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Abstract：
We previously reported that miR-195 exerts neuroprotection by inhibiting Sema3A and cerebral miR-195 levels decreased with age, both of which urged us to explore the role of miR-195 and miR-195-regulated Sema3 family members in age-associated dementia.
miR-195a KO mice were used to assess the effect of miR-195 on aging and cognitive functions. Sema3D was predicted as a miR-195 target by TargetScan and then verified by luciferase reporter assay, while effects of Sema3D and miR-195 on neural senescence were assessed by beta-galactosidase and dendritic spine density. Cerebral Sema3D was over-expressed by lentivirus and suppressed by si-RNA, and effects of over-expression of Sema3D and knockdown of miR-195 on cognitive functions were assessed by Morris Water Maze, Y-maze, and open field test. The effect of Sema3D on lifespan was assessed in Drosophila. Sema3D inhibitor was developed using homology modeling and virtual screening. One-way and two-way repeated measures ANOVA were applied to assess longitudinal data on mouse cognitive tests.
Cognitive impairment and reduced density of dendritic spine were observed in miR-195a knockout mice. Sema3D was identified to be a direct target of miR-195 and a possible contributor to age-associated neurodegeneration as Sema3D levels showed age-dependent increase in rodent brains. Injection of Sema3D-expressing lentivirus caused significant memory deficits while silencing hippocampal Sema3D improved cognition. Repeated injections of Sema3D-expressing lentivirus to elevate cerebral Sema3D for 10 weeks revealed a time-dependent decline of working memory. More importantly, analysis of the data on the Gene Expression Omnibus database showed that Sema3D levels were significantly higher in dementia patients than normal controls (p < 0.001). Over-expression of homolog Sema3D gene in the nervous system of Drosophila reduced locomotor activity and lifespan by 25%. Mechanistically, Sema3D might reduce stemness and number of neural stem cells and potentially disrupt neuronal autophagy. Rapamycin restored density of dendritic spines in the hippocampus from mice injected with Sema3D lentivirus. Our novel small molecule increased viability of Sema3D-treated neurons and might improve autophagy efficiency, which suggested Sema3D could be a potential drug target. Video Abstract CONCLUSION: Our results highlight the importance of Sema3D in age-associated dementia. Sema3D could be a novel drug target for dementia treatment.
miR-195a KO mice were used to assess the effect of miR-195 on aging and cognitive functions. Sema3D was predicted as a miR-195 target by TargetScan and then verified by luciferase reporter assay, while effects of Sema3D and miR-195 on neural senescence were assessed by beta-galactosidase and dendritic spine density. Cerebral Sema3D was over-expressed by lentivirus and suppressed by si-RNA, and effects of over-expression of Sema3D and knockdown of miR-195 on cognitive functions were assessed by Morris Water Maze, Y-maze, and open field test. The effect of Sema3D on lifespan was assessed in Drosophila. Sema3D inhibitor was developed using homology modeling and virtual screening. One-way and two-way repeated measures ANOVA were applied to assess longitudinal data on mouse cognitive tests.
Cognitive impairment and reduced density of dendritic spine were observed in miR-195a knockout mice. Sema3D was identified to be a direct target of miR-195 and a possible contributor to age-associated neurodegeneration as Sema3D levels showed age-dependent increase in rodent brains. Injection of Sema3D-expressing lentivirus caused significant memory deficits while silencing hippocampal Sema3D improved cognition. Repeated injections of Sema3D-expressing lentivirus to elevate cerebral Sema3D for 10 weeks revealed a time-dependent decline of working memory. More importantly, analysis of the data on the Gene Expression Omnibus database showed that Sema3D levels were significantly higher in dementia patients than normal controls (p < 0.001). Over-expression of homolog Sema3D gene in the nervous system of Drosophila reduced locomotor activity and lifespan by 25%. Mechanistically, Sema3D might reduce stemness and number of neural stem cells and potentially disrupt neuronal autophagy. Rapamycin restored density of dendritic spines in the hippocampus from mice injected with Sema3D lentivirus. Our novel small molecule increased viability of Sema3D-treated neurons and might improve autophagy efficiency, which suggested Sema3D could be a potential drug target. Video Abstract CONCLUSION: Our results highlight the importance of Sema3D in age-associated dementia. Sema3D could be a novel drug target for dementia treatment.
摘要：
背景：我们以前报道过miR-195通过抑制Sema3A发挥神经保护作用，脑miR-195水平随着年龄的增长而降低，这两项研究都促使我们探讨miR-195和miR-195调节的Sema3家族成员在年龄相关性痴呆中的作用.
方法：使用miR-195aKO小鼠评估miR-195对衰老和认知功能的影响。通过TargetScan将Sema3D预测为miR-195靶标，然后通过荧光素酶报告基因测定进行验证。而Sema3D和miR-195对神经衰老的影响是通过β-半乳糖苷酶和树突棘密度来评估的。大脑Sema3D被慢病毒过表达并被si-RNA抑制，通过Morris水迷宫评估了Sema3D过表达和miR-195敲低对认知功能的影响，Y-迷宫,和开放现场测试。在果蝇中评估了Sema3D对寿命的影响。使用同源建模和虚拟筛选开发Sema3D抑制剂。应用单向和双向重复测量ANOVA来评估小鼠认知测试的纵向数据。
结果：在miR-195a敲除小鼠中观察到认知损害和树突棘密度降低。Sema3D被鉴定为miR-195的直接靶标和年龄相关的神经变性的可能贡献者,因为Sema3D水平显示啮齿动物大脑的年龄依赖性增加。注射表达Sema3D的慢病毒引起显著的记忆缺陷,而沉默海马Sema3D改善认知。重复注射表达Sema3D的慢病毒以提高大脑Sema3D10周显示工作记忆的时间依赖性下降。更重要的是,对基因表达Omnibus数据库数据的分析表明，痴呆患者的Sema3D水平明显高于正常对照组（p<0.001）。同源物Sema3D基因在果蝇神经系统中的过度表达使运动活动和寿命减少了25％。机械上,Sema3D可能会减少神经干细胞的干性和数量，并可能破坏神经元自噬。雷帕霉素恢复了注射Sema3D慢病毒的小鼠海马中树突棘的密度。我们的新型小分子增加了Sema3D处理的神经元的活力，并可能提高自噬效率。这表明Sema3D可能是一个潜在的药物靶标。视频摘要结论：我们的结果强调了Sema3D在年龄相关性痴呆中的重要性。Sema3D可能是治疗痴呆症的新型药物靶标。
方法：使用miR-195aKO小鼠评估miR-195对衰老和认知功能的影响。通过TargetScan将Sema3D预测为miR-195靶标，然后通过荧光素酶报告基因测定进行验证。而Sema3D和miR-195对神经衰老的影响是通过β-半乳糖苷酶和树突棘密度来评估的。大脑Sema3D被慢病毒过表达并被si-RNA抑制，通过Morris水迷宫评估了Sema3D过表达和miR-195敲低对认知功能的影响，Y-迷宫,和开放现场测试。在果蝇中评估了Sema3D对寿命的影响。使用同源建模和虚拟筛选开发Sema3D抑制剂。应用单向和双向重复测量ANOVA来评估小鼠认知测试的纵向数据。
结果：在miR-195a敲除小鼠中观察到认知损害和树突棘密度降低。Sema3D被鉴定为miR-195的直接靶标和年龄相关的神经变性的可能贡献者,因为Sema3D水平显示啮齿动物大脑的年龄依赖性增加。注射表达Sema3D的慢病毒引起显著的记忆缺陷,而沉默海马Sema3D改善认知。重复注射表达Sema3D的慢病毒以提高大脑Sema3D10周显示工作记忆的时间依赖性下降。更重要的是,对基因表达Omnibus数据库数据的分析表明，痴呆患者的Sema3D水平明显高于正常对照组（p<0.001）。同源物Sema3D基因在果蝇神经系统中的过度表达使运动活动和寿命减少了25％。机械上,Sema3D可能会减少神经干细胞的干性和数量，并可能破坏神经元自噬。雷帕霉素恢复了注射Sema3D慢病毒的小鼠海马中树突棘的密度。我们的新型小分子增加了Sema3D处理的神经元的活力，并可能提高自噬效率。这表明Sema3D可能是一个潜在的药物靶标。视频摘要结论：我们的结果强调了Sema3D在年龄相关性痴呆中的重要性。Sema3D可能是治疗痴呆症的新型药物靶标。
