Sedova, E.S. | Shcherbinin, D.N. | Migunov, A.I. | Smirnov, Iu.A. | Logunov, D.Iu. | Shmarov, M.M. | Tsybalova, L.M. | Naroditskiĭ, B.S. | Kiselev, O.I. | Gintsburg, A.L.
This review covers the problems encountered in the construction and production of
new recombinant influenza vaccines. New approaches to the development of
influenza vaccines are investigated; they include reverse genetics methods,
production of virus-like particles, and DNA- and viral vector-based vaccines.
Such approaches as the delivery of foreign genes by DNA- and viral vector-based
vaccines can preserve the native structure of antigens. Adenoviral vectors are a
promising gene-delivery platform for a variety of genetic vaccines. Adenoviruses
can efficiently penetrate the human organism through mucosal epithelium, thus
providing long-term antigen persistence and induction of the innate immune
response. This review provides an overview of the practicability of the
production of new recombinant influenza cross-protective vaccines on the basis
of adenoviral vectors expressing hemagglutinin genes of different influenza
strains.
PMCID: PMC3548171
PMID: 23346377
Recombinant vaccine; influenza; immunization
Pluripotency is maintained by a complex system that includes the genetic and
epigenetic levels. Recent studies have shown that the genetic level
(transcription factors, signal pathways, and microRNAs) closely interacts with
the enzymes and other specific proteins that participate in the formation of the
chromatin structure. The interaction between the two systems results in the
unique chromatin state observed in pluripotent cells. In this review, the
epigenetic features of embryonic stem cells and induced pluripotent stem cells
are considered. Special attention is paid to the interplay of the transcription
factors OCT4, SOX2, and NANOG with the Polycomb group proteins and other
molecules involved in the regulation of the chromatin structure. The
participation of the transcription factors of the pluripotency system in the
inactivation of the X chromosome is discussed. In addition, the epigenetic
events taking place during reprogramming of somatic cells to the pluripotent
state and the problem of “epigenetic memory” are considered.
PMCID: PMC3548172
PMID: 23346378
embryonic stem cells; induced pluripotent stem cells; pluripotency; covalent histone modifications; DNA methylation
Cellular therapy of endodermal organs is one of the most important issues in
modern cellular biology and biotechnology. One of the most promising directions
in this field is the study of the transdifferentiation abilities of cells within
the same germ layer. A method for anin vitroinvestigation of
the cell differentiation potential (the cell culture in a three-dimensional
matrix) is described in this article. Cell cultures of postnatal salivary gland
cells and postnatal liver progenitor cells were obtained; their comparative
analysis under 2D and 3D cultivation conditions was carried out. Both cell types
have high proliferative abilities and can be cultivated for more than 20
passages. Under 2D cultivation conditions, the cells remain in an
undifferentiated state. Under 3D conditions, they undergo differentiation, which
was confirmed by a lower cell proliferation and by an increase in the
differentiation marker expression. Salivary gland cells can undergo hepatic and
pancreatic differentiation under 3D cultivation conditions. Liver progenitor
cells also acquire a pancreatic differentiation capability under conditions of
3D cultivation. Thus, postnatal salivary gland cells exhibit a considerable
differentiation potential within the endodermal germ layer and can be used as a
promising source of endodermal cells for the cellular therapy of liver
pathologies. Cultivation of cells under 3D conditions is a useful model for
thein vitroanalysis of the cell differentiation
potential.
PMCID: PMC3548173
PMID: 23346379
3D conditions; collagen gel; differentiation; endoderm; submandibular salivary gland cells; liver progenitor cells
G-protein-coupled receptors (GPCR) constitute one of the biggest families of
membrane proteins. In spite of the fact that they are highly relevant to
pharmacy, they have remained poorly explored. One of the main bottlenecks
encountered in structural-functional studies of GPCRs is the difficulty to
produce sufficient amounts of the proteins. Cell-free systems based on bacterial
extracts fromE. colicells attract much attention as an
effective tool for recombinant production of membrane proteins. GPCR production
in bacterial cell-free expression systems is often inefficient because of the
problems associated with the low efficiency of the translation initiation
process. This problem could be resolved if GPCRs were expressed in the form of
hybrid proteins with N-terminal polypeptide fusion tags. In the present work,
three new N-terminal fusion tags are proposed for cell-free production of the
human β2-adrenergic receptor, human M1 muscarinic acetylcholine receptor,
and human somatostatin receptor type 5. It is demonstrated that the application
of an N-terminal fragment (6 a.a.) of bacteriorhodopsin
fromExiguobacterium sibiricum(ESR-tag), N-terminal fragment
(16 а.о.) of RNAse A (S-tag), and Mistic protein fromB.
subtilisallows to increase the CF synthesis of the target GPCRs by
5–38 times, resulting in yields of 0.6–3.8 mg from 1 ml of the
reaction mixture, which is sufficient for structural-functional studies.
PMCID: PMC3548174
PMID: 23346380
Cell-free expression; GPCR; translation initiation
For prokaryotes in vitro, 16S rRNA and 20 ribosomal proteins are capable of
hierarchical self- assembly yielding a 30S ribosomal subunit. The self-assembly
is initiated by interactions between 16S rRNA and three key ribosomal proteins:
S4, S8, and S7. These proteins also have a regulatory function in the
translation of their polycistronic operons recognizing a specific region of
mRNA. Therefore, studying the RNA–protein interactions within binary
complexes is obligatory for understanding ribosome biogenesis. The
non-conventional RNA–protein contact within the binary complex of
recombinant ribosomal protein S7 and its 16S rRNA binding site (236 nucleotides)
was identified. UV–induced RNA–protein cross-links revealed that S7
cross-links to nucleotide U1321 of 16S rRNA. The careful consideration of the
published RNA– protein cross-links for protein S7 within the 30S subunit
and their correlation with the X-ray data for the 30S subunit have been
performed. The RNA – protein cross–link within the binary complex
identified in this study is not the same as the previously found cross-links for
a subunit both in a solution, and in acrystal. The structure of the binary
RNA–protein complex formed at the initial steps of self-assembly of the
small subunit appears to be rearranged during the formation of the final
structure of the subunit.
PMCID: PMC3548175
PMID: 23346381
ribosome; initiation; self-assembly; ribosomal protein S7; UV– induced cross-linking
The interaction between gold nanoparticles and particles of cholesteric
liquid-crystalline dispersions formed by double-stranded DNA and poly(I)×poly(C)
molecules is considered. It is shown that small-sized (~ 2 nm) gold
nanoparticles induce two different structural processes. First, they facilitate
the reorganization of the spatial cholesteric structure of the particles into a
nematic one. This process is accompanied by a fast decrease in the amplitude of
an abnormal band in the CD spectrum. Second, they induce cluster formation in a
“free space” between neighboring nucleic acid molecules fixed in the
structure of the quasinematic layers of liquid-crystalline particles. This
process is accompanied by slow development of the surface plasmon resonance band
in the visible region of the absorption spectrum. Various factors influencing
these processes are outlined. Some assumptions concerning the possible
mechanism(s) of fixation of gold nanoparticles between the neighboring
double-stranded nucleic acid molecules in quasinematic layers are
formulated.
PMCID: PMC3548176
PMID: 23346383
DNA; poly(I)×poly(C); liquid-crystalline dispersions of nucleic acids; gold nanoparticles; circular dichroism; absorption spectroscopy; abnormal optical activity; surface plasmon resonance; structure of biopolymer lyotropic liquid crystals; cytotoxicity of nanoparticles
This work is devoted to the investigation of the methanogenic archaea involved in
anaerobic digestion of cattle manure and maize straw on the basis of terminal
restriction fragment length polymorphism (T-RFLP) analysis of archaeal 16S rRNA
genes. The biological diversity and dynamics of methanogenic communities leading
to anaerobic degradation of agricultural organic wastes with biogas production
were evaluated in laboratory-scale digesters. T-RFLP analysis, along with the
establishment of archaeal 16S rRNA gene clone libraries, showed that the
methanogenic consortium consisted mainly of members of the
generaMethanosarcinaandMethanoculleus,with
a predominance ofMethanosarcinaspp. throughout the
experiment.
PMCID: PMC3548177
PMID: 23346384
9-(4’-Phosphonomethoxy-2’-cyclopenten-1’-yl)hypoxanthine and
9-(4’-phosphonomethoxy-2’,3’-dihydroxycyclopenten-1’-yl)hypoxanthine
were synthesized as isosteric carbocyclic analogues of
inosine-5’-monophosphate. The synthesized compounds were shown to be
capable of inhibiting the activity of human type II
inosine-5′-monophosphate dehydrogenase (IMPDH II) (IC50 = 500
µM) and to have no significant effects on the growth ofMycobacterium
tuberculosis.
PMCID: PMC3549521
PMID: 23346382
Carbocyclic nucleosides; competitive inhibition; inosine-5’-monophosphate; human IMPDH II,Mycobacterium tuberculosis
Cell techniques find increasing application in modern clinical practice. The II
and III phases of clinical trials are already under way for various cellular
products used for the restoration of the functions of the cornea, larynx, skin,
etc. However, the obtainment of functional cell types specific to different
organs and tissues still remains a subject of laboratory research. Liver is one
of the most important organs; the problems and prospects of cellular therapy for
liver pathologies are currently being actively studied. Cellular therapy of
liver pathologies is a complex multistage process requiring a thorough
understanding of the molecular mechanisms occurring in liver cells during
differentiation and regeneration. An analysis of the current cellular therapy
for liver pathologies is presented, the use of various cell types is described,
the main molecular mechanisms of hepatocyte differentiation are analyzed, and
the challenges and prospects of cell therapy for liver disorders are discussed
in this review.
PMCID: PMC3491890
PMID: 23150801
cell transplantation; cellular therapy; differentiation; liver
Cytokinins belong to one of the most important and well-known classes of plant
hormones. Discovered over half a century ago, cytokinins have retained the
attention of researchers due to the variety of the effects they have on the
growth and development of vegetable organisms, their participation in a plant
adaptation to external conditions, and the potential to be used in
biotechnology, agriculture, medicine and even cosmetics. The molecular mechanism
by which cytokinins function remained unknown for a long time. Things started to
change only in the 21stcentury, after the discovery of the receptors
for these phytohormones. It appeared that plants found ways to adapt a
two-component signal transduction system borrowed from prokaryotic organisms for
cytokinin signalling. This review covers the recent advances in research of the
molecular basis for the perception and transduction of the cytokinin signal.
Emphasis is placed on cytokinin receptors, their domain and three-dimensional
structures, subcellular localization, signalling activity, effect of mutations,
ligand-binding properties, and phylogeny.
PMCID: PMC3491891
PMID: 23150802
cytokinins; receptors; sensor histidine kinases; two-component systems; signal transduction
Polygenic diseases are caused by the joint contribution of a number of
independently acting or interacting polymorphic genes; the individual
contribution of each gene may be small or even unnoticeable. The carriage of
certain combinations of genes can determine the occurrence of clinically
heterogeneous forms of the disease and treatment efficacy. This review describes
the approaches used in a polygenic analysis of data in medical genomics, in
particular, pharmacogenomics, aimed at identifying the cumulative effect of
genes. This effect may result from the summation of gains of different genes or
be caused by the epistatic interaction between the genes. Both cases are
undoubtedly of great interest in investigating the nature of polygenic diseases.
The means that allow one to discriminate between these two possibilities are
discussed. The methods for searching for combinations of alleles of different
genes associated with the polygenic phenotypic traits of the disease, as well as
the methods for presenting and validating the results, are described and
compared. An attempt is made to evaluate the applicability of the existing
methods to an epistasis analysis. The results obtained by the authors using the
APSampler software are described and summarized.
PMCID: PMC3491892
PMID: 23150804
medical genomics; pharmacogenomics; polygenic analysis; epistasis
The results of the clinical use of thrombolytic and antithrombotic preparations
developed on the basis of protein conjugates obtained within the framework of
the conception of drug targeting delivery in the organism are considered. A
decrease has been noted in the number of biomedical projects focused on these
derivatives as a result of various factors: the significant depletion of
financial and organizational funds, the saturation of the pharmaceutical market
with preparations of this kind, and the appearance of original means for
interventional procedures. Factors that actively facilitate the conspicuous
potentiation of the efficacy of bioconjugates were revealed: the biomedical
testing of protein domains and their selected combinations, the optimization of
molecular sizes for the bioconjugates obtained, the density of target
localization, the application of cell adhesion molecules as targets, and the
application of connected enzyme activities. Enzyme antioxidants and the
opportunity for further elaboration of the drug delivery conception via the
elucidation and formation of therapeutic targets for effective drug reactions by
means of pharmacological pre- and postconditioning of myocardium arouse
significant interest.
PMCID: PMC3491893
PMID: 23150805
drug targeting delivery; protein bioconjugates; thrombolytics; antithrombotic agents; molecular size of bioconjugates; density of molecular targets; enzyme connected antioxidants; cell adhesion molecules; pharmacological pre- and post-conditioning of myocardium
Tuhvatulin, A.I. | Sysolyatina, E.V. | Scheblyakov, D.V. | Logunov, D.Yu. | Vasiliev, M.M. | Yurova, M.A. | Danilova, M.A. | Petrov, O.F. | Naroditsky, B.S. | Morfill, G.E. | Grigoriev, A.I. | Fortov, V.E. | Gintsburg, A.L. | Ermolaeva, S.A.
Non-thermal plasma (NTP) consists of a huge amount of biologically active
particles, whereas its temperature is close to ambient. This combination allows
one to use NTP as a perspective tool for solving different biomedical tasks,
including antitumor therapy. The treatment of tumor cells with NTP caused
dose-dependent effects, such as growth arrest and apoptosis. However, while the
outcome of NTP treatment has been established, the molecular mechanisms of the
interaction between NTP and eukaryotic cells have not been thoroughly studied
thus far. In this work, the mechanisms and the type of death of human colon
carcinoma HCT 116 cells upon application of non-thermal argon plasma were
studied. The effect of NTP on the major stress-activated protein p53 was
investigated. The results demonstrate that the viability of HCT116 cells upon
plasma treatment is dependent on the functional p53 protein. NTP treatment
caused an increase in the intracellular concentration of p53 and the induction
of the p53-controlled regulon. The p53-dependent accumulation of active
proapoptotic caspase-3 was shown in NTP-treated cells. The study was the first
to demonstrate that treatment of human colon carcinoma cells with NTP results in
p53-dependent apoptosis. The results obtained contribute to our understanding of
the applicability of NTP in antitumor therapy.
PMCID: PMC3491894
PMID: 23150806
non-thermal plasma; protein p53; apoptosis
Vitamin E derivatives are known to act as agents exhibiting cytotoxity against
tumor cells. The effect of vitamin E succinate on human epidermoid carcinoma
cell line A431 was investigated in this study using live imaging,
immunocytochemistry, and transmission electron microscopy. α-Tocopheryl
succinate-induced apoptotic cell death in A431 cells was shown to be both dose-
and time-dependent. The hyperproduction of reactive oxygen species, changes in
size, shape and ultrastructural characteristics of mitochondria followed by the
release of cytochromecfrom mitochondria to cytosol were
observed. These results suggest that α-tocopheryl succinate induces
apoptosis that occurs via the mitochondrial pathway. Mitochondria are shown to
be crucial targets in α-tocopheryl succinate-induced caspase-dependent cell
death in human carcinoma A431 cells.
PMCID: PMC3491895
PMID: 23150807
α-tocopheryl succinate; apoptosis; mitochondrial pathway; ROS; cytochromec
Grineva, N.I. | Duchovenskay, E.A. | Timofeev, A.M. | Akhlynina, T.V. | Gerasimova, L.P. | Borovkova, T.V. | Schmarov, D.A. | Sarycheva, N.G. | Naydenova, N.M. | Gavrichkova,
A.R. | Kolosova, L.Y. | Kolosheynova, T.I. | Kovaleva, L.G.
The genesp53, mdm2, p21, c-myc,bcr/abl, bcr, bcl2, bax,
and gapdh participate in the regulation of cell
proliferation and differentiation, apoptosis and cell distribution for the cell
cycle ex vivo in the Ph+cells of chronic myeloid
leukemia containing the Ph chromosome andbcr/abloncogene.
Expression of these genes correlates with regulation of cell proliferation and
differentiation by alternating proliferation and maturation stages for three
main Ph+cell types that occur under chronic myeloid leukemia. Thep53,
p21, mdm2, and gapdh genes overexpress in active
proliferating myeloid cells in the cell cycle S+ G2/M phases and when the phases
are coincident with the proliferation stage. Expression of these genes decreases
to a considerable level under alternation of the Ph+cell
proliferation and maturation stages and whenever the expression is greatly
diminished under significant neutrophil accumulation and especially under
repeated alternation of the stages. In the course of neutrophil maturation, gene
expression levels decrease in the range of gapdh > actin > c-myc,
bcr/abl,p21 > p53 > bcl2 > bax.The expression levels of
these genes in neutrophils are lower than those in myelocytes and lower by an
order of magnitude than that in the cells with a prolonged proliferation stage.
TheBcr/ablexpression gene under prolonged maturation and
neutrophil accumulation is inhibited; however it is enhanced by 2–3 times
for the proliferation stage with myelocyte accumulation.
Minimalbcr/ablexpression is observed under overexpression
ofp53, mdm2, p21, c-myc,as well as under cell maximum at
the S and G2/M phases. Bcr/abloverexpression is observed under
low expression of thep53, p21, mdm2genes. In the Ph+
cells with a high P/D efficiency index (5–20), overexpression of the
genes in the range ofbcr> gapdh>bcr/abl, as well as a
decreased expression of thep53, bcl2, mdm2, p21<< gapdh
genes is observed for Ph+cells from the CML blast crisis and
CML acceleration phase. Low control of cell proliferation and cell cycle by
gene-regulators presumably promotesbcr/abloverexpression and
activаtes the production ofbcr/abl+ cells.
Apoptosis in the Ph+ cells is induced by expression of thebax
> bcl2, р53, p21, c-myc andgapdhgenes.
The blocking of Ph+cell apoptosis, neutrophil accumulation, and
decrease in the expression of the p53, mdm2 and p21,
c-myc,bcr/abl genes occur at the maturation
stage.
PMCID: PMC3491896
PMID: 23150808
gene expression; regulation of cell proliferation and differentiation; cells containing Ph chromosome; chronic myeloid leukemia; RT-PCR, cell cycle; apoptosis
The present review summarizes data pertaining to the composition and structure of the
carbohydrate moiety (core oligosaccharide) and lipid component (lipid A) of the various
forms of lipopolysaccharide (LPS), one of the major pathogenicity factors
ofYersinia pestis, the cause of plague. The review addresses the
functions and the biological significance of genes for the biosynthesis of LPS, as well as
the biological properties of LPS in strains from various intraspecies groups ofY.
pestis and their mutants, including the contribution of LPS to the resistance
of bacteria to factors of the innate immunity of both insect-vectors and mammal-hosts.
Special attention is paid to temperature-dependent variations in the LPS structure, their
genetic control and roles in the pathogenesis of plague. The evolutionary aspect is
considered based on a comparison of the structure and genetics of the LPS ofY.
pestis and other enteric bacteria, including otherYersinia
species. The prospects of development of live plague vaccines created on the
basis ofY. pestis strains with the genetically modified LPS are
discussed.
PMCID: PMC3492934
PMID: 23150803
lipopolysaccharide; lipid A; plague; Yersinia pestis; immune response; antibiotic resistance
In this paper, we shall consider the main evolutionary stages that occurred
within the field of physicochemical biology during the 20th century, following
the determination of the tertiary structure of DNA by Watson and Crick and the
subsequent successes in the X-ray structural analysis of biopolymers. The
authors’ ideas on the pre-emptive problems and the methods used in
physicochemical biology in the 21st century are also presented, including an
investigation of the dynamics of biochemical processes, studies of the functions
of unstructured proteins, as well as single-molecule investigations of enzymatic
processes and of biopolymer tertiary structure formation.
PMCID: PMC3408702
PMID: 22872810
DNA structure; enzyme active sites; unstructured proteins; dynamics of
biochemical processes; single molecule studies of enzymatic processes and
biopolymer tertiary structure formation
Telomerase is an enzyme that maintains the length of the telomere. The telomere
length specifies the number of divisions a cell can undergo before it finally
dies (i.e. the proliferative potential of cells). For example, telomerase is
activated in embryonic cell lines and the telomere length is maintained at a
constant level; therefore, these cells have an unlimited fission potential. Stem
cells are characterized by a lower telomerase activity, which enables only
partial compensation for the shortening of telomeres. Somatic cells are usually
characterized by the absence of telomerase activity. Telomere shortening leads
to the attainment of the Hayflick limit, the transition of cells to a state of
senescence. The cells subsequently enter a state of crisis, accompanied by
massive cell death. The surviving cells become cancer cells, which are capable
both of dividing indefinitely and maintaining telomere length (usually with the
aid of telomerase). Telomerase is a reverse transcriptase. It consists of two
major components: telomerase RNA (TER) and reverse transcriptase (TERT). TER is
a non-coding RNA, and it contains the region which serves as a template for
telomere synthesis. An increasing number of articles focussing on the
alternative functions of telomerase components have recently started appearing.
The present review summarizes data on the structure, biogenesis, and functions
of telomerase.
PMCID: PMC3408703
PMID: 22872811
telomerase; reverse transcriptase; telomeres; mitochondria; DNA damage; gene
expression
Factor IX is a zymogen enzyme of the blood coagulation cascade. Inherited absence
or deficit of the IX functional factor causes bleeding disorder hemophilia B,
which requires constant protein replacement therapy. Reviewed herein are the
current state in the manufacturing of FIX, improved variants of the recombinant
protein for therapy, transgenic organisms for obtaining FIX, and the advances in
the gene therapy of hemophilia B.
PMCID: PMC3408704
PMID: 22872812
сoagulation factor IX; hemophilia B; heterologous protein expression
systems
Carriage frequencies of alleles and genotypes of theTGFB1 gene
polymorphous loci –509C>T (rs1800469), 869T>C (rs1982073), 915G>C
(rs1800471), which affect the level of cytokine TGF-β1 production, were
analyzed in the patients of Russian ethnic descent with myocardial infarction
(MI) (406 cases) and in the control group of the same ethnic descent (198
controls). Significant association with MI was observed in carriage frequencies
of the alleleTGFB1*–509T (p=0.046, OR
=1.45, 95% CI: 1.02-2.06), genotypes TGFB1*869T/T
(p=0.0024, OR =1.75, 95% CI: 1.22-2.51),
andTGFB1*915G/G (p=0.048, OR=1.76, 95% CI:
1.05-2.97). Linkage disequilibrium analysis for these SNPs has shown that the
associations revealed can be considered to be independent. A complex analysis of
MI association with combinations of alleles/genotypes of said SNPs indicates
their cumulative effect. An analysis of susceptibility to early-onset MI
(≤ 50 years old) revealed a positive association of the
alleleTGFB1*–509T (p=0.002, OR=2.24,
95% CI: 1.35-3.71) and genotypeTGFB1*869T/T
(p=0.008, OR=1.93, 95% CI: 1.18-3.15), as well as their
additivity. An analysis of susceptibility to recurrent MI revealed an
association of the genotypeTGFB1*–509T/T
(p=0.0078, OR=2.60, 95% CI: 1.28-5.28). The results
obtained indicate the important role of theTGFB1gene in
susceptibility to MI, including early-onset and recurrent MI, in Russians.
PMCID: PMC3408705
PMID: 22872813
myocardial infarction; Russians; genes; allelic polymorphism; transforming
growth factor β1;TGFB1; APSampler
A full-atomic molecular model of human apurinic/apyrimidinic endonuclease APE1,
an important enzyme in the DNA repair system, has been constructed. The research
consisted of hybrid quantum mechanics/molecular mechanics modeling of the
enzyme-substrate interactions, as well as calculations of the ionization states
of the amino acid residues of the active site of the enzyme. The choice of the
APE1 mechanism with an Asp210 residue as a proton acceptor was validated by
means of a generalization of modeling and experimental data. Interactions were
revealed in the active site that are of greatest significance for binding the
substrate and potential APE1 inhibitors (potential co-drugs of interest in the
chemo- and radiotherapy of oncological diseases).
PMCID: PMC3408706
PMID: 22872814
apurinic/apyrimidinic endonuclease; QM/MM; enzymatic mechanism; molecular
modeling; inhibition
The chemotactic properties of cyclophilin A are well-known. There exists however
a poor level of understanding regarding the hemostatic effects of this protein.
Herein it is shown that recombinant human cyclophilin A (rhСyA), in
contrast to the granulocyte colony-stimulating factor, is capable of
inhibitingin vitrothe formation of a fibrin clot, thereby
violating the spatial dynamics of clot growth; this effect is transient and
dose-independent. Furthermore, the hypothesis that the conformational changes in
the thrombin–rhCyA complex may mediate the anticoagulant effect of rhCyA
on the autowave processes of blood clotting is postulated.
PMCID: PMC3408707
PMID: 22880163
recombinant human cyclophilin A; spatial dynamics of clot growth; anticoagulant
activity
The Type III secretion system (T3SS) is currently considered to be one of the
main pathogenicity factors in Gram-negative bacteria, which exhibit different
types of parasitizing activity. The presence of this structure is essential for
the development of an acute infection; the chronicity of the infection is
fundamentally dependent upon its functioning. In this regard, T3TS is one of the
most promising targets for the development of broad-spectrum antimicrobial drugs
that do not develop resistance and are efficacious for the acute and chronic
forms of infection. The mechanism of action in drug development is based on the
specific inhibition of T3SS, which should interrupt the infectious process,
thereby enabling the immune system to eliminate the pathogen. As a result of
pilot screening using specific cellular and bacterial tests, followed by
chemical optimization and detailed characterization of the biological activity,
a new class of chlamydial T3SS inhibitors was obtained. The selected compounds
have obvious advantages over the currently available inhibitors of T3SS
pathogens thanks to the high inhibitory activity of these compounds with minimal
damaging effects on eukaryotic cells. Preclinical trials of the selected
inhibitors are currently under way.
PMCID: PMC3411183
PMID: 22880162
thiohydrazones; thiohydrazides; thiadiazines; type III secretion system;
citotoxicity; Chlamydia; inhibitors; microscopy; electron microscopy;
morphology
CCR5del32 Homozygous deletion in the chemokine receptor R5 gene
provides almost complete protection to individuals against HIV infection.
However, data relating to the protective effect forCCR5del32
heterozygous individuals have been contradictory. The frequency of
theCCR5del32allele in population control cohorts was
compared with that of a group of children (27 Kalmyks and 50 Russians) infected
by G-subtype HIV-1 in a nosocomial outbreak. The frequency of
theCCR5del32allele was shown to be lower among the infected
children in comparison with that of the control group; however, the difference
was small and statistically insignificant. Similar results were obtained in a
number of earlier studies. The insignificance of the small differences could be
a result of one of two reasons. (i) The fact that there is no protective effect
of the heterozygous state, and that the phenomenon depends only on the
fluctuation of allele frequencies. In this case, there would be no differences
even if the infected cohort is enlarged. (ii)The protective effect of the
heterozygous state is real; however, the size of the studied cohort is
insufficient to demonstrate it. In order to discern between these two reasons, a
meta-analysis of data from 25 published articles (a total of 5,963 HIV-infected
individuals and 5,048 individuals in the control group, including the
authors’ own data) was undertaken. A conclusion was drawn from the
meta-analysis that theCCR5del32 allele protects individuals
against the HIV infection even in a heterozygous state
(OR=1.22, 95%CI=1.10–1.36). The risk of
HIV infection forCCR5 wt/del32 heterozygotes was lower by at
least 13% as compared to that for wild typeCCR5
wt/wthomozygotes. Prior to this study, no data of
the type or any conclusions had been published for Caucasians. The mortality
rate in the 15 years following the infection was found to be approximately 40%
lower forCCR5del32 heterozygotes in comparison with that for
the wild type homozygotes in the studied group. The size of the studied group
was insufficient to claim difference validity
(OR=2.0;p= 0.705), even though the effect
quantitatively matched the published data. The features of the meta-analysis
influencing the threshold level and the statistical validity of the effects are
being discussed. The level of theCCR5del32 protective effect on
the chances to be infected with HIV and on the outcome of the HIV infection was
assessed for various ethnic groups.
PMCID: PMC3372986
PMID: 22708062
HIV; nosocomial infection; lethality risk; infection risk; chemokine receptor gene; alleleCCR5del32; meta-analysis
In this review the distinct aspects of somatic cell reprogramming are discussed.
The molecular mechanisms of generation of induced pluripotent stem (iPS) cells
from somatic cells via the introduction of transcription factors into adult
somatic cells are considered. Particular attention is focused on the generation
of iPS cells without genome modifications via the introduction of the mRNA of
transcription factors or the use of small molecules. Furthermore, the strategy
of direct reprogramming of somatic cells omitting the generation of iPS cells is
considered. The data concerning the differences between ES and iPS cells and the
problem of epigenetic memory are also discussed. In conclusion, the possibility
of using iPS cells in regenerative medicine is considered.
PMCID: PMC3372987
PMID: 22708059
reprogramming; iPS cells; ES cells; differentiation; transformation; pluripotency