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Murphy, R., G. McConell, D. Cameron-Smith, K. Watt, L. Ackland, B. Walzel, T. Wallimann, and R. Snow. Creatine transporter protein content, localization, and gene expression in rat skeletal muscle. Am J Physiol Cell Physiol 280: C415-C422, 2001.--The present study examined the gene expression and cellular localization of the creatine transporter (CreaT) protein in rat skeletal muscle. Soleus (SOL) and red (RG) and white gastrocnemius (WG) muscles were analyzed for CreaT mRNA, CreaT protein, and total creatine (TCr) content. Cellular location of the CreaT protein was visualized with immunohistochemical analysis of muscle cross sections. TCr was higher (P [is less than or equal to] 0.05) in WG than in both RG and SOL, and was higher in RG than in SOL. Total CreaT protein content was greater (P [is less than or equal to] 0.05) in SOL and RG than in WG. Two bands (55 and 70 kDa) of the CreaT protein were found in all muscle types. Both the 55-kDa (CreaT-55) and the 70-kDa (CreaT-70) bands were present in greater (P [is less than or equal to] 0.05) amounts in SOL and RG than in WG. SOL and RG had a greater amount (P [is less than or equal to] 0.05) of CreaT-55 than CreaT-70. Immunohistochemical analysis revealed that the CreaT was mainly associated with the sarcolemmal membrane in all muscle types. CreaT mRNA expression per microgram of total RNA was similar across the three muscle types. These data indicate that rat SOL and RG have an enhanced potential to transport Cr compared with WG, despite a higher TCr in the latter. phosphocreatine; metabolism; creatine supplementation.

Editorial. Argues against the tradeoffs recently made by President Bush when he decided to postpone imposing sanctions against the Soviet Union, following its crackdown on Lithuania, and the tradeoffs made by the United States government in its negotiations with financier Michael Milken.

Editorial. Discusses the threat the author says the thaw in East-West relations presents to President George Bush and the Republican party, due to the demographics of the constituency that elected him.

Editorial. Discusses US national security policy. Launch-on-warning policy; Problems; US-Soviet Intermediate-Range Nuclear Forces treaty.

Opinion of the editor. Discusses the effect the Intermediate Range Nuclear Forces treaty (INF) is having. Commends the treaty but feels much more should be done. Author is concerned about diminished public interest and relates why the magazine was created.

Chemical inhibitors are widely used to protect metallic alloys from corrosion in aqueous environments. This Letter investigates the possible synergistic behavior of a quaternary ammonium carboxylate compound toward the development of a new system taking advantage of the surface activity of a known antimicrobial surfactant molecule, hexadecyl trimethylammonium cation, combined with a known organic corrosion inhibitor, the trans -4-hydroxy-cinnamate anion. Short-term potentiodynamic polarization (PP) studies combined with immersion in aqueous chloride solutions demonstrated the high inhibition efficiency of the combination of ions, and NMR pfg-diffusion measurements revealed micellar formation that was concentration- and pH-dependent. The NMR data suggest that speciation changes occur in the solution that correlate with enhanced corrosion inhibition efficiency at higher pH and at concentrations above the CMC of the compound. This new contribution may provide a rational molecular design toward delivering corrosion inhibitors to a metal surface through controlled speciation in solution.

The increase in the incidence of food allergy is a growing problem for the western world. This review will focus on the findings from several macromolecular epithelial transport experiments and drug permeability studies to provide a recent comprehension of food allergen intestinal epithelial cell transport and the allergen-epithelial relationship. Specifically, this review will aim to answer whether allergens can permeate the intestinal barrier directly via intestinal epithelial cells, and whether this mode of transport affects downstream immune reactions. By improving our understanding of the interactions which take place during exposure of food allergens with the intestinal epithelium, we can begin to understand whether the epithelial barrier plays a major role in the allergic sensitization process rather than simply restricting the entry of allergens to the underlying lamina propria.

Peritoneal dissemination of ovarian carcinoma is mediated by epithelial-mesenchymal interconversions leading to the disruption of cell-cell contact and modulation of cell-extracellular matrix (ECM) interactions. The present study was designed to evaluate the effects of epidermal growth factor (EGF) as a modulator of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) signalling and changes in integrin expression during the process similar to EMT. A fibroblastic morphology with reduced intercellular cell contacts and increased cell motility was observed in ovarian cancer cell lines in response to EGF and was concomitant with the up regulation of EMT-associated N-cadherin and vimentin expression. These changes were accompanied by an increase in alpha2, alpha6 and beta1 integrin subunits and activation of JAK2 and STAT3 signalling which was suppressed by a specific JAK2 inhibitor. Consistent with the suppression of STAT3 activity, N-cadherin and vimentin expression were abrogated and was coherent with the loss of cell motility and the expression of alpha6 and beta1 integrin subunits. Neutralizing antibodies against alpha6 and beta1 subunits inhibited cancer cell migration. A strong correlation between the expression of N-cadherin, vimentin and JAK2/STAT3 levels were detected in high-grade ovarian tumors and was consistent with the previously reported enhanced expression of alpha6 integrin subunit in advanced tumors [Ahmed N, Riley C, Oliva K, Rice G, Quinn M. Ascites induces modulation of alpha6beta1 integrin and urokinase plasminogen activator receptor expression and associated functions in ovarian carcinoma. British Journal of Cancer 2005;92:1475-85]. Our data incorporating the clinical samples and the cancer cell lines is the first to demonstrate that JAK2/STAT3 pathway may be one of the downstream events in EMT-like process and alpha6beta1 integrin-mediated signalling in ovarian carcinomas.

Epidermal growth factor receptor (EGFR) is overexpressed in ovarian carcinomas, with direct or indirect activation of EGFR able to trigger tumour growth. We demonstrate significant activation of both signal transducer and activator of transcription (STAT)3 and its upstream activator Janus kinase (JAK)2, in high-grade ovarian carcinomas compared with normal ovaries and benign tumours. The association between STAT3 activation and migratory phenotype of ovarian cancer cells was investigated by EGF-induced epithelial-mesenchymal transition (EMT) in OVCA 433 and SKOV3 ovarian cancer cell lines. Ligand activation of EGFR induced a fibroblast-like morphology and migratory phenotype, consistent with the upregulation of mesenchyme-associated N-cadherin, vimentin and nuclear translocation of beta-catenin. This occurred concomitantly with activation of the downstream JAK2/STAT3 pathway. Both cell lines expressed interleukin-6 receptor (IL-6R), and treatment with EGF within 1 h resulted in a several-fold enhancement of mRNA expression of IL-6. Consistent with that, EGF treatment of both OVCA 433 and SKOV3 cell lines resulted in enhanced IL-6 production in the serum-free medium. Exogenous addition of IL-6 to OVCA 433 cells stimulated STAT3 activation and enhanced migration. Blocking antibodies against IL-6R inhibited IL-6 production and EGF- and IL-6-induced migration. Specific inhibition of STAT3 activation by JAK2-specific inhibitor AG490 blocked STAT3 phosphorylation, cell motility, induction of N-cadherin and vimentin expression and IL6 production. These data suggest that the activated status of STAT3 in high-grade ovarian carcinomas may occur directly through activation of EGFR or IL-6R or indirectly through induction of IL-6R signalling. Such activation of STAT3 suggests a rationale for a combination of anti-STAT3 and EGFR/IL-6R therapy to suppress the peritoneal spread of ovarian cancer.

Background/aims: The copper transporting ATPases, Menkes (ATP7A; MNK) and Wilson (ATP7B; WND) are essential for normal copper transport in the human body. The placenta is the key organ in copper supply to the fetus during pregnancy and it is one of the few organs in the body to express both of the ATPases. The placenta therefore provides a unique opportunity to elucidate the specific roles of these transporters within the one cell type., Methods/results: Using polarized placental Jeg-3 cells, siRNA technology and radio-labelled 64Cu transport assays, MNK and WND were shown to have distinct roles in the vectorial transport of copper. MNK transported copper from the cell via the basolateral membrane and in contrast, WND transported copper from the apical membrane. Inactivation of MNK resulted in decreased activity of two important cuproenzymes, lysyl oxidase and Cu/Zn-superoxide dismutase., Conclusions: Overall, these results provide definitive evidence for distinct roles of MNK and WND in the human placenta, and are consistent with a role for MNK in the transport of copper into the fetal circulation, and through delivery of copper to placental cuproenzymes, whilst WND contributes to the maintenance of placental copper homeostasis by transporting copper to the maternal circulation.

Cultured cells of a variety of different types from human Menkes' syndrome patients and brindled mouse mutants exhibit similarly altered responses to changes in extracellular copper concentration. This suggests that the mutations in the mouse and human are very similar and that mutant gene expression is occurring in many different tissues. Intracellular copper levels are markedly elevated in mutant cells in normal medium and in medium containing a hundred-fold higher copper. Some cell lines from heterozygotes possess elevated copper levels. Elevated extracellular copper and zinc are significantly more toxic to mutant cells. Mutant cells exhibit normal rates of uptake of copper-64 over a 10-min period but abnormally high accumulation over 24 hr and low rates of efflux. Menkes' fibroblasts become saturated with copper-64 at lower extracellular concentrations than for normal fibroblasts. These data support the idea of enhanced intracellular binding in mutant cells.