The influence of damage factors of the different nature on the lipid composition in the mice liver

The combined effect of the X-rays at the dose of 4 and 5 Gy and the Tween 80 (the 0.3% solution) in the 10% solution of the water acetone on the lipid composition in the mice Balb/c liver is studied after 1 month. It is revealed that the disturbance of the linear dependence of "biological effect-dose" is due to the enhancement of the action of the acute X-rays with sublethal doses after the preliminary administration of the low toxic chemical agents at low doses on the lipid composition of the mice liver. The decrease of differences in the scale of the correlation between the generalized phospholipid composition parameters in the mice liver after combined action of the chemical and physical factors is shown. The interrelation between the mice Balb/c survival and the ratio of the general phospholipid fractions of the lipid liver in the age control groups is found.     

Kinetics of Organ-Associated Natural Killer Cells and Intermediate CD3 Cells during Pulmonary and Hepatic Granulomatous Inflammation Induced by Mycobacterial Cord Factor

We investigated here the kinetics of natural killer (NK) cells and extrathymic T cells, which include intermediate CD3 cells and γδ T cells, in the cord factor-induced granulomatous inflammation of the lungs and liver. In Balb/c mice, pulmonary inflammation elevated the proportion of NK cells and that of extrathymic T cells to mononuclear cells in the lungs. C3H/He mice exhibited shorter-term inflammation of the lungs than Balb/c mice and accordingly showed a smaller increase in the proportions of pulmonary NK cells and intermediate CD3 cells. In the liver of Balb/c mice, hepatic NK cells increased as well with the granulomatous changes, while intermediate CD3 cells exhibited a transient decrease before they increased. The present study has demonstrated that granulomatous inflammation is accompanied by the increase of lung-associated NK cells and extrathymic T cells and that there exists a difference between these two mouse strains in the induction of these lymphocyte subsets by cord factor.     

Effect of factors from the Chernobyl exclusion zone on the level of cytochrome P-450 in mouse liver microsomes

The data concerning the influence of Chernobyl exclusive zone factors on cytochrome P-450 relative contents in liver microsome fractions of Balb/c, CC57W/Mv and C57 Black mice are submitted in this work Reliable diminishing of liver P-450 relative concentration in experimental animals, compared with respective isogenic control groups is shown to be varying depending on the mouse line and sex.     

The expression of ceruloplasmin, an angiogenic glycoprotein, by mouse embryonic fibroblasts

Balb/c 3T3, Swiss 3T3 and Rous sarcoma virus transformed Balb/c 3T3 mouse embryonic fibroblasts produced ceruloplasmin in vitro, whereas primary cultures prepared from the Balb/c mouse embryos did not produce ceruloplasmin. The amount of ceruloplasmin synthesis by the Balb/c 3T3 cell line is enhanced by Rous sarcoma virus-transformation (1.5-3 fold) and by treatment with dexamethasone (about 2.4 fold). The protein was identified as ceruloplasmin by immunoprecipitation with ceruloplasmin-specific polyclonal antibody, and by similarity of peptide maps, and subunit molecular weight (135,000 dalton) to that of authentic ceruloplasmin from primary cultures of mouse hepatocytes.     

EGFP标记的A20细胞构建小鼠B细胞播散型淋巴瘤模型

目的:A20细胞是来源于同系Balb/c小鼠大B细胞淋巴瘤的细胞系,能通过尾静脉接种建立小鼠B细胞播散型淋巴瘤的模型,但由于该细胞系缺乏细胞表面特异性标志而难于监测。本研究使用增强型绿色荧光蛋白(EGFP)标记A20细胞,试图建立易于监测的小鼠B细胞播散型淋巴瘤模型。方法:用含增强型绿色荧光蛋白(EGFP)的慢病毒载体将标记基因EGFP转入A20细胞,通过流式分选出EGFP+的A20细胞,体外培养后通过尾静脉注射接种于同系Balb/c小鼠体内,用流式细胞仪监测其外周血EGFP+细胞的百分率。当小鼠出现消瘦、毛发竖立、嗜睡等体征时,将小鼠处以安乐死;取动物脏器行石蜡包埋、病理切片、HE染色。结果:尾静脉注射1×106细胞于6只Balb/c小鼠体内,接种后15天可在外周血中检测到EGFP+细胞,平均生存时间为29.6±0.8天;在肝脏、脾脏、脊椎和淋巴结等多脏器成瘤,流式检测瘤细胞EGFP表达阳性。结论:经尾静脉注射接种A20细胞可建立小鼠B细胞播散型淋巴瘤模型,A20细胞经含EGFP的慢病毒标记后易于通过流式进行监测,为通过动物体内试验评价靶向治疗的疗效提供了保证。     

Oxidative stress and susceptibility to mitochondrial permeability transition precedes the onset of diabetes in autoimmune non-obese diabetic mice

Abstract

Beta cell destruction in type 1 diabetes (TID) is associated with cellular oxidative stress and mitochondrial pathway of cell death. The aim of this study was to determine whether oxidative stress and mitochondrial dysfunction are present in T1D model (non-obese diabetic mouse, NOD) and if they are related to the stages of disease development. NOD mice were studied at three stages: non-diabetic, pre-diabetic, and diabetic and compared with age-matched Balb/c mice. Mitochondria respiration rates measured at phosphorylating and resting states in liver and soleus biopsies and in isolated liver mitochondria were similar in NOD and Balb/c mice at the three disease stages. However, NOD liver mitochondria were more susceptible to calcium-induced mitochondrial permeability transition as determined by cyclosporine-A-sensitive swelling and by decreased calcium retention capacity in all three stages of diabetes development. Mitochondria H₂O₂ production rate was higher in non-diabetic, but unaltered in pre-diabetic and diabetic NOD mice. The global cell reactive oxygen species (ROS), but not specific mitochondria ROS production, was significantly increased in NOD lymphomononuclear and stem cells in all disease stages. In addition, marked elevated rates of 2′,7′-dichlorodihydrofluorescein (H₂DCF) oxidation were observed in pancreatic islets from non-diabetic NOD mice. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and lipidomic approach, we identified oxidized lipid markers in NOD liver mitochondria for each disease stage, most of them being derivatives of diacylglycerols and phospholipids. These results suggest that the cellular oxidative stress precedes the establishment of diabetes and may be the cause of mitochondrial dysfunction that is involved in beta cell death.     

不同周龄Balb／c小鼠脏器质量及其变化趋势分析

目的：测定不同周龄Balb／c小鼠主要脏器质量、脏器系数,并进行比较。方法：取120只3周龄、5周龄、7周龄的Balb／c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果：①雌性与雄性Balb／c小鼠脏器质量相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝有非常显著差异（P〈0．01）,脾、肺有显著差异（P〈0．05）;7周龄时肝、肺及双肾有非常显著差异（P〈0．01）,心、脾有显著差异（P〈0．05）。②雌性与雄性Balb／c小鼠脏器系数相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝、脾有非常显著差异（P〈0．01）,膀胱有显著差异（P〈0．05）;7周龄时肺、双肾有非常显著差异（P〈0．01）,脾、膀胱有显著差异（P〈0．05）。结论：随着周龄的增长,Balb／c雌、雄性小鼠之间,存在差异的脏器也在增多。     

不同周龄Balb/c小鼠脏器质量及其变化趋势分析

目的:测定不同周龄Balb/c小鼠主要脏器质量、脏器系数,并进行比较。方法:取120只3周龄、5周龄、7周龄的Balb/c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果:①雌性与雄性Balb/c小鼠脏器质量相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝有非常显著差异(P0.01),脾、肺有显著差异(P0.05);7周龄时肝、肺及双肾有非常显著差异(P0.01),心、脾有显著差异(P0.05)。②雌性与雄性Balb/c小鼠脏器系数相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝、脾有非常显著差异(P0.01),膀胱有显著差异(P0.05);7周龄时肺、双肾有非常显著差异(P0.01),脾、膀胱有显著差异(P0.05)。结论:随着周龄的增长,Balb/c雌、雄性小鼠之间,存在差异的脏器也在增多。     

Biodistribution of pH-sensitive immunoliposomes

Liposomes composed of either dioleoylphosphatidylethanolamine and oleic acid (pH-sensitive) or dioleoylphosphatidylcholine and oleic acid (pH-insensitive) were injected into C3H and Balb/c mice in order to determine the tissue distribution of both the lipid and the aqueous content. The lipid component was monitored by use of [3H]cholestanyl ether and the aqueous content was monitored by use of encapsulated 125I-tyraminyl-inulin. The pH-insensitive liposomes injected into both types of mice were rapidly cleared from the blood stream followed by accumulation primarily in the liver, followed by the spleen. The presence of a monoclonal antibody on the liposome surface caused a slight acceleration in liver accumulation, though generally gave the same profile as the antibody-free liposomes. pH-sensitive liposomes were leaky upon exposure to the mouse plasma following injection. The lipid component, though, displayed a large amount (e.g., 50-70% in C3H mice) of accumulation in the lung for up to 6 h, followed by a subsequent appearance in the liver and spleen. The presence of monoclonal antibody had no effect on the tissue distribution profile. These results indicate that the pH-sensitive liposomes, although ineffective as an aqueous drug delivery agent, may be effective as a means of delivering lipophilic drugs to the lung.     

Regular exercise prevents high-sucrose diet-induced fatty liver via improvement of hepatic lipid metabolism

Fatty liver is known as the initial stage in nonalcoholic fatty liver disease. Epidemiological studies have shown that regular exercise prevents accumulation of hepatic lipids, although the underlying mechanism is unclear. The purpose of this study was to investigate the effect of exercise on fatty liver associated with hepatic lipid metabolism. KK/Ta mice (6 weeks old) were divided into sedentary and exercise groups and compared with sedentary Balb/c mice. All the mice were fed a high-sucrose diet for 12 weeks. The KK/Ta mice in the exercise group performed a treadmill running exercise at 20 m/min for 30 min (3 times per week). Twelve weeks of regular exercise suppressed the accumulation of lipid in the liver, along with reduction in the level of lipid in the plasma. The levels of carnitine palmitoyl transferase II, acyl-coenzyme A dehydrogenase, and trifunctional enzyme, which are rate-limiting enzymes in fatty acid oxidation in the liver, were elevated by exercise. In addition, the expression of fatty acid synthase, a key lipogenetic enzyme, was reduced by exercise. Furthermore, regular exercise decreased the expression of heat shock protein 47, a marker of hepatic fibrosis, in the liver. Our results suggest that regular exercise prevents fatty liver via improvement of hepatic lipid metabolism.     

Defect in fatty acid esterification of dolichol in Niemann-Pick type C1 mouse livers in vivo

Fatty acid esterification of dolichol and cholesterol in Niemann-Pick type C1 mouse (Balb/c NIH npc1(-/-)) livers was investigated in response to treatment with peroxisomal proliferators. These inducers have hypolipidemic properties and influence the mevalonate pathway and the intracellular transport of the final products of this biosynthetic route. Such inducers are consequently interesting to use in a disease model with defective intracellular transport of lipids. In wild-type mice, the levels of dolichol and cholesterol found as free alcohols were not changed to any great extent upon treatment with the peroxisomal inducers dehydroepiandrosterone, clofibrate and diethylhexylphtalate. In contrast, the amounts of dolichyl esters increased whereas cholesteryl esters decreased by the same treatments. The rate of enzymatic esterification of dolichol in isolated microsomes was accordingly elevated after 5- to 7-day treatments with the efficient peroxisomal proliferators DEHP and PFOA, while the corresponding esterification of cholesterol was decreased. Upon peroxisomal induction in npc1(-/-) mice, the enzymatic dolichol esterification in vitro increased whereas the low concentration of dolichyl esters remained unchanged. The results thus demonstrate that the induction of fatty acid esterification of dolichol in vivo is impaired in npc1(-/-) mouse liver. It is therefore proposed that the intracellular lipid transport defect in npc1(-/-) mouse liver disables either dolichol and/or the fatty acid from reaching the site of esterification in vivo. This proposal was strengthened by the finding that the amount of dolichol was decreased in an isolated Golgi fraction from npc1(-/-) mice.     

The integration sites of endogenous and exogenous Moloney murine leukemia virus

Specific cDNA probes of Moloney and AKR murine leukemia viruses have been prepared to characterize the proviral integration sites of these viruses in the genomes of Balb/Mo and Balb/c mice. The genetically transmitted Moloney provirus of Balb/Mo mice was detected in a characteristic Eco RI DNA fragment of 16 x 10(6) daltons. No fragment of this size was detected in tissue DNAs from Balb/c mice infected as newborns with Moloney virus. We conclude that a viral integration site, occupied in preimplantation mouse embryos, is not necessarily occupied when virus infects cells in post-natal animals. Balb/Mo and Balb/c mice do carry the AkR structural gene in an Eco RI DNA fragment of 12 x 10(6) daltons. Further restriction analysis of this fragment indicated that both mouse lines carry one AKR-type provirus. Leukemogenesis in Balb/Mo and newborn infected Balb/c mice is accompanied by reintegration of Moloney viral sequences in new chromosomal sites of tumor tissues. Part of the reintegrated Moloney viral sequences are of subgenomic size. The AKR viral sequences, however, are not found in new sites. Further restriction analysis revealed that the development of Moloney virus-induced leukemia in Balb/Mo mice does not lead to detectable structural alteration of the genetically transmitted Moloney and AKR structural genes. Possible mechanisms of the reintegration process are also discussed.     

Isolation of a cyp2b10-like cDNA and of a clone derived from a cyp2b10-like pseudogene

By screening Balb/c male mouse liver cDNA library with a rat CYP2B1 cDNA probe, we have isolated a 1795 bp cyp2b10-like clone, referred to as P16. Its sequence exhibited 34 base differences (98% similarity) with the cyp2b10 published sequence, together with a 97% identity at the amino acid sequence level. By RT-PCR and PCR analyses with Balb/c female and male liver RNA and genomic DNA, using a region showing 8 base differences between the P16 and the cyp2b10 sequences, we have confirmed the identity of our cloned cDNA, and failed in finding a PCR product exhibiting a sequence 100% identical with that of cyp2b10. Our results therefore suggest that the P16 sequence is the authentic cyp2b10 sequence. We have also isolated a partial clone, P21, which 1609 bp sequence overlapped with that of P16, except for a T-->G transversion, giving rise to a premature TGA stop codon, indicating that it was derived from a pseudogene.     

Humanized Rag1-/- γc-/- mice support multilineage hematopoiesis and are susceptible to HIV-1 infection via systemic and vaginal routes

Several new immunodeficient mouse models for human cell engraftment have recently been introduced that include the Rag2(-/-)γc(-/-), NOD/SCID, NOD/SCIDγc(-/-) and NOD/SCIDβ2m(-/-) strains. Transplantation of these mice with CD34(+) human hematopoietic stem cells leads to prolonged engraftment, multilineage hematopoiesis and the capacity to generate human immune responses against a variety of antigens. However, the various mouse strains used and different methods of engrafting human cells are beginning to illustrate strain specific variations in engraftment levels, duration and longevity of mouse life span. In these proof-of-concept studies we evaluated the Balb/c-Rag1(-/-)γ(-/-) strain for engraftment by human fetal liver derived CD34(+) hematopoietic cells using the same protocol found to be effective for Balb/c-Rag2(-/-)γc(-/-) mice. We demonstrate that these mice can be efficiently engrafted and show multilineage human hematopoiesis with human cells populating different lymphoid organs. Generation of human cells continues beyond a year and production of human immunoglobulins is noted. Infection with HIV-1 leads to chronic viremia with a resultant CD4 T cell loss. To mimic the predominant sexual viral transmission, we challenged humanized Rag1(-/-)γc(-/-) mice with HIV-1 via vaginal route which also resulted in chronic viremia and helper T cell loss. Thus these mice can be further exploited for studying human pathogens that infect the human hematopoietic system in an in vivo setting.     

Molecular cloning of an immunoglobulin kappa constant gene from NZB mouse

An EcoRI fragment carrying the immunoglobulin C kappa gene and multiple J gene segments from the DNA of the NZB strain of mouse was cloned into lambda Ch 4A DNA. Subsequent characterization of the clone by heteroduplex analysis, restriction-enzyme mapping and DNA sequencing demonstrated that the organization of the J gene segments and the C kappa gene of NZB mouse was similar, if not identical, to that of DNA from the Balb/c strain of mouse. Since the amino acid sequence of the light chain of a plasmacytoma of NZB mouse shows a J region sequence different from that of Balb/c mouse, our results indicate that the new J sequence arose by somatic mutation.     

RNA干扰抑制人乙型肝炎病毒复制的研究

采用表达shRNA的载体构建了表达针对病毒HBsAgmRNA保守区的shRNA的质粒psiHBs,利用细胞模型和高压注射小鼠模型评价RNA干扰对HBV复制和基因表达的抑制作用。通过Western印迹检测细胞内的HBsAg,用ELISA检测细胞培养上清和血清中的HBsAg,采用Southern印迹检测HBV的复制中间体,最后通过免疫组化的方法检测肝组织切片中HBcAg的表达情况。结果显示pHBV1.3和psiHBs共转染HepG2后,与对照组相比病毒HBsAg和HBeAg的表达和病毒复制中间体的水平下降了90%以上,并且shRNA的作用效率存在序列特异性和剂量依赖性。在高压注射小鼠模型中,psiHBs表达的shRNA使小鼠血清中HBsAg的水平下降了80%以上,免疫组化检测显示,小鼠肝组织内HBcAg阳性细胞数减少了75.1%,而且shRNA的抑制作用至少能持续4d。研究显示载体表达的shRNA无论是在细胞或是在小鼠模型中都能对HBV的复制和基因的表达发挥序列特异性的抑制作用。本研究为我们下一步实现由RNAi介导的基因治疗提供了理论和技术支持。     

不同动物制备的抗血清对病毒抗原免疫反应的差异

血清学技术是病毒诊断、鉴定、分类及亲缘关系分析的重要手段。一般常用以制备抗病毒血清的动物是家兔,但也有采用其它动物的,如蛙、羊、豚鼠、鸡及小鼠等。本文比较了Balb/c小鼠、昆明种小鼠和新西兰大白兔对长叶车前花叶病毒上海分离株(RMVsh)和烟草花叶病毒普通株(TMVc)的免疫反应特征。     

Effect of anti-inflammatory agent administration on Balb/c mouse peritoneal macrophage activity]

A study of the mouse Balb/c peritoneal macrophages has been made after oral antiinflammatory drugs administration on animals which previously had an inflammation with carrageenan. The results show an enhancement of the number of the macrophages, of their enzymatic activities and of their proteins' content. These three parameters fall down more or less rapidly according to the considered antiinflammatory drug.