Impact of Canine Amniotic Mesenchymal Stem Cell Conditioned Media on the Wound Healing Process: In Vitro and In Vivo Study

The aim of this study was to provide a beneficial treatment effect of mesenchymal stem cell products derived from the canine amniotic membrane (AM-MSC) on the complicated wound healing process in dogs. AM-MSCs were characterized in terms of morphology, phenotypic profile, and multilineage differentiation potential. The in vitro study of the effect of canine amniotic mesenchymal stem cell conditioned media (AMMSC-CM) on a primary skin fibroblast cell culture scratch assay showed a decrease in the measured scratch area of about 66.39% against the negative control (Dulbecco's Modified Eagle's Medium-32.55%) and the positive control (Dulbecco's Modified Eagle's Medium supplemented with FGF2, N2, B27, and EGF-82.077%) after 72 h treatment. In the experimental study, seven dogs with complicated nonhealing wounds were treated with a combination of antibiotics, NSAIDs, and local AMMSC-CM application. After 15 days of therapy, we observed a 98.47% reduction in the wound surface area as opposed to 57.135% in the control group treated by conventional therapy based on debridement of necrotic tissue, antibiotic therapy, pain management, and change of wound dressing.

Brain Fluid Channels for Metabolite Removal

The adult human brain represents only 2 % of the body's total weight, however it is one of the most metabolically active organs in the mammalian body. Its high metabolic activity necessitates an efficacious waste clearance system. Besides the blood, there are two fluids closely linked to the brain and spinal cord drainage system: interstitial fluid (ISF) and cerebrospinal fluid (CSF). The aim of this review is to summarize the latest research clarifying the channels of metabolite removal by fluids from brain tissue, subarachnoid space (SAS) and brain dura (BD). Special attention is focused on lymphatic vascular structures in the brain dura, their localizations within the meninges, morphological properties and topographic anatomy. The review ends with an account of the consequences of brain lymphatic drainage failure. Knowledge of the physiological state of the clearance system is crucial in order to understand the changes related to impaired brain drainage.

In Vitro Model of Human Trophoblast in Early Placentation

The complex process of placental implantation and development affects trophoblast progenitors and uterine cells through the regulation of transcription factors, cytokines, adhesion receptors and their ligands. Differentiation of trophoblast precursors in the trophectoderm of early ontogenesis, caused by the transcription factors, such as CDX2, TEAD4, Eomes and GATA3, leads to the formation of cytotrophoblast and syncytiotrophoblast populations. The molecular mechanisms involved in placental formation inside the human body along with the specification and differentiation of trophoblast cell lines are, mostly due to the lack of suitable cell models, not sufficiently elucidated. This review is an evaluation of current technologies, which are used to study the behavior of human trophoblasts and other placental cells, as well as their ability to represent physiological conditions both in vivo and in vitro. An in vitro 3D model with a characteristic phenotype is of great benefit for the study of placental physiology. At the same time, it provides great support for future modeling of placental disease.

Bone Marrow-Derived Cells Participate in Composition of the Satellite Cell Niche in Intact and Regenerating Mouse Skeletal Muscle

The cellular components of the satellite cell niche participate in the regulation of skeletal muscle regeneration. Beside myogenic cells at different developmental stages, this niche is formed by cells of the immune system, the interstitial connective tissue and the vascular system. Unambiguous determination of the origin of these cell types could contribute to optimization of the cell-based therapy of skeletal muscle disorders. In our work, we intravenously transplanted mouse GFP⁺ unseparated bone marrow cells into whole-body lethally irradiated immunocompetent mice four weeks before cardiotoxin-induced injury of the recipients' skeletal muscles. Seven and 28 days after the toxin injection, the injured regenerating and contralateral intact muscles were examined for identification of GFP⁺ bone marrow-derived cells by direct fluorescence, protein immunohistochemistry and immunogold transmission electron microscopy. In both the intact and injured muscles, GFP positivity was determined in immune cells, mainly in macrophages, and in interstitial spindleshaped cells. Moreover, in the injured muscles, rare GFP+ endothelial cells of the blood vessels and newly formed myotubes and muscle fibres were present. Our results confirmed the ability of bone marrowderived cells to contribute to the cellular component of the satellite cell niche in the intact and regenerating skeletal muscle. These cells originated not only from haematopoietic stem cells, but obviously also from other stem or progenitor cells residing in the bone marrow, such as multipotent mesenchymal stromal cells and endothelial progenitors.

Expression of MRP2 and MDR1 transporters and other hepatic markers in rat and human liver and in WRL 68 cell line

Here we describe a comparative study of phenotypic properties of hepatic cells in situ and in vitro. We analyzed the expression levels and distribution patterns of ABC transporters MRP2 and MDR1, pan-cytokeratin, cytokeratin 18, albumin, alpha-fetoprotein and the specific hepatocyte marker OCH1E5 in the fetal and adult rat as well as human liver tissue and in human fetal hepatocytes of WRL 68 cell line using peroxidase immunohistochemistry or immunofluorescence. Transporters MRP2 and MDR1 were expressed in all examined liver tissues, except rat ED13 embryo. The immunopositivity of these proteins was localized to the canalicular membrane of differentiating and mature hepatocytes but in the later developmental stages and in the adult liver tissues it was also found in the apical membrane of cholangiocytes. In WRL 68 cells, MRP2 and MDR1 immunoreactivity appeared after 5-6 days of cultivation and both transporters were fully expressed in the plasmalemma and in the cytoplasm 9 days after the passage. In conclusion, we observed only moderate variances reflecting diverse ontogenetic phases between the fetal and adult liver tissue. To study functions of hepatocytes in vitro, WRL 68 cells have to differentiate prior to the examination. Our findings indicate that WRL 68 cells can undergo differentiation in vitro and their antigenic profile closely resembles hepatocytes in the human liver.

Experimental cauda equina compression induces HSP70 synthesis in dog

The heat shock protein 70 (HSP70) is a key component of the stress response induced by various noxious conditions such as heat, oxygen stress, trauma and infection. In present study we have assessed the consequences of the compression of lower lumbar and sacral nerve roots caused by a multiple cauda equina constrictions (MCEC) on HSP70 immunoreactivity (HSP70-IR) in the dog. Our data indicate that constriction of central processes evokes HSP70 up-regulation in the spinal cord (L7, S1-Co3) as well as in the corresponding dorsal root ganglion cells (DRGs) (L7-S1) two days following injury. A limited number of bipolar or triangular HSP-IR neurons were found in the lateral collateral pathway (LCP) as well as in the pericentral region (lamina X) of the spinal cord. In contrast, a high number of HSP70 exhibiting motoneurons with fine processes appeared in the ventral horn (laminae VIII-IX) of lumbosacral segments. Concomitantly, close to them a few lightly HSP70-positive neuronal somata or cell bodies lacking the HSP70-IR occurred. In the DRGs, HSP70 expression was mildly up-regulated in small and medium-sized neurons and in satellite cells. On the contrary, DRGs from intact or sham-operated dogs did not reveal HSP70 specific neuronal staining. In conclusion, we have demonstrated that the MCEC in dogs mimicking the cauda equina syndrome in clinical settings evokes expression of HSP70 synthesis in specific neurons of the lumbo-sacro-coccygeal spinal cord segments and in small and medium sized neurons of corresponding DRGs. This suggests that HSP70 may play an active role in neuroprotective processes partly by maintaining intracellular protein integrity and preventing the neuronal degeneration in this experimental paradigm.