located between cementum and alveolar bone has important role in regeneration of periodontal tissues damaged by mechanical or biochemical factors (Ozer et al., 2013). In order to maintain PDL homeostasis in both normal and pathologic conditions, resident PDL multipotent progenitors, or stem cell-like cells (PDLSCs) act depending on local tissue demands, since PDLSCs can differentiate into major cellular constituents of PDL, such are osteoblast, fibroblast, and cementoblasts, thus maintaining PDL structure and function (Bassir et al., 2016;Han, Menicanin, Gronthos, & Bartold, 2014;Liu et al., 2015;Mao, Robey, & Prockop, 2012;Zhu & Liang, 2015).Oral cavity presents host niche for pathogenic bacteria which may provoke host tissue inflammation, damage dental tissues homeostasis, and finally lead to gingivitis or periodontitis (Chatzivasileiou, Kriebel, Steinhoff, Kreikemeyer, & Lang, 2015), as well as various systemic diseases (Nagpal, Yamashiro, & Izumi, 2015;Seymour, Ford, Cullinan, Leishman, & Yamazaki, 2007 bovine serum (FBS; Capricorn-Scientific, Germany), 100 U/ml penicillin and 100 μg/ml streptomycin (Gibco, Thermo Fisher Scientific), and incubated at 37°C in humidified atmosphere containing 5% CO 2 (standard conditions). The medium was replaced twice a week, and after reaching the 90% of confluence, the cells were detached using 0.25% solution of trypsin/EDTA (Gibco). All experiments were performed using PDLSCs between passage two and six.Human peripheral blood mononuclear cells (MNCs) were isolated from fresh heparinized blood collected from 15 healthy voluntary unrelated donors by density gradient using lymphocyte separation medium Lymphocyte Separation Medium 1.077 g/ml (CapricornScientific). Purified MNCs were cultivated in RPMI-1640 medium (Sigma-Aldrich) supplemented with 10% FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, 100 U/ml penicillin, and 100 μg/ml streptomycin in standard conditions.Human endothelial cell line (EA.hy926) was purchased from The American Type Culture Collection (ATCC, CRL-2922), MD, and cultured in GM in standard conditions. antibodies (Thermo Scientific) and CD14 (Sigma-Aldrich). The percentage of nonspecific binding was determined by using the appropriate FITC-and PE-conjugated isotype control antibodies (R&D Systems). Flow cytometry was performed using flow cytometer Cytomics FC 500 (Beckman Coulter). | Phenotype analysis | Multilineage differentiationFor evaluation of multilineage differentiation capacity PDLSCs were cultivated in GM or corresponding differentiation medium (DM) with orwithout LPS (1000 ng/ml, purchased from Sigma-Aldrich) in standard conditions. Osteogenic DM contained DMEM supplemented with 5% FBS, 100 U/ml penicillin/streptomycin, 50 µM ascorbic acid-2-phosphate (Sigma-Aldrich), and 10 mM β-glycerophosphate (SigmaAldrich). For osteogenic differentiation detection, alkaline phosphatase (ALP) staining has been followed after 7 days of cultivation, while calcium in DMEM, 100 U/ml penicilin/streptomycin, 100 µg/ml isobutylmethylxanthine (IBMX; Sigma-Aldrich),...

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Mesenchymal stem cells from human adipose tissue (hASCs) are proposed as suitable tools for soft tissue engineering and reconstruction. Although it is known that hASCs have the ability to home to sites of inflammation and tumor niche, the role of inflammatory cytokines in the hASCs-affected tumor development is not understood. We found that interferon-c (IFN-c) and/or tumor necrosis factor-a (TNF-a) prime hASCs to produce soluble factors which enhance MCF-7 cell line malignancy in vitro. IFN-c and/or TNF-a-primed hASCs produced conditioned media (CM) which induced epithelial to mesenchymal transition (EMT) of MCF-7 cells by reducing E-Cadherin and increasing Vimentin expression. Induced EMT was accompanied by increased invasion, migration, and urokinase type-plasminogen activator (uPA) expression in MCF-7 cells. These effects were mediated by increased expression of transforming growth factor-b1(TGF-b1) in cytokines-primed hASCs, since inhibition of type I TGF-b1 receptor on MCF-7 cells and neutralization of TGF-b1 disabled the CM from primed hASCs to increase EMT, cell migration, and uPA expression in MCF-7 cells. Obtained data suggested that IFNc and/or TNF-a primed hASCs might enhance the malignancy of MCF-7 cell line by inducing EMT, cell motility and uPA expression in these cells via TGF-b1-Smad3 signalization, with potentially important implications in breast cancer progression.

Mesenchymal stem cells (MSCs) have the potential to migrate toward damaged tissues increasing tissue regeneration. Interleukin-17 (IL-17) is a proinflammatory cytokine with pleiotropic effects associated with many inflammatory diseases. Although IL-17 can modulate MSC functions, its capacity to regulate MSC migration is not well elucidated so far. Here, we studied the role of IL-17 on peripheral blood (PB) derived MSC migration and transmigration across endothelial cells. IL-17 increased PB-MSC migration in a wound healing assay as well as cell mobilization from collagen gel. Concomitantly IL-17 induced the expression of urokinase type plasminogen activator (uPA) without affecting matrix metalloproteinase expression. The incremented uPA expression mediated the capacity of IL-17 to enhance PB-MSC migration in a ERK1,2 MAPK dependent way. Also, IL-17 induced PB-MSC migration alongside with changes in cell polarization and uPA localization in cell protrusions. Moreover, IL-17 increased PB-MSC adhesion to endothelial cells and transendothelial migration, as well as increased the capacity of PB-MSC adhesion to fibronectin, in an uPA-dependent fashion. Therefore, our data suggested that IL-17 may act as chemotropic factor for PB-MSCs by incrementing cell motility and uPA expression during inflammation development.

State of tumor microenvironment (TME) is closely linked to regulation of tumor growth and progression affecting the final outcome, refractoriness, and relapse of disease. Interactions of tumor, immune, and mesenchymal stromal/stem cells (MSCs) have been recognized as crucial for understanding tumorigenesis. Due to their outstanding features, stem cell-like properties, capacity to regulate immune response, and dynamic functional phenotype dependent on microenvironmental stimuli, MSCs have been perceived as important players in TME. Signals provided by tumor-associated chronic inflammation educate MSCs to alter their phenotype and immunomodulatory potential in favor of tumor-biased state of MSCs. Adjustment of phenotype to TME and acquisition of tumor-promoting ability by MSCs help tumor cells in maintenance of permissive TME and suppression of antitumor immune response. Potential utilization of MSCs in treatment of tumor is based on their inherent ability to home tumor tissue that makes them suitable delivery vehicles for immune-stimulating factors and vectors for targeted antitumor therapy. Here, we review data regarding intrusive effects of inflammatory TME on MSCs capacity to affect tumor development through modification of their phenotype and interactions with immune system.

Adipose tissue is an attractive source of mesenchymal stem/stromal cells (MSCs) with potential applications in reconstructive plastic surgery and regenerative medicine. The aim of this study was to characterise human adipose tissue MSCs (ASCs) derived from healthy individuals and cancer patients and to compare their interactions with tumour cells. ASCs were isolated from adipose tissue of healthy donors, breast cancer-adjacent adipose tissue of breast cancer patients and tumour-adjacent adipose tissue of non-breast cancer patients. Their proliferation, differentiation, immunophenotype and gene expression were assessed and effects on the proliferation of human breast cancer cell line MCF-7 compared. ASCs from all sources exhibited similar morphology, proliferative and differentiation potential, showing the characteristic pattern of mesenchymal surface markers expression (CD90, CD105, CD44H, CD73) and the lack of HLA-DR and hematopoietic markers (CD11a, CD33, CD45, Glycophorin-CD235a), but uneven expression of CD34. ASCs also shared a common positive gene expression of HLA-DR, HLA-A, IL-6, TGF-β and HIF-1, but were negative for HLA-G, while the expression levels of Cox-2 and IDO-1 varied. All ASCs significantly stimulated the proliferation of MCF-7 tumour cells in direct mixed co-cultures and transwell system, although their conditioned media displayed antiproliferative activity. Data obtained showed that ASCs with similar characteristics are easily isolated from various donors and sites of origin, although ASCs could both suppress and favour tumour cells growth, emphasising the importance of cellular context within the microenvironment and pointing to the significance of safety studies to exclude any potential clinical risk of their application in regenerative medicine.

Adult stem cells have a great potential applicability in regenerative medicine and cell-based therapies. However, there are still many unresolved issues concerning their biology, and the influence of the local microenvironment on properties of stem cells has been increasingly recognized. Interleukin (IL-) 17, as a cytokine implicated in many physiological and pathological processes, should be taken into consideration as a part of a regulatory network governing tissue-associated stem cells' fate. This review is focusing on the published data on the effects of IL-17 on the properties and function of hematopoietic and mesenchymal stem cells and trying to discuss that IL-17 achieves many of its roles by acting on adult stem cells.