Use of messenger RNA differential display to identify interleukin-11-responsive genes in human umbilical cord blood mononuclear cells: IL-11 upregulates the expression of the hMAL gene.

Human umbilical cord blood (HUCB) mononuclear cells represent a source of hematopoietic stem and progenitor cells, including cells responsive to interleukin-11 (IL-11). To investigate the molecular mechanisms associated with IL-11 action, we have used HUCB mononuclear cells as a model system to identify genes that are transcriptional targets of IL-11. Using the technique of messenger RNA differential display, we have identified 17 candidate cDNA differentially expressed in mononuclear cells incubated without and with IL-11. Fifteen of these cDNA were recovered, and 11 were sequenced. DNA sequence analysis has identified one of these cDNA as being the human MAL gene, originally identified as a marker for intermediate stages of T cell differentiation. Northern analysis using a MAL-specific probe confirms the upregulation of MAL by IL-11 in HUCB cells.

Creating an effective marketing team. Six leading healthcare marketers offer their perspectives. Interview by Richard D. Stier.

Richard D. Stier, senior vice president and chief marketing officer, Adventist Health System, Shawnee Mission, Kansas, asked six top healthcare marketers to assume they had just been appointed vice president and chief marketing officer for a medium-sized, 300-bed, not-for-profit community hospital. Their mission: Create the most effective, powerhouse marketing team in the country.

Synthesis of low molecular weight heat shock peptides stimulated by ecdysterone in a cultured Drosophila cell line.

Treatment of Schneider's line 3 Drosophila cells with the steroid hormone ecdysterone rapidly stimulated the synthesis and accumulation of the polypeptide previously designated p7 [Berger, E. M., Ireland, R. C. & Wyss, C. (1980) Somatic Cell Genet. 6, 119-129]. In this report, p7 is identified as the 23,000-dalton heat shock polypeptide (hsp23). In addition to hsp23, the synthesis of the low molecular weight heat shock polypeptides hsp22, hsp26, and hsp27 was also stimulated by ecdysterone, although to different extents. Hybridization of a nick-translated genomic clone containing the hsp23 gene to a total RNA blot showed that ecdysterone stimulation of hsp23 synthesis was the result of an increase in the hsp23 RNA content of S3 cells. We detected no effect of the hormone on the synthesis of heat shock polypeptides hsp68, hsp70, and hsp83.

The DNA binding of purified Ah receptor heterodimer is regulated by redox conditions.

The Ah receptor from rat liver has been purified, using a specific oligonucleotide affinity column, in order to characterize the components of the receptor and to investigate features that modulate its DNA-binding activity. The purified DNA-binding form of rat Ah receptor contains three major components, with estimated molecular masses of 108, 98, and 96 kDa. Antibodies to two peptides from the mouse Ah receptor bind the 108-kDa protein, but not the 98-kDa protein, and bind weakly at the position of the 96-kDa protein. The sequences of four peptides from samples containing both the 96- and 98-kDa proteins are all highly similar to segments of the human Ah receptor nuclear translocator (Arnt) protein. Antibodies to a peptide from the human Arnt protein bind the 96- and 98-kDa proteins, but not the 108-kDa protein. These data show that the Ah receptor itself and two forms of the Arnt protein are the major components of the purified DNA-binding form of receptor. In gel shift assays the purified receptor forms two specifically bound complexes with a xenobiotic responsive element (XRE), which may correspond to Ah receptor heterodimers with either of the two forms of Arnt protein. The DNA binding of the purified heterodimer is substantially decreased under oxidizing conditions. Oxidation inhibits receptor DNA binding without greatly altering the size of the purified heterodimer. This sediments at 5.9S in its reduced form and at 6.5S in its oxidized form. Dithiothreitol restores the XRE binding of oxidized receptor, with similar effects on both of the receptor-XRE complexes. In the presence of nuclear extract, reduced thioredoxin also restores the XRE binding of oxidized receptor.

Tubulin content and synthesis in differentiating Drosophila cells in culture.

Drosophila Kc cells exposed to physiological doses of the moulting hormone, beta-ecdysone, elongate, become motile, and subsequently aggregate. This pattern of morphogenesis was found to require the assembly of a microtubular cytoskeleton. Tubulin content was significantly increased in hormone-treated cells when compared to controls, as measured by a 3H-colchicine-binding assay. However, determinations of rates of tubulin synthesis and breakdown revealed no difference between control and hormone-treated cells for either parameter. When tubulin content was assayed by methods that do not depend on colchicine-binding activity, no difference between hormone-treated and control cells was observed. These results are discussed in terms of a model in which beta-ecdysone affects the distribution of tubulin in "assembly-active" and "assembly-inactive" pools.

Primary structure of the mouse glycerol-3-phosphate dehydrogenase gene.

We have isolated from a BALB/c genomic library a 17.5-kilobase (kb) DNA fragment containing the entire mouse sn-glycerol-3-phosphate dehydrogenase (glycerol-P dehydrogenase) gene, and a substantial portion of the flanking regions. The DNA sequence of 10.8 kb of this fragment was determined. Using this information, together with the DNA sequence of several partial glycerol-P dehydrogenase cDNA clones and the rabbit glycerol-P dehydrogenase amino acid sequence, we determined the structural organization of the mouse glycerol-P dehydrogenase gene. The gene is 7.3 kb long and contains 8 exons. Transcription starts 19 base pairs 5' of the ATG initiation codon. Sequence analysis and S1 nuclease mapping indicated that the 8th exon contains coding sequences for the last 31 amino acids of glycerol-P-dehydrogenase, followed by 1.7 kb of 3' untranslated mRNA sequence. The mouse glycerol-P dehydrogenase amino acid sequence determined from the DNA sequence is 90% homologous with the rabbit enzyme. An examination of the exon/intron organization of the mouse glycerol-P dehydrogenase gene shows that intron 3 precisely separates the NAD-binding and the catalytic domains and intron 2 separates the adenine- and nicotinamide-binding regions.