Cancer Angiogenesis and Opportunity of Influence on Tumor by Changing Vascularization.

Based on the study of recent scientific literature devoted to neovascularization and angiogenesis in malignant neoplasms, it was concluded that there are many publications on each of the problems of tumor angiogenesis and vascularization. The formation of blood vessels in a tumor and certain aspects of the prognostic value of the severity of vascularization in almost all forms of cancer are considered. Special attention is paid to the peculiarities of angiogenesis in tumors of the female reproductive system. A large number of vessels in the tumor often indicates a poor prognosis. The influence of various factors on the initiation of angiogenesis and the process itself, as well as the possibility of suppressing such signals to slow down the formation of blood vessels and thus the development of the tumor are widely studied. The results of pharmacological suppression of tumor vessel formation demonstrate a good clinical outcome but one accompanied by a large number of severe adverse side effects. Such a significant amount of studies on each of the problems of tumor vascularization indicates the increasing importance of this area of oncology. At the same time, only a very small number of works are devoted to the study of the differences in angiogenesis and number of vessels between different parts of the tumor, as well as between the primary tumor node and its metastases. The refinement of the results is still to be done. It was noted that the expression of proangiogenic factors in metastases is usually higher than in the source of metastasis, and the expression in lymphogenous metastases is higher than in hematogenous ones.

Cell Technologies in the Stress Urinary Incontinence Correction.

The scientific literature of recent years contains a lot of data about using multipotent stromal cells (MSCs) for urinary incontinence correction. Despite this, the ideal treatment method for urinary incontinence has not yet been created. The cell therapy results in patients and experimental animals with incontinence have shown promising results, but the procedures require further optimization, and more research is needed to focus on the clinical phase. The MSC use appears to be a feasible, safe, and effective method of treatment for patients with urinary incontinence. However, the best mode for application of cell technology is still under study. Most clinical investigations have been performed on only a few patients and during rather short follow-up periods, which, together with an incomplete knowledge of the mechanisms of MSC action, does not make it possible for their widespread implementation. The technical details regarding the MSC application remain to be identified in more rigorous preclinical and clinical trials.

Morphology of the Myocardium after Experimental Bone Tissue Trauma and the Use of Extracellular Vesicles Derived from Mesenchymal Multipotent Stromal Cells.

The effect of extracellular vesicles (EVs) of various origins on the heart structures in the time of health and disease has been well studied. At the same time, data on the distribution of EVs throughout the body after introduction into the tissues and the possibility of the influence of these EVs on organs distant from the injection site are practically absent. It is also necessary to note a certain inconsistency in the results of various researchers: from articles on the direct absorption of EVs derived from mesenchymal multipotent stromal cells (MSC EVs) by cardiomyocytes to the data that the heart is inherently immune to drug delivery mediated by nanoparticles. In this regard, the morphological changes in the myocardium of outbred rabbits of both sexes weighing 3-4 kg were studied at various times after experimental trauma of the bone tissue in the proximal condyle of the tibia (PCT) and the use of MSC EVs. As a result of modeling the PCT defect, rabbits develop myocardial edema in the heart muscle by the 3rd day, their lymphatic vessels expand, and then, on the 7th day, the blood vessels become dilated. In the myocardium, the relative and absolute contents of neutrophils, erythrocytes, and macrophages increase, but the percentage of lymphocytes decreases. By day 10, almost all of these changes return to their initial values. The detected transformations of the myocardium are most likely due to the ingress of detritus with the blood flow from the PCT. The use of MSC EVs to influence the regeneration of damaged tissue of PCT promotes earlier dilatation of the blood vessels of the heart with pronounced diapedesis of erythrocytes or even hemorrhages, prolongation of edema, the formation of blood clots in vessels with obliteration of their lumen, sclerotic transformation of vascular walls and paravascular tissues. In the myocardium, the number density of neutrophils, the percentage of lymphocytes, and neutrophils become smaller, with a simultaneous increase in the relative numbers of erythrocytes and macrophages, and changes in the content of macrophages remained until the end of the observation-up to 10 days after the surgery. The discovered effect of MSC EVs is most likely associated with the suppression of the activity of the inflammatory process in the PCT area, which, in turn, was caused by a longer ingress of detritus with blood flow into the myocardium. The absence of statistically significant differences between changes in the myocardium of the left and right ventricles may indicate that both detritus from the surgical site and MSC EVs affect the heart spreading through the coronary artery system.

First Experimental Study of the Influence of Extracellular Vesicles Derived from Multipotent Stromal Cells on Osseointegration of Dental Implants.

Herein, the aim was to study the state of the bone tissue adjacent to dental implants after the use of extracellular vesicles derived from multipotent stromal cells (MSC EVs) of bone marrow origin in the experiment. In compliance with the rules of asepsis and antiseptics under general intravenous anesthesia with propofol, the screw dental implants were installed in the proximal condyles of the tibia of outbred rabbits without and with preliminary introduction of 19.2 µg MSC EVs into each bone tissue defect. In 3, 7, and 10 days after the operation, the density of bone tissue adjacent to different parts of the implant using an X-ray unit with densitometer was measured. In addition, the histological examinations of the bone site with the hole from the removed device and the soft tissues from the surface of the proximal tibial condyle in the area of intra-bone implants were made. It was found out that 3 days after implantation with the use of MSC EVs, the bone density was statistically significantly higher by 47.2% than after the same implantation, but without the injection of MSC EVs. It is possible that as a result of the immunomodulatory action of MSC EVs, the activity of inflammation decreases, and, respectively, the degree of vasodilation in bones and leukocyte infiltration of the soft tissues are lower, in comparison with the surgery performed in the control group. The bone fragments formed during implantation are mainly consolidated with each other and with the regenerating bone. Day 10 demonstrated that all animals with the use of MSC EVs had almost complete fusion of the screw device with the bone tissue, whereas after the operation without the application of MSC EVs, the heterogeneous histologic pattern was observed: From almost complete osseointegration of the implant to the absolute absence of contact between the foreign body and the new formed bone. Therefore, the use of MSC EVs during the introduction of dental implants into the proximal condyle of the tibia of rabbits contributes to an increase of the bone tissue density near the device after 3 days and to the achievement of consistently successful osseointegration of implants 10 days after the surgery.

Multipotent Stromal Cell Extracellular Vesicle Distribution in Distant Organs after Introduction into a Bone Tissue Defect of a Limb.

When administered intravenously, extracellular vesicles derived from multipotent stromal cells (MSC EVs) immediately pass through the lungs along with the blood and regularly spread to all organs. When administered intraperitoneally, they are absorbed either into the blood or into the lymph and are quickly disseminated throughout the body. The possibility of generalized spread of MSC EVs to distant organs in case of local intratissular administration remains unexplored. However, it is impossible to exclude MSC EV influence on tissues distant from the injection site due to the active or passive migration of these injected nanoparticles through the vessels. The research is based on findings obtained when studying the samples of lungs, heart, spleen, and liver of outbred rabbits of both sexes weighing 3-4 kg at various times after the injection of EVs derived from MSCs of bone marrow origin and labeled by PKH26 into an artificially created defect of the proximal condyle of the tibia. MSC EVs were isolated by serial ultracentrifugation and characterized by transmission electron microscopy and flow cytometry. After the introduction of MSC EVs into the damaged proximal condyle of the tibia of rabbits, these MSC EVs can be found most frequently in the lungs, myocardium, liver, and spleen. MSC EVs enter all of these organs with the blood flow. The lungs contained the maximum number of labeled MSC EVs; moreover, they were often associated with detritus and were located in the lumen of the alveoli. In the capillary network of various organs except the myocardium, MSC EVs are adsorbed by paravasal phagocytes; in some cases, specifically labeled small dust-like objects can be detected throughout the entire experiment-up to ten days of observation. Therefore, we can conclude that the entire body, including distant organs, is effected both by antigenic detritus, which appeared in the bloodstream after extensive surgery, and MSC EVs introduced from the outside.

Some Special Aspects of Liver Repair after Resection and Administration of Multipotent Stromal Cells in Experiment.

Changes in rat liver after resection and injection of autologous multipotent mesenchymal stromal cells of bone marrow origin (MSCs) transfected with the GFP gene and cell membranes stained with red-fluorescent lipophilic membrane dye were studied by light microscopy. It was found that after the introduction of MSCs into the damaged liver, their differentiation into any cells was not found. However, under the conditions of MSCs use, the number of neutrophils in the parenchyma normalizes earlier, and necrosis and hemorrhages disappear more quickly. It was concluded that the use of MSCs at liver resection for the rapid restoration of an organ is inappropriate, since the injected cells in vivo do not differentiate either into hepatocytes, into epithelial cells of bile capillaries, into endotheliocytes and pericytes of the vascular membranes, into fibroblasts of the scar or other connective tissue structures, or into any other cells present in the liver.

DNA methylation and gene expression profiling reveal MFAP5 as a regulatory driver of extracellular matrix remodeling in varicose vein disease.

AIM: To integrate transcriptomic and DNA-methylomic measurements on varicose versus normal veins using a systems biological analysis to shed light on the interplay between genetic and epigenetic factors. MATERIALS & METHODS: Differential expression and methylation were measured using microarrays, supported by real-time quantitative PCR and immunohistochemistry confirmation for relevant gene products. A systems biological 'upstream analysis' was further applied. RESULTS: We identified several potential key players contributing to extracellular matrix remodeling in varicose veins. Specifically, our analysis suggests MFAP5 acting as a master regulator, upstream of integrins, of the cellular network affecting the varicose vein condition. Possible mechanism and pathogenic model were outlined. CONCLUSION: A coherent model proposed incorporates the relevant signaling networks and will hopefully aid further studies on varicose vein pathogenesis.

Early-stage atherosclerosis in poloxamer 407-induced hyperlipidemic mice: pathological features and changes in the lipid composition of serum lipoprotein fractions and subfractions.

BACKGROUND: The aims of this study were to evaluate the effect of poloxamer 407 administration on atherogenic serum lipoprotein fractions and subfractions associated with cholesterol, triglycerides and phospholipids, as well as the onset of early atherosclerosis, in mice. METHODS: Mice were administered either sterile saline or poloxamer 407 (to induce a dose-controlled hyperlipidemia) for 1 month and then sacrificed at 1, 4 and 10 days after the last dose of poloxamer 407. Systolic and diastolic blood pressure, the activity of a cysteine protease (cathepsin B) in cardiac and liver tissue, and histological/morphological examination of heart and liver specimens was performed for each group of mice at each time point. Lastly, small angle X-ray scattering was utilized to analyze the lipoprotein fractions and subfractions associated with cholesterol, triglycerides and phospholipids for both groups of mice at each time point. Statistical analysis was performed using one-way, analysis-of-variance with post hoc analysis to determine significantly different mean values, while correlation analysis employed the Spearman test. RESULTS: Poloxamer 407-treated mice revealed significant hyperlipidemia, moderately elevated blood pressure, general lipidosis in liver cells, increased cysteine protease activity in heart tissue, and contractile-type changes in cardiomyocytes. Similar to humans, the onset of atherosclerosis in poloxamer 407-treated mice was characterized by a steady increase in serum low-density, intermediate-density and very-low-density lipoprotein fractions, as well as very-low-density lipoprotein subfractions. CONCLUSIONS: We would propose that the sustained elevation of serum atherogenic lipoprotein fractions and subfractions induced by the administration of poloxamer 407 to mice resulted in the morphological changes we observed in both heart and liver cells, which are suggested to precede atherosclerosis, since this is a well-established mouse model of atherosclerosis. Since most of the cellular, biochemical and physiological changes documented in the present study using poloxamer 407-treated mice are related to the symptoms of early atherosclerosis in humans, it is suggested that the poloxamer 407-induced mouse model of hyperlipidemia and atherosclerosis might prove beneficial as an experimental animal model with which to evaluate the pathological features observed in early-stage atherosclerosis.