IADR Abstract Archives
The Influence of Shear Stress on Exosome Secretion in hPDLSCs
Objectives: In response to mechanical force, human periodontal ligament stem cells (hPDLSCs) exert regenerative properties through the secretion of paracrine factors, including exosomes. Exosomes are 30-100 nm membrane-bound vesicles that encapsulate bioactive molecules, including proteins, lipids, mRNA, and non-coding RNA, facilitating cell-to-cell communication during tissue homeostasis. The exosomes derived from cyclic stretch-induced PDL cells have demonstrated the ability to regulate macrophage-mediated inflammation. Our previous study revealed that shear stress promoted the secretion of TGF-β1 and kynurenine in the conditioned medium (CM), further decreasing T cell proliferation and increasing Treg cell differentiation. In this study, we aim to investigate the effect of shear stress on exosome secretion by hPDLSCs.
Methods: The cells were subjected to a cone-shaped rotating machine that generated a shear stress of 5 dyn/cm2 for 3 h. The CM was collected for kynurenine measurement. The exosomes were isolated from CM using the ultra-centrifugal tube-based method and subsequently evaluated for nanoparticle size distribution and concentration using nanoparticle tracking analysis (NTA). Expression of exosome surface markers CD63 was detected using western blotting analysis.
Results: The particle size distribution analysis conducted using NTA revealed that the isolated vesicles exhibited dominant particle sizes of 126.85±20.15 nm and 103.5±12.8 nm in shear stress-derived exosome (SS-EXO) and non-shear stress-derived exosome (nSS-EXO), respectively. The average particle sizes were 140.4±15.27 nm and 190.15±50.5 nm in SS-EXO and nSS-EXO, respectively. The particle concentration of SS-EXO (5.28x107±1.68x107 particles/ml) was higher when compared to nSS-EXO (2.97107±7.35x106 particles/ml). Moreover, SS-EXO exhibited an increased CD63 protein expression compared to nSS-EXO.
Conclusions: Collectively, our results reveal that shear stress enhances the exosome secretion by hPDLSCs. However, further studies are needed to emphasize the role of shear stress on hPDLSCs response regarding exosome secretion, composition, and function.
Methods: The cells were subjected to a cone-shaped rotating machine that generated a shear stress of 5 dyn/cm2 for 3 h. The CM was collected for kynurenine measurement. The exosomes were isolated from CM using the ultra-centrifugal tube-based method and subsequently evaluated for nanoparticle size distribution and concentration using nanoparticle tracking analysis (NTA). Expression of exosome surface markers CD63 was detected using western blotting analysis.
Results: The particle size distribution analysis conducted using NTA revealed that the isolated vesicles exhibited dominant particle sizes of 126.85±20.15 nm and 103.5±12.8 nm in shear stress-derived exosome (SS-EXO) and non-shear stress-derived exosome (nSS-EXO), respectively. The average particle sizes were 140.4±15.27 nm and 190.15±50.5 nm in SS-EXO and nSS-EXO, respectively. The particle concentration of SS-EXO (5.28x107±1.68x107 particles/ml) was higher when compared to nSS-EXO (2.97107±7.35x106 particles/ml). Moreover, SS-EXO exhibited an increased CD63 protein expression compared to nSS-EXO.
Conclusions: Collectively, our results reveal that shear stress enhances the exosome secretion by hPDLSCs. However, further studies are needed to emphasize the role of shear stress on hPDLSCs response regarding exosome secretion, composition, and function.