29 research outputs found
A clinical case of a patient with probable cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) from Chuvashia
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome is a congenital small-vessel disease running with recurrent lacunar infarcts and leading to gradually progressive subcortical, pseudobulbar, and cerebellar syndromes and dementia. Neuroimaging reveal multiple lacunar infarcts in the basal ganglia, thalamus, pons Varolii, and cerebral hemispheric white matter, as well as cerebral atrophy. The specific feature of the disease is white matter lesion adjacent to the temporal horns of the lateral ventricles and to the external capsules. The paper describes a patient with CADASIL syndrome. The latter runs a progressive course and includes the following neurological disorders: cognitive, pyramidal, extrapyramidal, and axial ones. This clinical case was differentially diagnosed with multiple sclerosis, including with consideration for neuroimaging findings. The CADASIL syndrome is a rare potentially menacing neurological condition that is observed in young patients and requires a detailed examination using current diagnostic techniques
Transient Tumor-Fibroblast Interactions Increase Tumor Cell Malignancy by a TGF-Ξ² Mediated Mechanism in a Mouse Xenograft Model of Breast Cancer
Carcinoma are complex societies of mutually interacting cells in which there is a progressive failure of normal homeostatic mechanisms, causing the parenchymal component to expand inappropriately and ultimately to disseminate to distant sites. When a cancer cell metastasizes, it first will be exposed to cancer associated fibroblasts in the immediate tumor microenvironment and then to normal fibroblasts as it traverses the underlying connective tissue towards the bloodstream. The interaction of tumor cells with stromal fibroblasts influences tumor biology by mechanisms that are not yet fully understood. Here, we report a role for normal stroma fibroblasts in the progression of invasive tumors to metastatic tumors. Using a coculture system of human metastatic breast cancer cells (MCF10CA1a) and normal murine dermal fibroblasts, we found that medium conditioned by cocultures of the two cell types (CoCM) increased migration and scattering of MCF10CA1a cells in vitro, whereas medium conditioned by homotypic cultures had little effect. Transient treatment of MCF10CA1a cells with CoCM in vitro accelerated tumor growth at orthotopic sites in vivo, and resulted in an expanded pattern of metastatic engraftment. The effects of CoCM on MCF10CA1a cells were dependent on small amounts of active TGF-Ξ²1 secreted by fibroblasts under the influence of the tumor cells, and required intact ALK5-, p38-, and JNK signaling in the tumor cells. In conclusion, these results demonstrate that transient interactions between tumor cells and normal fibroblasts can modify the acellular component of the local microenvironment such that it induces long-lasting increases in tumorigenicity and alters the metastatic pattern of the cancer cells in vivo. TGF-Ξ² appears to be a key player in this process, providing further rationale for the development of anti-cancer therapeutics that target the TGF-Ξ² pathway
Outcomes of the multicenter monitoring of the causative agent of invasive listeriosis in the metropolis
Introduction. Invasive listeriosis is a rare disease posing a threat to high-risk groups and often leading to a fatal outcome. Its causative agent is Listeria monocytogenes, a ubiquitous saprophyte that has turned into an important foodborne pathogen with the growing industry of semi-cooked and ready-to-eat products.
The aim of the study is the characterization of L. monocytogenes isolates in the Moscow region and identification of possible causes of susceptibility to infection
Materials and methods. The multicenter monitoring of L. monocytogenes was conducted in the Moscow metropolitan area, using bacteriological and genomic methods for description of the pathogen, medical history collection and detailed analysis of patient case summaries.
Results. In the cohorts of patients with perinatal listeriosis (PL) and meningitis-septicemia (MS), invasive listeriosis had a year-round occurrence with slight upswings in MarchApril and JulyNovember. During the COVID-19 pandemic, in the MS group, the minimum age of patients decreased to 31 years and the proportion of deaths increased 1.57-fold compared to 20182019. During the pandemic, an increase in the diversity of L. monocytogenes genotypes was observed, along with changes in the spectrum of pathogen genotypes throughout the pandemic stages.
During the monitoring, a total of 73 L. monocytogenes clinical isolates belonging to 24 genotypes were described. Seven genotypes belonged to the first phylogenetic lineage (PLI); 14 genotypes belonged to PLII. The PL cohort had the highest proportion of PLI genotypes (52%). In the MS cohort, the group of men had the widest diversity of genotypes, 6 of which were identical to genotypes of food isolates. In the analysed set of isolates, 12 new profiles of internalin genes were identified and described. The whole genome sequencing detected the presence of plasmids in 9 of 58 genomes of clinical isolates. The comparison of core genomes revealed an epidemic relationship between isolates of the same genotype for ST4, ST21, and ST425.
Conclusion. The performed study presents a detailed description of the diversity and virulence of L. monocytogenes circulating in the Moscow metropolitan area, thus providing information for timely diagnosis and treatment of invasive listeriosis
Distinct Transcriptional Mechanisms Direct Expression of the Rat Dmrt1 Promoter in Sertoli Cells and Germ Cells of Transgenic Mice1
DMRT1 is a transcription factor expressed only in Sertoli cells and undifferentiated spermatogonia of the postnatal testis, where it is required for proper cellular differentiation and fertility. To elucidate the transcriptional regulatory regions that provide DMRT1's cell-specific expression, transgenic mice containing a LacZ reporter gene driven by variable amounts of rat Dmrt1 5β² flanking sequence, 9 kb and smaller, were evaluated. Examination of transgene expression by RT-PCR indicated that multiple promoter regions direct Dmrt1 to the testis and that sequences upstream of 2.8 kb are needed for both Sertoli cell expression and limiting transcriptional influence imposed by surrounding chromatin. Thus, whereas many of the transgenes were expressed in the testis, the ones with smaller promoters were significantly more prone to expression at ectopic sites or to complete silencing. Transgene expression in Sertoli cells and germ cells was assessed by immunohistochemistry and RT-PCR following busulfan treatment to remove germ cells. Both evaluations indicated expression of the 9- and 3.2-kb promoters in Sertoli cells and germ cells, whereas activity of smaller promoters was largely restricted to germ cells. In all, the present study provides in vivo evidence that distinct promoter sequences participate in Dmrt1 regulation in somatic cells and germ cells, with the β3.2 kb/β2.8 kb region directing expression in Sertoli cells and downstream sequences (β€1.3 kb) directing it in germ cells. Further exploration of the mechanisms restricting Dmrt1 expression to the testis revealed that FOXL2, a transcription factor required for differentiation of the ovary, repressed Dmrt1 promoter through the β3.2 kb/β2.8 kb regulatory region, offering a potential mechanism for Dmrt1 transcriptional silencing in granulosa cells
Sex-Specific Differences in Mouse DMRT1 Expression Are Both Cell Type- and Stage-Dependent During Gonad Development1
<i>Listeria monocytogenes</i> ST37 Distribution in the Moscow Region and Properties of Clinical and Foodborne Isolates
Listerias of the phylogenetic lineage II (PLII) are common in the European environment and are hypovirulent. Despite this, they caused more than a third of the sporadic cases of listeriosis and multi-country foodborne outbreaks. L. monocytogenes ST37 is one of them. During the COVID-19 pandemic, ST37 appeared in clinical cases and ranked second in occurrence among food isolates in the Moscow region. The aim of this study was to describe the genomic features of ST37 isolates from different sources. All clinical cases of ST37 were in the cohort of male patients (age, 48β81 years) with meningitisβsepticemia manifestation and COVID-19 or Influenza in the anamnesis. The core genomes of the fish isolates were closely related. The clinical and meat isolates revealed a large diversity. Prophages (2β4/genome) were the source of the unique genes. Two clinical isolates displayed pseudolysogeny, and excided prophages were A006-like. In the absence of plasmids, the assortment of virulence factors and resistance determinants in the chromosome corresponded to the hypovirulent characteristics. However, all clinical isolates caused severe disease, with deaths in four cases. Thus, these studies allow us to speculate that a previous viral infection increases human susceptibility to listeriosis
Effect of the Coat Protein N-Terminal Domain Structure on the Structure and Physicochemical Properties of Virions of Potato Virus X and Alternanthera Mosaic Virus
The amino acid sequences of the coat proteins (CPs) of the potexviruses potato virus X (PVX) and alternanthera mosaic virus (AltMV) share ~40% identity. The N-terminal domains of these proteins differ in the amino acid sequence and the presence of the N-terminal fragment of 28 residues (N peptide) in the PVX CP. Here, we determined the effect of the N-terminal domain on the structure and physicochemical properties of PVX and AltMV virions. The circular dichroism spectra of these viruses differed significantly, and the melting point of PVX virions was 10-12Β°C higher than that of AltMV virions. Alignment of the existing high-resolution 3D structures of the potexviral CPs showed that the RMSD value between the C-atoms was the largest for the N-terminal domains of the two compared models. Based on the computer modeling, the N peptide of the PVX CP is fully disordered. According to the synchrotron small-angle X-ray scattering (SAXS) data, the structure of CPs from the PVX and AltMV virions differ; in particular, the PVX CP has a larger portion of crystalline regions and, therefore, is more ordered. Based on the SAXS data, the diameters of the PVX and AltMV virions and helix parameters in solution were calculated. The influence of the conformation of the PVX CP N-terminal domain and its position relative to the virion surface on the virion structure was investigated. Presumably, an increased thermal stability of PVX virions vs. AltMV is provided by the extended N-terminal domain (N peptide, 28 amino acid residues), which forms additional contacts between the adjacent CP subunits in the PVX virion
Genetic and Epigenetic Aspects of Skin Collagen Fiber Turnover and Functioning
One of the most important functions of the skin, i.e., protection from mechanical damage, is ensured by collagen fibers and their interaction with other elements in the extracellular matrix. Collagen fiber turnover is a complex multi-stage process. At each stage, a disruption may occur, leading to a decrease in the mechanical properties of the connective tissue. Clinically, collagen formation disorders manifest themselves as increased flabbiness and looseness of the skin and as early signs of facial aging. In addition to the clinical picture, it is important for cosmetologists and dermatologists to understand the etiology and pathogenesis of collagenopathies. In our review, we summarized and systematized the available information concerning the role of genetic and epigenetic factors in skin collagen fiber turnover. Furthermore, we focused on the functions of different types of collagens present in the skin. Understanding the etiology of impaired collagen formation can allow doctors to prescribe pathogenetically based treatments, achieve the most effective results, and minimize adverse reactions
Structure and properties of virions and virus-like particles derived from the coat protein of Alternanthera mosaic virus
<div><p>Plant viruses and their virus-like particles (VLPs) have a lot of advantages for biotechnological applications including complete safety for humans. Alternanthera mosaic virus (AltMV) is a potentially promising object for design of novel materials. The 3D structures of AltMV virions and its VLPs were obtained by single particle EM at ~13Γ
resolution. The comparison of the reconstructions and a trypsin treatment revealed that AltMV CPs possesses a different fold in the presence (virions) and absence of viral RNA (VLPs). For the first time, the structure of morphologically similar virions and virus-like particles based on the coat protein of a helical filamentous plant virus is shown to be different. Despite this, both AltMV virions and VLPs are stable in a wide range of conditions. To provide a large amount of AltMV for biotechnology usage the isolation procedure was modified.</p></div
Difference map (red) between aligned to each other AltMV VLP and virion, superimposed onto a 3D structure of a VLP (transparent green).
<p><b>A.</b> Sagittal section. <b>B.</b> Cross section.</p