Platelet-Rich Plasma Reduces LPS-Stimulated Inflammatory Reaction in BV2 Cells by Blocking the TLR4-Mediated NF-κB/MAPKs Pathway

Abstract

Background: The study was designed to decipher the impact of platelet-rich plasma (PRP) on lipopolysaccharide (LPS)-mediated inflammation in BV2 (A murine cell line has been generated by infecting primary microglial cell cultures with a v-raf/v-myc oncogene carrying retrovirus (J2)) microglia. Method: BV2 microglia activation was induced by lipopolysaccharide (LPS) to establish an in vitro model of neuroinflammation. After pretreatment with different concentrations of PRP, the apoptosis of BV2 microglia was determined by flow cytometry, terminal deoxynucleotidyl transferase fluorescence labeling (TUNEL) and JC-1 assay. The production level of nitric oxide (NO) was determined by Griess method, and the mRNA (messenger RNA) expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The contents of TNF-α, IL-1β, IL-6, and prostaglandin E2 (PGE2) cytokines were determined by enzyme-linked immunosorbent assay (ELISA). The phosphorylation of nuclear factor kappa-B (NF-κB/P65), inhibitor of NF-κB α (IκBα), c-Jun N-terminal kinase (JNK), extracellular signal-regulated MAP kinases 1/2 (ERK1/2), and p38 mitogen-activated protein kinases (p38 MAPKs) in the NF-κB/MAPKs pathway was analyzed by Western blot. The nuclear translocation of phosphorylated NF-κB/P65 subunits was evaluated by laser confocal microscopy. Results: PRP decreased LPS-stimulated apoptosis of BV2 microglia (p < 0.05). Moreover, PRP inhibited the mRNA levels of TNF-α, IL-1β, IL-6, iNOS, and COX-2 and the NO level (p < 0.05), in addition, PRP also reduced the production of inflammatory mediators including TNF-α, IL-1β, IL-6, and PGE2 (p < 0.05), inhibited the protein levels of p-NF-κB/P65, p-IκBα, p-JNK, p-ERK1/2, and p-p38 in the NF-κB/MAPKs pathway in LPS-induced BV2 microglia (p < 0.05), decreased the nuclear translocation of p-NF-κB/p65 subunit (p < 0.05). Particularly, PRP at a concentration of 10% showed the optimal the inhibition effects. Conclusions: PRP attenuates LPS-mediated inflammation in BV2 microglia by blocking the TLR4-NF-κB/MAPKs axis.