Constitutive and IL 1-regulated murine complement gene expression is strain and tissue specific

To study the molecular mechanisms accounting for strain- and tissue-specific variations in the production of complement proteins, complementary DNA probes were used to assess qualitative and quantitative differences in specific mRNA content of complement proteins C2, factor B, and C3 in extracts of tissues (liver, lung, spleen, kidney, and peritoneal macrophages) isolated from various mouse strains. Northern blot analysis of total hepatic RNA revealed differences in C2, factor B, and C3 mRNA levels in strains that share B10 background but differ in the H-2 region (e.g., H-2k, H-2u, H-2d, H-2f). In each instance, hepatic mRNA specific for the individual gene product corresponded in amount to the serum levels. By contrast, specific mRNA content of C2 and factor B in macrophages differed significantly from those observed in liver for each strain. Modulation of C2, factor B, and C3 expression was studied after in vivo administration of recombinant IL 1 or endotoxin to H-2k (B10.AKM) or H-2u (B10.PL) strain mice. As assessed by Northern blot analysis, neither endotoxin nor IL 1 affected liver C2-specific mRNA but increased specific C2 mRNA levels in kidney and lung. For both strains, IL 1 increased specific factor B mRNA in all tissues examined except for the H-2u strain liver factor B mRNA content, which was not affected by IL 1, whereas that of H-2k mice was increased. The lack of factor B modulation by IL 1 in the H-2u lines was specific to that gene and not a reflection of a generalized IL 1 unresponsiveness. Differences in tissue and strain specific constitutive and IL 1-regulated expression of the C3 gene were also observed in the H-2u and H-2k strains.     

The aflatoxin-detoxifizyme specific expression in the parotid gland of transgenic pigs

Producing aflatoxin-detoxifizyme (ADTZ) in pigs to control the AFT contamination of pig feed is a new research strategy by transgenic technology. In this study, transgenic pigs specifically expressing ADTZ gene in the parotid gland were successfully produced by somatic cell nuclear transfer technology. The ADTZ activity in saliva of 6 transgenic pigs was found to be 7.11 ± 2.63 U/mL. The feeding trial with aflatoxin (AFT) results showed that there were significant difference about the serum biochemical index such as total protein (TP), albumin (ALB), globulin (GLB) contents and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity and AFT residues in serum and liver between the pigs in the test treatment (transgenic pigs) producing ADTZ and those in the positive control (P < 0.05). In order to investigate the inheritance of the transgene, 11 G1 transgenic pigs were successfully obtained. The ADTZ activity in saliva of 11 G1 transgenic pigs was found to be 5.82 ± 1.53 U/mL. The feeding trial with AFT results showed that the serum biochemical index containing TP, ALB and GLB contents and ALT and AST activity and AFB1 residues in serum and liver of the pigs in the test treatment (transgenic pigs) producing ADTZ were significantly different than those in the positive control (P < 0.05). The above results demonstrated that ADTZ produced in transgenic pigs could improve the effect of the AFT contamination of feed on pigs.     

On the mechanism of ribonuclease secretion in the murine exocrine pancreas

Summary In the rat pancreas, normal diurnal and pilocarpine-induced variations in the protein, ribonuclease (RNase), and water content were studied. The results show a considerable variation in the dirunal content of RNase, whereas the protein and water concentrations remained constant. Furthermore, the experiments provide evidence that RNase is secreted by means of a mechanism partly independent of other proteins and that every zymogen granule does not contain the same amount of the enzyme. The earlier presumption that there are at least two intracellular storage forms of the enzyme is confirmed and the intracellular variability in the capacity to attract anti-RNase antibodies is explained.     

The murine interleukin 1 beta gene: structure and evolution.

We have isolated from a genomic library a murine recombinant clone containing the gene coding for interleukin-1 beta m-RNA. A 7000 b.p. DNA fragment has been sequenced. Sequences homologous with human IL-1 beta cDNA have been found distributed within 7 exons. The translation of these sequences allows the prediction of a protein 269 aminoacids long. Hybridization of P388D1 RNA from cells stimulated with phorbol myristic acetate with a genomic DNA probe shows the existence of a 1.6 Kb murine IL-1 beta mRNA which is absent in the unstimulated cells. The comparative analysis between the murine IL-1 beta and the human IL-1 alpha genes shows extreme conservation of the aminoacids at the exon junctions. This observation together with the similarity in number and size of the exons suggests that these genes have diverged from a common ancestor.     

Embryogenesis of the murine endocrine pancreas; early expression of pancreatic polypeptide gene.

By immunofluorescence on cytospin preparations and on semithin sections of mouse pancreatic buds, we have found glucagon and pancreatic polypeptide (PP)-containing cells at embryonal day 10.5 (E 10.5) in dorsal buds and at E 11.5 in ventral buds. Insulin-containing cells appear in dorsal buds at E 11.5, and one to two days later in ventral buds. Somatostatin-containing cells are detectable from E 13.5 in both dorsal and ventral buds. A quantitative analysis shows that up to E 15.5, PP-containing cells are relatively abundant in both buds. By PCR amplification of oligo(dT)-primed cDNAs prepared from total pancreatic RNA, we also detect PP mRNA from E 10.5 onwards, thus confirming the early expression of the PP gene in the developing mouse pancreas. Analysis of endocrine cells in situ suggests three major patterns of cell distribution in embryonic pancreas. First, individual hormone-containing cells are located within the epithelium of pancreatic ducts. In both dorsal and ventral buds, the majority of these endocrine cells contain PP, but many also contain glucagon, insulin or somatostatin. Secondly, clusters of endocrine cells are found in the pancreatic interstitium. Many of these cells contain both glucagon and PP which, by immunogold labelling of consecutive thin sections, can be shown to co-exist within individual secretory granules. Finally, starting on E 18.5, typical islets are formed with centrally located B cells and with the adult 'one cell-one hormone' phenotype. These results suggest an intriguing ontogenic relationship between A- and PP-cells, and also indicate that PP-containing cells may occupy a hitherto unexpected place in the lineage of endocrine islet cells.     

Molecular cloning of four novel murine ribonuclease genes: unusual expansion within the ribonuclease A gene family.

We have characterized four novel murine ribonuclease genes that, together with the murine eosinophil-associated ribonucleases 1 and 2, form a distinct and unusual cluster within the RNase A gene superfamily. Three of these genes (mR-3, mR-4, mR-5) include complete open reading frames, encoding ribonucleases with eight cysteines and appropriately spaced histidines (His11 and His124) and lysine (Lys35) that are characteristic of this enlarging protein family; the fourth sequence encodes a non-functional pseudogene (mR-6P). Although the amino acid sequence similarities among these murine ribonucleases varies from 60 to 94%, they form a unique cluster, as each sequence is found to be more closely related to another of this group than to either murine angiogenin or to murine pancreatic ribonuclease. Interestingly, the relationship between the six genes in this 'mR cluster' and the defined lineages of the RNase A gene family could not be determined by amino acid sequence homology, suggesting the possibility that there are one or more additional ribonuclease lineages that have yet to be defined. Although the nature of the evolutionary constraints promoting this unusual expansion and diversification remain unclear, the implications with respect to function are intriguing.     

Isolation and expression of cDNA encoding the murine homologues of CD1.

The cDNA encoding the murine CD1.1 and CD1.2 gene products were isolated and their complete nucleotide sequence was determined. The nucleotide sequence and genomic organization of these molecules were similar to human CD1. The sequences in the alpha 1- alpha 3 domains were almost identical to previously reported genomic clones from a different strain, indicating limited polymorphism among these molecules. The predicted amino acid sequence in the transmembrane region and in the cytoplasmic tail was identical for CD1.1 and CD1.2. The two cDNA were also homologous in the 5' untranslated region but diverged in the 3' untranslated region. In contrast to human CD1, which is expressed at high levels in thymus, the expression of CD1 message in murine thymus was not detected in either thymus leukemia Ag positive or negative strains. Cell expressing murine CD1.1 were generated after transfer of the CD1.1 cDNA into murine cell lines. Immunoprecipitation with a rat anti-mouse CD1.1 mAb showed that the transfected CD1 was expressed on the cell surface as a beta 2-microglobulin-linked heterodimer. These results demonstrate that the murine and human CD1 genes, although encoding homologous transmembrane glycoproteins, are expressed in distinct tissues and may serve different functions.     

Genomic structure, tissue expression and chromosomal location of the LIM-only gene, SLIM1.

Human SLIM1 is a recently described gene of the LIM-only class encoding four and a half tandemly repeated LIM domains. LIM domains are double zinc finger structures which provide an interface for protein/protein interactions and are conserved in a variety of nuclear and cytoplasmic factors important in cell fate determination and cellular regulation. Here we report the structural organization, expression pattern and chromosomal localization of the human SLIM1 gene. SLIM1 was found to contain at least five exons with all four introns disrupting the coding region at a similar position relative to the respective complete LIM domains. Northern blot analysis confirmed strikingly high expression of SLIM1 in skeletal muscle and heart, with much lower expression observed in several other tissues including colon, small intestine and prostate. The SLIM1 gene was assigned to human chromosome Xq26 using fluorescence in situ hybridization.     

Premature induction of amylase in pancreas and parotid gland of growing rats by dexamethasone.

Studies were made on changes in the contents of alpha-amylase (EC 3.2.1.1) in the pancreas and parotid gland of rats during postnatal development, on the premature induction of this enzyme by hormones and on the existence of specific glucocorticoid receptors in these tissues. The amylase content in the pancreas increased from the 9th day after birth and reached the adult level on the 28th day, its content in the parotid gland increased rapidly from the 16th to the 28th day after birth and then rose more gradually to the adult level. Injection of dexamethasone into rats 6--8 days after birth induced increase in the amylase of the pancreas but not the parotid gland. However, injection of dexamethasone into weanling rats 21--23 days after birth resulted in precocious induction of amylase in both tissues. Specific glucocorticoid receptors were detectable in the parotid gland of rats from 6 days after birth but were almost undetectable in the pancreas until adolescence.     

Isolation, tissue distribution and prokaryotic expression of a novel human X-linked gene LHFPL1.

We report here the cloning and characterization of a novel human lipoma HMGIC fusion partner-like 1 (LHFPL1) gene, isolated from human brain cDNA library, and mapped to Xq23 by browsing the UCSC genomic database. LHFPL1 contains an ORF with length of 660bp, encoding a protein with a signal peptide sequence and three transmembrane regions, and its predicted molecular weight is 23.7kDa which coincides with the result of prokaryotic expression. LHFPL1 protein is postulated to be localized at endoplasmic reticulum. RT-PCR amplification in seventen human tissues revealed that LHFPL1 is expressed widely in all tissues, especially highly in lung, thymus, skeleton muscle, colon and ovary. In addition, it was demonstrated that LHFPL1 is also transcribed in six liver tumor cell lines.