Human Wharton's Jelly-Derived Stem Cells Display Immunomodulatory Properties and Transiently Improve Rat Experimental Autoimmune Encephalomyelitis

Opportunities and challenges: mesenchymal stem cells in the treatment of multiple sclerosis

Multiple sclerosis (MS) was once considered an untreatable disease. Through years of research, many drugs have been discovered and are widely used for the treatment of MS. However, the current treatment can only alleviate the clinical symptoms of MS and has serious side effects. Mesenchymal stem cells (MSCs) provide neuroprotection by migrating to injured tissues, suppressing inflammation, and fostering neuronal repair. Therefore, MSCs therapy holds great promise for MS treatment. This review aimed to assess the feasibility and safety of use of MSCs in MS treatment as well as its development prospect in clinical treatment by analysing the existing clinical studies.

Preclinical assessment of IL-1β primed human umbilical cord mesenchymal stem cells for tendon functional repair through TGF-β/IL-10 signaling

Background

Inadequate repair capacity and disturbed immune compartments are the main pathological causes of tendinopathy. Transplantation of mesenchymal stem cells (MSCs) become an effective clinic option to alleviate tendinopathy. Interleukin-1β (IL-1β) could confer on MSCs enhanced immunoregulatory capability to remodel the repair microenvironment favoring tissue repair. Therefore, IL-1β activated UC-MSCs (1βUC-MSCs) may exert favorable efficacy in promoting tendon repair in a preclinical tendinopathy rat model.

Methods

Tendon-derived stem cells (TDSCs) were isolated and characterized. In vitro, the levels of immunoregulatory-related cytokines such as IL-1β, IL-6, IL-10, and TGF-β secreted by 1βUC-MSCs and unprimed UC-MSCs was measured. And tendon-specific markers expressed by TDSCs cultured with primed cultured medium (CM) or unprimed CM were detected. In vivo, Achilles tendinopathy was induced by 30 μL collagenase I injection in Sprague Dawley rats. One week later, the rats were randomly injected with UC-MSCs primed with IL-1β (106 cells per tendon), UC-MSCs, or PBS. After rats were sacrificed, histological evaluation, electron microscopy, biomechanical tests, gait performance were conducted to evaluate the structural and functional recovery of Achilles tendons. The inflammation and metabolic state of the extracellular matrix, and the potential mechanism were assessed by immunohistochemical staining and Western blot.

Results

UC-MSCs were activated by IL-1β to secrete higher levels of IL-10 and TGF-β while the secretion levels of IL-6 and IL-1β were not changed significantly, promoting a higher expression level of COL I and TNMD in TDSCs under proinflammatory environment. In vivo, the transplanted 1βUC-MSCs could survive up to 5 weeks after injection with tenogenic differentiation and improved tendon healing histologically semi-quantified by modified Bonar scores. This structural regeneration was further confirmed by observation of ultrastructural morphology, and led to good functional recovery including improved biomechanical properties and gait performance. During this process, the inflammatory response and metabolism of the extracellular matrix was improved through TGF-β/IL-10 pathway.

Conclusion

This study demonstrated that the transplantation of UC-MSCs activated by IL-1β exhibited satisfactory ability for promoting tendon functional repair in a tendinopathy rat model. During this process, the balance of inflammatory response and extracellular matrix metabolism was remodeled, and the TGF-β/Smad2/3 and IL-10 signaling pathways were activated simultaneously. We cautiously conclude that the IL-1β primed UC-MSCs could be a promising strategy for enhancing the ability of MSCs to treat tendinopathy.

Facing the Challenges in the COVID-19 Pandemic Era: From Standard Treatments to the Umbilical Cord-Derived Mesenchymal Stromal Cells as a New Therapeutic Strategy

Coronavirus disease 2019 (COVID-19), the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which counts more than 650 million cases and more than 6.6 million of deaths worldwide, affects the respiratory system with typical symptoms such as fever, cough, sore throat, acute respiratory distress syndrome (ARDS), and fatigue. Other nonpulmonary manifestations are related with abnormal inflammatory response, the "cytokine storm", that could lead to a multiorgan disease and to death. Evolution of effective vaccines against SARS-CoV-2 provided multiple options to prevent the infection, but the treatment of the severe forms remains difficult to manage. The cytokine storm is usually counteracted with standard medical care and anti-inflammatory drugs, but researchers moved forward their studies on new strategies based on cell therapy approaches. The perinatal tissues, such as placental membranes, amniotic fluid, and umbilical cord derivatives, are enriched in mesenchymal stromal cells (MSCs) that exert a well-known anti-inflammatory role, immune response modulation, and tissue repair. In this review, we focused on umbilical-cord-derived MSCs (UC-MSCs) used in in vitro and in vivo studies in order to evaluate the weakening of the severe symptoms, and on recent clinical trials from different databases, supporting the favorable potential of UC-MSCs as therapeutic strategy.

Comparative Analysis of the Results of Stroke Treatment With Multiple Administrations of Wharton's Jelly Mesenchymal Stem Cells-Derived HE-ATMP and Standard Conservative Treatment: Case Series Study

Stroke remains still the leading cause of long-term disability worldwide. Although interventions such as early reperfusion, intravenous thrombolysis, and endovascular revascularization have shown neurological benefit in stroke patients, there is still lack of effective treatment enabling regeneration of nervous tissue after cerebral ischemic episodes. Cell therapy is an evolving opportunity for stroke survivors with residual neurological deficits. The purpose of this study was to evaluate safety and potential efficacy of multiple administration of Hospital Exemption-Advanced Therapy Medicinal Product (HE-ATMP) comprising 3 × 107 Wharton's jelly mesenchymal stem cells (WJMSCs). A study group was composed of six patients-three women and three men. The patients were qualified to the treatment with diagnosis of chronic stroke (2-24 months after cerebral ischemic episode), during 2 years. All the patients undergone repeated rounds of HE-ATMP administration to the CSF (cerebrospinal fluid) via lumbar puncture. The control group consisted of six patients (two women and four men) who experienced stroke, treated at the same time (follow-up period: 24 months) using standard treatment methods, without endovascular treatment. To evaluate the results of the therapy, we used both impairment scales [National Institutes of Health Stroke Score (NIHSS)] and functional outcomes scales [Modified Rankin Scale (MRS) and Barthel Index (BI)]. In four patients, who received at least three repeated rounds of HE-ATMP, we reported neurological improvement and reduction of functional neurodeficiency. The biggest improvement concerned the reduction of speech disorders in two cases; significant improvement in the field of motor skills in three patients and reduction of apraxia and improvement of logical communication skills in two patients were also reported. All the patients became more independent. Significant improvement of the neurological condition using the same scales was registered only in two patients from the control group. We did not report any adverse events in the treated group during follow-up. At 1-year follow-up, we demonstrate safety and beneficial effect of WJMSC transplantation including neurological improvement and reduction of functional neurodeficiency. We are aware that the samples size of this study is relatively small. The treatment regimen needs to be further tested in larger group of patients.

Mesenchymal stromal cell extracellular vesicles for multiple sclerosis in preclinical rodent models: A meta-analysis

INTRODUCTION

Extracellular vesicles (EVs), especially mesenchymal stem (stromal) cell-derived EVs (MSC-EVs), have gained attention as potential novel treatments for multiple sclerosis (MS). However, their effects remain incompletely understood. Thus, the purpose of this meta-analysis was to systematically review the efficacy of MSC-EVs in preclinical rodent models of MS.

METHODS

We searched PubMed, EMBASE, and the Web of Science databases up to August 2021 for studies that reported the treatment effects of MSC-EVs in rodent MS models. The clinical score was extracted as an outcome. Articles were peer-reviewed by two authors based on the inclusion and exclusion criteria. This meta-analysis was conducted using Stata 15.1 and R.

RESULTS

A total of twelve animal studies met the inclusion criteria. In our study, the MSC-EVs had a positive overall effect on the clinical score with a standardized mean difference (SMD) of -2.17 (95% confidence interval (CI)):-3.99 to -0.34, P = 0.01). A significant amount of heterogeneity was observed among the studies.

CONCLUSIONS

This meta-analysis suggests that transplantation of MSC-EVs in MS rodent models improved functional recovery. Additionally, we identified several critical knowledge gaps, such as insufficient standardized dosage units and uncertainty regarding the optimal dose of MSC-EVs transplantation in MS. These gaps must be addressed before clinical trials can begin with MSC-EVs.

Effect of Multiple Sclerosis Cerebrospinal Fluid and Oligodendroglia Cell Line Environment on Human Wharton's Jelly Mesenchymal Stem Cells Secretome

Multiple sclerosis (MS) is a neurological disorder of autoimmune aetiology. Experimental therapies with the use of mesenchymal stem cells (MSCs) have emerged as a response to the unmet need for new treatment options. The unique immunomodulatory features of stem cells obtained from Wharton’s jelly (WJ-MSCs) make them an interesting research and therapeutic model. Most WJ-MSCs transplants for multiple sclerosis use intrathecal administration. We studied the effect of cerebrospinal fluid (CSF) obtained from MS patients on the secretory activity of WJ-MSCs and broaden this observation with WJ-MSCs interactions with human oligodendroglia cell line (OLs). Analysis of the WJ-MSCs secretory activity with use of Bio-Plex Pro™ Human Cytokine confirmed significant and diverse immunomodulatory potential. Our data reveal rich WJ-MSCs secretome with markedly increased levels of IL-6, IL-8, IP-10 and MCP-1 synthesis and a favourable profile of growth factors. The addition of MS CSF to the WJ-MSCs culture caused depletion of most proteins measured, only IL-12, RANTES and GM-CSF levels were increased. Most cytokines and chemokines decreased their concentrations in WJ-MSCs co-cultured with OLs, only eotaxin and RANTES levels were slightly increased. These results emphasize the spectrum of the immunomodulatory properties of WJ-MSCs and show how those effects can be modulated depending on the transplantation milieu.

Human Olfactory Mesenchymal Stem Cells Are a Novel Candidate for Neurological Autoimmune Disease

Background: Human olfactory mesenchymal stem cells (OMSC) have become a novel therapeutic option for immune disorder or demyelinating disease due to their immunomodulatory and regenerative potentials. However, the immunomodulatory effects of OMSC still need to be elucidated, and comparisons of the effects of different MSCs are also required in order to select an optimal cell source for further applications. Results: In animal experiments, we found neural functional recovery and delayed EAE attack in the OMSC treatment group. Compared with umbilical cord-derived mesenchymal stem cells (UMSC) treatment group and the control group, the OMSC treatment group had a better neurological improvement, lower serum levels of IFN-γ, and a lower proportion of CD4+IFN-γ+ T splenic lymphocyte. We also observed OMSC effectively suppressed CD4+IFN-γ+ T cell proportion in vitro when co-cultured with human peripheral blood-derived lymphocytes. The OMSC-mediated immunosuppressive effect on human CD4+IFN-γ+ T cells was attenuated by blocking cyclooxygenase activity. Conclusion: Our results suggest that OMSC treatment delayed the onset and promoted the neural functional recovery in the EAE mouse model possibly by suppressing CD4+IFN-γ+ T cells. OMSC transplantation might become an alternative therapeutic option for neurological autoimmune disease.

Challenges and Improvements of Novel Therapies for Ischemic Stroke

Stroke is the third most common disease all over the world, which is regarded as a hotspot in medical research because of its high mortality and morbidity. Stroke, especially ischemic stroke, causes severe neural cell death, and no effective therapy is currently available for neuroregeneration after stroke. Although many therapies have been shown to be effective in preclinical studies of ischemic stroke, almost none of them passed clinical trials, and the reasons for most failures have not been well identified. In this review, we focus on several novel methods, such as traditional Chinese medicine, stem cell therapy, and exosomes that have not been used for ischemic stroke till recent decades. We summarize the proposed basic mechanisms underlying these therapies and related clinical results, discussing advantages and current limitations for each therapy emphatically. Based on the limitations such as side effects, narrow therapeutic window, and less accumulation at the injury region, structure transformation and drug combination are subsequently applied, providing a deep understanding to develop effective treatment strategies for ischemic stroke in the near future.

Mesenchymal stem cells as a treatment for multiple sclerosis: a focus on experimental animal studies

Multiple sclerosis (MS) is a progressive and debilitating neurological condition in which the immune system abnormally attacks the myelin sheath insulating the nerves. Mesenchymal stem cells (MSCs) are found in most adult tissues and play a significant systemic role in self-repair. MSCs have promising therapeutic effects in many diseases, such as autoimmune diseases, including MS. MSCs have been tested in MS animal models, such as experimental autoimmune encephalomyelitis. Other studies have combined other agents with MSCs, genetically modified MSCs, or used culture medium from MSCs. In this review, we will summarize these studies and compare the main factors in each study, such as the source of MSCs, the type of animal model, the route of injection, the number of injected cells, and the mechanism of action.

The Efficacy of Mesenchymal Stem Cell Therapies in Rodent Models of Multiple Sclerosis: An Updated Systematic Review and Meta-Analysis

Studies have demonstrated the potential of mesenchymal stem cell (MSC) administration to promote functional recovery in preclinical studies of multiple sclerosis (MS), yet the effects of MSCs on remyelination are poorly understood. We wished to evaluate the therapeutic effects of MSCs on functional and histopathological outcomes in MS; therefore, we undertook an updated systematic review and meta-analysis of preclinical data on MSC therapy for MS. We searched mainstream databases from inception to July 15, 2021. Interventional studies of therapy using naïve MSCs in in vivo rodent models of MS were included. From each study, the clinical score was extracted as the functional outcome, and remyelination was measured as the histopathological outcome. Eighty-eight studies published from 2005 to 2021 met the inclusion criteria. Our results revealed an overall positive effect of MSCs on the functional outcome with a standardized mean difference (SMD) of −1.99 (95% confidence interval (CI): −2.32, −1.65; p = 0.000). MSCs promoted remyelination by an SMD of −2.31 (95% CI: −2.84, −1.79; p = 0.000). Significant heterogeneity among studies was observed. Altogether, our meta-analysis indicated that MSC administration improved functional recovery and promoted remyelination prominently in rodent models of MS.

Human Fallopian Tube - Derived Mesenchymal Stem Cells Inhibit Experimental Autoimmune Encephalomyelitis by Suppressing Th1/Th17 Activation and Migration to Central Nervous System

Mesenchymal stem cells comprise a natural reservoir of undifferentiated cells within adult tissues. Given their self-renewal, multipotency, regenerative potential and immunomodulatory properties, MSCs have been reported as a promising cell therapy for the treatment of different diseases, including neurodegenerative and autoimmune diseases. In this study, we investigated the immunomodulatory properties of human tubal mesenchymal stem cells (htMSCs) using the EAE model. htMSCs were able to suppress dendritic cells activation downregulating antigen presentation-related molecules, such as MHCII, CD80 and CD86, while impairing IFN-γ and IL-17 and increasing IL-10 and IL-4 secretion. It further correlated with milder disease scores when compared to the control group due to fewer leukocytes infiltrating the CNS, specially Th1 and Th17 lymphocytes, associated with increased IL-10 secreting Tr1 cells. Conversely, microglia were less activated and infiltrating mononuclear cells secreted higher levels of IL-4 and IL-10 and expressed reduced chemokine receptors as CCR4, CCR6 and CCR8. qPCR of the spinal cords revealed upregulation of indoleamine-2,3-dioxygenase (IDO) and brain derived neurotrophic factor (BDNF). Taken together, here evidenced the potential of htMSCs as an alternative for the treatment of inflammatory, autoimmune or neurodegenerative diseases.

Evaluation of Edaravone effects on the differentiation of human adipose derived stem cells into oligodendrocyte cells in multiple sclerosis disease in rats

AIMS

Among all the treatments for Multiple Sclerosis, stem cell transplantation, such as ADSCs, has attracted a great deal of scientific attention. On the other hand, Edaravone, as an antioxidant component, in combination with stem cells, could increase the survival and differentiation potential of stem cells.

MAIN METHODS

42 rats were divided into: Control, Cuprizone (CPZ), Sham, Edaravone (Ed), hADSCs, and Ed/hADSCs groups. Following induction of cuprizone, induced MS model, behavioral tests were designed to evaluate motor function during. Luxal fast blue staining was done to measure the level of demyelination and remyelination. Immunofluorescent staining was used to evaluate the amount of MBP, OLIG2, and MOG proteins. The mRNA levels of human MBP, MOG, and OLIG2 and rat Mbp, Mog, and Olig2 were determined via RT-PCR.

KEY FINDINGS

Flow cytometry analysis exhibited that the extracted cells were positive for CD73 (93.8 ± 3%) and CD105 (91.6 ± 3%), yet negative for CD45 (2.06 ± 0.5%). Behavioral tests, unveiled a significant improvement in the Ed (P < 0.001), hADSCs (P < 0.001), and Ed/hADSCs (P < 0.001) groups compared to the others. In the Ed/hADSCs group, the myelin density was significantly higher than that in the Ed treated and hADSCs treated groups (P < 0.01). Edaravone and hADSCs increased the expression of Mbp, Mog, and Olig2 genes in the cuprizone rat models. Moreover, significant differences were seen between the Ed treated and hADSCs treated groups and the Ed/hADSCs group (P < 0.05 for Mbp and Olig2 and P < 0.01 for Mog).

SIGNIFICANCE

Edaravone in combination with hADSCs reduced demyelination and increased oligodendrogenesis in the cuprizone rat models.

Potential of Mesenchymal Stem Cells in the Rejuvenation of the Aging Immune System

Rapid growth of the geriatric population has been made possible with advancements in pharmaceutical and health sciences. Hence, age-associated diseases are becoming more common. Aging encompasses deterioration of the immune system, known as immunosenescence. Dysregulation of the immune cell production, differentiation, and functioning lead to a chronic subclinical inflammatory state termed inflammaging. The hallmarks of the aging immune system are decreased naïve cells, increased memory cells, and increased serum levels of pro-inflammatory cytokines. Mesenchymal stem cell (MSC) transplantation is a promising solution to halt immunosenescence as the cells have excellent immunomodulatory functions and low immunogenicity. This review compiles the present knowledge of the causes and changes of the aging immune system and the potential of MSC transplantation as a regenerative therapy for immunosenescence.

The preclinical and clinical implications of fetal adnexa derived mesenchymal stromal cells in wound healing therapy

Mesenchymal stromal cells (MSCs) isolated from fetal adnexa namely amniotic membrane/epithelium, amniotic fluid and umbilical cord have hogged the limelight in recent times, as a proposed alternative to MSCs from conventional sources. These cells which are identified as being in a developmentally primitive state have many advantages, the most important being the non-invasive nature of their isolation procedures, absence of ethical concerns, proliferation potential, differentiation abilities and low immunogenicity. In the present review, we are focusing on the potential preclinical and clinical applications of different cell types of fetal adnexa, in wound healing therapy. We also discuss the isolation-culture methods, cell surface marker expression, multi-lineage differentiation abilities, immune-modulatory capabilities and their homing property. Different mechanisms involved in the wound healing process and the role of stromal cells in therapeutic wound healing are highlighted. Further, we summarize the findings of the cell delivery systems in skin lesion models and paracrine functions of their secretome in the wound healing process. Overall, this holistic review outlines the research findings of fetal adnexa derived MSCs, their usefulness in wound healing therapy in human as well as in veterinary medicine.

Extracellular Vesicles From Perinatal Cells for Anti-inflammatory Therapy

Perinatal cells, including cells from placenta, fetal annexes (amniotic and chorionic membranes), umbilical cord, and amniotic fluid display intrinsic immunological properties which very likely contribute to the development and growth of a semiallogeneic fetus during pregnancy. Many studies have shown that perinatal cells can inhibit the activation and modulate the functions of various inflammatory cells of the innate and adaptive immune systems, including macrophages, neutrophils, natural killer cells, dendritic cells, and T and B lymphocytes. These immunological properties, along with their easy availability and lack of ethical concerns, make perinatal cells very useful/promising in regenerative medicine. In recent years, extracellular vesicles (EVs) have gained great interest as a new therapeutic tool in regenerative medicine being a cell-free product potentially capable, thanks to the growth factors, miRNA and other bioactive molecules they convey, of modulating the inflammatory microenvironment thus favoring tissue regeneration. The immunomodulatory actions of perinatal cells have been suggested to be mediated by still not fully identified factors (secretoma) secreted either as soluble proteins/cytokines or entrapped in EVs. In this review, we will discuss how perinatal derived EVs may contribute toward the modulation of the immune response in various inflammatory pathologies (acute and chronic) by directly targeting different elements of the inflammatory microenvironment, ultimately leading to the repair and regeneration of damaged tissues.

The therapeutic applications of mesenchymal stromal cells from human perinatal tissues in autoimmune diseases

The autoimmune diseases are characterized by overactivation of immune cells, chronic inflammation, and immune response to self-antigens, leading to the damage and dysfunction of multiple organs. Patients still do not receive desired clinical outcomes while suffer from various adverse effects imparted by current therapies. The therapeutic strategies based on mesenchymal stromal cell (MSC) transplantation have become the promising approach for the treatment of autoimmune diseases due to the immunomodulation property of MSCs. MSCs derived from perinatal tissues are collectively known as perinatal MSCs (PMSCs), which can be obtained via painless procedures from donors with lower risk of being contaminated by viruses than those MSCs from adult tissue sources. Therefore, PMSCs may be the ideal cell source for the treatment of autoimmune diseases. This article summarizes recent progress and possible mechanisms of PMSCs in treating autoimmune diseases in animal experiments and clinical studies. This review also presents existing challenges and proposes solutions, which may provide new hints on PMSC transplantation as a therapeutic strategy for the treatment of autoimmune diseases.

Mesenchymal Stem Cells in Multiple Sclerosis: Recent Evidence from Pre-Clinical to Clinical Studies

Multiple sclerosis (MS) is an autoimmune, demyelinating disease of the central nervous system. Nowadays, available therapies for MS can help to manage MS course and symptoms, but new therapeutic approaches are required. Stem cell therapy using mesenchymal stem cells (MSCs) appeared promising in different neurodegenerative conditions, thanks to their beneficial capacities, including the immunomodulation ability, and to their secretome. The secretome is represented by growth factors, cytokines, and extracellular vesicles (EVs) released by MSCs. In this review, we focused on studies performed on in vivo MS models involving the administration of MSCs and on clinical trials evaluating MSCs administration. Experimental models of MS evidenced that MSCs were able to reduce inflammatory cell infiltration and disease score. Moreover, MSCs engineered to express different genes, preconditioned with different compounds, differentiated or in combination with other compounds also exerted beneficial actions in MS models, in some cases also superior to native MSCs. Secretome, both conditioned medium and EVs, also showed protective effects in MS models and appeared promising to develop new approaches. Clinical trials highlighted the safety and feasibility of MSC administration and reported some improvements, but other trials using larger cohorts of patients are needed.

Improving the immunosuppressive potential of articular chondroprogenitors in a three-dimensional culture setting

Cartilage repair in osteoarthritic patients remains a challenge. Identifying resident or donor stem/progenitor cell populations is crucial for augmenting the low intrinsic repair potential of hyaline cartilage. Furthermore, mediating the interaction between these cells and the local immunogenic environment is thought to be critical for long term repair and regeneration. In this study we propose articular cartilage progenitor/stem cells (CPSC) as a valid alternative to bone marrow-derived mesenchymal stem cells (BMMSC) for cartilage repair strategies after trauma. Similar to BMMSC, CPSC isolated from osteoarthritic patients express stem cell markers and have chondrogenic, osteogenic, and adipogenic differentiation ability. In an in vitro 2D setting, CPSC show higher expression of SPP1 and LEP, markers of osteogenic and adipogenic differentiation, respectively. CPSC also display a higher commitment toward chondrogenesis as demonstrated by a higher expression of ACAN. BMMSC and CPSC were cultured in vitro using a previously established collagen-chondroitin sulfate 3D scaffold. The scaffold mimics the cartilage niche, allowing both cell populations to maintain their stem cell features and improve their immunosuppressive potential, demonstrated by the inhibition of activated PBMC proliferation in a co-culture setting. As a result, this study suggests articular cartilage derived-CPSC can be used as a novel tool for cellular and acellular regenerative medicine approaches for osteoarthritis (OA). In addition, the benefit of utilizing a biomimetic acellular scaffold as an advanced 3D culture system to more accurately mimic the physiological environment is demonstrated.

Mesenchymal stromal cells (MSCs) for neurodegenerative disease: A promising frontier

Neurodegenerative disorders are a variety of diseases including Alzheimer's (AD), Parkinson's (PD), and Huntington's diseases (HD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) along with some other less common diseases generally described by the advanced deterioration of central or peripheral nervous system, structurally or functionally. In the last two decades, mesenchymal stromal cells (MSCs) due to their unique assets encompassing self-renewal, multipotency and accessibility in association with low ethical concern open new frontiers in the context of neurodegenerative diseases therapy. Interestingly, MSCs can be differentiated into endodermal and ectodermal lineages (e.g., neurons, oligodendrocyte, and astrocyte), and thus could be employed to advance cell-based therapeutic strategy. Additionally, as inflammation ordinarily ensues as a local response provoked by microglia in the neurodegenerative diseases, MSCs therapy because of their pronounced immunomodulatory properties is noticed as a rational approach for their treatment. Recently, varied types of studies have been mostly carried out in vitro and rodent models using MSCs upon their procurement from various sources and expansion. The promising results of the studies in rodent models have motivated researchers to design and perform several clinical trials, with a speedily rising number. In the current review, we aim to deliver a brief overview of MSCs sources, expansion strategies, and their immunosuppressive characteristics and discuss credible functional mechanisms exerted by MSCs to treat neurodegenerative disorders, covering AD, PD, ALS, MS, and HD.

The potentials of umbilical cord-derived mesenchymal stem cells in the treatment of multiple sclerosis

Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple sclerosis is an autoimmune-based chronic disease, in which the myelin sheath of the central nervous system is destructed. Scientists have not discovered any cure for multiple sclerosis, and most of the treatments are rather palliative. The pursuit of a versatile treatment option, therefore, seems essential. The immunoregulatory and non-chronic rejection characteristics of mesenchymal stem cells, as well as their homing properties, recommend them as a prospective treatment option for multiple sclerosis. Different sources of mesenchymal stem cells have distinct characteristics and functional properties; in this regard, choosing the most suitable cell therapy approach seems to be challenging. In this review, we will discuss umbilical cord/blood-derived mesenchymal stem cells, their identified exclusive properties compared to another adult mesenchymal stem cells, and the expectations of their potential roles in the treatment of multiple sclerosis.

Umbilical cord-derived mesenchymal stem cells in neurodegenerative disorders: from literature to clinical practice

Mesenchymal stem cells (MSCs) have provided a promising tool for cell therapy. Umbilical cord (UC) is one of the best sources of MSCs since its collection is noninvasive, and effortless, and the cells from this source are more capable and prolific. It has been proven that the differentiation, migration and protective properties of UC-MSCs are superior compared with other kinds of stem cells. Moreover, incurable neurodegenerative diseases, such as Alzheimer's disease, multiple sclerosis, Parkinson's disease and Huntington, encourage scientists to apply UC-MSCs transplantation in order to find a definite treatment. This review will focus on the preclinical and clinical use of mesenchymal stem cells derived from human umbilical cord in the treatment of neurodegenerative disorders.

Progress in the treatment of osteoarthritis with umbilical cord stem cells

Osteoarthritis is a chronic degenerative joint disease with an incidence of 81% among people aged over 65 years in China. Osteoarthritis significantly decreases the quality of life of patients, causing physical and psychological damage and posing a serious economic burden. Clinical treatments for osteoarthritis include drug and surgical treatments. Drug treatment can successfully alleviate pain but not satisfactorily reverse joint damage, while surgical intervention is typically used to treat end-stage disease. Stem cells are multi-potential progenitor cells with self-renewal and multi-lineage differentiation abilities, and can differentiate into many kinds of cells, including chondrocytes. Umbilical cord stem cells, also known as Wharton’s jelly mesenchymal stem cells (WJ-MSCs), have become the first choice for cartilage regeneration engineering owing to their availability and convenience of collection. This article reviews the biological characterization of WJ-MSCs in recent years, their advantages compared with other stem cells, and their application in the treatment of osteoarthritis in animal experiments and clinical trials.

Mesenchymal stem cells in experimental autoimmune encephalomyelitis model of multiple sclerosis: A systematic review and meta-analysis

BACKGROUND/AIMS

Mesenchymal stem cells (MSCs) transplantation has been considered a possible therapeutic method for Multiple Sclerosis (MS). However, no quantitative data synthesis of MSCs therapy for MS exists. We conducted a systematic review and meta-analysis to evaluate the effects of MSCs in experimental autoimmune encephalomyelitis (EAE) animal model of MS.

METHODS

We identified eligible studies published from January 1980 to January 2017 by searching four electronic databases (PubMed, MEDLINE, Embase and Web of Science). The outcome was the effects of MSCs on clinical performance evaluated by the EAE clinical score.

RESULTS

36 preclinical studies including 675 animals in MSCs treatment group, and 693 animals in control group were included in this meta-analysis. We found that MSCs transplantation significantly ameliorated the symptoms and delayed the disease progression (SMD = -1.25, 95% CI: -1.45 to -1.05, P < 0.001). However, no significant differences in effect sizes were unveiled relative to clinical score standard (P = 0.35), type of MSCs (P = 0.35), source of MSCs (P = 0.06), MSCs dose (P = 0.44), delivery methods (P = 0.31) and follow up period (P = 0.73).

CONCLUSIONS

The current study showed that MSCs transplantation could ameliorate clinical performance in EAE animal model of MS. These findings support the further studies translate MSCs to treat MS in humans.

Neuro-Cells therapy improves motor outcomes and suppresses inflammation during experimental syndrome of amyotrophic lateral sclerosis in mice

Aims

Mutations in DNA/RNA‐binding factor (fused‐in‐sarcoma) FUS and superoxide dismutase‐1 (SOD‐1) cause amyotrophic lateral sclerosis (ALS). They were reproduced in SOD‐1‐G93A (SOD‐1) and new FUS[1‐359]‐transgenic (FUS‐tg) mice, where inflammation contributes to disease progression. The effects of standard disease therapy and anti‐inflammatory treatments were investigated using these mutants.

Methods

FUS‐tg mice or controls received either vehicle, or standard ALS treatment riluzole (8 mg/kg/day), or anti‐inflammatory drug a selective blocker of cyclooxygenase‐2 celecoxib (30 mg/kg/day) for six weeks, or a single intracerebroventricular (i.c.v.) infusion of Neuro‐Cells (a preparation of 1.39 × 10⁶ mesenchymal and hemopoietic human stem cells, containing 5 × 10⁵ of CD34⁺ cells), which showed anti‐inflammatory properties. SOD‐1 mice received i.c.v.‐administration of Neuro‐Cells or vehicle.

Results

All FUS‐tg‐treated animals displayed less marked reductions in weight gain, food/water intake, and motor deficits than FUS‐tg‐vehicle‐treated mice. Neuro‐Cell‐treated mutants had reduced muscle atrophy and lumbar motor neuron degeneration. This group but not celecoxib‐FUS‐tg‐treated mice had ameliorated motor performance and lumbar expression of microglial activation marker, ionized calcium‐binding adapter molecule‐1 (Iba‐1), and glycogen‐synthase‐kinase‐3ß (GSK‐3ß). The Neuro‐Cells‐treated‐SOD‐1 mice showed better motor functions than vehicle‐treated‐SOD‐1 group.

Conclusion

The neuropathology in FUS‐tg mice is sensitive to standard ALS treatments and Neuro‐Cells infusion. The latter improves motor outcomes in two ALS models possibly by suppressing microglial activation.

Perinatal Mesenchymal Stromal Cells and Their Possible Contribution to Fetal-Maternal Tolerance

During pregnancy, a successful coexistence between the mother and the semi-allogenic fetus occurs which requires a dynamic immune system to guarantee an efficient immune protection against possible infections and tolerance toward fetal antigens. The mechanism of fetal-maternal tolerance is still an open question. There is growing in vitro and in vivo evidence that mesenchymal stromal cells (MSC) which are present in perinatal tissues have a prominent role in generating a functional microenvironment critical to a successful pregnancy. This review highlights the immunomodulatory properties of perinatal MSC and their impact on the major immune cell subsets present in the uterus during pregnancy, such as natural killer cells, antigen-presenting cells (macrophages and dendritic cells), and T cells. Here, we discuss the current understanding and the possible contribution of perinatal MSC in the establishment of fetal-maternal tolerance, providing a new perspective on the physiology of gestation.

Topical Application of Human Wharton's Jelly Mesenchymal Stem Cells Accelerates Mouse Sciatic Nerve Recovery and is Associated with Upregulated Neurotrophic Factor Expression

Peripheral nerve regeneration following injury is often slow and impaired, which results in weakened and denervated muscle with subsequent atrophy. Human Wharton's jelly mesenchymal stem cells (hWJ-MSC) have potential regenerative properties which, however, remain unknown in mouse nerve recovery. This study investigated the effect of the topical application of hWJ-MSC onto repairing transected sciatic nerves in a mouse model. Human adipocyte-derived stem cells (hADSC) were used as a positive control. The sciatic nerve of BALB/c mice was transected at a fixed point and repaired under the microscope using 10-0 sutures. hWJ-MSC and hADSC were applied to the site of repair and mice were followed up for 1 year. The hWJ-MSC group had significantly better functional recovery of five-toe spread and gait angles compared with the negative control and hADSC groups. hWJ-MSC improved sciatic nerve regeneration in a dose-dependent fashion. The hWJ-MSC group had a better quality of regenerated nerve with an increased number of myelinated axons throughout. hWJ-MSC appear to be safe in mice after 1 year of follow-up. hWJ-MSC also expressed higher levels of neurotrophic factor-3, brain-derived neurotrophic factor, and glial-derived neurotrophic factor than hADSC. hWJ-MSC may promote better nerve recovery than hADSC because of this upregulation of neurotrophic factors.

Characteristics and clinical applications of Wharton's jelly-derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are widely used in the clinic because they involve fewer ethical issues and safety concerns compared to other stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). MSCs derived from umbilical cord Wharton's jelly (WJ-MSCs) have excellent proliferative potential and a faster growth rate and can retain their multipotency for more passages in vitro compared to adult MSCs from bone marrow or adipose tissue. WJ-MSCs are used clinically for repairing tissue injuries of the spinal cord, liver and heart with the aim of regenerating tissue. On the other hand, WJ-MSCs are also used clinically to ameliorate immune-mediated diseases based on their ability to modulate immune responses. In the field of tissue engineering, WJ-MSCs capable of differentiating into multiple cell lineages have been used to produce a variety of engineered tissues in vitro that can then be transplanted in vivo. This review discusses the characteristics of WJ-MSCs, the differences between WJ-MSCs and adult MSCs, clinical studies involving WJ-MSCs and future perspectives of WJ-MSC research and clinical applications. To summarize, WJ-MSCs have shown promise in treating a variety of diseases clinically. However, most clinical trials/studies reported thus far are relatively smaller in scale. The collected evidence is insufficient to support the routine use of WJ-MSC therapy in the clinic. Thus, rigorous clinical trials are needed in the future to obtain more information on WJ-MSC therapy safety and efficacy.

Human ES-derived MSCs correct TNF-α-mediated alterations in a blood-brain barrier model

Background

Immune cell trafficking into the CNS is considered to contribute to pathogenesis in MS and its animal model, EAE. Disruption of the blood–brain barrier (BBB) is a hallmark of these pathologies and a potential target of therapeutics. Human embryonic stem cell-derived mesenchymal stem/stromal cells (hES-MSCs) have shown superior therapeutic efficacy, compared to bone marrow-derived MSCs, in reducing clinical symptoms and neuropathology of EAE. However, it has not yet been reported whether hES-MSCs inhibit and/or repair the BBB damage associated with neuroinflammation that accompanies EAE.

Methods

BMECs were cultured on Transwell inserts as a BBB model for all the experiments. Disruption of BBB models was induced by TNF-α, a pro-inflammatory cytokine that is a hallmark of acute and chronic neuroinflammation.

Results

Results indicated that hES-MSCs reversed the TNF-α-induced changes in tight junction proteins, permeability, transendothelial electrical resistance, and expression of adhesion molecules, especially when these cells were placed in direct contact with BMEC.

Conclusions

hES-MSCs and/or products derived from them could potentially serve as novel therapeutics to repair BBB disturbances in MS.

Electronic supplementary material

The online version of this article (10.1186/s12987-019-0138-5) contains supplementary material, which is available to authorized users.

Immunomodulation with Human Umbilical Cord Blood Stem Cells Ameliorates Ischemic Brain Injury - A Brain Transcriptome Profiling Analysis

Our group previously demonstrated that administration of a CD34-negative fraction of human non- hematopoietic umbilical cord blood stem cells (UCBSC) 48 h after ischemic injury could reduce infarct volume by 50% as well as significantly ameliorate neurological deficits. In the present study, we explored possible mechanisms of action using next generation RNA sequencing to analyze the brain transcriptome profiles in rats with ischemic brain injury following UCBSC therapy. Two days after ischemic injury, rats were treated with UCBSC. Five days after administration, total brain mRNA was then extracted for RNAseq analysis using Illumina Hiseq 2000. We found 275 genes that were significantly differentially expressed after ischemic injury compared with control brains. Following UCBSC treatment, 220 of the 275 differentially expressed genes returned to normal levels. Detailed analysis of these altered transcripts revealed that the vast majority were associated with activation of the immune system following cerebral ischemia which were normalized following UCBSC therapy. Major alterations in gene expression profiles after ischemia include blood-brain-barrier breakdown, cytokine production, and immune cell infiltration. These results suggest that UCBSC protect the brain following ischemic injury by down regulating the aberrant activation of innate and adaptive immune responses.

Human Amniotic Membrane and Amniotic Membrane-Derived Cells: How Far Are We from Their Use in Regenerative and Reconstructive Urology?

Human amniotic membrane (hAM) is the innermost layer of fetal membranes, which surrounds the developing fetus and forms the amniotic cavity. hAM and hAM-derived cells possess many properties that make them suitable for use in regenerative medicine, such as low immunogenicity, promotion of epithelization, anti-inflammatory properties, angiogenic and antiangiogenic properties, antifibrotic properties, antimicrobial properties, and anticancer properties. Many pathological conditions of the urinary tract lead to organ damage or complete loss of function. Consequently, the reconstruction or replacement of damaged organs is needed, which makes searching for new approaches in regenerative and reconstructive urology a necessity. The use of hAM for treating defects in kidneys, ureters, urinary bladder, and urethra was tested in vitro in cell cultures and in vivo in mice, rats, rabbits, cats, dogs, and also in humans. These studies confirmed the advantages and the potential of hAM for use in regenerative and reconstructive urology as stated above. However, they also pointed out a few concerns we have to take into consideration. These are (1) the lack of a standardized protocol in hAM preparation and storage, (2) the heterogeneity of hAM, and especially (3) low mechanical strength of hAM. Before any wider use of hAM for treating urological defects, the protocols for preparation and storage will need to be standardized, followed by more studies on larger animals and clinical trials, which will altogether extensively assess the potential of hAM use in urological patients.

Transplanting Mesenchymal Stem Cells for Treatment of Ischemic Stroke

Stroke is a major disease that leads to high mortality and morbidity. Given the ageing population and the potential risk factors, the prevalence of stroke and socioeconomic burden associated with stroke are expected to increase. During the past decade, both prophylactic and therapeutic strategies for stroke have made significant progress. However, current therapies still cannot adequately improve the outcomes of stroke and may not apply to all patients. One of the significant advances in modern medicine is cell-derived neurovascular regeneration and neuronal repair. Progress in stem cell biology has greatly contributed to ameliorating stroke-related brain injuries in preclinical studies and demonstrated clinical potential in stroke treatment. Mesenchymal stem cells (MSCs) have the differentiating potential of chondrocytes, adipocytes, and osteoblasts, and they have the ability to transdifferentiate into endothelial cells, glial cells, and neurons. Due to their great plasticity, MSCs have drawn much attention from the scientific community. This review will focus on MSCs, stem cells widely utilized in current medical research, and evaluate their effect and potential of improving outcomes in ischemic stroke.

Stem cell therapy for neurological disorders: A focus on aging

Age-related neurological disorders continue to pose a significant societal and economic burden. Aging is a complex phenomenon that affects many aspects of the human body. Specifically, aging can have detrimental effects on the progression of brain diseases and endogenous stem cells. Stem cell therapies possess promising potential to mitigate the neurological symptoms of such diseases. However, aging presents a major obstacle for maximum efficacy of these treatments. In this review, we discuss current preclinical and clinical literature to highlight the interactions between aging, stem cell therapy, and the progression of major neurological disease states such as Parkinson's disease, Huntington's disease, stroke, traumatic brain injury, amyotrophic lateral sclerosis, multiple sclerosis, and multiple system atrophy. We raise important questions to guide future research and advance novel treatment options.

The Use of Human Mesenchymal Stem Cells as Therapeutic Agents for the in vivo Treatment of Immune-Related Diseases: A Systematic Review

Background: One of the greatest challenges for medicine is to find a safe and effective treatment for immune-related diseases. However, due to the low efficacy of the treatment available and the occurrence of serious adverse effects, many groups are currently searching for alternatives to the traditional therapy. In this regard, the use of human mesenchymal stem cells (hMSCs) represents a great promise for the treatment of a variety of immune-related diseases due to their potent immunomodulatory properties. The main objective of this study is, therefore, to present and summarize, through a systematic review of the literature, in vivo studies in which the efficacy of the administration of hMSCs for the treatment of immune-related diseases was evaluated. Methods: The article search was conducted in PubMed/MEDLINE, Scopus and Web of Science databases. Original research articles assessing the therapeutic potential of hMSCs administration for the in vivo treatment immune-related diseases, published from 1984 to December 2017, were selected and evaluated. Results: A total of 132 manuscripts formed the basis of this systematic review. Most of the studies analyzed reported positive results after hMSCs administration. Clinical effects commonly observed include an increase in the survival rates and a reduction in the severity and incidence of the immune-related diseases studied. In addition, hMSCs administration resulted in an inhibition in the proliferation and activation of CD19⁺ B cells, CD4⁺ Th1 and Th17 cells, CD8⁺ T cells, NK cells, macrophages, monocytes, and neutrophils. The clonal expansion of both Bregs and Tregs cells, however, was stimulated. Administration of hMSCs also resulted in a reduction in the levels of pro-inflammatory cytokines such as IFN-γ, TNF-α, IL-1, IL-2, IL-12, and IL-17 and in an increase in the levels of immunoregulatory cytokines such as IL-4, IL-10, and IL-13. Conclusions: The results obtained in this study open new avenues for the treatment of immune-related diseases through the administration of hMSCs and emphasize the importance of the conduction of further studies in this area.

An update on intracerebral stem cell grafts

INTRODUCTION

Primary neurological disorders are notoriously debilitating and deadly, and over the past four decades stem cell therapy has emerged as a promising treatment. Translation of stem cell therapies from the bench to the clinic requires a better understanding of delivery protocols, safety profile, and efficacy in each disease. Areas covered: In this review, benefits and risks of intracerebral stem cell transplantation are presented for consideration. Milestone discoveries in stem cell applications are reviewed to examine the efficacy and safety of intracerebral stem cell transplant therapy for disorders of the central nervous system and inform design of translatable protocols for clinically feasible stem cell-based treatments. Expert commentary: Intracerebral administration, compared to peripheral delivery, is more invasive and carries the risk of open brain surgery. However, direct cell implantation bypasses the blood-brain barrier and reduces the first-pass effect, effectively increasing the therapeutic cell deposition at its intended site of action. These benefits must be weighed with the risk of graft-versus-host immune response. Rigorous clinical trials are underway to assess the safety and efficacy of intracerebral transplants, and if successful will lead to widely available stem cell therapies for neurologic diseases in the coming years.

Interspecies Incompatibilities Limit the Immunomodulatory Effect of Human Mesenchymal Stromal Cells in the Rat

Mesenchymal stem/stromal cells (MSC) are an immunomodulatory cell population which are under preclinical and clinical investigation for a number of inflammatory conditions including transplantation. In this study, a well-established rat corneal transplantation model was used to test the ability of human MSC to prolong corneal allograft rejection-free survival using a pre-transplant intravenous infusion protocol previously shown to be efficacious with allogeneic rat MSC. Surprisingly, pre-transplant administration of human MSC had no effect on corneal allograft survival. In vitro, human MSC failed to produce nitric oxide and upregulate IDO and, as a consequence, could not suppress rat T-cell proliferation. Furthermore, human MSC were not activated by rat pro-inflammatory cytokines. Thus, interspecies incompatibility in cytokine signaling leading to failure of MSC licensing may explain the lack of in vivo efficacy of human MSC in a rat tissue allotransplant model. Interspecies incompatibilities should be taken into consideration when interpreting preclinical data efficacy data in the context of translation to clinical trial. Stem Cells 2018;36:1210-1215.

SPK1-transfected UCMSC has better therapeutic activity than UCMSC in the treatment of experimental autoimmune encephalomyelitis model of Multiple sclerosis

Multiple Sclerosis (MS), is a chronic inflammatory autoimmune disorder of the central nervous system that leads to chronic demyelination with axonal damage and neuronal loss. Mesenchymal stem cells (MSCs) represent a promising therapeutic approach for MS. In the current study, we investigated the effects of MSCs derived from the human umbilical cord (UCMSC) transfected by sphingosine kinase 1 (SPK1) gene. All the results showed that transplantation of UCMSCs gene modified by SPK1 (UCMSC-SPK1) dramatically reduce the severity of neurological deficits of the experimental autoimmune encephalomyelitis (EAE) mice, paralleling by reductions in demyelination, axonal loss, and astrogliosis. UCMSC-SPK1 transplantation also could inhibit the development of natural killer (NK) responses in the spleen of EAE mice, and increase the ratio of CD4⁺ CD25⁺ FoxP3⁺ (Treg) T cells. Furthermore, we described that a shift in the cytokine response from Th1/Th17 to Th2 was an underlying mechanism that suppressed CNS autoimmunity. UCMSCs transfected by SPK1 gene potentially offer a novel mode for the treatment of MS, and the specific mechanism of SPK1 in treating MS/EAE.

Human umbilical cord-derived mesenchymal stem cells reduce monosodium iodoacetate-induced apoptosis in cartilage

Objective:

The present study investigated the therapeutic potential and underlying mechanisms of human umbilical cord mesenchymal stem cells (HUCMSCs) on joint cartilage destruction induced by monosodium iodoacetate (MIA) in mice.

Materials and Methods:

HUCMSCs were tested for mesenchymal stem cell (MSC) characteristics including surface markers by flow cytometry and mesoderm differentiation (adipogenesis, osteogenesis, and chondrogenesis). Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and Western blot assay were used to evaluate MIA-induced chondrocyte apoptosis. In the in vivo study, 18 mice were divided into three groups (n = 6 each); normal saline (control), MIA-treated, and MIA-treated/HUCMSC-transplantation. Rota-Rods tests were used to evaluate MIA-induced cartilage destruction behaviors in mice. Histological changes in the mice cartilage were examined by immunohistochemistry.

Results:

HUCMSCs had an immunophenotype similar to bone marrow-derived MSCs and were able to differentiate into adipocytes, osteocytes, and chondrocytes. Conditioned medium of the HUCMSCs exhibited an anti-apoptotic effect and inhibited expression of caspase 3 in MIA-treated chondrocytes. HUCMSC transplantation assisted in recovery from movement impairment (from 30% on day 7 to 115% on day 14) and in regeneration and repair of cartilage damaged by MIA. (International Cartilage Repair Society score: 3.8 in the MIA group vs. 10.2 in the HUCMSC-treated group); HUCMSC transplantation ameliorated cartilage apoptosis through the caspase 3 pathway in MIA-induced cartilage destruction in mice.

Conclusion:

Taken together, these observations suggest that HUCMSC transplantation appears to be effective in protecting cartilage from MIA damage.

Sonic hedgehog (SHH) signaling improves the angiogenic potential of Wharton's jelly-derived mesenchymal stem cells (WJ-MSC)

Background

Wharton’s jelly-derived mesenchymal stem cells (WJ-MSC) show remarkable therapeutic potential to repair tissue upon injury via paracrine signaling by secreting diverse trophic factors that promote angiogenesis. However, the mechanisms and signaling pathways that regulate the induction of these specific factors are still mostly unknown. Emerging evidence suggests that Sonic hedgehog (SHH) plays a central role in angiogenesis and tissue maintenance. However, its contribution to the angiogenic potential of MSC has not been fully addressed. The aim of this work was to characterize the expression of the SHH pathway components in WJ-MSC primary cultures and to evaluate their angiogenic responsiveness to SHH signaling.

Methods

Primary cell cultures obtained from human umbilical cords were treated with pharmacological modulators of the SHH pathway. We evaluated the modulation of diverse trophic factors in cell lysates, conditioned medium, and functional in vitro assays. In addition, we determined the angiogenic potential of the SHH pathway in the chicken chorioallantoic membrane, an in vivo model.

Results

Our results show that WJ-MSC express components of the canonical SHH pathway and are activated by its signaling. In fact, we provide evidence of basal autocrine/paracrine SHH signaling in WJ-MSC. SHH pathway stimulation promotes the secretion of angiogenic factors such as activin A, angiogenin, angiopoietin 1, granulocyte-macrophage colony-stimulating factor, matrix metallometallopeptidase -9, and urokinase-type plasminogen activator, enhancing the pro-angiogenic capabilities of WJ-MSC both in vitro and in vivo.

Conclusion

WJ-MSC are a cell population responsive to SHH pathway stimulation. Basal SHH signaling is in part responsible for the angiogenic inductive properties of WJ-MSC. Overall, exogenous activation of the SHH pathway enhances the angiogenic properties of WJ-MSC, making this cell population an ideal target for treating tissue injury.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0653-8) contains supplementary material, which is available to authorized users.

* Tissue Engineering Strategies to Improve Osteogenesis in the Juvenile Swine Alveolar Cleft Model

Alveolar (gumline) clefts are the most common congenital bone defect in humans, affecting 1 in 700 live births. Treatment to repair these bony defects relies on autologous, cancellous bone transfer from the iliac crest. This harvest requires a second surgical site with increased surgical time associated with potential complications, while providing only limited cancellous bone. Improvements in treatment protocols that avoid these limitations would be beneficial to patients with clefts and other craniofacial bone defects. There have been steady advances in tissue-engineered (TE) solutions for long-bone defects and adult patients, but advances for the pediatric craniofacial skeleton have been slower to emerge. This study utilizes a previously established juvenile swine model with a surgically created, critical size alveolar defect to test the efficacy of umbilical cord (UC) mesenchymal stem cells (MSCs) treatments on nano-microfiber scaffolds. At 1 month after implanting our TE construct, mineralized tissue in the surgical gap was quantified through computed tomography (CT), and histology, and excised tissue was subjected to mechanical testing. Both undifferentiated and predifferentiated (toward an osteogenic lineage) UC MSCs generated bone within the cleft on a scale comparable to iliac crest cancellous bone, as evidenced by histology and CT scans. All of the pigs treated with scaffold/stem cell combinations had mineralized tissue within the defect, although without filling the entire defect. Several of the experimental animals exhibited poor and/or asymmetric maxillary growth 1 month after the initial surgery, especially if the surgical defect was located on the smaller side of an already asymmetric pig. Our results demonstrate that tissue engineering approaches using UC MSCs are a promising alternative for repair of the alveolar cleft. Data in the pig model demonstrate that implanted scaffolds are at least as good as the current gold standard treatment based on harvesting cancellous bone from the iliac crest, regardless of whether the cells seeded on the scaffold are precommitted to an osteogenic fate.

Crosstalk with Inflammatory Macrophages Shapes the Regulatory Properties of Multipotent Adult Progenitor Cells

Macrophages and microglia are key effector cells in immune-mediated neuroinflammatory disorders. Driving myeloid cells towards an anti-inflammatory, tissue repair-promoting phenotype is considered a promising strategy to halt neuroinflammation and promote central nervous system (CNS) repair. In this study, we defined the impact of multipotent adult progenitor cells (MAPC), a stem cell population sharing common mesodermal origin with mesenchymal stem cells (MSCs), on the phenotype of macrophages and the reciprocal interactions between these two cell types. We show that MAPC suppress the secretion of tumor necrosis factor alpha (TNF-α) by inflammatory macrophages partially through a cyclooxygenase 2- (COX-2-) dependent mechanism. In turn, we demonstrate that inflammatory macrophages trigger the immunomodulatory properties of MAPC, including an increased expression of immunomodulatory mediators (e.g., inducible nitric oxide synthase (iNOS) and COX-2), chemokines, and chemokine receptors. Macrophage-primed MAPC secrete soluble factors that suppress TNF-α release by macrophages. Moreover, the MAPC secretome suppresses the antigen-specific proliferation of autoreactive T cells and the T cell stimulatory capacity of macrophages. Finally, MAPC increase their motility towards secreted factors of activated macrophages. Collectively, these in vitro findings reveal intimate reciprocal interactions between MAPC and inflammatory macrophages, which are of importance in the design of MAPC-based therapeutic strategies for neuroinflammatory disorders in which myeloid cells play a crucial role.

Immunomodulatory effects of stem cells: Therapeutic option for neurodegenerative disorders

Stem cells have the capability of self-renewal and can differentiate into different cell types that might be used in regenerative medicine. Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) currently lack effective treatments. Although stem cell therapy is still on the way from bench to bedside, we consider that it might provide new hope for patients suffering with neurodegenerative diseases. In this article, we will give an overview of recent studies on the potential therapeutic use of mesenchymal stem cells (MSCs), neural stem cells (NSCs), embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and perinatal stem cells to neurodegenerative disorders and we will describe their immunomodulatory mechanisms of action in specific therapeutic modalities.

Modulation of host immune responses following non-hematopoietic stem cell transplantation: Translational implications in progressive multiple sclerosis

There exists an urgent need for effective treatments for those patients suffering from chronic/progressive multiple sclerosis (MS). Accordingly, it has become readily apparent that different classes of stem cell-based therapies must be explored at both the basic science and clinical levels. Herein, we provide an overview of the basic mechanisms underlying the pre-clinical benefits of exogenously delivered non-hematopoietic stem cells (nHSCs) in animal models of MS. Further, we highlight a number of early clinical trials in which nHSCs have been used to treat MS. Finally, we identify a series of challenges that must be met and ultimately overcome if such promising therapeutics are to be advanced from the bench to the bedside.

Bioactive molecules derived from umbilical cord mesenchymal stem cells

Umbilical cord mesenchymal stem cells (UCMSCs) retain their intrinsic stem cell potential while at the same time displaying high proliferation rates, powerful differentiation capacity, and low immunogenicity. They can also secrete multiple bioactive molecules that exert specific physiological functions. Thus, UCMSCs represent excellent candidates for cell therapy in regenerative medicine and tissue engineering. Abundant preclinical research on different disease models has shown that UCMSCs can accelerate wound or nerve damage recovery and suppress tumor progression. In fact, UCMSCs are thought to possess a higher therapeutic potential than MSCs derived from other tissues. Increasing evidence suggests that the mechanism underlying UCSMCs efficacy depends mostly on cell secretions, in contrast to the early paradigm of cell replacement and differentiation. In this review, we discuss UCMSCs biological characteristics, their secretome-based therapeutic mechanism, and potential applications.

Clinical Application of Autologous Adipose Stem Cells in Patients with Multiple Sclerosis: Preliminary Results

The clinical outcome of autologous adipose stem cell (ASC) treatment of patients with multiple sclerosis (MS) was investigated following one year of observation. Methods. The clinical and MRI outcomes of 16 ASC-treated patients with RRMS and SPMS are reported after a one-year follow-up period. Results. At 18 months of follow-up, some patients showed “enticing” improvements on some exploratory efficacy measures, although a significant benefit was not observed for any measure across the entire group. Neither the progression of disability nor relapses were observed in any cases. In four patients, we found new gadolinium+ (Gd+) lesions on MRI. Our results indicate that ASC therapy is safe and does not produce any substantial side effects. Disease progression-free survival (PFS) of 18 months was seen in all patients with RRMS and SPMS. In these patients, EDSS scores did not progress above baseline scores. Gd-enhancing lesions were observed in two cases with RRMS, but these patients did not exhibit changes in EDSS score. Conclusion. Intrathecal treatment with ASCs is an attractive form of therapy for patients with MS but should be reserved for cases with aggressive disease progression, for cases that are still in the inflammatory phase, and for the malignant form.

The effect of transplanted human Wharton's jelly mesenchymal stem cells treated with IFN-γ on experimental autoimmune encephalomyelitis mice

Interferon gamma (IFN-γ) increases the immunosuppressive property of human Wharton's jelly mesenchymal stem cells (hWJ-MSCs). In this study, we evaluated the therapeutic effects of IFN-γ primed WJ-MSCs in EAE mice. IFN-γ primed WJ-MSCs were injected on days 3 and 11 after EAE induction. 21 days after EAE induction, splenocytes and cervical lymph node cells were isolated and cell proliferation, secretion of inflammatory cytokines and frequency of regulatory T-cells was measured. On day 50 of the study, cell infiltration and gene expression of inflammatory cytokines in brain of mice were studied. Leukocyte infiltration and symptoms were significantly reduced in IFN-γ primed WJ-MSCs treated group compared to other groups. These cells showed significantly reduced proliferation and increased Treg cells as well as decreased secretion and gene expression of inflammatory cytokines in EAE mice. Our data suggest that IFN-γ may be used to stimulate the immunomodulatory property of WJ-MSCs in clinical situations.

Label-Free Imaging of Umbilical Cord Tissue Morphology and Explant-Derived Cells

In situ detection of MSCs remains difficult and warrants additional methods to aid with their characterization in vivo. Two-photon confocal laser scanning microscopy (TPM) and second harmonic generation (SHG) could fill this gap. Both techniques enable the detection of cells and extracellular structures, based on intrinsic properties of the specific tissue and intracellular molecules under optical irradiation. TPM imaging and SHG imaging have been used for label-free monitoring of stem cells differentiation, assessment of their behavior in biocompatible scaffolds, and even cell tracking in vivo. In this study, we show that TPM and SHG can accurately depict the umbilical cord architecture and visualize individual cells both in situ and during culture initiation, without the use of exogenously applied labels. In combination with nuclear DNA staining, we observed a variance in fluorescent intensity in the vessel walls. In addition, antibody staining showed differences in Oct4, αSMA, vimentin, and ALDH1A1 expression in situ, indicating functional differences among the umbilical cord cell populations. In future research, marker-free imaging can be of great added value to the current antigen-based staining methods for describing tissue structures and for the identification of progenitor cells in their tissue of origin.