Efficiency of mesenchymal stem cells in treatment of urinary incontinence: a systematic review on animal models

AIM

In recent years, the administration of stem cells has been considered a new option for treatment of urinary incontinence (UI). In the present study, the efficiency of mesenchymal stem cell (MSC) transplantation in the treatment of UI was evaluated.

METHODS

Combinations of the key words 'mesenchymal stem cells', 'MSCs', 'urinary incontinence', 'urethral sphincter' and 'involuntary urination' were searched in PubMed and Science Direct databases. Following application of exclusion criteria to the 1946 papers obtained and review and duplicate articles were removed, 23 articles were considered further. The search was limited to the animal model studies.

RESULTS

The data obtained from the evaluation of different studies indicated that the injected MSCs play an important role in the neovascularization and the recovery of muscle cells in UI models through the paracrine process.

CONCLUSION

The obtained data suggested that further trials are needed to be focused on clinical phase of MSC therapy on the patients affected by UI.

Human umbilical cord-derived mesenchymal stem cells ameliorate the enteropathy of food allergies in mice

Food allergy prevalence has steadily increased worldwide over the past decades and immunotherapeutic treatment strategies are gaining attention. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) exhibit similar immune regulatory properties to bone marrow-derived MSCs. hUC-MCSs can be prepared with fewer ethical constraints and are potential candidates for allergic disorder therapies. The current study aimed to investigate potential antiallergic properties of hUC-MSCs in mice with ovalbumin (OVA)-induced food allergy. Administration of hUC-MSCs cells intraperitoneally combined with oral gavage of the culture medium significantly alleviated OVA-induced diarrhea symptoms. Additionally, this treatment significantly decreased IgE levels and the percentage of T helper 2 cells in the blood, which were increased in mice with OVA-induced food allergy. The mRNA levels of the inflammatory cytokines interleukin-4 and tumor necrosis factor-α, and inflammatory cell infiltration in mouse colons were significantly decreased in hUC-MSCs-treated animals compared with mice with OVA-induced food allergy. Goblet cells were detected in colons of allergy-induced mice and their numbers were reduced following treatment with hUC-MSCs. In addition, treatment with hUC-MSCs reestablished the gut flora. The results revealed that hUC-MSCs may have a potential application in food allergy therapy.

Immunomodulatory effects of rhesus monkey bone marrow-derived mesenchymal stem cells in serum-free conditions

Mesenchymal stem cells (MSCs) have generated tremendous interest for treating various diseases due to their self-renewal and differentiation capacities. Many studies have demonstrated the immunoregulatory capability of MSCs; however, most of these studies were conducted with fetal bovine serum (FBS), which has an uncertain composition. In this study, we established a serum-free, xeno-free, completely chemically defined medium for the proliferation and expansion of rhesus monkey bone marrow (BM)-derived MSCs (rBMSCs) in vitro. The growth kinetics, characteristics, immunophenotype, and immunosuppressive abilities of rBMSCs grown in serum-free media (SFM) were evaluated and compared with those of cells grown in serum-containing media (SCM). Moreover, we employed RNA sequencing to evaluate the expression pattern of genes related to immune responses in both culture conditions. Compared to cells grown in SCM, rBMSCs grown in SFM exhibited better biological characteristics regarding cell proliferation and immunosuppressive abilities. Cells from both media types exhibited similar immunophenotypic expression patterns for CD29, CD34, CD45, HLA-DR, CD73, CD90, and CD105. Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and Gene Set Enrichment Analysis (GSEA) revealed that CXCL8 was downregulated by 4.1 fold in SFM-cultured rBMSCs compared with those in SCM. Furthermore, the mixed lymphocyte culture revealed that the proliferation activity and the expression levels of inflammatory factors of peripheral blood mononuclear cells (PBMCs) were significantly decreased after the addition of the CXCL8 neutralizing antibody, which was related to the elevated immunosuppressive abilities of SFM-suspended rBMSCs. These results suggest a possible cell culture method as well as immunoregulatory mechanisms for clinical cell therapies requiring nonanimal-derived components.

First Insights Into the M2 Inflammatory Response After Adipose-Tissue-Derived Stem Cell Injections in Radiation-Injured Muscles

The cutaneous radiation syndrome is the clinical consequence of local high-dose irradiation. It is characterized by extensive inflammation, necrosis, and poor revascularization of the skin, resulting in muscle inflammation and fibrosis. Based on these physiopathological processes, subcutaneous injections of adipose-tissue-derived stem/stromal cells have shown favorable effects on skin-wound healing in a minipig model of cutaneous radiation syndrome, in which muscle fibrosis persisted. Since fibrosis is mainly due to the inflammatory processes that often affect underlying tissues as well, the beneficial effects of intramuscular injections of adipose-tissue-derived stem/stromal cells on tissue recovery were evaluated. The polarization of the inflammatory response of irradiated muscle in a minipig model of cutaneous radiation syndrome was determined after acute local irradiation with 50 Gy gamma rays in a preliminary study (six minipigs). Analysis of the main inflammatory cytokines of the inflammatory response M1 (IL-1-beta and IL-6) and M2 (IL-10 and TGF-beta) by western blotting and in situ hybridization, as well as analysis of CD80/CD206 M1/M2 macrophage-specific markers by immunohistochemistry on minipig muscle samples, was performed 76 d after irradiation. The treatment of irradiated muscles with autologous adipose-tissue-derived stem/stromal cells led to an increase in IL-10 and TGF-beta, being associated with an increase in CD68+/CD206+ cells in this area. This highlights a polarization of M2 in the inflammatory response and indicates that adipose-tissue-derived stem/stromal cells may direct the irradiated tissues' inflammatory response towards a proregenerative outcome.

Mesenchymal Stem Cell-Based Immunomodulation: Properties and Clinical Application

Mesenchymal stem cells (MSCs) are multipotent stem cells characterized by self-renewal, production of clonal cell populations, and multilineage differentiation. They exist in nearly all tissues and play a significant role in tissue repair and regeneration. Additionally, MSCs possess wide immunoregulatory properties via interaction with immune cells in both innate and adaptive immune systems, leading to immunosuppression of various effector functions. Numerous bioactive molecules secreted by MSCs, particularly cytokines, growth factors, and chemokines, exert autocrine/paracrine effects that modulate the physiological processes of MSCs. These invaluable virtues of MSCs provide new insight into potential treatments for tissue damage and inflammation. In particular, their extensive immunosuppressive properties are being explored for promising therapeutic application in immune disorders. Recently, clinical trials for MSC-mediated therapies have rapidly developed for immune-related diseases following reports from preclinical studies declaring their therapeutic safety and efficacy. Though immunotherapy of MSCs remains controversial, these clinical trials pave the way for their widespread therapeutic application in immune-based diseases. In this review, we will summarize and update the latest research findings and clinical trials on MSC-based immunomodulation.

The ratio of ADSCs to HSC-progenitors in adipose tissue derived SVF may provide the key to predict the outcome of stem-cell therapy

BACKGROUND

Stromal vascular fraction (SVF) represents an attractive source of adult stem cells and progenitors, holding great promise for numerous cell therapy approaches. In 2017, it was reported that 1524 patients received autologous SVF following the enzymatic digestion of liposuction fat. The treatment was safe and effective and patients showed significant clinical improvement. In a collaborative study, we analyzed SVF obtained from 58 patients having degenerative, inflammatory, autoimmune diseases, and advanced stage cancer.

RESULTS

Flow analysis showed that freshly isolated SVF was very heterogeneous and harbored four major subsets specific to adipose tissue; CD34high CD45- CD31- CD146- adipose-derived stromal/stem cells (ADSCs), CD34low CD45+ CD206+CD31- CD146- hematopoietic stem cell-progenitors (HSC-progenitors), CD34high CD45- CD31+CD146+ adipose tissue-endothelial cells and CD45-CD34-CD31-CD146+ pericytes. Culturing and expanding of SVF revealed a homogenous population lacking hematopoietic lineage markers CD45 and CD34, but were positive for CD90, CD73, CD105, and CD44. Flow cytometry sorting of viable individual subpopulations revealed that ADSCs had the capacity to grow in adherent culture. The identity of the expanded cells as mesenchymal stem cells (MSCs) was further confirmed based on their differentiation into adipogenic and osteogenic lineages. To identify the potential factors, which may determine the beneficial outcome of treatment, we followed 44 patients post-SVF treatment. The gender, age, clinical condition, certain SVF-dose and route of injection, did not play a role on the clinical outcome. Interestingly, SVF yield seemed to be affected by patient's characteristic to various extents. Furthermore, the therapy with adipose-derived and expanded-mesenchymal stem cells (ADE-MSCs) on a limited number of patients, did not suggest increased efficacies compared to SVF treatment. Therefore, we tested the hypothesis that a certain combination, rather than individual subset of cells may play a role in determining the treatment efficacy and found that the combination of ADSCs to HSC-progenitor cells can be correlated with overall treatment efficacy.

CONCLUSIONS

We found that a 2:1 ratio of ADSCs to HSC-progenitors seems to be the key for a successful cell therapy. These findings open the way to future rational design of new treatment regimens for individuals by adjusting the cell ratio before the treatment.

Placenta-Derived Decidua Stromal Cells for Hemorrhagic Cystitis after Stem Cell Transplantation

BACKGROUND/AIMS

Hemorrhagic cystitis (HC) is a serious complication after hematopoietic stem cell transplantation (HSCT). Stromal cells have been tested as therapy for HC. Decidua stromal cells (DSCs) protect the fetus from the mother's immune system.

METHODS

Eleven patients with HC of grades 3-4 were treated with DSCs after HSCT. The median age was 33 years (range 8-50), and the median dose of DSCs was 1.5 × 106/kg (range 0.7-2.5). The patients were given 1 dose (1-4).

RESULTS

In 5 patients, HC disappeared within 5 days after DSC infusion. Patients who received DSCs within 3 days after the start of HC had a duration of HC of 5 days and a shorter duration of pain than patients who were given DSCs later (p = 0.02). Three patients received DSCs prepared in albumin instead of AB-plasma and tended to have a shorter duration of pain (p = 0.07). There was no infusion toxicity. Adverse events were those often seen after HSCT. Nine of the 11 patients (82%) were alive 1 year after HSCT.

CONCLUSIONS

Based on this pilot study, we started a randomized, placebo-controlled double-blind study using 2 doses of 1 × 106 DSCs/kg suspended in albumin for treatment of early HC.

Silver-pig skin nanocomposites and mesenchymal stem cells: suitable antibiofilm cellular dressings for wound healing

Background

Treatment of severe or chronic skin wounds is an important challenge facing medicine and a significant health care burden. Proper wound healing is often affected by bacterial infection; where biofilm formation is one of the main risks and particularly problematic because it confers protection to microorganisms against antibiotics. One avenue to prevent bacterial colonization of wounds is the use of silver nanoparticles (AgNPs); which have proved to be effective against non-multidrug-resistant and multidrug-resistant bacteria. In addition, the use of mesenchymal stem cells (MSC) is an excellent option to improve wound healing due to their capability for differentiation and release of relevant growth factors. Finally, radiosterilized pig skin (RPS) is a biomatrix successfully used as wound dressing to avoid massive water loss, which represents an excellent carrier to deliver MSC into wound beds. Together, AgNPs, RPS and MSC represent a potential dressing to control massive water loss, prevent bacterial infection and enhance skin regeneration; three essential processes for appropriate wound healing with minimum scaring.

Results

We synthesized stable 10 nm-diameter spherical AgNPs that showed 21- and 16-fold increase in bacteria growth inhibition (in comparison to antibiotics) against clinical strains Staphylococcus aureus and Stenotrophomonas maltophilia, respectively. RPS samples were impregnated with different AgNPs suspensions to develop RPS-AgNPs nanocomposites with different AgNPs concentrations. Nanocomposites showed inhibition zones, in Kirby–Bauer assay, against both clinical bacteria tested. Nanocomposites also displayed antibiofilm properties against S. aureus and S. maltophilia from RPS samples impregnated with 250 and 1000 ppm AgNPs suspensions, respectively. MSC were isolated from adipose tissue and seeded on nanocomposites; cells survived on nanocomposites impregnated with up to 250 ppm AgNPs suspensions, showing 35% reduction in cell viability, in comparison to cells on RPS. Cells on nanocomposites proliferated with culture days, although the number of MSC on nanocomposites at 24 h of culture was lower than that on RPS.

Conclusions

AgNPs with better bactericide activity than antibiotics were synthesized. RPS-AgNPs nanocomposites impregnated with 125 and 250 ppm AgNPs suspensions decreased bacterial growth, decreased biofilm formation and were permissive for survival and proliferation of MSC; constituting promising multi-functional dressings for successful treatment of skin wounds.

Electronic supplementary material

The online version of this article (10.1186/s12951-017-0331-0) contains supplementary material, which is available to authorized users.

Immunosuppressive function of mesenchymal stem cells from human umbilical cord matrix in immune thrombocytopenia patients

Human umbilical cord matrix/Wharton's Jelly (hUC)-derived mesenchymal stem cells (MSC) have been shown to have marked therapeutic effects in a number of inflammatory diseases and autoimmune diseases in humans based on their potential for immunosuppression and their low immunogenicity. Currently, no data are available on the effectiveness of UC-MSC transplantation in immune thrombocytopenia (ITP) patients. It was the objective of this study to assess the effect of allogeneic UC-MSCs on ITP patients in vitro and in vivo. Peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BM-MNCs) from ITP patients and healthy controls were co-cultured with UC-MSCs for three days and seven days, respectively. Flow cytometry and ELISA were applied to assess the various parameters. In PBMCs from ITP patients, the proliferation of autoreactive T, B lymphocytes and destruction of autologous platelets were dramatically suppressed by UC-MSCs. UC-MSCs not only suppressed co-stimulatory molecules CD80, CD40L and FasL expression but also in shifting Th1/Th2/Treg cytokines profile in ITP patients. UC-MSCs obviously reversed the dysfunctions of megakaryocytes by promoting platelet production and decreasing the number of living megakaryocytes as well as early apoptosis. In addition, the level of thrombopoietin was increased significantly. Our clinical study showed that UC-MSCs play a role in alleviating refractory ITP by increasing platelet numbers. These findings suggested that UC-MSCs transplantation might be a potential therapy for ITP.

Perianal fistulizing Crohn's disease: pathogenesis, diagnosis and therapy

Perianal fistulizing Crohn's disease has a major negative effect on patient quality of life and is a predictor of poor long-term outcomes. Factors involved in the pathogenesis of perianal fistulizing Crohn's disease include an increased production of transforming growth factor β, TNF and IL-13 in the inflammatory infiltrate that induce epithelial-to-mesenchymal transition and upregulation of matrix metalloproteinases, leading to tissue remodelling and fistula formation. Care of patients with perianal Crohn's disease requires a multidisciplinary approach. A complete assessment of fistula characteristics is the basis for optimal management and must include the clinical evaluation of fistula openings, endoscopic assessment of the presence of proctitis, and MRI to determine the anatomy of fistula tracts and presence of abscesses. Local injection of mesenchymal stem cells can induce remission in patients not responding to medical therapies, or to avoid the exposure to systemic immunosuppression in patients naive to biologics in the absence of active luminal disease. Surgery is still required in a high proportion of patients and should not be delayed when criteria for drug failure is met. In this Review, we provide an up-to-date overview on the pathogenesis and diagnosis of fistulizing Crohn's disease, as well as therapeutic strategies.

Metabolic syndrome alters expression of insulin signaling-related genes in swine mesenchymal stem cells

AIMS

Metabolic syndrome (MetS) is associated with insulin resistance (IR) and impaired glucose metabolism in muscle, fat, and other cells, and may induce inflammation and vascular remodeling. Endogenous reparative systems, including adipose tissue-derived mesenchymal stem/stromal cells (MSC), are responsible for repair of damaged tissue. MSC have also been proposed as an exogenous therapeutic intervention in patients with cardiovascular and chronic kidney disease (CKD). The feasibility of using autologous cells depends on their integrity, but whether in MetS IR involves adipose tissue-derived MSC remains unknown. The aim of this study was to examine the expression of mRNA involved in insulin signaling in MSC from subjects with MetS.

METHODS

Domestic pigs consumed a lean or obese diet (n=6 each) for 16weeks. MSC were collected from subcutaneous abdominal fat and analyzed using high-throughput RNA-sequencing for expression of genes involved in insulin signaling. Expression profiles for enriched (fold change>1.4, p<0.05) and suppressed (fold change<0.7, p<0.05) mRNAs in MetS pigs were functionally interpreted by gene ontology analysis. The most prominently upregulated and downregulated mRNAs were further probed.

RESULTS

We identified in MetS-MSC 168 up-regulated and 51 down-regulated mRNAs related to insulin signaling. Enriched mRNAs were implicated in biological pathways including hepatic glucose metabolism, adipocyte differentiation, and transcription regulation, and down-regulated mRNAs in intracellular calcium signaling and cleaving peptides. Functional analysis suggested that overall these alterations could increase IR.

CONCLUSIONS

MetS alters mRNA expression related to insulin signaling in adipose tissue-derived MSC. These observations mandate caution during administration of autologous MSC in subjects with MetS.

Mesenchymal stem cells in peripheral blood of severely injured patients

PURPOSE

Mesenchymal stem cells (MSCs) are primarily stromal cells present in bone marrow and other tissues that are crucial for tissue regeneration and can be mobilized into peripheral blood after different types of organ damage. However, little is known about MSC appearance in blood in the setting of polytrauma.

METHODS

We conducted a monocentered and longitudinal observational clinical study in 11 polytraumatized patients with an injury severity score (ISS) ≥ 24 to determine the numbers of MSCs in peripheral blood. Blood was collected from healthy volunteers and patients after polytrauma in the emergency room and 4, 12, 24, 48 h, 5 and 10 day later, and cells carrying MSC-surface markers (negative for CD45, positive for CD29, CD73, CD90, CD105, and CD166 in different combinations also employing the more stringent markers STRO1 and MSCA1) were detected and characterized using flow cytometry. Relative numbers of MSC-like cells were correlated with clinical parameters to evaluate if specific injury patterns had an influence on their presence in the blood cell pool.

RESULTS

We were able to detect MSC marker-positive cells in both cohorts; however, the percentage of those cells present in the blood of patients during the first 10 day after injury was mostly similar to healthy volunteers, and significantly lowers starting at 4 h post trauma for one marker combination when compared to controls. Furthermore, the presence of a pelvis fracture was partly correlated with reduced relative numbers of MSC-like cells detectable in blood.

CONCLUSIONS

Polytrauma in humans was associated with partly reduced relative numbers of MSC-like cells detected in peripheral blood in the time course after injury. Further studies need to define if this reduction was due to lower mobilization from the bone marrow or to active migration to the sites of injury.

Cryopreserved or Fresh Mesenchymal Stromal Cells: Only a Matter of Taste or Key to Unleash the Full Clinical Potential of MSC Therapy?

Mesenchymal stromal cells (MSCs) harbor great therapeutic potential for numerous diseases. From early clinical trials, success and failure analysis, bench-to-bedside and back-to-bench approaches, there has been a great gain in knowledge, still leaving a number of questions to be answered regarding optimal manufacturing and quality of MSCs for clinical application. For treatment of many acute indications, cryobanking may remain a prerequisite, but great uncertainty exists considering the therapeutic value of freshly thawed (thawed) and continuously cultured (fresh) MSCs. The field has seen an explosion of new literature lately, outlining the relevance of the topic. MSCs appear to have compromised immunomodulatory activity directly after thawing for clinical application. This may provide a possible explanation for failure of early clinical trials. It is not clear if and how quickly MSCs recover their full therapeutic activity, and if the "cryo stun effect" is relevant for clinical success. Here, we will share our latest insights into the relevance of these observations for clinical practice that will be discussed in the context of the published literature. We argue that the differences of fresh and thawed MSCs are limited but significant. A key issue in evaluating potency differences is the time point of analysis after thawing. To date, prospective double-blinded randomized clinical studies to evaluate potency of both products are lacking, although recent progress was made with preclinical assessment. We suggest refocusing therapeutic MSC development on potency and safety assays with close resemblance of the clinical reality.

Bone marrow and adipose mesenchymal stem cells attenuate cardiac fibrosis induced by methotrexate in rats

Mesenchymal stem cells (MSCs) are an ideal adult stem cell with capacity for self-renewal and differentiation with an extensive tissue distribution. The present study evaluates the therapeutic effects of bone marrow mesenchymal stem cells (BM-MSCs) or adipose-derived mesenchymal stem cells (AD-MSCs) against the development of methotrexate (MTX)-induced cardiac fibrosis versus dexamethasone (DEX). Rats were allocated into five groups; group 1, received normal saline orally; group 2, received MTX (14 mg/kg/week for 2 weeks); groups 3 and 4, treated once with 2 × 10⁶ cells of MTX + BM-MSCs and MTX + AD-MSCs, respectively; and group 5, MTX + DEX (0.5 mg/kg, for 7 days, P.O.). MTX induced cardiac fibrosis as marked changes in oxidative biomarkers and elevation of triglyceride, cholesterol, aspartate aminotransferase, gamma-glutamyl transferase, creatine kinase, and caspase-3, as well as deposited collagen. These injurious effects were antagonized after treatment with MSCs. So, MSCs possessed antioxidant, antiapoptotic, as well antifibrotic effects, which will perhaps initiate them as notable prospective for the treatment of cardiac fibrosis.

Ultrastructural characteristics of ovine bone marrow-derived mesenchymal stromal cells cultured with a silicon stabilized tricalcium phosphate bioceramic

Bioceramics are being used in experimental bone engineering application in association with bone marrow derived mesenchymal stem cells (BM-MSCs) as a new therapeutic tool, but their effects on the ultrastructure of BM-MSCs are yet unknown. In this study we report the morphological features of ovine (o)BM-MSCs cultured with Skelite, a resorbable bioceramic based on silicon stabilized tricalcium phosphate (SiTCP), able to promote the repair of induced bone defect in sheep model. oBM-MSCs were isolated from the iliac crest, cultured until they reached near-confluence and incubated with SiTCP. After 48 hr the monolayers were highly damaged and only few cells adhered to the plastic. Thus, SiTCP was removed, and after washing the cells were cultured until they became confluent. Then, they were trypsinizated and processed for transmission electron microscopy (TEM) and RT-PCR analysis. RT-PCR displayed that oBM-MSCs express typical surface marker for MSCs. TEM revealed the presence of electron-lucent cells and electron-dense cells, both expressing the CD90 surface antigen. The prominent feature of electron-lucent cells was the concentration of cytoplasmic organelles around the nucleus as well as large surface blebs containing glycogen or profiles of endoplasmic reticulum. The dark cells had a multilocular appearance by the presence of peripheral vacuoles. Some dark cells contained endocytic vesicles, lysosomes, and glycogen aggregates. oBM-MSCs showed different types of specialized interconnections. The comparison with ultrastructural features of untreated oBM-MSCs suggests the light and dark cells are two distinct cell types which were differently affected by SiTCP bioceramic. Skelite cultured ovine BM-MSCs display electron-dense and electron-lucent cells which are differently affected by this bioceramic. This suggests that they could play a different role in bioceramic based therapy.

Impaired mRNA Expression of the Migration Related Chemokine Receptor CXCR4 in Mesenchymal Stem Cells of COPD Patients

Defective tissue repair and remodeling are main aspects of Chronic Obstructive Pulmonary Disease (COPD) pathophysiology. Bone marrow mesenchymal stem cells (BM-MSCs) have been implicated in this direction, as their functional impairment and recruitment could possibly contribute to disease development and progression. The present study characterizes for the first time the expression of migration related chemokine receptors and their ligands in BM-MSCs from COPD patients. CXCR4/SDF1a and CCR7/CCL19-CCL21 mRNA levels were evaluated in BM-MSCs obtained from twelve COPD patients and seven healthy donors. SDF1a protein levels in sera and BM-MSCs' conditioned media were also evaluated. CXCR4, SDF1a, CCL19, and CCL21 mRNA levels were significantly reduced in COPD BM-MSCs while CCR7 levels were undetectable. Notably, SDF1a protein levels were marginally elevated in both patient sera and BM-MSCs' conditioned media while the increase in SDF1a serum levels significantly correlated with disease severity in COPD. Our findings show posttranscriptional regulation of SDF1a levels in BM-MSCs of COPD patients and significant downregulation of SDF1a and CXCR4 mRNA indicating an involvement of the SDF1a signaling pathway in the disease pathophysiology.

Intra-articular injection in the knee of adipose derived stromal cells (stromal vascular fraction) and platelet rich plasma for osteoarthritis

BACKGROUND

Stromal vascular fraction (SVF) can easily be obtained from a mini-lipoaspirate procedure of fat tissue and platelet rich plasma (PRP) can be obtained from peripheral blood. We evaluated the safety and preliminary efficacy of administering SVF and PRP intra-articularly into patients with osteoarthritis grade 1 and 2.

METHODS

A total of ten patients underwent a local tumescent liposuction procedure to remove approximately 100 ml of fat tissue from the abdomen. SVF was isolated using an enzyme digestion and resuspended in PRP for intra-articular injection in the knee. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and six-minute walk distance (6MWD) were used to evaluate clinical effects and included measure of patient's subjective assessment of pain, joint mobility, and physical disability. WOMAC score, 6MWD and laboratory tests were repeated at 3 and 6 months and 1, 1.5 and 2 years. XRAY and MRI were completed at 1 year.

RESULTS

The average total WOMAC score was 64 at baseline and significantly reduced to 52 at 3 months, 46 at 6 months, 42 at 1 year, 38 at 1.5 years, and 41 at 2 years. Patients walked an average of 1310 feet at baseline and demonstrated a statistically significant improvement at 3 and 6 months and 1, 1.5, and 2 years post treatment. Cartilage thickness as determined by MRI improved by at least 0.2 mm in six patients, was unchanged in two patients and decreased by at least 0.2 mm in two patients.

CONCLUSIONS

Overall, all of the patients were pleased with the treatment results. They reported a reduction in pain levels, especially after 3 months. More importantly, the procedure demonstrated a strong safety profile with no severe adverse events or complications reported. Trial registration NCT03089762; Name of registry: http://www.clinicaltrials.gov.

Immunologic properties of differentiated and undifferentiated mesenchymal stem cells derived from umbilical cord blood

The expression of immunogenic markers after differentiation of umbilical cord blood (UCB)-derived mesenchymal stem cells (MSC) has been poorly investigated and requires extensive in vitro and in vivo testing for clinical application. The expression of human leukocyte antigen (HLA) classes on UCB-derived MSC was tested by Fluorescence-activated cell sorting analysis and immunocytochemical staining. The undifferentiated MSC were moderately positive for HLA-ABC, but almost completely negative for HLA-DR. The MSC differentiated to chondrocytes expressed neither HLA-ABC nor HLA-DR. The proliferation of MSC was not significantly affected by the allogeneic lymphocytes stimulated with concanavalin A. The responder lymphocytes showed no significant decrease in proliferation in the presence of the MSC, but the apoptosis rate of the lymphocytes was increased in the presence of MSC. Taken together, these findings indicate that UCB-derived MSC differentiated to chondrocytes expressed less HLA class I and no class II antigens. The MSC showed an immunomodulatory effect on the proliferation and apoptosis of allogeneic lymphocytes. These data suggest that the differentiated and undifferentiated allogeneic MSC derived from umbilical cord blood can be a useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.

Mesenchymal stem cell transplantation in tight-skin mice identifies miR-151-5p as a therapeutic target for systemic sclerosis

Systemic sclerosis (SSc), an autoimmune disease, may cause significant osteopenia due to activation of the IL4Rα/mTOR pathway. Mesenchymal stem cell transplantation (MSCT) can ameliorate immune disorders in SSc via inducing immune tolerance. However, it is unknown whether MSCT rescues osteopenia phenotype in SSc. Here we show that MSCT can effectively ameliorate osteopenia in SSc mice by rescuing impaired lineage differentiation of the recipient bone marrow MSCs. Mechanistically, we show that donor MSCs transfer miR-151-5p to the recipient bone marrow MSCs in SSc mice to inhibit IL4Rα expression, thus downregulating mTOR pathway activation to enhance osteogenic differentiation and reduce adipogenic differentiation. Moreover, systemic delivery of miR-151-5p is capable of rescuing osteopenia, impaired bone marrow MSCs, tight skin, and immune disorders in SSc mice, suggesting that miR-151-5p may be a specific target for SSc treatment. Our finding identifies a previously unrecognized role of MSCT in transferring miRNAs to recipient stem cells to ameliorate osteopenia via rescuing a non-coding RNA pathway.

Isolation and Characterization of Human Chorionic Membranes Mesenchymal Stem Cells and Their Neural Differentiation

Mesenchymal stem cells (MSCs) can be obtained from a variety of human tissues. Placenta has become an attractive stem cell source for potential applications in regenerative medicine and tissue engineering. The aim of this study was to localize and characterize MSCs within human chorionic membranes (hCMSCs). For this purpose, immunofluorescence labeling with CD105 and CD90 were used to determine the distribution of MSCs in chorionic membranes tissue. A medium supplemented with a synthetic serum and various concentrations of neurotrophic factors and cytokines was used to induce hCMSCs to neural cells. The results showed that the CD90 positive cells were scattered in the chorionic membranes tissue, and the CD105 positive cells were mostly located around the small blood vessels. hCMSCs expressed typical mesenchymal markers (CD73, CD90, CD105, CD44 and CD166) but not hematopoietic markers (CD45, CD34) and HLA-DR. hCMSCs differentiated into adipocytes, osteocytes, chondrocytes, and neuronal cells, as revealed by morphological changes, cell staining, immunofluorescence analyses, and RT-PCR showing the tissue-specific gene presence for differentiated cell lineages after the treatment with induce medium. Human chorionic membranes may be the source of MSCs for treatment of nervous system injury.

RORγt+ Innate Lymphoid Cells Promote Lymph Node Metastasis of Breast Cancers

Cancer cells tend to metastasize first to tumor-draining lymph nodes, but the mechanisms mediating cancer cell invasion into the lymphatic vasculature remain little understood. Here, we show that in the human breast tumor microenvironment (TME), the presence of increased numbers of RORγt+ group 3 innate lymphoid cells (ILC3) correlates with an increased likelihood of lymph node metastasis. In a preclinical mouse model of breast cancer, CCL21-mediated recruitment of ILC3 to tumors stimulated the production of the CXCL13 by TME stromal cells, which in turn promoted ILC3-stromal interactions and production of the cancer cell motile factor RANKL. Depleting ILC3 or neutralizing CCL21, CXCL13, or RANKL was sufficient to decrease lymph node metastasis. Our findings establish a role for RORγt+ILC3 in promoting lymphatic metastasis by modulating the local chemokine milieu of cancer cells in the TME. Cancer Res; 77(5); 1083-96. ©2017 AACR.

Comparison of Adipose-Derived and Bone Marrow Mesenchymal Stromal Cells in a Murine Model of Crohn's Disease

BACKGROUND

Mesenchymal stromal cells (MSCs) have been used in the treatment of Crohn's disease (CD) because of the immunomodulatory ability.

AIM

The aim of this study was to investigate the therapeutic effect of adipose-derived MSCs (AD-MSCs) and to compare the therapeutic effect of AD-MSCs with that of bone marrow MSCs (BM-MSCs) in a murine model of CD.

METHODS

Murine colitis model of CD was created by trinitrobenzene sulfonic acid (TNBS). Twelve hours after treatment with TNBS, the mouse model was injected with MSCs intraperitoneally. Real-time polymerase chain reaction and immunohistochemistry staining were used to measure the expression levels of inflammatory cytokines in colonic tissues to investigate the therapeutic effect of AD-MSCs. The ten-day survival was recorded after infusion of MSCs.

RESULTS

Intraperitoneal injection of MSCs alleviated the clinical and histopathologic severity of intestinal inflammation, and improved the survival of the TNBS-induced mouse model of CD. AD-MSCs could effectively increase the expression of interleukin-10 and reduce the secretion of pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-12, and vascular endothelial growth factor. The mucosal injury was repaired by AD-MSCs. These effects were comparable between AD-MSCs and BM-MSCs.

CONCLUSIONS

The therapeutic effect appears similar between AD-MSCs and BM-MSCs in treating CD. AD-MSCs may be a potential alternative of cell-based therapy for CD.

Activation and Differentiation of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are multipotent cells and exhibit two main characteristics that define stem cells: self-renewal and differentiation. MSCs can migrate to sites of injury, inflammation, and tumor. Moreover, MSCs undergo myofibroblast like differentiation, including increased production of α-SMA in response to transforming growth factor-β (TGF-β), a growth factor commonly secreted by tumor cells to evade immune surveillance. Based on our previous finding hMSCs become activated and resemble carcinoma-associated myofibroblasts upon prolonged exposure to conditioned medium from MDAMB231 human breast cancer cells. Here, we show that keratinocyte conditioned medium (KCM) induces differentiation of MSCs to resemble dermal myofibroblast like cells using immunofluorescence techniques demonstrating punctate vinculin staining, and F-actin filaments.

Immunomodulatory Role of Mesenchymal Stem Cell Therapy in Vascularized Composite Allotransplantation

This review aims to summarize contemporary evidence of the in vitro and in vivo immunomodulatory effects of mesenchymal stem cells (MSCs) in promoting vascularized composite allotransplant (VCA) tolerance. An extensive literature review was performed to identify pertinent articles of merit. Prospective preclinical trials in mammal subjects receiving VCA (or skin allograft) with administration of MSCs were reviewed. Prospective clinical trials with intravascular delivery of MSCs in human populations undergoing solid organ transplant were also identified and reviewed. Sixteen preclinical studies are included. Eleven studies compared MSC monotherapy to no therapy; of these, ten reported improved graft survival, which was statistically significantly prolonged in eight. Eight studies analyzed allograft survival with MSC therapy as an adjunct to proven immunosuppressive regimens. In these studies, daily immunosuppression was transiently delivered and then stopped. In all studies, treatment-free graft survival was statistically significantly prolonged in animals that received MSC therapy. MSCs have been safely administered clinically and their use in renal transplant clinical trials provides evidence that they improve allograft transplant tolerance in clinical practice. There is potential for MSC induction therapy to overcome many of the obstacles to widespread VCA in clinical practice. Preclinical studies are needed before MSC-induced VCA tolerance becomes a clinical reality.

Indoleamine 2,3-Dioxygenase Is Dispensable for The Immunomodulatory Function of Stem Cells from Human Exfoliated Deciduous Teeth

Objective

In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth (SHED). We studied the role of the interferon gamma (IFN-γ)-indoleamine 2,3-dioxygenase (IDO)-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells (BMMSCs) under the same conditions.

Materials and Methods

In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells (PBMCs). These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan (1-MT) or neutralizing anti- human-IFN-γ antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity.

Results

SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-γ neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs.

Conclusion

SHED, like BMMSCs, produced the IDO enzyme. Although IFN-γ is one of inducer of IDO production in SHED, these cells were not affected by IFN-γ in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles.

Comparative study of adipose-derived stem cells and bone marrow-derived stem cells in similar microenvironmental conditions

Mesenchymal stem cells (MSCs), which were first isolated from the bone marrow, are now being extracted from various other tissues in the body, including the adipose tissue. The current study presents systematic evidence of how the adipose tissue-derived stem cells (ASCs) and bone marrow-derived mesenchymal stem cells (Bm-MSCs) behave when cultured in specific pro-adipogenic microenvironments. The cells were first characterized and identified as MSCs in terms of their morphology, phenotypic expression, self-renewal capabilities and multi-lineage potential. Subsequently, the proliferation and gene expression profiles of the cell populations cultured on two-dimensional (2D) adipose tissue extracellular matrix (ECM)-coated tissue culture plastic (TCP) and in three-dimensional (3D) AlgiMatrix® microenvironments were analyzed. Overall, it was found that adipogenesis was triggered in both cell populations due to the presence of adipose tissue ECM. However, in 3D microenvironments, ASCs and Bm-MSCs were predisposed to the adipogenic and osteogenic lineages respectively. Overall, findings from this study will contribute to ongoing efforts in adipose tissue engineering as well as provide new insights into the role of the ECM and cues provided by the immediate microenvironment for stem cell differentiation.

Transcriptional profiling reveals intrinsic mRNA alterations in multipotent mesenchymal stromal cells isolated from bone marrow of newly-diagnosed type 1 diabetes patients

Background

Bone marrow multipotent mesenchymal stromal cells (MSCs) are a diverse subset of precursors that contribute to the homeostasis of the hematopoietic niche. MSCs can be isolated and expanded in vitro and have unique immunomodulatory and regenerative properties that make them attractive for the treatment of autoimmune diseases, including type 1 diabetes (T1D). Whether autologous or allogeneic MSCs are more suitable for therapeutic purposes has not yet been established. While autologous MSCs may present abnormal function, allogeneic cells may be recognized and rejected by the host immune system. Thus, studies that investigate biological characteristics of MSCs isolated from T1D patients are essential to guide future clinical applications.

Methods

Bone marrow-derived MSCs from recently diagnosed type 1 diabetes patients (T1D-MSCs) were compared with those from healthy individuals (C-MSCs) for morphological and immunophenotypic characteristics and for differentiation potential. Bioinformatics approaches allowed us to match absolute and differential gene expression of several adhesion molecules, immune mediators, growth factors, and their receptors involved with hematopoietic support and immunomodulatory properties of MSCs. Finally, the differentially expressed genes were collated for functional pathway enrichment analysis.

Results

T1D-MSCs and C-MSCs were similar for morphology, immunophenotype, and differentiation potential. Our absolute gene expression results supported previous literature reports, while also detecting new potential molecules related to bone marrow-derived MSC functions. T1D-MSCs showed intrinsic abnormalities in mRNA expression, including the immunomodulatory molecules VCAM-1, CXCL12, HGF, and CCL2. Pathway analyses revealed activation of sympathetic nervous system and JAK STAT signaling in T1D-MSCs.

Conclusions

Collectively, our results indicate that MSCs isolated from T1D patients present intrinsic transcriptional alterations that may affect their therapeutic potential. However, the implications of these abnormalities in T1D development as well as in the therapeutic efficacy of autologous MSCs require further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0351-y) contains supplementary material, which is available to authorized users.

MiR-124 suppresses the chemotactic migration of rat mesenchymal stem cells toward HGF by downregulating Wnt/β-catenin signaling

Mesenchymal stem cells (MSCs) exhibit the potential to repair a wide variety of injured adult tissues. The migration capability of MSCs is an important determinant of the efficiency of MSC transplant therapy. MicroRNAs (miRNAs) are increasingly implicated in regulating the migration of MSCs. Herein, we show that the expression of miR-124 was downregulated in rat MSCs (rMSCs) treated with hepatocyte growth factor (HGF). Overexpression of miR-124 significantly reduced the chemotactic migration of rMSCs toward HGF, while inhibition of endogenous miR-124 promoted the chemotactic migration. A further study revealed that miR-124 directly targeted FZD4 and LRP6, which encode a receptor and co-receptor of the Wnt/β-catenin signaling pathway, respectively, thus reducing the activity of this signaling. Consistently, activation of the Wnt/β-catenin signaling pathway by LiCl and ΔN89β-catenin rescued the inhibitory effect of miR-124 on the chemotactic migration of rMSCs toward HGF, while inhibition of Wnt/β-catenin signaling by FH535 abrogated the enhanced chemotactic response achieved by the miR-124 inhibitor. Collectively, our study demonstrates that miR-124 downregulates Wnt/β-catenin signaling via targeting FZD4 and LRP6 and thus suppresses the chemotactic migration of rMSCs toward HGF.

Mesenchymal Stem Cells Shed Amphiregulin at the Surface of Lung Carcinoma Cells in a Juxtacrine Manner

Solid tumors comprise cancer cells and different supportive stromal cells, including mesenchymal stem cells (MSCs), which have recently been shown to enhance tumor growth and metastasis. We provide new mechanistic insights into how bone marrow (BM)–derived MSCs co-injected with Lewis lung carcinoma cells promote tumor growth and metastasis in mice. The proinvasive effect of BM-MSCs exerted on tumor cells relies on an unprecedented juxtacrine action of BM-MSC, leading to the trans-shedding of amphiregulin (AREG) from the tumor cell membrane by tumor necrosis factor-α–converting enzyme carried by the BM-MSC plasma membrane. The released soluble AREG activates cancer cells and promotes their invasiveness. This novel concept is supported by the exploitation of different 2D and 3D culture systems and by pharmacological approaches using a tumor necrosis factor-α–converting enzyme inhibitor and AREG-blocking antibodies. Altogether, we here assign a new function to BM-MSC in tumor progression and establish an uncovered link between AREG and BM-MSC.

Micro-vesicles derived from bone marrow stem cells protect the kidney both in vivo and in vitro by microRNA-dependent repairing

AIMS

Micro-vesicles (MVs) from bone mesenchymal stem cells (MSCs) have been shown to contribute to the recovery of damaged kidney. The aims of the present study are to investigate the biological effects and repair mechanisms of MVs.

METHODS

Micro-vesicles were obtained from MSC supernatants. In vitro, the proximal tubular epithelial cells (HK-2) were treated with transforming growth factor (TGF-β1). The expressions of E-cadherin and α-smooth muscle actin (α-SMA) were evaluated. In vitro, the mice were divided into: control, unilateral ureteral obstruction (UUO), UUO+MSC, and UUO+MV group. MVs and MSCs were injected after surgery. The mice were killed 7/14 days after surgery and handled for further tests. The micro-RNA expressions were labeled using the miRCURY Hy3/Hy5 Power labeling kit and hybridized on the miRCURY LNA Array.

RESULTS

In vitro, MV reversed transforming growth factor-β1 (TGF-β1)-induced morphological changes, and firmed the expression of E-cadherin and reduced the secretion of α-SMA in HK2 cells. In vivo, the level of blood urea nitrogen (BUN) in the MV and MSC group was lower than the UUO (P < 0.01). The Scr level decreased after 7 days of MV treatment (P < 0.05). Administration of MSC and MV reduced Scr level at day 14 (P < 0.05). The level of serum UA decreased with MV administration (day 7,14, P < 0.01). Herein, a total of 503 expressed miRNAs were detected, of which, 266 were in MSC, including 237 in MVs.

CONCLUSION

Micro-vesicles (MVs) protect kidneys both in vivo and vitro, and MVs are superior to MSCs in some respects. MVs can be a potential therapy in treatment of kidney diseases.

Human periodontal ligament stem cells suppress T-cell proliferation via down-regulation of non-classical major histocompatibility complex-like glycoprotein CD1b on dendritic cells

BACKGROUND AND OBJECTIVE

Periodontal ligament stem cells (PDLSCs) from the periodontal ligament tissue were recently identified as mesenchymal stem cells (MSCs). The capabilities of PDLSCs in periodontal tissue or bone regeneration have been reported, but their immunomodulatory role in T-cell immune responses via dendritic cells (DCs), known as the most potent antigen-presenting cell, has not been studied. The aim of this study is to understand the immunological function of homogeneous human STRO-1⁺ CD146⁺ PDLSCs in DC-mediated T-cell immune responses to modulate the periodontal disease process.

MATERIAL AND METHODS

We utilized highly purified (> 95%) human STRO-1⁺ CD146⁺ PDLSCs and human bone marrow mesenchymal stem cells (BMSCs). Each stem cell was co-cultured with human monocyte-derived DCs in the presence of lipopolysaccharide isolated from Porphyromonas gingivalis, a major pathogenic bacterium responsible for periodontal disease, in vitro to examine the immunological effect of each stem cell on DCs and DC-mediated T-cell proliferation.

RESULTS

We discovered that STRO-1⁺ CD146⁺ PDLSCs, as well as BMSCs, significantly decreased the level of non-classical major histocompatibility complex glycoprotein CD1b on DCs, resulting in defective T-cell proliferation, whereas most human leukocyte antigens and the co-stimulatory molecules CD80 and CD86 in/on DCs were not significantly affected by the presence of BMSCs or STRO-1⁺ CD146⁺ PDLSCs.

CONCLUSIONS

This study unveiled an immunomodulatory role of STRO-1⁺ CD146⁺ PDLSCs in negatively regulating DC-mediated T-cell immune responses, demonstrating their potential to be utilized in promising new stem cell therapies.

Enhancement of the immunoregulatory potency of mesenchymal stromal cells by treatment with immunosuppressive drugs

BACKGROUND AIMS

Multipotent mesenchymal stromal cells (MSCs) are distinguished by their ability to differentiate into a number of stromal derivatives of interest for regenerative medicine, but they also have immunoregulatory properties that are being tested in a number of clinical settings.

METHODS

We show that brief incubations with rapamycin, everolimus, FK506 or cyclosporine A increase the immunosuppressive potency of MSCs and other cell types.

RESULTS

The treated MSCs are up to 5-fold more potent at inhibiting the induced proliferation of T lymphocytes in vitro. We show that this effect probably is due to adsorption of the drug by the MSCs during pre-treatment, with subsequent diffusion into co-cultures at concentrations sufficient to inhibit T-cell proliferation. MSCs contain measurable amounts of rapamycin after a 15-min exposure, and the potentiating effect is blocked by a neutralizing antibody to the drug. With the use of a pre-clinical model of acute graft-versus-host disease, we demonstrate that a low dose of rapamycin-treated but not untreated umbilical cord-derived MSCs significantly inhibit the onset of disease.

CONCLUSIONS

The use of treated MSCs may achieve clinical end points not reached with untreated MSCs and allow for infusion of fewer cells to reduce costs and minimize potential side effects.

Secretome of mesenchymal progenitors from the umbilical cord acts as modulator of neural/glial proliferation and differentiation

It was recently shown that the conditioned media (CM) of Human Umbilical Cord Perivascular Cells (HUCPVCs), a mesenchymal progenitor population residing within the Wharton Jelly of the umbilical cord, was able to modulate in vitro the survival and viability of different neuronal and glial cells populations. In the present work, we aimed to assess if the secretome of HUCPVCs is able to 1) induce the differentiation of human telencephalon neural precursor cells (htNPCs) in vitro, and 2) modulate neural/glial proliferation, differentiation and survival in the dentate gyrus (DG) of adult rat hippocampus. For this purpose, two separate experimental setups were performed: 1) htNPCs were incubated with HUCPVCs-CM for 5 days after which neuronal differentiation was assessed and, 2) HUCPVCs, or their respective CM, were injected into the DG of young adult rats and their effects assessed 7 days later. Results revealed that the secretome of HUCPVCs was able to increase neuronal cell differentiation in vitro; indeed, higher densities of immature (DCX(+) cells) and mature neurons (MAP-2(+) cells) were observed when htNPCs were incubated with the HUCPVCs-CM. Additionally, when HUCPVCs and their CM were injected in the DG, results revealed that both cells or CM were able to increase the endogenous proliferation (BrdU(+) cells) 7 days after injection. It was also possible to observe an increased number of newborn neurons (DCX(+) cells), upon injection of HUCPVCs or their respective CM. Finally western blot analysis revealed that after CM or HUCPVCs transplantation, there was an increase of fibroblast growth factor-2 (FGF-2) and, to a lesser extent, of nerve growth factor (NGF) in the DG tissue. Concluding, our results have shown that the transplantation of HUCPVCs or the administration of their secretome were able to potentiate neuronal survival and differentiation in vitro and in vivo.

Leptin and Neutrophil-Activating Peptide 2 Promote Mesenchymal Stem Cell Senescence Through Activation of the Phosphatidylinositol 3-Kinase/Akt Pathway in Patients With Systemic Lupus Erythematosus

OBJECTIVE

Mesenchymal stem cells (MSCs) derived from patients with systemic lupus erythematosus (SLE) exhibit enhanced senescence. Cellular senescence has been reported to be induced by several inflammatory cytokines, including interferon-α (IFNα) and IFNγ, that are involved in the pathogenesis of SLE. We undertook this study to investigate whether the inflammatory environment in SLE could affect MSC senescence.

METHODS

Cellular senescence was measured by staining of senescence-associated β-galactosidase and by expression of the cell cycle inhibitors p53 and p21. Eighty cytokines and chemokines in serum from healthy controls and patients with SLE were identified by cytokine antibody array.

RESULTS

SLE serum promoted senescence of MSCs, which was reversed by the phosphatidylinositol 3-kinase (PI3K)/Akt signaling inhibitor LY294002 but not by the JAK/STAT inhibitor AG490 and not by the MEK/ERK inhibitor PD98059. Cytokine antibody array analysis revealed that leptin and neutrophil-activating peptide 2 (NAP-2) were the 2 factors most significantly elevated in SLE serum compared with normal serum. Blockade of leptin or NAP-2 in MSC cultures abolished SLE serum-induced senescence, while direct addition of these 2 factors could promote senescence in cultures of normal MSCs. Inhibition of PI3K/Akt signaling with LY294002 reduced leptin- and NAP-2-induced senescence in MSCs.

CONCLUSION

Taken together, our data show that leptin and NAP-2 act synergistically to promote MSC senescence through enhancement of the PI3K/Akt signaling pathway in SLE patients.

miR-335 correlates with senescence/aging in human mesenchymal stem cells and inhibits their therapeutic actions through inhibition of AP-1 activity

MicroRNAs, small noncoding RNAs, regulate gene expression primarily at the posttranscriptional level. We previously found that miR-335 is critically involved in the regulation and differentiation capacity of human mesenchymal stem cells (hMSCs) in vitro. In this study, we investigated the significance of miR-335 for the therapeutic potential of hMSCs. Analysis of hMSCs in ex vivo culture demonstrated a significant and progressive increase in miR-335 that is prevented by telomerase. Expression levels of miR-335 were also positively correlated with donor age of hMSCs, and were increased by stimuli that induce cell senescence, such as γ-irradiation and standard O2 concentration. Forced expression of miR-335 resulted in early senescence-like alterations in hMSCs, including: increased SA-β-gal activity and cell size, reduced cell proliferation capacity, augmented levels of p16 protein, and the development of a senescence-associated secretory phenotype. Furthermore, overexpression of miR-335 abolished the in vivo chondro-osseous potential of hMSCs, and disabled their immunomodulatory capacity in a murine experimental model of lethal endotoxemia. These effects were accompanied by a severely reduced capacity for cell migration in response to proinflammatory signals and a marked reduction in Protein Kinase D1 phosphorylation, resulting in a pronounced decrease of AP-1 activity. Our results demonstrate that miR-335 plays a key role in the regulation of reparative activities of hMSCs and suggests that it might be considered a marker for the therapeutic potency of these cells in clinical applications.

CB(2) and TRPV(1) receptors oppositely modulate in vitro human osteoblast activity

In the current study, we have investigated the effect of CB2 and TRPV1 receptor ligands on in vitro osteoblasts from bone marrow of human healthy donors. A pivotal role for the endocannabinoid/endovanilloid system in bone metabolism has been highlighted. We have demonstrated a functional cross-talk between CB2 and TRPV1 in human osteoclasts, suggesting these receptors as new pharmacological target for the treatment of bone resorption disease as osteoporosis. Moreover, we have shown the presence of these receptors on human mesenchimal stem cells, hMSCs. Osteoblasts are mononucleated cells originated from hMSCs by the essential transcription factor runt-related transcription factor 2 and involved in bone formation via the synthesis and release of macrophage colony-stimulating factor, receptor activator of nuclear factor kappa-B ligand and osteoprotegerin. For the first time, we show that CB2 and TRPV1 receptors are both expressed on human osteoblasts together with enzymes synthesizing and degrading endocannabinoids/endovanilloids, and oppositely modulate human osteoblast activity in culture in a way that the CB2 receptor stimulation improves the osteogenesis whereas TRPV1 receptor stimulation inhibits it.

Are stem cells a potential therapeutic tool in coeliac disease?

Despite the growing understanding of its pathogenesis, the treatment of coeliac disease is still based on a lifelong gluten-free diet that, although efficacious, is troublesome for affected patients, and a definitive cure is still an unmet need. In this regard, the development of new chemical- and biological-derived agents has often resulted in unsatisfactory effects when tested in vivo, probably because of their ability to target only a single pathway, whilst the immunological cascade responsible for tissue injury is complex and redundant. The advent of cellular therapies, mainly based on the use of stem cells, is an emerging area of interest since it has the advantage of a multi-target strategy. Both haematopoietic and mesenchymal stem cells have been employed in the treatment of refractory patients suffering from autoimmune diseases, with promising results. However, the lack of immunogenicity makes mesenchymal stem cells more suitable than their haematopoietic counterpart, since their transplantation may be performed in the absence of a myeloablative conditioning regimen. In addition, mesenchymal stem cells have been shown to harbour strong modulatory effects on almost all cells involved in immune response, together with a potent regenerative action. It is therefore conceivable that over the next few years their therapeutic use will increase as their biological interactions with injured tissues become clearer.

Culture of human mesenchymal stem cells using a candidate pharmaceutical grade xeno-free cell culture supplement derived from industrial human plasma pools

INTRODUCTION

Fetal bovine serum (FBS) is an animal product used as a medium supplement. The animal origin of FBS is a concern if cultured stem cells are to be utilized for human cell therapy. Therefore, a substitute for FBS is desirable. In this study, an industrial, xeno-free, pharmaceutical-grade supplement for cell culture (SCC) under development at Grifols was tested for growth of human mesenchymal stem cells (hMSCs), cell characterization, and differentiation capacity.

METHODS

SCC is a freeze-dried product obtained through cold-ethanol fractionation of industrial human plasma pools from healthy donors. Bone marrow-derived hMSC cell lines were obtained from two commercial suppliers. Cell growth was evaluated by culturing hMSCs with commercial media or media supplemented with SCC or FBS. Cell viability and cell yield were assessed with an automated cell counter. Cell surface markers were studied by indirect immunofluorescence assay. Cells were cultured then differentiated into adipocytes, chondrocytes, osteoblasts, and neurons, as assessed by specific staining and microscopy observation.

RESULTS

SCC supported the growth of commercial hMSCs. Starting from the same number of seeded cells in two consecutive passages of culture with medium supplemented with SCC, hMSC yield and cell population doubling time were equivalent to the values obtained with the commercial medium and was consistent among lots. The viability of hMSCs was higher than 90%, while maintaining the characteristic phenotype of undifferentiated hMSCs (positive for CD29, CD44, CD90, CD105, CD146, CD166 and Stro-1; negative for CD14 and CD19). Cultured hMSCs maintained the potential for differentiation into adipocytes, chondrocytes, osteoblasts, and neurons.

CONCLUSIONS

The tested human plasma-derived SCC sustains the adequate growth of hMSCs, while preserving their differentiation capacity. SCC can be a potential candidate for cell culture supplement in advanced cell therapies.

Diabetes reduces mesenchymal stem cells in fracture healing through a TNFα-mediated mechanism

AIMS/HYPOTHESIS

Diabetes interferes with bone formation and impairs fracture healing, an important complication in humans and animal models. The aim of this study was to examine the impact of diabetes on mesenchymal stem cells (MSCs) during fracture repair.

METHODS

Fracture of the long bones was induced in a streptozotocin-induced type 1 diabetic mouse model with or without insulin or a specific TNFα inhibitor, pegsunercept. MSCs were detected with cluster designation-271 (also known as p75 neurotrophin receptor) or stem cell antigen-1 (Sca-1) antibodies in areas of new endochondral bone formation in the calluses. MSC apoptosis was measured by TUNEL assay and proliferation was measured by Ki67 antibody. In vitro apoptosis and proliferation were examined in C3H10T1/2 and human-bone-marrow-derived MSCs following transfection with FOXO1 small interfering (si)RNA.

RESULTS

Diabetes significantly increased TNFα levels and reduced MSC numbers in new bone area. MSC numbers were restored to normal levels with insulin or pegsunercept treatment. Inhibition of TNFα significantly reduced MSC loss by increasing MSC proliferation and decreasing MSC apoptosis in diabetic animals, but had no effect on MSCs in normoglycaemic animals. In vitro experiments established that TNFα alone was sufficient to induce apoptosis and inhibit proliferation of MSCs. Furthermore, silencing forkhead box protein O1 (FOXO1) prevented TNFα-induced MSC apoptosis and reduced proliferation by regulating apoptotic and cell cycle genes.

CONCLUSIONS/INTERPRETATION

Diabetes-enhanced TNFα significantly reduced MSC numbers in new bone areas during fracture healing. Mechanistically, diabetes-enhanced TNFα reduced MSC proliferation and increased MSC apoptosis. Reducing the activity of TNFα in vivo may help to preserve endogenous MSCs and maximise regenerative potential in diabetic patients.

Retrotransposition of long interspersed nucleotide element-1 is associated with colitis but not tumors in a murine colitic cancer model

Long interspersed element-1 (L1) is a transposable element that can move within the genome, potentially leading to genome diversity and modified gene function. Although L1 activity in somatic cells is normally suppressed through DNA methylation, some L1s are activated in tumors including colorectal carcinoma. However, how L1-retrotransposition (L1-RTP) is involved in gastrointestinal disorders remains to be elucidated. We hypothesized that L1-RTP in somatic cells might contribute to colitis-associated cancer (CAC). To address this, we employed an experimental model of CAC using transgenic L1-reporter mice carrying a human L1-EGFP reporter gene. Mice were subjected to repeated cycles of colitis induced by administration of dextran sodium sulfate (DSS) in drinking water with injection of carcinogen azoxymethane (AOM). L1-RTP levels were measured by a quantitative polymerase chain reaction targeting the newly inserted reporter EGFP in various tissues and cell types, including samples obtained by laser microdissection and cell sorting with flow cytometry. DNA methylation levels of the human L1 promoter were analyzed by bisulfite pyrosequencing. AOM+DSS-treated mice exhibited significantly higher levels of L1-RTP in whole colon tissue during the acute phase of colitis when compared with control naïve mice. L1-RTP levels in whole colon tissue were positively correlated with the histological severity of colitis and degree of neutrophil infiltration into the lamina propria (LP), but not with tumor development in the colon. L1-RTP was enriched in LP mesenchymal cells rather than epithelial cells (ECs), myeloid, or lymphoid cells. DNA methylation levels of the human L1 promoter region showed a negative correlation with L1-RTP levels. L1-RTP was absent from most tumors found in 22-week-old mice. In conclusion, we demonstrated that L1-RTP was induced in the mouse CAC mucosa in accordance with the acute inflammatory response; however, retrotransposition appears not to have direct relevance to colitis-induced cancer initiation.

State-of-the-Art management of knee osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis found in the United States' population and is also the most common disease of joints in adults throughout the world with the knee being the most frequently affected of all joints. As the United States' population ages along with the increasing trends in obesity prevalence in other parts of the world, it is expected that the burden of OA on the population, healthcare system, and overall economy will continue to increase in the future without making major improvements in managing knee OA. Numerous therapies aim to reduce symptoms of knee OA and continued research has helped to further understand the complex pathophysiology of its disease mechanism attempting to uncover new potential targets for the treatment of OA. This review article seeks to evaluate the current practices for managing knee OA and discusses emerging therapies on the horizon. These practices include non-pharmacological treatments such as providing patient education and self-management strategies, advising weight loss, strengthening programs, and addressing biomechanical issues with bracing or foot orthoses. Oral analgesics and anti-inflammatories are pharmacologicals that are commonly used and the literature overall supports that some of these medications can be helpful for managing knee OA in the short-term but are less effective for long-term management. Additionally, more prolonged use significantly increases the risk of serious associated side effects that are not too uncommon. Disease-modifying osteoarthritis drugs are being researched as a treatment modality to potentially halt or slow disease progression but data at this time is limited and continued studies are being conducted to further investigate their effectiveness. Intra-articular injectables are also implemented to manage knee OA ranging from corticosteroids to hyaluronans to more recently platelet-rich plasma and even stem cells while several other injection therapies are presently being studied. The goal of developing new treatment strategies for knee OA is to prolong the need for total knee arthroplasty which should be utilized only if other strategies have failed. High tibial osteotomy and unicompartmental knee arthroplasty are potential alternatives if only a single compartment is involved with more data supporting unicompartmental knee arthroplasty as a good treatment option in this scenario. Arthroscopy has been commonly used for many years to treat knee OA to address degenerative articular cartilage and menisci, however, several high-quality studies have shown that it is not a very effective treatment for the majority of cases and should generally not be considered when managing knee OA. Improving the management of knee OA requires a multi-faceted treatment approach along with continuing to broaden our understanding of this complex disease so that therapeutic advancements can continue to be developed with the goal of preventing further disease progression and even potentially reversing the degenerative process.

Role of adipose-derived stem cells in wound healing

Impaired wound healing remains a challenge to date and causes debilitating effects with tremendous suffering. Recent advances in tissue engineering approaches in the area of cell therapy have provided promising treatment options to meet the challenges of impaired skin wound healing such as diabetic foot ulcers. Over the last few years, stem cell therapy has emerged as a novel therapeutic approach for various diseases including wound repair and tissue regeneration. Several different types of stem cells have been studied in both preclinical and clinical settings such as bone marrow-derived stem cells, adipose-derived stem cells (ASCs), circulating angiogenic cells (e.g., endothelial progenitor cells), human dermal fibroblasts, and keratinocytes for wound healing. Adipose tissue is an abundant source of mesenchymal stem cells, which have shown an improved outcome in wound healing studies. ASCs are pluripotent stem cells with the ability to differentiate into different lineages and to secrete paracrine factors initiating tissue regeneration process. The abundant supply of fat tissue, ease of isolation, extensive proliferative capacities ex vivo, and their ability to secrete pro-angiogenic growth factors make them an ideal cell type to use in therapies for the treatment of nonhealing wounds. In this review, we look at the pathogenesis of chronic wounds, role of stem cells in wound healing, and more specifically look at the role of ASCs, their mechanism of action and their safety profile in wound repair and tissue regeneration.

Cell senescence abrogates the therapeutic potential of human mesenchymal stem cells in the lethal endotoxemia model

Mesenchymal stem cells (MSCs) possess unique paracrine and immunosuppressive properties, which make them useful candidates for cellular therapy. Here, we address how cellular senescence influences the therapeutic potential of human MSCs (hMSCs). Senescence was induced in bone marrow-derived hMSC cultures with gamma irradiation. Control and senescent cells were tested for their immunoregulatory activity in vitro and in vivo, and an extensive molecular characterization of the phenotypic changes induced by senescence was performed. We also compared the gene expression profiles of senescent hMSCs with a collection of hMSCs used in an ongoing clinical study of Graft Versus Host disease (GVHD). Our results show that senescence induces extensive phenotypic changes in hMSCs and abrogates their protective activity in a murine model of LPS-induced lethal endotoxemia. Although senescent hMSCs retain an ability to regulate the inflammatory response on macrophages in vitro, and, in part retain their capacity to significantly inhibit lymphocyte proliferation, they have a severely impaired migratory capacity in response to proinflammatory signals, which is associated with an inhibition of the AP-1 pathway. Additionally, expression analysis identified PLEC, C8orf48, TRPC4, and ZNF14, as differentially regulated genes in senescent hMSCs that were similarly regulated in those hMSCs which failed to produce a therapeutic effect in a GVHD trial. All the observed phenotypic alterations were confirmed in replicative-senescent hMSCs. In conclusion, this study highlights important changes in the immunomodulatory phenotype of senescent hMSCs and provides candidate gene signatures which may be useful to evaluate the therapeutic potential of hMSCs used in future clinical studies.

Noninvasive MRI and multilineage differentiation capability of ferritin-transduced human mesenchymal stem cells

Molecular imaging can be a breakthrough tool for the investigation of the behavior and ultimate feasibility of transplanted human mesenchymal stem cells (hMSCs) inside the body, and for the development of guidelines and recommendations based on the treatment and evaluation of stem cell therapy for patients. The goals of this study were to evaluate the multilineage differentiation ability of hMSCs expressing an MRI reporter, human ferritin heavy chain (FTH) and to investigate the feasibility of using FTH-based MRI to provide noninvasive imaging of transplanted hMSCs. The transduction of FTH and green fluorescence protein (GFP) did not influence the expression of the mesenchymal stem cell surface markers (CD29+/CD105+/CD34-/CD45-) or the self-renewal marker genes [octamer-binding transcription factor 4 (OCT-4) and SRY (sex determining region Y)-box 2 (Sox-2)], cell viability, migration ability and the release of cytokines [interleukin-5 (IL-5), IL-10, IL-12p70, tumor necrosis factor-α (TNF-α)]. FTH-hMSCs retained the capacity to differentiate into adipogenic, chondrogenic, osteogenic and neurogenic lineages. The transduction of FTH led to a significant enhancement in cellular iron storage capacity and caused hypointensity and a significant increase in R2 * values of FTH-hMSC-collected phantoms and FTH-hMSC-transplanted sites of the brain, as shown by in vitro and in vivo MRI performed at 9.4 T, compared with control hMSCs. This study revealed no differences in biological characteristics between hMSCs and FTH-hMSCs and, therefore, these cells could be used for noninvasive monitoring with MRI during stem cell therapy for brain injury. Our study suggests the use of FTH for in vivo long-term tracking and ultimate fate of hMSCs without alteration of their characteristics and multidifferentiation potential.

Mesenchymal stem cell insights: prospects in cardiovascular therapy

Ischemic heart damage usually triggers cardiomyopathological remodeling and fibrosis, thus promoting the development of heart functional failure. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with multipotent and hypoimmunogenic characters to aid tissue repair and avoid immune responses, respectively. Numerous experimental findings have proven the feasibility, safety, and efficiency of MSC therapy for cardiac regeneration. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs to treat ischemia heart diseases has been tested in phase I/II clinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat ischemic and nonischemic cardiovascular disorders. The molecular mechanism behind the efficacy of MSCs on promoting engraftment and accelerating the speed of heart functional recovery is still waiting for clarification. It is hypothesized that cardiomyocyte regeneration, paracrine mechanisms for cardiac repair, optimization of the niche for cell survival, and cardiac remodeling by inflammatory control are involved in the interaction between MSCs and the damaged myocardial environment. This review focuses on recent experimental and clinical findings related to cellular cardiomyoplasticity. We focus on MSCs, highlighting their roles in cardiac tissue repair, transdifferentiation, the MSC niche in myocardial tissues, discuss their therapeutic efficacy that has been tested for cardiac therapy, and the current bottleneck of MSC-based cardiac therapies.

Resveratrol mimics insulin activity in the adipogenic commitment of human bone marrow mesenchymal stromal cells

Bone marrow mesenchymal stromal cells (BM-MSCs) are multipotent cells capable of differentiating toward osteoblatic and adipocytic phenotypes. BM-MSCs play several key roles including bone remodeling, establishment of hematopoietic niche and immune tolerance induction. Here, we investigated the effect of resveratrol (RSV), a therapeutically promising natural polyphenol, on the commitment of human BM-MSCs primary cultures. Cell differentiation was evaluated by means of morphological analysis, specific staining and expression of osteogenic and adipocytic master genes (Runx-2, PPARγ). To maintain BM-MSC multipotency, all experiments were performed on cells at very early passages. At any concentration RSV, added to standard medium, did not affect the phenotype of confluent BM-MSCs, while, when added to osteogenic or adipogenic medium, 1 μM RSV enhances the differentiation toward osteoblasts or adipocytes, respectively. Conversely, the addition of higher RSV concentration (25 μM) to both differentiation media resulted exclusively in BM-MSCs adipogenesis. Surprisingly, the analysis of RSV molecular effects demonstrated that the compound completely substitutes insulin, a key component of adipogenic medium. We also observed that RSV treatment is associated to enhanced phosphorylation of CREB, a critical effector of insulin adipogenic activity. Finally, our observations contribute to the mechanistic elucidation of the well-known RSV positive effect on insulin sensitivity and type 2 diabetes mellitus.

CXCR4 receptor overexpression in mesenchymal stem cells facilitates treatment of acute lung injury in rats

Novel therapeutic regimens for tissue renewal incorporate mesenchymal stem cells (MSCs) as they differentiate into a variety of cell types and are a stem cell type that is easy to harvest and to expand in vitro. However, surface chemokine receptors, such as CXCR4, which are involved in the mobilization of MSCs, are expressed only on the surface of a small proportion of MSCs, and the lack of CXCR4 expression may underlie the low efficiency of homing of MSCs toward tissue damage, which results in a poor curative effect. Here, a rat CXCR4 expressing lentiviral vector was constructed and introduced into MSCs freshly prepared from rat bone marrow. The influence of CXCR4 expression on migration, proliferation, differentiation, and paracrine effects of MSCs was examined in vitro. The in vivo properties of CXCR4-MSCs were also investigated in a model of acute lung injury in rats induced by lipopolysaccharide. Expression of CXCR4 in MSCs significantly enhanced the chemotactic and paracrine characteristics of the cells in vitro but did not affect self-renewal or differentiation into alveolar and vascular endothelial cells. In vivo, CXCR4 improved MSC homing and colonization of damaged lung tissue, and furthermore, the transplanted CXCR4-MSCs suppressed the development of acute lung injury in part by modulating levels of inflammatory molecules and the neutrophil count. These results indicated that efficient mobilization of MSCs to sites of tissue injury may be due to CXCR4, and therefore, increased expression of CXCR4 may improve their therapeutic potential in the treatment of diseases where tissue damage develops.