Therapeutic Potential of Wharton's Jelly Mesenchymal Stem Cells for Diabetes: Achievements and Challenges

Harnessing the ubiquitin proteasome system as a key player in stem cell biology

Intracellular proteins take part in almost every body function; thus, protein homeostasis is of utmost importance. The ubiquitin proteasome system (UPS) has a fundamental role in protein homeostasis. Its main role is to selectively eradicate impaired or misfolded proteins, thus halting any damage that could arise from the accumulation of these malfunctioning proteins. Proteasomes have a critical role in controlling protein homeostasis in all cell types, including stem cells. We will discuss the role of UPS enzymes as well as the 26S proteasome complex in stem cell biology from several angles. First, we shall overview common trends of proteasomal activity and gene expression of different proteasomal subunits and UPS enzymes upon passaging and differentiation of stem cells toward various cell lineages. Second, we shall explore the effect of modulating proteasomal activity in stem cells and navigate through the interrelation between proteasomes' activity and various proteasome-related transcription factors. Third, we will shed light on curated microRNAs and long non-coding RNAs using various bioinformatics tools that might have a possible role in regulating UPS in stem cells and possibly, upon manipulation, can enhance the differentiation process into different lineages and/or delay senescence upon cell passaging. This will help to decipher the role played by individual UPS enzymes and subunits as well as various interrelated molecular mediators in stem cells' maintenance and/or differentiation and open new avenues in stem cell research. This can ultimately provide a leap toward developing novel therapeutic interventions related to proteasome dysregulation.

Wharton's Jelly Mesenchymal Stem Cell Conditioned Medium Ameliorates Diabetes-Induced Testicular Damage and Sperm Abnormalities by Mitigating Oxidative Stress, Apoptosis, and Inflammation

Diabetes leads to testicular damage and infertility. Mesenchymal stem cells and their secretory trophic factors have shown potential as regenerative therapies for diabetes and its associated complications. This study examined the effects of conditioned medium derived from Wharton's jelly mesenchymal stem cells (WJMSCs-CM) on sperm parameters, reproductive hormones, biochemical parameters, and histological changes in the testes of diabetic rats. Fifty-six male Sprague-Dawley rats (250-300 g) were assigned to eight groups: control, diabetes, and six diabetic groups receiving early or late treatments with WJMSCs-CM (D-CME, D-CML), insulin (D-INSE, D-INSL), or DMEM (D-DME, D-DML). In the early treatment groups, insulin (3 U/day, subcutaneously) and WJMSCs-CM (10 mg/week, intraperitoneally) were administered immediately after diabetes induction; in the late treatment groups, these interventions began 30 days postinduction. Blood glucose and insulin levels, along with sperm parameters, were assessed. Sex hormones, testicular antioxidant enzyme activity, malondialdehyde (MDA), and glutathione (GSH) concentrations were measured using colorimetric methods. Real-time PCR detected Bax, Bcl-2, and tumor necrosis factor-alpha (TNF-α) gene expression. Our results showed that diabetes increased blood glucose levels, decreased insulin and sex hormone levels, induced testicular oxidative stress and apoptosis, and reduced sperm parameters compared to the control. WJMSCs-CM significantly ameliorated hyperglycemia, increased insulin and sex hormone levels, and improved sperm quality. In WJMSCs-CM-treated diabetic rats, MDA levels were reduced, while GSH and antioxidant enzyme activity increased. Furthermore, WJMSCs-CM decreased the testicular Bax/Bcl-2 ratio and TNF-α expression, as well as enhanced spermatogenic, Sertoli, and Leydig cells. In conclusion, WJMSC-CM administration effectively mitigated diabetes-induced testicular damage by reducing oxidative stress, inflammation, and apoptosis. Early treatment with WJMSCs-CM was more effective than late treatment for diabetes-induced reproductive dysfunction.

Enhanced anti-tumor efficacy of S3I-201 in breast cancer mouse model through Wharton jelly- exosome

OBJECTIVE

Exosomes, membrane-enveloped vesicles found in various cell types, including Wharton's jelly mesenchymal stem cells, play a crucial role in intercellular communication and regulation. Their use as a cell-free nanotechnology and drug delivery system has attracted attention. Triple-negative breast cancer (TNBC) is a major global health problem and is characterized by a high mortality rate. This study investigates the potential of Wharton's Jelly mesenchymal stem cell-derived exosomes (WJ-Exo) as carriers of S3I-201 and their effects on STAT3 expression in breast cancer cell lines, and evaluates whether these exosomes can enhance the anti-tumor effect of S3I-201.

METHODS

The filtered WJ-Exos were analyzed by Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM), Dynamic Light Scattering (DLS), flow cytometry, and Western blotting. These exosomes were then used for loading with S3I-201, resulting in the nano-formulation WJ-Exo(S3I-201). The effect of WJ-Exo(S3I-201) on 4T1 cancer cells was investigated in vitro using MTT assay, flow cytometry, wound healing assay, Western blotting and Quantitative Real-Time Polymerase chain reaction (qPCR) analysis. Finally, the therapeutic efficacy of the nano-formulation was investigated in vivo using a tumor-bearing mouse model.

RESULTS

In vitro experiments showed that co-incubation of 4T1 cells with the nano-formulation resulted in a significant reduction in p-STAT3 levels, induction of apoptosis, modulation of Bcl-2, Bax and caspase-3 protein and gene expression, and inhibition of migration. In vivo, treatment of tumor-bearing mice with WJ-Exo(S3I-201) showed a strong antitumor effect that exceeded the efficacy observed in the S3I-201 group.

CONCLUSION

Our results demonstrate that WJ-Exo is an effective carrier for targeting S3I-201 to tumor cells and enhances the therapeutic efficacy of S3I-201 in tumor-bearing mice.

Application of mesenchymal stem cells derived from the umbilical cord or Wharton's jelly and their extracellular vesicles in the treatment of various diseases

Mesenchymal stem cells (MSCs) originating from the umbilical cord (UC) or Wharton's jelly (WJ) have attracted substantial interest due to their potential to augment therapeutic approaches for a wide range of disorders. These cells demonstrate a wide range of capabilities in the process of differentiating into a multitude of cell types. Additionally, they possess a significant capacity for proliferation and are conveniently accessible. Furthermore, they possess a status of being immune-privileged, exhibit minimal tumorigenic characteristics, and raise minimal ethical concerns. Consequently, they are well-suited candidates for tissue regeneration and the treatment of diseases. Additionally, UC-derived MSCs offer a substantial yield compared to other sources. The therapeutic effects of these MSCs are closely associated with the release of nanosized extracellular vesicles (EVs), including exosomes and microvesicles (MVs), containing lipids, microRNAs, and proteins that facilitate intercellular communication. Due to their reduced tumorigenic and immunogenic characteristics, in addition to their convenient manipulability, EVs have arisen as a viable alternative for the management of disorders. The favorable characteristics of UC-MSCs or WJ-MSCs and their EVs have generated significant attention in clinical investigations encompassing diverse pathologies. Therefore, we present a review encompassing current preclinical and clinical investigations, examining the implications of UC-MSCs in diverse diseases, including those affecting bone, cartilage, skin, liver, kidney, neural, lung, cardiovascular, muscle, and retinal tissues, as well as conditions like cancer, diabetes, sepsis, and others.

Mesenchymal stromal cells derived from various tissues: Biological, clinical and cryopreservation aspects: Update from 2015 review

Mesenchymal stromal cells (MSCs) have become one of the most investigated and applied cells for cellular therapy and regenerative medicine. In this update of our review published in 2015, we show that studies continue to abound regarding the characterization of MSCs to distinguish them from other similar cell types, the discovery of new tissue sources of MSCs, and the confirmation of their properties and functions that render them suitable as a therapeutic. Because cryopreservation is widely recognized as the only technology that would enable the on-demand availability of MSCs, here we show that although the traditional method of cryopreserving cells by slow cooling in the presence of 10% dimethyl sulfoxide (Me2SO) continues to be used by many, several novel MSC cryopreservation approaches have emerged. As in our previous review, we conclude from these recent reports that viable and functional MSCs from diverse tissues can be recovered after cryopreservation using a variety of cryoprotectants, freezing protocols, storage temperatures, and periods of storage. We also show that for logistical reasons there are now more studies devoted to the cryopreservation of tissues from which MSCs are derived. A new topic included in this review covers the application in COVID-19 of MSCs arising from their immunomodulatory and antiviral properties. Due to the inherent heterogeneity in MSC populations from different sources there is still no standardized procedure for their isolation, identification, functional characterization, cryopreservation, and route of administration, and not likely to be a "one-size-fits-all" approach in their applications in cell-based therapy and regenerative medicine.

Autophagy enhances the differentiation of insulin-producing cells from Wharton's jelly-derived mesenchymal stem cells

Autophagy disruption suppresses insulin production and induces diabetes. The role of autophagy in the differentiation of Wharton's jelly (WJ)-derived mesenchymal stem cells (WJSCs) into insulin-producing cells (IPCs) was investigated in this experimental study. The WJSCs were incubated in a differentiation medium (DM) with or without an autophagy inhibitor (3-methyladenine: 3MA). The differentiation of IPCs was confirmed by flow cytometry analysis of PDX-1 and insulin-positive cells, insulin secretion, and the high expression of β cell-specific genes, Glucose transporter 2 (GLUT-2), and INSULIN. Autophagy has been assessed by calculating the percentage of Acridine orange (AO)-positive cells, expression of autophagy-related genes, and the LC3B/LC3A ratio. β cell-specific genes were up-regulated in the DM group, and 3MA decreased their expression. In the DM+3MA-treated cells, the expression of GLUT-2 and INSULIN genes and insulin secretion decreased compared to the DM group. In cells treated with 3MA, there was a significant decrease in the percentage of PDX-1 and insulin-positive cells compared to 3MA-untreated cells. Additionally, in the group receiving both DM and 3MA treatment, the expression of autophagy-related genes, the LC3B/LC3A protein ratio, and the percentage of AO-stained cells were significantly reduced compared to the group receiving only DM treatment. These findings suggest autophagy is essential for β cell differentiation and insulin secretion.

The effect of diabetes mellitus on differentiation of mesenchymal stem cells into insulin-producing cells

BACKGROUND

Diabetes mellitus (DM) is a global epidemic with increasing incidences. DM is a metabolic disease associated with chronic hyperglycemia. Aside from conventional treatments, there is no clinically approved cure for DM up till now. Differentiating mesenchymal stem cells (MSCs) into insulin-producing cells (IPCs) is a promising approach for curing DM. Our study was conducted to investigate the effect of DM on MSCs differentiation into IPCs in vivo and in vitro.

METHODS

We isolated adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of normal and STZ-induced diabetic Sprague-Dawley male rats. Afterwards, the in vitro differentiation of normal-Ad-MSCs (N-Ad-MSCs) and diabetic-Ad-MSCs (DM-Ad-MSCs) into IPCs was compared morphologically then through determining the gene expression of β-cell markers including neurogenin-3 (Ngn-3), homeobox protein (Nkx6.1), musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), and insulin-1 (Ins-1) and eventually, through performing glucose-stimulated insulin secretion test (GSIS). Finally, the therapeutic potential of N-Ad-MSCs and DM-Ad-MSCs transplantation was compared in vivo in STZ-induced diabetic animals.

RESULTS

Our results showed no significant difference in the characteristics of N-Ad-MSCs and DM-Ad-MSCs. However, we demonstrated a significant difference in their abilities to differentiate into IPCs in vitro morphologically in addition to β-cell markers expression, and functional assessment via GSIS test. Furthermore, the abilities of both Ad-MSCs to control hyperglycemia in diabetic rats in vivo was assessed through measuring fasting blood glucose (FBGs), body weight (BW), histopathological examination of both pancreas and liver and immunoexpression of insulin in pancreata of study groups.

CONCLUSION

Our findings reveal the effectiveness of N-Ad-MSCs in differentiating into IPCs in vitro and controlling the hyperglycemia of STZ-induced diabetic rats in vivo compared to DM-Ad-MSCs.

Silencing of forkhead box protein O-1 (FOXO-1) enhances insulin-producing cell generation from adipose mesenchymal stem cells for diabetes therapy

AIMS

Generation of mature β-cells from MSCs has been a challenge in the field of stem cell therapy of diabetes. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) have made their mark in regenerative medicine, and provide several advantages compared to other MSCs sources. Forkhead box protein O-1 (FOXO-1) is an important transcription factor for normal development of β-cells, yet its over expression in β-cells may cause glucose intolerance. In this study, we isolated, characterized Ad-MSCs from rat epididymal fat pads, differentiated these MSCs into insulin producing cells (IPCs) and studied the role of FOXO-1 in such differentiation.

MATERIALS AND METHODS

We examined the expression of FOXO-1 and its nuclear cytoplasmic localization in the generated IPCs. Afterwards we knocked down FOXO-1 using siRNA targeting FOXO-1 (siFOXO-1). The differentiated siFOXO-1 IPCs were compared to non-targeting siRNA (siNT) IPCs regarding expression of β-cell markers by qRT-PCR and western blotting, dithizone (DTZ) staining and glucose stimulated insulin secretion (GSIS).

KEY FINDINGS

Isolated Ad-MSCs exhibited all characteristics of MSCs and can generate IPCs. FOXO-1 was initially elevated during differentiation followed by a decline towards end of differentiation. FOXO-1 was dephosphorylated and localized to the nucleus upon differentiation into IPCs. Knock down of FOXO-1 improved the expression of β-cell markers in final differentiated IPCs, improved DTZ uptake and showed increased insulin secretion upon challenging with increased glucose concentration.

SIGNIFICANCE

These results portray FOXO-1 as a hindering factor of generation of IPCs whose down-regulation can generate more mature IPCs for MSCs therapy of diabetes mellitus.

The Immunomodulatory effect of exosomes in diabetes: a novel and attractive therapeutic tool in diabetes therapy

Exosomes carry proteins, metabolites, nucleic acids and lipids from their parent cell of origin. They are derived from cells through exocytosis, are ingested by target cells, and can transfer biological signals between local or distant cells. Therefore, exosomes are often modified in reaction to pathological processes, including infection, cancer, cardiovascular diseases and in response to metabolic perturbations such as obesity and diabetes, all of which involve a significant inflammatory aspect. Here, we discuss how immune cell-derived exosomes origin from neutrophils, T lymphocytes, macrophages impact on the immune reprogramming of diabetes and the associated complications. Besides, exosomes derived from stem cells and their immunomodulatory properties and anti-inflammation effect in diabetes are also reviewed. Moreover, As an important addition to previous reviews, we describes promising directions involving engineered exosomes as well as current challenges of clinical applications in diabetic therapy. Further research on exosomes will explore their potential in translational medicine and provide new avenues for the development of effective clinical diagnostics and therapeutic strategies for immunoregulation of diabetes.

Evaluation of the efficacy of mesenchymal stem cells derived conditioned medium in the treatment of striae distensae: a double blind randomized clinical trial

BACKGROUND

Striae distensae is a disfiguring atrophic skin condition that impairs the body's aesthetic image. Despite the variety of conducted studies, there is controversy regarding the best modalities. Human mesenchymal stem cells are considered a rich source for scar treatment. Skin needling is among the most efficient and safe aesthetic and therapeutic devices. This study aimed to evaluate the efficacy of the combination of needling and intradermal injection of mesenchymal stem cells compared to skin needling alone for treating striae distensae.

METHOD

This study was a randomized, double-blind clinical trial involving 10 women aged 18-60. Each striae lesion was divided into two parts, with one side receiving needling and intradermal injection of conditioned medium, while the other side received needling and intradermal injection of normal saline. This treatment was administered in three sessions with three-week intervals. Patients were evaluated before the first intervention and three months after the final session. Three months after the completion of the intervention, patients' lesions were evaluated using biometric criteria, physician evaluation, and patient self-assessment.

RESULTS

The results demonstrated a significant improvement in dermal and complete thickness and skin density in patients treated with microneedling. All skin ultrasound parameters improved significantly in patients receiving the combination of needling and conditioned medium. When comparing the two groups, significantly higher physician and patient satisfaction was observed in the combination group. However, the comparison of biometric indices improvement wasn't significant between these groups.

CONCLUSION

The combination of human mesenchymal stem cells with microneedling could be considered a novel effective option for stretch marks.

Nervonic Acid Inhibits Replicative Senescence of Human Wharton's Jelly-Derived Mesenchymal Stem Cells

Cellular senescence causes cell cycle arrest and promotes permanent cessation of proliferation. Since the senescence of mesenchymal stem cells (MSCs) reduces proliferation and multipotency and increases immunogenicity, aged MSCs are not suitable for cell therapy. Therefore, it is important to inhibit cellular senescence in MSCs. It has recently been reported that metabolites can control aging diseases. Therefore, we aimed to identify novel metabolites that regulate the replicative senescence in MSCs. Using a fecal metabolites library, we identified nervonic acid (NA) as a candidate metabolite for replicative senescence regulation. In replicative senescent MSCs, NA reduced senescence-associated β-galactosidase positive cells, the expression of senescence-related genes, as well as increased stemness and adipogenesis. Moreover, in non-senescent MSCs, NA treatment delayed senescence caused by sequential subculture and promoted proliferation. We confirmed, for the first time, that NA delayed and inhibited cellular senescence. Considering optimal concentration, duration, and timing of drug treatment, NA is a novel potential metabolite that can be used in the development of technologies that regulate cellular senescence.

Stem Cell-Based Tissue Engineering Approaches for Diabetic Foot Ulcer: a Review from Mechanism to Clinical Trial

Diabetic foot ulcer (DFU) is a complication from incomplete or prolonged wound healing, at times requires amputation, putting substantial health and socioeconomic burden. Wound healing is a dynamic overlapping process that can be regulated by arrays of molecular factors showing redundancy in function. However, dysregulation in the mechanism of angiogenesis, extra cellular matrix (ECM) formation and immune modulation are the major causes for impair wound healing in hyperglycaemic patients. Despite development of wound care research, there is a lack of well-accepted targeted therapy with multidisciplinary approach for DFU treatment. Stem cell therapy holds a promising outcome both in preclinical and clinical trials because of its ability to promote healing via regeneration and specialized tissue differentiation. Among different types of stem cells, regenerative potential of mesenchymal stem cell (MSC) is well demonstrated in both experimental and clinical trial. Still there is a huge knowledge gap among medical practitioners for deciding the best stem cell source, administration route, and safety. This review strengthens the fact that why stem cell therapy is a promising candidate to treat DFU and cited multiple tissue engineering and biomaterial-based approaches for delivering stem cells and their aftermath paracrine events. Based on the pre-clinical and clinical studies, the review tried to come up with optimum stem cell source and delivery route for the treatment of DFU. At last, the review glances on possible direction to enhance therapeutics strategy for the same, including different approaches like: phytocompounds, exosomes, scaffold geometry, cell preconditioning and licensing etc.

Ohwia caudata aqueous extract attenuates doxorubicin-induced mitochondrial dysfunction in Wharton's jelly-derived mesenchymal stem cells

Mitochondrial dysfunction has been linked to many diseases, including organ degeneration and cancer. Wharton's jelly-derived mesenchymal stem cells provide a valuable source for stem cell-based therapy and represent an emerging therapeutic approach for tissue regeneration. This study focused on screening the senomorphic properties of Ohwia caudata aqueous extract as an emerging strategy for preventing or treating mitochondrial dysfunction in stem cells. Wharton's jelly-derived mesenchymal stem cells were incubated with 0.1 μM doxorubicin, for 24 h to induce mitochondrial dysfunction. Next, the cells were treated with a series concentration of Ohwia caudata aqueous extract (25, 50, 100, and 200 μg/mL) for another 24 h. In addition, an untreated control group and a doxorubicin-induced mitochondrial dysfunction positive control group were maintained under the same conditions. Our data showed that Ohwia caudata aqueous extract markedly suppressed doxorubicin-induced mitochondrial dysfunction by increasing Tid1 and Tom20 expression, decreased reactive oxygen species production, and maintained mitochondrial membrane potential to promote mitochondrial stability. Ohwia caudata aqueous extract retained the stemness of Wharton's jelly-derived mesenchymal stem cells and reduced the apoptotic rate. These results indicate that Ohwia caudata aqueous extract protects Wharton's jelly-derived mesenchymal stem cells against doxorubicin-induced mitochondrial dysfunction and can potentially prevent mitochondrial dysfunction in other cells. This study provides new directions for the medical application of Ohwia caudata.

Safety evaluation of human umbilical cord-mesenchymal stem cells in type 2 diabetes mellitus treatment: A phase 2 clinical trial

BACKGROUND

Progressive pancreatic β cell dysfunction is a fundamental aspect of the pathology underlying type 2 diabetes mellitus (T2DM). Recently, mesenchymal stem cell (MSC) transplantation has emerged as a new therapeutic method due to its ability to promote the regeneration of pancreatic β cells. However, current studies have focused on its efficacy, and there are few clinical studies on its safety.

AIM

To evaluate the safety of human umbilical cord (hUC)-MSC infusion in T2DM treatment.

METHODS

An open-label and randomized phase 2 clinical trial was designed to evaluate the safety of hUC-MSC transplantation in T2DM in a Class A hospital. Ten patients in the placebo group received acellular saline intravenously once per week for 3 wk. Twenty-four patients in the hUC-MSC group received hUC-MSCs (1 × 106 cells/kg) intravenously once per week for 3 wk. Diabetic clinical symptoms and signs, laboratory findings, and imaging findings were evaluated weekly for the 1st mo and then at weeks 12 and 24 post-treatment.

RESULTS

No serious adverse events were observed during the 24-wk follow-up. Four patients (16.7%) in the hUC-MSC group experienced transient fever, which occurred within 24 h after the second or third infusion; this did not occur in any patients in the placebo group. One patient from the hUC-MSC group experienced hypoglycemic attacks within 1 mo after transplantation. Significantly lower lymphocyte levels (weeks 2 and 3) and thrombin coagulation time (week 2) were observed in the hUC-MSC group compared to those in the placebo group (all P < 0.05). Significantly higher platelet levels (week 3), immunoglobulin levels (weeks 1, 2, 3, and 4), fibrinogen levels (weeks 2 and 3), D-dimer levels (weeks 1, 2, 3, 4, 12, and 24), and neutrophil-to-lymphocyte ratios (weeks 2 and 3) were observed in the hUC-MSC group compared to those in the placebo group (all P < 0.05). There were no significant differences between the two groups for tumor markers (alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 199) or blood fat. No liver damage or other side effects were observed on chest X-ray.

CONCLUSION

Our study suggested that hUC-MSC transplantation has good tolerance and high safety in the treatment of T2DM. It can improve human immunity and inhibit lymphocytes. Coagulation function should be monitored vigilantly for abnormalities.

Wharton's jelly mesenchymal stem cells: a concise review of their secretome and prospective clinical applications

Accumulating evidence indicates that most primary Wharton's jelly mesenchymal stem cells (WJ-MSCs) therapeutic potential is due to their paracrine activity, i.e., their ability to modulate their microenvironment by releasing bioactive molecules and factors collectively known as secretome. These bioactive molecules and factors can either be released directly into the surrounding microenvironment or can be embedded within the membrane-bound extracellular bioactive nano-sized (usually 30-150 nm) messenger particles or vesicles of endosomal origin with specific route of biogenesis, known as exosomes or carried by relatively larger particles (100 nm-1 μm) formed by outward blebbing of plasma membrane called microvesicles (MVs); exosomes and MVs are collectively known as extracellular vesicles (EVs). The bioactive molecules and factors found in secretome are of various types, including cytokines, chemokines, cytoskeletal proteins, integrins, growth factors, angiogenic mediators, hormones, metabolites, and regulatory nucleic acid molecules. As expected, the secretome performs different biological functions, such as immunomodulation, tissue replenishment, cellular homeostasis, besides possessing anti-inflammatory and anti-fibrotic effects. This review highlights the current advances in research on the WJ-MSCs' secretome and its prospective clinical applications.

Human Hematopoietic Stem/Progenitor Cells in Type One Diabetes Mellitus Treatment: Is There an Ideal Candidate?

Type 1 diabetes mellitus (T1DM) is a highly prevalent autoimmune disease causing the destruction of pancreatic islet β-cells. The resulting insulin production deficiency leads to a lifelong need for insulin re-placement therapy, systemic complications, and reduced life quality and expectancy. Cell therapy has been extensively attempted to restore insulin independence (IID), and autologous nonmyeloablative hematopoietic stem cell transplantation (AHST) has appeared to give the most promising results, but with a highly variable quote of patients achieving IID across the studies. We performed a comprehensive review of the trials involving stem cells, and in particular AHST, for the treatment of T1DM. We then pooled the patients enrolled in the different trials and looked for the patient characteristics that could be associated with the achievement of IID. We found a significantly higher probability of achieving IID in older patients (OR 1.17, 95%CI 1.06–1.33, p = 0.002) and a significantly lower probability in patients with a history of ketoacidosis (OR 0.23, 95%CI 0.06–0.78, p = 0.023). This suggests that there could be a population of patients more likely to benefit from AHST, but further data would be required to depict the profile of the ideal candidate.

Cell-binding peptides on the material surface guide stem cell fate of adhesion, proliferation and differentiation

Human cells, especially stem cells, need to communicate and interact with extracellular matrix (ECM) proteins, which not only serve as structural components but also guide and support cell fate and properties such as cell adhesion, proliferation, survival and differentiation. The binding of the cells with ECM proteins or ECM-derived peptides via cell adhesion receptors such as integrins activates several signaling pathways that determine the cell fate, morphological change, proliferation and differentiation. The development of synthetic ECM protein-derived peptides that mimic the biological and biochemical functions of natural ECM proteins will benefit academic and clinical application. Peptides derived from or inspired by specific ECM proteins can act as agonists of each ECM protein receptor. Given that most ECM proteins function in cell adhesion via integrin receptors, many peptides have been developed that bind to specific integrin receptors. In this review, we discuss the peptide sequence, immobilization design, reaction method, and functions of several ECM protein-derived peptides. Various peptide sequences derived from mainly ECM proteins, which are used for coating or grafting on dishes, scaffolds, hydrogels, implants or nanofibers, have been developed to improve the adhesion, proliferation or differentiation of stem cells and to culture differentiated cells. This review article will help to inform the optimal choice of ECM protein-derived peptides for the development of scaffolds, implants, hydrogels, nanofibers and 2D cell culture dishes to regulate the proliferation and direct the differentiation of stem cells into specific lineages.

Tissue engineering approaches and generation of insulin-producing cells to treat type 1 diabetes

Tissue engineering (TE) has become a new effective solution to a variety of medical problems, including diabetes. Mesenchymal stem cells (MSCs), which have the ability to differentiate into endodermal and mesodermal cells, appear to be appropriate for this function. The purpose of this review was to evaluate the outcomes of various researches on the insulin-producing cells (IPCs) generation from MSCs with TE approaches to increase efficacy of type 1 diabetes treatments. The search was performed in PubMed/Medline, Scopus and Embase databases until 2021. Studies revealed that MSCs could also differentiate into IPCs under certain conditions. Therefore, a wide range of protocols have been used for this differentiation, but their effectiveness is very different. Scaffolds can provide a microenvironment that enhances the MSCs to IPCs differentiation, improves their metabolic activity and up-regulate pancreatic-specific transcription factors. They also preserve IPCs architecture and enhance insulin production as well as protect against cell death. This systematic review offers a framework for prospective research based on data. In vitro and in vivo evidence suggests that scaffold-based TE can improve the viability and function of IPCs.

Perinatal Stem Cell Therapy to Treat Type 1 Diabetes Mellitus: A Never-Say-Die Story of Differentiation and Immunomodulation

Human term placenta and other postpartum-derived biological tissues are promising sources of perinatal cells with unique stem cell properties. Among the massive current research on stem cells, one medical focus on easily available stem cells is to exploit them in the design of immunotherapy protocols, in particular for the treatment of chronic non-curable human diseases. Type 1 diabetes is characterized by autoimmune destruction of pancreatic beta cells and perinatal cells can be harnessed both to generate insulin-producing cells for beta cell replenishment and to regulate autoimmune mechanisms via immunomodulation capacity. In this study, the strong points of cells derived from amniotic epithelial cells and from umbilical cord matrix are outlined and their potential for supporting cell therapy development. From a basic research and expert stem cell point of view, the aim of this review is to summarize information regarding the regenerative medicine field, as well as describe the state of the art on possible cell therapy approaches for diabetes.

New therapeutic approaches for type 1 diabetes: Disease-modifying therapies

It has been 100 years since the first successful clinical use of insulin, yet it remains the only treatment option for type 1 diabetes mellitus (T1DM) patients. Advances in diabetes care, such as insulin analogue therapies and new devices, including continuous glucose monitoring with continuous subcutaneous insulin infusion have improved the quality of life of patients but have no impact on the pathogenesis of the disease. They do not eliminate long-term complications and require several lifestyle sacrifices. A more ideal future therapy for T1DM, instead of supplementing the insufficient hormone production (a consequence of β-cell destruction), would also aim to stop or slow down the destructive autoimmune process. The discovery of the autoimmune nature of type 1 diabetes mellitus has presented several targets by which disease progression may be altered. The goal of disease-modifying therapies is to target autoimmune mechanisms and prevent β-cell destruction. T1DM patients with better β-cell function have better glycemic control, reduced incidence of long-term complications and hypoglycemic episodes. Unfortunately, at the time symptomatic T1DM is diagnosed, most of the insulin secreting β cells are usually lost. Therefore, to maximize the salvageable β-cell mass by disease-modifying therapies, detecting autoimmune markers in an early, optimally presymptomatic phase of T1DM is of great importance. Disease-modifying therapies, such as immuno- and regenerative therapies are expected to take a relevant place in diabetology. The aim of this article was to provide a brief insight into the pathogenesis and course of T1DM and present the current state of disease-modifying therapeutic interventions that may impact future diabetes treatment.

Effectiveness and safety of human umbilical cord-mesenchymal stem cells for treating type 2 diabetes mellitus

BACKGROUND

Progressive pancreatic β-cell dysfunction is a fundamental part of the pathology of type 2 diabetes mellitus (T2DM). Cellular therapies offer novel opportunities for the treatment of T2DM to improve the function of islet β-cells.

AIM

To evaluate the effectiveness and safety of human umbilical cord-mesenchymal stem cell (hUC-MSC) infusion in T2DM treatment.

METHODS

Sixteen patients were enrolled and received 1 × 10⁶ cells/kg per week for 3 wk as intravenous hUC-MSC infusion. The effectiveness was evaluated by assessing fasting blood glucose, C-peptide, normal glycosylated hemoglobin A1c (HbA1c), insulin resistance index (homeostatic model assessment for insulin resistance), and islet β-cell function (homeostasis model assessment of β-cell function). The dosage of hypoglycemic agents and safety were evaluated by monitoring the occurrence of any adverse events (AEs).

RESULTS

During the entire intervention period, the fasting plasma glucose level was significantly reduced [baseline: 9.3400 (8.3575, 11.7725), day 14 ± 3: 6.5200 (5.2200, 8.6900); P < 0.01]. The HbA1c level was significantly reduced on day 84 ± 3 [baseline: 7.8000 (7.5250, 8.6750), day 84 ± 3: 7.150 (6.600, 7.925); P < 0.01]. The patients’ islet β-cell function was significantly improved on day 28 ± 3 of intervention [baseline: 29.90 (16.43, 37.40), day 28 ± 3: 40.97 (19.27, 56.36); P < 0.01]. The dosage of hypoglycemic agents was reduced in all patients, of whom 6 (50%) had a decrement of more than 50% and 1 (6.25%) discontinued the hypoglycemic agents. Four patients had transient fever, which occurred within 24 h after the second or third infusion. One patient (2.08%) had asymptomatic nocturnal hypoglycemia after infusion on day 28 ± 3. No liver damage or other side effects were reported.

CONCLUSION

The results of this study suggest that hUC-MSC infusion can improve glycemia, restore islet β-cell function, and reduce the dosage of hypoglycemic agents without serious AEs. Thus, hUC-MSC infusion may be a novel option for the treatment of T2DM.

Topical Biological Agents as Adjuncts to Improve Wound Healing in Chronic Diabetic Wounds: A Systematic Review of Clinical Evidence and Future Directions

Diabetes is a leading chronic illness in the modern world and 19-34% develop chronic diabetic foot ulcers (DFUs) in their lifetime, often necessitating amputation. The reduction in tissue growth factors and resulting imbalance between proteolytic enzymes and their inhibitors, along with systemic factors impairing healing appear particularly important in chronic wounds. Growth factors applied topically have thus been suggested to be a non-invasive, safe, and cost-effective adjunct to improve wound healing and prevent complications. Comprehensive database searches of MEDLINE via PubMed, EMBASE, Cochrane, and ClinicalTrials.gov were performed to identify clinical evidence and ongoing trials. The risk of bias analysis included randomized controlled trials (RCTs) was performed using the Cochrane Risk of Bias 2.0 tool. We included randomized controlled trials that compared the use of a topical biologic growth factor-containing regimen to any other regimen. Primary outcomes of interest were time to wound closure, healing rate, and time. Secondary outcomes included the incidence of adverse events such as infection. A total of 41 trials from 1992-2020 were included in this review, with a total recorded 3,112 patients. Platelet-derived growth factors (PDGF) in the form of becaplermin gel are likely to reduce the time of closure, increase the incidence of wound closure, and complete wound healing. Human umbilical cord-related treatments, dehydrated human amnion and chorion allograft (dHACA), and hypothermically stored amniotic membrane (HSAM), consistently increased the rates and incidence of complete ulcer healing while reducing ulcer size and time to complete ulcer healing. Fibroblast growth factor-1 (FGF1) showed only a slight benefit in multiple studies regarding increasing complete ulcer healing rates and incidence while reducing ulcer size and time to complete ulcer healing, with a few studies showing no statistical difference from placebo. Platelet-rich fibrin (PRF) is consistent in reducing the time to complete ulcer healing and increasing wound healing rate but may not reduce ulcer size or increase the incidence of complete ulcer healing. Targeting the wound healing pathway via the extrinsic administration of growth factors is a promising option to augment wound healing in diabetic patients. Growth factors have also shown promise in specific subgroups of patients who are at risk of significantly impaired wound healing such as those with a history of secondary infection and vasculopathy. As diabetes impairs multiple stages of wound healing, combining growth factors in diabetic wound care may prove to be an area of interest. Evidence from this systematic literature review suggests that topical adjuncts probably reduce time to wound closure, reduce healing time, and increase the healing rate in patients with chronic DFUs.

Recovery of Human Embryonic Stem Cells-Derived Neural Progenitors Exposed to Hypoxic-Ischemic-Reperfusion Injury by Indirect Exposure to Wharton's Jelly Mesenchymal Stem Cells Through Phosphatidyl-inositol-3-Kinase Pathway

Increasing evidence suggests that mesenchymal stem cells(MSCs) have beneficial effects in hypoxic ischemic reperfusion injury, but the underlying mechanisms are unclear. Here, we first examined the effect of OGD reperfusion injury on the vulnerability of human NPs derived from human embryonic stem cells (hESCs) with regard to cell survival and oxidative stress. Cellular deregulation was assessed by measuring glutathione levels, basal calcium and intracellular calcium [Ca2+]i response under KCl stimulation, as well as the key parameters of proliferation, glial progenitor marker expression and migration. Next, the influence of WJ-MSCs in recovering these parameters was evaluated, and the role of Phosphatidyl-inositol-3-Kinase(PI3K) pathway in actuating the protective effect was assessed. OGD reperfusion injury induced significant increases in cell death, ROS generation, oxidative stress susceptibility and decreased glutathione levels in NPs, accompanied by rises in basal [Ca2+]i, KCl-induced [Ca2+]i, expression of K+ leak channel(TASK1), and declines in proliferation, migration potential and glial progenitor population. The introduction of WJ-MSCs(after 2 h of reperfusion) through a non-contact method brought about significant improvement in all these cellular parameters as observed after 24hrs, and the PI3K pathway played an important role in the neuroprotection process. Presence of WJ-MSCs increased the expression of survival signals like phosphorylated Akt/Akt and PI3K in the OGD-reperfused NPs. Our data clearly demonstrate for the first time that soluble factors from WJ-MSCs can not only ameliorate survival, proliferation, migration and glial progenitor expression of OGD-reperfused NPs, but also regulate their intracellular Ca2+ response to KCl stimulation and expression of TASK1 through the PI3K pathway.

Topical spray of Wharton's jelly mesenchymal stem cells derived from umbilical cord accelerates diabetic wound healing

BACKGROUND & AIM

Cell-based therapy utilizing mesenchymal stem cells (MSCs) is currently being investigated as a therapeutic agent for chronic wounds. There is no evidence regarding effectiveness of the spray and local transfer of this cellular product in diabetic wound healing. Accordingly, the present study, using clinical, pathological and biometric parameters, investigated the effectiveness of the spray of these cells in the healing of diabetic wounds in rats.

METHODS

Three days after the induction of diabetes (50 mg/kg single dose of streptozotocin) a circular excision was created on the back of rats. Diabetic rats were divided into two groups (n=21): Control and WJ-MSCs group. Sampling of the studied groups was performed on days 7, 14 and 21 after wounding. Histological, ultrasound imaging of dermis and epidermis in the wound area for thickness and density measurement and skin elasticity were evaluated.

RESULTS

Our results on days 7, 14, and 21 after wounding showed that the wound closure, thickness and density of new epidermis and dermis, as well as skin elasticity in healed wound were significantly higher in WJ-MSCs group compared to the Control group.

CONCLUSION

Application of WJ-MSCs suspension spray on the wound area can accelerate healing in diabetic wounds. Our findings may potentially provide a helpful therapeutic strategy for patients with a diabetic wound.

Human Wharton's Jelly Mesenchymal Stem Cells Secretome Inhibits Human SARS-CoV-2 and Avian Infectious Bronchitis Coronaviruses

Human SARS-CoV-2 and avian infectious bronchitis virus (IBV) are highly contagious and deadly coronaviruses, causing devastating respiratory diseases in humans and chickens. The lack of effective therapeutics exacerbates the impact of outbreaks associated with SARS-CoV-2 and IBV infections. Thus, novel drugs or therapeutic agents are highly in demand for controlling viral transmission and disease progression. Mesenchymal stem cells (MSC) secreted factors (secretome) are safe and efficient alternatives to stem cells in MSC-based therapies. This study aimed to investigate the antiviral potentials of human Wharton’s jelly MSC secretome (hWJ-MSC-S) against SARS-CoV-2 and IBV infections in vitro and in ovo. The half-maximal inhibitory concentrations (IC50), cytotoxic concentration (CC50), and selective index (SI) values of hWJ-MSC-S were determined using Vero-E6 cells. The virucidal, anti-adsorption, and anti-replication antiviral mechanisms of hWJ-MSC-S were evaluated. The hWJ-MSC-S significantly inhibited infection of SARS-CoV-2 and IBV, without affecting the viability of cells and embryos. Interestingly, hWJ-MSC-S reduced viral infection by >90%, in vitro. The IC50 and SI of hWJ-MSC secretome against SARS-CoV-2 were 166.6 and 235.29 µg/mL, respectively, while for IBV, IC50 and SI were 439.9 and 89.11 µg/mL, respectively. The virucidal and anti-replication antiviral effects of hWJ-MSC-S were very prominent compared to the anti-adsorption effect. In the in ovo model, hWJ-MSC-S reduced IBV titer by >99%. Liquid chromatography-tandem mass spectrometry (LC/MS-MS) analysis of hWJ-MSC-S revealed a significant enrichment of immunomodulatory and antiviral proteins. Collectively, our results not only uncovered the antiviral potency of hWJ-MSC-S against SARS-CoV-2 and IBV, but also described the mechanism by which hWJ-MSC-S inhibits viral infection. These findings indicate that hWJ-MSC-S could be utilized in future pre-clinical and clinical studies to develop effective therapeutic approaches against human COVID-19 and avian IB respiratory diseases.

Characteristics and regulation of mesenchymal stem cell plasticity by the microenvironment — specific factors involved in the regulation of MSC plasticity

Mesenchymal stem cells (MSCs), multipotent stromal cells, have attracted extensive attention in the field of regenerative medicine and cell therapy due to the capacity of self-renewal, multilineage differentiation, and immune regulation. MSCs have different cellular effects in different diseases, and even have markedly different curative effects with different tissue sources, indicating the plasticity of MSCs. The phenotypes, secreted factors, and proliferative, migratory, differentiating, and immunomodulatory effects of MSCs depend on certain mediators present in their microenvironment. Understanding microenvironmental factors and their internal mechanisms in MSC responses may help in subsequent prediction and improvement of clinical benefits. This review highlighted the recent advances in MSC plasticity in the physiological and pathological microenvironment and multiple microenvironmental factors regulating MSC plasticity. It also highlighted some progress in the underlying molecular mechanisms of MSC remodeling in the microenvironment. It might provide references for the improvement in vitro culture of MSCs, clinical application, and in vivo induction.

Comparative Analysis of the Therapeutic Effects of Amniotic Membrane and Umbilical Cord Derived Mesenchymal Stem Cells for the Treatment of Type 2 Diabetes

Type 2 diabetes mellitus (T2DM), one of the most common carbohydrate metabolism disorders, is characterized by chronic hyperglycemia and insulin resistance (IR), and has become an urgent global health challenge. Mesenchymal stem cells (MSCs) originating from perinatal tissues such as umbilical cord (UC) and amniotic membrane (AM) serve as ideal candidates for the treatment of T2DM due to their great advantages in terms of abundant source, proliferation capacity, immunomodulation and plasticity for insulin-producing cell differentiation. However, the optimally perinatal MSC source to treat T2DM remains elusive. This study aims to compare the therapeutic efficacy of MSCs derived from AM and UC (AMMSCs and UCMSCs) of the same donor in the alleviation of T2DM symptoms and explore the underlying mechanisms. Our results showed that AMMSCs and UCMSCs displayed indistinguishable immunophenotype and multi-lineage differentiation potential, but UCMSCs had a much higher expansion capacity than AMMSCs. Moreover, we uncovered that single-dose intravenous injection of either AMMSCs or UCMSCs could comparably reduce hyperglycemia and improve IR in T2DM db/db mice. Mechanistic investigations revealed that either AMMSC or UCMSC infusion could greatly improve glycolipid metabolism in the liver of db/db mice, which was evidenced by decreased liver to body weight ratio, reduced lipid accumulation, upregulated glycogen synthesis, and increased Akt phosphorylation. Taken together, these data indicate that the same donor-derived AMMSCs and UCMSCs possessed comparable effects and shared a similar hepatoprotective mechanism on the alleviation of T2DM symptoms.

A Robust and Highly Efficient Approach for Isolation of Mesenchymal Stem Cells From Wharton's Jelly for Tissue Repair

Mesenchymal stem cells derived from umbilical cord Wharton's Jelly (WJ-MSCs) are emerging as promising therapeutics for a variety of diseases due to their ability of regeneration and immunomodulation, and their non-tumorigenic and non-immunogenic properties. Although multiple protocols have been developed for WJ-MSC isolation, insufficient cell numbers, heterogeneous cell population, and variations in procedures between different laboratories impede further clinical applications. Here, we compared six widely used WJ-MSC isolation methods regarding cell morphology, yield, purity, proliferation rate, and differentiation potential. Based on these analyses, we identified that the inefficiency of the extracellular matrix digestion results in low cell yield. Thus, we developed a new method called "Mince-Soak-Digest (MSD)" to isolate MSCs from WJ by incorporating a soaking step to facilitate the digestion of the extracellular matrix and release of the cells. Our newly developed method generates significantly higher cell yield (4- to 10-fold higher) than six widely used methods that we tested with high purity and consistency. Importantly, by transplantation of WJ-MSCs to the rat uterus, we repair the endometrial injury and restore the fertility of the rats. In conclusion, our results provide a robust and highly efficient approach for the isolation of WJ-MSCs to restore injured tissue. The higher efficiency of MSD assures the abundance of WJ-MSCs for clinical applications. Furthermore, the reliability of MSD contributes to the standardization of WJ-MSC isolation, which eliminates the discrepancies due to isolation procedures, thus facilitating the evaluation of the efficacy of WJ-MSCs across various human clinical applications.

Bioprinting of Stem Cells in Multimaterial Scaffolds and Their Applications in Bone Tissue Engineering

Bioprinting stem cells into three-dimensional (3D) scaffolds has emerged as a new avenue for regenerative medicine, bone tissue engineering, and biosensor manufacturing in recent years. Mesenchymal stem cells, such as adipose-derived and bone-marrow-derived stem cells, are capable of multipotent differentiation in a 3D culture. The use of different printing methods results in varying effects on the bioprinted stem cells with the appearance of no general adverse effects. Specifically, extrusion, inkjet, and laser-assisted bioprinting are three methods that impact stem cell viability, proliferation, and differentiation potential. Each printing method confers advantages and disadvantages that directly influence cellular behavior. Additionally, the acquisition of 3D bioprinters has become more prominent with innovative technology and affordability. With accessible technology, custom 3D bioprinters with capabilities to print high-performance bioinks are used for biosensor fabrication. Such 3D printed biosensors are used to control conductivity and electrical transmission in physiological environments. Once printed, the scaffolds containing the aforementioned stem cells have a significant impact on cellular behavior and differentiation. Natural polymer hydrogels and natural composites can impact osteogenic differentiation with some inducing chondrogenesis. Further studies have shown enhanced osteogenesis using cell-laden scaffolds in vivo. Furthermore, selective use of biomaterials can directly influence cell fate and the quantity of osteogenesis. This review evaluates the impact of extrusion, inkjet, and laser-assisted bioprinting on adipose-derived and bone-marrow-derived stem cells along with the effect of incorporating these stem cells into natural and composite biomaterials.

Peptide Conjugate on Multilayer Graphene Oxide Film for the Osteogenic Differentiation of Human Wharton's Jelly-Derived Mesenchymal Stem Cells

Graphene oxide (GO) is extensively studied as a template material for mesenchymal stem cell application due to its two-dimensional nature and unique functionalization chemistries. Herein, a new type of peptide-conjugated multilayer graphene oxide (peptide/m-GO film) was fabricated and used as biomaterial for culturing human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs). The characterization of the peptide/m-GO films was performed, and the biocompatibility of the WJ-MSCs on the peptide/m-GO films was investigated. The results demonstrated that the peptide conjugate on the m-GO film did not hamper the normal growth of WJ-MSCs but supported the growth of WJ-MSCs after the 6-day culture period. In addition, the osteogenic differentiation of WJ-MSCs on the peptide/m-GO films was enhanced as compared with the parent m-GO film. Therefore, such peptide-conjugated m-GO films could provide a highly biocompatible and multifunctional 2D material to tailor the potential application of WJ-MSCs in bone tissue regeneration.

The promise(s) of mesenchymal stem cell therapy in averting preclinical diabetes: lessons from in vivo and in vitro model systems

Obesity (Ob) poses a significant risk factor for the onset of metabolic syndrome with associated complications, wherein the Mesenchymal Stem Cell (MSC) therapy shows pre-clinical success. Here, we explore the therapeutic applications of human Placental MSCs (P-MSCs) to address Ob-associated Insulin Resistance (IR) and its complications. In the present study, we show that intramuscular injection of P-MSCs homed more towards the visceral site, restored HOMA-IR and glucose homeostasis in the WNIN/GR-Ob (Ob-T2D) rats. P-MSC therapy was effective in re-establishing the dysregulated cytokines. We report that the P-MSCs activates PI3K-Akt signaling and regulates the Glut4-dependant glucose uptake and its utilization in WNIN/GR-Ob (Ob-T2D) rats compared to its control. Our data reinstates P-MSC treatment's potent application to alleviate IR and restores peripheral blood glucose clearance evidenced in stromal vascular fraction (SVF) derived from white adipose tissue (WAT) of the WNIN/GR-Ob rats. Gaining insights, we show the activation of the PI3K-Akt pathway by P-MSCs both in vivo and in vitro (palmitate primed 3T3-L1 cells) to restore the insulin sensitivity dysregulated adipocytes. Our findings suggest a potent application of P-MSCs in  pre-clinical/Ob-T2D management.

The Effects of Mesenchymal Stem Cell on Colorectal Cancer

Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract with nonobvious early symptoms and late symptoms of anemia, weight loss, and other systemic symptoms. Its morbidity and fatality rate are next only to gastric cancer, esophageal cancer, and primary liver cancer among digestive malignancies. In addition to the conventional surgical intervention, other therapies such as radiotherapy and chemotherapy and new treatment methods such as biologics and microbiological products have been introduced. As a promising cell therapy, mesenchymal stem cell (MSC) has attracted extensive research attention. MSCs are early undifferentiated pluripotent stem cells, which have the common features of stem cells, including self-replication, self-division, self-renewal, and multidirectional differentiation. MSCs come from a wide range of sources and can be extracted from a variety of tissues such as the bone marrow, umbilical cord, and fat. Current studies have shown that MSCs have a variety of biological functions such as immune regulation, tissue damage repair, and therapeutic effects on tumors such as CRC. This review outlines the overview of MSCs and CRC and summarizes the role of MSC application in CRC.

Adipose-derived stromal/stem cells and extracellular vesicles for cancer therapy

INTRODUCTION

Mesenchymal stromal/stem cells (MSCs) hold great perspective for the therapy of a host of diseases due to regenerative and anti-inflammatory properties by differentiation into diverse cell populations, homing to damaged tissue regions, paracrine effects, and release of extracellular vesicles.

AREAS COVERED

This review describes the isolation, characterization, and potential use of MSCs and ADSCs for benign and malignant diseases. The MSCs may be administered as whole cells or in form of their secretome that is held responsible for most of their beneficial effects. A special constituent of the paracrine components are the extracellular vesicles (EVs) that carry a biologically potent cargo of proteins, cytokines, and RNA.

EXPERT OPINION

The applications of MSCs and ADSCs are amply documented and have been investigated in preclinical models and many unregulated and a few controlled trials. Larger numbers of MSCs and ADSCs can be obtained for allogeneic transfer but imply difficulties including perseverance of the cells in vivo and possible differentiation into harmful cell types. MSC-derived cell-free preparations are easier to handle and manufacture for various applications. Especially, with the help of bioreactors, EVs can be obtained in excessive numbers and preloaded or charged with proteins, cytokines, and regulatory RNA specimen to treat inflammatory diseases and cancer.

Mesenchymal Stem Cell-Derived Extracellular Vesicles to the Rescue of Renal Injury

Acute kidney injury (AKI) and chronic kidney disease (CKD) are rising in global prevalence and cause significant morbidity for patients. Current treatments are limited to slowing instead of stabilising or reversing disease progression. In this review, we describe mesenchymal stem cells (MSCs) and their constituents, extracellular vesicles (EVs) as being a novel therapeutic for CKD. MSC-derived EVs (MSC-EVs) are membrane-enclosed particles, including exosomes, which carry genetic information that mimics the phenotype of their cell of origin. MSC-EVs deliver their cargo of mRNA, miRNA, cytokines, and growth factors to target cells as a form of paracrine communication. This genetically reprograms pathophysiological pathways, which are upregulated in renal failure. Since the method of exosome preparation significantly affects the quality and function of MSC-exosomes, this review compares the methodologies for isolating exosomes from MSCs and their role in tissue regeneration. More specifically, it summarises the therapeutic efficacy of MSC-EVs in 60 preclinical animal models of AKI and CKD and the cargo of biomolecules they deliver. MSC-EVs promote tubular proliferation and angiogenesis, and inhibit apoptosis, oxidative stress, inflammation, the epithelial-to-mesenchymal transition, and fibrosis, to alleviate AKI and CKD. By reprogramming these pathophysiological pathways, MSC-EVs can slow or even reverse the progression of AKI to CKD, and therefore offer potential to transform clinical practice.

Mitigation of Sodium Iodate-Induced Cytotoxicity in Retinal Pigment Epithelial Cells in vitro by Transgenic Erythropoietin-Expressing Mesenchymal Stem Cells

Mesenchymal stem cells (MSC) have shown promise in restoring the vision of patients in clinical trials. However, this therapeutic effect is not observed in every treated patient and is possibly due to the inefficacies of cell delivery and high cell death following transplantation. Utilizing erythropoietin can significantly enhance the regenerative properties of MSCs and hence improve retinal neuron survivability in oxidative stress. Hence, this study aimed to investigate the efficacy of conditioned medium (CM) obtained from transgenic human erythropoietin-expressing MSCs (MSC _EPO ) in protecting human retinal pigment epithelial cells from sodium iodate (NaIO₃)-induced cell death. Human MSC and MSC _EPO were first cultured to obtain conditioned media (CM). The IC₅₀ of NaIO₃ in the ARPE-19 culture was then determined by an MTT assay. After that, the efficacy of both MSC-CM and MSC-CM _EPO in ARPE-19 cell survival were compared at 24 and 48 h after NaIO₃ treatment with MTT. The treatment effects on mitochondrial membrane potential was then measured by a JC-1 flow cytometric assay. The MTT results indicated a corresponding increase in cell survivability (5-58%) in the ARPE-19 cell cultures. In comparison to MSC-CM, the use of conditioned medium collected from the MSC-CM _EPO further enhanced the rate of ARPE-19 survivability at 24 h (P < 0.05) and 48 h (P < 0.05) in the presence of NaIO₃. Furthermore, more than 90% were found viable with the JC-1 assay after MSC-CM _EPO treatment, showing a positive implication on the mitochondrial dynamics of ARPE-19. The MSC-CM _EPO provided an enhanced mitigating effect against NaIO₃-induced ARPE-19 cell death over that of MSC-CM alone during the early phase of the treatment, and it may act as a future therapy in treating retinal degenerative diseases.

Immunoregulatory therapy strategies that target cytokine storms in patients with COVID-19 (Review)

A cytokine storm is an uncontrolled, excessive immune response that contributes to the pathogenesis of coronavirus disease 2019 (COVID-19). Viral infections lead to the loss of negative feedback in immune regulation and an abnormal elevation of the levels of multiple cytokines. In COVID-19, this causes diffuse damage to alveolar functions and may culminate in multiple organ dysfunction. Immunoregulatory therapies target the cytokine storms induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, and include monoclonal antibodies, recombinant granulocyte-macrophage colony stimulating factor, interferon, mesenchymal stem cell-based therapy, thymosin, immunoglobulins and blood purification therapies. These approaches may be effective in the alleviation of COVID-19 symptoms. In this review, cytokine storms caused by SARS-CoV-2 infections are evaluated and discussed, and advances in immunoregulatory therapy strategies for patients with COVID-19 are reviewed.

Mesenchymal Stem Cell-Based Therapy for Diabetes Mellitus: Enhancement Strategies and Future Perspectives

Diabetes mellitus (DM), a chronic disorder of carbohydrate metabolism, is characterized by the unbridled hyperglycemia resulted from the impaired ability of the body to either produce or respond to insulin. As a cell-based regenerative therapy, mesenchymal stem cells (MSCs) hold immense potency for curing DM duo to their easy isolation, multi-differentiation potential, and immunomodulatory property. However, despite the promising efficacy in pre-clinical animal models, naive MSC administration fails to exhibit clinically satisfactory therapeutic outcomes, which varies greatly among individuals with DM. Recently, numbers of innovative strategies have been applied to improve MSC-based therapy. Preconditioning, genetic modification, combination therapy and exosome application are representative strategies to maximize the therapeutic benefits of MSCs. Therefore, in this review, we summarize recent advancements in mechanistic studies of MSCs-based treatment for DM, and mainly focus on the novel approaches aiming to improve the anti-diabetic potentials of naive MSCs. Additionally, the potential directions of MSCs-based therapy for DM are also proposed at a glance.

Effects of the secretome of human Wharton's jelly mesenchymal stem cells on the proliferation and apoptosis gene expression of the retinal pigmented epithelium

Human retinal pigmented epithelium (RPE) can undergo an uncontrolled proliferation in some disorders such as retinal detachment associated with proliferative vitreoretinopathy (PVR). The present study was conducted to evaluate the effect of the conditioned medium secreted by human Wharton's jelly mesenchymal stem cells (WJMSCs-CM) on the proliferation and apoptosis gene expression of the RPE. WJMSCs-CM was collected from WJMSCs after two periods of 24-h and 9-h culture in serum-free medium. RPE cells were cultured in WJMSCs-CM versus serum-deprived media for 24 h. The effect of WJMSCs-CM on RPE cell proliferation was determined using the MTT assay. Relative expression of apoptotic genes (Bcl2, Bax, and IL-1B) was also assessed by real-time PCR. MTT assay demonstrated that RPE cell viability was reduced significantly in WJMSCs-CM treated RPE cells compared to those cultured in serum-deprived medium (64.23 ± 2.44 vs 100.10 ± 5.68; P = 0.006). Moreover, the expression of anti-apoptotic Bcl2 was significantly decreased in WJMSCs-CM compared to serum-deprived medium (0.52 ± 0.06 in WJMSCs-CM vs 1.02 ± 0.2 in serum-free treatment; P = 0.03), while the expression of pro-apoptotic biomarkers of Bax and IL-1B was not significantly different between the two treatments. The represented data showed that WJMSCs-CM can induce apoptosis in RPE cells in vitro through activating apoptosis pathways. This proof-of-the-concept study provides basic evidence for the possible effect of WJMSCs-CM on preventing PVR.

From Mesenchymal Stromal/Stem Cells to Insulin-Producing Cells: Progress and Challenges

Mesenchymal stromal cells (MSCs) are an attractive option for cell therapy for type 1 diabetes mellitus (DM). These cells can be obtained from many sources, but bone marrow and adipose tissue are the most studied. MSCs have distinct advantages since they are nonteratogenic, nonimmunogenic and have immunomodulatory functions. Insulin-producing cells (IPCs) can be generated from MSCs by gene transfection, gene editing or directed differentiation. For directed differentiation, MSCs are usually cultured in a glucose-rich medium with various growth and activation factors. The resulting IPCs can control chemically-induced diabetes in immune-deficient mice. These findings are comparable to those obtained from pluripotent cells. PD-L1 and PD-L2 expression by MSCs is upregulated under inflammatory conditions. Immunomodulation occurs due to the interaction between these ligands and PD-1 receptors on T lymphocytes. If this function is maintained after differentiation, life-long immunosuppression or encapsulation could be avoided. In the clinical setting, two sites can be used for transplantation of IPCs: the subcutaneous tissue and the omentum. A 2-stage procedure is required for the former and a laparoscopic procedure for the latter. For either site, cells should be transplanted within a scaffold, preferably one from fibrin. Several questions remain unanswered. Will the transplanted cells be affected by the antibodies involved in the pathogenesis of type 1 DM? What is the functional longevity of these cells following their transplantation? These issues have to be addressed before clinical translation is attempted. Graphical Abstract Bone marrow MSCs are isolated from the long bone of SD rats. Then they are expanded and through directed differentiation insulin-producing cells are formed. The differentiated cells are loaded onto a collagen scaffold. If one-stage transplantation is planned, a drug delivery system must be incorporated to ensure immediate oxygenation, promote vascularization and provide some growth factors. Some mechanisms involved in the immunomodulatory function of MSCs. These are implemented either by cell to cell contact or by the release of soluble factors. Collectively, these pathways results in an increase in T-regulatory cells.

Therapeutic efficacy of umbilical cord-derived stem cells for diabetes mellitus: a meta-analysis study

BACKGROUND

Stem cell therapy provides great hope for patients with diabetes mellitus (DM). DM is a seriously alarming metabolic disease characterized by hyperglycemia and β cell dysfunction. Efficient novel therapeutic modalities to treat DM are indeed warranted. Stem cells (SC) derived from the umbilical cord specifically provide several advantages and unique characteristics being a readily available non-invasive source, with an additional credit for their banking potential. This meta-analysis study aims to provide a focused assessment for therapeutic efficacy of umbilical cord (UC)-derived SC-transplantation, namely Wharton's jelly mesenchymal stem cells (WJ-MSCs) and umbilical cord blood (UCB) for DM.

METHODS

The clinical efficacy was evaluated based on glycemic control status (reflected on HbA1c%) and β cell function (reflected on C-peptide levels), as well as the daily insulin requirement in diabetic patients after receiving UC-derived SC-transplantation compared to baseline values. Moreover, we assessed these outcome measures in patients who received such intervention compared to those who did not receive it in randomized/non-randomized controlled clinical trials. We employed a random-effects model and standardized mean difference for this meta-analysis.

RESULTS

Eleven eligible clinical studies were included; WJ-MSCs (6 studies; 172 patients including 71 controls) and UCB (5 studies; 74 patients including 15 controls). WJ-MSCs significantly improved HbA1c% (pooled-estimate - 1.085; 95%CI (- 1.513, - 0.657); p < 0.001) and C-peptide levels (pooled-estimate 1.008; 95%CI (0.475, 1.541); p < 0.001), as well as the daily insulin-requirement (pooled-estimate - 2.027; 95%CI (- 3.32, - 0.733); p = 0.002). On the contrary, UCB was found to be uniformly ineffective; HbA1c% (pooled-estimate - 0.091, 95%CI (- 0.454, 0.271); p = 0.622), significantly deteriorated C-peptide levels (pooled-estimate - 0.789; 95%CI (- 1.252, - 0.325); p < 0.001) and daily insulin-requirement (pooled-estimate 0.916; 95%CI (0.247, 1.585); p = 0.007). All these observations remained consistent when we carried out sub-group meta-analysis for T1DM and T2DM and also when we compared patients who received WJ-MSCs or UCB to controls.

CONCLUSIONS

The results of our meta-analysis provide a clear evidence for the superior efficacy of WJ-MSCs over UCB in DM. This sheds lights on the importance to consider banking of WJ-MSCs together with the well-established routine UCB-banking, especially for those with family history of DM. Additionally, further clinical studies are required to investigate therapeutic efficacy of selected/enriched UCB-derived cell populations with immunomodulatory/regenerative potential in DM.

Mesenchymal Stem Cells and Their Extracellular Vesicles: A Potential Game Changer for the COVID-19 Crisis

Corona virus disease 2019 (COVID-19) is a global public health crisis. The high infectivity of the disease even from non-symptomatic infected patients, together with the lack of a definitive cure or preventive measures are all responsible for disease outbreak. The severity of COVID-19 seems to be mostly dependent on the patients' own immune response. The over-activation of the immune system in an attempt to kill the virus, can cause a "cytokine storm" which in turn can induce acute respiratory distress syndrome (ARDS), as well as multi-organ damage, and ultimately may lead to death. Thus, harnessing the immunomodulatory properties of mesenchymal stem cells (MSCs) to ameliorate that cytokine-storm can indeed provide a golden key for the treatment of COVID-19 patients, especially severe cases. In fact, MSCs transplantation can improve the overall outcome of COVID-19 patients via multiple mechanisms; first through their immunomodulatory effects which will help to regulate the infected patient inflammatory response, second via promoting tissue-repair and regeneration, and third through their antifibrotic effects. All these mechanisms will interplay and intervene together to enhance lung-repair and protect various organs from any damage resulting from exaggerated immune-response. A therapeutic modality which provides all these mechanisms undoubtedly hold a strong potential to help COVID-19 patients even those with the worst condition to hopefully survive and recover.

Development and validation of an ultrasensitive LC-MS/MS method for the quantification of cetagliptin in human plasma and its application in a microdose clinical trial

This study established and validated an LC-MS/MS method for the ultrasensitive determination of cetagliptin in human plasma. Sample pretreatment was achieved by liquid-liquid extraction with ethyl acetate, and chromatographic separation was performed on an XB-C₁₈ analytical column (50 × 2.1 mm, 5 μm) with gradient elution (0.1% formic acid in acetonitrile and 0.1% formic acid) at a flow rate of 1.0 mL/min. For mass spectrometric detection, multiple reaction monitoring was used, and the ion transitions monitored were m/z 421.2-86.0 for cetagliptin and m/z 424.2-88.0 for cetagliptin-d3. Method validation was performed according to the U.S. Food and Drug Administration Bioanalytical Method Validation Guidance, for which the calibration curve was linear in the range of 50.0-2000 pg/mL. All of the other results, such as selectivity, lower limit of quantitation, precision, accuracy, matrix effect, recovery, and stability, met the acceptance criteria. The validated method was successfully applied in a microdose clinical trial to systematically investigate the pharmacokinetic profile of cetagliptin in healthy subjects. Both rapid absorption and prolonged duration demonstrate the potential value of cetagliptin for diabetes treatment.

Efficacy of Fe3O4@polydopamine nanoparticle-labeled human umbilical cord Wharton's jelly-derived mesenchymal stem cells in the treatment of streptozotocin-induced diabetes in rats

Diabetes mellitus (DM) is characterized by the irreversible destruction of insulin-secreting pancreatic β-islet cells and requires life-long exogenous insulin therapy. Umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) have been shown to improve islet function in animal models of diabetes. However, inadequate MSC homing to injured sites has limited their efficacy. Since efficient cell therapy heavily relies on appropriate homing to target tissues, increasing the specificity to the target organ and the extent of homing of the injected WJ-MSCs is paramount to successful clinical outcomes. Therefore, in this study, we synthesized Fe₃O₄@polydopamine nanoparticle (NP)-labeled MSCs and evaluated their therapeutic efficacy in a clinically relevant rat model of streptozotocin-induced diabetes using an external magnetic field. We found that NPs were successfully incorporated into WJ-MSCs and did not negatively affect stem cell properties. Magnetic targeting of WJ-MSCs contributed to long-term cell retention in pancreatic tissue and improved the islet function of diabetic rats, compared to injection of WJ-MSC alone. In addition, anti-inflammatory effects and the anti-apoptotic capacity of WJ-MSCs appeared to play a major role in the functional and structural recovery of the pancreas. Thus, therapy relying on the magnetic targeting of WJ-MSCs may serve as an effective approach for DM treatment.

Limited Potential or Unfavorable Manipulations? Strategies Toward Efficient Mesenchymal Stem/Stromal Cell Applications

Despite almost 50 years of research and over 20 years of preclinical and clinical studies, the question of curative potential of mesenchymal stem/stromal cells (MSCs) is still widely discussed in the scientific community. Non-reproducible treatment outcomes or even absence of treatment effects in comparison to control groups challenges the potential of these cells for routine application both in tissue engineering and in regenerative medicine. One of the reasons of such outcomes is non-standardized and often disadvantageous ex vivo manipulation of MSCs prior therapy. In most cases, clinically relevant cell numbers for MSC-based therapies can be only obtained by in vitro expansion of isolated cells. In this mini review, we will discuss point by point possible pitfalls in the production of human MSCs for cell therapies, without consideration of material-based applications. Starting with cell source, choice of donor and recipient, as well as isolation methods, we will then discuss existing expansion protocols (two-/three-dimensional cultivation, basal medium, medium supplements, static/dynamic conditions, and hypoxic/normoxic conditions) and influence of these strategies on the cell functionality after implantation. The role of potency assays will also be addressed. The final aim of this mini review is to illustrate the heterogeneity of current strategies for gaining MSCs for clinical applications with their strengths and weaknesses. Only a careful consideration and standardization of all pretreatment processes/methods for the different applications of MSCs will ensure robust and reproducible performance of these cell populations in the different experimental and clinical settings.

Cellular Senescence as the Pathogenic Hub of Diabetes-Related Wound Chronicity

Diabetes is constantly increasing at a rate that outpaces genetic variation and approaches to pandemic magnitude. Skin cells physiology and the cutaneous healing response are progressively undermined in diabetes which predisposes to lower limb ulceration, recidivism, and subsequent lower extremities amputation as a frightened complication. The molecular operators whereby diabetes reduces tissues resilience and hampers the repair mechanisms remain elusive. We have accrued the notion that diabetic environment embraces preconditioning factors that definitively propel premature cellular senescence, and that ulcer cells senescence impair the healing response. Hyperglycemia/oxidative stress/mitochondrial and DNA damage may act as major drivers sculpturing the senescent phenotype. We review here historical and recent evidences that substantiate the hypothesis that diabetic foot ulcers healing trajectory, is definitively impinged by a self-expanding and self-perpetuative senescent cells society that drives wound chronicity. This society may be fostered by a diabetic archetypal secretome that induces replicative senescence in dermal fibroblasts, endothelial cells, and keratinocytes. Mesenchymal stem cells are also susceptible to major diabetic senescence drivers, which accounts for the inability of these cells to appropriately assist in diabetics wound healing. Thus, the use of autologous stem cells has not translated in significant clinical outcomes. Novel and multifaceted therapeutic approaches are required to pharmacologically mitigate the diabetic cellular senescence operators and reduce the secondary multi-organs complications. The senescent cells society and its adjunctive secretome could be an ideal local target to manipulate diabetic ulcers and prevent wound chronification and acute recidivism. This futuristic goal demands harnessing the diabetic wound chronicity epigenomic signature.