Abstract:

Objective To observe the changes of inflammation responses induced by lipopolysaccharide （LPS） in the single cultured Müller cells system and co-culture system of Müller cells and microglia of the mice， and to elucidate the interaction between the Müller cells and the microglia. Methods The Müller cells QMMuC-1 and microglia BV2 were cultured， and immunofluorescence staining was used to observe the morphology of two kinds of cells. The experiment was divided into single-culture control group ［QMMuC-1 cells cultured alone， treated with phosphate buffer saline（PBS）］， co-culture control group （QMMuC-1 cells and BV2 cells co-cultured with the ratio of 1∶1， treated with PBS buffer）， single-culture experimental group （QMMuC-1 cells cultured alone， treated with 10 mg·L^－1 LPS）， and co-culture experimental group （QMMuC-1 cells and BV2 cells co-cultured， treated with 10 mg·L^－1 LPS）. Immunofluorescence staining was used to observe the levels of glial fibrillary acidic protein （GFAP） in the cells in various groups； real-time fluorescence quantitative PCR （RT-qPCR） method was used to detect the expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） mRNA in the QMMuC-1 cells in various groups. Results The expressions of glutamine synthetase （GS） and GFAP in the QMMuC-1 cells were positive， and the expression of ionized calcium-binding adapter molecule 1 （Iba-1） in the BV2 cells was positive. Compared with single-culture control group， the level of GFAP in the QMMuC-1 cells in single-culture experimental group was increased by 1.7 fold （P=0.005）. Compared with co-culture control group， the level of GFAP in the QMMuC-1 cells in co-culture experimental group was increased by 2 fold （P=0.003），and the morphology of the cells gradually became fusiform. Compared with single-culture experimental group， the level of GFAP in the QMMuC-1 cells in co-culture experimental group was increased by 1.4 fold （P=0.0006）， and most cells exhibited a fusiform shape. Compared with single-culture control group， the expression levels of IL-1β， IL-6， and TNF-α mRNA in the QMMuC-1 cells in single-culture experimental group were increased， but the expression levels had no significant differences（P>0.05）. Compared with co-culture control group， the expression levels of IL-1β， IL-6， and TNF-α mRNA in the QMMuC-1 cells in co-culture experimental group were increased （P<0.05）. Compared with single-culture experimental group， the expression levels of IL-1β and TNF-α mRNA in the QMMuC-1 cells in co-culture experimental group were increased （P<0.05）. Conclusion LPS may induce the release of inflammatory cytokines from the activated microglia， which subsequently act on the Müller cells and exacerbate the inflammatory response in the Müller cells.

Key words: Müller cells, Microglia, Co-culture, Lipopolysaccharides, Inflammatory response