HIV-1-associated neurocognitive disorders (HAND) are characterized by chronic CNS inflammation. Previous studies have shown that HIV-1 gp120 causes learning and memory deficits in mice and neuroinflammation in neurons and microglia through impaired autophagy. However, the regulation of autophagy in this context is unclear. We found that lncRNA SNHG1 is upregulated in HIV-1 gp120-induced microglial inflammation. Reducing SNHG1 levels alleviates this inflammation by increasing early autophagy protein ULK1, decreasing late autophagy protein p62, and enhancing the LC3B II/I ratio. Autophagy inhibitors 3-MA and CQ can reverse or enhance the effects of SNHG1 knockdown on microglial inflammation. The study suggests that knocking down lncRNA SNHG1 may enhance early autophagy initiation and late degradation, reducing neuroinflammation. The Wnt pathway inhibitor FH535 further improved this effect by increasing ULK1 protein and the LC3B II/I ratio. In contrast, the Sirt1 inhibitor EX527 activated the Wnt pathway, decreased the LC3B II/I ratio, and worsened neuroinflammation. Thus, lncRNA SNHG1 knockdown might regulate autophagy via the Sirt1-Wnt pathway to alleviate HIV-1 gp120-induced neuroinflammation, offering a new approach for HAND prevention and treatment.

目的:探讨人类免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)gp120 V3环致CHME-5小胶质细胞炎症反应与铁死亡的关系,并观察p53和铁死亡对该炎症反应的影响及可能机制.方法:体外培养人源CHME-5小胶质细胞,设立空白组、随机肽段组、HIV-1 gp120 V3环组、HIV-1 gp120 V3环+ferrostatin-1(Fer-1;铁死亡抑制剂)组和HIV-1 gp120 V3环+pifithrin-α(p53抑制剂)组.分别采用HIV-1 gp120 V3环(终浓度2 mg/L)和随机肽段(终浓度2 mg/L)处理CHME-5细胞24 h;Fer-1(终浓度20 μmol/L)和pifithrin-α(终浓度10 μmol/L)预处理CHME-5细胞2 h,HIV-1 gp120 V3环(终浓度2 mg/L)再处理24 h.ELISA法检测各组细胞上清液中炎症因子水平;Western blot法检测铁死亡相关蛋白[转铁蛋白受体1(transferrin receptor-1,TFR-1)、溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)和谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)]及p53的蛋白表达;酶标仪法检测细胞内亚铁离子(Fe2+)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性.结果:(1)ELISA结果显示,与对照组相比,gp120 V3环组炎症因子白细胞介素1β(interleukin-1β,IL-1β)、IL-6和肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)水平显著升高(P＜0.01);与gp120 V3环组相比,gp120 V3环+Fer-1组和gp120 V3环+pifithrin-α组炎症因子IL-1β、IL-6和TNF-α水平显著下降(P＜0.01);(2)Western blot结果显示,与对照组相比,gp120 V3环组蛋白p53显著上调(P＜0.01),铁死亡相关蛋白TFR-1显著上调(P＜0.01),SLC7A11和GPX4显著下调(P＜0.01);与gp120 V3环组相比,gp120 V3环+pifithrin-α组铁死亡相关蛋白TFR-1显著下降(P＜0.05),SLC7A11和GPX4蛋白显著升高(P＜0.05);(3)与对照组相比,gp120 V3环组Fe2+含量显著增加(P＜0.01),GSH-Px活性显著降低(P＜0.01);与gp120 V3环组相比,gp120 V3环+Fer-1组和gp120 V3环+pifithrin-α组Fe2+含量显著下降(P＜0.05),GSH-Px活性显著升高(P＜0.01).结论:HIV-1 gp120 V3环致CHME-5小胶质细胞炎症中存在铁死亡,且抑制铁死亡能减轻炎症.HIV-1 gp120 V3环致CHME-5小胶质细胞炎症与p53蛋白调控铁死亡有关,抑制p53可减轻铁死亡和炎症反应.

目的:探讨自噬关键蛋白p62在HIV-1 gp120 V3环所致小鼠神经炎症中的作用及相关信号分子机制.方法:野生型C57BL6小鼠随机分成4组:空白组、假手术组(人工脑脊液组)、模型组(gp120 V3环组)及gp120 V3环+NF-κB活化阻滞剂BAY 11-7082组,每组12只.用Morris水迷宫检测小鼠学习记忆能力;免疫荧光染色检测海马和皮层Iba-1表达水平;ELISA法检测海马和皮层炎症因子的表达水平;Western blot检测海马和皮层相关蛋白表达水平.结果:(1)Morris水迷宫结果显示,与空白组相比,模型组小鼠逃避潜伏期显著延长(P<0.01),平台区域停留时间及穿越平台次数显著减少(P<0.05);与模型组相比,gp120 V3环+BAY 11-7082组小鼠逃避潜伏期显著缩短(P<0.01),平台区域停留时间及穿越平台次数显著增加(P<0.05).(2)免疫荧光染色结果显示,与空白组相比,模型组海马和皮层Iba-1荧光强度显著增强(P<0.05);与模型组相比,gp120 V3环+BAY 11-7082组海马和皮层Iba-1荧光强度显著降低(P<0.05).(3)ELISA结果显示,与空白组相比,模型组IL-1β、TNF-α和IL-6水平均显著上调(P<0.05);与模型组相比,gp120 V3环+BAY 11-7082组IL-1β、TNF-α和IL-6水平显著下调(P<0.05).(4)Western blot结果显示,与空白组相比,模型组p62蛋白表达水平显著上调(P<0.01),p-p65/p65及p-IκB/IκB比值均显著升高(P<0.01);与模型组相比,gp120 V3环+BAY 11-7082组p62蛋白显著下调(P<0.05),p-p65/p65及p-IκB/IκB比值均显著下降(分别P<0.01和P<0.05).结论:HIV-1 gp120 V3环所致小鼠学习记忆功能障碍的机制可能与通过激活p62/NF-κB信号通路引起神经炎症有关,p62-NF-κB正反馈环的抑制可能会减轻神经炎症.

HIV-associated neurocognitive disorders (HAND) are a collective name for neurological disorders associated with HIV-1 infection. The incidence and severity of HAND are increased by concomitant opioid use disorder, such as heroin and morphine abuse. Our previous study showed that the HIV-1 envelope protein gp120 and morphine synergistically induce apoptosis in rat hippocampal neurons. However, the underlying mechanism remains unclear. We hypothesized that morphine and gp120 activated the neuronal apoptosis signaling pathway via their typical membrane receptors. If they shared key signaling molecules, their induction of neuronal apoptosis could be inhibited by blocking these targets. We found that morphine and gp120V3 loop synergistically induced hippocampal neuron apoptosis, mediated by activating the extracellular signal-regulated kinase (ERK) pathway, increasing the intracellular Ca2 + concentration and expression of caspase-, and reducing the mitochondrial membrane potential. The ERK inhibitor PD98509 and the phosphatidylinositol 3-kinase activator IGF-1 blocked this effect. These results indicate that ERK plays a crucial role in the apoptosis of hippocampal neurons in HAND.

Combined antiretroviral therapy (cART) has significantly increased the life expectancy of AIDS patients; however, the prevalence of the neurocognitive impairment associated with HIV-1 continues to rise. HIV-1 gp120, an important subunit of the envelope spikes that decorate the surface of virions, is found to activate microglia in central nervous system (CNS) which leads to the cognitive and behavioral dysfunction known as HIV-1 associated neurocognitive disorder(HAND), and the V3 loop is the most important toxic domain of gp120. A study has shown that autophagy plays key role in the activation of microglia, p62 is an important autophagy substrate protein that is elevated in neuroinflammation. In this study, we sought to explore the role of p62 in gp120 V3 loop-mediated microglial activation. Our results demonstrated that exposure of CHME-5 cells to the gp120 V3 loop resulted in elevated inflammatory cytokines, accompanied by autophagy dysfunction and p62 upregulation. Subsequently, we found that the p62-dependent Nrf2 noncanonical signaling pathway was activated and that HO-1, the target protein of Nrf2, was also upregulated. Interestingly, the elevation of inflammatory factors caused by the gp120 V3 loop was significantly alleviated after knocking down p62, Nrf2 and HO-1. Further investigation revealed that in the microglial inflammation induced by the gp120 V3 loop, up-regulated HO-1 promoted the expression of iNOS by interacting with iNOS, while enhanced autophagy by RAPA promoted the degradation of iNOS and alleviated inflammation. These findings provide a new perspective on the relationship between noncanonical Nrf2 activation and autophagy in microglial inflammation and an experimental basis for HAND prevention and treatment.

Autophagy is a lysosome-mediated cell content- dependent degradation pathway that leads to enhanced inflammation in an uncontrolled state. This study examined the role of autophagy in lipopolysaccharide (LPS)-induced brain inflammation and the effects of the traditional Chinese medicine ligustrazine on LPS-induced neurocognitive impairment in rats. Furthermore, the molecular mechanisms by which ligustrazine influences neurocognitive impairments were explored. The production of the inflammatory mediators interleukin (IL)-1β and tumor necrosis factor (TNF)-α was analyzed using ELISAs, and the expression levels of the autophagy marker microtubule-associated protein light chain 3 (LC3) II/I were analyzed using western blotting. LPS exposure upregulated the expression of IL-1β and TNF-α and downregulated the expression of LC3 II/I. Ligustrazine activated autophagy by preventing the expression of phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (p-AKT), and phosphorylated mammalian target of rapamycin (p-mTOR). The present results suggest that ligustrazine improved LPS-induced neurocognitive impairments by activating autophagy and ameliorated neuronal injury by regulating the PI3K/AKT/mTOR signaling pathway. These findings provide an important reference for the prevention and treatment of neuroinflammation.

目的:探讨中药单体川芎嗪对脂多糖(lipopolysaccharide,LPS)诱导的神经认知障碍的影响及其功能影像学机制.方法:将36只SD大鼠随机分成空白对照组、假手术组、模型组(LPS组)、低剂量川芎嗪组、中剂量川芎嗪组和高剂量川芎嗪组,每组6只.模型组及低剂量、中剂量和高剂量川芎嗪组均行侧脑室注射LPS,每只150μg;假手术组侧脑室注射等量的脑脊液;空白对照组不做处理;低、中和高剂量川芎嗪组分别腹腔注射50 mg/kg、100 mg/kg和200 mg/kg的盐酸川芎嗪注射液.用Morris水迷宫实验观察LPS对神经认知障碍的影响;酶联免疫吸附测定(ELISA)法检测脑组织匀浆中白细胞介素1β(IL-1β)和肿瘤坏死因子 α(TNF-α)的含量;同时用影像学扫描IVIM D和IVIM D*功能序列,测定LPS致神经认知障碍的影像学纯水分子的扩散运动成分和血流灌注相关的扩散运动.结果:Morris水迷宫大鼠空间学习和记忆结果显示:与对照组比,模型组的逃避潜伏期延长,平台周边穿梭次数减少,目标象限停留时间缩短(P<0.05);与模型组相比,低剂量川芎嗪组逃避潜伏期缩短,平台周边穿梭次数增加,目标象限停留时间延长(P<0.05),中、高剂量川芎嗪组无显著差异.ELISA结果显示:与对照组比,模型组皮层和海马区的IL-1β和TNF-α均增加(P<0.05);与模型组比,低剂量组皮层和海马区IL-1β和TNF-α均降低(P<0.05),中、高剂量组无显著差异.影像结果显示:与对照组比,模型组皮层和海马的IVIM D、IVIM D*和f值均降低(P<0.05);与模型组比,低剂量组皮层和海马的IVIM D、IVIM D*和f值均升高(P<0.05),中、高剂量组IVIM D、IVIM D*和f值无显著差异.结论:川芎嗪具有减轻LPS所致大鼠神经认知障碍的作用,其机制可能与川芎嗪通过促进脑中水分子扩散运动和脑血流灌注而抑制炎症反应有关.

Neuroinflammation is a predisposing factor for several neurodegenerative diseases. The purpose of this study was to evaluate the protective effect of madecassoside (MA) in lipopolysaccharide (LPS)-induced cognitive impairment and neuroinflammation in rats. MA has many protective effects such as antioxidant and anti-inflammatory properties. We investigated whether MA could improve neurocognitive dysfunction caused by intracerebroventricular injection of LPS. We examined the effects and mechanisms of action of MA on LPS-induced neuroinflammation in the cortex and hippocampus. Our study revealed that MA (120 mg/kg, i.g) treatment for 14 days reduced LPS-induced neurotoxicity by reducing cognitive impairments and suppressing the production of inflammatory cytokines such as interleukin 1 beta (IL-1 beta), tumor necrosis factor alpha(TNF-alpha), and interleukin 6(IL-6) via activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. Furthermore, MA treatment enhanced protein levels of heme oxygenase (HO)-1 by upregulating Nrf2 in LPS-stimulated neurotoxicity. Collectively, these results suggest that MA is effective in preventing neurodegenerative diseases by improving memory functions due to its anti-inflammatory activities and activation of Keapl-Nrf2/HO-1 signaling. As such, MA may be a potential therapy for addressing memory impairment caused by neuroinflammation.

In this study, we investigated lipopolysaccharide (LPS)-induced cognitive impairment and neuroinflammation in C57BL/6J mice by using behavioral tests, immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and Western blot. We found that LPS treatment leads to sickness behavior and cognitive impairment in mice as shown in the Morris water maze and passive avoidance test, and these effects were accompanied by microglia activation (labeled by ionized calcium binding adaptor molecule-1, IBA-1) and neuronal cell loss (labeled by microtubule-associated protein 2, MAP-2) in the hippocampus. The levels of interleukin-4 (IL-4) and interleukin-10 (IL-10) in the serum and brain homogenates were reduced by the LPS treatment, while the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), prostaglandin E2 (PGE 2 ) and nitric oxide (NO) were increased. In addition, LPS promoted the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the brain homogenates. The Western blot analysis showed that the nuclear factor kappa B (NF-κB) signaling pathway was activated in the LPS groups. Furthermore, VIPER, which is a TLR-4-specific inhibitory peptide, prevented the LPS-induced neuroinflammation and cognitive impairment. These data suggest that LPS induced cognitive impairment and neuroinflammation via microglia activation by activating the NF-kB signaling pathway; furthermore, we compared the time points, doses, methods and outcomes of LPS administration between intraperitoneal and intracerebroventricular injections of LPS in LPS-induced neuroinflammation and cognitive impairment, and these data may provide additional insight for researchers performing neuroinflammation research.

Human immunodeficiency virus (HIV) infects human peripheral blood, which also invade the central nervous system (CNS) and trigger HIV-1 associated neurocognitive disorder (HAND), mainly manifested in inattention, feelings indifferent and memory disorders, which could lead to inconvenience for daily work and life of patients. According to the degree of neurocognitive impairment, HAND is divided into three types: asymptomatic neurocognitive impairment (ANI), mild neurocognitive disorder (MND) and HIV-associated dementia (HAD). HAND has become an essential chronic central nervous system complication of patients with acquired immunodeficiency syndrome (AIDS). Patients with AIDS have undergone combined antiretroviral therapy (cART). After the inhibition of systemic viral replication, the number of patients complicated with severe HIV-related dementia decreased significantly, and with prolongation of survival period. At present, the pathogenesis of HAND is not clear, and the related risk factors need to be furtherly explored. In this paper, the research progress of risk factors related to HAND is reviewed, which provides a new idea for the diagnosis and pathogenesis of HAND. Key words: Human immunodeficiency virus; Neurocognitive disorder; Risk factor; Age; Genetic phenomena

针对留学生教学的特殊性,并结合病理生理学实验课英文教学特点,通过系统、有序的实验前教学组织,有效的实验教学管理,客观公正的教学效果评价,可充分调动留学生的学习主动性,提高留学生病理生理学实验课的教学质量和效果.

AIM:To investigate the effects of Chinese traditional medicine-selected recipe Q0409 on the ability of learning and memory in SAM-P/8 mice. METHODS:Total 91 mice (4-month-old SAM-P/8 mice, SAM-R/1 mice and Kunming mice) were used in the study, in which the male and female animals were labeled separately. According to the performance of Morris water maze test, the mice were divided into 5 groups randomly. The mice were fed with different drugs or distilled water for 60 d (from 4 months to 6 months). The mice were fed with the drugs from 61 d to 65 d, and 1 h later each time, the Morris water maze test was carried out. After this Morris test were finished at 65 d, the mice were killed immediately and their hippocampal tissues were isolated. Half of the hippocampal tissues were added with precooled normal saline and made into 10% (g/mL) homogenate for detecting the protein content and acetyl cholinesterase (AChE) activity. The other half was fixed with 4% paraformaldehyde and embedded with paraffin for immunohistochemical staining of amyloid β-protein (Aβ). RESULTS:Compared with model group, the results of navigation training and spatial probe training in Morris water maze test were significantly improved (P<0.05), and the activity of AChE in the hippocampal ho-mogenate was significantly decreased (P<0.05) in Q0409 treatment group. No difference in Q0409 group was observed compared with control group and positive drug (huperzine A) group. Immunohistochemical staining showed no typical "se-nile plaques" in the male mice of Q0409 group, while there was shallower and smaller brown staining in the hippocampus of the female mice of Q0409 group. The positive area of Aβ deposition decreased in the CA1 area of hippocampal tissues in Q0409 group. These results were similar to those in positive drug group. CONCLUSION:Q0409 improves the ability of learning and memory in SAM-P/8 mice, which is related to the inhibition of AChE activity and the reduction of Aβ protein deposition in the hippocampus. The effects is similar to those of huperzine A.

Objective To investigate the effect and the potential mechanism of Senegenin (Sen) against injury induced by hypoxia/reoxygenation (H/R) in highly differentiated PC12 cells. Methods The cultured PC12 cells were treated with H/R in the presence or absence of Sen (60 μmol/L). Four groups were included in the experiment: control group, H/R group, H/R+Sen group and Sen group. Cell viability of each group and the level of lactate dehydrogenase (LDH) in culture medium were detected for the pharmacological effect of Sen. Hoechst 33258 staining and annexin V/propidium iodide double staining were used to analyze the apoptosis rate. Moreover, mitochondrial membrane potential (△Ψm), reactive oxygen species (ROS) and intracellular free calcium ([Ca 2+ ]i) were measured by fluorescent staining and flow cytometry. Cleaved caspase-3 and activity of NADPH oxidase (NOX) were determined by colorimetric protease assay and enzyme linked immunosorbent assay, respectively. Results Sen significantly elevated cell viability ( P <0.05), decreased the leakage of LDH ( P <0.05) and apoptosis rate ( P <0.05) in H/R-injured PC12 cells. Sen maintained the value of △Ψm ( P <0.05) and suppressed the activity of caspase-3 ( P <0.05). Moreover, Sen reduced ROS accumulation P <0.05) and [Ca 2+ ]i increment ( P <0.05) by inhibiting the activity of NOX ( P <0.05). Conclusion Sen may exert cytoprotection against H/R injury by decreasing the levels of intracellular ROS and [Ca 2+ ] i , thereby suppressing the mitochondrial pathway of cellular apoptosis.

AIM:To investigate the effects of thalidomide ( THD) on the activation of connective tissue growth factor ( CTGF) gene promoter induced by transforming growth factor β1 ( TGF-β1 ) in human embryonic lung fibroblasts ( HELF) .METHODS:DNA sequence of CTGF gene promoter was cloned into luciferase reporter gene vector to construct the recombinant eukaryotic expression vector pGL 3-CTGFP, and the recombinant vector was transfected into HELF cell line.The effects of TGF-β1 and THD on the activation of CTGF gene promoter were detected by dual-luciferase analysis . RESULTS:TGF-β1 increased the reporter gene activity dose-dependently (P<0.05), with a plateau at 5 μg/L being 2.16 folds as high as the control .TGF-β1-induced increase in the reporter gene activity was also time-dependent ( P<0.05).After exposure to TGF-β1(5 μg/L), the level of luciferase activity reached its peak at 12 h and was 2.52 folds as high as the control .THD significantly inhibited TGF-β1-induced increase in the reporter gene activity in a dose-dependent manner , but its basal activity was not changed .CONCLUSION: TGF-β1 stimulates the transcriptional activity of CTGF gene promoter in HELF cells in a dose-and time-dependent manner , while THD may inhibit the effects dose-dependently .

Pro-inflammatory factors released by activated microglia may contribute to the progression of neurodegenerative diseases. As a natural phenolic acid, chlorogenic acid (CGA) has been shown to have anti-inflammatory properties. However, it is unclear whether CGA has the ability to mediate microglial activation. The present study investigated the role of CGA in lipopolysaccharide (LPS)-stimulated microglia. Our data demonstrated that CGA significantly suppressed NO production and TNF-α release in LPS-stimulated primary microglia. In addition, CGA decreased LPS-stimulated phosphorylation and degradation of inhibitory kappa B-alpha (IκBα), and prevented translocation of nuclear factor-kappaB (NF-κB). Furthermore, CGA prevented neurotoxicity caused by microglial activation and ultimately improved survival of dopaminergic (DA) neuron. Finally, in vivo data showed that CGA pretreatment attenuated LPS-induced IL-1β and TNF-α release in substantia nigra (SN). Our results suggested that the pretreatment of CGA significantly inhibits the microglial activation, and CGA may be neuroprotective for pro-inflammatory factor-mediated neurodegenerative disorders.

Aim To study the effect and its mechanism of Glycyl-L-glutamine(Gly-Gln) on mitochondrial membrane potentials,apoptosis,and the release of myocardial enzymes of cardiomyocytes suffering from hypoxia/reoxygenation(H/R) injury.Methods A cardiac H/R model in vitro was established with primary cultured neonate rat cardiomyocytes.There were some experimental groups:(1)control group,(2)H/R gr-oup,(3)H/R+Gly-Gln(1,4,16 mmol·L-1) group,(4)Gly-Gln(1,4,16 mmol·L-1) group.The viability of cardiomyocytes was observed by MTT assay.The contents of lactate dehydrogenase(LDH) and creatine kinase(CK) in the culture solution of various groups were determined.The apoptotic rate of cardiomyocytes was analysed by AnnexinV/PI double staining.The mitochondrial membrane potential(△Ψm) of cardiomyocytes was measured by JC-1 as a fluorescent molecular probe.Results Gly-Gln increased remarkably viability of cardiomyocytes suffering from H/R injury(P<0.01),inhibited the release of LDH and CK which induced by H/R injury(P<0.05).This effect of Gly-Gln was in a dose-dependent manner within certain concentration range.Gly-Gln reduced the apoptotic rate of cardiomyocytes(P<0.01).The △Ψm of cardiomyocyte was lower in H/R group than that in control group(P<0.01).But the △Ψm was higher in H/R+ Gly-Gln group than that in H/R group(P<0.01).Conclusion Gly-Gln promotes the survival of cardiomyocytes subjecting to H/R injury,reduces the release of myocardial enzymes induced by H/R injury,and prevents the apoptosis and decrement in mitochondrial membrane potential of cardiomyocytes suffering from H/R injury.

AIM:To study the protection of Glycyl-L-Glutamine(Gly-Gln) against myocardial ischemia/reperfusion(I/R) injury in the isolated rat heart.METHODS:A model of myocardial ischemia-reperfusion injury was established with a Langendorff apparatus.Thirty male SD rats were randomly divided into four groups:control group,Gly-Gln group,I/R group and I/R+Gly-Gln group.Both I/R and I/R+Gly-Gln group were pre-perfused for 30 min,followed by 20 min ischemia and 40 min reperfusion.During reperfusion I/R+Gly-Gln group was perfused with Gly-Gln perfusate.Control group was kept perfused for 90 min.Gly-Gln group Gly-Gln perfusate was also kept perfused for 90 min.The left ventricular end-diastolic pressure(LVEDP),left ventricular developed pressure(LVDP),±dp/dtmax,heart rate(HR),monophasic action potentials(MAP) was measured during perfusion.The coronary effluent fluid was collected at different certain times.The activities of lactic dehydrogenase(LDH) and creatine kinase(CK) were determined.RESULTS:The isolated rat heart function decreased severely after 20 min ischemia and 40 min reperfusion(I/R):the LVEDP increased and the LVDP,±dp/dtmax decreased.But the LVEDP decreased and the LVDP,±dp/dtmax increased in I/R+Gly-Gln group compared with I/R group.Moreover,the activities of LDH and CK in the coronary effluent fluid decreased remarkably in I/R+Gly-Gln group compared with I/R group.CONCLUSION:Gly-Gln can play a protective role against myocardial I/R injury in isolated rat hearts via maintaining the left ventricular function and decreasing the release of LDH and CK.

Previous studies have demonstrated that glycine (GLY) markedly reduces lipopolysaccharide (LPS)-induced myocardial injury. However, the mechanism of this effect is still unclear. The present study investigated the effect of GLY on cytosolic calcium concentration ([Ca2+]c) and tumor necrosis factor-α (TNFα) production in cardiomyocytes exposed to LPS, as well as whether the glycine-gated chloride channel is involved in this process. Neonatal rat cardiomyocytes were isolated, and the [Ca2+]c and TNFα levels were determined by using Fura-2 and a Quantikine enzyme-linked immunosorbent assay, respectively. The distribution of the GLY receptor and GLY-induced currents in cardiomyocytes were also investigated using immunocytochemistry and the whole-cell patch-clamp technique, respectively. LPS at concentrations ranging from 10 ng/mL to 100 μg/mL significantly stimulated TNFα production. GLY did not inhibit TNFα production induced by LPS at concentrations below 10 ng/mL but did significantly decrease TNFα release stimulated by 100 μg/mL LPS and prevented an LPS-induced increase in [Ca2+]c, which was reversed by strychnine, a glycine receptor antagonist. GLY did not block the isoproterenol-induced increase in [Ca2+]c, but did prevent the potassium chloride-induced increase in [Ca2+]c in cardiomyocytes. Strychnine reversed the inhibition of the KCl–stimulated elevation in [Ca2+]c by GLY. In chloride-free buffer, GLY had no effect on the dipotassium hydrogen phosphate-induced increase in [Ca2+]c. Furthermore, GLY receptor α1 and β subunit-immunoreactive spots were observed in cardiomyocytes, and GLY-evoked currents were blocked by strychnine. Cardiomyocytes possess the glycine-gated chloride channel, through which GLY prevents the increase in [Ca2+]c and inhibits the TNFα production induced by LPS at high doses in neonatal rat cardiomyocytes.

AIM:To observe effect of rhynchophylline(Rhy) on mortality and organ injury in endotoxemic mice and further investigate the mechanisms of its actions.METHODS:Male mice were randomly assigned into control,LPS,Rhy +LPS and Rhy group,and injected subcutaneously with normal saline(0.05 mL/10 g),or rhynchophylline once a day for 3 d,1 h after subcutaneously treatment on day 3,LPS(20 mg/kg) or normal saline was injected intraperitoneally.Survival rate was recorded every 12 h for 6 d.In another experiment,12 h after LPS injection,the left lung and intestine tissue sections were prepared for histological analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight(W/D),the serum was collected to detect the concentrations of alanine aminotransferase(ALT),aspartate aminotransferase(AST),bloodureanitrogen(BUN) and creatinine(Cr).In addition,the concentrations of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β) and interleukin-10(IL-10) in serum at 2 h after LPS challenge were detected by enzyme-linked immunosorbent assay.The concentration of NO in serum at 8 h was detected by enzymic method.The effect of Rhy on survival rate of mice subjected to cecal ligation and puncture(CLP) was also observed.RESULTS:Mortality of mice challenged with LPS alone was higher significantly than that in control at 24 h after LPS challenge,pretreated with Rhy at a dose of 8 or 16 mg/kg increased markedly the survival rate of LPS-challenged mice.However,Rhy at a dose of 8 mg/kg significantly increased mortality of mice subjected to CLP.In the histological analysis,severe inflammation was observed both in the lung and intestine tissues in the LPS group.LPS elevated lung W/D,the levels of ALT,AST,BUN,Cr,TNF-α,IL-1β,IL-10 and NO in serum.Pretreatment with Rhy had no obvious improvement in the lung and intestine tissue injury,and no significant depression in the lung W/D and the serum levels of ALT,AST,BUN,Cr,IL-1β,IL-10 and NO,but decreased the level of TNF-α in serum significantly in LPS-treated mice.CONCLUSION:Pretreatment with Rhy reduces the mortality in endotoxemic mice,but not decrease the mortality of mice challenged with CLP,at least in part,through inhibiting the synthesis and secretion of TNF-α.

AIM: To observe the effects of glycine on hypoxia-reoxygenation(H/R)-induced myocardial dysfunction,and to further clarify the protection of glycine(GLY) against myocardial ischemia/reperfusion injury and its mechanism.METHODS: A cardiac H/R model was established using a Langendorff isolated heart preparation.The left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),left ventricular developed pressure(LVDP),the maximum rising and dropping rates of left ventricular pressure(dp/dtmax and dp/dtmin) were observed.The coronary effluents at different time points were collected respectively to detect the concentration of superoxide dismutase(SOD) and malondialdehyde(MDA).RESULTS: The indexes of cardiac functions in H/R group were lower than those in other groups.After H/R,the indexes in GLY plus H/R group were higher than those in H/R group.Glycine inverted the effects of the decrease in SOD and the increase in MDA concentrations induced by H/R.CONCLUSION: Glycine ameliorates the cardiac functions under the condition of hypoxia-reoxygenation injury in isolated rat hearts.The mechanisms may be related to suppressing lipid peroxidation.