MORPHOLOGICAL MONITORING OF EXPERIMENTAL LIVER FIBROSIS IN RATS

Background. Though thioacetamide (TAA)-induced liver fibrosis (LF) is recognized as a classical model of toxic liver damage, there is no literature data on the description of its successive stages of histological and ultrastructural changes in various cell populations involved in fibrosis. Objective. To conduct morphological monitoring of fibrosis formation in the liver of rats using the TAA model of LF based on histological and ultrastructural changes in hepatocytes and perisinusoidal lipocytes (HSC). Material and methods. The experiment was carried out on 18 sexually mature male rats. LF was modeled by intraperitoneal injection of 2% TAA solution at a dose of 10 ml / kg every other day. Light microscopy of semi-thin sections of the liver was performed, as well as electron microscopy of ultrathin sections. Results. The study of semi-thin sections of rat liver tissue from the control group showed a normal architecture of the parenchyma, a large number of HSCs containing large lipid droplets ("resting" phenotype), a very small amount of cytoplasmic matrix poor in membrane organelles. In the animals that were receiving TAA for 4 weeks, a mesenchymalepithelial transition of HSCs from the "resting" type to a fibrogenic state (fibrogenic phenotype) was recorded, that was accompanied by a gradual decrease in the number of retinol-containing drops and the appearance of fibroblastlike cells (FLC) in HSCs. In the animals, that were receiving TAA for 12 weeks, the pool of fibrogenic cells in the liver increased, a mesothelial-mesenchymal transition occurred, characterized by the mesothelial cell migration deeper into the parenchyma and their acquisition of a mesenchymal phenotype. Lipid containing activated FLC were also found in fibrous tissue around the central vein. Foci of hepatic tissue destruction caused by necrosis and apoptosis of hepatocytes were much more common. Conclusions. Administration of TAA induces liver fibrosis while histological and ultrastructural monitoring of the state of hepatocytes and HSCs allows to monitor all stages of fibrosis, clarifying the mechanisms of damage to intracellular organelles and variants of hepatocyte death. This model of LF in rats can be used to test new antifibrotic drugs.

Cytoplasmic Matrix and Viroplasms Inclusions in the Presence of Gold Nanoparticles (AuNPs)

Cellular ultrastructure micrographs revealed striking changes resulting from the Barley Yellow Dwarf Virus (BYDV-PAV) infection in Electron microscopy. In the cytoplasm, the Gold nanoparticles (AuNPs) may bind with different cytoplasmic organelles and interfere with the treated site’s metabolic processes. The micrographs of the treated plant leave with AuNPs showing; Endosomes, amorphous bodies, slender filaments fibers, myelin bodies with a high concentration of virus particles, and Gold Nanoparticles distributed in a circulated shape in the cytoplasm with virus particles.

INCLUSION BODIES IN ORAL DISEASES – AN OVERVIEW

The inclusion bodies are tiny particles found freely suspended and floating within the cytoplasmic matrix. Due to this, it is also called as cytoplasmic inclusions. These are formed with decreasing pH and from the pool of soluble fusion proteins within the cell. They are the elementary bodies, formed during infectious diseases or within the virus-infected cells such as rabies, herpes, measles, etc. Disease progression occurs with biochemical and cellular changes. Inclusion bodies are used in staging the diseases and aid in planning the treatment. This article aims to review the inclusion bodies in various oral lesions and their morphology.

Photochemical Internalization for Intracellular Drug Delivery. From Basic Mechanisms to Clinical Research

Photochemical internalisation (PCI) is a unique intervention which involves the release of endocytosed macromolecules into the cytoplasmic matrix. PCI is based on the use of photosensitizers placed in endocytic vesicles that, following light activation, lead to rupture of the endocytic vesicles and the release of the macromolecules into the cytoplasmic matrix. This technology has been shown to improve the biological activity of a number of macromolecules that do not readily penetrate the plasma membrane, including type I ribosome-inactivating proteins (RIPs), gene-encoding plasmids, adenovirus and oligonucleotides and certain chemotherapeutics, such as bleomycin. This new intervention has also been found appealing for intracellular delivery of drugs incorporated into nanocarriers and for cancer vaccination. PCI is currently being evaluated in clinical trials. Data from the first-in-human phase I clinical trial as well as an update on the development of the PCI technology towards clinical practice is presented here.

CYTOMORPHOLOGICAL TRANSFORMATIONS IN YADK-04 CELLS DURING INTERACTION WITH PESTE DE PETITS RUMINANTS VIRUS

The paper presents experimental study results of the cytopathic effect of peste de petits ruminants virus on a goat gonad continuous cell line (YaDK-04). The interaction of peste de petits ruminants virus with cells at different stages of its reproduction was shown using a combination of phase-contrast and luminescent microscopy. It was found that at the initial stage of interaction (20–24 hours) the cells became rounded and de-adhered, and the monolayer was partially loosened. On day 2 post reproduction the most part of the culture monolayer affected by the virus began to destruct, and the cell nuclei were displaced to periphery. At the terminal stage (72 hours) the destruction of monolayer cells and cytoplasmic matrix, deformation and partial lysis of the nuclei and cytoplasm, aggregation of detritus occurred. At the final stage of reproduction (96 hours) the peste de petits ruminants virus diffused into the culture medium, the fluorescence in the yellow spectrum decreased significantly, but the virus titer reached 6.89 lg TCD50/cm3.

Structural changes of the intestinal epithelial barrier of the duodenum of rats in burn injury of skin under experimental streptozotocin-induced diabetes mellitus

The aim of the study was to study the structural changes of the intestinal epithelial barrier in the duodenum in burn injury of skin in rat under experimental streptozotocin-induced diabetes mellitus. The study was carried out on laboratory white adult rats-males weighing 180-210 g. The control group consisted of 21 animals without somatic pathology, the first experimental group was 21 rats with burn skin injury, the second experimental group was 21 rats with burn skin and experimental streptozotocin-induced diabetes mellitus. The experimental diabetes model was reproduced by administering streptozotocin to the rats intraperitoneally at a single dose of 50 mg/kg. Thermal burn skin damage in rats corresponded to II – A-B degrees of dermal surface burn (according to the old classification III – A degree) with a total area of 21-23 % of the body surface with the development of burn shock. Duodenum was selected for morphological studies, fragments of which were processed by conventional methods of light and electron microscopy. The main criteria for assessing damage to the duodenal mucosa enterocytes were the results of a study comparing histological and ultrastructural data in dynamics at 7, 14, and 21 days after skin burns. The results of the studies showed that the base of damage to the intestinal epithelial barrier of the duodenum are deep destructive changes, which after 21 days (in the stage of septicotoxemia), as a rule, are not reverse and develop on the background of significant intoxication of the body. There was a decrease in the number of tight junctions in the intestinal epithelial barrier of the duodenum of rats of the first and second experimental groups and a loss of ordering (acquisition of some chaotic nature) of their localization as the time after burn injury increased. For the most part, the intestinal epithelial barrier loses the integrity of the cellular component with partial preservation of the basement membrane (the first occurs both due to necrosis of the enterocytes with a brush border and due to complete destruction of goblet cells). In all cases, defects exist in the intestinal epithelial barrier, which are potential pathways for paracellular translocation of the pathogenic contents of the duodenum. It is not inconceivable that part of this intestinal pathogenic content can be translocated also by partially damaged cells. Evidence of the latter is the presence of microbial bodies in the cytoplasm of cells with partially destroyed plasmalemma (but preserved organelles and nucleus). An adaptive mechanism for ensuring the repair of damaged enterocytes is selective autophagy, which acts as a factor in the recycling of destroyed organelles and the cytoplasmic matrix, aimed primarily at maintaining cell viability.

Endoplasmic reticulum-to-Golgi transitions upon herpes virus infection

Background: Herpesvirus capsids are assembled in the nucleus, translocated to the perinuclear space by budding, acquiring tegument and envelope, or released to the cytoplasm via impaired nuclear envelope. One model proposes that envelopment, “de-envelopment” and “re-envelopment” is essential for production of infectious virus. Glycoproteins gB/gH were reported to be essential for de-envelopment, by fusion of the “primary” envelope with the outer nuclear membrane. Yet, a high proportion of enveloped virions generated from genomes with deleted gB/gH were found in the cytoplasm and extracellular space, suggesting the existence of alternative exit routes.Methods: We investigated the relatedness between the nuclear envelope and membranes of the endoplasmic reticulum and Golgi complex, in cells infected with either herpes simplex virus 1 (HSV-1) or a Us3 deletion mutant thereof, or with bovine herpesvirus 1 (BoHV-1) by transmission and scanning electron microscopy, employing freezing technique protocols.Results: The Golgi complex is a compact entity in a juxtanuclear position covered by a membrane on thecisface. Golgi membranes merge with membranes of the endoplasmic reticulum forming an entity with the perinuclear space. All compartments contained enveloped virions. After treatment with brefeldin A, HSV-1 virions aggregated in the perinuclear space and endoplasmic reticulum, while infectious progeny virus was still produced.Conclusions: The data suggest that virions derived by budding at nuclear membranes are intraluminally transported from the perinuclear space via Golgi -endoplasmic reticulum transitions into Golgi cisternae for packaging. Virions derived by budding at nuclear membranes are infective like Us3 deletion mutants, which accumulate in the perinuclear space. Therefore, i) de-envelopment followed by re-envelopment is not essential for production of infective progeny virus, ii) the process taking place at the outer nuclear membrane is budding not fusion, and iii) naked capsids gain access to the cytoplasmic matrix via impaired nuclear envelope as reported earlier.

De novo organelle biogenesis in the cyanobacterium TDX16 released from the green algaHaematococcus pluvialis

It is believed that eukaryotes arise from prokaryotes, which means that organelles can form in the latter. Such events, however, had not been observed previously. Here, we report the biogenesis of organelles in the endosymbiotic cyanobacterium TDX16 that escaped from its senescent/necrotic host cell of green algaHaematococcus pluvialis. In brief, organelle biogenesis in TDX16 initiated with cytoplasm compartmentalization, followed by de-compartmentalization, DNA allocation, and re-compartmentalization, as such two composite organelles-the primitive chloroplast and primitive nucleus sequestering minor and major fractions of cellular DNA respectively were formed. Thereafter, the eukaryotic cytoplasmic matrix was built up from the matrix extruded from the primitive nucleus; mitochondria were assembled in and segregated from the primitive chloroplast, whereby the primitive nucleus and primitive chloroplast matured into nucleus and chloroplast respectively; while most mitochondria turned into double-membraned vacuoles after matrix degradation. Results of pigment analyses, 16S rRNA and genome sequencing revealed that TDX16 is a phycocyanin-containing cyanobacterium resemblingChroococcidiopsis thermalis, which had acquired 9,017,401bp DNAs with 10301 genes form its host. Therefore, organelle biogenesis in TDX16 was achieved by hybridizing the acquired eukaryotic DNAs with its own ones and expressing the hybrid genome.Organelle biogenesis in TDX16 results in its transition into a new eukaryotic alga TDX16-DE, which provides a reference to re-understand the development, structure, function and association of organelles in eukaryotes and the reasons behind them, and has implications on other sections of biology, particularly cancer biology and evolutionary biology: (1) the formation and maturation of the small organelle-less nascent cancer cells share striking similarities with TDX16 development and transition, so, it is most likely that cancer cells arise from bacteria; (2) organelle biogenesis in TDX16 uncovers a way of new organelle and new single-celled eukaryote formation, and in light of which, the ancestral organelles were likely formed in rather than transformed form the endosymbiotic prokaryotes that had acquired their hosts’ DNAs.

Cellular Calcium Distribution Modulates the Growth of Callus and Protoplasts of Halophyte Mangrove Plant, Avicennia Alba - an X-ray Microanalysis

Two cultured cell lines were developed from cotyledons of a halophyte mangrove, Avicennia alba.In the high-Ca callus line, which was sub-cultured in amodified amino acid medium containing 3 mM CaCl2, growth of calluses and their protoplasts were both inhibited by low concentrations of CaCl2 in the culture medium. Removal of Ca2+ from the culture medium stimulated callus growth and the calluses could be sub-cultured without CaCl2 (low-Ca callus line). The intra- (cytoplasmic matrix and vacuole) and extra- (cell wall) cellular concentrations of elements, i.e., [Ca], [K], [Cl], [Na], [Mg], [P] and [S] were investigated using quantitative X-ray microanalysis of cryosections of calluses from bothcell lines. [Ca] was high in the cytoplasmic matrix and cell wall of the high-Ca line. [Ca] was lowered in the low-Calineinall cell compartments, though still detected. Ca-containing electron-dense precipitates were accumulated in the middle lamella of cell walls in resin-embedded sections of the high-Ca line. CaCl2 in the medium stimulated protoplast growth only in the low-Caline. These results suggested that a low cellular [Ca] is needed for protoplasts growth of A. alba. The importance of cellular [Ca] for the growth of halophilic mangrove plant cells was discussed.