Fig. 4

Neurons interact with microglia via the FKN/CX3CR1 axis in HT22-BV2 cocultures and enhance the release of BDNF by BV2 microglia. A Diagram of the HT22-BV2 coculture experiment. B Representative western blot images showing CX3CR1/FKN/proBDNF/BDNF/iba1 protein produced by BV2 cells in the presence of HT22 cells. C Quantification of CX3CR1/FKN/proBDNF/BDNF/iba1 protein levels in neuron- and neuron + cultures. Mean ± SEM; unpaired t test versus neuron- group; n = 3 rats per group; *P < 0.05. D Western blot images showing proBDNF/BDNF/iba1 protein produced by BV2 cells in response to FKN stimulation. E Quantification of proBDNF and BDNF protein levels in the VEH group and FKN group. Mean ± SEM; unpaired t test versus VEH group; n = 3 rats per group; *P < 0.05. F Representative western blot films showing proBDNF, BDNF, and iba1 protein produced by BV2 cells in the VEH group and the LPS group. G Western blot analysis showed that the proBDNF, BDNF, and iba1 protein levels in the LPS group were upregulated compared to those in the VEH group. Mean ± SEM; unpaired t test versus VEH group; n = 3 per group; *P < 0.05. H Representative immunofluorescence staining of BDNF (green) and iba1 (red) in the VEH and LPS groups. Scale bar = 20 μm. VEH, vehicle