Mode-actions of the Na(+)-Ca2+ exchanger: from genes to mechanisms to a new strategy in brain disorders

Biomed Pharmacother. 1998;52(4):145-56. doi: 10.1016/s0753-3322(98)80203-5.

Abstract

Mode-actions of the Na(+)-Ca2+ exchanger from genes to mechanisms to a new strategy for brain disorders were comparatively studied in oxidative stress. In transfected Chinese hamster ovary (CHO) cells steadily expressing the Na(+)-Ca2+ exchanger's gene, Ca(2+)-efflux via an active mode of the Na(+)-Ca2+ exchanger was elicited by hydrogen peroxide (H2O2) after preincubation of the cell with a Ca(2+)-free medium, whereas Ca(2+)-influx via a reverse mode of the Na(+)-Ca2+ exchanger was dramatically evoked by H2O2 after preincubation of the cell with a Ca2+ medium, as a prelude to neuronal death. According to [45Ca2+] uptake of transfected CHO cells at given time intervals or extracellular Na+[Na+]o gradients, hyperbola, logarithmic and sigmoid curve equations of the Na(+)-Ca2+ exchanger's mode-actions were respectively defined in the absence and the presence of H2O2. The Na(+)-Ca2+ exchanger's conformational transition in oxidative stress was dominated by adenosine triphosphate (ATP)-dependent cytoskeletal redox modification, cation-pi interactions and secondary Ca2+ activation. These mechanisms were used to generate an intracellulary distributed tetra-cluster (named VISA931) for rescuing G-protein agonist-sensitive signal transduction and cortico-cerebral somatosensory evoke potential (SEP) from oxidation via activating forward operation of the Na(+)-Ca2+ exchanger, the beta-adrenergic and the P2-purinergic receptors, blocking Ca2+ influx and catalyzing the dismutation of superoxide anions (O2-.) to H2O2. In conclusion, knowledge-based drug design is a new strategy for developing promising candidates of neuroprotective agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aluminum Compounds / pharmacology
  • Animals
  • Brain Diseases / genetics*
  • Brain Diseases / metabolism*
  • Brain Diseases / physiopathology
  • CHO Cells
  • Calcium / metabolism*
  • Cerebral Cortex / physiology
  • Cricetinae
  • Dogs
  • Electron Spin Resonance Spectroscopy
  • Evoked Potentials, Somatosensory / physiology*
  • Fluorides / pharmacology
  • GTP-Binding Proteins / antagonists & inhibitors
  • GTP-Binding Proteins / physiology
  • Humans
  • In Vitro Techniques
  • Muscle Tonus
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / physiology*
  • Oxidative Stress
  • Rabbits
  • Recombinant Proteins / metabolism
  • Signal Transduction
  • Sodium-Calcium Exchanger / genetics*
  • Sodium-Calcium Exchanger / metabolism*
  • Superoxides / metabolism
  • Transfection
  • Vasoconstriction / drug effects
  • Vasoconstriction / physiology*

Substances

  • Aluminum Compounds
  • Recombinant Proteins
  • Sodium-Calcium Exchanger
  • Superoxides
  • tetrafluoroaluminate
  • GTP-Binding Proteins
  • Fluorides
  • Calcium