目的:研究臭氧对慢性压迫性坐骨神经损伤（chronic constriction injury of the sciatic nerve, CCI）模型小鼠疼痛的影响，探讨CCI模型小鼠脊髓Homer1b/c在此过程中的作用。方法:按随机数字表法将62只雄性昆明小鼠分为8组（每组8只）：假手术组（S1组）、注射纯氧对照组（S2组）、CCI术后第7天组（C1组）、CCI术后第13天组（C2组）、术后第7天注射臭氧组（O1组）、术后第7~13天注射臭氧组（O2组）、鞘内注射反义寡核苷酸组（AS组）、鞘内注射生理盐水对照组（NS组）。各组小鼠均选择左侧坐骨神经建立CCI模型，术后7 d小鼠出现左后肢负重减少、挛缩等体征，且无肢体瘫痪、自噬等现象视为建立模型成功。术后第7天开始观测机械缩足阈值（mechanical withdrawal threshold, MWT）和热缩足潜伏期（thermal withdraw latency, TWL），Western blot法检测脊髓Homer1b/c和代谢型谷氨酸受体（metabotropic glutamate receptor, mGluR）5表达水平，免疫荧光法检测Homer1b/c和mGluR5在脊髓的分布与表达。S1组只游离神经不结扎，术后第7天观测MWT和TWL；S2组行左侧坐骨神经结扎，逐层缝合，在术后第7天注射纯氧2、4、8、24 h后观测MWT；C1组行左侧坐骨神经结扎，逐层缝合，术后第7天观测MWT和TWL，其中MWT观测时间点同O1组；C2组行左侧坐骨神经结扎，逐层缝合，术后第7~13天观测MWT和TWL；O1组行左侧坐骨神经结扎，逐层缝合，在术后第7天注射臭氧，观测注射后2、4、8、24 h的MWT和注射后2 h的TWL；O2组行左侧坐骨神经结扎，逐层缝合，在术后第7~13天每天注射臭氧2 h后观测MWT；AS组行左侧坐骨神经结扎，逐层缝合，在术后第4天起鞘内注射Homer1b/c的反义寡核苷酸至第7天，术后第4~9天观测MWT；NS组为AS组的生理盐水对照组，与AS组相同时间点观测MWT。结果:与S1组比较，C1和C2组小鼠MWT及TWL均降低（ P<0.05）；与C1组比较，O1组小鼠MWT升高（ P<0.05），而TWL差异无统计学意义（ P>0.05）；与C1组比较，O1组小鼠MWT在注射臭氧2、4 h后升高（ P<0.05），S2组小鼠MWT差异无统计学意义（ P>0.05）；与C2组比较，O2组小鼠MWT升高（ P<0.05）；与NS组比较，AS组小鼠MWT在术后第8、9天显著升高（ P<0.05）。与S1组比较，C2组和O2组小鼠Homer1b/c表达水平升高（ P<0.05）；与C2组比较，O2组小鼠Homer1b/c表达水平降低（ P<0.05）；S1组、C2组、O2组小鼠的mGluR5表达水平差异无统计学意义（ P>0.05）；与S1组比较，NS组和AS组小鼠Homer1b/c表达水平升高（ P<0.05）；与NS组比较，AS组小鼠Homer1b/c表达水平降低（ P<0.05）。与S1组比较，C1组小鼠Homer1b/c的表达增多；与C1组比较，O2组、AS组小鼠Homer1b/c表达减少；S1组、C1组、O2组和AS组小鼠的mGluR5表达未见明显差异。双重染色融合后，与S1组比较，C1组小鼠Homer1b/c表达位置与mGluR5的位置相近；与C1组比较，O2组和AS组小鼠Homer1b/c表达位置与mGluR5相近的结果减少。 结论:臭氧可以抑制CCI模型小鼠的机械痛敏，其机制可能是抑制Homer1b/c的产生，减少与mGluR5的相互作用。

神经病理性疼痛（neuropathic pain, NP）的既往研究中关于Homer1蛋白和Ⅰ组代谢型谷氨酸受体（metabotropic glutamate receptor, mGluRs）在疼痛信号转导中的作用相对明确，但它们相互之间的关系并不清楚，在突触后膜中Homer1蛋白和Ⅰ组mGluRs可以相互作用并对疼痛信号转导和疼痛维持有重要影响，Homer1蛋白可能是其中的关键靶点。Homer1b/c作为重要的突触后致密物在突触可塑性调节和突触信号传递中起重要作用。文章综述了Homer1蛋白特殊的果蝇激活蛋白/血管舒张刺激磷酸蛋白同源结构域1（enabled protein of drosophila/vasodilator-stimulated phosphoprotein homology, EVH1）和螺旋卷曲（coiled-coil, C-C）结构在脊髓突触后膜通过与不同突触后蛋白结合产生NP作用，mGluRs在神经损伤模型的潜在作用机制中与上述作用可能存在共同的作用机制。

目的 研究Homer1b/c蛋白在谷氨酸兴奋性毒性损伤诱发的细胞自噬中的作用及机制.方法 选用小鼠海马神经元HT22 细胞,通过 500 μmol/L L-谷氨酸处理建立细胞损伤模型.用siRNA慢病毒转染方式下调Homer1b/c表达,用 10 μmol/L钙离子螯合剂BAPTA-AM、10 mmol/L内质网应激抑制剂4-PBA分别抑制细胞内钙离子释放和内质网应激后,使用蛋白质印迹法检测细胞中Homer1b/c蛋白,自噬效应蛋白[beclin-1、微管相关蛋白 1 轻链 3(LC3)]及内质网应激标志蛋白[C/EBP同源蛋白(CHOP)、葡萄糖调节蛋白 78(GRP 78)]的表达水平.结果 L-谷氨酸处理HT22细胞12 h后,细胞中beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值均较对照组升高(均P＜0.05);与转染对照组相比,下调Homer1b/c表达可降低细胞中beclin-1 表达和LC3-Ⅱ/LC3-Ⅰ比值(均P＜0.05);抑制细胞内钙离子释放和内质网应激均能降低细胞中beclin-1 表达和LC3-Ⅱ/LC3-Ⅰ比值(均P＜0.05);下调Homer1b/c表达后,抑制细胞内钙离子释放和内质网应激未能进一步降低细胞中beclin-1 表达和LC3-Ⅱ/LC3-Ⅰ比值.结论 Homer1b/c能够调节谷氨酸兴奋性毒性损伤诱发的细胞自噬,其调节作用可能与内质网功能有关.

Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NLRP3 inflammasome activation and leads to visual damage.Homer1a is reported to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homer1a on NLRP3 inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models were constructed using C57BL/6J and Homer1flox/-/Homer1a+/-/Nestin-Cre+/-mice with elevated lOP-induced retinal ischemia/reperfusion injury.For in vitro experiments,the oxygen-glucose deprivation/reperfusion injury model was constructed with Muller cells.We found that Homer1a overexpression ameliorated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homer1a knockdown promoted NF-κB P65Ser536 activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1β and interleukin-18.The opposite results were observed with Homer1a overexpression.Finally,the combined administration of Homer1a protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1flox/-/Homer1a+/-/Nestin-Cre+/-mice and apoptosis in Muller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and Muller cells via the caspase-8/NF-κB P65/NLRP3 pathway after I/R injury.

目的:了解竹节参皂苷Ⅳa及其衍生物药理活性和作用机制的研究进展,为其进一步开发利用提供参考.方法:以"竹节参""竹节参皂苷""竹节参皂苷Ⅳa""衍生物""药理活性""Chikusetsusaponin""ChikusetsusaponinⅣa""Panacis Japonici""Derivative""Pharmacological activity"等为关键词,组合查询1989年1月-2017年12月发表并收录于中国知网、万方、维普、PubMed、Web of Science等数据库的相关文献,就竹节参皂苷Ⅳa及其衍生物的种类、药理活性、作用机制及靶点进行归纳与总结.结果与结论:共检索得到相关文献489篇,其中有效文献43篇.具药理活性的相关化合物包括竹节参皂苷Ⅳa、竹节参皂苷Ⅳa甲酯、竹节参皂苷Ⅳa丁酯、去葡萄糖竹节参皂苷Ⅳa,主要药理活性为保护心/脑、调节代谢、抗炎、抗凝血、抗肿瘤、抗病毒等.其相关作用机制及靶点主要包括激活沉默信息调节因子2相关酶1/细胞外调节蛋白激酶1/2/突触后膜骨架蛋白Homer1a途径,增强机体清除氧自由基的能力、降低心肌细胞膜脂质过氧化的程度,上调同源丢失性磷酸酶张力蛋白、下调核因子κB的表达,调节Ca2+、K+、Na+等离子的跨膜转运,促进糖原合酶激酶3β的磷酸化,抑制蛋白激酶C的磷酸化,抑制细胞外因子/β-联蛋白信号通路,抑制炎症因子表达,抑制血小板聚集,诱导肿瘤细胞周期停滞及凋亡,导致病毒直接失活或抑制子代病毒释放等.目前尚缺乏竹节参皂苷Ⅳa及其衍生物单体药理活性及作用机制的系统性深入研究,同时上述化合物是否具有其他药理作用、其药动学特征及剂型研发等均有待进一步探索.

Ischemic and traumatic insults to the central nervous system account for most serious acute and fatal brain injuries and are usually characterized by primary and secondary damage. Secondary damage presents the greatest challenge for medical staff; however, there are currently few effective therapeutic targets for secondary damage. Homer proteins are postsynaptic scaffolding proteins that have been implicated in ischemic and traumatic insults to the central nervous system. Homer signaling can exert either positive or negative effects during such insults, depending on the specific subtype of Homer protein. Homer 1b/c couples with other proteins to form postsynaptic densities, which form the basis of synaptic transmission, while Homer1a expression can be induced by harmful external factors. Homer 1c is used as a unique biomarker to reveal alterations in synaptic connectivity before and during the early stages of apoptosis in retinal ganglion cells, mediated or affected by extracellular or intracellular signaling or cytoskeletal processes. This review summarizes the structural features, related signaling pathways, and diverse roles of Homer proteins in physiological and pathological processes. Upregulating Homer1a or downregulating Homer1b/c may play a neuroprotective role in secondary brain injuries. Homer also plays an important role in the formation of photoreceptor synapses. These findings confirm the neuroprotective effects of Homer, and support the future design of therapeutic drug targets or gene therapies for ischemic and traumatic brain injuries and retinal disorders based on Homer proteins.