【作者】 董银凤；

【导师】 胡刚；

【作者基本信息】 南京医科大学 ， 药理学， 2013， 博士

【摘要】 脑卒中是一类高发病率、高致死率和高致残率的中枢神经系统疾病。脑卒中包括缺血性脑卒中和出血性脑卒中。目前的研究认为,与脑卒中发生发展相关的病理机制包括：能量耗竭、兴奋性毒性、钙超载、氧化应激、炎症和凋亡等。虽然脑卒中的病理机制研究取得较大进展,但向临床应用的有效转化均失败。脑卒中尚缺乏理想有效的治疗药物,组织纤维蛋白酶原激活剂(tissue plasminogen activator, tPA)依然是当前治疗脑卒中的主要药物。但是,tPA严格的有效治疗时间窗及其不良反应等原因极大地限制了其在临床的应用。因此,研究、阐明脑卒中所致神经损伤的病理机制、寻找有效的生物靶点、研发理想的治疗药物显得尤为迫切。ATP敏感性钾通道(ATP-sensitive potassium channel, K-ATP)是一种偶联细胞代谢与电活动、非电压依赖性的特殊钾离子通道,由内向整流钾通道(inwardly rectifying potassium channel, Kir)和磺酰脲受体(sulphonylurea receptor, SUR)亚单位以4：4的比例组合形成的异构八聚体,广泛分布于机体的多种组织与器官。长期以来,K-ATP通道与脑卒中相关性的研究大多关注于神经元Kir6.2/K-ATP通道,研究表明Kir6.2/K-ATP通道主要通过调节神经元膜电位的去极化而影响缺血性脑损伤。过去对脑卒中的研究主要集中于对神经元的保护。近年来,研究显示脑内的胶质细胞在脑缺血过程中扮演着重要的角色,其参与脑卒中的发生、发展以及后期的神经再生与修复。本实验室前期研究显示,Kir6.1/K-ATP通道高表达于脑内的星形胶质细胞、小胶质细胞和神经干细胞。但是,Kir6.1/K-ATP通道是否参与脑缺血损伤目前尚无研究报道。因此,本文工作主要研究Kir6.1/K-ATP通道在脑缺血再灌注损伤中的作用及机制,旨在为脑卒中的治疗提供新思路和新策略。本文第一部分工作应用野生型(Wild-type, WT)小鼠与Kir6.1敲减(Kir6.1heterozygote knockout, Kir6.1+/-)小鼠制备大脑中动脉阻塞(middle cerebral artery occlusion, MCAO)导致的局灶性脑缺血模型,观察Kir6.1敲减对脑缺血再灌注急性期神经损伤的影响。研究结果显示,Kir6.1/K-ATP通道敲减加重小鼠局灶性脑缺血再灌注急性期的神经损伤,损伤机制与脑缺血后内质网应激与炎症反应的增强有关：基于第一部分研究发现Kir6.1/K-ATP通道在脑缺血炎症机制中的重要作用,第二部分工作研究调节BV-2细胞Kir6.1/K-ATP通道对氧糖剥夺／复糖复氧(oxygen-glucose deprivation/reperfusion, OGD/R)所致小胶质细胞炎症反应的影响。研究结果表明,K-ATP通道开放剂Cromakalim能够减轻OGD/R诱导的小胶质细胞的炎症反应,提示小胶质细胞Kir6.1/K-ATP通道是调节脑卒中炎症反应的重要靶点；第三部分基于星形胶质细胞在脑内的重要作用,研究星形胶质细胞Kir6.1/K-ATP通道对缺血性脑损伤过程的调节。研究结果显示,K-ATP通道开放剂Nicorandil能够减轻OGD所致星形胶质细胞的内质网应激与炎症反应。应用星形胶质细胞Kir6.1亚基特异性缺失的小鼠制备MCAO模型的研究发现,星形胶质细胞Kir6.1/K-ATP通道的特异性缺失加重脑缺血再灌注损伤。研究结果提示星形胶质细胞Kir6.1/K-ATP通道是缺血性脑损伤的重要靶标。第一部分Kir6.1基因敲减对小鼠局灶性脑缺血再灌注急性期神经损伤的影响目的：研究Kir6.1基因敲减对小鼠局灶性脑缺血再灌注急性期神经损伤的影响。方法：应用2-3月龄WT及Kir6.1+/-雄性小鼠,采用线栓法建立MCAO模型,缺血1h分别再灌24h和72h。脑缺血急性期(再灌24h和72h),主要通过比较再灌不同时间小鼠的死亡率以及神经运动功能缺陷,应用2’3’5-氯化三苯基四氮唑(2’3’5-triphenyltetrazoliumchloride, TTC)染色法比较脑梗死体积的大小；伊文氏蓝(Evan’s blue, EB)渗出法比较BBB通透性的改变；通过免疫组织化学染色法比较缺血脑组织内神经元、星形胶质细胞、小胶质细胞及血管基底膜的形态与数量的改变；运用蛋白质免疫印迹(Western blot)法检测基质金属蛋白酶9(matrix metalloproteinases9, MMP-9),内质网应激相关蛋白：糖调节蛋白78(glucose-regulated protein78, GRP78)、转录因子C/EBP同源蛋白(C/EBP-homologous protein, CHOP)和凋亡执行蛋白caspase-12以及炎症相关蛋白：核转录因子κB (nuclear factor-κB, NF-κB)、NOD样受体pyrin结合区域3(NOD-like receptor pyrin domain containing three, NLRP3)和caspase-1的表达变化；应用酶联免疫吸附法(enzyme-linked immunosorbent assay, ELISA)测定缺血脑组织中白介素-1beta (interleukin-1β, IL-1β)和肿瘤坏死因子-alpha (tumor necrosis factor-α、TNF-α)的含量。结果：1. Kir6.1基因敲减加重小鼠局灶性脑缺血再灌注所致的急性损伤Kir6.1基因敲减加重小鼠脑缺血再灌注急性期的神经运动功能障碍,增加脑梗死体积；Kir6.1基因敲减加重小鼠脑缺血后BBB的破坏,增加缺血脑组织中激活型MMP-9的表达以及血管基底膜胶原蛋白Collagen-IV的降解；Kir6.1基因敲减增加小鼠脑缺血再灌注损伤后脑梗死区神经元的丢失,促进脑梗死周围区胶质细胞的增殖与活化。2. Kir6.1基因敲减增强脑缺血再灌注损伤所致的内质网应激与炎症反应Kir6.1基因敲减上调脑缺血再灌注损伤诱导的内质网应激相关蛋白,包括伴侣分子GRP78、转录因子CHOP和凋亡蛋白caspase-12;同时,Kir6.1基因敲减还增强脑缺血后的炎症反应,促进缺血脑组织内促炎因子TNF-a和IL-1β的释放。结论：1.Kir6.1/K-ATP通道敲减加重小鼠局灶性脑缺血再灌注所致的急性神经损伤。2.Kir6.1/K-ATP通道敲减加重脑缺血再灌注损伤与增强脑缺血所致的内质网应激与炎症反应有关。第二部分Kir6.1/K-ATP通道在氧糖剥夺/复糖复氧所致BV-2细胞炎症反应中的作用目的：研究开放小胶质细胞K-ATP通道对氧糖剥夺/复糖复氧所致BV-2细胞炎症反应的影响。方法：培养BV-2细胞,首先,通过细胞免疫荧光化学染色法验证BV-2细胞中K-ATP通道各亚基的表达；其次,通过Western blot检测氧糖剥夺模型下BV-2细胞K-ATP通道各亚基的表达变化,分别运用ELISA和Western blot方法比较氧糖剥夺模型下小胶质细胞炎症因子IL-1β的释放以及介导IL-1β产生的炎症小体的激活；最后,给予K-ATP通道开放剂Cromakalim预处理1h,运用ELISA和Western blot方法比较Cromakalim对OGD/R所致BV-2细胞炎症因子IL-1D的释放以及NLRP3和caspase-1表达的影响。结果：1.氧糖剥夺诱导BV-2细胞炎症小体的激活并促进IL-1p的产生OGD/R下调BV-2细胞K-ATP通道的Kir6.1亚基；OGD/R上调BV-2细胞NLRP3和caspase-1的表达、促进炎症小体的激活,从而升高IL-1p的水平。2.开放K-ATP通道减轻氧糖剥夺所致BV-2细胞的炎症反应K-ATP通道开放剂Cromakalim预处理显著抑制OGD/R所致BV-2细胞IL-1p释放的增加；Cromakalim预处理抑制OGD/R诱导BV-2细胞NLRP3和caspase-1的表达上调、抑制炎症小体的激活,从而减少IL-1p的生成。结论：1.OGD/R导致BV-2细胞炎症小体的激活,促进IL-1p的产生与释放。2.开放BV-2细胞Kir6.1/K-ATP通道抑制OGD/R所致炎症小体的激活,进而减少IL-1p的产生。第三部分星形胶质细胞Kir6.1/K-ATP通道在缺血性脑损伤中的作用目的：研究特异性表达于星形胶质细胞的Kir6.1/K-ATP通道在缺血性脑损伤中的作用。方法：应用2-3月龄WT和Kir6.1敲除(Kir6.1homozygote knockout, Kir6.1-/-)的雄性小鼠,首先通过Real-time PCR筛选两基因型小鼠脑组织中表达差异的microRNAs;将WT小鼠应用线栓法制备MCAO模型,缺血1h再灌注24h后,观察脑缺血再灌注损伤对相关microRNAs表达的影响。其次,培养WT小鼠原代的星形胶质细胞,应用Real-time PCR方法比较OGD/R对与星形胶质细胞功能相关的miR-181a和miR-7表达的影响。同时,给予K-ATP通道开放剂Nicorandil预处理1h,分别运用ELISA和Western blot检测星形胶质细胞释放的炎症因子TNF-α、IL-1β和IL-10,内质网应激相关蛋白GRP78、CHOP和caspase-12以及与IL-1β生成相关的NLRP3和caspase-1的表达。最后,应用星形胶质细胞特异性敲除Kir6.1亚基的小鼠制备MCAO模型,通过神经运动功能评分的比较并结合TTC染色法比较脑梗死体积的大小,观察星形胶质细胞Kir6.1/K-ATP通道的特异性缺失对脑缺血再灌注损伤的影响,从在体水平验证星形胶质细胞Kir6.1/K-ATP通道在缺血性脑损伤中的作用。结果：1.Kir6.1基因缺失和缺血性脑损伤均下调miR-7基础状态下,Kir6.1基因缺失下调脑内miR-7与miR-124水平；局灶性脑缺血再灌注损伤显著降低小鼠脑内miR-7.增加miR-181a与miR-290-5p的表达：OGD/R使星形胶质细胞内miR-7的表达减少、miR-181a的表达增加。2.开放K-ATP通道减轻氧糖剥／复糖复氧夺所致星形胶质细胞的内质网应激与炎症反应K-ATP通道开放剂Nicorandil预处理显著抑制OGD/R所致星形胶质细胞Kir6.1亚基和高迁移率组盒蛋白B1(high-mobility group box1,HMGB1)的表达下调；Nicorandil预处理减轻OGD/R所致内质网应激相关蛋白伴侣分子GRP78.转录因子CHOP和凋亡蛋白caspase-12的表达增加,因而减轻星形胶质细胞的内质网应激；通过降低Nicorandil预处理抑制OGD/R所致星形胶质细胞的活化,减少致炎因子TNF-a和IL-1p的释放；降低OGD/R所致星形胶质细胞NLRP3和caspase-1的表达增高,减少IL-1β的生成;Nicorandil抑制OGD/R所致星形胶质细胞miR-7的表达下调,miR-7靶向作用于NLRP3.负性调控NLRP3的表达。3.星形胶质细胞Kir6.1/K-ATP通道特异性缺失加重缺血性脑损伤特异性敲除星形胶质细胞Kir6.1/K-ATP通道,增加小鼠局灶性脑缺血再灌注损伤后的脑梗死体积,并加重脑缺血损伤所致的神经运动功能障碍。结论：1.开放Kir6.1/K-ATP通道抑制OGD/R所致星形胶质细胞的内质网应激与炎症反应。2.星形胶质细胞Kir6.1/K-ATP通道的特异性缺失能够加重小鼠局灶性脑缺血再灌注损伤。综上所述,本文工作的主要创新之处在于：1、Kir6.1/K-ATP通道缺失加重小鼠局灶性脑缺血再灌注所致的急性神经损伤Kir6.1基因敲减加重脑缺血再灌注损伤,增强脑缺血所致的内质网应激与炎症反应。研究结果表明：Kir6.1/K-ATP通道是参与脑缺血急性期神经损伤的重要靶点,拓展了Kir6.1/K-ATP通道在脑缺血再灌注损伤中的研究。2、Kir6.1/K-ATP通道抑制OGD/R所致小胶质细胞的炎症反应K-ATP通道开放剂Cromakalim预处理显著改善OGD/R所致小胶质细胞的炎症反应,抑制炎症因子IL-1β的释放以及IL-1p生成相关的炎症小体的激活。研究结果提示：Kir6.1/K-ATP通道可调节OGD/R所致小胶质细胞的炎症反应。3、星形胶质细胞Kir6.1/K-ATP通道是调节脑缺血炎症反应的重要靶标开放Kir6.1/K-ATP通道抑制OGD/R所致星形胶质细胞的内质网应激与炎症反应：特异性敲除星形胶质细胞Kir6.1/K-ATP通道加重小鼠局灶性脑缺血再灌注损伤；Kir6.1/K-ATP通道缺失和脑缺血均可降低脑内miR-7的表达,靶向作用于NLRP3炎症小体、调节星形胶质细胞的炎症反应。研究结果表明,星形胶质细胞Kir6.1/K-ATP通道是参与脑卒中炎症反应调节的重要靶标,提示miR-7可能是Kir6.1/K-ATP通(?)的调节靶点。更多还原

【Abstract】 Stroke is a central nervous system disease with highest morbidity, highest mortality and disability rate. Stroke is mainly classified into ischemic stroke and hemorrhagic stroke. Nowadays, the progressive injury following stroke originates from the complex pathologic mechamisms, including energy exhaustion, excitotoxicity, calcium overloading, oxidative stress, inflammation and apoptosis. Though there is some progress in animal experiments, it’s not successful in the stroke translational researches. At present, there is no ideal drug for stroke. Currently, tissue plasminogen activator (tPA) is the main treatment drugs for stroke. However, this treatment is only appropriate for a very small number of patients, due to a narrow time window and adverse reactions. So, it is necessary to clarify the pathophysiological mechanisms of stroke, which is essential for drug development, all these are urgent for stroke treatment.ATP-sensitive potassium (K-ATP) channels are an unsual and non-voltage dependent potassium channel, which provide a unique link between cellular energetics and electric excitability. They are eight heteromultimers composed of four inwardly rectifying potassium channel (Kir6.x) and four sulfonylurea receptors (SURs). These channels widely distribute all round the organism. For a long time, as to the study of K-ATP channels in stroke, there are only some researches about the roles of Kir6.2/K-ATP channels, which mainly express in neurons. These results showed that Kir6.2/K-ATP channels, which affected brain ischemic injury via potentiating the depolarization of cellular membrane potential. In the past few years, scientists focused on the neuroprotection of neurons against stroke. Recently, more and more studies clarified the importance of glia in stroke. In particular, astrocytes, which are abundant in the brain, appear to be important regulators of post-ischemic inflammatory responses and glial scar formation, all of them are significant in the neurogenesis and repair after stroke. In our previous studies, Kir6.1/K-ATP channels widely distribute in the brain, among astrocytes, microglia and neural stem cells, all these play essential roles in the development of stroke. However, whether Kir6.1/K-ATP associates with stroke or not? Up to now, there is no research about them in stroke. Therefore, this topic is to reveal the roles of Kir6.1/K-ATP channels in brain ischemic injury, and discovery new targets for stroke treatment.So, in part I, we subjected both wild-type (WT) mice and Kir6.1heterozygote knockout (Kir6.1+/-) mice to cerebral ischemia/reperfusion injury with middle cerebral artery occlusion (MCAO) model, and to investigate the impacts of Kir6.1subunit knockdown on ischemic stroke. Our data reveals that the downregulation of Kir6.1/K-ATP channels is more susceptible to brain ischemia, which is related to enhancing ER stress and inflammatory responses during the brain ischemic injury. According to part Ⅰ, we found that Kir6.1/K-ATP channels played an essential part in post-ischemic inflammation. Then, in part Ⅱ, we focused on the roles of Kir6.1/K-ATP channels expressed in BV-2cell lines in OGD/R-induced inflammation. These results showed that opening Kir6.1/K-ATP channels could attenuate OGD/R-induced inflammation in BV-2cell lines, which implied that Kir6.1/K-ATP channels expressed in microglia were an important target for regulating post-ischemic inflammation. As to astrocytes play an important role in the brain. Accordingly, in part III, we concentrated on the roles of Kir6.1/K-ATP channels expressed in astrocytes in the brain ischemic injury. We found that opening Kir6.1/K-ATP channels expressed in astrocytes could inhibit OGD/R-induced ER stress and inflammation. Then, we subjected Kir6.1conditional knockout mice to MCAO model, and found astrocytes null for Kir6.1aggravated brain ischemic injury. These results suggested that Kir6.1/K-ATP channels expressed in astrocytes might be an essential target for stroke treatment.Part I Effects of Kir6.1gene heterozygote knockout on the focal cerebral ischemia/reperfusion injury in miceAIM:To investigate the effects of Kir6.1gene heterozygote knockout on focal cerebral ischemia/reperfusion injury in mice.METHODS:We subjected two to three-month-old WT and Kir6.1+/-male mice to cerebral ischemia by MCAO model with a modified intralumenal filament technique as described previously. They were all peformed by ischemia1h and reperfusion24h or72h. The mortality rate and neurological deficits were measured in each group after cerebral ischemia. The infarct size was determined by staining coronal brain slices with235-triphenyltetrazoliumchloride (TTC), the extravasation of Evan’s blue (EB) made known the BBB disruption. Moreover, we observed the changes of neurons, astrocytes, microglia and neurovascular substrates by immunohistochemistry staining, and applied Western blot assay to analyse expression of matrix metalloproteinases9(MMP-9), ER stress related proteins, including glucose-regulated protein78(GRP78), C/EBP-homologous protein (CHOP), caspase-12, and inflammatory related proteins, such as nuclear factor κB (NF-κB), NOD-like receptor pyrin domain containing three (NLRP3) and caspase-1. Furthermore, we detected the contents of interleukin-lbeta (IL-1β) and tumor necrosis factor-alpha (TNF-a) in the ischemic brain tissues by enzyme-linked immunoabsorbent assay (ELISA).RESULTS:1. Kir6.1gene knockdown exacerbated acute neural injury induced by cerebral ischemia/reperfusion injury in miceKir6.1gene knockdown aggravated the neurological disorder and infarct size after brain ischemic injury in mice. Kir6.1gene knockdown exacerbated BBB extravasation, increased expression of activated MMP-9and advanced Collagen-IV degradation. Kir6.1gene knockdown exacerbated neuronal death in the core infarct area, and promoted glial responses in the peri-infarct area after cerebral ischemia/reperfusion injury.2. Kir6.1gene knockdown exacerbated brain ischemic injury via enhancing ER stress and post-ischemic inflammationKir6.1gene knockdown enhanced ER stress induced by ischemic injury, by upregulating ER stress-related proteins, including molecular chaperone GRP78, transcription factor CHOP and apoptosis executor caspase-12. Kir6.1gene knockdown intensified post-ischemic inflammation, and promoted production of inflammatory factors TNF-a and IL-1β.CONCLUSIONS:1. Kir6.1/K-ATP channels knockdown aggravates the brain ischemic injury induced by focal cerebral ischemia/reperfusion in mice.2. Kir6.1/K-ATP channels knockdown exacerbates cerebral ischemia and reperfusion injury via advancing ER stress and post-ischemic inflammation. Part II Roles of Kir6.1/K-ATP channels in OGD/R-induced inflammation in BV-2cell linesAIM:To investigate the roles of K-ATP channels expressed in microglia in the OGD/R-induced inflammation.METHODS:BV-2cell lines were used in the following experiments. Firstly, we used immunofluorescence images to validate K-ATP channels subunits expressed in BV-2cell lines. Secondly, we analysed the changes of K-ATP channels subunits after OGD/R by Western blot, and then observed inflammatory cytokine IL-1β release and inflammasome activation, which cleaved proIL-1β into mature IL-1β, by ELISA and Western blot assays respectively. Finally, we pretreated BV-2cell lines with K-ATP channels opener (Cromakalim)1h before OGD, compared the production of IL-1β and the expression of NLRP3and caspase-1by ELISA and Western blot assays respectively.RESULTS:1. Oxygen-glucose deprivation induced inflammasome activation and promoted IL-1β production in BV-2cell linesOGD/R induced K-ATP channels Kir6.1subunit downregulation. OGD/R upregulated NLRP3and caspase-1, and induced inflammasome activation, which lead to an increase of IL-ip release from BV-2cell lines.2. Opening K-ATP channels inhibited OGD/R-induced inflammation in BV-2cell linesK-ATP channels opener (Cromakalim) pretreatment could ameliorate OGD/R-induced IL-1β release from BV-2cell lines. Pretreatment with Cromakalim could inhibit OGD/R-induced upregulation of NLRP3and caspase-1, and impeded activation of inflammasome, all of these resulted in the decrease of IL-1β. CONCLUSIONS:1. OGD/R results in activation of inflammasome and increases IL-1β production in BV-2cell lines.2. Opening Kir6.1/K-ATP channels inhibites inflammasome activation, which decreases production of IL-1β in BV-2cell lines.Part III Roles of Kir6.1/K-ATP channels expressed in astrocytes in the brain ischemic injuryAIM:To investigate the effects of Kir6.1/K-ATP channels specificly expressed in astrocytes on brain ischemic injury.METHODS:We selected two to three-month-old WT and Kir6.1homozygote knockout (Kir6.1-/-) male mice, and screened the expression of microRNAs between both genetype mice by Real-time PCR analyses. Next, we subjected WT mice to brain ischemia by MCAO model as described previously and analysed changes of related microRNAs. Thirdly, we isolated primary astrocytes from the cortex of WT mice, and observed the expression of miR-181a and miR-7after OGD by Real-time PCR assays. Moreover, we pretreated primary astrocyte with Nicorandil1h before OGD, and detected release of pro-inflammatory factors TNF-α, IL-1β and IL-10by ELISA. Expression of GRP78, CHOP, caspase-12, NLRP3and caspase-1, which were relevant to ER stress and inflammation, were determined by Western blot. Finally, in order to verify the influence of Kir6.1/K-ATP channels expressed in astrocytes deficiency on brain ischemic injury in vivo, we introduced Kir6.1conditional knockout mice and subjected them to MCAO model. We utilized the neurological score and TTC staining to assess the neurological disorder and infarct size. RESULTS:1. Either Kir6.1gene deficiency or brain ischemic injury caused downregulation of miR-7At the baseline, Kir6.1knockout caused downregulation of miR-7and miR-124. Brain ischemia induced downregulation of miR-7, upregulation of miR-181a and miR-290-5p. Moreover, OGD/R caused downregulation of miR-7and upregulation of miR-181a in primary astrocytes.2. Opening K-ATP channels decreased ER stress and inflammation induced by OGD/R in primary astrocytesPretreatment with K-ATP channels opener (Nicorandil) could inhibited OGD/R-induced downregulation of Kir6.1subunit and high-mobility group boxl (HMGB1). Nicorandil decreased expression of ER stress-related proteins, including molecular chaperone GRP78, transcription factor CHOP and apoptosis executor caspase-12. So it could attenuate ER stress induced by OGD/R model. Nicorandil decreased OGD/R-induced TNF-α and IL-1β release from astrocytes, it could also inhibit OGD/R-induced upregulation of NLRP3and caspase-1, impeded inflammasome activation and decreased production of IL-1β.Nicorandil downregulated OGD/R-induced the increase of miR-7, and targeted the NLRP3inflammasome, which inversely correlated to the expression of NLRP3.3. Kir6.1/K-ATP channels deficiency in astrocytes aggravated cerebral ischemia/reperfusion injuryCompared to contol group mice, there was larger infarct size in the mice, which were deficient by Kir6.1/K-ATP channels expressed in astrocytes. Moreover, it’s also accompanied by severer neurological disorder.CONCLUSIONS:1. Opening Kir6.1/K-ATP channels attenuates OGD/R-induced ER stress and inflammatory responses in primary astrocytes.2. Kir6.1/K-ATP channels deficiency in astrocytes aggravates focal cerebral ischemia/reperfusion injury in mice. SUMMARY:1. Kir6.1/K-ATP channels deficiency exacerbates acute neural injury induced by focal cerebral ischemia/reperfusionKir6.1gene knockdown aggravated cerebral ischemia/reperfusion injury, and enhanced ER stress and post-ischemic inflammation. These results indicate that Kir6.1/K-ATP channels are important targets for the acute brain ischemic injury, which expands the study of Kir6.1/K-ATP channels to stroke.2. Kir6.1/K-ATP channels inhibites OGD/R-induced inflammation in BV-2cell linesCromakalim opening Kir6.1/K-ATP channels decreased OGD/R-induced inflammatory responses in BV-2cell lines, including inhibiting IL-1β release and inflammasome activation. These results suggest Kir6.1/K-ATP channels expressed in microglia might be a new target for OGD/R-induced inflammation.3. Kir6.1/K-ATP channels expressed in astrocytes are an important target for post-ischemic inflammation in brain ischemiaOpening Kir6.1/K-ATP channels could inhibite inflammation induced by OGD/R in astrocytes. Kir6.1conditional knockout in astrocytes could exacerbate cerebral ischemia/reperfusion injury. Both Kir6.1/K-ATP channels deficiency and cerebral ischemia could induce downregulation of miR-7. While miR-7targeted NLRP3inflammasome and regulated astrocytic inflammation. These results indicate that Kir6.1/K-ATP channels expressed in astrocytes are an essential target for the post-ischemic inflammation of stroke, and it also implies that miR-7might be a regulator of Kir6.1/K-ATP channels.更多还原