Anti-CX3CL1 monoclonal antibody, clone 92607

Background Microglial polarization is a dynamic response to acute brain hypoxia induced by stroke and traumatic brain injury (TBI). However, studies on the polarization of microglia in chronic cerebral circulation insufficiency (CCCI) are limited. Our objective was to investigate the effect of CCCI on microglial polarization after chronic brain hypoperfusion (CBH) and explore the underlying molecular mechanisms. Methods CBH model was established by bilateral common carotid artery occlusion (2-vessel occlusion, 2VO) in rats. Using the stereotaxic injection technique, lenti-pre-miR-195and anti-miR-195oligonucleotide fragments (lenti-pre-AMO-miR-195) were injeted into the CA1 region of the hippocampus to construct animal models with high or low expression ofmiR-195. Immunofluorescence staining and flow cytometry were conducted to examine the status of microglial polarization. In vitro, Transwell co-culture system was taken to investigate the role ofmiR-195on neuronal-microglial communication through CX3CL1-CX3CR1 signaling. Quantitative real-time PCR was used to detect the level ofmiR-195and inflammatory factors. The protein levels of CX3CL1 and CX3CR1 were evaluated by both western blot and immunofluorescence staining. Results CBH induced by 2VO initiated microglial/macrophage activation in the rat hippocampus from 1 week to 8 weeks, as evaluated by increased ratio of (CD68(+)and CD206(+))/Iba-1 immunofluorescence. And the microglial/macrophage polarization was shifted towards the M1 phenotype at 8 weeks following CBH. The expression of CX3CL1 and CX3CR1 was increased in the hippocampus of 2VO rats at 8 weeks. An in vitro study in a Transwell co-culture system demonstrated that transfection of either primary-cultured neonatal rat neurons (NRNs) or microglial BV2 cells with AMO-195-induced M1 polarization of BV2 cells and increased CX3CL1 and CX3CR1 expression and that these effects were reversed bymiR-195mimics. Furthermore, the upregulation ofmiR-195induced by lenti-pre-miR-195injection prevented microglial/macrophage polarization to M1 phenotype triggered by hippocampal injection of lenti-pre-AMO-miR-195and 2VO surgery. Conclusions Our findings conclude that downregulation ofmiR-195in the hippocampus is involved in CBH-induced microglial/macrophage polarization towards M1 phenotype by governing communication between neurons and microglia through the regulation of CX3CL1 and CX3CR1 signaling. This indicates thatmiR-195may provide a new strategy for clinical prevention and treatment of CBH.

Obstructive sleep apnea (OSA) is the most common sleep disorder affecting 2-4 % of the adult population. In addition to several potential mechanisms, inflammation is one of the suggested etiological factors in OSA. Fractalkine/CX3CL1 which is detected in activated or stressed endothelium, smooth muscle cells, skeletal muscle cells, macrophages, neurons, and hepatocytes is an inflammatory marker and attracts attention of sleep specialists in OSA pathogenesis. In this study, we had two goals. The first one was to investigate the role of fractalkine in OSA pathogenesis while the second one was to detect the impact of OSA treatment with positive airway pressure (PAP) on serum fractalkine levels. This study included 34 patients (6 females, 28 males) diagnosed as OSA and 20 healthy controls (4 females, 16 males). Initial serum fractalkine levels of both groups were first evaluated in order to demonstrate any potential relation of OSA with fractalkine. Subsequently, serum fractalkine levels of the OSA patients were evaluated following 1 week of PAP treatment to demonstrate the impact of PAP treatment on serum fractalkine levels. Although there was no significant difference between OSA patients and healthy controls by means of plasma fractalkine levels (p, 0.67) statistically, plasma fractalkine levels significantly decreased in OSA patients after 1 week of PAP treatment (p, 0.001). This study showed that fractalkine, a potential mediator of chronic inflammation, was not sensitive in diagnosing OSA but might be an indicator of the success of OSA treatment.