles Dipeptidyl peptidase IV Human whole saliva Gastrointestinal condition Alix, programmed cell death 6-interacting protein DLS, dynamic light scattering DPP IV, dipeptidyl peptidase IV EVs, extracellular vesicles Exosomes MCA, 4-methyl-coumaryl-7-amide PBS, phosphate buffered saline PLA2, phospholipase A2 SD, standard deviation TEM, transmission electron microscopic TSG101, tumor susceptibility gene 101 WS, whole saliva