Specified risk material and topographical distribution of lymphoreticular tissue of the bovine tongue

The elimination of specified risk material from food is crucial to restricting the risk to public health arising from bovine spongiform encephalopathy. The distribution of lymphoreticular tissue as potential specified risk material of the bovine lingual tonsil is described in relation to topographical anatomical landmarks. The definition of a proper landmark is a prerequisite for establishing adequate legal regulations concerning the removal of the lingual tonsil after slaughter. The main parameter to identify the lymphoreticular tissue in this study was the immunohistochemical identification of the follicular dendritic cells in the lingual tonsil. Lymph nodules were detected in areas up to 30 mm rostral of a given macroscopic landmark, i.e., the most caudal of the papillae vallatae. This area must therefore be adequately removed from the bovine tongue in the slaughterhouse. The current method for the removal of the lingual tonsil tissue according to Regulation (EC) 999/2001 at the slaughterhouse and alternatives to this method are discussed.

Chromosomal rearrangements after ex vivo Epstein-Barr virus (EBV) infection of human B cells

The Epstein-Barr virus (EBV) is carried by more than 90% of the adult world population and has been implicated in several human malignancies. Its ability to induce unlimited in vitro proliferation of B cells is frequently used to generate lymphoblastoid cell lines (LCLs). In this study, we have investigated the evolution of two LCLs up to 25 weeks after EBV infection. LCLs were karyotyped once a month by spectral karyotyping (SKY). LCLs but not mitogen-activated B cells showed evidence of DNA damage and DNA damage response within the first 2 weeks. After 4 weeks, the former, but not the latter, showed a high level of non-clonal structural aberrations, mainly deletions, fragments, dicentric chromosomes and unbalanced translocations. Genomic instability decreased thereafter over time. Nonrandom aneuploidy 12 weeks after infection showed clonal evolution in culture. After 25 weeks post-infection, most cells exhibited karyotypic stability. Chromosomal aberrations were compatible with telomere dysfunction, although in the absence of telomere shortening. The telomere capping protein TRF2 was partially displaced from telomeres in EBV-infected cells, suggesting an EBV-mediated uncapping problem. In conclusion, this study suggests that DNA damage and telomere dysfunction contribute to EBV-related chromosomal instability in early LCLs.

Nuclear receptors and their role in Epstein -- Barr virus induced B cell transformation

Epstein - Barr virus (EBV) is a lymphotropic virus that infects more than 90% of the human population, and targets B cells for infection. Infection of human B cells leads to the malignant transformation and eventual immortalization. In latency III infection six EBV-encoded nuclear antigens (EBNAs) and three latent membrane proteins (LMPs) are expressed in the transformed cells that can grow as a lymphoblastoid cell lines in vitro . These proteins hijack the normal B cell growth pathways by activating the constitutive growth promotion and external survival signals. We have determined a set of the nuclear receptors that are up- (and down-) regulated in the latency III infected cells at the mRNA level. In the present paper we discussed the possible role of these receptors in B cell transformation upon EBV infection based on the literature data.

Expression profile of nuclear receptors upon Epstein -- Barr virus induced B cell transformation

BACKGROUND

Infection of human B cells with Epstein - Barr virus (EBV) induces metabolic activation, morphological transformation, cell proliferation and eventual immortalization.

AIM

To identify the nuclear receptors, which are the cellular interaction partners of EBNAs, that will help to elucidate the mechanism of B cell transformation.

METHODS

We have compared the nuclear receptor profile in the naïve and EBV-transformed B-lymphocytes, using TaqMan LDA microfluidic card technology.

RESULTS

Out of 48 nuclear receptor, 17 showed differential expression at the mRNA level. The expression of 5 genes was elevated in EBV-transformed cells, whereas 12 genes were downregulated in lymphoblastoid cells (LCLs). 7 genes were studied at the protein level; 2 genes were up regulated (Nr2F2 and RARA) and 4 genes were down regulated (ERB, NUR77, PPARG, and VDR) in LCLs.

CONCLUSION

The nuclear receptor profiling on EBV infected B cells showed alterations of nuclear receptors expression at both mRNA and protein levels compared with non infected peripheral blood cells. Further analysis on a possible role of each nuclear receptor in EBV induced cell transformation should be performed.

Interactions of breast cancer cells with the microenvironment of the human bone marrow

e22097

Background: Bone is one of the most favored sites for metastasis of breast cancer cells (BrCa) resulting in the formation of osteolytic and/or osteoblastic lesions. There is increasing evidence that the bone marrow (BM) microenvironment plays a pivotal role in modulating tumor cell homing to the bone, metastasis and progression. However, the molecular crosstalk between BrCa cells and the cellular and extracellular components of the bone marrow leading to osteotropism still remains a poorly characterized step in the metastatic process. Methods: Cell adhesion and migration assays using the invasive MDA-MB-231 and the noninvasive MCF7 BrCa cell lines were performed to investigate the impact of BM components on cellular functions of tumor cells. Results: Cell-matrix adhesion assays showed a strong and concentration-dependent attachment of BrCa cells to several extracellular matrix components present in the human bone marrow such as fibronectin, different laminin isoforms, collagens type I and IV or tenascin-C. Moreover, the BrCa cells attached avidly to the BM-derived primary osteoblasts, whereas the binding to stromal cells was significantly weaker. Notably, cell-cell adhesion experiments with primary osteoclasts revealed an anti-adhesive effect on tumor cell binding leading to no attachment activity of BrCa cells with the cell surface of primary osteoclasts. The influence of cellular components of the BM on tumor cell migration was analyzed by cell migration assays using conditioned media of osteoblasts, osteoclasts and stromal cells or a modified Transwell chamber technique. The migration assays with invasive MDA-MB-231 cells clearly showed that osteoblasts, but not osteoclasts or stromal cells released factors which led to a faster wound closure, suggesting an enhanced migratory ability of the metastatic tumor cells, whereas the migration of nonmetastatic MCF7 cells was unaffected. Conclusions: These data indicate that the crosstalk with osteoblasts affects both the adhesive and the migratory ability of BrCa cells favoring the bone colonization process. Furthermore, the presented experimental conditions may provide useful tools to study effects of antiresorptive drugs like bisphosphonates to improve therapeutic strategies for treatment metastatic bone disease.

No significant financial relationships to disclose.

Gnao1 (G alphaO protein) is a likely genetic contributor to variation in physical dependence on opioids in mice

Chronic exposure to opioids leads to physical dependence, which manifests as the symptoms of drug withdrawal. Interindividual differences in withdrawal symptom severity are well known, and at least partially due to genetic variation. To identify genes contributing to variation in withdrawal severity, we chronically treated 30 strains of the AcB/BcA recombinant congenic mouse strain set, including their A/J and C57BL/6J (B6) progenitors, with morphine for seven days and compared jumping frequencies--a sensitive and widely used index of withdrawal magnitude--during naloxone-precipitated withdrawal (NPW). Jumping frequencies of B6 mice were more than threefold greater than values obtained in A/J mice. Visual inspection of the genomic distribution of parental haplotypes in the AcB/BcA strains identified a putative quantitative trait locus (QTL) localized to chromosome 8 (90-117 Mb), and this QTL was confirmed in a B6AF2 intercross. The most salient candidate gene within this QTL, Gnao1 (guanine nucleotide binding protein, alpha(o); G alpha(o); 96.3 Mb), was tested for functional relevance using quantitative PCR and an antisense oligodeoxynucleotide strategy. The expression of Gnao1 in the locus coeruleus was found to be upregulated in morphine-dependent B6 but not A/J mice. Antisense knockdown of Gnao1 reduced NPW jumping in B6, but not A/J, mice rendered dependent on either morphine or heroin, largely rescuing the original strain difference. These data strongly implicate the G alpha(o) protein in the locus coeruleus as contributing to interindividual variability in physical dependence on opioids in mice.

Compartment model of prenalterol

In previous pharmacokinetic studies in healthy subjects the time course of plasma concentration of prenalterol was described by a short distribution phase (alpha-phase) with a mean half-life of about 8 minutes and an elimination phase (beta-phase) with an average half- life of about two hours [1, 2]. The aim of this joint study was to check the pharmacokinetic data obtained after intravenous single dose administration with the computer program TOPFIT [3] using different compartment models and to test the predictive power of the chosen kinetic model for plasma concentration data after repetitive intravenous prenalterol dosing.

Transforming growth factor β1 and laminin-111 cooperate in the induction of interleukin-16 expression in synovial fibroblasts from patients with rheumatoid arthritis

Objectives:

In synovial tissues of patients with rheumatoid arthritis (RA), strong expression of laminins and integrins co-localises with increased expression of inflammatory cytokines. Synovial fibroblasts (SF) contribute to the pathogenesis of RA through increased expression of cytokines and chemoattractant factors, one of which is interleukin-16 (IL16). A study was undertaken to investigate the regulatory pathways of IL16 in SF from patients with RA (RA-SF) and osteoarthritis (OA-SF).

Methods:

SF were seeded in laminin-coated flasks and activated by the addition of cytokines. The expression of IL16 was investigated by quantitative RT-PCR, immunoblotting and ELISA; its biological activity was determined by a cell migration assay. Cell–matrix interactions were investigated by cell binding and attachment assays. Relevant intracellular signalling pathways were studied by immunoblotting and with pharmacological blocking reagents.

Results:

Stimulation of SF with transforming growth factor β1 (TGF-β1) and growth on laminin-111 (LM-111) significantly increased the expression of IL16. Binding to LM-111 induced significantly more IL16 mRNA in RA-SF than in OA-SF (p<0.05). The IL16 cytokine was detected in supernatants of TGF-β1-activated and in LM-111+TGF-β1-activated RA-SF (38 to 62 pg/ml), but not in supernatants of OA-SF. This IL16 regulation involved p38MAPK, ERK1/2 and SMAD2 signalling, but not NFκB.

Conclusions:

Binding of RA-SF to LM-111 in the presence of TGF-β1 triggers a significant IL16 response and thus may contribute to the infiltration of CD4+ lymphocytes into synovial tissues. This mode of IL16 induction represents a novel pathway leading to IL16 production in RA-SF but not in OA-SF, which operates independently of NFκB signalling.