| Objectives: Observe the effects of REM sleep deprivation on m RNA expression of IL-17 and IL-17 F,inflammatory protein expression of IL-17 and p-p38 MAPK of mouse hippocampus,and hippocampal cell proliferation in dentate gyrus;further research the relationship of REM sleep deprivtion,IL-17/p38 mitogen activated protein kinase pathway and hippocampal cell proliferation in dentate gyrus,and the probable mechanism of sleep deprivation on hippocampal cell proliferation,thus provide theoretical basis for prevention and cure of sleep deprivation induced cognitive impairment.Method: Adult C57BL/6J mouse aged 8-10 weeks were devided into 6 groups randomly,12 individuals per group: group A(also named blank control group),fed in suitable environment for 1 week;group B(sleep deprovation for 3 days): fed in suitable environment for 1 week,and then sleep deprivation by modified multiple platforms method(MMPM)for 3 days;group C(intraperitoneally injection of normal saline): fed in suitable environment for 1 week,intraperitoneally injection of normal saline 80 ul,then killed them after 3 days;group D(intraperitoneally injection of exogenous IL-17 solution): fed in suitable environment for 1 week,intraperitoneally injection of exogenous IL-17 solution 80 ul,then killed them after 3 days;group E(sleep deprivation for 3 days and intraperitoneally injection of DMSO): fed in suitable environment for 1 week,and then sleep deprivation by MMPM for 3 days,intraperitoneally injection of DMSO 50 ul before sleep deprivation,killed them after sleep deprivation;group F(sleep deprivation for 3 days and intraperitoneally injection of SB203580): fed in suitable environment for 1 week,and then sleep deprivation by MMPM for 3 days,intraperitoneally injection of SB203580 solution 80 ul before sleep deprivation,then killed them after sleep deprivation.All mouse were kept in the environment of illumination for 12h(9:00-21:00)and darkness for 12h(21:00-9:00),and intraperitoneally injected Brd U(100mg/kg)at 2h before death.The m RNA expression of IL-17、IL-17F、β-actin in hippocampus was examined by Real-time PCR;The protein expression of IL-17 、 p-p38 MAPK 、 β-actin inhippocampus was examined by Western-blot;the coexpression of neural progenitor cell marker SOX2 and IL-17 recepter A and C was observed by double-labeled immunofluorescence.Positive cells of p-p38 MAPK and Brd U in dentate gyrus of hippocampus were counted by immunofluorescence.Results: 1、Compared with group A,RT-PCR showed m RNA expression of IL-17、IL-17 F increased significantly in group B(P<0.001,P=0.012,respectively);Western-blot showed protein expression of IL-17 、 p-p38 increased significantly in group B(P=0.022,P=0.011,respectively);Immunofluorescent staining showed positive cells of p-p38 in dentate gyrus of hippocampus increased significantly,positive cells of Brd U decreased significantly in group B(P=0.046,P<0.001,respectively);2、Double-labelling immunofluorescence showed the coexpression of neural prog-enitor cell marker SOX-2 and IL-17 recepter A and C 3、Compared with group C,there was no difference in the m RNA expression of IL-17 and IL-17 F in hippocampus in group D(P=0.684,P=0.220,respectively),but the protein level of IL-17 in hippocampus increased significantly in group D(P=0.001),the protein expression of p-p38 in hippocampus increased significantly in group D(P=0.010);In addition,positive cells of p-p38 in dentate gyrus of hippocampus increased,positive cells of Brd U in dentate gyrus of hippocampus decreased in dentate gyrus of hippocampus in group D,the differennces were significant(P=0.038,P<0.001,respectively);4、Compared with group E,there was no difference in the m RNA expression of IL-17 and IL-17 F in hippocampus,no difference in the protein expression of IL-17 in hippocampus in group F(P=0.733,P=0.893,P=0.064,respectively),the protein expression of p-p38 in hippocampus decreased significantly in group F(P=0.013).In addition,positive cells of p-p38 decressed in dentate gyrus of hippocampus,positive cells of Brd U in dentate gyrus of hippocampus increased in dentate gyrus of hippocampus in group F,the differennces were significant(P<0.001,P=0.006,respectively)。Conclusions: 1、Suppressed hippocampal cell proliferation in dentate gyrus after REM sleepdeprivation for 3 days,may be one of the mechanism of sleep deprivation induced cognitive impairment.2、Expression of IL-17 in hippocampus increased after REM sleep deprivation for 3 days,p38 pathway is activated.3、Neural progenitor cell in hippocampus express IL-17 RA and IL-17RC;4、Intraperitoneally injection of IL-17 activate p38 pathway,along with suppressed hippocampal cell proliferation in dentate gyrus;Intraperitoneally injection of p38 MAPK inhibitor SB203580 inhibites the phosphorylation of p38,along with incresed hippocampal cell proliferation in dentate gyrus;IL-17 A combines with IL-17 RA and IL-17 RC,and then activate p38 pathway,thus,affect the hippocampal cell proliferation in dentate gyrus.5、The mechanism of suppressed hippocampal cell proliferation in dentate gyrus after REM sleep deprivation may be that sleep deprivation induced incerased expression of proinflammatory cytokine IL-17 in m RNA and protein level.Then IL-17 combine with its receptor IL-17 RA and IL-17 RC in Neural progenitor cell,p38 pathway is activated,thus,may directly affects the hippocampal cell proliferation in dentate gyrus,or affects the hippocampal cell proliferation in dentate gyrus in an indirectly way by changing the inflammatory environment and enhancing the role of other inflammatory factor.In conclusion,p38 pathway has a close relationship with suppressed hippocampal cell proliferation in dentate gyrus after REM sleep deprivation,which may be one of the mechanism of sleep deprivation induced cognitive impairment,or participate in the development of neurodegenerative disese.IL-17 may paly an important role in the suppressed hippocampal cell proliferation in dentate gyrus after sleep deprivation,by activating p38 MAPK pathway. |
PDF Full Text Request