Tissue distribution of sialic acid-linked influenza virus receptors in beagle dogs.

Reports of influenza A virus infections in dogs has received considerable attention from veterinarians, virologists, and epidemiologists. Interaction between influenza viral hemagglutinin and cell oligosaccharides containing sialic acid residues results in infection. Sialic acids have an α-2,3-linkage to the penultimate galactose in the avian influenza virus receptor and an α-2,6-linkage in the human receptor. To date, there are no detailed data on the tissue distribution or histological features of either type of sialic acid-linked influenza virus receptors in beagle dogs, which are common laboratory animals and pets. We conducted the current study to visualize the in situ tissue distribution of both sialic acid-linked influenza virus receptors in various organs of beagle dogs using Maackia amurensis lectin II and Sambucus nigra agglutinin. Both α-2,3- and α-2,6-sialic acid-linked receptors were detected in the endothelial cells of the respiratory tract and other organs. Endothelial cells of most gastrointestinal organs were negative for α-2,3-sialic acid-linked receptors in the dogs. Our results suggested that these canine organs may be affected by influenza virus infection. The findings from our study will also help evaluate the occurrence and development of influenza virus infections in dogs.

Na+/H+ exchanger 1 gene expression in tissues of yellow chicken.

The Na(+)/H(+) exchanger 1 (NHE1) transmembrane protein regulates intracellular pH, cell survival, cell growth, cell differentiation and plays a critical role in the progression of some diseases, including the pathogenesis of J avian leukosis. The chicken is an ideal model to study the function of NHE1 because it has developed highly efficient Na(+)-absorptive mechanisms in its small and large intestines. To date, there has been no detailed expression analysis to determine NHE1 expression in various tissues of the chicken. We determined the mRNA and protein expression levels of avian NHE1 by real-time quantitative PCR and immunohistochemical analysis. NHE1 mRNA was detected in all chicken tissues examined. Protein expression levels varied widely among tissues and did not always correlate with mRNA expression. Determining the mRNA and protein of NHE1 expression patterns in chicken should help to delineate the NHE1 role in different tissues and its contribution to physiological and pathological processes. These data provide the basis for examining the distinct function of chicken NHE1 compared with its mammalian counterpart.