ROS & RNS

• ROS & RNS may be exogenous but also are produced in all eukaryotic cells
• They consist of a number of species
• The chemistry of both ROS and RNS is influenced by the presence of a transition metal such as iron
• Enzyme systems are present that produce and degrade some ROS & RNS
  • ROS/RNS under the control of enzyme systems are thought to participate in cellular signaling
  • ROS/RNS participate in controlling such activities as metabolism, proliferation, migration, differentiation, cytoskeleton dynamics
  • Some modifications of macromolecules by ROS/RNS e.g. at cysteine residues (creating disulfide bonds and altering protein structure) are reversible; these are thought to be important in cell signaling
• In excess, ROS/RNS react with lipids, proteins and nucleic acids, altering structure and function
  • Irreversible modifications are thought to participate in cellular damage
• ROS & RNS have been implicated in cardiovascular diseases:
  • Hypertension
  • CHF
  • Atherosclerosis
  • Atrial fibrillation
  • Cardiovascular complications of diabetes
• Measurement of specific ROS/RNS and therefore identification of which ROS/RNS are involved in which processes in which context are hindered by:
  • Their short half-life (as little as nanoseconds)
  • Low concentrations
  • Subcellular locations
  • Lack (to date) of specific, sensitive, robust, and reproducible assays
• Multiple assays have been developed and increasing information on ROS/RNS and their cellular biology, relevance to clinical endpoints, and interventions to optimize outcomes are expected in the coming years