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Wigerblad G, Huie JR, Yin HZ, Leinders M, Pritchard RA, Koehrn FJ, Xiao WH, Bennett GJ, Huganir RL, Ferguson AR, Weiss JH, Svensson CI, Sorkin LS. Inflammation-induced GluA1 trafficking and membrane insertion of Ca 2+ permeable AMPA receptors in dorsal horn neurons is dependent on spinal tumor necrosis factor, PI3 kinase and protein kinase A. Exp Neurol 2017; 293:144-158. [PMID: 28412220 DOI: 10.1016/j.expneurol.2017.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 04/06/2017] [Accepted: 04/10/2017] [Indexed: 11/28/2022]
Abstract
Peripheral inflammation induces sensitization of nociceptive spinal cord neurons. Both spinal tumor necrosis factor (TNF) and neuronal membrane insertion of Ca2+ permeable AMPA receptor (AMPAr) contribute to spinal sensitization and resultant pain behavior, molecular mechanisms connecting these two events have not been studied in detail. Intrathecal (i.t.) injection of TNF-blockers attenuated paw carrageenan-induced mechanical and thermal hypersensitivity. Levels of GluA1 and GluA4 from dorsal spinal membrane fractions increased in carrageenan-injected rats compared to controls. In the same tissue, GluA2 levels were not altered. Inflammation-induced increases in membrane GluA1 were prevented by i.t. pre-treatment with antagonists to TNF, PI3K, PKA and NMDA. Interestingly, administration of TNF or PI3K inhibitors followed by carrageenan caused a marked reduction in plasma membrane GluA2 levels, despite the fact that membrane GluA2 levels were stable following inhibitor administration in the absence of carrageenan. TNF pre-incubation induced increased numbers of Co2+ labeled dorsal horn neurons, indicating more neurons with Ca2+ permeable AMPAr. In parallel to Western blot results, this increase was blocked by antagonism of PI3K and PKA. In addition, spinal slices from GluA1 transgenic mice, which had a single alanine replacement at GluA1 ser 845 or ser 831 that prevented phosphorylation, were resistant to TNF-induced increases in Co2+ labeling. However, behavioral responses following intraplantar carrageenan and formalin in the mutant mice were no different from littermate controls, suggesting a more complex regulation of nociception. Co-localization of GluA1, GluA2 and GluA4 with synaptophysin on identified spinoparabrachial neurons and their relative ratios were used to assess inflammation-induced trafficking of AMPAr to synapses. Inflammation induced an increase in synaptic GluA1, but not GluA2. Although total GluA4 also increased with inflammation, co-localization of GluA4 with synaptophysin, fell short of significance. Taken together these data suggest that peripheral inflammation induces a PI3K and PKA dependent TNFR1 activated pathway that culminates with trafficking of calcium permeable AMPAr into synapses of nociceptive dorsal horn projection neurons.
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Affiliation(s)
- G Wigerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - J R Huie
- Department of Neurological Surgery, UC San Francisco, San Francisco, CA, USA
| | - H Z Yin
- Department of Neurology, UC Irvine, Irvine, CA, USA
| | - M Leinders
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA
| | - R A Pritchard
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA
| | - F J Koehrn
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA
| | - W-H Xiao
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA
| | - G J Bennett
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA
| | - R L Huganir
- Department of Neuroscience, Howard Hughes Medical Institute, Johns Hopkins University, Baltimore, MD, USA
| | - A R Ferguson
- Department of Neurological Surgery, UC San Francisco, San Francisco, CA, USA
| | - J H Weiss
- Department of Neurology, UC Irvine, Irvine, CA, USA
| | - C I Svensson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - L S Sorkin
- Department of Anesthesiology, UC San Diego, La Jolla, CA, USA.
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Madden AMK, Paul AT, Pritchard RA, Michel R, Zup SL. Serotonin promotes feminization of the sexually dimorphic nucleus of the preoptic area, but not the calbindin cell group. Dev Neurobiol 2016; 76:1241-1253. [DOI: 10.1002/dneu.22386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/30/2015] [Accepted: 02/16/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Amanda M. K. Madden
- Graduate Program in Developmental and Brain Sciences; University of Massachusetts Boston; Boston Massachusetts 02125
- Psychology Department; University of Massachusetts Boston; Boston Massachusetts 02125
| | - Alexandria T. Paul
- Psychology Department; University of Massachusetts Boston; Boston Massachusetts 02125
| | - Rory A. Pritchard
- Psychology Department; University of Massachusetts Boston; Boston Massachusetts 02125
| | - Rebecca Michel
- Psychology Department; University of Massachusetts Boston; Boston Massachusetts 02125
| | - Susan L. Zup
- Graduate Program in Developmental and Brain Sciences; University of Massachusetts Boston; Boston Massachusetts 02125
- Psychology Department; University of Massachusetts Boston; Boston Massachusetts 02125
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Abstract
The degradation of the prostaglandin fenprostalene (III) was studied in aqueous solution. The reaction was both specific acid and base catalyzed. The only reaction found to occur was hydrolysis of the methyl ester at C-1. Activation energies for the acid- and base-catalyzed reactions were determined and are nearly identical to that for the hydrolysis of ethyl acetate, a model ester. A competing acid-catalyzed reaction of the C-1 free acid of III was found to be approximately 10 times slower than the hydrolysis of III.
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