The chemokine CCL2 activates p38 mitogen-activated protein kinase pathway in cultured rat hippocampal cells

Abstract

Emerging evidence indicates that chemokines can regulate both the physiology and biochemistry of CNS neurons and glia. In the current study, Western blot analysis showed that in rat hippocampal neuronal/glial cultures the signal transduction pathway activated by CCL2, a chemokine expressed in the normal brain and at elevated levels during neuroinflammation, involves a G-protein coupled receptor, p38 MAPK as well as its immediate upstream kinase MKK3/6, and the downstream transcription factor CREB. ERK 1/2 and the transcription factors STAT1 and STAT3 do not play a prominent role. CCL2 also altered Ca 2+ influx and synaptic network activity in the hippocampal neurons. These results suggest an important role for p38 MAPK and CREB in hippocampal actions of CCL2.

Korean Red Ginseng Extract Exhibits Neuroprotective Effects through Inhibition of Apoptotic Cell Death

“…Similar to the findings in the cells treated with NMDA in the absence of KRG extract (Fig. 3B, b), a considerably large number of TUNEL-positive cells was evident in the culture exposed to A β (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) for 18 h (Figs. 5B, b, C, b).…”

“…4B, exposure of cells to A β (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) increased intracellular ROS levels, which was significantly inhibited by the co-treatment with KRG extract at 0.3 and 1 mg/mL. In contrast, memantine had no effect on the A β (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) -induced injury or ROS at the concentration tested (data not shown).…”

“…To investigate effects of KRG extract on the neuronal damage induced by glutamate, NMDA or A β (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) , the cells were simultaneously treated with various concentrations of KRG extract in combination with the respective insults as mentioned above. Following the desired treatments, the viability of cells was assessed as described below.…”

“…After being denatured at 100°C in Laemmli sample buffer containing 100 mM dithiothreitol, equal amount of lysate proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) on either 8% or 12% gels. 28) Resolved proteins were electrophoretically transferred to nitrocellulose membrane (Schleicher and Schnell Bioscience, Dassel, Germany) for 1.5 h at 100 V. The membranes were blocked with 5% skim milk for 1.5 h at room temperature and incubated overnight at 4°C with the specific primary antibodies as mentioned in the figure legends. After washing, the membranes were incubated for 1.5 h with appropriate HRP-conjugated anti-IgG secondary antibodies, and the immunoreactive bands were detected by Bio-Rad ChemiDoc XRS imaging system using SuperSignal West Pico ECL reagent (Thermo Fisher Scientific, Rockford, IL, U.S.A.).…”

“…The cells were then washed with HCSS and maintained in MEM for 22-24 h in the incubator. To induce neurotoxicity by A β , cells were exposed to aggregated A β (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) at a final concentration of 40 µM in MEM for 24 h at 37°C. 24) The control cells were treated with MEM without any agent.…”