Simulate Neuronal Action Potential's Effect On The Function Of Activated Microglia

Objectives: Microglia are important immune effector cells in the central nervou s system. It mediates inflammatory reaction in brain injury, and frequent close contact with the neurons in the brain,which plays synaptic pruning founction a nd the plasticity of neural development process. Neuronal action potential is ne rve electrical signals. The interaction of neurons and microglia has certain infl uence with brain development and various pathological process development of the central nervous system. So we believe that there are neuronal electrical si gnals take part in this progress,and play an important role in mediating inflam matory reaction,synaptic pruning and induced neuronal apoptosis function of microglia,it also has influences with brain development and various pathologic al process development of the central nervous system. In order to verify these assumptions. We observe the effect of simulate action potential on lipopolysac charide induced the function of activated BV2 microglia cells.The purpose of t his experiment is to prove that neuronal action potential play an important role in adjusting the function of activated microglia.Methods: We use the BV2 cells to respresent the microglia. We observe the ef fect of simulate action potential on lipopolysaccharide induced the function of activated BV2 microglia cells. The experiment is divided into three groups con trol group, LPS group and LPS + SAP group. In the LPS group, BV2 cells w ere activated by lipopolysaccharide(100ng, 12h). And under the same conditio n BV2 cells,were stimulated by simulated neuronal action potential(SAP; 30 Hz, 5min/h) after stimulated by LPS in the LPS + SAP group. The flow cyto metry was used to detect the expression of cells surface antigens CD45 and a dhesive factors CD54. Then we use the CCK-8 method to observe the effect o f SAP on the proliferation of BV2 cells. The Real- time PCR technique was used to calculate the expression of inflammation factors m RNA such as i NOS, TNF-?, IL-1?, COX2,and apoptosis genes such as BAX, Bcl2, Caps3, Fas a nd Fas L. The software package SPSS17.0 was used for statistical analysis, P<0.05 as the difference was statistically significant.Results: 1) The result of CD45 and CD54: after the stimulation of LPS, the cells surface antigens CD45 and the adhesive factors CD54 of BV2 cells was significantly increased(P<0.05). Compare to LPS group, the LPS + SAP gro up the number of CD45 and CD54 positive cells significantly reduce(P<0.05) 3)The result of the inflammation factors m RNA :after the stimulation of LPS, the BV2 cells express inflammation factors m RNA such as i NOS, TNF-?, IL-1? and COX2 significantly higher than control group(P>0.05), Compare to LP S group, in the LPS + SAP group there have i NOS, TNF-? and IL-1? three inflammation factors m RNA significantly reduce(P<0.05),But the expression of COX2 has no significant differences(P>0.05). 4)The result of the proliferation of BV2 cells: after the stimulation of LPS, in creased the BV2 cells proliferation,but after give it SAP,we found the cells proliferation rate dropped significantly(P<0.05). 5)The result of expression of apoptosis-related genes: compare to LPS group, i n the LPS + SAP group the BV2 cells express BAX, Bcl2, Caps3 and Fas f our apoptosis genes have no significant differences(P>0.05). While the apopto sis-related genes Fas L significantly reduce(P<0.01).Conclusions: 1) Simulate action potential could suppress the inflammation and proliferation of activated BV2 cells, while it would not affect the apoptosis of BV2 cells. but it significantly reduce the apoptosis-related gene Fas L express ion. Therefore it coud reduce the affection of that other around cells induced apoptosis by activated BV2 cells. 2)we can infer that, during the close contact of microglia and neurons synap tic, the Immune inflammatory reaction, synaptic pruning, induce apoptosis of n eurons, brain development and a variety pathological process of central nervous system disease, the neurons action potential plays an important role in the a ctivated microglia adjustment itself function. When the activated microglial cell s detecte the normal neurons action potential signals, it will reduce itself funct ion, by reducing expressing inflammatory factors, appreciation rate, phagocytosi sing and inducing the apoptosis,to avoid normal neurons being accidentally inj ured. This is a protective effect of nerve tissue.