College of Engineering, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA.
Nanomedicine. 2013 Jul;9(5):636-45. doi: 10.1016/j.nano.2012.10.011. Epub 2012 Nov 22.
Distinct biochemical, electrochemical and electromechanical coupling processes of pancreatic β-cells may well underlie different response patterns of insulin release from glucose and capsaicin stimulation. Intracellular Ca(2+) levels increased rapidly and dose-dependently upon glucose stimulation, accompanied with about threefold rapid increases in cellular stiffness. Subsequently, cellular stiffness diminished rapidly and settled at a value about twofold of the baseline. Capsaicin caused a similar transient increase in intracellular Ca(2+) changes. However, cellular stiffness increased gradually to about twofold until leveling off. The current study characterizes for the first time the biophysical properties underlying glucose-induced biphasic responses of insulin secretion, distinctive from the slow and single-phased stiffness response to capsaicin despite similar changes in intracellular Ca(2+) levels. The integrated AFM nanorobotics and optical investigation enables the fine dissection of mechano-property from ion channel activities in response to specific and non-specific agonist stimulation, providing novel biomechanical markers for the insulin secretion process.
This study characterizes the biophysical properties underlying glucose-induced biphasic responses of insulin secretion. Integrated AFM nanorobotics and optical investigations provided novel biomechanical markers for the insulin secretion process.
胰腺β细胞的不同生化、电化学和机电耦联过程可能是葡萄糖和辣椒素刺激胰岛素分泌产生不同反应模式的基础。细胞内 Ca(2+)水平在葡萄糖刺激下迅速且呈剂量依赖性增加，同时细胞硬度也迅速增加约三倍。随后，细胞硬度迅速下降并稳定在基线的两倍左右。辣椒素也引起类似的细胞内 Ca(2+)变化的短暂增加。然而，细胞硬度逐渐增加到约两倍，然后趋于稳定。本研究首次描述了葡萄糖诱导胰岛素分泌双相反应的生物物理特性，与辣椒素引起的缓慢和单相硬度反应不同，尽管细胞内 Ca(2+)水平发生相似变化。集成的原子力显微镜纳米机器人和光学研究能够精细区分对特定和非特异性激动剂刺激的机械性能与离子通道活性，为胰岛素分泌过程提供新的生物力学标志物。
本研究描述了葡萄糖诱导胰岛素分泌双相反应的生物物理特性。集成的原子力显微镜纳米机器人和光学研究为胰岛素分泌过程提供了新的生物力学标志物。
