Irina Zalenskaya - Academia.edu (original) (raw)

Papers by Irina Zalenskaya

PLOS ONE, 2015

Inflammation and immune activation of the cervicovaginal mucosa are considered factors that incre... more Inflammation and immune activation of the cervicovaginal mucosa are considered factors that increase susceptibility to HIV infection. Therefore, it is essential to screen candidate anti-HIV microbicides for potential mucosal immunomodulatory/inflammatory effects prior to further clinical development. The goal of this study was to develop an in vitro method for preclinical evaluation of the inflammatory potential of new candidate microbicides using a microarray gene expression profiling strategy. To this end, we compared transcriptomes of human vaginal cells (Vk2/E6E7) treated with well-characterized pro-inflammatory (PIC) and non-inflammatory (NIC) compounds. PICs included compounds with different mechanisms of action. Gene expression was analyzed using Affymetrix U133 Plus 2 arrays. Data processing was performed using GeneSpring 11.5 (Agilent Technologies, Santa Clara, CA). Microarraray comparative analysis allowed us to generate a panel of 20 genes that were consistently deregulated by PICs compared to NICs, thus distinguishing between these two groups. Functional analysis mapped 14 of these genes to immune and inflammatory responses. This was confirmed by the fact that PICs induced NFkB pathway activation in Vk2 cells. By testing microbicide candidates previously characterized in clinical trials we demonstrated that the selected PIC-associated genes properly identified compounds with mucosa-altering effects. The discriminatory power of these genes was further demonstrated after culturing vaginal cells with vaginal bacteria. Prevotella bivia, prevalent bacteria in the disturbed microbiota of bacterial vaginosis, induced strong upregulation of seven selected PIC-associated genes, while a commensal Lactobacillus gasseri associated to vaginal health did not cause any changes. In vitro evaluation of the immunoinflammatory potential of microbicides using the PIC-associated genes defined in this study could help in the initial screening of candidates prior to entering clinical trials. Additional characterization of these genes can provide further insight into the cervicovaginal immunoinflammatory and mucosal-altering processes that facilitate or limit HIV transmission with implications for the design of prevention strategies.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology, 2004

In human spermatozoa, the arrangement of chromosomes is non-random. Characteristic features are a... more In human spermatozoa, the arrangement of chromosomes is non-random. Characteristic features are association of centromeres in the interior chromocenter and peripheral location of telomeres. In this paper, we have investigated the highest level of order in DNA packing in sperm--absolute and relative intranuclear chromosome positioning. Asymmetrical nuclear shape, existence of a defined spatial marker, and the haploid complement of chromosomes facilitated an experimental approach using in situ hybridization. Our results showed the tendency for non-random intranuclear location of individual chromosome territories. Moreover, centromeres demonstrated specific intranuclear position, and were located within a limited area of nuclear volume. Additionally, the relative positions of centromeres were non-random; some were found in close proximity, while other pairs showed significantly greater intercentromere distances. Therefore, a unique and specific adherence may exist between chromosomes i...

International review of cytology, 2002

Telomeres are terminal chromosomal domains that protect chromosome ends from degradation and fusi... more Telomeres are terminal chromosomal domains that protect chromosome ends from degradation and fusion and promote complete replication of DNA. Telomeres are involved in the regulation of cellular replicative lifespan and tumorigenesis. These important functions of the telomeres have evoked high interest: numerous studies have resulted in a detailed description of telomere composition and structure in somatic cells. Much less is known about telomeres in germline cells. Emerging novel features and unique behavior of telomeres in the process of gamete differentiation suggest that they may have additional germline-specific function(s). This review describes recent studies revealing changes in the telomere organization in the course of differentiation from the germline stem cells to mature sperm in mammals. Similarities and differences between somatic and spermatogenic cells in telomere nuclear localization, protein composition, DNA length, telomerase activity, and chromatin structure are ...

Contraception, 2013

Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is ... more Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is important for accurately studying the efficacy of vaginal microbicides and contraceptives. Y-chromosome biomarkers offer better stability, sensitivity, and specificity than protein biomarkers. TSPY4 belongs to the TSPY (testis-specific protein Y-encoded) family of homologous genes on the Y-chromosome. Using a multiplex PCR amplifying TSPY4, amelogenin, and Sex-determining region in the Y chromosome (SRY), our objective was to determine whether a gene in the TSPY family was a more sensitive marker of semen exposure in cervicovaginal fluids than SRY. The multiplex polymerase chain reaction (PCR) was developed using sperm and vaginal epithelial (female) DNA. Diluted sperm DNA and mixed male/female DNA was used to determine the sensitivity of the multiplex PCR. Potential interference of TSPY4 amplification by components in cervicovaginal and seminal fluids was determined. TSPY4 and SRY ampli...

American journal of reproductive immunology (New York, N.Y. : 1989), 2014

Semen deposition results in modulated immunity and an inflammatory response of the genital mucosa... more Semen deposition results in modulated immunity and an inflammatory response of the genital mucosa, which promotes conditions facilitating conception and pregnancy. These semen-induced alterations in the female reproductive tract can also have implications for the sexual transmission of viral infections such as HIV-1. Semen is not only a vector for HIV-1 but also a carrier for pro- and antiviral factors. Semen induces significant mucosal changes upregulating gene, and transcription factors leading to recruitment and activation of HIV target cells, stimulation of HIV replication and potentiation of Toll-like receptor responses. Although more research is needed to clearly elucidate the resulting collective effects of all these factors, semen modulation of the cervicovaginal microenvironment and immune system appears to lead, through multiple mechanisms, to mucosal changes facilitating viral entry and replication, likely resulting in enhanced susceptibility to acquire HIV-1 infection.

PLoS genetics, 2014

To achieve the extreme nuclear condensation necessary for sperm function, most histones are repla... more To achieve the extreme nuclear condensation necessary for sperm function, most histones are replaced with protamines during spermiogenesis in mammals. Mature sperm retain only a small fraction of nucleosomes, which are, in part, enriched on gene regulatory sequences, and recent findings suggest that these retained histones provide epigenetic information that regulates expression of a subset of genes involved in embryo development after fertilization. We addressed this tantalizing hypothesis by analyzing two mouse models exhibiting abnormal histone positioning in mature sperm due to impaired poly(ADP-ribose) (PAR) metabolism during spermiogenesis and identified altered sperm histone retention in specific gene loci genome-wide using MNase digestion-based enrichment of mononucleosomal DNA. We then set out to determine the extent to which expression of these genes was altered in embryos generated with these sperm. For control sperm, most genes showed some degree of histone association, ...

AIDS Research and Human Retroviruses, 2014

Epigenetics and Human Health, 2010

... J Cell Sci 118:18111820 274 O. Mudrak et al. Page 15. ... Chromosome Res 11:503512 Gurevitc... more ... J Cell Sci 118:18111820 274 O. Mudrak et al. Page 15. ... Chromosome Res 11:503512 Gurevitch M, Amiel A, Ben-Zion M, Fejgin M, Bartoov B (2001) Acrocentric centromere organi-zation within the chromocenter of the human sperm nucleus. ...

Sperm Chromatin for the Researcher, 2013

Sperm Chromatin, 2011

Similar to interphase chromosomes, mammalian supercompact and genetically inactive sperm chromati... more Similar to interphase chromosomes, mammalian supercompact and genetically inactive sperm chromatin is arranged in non-overlapping chromosome territories. Recent works demonstrate that chromosome territories in sperm have defined and nonrandom ...

Systems Biology in Reproductive Medicine, 2008

Reproduction, Fertility and Development, 2007

During the process of mammalian spermiogenesis, a significant reorganisation of the chromatin str... more During the process of mammalian spermiogenesis, a significant reorganisation of the chromatin structure occurs involving the sequential substitution of somatic histones with protamines. In the human sperm nucleus, approximately 15% of the basic nuclear protein complement is maintained as histones. Human testis/sperm-specific histone H2B (hTSH2B) is a variant of the histone H2B expressed exclusively in spermatogenic germline cells and present in some mature sperm cells. Thus, this protein marks a subpopulation of sperm cells in the ejaculate. Using indirect immunofluorescence, we examined the influence of hTSH2B on zona pellucida binding and sperm head decondensation in amphibian egg cell-free extract. As suggested by previous studies, we found that hTSH2B can be localised in only approximately 30% of sperm cells within a given ejaculate. We established that the presence of hTSH2B does not influence sperm zona pellucida binding capacity. Finally, we found that decondensation occurred more rapidly and to a greater extent in those cells containing hTSH2B. We propose that the presence or absence of hTSH2B within spermatozoa influences pronuclei formation and the activation of paternal genes following fertilisation and during early embryonic development.

Protein & Peptide Letters, 2011

During late stages of spermatogenesis in mammals, most histones bound to DNA are replaced by prot... more During late stages of spermatogenesis in mammals, most histones bound to DNA are replaced by protamines (PRM), which results in formation of supercondensed and genetically inert sperm chromatin. At fertilization, mature spermatozoon penetrates oocyte and chromatin is remodeled &amp;amp;amp;amp;amp;quot;back&amp;amp;amp;amp;amp;quot; from nucleoprotamine to nucleohistone state. While being crucial for activation of male genome and ultimately for initiation of embryonic development, this process is poorly studied, especially in humans. Data on model animals concerning PRM to histones exchange post fertilization are few and contradictory. As direct experimentation with human embryos is impossible due to ethical, legal and technical reasons, we evaluate the timing and mode of PRM removal in a heterologous ICSI system using hamster ova injected with human sperm. Localization of human PRM 1 and 2 in hybrid zygotes was established using immunofluorescence. We observed a marked zygote to zygote variability in male pronuclei size for any time point post ICSI and demonstrated that PRM removal correlates with the developing pronuclei area rather than time after injection. Overall, the disappearance of protamines from sperm is rather rapid and most likely completed within 1 hr. We propose that the critical characteristic influencing PRM removal after heterologous fertilization is the intrinsic heterogeneity of the human sperm population. The same yet unexplored variance may be one of the reasons for canceled, delayed or aberrant early embryonic development during natural or artificial fertilization in humans.

Nucleic Acids Research, 1985

A refined map for the linear arrangement of histones along DNA in nucleosomal core particles has ... more A refined map for the linear arrangement of histones along DNA in nucleosomal core particles has been determined by DNA-protein crosslinking. On one strand of 145-bp core DNA, histones are aligned in the following order:

Nucleic Acids Research, 1981

Comparison has been made between sea urchin and starfish sperm chromatin. The only protein by whi... more Comparison has been made between sea urchin and starfish sperm chromatin. The only protein by which chromatins from these sources differ significantly is histone B. Sea urchin sperm H2B is known to contain an elongated N-terainal region enriched in Argo Analysis of the micrococcal nuclease digests of sea urchin and starfibh nuclei in one-and two-dinsional electrophoresis has show that sperm chromatin of both animals consists of repeatel units similar in genera-l features to those of rat tbymus or liver. However, DNA repeat length in chromatin of sea urchin sperm (23? bp) is higer than that of starfish sperm (224 bp), while the core DElength does not differ and is the same as in tie chromatin of rat liver or thymus. A suggestion has been made that the N-terminal region of histone H2B is associated with the linker DNA and is responsible for the increased length of sea urchin linker DNA.

Molecular Biology Reports, 1985

Complexes of histone H 1 from sea urchin sperm (H I S) and calft hymus (H l T) with superhelical ... more Complexes of histone H 1 from sea urchin sperm (H I S) and calft hymus (H l T) with superhelical DNA I and relaxed circular DNA I1 have been analyzed by analytical sedimentation. Similar to HIT, the highly basic and relatively arginine-rich histone HIS preferentially interacts with DNA I compared to DNA II under competition conditions. However, HIS induces a stronger aggregation of both forms of DNA than H IT. Below 0.05 M NaC1, the soluble complexes formed by both histones have similar properties, but aggregation proceeds in a different manner: HIS induces a stronger aggregation of DNA II as compared to DNA I, whereas HIT fails to aggregate DNA I.

Journal of Proteome Research, 2008

Previous studies gave differing results as to whether the testis-specific histone H1t was phospho... more Previous studies gave differing results as to whether the testis-specific histone H1t was phosphorylated during rodent spermatogenesis. We show here that histones extracted from germ cell populations enriched with spermatids at different stages of development in rat testes reveal an electrophoretic shift in the position of H1t to slower mobilities in elongating spermatids as compared to that from preceding stages. Alkaline phosphatase treatment and radioactive labeling with (32)P demonstrated that the electrophoretic shift is due to phosphorylation. Mass spectrometric analysis of histone H1t purified from sexually mature mice and rat testes confirmed the occurrence of singly, doubly, and triply phosphorylated species, with phosphorylation sites predominantly found at the C-terminal end of the molecule. Furthermore, using collision-activated dissociation (CAD) and electron transfer dissociation (ETD), we have been able to identify the major phosphorylation sites. These include a new, previously unidentified putative H1t-specific cdc2 phosphorylation site in linker histones. The presence of phosphorylation at the C-terminal end of H1t and the timing of its appearance suggest that this post-translational modification is involved in the reduction of H1t binding strength to DNA. It is proposed that this could participate in the opening of the chromatin fiber in preparation for histone displacement by transition proteins in the next phase of spermiogenesis.

International Journal of Biological Macromolecules, 1983

The nucleosome core histone complex in solution at 2 M NaCl and pH 7 has a radius of gyration, R~... more The nucleosome core histone complex in solution at 2 M NaCl and pH 7 has a radius of gyration, R~, of 3.48 nm and a maximum dimension, L, of12 nm. Its shape is disc-like with a mean thickness of 3 nm. The radius of gyration determined by us is of the same value as the radius of 9yration of the complex in intact core particles (Braddock et al., Biopolymers 1981,20, 327). Thus, we conclude that the basic histone tails of the protein complex project about 2 nm from its central part.

International Journal of Biological Macromolecules, 1986

Circular dichroism (c.d.) and turbidity measurements have been performed to study the structural ... more Circular dichroism (c.d.) and turbidity measurements have been performed to study the structural behaviour of the marine invertebrate sperm-specific histones H1, H2B and of the mollusc sperm-specific protein 2andtheirdependenceonionicstrengthaswellastheformationofcomplexesoftheseproteinswithDNA.SeaurchinspermhistonesHlfromStrongylocentrotusintermediusorStrongylocentrotusdroebachiensisattain,at2MNaCl,ahigherhelicitythanhistonesHIfrqmthespermofthebivalvemolluscChlamisislandicusorfromcalfthymus.ThisextrahelicalpartoftheseaurchinspermhistonesHIisrapidlydigestedbytrypsin.ThecomplexesofthemarineinvertebrateHIand2 and their dependence on ionic strength as well as the formation of complexes of these proteins with DN A. Sea urchin sperm histones H l from Strongylocentrotus intermedius or Strongylocentrotus droebachiensis attain, at 2 M N aCl, a higher helicity than histones HI frqm the sperm of the bivalve mollusc Chlamis islandicus or from calf thymus. This extra helical part of the sea urchin sperm histones HI is rapidly digested by trypsin. The complexes of the marine invertebrate HI and 2andtheirdependenceonionicstrengthaswellastheformationofcomplexesoftheseproteinswithDNA.SeaurchinspermhistonesHlfromStrongylocentrotusintermediusorStrongylocentrotusdroebachiensisattain,at2MNaCl,ahigherhelicitythanhistonesHIfrqmthespermofthebivalvemolluscChlamisislandicusorfromcalfthymus.ThisextrahelicalpartoftheseaurchinspermhistonesHIisrapidlydigestedbytrypsin.ThecomplexesofthemarineinvertebrateHIand2 proteins with DNA are characterized by c.d. spectra with strong negative ellipticities corresponding to the (-PSl)-type c.d. spectra of calf thymus H1-DNA complexes. The arginine content of the histones correlates with the ionic strength at which the formation of the protein-D N A complexes begins. The higher the arginine content the higher is the ionic strength at which complex formation sets in once ionic strength is reduced. The results of the investigations on H2B-DNA complexes point to a possible involvement of H2B from sea urchin sperm in the condensation of sea urchin sperm chromatin.