Umbilical Cord-Derived Mesenchymal Stem Cells Are Able to Use bFGF Treatment and Represent a Superb Tool for Immunosuppressive Clinical Applications

Study on Preclinical Safety and Toxic Mechanism of Human Umbilical Cord Mesenchymal Stem Cells in F344RG Rats

Mesenchymal stem cells have made remarkable progress in recent years. Many studies have reported that human umbilical cord mesenchymal stem cells (hUC-MSCs) have no toxicity, but thromboembolism appeared in patients treated with hUC-MSCs. Therefore, people are still worried about the safety of clinical application. The study aims to determine the safety, potential toxic mechanism and biodistribution of hUC-MSCs. F344RG rats were given 5 or 50 million cells/kg of hUC-MSCs by single administration in compliance with Good Laboratory Practice standards. Standard toxicity was performed. RNA sequencing was then performed to explore the potential toxic mechanisms. In parallel, the biodistribution of hUC-MSCs was examined. The dose of 5 million cells/kg hUC-MSCs had no obvious toxicity on symptom, weight, food intake, hematology, serum biochemistry, urine biochemistry, cytokines, and histopathology. However, blood-tinged secretions in the urethral orifice and 20% mortality occurred at 50 million cells/kg. Disseminated intravascular coagulopathy (DIC) is the leading cause of death. hUC-MSCs significantly upregulated complement and coagulation cascade pathways gene expression, resulting in DIC. Besides, hUC-MSCs upregulated fibrinolytic system suppressor genes A2m, Serping1 and Serpinf2. hUC-MSCs survived in rats for less than 28 days, no hUC-MSC was detected in tissues outside the lungs. There was no toxicity in F344RG rats at 5 million cells/kg, but some toxicities were detected at 50 million cells/kg. hUC-MSCs significantly upregulated complement and coagulation cascade pathways, upregulated the expression of fibrinolytic system suppressor genes A2m, Serping1 and Serpinf2, to inhibit fibrinolytic system, caused DIC, which provided a new insight into the toxic mechanism of hUC-MSCs.

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

Background

The isolation of Mesenchymal Stem Cells (MSCs) from various tissues is possible, with the umbilical cord emerging as a competitive alternative to bone marrow. In order to fulfill the demands of cell therapy, it is essential to generate stem cells on a clinical scale while minimizing time, cost, and contamination. Here is a simple and effective protocol for isolating MSC from Wharton's Jelly (WJ-MSC) using the explant method with various supplements.

Methods

Utilizing the explant method, small fragments of Wharton's jelly from the human umbilical cord were cultured in a flask. The multipotency of the isolated cells, were confirmed by their differentiation ability to osteocyte and adipocyte. Additionally, the immunophenotyping of WJ-MSCs showed positive expression of CD73, CD90, and CD105, while remaining negative for hematopoietic markers CD34 and CD45, meeting the criteria for WJ-MSC identification. Following that, to evaluate cells' proliferative capacity, various supplements, including basic Fibroblast Growth Factor (bFGF), Non-Essential amino acids (NEA), and L-Glutamine (L-Gln) were added to either alpha-Minimal Essential Medium (α-MEM) or Dulbecco's Modified Eagle's Medium-F12 (DMEM-F12), as the basic culture media.

Results

WJ-MSCs isolated by the explant method were removed from the tissue after seven days and transferred to the culture medium. These cells differentiated into adipocyte and osteocyte lineages, expressing CD73, CD90, and CD105 positively and CD34 and CD45 negatively. The results revealed that addition of bFGF to α-MEM or DMEMF12 media significantly increased the proliferation of MSCs when compared to the control group. However, there were no significant differences observed when NEA or LGln were added.

Conclusion

Although bFGF considerably enhances cell proliferation, our study demonstrates that MSCs can grow and expand when properly prepared Wharton's jelly tissues of the human umbilical cord.

Engineered exosomes derived from stem cells: a new brain-targeted strategy

INTRODUCTION

Using engineered exosomes produced from stem cells is an experimental therapeutic approach for treating brain diseases. According to reports, preclinical research has demonstrated notable neurogenesis and angiogenesis effects using modified stem cell-derived exosomes. These biological nanoparticles have a variety of anti-apoptotic, anti-inflammatory, and antioxidant properties that make them very promising for treating nervous system disorders.

AREAS COVERED

This review examines different ways to enhance the delivery of modified stem cell-derived exosomes, how they infiltrate the blood-brain barrier (BBB), and how they facilitate their access to the brain. We would also like to determine whether these nanoparticles have the most significant transmission rates through BBB when targeting brain lesions.

EXPERT OPINION

Using engineered stem cell-derived exosomes for treating brain disorders has generated considerable attention toward clinical research and application. However, stem cell-derived exosomes lack consistency, and their mechanisms of action are uncertain. Therefore, upcoming research needs to prioritize examining the underlying mechanisms and strategies via which these nanoparticles combat neurological disorders.

Thermostable Basic Fibroblast Growth Factor Enhances the Production and Activity of Human Wharton's Jelly Mesenchymal Stem Cell-Derived Extracellular Vesicles

Wharton's jelly-derived mesenchymal stem cell (WJ-MSC)-derived exosomes contain a diverse cargo and exhibit remarkable biological activity, rendering them suitable for regenerative and immune-modulating functions. However, the quantity of secretion is insufficient. A large body of prior work has investigated the use of various growth factors to enhance MSC-derived exosome production. In this study, we evaluated the utilization of thermostable basic fibroblast growth factor (TS-bFGF) with MSC culture and exosome production. MSCs cultured with TS-bFGF displayed superior proliferation, as evidenced by cell cycle analysis, compared with wild-type bFGF (WT-bFGF). Stemness was assessed through mRNA expression level and colony-forming unit (CFU) assays. Furthermore, nanoparticle tracking analysis (NTA) measurements revealed that MSCs cultured with TS-bFGF produced a greater quantity of exosomes, particularly under three-dimensional culture conditions. These produced exosomes demonstrated substantial anti-inflammatory and wound-healing effects, as confirmed by nitric oxide (NO) assays and scratch assays. Taken together, we demonstrate that utilization of TS-bFGF for WJ-MSC-derived exosome production not only increases exosome yield but also enhances the potential for various applications in inflammation regulation and wound healing.

Dual impacts of mesenchymal stem cell-derived exosomes on cancer cells: unravelling complex interactions

Mesenchymal stem cells (MSCs) are multipotent, self-renewing stromal cells found in a variety of adult tissues. MSCs possess a remarkable ability to migrate towards tumor sites, known as homing. This homing process is mediated by various factors, including chemokines, growth factors, and extracellular matrix components present in the tumor microenvironment. MSCs release extracellular vesicles known as exosomes (MSC-Exos), which have been suggested to serve a key role in mediating a wide variety of MSC activities. Through cell-cell communication, MSC-Exos have been shown to alter recipient cell phenotype or function and play as a novel cell-free alternative for MSC-based cell therapy. However, MSC recruitment to tumors allows for their interaction with cancer cells and subsequent regulation of tumor behavior. MSC-Exos act as tumor niche modulators via transferring exosomal contents, such as specific proteins or genetic materials, to the nearby cancer cells, leading to either promotion or suppression of tumorigenesis, angiogenesis, and metastasis, depending on the specific microenvironmental cues and recipient cell characteristics. Consequently, there is still a debate about the precise relationship between tumor cells and MSC-Exos, and it is unclear how MSC-Exos impacts tumor cells. Although the dysregulation of miRNAs is caused by the progression of cancer, they also play a direct role in either promoting or inhibiting tumor growth as they act as either oncogenes or tumor suppressors. The utilization of MSC-Exos may prove to be an effective method for restoring miRNA as a means of treating cancer. This review aimed to present the existing understanding of the impact that MSC-Exos could have on cancer. To begin with, we presented a brief explanation of exosomes, MSCs, and MSC-Exos. Following this, we delved into the impact of MSC-Exos on cancer growth, EMT, metastasis, angiogenesis, resistance to chemotherapy and radiotherapy, and modulation of the immune system. Opposing effects of mesenchymal stem cells-derived exosomes on cancer cells.

Truncated vitronectin with E-cadherin enables the xeno-free derivation of human embryonic stem cells

Human embryonic stem cells (hESCs) have unique abilities that enable their use in cell therapy, disease modeling, and drug development. Their derivation is usually performed using a feeder layer, which is undefined and can potentially cause a contamination by xeno components, therefore there is a tendency to replace feeders with xeno-free defined substrates in recent years. Three hESC lines were successfully derived on the vitronectin with a truncated N-terminus (VTN-N) in combination with E-cadherin in xeno-free conditions for the first time, and their undifferentiated state, hESC morphology, and standard karyotypes together with their potential to differentiate into three germ layers were confirmed. These results support the conclusion that the VTN-N/E-cadherin is a suitable substrate for the xeno-free derivation of hESCs and can be used for the derivation of hESCs according to good manufacturing practices.

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.

Different priming strategies improve distinct therapeutic capabilities of mesenchymal stromal/stem cells: Potential implications for their clinical use

Mesenchymal stromal/stem cells (MSCs) have shown significant therapeutic potential, and have therefore been extensively investigated in preclinical studies of regenerative medicine. However, while MSCs have been shown to be safe as a cellular treatment, they have usually been therapeutically ineffective in human diseases. In fact, in many clinical trials it has been shown that MSCs have moderate or poor efficacy. This inefficacy appears to be ascribable primarily to the heterogeneity of MSCs. Recently, specific priming strategies have been used to improve the therapeutic properties of MSCs. In this review, we explore the literature on the principal priming approaches used to enhance the preclinical inefficacy of MSCs. We found that different priming strategies have been used to direct the therapeutic effects of MSCs toward specific pathological processes. Particularly, while hypoxic priming can be used primarily for the treatment of acute diseases, inflammatory cytokines can be used mainly to prime MSCs in order to treat chronic immune-related disorders. The shift in approach from regeneration to inflammation implies, in MSCs, a shift in the production of functional factors that stimulate regenerative or anti-inflammatory pathways. The opportunity to fine-tune the therapeutic properties of MSCs through different priming strategies could conceivably pave the way for optimizing their therapeutic potential.

Banking of perinatal mesenchymal stem/stromal cells for stem cell-based personalized medicine over lifetime: Matters arising

Mesenchymal stromal/stem cells (MSCs) are currently applied in regenerative medicine and tissue engineering. Numerous clinical studies have indicated that MSCs from different tissue sources can provide therapeutic benefits for patients. MSCs derived from either human adult or perinatal tissues have their own unique advantages in their medical practices. Usually, clinical studies are conducted by using of cultured MSCs after thawing or short-term cryopreserved-then-thawed MSCs prior to administration for the treatment of a wide range of diseases and medical disorders. Currently, cryogenically banking perinatal MSCs for potential personalized medicine for later use in lifetime has raised growing interest in China as well as in many other countries. Meanwhile, this has led to questions regarding the availability, stability, consistency, multipotency, and therapeutic efficiency of the potential perinatal MSC-derived therapeutic products after long-term cryostorage. This opinion review does not minimize any therapeutic benefit of perinatal MSCs in many diseases after short-term cryopreservation. This article mainly describes what is known about banking perinatal MSCs in China and, importantly, it is to recognize the limitation and uncertainty of the perinatal MSCs stored in cryobanks for stem cell medical treatments in whole life. This article also provides several recommendations for banking of perinatal MSCs for potentially future personalized medicine, albeit it is impossible to anticipate whether the donor will benefit from banked MSCs during her/his lifetime.

Mesenchymal stem cells in ischemic tissue regeneration

Diseases caused by ischemia are one of the leading causes of death in the world. Current therapies for treating acute myocardial infarction, ischemic stroke, and critical limb ischemia do not complete recovery. Regenerative therapies opens new therapeutic strategy in the treatment of ischemic disorders. Mesenchymal stem cells (MSCs) are the most promising option in the field of cell-based therapies, due to their secretory and immunomodulatory abilities, that contribute to ease inflammation and promote the regeneration of damaged tissues. This review presents the current knowledge of the mechanisms of action of MSCs and their therapeutic effects in the treatment of ischemic diseases, described on the basis of data from in vitro experiments and preclinical animal studies, and also summarize the effects of using these cells in clinical trial settings. Since the obtained therapeutic benefits are not always satisfactory, approaches aimed at enhancing the effect of MSCs in regenerative therapies are presented at the end.

Mechanism of Mesenchymal Stem Cells as a Multitarget Disease- Modifying Therapy for Parkinson's Disease

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders, affecting the basal nuclei, causing impairment of motor and cognitive functions. Loss of dopaminergic (DAergic) neurons or their degeneration and the aggregation of Lewy bodies is the hallmark of this disease. The medications used to treat PD relieve the symptoms and maintain quality of life, but currently, there is no cure. There is a need for the development of therapies that can cease or perhaps reverse neurodegeneration effectively. With the rapid advancements in cell replacement therapy techniques, medical professionals are trying to find a cure by which restoration of dopamine neurotransmitters can occur. Researchers have started focusing on cell-based therapies using mesenchymal stem cells (MSCs) due to their abundance in the body, the ability of proliferation, and immunomodulation. Here we review the MSC-based treatment in Parkinson's disease and the various mechanisms it repairs DAergic neurons in parkinsonian patients.

Mesenchymal stem cell-derived exosomes as a new therapeutic strategy in the brain tumors

Brain tumors are one of the most mortal cancers, leading to many deaths among kids and adults. Surgery, chemotherapy, and radiotherapy are available options for brain tumor treatment. However, these methods are not able to eradicate cancer cells. The blood-brain barrier (BBB) is one of the most important barriers to treat brain tumors that prevents adequate drug delivery to brain tissue. The connection between different brain parts is heterogeneous and causes many challenges in treatment. Mesenchymal stem cells (MSCs) migrate to brain tumor cells and have anti-tumor effects by delivering cytotoxic compounds. They contain very high regenerative properties, as well as support the immune system. MSCs-based therapy involves cell replacement and releases various vesicles, including exosomes. Exosomes receive more attention due to their excellent stability, less immunogenicity and toxicity compare to cells. Exosomes derived from MSCs can develop a powerful therapeutic strategy for different diseases and be a hopeful candidate for cell-based and cell-free regenerative medicine. These nanoparticles contain nucleic acid, proteins, lipids, microRNAs, and other biologically active substances. Many studies show that each microRNA can prevent angiogenesis, migration, and metastasis in glioblastoma. These exosomes can-act as a suitable nanoparticle carrier for therapeutic applications of brain tumors by passing through the BBB. In this review, we discuss potential applications of MSC and their produced exosomes in the treatment of brain tumors.

Changes in the Transcriptome Profiles of Human Amnion-Derived Mesenchymal Stromal/Stem Cells Induced by Three-Dimensional Culture: A Potential Priming Strategy to Improve Their Properties

Mesenchymal stromal/stem cells (MSCs) are believed to function in vivo as a homeostatic tool that shows therapeutic properties for tissue repair/regeneration. Conventionally, these cells are expanded in two-dimensional (2D) cultures, and, in that case, MSCs undergo genotypic/phenotypic changes resulting in a loss of their therapeutic capabilities. Moreover, several clinical trials using MSCs have shown controversial results with moderate/insufficient therapeutic responses. Different priming methods were tested to improve MSC effects, and three-dimensional (3D) culturing techniques were also examined. MSC spheroids display increased therapeutic properties, and, in this context, it is crucial to understand molecular changes underlying spheroid generation. To address these limitations, we performed RNA-seq on human amnion-derived MSCs (hAMSCs) cultured in both 2D and 3D conditions and examined the transcriptome changes associated with hAMSC spheroid formation. We found a large number of 3D culture-sensitive genes and identified selected genes related to 3D hAMSC therapeutic effects. In particular, we observed that these genes can regulate proliferation/differentiation, as well as immunomodulatory and angiogenic processes. We validated RNA-seq results by qRT-PCR and methylome analysis and investigation of secreted factors. Overall, our results showed that hAMSC spheroid culture represents a promising approach to cell-based therapy that could significantly impact hAMSC application in the field of regenerative medicine.

In vitro effects of conditioned medium from bioreactor cultured human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on skin-derived cell lines

Introduction

When stem cells are grafted into tissues, they differentiate and form specialized cells. However, the proficiency of stem cells to endure and assimilate the host cell is dependent on various growth factors and cytokines. According to various studies, these factors are available in the spent media of harvested stem cells, which can be used for treatment in regenerative medicine and cosmetic products. There are differences in cytokine secretion depending on the culture environment, which are clarified in this paper.

Methods

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) were cultured either in a bioreactor or in a flask. The conditioned medium from the hUC-MSC cultures in the flask and in the bioreactor was designated as “FM” and “BM”, respectively. We assessed the effects of FM and BM on UVB-induced oxidative stress, anti-aging, and melanogenic properties. The amount of growth factors, cell viability, hyaluronic acid (HA), pro-collagen, and pro-melanin were quantitatively evaluated in the FM and BM treated groups. The induction of HA and collagen synthesis was measured in CCD-986SK cells. For melanogenesis, the effects of FM and BM on melanin content and tyrosinase activity were measured in SK-MEL-31 cells.

Results

In the present study, the secretion of growth factors, HA, and pro-collagen was significantly higher in the BM treatment, compared to that in the FM treatment. BM protected CCD-986SK cells against death from UVB induced oxidative stress. BM increased the promoter activity of the anti-oxidant genes SOD1, CAT, and GP; and downregulated the accelerating collagen decomposition gene, MMP-1, induced by UVB irradiation. In α-melanocyte-stimulating hormone (α-MSH) stimulated SK-MEL-31 cells, BM reduced melanin production and decreased the levels of MITF, tyrosinase, TRP-1, and TRP-2. These results suggest that BM could be used as a skin protection agent, because of its anti-apoptotic, anti-aging, and anti-melanogenic properties. This could be attributed to the differences in culturing methods; it is difficult to maintain the temperature and sterility in FM culture, when compared to that in the automated culturing conditions of the BM system.

Conclusions

Collectively, our results indicate that using BM-conditioned hUC-MSC medium is very efficient process for producing raw materials for developing functional cosmetics.

Engineered basic fibroblast growth factor-overexpressing human umbilical cord-derived mesenchymal stem cells improve the proliferation and neuronal differentiation of endogenous neural stem cells and functional recovery of spinal cord injury by activating the PI3K-Akt-GSK-3β signaling pathway

Objectives

To investigate the safety for clinic use and therapeutic effects of basic fibroblast growth factor (bFGF)-overexpressing human umbilical cord-derived mesenchymal stem cells (HUCMSCs) in mice with completely transected spinal cord injury (SCI).

Methods

Stable bFGF-overexpressing HUCMSCs clones were established by electrotransfection and then subjected to systematic safety evaluations. Then, bFGF-overexpressing and control HUCMSCs were used to treat mice with completely transected SCI by tail intravenous injection. Therapeutic outcomes were then investigated, including functional recovery of locomotion, histological structures, nerve regeneration, and recovery mechanisms.

Results

Stable bFGF-overexpressing HUCMSCs met the standards and safety of MSCs for clinic use. In the mouse SCI model, stable bFGF-overexpressing HUCMSCs markedly improved therapeutic outcomes such as reducing glial scar formation, improving nerve regeneration and proliferation of endogenous neural stem cells (NSCs), and increasing locomotion functional recovery of posterior limbs compared with the control HUCMSCs group. Furthermore, bFGF-overexpressing HUCMSCs promoted the proliferation and neuronal differentiation of NSCs in vitro through the PI3K-Akt-GSK-3β pathway.

Conclusion

bFGF-overexpressing HUCMSCs meet the requirements of clinical MSCs and improve evident therapeutic outcomes of mouse SCI treatment, which firmly supports the safety and efficacy of gene-modified MSCs for clinical application.

Therapeutic Properties of Mesenchymal Stromal/Stem Cells: The Need of Cell Priming for Cell-Free Therapies in Regenerative Medicine

Mesenchymal stromal/stem cells (MSCs) are multipotent adult stem cells that support homeostasis during tissue regeneration. In the last decade, cell therapies based on the use of MSCs have emerged as a promising strategy in the field of regenerative medicine. Although these cells possess robust therapeutic properties that can be applied in the treatment of different diseases, variables in preclinical and clinical trials lead to inconsistent outcomes. MSC therapeutic effects result from the secretion of bioactive molecules affected by either local microenvironment or MSC culture conditions. Hence, MSC paracrine action is currently being explored in several clinical settings either using a conditioned medium (CM) or MSC-derived exosomes (EXOs), where these products modulate tissue responses in different types of injuries. In this scenario, MSC paracrine mechanisms provide a promising framework for enhancing MSC therapeutic benefits, where the composition of secretome can be modulated by priming of the MSCs. In this review, we examine the literature on the priming of MSCs as a tool to enhance their therapeutic properties applicable to the main processes involved in tissue regeneration, including the reduction of fibrosis, the immunomodulation, the stimulation of angiogenesis, and the stimulation of resident progenitor cells, thereby providing new insights for the therapeutic use of MSCs-derived products.

Conditioned Medium from Human Amnion-Derived Mesenchymal Stromal/Stem Cells Attenuating the Effects of Cold Ischemia-Reperfusion Injury in an In Vitro Model Using Human Alveolar Epithelial Cells

The clinical results of lung transplantation (LTx) are still less favorable than other solid organ transplants in both the early and long term. The fragility of the lungs limits the procurement rate and can favor the occurrence of ischemia-reperfusion injury (IRI). Ex vivo lung perfusion (EVLP) with Steen Solution^TM (SS) aims to address problems, and the implementation of EVLP to alleviate the activation of IRI-mediated processes has been achieved using mesenchymal stromal/stem cell (MSC)-based treatments. In this study, we investigated the paracrine effects of human amnion-derived MSCs (hAMSCs) in an in vitro model of lung IRI that includes cold ischemia and normothermic EVLP. We found that SS enriched by a hAMSC-conditioned medium (hAMSC-CM) preserved the viability and delayed the apoptosis of alveolar epithelial cells (A549) through the downregulation of inflammatory factors and the upregulation of antiapoptotic factors. These effects were more evident using the CM of 3D hAMSC cultures, which contained an increased amount of immunosuppressive and growth factors compared to both 2D cultures and encapsulated-hAMSCs. To conclude, we demonstrated an in vitro model of lung IRI and provided evidence that a hAMSC-CM attenuated IRI effects by improving the efficacy of EVLP, leading to strategies for a potential implementation of this technique.