Activation of astrocytes by advanced glycation end products: cytokines induction and nitric oxide release.
Abstract
AIM: To investigate whether two kinds of in vitro prepared advanced glycation end
products (AGE), Glu-BSA and Gal-BSA, could induce proinflammatory mediators
IL-1beta and TNF-alpha, as well as oxidative stress and nitric oxide (NO), in
astrocytes, thus contributing to brain injury.
METHODS: Radioimmunoassay and RT-PCR technique were used to detect two cytokines'
level and existence of receptor for AGE (RAGE). DTNB reaction was used to measure
reduced glutathione (GSH) level. NO content was assayed using Griess reagent
provided by Promega.
RESULTS: Enhanced protein levels of both cytokines in supernatants and cell
lysates of astroglia cultures were detected after treated with AGE-BSA 1 g/L,
especially Gal-BSA, for 72 h. The increases were also in a
concentration-dependent manner. Changes in protein levels might be attributed to
changes in transcriptional levels documented by semi-quantitative RT-PCR. Both
AGE-BSA could also reduce astrocytic GSH and induce NO release. RAGE was detected
in astrocytes.
CONCLUSION: Enhanced levels of astrocytic proinflammatory mediators IL-1beta and
TNF-alpha, and oxidative stress caused by AGE might contribute to, at least
partially, the detrimental effects of AGE in neuronal disorders and aging brain.
Keywords:
products (AGE), Glu-BSA and Gal-BSA, could induce proinflammatory mediators
IL-1beta and TNF-alpha, as well as oxidative stress and nitric oxide (NO), in
astrocytes, thus contributing to brain injury.
METHODS: Radioimmunoassay and RT-PCR technique were used to detect two cytokines'
level and existence of receptor for AGE (RAGE). DTNB reaction was used to measure
reduced glutathione (GSH) level. NO content was assayed using Griess reagent
provided by Promega.
RESULTS: Enhanced protein levels of both cytokines in supernatants and cell
lysates of astroglia cultures were detected after treated with AGE-BSA 1 g/L,
especially Gal-BSA, for 72 h. The increases were also in a
concentration-dependent manner. Changes in protein levels might be attributed to
changes in transcriptional levels documented by semi-quantitative RT-PCR. Both
AGE-BSA could also reduce astrocytic GSH and induce NO release. RAGE was detected
in astrocytes.
CONCLUSION: Enhanced levels of astrocytic proinflammatory mediators IL-1beta and
TNF-alpha, and oxidative stress caused by AGE might contribute to, at least
partially, the detrimental effects of AGE in neuronal disorders and aging brain.