Access of non-residents to transplantation of deceased donor organs: practices and strategies in the European setting

The access of non-resident patients to the deceased donor waiting list (DDWL) poses different challenges. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) has studied this phenomenon in the European setting. A questionnaire was circulated among the Council of Europe member states to inquire about the criteria applied for non-residents to access their DDWL. Information was compiled from 28 countries. Less than 1% of recipients of deceased donor organs were non-residents. Two countries never allow non-residents to access the DDWL, four allow access without restrictions and 22 only under specific conditions. Of those, most give access to non-resident patients already in their jurisdictions who are in a situation of vulnerability (urgent life-threatening conditions). In addition, patients may be given access: (i) after assessment by a specific committee (four countries); (ii) within the framework of official cooperation agreements (15 countries); and (iii) after patients have officially lived in the country for a minimum length of time (eight countries). The ethical and legal implications of these policies are discussed. Countries should collect accurate information about residency status of waitlisted patients. Transparent criteria for the access of non-residents to DDWL should be clearly defined at national level.

Cooperative role of the glucagon-like peptide-1 receptor and β3-adrenergic-mediated signalling on fat mass reduction through the downregulation of PKA/AKT/AMPK signalling in the adipose tissue and muscle of rats

AIM

To explore the cooperation of GLP-1 receptor and β3-adrenergic receptor (β3-AR)-mediated signalling in the control of fat mass/feeding behaviour by studying the effects of a combined therapy composed of the GLP-1R agonist liraglutide and the β3-AR agonist CL316243.

METHODS

The study included the analysis of key mechanisms regulating lipid/cholesterol metabolism, and thermogenesis in brown (BAT) and epididymal white (eWAT) adipose tissues, abdominal muscle and liver of male rats.

RESULTS

CL316243 (1 mg kg^-1 ) and liraglutide (100 μg kg^-1 ) co-administration over 6 days potentiated an overall negative energy balance (reduction in food intake, body weight gain, fat/non-fat mass ratio, liver fat content, and circulating levels of non-essential fatty acids, triglycerides, very low-density lipoprotein-cholesterol and leptin). These effects were accompanied by increased plasma levels of insulin and IL6. We also observed increased gene expression of uncoupling proteins regulating thermogenesis in BAT/eWAT (Ucp1) and muscle (Ucp2/3). Expression of transcription factor and enzymes involved either in de novo lipogenesis (Chrebp, Acaca, Fasn, Scd1, Insig1, Srebp1) or in fatty acid β-oxidation (Cpt1b) was enhanced in eWAT and/or muscle but decreased in BAT. Pparα and Pparγ, essentials in lipid flux/storage, were decreased in BAT/eWAT but increased in the muscle and liver. Cholesterol synthesis regulators (Insig2, Srebp2, Hmgcr) were particularly over-expressed in muscle. These GLP-1R/β3-AR-induced metabolic effects were associated with the downregulation of cAMP-dependent signalling pathways (PKA/AKT/AMPK).

CONCLUSION

Combined activation of GLP-1 and β3-ARs potentiate changes in peripheral pathways regulating lipid/cholesterol metabolism in a tissue-specific manner that favours a switch in energy availability/expenditure and may be useful for obesity treatment.

Single administration of recombinant IL-6 restores the gene expression of lipogenic enzymes in liver of fasting IL-6-deficient mice

BACKGROUND AND PURPOSE

Lipogenesis is intimately controlled by hormones and cytokines as well as nutritional conditions. IL-6 participates in the regulation of fatty acid metabolism in the liver. We investigated the role of IL-6 in mediating fasting/re-feeding changes in the expression of hepatic lipogenic enzymes.

EXPERIMENTAL APPROACH

Gene and protein expression of lipogenic enzymes were examined in livers of wild-type (WT) and IL-6-deficient (IL-6(-/-) ) mice during fasting and re-feeding conditions. Effects of exogenous IL-6 administration on gene expression of these enzymes were evaluated in vivo. The involvement of STAT3 in mediating these IL-6 responses was investigated by using siRNA in human HepG2 cells.

KEY RESULTS

During feeding, the up-regulation in the hepatic expression of lipogenic genes presented similar time kinetics in WT and IL-6(-/-) mice. During fasting, expression of lipogenic genes decreased gradually over time in both strains, although the initial drop was more marked in IL-6(-/-) mice. Protein levels of hepatic lipogenic enzymes were lower in IL-6(-/-) than in WT mice at the end of the fasting period. In WT, circulating IL-6 levels paralleled gene expression of hepatic lipogenic enzymes. IL-6 administration in vivo and in vitro showed that IL-6-mediated signalling was associated with the up-regulation of hepatic lipogenic enzyme genes. Moreover, silencing STAT3 in HepG2 cells attenuated IL-6 mediated up-regulation of lipogenic gene transcription levels.

CONCLUSIONS AND IMPLICATIONS

IL-6 sustains levels of hepatic lipogenic enzymes during fasting through activation of STAT3. Our findings indicate that clinical use of STAT3-associated signalling cytokines, particularly against steatosis, should be undertaken with caution.

Decontamination of prions in a plasma product manufacturing environment

BACKGROUND

The high resistance of prions to inactivating treatments requires the proper management of decontaminating procedures of equipment in contact with materials of human or animal origin destined for medical purposes. Sodium hydroxide (NaOH) is widely used today for this purpose as it inactivates a wide variety of pathogens including prions.

STUDY DESIGN AND METHODS

Several NaOH treatments were tested on prions bound to either stainless steel or chromatographic resins in industrial conditions with multiple prion strains.

RESULTS

Data show a strong correlation between inactivation results obtained by immunochemical detection of the prion protein and those obtained with infectivity assays and establish effective inactivation treatments for prions bound to stainless steel or chromatographic resins (ion exchange and affinity), including treatments with lower NaOH concentrations. Furthermore, no obvious strain-specific behavior difference was observed between experimental models.

CONCLUSION

The results generated by these investigations show that industrial NaOH decontamination regimens (in combination with the NaCl elution in the case of the chromatography process) attain substantial prion inactivation and/or removal between batches, thus providing added assurance to the biologic safety of the final plasma-derived medicinal products.

Manufacture of plasma-derived products in France and measures to prevent the risk of vCJD transmission: Precautionary measures and efficacy of manufacturing processes in prion removal

The emergence of the variant Creutzfeldt-Jakob disease in the mid 1990s soon raised concerns about its possible transmission through the use of blood and plasma-derived medicinal products. A risk analysis approach was initiated by health authorities, based on updated scientific knowledge and precautionary measures were implemented in France and other countries for the management of this new possible risk. Assessment of the vCJD risk is based on epidemiology and estimates of the number of potential cases in the future, on blood infectivity data from models of transmissible spongiform encephalopathies and on data from studies of the capacity of manufacturing processes to remove the agent, should it be present in the plasma of infected donors. The transmission of vCJD by non leukocyte-depleted labile blood components has recently been confirmed. There have been no reports of cases associated with the use of plasma-derived products and the scientific data, and risk analyses for those plasma products, which are of the greatest therapeutic interest, support their safety with respect to this transmission risk. The precautionary measures applied in France and the data contributing to the risk assessment of plasma products are reviewed and updated in the present paper. The uncertainties, which remain, are also addressed and discussed, as well as the ongoing research and developments in this area.

Prion protein prevents human breast carcinoma cell line from tumor necrosis factor alpha-induced cell death

To define genetic determinants of tumor cell resistance to the cytotoxic action of tumor necrosis factor alpha (TNF), we have applied cDNA microarrays to a human breast carcinoma TNF-sensitive MCF7 cell line and its established TNF-resistant clone. Of a total of 5760 samples of cDNA examined, 3.6% were found to be differentially expressed in TNF-resistant 1001 cells as compared with TNF-sensitive MCF7 cells. On the basis of available literature data, the striking finding is the association of some differentially expressed genes involved in the phosphatidylinositol-3-kinase/Akt signaling pathway. More notably, we found that the PRNP gene coding for the cellular prion protein (PrP(c)), was 17-fold overexpressed in the 1001 cell line as compared with the MCF7 cell line. This differential expression was confirmed at the cell surface by immunostaining that indicated that PrP(c) is overexpressed at both mRNA and protein levels in the TNF-resistant derivative. Using recombinant adenoviruses expressing the human PrP(c,) our data demonstrate that PrP(c) overexpression converted TNF-sensitive MCF7 cells into TNF-resistant cells, at least in part, by a mechanism involving alteration of cytochrome c release from mitochondria and nuclear condensation.

Nervous and nonnervous cell transduction by recombinant adenoviruses that inducibly express the human PrP

The study of the prion protein (PrP) physiological functions or its specific role in transmissible spongiform encephalopathies (TSE) requires new tools, particularly those able to induce PrP overexpression in a large range of cells, in vivo as well as in vitro. Here we describe the construction of two recombinant adenoviruses encoding the human PrP either with a valine at position 129 (AdTRVal) or a methionine (AdTRMet). Both genes were put under the control of the tetracycline-responsive promoter, allowing tight regulation of PrP expression. AdTRVal and AdTRMet induced high expression of the human PrP in CHO-KI cells and in organotypic brain slices in culture. The proteins expressed from these viruses exhibited a glycosylphosphatidyl inositol (GPI) anchor, proper glycosylation and sensitivity to proteinase K digestion. AdTRVal and AdTRMet will allow future studies on the human PrP and on the role of the codon 129 polyphormism in human TSE.