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MODY is a group of genetically and clinically heterogeneous forms of diabetes characterized by autosomal dominant inheritance and is subdivided in 13 subtypes dependent on the gene involved. The subtype MODY9 is a very rare form caused by mutations in the gene encoding the PAX4 transcription factor which is engaged in differentiation of pancreatic beta-cells. PAX4 contains two DNA-binding domains—Paired and Homeo. Expression of the human PAX4 gene is tissue-specific. The alternatively spliced mRNA variants encode for protein isoforms which differ within their N- and C-terminal regions. In this study, the transcriptional activities of the human PAX4 variants, both known and new ones, were determined. The full-length PAX4 containing intact DNA-binding domains was found to have maximal activity in transient expression system of the firefly luciferase reporter gene under control of the insulin promoter in HEK293 cells. The transcriptional activity is significantly reduced in the variants lacking eight N-terminal amino acid residues and/or variants whose Homeo domain is truncated from the C-terminus. Similar data were obtained with the glucagon promoter reporter system. The aberrant PAX4 variants were shown to retain stability and nuclear localization. [ABSTRACT FROM AUTHOR]

Identification of progesterone selective agonists and antagonists that act through one of the nuclear progesterone receptor isoforms is of particular importance for the development of tissue-specific drugs in gynecology and anticancer therapy. Fourteen pregna-D′6- and pregna-D′3-pentarane progesterone derivatives with 16α,17α-cycloalkane groups and two progesterone 3-deoxyderivatives were examined for their ability to regulate transcriptional activity of human nuclear progesterone receptor isoform B (nPR-B) expressed in Saccharomyces cerevisiae yeast. Transcriptional activity of nPR-B was measured from the expression of the β-galactosidase reporter gene with a hormone-responsible element in the promoter. Among the compounds tested, two were full progesterone agonists, four were partial agonists, one compound possessed both agonistic and antagonistic activity, one compound displayed only partial antagonistic activity, and eight compounds did not show any activity. Modifications of the pentarane structure, precisely, introduction of an additional double bound in the A or B rings and/or modification at the 6th position of progesterone, lead to a switch from the complete agonistic activity to partial agonistic or mixed activities. These modifications enable progestins to act as selective modulators of progesterone receptor. Steroids with reduced A-ring and 3-ketogroups lose their ability to regulate PR-B activity. Both 3-deoxycompounds, being selective ligands of progesterone membrane receptors, do not affect PR-B activity. [ABSTRACT FROM AUTHOR]

The t(8;21)(q22;q22) rearrangement represents the most common chromosomal translocation in acute myeloid leukemia (AML). It results in a transcript encoding for the fusion protein AML1-ETO (AE) with transcription factor activity. AE is considered to be an attractive target for treating t(8;21) leukemia. However, AE expression alone is insufficient to cause transformation, and thus the potential of such therapy remains unclear. Several genes are deregulated in AML cells, including KIT that encodes a tyrosine kinase receptor. Here, we show that AML cells transduced with short hairpin RNA vector targeting AE mRNAs have a dramatic decrease in growth rate that is caused by induction of apoptosis and deregulation of the cell cycle. A reduction in KIT mRNA levels was also observed in AE-silenced cells, but silencing KIT expression reduced cell growth but did not induce apoptosis. Transcription profiling of cells that escape cell death revealed activation of a number of signaling pathways involved in cell survival and proliferation. In particular, we find that the extracellular signal-regulated kinase 2 (ERK2; also known as mitogen-activated protein kinase 1 (MAPK1)) protein could mediate activation of 23 out of 29 (79%) of these upregulated pathways and thus may be regarded as the key player in establishing the t(8;21)-positive leukemic cells resistant to AE suppression. [ABSTRACT FROM AUTHOR]

In the present study, we have applied the siRNA approach to reduce the expression of AML1-ETO and RUNX1(K83N) oncogenes, which are frequently found in leukemic cells. We have designed small hairpin RNAs (shRNA) for targeting AML1-ETO oncogene and a region close to the 5′-untranslated region of mRNA for the mutant RUNX1(K83N) oncogene and expressed the shRNAs in lentiviral vectors. We report a stable reduction in expression of oncogenes following the introduction of shRNAs into cells. [ABSTRACT FROM AUTHOR]

A method for genotyping of biological material for AB0, HLA-DQA1, and AMEL loci is described. The method utilizes allele-specific SNP typing with th e help of hydrogel biochip technology. Amplified fluorescentlylabeled fragments of genes were hybridized with SNP-specific DNA probes immobilized on a biochip. The alleles of the gene in a sample were determined according to the distribution of the fluorescent signal. The minimal amount of biological material required for the assay is 100 pg of DNA. The biochip assay was used to analyze 442 DNA specimens of the Eastern Slavic population of Russia and to determine the allelic frequencies of AB0 and HLA-DQA1 loci. The feasibility of genotyping the biological traces of investigative value, such as cigarette butts, sweat traces on paper, and swabs of the lip of the glass, was demonstrated. This assay is applicable in forensic studies. The significance of identification for the used loci is 99.6%. [ABSTRACT FROM AUTHOR]

The potential role of estrogens in regulation of metabolism in arteries of men was studied. Contents of mRNAs of sex hormone receptors, of some enzymes of their metabolism, and of some potential markers of the hormone effects were determined by real-time polymerase chain reaction in fragments of 18–54-year-old men’s large arteries with and without atherosclerotic lesions. Contents of estrogen receptor alpha (ERα) and transferrin receptor mRNAs were significantly different in undamaged fragments of the aorta and of the carotid and coronary arteries. Contents of some mRNAs in the carotid artery and aorta were found to correlate, which suggested a similarly directed regulation of their expressions. The levels of ERα and aromatase mRNAs negatively correlated with the blood plasma concentration of estradiol. Levels of steroid sulfatase and aromatase mRNAs were lower and the level of estrogen sulfotransferase mRNA was higher in blood vessel fragments with atherosclerotic lesions than in undamaged fragments. It is suggested that large arteries should be different in sensitivity to estrogens and that atherosclerotic lesions could lead to local suppression of the effect of estrogen on the cells of arteries. [ABSTRACT FROM AUTHOR]

Steroid 21-hydroxylase (CYP21A2) is a key enzyme of glucocorticoid and mineralocorticoid biosynthesis in the adrenal cortex and belongs to the family of microsomal cytochrome P450. CYP21A2 deficiency is the most common cause of human congenital adrenal hyperplasia (CAH). Human CYP21A2 and its C169R mutant, observed in a patient with classic CAH, were expressed in Sf9 and Hi5 insect cells infected with recombinant baculoviruses. Functional CYP21A2 was produced to 28% of the total microsomal protein under optimal conditions. The C169R mutation did not affect the efficiency of CYP21A2 synthesis in insect cells, nor did it prevent CYP21A2 incorporation in membranes of the endoplasmic reticulum. Functional analysis in vitro showed that the mutant enzyme almost completely lacked the catalytic activity towards two substrates, progesterone and 17-hydroxyprogesterone. [ABSTRACT FROM AUTHOR]

A new set of eukaryotic expression vectors was constructed on the basis of baculoviruses. EcoRI fragments S, J, and P with the genes for late viral proteins p35 (polyhedrin), p39, and p10 were cloned from genomic DNA of the nuclear polyhedrosis virus. The promoter regions of these genes were used to construct double-and triple-promoter expression vectors. Baculovirus vectors containing an expression cassette with the cytomegalovirus promoter and the green fluorescent protein reporter gene were designed to express the cloned genes in cultured mammalian cells. [ABSTRACT FROM AUTHOR]

The presence of prolactin receptor and peculiarities of its isoform expression in bile duct cells (cholangiocytes) differentially isolated from rat liver under different conditions were investigated in the present study. Normal cholangiocytes express prolactin receptor at relatively low level comparable to those of some prolactin-dependent tissues. Long receptor isoform is predominant in cholangiocytes but not in hepatocytes. The prolactin receptor level increases significantly under obstructive cholestasis due to evaluation of long and appearance of short isoforms. In rat cholangiocytes, unlike other tissues, the main positive regulators of prolactin receptor expression are cholestasis-induced factors instead of sex hormone and prolactin levels. Long isoform is predominant and induced primarily by cholestasis-induced factors. [ABSTRACT FROM AUTHOR]

The effects of obstructive cholestasis and sex hormones on the total content of prolactin receptor mRNA and ratio of mRNAs of its short and long isoforms have been studied in rat hepatocytes. Obstructive cholestasis caused insignificant changes in total content of prolactin receptor mRNA, but the proportion of mRNA of the long isoform increased. Comparison of prolactin receptor mRNA levels in gonadectomized and intact animals revealed opposite effects of male and female sex hormones on total mRNA, but both groups of these hormones increased the proportion of prolactin receptor short form mRNA. Changes in ratio of mRNA of receptor isoforms found in rat hepatocytes under obstructive cholestasis did not depend on levels of sex hormones. Obstructive cholestasis and sex hormones are suggested to regulate the content of long and short prolactin receptor isoforms in hepatocytes independently. [ABSTRACT FROM AUTHOR]

The human growth hormone receptor gene (GHR) is an example of complex transcription unit. The gene has a very long 5′-regulatory region and contains multiple alternative 5′-untranslated exons that are spliced to the protein-coding exons. Its transcription is driven by several promoters that reside far upstream of the coding region. The complete nucleotide sequence of the human GHR gene is now known. This paper summarizes the data on the human GHR gene structure analysis and mapping of alternative 5′-untranslated exons. The data of the promoter activity assay in the reporter gene transient expression system, as well as the results of studying the potential regulatory role of the short upstream open reading frame located in one of the 5′-untranslated exons are presented. The search for repeated elements in the human GHR gene was done, and several polymorphic markers that can be used in studies of GHR association with various diseases were characterized. [ABSTRACT FROM AUTHOR]

Using electromobility shift assay the interaction of fragments of two paralogous rat estrogen sulfotransferase (Ste) genes with proteins of nuclear extracts from male and female rat liver was studied. Male-specific DNA–protein complexes were revealed with labeled oligonucleotides corresponding to fragments +1150/+1449, +1358/+1449, +1397/+1449, and +1417/+1449 of intron 1 of the Ste1 gene. The removal of a 20 bp region corresponding to the sequence +1430/+1449, or even either 5"- or 3"-terminal 5 bp of this region abolished the selective interaction of the oligonucleotides with the malespecific protein(s). According to the results of the experiments on mutual competition of the oligonucleotides, the fragment of the Ste2 gene corresponding to the sequence +1397/+1449 of the Ste1 gene formed complexes with the same male-specific protein(s) as the fragment of the Ste1 gene did. The data suggest the mapped element to participate in gender differentiation of the expression of the Ste1 and Ste2 genes. [ABSTRACT FROM AUTHOR]

Estrogen sulfotransferases (STE) are members of a large superfamily of sulfotransferases. The expression of rat Ste genes is regulated in a tissue- and sex-specific manner. The cDNAs of two closely related rat estrogen sulfotransferases have been cloned earlier. By PCR performed on rat genomic DNA, we have amplified fragments of two estrogen sulfotransferase genes, Ste1 and Ste2, and established their exon–intron organization. By rapid amplification of the 5"-terminal cDNA sequences, the two variants of 5"-untranslated regions of both Ste1 and Ste2 mRNA were found. These variants are produced through transcription initiation from sites located in front of the alternative exons 1a and 1b and alternative splicing. Intron 1 of Ste1 gene contains the repeated element of ID family inserted after duplication of the ancestor gene. [ABSTRACT FROM AUTHOR]

The article discusses about the ratio of prolactin receptor isoforms in rat hepatocytes. Pituitary hormone prolactin (Prl) is involved in regulation of behavior and reproduction, water salt balance and immunity, growth and development, endocrine and metabolic processes [1]. It is also an important regulator of liver functions. In target cells, at least two alternative forms of the Prl receptor (PrlR) were found: the long form responsible for intracellular signal transduction, and the short one that is mainly a negative modulator of the activity of the long form.