To Explore The Effect Of Cannabinoid Receptor On Macrophage Polarization And Immune Function Under Chronic Intermittent Hypoxia

Background and purpose:Obstructive Sleep Apnea（OSA）is a common sleep-disordered breathing disease that is currently recognized as a major public health problem.The upper respiratory tract appears partial or complete obstruction during sleep.Chronic Intermittent Hypoxia（CIH）is its main pathophysiological feature,which can further cause systemic inflammatory cascade and immune dysfunction,and eventually lead to chronic damage of multiple systems and organs throughout the body,and seriously affect human health and daily life.In this study,we established a CIH mouse model to explore the regulatory effect of cannabinoid receptor 1（CB1R）on macrophage polarization and immune function under CIH conditions,and provided a theoretical basis for finding new therapeutic targets for OSA and its complications.Methods:Healthy male C57BL/6 mice aged 4 to 5 weeks were randomized to normoxic control NC,CIH（6、10 weeks）,and CIH+CB1R antagonist intervention groups（6、10weeks）.A chronic intermittent hypoxia mouse model was established using the US Biosopherix A84 hypoxia chamber to create a CIH environment（5%O₂30S and 21%O₂90S cycles,balanced with nitrogen gas for 8 hours per day）,and the CIH+CB1R antagonist intervention group received CB1R receptor antagonist AM251 intraperitoneally for 6 and10 weeks before entering the chamber.After exposure,the spleen was isolated,and the expression levels of two macrophage surface markers CD86 and CD206m RNA by q RT-PCR,and the expression of inflammatory cytokines IL-6 and IL-10 in mouse were determined by enzyme-linked immunosorbent assay（ELISA）.The spleen tissues of mice were stained for HE and examined by light microscopy.Results:（1）CB1R expression was upregulated in the CIH group and significantly higher in the 10 W CIH group than in the 6 W CIH group,and the spleen CB1R expression was suppressed after administration of the CB1R antagonist AM251;（2）CIH can lead to morphological changes in the spleen,such as changes in the proportion of medulla,the distinction between white pulp and red pulp boundaries was not obvious,and the arterioles,and the lymphocyte hyperplasia and disorder in the lymphatic sheath around arterioles;targeted sealing of CB1R can reduce the spleen injury caused by CIH;（3）Compared with the NC group,The CIH group had increased CD86m RNA expression and significantly increased IL-6 levels,and macrophages tended to M1 polarization;after targeted sealing of CB1R,CD206m RNA expression increased,levels of IL-10 increased,and macrophages were polarized to M2.conclusion:（1）CB1R expression was upregulated in spleen tissues by CIH and positively correlated with the duration of CIH;（2）High expression of CB1R can lead to the damage of the mouse spleen tissue,and the mouse spleen tissue damage is reduced after targeted sealing of CB1R;（3）High expression of CB1R promotes macrophages tend to M1 type polarization and promote inflammation;after targeting sealing CB1R,macrophages tend to M2 type polarization,which has the effect of inhibiting inflammation.