The role of functional single nucleotide polymorphisms of the human glucocorticoid receptor gene NR3C1 in Polish patients with bronchial asthma

N363S and ER22/23EK polymorphisms observed within glucocorticoid receptor gene (NR3C1) may play an important role in the development of bronchial asthma. NR3C1 gene is associated with an altered sensitivity to GCs. The aim of the research project was to study the correlation between this NR3C1 gene polymorphisms and occurrence of asthma in the population of Polish asthmatics. Peripheral blood was obtained from 207 healthy volunteers and 221 asthma patients. Genotyping was carried out with PCR-RFLP method. In the groups of patients with uncontrolled moderate asthma and uncontrolled severe disease, the genotype distribution for the investigated polymorphisms was as follows: N363S-AA, AG, GG occurring with 0.881/0.073/0.046 frequency and ER22/23EK-GG, GA, AA occurring with 0.963/0.037/0.000 frequency. Chi-square analysis revealed a significantly different (P < 0.05) distribution between cases and controls for the N363S polymorphisms. The N363S polymorphism of NR3C1 gene is significantly associated with bronchial asthma, susceptibility to the development of moderate to severe form of uncontrolled bronchial asthma.     

Mobilizable narrow host range plasmids as natural suicide vectors enabling horizontal gene transfer among distantly related bacterial species

Klebsiella pneumoniae 287-w carries three small narrow host range (NHR) plasmids (pIGMS31, pIGMS32, and pIGRK), which could be maintained in several closely related species of Gammaproteobacteria, but not in Alphaproteobacteria. The plasmids contain different mobilization systems (MOB), whose activity in Escherichia coli was demonstrated in the presence of the helper transfer system originating from plasmid RK2. The MOBs of pIGMS31 and pIGMS32 are highly conserved in many bacterial plasmids (members of the MOB family), while the predicted MOB of pIGRK has a unique structure, encoding a protein similar to phage-related integrases. The MOBs of pIGMS31 and pIGMS32 enabled the transfer of heterologous replicons from E. coli into both gammaproteobacterial and alphaproteobacterial hosts, which suggests that these NHR plasmids contain broad host range MOB systems. Such plasmids therefore represent efficient carrier molecules, which may act as natural suicide vectors promoting the spread of diverse genetic information (including other types of mobile elements, e.g. resistance transposons) among evolutionarily distinct bacterial species. Thus, mobilizable NHR plasmids may play a much more important role in horizontal gene transfer than previously thought.     

Contribution of STAT4 gene single-nucleotide polymorphism to systemic lupus erythematosus in the Polish population

The STAT4 has been found to be a susceptible gene in the development of systemic lupus erythematosus (SLE) in various populations. There are evident population differences in the context of clinical manifestations of SLE, therefore we investigated the prevalence of the STAT4 G > C (rs7582694) polymorphism in patients with SLE (n = 253) and controls (n = 521) in a sample of the Polish population. We found that patients with the STAT4 C/G and CC genotypes exhibited a 1.583-fold increased risk of SLE incidence (95 % CI = 1.168-2.145, p = 0.003), with OR for the C/C versus C/G and G/G genotypes was 1.967 (95 % CI = 1.152-3.358, p = 0.0119). The OR for the STAT4 C allele frequency showed a 1.539-fold increased risk of SLE (95 % CI = 1.209-1.959, p = 0.0004). We also observed an increased frequency of STAT4 C/C and C/G genotypes in SLE patients with renal symptoms OR = 2.259 (1.365-3.738, p = 0.0014), (p (corr) = 0.0238) and in SLE patients with neurologic manifestations OR = 2.867 (1.467-5.604, p = 0.0016), (p (corr) = 0.0272). Moreover, we found a contribution of STAT4 C/C and C/G genotypes to the presence of the anti-snRNP Ab OR = 3.237 (1.667-6.288, p = 0.0003), (p (corr) = 0.0051) and the presence of the anti-Scl-70 Ab OR = 2.665 (1.380-5.147, p = 0.0028), (p (corr) = 0.0476). Our studies confirmed an association of the STAT4 C (rs7582694) variant with the development of SLE and occurrence of some clinical manifestations of the disease.     

Insights into Chi recognition from the structure of an AddAB-type helicase-nuclease complex

In bacterial cells, processing of double-stranded DNA breaks for repair by homologous recombination is dependent upon the recombination hotspot sequence Chi and is catalysed by either an AddAB- or RecBCD-type helicase-nuclease. Here, we report the crystal structure of AddAB bound to DNA. The structure allows identification of a putative Chi-recognition site in an inactivated helicase domain of the AddB subunit. By generating mutant protein complexes that do not respond to Chi, we show that residues responsible for Chi recognition are located in positions equivalent to the signature motifs of a conventional helicase. Comparison with the related RecBCD complex, which recognizes a different Chi sequence, provides further insight into the structural basis for sequence-specific ssDNA recognition. The structure suggests a simple mechanism for DNA break processing, explains how AddAB and RecBCD can accomplish the same overall reaction with different sets of functional modules and reveals details of the role of an Fe-S cluster in protein stability and DNA binding.     

Role of damage-specific DNA polymerases in M13 phage mutagenesis induced by a major lipid peroxidation product trans-4-hydroxy-2-nonenal

One of the major lipid peroxidation products trans-4-hydroxy-2-nonenal (HNE), forms cyclic propano- or ethenoadducts bearing six- or seven-carbon atom side chains to G > C ? A > T. To specify the role of SOS DNA polymerases in HNE-induced mutations, we tested survival and mutation spectra in the lacZα gene of M13mp18 phage, whose DNA was treated in vitro with HNE, and which was grown in uvrA^? Escherichia coli strains, carrying one, two or all three SOS DNA polymerases. When Pol IV was the only DNA SOS polymerase in the bacterial host, survival of HNE-treated M13 DNA was similar to, but mutation frequency was lower than in the strain containing all SOS DNA polymerases. When only Pol II or Pol V were present in host bacteria, phage survival decreased dramatically. Simultaneously, mutation frequency was substantially increased, but exclusively in the strain carrying only Pol V, suggesting that induction of mutations by HNE is mainly dependent on Pol V. To determine the role of Pol II and Pol IV in HNE induced mutagenesis, Pol II or Pol IV were expressed together with Pol V. This resulted in decrease of mutation frequency, suggesting that both enzymes can compete with Pol V, and bypass HNE-DNA adducts in an error-free manner. However, HNE-DNA adducts were easily bypassed by Pol IV and only infrequently by Pol II.Mutation spectrum established for strains expressing only Pol V, showed that in uvrA^? bacteria the frequency of base substitutions and recombination increased in relation to NER proficient strains, particularly mutations at adenine sites. Among base substitutions A:T → C:G, A:T → G:C, G:C → A:T and G:C → T:A prevailed.The results suggest that Pol V can infrequently bypass HNE-DNA adducts inducing mutations at G, C and A sites, while bypass by Pol IV and Pol II is error-free, but for Pol II infrequent.     

Is callose a barrier for lead ions entering <Emphasis Type="Italic">Lemna minor</Emphasis> L. root cells?

Plants have developed a range of strategies for resisting environmental stresses. One of the most common is the synthesis and deposition of callose, which functions as a barrier against stress factor penetration. The aim of our study was to examine whether callose forms an efficient barrier against Pb penetration in the roots of Lemna minor L. exposed to this metal. The obtained results showed that Pb induced callose synthesis in L. minor roots, but it was not deposited regularly in all tissues and cells. Callose occurred mainly in the protoderm and in the centre of the root tip (procambial central cylinder). Moreover, continuous callose bands, which could form an efficient barrier for Pb penetration, were formed only in the newly formed and anticlinal cell walls (CWs); while in other CWs, callose formed only small clusters or incomplete bands. Such an arrangement of callose within root CWs inefficiently protected the protoplast from Pb penetration. As a result, Pb was commonly present inside the root cells. In the light of the results, the barrier role of callose against metal ion penetration appears to be less obvious than previously believed. It was indicated that induction of callose synthesis is not enough for a successful blockade of the stress factor penetration. Furthermore, it would appear that the pattern of callose distribution has an important role in this defence strategy.     

Organelle evolution: Paulinella breaks a paradigm

It is commonly assumed that transformations of endosymbionts into organelles are exceptionally rare evolutionary events because of hypothetical difficulties in the origin of an import apparatus for nuclear-encoded, organelle-targeted proteins along with their targeting signals. A challenge to this view comes from recent studies of protein import into the cyanobacterial endosymbionts/organelles of Paulinella chromatophora.     

Long-term changes in numbers of geese stopping over and wintering in south-western Poland

South-western Poland belongs to the key staging areas for geese in Europe, supporting some 100000 birds in recent years. We compared goose counts conducted in the 1970s, 1990s and during 2009–2011 in this region, and linked the findings to the recent assessments of trends in the flyway-populations. Numbers increased several dozen times between the first two counts and have stabilized to the present. More than 14% of the flyway Tundra Bean Goose (Anser fabalis rossicus) stopped over in SW Poland on passage. Smaller numbers of White-fronted Goose (A. albifrons), Greylag Goose (A. anser), and four other rarer species, have all increased since the 1970s. The likely factors responsible for these changes are mild weather conditions, increased availability of large water bodies and shifts in winter ranges of particular species. Temporal mismatch between SW Poland and the total flyways in Bean and White-fronted Geese was recorded when we compared the long-term and the short-term population trends. Increasing reports of other species in SW Poland match the general tendencies in Europe. These data document that regional trends are not a simple reflection of those in flyways as a whole. To understand changes in goose populations a re-established international count network is desired.     

Dependence between Cu concentration in the liver,kidneys and skeletal muscles of canine females

The aim of the investigations was the determination of the Cu contents in the liver, kidneys and skeletal muscles of canine females. Material for research was collected post mortem from 45 animals aged 1 to 18 years coming from the Warsaw area. The effect of the health state, age and life conditions on the distribution of copper in the investigated organs was estimated. That element was determined using the method of inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the liver, the average Cu contents amounted to 24.04 mg kg⁻¹ wet weight, in kidneys to 2.90 mg kg⁻¹ wet weight and in muscles to 0.94 mg kg⁻¹ wet weight. The highest values of copper content in particular tissues and organs were noted in the group of animals with neoplastic changes. In respect to the animal age the highest mean values of the copper content were noted in the oldest animals. They amounted to 30.97 mg kg⁻¹ in the liver, 3.34 mg kg⁻¹ in kidneys and 1.18 mg kg⁻¹ wet weight in muscles. Considering life conditions of the dogs it was observed that the higher mean values in all the investigated organs occurred in dogs coming from the urban areas.