乳酸菌源有机硒对肝损伤小鼠脾脏脂质过氧化和NK细胞活性的保护效应研究

本文通过研究乳酸菌源有机硒干预CCl_4致肝损伤小鼠脾脏NK细胞活性和脂质过氧化反应的变化,探讨该有机硒在抗损伤保护过程中的效应及其机制。分别选用60只健康成年小鼠,雌雄对半,随机分成对照组(C组),有机硒组(Se组),CCl_4组、CCl_4-有机硒保护组(CCl_4-Se组),每组15只。通过腹腔注射CCl_4诱发肝损伤后,分别在第2、4周检测脾脏NK细胞活性及其组织匀浆GSH-Px、CAT、SOD活性和MDA含量变化、结果显示,在整个实验期内,C组、Se组和CCl_4-Se组脾组织匀浆GSH—Px、CAT和SOD活性均高于或明显高于CCl_4组,Se和CCl_4-Se组与C组比较除SOD活性在第4周有明显升高外均差异不显著;CCl_4组小鼠脾脏MDA含量均显著高于C组、Se组和CCl_4-Se组,而CCl_4-Se组与C组接近,Se组较CCl_4-Se组和C组低;Se组NK细胞活性最高,第4周明显高于C组,CCl_4组最低且低于或明显低于CCl_4-Se、Se和C组,CCl_4-Se组与C组无明显差异。结果提示,乳酸菌源有机硒能够提高正常机体抗氧化能力,在干预肝损伤过程中,可以通过改善和提高脾组织抗氧化酶活性及NK细胞活性发挥积极有效的作用。     

低能量激光照射对小鼠脾脏NK细胞活性影响的试验研究

目的：研究能量激光照射对小鼠NK细胞活性的影响,以便从NK细胞活性的角度阐明其免疫调节效应。方法：以BALB／c小鼠为研究对象,应用7.337J/cm^2,11．00J/cm^2,14．67J/cm^2,22．00J/cm^2和36．67J/cm^2五种剂量的氦氖激光作小鼠内眼角照射,连续照射8d,并于照射开始后第3d,6d,9d,13d和第17d,动脉监测实验鼠脾脏NK细胞活性。结果：以日剂量为7.33J/cm^2,11.00J/cm^2,14.67J/cm^2和22.00J/cm^2LELI照射小鼠四个剂量组均可增强NL细胞的活性（P＜0．01或P＜0．05）,但其峰值的出现随着LELI剂量的增大而加快,22．00J/cm^2剂量组在第3d就达到峰值,而其余三组则分别在第9d或第13d时达到峰值,与相相反,大剂量36.6J/cm^2ELEI组NK活性则表现出明显的抑制效应。结论：适当剂量的低能量激光照射剂可对小鼠脾脏NK细胞活性产生增强效应,而过大剂是LELI则产生抑制效应。     

薄芝糖肽对小鼠实验性肝损伤的保护作用

目的观察薄芝糖肽注射液对四氯化碳(CCl4)肝中毒小鼠的抗氧化作用.方法小鼠腹腔注射40% CCl4液体石蜡诱发急性肝损伤.然后治疗组给予薄芝糖肽注射液,以盐水代替薄芝糖肽注射液作为阴性对照,以联苯双酯代替薄芝糖肽注射液作为治疗阳性对照.以血清谷丙转氨酶(ALT)活性和肝组织中脂质过氧化产物(MDA)、抗氧化剂还原型谷胱甘肽(GSH)含量作为观测指标.结果注射CCl4各组小鼠都出现ALT活力急剧升高,肝组织中MDA含量明显增多,同时GSH含量明显减少,证实急性肝损伤模型成立,并且表明与过氧化作用有关.经薄芝糖肽治疗的小鼠,ALT活力在几天之内恢复到正常水平,与盐水对照组差异显著(p＜0.05);薄芝糖肽一方面抑制CCl4诱导的MDA含量升高,同时又可抑制GSH含量的减少(p＜0.05).结论用CCl4造成实验性小鼠肝损伤,小鼠血清谷丙转氨酶大幅度升高,肝组织中脂质过氧化产物丙二醛明显增高的同时,抗氧化剂还原型谷胱甘肽含量明显降低.经薄芝糖肽注射液治疗,可使ALT在几天之内降至正常,同时使肝组织中抗氧化剂还原型谷胱甘肽含量明显回升,使过氧化产物得到尽快清除.提示薄芝糖肽具有直接或间接的抗氧化作用.     

冷应激诱导的脾脏NK细胞活性下降和脑内c-fos表达

目的 :观察单一冷应激对大鼠脾脏NK细胞活性的影响以及脑内Fos表达。方法 :大鼠置于 4℃的冷室 4h。采用YAC 1细胞51Cr释放法测定脾脏NK细胞的活性。用免疫细胞化学观察脑内有关核团的Fos表达 ,以及PVN和LC中Fos表达阳性的神经元的性质。结果 :单一冷应激能使脾脏NK细胞活性明显下降 ,下丘脑室旁核 (PVN)和脑干蓝斑 (LC)出现明显的Fos表达。双染实验表明 ,PVN中有部分神经元同时表达精氨酸加压素 (AVP) ,LC中大多数神经元同时表达酪氨酸羟化酶 (TH)。结论 :PVN中的AVP能神经元和LC中的儿茶酚胺能神经元很可能参与冷应激诱发的脾脏NK细胞活性的下降     

“716”中药复方对BALB/c小鼠NK细胞活性影响的研究

临床观察表明,“716”中药复方对儿童易患的多种病毒性疾病具有较好的疗效。本文研究了“716”中药复方对BALB/c小鼠NK细胞活性的影响,以探讨其作用机制。结果显示:1)体外,当药物浓度≥1.25mg/ml时,NK细胞对L929细胞的溶活解性有较大的提高;2)体内,实验组动物NK细胞对L929细胞溶解性活显著增加(P<0.01)。提示,“716”中药复方对NK细胞活性的促进作用可能是其重要的作用机制之一。     

软骨多糖对荷瘤小鼠免疫功能影响的初步研究

目的研究软骨多糖对荷瘤小鼠的作用,并探讨其对免疫功能的影响。方法采用小鼠肉瘤S180细胞建立动物腹水瘤模型,然后随机将小鼠分为生理盐水对照组和软骨多糖给药组,连续腹腔注射生理盐水或软骨多糖,分别测量ConA和LPS刺激下小鼠脾细胞淋巴增殖情况、外周血NK细胞的活性,及外周血单个核细胞E花环形成率。结果软骨多糖能刺激淋巴细胞增殖,明显提高NK细胞的活性,提高E花环形成率。结论软骨多糖能通过增强S180荷瘤小鼠的免疫功能而抑制肿瘤的生长。     

细胞毒性T淋巴细胞相关抗原4(CTLA4)敲除和人源化小鼠模型的建立

目的 建立细胞毒性T淋巴细胞相关抗原4(CTLA4)基因人源化小鼠模型,为靶向CTLA4的肿瘤治疗性抗体研发和筛选提供有效的小鼠模型.方法 利用CRISPR/Cas9技术,建立CTLA4基因人源化和敲除小鼠模型,利用PCR、RT-PCR、Western Blot、免疫组织化学和流式细胞术的方法对其进行鉴定及分析.将小鼠...     

一种新的人源化抗CD19嵌合抗原受体NK细胞的制备和对体外肿瘤细胞杀伤作用

摘要 目的：构建人源化抗CD19嵌合抗原受体NK细胞（hCAR19-NK）,并且在体外证明其对CD19 阳性血液病肿瘤细胞杀伤作用。方法：构建人源化的第二代CD19 CAR的逆转录病毒载体,使用辐照的K562-4-1BBL-mIL21细胞刺激外周血来源的NK细胞,通过逆转录病毒转导NK细胞获得hCAR19-NK细胞;采用流式细胞术和Western blot检测转导效率;采用4 h荧光杀伤实验和ELISA法检测hCAR19-NK细胞对淋巴瘤细胞的杀伤能力和IFN-γ释放水平;采用CD107a脱颗粒实验评估淋巴瘤细胞对hCAR19-NK细胞的特异性激活;比较对照组（Mock）和hCAR19-NK组细胞扩增倍数。结果：流式细胞术和Western blot 证明构建的CAR可以成功转导外周血来源的NK细胞;4 h荧光杀伤实验证明随着效靶比例升高,hCAR19-NK对Raji-GL杀伤率增加,明显高于Mock组;ELISA法检测显示Raji和K562-CD19作为靶细胞时,hCAR19-NK细胞的IFN-γ释放明显高于Mock组（P<0.01）;CD19⁺细胞（Raji和K562-CD19）可以特异性刺激hCAR19-NK细胞表达CD107a,具有统计学意义（P<0.05）;Mock组和hCAR19-NK组细胞扩增倍数无显著差异。结论：成功构建了可以杀伤CD19⁺ 肿瘤的人源化scFv的第二代hCAR19-NK细胞。     

Protective effect of black tea extract on the levels of lipid peroxidation and antioxidant enzymes in liver of mice with pesticide-induced liver injury

Sub-acute hepatotoxicity was induced in mice by exposure to pesticides. The effect of pretreatment with aqueous black tea extract on lipid peroxidation and antioxidants in the liver was investigated. Administering a combination dose of chlorpyriphos and cypermethrin (20 mg kg(-1) each) on alternate days over a 15-day period to male mice resulted in induction of sub-acute toxicity as reflected by elevated levels of liver damage marker enzymes alkaline phosphatase(ALP), aspartate transaminase(AST) and alanine transaminase(ALT). Significantly elevated levels of lipid peroxidation were observed in the experimental group (group III) as compared with control mice. Decreased activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), total thiol, glutathione peroxidase (GPx), glutathione reductase(GR) and glutathione-S-transferase (GST) were also observed in pesticide-treated as compared to control mice. Aqueous black tea extract was given as a pretreatment to group IV mice at a dose of 200 mg ml(-1) polyphenols before the pesticide dose, which significantly decreased the levels of lipid peroxidation and significantly elevated the activities of SOD, CAT, GSH, total thiol, GPx, GR and GST in liver to levels similar to the controls. Thus, the data offer support for the claim that the central mechanism of pesticide action occurs via changes in cellular oxidative status and shows conclusively that supplementation with black tea extract protects against the free radical-mediated oxidative stress in hepatocytes of animals with pesticide-induced liver injury.     

Protective effect of lycopene on lipid peroxidation and oxidative DNA damage in cell culture

A high incidence of cancer has been correlated with chronic iron overload, and carotenoids are of interest as possible anticarcinogens. We have investigated the effect of lycopene on lipid peroxidation and on the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) in CV1-P monkey cells exposed to ferric nitrilotriacetate (Fe-NTA) plus ascorbate. Cells supplemented with lycopene (20 pmol/10(6) cells) showed a reduction of 86% in Fe-NTA/ascorbate-induced lipid peroxidation (TBARS). Levels of 8-oxodGuo rose from 1.59+/-0.09 residues/10(6) dGuo in the control cells to 14.02+/-0.41 residues/10(6) dGuo after incubation with (1:4 mM) Fe-NTA/ascorbate (40 microM). Lycopene supplementation decreased in 77% the 8-oxodGuo levels in Fe-NTA/ascorbate-treated cells. These results indicate that lycopene can protect mammalian cells against membrane and DNA damage and possibly play a protective role against tumor promotion associated with oxidative damage.     

Protective effect of vitamin E on spinal cord injury by compression and concurrent lipid peroxidation

Studies were made on the influence of vitamin E on the effects of compression injury of the spinal cord associated with ischemia in rats. The motor disturbance induced by spinal cord injury was greatly reduced by vitamin E supplementation. After injury, the spinal cord evoked potentials showed greater recovery of both amplitude and latency in the vitamin E-supplemented group than in the control group. Spinal cord blood flow was promptly restored and remained normal after injury in the vitamin E-supplemented group, but was significantly decreased from 3 h after injury in the control group. Thiobarbituric acid (TBA)—reactive substances in the spinal cord was immediately increased by compression injury in both groups, and after injury it persisted at a high value for 24 h in the control group, but decreased within 1 h in the vitamin E-supplemented group. Pathological examination of the spinal cord showed less damage, such as bleeding and edema, in the vitamin E-supplemented group than in the control group. Vitamin E may have protective effects on the spinal cord by inhibiting damage induced by lipid peroxidation and/or by sustaining the blood flow by maintaining the normal metabolism of arachidonic acid.     

Effect of chitosan on lipid peroxidation in toxic liver injury

Lipid peroxidation was intensified by tetrachloromethane in liver. Concentration of lipid peroxidation products was decreased after chitosan injections. It was shown that application of chitosan had a positive effect on the liver of mice intoxicated by tetrachloromethane.     

Protective effect of L-theanine on carbon tetrachloride-induced acute liver injury in mice

We studied effects of L-theanine, a unique amino acid in tea, on carbon tetrachloride (CCl(4))-induced liver injury in mice. The mice were pre-treated orally with L-theanine (50, 100 or 200 mg/kg) once daily for seven days before CCl(4) (10 ml/kg of 0.2% CCl(4) solution in olive oil) injection. L-theanine dose-dependently suppressed the increase of serum activity of ALT and AST and bilirubin level as well as liver histopathological changes induced by CCl(4) in mice. L-theanine significantly prevented CCl(4)-induced production of lipid peroxidation and decrease of hepatic GSH content and antioxidant enzymes activities. Our further studies demonstrated that L-theanine inhibited metabolic activation of CCl(4) through down-regulating cytochrome P450 2E1 (CYP2E1). As a consequence, L-theanine inhibited oxidative stress-mediated inflammatory response which included the increase of TNF-α and IL-1β in sera, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in livers. CCl(4)-induced activation of apoptotic related proteins including caspase-3 and PARP in mouse livers was also prevented by L-theanine treatment. In summary, L-theanine protects mice against CCl(4)-induced acute liver injury through inhibiting metabolic activation of CCl(4) and preventing CCl(4)-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis.     

Protective effect of glycine supplementation on the levels of lipid peroxidation and antioxidant enzymes in the erythrocyte of rats with alcohol-induced liver injury

We studied the effect of glycine supplementation on lipid peroxidation and antioxidants in the erythrocyte membrane, plasma and hepatocytes of rats with alcohol-induced hepatotoxicity. Administering ethanol (20%) for 60 days to male Wistar rats resulted in significantly elevated levels of erythrocyte membrane, plasma and hepatocyte thiobarbituric acid reactive substances (TBARS) as compared with those of the experimental control rats. Decreased activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) were also observed on alcohol supplementation as compared with those of the experimental control rats. Glycine was administered at a dose of 0.6 g kg(-1) body weight to rats with alcohol-induced liver injury, which significantly decreased the levels of TBARS and significantly elevated the activities of SOD, CAT, GSH, GPx and GR in the erythrocyte membrane, plasma and hepatocytes as compared to that of untreated alcohol supplemented rats. Thus, our data indicate that supplementation with glycine offers protection against free radical-mediated oxidative stress in the erythrocyte membrane, plasma and hepatocytes of animals with alcohol-induced liver injury.     

Effect of lecithin on liver microsomal lipid peroxidation]

The effect of exogeneous (egg) lecithin on peroxidation of microsomal lipids was studied with the view of elucidating the role of various components of lipid substrate in the overall oxidation rate of the lipids. The following processes were studied a) NADPH-dependent microsomal lipid peroxidation in the presence of lecithin; b) ascorbate-dependent microsomal lipid peroxidation in the presence of lecithin; c) oxidation of lipid mixture, isolated from the microsomes, and that of lecithin in the presence of the Fe2+ + ascorbate system; 4) oxidation of lecithin induced by the Fe2+ + ascorbate system. It was found that in the presence of exogeneous lecithin the oxidation of microsomal lipids in inhibited, which is probably due to the peculiarities of lecithin oxidation. It was shown that the specific rate of lecithin oxidation is decreased with an increase in lecithin concentration. Possible mechanisms of lecithin effect on microsomal lipid peroxidation are discussed.     

Protective role of L-carnitine on liver and heart lipid peroxidation in atherosclerotic rats

Lipid peroxides are considered to be the initiation factor for atherosclerosis. Present study depicts that L-carnitine treatment (300 mg/kg body weight/day) for 7 and 14 days caused significant reduction in the tissue lipid peroxidations. It also shows marked improvement in the antioxidant status. By this way carnitine maintain the normal function of the cells.     

Rabbit liver microsomal lipid peroxidation. The effect of lipid on the rate of peroxidation

Rat and rabbit liver microsomes catalyze an NADPH-cytochrome P-450 reductase-dependent peroxidation of endogenous lipid in the presence of the chelate, ADP-Fe3+. Although liver microsomes from both species contain comparable levels of NADPH-cytochrome P-450 reductase and cytochrome P-450, the rate of lipid peroxidation (assayed by malondialdehyde and lipid hydroperoxide formation) catalyzed by rabbit liver microsomes is only about 40% of that catalyzed by rat liver microsomes. Microsomal lipid peroxidation was reconstituted with liposomes made from extracted microsomal lipid and purified protease-solubilized NADPH-cytochrome P-450 reductase from both rat and rabbit liver microsomes. The results demonstrated that the lower rates of lipid peroxidation catalyzed by rabbit liver microsomes could not be attributed to the specific activity of the reductase. Microsomal lipid from rabbit liver was found to be much less susceptible to lipid peroxidation. This was due to the lower polyunsaturated fatty acid content rather than the presence of antioxidants in rabbit liver microsomal lipid. Gas-liquid chromatographic analysis of fatty acids lost during microsomal lipid peroxidation revealed that the degree of fatty acid unsaturation correlated well with rates of lipid peroxidation.