A Simple High Yield Technique for Isolation of Wharton's Jelly-derived Mesenchymal Stem Cell.

Background: The isolation of Mesenchymal Stem Cells (MSCs) from various tissues is possible, with the umbilical cord emerging as a competitive alternative to bone marrow. In order to fulfill the demands of cell therapy, it is essential to generate stem cells on a clinical scale while minimizing time, cost, and contamination. Here is a simple and effective protocol for isolating MSC from Wharton's Jelly (WJ-MSC) using the explant method with various supplements. Methods: Utilizing the explant method, small fragments of Wharton's jelly from the human umbilical cord were cultured in a flask. The multipotency of the isolated cells, were confirmed by their differentiation ability to osteocyte and adipocyte. Additionally, the immunophenotyping of WJ-MSCs showed positive expression of CD73, CD90, and CD105, while remaining negative for hematopoietic markers CD34 and CD45, meeting the criteria for WJ-MSC identification. Following that, to evaluate cells' proliferative capacity, various supplements, including basic Fibroblast Growth Factor (bFGF), Non-Essential amino acids (NEA), and L-Glutamine (L-Gln) were added to either alpha-Minimal Essential Medium (α-MEM) or Dulbecco's Modified Eagle's Medium-F12 (DMEM-F12), as the basic culture media. Results: WJ-MSCs isolated by the explant method were removed from the tissue after seven days and transferred to the culture medium. These cells differentiated into adipocyte and osteocyte lineages, expressing CD73, CD90, and CD105 positively and CD34 and CD45 negatively. The results revealed that addition of bFGF to α-MEM or DMEMF12 media significantly increased the proliferation of MSCs when compared to the control group. However, there were no significant differences observed when NEA or LGln were added. Conclusion: Although bFGF considerably enhances cell proliferation, our study demonstrates that MSCs can grow and expand when properly prepared Wharton's jelly tissues of the human umbilical cord.

Synergistic effects of mesenchymal stem cell-derived extracellular vesicles and dexamethasone on macrophage polarization under inflammatory conditions.

The undesirable inflammation and the excessive M1 macrophage activity may lead to inflammatory diseases. Corticosteroids and stem cell therapy are used in clinical practice to promote anti-inflammatory responses. However, this protocol has limitations and is associated with numerous side effects. In this study, the synergistic anti-inflammatory effects of dexamethasone (Dex) and mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) were evaluated to enhance the polarization of M1 inflammatory macrophages into the anti-inflammatory (M2) phenotype. Hence, we designed different combinations of Dex and EVs using three methods, including EVs isolated from Dex-preconditioned MSCs (Pre-Dex-EVs), EVs loaded with Dex (L-Dex-EVs), and EVs and Dex co-administration (Dex + EVs). All designed EVs had a significant effect on reducing the expression of M1-related genes (iNOS, Stat1, and IRF5), cytokines (IL6 and TNF-a), and CD markers (CD86) in lipopolysaccharide-stimulated macrophages. On the other hand, these combinations promoted the expression of alternative-activated M2-related genes (Arg-1, Stat6, and IRF4), cytokine (IL10), and CD markers (CD206).The combination of Dex and MSC-EVs enhances the effectiveness of both and synergistically promotes the conversion of inflammatory macrophages into an anti-inflammatory state.

Therapeutic and immunomodulatory potentials of mesenchymal stromal/stem cells and immune checkpoints related molecules.

Mesenchymal stromal/stem cells (MSCs) are used in many studies due to their therapeutic potential, including their differentiative ability and immunomodulatory properties. These cells perform their therapeutic functions by using various mechanisms, such as the production of anti-inflammatory cytokines, growth factors, direct cell-to-cell contact, extracellular vesicles (EVs) production, and mitochondrial transfer. However, mechanisms related to immune checkpoints (ICPs) and their effect on the immunomodulatory ability of MSCs are less discussed. The main function of ICPs is to prevent the initiation of unwanted responses and to regulate the immune system responses to maintain the homeostasis of these responses. ICPs are produced by various types of immune system regulatory cells, and defects in their expression and function may be associated with excessive responses that can ultimately lead to autoimmunity. Also, by expressing different types of ICPs and their ligands (ICPLs), tumor cells prevent the formation and durability of immune responses, which leads to tumors' immune escape. ICPs and ICPLs can be produced by MSCs and affect immune cell responses both through their secretion into the microenvironment or direct cell-to-cell interaction. Pre-treatment of MSCs in inflammatory conditions leads to an increase in their therapeutic potential. In addition to the effect that inflammatory environments have on the production of anti-inflammatory cytokines by MSCs, they can increase the expression of various types of ICPLs. In this review, we discuss different types of ICPLs and ICPs expressed by MSCs and their effect on their immunomodulatory and therapeutic potential.

Mesenchymal Stem Cell-Derived Extracellular Vesicle Therapy for Asthma in Murine Models: A Systematic Review and Meta-analysis.

BACKGROUND: Asthma is a common disease, and among the most predominant causes of the years lived with disability. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as a promising avenue for asthma management. The objective of this study is to perform a systematic review and meta-analysis of pre-clinical studies investigating the therapeutic use of MSC-EVs in murine models of asthma. METHODS: A systematic search of electronic databases was performed. Meta-analyses were conducted on broncho-alveolar lavage fluid (BALF) cells and cytokines, as well as airway hyper-responsiveness Penh values and histological staining scores to determine the efficacy of MSC-EVs-based therapy, comparing treated rodents with untreated ones. BALF IL-4, BALF total cells, and BALF eosinophils were chosen as the primary outcomes, while airway hyper-responsiveness Penh values, BALF cytokines excluding IL-4, and histological staining scores were chosen as secondary outcomes. RESULTS: A total of 19 eligible studies were included in the current systematic review, with 9 assessing BALF IL-4, 11 assessing BALF total cells, and 10 assessing BALF eosinophils. Pooled Hedges' g (p-value) for each outcome was - 4.407 (< 0.001), -4.976 (< 0.001), and - 4.071 (< 0.001), showing that MSC-EVs therapy inhibits asthma pathology. Changes in secondary outcomes also indicated a reduction in inflammation, goblet cell hyperplasia, and airway hyper-responsiveness. Subgroup analyses did not reveal significant disparities between the type of rodents and administration routes, and meta-regressions were only significant for MSC-EVs source and dose in the IL-4 meta-analysis, and for administration frequency and time from the last challenge to sacrifice in the BALF total cell meta-analysis. CONCLUSION: This review highlights the current pre-clinical evidence of MSC-EVs therapy for asthma and finds its application ameliorates multiple aspects of asthma's pathology. We further underline the importance of MSC-EVs source, dose, administration frequency, and timing on the therapeutic effect and warrant further investigation and clinical translation to assess the best treatment regimen and to gauge the efficacy of EV therapy in human asthma cases.

The impact understanding of exosome therapy in COVID-19 and preparations for the future approaches in dealing with infectious diseases and inflammation.

Cytokine storms, which result from an abrupt, acute surge in the circulating levels of different pro-inflammatory cytokines, are one of the complications associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to assess the effect of exosomes on the release of pro-inflammatory cytokines in patients with coronavirus disease 2019 (COVID-19) and compare it with a control group. The cytokines evaluated in this study were TNF-α, IL-6, IL-17, and IFN-γ. The study compared the levels of these pro-inflammatory cytokines in the peripheral blood mononuclear cells (PBMCs) of five COVID-19 patients in the intensive care unit, who were subjected to both inactivated SARS-CoV-2 and exosome therapy, with those of five healthy controls. The cytokine levels were quantified using the ELISA method. The collected data was analyzed in SPSS Version 26.0 and GraphPad Prism Version 9. According to the study findings, when PBMCs were exposed to inactivated SARS-CoV-2, pro-inflammatory cytokines increased in both patients and healthy controls. Notably, the cytokine levels were significantly elevated in the COVID-19 patients compared to the control group P-values were < 0.001, 0.001, 0.008, and 0.008 for TNF-α, IL-6, IL-17, and IFN-γ, respectively. Conversely, when both groups were exposed to exosomes, there was a marked reduction in the levels of pro-inflammatory cytokines. This suggests that exosome administration can effectively mitigate the hyperinflammation induced by COVID-19 by suppressing the production of pro-inflammatory cytokines in patients. These findings underscore the potential safety and efficacy of exosomes as a therapeutic strategy for COVID-19.

Decellularized Placental Sponge: A Platform for Coculture of Mesenchymal Stem Cells/Macrophages to Assess an M2 Phenotype and Osteogenic Differentiation In Vitro and In Vivo.

Effective communication between immune and bone-forming cells is crucial for the successful healing of bone defects. This study aimed to assess the potential of a decellularized placental sponge (DPS) as a coculture system for inducing M1/M2 polarization in macrophages and promoting osteogenic differentiation in adipose-derived mesenchymal stem cells (AD-MSCs), both in vitro and in vivo. We prepared the DPS and conducted a comprehensive characterization of its biomechanical properties, antibacterial activity, and biocompatibility. In vitro, we examined the influence of the DPS on the polarization of macrophages cocultured with AD-MSCs through nitric oxide assays, cytokine assays, phagocytosis tests, and real-time polymerase chain reaction (PCR). For in vivo assessment, we utilized micro-CT imaging, histological evaluations, and real-time PCR to determine the impact of the DPS seeded with Wharton's jelly mesenchymal stem cells (WJ-MSCs) on bone regeneration in a calvarial bone defect model. The coculture of AD-MSCs and macrophages on the DPS led to increased production of IL-10, upregulation of CD206, Arg1, and YM1 gene expression, and enhanced phagocytic capacity for apoptotic thymocytes. Concurrently, it reduced the secretion of TNF-α and nitric oxide (NO), downregulated the expression of CD86, NOS2, and IRF5 genes, and decreased macrophage phagocytosis of yeast. These results indicated polarization of macrophages toward an M2-like phenotype. In vivo, the presence of the DPS resulted in enhanced bone formation at the defect site. Immunostaining demonstrated that both the DPS and DPS + WJ-MSC constructs induced macrophage polarization toward an M2 phenotype, as compared to the control defect. In conclusion, this immunomodulatory effect, coupled with its biocompatibility and biomechanical properties resembling natural bone, positions the DPS as an attractive candidate for further exploration in the field of bone tissue engineering and regenerative medicine.

Distinctive Expression of Metastamirs in Breast Cancer Mesenchymal Stem Cells Isolated from Solid Tumor.

BACKGROUND: MSCs are a part of the tumor microenvironment, which secrete cytokines and chemokines. They can affect metastasis and the growth of tumors. metastamiRs are newly recognized regulatory elements of the metastasis pathway which are involved in epithelial-to-mesenchymal transition (EMT). OBJECTIVE: In the present study, we aimed to assess the expression profile of metastamiRs in the context of MSCs in correlation with their invasion and migration power. METHODS: tumor-isolated BC-MSCs and normal human mammary epithelial cells (HMECs) along with MCF-7, MDA-MB231, and MCF-10A cells were prepared and confirmed for their identity. The cells were assessed for CD44+CD24¯ percentage, Oct-4, and Survivin expression. GEO, KEGG, and TCGA databases were investigated to detect differential miR-expressions. Real-time PCR for 13 miRs was performed using LNA primers. Ultimately, Transwell-Matrigel assays as used to assess the level of migration and invasion. RESULTS: Our results indicated that some oncomiRs like miR-10b were upregulated in BC-MSCs, while the levels of miR-373 and miR-520c were similar to the MCF-10A. Generally, miR-200 family members were on lower levels compared to the other miR-suppressor (miR-146a, 146b, and 335). miR-31 and 193b were up-regulated in MCF-10A. The most invasiveness was observed in the MDA-MB231 cell line. CONCLUSION: We have demonstrated that the miR-expression levels of BC-MSCs are somewhat in between MCF-7 and MDA-MB231 miR-expression levels. This could be the logic behind the moderate level of invasion in BC-MSCs. Therefore, miR-therapy approaches such as miR-mimic or antagomiRs could be used for BC-MSCs in clinical cancer therapy.

Engineering chimeric autoantibody receptor T cells for targeted B cell depletion in multiple sclerosis model: An in-vitro study.

Background: Recent evidence suggests that B cells and autoantibodies have a substantial role in the pathogenesis of Multiple sclerosis. T cells could be engineered to express chimeric autoantibody receptors (CAARs), which have an epitope of autoantigens in their extracellular domain acting as bait for trapping autoreactive B cells. This study aims to assess the function of designed CAAR T cells against B cell clones reactive to the myelin basic protein (MBP) autoantigen. Methods: T cells were transduced to express a CAAR consisting of MBP as the extracellular domain. experimental autoimmune encephalomyelitis (EAE) was induced by injecting MBP into mice. The cytotoxicity, proliferation, and cytokine production of the MBP-CAAR T cells were investigated in co-culture with B cells. Results: MBP-CAAR T cells showed higher cytotoxic activity against autoreactive B cells in all effector-to-target ratios compared to Mock T cell (empty vector-transduced T cell) and Un-T cells (un-transduced T cell). In co-cultures containing CAAR T cells, there was more proliferation and inflammatory cytokine release as compared to Un-T and Mock T cell groups. Conclusion: Based on these findings, CAAR T cells are promising for curing or modulating autoimmunity and can be served as a new approach for clone-specific B cell depletion therapy in multiple sclerosis.

In vitro naive CD4+ T cell differentiation upon treatment with miR-29b-loaded exosomes from mesenchymal stem cells.

BACKGROUND: Gene regulation by microRNA (miRNA) is central in T lymphocytes differentiation processes. Here, we investigate miRNA-29b (miR-29b) roles in the reprogramming of T cell differentiation, which can be a promising therapeutic avenue for various types of inflammatory disorders such as rheumatoid arthritis and multiple sclerosis. METHODS AND RESULTS: Adipose Mesenchymal Stem Cell-derived exosomes (AMSC-Exo) enriched with miR-29b were delivered into naive CD4+ T (nCD4+) cells. The expression level of important transcription factors including RAR-related orphan receptor gamma (RORγt), GATA3 binding protein (GATA3), T-box transcription factor 21, and Forkhead box P3 was determined by quantitative Real-Time PCR. Moreover, flow cytometry and Enzyme-linked Immunosorbent Assay were respectively used to measure the frequency of T regulatory cells and the levels of cytokines production (Interleukin 17, Interleukin 4, Interferon-gamma, and transforming growth factor beta. This study indicates that the transfection of miR-29b mimics into T lymphocytes through AMSC-Exo can alter the CD4+ T cells' differentiation into other types of T cells. CONCLUSIONS: In conclusion, AMSC-Exo-based delivery of miR-29b can be considered as a new fascinating avenue for T cell differentiation inhibition and the future treatment of several inflammatory disorders.

The combination of mesenchymal stem cell- and hepatocyte-derived exosomes, along with imipenem, ameliorates inflammatory responses and liver damage in a sepsis mouse model.

Aim Sepsis is a medical emergency with no definitive treatment. Animal experiments have confirmed the therapeutic characteristics of exosomes in reducing inflammation and tissue damage. The study investigates the effect of MSC and hepatocyte-derived exosomes along with imipenem in controlling systemic and local (liver) inflammation in a mouse model of sepsis. MAIN METHODS: To induce sepsis in C57BL/6 mice, the Cecal Ligation and Puncture (CLP) model was used. The mice were given various treatments, including imipenem, MSC-derived exosomes, hepatocyte-derived exosomes, and a mixture of exosomes. Blood and liver samples were collected and analyzed for cell blood count, liver enzymes, NO levels, cytokine concentrations, and bacterial presence. The percentages of TCD3 + CD4+/CD8+ and Treg in the spleen and mesenteric lymph nodes were also assessed using flow cytometry. The pathological changes were assessed in the liver, lung, and heart tissues. In addition, the cytokine content of exosomes was measured by ELISA. KEY FINDINGS: Our results demonstrated that MSC-derived exosomes+imipenem could control systemic and local inflammation and increase the TCD4+ and Treg populations. Hepatocyte-derived exosomes+imipenem reduced inflammation in the liver and increased the TCD8+ and Treg populations. The mixture of exosomes+imipenem had the best function in reducing inflammation, maintaining all T lymphocyte populations, reducing liver damage, and ultimately increasing the survival rate. SIGNIFICANCE: The mixture of exosomes derived from MSCs and hepatocytes, along with imipenem, in the inflammatory phase of sepsis could be a promising therapeutic strategy in sepsis treatment.

Exosomes derived from rapamycin-treated 4T1 breast cancer cells induced polarization of macrophages to M1 phenotype.

M2 macrophages are the most prevalent type in the tumor microenvironment and their polarization to M1 type can be used as a potential cancer immunotherapy. Here, we investigated the role of tumor microenvironment and particularly purified exosomes in M2 to M1 macrophage polarization. Rapamycin treatment on triple-negative breast cancer cells (TNBC) was performed. Tumor cells-derived exosomes (called texosomes) were isolated and characterized using scanning electron microscopy, transmission electron microscopy, dynamic light scattering, high-performance liquid chromatography, Fourier transform infrared, and Western blot assays. M2 mouse peritoneal macrophages were treated with rapamycin or rapamycin-texosome. Then, M1/M2 phenotype-specific marker genes and proteins were measured to assess the degree of M2 to M1 polarization. Finally, nitric oxide (NO) production, phagocytosis, and efferocytosis assays were assessed to verify the functionality of the polarized macrophages. Purified rapamycin-texosomes significantly increased the expression of the M1 markers (Irf5, Nos2, and CD86) and decreased M2 markers (Arg, Ym1, and CD206). In addition, the levels of M1-specific cytokines tumor necrosis factor alpha and interleukin 1ß (IL-1ß) were increased, whereas the levels of M2 specific cytokines IL-10 and transforming growth factor beta were declined. Furthermore, texosome treatment increased NO concentration and phagocytosis and decreased efferocytosis indicating M1 polarization. These findings suggest rapamycin-texosomes can induce M2 to M1 macrophages polarization as a potential immunotherapy for TNBC.

Impact of the MCP-1-2518A>G polymorphism on COVID-19 severity in the Iranian population: A case-control study.

As a result of SARS-CoV-2 infection, the host's immune system is disrupted, and chemokines and cytokines are intensified to eliminate the virus, resulting in cytokine storm syndrome and acute respiratory distress syndrome (ARDS). Patients with COVID-19 have been observed to have elevated levels of MCP-1, a chemokine associated with the severity of the disease. In some diseases, polymorphisms in the regulatory region of the MCP-1 gene correspond to serum levels and disease severity. An attempt was made in this study to assess the relationship between MCP-1 G-2518A and serum MCP-1 levels in Iranian COVID-19 patients and the severity of the disease. In this study, patients were randomly sampled from outpatients on the first day of diagnosis and from inpatients on the first day of their hospitalization. Patients were classified into the outpatient (without symptoms or with mild symptoms) and inpatient (with moderate, severe, and critical symptoms) groups. The serum level of MCP-1 was measured by ELISA and the frequency of MCP-1 G-2518A gene polymorphism genotypes in COVID-19 patients was checked by the RFLP-PCR method. Participants with COVID-19 infection had a higher rate of underlying diseases, such as diabetes, high blood pressure, kidney disease, and cardiovascular disease than the control group (P-value < 0.001). Also, the frequency of these factors in inpatients was significantly higher compared to outpatients (P-value < 0.001). Additionally, the level of MCP-1 in serum was significantly different with an average of 11.90 in comparison to 2.98 in the control group (P-value, 0.05), which is attributed to elevated serum levels among patients in hospitals with an average of 11.72 in comparison to 2.98 in the control group. Compared with outpatients, inpatients had a higher frequency of the G allele of the MCP-1-2518 polymorphism (P-value < 0.05), while a notable difference was observed in the serum level of MCP-1 in COVID-19 patients with the MCP-1-2518 AA genotype in the whole group in comparison to the control group (P-value: 0.024). Totally, the results showed that a high frequency of the G allele is related to hospitalization and poor outcome in COVID-19 cases.

Exosomal delivery of 7SK long non-coding RNA suppresses viability, proliferation, aggressiveness and tumorigenicity in triple negative breast cancer cells.

AIMS: RN7SK (7SK), a highly conserved non-coding RNA, serves as a transcription regulator via interaction with a few proteins. Despite increasing evidences which support the cancer-promoting roles of 7SK-interacting proteins, limited reports address the direct link between 7SK and cancer. To test the hypothetic suppression of cancer by overexpression of 7SK, the effects of exosomal 7SK delivery on cancer phenotypes were studied. MATERIALS AND METHODS: Exosomes derived from human mesenchymal stem cells were loaded with 7SK (Exo-7SK). MDA-MB-231, triple negative breast cancer (TNBC), cell line was treated with Exo-7sk. Expression levels of 7SK were evaluated by qPCR. Cell viability was assessed via MTT and Annexin V/PI assays as well as qPCR assessment of apoptosis-regulating genes. Cell proliferation was evaluated by growth curve analysis, colony formation and cell cycle assays. Aggressiveness of TNBCs was evaluated via transwell migration and invasion assays and qPCR assessment of genes regulating epithelial to mesenchymal transition (EMT). Moreover, tumor formation ability was assessed using a nude mice xenograft model. KEY FINDINGS: Treatment of MDA-MB-231 cells with Exo-7SK resulted in efficient overexpression of 7SK; reduced viability; altered transcription levels of apoptosis-regulating genes; reduced proliferation; reduced migration and invasion; altered transcription of EMT-regulating genes; and reduced in vivo tumor formation ability. Finally, Exo-7SK reduced mRNA levels of HMGA1, a 7SK interacting protein with master gene regulatory and cancer promoting roles, and its bioinformatically-selected cancer promoting target genes. SIGNIFICANCE: Altogether, as a proof of the concept, our findings suggest that exosomal delivery of 7SK may suppress cancer phenotypes via downregulation of HMGA1.

Exosome engineering in cell therapy and drug delivery.

Cell-derived exosomes have opened new horizons in modern therapy for advanced drug delivery and therapeutic applications, due to their key features such as low immunogenicity, high physicochemical stability, capacity to penetrate into tissues, and the innate capacity to communicate with other cells over long distances. Exosome-based liquid biopsy has been potentially used for the diagnosis and prognosis of a range of disorders. Exosomes deliver therapeutic agents, including immunological modulators, therapeutic drugs, and antisense oligonucleotides to certain targets, and can be used as vaccines, though their clinical application is still far from reality. Producing exosomes on a large-scale is restricted to their low circulation lifetime, weak targeting capacity, and inappropriate controls, which need to be refined before being implemented in practice. Several bioengineering methods have been used for refining therapeutic applications of exosomes and promoting their effectiveness, on the one hand, and addressing the existing challenges, on the other. In the short run, new diagnostic platforms and emerging therapeutic strategies will further develop exosome engineering and therapeutic potential. This requires a thorough analysis of exosome engineering approaches along with their merits and drawbacks, as outlined in this paper. The present study is a comprehensive review of novel techniques for exosome development in terms of circulation time in the body, targeting capacity, and higher drug loading/delivery efficacies.

In vitro treatment of murine splenocytes with extracellular vesicles derived from mesenchymal stem cells altered the mRNA levels of the master regulator genes of T helper cell subsets.

INTRODUCTION: The purpose of the current study was to evaluate the effect of mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) on the production of cytokines and expression of genes, which are corresponded to the subsets of T helper cells. MATERIALS AND METHODS: The supernatant of the second passage of MSCs that had been isolated from C57BL/6 mice abdominal adipose tissue was used to collect the MSC-EV. Splenocytes of healthy mice were activated using anti-CD3 and anti-CD28 antibodies and simultaneously were treated using the MSC-EVs. The proliferation rate of lymphocytes and the frequency of regulatory T cells were measured using flow cytometry. In addition, the expressions of T helper cell subset-specific transcription factors were evaluated using a real-time PCR assay. To appraise the effects of MSC-EV on splenocytes, the levels of IFN-γ, IL-17A, IL-10, and TGF-ß were measured using ELISA. RESULTS: The results showed that the treatment of the CD3/CD28-activated splenocytes with MSC-EV did not statistically change the proliferation of CD3+ splenocytes. However, after the treatment, the mRNA levels of Foxp3 and Elf4 as well as the frequency of regulatory T cells was significantly higher when compared to the control group. The expression levels of Gata3, Rorc, and Tbx21 were down-regulated while, the corresponding cytokines levels did not alter. CONCLUSION: The results revealed that the in vitro treatment of MSC-EV was associated with the increase in the frequency of CD4+CD25+FOXP3+ T cells and upregulation of Foxp3 mRNA level.

Mechanisms behind therapeutic potentials of mesenchymal stem cell mitochondria transfer/delivery.

Mesenchymal stromal/stem cells (MSCs) perform their therapeutic effects through various mechanisms, including their ability to differentiate, producing different growth factors, immunomodulatory factors, and extracellular vesicles (EVs). In addition to the mentioned mechanisms, a new aspect of the therapeutic potential of MSCs has recently been noticed, which occurs through mitochondrial transfer. Various methods of MSCs mitochondria transfer have been used in studies to benefit from their therapeutic potential. Among these methods, mitochondrial transfer after MSCs transplantation in cell-to-cell contact, EVs-mediated transfer of mitochondria, and the use of MSCs isolated mitochondria (MSCs-mt) are well studied. Pathological conditions can affect the cells in the damaged microenvironment and lead to cells mitochondrial damage. Since the defect in the mitochondrial function of the cell leads to a decrease in ATP production and the subsequent cell death, restoring the mitochondrial content, functions, and hemostasis can affect the functions of the damaged cell. Various studies show that the transfer of MSCs mitochondria to other cells can affect vital processes such as proliferation, differentiation, cell metabolism, inflammatory responses, cell senescence, cell stress, and cell migration. These changes in cell attributes and behavior are very important for therapeutic purposes. For this reason, their investigation can play a significant role in the direction of the researchers'.

Mesenchymal stem cell-based therapy as a new therapeutic approach for acute inflammation.

Acute inflammatory diseases such as acute colitis, kidney injury, liver failure, lung injury, myocardial infarction, pancreatitis, septic shock, and spinal cord injury are significant causes of death worldwide. Despite advances in the understanding of its pathophysiology, there are many restrictions in the treatment of these diseases, and new therapeutic approaches are required. Mesenchymal stem cell-based therapy due to immunomodulatory and regenerative properties is a promising candidate for acute inflammatory disease management. Based on preclinical results, mesenchymal stem cells and their-derived secretome improved immunological and clinical parameters. Furthermore, many clinical trials of acute kidney, liver, lung, myocardial, and spinal cord injury have yielded promising results. In this review, we try to provide a comprehensive view of mesenchymal stem cell-based therapy in acute inflammatory diseases as a new treatment approach.

Coculture of adipose-derived mesenchymal stem cells/macrophages on decellularized placental sponge promotes differentiation into the osteogenic lineage.

BACKGROUND: Several factors like three-dimensional microstructure, growth factors, cytokines, cell-cell communication, and coculture with functional cells can affect the stem cells behavior and differentiation. The purpose of this study was to investigate the potential of decellularized placental sponge as adipose-derived mesenchymal stem cells (AD-MSCs) and macrophage coculture systems, and guiding the osteogenic differentiation of stem cells. METHODS: The decellularized placental sponge (DPS) was fabricated, and its mechanical characteristics were evaluated using degradation assay, swelling rate, and pore size determination. Its structure was also investigated using hematoxylin and eosin staining and scanning electron microscopy. Mouse peritoneal macrophages and AD-MSCs were isolated and characterized. The differentiation potential of AD-MSCs co-cultured with macrophages was evaluated by RT-qPCR of osteogenic genes on the surface of DPS. The in vivo biocompatibility of DPS was determined by subcutaneous implantation of scaffold and histological evaluations of the implanted site. RESULTS: The DPS had 67% porosity with an average pore size of 238 µm. The in vitro degradation assay showed around 25% weight loss during 30 days in PBS. The swelling rate was around 50% during 72 h. The coculture of AD-MSCs/macrophages on the DPS showed a significant upregulation of four differentiation osteogenic lineage genes in AD-MSCs on days 14 and 21 and a significantly higher mineralization rate than the groups without DPS. Subcutaneous implantation of DPS showed in vivo biocompatibility of scaffold during 28 days follow-up. CONCLUSIONS: Our findings suggest the decellularized placental sponge as an excellent bone substitute providing a naturally derived matrix substrate with biostructure close to the natural bone that guided differentiation of stem cells toward bone cells and a promising coculture substrate for crosstalk of macrophage and mesenchymal stem cells in vitro.