Effects of L-glutamate and ADP on immunomodulation of microglia, relevance to stroke

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2017
Thesis identifier
  • T14683
Person Identifier (Local)
  • 201560798
Qualification Level
Qualification Name
Department, School or Faculty
  • Background: Microglia are resident glial cells of the CNS, with potent immunomodulatory effects in stroke. Their defined split nature of both pro-inflammatory and anti-inflammatory paves research to define their behaviour under a variety of conditions. ADP and L-glutamate are abundant in the extracellular fluid following brain insults such as stroke and therefore they may represent influential mediators in controlling microglial cell function. Methods: In vitro, exogenous ADP/L-glutamate (50μg/ml) was applied to BV-2 microglia cells and key aspects of cell function were measured by Western blotting, including p-ERK and p.p38, proteins involved in a cascade of events, as well as iNOS and arginase 1 to assess microglial phenotype. NO release was assessed by Griess assay and chemotactic behaviour was analysed using microfluidics and time lapse imaging. In addition, the effects of pre-conditioning with ADP on microglia was assessed by measuring iNOS expression in response to LPS (1μg/ml) stimulation.Results: ADP significantly increased (p<0.05), whereas L-glutamate significantly (p<0.0001) decreased p-ERK expression over a 2-hour stimulation. Both ADP and L-glutamate significantly increased BV-2 microglia velocity (p<0.0001 and p<0.001, respectively) compared to control (0.9383 ± 0.07580 m/s and 0.7325 ± 0.06120 m/s for ADP and L-glutamate respectively versus 0.4392 ± 0.04795 m/s for control). ADP visually enhanced iNOS after 24 hours of exposure whereas pre-conditioning with ADP before LPS exposure appeared to reduced iNOS expression compared with LPS alone or ADP and LPS co-exposure.Conclusions: Both L-glutamate and ADP have the capacity to act as chemoattractant's and modulate microglia with opposing effects on p-ERK, with possible pro-inflammatory effects induced by ADP as observed by increased iNOS expression. However, pre-conditioning with ADP may reduce pro-inflammatory effects of LPS, highlighting a possible therapeutic avenue to reduce neuroinflammation. In summary, L-glutamate and ADP are highly influential in controlling microglia behaviour, the outcome of which may be dependent on the inflammatory microenvironment.
Resource Type
  • Date of award is 2017.
Date Created
  • 2017
Former identifier
  • 9912563993002996