Association of polymorphic markers of the lipid metabolism genes with diabetic polyneuropathy in type 1 diabetes mellitus

A possible association of the polymorphic markers 2/3/4 of the apolipoprotein E gene (APOE) and I /D of the apolipoprotein B gene (APOB) with diabetic polyneuropathy (DPN) was analyzed in patients with type 1 diabetes mellitus (T1DM) with (N=86) or without (N=94) clinical signs of DPN. The two groups did not differ significantly in allele and genotype frequencies of the 2/3/4 polymorphic marker of the APOE gene. Analysis of the allele and genotype frequency distributions of the I/D polymorphic marker of the APOB gene showed that risk of DPN is higher in carriers of allele I or genotype I/I (OR=1.66 and 2.01, respectively) and lower in carriers of allele D (OR=0.60). The results implicate the APOB gene, which codes for one of the major components of the lipid metabolism system, in DPN development in patients with T1DM.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 2, 2005, pp. 230–234.Original Russian Text Copyright © 2005 by Voronko, Yakunina, Strokov, Lavrova, Nosikov.     

A Kinetic Method for Tungsten Determination in Tungsten-Containing Enzymes

A highly sensitive method for tungsten detection in proteins based on the ability of this metal to catalyze the oxidation of rubeanic acid with hydrogen peroxide is described. The method allows the determination of tungsten in protein samples in the concentration range of 0.05 to 0.4 g/ml. Molybdenum, at a concentration lower than half the concentration of tungsten, as well as iron, selenium, and pterin at concentrations 2.5 times higher than that of tungsten, had no effect on tungsten determination by this method.     

Polymorphic markers Ala455Val of the THBD gene and Arg353Gln of the F7 gene and association with unfavorable outcomes of coronary atherosclerosis in patients with a history of acute ischemic heart disease

The polymorphic markers Ala455Val of the THBD gene and Arg353Gln of the F7 gene were tested for association with the frequency of unfavorable outcomes in patients with a history of acute ischemic heart disease. The study involved 1145 patients hospitalized in cardiology clinics of Moscow, St. Petersburg, Kazan, Chelyabinsk, Perm, Stavropol, and Rostov-on-Don because of acute ischemic heart disease. The patients were followed up for up to 62.5 months. None of the markers displayed a significant association with the time to an endpoint. The patients were then grouped by sex. In females, the frequency of unfavorable outcomes (fatal or nonfatal myocardial infarction and fatal or nonfatal stroke) was higher in carriers of allele Val of the Ala344Val polymorphic marker of the THBD gene and carriers of genotype Arg/Arg of the Arg353Gln polymorphic marker of the F7 gene, but the difference was not statistically significant. Such an increase in frequency was not observed in males. To study the combined effect of the polymorphic markers of the THBD and F7 genes, the course of ischemic heart disease was compared for two female subgroups. One included carriers of allele Val of the Ala344Val polymorphic marker of the THBD gene and genotype Arg/Arg of the Arg353Gln polymorphic marker of the F7 gene; the other subgroup included carriers ofgenotype Ala/Ala of the Ala455Val polymorphic marker of the THBD gene and allele Gln of the Arg353Gln polymorphic marker of the F7 gene. The frequency of unfavorable outcomes in the first subgroup was higher than in the second one. The time to an endpoin was 40.5 months (95% confidence interval (CI) 33.5-47.6) in the first subgroup and 51.6 months (95% CI 45.0-58.1) in the second subgroup (chi2 = 4.15, P = 0.042). The results made it possible to assume that the F7 and THBD genes play an important role in genetic predisposition to unfavorable outcomes in patients with a history of acute ischemic heart disease.     

Genetic factors in the development of chronic kidney disease in patients with diabetes mellitus

Patients with diabetes mellitus (DM) represent a risk group for developing chronic kidney disease (CKD), the terminal stages of which require renal replacement therapy. The study of genetic predisposition to CKD is of special significance from the perspective of the prediction and identification of risk groups at the preclinical stage. The present study is a review of the world literature on the genetics of CKD in diabetes and also includes data of our own studies.     

Cell differentiation as assayed by the topography and number of ribosomal genes

In situ hybridization, Ag-staining and electron microscopy were used to study the distribution of ribosomal genes in isolated nuclei of rat cerebellar cells and the correspondence of the ribosomal genome topography to the nucleolar structure. rDNA-DNA autoradiography revealed clusters of silver grains, as well as diffuse groups and rows. The cluster frequencies corresponded to the frequencies of nucleoli on Ag-stained slides. Competitive hybridization in situ using unlabelled rat rRNA and hybridization with a nonspacer rDNA fragment showed that the diffuse groups and rows of grains also correspond to the ribosomal genes. Spatial organization of the ribosomal genome in the Purkinje cells differs from that in the other cerebellar neurons and glial cells. A 1.5-fold redundancy of the ribosomal genes was found in some Purkinje cells, while most of these as well as microneurons contained the diploid value of the genes.     

Localization and structure of endonuclease cleavage sites involved in the processing of the rat 32S precursor to ribosomal RNA.

The initial endonuclease cleavage site in 32 S pre-rRNA (precursor to rRNA) is located within the rate rDNA sequence by S1-nuclease protection mapping of purified nucleolar 28 S rRNA and 12 S pre-rRNA. The heterogeneous 5'- and 3'-termini of these rRNA abut and map within two CTC motifs in tSi2 (internal transcribed spacer 2) located at 50-65 and 4-20 base-pairs upstream from the homogeneous 5'-end of the 28 S rRNA gene. These results show that multiple endonuclease cleavages occur at CUC sites in tSi2 to generate 28 S rRNA and 12 S pre-rRNA with heterogeneous 5'- and 3'-termini, respectively. These molecules have to be processed further to yield mature 28 S and 5.8 S rRNA. Thermal-denaturation studies revealed that the base-pairing association in the 12 S pre-rRNA:28 S rRNA complex is markedly stronger than that in the 5.8 S:28 S rRNA complex. The sequence of about one-quarter (1322 base-pairs) of the 5'-part of the rat 28 S rDNA was determined. A computer search reveals the possibility that the cleavage sites in the CUC motifs are single-stranded, flanked by strongly base-paired GC tracts, involving tSi2 and 28 S rRNA sequences. The subsequent nuclease cleavages, generating the termini of mature rRNA, seem to be directed by secondary-structure interactions between 5.8 S and 28 S rRNA segments in pre-rRNA. An analysis for base-pairing among evolutionarily conserved sequences in 32 S pre-rRNA suggests that the cleavages yielding mature 5.8 S and 28 S rRNA are directed by base-pairing between (i) the 3'-terminus of 5.8 S rRNA and the 5'-terminus of 28 S rRNA and (ii) the 5'-terminus of 5.8 S rRNA and internal sequences in domain I of 28 S rRNA. A general model for primary- and secondary-structure interactions in pre-rRNA processing is proposed, and its implications for ribosome biogenesis in eukaryotes are briefly discussed.     

Elimination of introns from the interleukin 1 beta genome by DNA amplification and expression of interleukin 1 beta in Escherichia coli]

The use of the polymerase chain reaction was proposed for intron excision from genomic genes with known nucleotide sequences. Three exons (5, 6 and 7) of genomic interleukin 1 beta gene were amplified by means of thermostable DNA polymerase TthI from Thermus thermophilus on the base of cloned in M13 phage human genomic interleukin 1 beta gene. Synthetic oligonucleotides complementary to sequences flanking exons were used as primers. The fragments obtained by exon DNA amplification were joined in the correct order due to reciprocal complementation of end sequences, that was foreseen during synthesis of oligonucleotide primers followed by amplification of the enlarged fragments. As a result the structural interleukin-1 beta gene consisting of three exons was assembled. DNA sequences carrying the ATG initiation codon and XbaI recognition site at the 5'-end, and PstI recognition site at the 3'-end (essential for insertion into the expression vector) were formed by the additional end sequences of primers. The nucleotide sequence analysis of the obtained structural gene revealed its complete identity with natural interleukin 1 beta human gene. We created the expression vector pPR114 with phage lambda promoter PR thermo-inducible in case of the cIts857 repressor presence in cells. It was used for expression of the present gene. The interleukin 1 beta synthesized in E. coli had biological activity.     

Properties of nitrate reductase from Fusarium oxysporum 11dn1 fungi grown under aerobic and anaerobic conditions

Production of nitrate reductase was studied in 15 species of microscopic fungi grown on a nitrate-containing medium. Experiments were performed with Fusarium oxysporum 11dn1, a fungus capable of producing nitrous oxide as the end product of denitrification. Moreover, a shift from aerobic to anaerobic conditions of growth was accompanied by a sharp increase in the activity of nitrate reductase. Studies of nitrate reductase from the mycelium of Fusarium oxysporum 11dn1, grown under aerobic and anaerobic conditions, showed that this enzyme belongs to molybdenum-containing nitrate reductases. The enzymes under study differed in the molecular weight, temperature optimum, and other properties. Nitrate reductase from the mycelium grown under aerobic conditions was shown to belong to the class of assimilatory enzymes. However, nitrate reductase from the mycelium grown anaerobically had a dissimilatory function. An increase in the activity of dissimilatory nitrate reductase, observed under anaerobic conditions, was associated with de novo synthesis of the enzyme.     

Polymorphic markers of the NO synthase genes and genetic predisposition to diabetic polyneuropathy in type 1 diabetes mellitus

The allele and genotype frequency distributions of polymorphic markers of the NOS1, NOS2, and NOS3 genes coding for three different NO synthases were compared for type 1 diabetes mellitus (T1DM) patients with or without diabetic polyneuropathy (DPN). The groups (total 180 patients, ethnic Russians or East Slavs from Moscow) had nonoverlapping (polar) phenotypes. Group DPN+ included patients with DPN and T1DM duration of no more than 5 years. Control group DPN- included patients without DPN and with T1DM duration of at least 10 years. No significant differences in allele and genotype frequency distributions were revealed for the polymorphic markers (CA) _n of gene NOS1 (CCTTT) _n of gene NOS2, and ecNOS4a/4b and Glu298Asp of gene NOS3, suggesting a lack of association between the polymorphic markers and DPN. In the case of the (CCTTT) _n polymorphic marker of the NOS2 gene, a tendency toward an association with DPN was observed for allele 14. Carriers of this allele have a lower risk of DPN in T1DM.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 2, 2005, pp. 224–229.Original Russian Text Copyright © 2005 by Zotova, Voronko, Bursa, Galeev, Strokov, Nosikov.