神经肌肉电刺激通过调控白细胞介素6/信号转导子及转录激活子3信号通路促进脊髓损伤后小鼠运动功能恢复

目的观察神经肌肉电刺激(NMES)对脊髓损伤后小鼠白细胞介素6(IL-6)/STAT3信号通路的影响,探讨其对运动功能恢复的机制。方法选取SPF级小鼠72只随机分成假手术(sham)组、脊髓损伤组(SCI)和NMES组。利用BMS评分、斜坡实验与电生理(EMG)评估小鼠脊髓损伤后肢体运动恢复情况。Western blotting和Real-time PCR检测各组小鼠脊髓组织中相关炎症因子、IL-6/STAT3信号通路与胶质纤维酸性蛋白(GFAP)和脑源性神经营养因子(BDNF)的表达。HE染色观察各组小鼠脊髓形态结构。结果NMES组BMS评分和小鼠斜坡实验均高于SCI组(P<0.05);NMES组小鼠运动诱发电位(MEP)最大振幅高于SCI组(P<0.05);NMES组脊髓组织TNF-α、IL-12A与GFAP表达量均低于SCI组(P<0.05),TGF-β、IL-10与BDNF表达量均高于SCI组(P<0.05);与SCI组相比,NMES组小鼠脊髓空洞较少,脊髓形态修复较好;与SCI组相比,NMES组IL-6/STAT3信号通路蛋白表达均低于SCI组(P<0.05)。结论神经肌肉电刺激通过抑制IL-6/STAT3信号通路发挥抗炎作用,从而促进脊髓损伤后小鼠后肢运动功能的恢复。

SOCS3 Expression Correlates with Severity of Inflammation in Mouse Hepatitis Virus Strain 3-induced Acute Liver Failure and HBV-ACLF

Summary： Recently, suppressor of cytokine signaling-3 （SOCS3） has been shown to be an inducible endogenous negative regulator of Janus kinase/signal transducers and activators of transcription （JAK/STAT） pathway which is relevant in inflammatory response, while its functions in acute liver failure and HBV-induced acute-on-chronic liver failure （HBV-ACLF） have not been fully elucidated. In this study, we explored the role of SOCS3 in the development of mouse hepatitis virus strain 3 （MHV-3）-induced acute liver failure and its expression in liver and peripheral blood mononuclear cells （PBMCs） of patients with HBV-ACLF. Inflammation-related gene expression was detected by real-time PCR, immtmohistochemistry and Western blotting. The correlation between SOCS3 level and liver injury was studied. Our results showed that the SOCS3 expression was significantly elevated in both the liver tissue and PBMCs from patients with HBV-ACLF compared to mild chronic hepatitis B （CHB）. Moreover, a time course study showed that SOCS3 level was increased remarkably in the liver of BALB/cJ mice at 72 h post-infection. Pro-inflammatory cytokines, interleukin （IL）-1 β, IL-6, and tumor necrosis factor （TNF）-α, were also increased significantly at 72 h post-infection. There was a close correlation between hepatic SOCS3 level and IL-6, and the severity of liver injury defined by alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels, respectively. These data suggested that SOCS3 may play a pivotal role in the pathogenesis of MHV-3-induced acute liver failure and HBV-ACLF.

Cytotoxicity of seven recent dentine bonding agents on mouse 3T3 fibroblast cells

Today it is generally accepted that most bonding agents are cytotoxic. In this study the relative cytotoxicity of seven recent dentine bonding agents on mouse 3T3 fibroblast cells were investigated. Materials and Methods. Near-confluent mouse 3T3 fibroblast cells were exposed to Dulbecco Modified Eagle’s Medium containing extractions from the seven different bonding agents. The cell survival rate was then determined using the standard MTT assay. Results. The cell survival rate ranking is: iBond (94%) < Gbond (78%) < Xeno V (71%) < Adper Easy Bond (63%) < Xeno V+ (61%) < Adper Scotchbond SE (33%) < XP Bond (32%). Part A of Adper Scotchbond SE had a survival rate of 35% and part B 38%. These two parts did not differ significantly. Adper Scotchbond SE and XP Bond do not differ significantly. While Xeno V+, Xeno V and Adper Easy Bond do not differ. (p < 5%;Tukey-Kramer Multiple-Comparison Test). Conclusion. All of the tested adhesive bonding agents were cytotoxic with survival rate of 3T3 cells between 94% to 31%. Of the 7 bonding agents tested iBond was found to be only slightly toxic and by far the least toxic. The two bonding agents (XP Bond and Adper Scotchbond SE) containing UDMA plus TEGDMA plus HEMA plus camphorquinone were found to be the most toxic.

小鼠^(13)N-NH_(3)·H_(2)O心肌灌注Micro-PET显像中尾静脉注射技术的优化与评估

目的通过自制小鼠尾静脉留置针,为小鼠^(13)N-NH_(3)·H_(2)O心肌灌注显像提供实用、快捷、成功率高的实验工具,并总结归纳出一套流畅、高效的实验流程。方法实验组和对照组分别使用本实验室自制的鼠尾静脉留置针及人外周浅静脉一次性使用静脉留置针(洁瑞26G)为小鼠行尾静脉留置针穿刺,经留置针推注^(13)N-NH_(3)·H_(2)O,配合Micro-PET动态采集,记录图像采集的成功率及图像质量并评价两组注射的优缺点。结果两组实验在穿刺成功率、穿刺时间、药物残留量、图像质量及小鼠尾部放射性药物残留量5方面差异均具有统计学意义(P<0.05)。综合比较,自制留置针制作及操作简便、穿刺成功率高、对鼠尾静脉损伤小,且在图像采集成功率及质量方面均占优势。结论自制鼠尾静脉留置针联合优化的实验流程,能显著提高鼠尾静脉穿刺成功率和图像质量,很好地应用于小鼠^(13)N-NH_(3)·H_(2)O心肌灌注Micro-PET显像中。

Transglutaminase 3 expression in C57BL/6J mouse embryo epidermis and the correlation with its differentiation

Epidermal-type transglutaminase 3 (TGM3) is involved in the cross-linking of structural proteins to form the cornifiedenvelope in the epidermis. In the present study, we detected the expression of TGM3 in the mouse embryo using RT-PCR.TGM3 mRNA is weakly presented from E11.5 to E14.5 and increases significantly from E15.5 to birth. Then wedetermined the spatial and temporal expression pattern of TGM3 in the skin and other organs by in situ hybridization. Wefound a deprivation of TGM3 in skin at E11.5, while a rich supply in periderm cells and a weak expression in basal cellsfrom E12.5 to E14.5. From the period of E15.5 to E16.5, after keratinization in the epidermis, TGM3 was expressed inthe granular and cornified layers. The electron microscopic observation of the C57BL/6J mouse limb bud skin develop-ment provided several morphological evidences for the epidermal differentiation. The above findings suggest that theexpression of TGM3 plays a important role in the epidermis differentiation in embryogenesis.

A Three-Dimensional (3D) Environment to Maintain the Integrity of Mouse Testicular Can Cause the Occurrence of Meiosis

Adhesions between different cells and extracellular matrix have been studied extensively in vitro, but little is known about their functions in testicular tissue counterparts. Spermatogonia and their companion somatic cells maintain a close association throughout spermatogenesis and this association is necessary for normal spermatogenesis. In order to keep the relative integrity of the testicular tissues, and to detect the development in vitro, culture testicular tissues in a three- dimensional （3D） agarose matrix was examined. Testicular tissues isolated from 6.5 d postpartum （dpp） mouse were cultured on the top of the matrix for 26 d with a medium height up to 4/5 of the 3D agarose matrix. The results showed that in this 3D culture environment, each type of testicular cells kept the same structure, localization and function as in vivo and might be more biologically relevant to living organisms. After culture, germ cell marker VASA and meiosis markers DAZL and SCP3 showed typical positive analysed by immunofluorescence staining and RT-PCR. It demonstrated that this 3D culture system was able to maintain the number of germ cells and promote the meiosis initiation of male germ cells.

N-methyl-D-aspartate receptor subtype 3A promotes apoptosis in developing mouse brain exposed to hyperoxia

In the present study, 7 day postnatal C57/BL6 wild-type mice （hyperoxia group） and 7 day postnatal N-methyI-D-aspartate receptor subtype 3A knockout mice （NR3A KO group） were exposed to 75% oxygen and 15% nitrogen in a closed container for 5 days. Wild-type mice raised in normoxia served as controls. TdT-mediated dUTP nick end labeling （TUNEL）/neuron-specific nuclear protein （NeuN） and 5-bromo-2＇-deoxyuridine （BrdU）/NeuN immunofluorescence staining showed that the number of apoptotic cells and the number of proliferative cells in the dentate subgranular zone significantly increased in the hyperoxia group compared with the control group. However, in the same hyperoxia environment, the number of apoptotic cells and the number of proliferative cells significantly decreased in the NR3A KO group compared with hyperoxia group. TUNEL＋/NeuN＋ and BrdU＋/NeuN~ cells were observed in the NR3A KO and the hyperoxia groups. These results demonstrated that the NR3A gene can promote cell apoptosis and mediate the potential damage in the developing brain induced by exposure to non-physiologically high concentrations of oxygen.

Effects of DHRS3 in C2C12 Myoblast Differentiation and Mouse Skeletal Muscle Injury

Myoblast differentiation is an essential process during skeletal muscle development.C2C12 myoblast is a commonly used experimental model to study muscle cell differentiation in vitro.Dehydrogenase/reductase(SDR family)member 3(DHRS3)is a highly conserved member in short-chain alcohol dehydrogenase/reductase superfamily and has been shown to be involved in the metabolism of retinol.Previous experimental results showed that the expression of DHRS3 increased significantly during the differentiation of myoblasts differentiation.However,the effect of DHRS3 on mouse muscle cell differentiation was unclear.The objective of current study was to determine if DHRS3 affected muscle cell differentiation,and if DHRS3 was involved in muscle regeneration.Protein expression was determined by western blot and immunofluorescence analysis.The activation and inhibition of DHRS3 increased and decreased C2C12 myoblast differentiation respectively,which indicated that DHRS3 could affect C2C12 myoblast differentiation.DHRS3 expression was significantly changed during muscle regeneration,with the regeneration of muscle injury,the expression of DHRS3 tended to increase first and then decrease.It suggested that DHRS3 might be involved in muscle regeneration.In summary,this study confirmed the involvement of DHRS3 in C2C12 myoblast differentiation and mouse skeletal muscle regeneration and provided a theoretical basis for further elucidating the molecular mechanism of muscle development.

In vitro responses of human pulp cells and 3T3 mouse fibroblasts to six contemporary dental restoratives

In vitro responses of human primary pulp cells (HPCs) and 3T3 mouse fibroblasts to six contempo-rary commercial dental restoratives were evaluated using the WST-1 assay. The results show that Fuji II is not cytotoxic to both cells. Fuji II LC is not cyto-toxic to HPCs but cytotoxic to 3T3 cells, indicating that 3T3 cells are more vulnerable to 2-hydroxyethyl methacrylate (HEMA) than HPCs. Vitremer is very cytotoxic probably due to having diphenyliodonium chloride and HEMA in it. Z100 is very cytotoxic probably due to having triethylene glycol dimethacry-late (TEGDMA) in it. P60 is cytotoxic but less cyto-toxic than Z100 probably due to no TEGDMA in it. Durelon is the most cytotoxic among the six materials studied probably due to the high cytotoxicity of zinc ions. Additionally, the cytotoxcity of the tested mate-rials was found to be dose-dependent.

DDX3X/NF-κB通路介导蛛网膜下腔出血小鼠早期神经元凋亡

目的:研究DDX3X/NF-κB通路在蛛网膜下腔出血(SAH)小鼠早期神经元凋亡过程中的作用。方法:利用颈内动脉穿刺的方法构建SAH小鼠模型,对小鼠进行神经功能评分。使用表达DDX3X靶向shRNA的重组慢病毒(Lv-shDDX3X)预先敲低脑内DDX3X的表达,或者通过NF-κB抑制剂NF-κB-IN-1(简称IN-1)抑制NF-κB信号通路,利用Western Blot检测小鼠皮质DDX3X和NF-κB(p65)的表达,通过TUNEL/NeuN染色检测各组小鼠大脑皮质神经元的凋亡。结果:SAH术后24 d小鼠神经功能显著障碍(P<0.05),皮质中DDX3X表达显著增加而NF-κB(p65)的表达显著降低(P<0.05)。预先敲低DDX3X后,小鼠神经功能显著恢复,NF-κB(p65)蛋白表达显著高于SAH组(P<0.05);当在敲低DDX3X表达的同时使用IN-1抑制NF-κB活性,则小鼠神经功能恢复不明显。TUNEL/NeuN染色显示敲低DDX3X表达后小鼠脑组织中TUNEL阳性的死亡神经元数量少于SAH组(P<0.05),而如果在敲低DDX3X表达的同时使用IN-1抑制NF-κB活性,则TUNEL阳性的神经元数量减少不明显。结论:DDX3X/NF-κB通路介导了SAH后早期脑损伤小鼠的细胞死亡。

Kanglaite combined Gemcitabine inhibits growth of nude mouse subcutaneous transplantation tumor of human PC-3 pancreatic cancer cell

Objective:To study the mechanisms of pancreatic cancer treatment with Kanglaite combined Gemcitabine by investigating the relationship between the apoptosis and the expression of bcl-2, Bax and VEGF in pancreatic cancer cells.Methods:Nude mouse subcutaneous transplantation tumor model of Human PC-3 pancreatic cancer was established; the expressions of bcl-2, Bax and VEGF of transplantation tumor cell were determined; the earlier apoptosis rate of pancreatic cancer cell and the gross tumor volume were determined. Results:Kanglaite combined Gemcitabine remarkably decreased the protein expression of bcl-2,raised the expression of Bax,increased the apoptosis rate of the pancreatic cancer and contract the gross tumor volume. Kanglaite greatly decreased the protein expression of VEGF of the tumor cell. Conclusion:Therapeutic efficacy of Kanglaite combined Gemcitabine is far better than separate use of the two medicines in the pancreatic cancer transplantation tumor treatment.

炙马钱子对重症肌无力小鼠血清MMP-3及抗MuSK抗体影响

目的探讨炙马钱子通过调节基质金属蛋白酶3(MMP-3)致使重症肌无力发病机制。方法45只8周雄性C57BL/6J小鼠,麻醉后,随机抽取37只模型组小鼠,共用40μg的肌肉特异性酪氨酸激酶(MuSK)乳化在100μL磷酸盐缓冲溶液(PBS)和100μL完全弗氏佐剂(CFA)腹腔、后脚注射,剩余8只正常组注射100μL PBS和100μL CFA佐剂,并24 h内注射环磷酰胺(300 mg/kg,溶解在0.9%的生理盐水中配置成10 mg/mL的终浓度)抑制免疫抵抗。30 d补充注射1次,通过小鼠体征及行为学等观察确定造模周期。在造模成功当天,将小鼠随机分为正常组、模型组、炙马钱子组、AG490组,每组8只,炙马钱子组予炙马钱子250 mg/(kg·d)连续灌胃30 d;AG490组予炙马钱子250 mg/(kg·d)连续灌胃30 d,AG4905 mg/(kg·d)连续腹腔注射30 d;正常组和模型组灌胃等量0.9%的生理盐水。采用酶联免疫吸附(ELISA)法检测血清MuSK滴度,蛋白质印迹法(Western blot)检测各组神经肌肉接头处中MMP-3的蛋白表达水平。结果MuSK滴度水平:正常组MuSK滴度水平最低(3.23±1.89);与模型组比较,炙马钱子组、AG490组血清MuSK滴度显著降低[(242.12±24.69)、(133.68±27.27)比(856.93±32.44),P<0.05],且随着给药时间的延长,炙马钱子组、AG490组MuSK滴度水平逐渐下降。MMP-3的蛋白表达水平:正常组MMP-3的蛋白表达水平最低(1.00±0.07);与模型组比较,炙马钱子组、AG490组MMP-3的蛋白表达水平逐渐下降[(1.60±0.10)、(1.27±0.13)比(2.30±0.11),P<0.05]。结论炙马钱子可能通过使MMP-3合成减少,降低MuSK抗体,达到治疗重症肌无力的作用。

石菖蒲水提物对3xTg-AD小鼠肠道菌群的影响

目的:研究石菖蒲水提物对3xTg-AD小鼠盲肠和结肠菌群的影响。方法:将雄性5月龄3xTg-AD小鼠20只随机分为3xTg-AD组(M)、石菖蒲水提物4g/kg组(D)、石菖蒲水提物8g/kg组(Z)和石菖蒲水提物16g/kg组(G),每组5只;4只雄性同月龄C57BL/6J小鼠设为野生对照组(W)。给药4个月后,采用Morris水迷宫法检测各组小鼠学习记忆能力,通过16S rRNA测序方法检测各组小鼠盲肠和结肠菌群的组成,KEGG通路分析菌群功能。结果:与野生对照组小鼠比较,3xTg-AD小鼠学习记忆能力明显降低,肠道菌群从门到属水平均发生了显著变化,盲肠菌群中Turicibacter和结肠菌群中Allobaculum显著增多(P<0.05,P<0.05)。与3xTg-AD组小鼠比较,石菖蒲水提物16g/kg组小鼠的学习记忆能力明显提高;在门水平上结肠菌群中Bacteroidetes显著增加(P<0.05)、Firmicutes显著减少(P<0.05),在属水平上盲肠菌群中Turicibacter和结肠菌群中Allobaculum显著减少(P<0.05,P<0.05)。结论:石菖蒲能提高3xTg-AD小鼠的学习记忆能力,改善肠道菌群失调。

Effect of Lanthanum on Acid Secretion from Isolated Mouse Stomach in Vitro

To explore the effect and the mechanism of La^(3+) on gastric acid secretion (GAS) of isolated mouse stomach with perfused lumen, 12 cm H_2O column intragastric pressure-provided, whole stomach preparations from mice were incubated in buffer at 37 ℃ in vitro, and perfusate was measured for pH with a pHS-3 type pH meter. The results show that La^(3+) (0.41～820×10^(-6) mol·L^(-1)) significantly promotes GAS in a concentration-dependant manner. Proglutamine, a blocker of gastrin receptor, potently inhibits GAS, and it may block the promotive effect of La^(3+) on GAS, and this effect increases with the increase of proglutamin concentration. Cimetidine, a blocker of histamine H_2 receptor, also potently inhibits GAS, and blocks the promotive effect of La^(3+) on GAS in the same manner with proglutamine. These results suggest that La^(3+) promotes GAS in isolated stomach possibly by stimulating the releases of gastrin from G cell and Histamine from ECL cell or by activating the gastrin receptors and Histamine H_2 receptors on the parietal cell, thereby accelerating the acid secretion of parietal cells in stomach.

Isatin decreases Bax protein expression in the substantia nigra of a mouse model of Parkinson's disease

The present study observed the action of 1H-indole-2, 3-dione （isatin） on Bax protein expression in the substantia nigra of a Parkinson＇s disease animal model. Parkinson＇s disease-like behaviors were induced in C57BL/6J mice treated with 1-methyl-4-phenyl-1,2, 3, 6-tetrahydropyridine （MPTP） Bax protein expression was significantly reduced in isatin （100, 200 mg/kg）-pretreated mice. Results demonstrate that isatin plays a neuroprotective role in mice treated with MPTP by down-regulating Bax protein expression.

Adenosine monophosphate-activated protein kinase activation enhances embryonic neural stem cell apoptosis in a mouse model of amyotrophic lateral sclerosis

Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.

Astrocyte reactivity in related brain regions in a mouse model of MPTP-induced Parkinson's disease

BACKGROUND： Severe injury to dopaminergic neuronal cell bodies and their axon terminals in the substantia nigra pars compacta （SNC） has been observed in both Parkinson＇s disease （PD） patients or in 1-methy-4-phenyl-1,2,3,6-tetrahydropyrindine（MPTP）-induced PD animal models, but only slight injury occurs in the adjacent ventral tegmentat area （VTA）. The mechanisms underlying this selective injury remain poorly understood. OBJECTIVE： To comparatively observe astrocyte reactivity in the SNC, caudate putamen （CPu）, VTA, and frontal association cortex （FrA）. DESIGN, TIME AND SETTING： A cellular and molecular biology, randomized, controlled experiment was performed at the Institute of Neurobiology, Department of Human Anatomy, Medical School of Nantong University, between December 2006 and September 2008. MATERIALS： A total of 80 healthy adult male C57BL/6 mice were included in this study. MPTP was purchased from Sigma, USA. METHODS： Mice were randomly divided into a model group （n = 64） and a sham-operated group （n = 16）. PD was induced in the mice from the model group by intraperitoneal injection of 20 mg/kg MPTP, once every three hours, for a total of 4 times. MAIN OUTCOME MEASURES： Tyrosine hydroxylase （TH）-immunoreactive neurons and glial fibrillary acidic protein （GFAP）-immunoreactive astrocytes were examined by dual immunofluorescence labeling. GFAP-immunoreactive astrocytes in the CPu and FrA were determined by immunofluorescent staining. GFAP mRNA expression in the SNC, CPu, VTA, and FrA was detected using real-time polymerase chain reaction. TH protein levels in the TH-immunoreactive axon terminals of the CPu and FrA were detected by Western blotting. RESULTS： Numbers of TH-immunoreactive neurons in the SNC, and TH protein level in the CPu, markedly decreased （by approximately 68%） 1 day after MPTP injection, and gradually increased at 3 days. Simultaneously, astrocyte reactivity was strengthened, in particular at 7 days. However, after MPTP injection, decreases in the numbers of TH-immunoreactive neurons in the VTA, and TH protein levels in the FrA, were less apparent （approximately 15%）. Also, no obvious astrocyte reactivity was observed. CONCLUSION： In a mouse model of PD, astrocyte reactivity was apparent in the SNC and CPu, but not the VTA or FrA. In addition, astrocyte reactivity was greater in regions where injury to dopaminergic neurons was more severe.

急性肾缺血再灌注损伤模型小鼠线粒体去乙酰化酶3的表达

背景:对比剂肾病已经成为医院获得性急性肾损伤的主要原因之一,其本质是肾脏的急性缺血再灌注损伤,其中去乙酰化酶3在其中发挥的作用还不清楚。目的:探索不同肾脏缺血时间对去乙酰化酶3表达的影响及其与线粒体损伤相关指标的关系。方法:构建C57BL/6J小鼠急性肾脏缺血模型,给予不同的缺血时间(15,20,25,30 min),再灌注48 h。根据缺血时间,分为对照组、假手术组、缺血15,20,25,30 min再灌注组,每组8只。术后48 h,检测血清肌酐、尿素氮水平,TUNEL试剂盒检测肾组织细胞凋亡情况,荧光素酶发光法检测肾组织ATP水平,苏木精-伊红染色观察肾组织病理变化,透射电镜下观察线粒体变化,Western blot检测去乙酰化酶3和线粒体动力相关蛋白1、线粒体融合蛋白1的表达。结果与结论:①血清肌酐、尿素氮、组织病理评分及凋亡指数在各缺血组中逐渐升高;②肾组织线粒体结构损伤在各缺血组中逐渐加重,ATP含量总体下降;③正常对照组与假手术组及缺血15min再灌注组的去乙酰化酶3蛋白水平无差异;与缺血15min再灌注组比较,缺血20 min再灌注组的去乙酰化酶3蛋白水平升高(P<0.05),缺血25 min继续升高(P<0.05),缺血30 min表达最高(P<0.05);④与假手术组比较,线粒体融合蛋白1在缺血15-20 min升高(P<0.05);与缺血15 min再灌注组比较,线粒体融合蛋白1在缺血25 min和30 min进一步升高(P<0.05);⑤缺血15 min再灌注组的线粒体动力相关蛋白1水平达高峰,与缺血15 min再灌注组比较,缺血20 min再灌注组的线粒体动力相关蛋白1水平有所下降(P<0.05),缺血25 min再灌注组进一步下降(P<0.05);⑥相关性研究发现,ATP与去乙酰化酶3存在显著负相关(r=-0.77,P<0.05),去乙酰化酶3与线粒体动力相关蛋白1存在负向相关性(r=-0.52,P<0.05),去乙酰化酶3与线粒体融合蛋白1存在正向相关性(r=0.72,P<0.05);⑦结果表明,肾脏缺血再灌注损伤时,ATP水平下降会刺激肾组织线粒体去乙酰化酶3表达呈现时间依赖性增高,进而促进线粒体融合,抑制线粒体裂解,起到保护线粒体、维持能量代谢的作用,提示去乙酰化酶3可能是减轻肾脏缺血再灌注损伤的干预靶点。

METTL3/AMPK通路在七氟烷诱发小鼠认知功能损伤中的作用

目的探讨m6A甲基转移酶3(METTL3)/AMP活化蛋白激酶(AMPK)通路在七氟烷(SEV)诱发小鼠认知功能损伤中的作用。方法将出生后6 d小鼠随机分为4组(每组8只):Ctrl+sh-NC组、SEV+sh-NC组、Ctrl+sh-METTL3组和SEV+sh-METTL3组。在出生后60~65 d进行Morris水迷宫测试评估空间记忆,然后处死小鼠收集海马组织,通过斑点印迹法分析mRNA m6A甲基化,高尔基染色观察海马DG亚区的树突,免疫印迹分析METTL3、AMPK蛋白表达。体外实验考察METTL3上调对小鼠海马神经元细胞系(HT-22)中m6A水平和AMPK的mRNA稳定性影响。结果暴露于SEV的小鼠海马组织中m6A水平和甲基转移酶METTL3水平显著增加(P<0.05)。与sh-NC+SEV组相比,sh-METTL3+SEV组逃避潜伏期显著缩短(P<0.05),平台穿越时间和象限时间显著增加(P<0.05),以及DG区树突棘的数量和BDNF、p-AMPK表达均显著增加(P<0.05)。METTL3过表达质粒显著增加了HT-22细胞中的m6A水平(P<0.01),同时降低了BDNF和p-AMPK表达(P<0.05)。METTL3上调显著降低了AMPK mRNA稳定性(P<0.05)。结论METTL3敲低通过m6A介导的AMPK mRNA稳定性的降低减轻了SEV诱导的幼鼠认知功能损伤。

CHI3L1在川崎病样血管炎小鼠模型冠状动脉损伤中的作用及机制研究

目的探究壳多糖酶3样蛋白1(chitinase-3-like protein 1,CHI3L1)在川崎病(Kawasaki disease,KD)样血管炎小鼠模型冠状动脉损伤中的作用及其潜在机制。方法将4周龄雄性SPF级C57BL/6小鼠随机分为正常对照组和模型组,每组10只。模型组小鼠通过腹腔注射干酪乳杆菌细胞壁提取物(lactobacilluscaseicell wall extract,LCWE)0.5 mL构建KD样血管炎小鼠模型,对照组腹腔注射等量的生理盐水。注射后第3天、第7天和第14天观察小鼠的一般情况。采用苏木精-伊红染色法观察冠状动脉组织病理学变化。采用酶联免疫吸附法检测小鼠血清中CHI3L1水平。采用免疫荧光染色法检测CHI3L1、血管性血友病因子(von Willebrand factor,vWF)、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)在冠状动脉组织中的表达及定位。采用Western blot法检测冠状动脉组织中CHI3L1、vWF、血管内皮钙黏蛋白(vascular endothelial cadherin,VE cadherin)、半胱天冬酶-3(Caspase-3)、B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)、核转录因子κB(nuclear factor-κB,NF-κB)及磷酸化NF-κB(p-NF-κB)表达情况。结果模型组小鼠血清中CHI3L1含量较对照组明显升高(P<0.05)。与对照组相比,模型组小鼠冠状动脉组织中CHI3L1表达高于对照组,vWF表达低于对照组。模型组小鼠CHI3L1、Bax、Caspase-3、NF-κB及p-NF-κB蛋白相对表达量明显高于对照组(P<0.05)。模型组vWF、VE cadherin和Bcl-2蛋白相对表达量低于对照组(P<0.05)。结论LCWE诱导的KD样血管炎小鼠模型中,血清及冠状动脉CHI3L1的表达水平升高,可能通过炎性反应介导血管内皮细胞凋亡在冠状动脉损伤中发挥作用。