RELATIONSHIP BETWEEN SINGLE NUCLEOTIDE POLYMORPHISMS IN CYTOKINE GENES AND CLINICAL LABORATORY PARAMETERS IN PATIENTS WITH MULTIPLE MYELOMA

Multiple myeloma is the most common form of paraproteinemic hemoblastosis, which is characterized by variability of clinical manifestations, forms, and variants. Limited efficiency of antitumor immune protection in the patient plays an important role in progression of this disease. Survival of myeloma cells is promoted by some growth factors, including a number of interleukins. Cytokines and chemokines are secreted in response to intercellular interactions and stimulate tumor growth, inhibition of osteoblasts and increase of the osteoclastic activity. Cytokine genes show a significant allelic polymorphism. A single gene may exhibit numerous polymorphic sites located in exons, introns and promoter regulatory areas. Single nucleotide substitutions in the promoter region of cytokine genes are known to have a huge impact upon secretion and biological activity of these factors. Therefore, a study of allelic gene variants determining the levels of cytokine production will allow of establishing new immunogenetic factors associated with a high risk of disease development, including multiple myeloma. We have studied single nucleotide polymorphism in cytokine genes (IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG), and clinical laboratory parameters (serum levels of albumin, β2-microglobulin, and hemoglobin) determining severity grade of multiple myeloma in 80 patients living in the North-Western region of Russia. It was found that the presence of certain cytokine gene variants, i.e., IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, IL-6 nt565 GG or IL-1α -889 TT, IL- 1β +3962 TT or IL-6 -174 GG, IL-6 nt565 GG was associated with low albumin levels (< 3.5 g/DL), and high levels of β2-microglobulin (> 5.5 mg/l). A combination of all the four negative variants in homozygous state (IL- 1α TT -889, IL-1β +3962 TT, IL-6 -174 GG and IL-6 nt565 GG) increases the chance of six-fold reduction of albumin levels (p < 0.05); combinations of homozygous IL-1α TT -889, IL-1β +3962 TT, IL-6-174 GG. and IL-6 nt565 GG are associated with increased chance of high-level β2-microglobulin (> 5.5 mg/l) by more than two times. This data allow to consider IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG genotypes additional negative immunogenetic factors in the prognosis of multiple myeloma

Evolution of oxygen-ion and proton conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), located near pyrochlore fluorite phase boundary

Sm2-xCaxZr2O7-x/2 (x = 0, 0.05, 0.1) and Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1) mixed oxides in a pyrochlore-fluorite morphotropic phase region were prepared via the mechanical activation of oxide mixtures, followed by annealing at 1600 ?C. The structure of the solid solutions was studied by X-ray diffraction and refined by the Rietveld method, water content was determined by thermogravimetry (TG), their bulk and grain-boundary conductivity was determined by impedance spectroscopy in dry and wet air (100-900 ?C), and their total conductivity was measured as a function of oxygen partial pressure in the temperature range: 700-950 ?C. The Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) pyrochlore solid solutions, lying near the morphotropic phase boundary, have proton conductivity contribution both in the grain bulk and on grain boundaries below 600 ?C, and pure oxygen-ion conductivity above 700 ?C. The 500 ?C proton conductivity contribution of Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) is ~ 1 ? 10-4 S/cm. The fluorite-like Gd2-xCaxZr2O7-x/2 (x = 0.1) solid solution has oxygen-ion bulk conductivity in entire temperature range studied, whereas proton transport contributes to its grain-boundary conductivity below 700 ?C. As a result, of the morphotropic phase transition from pyrochlore Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) to fluorite-like Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1), the bulk proton conductivity disappears and oxygen-ion conductivity decreases. The loss of bulk proton conductivity of Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1) can be associated with the fluorite structure formation. It is important to note that the degree of Ca substitution in such solid solutions (Ln2-xCax)Zr2O7-? (Ln = Sm, Gd) is low, x < 0.1. In both series, grain-boundary conductivity usually exceeds bulk conductivity. The high grain-boundary proton conductivity of Ln2-xCaxZr2O7-x/2 (Ln = Sm, Gd; x = 0.1) is attributable to the formation of an intergranular CaZrO3-based cubic perovskite phase doped with Sm or Gd in Zr sublattice. ? 2019 by the authors.371C-9F16-EBDE | Eduarda GomesN/

Fused eco29kIR- and M genes coding for a fully functional hybrid polypeptide as a model of molecular evolution of restriction-modification systems

<p>Abstract</p> <p>Background</p> <p>The discovery of restriction endonucleases and modification DNA methyltransferases, key instruments of genetic engineering, opened a new era of molecular biology through development of the recombinant DNA technology. Today, the number of potential proteins assigned to type II restriction enzymes alone is beyond 6000, which probably reflects the high diversity of evolutionary pathways. Here we present experimental evidence that a new type IIC restriction and modification enzymes carrying both activities in a single polypeptide could result from fusion of the appropriate genes from preexisting bipartite restriction-modification systems.</p> <p>Results</p> <p>Fusion of <it>eco29kIR </it>and <it>M </it>ORFs gave a novel gene encoding for a fully functional hybrid polypeptide that carried both restriction endonuclease and DNA methyltransferase activities. It has been placed into a subclass of type II restriction and modification enzymes - type IIC. Its MTase activity, 80% that of the M.Eco29kI enzyme, remained almost unchanged, while its REase activity decreased by three times, concurrently with changed reaction optima, which presumably can be caused by increased steric hindrance in interaction with the substrate. <it>In vitro </it>the enzyme preferentially cuts DNA, with only a low level of DNA modification detected. <it>In vivo </it>new RMS can provide a 10²-fold less protection of host cells against phage invasion.</p> <p>Conclusions</p> <p>We propose a molecular mechanism of appearing of type IIC restriction-modification and M.SsoII-related enzymes, as well as other multifunctional proteins. As shown, gene fusion could play an important role in evolution of restriction-modification systems and be responsible for the enzyme subclass interconversion. Based on the proposed approach, hundreds of new type IIC enzymes can be generated using head-to-tail oriented type I, II, and III restriction and modification genes. These bifunctional polypeptides can serve a basis for enzymes with altered recognition specificities. Lastly, this study demonstrates that protein fusion may change biochemical properties of the involved enzymes, thus giving a starting point for their further evolutionary divergence.</p

Small Cofactors May Assist Protein Emergence from RNA World: Clues from RNA-Protein Complexes

It is now widely accepted that at an early stage in the evolution of life an RNA world arose, in which RNAs both served as the genetic material and catalyzed diverse biochemical reactions. Then, proteins have gradually replaced RNAs because of their superior catalytic properties in catalysis over time. Therefore, it is important to investigate how primitive functional proteins emerged from RNA world, which can shed light on the evolutionary pathway of life from RNA world to the modern world. In this work, we proposed that the emergence of most primitive functional proteins are assisted by the early primitive nucleotide cofactors, while only a minority are induced directly by RNAs based on the analysis of RNA-protein complexes. Furthermore, the present findings have significant implication for exploring the composition of primitive RNA, i.e., adenine base as principal building blocks

Conformational Basis for Asymmetric Seeding Barrier in Filaments of Three- and Four-Repeat Tau

*S Supporting Information ABSTRACT: Tau pathology in Alzheimer’s disease is intimately linked to the deposition of proteinacious filaments, which akin to infectious prions, have been proposed to spread via seeded conversion. Here we use double electron−electron resonance (DEER) spectroscopy in combination with extensive computational analysis to show that filaments of three- (3R) and four-repeat (4R) tau are conformationally distinct. Distance measurements between spin labels in the third repeat, reveal tau amyloid filaments as ensembles of known β-strand−turn−β-strand U-turn motifs. Whereas filaments seeded with 3R tau are structurally homogeneous, filaments seeded with 4R tau are heterogeneous, composed of at least three distinct conformers. These findings establish a molecular basis for the seeding barrier between different tau isoforms and offer a new powerful approach for investigating the composition and dynamics of amyloid fibril ensembles

Avoidance of recognition sites of restriction-modification systems is a widespread but not universal anti-restriction strategy of prokaryotic viruses

Abstract Background Restriction-modification (R-M) systems protect bacteria and archaea from attacks by bacteriophages and archaeal viruses. An R-M system specifically recognizes short sites in foreign DNA and cleaves it, while such sites in the host DNA are protected by methylation. Prokaryotic viruses have developed a number of strategies to overcome this host defense. The simplest anti-restriction strategy is the elimination of recognition sites in the viral genome: no sites, no DNA cleavage. Even a decrease of the number of recognition sites can help a virus to overcome this type of host defense. Recognition site avoidance has been a known anti-restriction strategy of prokaryotic viruses for decades. However, recognition site avoidance has not been systematically studied with the currently available sequence data. We analyzed the complete genomes of almost 4000 prokaryotic viruses with known host species and more than 17,000 restriction endonucleases with known specificities in terms of recognition site avoidance. Results We observed considerable limitations of recognition site avoidance as an anti-restriction strategy. Namely, the avoidance of recognition sites is specific for dsDNA and ssDNA prokaryotic viruses. Avoidance is much more pronounced in the genomes of non-temperate bacteriophages than in the genomes of temperate ones. Avoidance is not observed for the sites of Type I and Type IIG systems and is very rarely observed for the sites of Type III systems. The vast majority of avoidance cases concern recognition sites of orthodox Type II restriction-modification systems. Even under these constraints, complete or almost complete elimination of sites is observed for approximately one-tenth of viral genomes and a significant under-representation for approximately one-fourth of them. Conclusions Avoidance of recognition sites of restriction-modification systems is a widespread but not universal anti-restriction strategy of prokaryotic viruses

Case of severe liver damage in COVID-19

The 2019 outbreak of coronavirus disease (COVID-19) caused by severe acute coronavirus 2 respiratory syndrome (SARS-CoV-2) has been a  global concern since December 2019. Although most patients with COVID-19  have mild clinical manifestations, in about 5% of these patients the disease eventually progresses to severe lung injury or even multiple organ dysfunction. This situation presents various problems for hepatology. In the context of liver damage in patients with COVID-19, several key problems need to be addressed. For example, it is important to determine whether a SARS-CoV-2 can directly enter the liver, especially when it appears that ACE2 is marginally expressed in hepatocytes. In addition, the mechanisms underlying liver dysfunction in patients with COVID-19 are multifactorial and are associated with hyperinflammation, dysregulated immune responses, abnormal coagulation, and drugs. The  article describes the  potential pathogenesis of  liver damage associated with COVID-19. Histopathological evidence suggests a marked disruption of the intrahepatic network of blood vessels secondary to systemic changes caused by a virus that can trigger a coagulation cascade and damage the endothelial layer of blood vessels. There is also a clinical case of polyethylene damage to the liver in a young man who led to death. Against the background of infection COVID-19 he developed massive thrombosis of the liver vessels, followed by the development of necrosis — fibrosis — cirrhosis — acute liver failure, which caused death