title: Enhancement of morphological plasticity in hippocampal neurons by a physically modified saline via phosphatidylinositol-3 kinase.
abstract: Increase of the density of dendritic spines and enhancement of synaptic transmission through ionotropic glutamate receptors are important events, leading to synaptic plasticity and eventually hippocampus-dependent spatial learning and memory formation. Here we have undertaken an innovative approach to upregulate hippocampal plasticity. RNS60 is a 0.9% saline solution containing charge-stabilized nanobubbles that are generated by subjecting normal saline to Taylor-Couette-Poiseuille (TCP) flow under elevated oxygen pressure. RNS60, but not NS (normal saline), PNS60 (saline containing a comparable level of oxygen without the TCP modification), or RNS10.3 (TCP-modified normal saline without excess oxygen), stimulated morphological plasticity and synaptic transmission via NMDA- and AMPA-sensitive calcium influx in cultured mouse hippocampal neurons. Using mRNA-based targeted gene array, real-time PCR, immunoblot, and immunofluorescence analyses, we further demonstrate that RNS60 stimulated the expression of many plasticity-associated genes in cultured hippocampal neurons. Activation of type IA, but not type IB, phosphatidylinositol-3 (PI-3) kinase by RNS60 together with abrogation of RNS60-mediated upregulation of plasticity-related proteins (NR2A and GluR1) and increase in spine density, neuronal size, and calcium influx by LY294002, a specific inhibitor of PI-3 kinase, suggest that RNS60 upregulates hippocampal plasticity via activation of PI-3 kinase. Finally, in the 5XFAD transgenic model of Alzheimer's disease (AD), RNS60 treatment upregulated expression of plasticity-related proteins PSD95 and NR2A and increased AMPA- and NMDA-dependent hippocampal calcium influx. These results describe a novel property of RNS60 in stimulating hippocampal plasticity, which may help AD and other dementias.
authors.affiliation: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America.
authors.forename: Avik
authors.initials: A
authors.lastname: Roy
authors.affiliation: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America.
authors.forename: Khushbu K
authors.initials: KK
authors.lastname: Modi
authors.affiliation: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Khasnavis
authors.affiliation: Revalesio Corporation, Tacoma, WA, United States of America.
authors.forename: Supurna
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Revalesio Corporation, Tacoma, WA, United States of America.
authors.forename: Richard
authors.initials: R
authors.lastname: Watson
authors.affiliation: Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America.
authors.forename: Kalipada
authors.initials: K
authors.lastname: Pahan
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D058543:Class Ia Phosphatidylinositol 3-Kinase / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects*; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D051379:Mice; D009473:Neuronal Plasticity / Q000187:drug effects*; D009474:Neurons / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D012965:Sodium Chloride; D058543:Class Ia Phosphatidylinositol 3-Kinase; D010100:Oxygen; D002118:Calcium