新生时期的Toll样受体(TLR)3激活会产生与神经精神疾病起源有关的反应。虽然神经精神疾病存在性二态性,尚不清楚大脑对TLR3激活的反应是否具有性别特异性.我们假设出生后(P)8天模型中的polyI:C会诱导性二态炎症反应。C57BL6小鼠在P8时接受腹膜内注射聚I:C(10mg/kg)或媒介物[生理盐水(NS)]。在6或14小时杀死幼鼠,进行caspase3和8活性测定,NFkBELISA,IRF3、AP1和GFAP蛋白质印迹和细胞因子/趋化因子基因表达实时qRT-PCR(4-6/组)。在聚I:C后24小时(P9)或7天(P15)杀死第二组幼崽,以评估海马中星形胶质细胞(GFAP)和小胶质细胞(Iba1)的激活,使用免疫组织化学的丘脑和皮质,使用实时RT-PCR和MSD,以及细胞因子/趋化因子的基因和蛋白质表达,分别(4-6/组)。采用非参数分析。聚I:C后六个小时,在聚I:C处理的细胞溶质部分中的caspase-3和-8活性比NS处理的雌性小鼠高1.6和2.8倍,分别,而促炎细胞因子的基因表达在男女均上调。在聚I:C之后,IRF3核易位在雌性小鼠中发生较早(6小时),在雄性小鼠中发生较晚(14小时)。在聚I:C后14小时,只有雄性小鼠的核NFκB水平也升高(88%,p<0.001)和GFAP表达与持续的IL-6和FAS基因上调(110%和77%,分别为;p<0.001)和IL-10基因下调(-42%,p<0.05)。在聚I:C后24小时,IL-1β,CXCL-10,TNF-α,和MCP-1在两种性别中都有类似的增加,但在暴露后7天,仅在雌性小鼠中CXCL-10和INFγ增加而IL-10减少。因此,小胶质细胞激活在polyI:C后7天持续在海马中,雌性小鼠的丘脑和皮质。这项初步研究表明,TLR3激活可能在发育中的新生小鼠大脑中产生性二态反应,并在雌性小鼠中早期激活caspase依赖性途径,激活两性的炎症级联反应,然后在雌性小鼠中持续存在。进一步的有力研究对于证实这些特定性别的发现至关重要。
Toll-like receptor (TLR)3 activation during the neonatal period produces responses linked to the origins of neuropsychiatric disorders. Although there is sexual dimorphism in neuropsychiatric disorders, it is unknown if brain responses to TLR3 activation are sex-specific. We hypothesized that poly I:C in a post-natal day (P)8 model induces a sexually dimorphic inflammatory responses. C57BL6 mice received intraperitoneal injection of poly I:C (10 mg/kg) or vehicle [normal saline (NS)] at P8. Pups were killed at 6 or 14 h for
caspase 3 and 8 activity assays, NFkB ELISA, IRF3, AP1, and GFAP western blotting and cytokines/chemokines gene expression real time qRT-PCR (4-6/group). A second group of pups were killed at 24 h (P9) or 7 days (P15) after poly I:C to assess astrocytic (GFAP) and microglia (Iba1) activation in the hippocampus, thalamus and cortex using immunohistochemistry, and gene and protein expression of cytokines/chemokines using real time RT-PCR and MSD, respectively (4-6/group). Non-parametric analysis was applied. Six hours after poly I:C,
caspase-3 and -8 activities in cytosolic fractions were 1.6 and 2.8-fold higher in poly I:C-treated than in NS-treated female mice, respectively, while gene expressions of pro-inflammatory cytokines were upregulated in both sexes. After poly I:C, IRF3 nuclear translocation occurred earlier (6 h) in female mice and later (14 h) in male mice. At 14 h after poly I:C, only male mice also had increased nuclear NFκB levels (88%, p < 0.001) and GFAP expression coinciding with persistent IL-6 and FAS gene upregulation (110 and 77%, respectively; p < 0.001) and IL-10 gene downregulation (-42%, p < 0.05). At 24 h after poly I:C, IL-1β, CXCL-10, TNF-α, and MCP-1 were similarly increased in both sexes but at 7 days after exposure, CXCL-10 and INFγ were increased and IL-10 was decreased only in female mice. Accordingly, microglial activation persisted at 7 days after poly I:C in the hippocampus, thalamus and cortex of female mice. This preliminary
study suggests that TLR3 activation may produce in the developing neonatal mouse brain a sexually dimorphic response with early activation of
caspase-dependent pathways in female mice, activation of inflammatory cascades in both sexes, which then persists in female mice. Further well-powered studies are essential to confirm these sex-specific findings.