Project description:Mesenchymal stromal cells (MSCs) are multipotent cells obtained from many tissues including bone marrow, adipose tissue, umbilical cord, amniotic fluid, and placenta. MSCs are the leading cell source for stem cell therapy due to their regenerative and immunomodulatory properties, their low risk of tumorigenesis and lack of ethical constraints. However, clinical applications of MSCs remain limited. MSC therapeutic development continues to pose challenges in terms of preparation, purity, consistency, efficiency, reproducibility, processing time and scalability. Additionally, there are issues with their poor engraftment and survival in sites of disease or damage that limit their capacity to directly replace damaged cells. A key recent development in MSC research, however, is the now widely accepted view that MSCs primarily exert therapeutic effects via paracrine factor secretion. One of the major paracrine effectors are extracellular vesicles (EVs). EVs represent a potential cell-free alternative to stem cell therapy but are also rapidly emerging as a novel therapeutic platform in their own right, particularly in the form of engineered EVs (EEVs) tailored to target a broad range of clinical indications. However, the development of EVs and EEVs for therapeutic application still faces a number of hurdles, including the establishment of a consistent, scalable cell source, and the development of robust GMP-compliant upstream and downstream manufacturing processes. In this review we will highlight the clinical challenges of MSC therapeutic development and discuss how EVs and EEVs can overcome the challenges faced in the clinical application of MSCs.
Project description:The COVID-19 epidemic represents an unprecedented global health emergency, further aggravated by the lack of effective therapies. For this reason, several clinical trials are testing different off-label drugs, already approved for other pathologies. Mesenchymal stem/stromal cells (MSCs) have been tested during the last two decades for the treatment of various pathologic conditions, including acute and chronic lung diseases, both in animal models and in patients. In particular, promising results have been obtained in the experimental therapy of acute respiratory distress syndrome, which represents the most threatening complication of COVID-19 infection. Furthermore, more recently, great interest has been devoted to the possible clinical applications of extracellular vesicles secreted by MSCs, nanoparticles that convey much of the biological effects and of the therapeutic efficacy of their cells of origin. This review summarizes the experimental evidence underlying the possible use of MSCs and of MSC-EVs in severe COVID-19 infection and underlines the need to evaluate the possible efficacy of these therapeutic approaches through controlled studies under the supervision of the Regulatory Authorities.
Project description:BACKGROUND:Silicosis is an occupational disease that affects workers who inhale silica particles, leading to extensive lung fibrosis and ultimately causing respiratory failure. Mesenchymal stromal cells (MSCs) have been shown to exert therapeutic effects in lung diseases and represent an alternative treatment for silicosis. Recently, it has been suggested that similar effects can be achieved by the therapeutic use of extracellular vesicles (EVs) obtained from MSCs. The aim of this study was to investigate the effects of adipose-tissue-derived MSCs (AD-MSCs) or their EVs in a model of silicosis. METHODS:Silicosis was induced by intratracheal instillation of silica in C57BL/6 mice. After the onset of disease, animals received saline, AD-MSCs, or EVs, intratracheally. RESULTS:At day 30, AD-MSCs and EVs led to a reduction in collagen fiber content, size of granuloma, and in the number of macrophages inside granuloma and in the alveolar septa. In addition, the expression levels of interleukin 1? and transforming growth factor beta in the lungs were decreased. Higher dose of EVs also reduced lung static elastance when compared with the untreated silicosis group. CONCLUSIONS:Both AD-MSCs and EVs, locally delivered, ameliorated fibrosis and inflammation, but dose-enhanced EVs yielded better therapeutic outcomes in this model of silicosis.
Project description:AimsPlatelet concentrates, like platelet-rich plasma (PRP) and platelet lysate (PL), are widely used in regenerative medicine, especially in bone regeneration. However, the lack of standard procedures and controls leads to high variability in the obtained results, limiting their regular clinical use. Here, we propose the use of platelet-derived extracellular vesicles (EVs) as an off-the-shelf alternative for PRP and PL for bone regeneration. In this article, we evaluate the effect of PL-derived EVs on the biocompatibility and differentiation of mesenchymal stromal cells (MSCs).MethodsEVs were obtained first by ultracentrifugation (UC) and then by size exclusion chromatography (SEC) from non-activated PL. EVs were characterized by transmission electron microscopy, nanoparticle tracking analysis, and the expression of CD9 and CD63 markers by western blot. The effect of the obtained EVs on osteoinduction was evaluated in vitro on human umbilical cord MSCs by messenger RNA (mRNA) expression analysis of bone markers, alkaline phosphatase activity (ALP), and calcium (Ca2+) content.ResultsOsteogenic differentiation of MSCs was confirmed when treated with UC-isolated EVs. In order to disprove that the effect was due to co-isolated proteins, EVs were isolated by SEC. Purer EVs were obtained and proved to maintain the differentiation effect on MSCs and showed a dose-dependent response.ConclusionPL-derived EVs present an osteogenic capability comparable to PL treatments, emerging as an alternative able to overcome PL and PRP limitations.Cite this article: Bone Joint Res 2020;9(10):667-674.
Project description:Outstanding progress has been achieved in developing therapeutic options for reasonably alleviating symptoms and prolonging the lifespan of patients suffering from myocardial infarction (MI). Current treatments, however, only partially address the functional recovery of post-infarcted myocardium, which is in fact the major goal for effective primary care. In this context, we largely investigated novel cell and TE tissue engineering therapeutic approaches for cardiac repair, particularly using multipotent mesenchymal stromal cells (MSC) and natural extracellular matrices, from pre-clinical studies to clinical application. A further step in this field is offered by MSC-derived extracellular vesicles (EV), which are naturally released nanosized lipid bilayer-delimited particles with a key role in cell-to-cell communication. Herein, in this review, we further describe and discuss the rationale, outcomes and challenges of our evidence-based therapy approaches using Wharton's jelly MSC and derived EV in post-MI management.
Project description:Mesenchymal-epithelial interactions play an important role in renal tubular morphogenesis and in maintaining the structure of the kidney. The aim of this study was to investigate whether extracellular vesicles (EVs) produced by human renal proximal tubular epithelial cells (RPTECs) may induce mesenchymal-epithelial transition of bone marrow-derived mesenchymal stromal cells (MSCs). To test this hypothesis, we characterized the phenotype and the RNA content of EVs and we evaluated the in vitro uptake and activity of EVs on MSCs. MicroRNA (miRNA) analysis suggested the possible implication of the miR-200 family carried by EVs in the epithelial commitment of MSCs. Bone marrow-derived MSCs were incubated with EVs, or RPTEC-derived total conditioned medium, or conditioned medium depleted of EVs. As a positive control, MSCs were co-cultured in a transwell system with RPTECs. Epithelial commitment of MSCs was assessed by real time PCR and by immunofluorescence analysis of cellular expression of specific mesenchymal and epithelial markers. After one week of incubation with EVs and total conditioned medium, we observed mesenchymal-epithelial transition in MSCs. Stimulation with conditioned medium depleted of EVs did not induce any change in mesenchymal and epithelial gene expression. Since EVs were found to contain the miR-200 family, we transfected MSCs using synthetic miR-200 mimics. After one week of transfection, mesenchymal-epithelial transition was induced in MSCs. In conclusion, miR-200 carrying EVs released from RPTECs induce the epithelial commitment of MSCs that may contribute to their regenerative potential. Based on experiments of MSC transfection with miR-200 mimics, we suggested that the miR-200 family may be involved in mesenchymal-epithelial transition of MSCs.
Project description:Extracellular vesicles (EVs) have been recently identified as vital components of cell-based therapies based on the observation that conditioned media from cultured stromal cells reproduce some of the beneficial effects of intact cells. In order to obtain clinically active EVs derived from Mesenchymal Stromal Cells (MSCs) different procedures have been reported in the literature. Usually, non-confluent cells are incubated with culture medium for 48 h either with EV-depleted Fetal Bovine Serum (FBS) or without FBS. Our aim was to compare the effects of EVs isolated by ultracentrifugation from human umbilical cord MSC conditioned media obtained using these two conditions: with EV-depleted FBS (UC) or without FBS (UCw/o) on the mRNA expression levels of extracellular matrix related genes using the mouse chondrogenic cell line ATDC-5. We observed a deleterious effect on chondrogenic cells treated with UCw/o, showing higher mRNA expression levels of different metalloproteinases and decorin (Dcn) and lower collagen (Col1a1 and Col2a1) and aggrecan (Acan) mRNA levels. To elucidate whether this deleterious effect was induced by the EVs or by any proteins co-purified in the EV pellet, we used size exclusion chromatography (SEC) to further purify the EV pellet, obtaining an EV enriched fraction (EV or EVw/o) and a protein enriched fraction (Prot or Protw/o). Our results pointed that the negative effect on the chondrogenic cell line was due to the contaminant proteins coisolated with the EVs by ultracentrifugation and not from the EVs themselves. Thus, these results highlight the importance of working with well purified EV preparations to specifically achieve their therapeutic effect.
Project description:The immunosuppressive potential of mesenchymal stem cells has been extensively investigated in many studies in vivo and in vitro. In recent years, a variety preclinical and clinical studies have demonstrated that mesenchymal stem cells ameliorate immune-mediated disorders, including autoimmune diseases. However, to date mesenchymal stem cells have not become a widely used therapeutic agent due to safety challenges, high cost and difficulties in providing long term production. A key mechanism underpinning the immunomodulatory effect of MSCs is the production of paracrine factors including growth factors, cytokines, chemokines, and extracellular vesicles (EVs). MSCs derived EVs have become an attractive therapeutic agent for immunomodulation and treatment of immune-mediated disorders. In addition to many preclinical studies of MSCs derived EVs, their beneficial effects have been observed in patients with both acute graft-vs.-host disease and chronic kidney disease. In this review, we discuss the current findings in the field of MSCs derived EVs-based therapies in immune-mediated disorders and approaches to scale EV production for clinical use.
Project description:Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) possess pro-regenerative potential in different animal models with renal injury. EVs contain different molecules, including proteins, lipids and nucleic acids. Among the shuttled molecules, miRNAs have a relevant role in the pro-regenerative effects of EVs and are a promising target for therapeutic interventions. The aim of this study was to increase the content of specific miRNAs in EVs that are known to be involved in the pro-regenerative effect of EVs, and to assess the capacity of modified EVs to contribute to renal regeneration in in vivo models with acute kidney injuries. To this purpose, MSCs were transiently transfected with specific miRNA mimics by electroporation. Molecular analyses showed that, after transfection, MSCs and derived EVs were efficiently enriched in the selected miRNAs. In vitro and in vivo experiments indicated that EVs engineered with miRNAs maintained their pro-regenerative effects. Of relevance, engineered EVs were more effective than EVs derived from naïve MSCs when used at suboptimal doses. This suggests the potential use of a low amount of EVs (82.5 × 106) to obtain the renal regenerative effect.
Project description:In the last decade, the secreting activity of mesenchymal stem/stromal cells (MSCs) has been widely investigated, due to its possible therapeutic role. In fact, MSCs release extracellular vesicles (EVs) containing relevant biomolecules such as mRNAs, microRNAs, bioactive lipids, and signaling receptors, able to restore physiological conditions where regenerative or anti-inflammatory actions are needed. An actual advantage would come from the therapeutic use of EVs with respect to MSCs, avoiding the possible immune rejection, the lung entrapment, improving the safety, and allowing the crossing of biological barriers. A number of concerns still have to be solved regarding the mechanisms determining the beneficial effect of MSC-EVs, the possible alteration of their properties as a consequence of the isolation/purification methods, and/or the best approach for a large-scale production for clinical use. Most of the preclinical studies have been successful, reporting for MSC-EVs a protecting role in acute kidney injury following ischemia reperfusion, a potent anti-inflammatory and anti-fibrotic effects by reducing disease associated inflammation and fibrosis in lung and liver, and the modulation of both innate and adaptive immune responses in graft versus host disease (GVHD) as well as autoimmune diseases. However, the translation of MSC-EVs to the clinical stage is still at the initial phase. Herein, we discuss the therapeutic potential of an acellular product such as MSC derived EVs (MSC-EVs) in acute and chronic pathologies.