Effects of LPLI on microglial phagocytosis in LPS-induced neuroinflammation model

Abstract

Microglial activation plays an important role in neurodegenerative diseases. Once activated, they have macrophage-like capabilities, which can be bene¯cial by phagocytosis and harmful by secretion of neurotoxins. However, the resident microglia always fail to trigger an e®ective phagocytic response to clear dead cells or A deposits during the progression of neurodegeneration. Therefore, the regulation of microglial phagocytosis is considered a useful strategy in searching for neuroprotective treatments. In this study, our results showed that low-power laser irradiation (LPLI) (20 J/cm 2 ) could enhance microglial phagocytic function in LPS-activated microglia. We found that LPLI-mediated microglial phagocytosis is a Rac-1-dependent actin-based process, that a constitutively activated form of Rac1 (Rac1Q61L) induced a higher level of actin polymerization than cells transfected with wild-type Rac1, whereas a dominant negative form of Rac1 (Rac1T17N) markedly suppressed actin polymerization. In addition, the involvement of Rac1 activation after LPLI treatment was also observed by using a Raichu°uorescence resonance energy transfer (FRET)-based biosensor. We also found that PI3K/Akt pathway was required in the LPLI-induced Rac1 activation. Our research may provide a feasible therapeutic approach to control the progression of neurodegenerative diseases.

Real-time detection of LMP1/LMP1 interaction in MβCD-induced apoptosis of nasopharyngeal carcinoma cells using FRET method

“…Fluorescence resonance energy transfer (FRET) method allows real-time monitoring of proteinprotein interactions and visualizing of the subcellular distribution of protein complex in live cells. [23][24][25][26] This method evaluates protein-protein interactions by measuring the transferred energy from donor°uorophore to receptor°uorophore, when the distance between donor°uorophore and receptor°uorophore is less than 10 nm. FRET method has been successfully used to detect interaction between LMP1 and PRA1, and visualize the subcellular distribution of LMP1/PRA1 complex.…”