The Effect of Normoxic and Hypoxic U-87 Glioblastoma Paracrine Secretion on the Modulation of Brain Endothelial Cells

Background: Glioblastoma multiforme (GBM) is a highly invasive brain tumour, characterized by its ability to secrete factors promoting its virulence. Brain endothelial cells (BECs) in the GBM environment are physiologically modulated. The present study investigated the modulatory effects of normoxically and hypoxically induced glioblastoma U-87 cell secretions on BECs. Methods: Conditioned media (CM) were derived by cultivating U-87 cells under hypoxic incubation (5% O2) and normoxic incubation (21% O2). Treated bEnd.3 cells were evaluated for mitochondrial dehydrogenase activity, mitochondrial membrane potential (ΔΨm), ATP production, transendothelial electrical resistance (TEER), and endothelial tight-junction (ETJ) gene expression over 96 h. Results: The coculture of bEnd.3 cells with U-87 cells, or exposure to either hypoxic or normoxic U-87CM, was associated with low cellular viability. The ΔΨm in bEnd.3 cells was hyperpolarized after hypoxic U-87CM treatment (p < 0.0001). However, normoxic U-87CM did not affect the state of ΔΨm. BEC ATP levels were reduced after being cocultured with U-87 cells, or with hypoxic and normoxic CM (p < 0.05). Suppressed mitochondrial activity in bEnd.3 cells was associated with increased transendothelial permeability, while bEnd.3 cells significantly increased the gene expression levels of ETJs (p < 0.05) when treated with U-87CM. Conclusions: Hypoxic and normoxic glioblastoma paracrine factors differentially suppressed mitochondrial activity in BECs, increasing the BECs’ barrier permeability.

Peri-Prostatic Adipocyte-Released TGFβ Enhances Prostate Cancer Cell Motility by Upregulation of Connective Tissue Growth Factor

Periprostatic adipose tissue (PPAT) has emerged as a key player in the prostate cancer (PCa) microenvironment. In this study, we evaluated the ability of PPAT to promote PCa cell migration, as well as the molecular mechanisms involved. Methods: We collected conditioned mediums from in vitro differentiated adipocytes isolated from PPAT taken from PCa patients during radical prostatectomy. Migration was studied by scratch assay. Results: Culture with CM of human PPAT (AdipoCM) promotes migration in two different human androgen-independent (AI) PCa cell lines (DU145 and PC3) and upregulated the expression of CTGF. SB431542, a well-known TGFβ receptor inhibitor, counteracts the increased migration observed in presence of AdipoCM and decreased CTGF expression, suggesting that a paracrine secretion of TGFβ by PPAT affects motility of PCa cells. Conclusions: Collectively, our study showed that factors secreted by PPAT enhanced migration through CTGF upregulation in AI PCa cell lines. These findings reveal the potential of novel therapeutic strategies targeting adipocyte-released factors and TGFβ/CTGF axis to fight advanced PCa dissemination.

Application of some graphene derivatives to increase the efficiency of stem cell therapy

: Graphene and its derivatives have application potential in many areas such as environmental technology, catalysis, biomedicine, and in particular, stem cell-based differentiation and regenerative therapies. Mesenchymal stem cell transplantation has emerged as a potential therapy for some diseases, such as acute kidney damage, liver failure and myocardial infarction. However, the poor survival of transplanted stem cells in such applications has significantly limited their therapeutic effectiveness. Graphene-based materials can improve the therapeutic efficacy of stem cells as they prevent the death of implanted cells by attaching them prior to implantation and increasing their paracrine secretion. In this review, we will highlight a number of recent studies that have investigated the potential use of graphene or its derivatives in stem cell applications and the prevention of transplanted stem cells from cell death, thereby improving their therapeutic efficacy.

Preclinical Evaluation of Bone Marrow Mesenchymal Stem Cells Overexpressing MicroRNA-126 to Treat Critical Limb Ischemia

Introduction: Critical limb ischemia (CLI) considered as the most severe form of peripheral artery disease (PAD). Current therapy for CLI are surgical reconstruction and endovascular therapy or limb amputation (for patients with no treatment options). Neovasculogenesis induced by stem cells including mesenchymal stem cells (MSCs) therapy is a promising approach to treat CLI. But this method of treatment faces challenges such as: MSCs survival and paracrine secretion. MicroRNAs are post transcriptional regulatory molecules that regulate many biological processes including VEGF pathway. MicroRNAs could be used to increase viability and angiogenic potential of MSCs. This study was conducted to reinforce and increase the angiogenic potential of BM-MSCs by using microRNA-126 and evaluate the effect of this stem cell gene therapy on treatment of ischemic tissues in CLI mouse models. Methods: BM-MSCs were isolated from male C57 BL/6 inbred mice and characterized by morphology, flow cytometry, differentiation to osteocyte and adipocyte. Transformed BM-MSCs containing miR-126 were produced by using lentiviral vector. Then femoral artery ligation and total excision of the femoral artery was performed on C57BL/6 mice to create CLI model. Animals were allocated to control, BM-MSCs, virus and BM-MSCs miR-126 groups and defined number of the cells and virus were injected 24 h after surgery. In order to determine in vitro and in vivo effects, the following tests were performed: wound healing assay, behavioral tests including: Tarlov, Ischemia, Modified ischemia, Function and the grade of limb necrosis scores, donor cell survival assay, real-time PCR and histological analysis. Results: Results indicated that during 28 days after transplantation, BM-MSCs and virus groups had an enhancing effect on angiogenesis. BM-MSCs miR-126 group had remarkable effect on endothelial cell migration, muscle restructure, functional improvements and neovascularization in ischemic tissues and led to more effective treatment. In vivo evaluation showed that miR-126 could increase BM-MSCs survival and paracrine secretion of angiogenic factors such as VEGF, and led to remarkable functional improvements and neovascularization in ischemic tissues. Conclusions: According to the obtained results, it could concluded that combination of BM-MSCs and miR-126 leads to more effective recovery from critical limb ischemia compared to using them alone. In fact, miR-126 can be used as a strong modifier to reinforce the angiogenic potential of BM-MSCs, leading to more effective treatment for CLI.

Interplay between mesenchymal stromal cells and immune system: clinical applications in immune-related diseases

Mesenchymal stromal cells (MSCs) are a mesodermal stem cell population, with known self-renewal and multilineage differentiation properties. In the last century, MSCs have been widely used in regenerative medicine and tissue engineering approaches. MSCs initially were isolated from bone marrow aspirates, but currently have been identified in a great number of tissues of the human body. Besides their utilization in regenerative medicine, MSCs possess significant immunoregulatory/immunosuppressive properties, through interaction with the cells of innate and adaptive immunity. MSCs can exert their immunomodulatory properties with either cell-cell contact or via paracrine secretion of molecules, such as cytokines, growth factors and chemokines. Of particular importance, the MSCs’ immunomodulatory properties are explored as promising therapeutic strategies in immune-related disorders, such as autoimmune diseases, graft versus host disease, cancer. MSCs may also have an additional impact on coronavirus disease-19 (COVID-19), by attenuating the severe symptoms of this disorder. Nowadays, a great number of clinical trials, of MSC-mediated therapies are evaluated for their therapeutic potential. In this review, the current knowledge on cellular and molecular mechanisms involved in MSC-mediated immunomodulation were highlighted. Also, the most important aspects, regarding their potential application in immune-related diseases, will be highlighted. The broad application of MSCs has emerged their role as key immunomodulatory players, therefore their utilization in many disease situations is full of possibilities for future clinical treatment.

Preclinical Evaluation of Bone Marrow Mesenchymal Stem Cells Overexpressing MicroRNA-126 to Treat Critical Limb Ischemia

Background: Critical limb ischemia (CLI) considered as the most severe form of peripheral artery disease (PAD), and characterized by ischemic rest pain and non-healing ulcers. CLI being associated with a high risk of major amputation, cardiovascular events and death. Current therapy for CLI are surgical reconstruction and endovascular therapy or limb amputation (for patients with no treatment options). Neovasculogenesis induced by stem cells including mesenchymal stem cells (MSCs) therapy is a promising approach to treat CLI. But this method of treatment faces challenges that reduce its effectiveness, such as: MSCs survival and paracrine secretion. MicroRNAs are post transcriptional regulatory molecules that regulate many biological processes including VEGF pathway. Therefore, microRNAs could be used to increase viability and angiogenic potential of MSCs. This study was conducted to reinforce and increase the angiogenic potential of BM-MSCs by using microRNA-126 and evaluate the effect of this stem cell gene therapy on treatment of ischemic tissues in CLI mouse models. Results: Our cellular, molecular and functional tests indicated that during 28 days after transplantation, BM-MSCs and virus groups had an enhancing effect on angiogenesis. BM-MSCs miR-126 group had remarkable effect on endothelial cell migration, muscle restructure, functional improvements and neovascularization in ischemic tissues and led to more effective treatment. On the other hand, miR-126 could increase paracrine secretion of BM-MSCs. Additionally, in vivo evaluation showed that miR-126 could increase BM-MSCs survival and paracrine secretion of angiogenic factors such as VEGF, and led to remarkable functional improvements and neovascularization in ischemic tissues. Conclusion: According to the obtained results, it could concluded that combination of BM-MSCs and miR-126 leads to more effective recovery from critical limb ischemia compared to using them alone. In fact, miR-126 can be used as a strong modifier to reinforce the angiogenic potential of BM-MSCs, leading to more effective treatment for CLI.

Effect of Ascorbic Acid on Differentiation, Secretome and Stemness of Stem Cells from Human Exfoliated Deciduous Tooth (SHEDs)

Stem cells from human exfoliated deciduous teeth (SHEDs) are considered a type of mesenchymal stem cells (MSCs) because of their unique origin from the neural crest. SHEDs can self-renewal and multi-lineage differentiation with the ability to differentiate into odontoblasts, osteoblast, chondrocytes, neuronal cells, hepatocytes, adipocytes, etc. They are emerging as an ideal source of MSCs because of their easy availability and extraordinary cell number. Ascorbic acid, or vitamin C, has many cell-based applications, such as bone regeneration, osteoblastic differentiation, or extracellular matrix production. It also impacts stem cell plasticity and the ability to sustain pluripotent activity. In this study, we evaluate the effects of ascorbic acid on stemness, paracrine secretion, and differentiation into osteoblast, chondrocytes, and adipocytes. SHEDs displayed enhanced multifaceted activity, which may have applications in regenerative therapy.

Ouabain Enhances Gap Junctional Intercellular Communication by Inducing Paracrine Secretion of Prostaglandin E2

Ouabain is a cardiac glycoside that has been described as a hormone, with interesting effects on epithelial physiology. We have shown previously that ouabain induces gap junctional intercellular communication (GJIC) in wild, sensitive cells (MDCK-S), but not in cells that have become insensitive (MDCK-I) by modifying their Na+-K+-ATPase. We have also demonstrated that prostaglandin E2 (PGE2) is able to induce increased GJIC by a mechanism other than ouabain, that does not depend on Na+-K+-ATPase. In this work we show, by dye transfer assays, that when MDCK-S and MDCK-I are randomly mixed, to form monolayers, the latter stablish GJIC, because of stimulation by a compound released to the extracellular media, by MDCK-S cells, after treatment with ouabain, as evidenced by the fact that monolayers of only MDCK-I cells, treated with a conditioned medium (CM) that is obtained after incubation of MDCK-S monolayers with ouabain, significantly increase their GJIC. The further finding that either (1) pre-treatment with COX-2 inhibitors or (2) addition to CM of antagonists of EP2 receptor abolish CM’s ability to induce GJIC in MDCK-I monolayers indicate that PGE2 is the GJIC-inducing compound. Therefore, these results indicate that, in addition to direct stimulation, mediated by Na+-K+-ATPase, ouabain enhances GJIC indirectly through the paracrine production of PGE2.

Mesenchymal Stem Cells for Mitigating Radiotherapy Side Effects

Radiation therapy for cancers also damages healthy cells and causes side effects. Depending on the dosage and exposure region, radiotherapy may induce severe and irreversible injuries to various tissues or organs, especially the skin, intestine, brain, lung, liver, and heart. Therefore, promising treatment strategies to mitigate radiation injury is in pressing need. Recently, stem cell-based therapy generates great attention in clinical care. Among these, mesenchymal stem cells are extensively applied because it is easy to access and capable of mesodermal differentiation, immunomodulation, and paracrine secretion. Here, we summarize the current attempts and discuss the future perspectives about mesenchymal stem cells (MSCs) for mitigating radiotherapy side effects.