Inactivation of the peroxisomal ABCD2 transporter in the mouse leads to late-onset ataxia involving mitochondria, Golgi and endoplasmic reticulum damage

ATP-binding cassette (ABC) transporters facilitate unidirectional translocation of chemically diverse substances, ranging from peptides to lipids, across cell or organelle membranes. In peroxisomes, a subfamily of four ABC transporters (ABCD1 to ABCD4) has been related to fatty acid transport, because patients with mutations in ABCD1 (ALD gene) suffer from X-linked adrenoleukodystrophy (X-ALD), a disease characterized by an accumulation of very-long-chain fatty acids (VLCFAs). Inactivation in the mouse of the abcd1 gene leads to a late-onset neurodegenerative condition, comparable to the late-onset form of X-ALD [Pujol, A., Hindelang, C., Callizot, N., Bartsch, U., Schachner, M. and Mandel, J.L. (2002) Late onset neurological phenotype of the X-ALD gene inactivation in mice: a mouse model for adrenomyeloneuropathy. Hum. Mol. Genet., 11, 499-505.]. In the present work, we have generated and characterized a mouse deficient for abcd2, the closest paralog to abcd1. The main pathological feature in abcd2-/- mice is a late-onset cerebellar and sensory ataxia, with loss of cerebellar Purkinje cells and dorsal root ganglia cell degeneration, correlating with accumulation of VLCFAs in the latter cellular population. Axonal degeneration was present in dorsal and ventral columns in spinal cord. We have identified mitochondrial, Golgi and endoplasmic reticulum damage as the underlying pathological mechanism, thus providing evidence of a disturbed organelle cross-talk, which may be at the origin of the pathological cascade.     

Differential stability and fusion activity of Lyssavirus glycoprotein trimers

The oligomeric structure and the fusion activity of lyssavirus glycoprotein (G) was studied by comparing G from Mokola virus (GMok) and rabies virus (PV strain) (GPV), which are highly divergent lyssaviruses. G expressed at the surface of BSR cells upon either plasmid transfection or virus infection are shown to be mainly trimeric after cross-linking experiments. However, solubilization by a detergent (CHAPS) and analysis in sucrose sedimentation gradient evidenced that GMok trimer is less stable than GPV trimer. A chimeric glycoprotein (G Mok-PV) associating the N-terminal half of GMok to the C-terminal half part of GPV formed trimers with an intermediate stability, indicating that the G C-terminal domain is essential in trimer stability. A cell to cell fusion assay revealed that GMok (and not G Mok-PV) was able to induce fusion at a higher pH (0.5 pH unit) than GPV. Such differences in the oligomeric structure stability and in the fusion activity of lyssavirus glycoproteins may partly account for the previously reported differences of their immunogenic and pathogenic properties.     

A molecular biologic study of extracellular matrix components during the development of glomerulosclerosis in murine chronic graft-versus-host disease.

BACKGROUND: We studied the development of glomerulosclerosis in murine chronic graft-versus-host disease, a model for human systemic lupus erythematosus. EXPERIMENTAL DESIGN: The disease was induced in (C57BL10 x DBA/2)F1 hybrids by injection of DBA/2 lymphocytes leading to deposition of auto-antibodies in the glomeruli, and a lupus type of nephritis morphologically. We have determined the levels of mRNA coding for laminin (B1 and B2), a 67 kilodalton laminin binding protein, and types I and IV collagen, in control and graft-versus host disease mice at various times after disease induction. RESULTS: Laminin and collagen mRNAs were increased in whole kidneys 4 weeks after induction of the disease. At week 10, all animals displayed dramatic stimulation of alpha 1(I), alpha 1(IV), laminin B1, and B2 mRNAs. The 67 kilodalton laminin binding protein mRNA was also doubled from week 4 to 16. In isolated glomeruli, the mRNA level coding for laminin B2 was already significantly increased from week 8. This enhancement of laminin synthesis corresponds to the mesangial expansion and to the development of laminin-containing spike formations of the glomerular basement membrane at week 8. CONCLUSIONS: The expansion of the mesangial matrix in murine chronic graft-versus-host disease is caused at least in part, by an increased production of extracellular matrix components by glomerular cells. These results demonstrate that the increase of specific extracellular matrix components mRNAs precedes light microscopic changes. Quantitative evaluation of the mRNA levels coding for extracellular matrix proteins may reveal a useful method for the early detection of the development of glomerular sclerosis at the stage preceding the onset of anatomo-clinical changes.     

Epicutaneous immunotherapy protects cashew-sensitized mice from anaphylaxis

Background

The prevalence of tree nut allergy has increased worldwide, and cashew has become one of the most common food allergens. More critically, cashew allergy is frequently associated with severe anaphylaxis. Despite the high medical need, no approved treatment is available and strict avoidance and preparedness for prompt treatment of allergic reactions are considered dual standard of care. In the meantime, Phase III study results suggest investigational epicutaneous immunotherapy (EPIT) may be a relevant and safe treatment for peanut allergy and may improve the quality of life for many peanut allergic children.

Objective

We aimed to evaluate the capacity of EPIT to provide protection against cashew-induced anaphylaxis in a relevant mouse model.

Methods

The efficacy of EPIT was evaluated by applying patches containing cashew allergens to cashew-sensitized mice. As negative control, sham mice received patches containing excipient. Following treatment, mice were challenged orally to cashew and anaphylactic symptoms, as well as plasmatic levels of mast-cell proteases (mMCP)-1/7, were quantified.

Results

Of 16 weeks of EPIT significantly protects against anaphylaxis by promoting a faster recovery of challenged mice. This protection was characterized by a significant reduction of temperature drop and clinical symptoms, 60 minutes after challenge. This was associated with a decrease in mast-cell reactivity as attested by the reduction of mMCP-1/7 in plasma, suggesting that EPIT specifically decrease IgE-mediated anaphylaxis.

Conclusion

We demonstrate that EPIT markedly reduced IgE-mediated allergic reactions in a mouse model of cashew allergy, which suggests that EPIT may be a relevant approach to treating cashew allergy.

     

~(131)I治疗Graves’病后发生甲低与TGA,TMA及TRAb的关系

目的 :从甲状腺自身免疫方面探讨1 3 1 I治疗甲亢的效果及甲低发生的因素。方法 :选择1 3 1 I治疗的88例Graves’病甲亢患者随访 3年 ,分为第 1组 (TGA、TMA、TRAb均阳性 )和第二组 (TGA、TMA阴性 ,TRAb阳性 )。采用x2 分析自身抗体水平与甲低发生的关系。结果 :1组甲低发生率为 31 4 % ,2组为 3 8% ,1组明显高于 2组 ,差异有显著性。结论 :TGA、TMA和TRAb水平与确定1 3 1 I剂量及甲低的发生关系密切。认为TGA、TMA水平高的患者应酌情减少1 3 1 I用量     

丹参对急性缺血后再灌注心肌磷脂肌醇系统变化的影响

本文首镒报道采用大鼠在体心肌缺血后再灌注模型观察丹参对急性短时间缺血后再灌注心肌磷脂肌醇代谢的影响。结果显示：急性缺血１０ｍｉｎ后灌注１０ｍｉｎ，心肌磷脂肌醇信息传递系统功能明显增强，其磷脂酰肌醇－４，５－二磷酸和肌醇－１，４，５－三磷酸水平显著高于非缺血对照组和缺血组；丹参能显著抑制急性缺血后再灌注心肌磷脂肌醇系统的高功能状态，其ＰＩＰ２和ＩＰ３水平明显低于缺血组和缺血再灌注组。     

A solid-phase blocking ELISA for detection of antibodies to Nipah virus

A monoclonal antibody (MAb) based solid-phase blocking ELISA was developed for detection of antibodies to Nipah virus. The ELISA was designed to detect remaining antigens on the plate with anti-Nipah MAb conjugate after the reaction with sample serum, and enabled simple procedure, detection of neutralizing antibody to Nipah virus, and application of samples from different animal species. Forty of 200 swine reference sera examined were positive by the ELISA, of which thirty seven were found positive by serum neutralization test. Sera from a total of 131 fruit bats captured in Malaysia were also tested and all found negative by the both tests. It is considered that the solid-phase blocking ELISA can be used as a screening test for Nipah virus infection followed by the serum neutralization test as confirmatory test.     

Differential expression of FIZZ1 and Ym1 in alternatively versus classically activated macrophages

Alternatively activated macrophages (aaMphi) display molecular and biological characteristics that differ from those of classically activated macrophages (caMphi). Recently, we described an experimental model of murine trypanosomosis in which the early stage of infection of mice with a Trypanosoma brucei brucei variant is characterized by the development of caMphi, whereas in the late and chronic stages of infection, aaMphi develop. In the present study, we used suppression subtractive hybridization (SSH) to identify genes that are expressed differentially in aaMphi versus caMphi elicited during infection with this T. b. brucei variant. We show that FIZZ1 and Ym1 are induced strongly in in vivo- and in vitro-elicited aaMphi as compared with caMphi. Furthermore, we demonstrate that the in vivo induction of FIZZ1 and Ym1 in macrophages depends on IL-4 and that in vitro, IFN-gamma antagonizes the effect of IL-4 on the expression of FIZZ1 and Ym1. Collectively, these results open perspectives for new insights into the functional properties of aaMphi and establish FIZZ1 and Ym1 as markers for aaMphi.     

Experimenters' expectation and subjects' knowledge of hypotheses in simple reaction time to lateralized visual stimuli

Researchers in experimental neuropsychology usually recruit "naive" normal subjects. In this preliminary study, we attempt to consider the role of such a selection. Sixty-four normal, right-handed subjects were enlisted for an experiment on simple reaction times to laterally displayed visual stimuli for which, according to the literature, no cerebral asymmetry is expected. In the course of the experiment, the subjects were "informed" about the hypothesis of the current research. Four subgroups of 16 subjects received four different kinds of information, one for each subgroup; moreover, in each subgroup, half the subjects were examined by an experimenter who hoped to modify the performance and the other half by an experimenter who supposed that information would not affect the behavior of the subjects. The results do not reveal any effect of instructions or experimenters and are discussed to plan future research.