Effect of γδ T cells on the Proliferation, Apoptosis and Autophagy of Multiple Myeloma Cells / 中国实验血液学杂志

AbstractObjective: To investigate the effect of γδ T cells on the proliferation, apoptosis and autophagy of multiple myeloma cells.@*METHODS@#Peripheral blood mononuclear cells (PBMNC) were isolated from healthy volunteers, and stimulated with zoledronic acid (Zol) in combination with rhIL-2. Flow cytometry analysis was used to detected the purity of γδ T cells. γδ T cells were collected and co-cultured with RPMI-8226 or U-266 cells at different effector target ratios. The proliferation of RPMI-8226 or U-266 cell lines were detected by CCK-8. Cell cycle and cell apoptosis were detected by flow cytometry and Western blot．The expressions of autophagy-related proteins were detected by Western blot.@*RESULTS@#γδ T cells can be expanded in vitro. γδ T cells could inhibit the proliferation of RPMI-8226 or U-266 cells, induced cell cycle arrest and promoted apoptosis in an effector target-dependent manner. In addition, γδ T cells could induce autophagy of myeloma cells, inhibited the expression of autophagy-related PI3K, P-AKT and P-mTOR, while increased the expression of AMPK and Beclin-1.@*CONCLUSION@#γδ T cells can inhibit the proliferation of RPMI-8226 and U-266 myeloma cells, induce cell cycle arrest, promote apoptosis, and enhance autophagy in vitro. The mechanism may be related to inhibition of PI3K/AKT/mTOR signaling pathway and/or activation of AMPK/Beclin-1 signaling pathway.

Stress rate and creep behaviors of cancellous bone under uniaxial compression / 中国组织工程研究

BACKGROUND: Cancellous bone, as an important part of bone, is a kind of porous, inhomogeneous, anisotropic and viscoelastic structure, which plays a critical role in load transmission and energy absorption. Therefore,research on its mechanical properties is of great significance.OBJECTIVE: To investigate the compressive properties of cancellous bone at different stress rates and its creep behaviors at different stress levels.METHODS: The fresh cancellous bone from pig femur was used as the material, and subjected to different stress until the compressive strain of sample was up to 5%. The constant compressive stress levels were loaded on the surface of cancellous bone for 7200 s to observe its creep behaviors.RESULTS AND CONCLUSION: (1) In the uniaxial compression test, the stress values and Young's modulus increased with the stress rate increasing under the same strain value. (2) The stress-strain curves of cancellous bone were different at different loading rates, indicating that the mechanical properties of cancellous bone depend on the loading rate. (3) In the creep test, the creep strain increased with the increase of stress level, but the creep compliance decreased with the increase of stress level. (4) These results suggest that the stress rate and stress level have significant influence on compressive properties of cancellous bone, which provide reference for avoiding cancellous bone injury.