title: Cellular biophysical dynamics and ion channel activities detected by AFM-based nanorobotic manipulator in insulinoma β-cells.
abstract: 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.
  
  
  BACKGROUND
  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.
authors.affiliation: College of Engineering, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA.
authors.forename: Ruiguo
authors.initials: R
authors.lastname: Yang
authors.forename: Ning
authors.initials: N
authors.lastname: Xi
authors.forename: King Wai Chiu
authors.initials: KW
authors.lastname: Lai
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Patterson
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Chengeng
authors.initials: C
authors.lastname: Qu
authors.forename: Beihua
authors.initials: B
authors.lastname: Zhong
authors.forename: Donna H
authors.initials: DH
authors.lastname: Wang
mesh_terms: D055592:Biophysical Phenomena; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007340:Insulinoma / Q000378:metabolism* / Q000473:pathology; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000295:instrumentation*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology; D012371:Robotics / Q000295:instrumentation*
chemical_list: D007328:Insulin; D007473:Ion Channels; D000242:Cyclic AMP; D005947:Glucose; D002211:Capsaicin; D002118:Calcium