Immunomodulatory effect of mesenchymal stem cells

Leveraging stem cells to combat hepatitis: a comprehensive review of recent studies

Hepatitis is a significant global public health concern, with viral infections being the most common cause of liver inflammation. Antiviral medications are the primary treatments used to suppress the virus and prevent liver damage. However, the high cost of these drugs and the lack of awareness and stigma surrounding the disease create challenges in managing hepatitis. Stem cell therapy has arisen as a promising therapeutic strategy for hepatitis by virtue of its regenerative and immunomodulatory characteristics. Stem cells have the exceptional capacity to develop into numerous cell types and facilitate tissue regeneration, rendering them a highly promising therapeutic avenue for hepatitis. In animal models, stem cell therapy has demonstrated worthy results by reducing liver inflammation and improving liver function. Furthermore, clinical trials have been undertaken to assess the safety and effectiveness of stem cell therapy in individuals with hepatitis. This review aims to explore the involvement of stem cells in treating hepatitis and highlight the findings from studies conducted on both animals and humans. The objective of this review is to primarily concentrate on the ongoing and future clinical trials that assess the application of stem cell therapy in the context of hepatitis, including the transplantation of autologous bone marrow-derived stem cells, human induced pluripotent stem cells, and other mesenchymal stem cells. In addition, this review will explore the potential merits and constraints linked to stem cell therapy for hepatitis, as well as its prospective implications in the management of this disease.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

A biological and a mathematical model of SLE treated by mesenchymal stem cells covering all the stages of the disease

In this study, we proposed a biological model explaining the progress of autoimmune activation along different stages of systemic lupus erythematosus (SLE). For any upcoming stage of SLE, any new component is introduced, when it is added to the model. Particularly, the interaction of mesenchymal stem cells, with the components of the model, is specified in a way that both the inflammatory and anti-inflammatory functions of these cells would be covered. The biological model is then recapitulated to a model with less complexity that explains the main features of the problem. Later, a 7th-order mathematical model for SLE is proposed, based on this simplified model. Finally, the range of validity of the proposed mathematical model was assessed. For this purpose, we simulated the model and analyzed the simulation results in case of some known behaviors of the disease, such as tolerance breach, the appearance of systemic inflammation, development of clinical signs, and occurrence of flares and improvements. The model was able to reproduce these events, qualitatively.

An Outstanding Role of Adipose Tissue in Canine Stem Cell Therapy

Adipose tissue, previously known as connective tissue with a role in energy storage, is currently changing the course of treatments in veterinary medicine. Recent studies have revealed one particularly impressive function among all the newly discovered functions of adipose tissue. The interactive cells hosted by adipose tissue, the stromal vascular fraction (SVF), and their role in treating numerous diseases have provided a prospective course of research with positive outcomes in regenerative veterinary medicine (RVM). This review describes the main features of adipose tissue, emphasizing an eclectic combination of cells within the SVF and its thus far researched therapeutic possibilities in canine RVM. An afterwards focus is on a highly researched component of the SVF, adipose-derived mesenchymal stem cells (ASCs), which were shown to have an extraordinary impact relying on several proposed mechanisms of action on mitigating pathologies in canines. Furthermore, ASC therapy showed the most significant results in the orthopaedics field and in neurology, dermatology, ophthalmology, gastroenterology, and hepatology, which elevates the possibilities of ASC therapy to a whole new level. Therefore, this review article aims to raise awareness of the importance of research on cellular components, within abundant and easily accessible adipose tissue, in the direction of regenerative therapy in canines, considering the positive outcomes so far. Although the focus is on the positive aspects of cellular therapy in canines, the researchers should not forget the importance of identifying the potential negative aspects within published and upcoming research. Safe and standardized treatment represents a fundamental prerequisite for positively impacting the lives of canine patients.

Synovium Derived Mesenchymal Stromal Cells (Sy-MSCs): A Promising Therapeutic Paradigm in the Management of Knee Osteoarthritis

Synovium-derived mesenchymal stromal cell (Sy-MSC) is a newer member of the mesenchymal stromal cell families. The first successful demonstration of the mesenchymal stromal cell from the human synovial membrane was done in 2001 and since then its potential role for musculoskeletal regeneration has been keenly documented. The regenerative effects of Sy-MSCs are through paracrine signaling, direct cell-cell interactions, and extracellular vehicles. Sy-MSCs possess superior chondrogenicity than other sources of mesenchymal stromal cells. This article aims to outline the advancement of synovium-derived mesenchymal stromal cells along with a specific insight into the application for managing osteoarthritis knee.

Adipose-Derived Mesenchymal Stem Cells: A Promising Tool in the Treatment of pre mature ovarian failure

Despite being rare, primary ovarian insufficiency (POI) is a significant cause of infertility and deficiency of ovarian hormone in women. Several health risks are also associated with POI, which include dry eye syndrome, reduced density of bones and enhanced fracture risks, troublesome menopausal symptoms, early development of cardiovascular disease, and psychological effects such as declined cognition, reduced perceived psychological support, anxiety, and depression. Replacing premenopausal levels of ovarian sex steroids through proper hormone replacement therapy could improve the quality of life for POI women and ameliorate related health risks. Herein, POI and its complications, in addition to hormone replacement therapies, which are safe and effective, are discussed. It is proposed that the use of HRT) Hormone replacement therapy (formulations which mimic normal production of ovarian hormones could reduce POI-associated morbidity rates if they are continued by the age 50, which is approximately the natural age of menopause. Particular populations of POI women are also addressed, which include those with enhanced risk of ovarian or breast cancer, those with Turner syndrome, those approaching natural menopause, and those who are breastfeeding. It is generally predicted that stem cell-based therapies would be both safe and effective. In fact, several types of cells have been described as safe, though their effectiveness and therapeutic application are yet to be defined. Several factors exist which could affect the results of treatment, such as cell handling, ex-vivo preparation strategies, variations in tissue of origin, potency, and immunocompatibility. Accordingly, cell types potentially effective in regenerative medicine could be recognized. Notably, products of MSCs from various sources of tissues show different levels of regenerative capabilities. The ultimate focus of the review is on adipose tissue-derive MCSs (ADMSCs), which possess exceptional features such as general availability, great ability to proliferate and differentiate, immunomodulatory capabilities, and low immunogenicity.

Mesenchymal stem cells: ideal seeds for treating diseases

Mesenchymal stem cells (MSCs), a kind of multipotent stem cells with self-renewal ability and multi-differentiation ability, have become the “practical stem cells” for the treatment of diseases. MSCs have immunomodulatory properties and can be used to treat autoimmune diseases, such as systemic lupus erythematosus (SLE) and Crohn’s disease. MSCs also can be used in cancer and aging. At present, many clinical experiments are using MSCs. MSCs can reduce the occurrence of inflammation and apoptosis of tissue cells, and promote the proliferation of endogenous tissue and organ cells, so as to achieve the effect of repairing tissue and organs. MSCs presumably also play an important role in Corona Virus Disease 2019 (COVID-19) infection.

A Phase I Study to Evaluate Two Doses of Wharton's Jelly-Derived Mesenchymal Stromal Cells for the Treatment of De Novo High-Risk or Steroid-Refractory Acute Graft Versus Host Disease

BACKGROUND

Because of their well-described immunosuppressive properties, allogeneic adult human mesenchymal stromal cells (MSC) derived from bone marrow have demonstrated safety and efficacy in steroid refractory acute graft versus host disease (SR aGVHD). Clinical trials have resulted in variable success and an optimal source of MSC has yet to be defined. Based on the importance of maternal-fetal interface immune tolerance, extraembryonic fetal tissues, such as the umbilical cord, may provide an superior tissue source of MSC to mediate immunomodulation in aGVHD.

METHODS

A two-dose cohort trial allogeneic Wharton's Jelly-derived mesenchymal stromal cells (WJMSC, referred to as MSCTC-0010, here) were tested in 10 patients with de novo high risk (HR) or SR aGVHD post allogeneic hematopoietic stem cell transplantation (allo-HCT). Following Good Manufacturing Practices isolation, expansion and cryostorage, WJMSC were thawed and administered via intravenous infusions on days 0 and 7 at one of two doses (low dose cohort, 2 × 10⁶/kg, n = 5; high dose cohort, 10 × 10⁶/kg, n = 5). To evaluate safety, patients were monitored for infusion related toxicity, Treatment Related Adverse Events (TRAE) til day 42, or ectopic tissue formation at day 90. Clinical responses were monitored at time points up to 180 days post infusion. Serum biomarkers ST2 and REG3α were acquired 1 day prior to first MSCTC-0010 infusion and on day 14.

RESULTS

Safety was indicated, e.g., no infusion-related toxicity, no development of TRAE, nor ectopic tissue formation in either low or high dose cohort was observed. Clinical response was suggested at day 28: the overall response rate (ORR) was 70%, 4 of 10 patients had a complete response (CR) and 3 had a partial response (PR). By study day 90, the addition of escalated immunosuppressive therapy was necessary in 2 of 9 surviving patients. Day 100 and 180 post infusion survival was 90% and 60%, respectively. Serum biomarker REG3α decreased, particularly in the high dose cohort, and with REG3α decrease correlated with clinical response.

CONCLUSIONS

Treatment of patients with de novo HR or SR aGVHD with low or high dose MSCTC-0010 was safe: the infusion was well-tolerated, and no TRAEs or ectopic tissue formation was observed. A clinical improvement was seen in about 70% patients, with 4 of 10 showing a complete response that may have been attributable to MSCTC-0010 infusions. These observations indicate safety of two different doses of MSCTC-0010, and suggest that the 10 × 10⁶ cells/ kg dose be tested in an expanded randomized, controlled Phase 2 trial. Graphical abstract.

Mesenchymal stem cells - a promising strategy for treating knee osteoarthritis

AIMS

The purpose of our study was to determine whether mesenchymal stem cells (MSCs) are an effective and safe therapeutic agent for the treatment of knee osteoarthritis (OA), owing to their cartilage regeneration potential.

METHODS

We searched PubMed, Embase, and the Cochrane Library, with keywords including "knee osteoarthritis" and "mesenchymal stem cells", up to June 2019. We selected randomized controlled trials (RCTs) that explored the use of MSCs to treat knee OA. The visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), adverse events, and the whole-organ MRI score (WORMS) were used as the primary evaluation tools in the studies. Our meta-analysis included a subgroup analysis of cell dose and cell source.

RESULTS

Seven trials evaluating 256 patients were included in the meta-analysis. MSC treatment significantly improved the VAS (mean difference (MD), -13.24; 95% confidence intervals (CIs) -23.28 to -3.20, p = 0.010) and WOMAC (MD, -7.22; 95% CI -12.97 to -1.47, p = 0.010). The low-dose group with less than 30 million cells showed lower p-values for both the VAS and WOMAC. Adipose and umbilical cord-derived stem cells also had lower p-values for pain scores than those derived from bone marrow.

CONCLUSION

Overall, MSC-based cell therapy is a relatively safe treatment that holds great potential for OA, evidenced by a positive effect on pain and knee function. Using low-dose (25 million) and adipose-derived stem cells is likely to achieve better results, but further research is needed. Cite this article: Bone Joint Res 2020;9(10):719-728.

Anti-VEGF Drugs in the Treatment of Multiple Myeloma Patients

The interaction between the bone marrow microenvironment and plasma cells plays an essential role in multiple myeloma progression and drug resistance. The vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) pathway in vascular endothelial cells activates and promotes angiogenesis. Moreover, VEGF activates and promotes vasculogenesis and vasculogenic mimicry when it interacts with VEGF receptors expressed in precursor cells and inflammatory cells, respectively. In myeloma bone marrow, VEGF and VEGF receptor expression are upregulated and hyperactive in the stromal and tumor cells. It has been demonstrated that several antiangiogenic agents can effectively target VEGF-related pathways in the preclinical phase. However, they are not successful in treating multiple myeloma, probably due to the vicarious action of other cytokines and signaling pathways. Thus, the simultaneous blocking of multiple cytokine pathways, including the VEGF/VEGFR pathway, may represent a valid strategy to treat multiple myeloma. This review aims to summarize recent advances in understanding the role of the VEGF/VEGFR pathway in multiple myeloma, and mainly focuses on the transcription pathway and on strategies that target this pathway.

Mesenchymal Stem Cells and Atopic Dermatitis: A Review

Mesenchymal stem/stromal cells (MSCs) are stromal-derived non-hematopoietic progenitor cells that reside in and can be expanded from various tissues sources of adult and neonatal origin, such as the bone marrow, umbilical cord, umbilical cord blood, adipose tissue, amniotic fluid, placenta, dental pulp and skin. The discovery of the immunosuppressing action of MSCs on T cells has opened new perspectives for their use as a therapeutic agent for immune-mediated disorders, including allergies. Atopic dermatitis (AD), a chronic and relapsing skin disorder that affects up to 20% of children and up to 3% of adults worldwide, is characterized by pruritic eczematous lesions, impaired cutaneous barrier function, Th2 type immune hyperactivation and, frequently, elevation of serum immunoglobulin E levels. Although, in the dermatology field, the application of MSCs as a therapeutic agent was initiated using the concept of cell replacement for skin defects and wound healing, accumulating evidence have shown that MSC-mediated immunomodulation can be applicable to the treatment of inflammatory/allergic skin disorders. Here we reviewed the pre-clinical and clinical studies and possible biological mechanisms of MSCs as a therapeutic tool for the treatment of atopic dermatitis.

Medicinal signaling cells: A potential antimicrobial drug store

Medicinal signaling cells (MSCs) are multipotent cells derived from mammalian bone marrow and periosteum that can be extended in culture. They can keep their ability in vitro to form a variety of mesodermal phenotypes and tissues. Over recent years, there has been great attention over MSCs since they can impact the organ transplantation as well as autoimmune and bacterial diseases. MSCs can secrete different bioactive factors such as growth factors, antimicrobial peptides/proteins and cytokines that can suppress the immune system and prevent infection via direct and indirect mechanisms. Moreover, MSCs are able to increase bacterial clearance in sepsis models by producing antimicrobial peptides such as defensins, cathelicidins, lipocalin and hepcidin. It is the aim of the present review to focus on the antibacterial effector functions of MSCs and their mechanisms of action against the pathogenic microbes.

Mesenchymal Stem Cell-Derived Exosomes: A Promising Therapeutic Ace Card to Address Autoimmune Diseases

With the development of novel treatments for autoimmune disorders, it has become a popular research focus which mesenchymal stem cells (MSCs) have the capacity to counteract with autoimmune diseases progression. One of the underlying mechanisms behind their activities is the release of extracellular vesicles especially exosomes. MSC-derived exosomes are hypoimmunogenic nanocarriers which contain numerous immunoregulatory factors and similar to other exosomes, are able to pass through boundaries like the blood-brain barrier (BBB). Accumulating evidence provided by animal studies has demonstrated that MSC-derived exosomes, as a novel therapy, can re-induce self-tolerance, without subsequent complications reported for other treatments. Therefore, therapeutic applications of MSC-derived exosomes are contributing to core advances in the field of autoimmune diseases. Here, we briefly describe the biological characteristics of MSC-derived exosomes and review the experimentally verified outcomes for autoimmune disease therapy purposes.

5-Azacytidine restores interleukin 6-increased production in mesenchymal stromal cells from myelodysplastic patients

INTRODUCTION

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematological diseases. In addition to defects in hematologic progenitor and stem cells, dysfunctions in the bone marrow microenvironment (BMM) participate in the MDS pathogenesis. Furthermore, the immune response is deregulated by the pro-inflammatory response prevailing in low-risk MDS, while immunosuppression predominates in high-risk MDS. Mesenchymal stromal cells (MSC), part of the BMM, are characterized by plastic adherent growth and multipotentiality. They exhibit immunomodulatory properties and sustain hematopoiesis. There is conflicting evidence regarding their status in MDS. The aim of this study was to characterize MDS-MSC and evaluate the effect of 5-Azacytidine.

METHODS

The MSC from MDS patients and controls were cultured and characterized according to the International Society of Cell Therapy recommendations. Immunomodulatory properties were assessed by studying the MSD cytokine production, using the cytometric bead array. We evaluated the effect of 5-Azacytidine on the MSC cytokine production.

RESULTS

We included 35 MDS patients and 22 controls. The MSC from patients and controls were cultured and characterized. The MSC from patients showed morphological differences, but there were no differences in immunophenotype or multipotentiality. The interleukin 6 (IL-6) was the main MSC secreted cytokine. The MDS-MSC produced higher levels of IL-6, IL-17, interferon gamma, or interferon γ (INF-γ), and tumor necrosis factor alpha (TNF-α). The in vitro 5-Azacytidine treatment induced a significant decrease in the IL-6 production by MDS-MSC.

CONCLUSIONS

The MDS-MSC show an increased production of pro-inflammatory cytokines. The in vitro treatment with 5-Azacytidine lead to a significant reduction in the IL-6 production by the MDS-MSC, restoring the IL-6 levels to those found in controls. The MSC produced inflammatory cytokines involved in the MDS pathogenesis, representing a potential future therapeutic target. Moreover, 5-Azacytidine may have a stromal effect, modulating the immune response in MDS.

Improvement of Human Sperm Vacuolization and DNA Fragmentation Co-Cultured with Adipose-Derived Mesenchymal Stem Cell Secretome: In Vitro Effect

Background and Objectives

Oxidative stress (OS) is known to be an important factor of male infertility. Adipose-derived mesenchymal stem cells (AD-MSCs) are known to have immune-modulatory and anti-oxidant effects through their secretions, hence raising the idea of their potential benefit to improve sperm parameters. This study aims at investigating the effect of AD-MSCs conditioned medium (CM) on human sperm parameters in the presence and absence of H₂O₂-induced OS.

Methods and Results

Sperm samples were collected from 30 healthy men and divided into two groups: non-stressed and H₂O₂-stressed. Isolated AD-MSCs from healthy donors undergoing liposuction were cultured and CM was collected at 24, 48 and 72 h. Both sperm groups were cultured with CM and a time course was performed followed by an evaluation of sperm parameters. The incubation of non-stressed and stressed sperm samples with AD-MSCs-CM for 24 h was found to have the optimum impact on sperm vacuolization, DNA fragmentation and OS levels in comparison to other incubation timings, while preserving motility, viability and morphology of cells. Incubation with CM improved all sperm parameters except morphology in comparison to the non-treated group, with the best effect noted with CM collected at 24 h rather than 48 or 72 h for sperm vacuolization and DNA fragmentation. When compared to fresh semen parameters (T0), samples cultured with CM 24 h showed a significant decrease in sperm vacuolization and DNA fragmentation while keeping other parameters stable.

Conclusions

AD-MSCSs-CM improves sperm quality, and hence can be used in treating infertility and subsequently enhancing IVF outcomes.

Antenatal prevention of cerebral palsy and childhood disability: is the impossible possible?

This review covers our current knowledge of the causes of perinatal brain injury leading to cerebral palsy-like outcomes, and argues that much of this brain damage is preventable. We review the experimental evidence that there are treatments that can be safely administered to women in late pregnancy that decrease the likelihood and extent of perinatal brain damage that occurs because of acute and severe hypoxia that arises during some births, and the additional impact of chronic fetal hypoxia, infection, inflammation, growth restriction and preterm birth. We discuss the types of interventions required to ameliorate or even prevent apoptotic and necrotic cell death, and the vulnerability of all the major cell types in the brain (neurons, astrocytes, oligodendrocytes, microglia, cerebral vasculature) to hypoxia/ischaemia, and whether a pan-protective treatment given to the mother before birth is a realistic prospect.

Allogeneic transplantation of mobilized dental pulp stem cells with the mismatched dog leukocyte antigen type is safe and efficacious for total pulp regeneration

Background

We recently demonstrated that autologous transplantation of mobilized dental pulp stem cells (MDPSCs) was a safe and efficacious potential therapy for total pulp regeneration in a clinical study. The autologous MDPSCs, however, have some limitations to overcome, such as limited availability of discarded teeth from older patients. In the present study, we investigated whether MDPSCs can be used for allogeneic applications to expand their therapeutic use.

Methods

Analysis of dog leukocyte antigen (DLA) was performed using polymerase chain reaction from blood. Canine allogeneic MDPSCs with the matched and mismatched DLA were transplanted with granulocyte-colony stimulating factor in collagen into pulpectomized teeth respectively (n = 7, each). Results were evaluated by hematoxylin and eosin staining, Masson trichrome staining, PGP9.5 immunostaining, and BS-1 lectin immunostaining performed 12 weeks after transplantation. The MDPSCs of the same DLA used in the first transplantation were further transplanted into another pulpectomized tooth and evaluated 12 weeks after transplantation.

Results

There was no evidence of toxicity or adverse events of the allogeneic transplantation of the MDPSCs with the mismatched DLA. No adverse event of dual transplantation of the MDPSCs with the matched and mismatched DLA was observed. Regenerated pulp tissues including neovascularization and neuronal extension were quantitatively and qualitatively similar at 12 weeks in both matched and mismatched DLA transplants. Regenerated pulp tissue was similarly observed in the dual transplantation as in the single transplantation of MDPSCs both with the matched and mismatched DLA.

Conclusions

Dual allogeneic transplantation of MDPSCs with the mismatched DLA is a safe and efficacious method for total pulp regeneration.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0855-8) contains supplementary material, which is available to authorized users.

Effects of Educated Monocytes with Xenogeneic Mesenchymal Stem Cell-Derived Conditioned Medium in a Mouse Model of Chronic Asthma

BACKGROUND

This study was conducted to determine the potential of the monocytes educated with rat bone marrow mesenchymal stem cell-derived conditioned medium (MCM) in ameliorating animal model of asthma.

METHODS

Chronic asthma was induced in the BALB/c mice using ovalbumin (OVA) sensitization. The monocytes were isolated from blood of mice and supplemented with 50% MCM or negative control media. After 24 h, the cells were designated as "non-educated or educated". Fourteen weeks after the onset of the study, animals were treated with educated or non-educated monocytes twice with a 1-week interval.

RESULTS

The educated monocytes showed a reduction in the potential production of the respiratory burst and nitric oxide and the secretion of IL-12 and IL-4 compared to non-educated monocytes. Conversely, these monocytes exhibited a significant increase in the production of IL-10 and TGF-?. Also, the levels of CD68+/CD206+ cells significantly increased in the population of educated monocytes. More importantly, the severity of histopathological lesions, NF-?B p65 mRNA level in lung tissues, total serum IgE and the total cell count, as well as the eosinophil count in the bronchoalveolar lavage fluid, were significantly decreased in OVA-inhaled mice treated with educated monocytes compared to OVA-sensitized group receiving non-educated monocytes. With no advantage in up-regulation of Foxp3 Treg cells, the treatment with educated monocytes reduced the secretion of IL-5 and IL-13 by splenocytes of asthma mice more than splenocytes of the asthma mice treated with non-educated monocytes.

CONCLUSION

The educated monocytes with MCM may be as a promising strategy for cell-based therapies of asthma.

Caffeine Augments The Instruction of Anti-Inflammatory Macrophages by The Conditioned Medium of Mesenchymal Stem Cells

Objective

Mesenchymal stem cells (MSCs) have been shown to produce adenosine, express adenosine receptors, and communicate with macrophages and other cells. However, there is no information about the role of caffeine, as a popular drink and adenosine antagonist, on the crosstalk between MSCs and immune cells. The aim of the current study is to evaluate the effects of the conditioned medium of MSCs treated with caffeine on macrophages.

Materials and Methods

In this experimental study, MSCs were isolated from bone marrow of rats and pulsed with different concentrations of caffeine (0, 0.1, 0.5 and 1 mM) for 72 hours. The conditioned medium of MSCs was collected after 24 hours, then incubated with macrophages for 24 hours. Finally, the functions of the macrophages were evaluated.

Results

Conditioned medium of MSCs treated with caffeine significantly enhanced phagocytosis and simultaneously regressed expression of reactive oxygen species (ROS) and nitric oxide (NO) as well as IL-12 by macrophages compared to the supernatants of MSCs alone. The conditioned medium of MSCs pulsed with caffeine at low to moderate concentrations preserved the neutral red uptake by macrophages and elevated IL-10 secretion by macrophages. A high concentration of caffeine could interfere with the two latter effects of supernatants of MSCs on the macrophages.

Conclusion

Collectively, caffeine treatment of MSCs appeared to augment the instruction of anti-inflammatory macrophages by conditioned medium of MSCs. These findings might offer new insight into the potential mechanisms that underlie the immunomodulatory and anti-inflammatory effects of caffeine.

Correlation of CDC42 Activity with Cell Proliferation and Palmitate-Mediated Cell Death in Human Umbilical Cord Wharton's Jelly Derived Mesenchymal Stromal Cells

RHO GTPases regulate cell migration, cell-cycle progression, and cell survival in response to extracellular stimuli. However, the regulatory effects of RHO GTPases in mesenchymal stromal cells (MSCs) are unclear. Herein, we show that CDC42 acts as an essential factor in regulating cell proliferation and also takes part in lipotoxic effects of palmitate in human umbilical cord Wharton's jelly derived MSCs (hWJ-MSCs). Cultured human bone marrow, adipose tissue, and hWJ-MSC derived cells had varying pro-inflammatory cytokine secretion levels and cell death rates when treated by palmitate. Strikingly, the proliferation rate of these types of MSCs correlated with their sensitivity to palmitate. A glutathione-S-transferase pull-down assay demonstrated that hWJ-MSCs had the highest activation of CDC42, which was increased by palmitate treatment in a time-dependent manner. We demonstrated that palmitate-induced synthesis of pro-inflammatory cytokines and cell death was attenuated by shRNA against CDC42. In CDC42 depleted hWJ-MSCs, population-doubling levels were notably decreased, and phosphorylation of ERK1/2 and p38 MAPK was reduced. Our data therefore suggest a mechanistic role for CDC42 activity in hWJ-MSC proliferation and identified CDC42 activity as a promising pharmacological target for ameliorating lipotoxic cell dysfunction and death.

Effect of single intralesional treatment of surgically induced equine superficial digital flexor tendon core lesions with adipose-derived mesenchymal stromal cells: a controlled experimental trial

Background

Adipose tissue is a promising source of mesenchymal stromal cells (MSCs) for the treatment of tendon disease. The goal of this study was to assess the effect of a single intralesional implantation of adipose tissue-derived mesenchymal stromal cells (AT-MSCs) on artificial lesions in equine superficial digital flexor tendons (SDFTs).

Methods

During this randomized, controlled, blinded experimental study, either autologous cultured AT-MSCs suspended in autologous inactivated serum (AT-MSC-serum) or autologous inactivated serum (serum) were injected intralesionally 2 weeks after surgical creation of centrally located SDFT lesions in both forelimbs of nine horses. Healing was assessed clinically and with ultrasound (standard B-mode and ultrasound tissue characterization) at regular intervals over 24 weeks. After euthanasia of the horses the SDFTs were examined histologically, biochemically and by means of biomechanical testing.

Results

AT-MSC implantation did not substantially influence clinical and ultrasonographic parameters. Histology, biochemical and biomechanical characteristics of the repair tissue did not differ significantly between treatment modalities after 24 weeks. Compared with macroscopically normal tendon tissue, the content of the mature collagen crosslink hydroxylysylpyridinoline did not differ after AT-MSC-serum treatment (p = 0.074) while it was significantly lower (p = 0.027) in lesions treated with serum alone. Stress at failure (p = 0.048) and the modulus of elasticity (p = 0.001) were significantly lower after AT-MSC-serum treatment than in normal tendon tissue.

Conclusions

The effect of a single intralesional injection of cultured AT-MSCs suspended in autologous inactivated serum was not superior to treatment of surgically created SDFT lesions with autologous inactivated serum alone in a surgical model of tendinopathy over an observation period of 22 weeks. AT-MSC treatment might have a positive influence on collagen crosslinking of remodelling scar tissue. Controlled long-term studies including naturally occurring tendinopathies are necessary to verify the effects of AT-MSCs on tendon disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0564-8) contains supplementary material, which is available to authorized users.

A Comparative Study to Evaluate Myogenic Differentiation Potential of Human Chorion versus Umbilical Cord Blood-derived Mesenchymal Stem Cells

OBJECTIVE

Musculodegenerative diseases threaten the life of many patients in the world. Since drug administration is not efficient in regeneration of damaged tissues, stem cell therapy is considered as a good strategy to restore the lost cells. Since the efficiency of myogenic differentiation potential of human Chorion- derived Mesenchymal Stem Cells (C-MSCs) has not been addressed so far; we set out to evaluate myogenic differentiation property of these cells in comparison with Umbilical Cord Blood- derived Mesenchymal Stem Cells (UCB-MSCs) in the presence of 5-azacytidine.

MATERIALS & METHODS

To do that, neonate placenta Umbilical Cord Blood were transferred to the lab. After characterization of the isolated cells using flowcytometry and multilineage differentiation capacity, the obtained Mesenchymal Stem Cells were cultured in DMEM/F12 supplemented with 2% FBS and 10μM of 5-azacytidine to induce myogenic differentiation. Real-time PCR and immunocytochemistry were used to assess the myogenic properties of the cells.

RESULTS

Our data showed that C-MSCs and UCB-MSCs were spindle shape in morphology. They were positive for CD90, CD73 and CD44 antigens, and negative for hematopoietic markers. They also differentiated into osteoblast and adipoblast lineages. Real-time PCR results showed that the cells could express MyoD, desmin and α-MHC at the end of the first week (P<0.05). No significant upregulation was detected in the expression of GATA-4 in both groups. Immunocytochemical staining revealed the expression of Desmin, cTnT and α-MHC.

CONCLUSIONS

Results showed that these cells are potent to differentiate into myoblast- like cells. An upregulation in the expression of some myogenic markers (desmin, α- MHC) was observed in C-MSCs in comparison with UCB-MSCs.

Persistence and proliferation of human mesenchymal stromal cells in the right ventricular myocardium after intracoronary injection in a large animal model of pulmonary hypertension

BACKGROUND AIMS

In this study, we demonstrate long-term persistence of human mesenchymal stromal cells (hMSCs) after intracoronary injection in a large animal model of pulmonary hypertension (PH).

METHODS

Commercially available placenta-derived hMSCs were used. Experiments were conducted on 14 female Yorkshire swine. Four animals served as controls, and 10 underwent pulmonary vein (PV) banding. After 12 ± 2 weeks, PH and PV dysfunction were confirmed by right heart catheterization and cardiac magnetic resonance imaging. hMSCs were injected in the marginal branch of the right coronary artery. Tissues were harvested 6, 9 or 24 days after infusion.

RESULTS

After 12 ± 2 weeks after PV banding, all subjects had increased mean pulmonary artery pressure (13.6 ± 3.6 versus 30.8 ± 4.5 mm Hg, P < 0.007) and a decrease in right ventricular ejection fraction from 51.7 ± 5.7% versus 30.5 ± 11.3% (P = 0.003). Intracoronary injection of hMSCs was well tolerated. Up to 24 days after hMSC injection, immunohistochemistry revealed extravascular viable human CD105⁺ mononuclear cells in the right ventricle (RV) that were Ki67⁺. This was confirmed by fluorescence in situ hybridization. CD45⁺ porcine inflammatory cells were identified, commonly seen adjacent to areas of healing microscopic infarction that likely dated to the time of the original hMSC injection. Anti-CD31 staining produced strong signals in areas of injected hMSCs. Immunohistochemistry staining for vascular cell adhesion molecule-1 showed upregulation in the clusters, where mononuclear cells were located.

CONCLUSIONS

hMSCs injected via intracoronary infusion survived up to 24 days and demonstrated proliferative capacity. hMSCs can persist long term in the RV and are potential cell source for tissue repair in RV dysfunction.

Nicotine can modulate the effects of the mesenchymal stem cells on neutrophils

PURPOSE

It has been revealed that mesenchymal stem cells (MSCs) express some of the nicotinic receptor subunits. Moreover, the crosstalk between MSCs and neutrophils is not far-fetched. Therefore, the aim of the present study is to determine the role of nicotine on the effects of MSCs on neutrophils.

METHODS

After the isolation of mesenchymal stem cells from the bone marrow of rats, these cells were pulsed with different concentrations of nicotine (0, 0.1, 0.5, and 1μM) for different periods (24, 48, and 72h). Then, the neutrophils were co-cultured with MSCs for 4h and the functions of neutrophils were evaluated.

RESULTS

The obtained findings showed that MSCs pulsed with nicotine significantly enhanced the viability and the phagocytic activity of co-cultured neutrophils and simultaneously, decreased the production of reactive oxygen substances (ROS), induced by f-MLP in neutrophils, more profound than MSCs without treatment. Moreover, MSCs, pulsed with nicotine at low to moderate concentrations, preserved the respiratory burst, triggered by opsonized yeast in neutrophils. Nevertheless, a high concentration of nicotine can interfere with the latter aspect of the crosstalk between MSCs and neutrophils.

CONCLUSION

The obtained data can offer a new insight into the potential mechanisms, underlying the immunomodulatory effects of nicotine.

Exosomes from Human Umbilical Cord Mesenchymal Stem Cells: Identification, Purification, and Biological Characteristics

Our and other groups have discovered that mesenchymal stem cells (MSCs) derived exosomes are a novel therapeutical modality for many diseases. In this study, we summarized a method to extract and purify hucMSCs-exosomes using ultrafiltration and gradient centrifugation in our laboratory and proved that hucMSCs-exosomes prepared according to our procedure were stable and bioactive. Results showed that exosomes derived from hucMSC were 40~100 nm and CD9 and CD81 positive. Functionally, hucMSCs-exosomes promoted cell proliferation and protected against oxidative stress-induced cell apoptosis in vitro by activation of ERK1/2 and p38. Interestingly, UV exposure abrogated the regulatory roles of exosomes under oxidative stress, indicating that hucMSCs-exosomes may regulate cell growth and apoptosis by exosomal shuttle of RNA. Furthermore, cytokine profile analysis revealed that hucMSCs-exosomes contained high dose of IL-6, IL-8, and other cytokines. The established method is practical and efficient, which provides a basis for further evaluating the potential of hucMSCs-exosomes as therapeutic agents.

Evaluating Effect of Mesenchymal Stem Cells on Expression of TLR2 and TLR4 in Mouse DCs

PURPOSE

Mesenchymal stem cells (MSCs) are multipotent cells and recent findings suggest immunomodulatory effect of them on immune cells including T cells and dendritic cells (DCs). DCs are the most potent antigen presenting cells. It seems because of immunoregulatory properties of MSCs, they can affect the maturation and differentiation of DCs. DCs express a kind of surface receptors called toll-like receptors (TLRs) and play a key role in maturation process and activation of DCs. The aim of this study was to evaluate expression of TLR2 and TLR4 on DCs after exposure to mesenchymal stem cell's supernatant in culture media containing LPS and devoid of it.

METHODS

In this experimental study, MSCs and DCs were extracted from adult Balb/c mouse bone marrow and spleen, respectively. MSCs supernatant were collected 24 and 48 h after 5(th) passage, and in adjusted with DCs culture. Isolated DCs were co-cultured with MSCs supernatant, incubation time were 24 and 48 hours. mRNA levels of TLR2 and TLR4 were evaluated using real time PCR technique.

RESULTS

The results demonstrated that although, expressions of these two receptors were up-regulated in culture media lacking LPS in comparison with the control group but the increase was not significant. There were no significant associations between LPS stimulated DCs with and without MSCs supernatants.

CONCLUSION

According to the results presented here, it appears that TLR2 and TLR4 gene expressions on the DCs are not affected by MSCs supernatant.

Immunomodulatory effects of umbilical cord-derived mesenchymal stem cells

Umbilical cord blood (UCB) is of great interest as a source of stem cells for use in cellular therapies. The immunomodulatory effect of mesenchymal stem cells (MSCs) originating from bone marrow, adipose tissue and amniotic membrane has previously been reported. In this study, MSCs were isolated from UCB with the aim of evaluating their immunomodulatory effects on proliferation of PB lymphocytes by two different techniques; namely, 5-bromo-2-deoxyuridine ELISA and a carboxy fluorescein diacetate succinimidyl ester flow cytometric technique. MSCs were isolated from UCB, propagated until Passage four, and then characterized for cell surface markers by flow cytometry and ability to differentiate towards osteocytes and adipocytes. Immunosuppressive effects on PB lymphocytes were examined by co-culturing mitomycin C-treated UCB MSCs with mitogen-stimulated lymphocytes for 72 hr. Thereafter, proliferation of lymphocytes was detected by CFSE flow cytometry and colorimetric ELISA. The titers of cytokines in cell culture supernatant were also assayed to clarify possible mechanisms of immunomodulation. UCB MSCs suppressed mitogen-stimulated lymphocyte proliferation, which occurs via both cell-cell contact and cytokine secretion. Titers of transforming growth factor beta and IL 10 increased, whereas that of IFN-γ decreased in the supernatants of co-cultures. Thus, UCB MSCs suppress the proliferation of mitogen-stimulated lymphocytes. However further in vivo studies are required to fully evaluate the immunomodulatory effects of UCB MSCs.

Effect of mesenchymal stromal cells for articular cartilage degeneration treatment: a meta-analysis

BACKGROUND AIMS

Articular cartilage is an avascular tissue that has limited capacity for self-repair. Mesenchymal stromal cells have been considered as potential candidates for cartilage regeneration. However, clinical results of cartilage formation with the use of these cells need evaluation. We aimed to assess the effect of mesenchymal stromal cell treatment on articular cartilage defects.

METHODS

We searched PubMed, Embase and the Cochrane Central Register of Controlled Trials with key words including "cartilage," "clinical trial," "mesenchymal," "stromal" and "stem cell" up to December 3, 2014. We selected the controlled trial that used treatment with mesenchymal stromal cells on cartilage injury compared with other treatment. We assessed the results of the meta-analysis by means of the error matrix approach. The outcome measures were ranked as comprehensive evaluation index, highest relevance; unilateral evaluation index, medial relevance; and single evaluation index, lowest relevance.

RESULTS

Eleven trials assessing 558 patients were included in the meta-analysis. Stem cell treatment significantly improved the American Orthopedic Foot and Ankle Society Scale (Standard Mean Difference, SMD, 0.91; 95% confidence interval [CI], 0.52 to 1.29). The Osteo-Arthritis Outcome Score was also significantly improved in stem cell treatment (SMD, 2.81; 95% CI, 2.02 to 3.60). Other comprehensive evaluation indexes, such as the American Knee Society Knee Score System (SMD -0.12, 95% CI, -1.02 to 0.78), the Hospital for Special Surgery Knee Rating Scale (SMD, 0.24, 95% CI, -0.56 to 1.05) and the International Knee Documentation Committee (SMD, -0.21; 95% CI, -0.77 to 0.34), appeared to have no significant differences by use of stem cell and other treatments. Overall, there was no obvious advantage regarding the application of stem cells to treat cartilage injury, compared with other treatments.

CONCLUSIONS

In conclusion, assessment of the comprehensive evaluation index indicated that there were no significant differences after stem cell treatment. However, assessment of clinical symptoms and cartilage morphology showed significant improvement after stem cell treatment.

Amnion-derived multipotent progenitor cells inhibit blood monocyte differentiation into mature dendritic cells

Cells derived from the placenta have become the focus of extensive research concerning their ability to be used for regenerative medicine or cellular therapies. In a previous study, we characterized amnion-derived multipotent progenitor cells, or AMP cells, by in vitro methods and showed they were able to inhibit antigen-specific T-cell proliferation in a cell-to-cell contact-dependent fashion. Here we examine specific mechanisms involved in immunomodulation by AMP cells. We found that AMP cells significantly inhibited monocyte-derived myeloid dendritic cell (DC) maturation when placed in coculture. Cocultured monocytes retained the nondifferentiated macrophage marker CD14 while exhibiting significant reduction in DC maturation markers CD83 and CD1a, indicating an immature DC maturation state that is pivotal in determining its immune stimulatory or regulatory status. This effect was again dependent on cell-to-cell contact interaction. We also found a significant shift in cytokines present in the microenvironment of cocultures, which indicated a regulatory DC function rather than a stimulatory cell type. Here supernatants taken from AMP cell/monocyte cocultures yielded significant levels of regulatory cytokines, such as PGE2, IL-6, IL-10, and MIC-1. The soluble form of HLA-G was also found at higher levels in cocultures. In contrast, supernatants contained significantly less amounts of the T-cell-stimulating factor IL-12, which is normally produced by activated DCs. Interestingly, cocultured monocytes acquired significant expression of HLA-G on their cell surface over time. HLA-G has multifaceted immunological implications and may be a key molecule in influencing these cells to behave as regulatory DCs. Together, the influence of AMP cells on maturing DCs may favor a regulatory pathway that can be useful for therapeutic applications for immune-mediated disorders or transplantation therapies.

Murine model: maternal administration of stem cells for prevention of prematurity

OBJECTIVE

Using a mouse model of intrauterine inflammation, we have demonstrated that exposure to inflammation induces preterm birth and perinatal brain injury. Mesenchymal stem cells (MSCs) have been shown to exhibit immunomodulatory effects in many inflammatory conditions. We hypothesized that treatment with human adipose tissue-derived MSCs may decrease the rate of preterm birth and perinatal brain injury through changes in antiinflammatory and regulatory milieu.

STUDY DESIGN

A mouse model of intrauterine inflammation was used with the following groups: (1) control; (2) intrauterine inflammation (lipopolysaccharide); and (3) intrauterine lipopolysaccharide+intraperitoneal (MSCs). Preterm birth was investigated. Luminex multiplex enzyme-linked immunosorbent assays were performed for protein levels of cytokines in maternal and fetal compartments. Immunofluorescent staining was used to identify and localize MSCs and to examine microglial morphologic condition and neurotoxicity in perinatal brain. Behavioral testing was performed at postnatal day 5.

RESULTS

Pretreatment with MSCs significantly decreased the rate of preterm birth by 21% compared with the lipopolysaccharide group (P<.01). Pretreatment was associated with increased interleukin-10 in maternal serum, increased interleukin-4 in placenta, decreased interleukin-6 in fetal brain (P<.05), decreased microglial activation (P<.05), and decreased fetal neurotoxicity (P<.05). These findings were associated with improved neurobehavioral testing at postnatal day 5 (P<.05). Injected MSCs were localized to placenta.

CONCLUSION

Maternally administered MSCs appear to modulate maternal and fetal immune response to intrauterine inflammation in the model and decrease preterm birth, perinatal brain injury, and motor deficits in offspring mice.

Stem cell therapy in intracerebral hemorrhage rat model

Intracerebral hemorrhage (ICH) is a very complex pathology, with many different not fully elucidated etiologies and prognostics. It is the most severe subtype of stroke, with high mortality and morbidity rates. Unfortunately, despite the numerous promising preclinical assays including neuroprotective, anti-hypertensive, and anti-inflammatory drugs, to this moment only symptomatic treatments are available, motivating the search for new alternatives. In this context, stem cell therapy emerged as a promising tool. However, more than a decade has passed, and there is still much to be learned not only about stem cells, but also about ICH itself, and how these two pieces come together. To date, rats have been the most widely used animal model in this research field, and there is much more to be learned from and about them. In this review, we first summarize ICH epidemiology, risk factors, and pathophysiology. We then present different methods utilized to induce ICH in rats, and examine how accurately they represent the human disease. Next, we discuss the different types of stem cells used in previous ICH studies, also taking into account the tested transplantation sites. Finally, we summarize what has been achieved in assays with stem cells in rat models of ICH, and point out some relevant issues where attention must be given in future efforts.

Mesenchymal stem cell in vitro labeling by hybrid fluorescent magnetic polymeric particles for application in cell tracking

Mesenchymal stem cells (MSCs) are a type of adult stem cell that contains multi-differentiation and proliferative properties and that shows high treatment implications for many clinical problems. The outcome of stem cell transplantation is still limited due to many factors, especially their survival and their interaction with the microenvironment after transplantation. Molecular imaging is a challenging technique that has been used to overcome this limitation and is based on the concept of labeling cells with tractable, visible, and non-toxic materials to track the cells after transplantation. In this study, magnetic polymeric nanoparticles (MPNPs) were used to directly label Wharton's jelly-derived MSCs (WJ-MSCs). After labeling, the growth rate and the viability of the MSCs as well as the time of exposure were determined. The 3D images of WJ-MSCs labeled with MPNPs for 24 h were created using confocal microscopy. The results showed that, after incubation with fluorescent MPNPs for over 8 h, the growth rate and cell viability of the WJ-MSCs was similar to those of the control. Three-dimensional imaging revealed that the fluorescent MPNPs could infiltrate into the cells and spread into the cytoplasm, which suggests that the synthesized fluorescent MPNPs could possibly label MSCs for cell tracking study and be further developed for in vivo applications.

Wharton's Jelly-Derived Mesenchymal Stromal Cells as a Promising Cellular Therapeutic Strategy for the Management of Graft-versus-Host Disease

Allogeneic hematopoietic cell transplantation (allo-HCT), a treatment option in hematologic malignancies and bone marrow failure syndromes, is frequently complicated by Graft-versus-host disease (GVHD). The primary treatment for GVHD involves immune suppression by glucocorticoids. However, patients are often refractory to the steroid therapy, and this results in a poor prognosis. Therefore alternative therapies are needed to treat GVHD. Here, we review data supporting the clinical investigation of a novel cellular therapy using Wharton’s jelly (WJ)-derived mesenchymal stromal cells (MSCs) as a potentially safe and effective therapeutic strategy in the management of GVHD. Adult-derived sources of MSCs have demonstrated signals of efficacy in the management of GVHD. However, there are limitations, including: limited proliferation capacity; heterogeneity of cell sources; lengthy expansion time to clinical dose; expansion failure in vitro; and a painful, invasive, isolation procedure for the donor. Therefore, alternative MSC sources for cellular therapy are sought. The reviewed data suggests MSCs derived from WJ may be a safe and effective cellular therapy for GVHD. Laboratories investigated and defined the immune properties of WJ-MSCs for potential use in cellular therapy. These cells represent a more uniform cell population than bone marrow-derived MSCs, displaying robust immunosuppressive properties and lacking significant immunogenicity. They can be collected safely and painlessly from individuals at birth, rapidly expanded and stored cryogenically for later clinical use. Additionally, data we reviewed suggested licensing MSCs (activating MSCs by exposure to cytokines) to enhance effectiveness in treating GVHD. Therefore, WJCs should be tested as a second generation, relatively homogeneous allogeneic cell therapy for the treatment of GVHD.

Human bone marrow stromal cells lose immunosuppressive and anti-inflammatory properties upon oncogenic transformation

Because of their immunomodulatory properties, human bone marrow stromal cells (hBMSCs) represent promising stem cells for treatment of immune disorders. hBMSCs expansion precedes their clinical use, so the possibility that hBMSCs undergo spontaneous transformation upon long-term culture should be addressed. Whether hBMSCs retain immunosuppressive and anti-inflammatory properties upon oncogenic transformation remains unknown. Using sequentially mutated hBMSCs and spontaneously transformed hBMSCs, we report that, upon oncogenic transformation, hBMSCs lose immunosuppressive and anti-inflammatory properties in vitro and in vivo. Transcriptome profiling and functional assays reveal immune effectors underlying the loss of immunomodulation in transformed hBMSCs. They display a proinflammatory transcriptomic signature, with deregulation of immune and inflammatory modulators and regulators of the prostaglandin synthesis. Transformed hBMSCs lose their capacity to secrete the immunosuppressive prostacyclins prostaglandin E2 (PGE2) and PGI2 but produce proinflammatory thromboxanes. Together, the immunoregulatory profile adopted by hBMSCs largely depends on intrinsic genetic-molecular determinants triggered by genomic instability/oncogenic transformation.

•

Oncogenic hBMSCs display robustly impaired immune properties

•

Transformed hBMSCs display a proinflammatory transcriptomic signature

•

Transformed hBMSCs lose capacity to secrete immunosuppressive prostacyclins

•

Transformed hBMSCs gain the capacity to produce proinflammatory thromboxanes

Conditioned medium from horse amniotic membrane-derived multipotent progenitor cells: immunomodulatory activity in vitro and first clinical application in tendon and ligament injuries in vivo

We have recently demonstrated that heterologous transplantation of horse amniotic membrane-derived mesenchymal cells (AMCs) can be useful for cell therapy applications in tendon diseases, and hypothesized that these cells may promote tendon repair via paracrine-acting molecules targeting inflammatory processes. To test this hypothesis, here we examined the immunomodulatory characteristics of AMCs and of their conditioned medium (AMC-CM) in vitro, and studied the potential therapeutic effect of AMC-CM in thirteen different spontaneous horse tendon and ligament injuries in vivo. Our results demonstrate that AMCs are capable of inhibiting peripheral blood mononuclear cell (PBMC) proliferation after allogenic stimulation either when cocultured in cell-to-cell contact, or when the two cell types are physically separated by a transwell membrane, suggesting that soluble factors are implicated in this phenomenon. Our hypothesis is further supported by the demonstration that PBMC proliferation is inhibited by AMC-CM. In our in vivo studies, no significant adverse effects were observed in treated tendons, and clinical and ultrasonographical evaluation did not reveal evidence of inappropriate tissue or tumor formation. Clinical outcomes were favorable and the significantly lower rate (15.38%) of reinjuries observed compared to untreated animals, suggests that treatment with AMC-CM is very efficacious. In conclusion, this study identifies AMC-CM as a novel therapeutic biological cell-free product for treating horse tendon and ligament diseases.

Impact of passing mesenchymal stem cells through smaller bore size needles for subsequent use in patients for clinical or cosmetic indications

Background

Numerous preclinical and clinical studies have investigated the regenerative potential and the trophic support of mesenchymal stem cells (MSCs) following their injection into a target organ. Clinicians favor the use of smallest bore needles possible for delivering MSCs into vascular organs like heart, liver and spleen. There has been a concern that small needle bore sizes may be detrimental to the health of these cells and reduce the survival and plasticity of MSCs.

Methods

In this report, we aimed to investigate the smallest possible bore size needle which would support the safe delivery of MSCs into various tissues for different clinical or cosmetic applications. To accomplish this we injected cells via needle sizes 24, 25 and 26 G attached to 1 ml syringe in the laboratory and collected the cells aseptically. Control cells were ejected via 1 ml syringe without any needle. Thereafter, the needle ejected cells were cultured and characterized for their morphology, attachment, viability, phenotypic expression, differentiation potential, cryopreservation and in vivo migration abilities. In the second phase of the study, cells were injected via 26 G needle attached to 1 ml syringe for 10 times.

Results

Similar phenotypic and functional characteristics were observed between ejected and control group of cells. MSCs maintained their cellular and functional properties after single and multiple injections.

Conclusions

This study proves that 26 G bore size needles can be safely used to inject MSCs for clinical/therapeutics purposes.

Promise(s) of mesenchymal stem cells as an in vitro model system to depict pre-diabetic/diabetic milieu in WNIN/GR-Ob mutant rats

Background

Development of model systems have helped to a large extent, in bridging gap to understand the mechanism(s) of disease including diabetes. Interestingly, WNIN/GR-Ob rats (Mutants), established at National Centre for Laboratory Animals (NCLAS) of National Institute of Nutrition (NIN), form a suitable model system to study obesity with Type 2 diabetes (T2D) demonstrating several secondary complications (cataract, cardiovascular complications, infertility, nephropathy etc). The present study has been carried out to explore the potent application(s) of multipotent stem cells such as bone marrow mesenchymal stem cells (BM-MSCs), to portray features of pre-diabetic/T2D vis-à-vis featuring obesity, with impaired glucose tolerance (IGT), hyperinsulinemia (HI) and insulin resistance (IR) seen with Mutant rats akin to human situation.

Methodology/Principal Findings

Primary cultures of BM-MSCs (third passage) from Mutants, its lean littermate (Lean) and parental control (Control) were characterized for: proliferation markers, disease memory to mark obesity/T2D/HI/IR which included phased gene expression studies for adipogenic/pancreatic lineages, inflammatory markers and differentiation ability to form mature adipocytes/Insulin-like cellular aggregates (ILCAs). The data showed that BM-MSCs from Mutant demonstrated a state of disease memory, depicted by an upregulated expression of inflammatory markers (IL-6, TNFα); increased stem cell recruitment (Oct-4, Sox-2) and proliferation rates (CD90+/CD29+, PDA, ‘S’ phase of cell cycle by FACS and BrdU incorporation); accelerated preadipocyte induction (Dact-1, PPARγ2) with a quantitative increase in mature adipocyte formation (Leptin); ILCAs, which were non-responsive to high glucose did confer the Obese/T2D memory in Mutants. Further, these observations were in compliance with the anthropometric data.

Conclusions

Given the ease of accessibility and availability of MSCs, the present study form the basis to report for the first time, application of BM-MSCs as a feasible in vitro model system to portray the disease memory of pre-clinical/T2D with IR - a major metabolic disorder of global concern.

Stem cells for reprogramming: could hUMSCs be a better choice?

Human umbilical cord mesenchymal stem cells (hUMSC) are primitive multipotent cells capable of differentiating into cells of different lineages. They can be an alternative source of pluripotent cells since they are ethically and regulatory approved, are easily obtained and have low immunogenicity compared to embryonic stem cells which are dogged with numerous controversies. hUMSC can be a great source for cell and transplantation therapy.

Cell-based therapies for tendon and ligament injuries

Tendon and ligament injuries have proved difficult to treat effectively. Cell-based therapies offer the potential to harness the complex protein synthetic machinery of the cell to induce a regenerative response rather than fibrous scarring. This article reviews the current state of play with respect to the clinically used cell preparations for the treatment of tendon and ligaments overstrain injuries.

Promising cellular therapeutics for prevention or management of graft-versus-host disease (a review)

Graft-versus-host disease (GVHD) frequently occurs following allogeneic hematopoietic stem cell transplantation. The primary treatment for GVHD involves immune suppression by glucocorticoids. If patients become refractory to steroids, they have a poor prognosis. Therefore, there is a pressing need for alternative therapies to treat GVHD. Here, we review clinical data which demonstrate that a cellular therapy using mesenchymal stromal cells (MSCs) is safe and effective for GVHD. Since MSCs derived from bone marrow present certain limitations (such as time lag for expansion to clinical dose, expansion failure in vitro, painful and invasive bone marrow MSC isolation procedures), alternative sources of MSCs for cellular therapy are being sought. Here, we review data which support the notion that MSCs derived from Wharton's jelly (WJ) may be a safe and effective cellular therapy for GVHD. Many laboratories have investigated the immune properties of these discarded MSCs with an eye towards their potential use in cellular therapy. We also review data which support the notion that the licensing of MSCs (meaning the activation of MSCs by prior exposure to cytokines such as interferon-γ) may enhance their effectiveness for treatment of GVHD. In conclusion, WJCs can be collected safely and painlessly from individuals at birth, similar to the collection of cord blood, and stored cryogenically for later clinical use. Therefore, WJCs should be tested as a second generation, off-the-shelf cell therapy for the prevention or treatment of immune disorders such as GVHD.

Induced bone marrow mesenchymal stem cells improve cardiac performance of infarcted rat hearts

We investigated whether transplantation of bone marrow mesenchymal stem cells (BMSC) with induced BMSC (iBMSC) or uninduced BMSC (uBMSC) into the myocardium could improve the performance of post-infarcted rat hearts. BMSCs were specified by flowcytometry. IBMSCs were cocultured with rat cardiomyocyte before transplantation. Cells were injected into borders of cardiac scar tissue 1 week after experimental infarction. Cardiac performance was evaluated by echocardiography at 1, 2, and 4 weeks after cellular or PBS injection. Langendorff working-heart and histological studies were performed 4 weeks after treatment. Myogenesis was detected by quantitative PCR and immunofluorescence. Echocardiography showed a nearly normal ejection fraction (EF) in iBMSC-treated rats and all sham control rats but a lower EF in all PBS-treated animals. The iBMSC-treated heart, assessed by echocardiography, improved fractional shortening compared with PBS-treated hearts. The coronary flow (CF) was decreased obviously in PBS and uBMSC-treated groups, but recovered in iBMSC-treated heart at 4 weeks (P < 0.01). Immunofluorescent microscopy revealed co-localization of Superparamagnetic iron oxide (SPIO)-labeled transplanted cells with cardiac markers for cardiomyocytes, indicating regeneration of damaged myocardium. These data provide strong evidence that iBMSC implantation is of more potential to improve infarcted cardiac performance than uBMSC treatment. It will open new promising therapeutic opportunities for patients with post-infarction heart failure.

Antileukemia and antitumor effects of the graft-versus-host disease: a new immunovirological approach

In leukemic mice, the native host's explicit and well-defined immune reactions to the leukemia virus (a strong exogenous antigen) and to leukemia cells (pretending in their native hosts to be protected "self" elements) are extinguished and replaced in GvHD (graft-versus-host disease) by those of the immunocompetent donor cells. In many cases, the GvHD-inducer donors display genetically encoded resistance to the leukemia virus. In human patients only antileukemia and anti-tumor cell immune reactions are mobilized; thus, patients are deprived of immune reactions to a strong exogenous antigen (the elusive human leukemia-sarcoma retroviruses). The innate and adaptive immune systems of mice have to sustain the immunosuppressive effects of leukemia-inducing retroviruses. Human patients due to the lack of leukemiainducing retroviral pathogens (if they exist, they have not as yet been discovered), escape such immunological downgrading. After studying leukemogenic retroviruses in murine and feline (and other mammalian) hosts, it is very difficult to dismiss retroviral etiology for human leukemias and sarcomas. Since no characterized and thus recognized leukemogenic-sarcomagenic retroviral agents are being isolated from the vast majority of human leukemias-sarcomas, the treatment for these conditions in mice and in human patients vastly differ. It is immunological and biological modalities (alpha interferons; vaccines; adoptive lymphocyte therapy) that dominate the treatment of murine leukemias, whereas combination chemotherapy remains the main remission-inducing agent in human leukemias-lymphomas and sarcomas (as humanized monoclonal antibodies and immunotoxins move in). Yet, in this apparently different backgrounds in Mus and Homo, GvHD, as a treatment modality, appears to work well in both hosts, by replacing the hosts' anti-leukemia and anti-tumor immune faculties with those of the donor. The clinical application of GvHD in the treatment of human leukemias-lymphomas and malignant solid tumors remains a force worthy of pursuit, refinement and strengthening. Graft engineering and modifications of the inner immunological environment of the recipient host by the activation or administration of tumor memory T cells, selected Treg cells and natural killer (NKT) cell classes and cytokines, and the improved pharmacotherapy of GvHD without reducing its antitumor efficacy, will raise the value of GvHD to the higher ranks of the effective antitumor immunotherapeutical measures. Clinical interventions of HCT/HSCT (hematopoietic cell/stem cell transplants) are now applicable to an extended spectrum of malignant diseases in human patients, being available to elderly patients, who receive non-myeloablative conditioning, are re-enforced by post-transplant donor lymphocyte (NK cell and immune T cell) infusions and post-transplant vaccinations, and the donor cells may derive from engineered grafts, or from cord blood with reduced GvHD, but increased GvL/GvT-inducing capabilities (graft-versus leukemia/tumor). Post-transplant T cell transfusions are possible only if selected leukemia antigen-specific T cell clones are available. In verbatim quotation: "Ultimately, advances in separation of GvT from GvHD will further enhance the potential of allogeneic HCT as a curative treatment for hematological malignancies" (Rezvani, A.R. and Storb, R.F., Journal of Autoimmunity 30:172-179, 2008 (see in the text)). It may be added: for cure, a combination of the GvL/T effects with new targeted therapeutic modalities, as elaborated on in this article, will be necessary.