Context-Specific Osteogenic Potential of Mesenchymal Stem Cells

Despite the great progress in the field of bone tissue regeneration, the early initiating mechanisms of osteogenic differentiation are not well understood. Cells capable of osteogenic transformation vary from mesenchymal stem cells of various origins to mural cells of vessels. The mechanisms of pathological calcification are thought to be similar to those of bone formation. Notch signaling has been shown to play an important role in osteogenic differentiation, as well as in pathological calcification. Nevertheless, despite its known tissue- and context-specificity, the information about its role in the osteogenic differentiation of different cells is still limited. We compared mesenchymal stem cells from adipogenic tissue (MSCs) and interstitial cells from the aortic valve (VICs) by their ability to undergo Notch-dependent osteogenic differentiation. We showed differences between the two types of cells in their ability to activate the expression of proosteogenic genes RUNX2, BMP2, BMP4, DLX2, BGLAP, SPRY, IBSP, and SPP1 in response to Notch activation. Untargeted metabolomic profiling also confirms differences between MSCs and VICs in their osteogenic state. Analysis of the activity of RUNX2 and SPP1 promoters shows fine-tuned dose-dependency in response to Notch induction and suggests a direct link between the level of Notch activation, and the proostogenic gene expression and corresponding osteogenic induction. Our data suggest that osteogenic differentiation is a context-dependent process and the outcome of it could be cell-type dependent.

FEATURES OF THE MINERAL COMPOSITION OF NANOBACTERIA FROM HUMAN AND ANIMAL BLOOD AND THEIR RADIATION IN VITRO

Currently, in the field of medicine and veterinary medicine there are still a lot of unsolved problems associated with the lack of effective methods to combat a number of diseases. This list should include diseases associated with pathological calcification of organs and tissues of humans and 2 animals, and damage to lymphoid tissues by pathogens of viral and bacterial etiology. At the same time, the discovery at the end of the last century of a new type of microorganism, nanobacteria or dwarf bacteria, did not change the situation for a number of socially significant diseases. One of the most likely reasons is that scientists are still unable to determine the nature of nanobacteria - these are mineral complexes or living smallest formations. Detection in the blood of humans and animals of structures with nanometer size with pronounced morphological signs of prokaryotes leaves no doubt about their living nature.

Focal ossification as one of the reasons for erroneous diagnosis of chorioretinal lesions

Focal calcifications of the retina and choroid occur usually in such well-known tumors as: retinoblastoma, choroidal osteoma, choroidal hemangioma, retinal astrocytoma. In addition, cases of idiopathic or secondary calcification are known, the most common of them is sclerochoroidal calcification. The article provides a detailed analysis of the clinical and tomographic pictures of ossifying conditions occurring in adults. It is shown that, in addition to a different ophthalmoscopic picture, these conditions are characterized by a different level of localization of the pathological calcification zone and a different stage of retinal damage.