Suppression of nuclear factor-κB activation and inflammation in microglia by physically modified saline

J Biol Chem. 2012 Aug 24;287(35):29529-42. doi: 10.1074/jbc.M111.338012. Epub 2012 Jun 29.

Abstract

Chronic inflammation involving activated microglia and astroglia is becoming a hallmark of many human diseases, including neurodegenerative disorders. Although NF-κB is a multifunctional transcription factor, it is an important target for controlling inflammation as the transcription of many proinflammatory molecules depends on the activation of NF-κB. Here, we have undertaken a novel approach to attenuate NF-κB activation and associated inflammation in activated glial cells. RNS60 is a 0.9% saline solution containing charge-stabilized nanostructures that are generated by subjecting normal saline to Taylor-Couette-Poiseuille (TCP) flow under elevated oxygen pressure. RNS60, but not normal saline, RNS10.3 (TCP-modified saline without excess oxygen), and PNS60 (saline containing excess oxygen without TCP modification) were found to inhibit the production of nitric oxide (NO) and the expression of inducible NO synthase in activated microglia. Similarly, RNS60 also inhibited the expression of inducible NO synthase in activated astroglia. Inhibition of NF-κB activation by RNS60 suggests that RNS60 exerts its anti-inflammatory effect through the inhibition of NF-κB. Interestingly, RNS60 induced the activation of type IA phosphatidylinositol (PI) 3-kinase and Akt and rapidly up-regulated IκBα, a specific endogenous inhibitor of NF-κB. Inhibition of PI 3-kinase and Akt by either chemical inhibitors or dominant-negative mutants abrogated the RNS60-mediated up-regulation of IκBα. Furthermore, we demonstrate that RNS60 induced the activation of cAMP-response element-binding protein (CREB) via the PI 3-kinase-Akt pathway and that RNS60 up-regulated IκBα via CREB. These results describe a novel anti-inflammatory property of RNS60 via type IA PI 3-kinase-Akt-CREB-mediated up-regulation of IκBα, which may be of therapeutic benefit in neurodegenerative disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Enzyme Activation / drug effects
  • Enzyme Activation / physiology
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology
  • Humans
  • I-kappa B Proteins / metabolism
  • Inflammation / metabolism
  • Mice
  • Microglia
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Neurodegenerative Diseases / drug therapy
  • Neurodegenerative Diseases / metabolism
  • Nitric Oxide / biosynthesis
  • Nitric Oxide Synthase Type II / biosynthesis
  • Oxygen / pharmacology*
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • Sodium Chloride / pharmacology*

Substances

  • Creb1 protein, mouse
  • Cyclic AMP Response Element-Binding Protein
  • I-kappa B Proteins
  • NF-kappa B
  • NFKBIA protein, human
  • Nerve Tissue Proteins
  • Nfkbia protein, mouse
  • NF-KappaB Inhibitor alpha
  • Nitric Oxide
  • Sodium Chloride
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Oxygen