IADR Abstract Archives
Hippo/YAP-targeted TGF-β1 is essential for shear stress-induced immunomodulation in hPDLSCs
Objectives: Human periodontal ligament stem cells (hPDLSCs) exhibit significant immunomodulatory properties in response to shear stress, inhibiting T cell proliferation and promoting Treg cell differentiation. Our previous study indicated that Yes-associated protein (YAP), a downstream effector of the Hippo signaling pathway, functions as a mechanosensitive transcriptional activator that regulates osteo-adipogenic fate decision in hPDLSCs. In this study, we aimed to investigate whether YAP is involved in the immunosuppressive properties of hPDLSCs in response to shear stress loading.
Methods: The hPDLSCs were subjected to shear stress at different magnitudes (0.5, 5, and 10 dyn/cm2) and were investigated for immunomodulatory characteristics using qRT-PCR, western blot, and ELISA. The hPDLSCs were transfected with YAP-specific shRNA for YAP silencing. The effects of the shear stress on the immunosuppressive properties of hPDLSCs were determined by treating T cells with a conditioned medium derived from shear stress-induced hPDLSCs (SS-CM). T cell proliferation and Treg differentiation were examined using a resazurin assay and flow cytometry analysis, respectively. The role of TGF-β1 was confirmed by using SB431542, the specific TGF-β1 inhibitor.
Results: Our data showed that shear stress at 5 dyn/cm2 upregulated the mRNA expression of TGF-β1 and IDO. The amount of kynurenine product and active TGF-β1 increased in SS-CM compared to the control CM. SS-CM remarkedly decreased T cell proliferation, which was abolished by SB431542. The suppression of YAP reduced the TGF-β1 mRNA expression in hPDLSCs, and the TGF-β1 secretion in SS-CM. Subsequently, these SS-CM derived from YAP knockdown cells increased T cell proliferation and decreased CD4+CD25hiCD127lo/- Treg cell population, compared to the control SS-CM.
Conclusions: Our finding indicated that YAP plays a critical role in promoting the immunosuppressive capacity of hPDLSCs via TGF-β1 signaling in response to shear stress loading.
Methods: The hPDLSCs were subjected to shear stress at different magnitudes (0.5, 5, and 10 dyn/cm2) and were investigated for immunomodulatory characteristics using qRT-PCR, western blot, and ELISA. The hPDLSCs were transfected with YAP-specific shRNA for YAP silencing. The effects of the shear stress on the immunosuppressive properties of hPDLSCs were determined by treating T cells with a conditioned medium derived from shear stress-induced hPDLSCs (SS-CM). T cell proliferation and Treg differentiation were examined using a resazurin assay and flow cytometry analysis, respectively. The role of TGF-β1 was confirmed by using SB431542, the specific TGF-β1 inhibitor.
Results: Our data showed that shear stress at 5 dyn/cm2 upregulated the mRNA expression of TGF-β1 and IDO. The amount of kynurenine product and active TGF-β1 increased in SS-CM compared to the control CM. SS-CM remarkedly decreased T cell proliferation, which was abolished by SB431542. The suppression of YAP reduced the TGF-β1 mRNA expression in hPDLSCs, and the TGF-β1 secretion in SS-CM. Subsequently, these SS-CM derived from YAP knockdown cells increased T cell proliferation and decreased CD4+CD25hiCD127lo/- Treg cell population, compared to the control SS-CM.
Conclusions: Our finding indicated that YAP plays a critical role in promoting the immunosuppressive capacity of hPDLSCs via TGF-β1 signaling in response to shear stress loading.