Immunosuppressive properties of mesenchymal stromal cells derived from amnion, placenta, Wharton's jelly and umbilical cord

Fucoxanthin diminishes oxidative stress damage in human placenta-derived mesenchymal stem cells through the PI3K/Akt/Nrf-2 pathway

Placenta-derived mesenchymal stem cells (PL-MSCs) have therapeutic potential in various clinical contexts due to their regenerative and immunomodulatory properties. However, with increasing age or extensive in vitro culture, their viability and function are gradually lost, thus restricting their therapeutic application. The primary cause of this deterioration is oxidative injury from free radicals. Therefore, enhancing cell viability and restoring cellular repair mechanisms of PL-MSCs in an oxidative stress environment are crucial in this context. Fucoxanthin, a carotenoid derived from brown seaweed, demonstrates antioxidant activity by increasing the production of antioxidant enzymes and lowering the levels of reactive oxygen species (ROS). This study aimed to determine whether fucoxanthin protects PL-MSCs from hydrogen peroxide (H2O2)-induced oxidative stress. After characterization, PL-MSCs were co-treated with fucoxanthin and H2O2 for 24 h (co-treatment) or pre-treated with fucoxanthin for 24 h followed by H2O2 for 24 h (pre-treatment). The effects of fucoxanthin on cell viability and proliferation were examined using an MTT assay. The expression of antioxidant enzymes, PI3K/Akt/Nrf-2 and intracellular ROS production were investigated in fucoxanthin-treated PL-MSCs compared to the untreated group. The gene expression and involvement of specific pathways in the cytoprotective effect of fucoxanthin were investigated by high-throughput NanoString nCounter analysis. The results demonstrated that co-treatment and pre-treatment with fucoxanthin restored the viability and proliferative capacity of PL-MSCs. Fucoxanthin treatment increased the expression of antioxidant enzymes in PL-MSCs cultured under oxidative stress conditions and decreased intracellular ROS accumulation. Markedly, fucoxanthin treatment could restore PI3K/Akt/Nrf-2 expression in H2O2-treated PL-MSCs. High-throughput analysis revealed up-regulation of genes involved in cell survival pathways, including cell cycle and proliferation, DNA damage repair pathways, and down-regulation of genes in apoptosis and autophagy pathways. This study demonstrated that fucoxanthin protects and rescues PL-MSCs from oxidative stress damage through the PI3K/Akt/Nrf-2 pathway. Our data provide the supporting evidence for the use of fucoxanthin as an antioxidant cytoprotective agent to improve the viability and proliferation capacity of PL-MSCs both in vitro and in vivo required to increase the effectiveness of MSC expansion for therapeutic applications.

Electrospun Scaffolds of Polylactic Acid, Collagen, and Amorphous Calcium Phosphate for Bone Repair

Most electrospun scaffolds for bone tissue engineering typically use hydroxyapatite (HA) or beta tricalcium phosphate (β-TCP). However, the biological activity of these crystalline compounds can be limited due to their low solubility. Therefore, amorphous calcium phosphate (ACP) may be an alternative in bone repair scaffolds. This study analyzes the morphology, porosity, mechanical strength, and surface chemistry of electrospun scaffolds composed of polylactic acid and collagen integrated with hydroxyapatite (MHAP) or amorphous calcium phosphate (MACP). In addition, the in vitro biocompatibility, osteogenic differentiation, and growth factor production associated with bone repair using human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) are evaluated. The results show that the electrospun MHAP and MACP scaffolds exhibit a fibrous morphology with interconnected pores. Both scaffolds exhibit favorable biocompatibility and stimulate the proliferation and osteogenesis of hWJ-MSCs. However, cell adhesion and osteocalcin production are greater in the MACP scaffold compared to the MHAP scaffold. In addition, the MACP scaffold shows significant production of bone-repair-related growth factors such as transforming growth factor-beta 1 (TGF-β1), providing a solid basis for its use in bone tissue engineering.

Innovative Approaches and Advances for Hair Follicle Regeneration

Pathological hair loss (also known as alopecia) and shortage of hair follicle (HF) donors have posed an urgent requirement for HF regeneration. With the revelation of mechanisms in tissue engineering, the proliferation of HFs in vitro has achieved more promising trust for the treatments of alopecia and other skin impairments. Theoretically, HF organoids have great potential to develop into native HFs and attachments such as sweat glands after transplantation. However, since the rich extracellular matrix (ECM) deficiency, the induction characteristics of skin-derived cells gradually fade away along with their trichogenic capacity after continuous cell passaging in vitro. Therefore, ECM-mimicking support is an essential prelude before HF transplantation is implemented. This review summarizes the status of providing various epidermal and dermal cells with a three-dimensional (3D) scaffold to support the cell homeostasis and better mimic in vivo environments for the sake of HF regeneration. HF-relevant cells including dermal papilla cells (DPCs), hair follicle stem cells (HFSCs), and mesenchymal stem cells (MSCs) are able to be induced to form HF organoids in the vitro culture system. The niche microenvironment simulated by different forms of biomaterial scaffold can offer the cells a network of ordered growth environment to alleviate inductivity loss and promote the expression of functional proteins. The scaffolds often play the role of ECM substrates and bring about epithelial-mesenchymal interaction (EMI) through coculture to ensure the functional preservation of HF cells during in vitro passage. Functional HF organoids can be formed either before or after transplantation into the dermis layer. Here, we review and emphasize the importance of 3D culture in HF regeneration in vitro. Finally, the latest progress in treatment trials and critical analysis of the properties and benefits of different emerging biomaterials for HF regeneration along with the main challenges and prospects of HF regenerative approaches are discussed.

Osteogenic differentiation and proliferation potentials of human bone marrow and umbilical cord-derived mesenchymal stem cells on the 3D-printed hydroxyapatite scaffolds

Mesenchymal stem cells (MSCs) are a promising candidate for bone repair. However, the maintenance of MSCs injected into the bone injury site remains inefficient. A potential approach is to develop a bone-liked platform that incorporates MSCs into a biocompatible 3D scaffold to facilitate bone grafting into the desired location. Bone tissue engineering is a multistep process that requires optimizing several variables, including the source of cells, osteogenic stimulation factors, and scaffold properties. This study aims to evaluate the proliferation and osteogenic differentiation potentials of MSCs cultured on 2 types of 3D-printed hydroxyapatite, including a 3D-printed HA and biomimetic calcium phosphate-coated 3D-printed HA. MSCs from bone marrow (BM-MSCs) and umbilical cord (UC-MSCs) were cultured on the 3D-printed HA and coated 3D-printed HA. Scanning electron microscopy and immunofluorescence staining were used to examine the characteristics and the attachment of MSCs to the scaffolds. Additionally, the cell proliferation was monitored, and the ability of cells to differentiate into osteoblast was assessed using alkaline phosphatase (ALP) activity and osteogenic gene expression. The BM-MSCs and UC-MSCs attached to a plastic culture plate with a spindle-shaped morphology exhibited an immunophenotype consistent with the characteristics of MSCs. Both MSC types could attach and survive on the 3D-printed HA and coated 3D-printed HA scaffolds. The MSCs cultured on these scaffolds displayed sufficient osteoblastic differentiation capacity, as evidenced by increased ALP activity and the expression of osteogenic genes and proteins compared to the control. Interestingly, MSCs grown on coated 3D-printed HA exhibited a higher ALP activity and osteogenic gene expression than those cultured on the 3D-printed HA. The finding indicated that BM-MSCs and UC-MSCs cultured on the 3D-printed HA and coated 3D-printed HA scaffolds could proliferate and differentiate into osteoblasts. Thus, the HA scaffolds could provide a suitable and favorable environment for the 3D culture of MSCs in bone tissue engineering. Additionally, biomimetic coating with octacalcium phosphate may improve the biocompatibility of the bone regeneration scaffold.

Significance of Placental Mesenchymal Stem Cell in Placenta Development and Implications for Preeclampsia

The well-developed placentation is fundamental for the reproductive pregnancy while the defective placental development is the pathogenetic basis of preeclampsia (PE), a dangerous complication of pregnancy comprising the leading causes of maternal and perinatal morbidity and mortality. Placenta-derived mesenchymal stem cells (PMSCs) are a group of multipotent stem cells that own a potent capacity of differentiating into constitutive cells of vessel walls. Additionally, with the paracrine secretion of various factors, PMSCs inextricably link and interact with other component cells in the placenta, collectively improving the placental vasculature, uterine spiral artery remolding, and uteroplacental interface immunoregulation. Recent studies have further indicated that preeclamptic PMSCs, closely implicated in the abnormal crosstalk between other ambient cells, disturb the homeostasis and development in the placenta. Nevertheless, PMSCs transplantation or PMSCs exosome therapies tend to improve the placental vascular network and trophoblastic functions in the PE model, suggesting PMSCs may be a novel and putative therapeutic strategy for PE. Herein, we provide an overview of the multifaceted contributions of PMSCs in early placental development. Thereinto, the intensive interactions between PMSCs and other component cells in the placenta were particularly highlighted and further extended to the implications in the pathogenesis and therapeutic strategies of PE.

Wharton's jelly-derived stromal cells and their cell therapy applications in allogeneic haematopoietic stem cell transplantation

For decades, mesenchymal stromal cells (MSCs) have been of great interest in the fields of regenerative medicine, tissue engineering and immunomodulation. Their tremendous potential makes it desirable to cryopreserve and bank MSCs to increase their accessibility and availability. Postnatally derived MSCs seem to be of particular interest because they are harvested after delivery without ethical controversy, they have the capacity to expand at a higher rate than adult‐derived MSCs, in which expansion decreases with ageing, and they have demonstrated immunological and haematological supportive properties similar to those of adult‐derived MSCs. In this review, we focus on MSCs obtained from Wharton's jelly (the mucous connective tissue of the umbilical cord between the amniotic epithelium and the umbilical vessels). Wharton's jelly MSCs (WJ‐MSCs) are a good candidate for cellular therapy in haematology, with accumulating data supporting their potential to sustain haematopoietic stem cell engraftment and to modulate alloreactivity such as Graft Versus Host Disease (GVHD). We first present an overview of their in‐vitro properties and the results of preclinical murine models confirming the suitability of WJ‐MSCs for cellular therapy in haematology. Next, we focus on clinical trials and discuss tolerance, efficacy and infusion protocols reported in haematology for GVHD and engraftment.

Injection of Micronized Human Amnion/Chorion Membrane Results in Increased Early Supraspinatus Muscle Regeneration in a Chronic Model of Rotator Cuff Tear

Surgical repair of severe rotator cuff tear often results in retear due to unaddressed muscle degeneration. The objective of this study was to test the regenerative potential of micronized dehydrated Human Amnion/Chorion Membrane (dHACM), in a clinically relevant delayed reattachment model of rotator cuff repair. Micronized dHACM was injected into rat supraspinatus muscle during tendon re-attachment surgery, three weeks after original tendon injury. One week after material injection, inflammatory and mesenchymal stem cell infiltration into supraspinatus muscles was assessed via flow cytometry. Histological methods were utilized to assess structural and regenerative changes in muscle one and three weeks after material injection. Micronized dHACM injection resulted in increased M1-like macrophages (17.1 [Formula: see text] fold change over contralateral controls) and regenerating muscle fibers (4.3% vs 1.7% in saline treated muscles) one week after injection compared to saline treated muscles. Tendon reattachment itself exhibited intrinsic healing in this model, demonstrated by a general return of muscle weight and reduced fibrosis. Our results indicate that injection of micronized dHACM may initiate an inflammatory response in degenerated muscle that promotes early muscle regeneration, and that our animal model may be a suitable platform for studying treatments in muscle at early timepoints, before intrinsic healing occurs.

Allogenic Use of Human Placenta-Derived Stromal Cells as a Highly Active Subtype of Mesenchymal Stromal Cells for Cell-Based Therapies

The application of mesenchymal stromal cells (MSCs) from different sources, including bone marrow (BM, bmMSCs), adipose tissue (atMSCs), and human term placenta (hPSCs) has been proposed for various clinical purposes. Accumulated evidence suggests that the activity of the different MSCs is indirect and associated with paracrine release of pro-regenerative and anti-inflammatory factors. A major limitation of bmMSCs-based treatment for autologous application is the limited yield of cells harvested from BM and the invasiveness of the procedure. Similar effects of autologous and allogeneic MSCs isolated from various other tissues were reported. The easily available fresh human placenta seems to represent a preferred source for harvesting abundant numbers of human hPSCs for allogenic use. Cells derived from the neonate tissues of the placenta (f-hPSC) can undergo extended expansion with a low risk of senescence. The low expression of HLA class I and II on f-hPSCs reduces the risk of rejection in allogeneic or xenogeneic applications in normal immunocompetent hosts. The main advantage of hPSCs-based therapies seems to lie in the secretion of a wide range of pro-regenerative and anti-inflammatory factors. This renders hPSCs as a very competent cell for therapy in humans or animal models. This review summarizes the therapeutic potential of allogeneic applications of f-hPSCs, with reference to their indirect pro-regenerative and anti-inflammatory effects and discusses clinical feasibility studies.

MicroRNA treatment modulates osteogenic differentiation potential of mesenchymal stem cells derived from human chorion and placenta

Mesenchymal stem cells (MSCs) are important in regenerative medicine because of their potential for multi-differentiation. Bone marrow, chorion and placenta have all been suggested as potential sources for clinical application. However, the osteogenic differentiation potential of MSCs derived from chorion or placenta is not very efficient. Bone morphogenetic protein-2 (BMP-2) plays an important role in bone development. Its effect on osteogenic augmentation has been addressed in several studies. Recent studies have also shown a relationship between miRNAs and osteogenesis. We hypothesized that miRNAs targeted to Runt-related transcription factor 2 (Runx-2), a major transcription factor of osteogenesis, are responsible for regulating the differentiation of MSCs into osteoblasts. This study examines the effect of BMP-2 on the osteogenic differentiation of MSCs isolated from chorion and placenta in comparison to bone marrow-derived MSCs and investigates the role of miRNAs in the osteogenic differentiation of MSCs from these sources. MSCs were isolated from human bone marrow, chorion and placenta. The osteogenic differentiation potential after BMP-2 treatment was examined using ALP staining, ALP activity assay, and osteogenic gene expression. Candidate miRNAs were selected and their expression levels during osteoblastic differentiation were examined using real-time RT-PCR. The role of these miRNAs in osteogenesis was investigated by transfection with specific miRNA inhibitors. The level of osteogenic differentiation was monitored after anti-miRNA treatment. MSCs isolated from chorion and placenta exhibited self-renewal capacity and multi-lineage differentiation potential similar to MSCs isolated from bone marrow. BMP-2 treated MSCs showed higher ALP levels and osteogenic gene expression compared to untreated MSCs. All investigated miRNAs (miR-31, miR-106a and miR148) were consistently downregulated during the process of osteogenic differentiation. After treatment with miRNA inhibitors, ALP activity and osteogenic gene expression increased over the time of osteogenic differentiation. BMP-2 has a positive effect on osteogenic differentiation of chorion- and placenta-derived MSCs. The inhibition of specific miRNAs enhanced the osteogenic differentiation capacity of various MSCs in culture and this strategy might be used to promote bone regeneration. However, further in vivo experiments are required to assess the validity of this approach.

Human mesenchymal stem cell treatment of premature ovarian failure: new challenges and opportunities

Premature ovarian failure (POF) is one of the common disorders found in women leading to 1% female infertility. Clinical features of POF are hypoestrogenism or estrogen deficiency, increased gonadotropin level, and, most importantly, amenorrhea. With the development of regenerative medicine, human mesenchymal stem cell (hMSC) therapy brings new prospects for POF. This study aimed to describe the types of MSCs currently available for POF therapy, their biological characteristics, and their mechanism of action. It reviewed the latest findings on POF to provide the theoretical basis for further investigation and clinical therapy.

Combined Use of Recombinant Human BMP-7 and Osteogenic Media May Have No Ideal Synergistic Effect on Leporine Bone Regeneration of Human Umbilical Cord Mesenchymal Stem Cells Seeded on Nanohydroxyapatite/Collagen/Poly (l-Lactide)

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising alternative source of mesenchymal stem cells (MSCs) that are enormously attractive for clinical use. This study was designed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) and/or osteogenic media (OMD) on bone regeneration of hUC-MSCs seeded on nanohydroxyapatite/collagen/poly(l-lactide) (nHAC/PLA) in a rabbit model. The characteristics of stem cells were analyzed by plastic adherence, cell phenotype, and multilineage differentiation potential. Cell proliferation was examined using cell counting kit-8 assay. Osteogenic differentiation was evaluated by quantitative Ca²⁺ concentration, PO₄^3- concentration, alkaline phosphatase (ALP) activity, osteocalcin (OCN) secretion, and mineralized matrix formation. Bone regeneration was investigated in jaw bone defect repair in rabbit by microcomputed tomography, fluorescent labeling, and hematoxylin and eosin staining. Except for initial stress response, OMD and OMD + rhBMP-7 inhibited the proliferation of hUC-MSCs seeded on nHAC/PLA; rhBMP-7 inhibited cell proliferation in the nonlogarithmic phase and attenuated the inhibitory effect of OMD on cell proliferation. The inhibitory effects of OMD, rhBMP-7, and OMD + rhBMP-7 on cell proliferation were ranked as OMD > OMD + rhBMP-7 > rhBMP-7. OMD, rhBMP-7, and OMD + rhBMP-7 promoted Ca²⁺ concentration, PO₄^3- concentration, ALP activity, OCN secretion, and mineralized matrix formation of hUC-MSCs seeded on nHAC/PLA. The promoting effects of OMD, rhBMP-7, and OMD+rhBMP-7 on Ca²⁺ concentration, PO₄^3- concentration, ALP activity, OCN secretion, and mineralized matrix formation were ranked as rhBMP-7 > OMD > OMD + rhBMP-7, OMD > OMD + rhBMP-7 > rhBMP-7, OMD > rhBMP-7 > OMD + rhBMP-7, rhBMP-7 > OMD + rhBMP-7 > OMD, and OMD > rhBMP-7 > OMD + rhBMP-7, respectively. In rabbit jaw bone defect repair, OMD, rhBMP-7, and OMD + rhBMP-7 enhanced bone regeneration of hUC-MSCs seeded on nHAC/PLA, but the largest bone mineral apposition rate and bone formation were presented in cultures with rhBMP-7. These findings suggested that the combined use of rhBMP-7 and OMD may have no ideal synergistic effect on bone regeneration of hUC-MSCs seeded on nHAC/PLA in rabbit jaw bone defect.

Alleviation of acute radiation-induced bone marrow failure in mice with human fetal placental stromal cell therapy

Purpose

Selected placental mesenchymal stromal cells isolated from the fetal mesenchymal placental tissues (f-hPSCs) were tested as cell therapy of lethal acute radiation syndrome (ARS) with bone marrow regeneration and induced extramedullary hematopoiesis.

Methods and materials

f-hPSCs were isolated from the chorionic plate of human placentae and further expanded in regular culture conditions. 2 × 10⁶ f-hPSCs were injected on days 1 and 4 to 8-Gy total body irradiated (TBI) C3H mice, both intramuscularly and subcutaneously. Pre-splenectomized TBI mice were used to test the involvement of extramedullary spleen hematopoiesis in the f-hPSC-induced hematopoiesis recovery in the TBI mice. Weight and survival of the mice were followed up within the morbid period of up to 23 days following irradiation. The role of hematopoietic progenitors in the recovery of treated mice was evaluated by flow cytometry, blood cell counts, and assay of possibly relevant growth factors.

Results and conclusions

The survival rate of all groups of TBI f-hPSC-treated mice at the end of the follow-up was dramatically elevated from < 10% in untreated to ~ 80%, with a parallel regain of body weight, bone marrow (BM) recovery, and elevated circulating progenitors of blood cell lineages. Blood erythropoietin levels were elevated in all f-hPSC-treated mice. Extramedullary splenic hematopoiesis was recorded in the f-hPSC-treated mice, though splenectomized mice still had similar survival rate. Our findings suggest that the indirect f-hPSC life-saving therapy of ARS may also be applied for treating other conditions with a failure of the hematopoietic system and severe pancytopenia.

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

Mesenchymal stem cells (MSCs) have become a promising tool in cellular therapy for restoring immune system haemostasis; however, the success of clinical trials has been impaired by the lack of standardized manufacturing processes. This study aims to determine the suitability of source tissues and culture media for the production of MSC-based advanced therapy medicinal products (ATMPs) and to define parameters to extend the set of release criteria. MSCs were isolated from umbilical cord (UC), bone marrow and lipoaspirate and expanded in three different culture media. MSC phenotype, proliferation capacity and immunosuppressive parameters were evaluated in normal MSCs compared to primed MSCs treated with cytokines mimicking an inflammatory environment. Compared to bone marrow and lipoaspirate, UC-derived MSCs (UC-MSCs) showed the highest proliferative capacity, which was further enhanced by media supplemented with bFGF, while the cells maintained their immunosuppressive characteristics. Moreover, UC-MSCs expanded in the bFGF-enriched medium were the least sensitive to undesirable priming-induced changes in the MSC phenotype. Surface markers and secreted factors were identified to reflect the cell response to inflammatory priming and to be variable among MSCs from different source tissues. This study demonstrates that UC is a favorable cell source for manufacturing MSC-based ATMPs for immunosuppressive applications. UC-MSCs are able to use the bFGF-enriched medium for higher cell yields without the impairment of immunosuppressive parameters and undesirable phenotype changes after inflammatory preconditioning of MSCs before transplantation. Additionally, immunosuppressive parameters were identified to help finding predictors of clinically efficient MSCs in the following clinical trials.

Human amniotic mesenchymal stem cells alleviate paraquat-induced pulmonary fibrosis in rats by inhibiting the inflammatory response

AIMS

To investigate the therapeutic effects of human amniotic mesenchymal stem cells (hAMSCs) on paraquat (PQ)-induced pulmonary fibrosis in rats and investigate the inflammatory mechanisms.

MAIN METHODS

hAMSCs were identified by morphological, flow cytometry and immunocytochemistry. A pulmonary fibrosis model was induced by administering PQ to rats. The hAMSCs group was treated with hAMSCs after 6 h of PQ poisoning. At 21 days after hAMSCs transplantation, lungs were harvested for H&E, Masson and immunohistochemical staining to evaluate pulmonary histopathology, collagen deposition, CD3+ cell infiltration and hAMSCs colonization. Arterial blood was used for lactic acid analysis and venous blood was used to detect TNF-α, IL-6, and TGF-β1 by ELISA method.

KEY FINDINGS

hAMSCs can improve the lung structure and decrease collagen deposition induced by PQ. The membranes of CD3+ T cell in the PQ group were round and complete, while that in the hAMSCs group rats exhibited punctate or diffuse staining. In addition, the CD3+ cell was decreased by hAMSCs administration, and MAB1281-positive cells were detected in lung of hAMSCs group rats. The survival rate of the hAMSCs group was significantly higher than that of the PQ group at 21 days after injection. TNF-α, IL-6, TGF-β1 and lactic acid were significantly decreased by hAMSCs administration.

SIGNIFICANCE

hAMSCs have a significant therapeutic effect on pulmonary fibrosis induced by acute PQ poisoning and can improve survival rate in rats. Furthermore, hAMSCs administration can improve lung histopathology and reduce collagen deposition by reducing inflammatory CD3+ T cell infiltration, inflammatory cytokine expression and lactic acid levels.

Locally Delivered Umbilical Cord Mesenchymal Stromal Cells Reduce Chronic Inflammation in Long-Term Nonhealing Wounds: A Randomized Study

Inflammation is part of a complex biological response to injury that mediates a rapid mobilization of cells and triggers the restoration of tissue homeostasis. The systemic diseases of the connective tissues, repetitive strain injuries, neuropathy, and vascular impairment lead to the development of a chronic inflammatory state. In such cases, a forced intervention is required to trigger tissue regeneration. Mesenchymal stromal cells (MSCs) have been considered a perspective tool for regenerative medicine because of their ability to change the expression and secretory profile under the influence of signals from the microenvironment to perform a regulatory function at the site of tissue damage. In this study, MSCs were isolated from the human umbilical cord (UCMSCs). The ability of UCMSCs to regulate chronic inflammation was investigated in a randomized placebo-controlled pilot study to assess the efficacy and safety of UCMSC therapy in patients with nonhealing wounds. A total of 108 patients with chronic wounds of different etiologies were randomly divided into two groups according to the criteria of inclusion and exclusion. The group (n = 59) that was treated with a single local subcutaneous infusion of UCMSCs around the wound periphery showed a pronounced growth of granulation tissue, improved blood microcirculation, and reduction in wound size compared to the placebo group (n = 49). No prominent adverse events were detected in patients from the UCMSC group during the 1-year follow-up period. This research has demonstrated that locally delivered allogeneic UCMSCs can contribute to chronic wound repair and provide an additional support toward new therapeutic strategies. Registration certificate №FS2006/341 was issued by the Federal Service for Surveillance in Healthcare.

GLP-1 Gene-Modified Human Umbilical Cord Mesenchymal Stem Cell Line Improves Blood Glucose Level in Type 2 Diabetic Mice

Type 2 diabetes constitutes a serious threat to the health of patients, but there is currently no ideal treatment in the clinic. Glucagon-like peptide-1 and human umbilical cord mesenchymal stem cells have been confirmed to have antidiabetic effects, but both of them have certain defects in the process of antidiabetes, which cannot meet the need of clinical treatment. We hypothesized that human umbilical cord mesenchymal stem cells can be used as a vector to construct a novel cell line that expresses GLP-1 in vivo for a long time. And this cell strain results in lowering blood glucose in type 2 diabetic mice. The results showed that after 3 weeks of intramuscular injection of the new cell line, the fasting blood glucose of type 2 diabetic mice returned to the normal range, and the hypoglycemic effect was maintained within 3 weeks after putting an end to the drug. At the same time, during the administration, the mice lost weight, the food intake decreased, the half-life of GLP-1 in the body prolonged, the IR reduced, and the pancreatic function recovered. The results of this study indicate that the novel cell line can prolong the half-life of GLP-1 in vivo and effectively lower blood sugar, which is a feasible method to improve type 2 diabetes.

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

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

Human amniotic mesenchymal stem cells improve the follicular microenvironment to recover ovarian function in premature ovarian failure mice

Background

Many adult women younger than 40 years old have premature ovarian failure (POF) and infertility. Previous studies confirmed that different tissue-derived stem cells could restore ovarian function and folliculogenesis in chemotherapy-induced POF mice. The aim of this study was to explore the therapeutic efficacy and underlying mechanisms of human amniotic mesenchymal stem cells (hAMSCs) transplantation for hydrogen peroxide-induced ovarian damage.

Methods

Bilateral ovaries of female mice were burned with 10% hydrogen peroxide to establish a POF model. After 24 h of treatment, hAMSCs and diethylstilbestrol were administered to POF mice by intraperitoneal injection and intragastric administration, respectively. After either 7 or 14 days, ovarian function was evaluated by the oestrus cycle, hormone levels, ovarian index, fertility rate, and ovarian morphology. The karyotype was identified in offspring by the G-banding technique. hAMSCs tracking, immunohistochemical staining, and real-time polymerase chain reaction (PCR) were used to assess the molecular mechanisms of injury and repair.

Results

The oestrus cycle was recovered after hAMSCs transplantation at 7 and 14 days. Oestrogen levels increased, while follicle-stimulating hormone levels decreased. The ovarian index, fertility rate, and population of follicles at different stages were significantly increased. The newborn mice had no obvious deformity and showed normal growth and development. The normal offspring mice were also fertile. The tracking of hAMSCs revealed that they colonized in the ovarian stroma. Immunohistochemical and PCR analyses indicated that changes in proteins and genes might affect mature follicle formation.

Conclusions

These results suggested that hAMSCs transplantation can improve injured ovarian tissue structure and function in oxidatively damaged POF mice. Furthermore, the mechanisms of hAMSCs are related to promoting follicular development, granulosa cell proliferation, and secretion function by improving the local microenvironment of the ovary.

The Immunomodulatory Potential of Wharton's Jelly Mesenchymal Stem/Stromal Cells

The benefits attributed to mesenchymal stem/stromal cells (MSC) in cell therapy applications are mainly attributed to the secretion of factors, which exhibit immunomodulatory and anti-inflammatory effects and stimulate angiogenesis. Despite the desirable features such as high proliferation levels, multipotency, and immune response regulation, there are important variables that must be considered. Although presenting similar morphological aspects, MSC collected from different tissues can form heterogeneous cellular populations and, therefore, manifest functional differences. Thus, the source of MSC should be a factor to be considered in the development of novel therapies. The following text presents an updated review of recent research outcomes related to Wharton's jelly mesenchymal stem/stromal cells (WJ-MSC), harvested from umbilical cords and considered novel and potential candidates for the development of cell-based approaches. This text highlights information on how WJ-MSC affect immune responses in comparison with other sources of MSC.

Effect of ectopic high expression of transcription factor OCT4 on the "stemness" characteristics of human bone marrow-derived mesenchymal stromal cells

OBJECTIVE

To investigate the effect of ectopic high expression of OCT4 on the stemness characteristics of bone marrow-derived mesenchymal stromal cells (BM-MSCs).

METHODS

BM-MSCs were collected from three de novo acute lymphoblastic leukemia (ALL) and three aplastic anemia patients (AA), which were cultivated by the whole bone marrow adherent method. Surface markers of BM-MSCs were analyzed by flow cytometry (FCM); meanwhile, growth characteristics were observed with a phase contrast microscope, and population doubling time (PDT) was calculated. The optimal generation cells (P4) were used for the subsequent experiments. Recombinant plasmid pcDNA3.1-OCT4 was constructed and transferred into ALL MSCs by liposome transfection. The cells with stable and high expression of OCT4 were selected by G418 resistance screening and subcloning, of which the expression of OCT4 was verified by FCM, cellular immunofluorescence assay (CIFA), and RT-PCR. The expression of stemness-related transcription factors (TFs) (NANOG, SOX2) and the embryonic stem cell (ESC)-related surface markers (SSEA4, TRA-1-60, and TRA-1-81) were analyzed by FCM, RT-PCR, and CIFA. Embryonic body (EB) formation was performed with the above cells, and triembryonic differentiation marker genes were evaluated by RT-PCR.

RESULTS

The primary passage of AA MSCs grew more slowly and had longer PDT (16 days on average) than ALL MSCs (10 days on average). AA MSCs presented the same typical morphology and similar expression levels of specific mesenchymal markers as ALL MSCs, whereas the latter had a much better proliferative capacity in P4 cells (P < 0.05). Besides, the expression levels of surface markers in ALL MSCs were slightly higher than that in AA MSCs in P4, P7, and P10 cells (P < 0.05). Cell lines with stable and high expression of OCT4 were successfully established from ALL MSCs, which were confirmed by CIFA, FCM, and RT-PCR. Compared with untransfected parental MSCs, the mean expression levels of TFs in OCT4 overexpression MSCs were increased from 0.63 ± 0.37% to 39.39 ± 1.85% (NANOG) and from 14.34 ± 2.44% to 91.45 ± 4.56% (SOX2). The average expression levels of ESC surface markers were increased from 3.33 ± 2.35%, 1.59 ± 1.29%, and 1.46 ± 0.86% to 84.98 ± 9.2%, 57.28 ± 6.72%, and 75.88 ± 7.35% respectively for SSEA-4, TRA-1-60, and TRA-1-81, which were confirmed by CIFA analysis. Moreover, the OCT4 overexpression MSCs could form EBs ex vivo and express ectoderm (TUBB3, WNT1), mesoderm (Brachyury, TBX20), and endoderm (SPARC) genes.

CONCLUSION

Ectopic high expression of transcription factor OCT4 in BM-MSCs may drive them to grow as ESC-like cells with "stemness" characteristics. Single OCT4 transfection can upregulate the expression of other stemness-related transcription factors such as NANOG and SOX2.

The Immunomodulatory Properties of Amniotic Cells: The Two Sides of the Coin

Among the many cell types useful in developing therapeutic treatments, human amniotic cells from placenta have been proposed as valid candidates. Both human amniotic epithelial and mesenchymal stromal cells, and the conditioned medium generated from their culture, exert multiple immunosuppressive activities. Indeed, they inhibit T and B cell proliferation, suppress inflammatory properties of monocytes, macrophages, dendritic cells, neutrophils, and natural killer cells, while promoting induction of cells with regulatory functions such as regulatory T cells and anti-inflammatory M2 macrophages. These properties have laid the foundation for their use for the treatment of inflammatory-based diseases, and encouraging results have been obtained in different preclinical disease models where exacerbated inflammation is present. Moreover, an immune-privileged status of amniotic cells has been often highlighted. However, even if long-term engraftment of amniotic cells has been reported into immunocompetent animals, only few cells survive after infusion. Furthermore, amniotic cells have been shown to be able to induce immune responses in vivo and, under specific culture conditions, they can stimulate T cell proliferation in vitro. Although immunosuppressive properties are a widely recognized characteristic of amniotic cells, immunogenic and stimulatory activities appear to be less reported, sporadic events. In order to improve therapeutic outcome, the mechanisms responsible for the suppressive versus stimulatory activity need to be carefully addressed. In this review, both the immunosuppressive and immunostimulatory activity of amniotic cells will be discussed.

Comparative evaluation of mesenchymal stromal cells from umbilical cord and amniotic membrane in xeno-free conditions

BACKGROUND

Within the past years, umbilical cord (UC) and amniotic membrane (AM) expanded in human platelet lysate (PL) have been found to become increasingly candidate of mesenchymal stromal cells (MSCs) in preclinical and clinical studies. Different sources of MSCs have different properties, and lead to different therapeutic applications. However, the similarity and differences between the AMMSCs and UCMSCs in PL remain unclear.

RESULTS

In this study, we conduct a direct head-to-head comparison with regard to biological characteristics (morphology, immunophenotype, self-renewal capacity, and trilineage differentiation potential) and immunosuppression effects of AMMSCs and UCMSCs expanded in PL. Our results indicated that AMMSCs showed similar morphology, immunophenotype, proliferative capacity and colony efficiency with UCMSCs. Moreover, no significantly differences in osteogenic, chondrogenic and adipogenic differentiation potential were observed between the two types of cells. However, AMMSCs exhibited higher PGE₂ expression and IDO activity compared with UCMSCs when primed by IFN-γ and (or) TNF-α induction, and AMMSCs showed a higher inhibitory effect on PBMCs proliferation than UCMSCs.

CONCLUSION

The results suggest that AMMSCs expanded in PL showed similar morphology, immunophenotype, self-renewal capacity, and trilineage differentiation potential with UCMSCs. However, AMMSCs possessed superior immunosuppression effects in comparison with UCMSCs. These results suggest that AMMSCs in PL might be more suitable than UCMSCs for treatment of immune diseases. This work provides a novel insight into choosing the appropriate source of MSCs for treatment of immune diseases.

Isolation of human mesenchymal stem cells from amnion, chorion, placental decidua and umbilical cord: comparison of four enzymatic protocols

OBJECTIVE

To compare four enzymatic protocols for mesenchymal stem cells (MSCs) isolation from amniotic (A-MSC) and chorionic (C-MSC) membranes, umbilical cord (UC-MSC) and placental decidua (D-MSC) in order to define a robust, practical and low-cost protocol for each tissue.

RESULTS

A-MSCs and UC-MSCs could be isolated from all samples using trypsin/collagenase-based protocols; C-MSCs could be isolated from all samples with collagenase- and trypsin/collagenase-based protocols; D-MSCs were isolated from all samples exclusively with a collagenase-based protocol.

CONCLUSIONS

The trypsin-only protocol was least efficient; the collagenase-only protocol was best for C-MSCs and D-MSCs; the combination of trypsin and collagenase was best for UC-MSCs and none of tested protocols was adequate for A-MSCs isolation.

Pigment epithelium-derived factor from ARPE19 promotes proliferation and inhibits apoptosis of human umbilical mesenchymal stem cells in serum-free medium

Clinical expansion of mesenchymal stem cells (MSCs) is hampered by the lack of knowledge regarding how to prevent MSC apoptosis and promote their proliferation in serum-free medium. Our in vitro studies demonstrated that human umbilical cord MSCs (HUCMSCs) underwent apoptosis in the serum-free medium. When HUCMSCs were co-cultured with retinal pigment epithelial cells (ARPE19), however, HUCMSCs exhibited normal growth and morphology in serum-free medium. Their colony formation was promoted by the conditioned medium (CM) of ARPE19 cells on Matrigel. Proteomics analysis showed that pigment epithelium-derived factor (PEDF) was one of the most abundant extracellular proteins in the ARPE19 CM, whereas enzyme-linked immunosorbent assay confirmed that large amounts of PEDF was secreted from ARPE19 cells. Adding anti-PEDF-blocking antibodies to the co-culture of HUCMSCs with ARPE19 cells increased apoptosis of HUCMSCs. Conversely, treatment with PEDF significantly reduced apoptosis and increased proliferation of HUCMSCs in serum-free medium. PEDF was further demonstrated to exert this anti-apoptotic effect by inhibiting P53 expression to suppress caspase activation. In vivo studies demonstrated that co-injection of HUCMSCs with ARPE19 cells in immunocompromised NOD-SCID mice also increased survival and decreased apoptosis of HUCMSCs. PEDF also showed no negative effect on the mesoderm differentiation capability of HUCMSCs. In conclusion, this study is the first to demonstrate that PEDF promotes HUCMSC proliferation and protects them from apoptosis by reducing p53 expression in the serum-free medium. This study provides crucial information for clinical-scale expansion of HUCMSCs.

The Effects of BMP-2, miR-31, miR-106a, and miR-148a on Osteogenic Differentiation of MSCs Derived from Amnion in Comparison with MSCs Derived from the Bone Marrow

Mesenchymal stromal cells (MSCs) offering valuable anticipations for the treatment of degenerative diseases. They can be found in many tissues including amnion. MSCs from amnion (AM-MSCs) can differentiate into osteoblast similar to that of bone marrow-derived MSCs (BM-MSCs). However, the ability is not much efficient compared to BM-MSCs. This study aimed to examine the effects of BMP-2 and miRNAs on osteogenic differentiation of AM-MSCs compared to those of BM-MSCs. The osteogenic differentiation capacity after miRNA treatment was assessed by ALP expression, ALP activity, and osteogenic marker gene expression. The results showed that the osteogenic differentiation capacity increased after BMP-2 treatment both in AM-MSCs and BM-MSCs. MiR-31, miR-106a, and miR-148a were downregulated during the osteogenic differentiation. After transfection with anti-miRNAs, ALP activity and osteogenic genes were increased over the time of differentiation. The data lead to the potential for using AM-MSCs as an alternative source for bone regeneration. Moreover, the information of miRNA expression and function during osteogenic differentiation may be useful for the development of new therapeutics or enhanced an in vitro culture technique required for stem cell-based therapies in the bone regeneration.

Involvement of WNT Signaling in the Regulation of Gestational Age-Dependent Umbilical Cord-Derived Mesenchymal Stem Cell Proliferation

Mesenchymal stem cells (MSCs) are a heterogeneous cell population that is isolated initially from the bone marrow (BM) and subsequently almost all tissues including umbilical cord (UC). UC-derived MSCs (UC-MSCs) have attracted an increasing attention as a source for cell therapy against various degenerative diseases due to their vigorous proliferation and differentiation. Although the cell proliferation and differentiation of BM-derived MSCs is known to decline with age, the functional difference between preterm and term UC-MSCs is poorly characterized. In the present study, we isolated UC-MSCs from 23 infants delivered at 22–40 weeks of gestation and analyzed their gene expression and cell proliferation. Microarray analysis revealed that global gene expression in preterm UC-MSCs was distinct from term UC-MSCs. WNT signaling impacts on a variety of tissue stem cell proliferation and differentiation, and its pathway genes were enriched in differentially expressed genes between preterm and term UC-MSCs. Cell proliferation of preterm UC-MSCs was significantly enhanced compared to term UC-MSCs and counteracted by WNT signaling inhibitor XAV939. Furthermore, WNT2B expression in UC-MSCs showed a significant negative correlation with gestational age (GA). These results suggest that WNT signaling is involved in the regulation of GA-dependent UC-MSC proliferation.

Comparison of human mesenchymal stromal cells from four neonatal tissues: Amniotic membrane, chorionic membrane, placental decidua and umbilical cord

BACKGROUND

Mesenchymal stromal cells (MSCs) are being investigated as a potential alternative for cellular therapy. This study was designed to compare the biological characteristics of MSCs isolated from amniotic membrane (A-MSCs), chorionic membrane (C-MSCs), placental decidua (D-MSCs) and umbilical cord (UC-MSCs) to ascertain whether any one of these sources is superior to the others for cellular therapy purposes.

METHODS

MSCs were isolated from amniotic membrane, chorionic membrane, umbilical cord and placental decidua. Immunophenotype, differentiation ability, cell size, cell complexity, polarity index and growth kinetics of MSCs isolated from these four sources were analyzed.

RESULTS

MSCs were successfully isolated from all four sources. Surface marker profile and differentiation ability were consistent with human MSCs. C-MSCs in suspension were the smallest cells, whereas UC-MSCs presented the greatest length and least width. A-MSCs had the lowest polarity index and UC-MSCs, as more elongated cells, the highest. C-MSCs, D-MSCs and UC-MSCs exhibited similar growth capacity until passage 8 (P8); C-MSCs presented better lifespan, whereas insignificant proliferation was observed in A-MSCs.

DISCUSSION

Neonatal and maternal tissues can serve as sources of multipotent stem cells. Some characteristics of MSCs obtained from four neonatal tissues were compared and differences were observed. Amniotic membrane was the least useful source of MSCs, whereas chorionic membrane and umbilical cord were considered good options for future use in cell therapy because of the known advantages of immature cells.

Immunomodulatory properties of human placental mesenchymal stem/stromal cells

Mesenchymal stem/stromal cells (MSCs) are isolated from various fetal and adult tissues such as bone marrow, adipose tissue, cord blood and placenta. Placental MSCs (pMSCs), the main focus of this review, are relatively new MSC types that are not as intensively studied compared with bone marrow-derived MSCs (BMMSCs). MSCs modulate the immune functions of important immune cells involved in alloantigen recognition and elimination, including antigen presenting cells (APCs), T cells, B cells and natural killer (NK) cells. Clinical trials, both completed and underway, employ MSCs to treat various human immunological diseases, such as multiple sclerosis (MS) and type 1 diabetes. However, the mechanisms that mediate the immunosuppressive effects of pMSCs are still largely unknown, and the safety of pMSC use in clinical settings needs further confirmation. Here, we review the current knowledge of the immunosuppressive properties of placental MSCs.

Effect of 2-octylcyanoacrylate on placenta derived mesenchymal stromal cells on extracellular matrix

PURPOSE

Determine the effect of 2-octylcyanoacrylate on placenta derived mesenchymal stromal cells (PMSCs) seeded onto extracellular matrix (ECM) in order to assess its biocompatibility as a potential adhesive for in-vivo fetal cell delivery.

METHODS

PMSCs isolated from chorionic villus tissue were seeded onto ECM. A MTS proliferation assay assessed cellular metabolic activity at various time points in PMSC-ECM with direct, indirect, and no glue contact. Conditioned media collected prior to and 24 hours after glue exposure was analyzed for secretion of human brain-derived neurotrophic factor, hepatocyte growth factor, and vascular endothelial growth factor.

RESULTS

Direct and indirect contact with 2-octylcyanoacrylate results in progressively decreased cellular metabolic activity over 24 hours compared to no glue controls. Cells with direct contact are less metabolically active than cells with indirect contact. 24 hours of glue exposure resulted in suppression of growth factor secretion that is near complete with direct contact.

DISCUSSION

Exposure to 2-octylcyanoacrylate results in decreased metabolic activity and decreased measurable secretion of growth factors by PMSCs seeded onto ECM. Thus, the application of 2-octylcyanoacrylate glue should be limited when working with cell-engineered scaffolds as its inhibitory effects on cell growth and secretory function can limit the therapeutic potential of cell-based interventions.

Comparison of the proliferation, migration and angiogenic properties of human amniotic epithelial and mesenchymal stem cells and their effects on endothelial cells

In vivo studies have shown that amnion-produced growth factors participate in many diseases that involve angiogenesis, re-epithelialization and immunomodulation. Although human amniotic epithelial cells (hAECs) and human amniotic mesenchymal stem cells (hAMSCs) can be obtained from amniotic membranes, there is little information regarding their biological differences. The aim of the present study was to isolate and characterize cells from human amnions, to investigate the biological potential and behavior of these cells on the function of endothelial cells in vivo and in vitro and to examine variations in the expression profile of growth factors in different human amnion-derived cell types. Amnion fragments were enzymatically digested into two cell fractions, which were analyzed by mesenchymal and epithelial cell markers. Human aortic endothelial cells (hAoECs) were cultured with conditioned medium (CdM) collected from hAECs or hAMSCs. We used scratch and Transwell assays to evaluate migration ability; Cell Counting Kit-8 (CCK-8) and cell cycle analysis to evaluate proliferation ability; and a Matrigel tube formation assay to evaluate angiogenesis ability. To detect expression of angiogenesis-related genes, qPCR and enzyme-linked immunosorbent assay (ELISA) analyses were conducted. As stem cells, hAECs and hAMSCs all expressed the stem cell markers SSEA-4, OCT-4 and SOX-2. CdM obtained from hAECs promoted cell migration; CdM obtained from hAMSCs promoted cell proliferation; CdM obtained from hAECs and hAMSCs both promoted angiogenesis in hAoECs. Amnion-derived cells secreted significant amounts of angiogenic factors including HGF, IGF-1, VEGF, EGF, HB-EGF and bFGF, although differences in the cellular expression profile of these soluble factors were observed. Our results highlight that human amniotic epithelial and mesenchymal stem cells, which showed differences in their soluble factor secretion and angiogenic functions, could be ideal cell sources for regenerative medicine.

Bone morphogenetic protein-2 enhances the osteogenic differentiation capacity of mesenchymal stromal cells derived from human bone marrow and umbilical cord

Mesenchymal stromal cells (MSCs) are multipotent cells that can give rise to different cell types of the mesodermal lineages. They are powerful sources for cell therapy in regenerative medicine as they can be isolated from various tissues, and can be expanded and induced to differentiate into multiple lineages. Recently, the umbilical cord has been suggested as an alternative source of MSCs. Although MSCs derived from the umbilical cord can be induced to differentiate into osteoblasts with a phenotypic similarity to that of bone marrow-derived MSCs, the differentiation ability is not consistent. In addition, MSCs from the umbilical cord require a longer period of time to differentiate into osteoblasts. Previous studies have demonstrated the benefits of bone morphogenetic protein-2 (BMP-2) in bone tissue regeneration. In addition, several studies have supported the use of BMP-2 in periodontal regeneration, sinus lift bone-grafting and non-unions in oral surgery. Although the use of BMP-2 for bone tissue regeneration has been extensively investigated, the BMP-2-induced osteogenic differentiation of MSCs derived from the umbilical cord has not yet been fully examined. Therefore, in this study, we aimed to examine the effects of BMP-2 on the osteogenic differentiation of MSCs derived from umbilical cord compared to that of MSCs derived from bone marrow. The degree of osteogenic differentiation following BMP-2 treatment was determined by assessing alkaline phosphatase (ALP) activity, and the expression profiles of osteogenic differentiation marker genes, osterix (Osx), Runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn). The results revealed that BMP-2 enhanced the osteogenic differentiation capacity of MSCs derived from both bone marrow and umbilical cord as demonstrated by increased ALP activity and the upregulation of osteogenic differentiation marker genes. The enhancement of the osteogenic differentiation capacity of MSCs by BMP-2 suggests that these MSCs may be used as alternative sources for bone engineering or cell therapy in regenerative medicine.

Umbilical Cord Tissue-Derived Mesenchymal Stem Cells Induce T Lymphocyte Apoptosis and Cell Cycle Arrest by Expression of Indoleamine 2, 3-Dioxygenase

It has been reported that human mesenchymal stem cells are able to inhibit T lymphocyte activation; however, the discrepancy among different sources of MSCs is not well documented. In this study, we have compared the MSCs from bone marrow (BM), adipose tissue (AT), placenta (PL), and umbilical cord (UC) to determine which one displayed the most efficient immunosuppressive effects on phytohemagglutinin-induced T cell proliferation. Among them we found that hUC-MSC has the strongest effects on inhibiting T cell proliferation and is chosen to do the further study. We observed that T lymphocyte spontaneously released abundant IFN-γ. And IFN-γ secreted by T lymphocyte could induce the expression of indoleamine 2, 3-dioxygenase (IDO) in hUC-MSCs. IDO was previously reported to induce T lymphocyte apoptosis and cell cycle arrest in S phase. When cocultured with hUC-MSCs, T lymphocyte expression of caspase 3 was significantly increased, while Bcl2 and CDK4 mRNA expression decreased dramatically. Addition of 1-methyl tryptophan (1-MT), an IDO inhibitor, restored T lymphocyte proliferation, reduced apoptosis, and induced resumption of the cell cycle. In addition, the changes in caspase 3, CDK4, and Bcl2 expression were reversed by 1-MT. These findings demonstrate that hUC-MSCs induce T lymphocyte apoptosis and cell cycle arrest by expressing abundant IDO and provide an explanation for some of the immunomodulatory effects of MSCs.

Therapeutic targets and emerging treatment options in gastrointestinal acute graft-versus-host disease

Introduction

Graft-versus-host disease (GVHD) continues to be the major lethal complication of allogeneic hematopoietic stem cell transplantation (HCT) but the standard of care, high dose steroids, has not changed in 40 years. Approximately 50% of GVHD patients will develop steroid refractory disease, typically involving the gastrointestinal (GI) tract, which has a very poor prognosis. Newly developed GVHD biomarker-based risk scores provide the first opportunity to treat patients at the onset of symptoms according to risk of steroid failure. Furthermore, improvements in our understanding of the pathobiology of GVHD, its different signaling pathways, involved cytokines, and the role of post-translational and epigenetic modifications, has identified new therapeutic targets for clinical trials.

Areas covered

This manuscript summarizes the pathophysiology, diagnosis, staging, current and new targeted therapies for GVHD, with an emphasis on GI GVHD. A literature search on PubMed was undertaken and the most relevant references included.

Expert Opinion

The standard treatment for GVHD, high dose steroids, offers less than optimal outcomes as well as significant toxicities. Better treatments, especially for GI GVHD, are needed to reduce non-relapse mortality after allogeneic HCT. The identification of high risk patients through a biomarker-defined scoring system offers a personalized approach to a disease that still requires significant research attention.

Expression of Hes1 during transdifferentiation of hUMSCs into islet progenitor cells

AIM: To detect the expression of Hes1 during the transdifferentiation of human umbilical cord mesenchyreal stem cells (hUMSCs) into islet progenitor cells.

METHODS: After hUMSCs were isolated, cultivated and identified, hUMSCs at passage 5 were subjected staged induction to differentiate into islet precursor cells. Cell morphology was observed using an inverted phase contrast microscope. The expressions of insulin, neurogenin 3 (Ngn3) and glucagon after induction were detected by immunocytochemistry. The expression of Hes1 and Ngn3 was evaluated by immunocytochemistry and Western blot on 7 d, 14 d, and 21 d after induction.

RESULTS: After induction, HUMSCs became larger and colony-like, which is the characteristic of pancreatic progenitor cells. The expression of Ngn3, insulin and glucagon was positive. The level of Ngn3 increased gradually in the process of induction, peaked on 14 d (E2) and fell down on 21 d (E3). However, Hes1 remained unchanged from 7 d to 14 d, but was reduced on 21 d (E3).

CONCLUSION: The Notch signaling pathways' node molecule Hes1 may play an important role in the transdifferentiation of hUMSCs into islet progenitor cells.

Sustained release of bioactive protein from a lyophilized tissue-engineered construct promotes the osteogenic potential of mesenchymal stem cells

Tissue-engineered constructs (TECs) seeded with mesenchymal stem cells (MSCs) represent a therapy for large bone defects. However, massive cell death in TECs in the early postimplantation period prompted us to investigate the osteoinductive mechanism of TECs. Previous studies demonstrated that stem cell extracts retained equivalent levels of bioactive proteins and exhibited an osteoinductive nature similar to that of intact cells. These data led us to hypothesize that despite the massive cell death in TECs, devitalized MSC-derived proteins remain on the scaffolds and are released to improve cell function. Here, TECs were prepared using demineralized bone matrix seeded with human umbilical cord Wharton's jelly-derived MSCs (hWJMSCs), and the cells seeded in TECs were devitalized by lyophilizing the TECs. Scanning electron microscopy, BCA protein assays, quantitative cytokine array analysis and immunofluorescent staining indicated that approximately 3 mg/cm(3) of total protein and 49 types of cytokines derived from hWJMSCs were preserved in the lyophilized TECs (LTECs). The sustainable release of total protein and cytokines from LTECs lasted for more than 2 weeks. The released protein improved the osteogenic behavior of and gene expression in MSCs. Furthermore, the lyophilized hWJMSC-derived proteins had immunoregulatory properties similar to those of live MSCs in mixed lymphocyte reactions. Collectively, we present a novel perspective on the osteoinductive mechanism of TECs and introduce LTECs as new systems for delivering multiple cytokines to enhance MSC behavior.

Amniotic membrane mesenchymal cells-derived factors skew T cell polarization toward Treg and downregulate Th1 and Th17 cells subsets

We previously demonstrated that cells derived from the mesenchymal layer of the human amniotic membrane (hAMSC) and their conditioned medium (CM-hAMSC) modulate lymphocyte proliferation in a dose-dependent manner. In order to understand the mechanisms involved in immune regulation exerted by hAMSC, we analyzed the effects of CM-hAMSC on T-cell polarization towards Th1, Th2, Th17, and T-regulatory (Treg) subsets. We show that CM-hAMSC equally suppresses the proliferation of both CD4⁺ T-helper (Th) and CD8⁺ cytotoxic T-lymphocytes. Moreover, we prove that the CM-hAMSC inhibitory ability affects both central (CD45RO⁺CD62L⁺) and effector memory (CD45RO⁺CD62L⁻) subsets. We evaluated the phenotype of CD4⁺ cells in the MLR setting and showed that CM-hAMSC significantly reduced the expression of markers associated to the Th1 (T-bet⁺CD119⁺) and Th17 (RORγt⁺CD161⁺) populations, while having no effect on the Th2 population (GATA3⁺CD193⁺/GATA3⁺CD294⁺cells). T-cell subset modulation was substantiated through the analysis of cytokine release for 6 days during co-culture with alloreactive T-cells, whereby we observed a decrease in specific subset-related cytokines, such as a decrease in pro-inflammatory, Th1-related (TNFα, IFNγ, IL-1β), Th2 (IL-5, IL-6), Th9 (IL-9), and Th17 (IL-17A, IL-22). Furthermore, CM-hAMSC significantly induced the Treg compartment, as shown by an induction of proliferating CD4⁺FoxP3⁺ cells, and an increase of CD25⁺FoxP3⁺ and CD39⁺FoxP3⁺ Treg in the CD4⁺ population. Induction of Treg cells was corroborated by the increased secretion of TGF-β. Taken together, these data strengthen the findings regarding the immunomodulatory properties of CM-hAMSC derived from human amniotic membrane MSC, and in particular provide insights into their effect on regulation of T cell polarization.

Immunomodulation of endothelial differentiated mesenchymal stromal cells: impact on T and NK cells. Immunol Cell Biol. 2016;94:342-356. [PMID: 26510892 DOI: 10.1038/icb.2015.94]

Wharton's jelly mesenchymal stromal cells (WJ-MSCs) are promising candidates for tissue engineering, as their immunomodulatory activity allows them to escape immune recognition and to suppress several immune cell functions. To date, however, few studies have investigated the effect of differentiation of the MSCs on this immunomodulation. To address this question, we sought to determine the impact of differentiation toward endothelial cells on immunoregulation by WJ-MSCs. Following differentiation, the endothelial-like cells (ELCs) were positive for CD31, vascular endothelial cadherin and vascular endothelial growth factor receptor 2, and able to take up acetylated low-density lipoproteins. The expression of HLA-DR and CD86, which contribute to MSCs immunoprivilege, was still weak after differentiation. We then co-cultured un- and differentiated MSCs with immune cells, under conditions of both direct and indirect contact. The proliferation and phenotype of the immune cells were analyzed and the mediators secreted by both ELCs and WJ-MSCs quantified. Interleukin (IL)-6, IL-1β, prostaglandin E2 and in particular indoleamine-2,3-dioxygenase expression were upregulated in ELCs on stimulation by T and NK cells, suggesting the possible involvement of these factors in allosuppression. ELCs co-cultured with T cells were able to generate CD25(+) T cells, which were shown to be of the CD4(+)CD25(+)FoxP3(+) regulatory subset. Direct contact between NK cells and ELCs or WJ-MSCs decreased the level of NK-activating receptor natural-killer group 2, member D. Moreover, direct co-culturing with ELCs stimulates CD73 acquisition on NK cells, a mechanism which may induce adenosine secretion by the cells and lead to an immunosuppressive function. Taken together, our results show that ELCs obtained following differentiation of WJ-MSCs remain largely immunosuppressive.

Human umbilical cord mesenchymal stem cells: an overview of their potential in cell-based therapy

INTRODUCTION

Human umbilical cord mesenchymal stem cells (HUC-MSCs) are one of the typical adult stem cells; they have superiorities including low immunogenicity, non-invasive harvest procedure, easy expansion in vitro, and ethical access compared with stem cells from other sources. Therefore, HUC-MSCs are a promising candidate for cell-based therapy.

AREAS COVERED

Here we reviewed the development of stem cell-based therapy, the manufacturing and banking process of HUC-MSCs, the emerging clinical studies in the field of cancer, central nervous system diseases, liver diseases and graft-versus-host disease, the potential therapeutic mechanisms, as well as challenges of HUC-MSCs in clinical translation.

EXPERT OPINION

HUC-MSCs seem to be an optimal choice for stem cell-based therapy. However, before the cells translate from basic to clinical research, some problems still remain to be solved: i) building regulatory guidelines as well as an efficient and safe manufacturing procedure; ii) establishing donor's genetic testing and long-term closely monitoring system; iii) conducting further clinical trials to determine the optimum and standard dosage, time, route, frequency and many other technical issues of HUC-MSCs transplantation.

Elimination of allogeneic multipotent stromal cells by host macrophages in different models of regeneration

Allogeneic multipotent stromal cells were previously thought to be poorly recognized by host immune system; the prolonged survival in host environments was explained by their immune privileged status. As long as the concept is currently reconsidered, the routes of elimination of allogeneic multipotent stromal cells by host immunity must be taken into account. This is necessary for correct comprehension of their therapeutic action. The study was focused upon survival of umbilical cord-derived allogeneic multipotent stromal cells in different rat models of tissue regeneration induced by partial hepatectomy or by critical limb ischemia. The observations were carried out by means of vital labeling of the cells with PKH26 prior to injection, in combination with differential immunostaining of host macrophages with anti-CD68 antibody. According to the results, allogeneic multipotent stromal cells are specifically eliminated by host immune system; the efficacy can reach 100%. Massive clearance of transplanted cells by host macrophages is accompanied by appropriation of the label by the latter, and this is a pronounced case of misleading presentation of exogenous label by host cells. The study emphasizes the role of macrophages in host response and also the need of additional criteria for correct data interpretation.

Immunoregulation by mesenchymal stem cells: biological aspects and clinical applications. J Immunol Res. 2015;2015:394917. [PMID: 25961059 PMCID: PMC4417567 DOI: 10.1155/2015/394917]

Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiation into mesenchymal lineages and that can be isolated from various tissues and easily cultivated in vitro. Currently, MSCs are of considerable interest because of the biological characteristics that confer high potential applicability in the clinical treatment of many diseases. Specifically, because of their high immunoregulatory capacity, MSCs are used as tools in cellular therapies for clinical protocols involving immune system alterations. In this review, we discuss the current knowledge about the capacity of MSCs for the immunoregulation of immunocompetent cells and emphasize the effects of MSCs on T cells, principal effectors of the immune response, and the immunosuppressive effects mediated by the secretion of soluble factors and membrane molecules. We also describe the mechanisms of MSC immunoregulatory modulation and the participation of MSCs as immune response regulators in several autoimmune diseases, and we emphasize the clinical application in graft versus host disease (GVHD).

The expression of neurogenic markers after neuronal induction of chorion-derived mesenchymal stromal cells

OBJECTIVES

Chorion is a tissue of early embryologic period that is discarded after delivery. It might be the potential source of mesenchymal stromal cells (MSCs) that can be used for research and eventually for therapeutic studies. At present, the biological properties and the differentiation capacity of chorion-derived MSCs are still poorly characterised. The objective of this study is to characterise and explore the differentiating potential of chorion-derived MSCs towards the neuronal lineages.

METHODS

Chorionic membrane was digested with enzyme and cultured in Dulbecco's Modified Eagle's medium supplemented with 10% fetal bovine serum. The expression of MSC markers was examined using flow cytometry. The adipogenic, osteogenic and neurogenic differentiation were examined by culturing in appropriate induction media. The expression of neuronal markers was determined by immunofluorescence and quantitative real time-PCR.

RESULTS

Chorion-derived MSCs were easily expanded up to 20 passages. They were positive for MSC markers (CD73, CD90 and CD105), and negative for haematopoietic markers (CD34 and CD45). Chorion-derived MSCs could differentiate into several mesodermal-lineages including adipocytes and osteoblasts. Moreover, chorion-derived MSCs could differentiate into neuronal-like cells as characterised by cell morphology and the presence of neural markers including MAP-2, glial fibrillary acidic protein (GFAP) and beta-tubulin III.

DISCUSSION

Chorion-derived MSCs can be readily obtained and expanded in culture. These cells also have transdifferentiation capacity as evidenced by their neuronal differentiation potential. Therefore, chorion can be used as an alternative source of MSCs for stem cell therapy in nervous system disorders.

Early gestation chorionic villi-derived stromal cells for fetal tissue engineering

AIM: To investigate the potential for early gestation placenta-derived mesenchymal stromal cells (PMSCs) for fetal tissue engineering.

METHODS: PMSCs were isolated from early gestation chorionic villus tissue by explant culture. Chorionic villus sampling (CVS)-size tissue samples (mean = 35.93 mg) were used to test the feasibility of obtaining large cell numbers from CVS within a clinically relevant timeframe. We characterized PMSCs isolated from 6 donor placentas by flow cytometry immunophenotyping, multipotency assays, and through immunofluorescent staining. Protein secretion from PMSCs was examined using two cytokine array assays capable of probing for over 70 factors in total. Delivery vehicle compatibility of PMSCs was determined using three common scaffold systems: fibrin glue, collagen hydrogel, and biodegradable nanofibrous scaffolds made from a combination of polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA). Viral transduction of PMSCs was performed using a Luciferase-GFP-containing lentiviral vector and efficiency of transduction was tested by fluorescent microscopy and flow cytometry analysis.

RESULTS: We determined that an average of 2.09 × 10⁶ (SD ± 8.59 × 10⁵) PMSCs could be obtained from CVS-size tissue samples within 30 d (mean = 27 d, SD ± 2.28), indicating that therapeutic numbers of cells can be rapidly expanded from very limited masses of tissue. Immunophenotyping by flow cytometry demonstrated that PMSCs were positive for MSC markers CD105, CD90, CD73, CD44, and CD29, and were negative for hematopoietic and endothelial markers CD45, CD34, and CD31. PMSCs displayed trilineage differentiation capability, and were found to express developmental transcription factors Sox10 and Sox17 as well as neural-related structural proteins NFM, Nestin, and S100β. Cytokine arrays revealed a robust and extensive profile of PMSC-secreted cytokines and growth factors, and detected 34 factors with spot density values exceeding 10³. Detected factors had widely diverse functions that include modulation of angiogenesis and immune response, cell chemotaxis, cell proliferation, blood vessel maturation and homeostasis, modulation of insulin-like growth factor activity, neuroprotection, extracellular matrix degradation and even blood coagulation. Importantly, PMSCs were also determined to be compatible with both biological and synthetic material-based delivery vehicles such as collagen and fibrin hydrogels, and biodegradable nanofiber scaffolds made from a combination of PLA and PLGA. Finally, we demonstrated that PMSCs can be efficiently transduced (> 95%) with a Luciferase-GFP-containing lentiviral vector for future in vivo cell tracking after transplantation.

CONCLUSION: Our findings indicate that PMSCs represent a unique source of cells that can be effectively utilized for in utero cell therapy and tissue engineering.

Human umbilical cord mesenchymal stem cells: a new era for stem cell therapy

The human umbilical cord is a promising source of mesenchymal stem cells (HUCMSCs). Unlike bone marrow stem cells, HUCMSCs have a painless collection procedure and faster self-renewal properties. Different derivation protocols may provide different amounts and populations of stem cells. Stem cell populations have also been reported in other compartments of the umbilical cord, such as the cord lining, perivascular tissue, and Wharton's jelly. HUCMSCs are noncontroversial sources compared to embryonic stem cells. They can differentiate into the three germ layers that promote tissue repair and modulate immune responses and anticancer properties. Thus, they are attractive autologous or allogenic agents for the treatment of malignant and nonmalignant solid and soft cancers. HUCMCs also can be the feeder layer for embryonic stem cells or other pluripotent stem cells. Regarding their therapeutic value, storage banking system and protocols should be established immediately. This review critically evaluates their therapeutic value, challenges, and future directions for their clinical applications.

Human umbilical cord mesenchymal stem cells promote carcinoma growth and lymph node metastasis when co-injected with esophageal carcinoma cells in nude mice

Background

Human umbilical cord blood derived-mesenchymal stem cells (hUCMSCs) offer an attractive alternative to bone marrow-derived MSCs (BMMSCs) for cell-based therapy as it is a less invasive source of biological material. However, limited studies have been conducted with hUCMSCs as compared to BMMSCs. The present study was conducted to evaluate the effects of hUCMSCs in esophageal carcinoma (EC).

Methods

hUCMSCs together with EC cells were transplanted subcutaneously into BALB/c nude mice to observe the effects of hUCMSCs on tumor establishment. hUCMSCs injected through the caudal vein to the mice with pre-established EC to observe the effects of hUCMSCs on tumor outgrowth. In order to elucidate the underlying mechanisms, we also performed in vitro experiments including directly co-culture, transwell assay, proliferation assay and western blotting analysis.

Results

hUCMSCs promoted EC formation in nude mice. In the in vivo model of pre-established EC, intravenously injected hUCMSCs potently promoted tumor growth. When in vitro co-cultured with hUCMSCs, EC cells proliferation increased. After co-cultured with hUCMSCs through transwell system, EC cells showed increased proliferation. Through transwell assay, we also observed that EC cells recruited MSCs, and MSCs promoted EC cells migration and invasion. Western blotting data showed that the expressions of proliferation related proteins Bcl-2, survivin and metastasis related proteins MMP-2 and MMP-9 were up-regulated in the EC cells transwell co-cultured with hUCMSCs.

Conclusions

Our results indicated that hUCMSCs could favor tumor growth in vivo and in vitro. Thus, the exploitation of hUCMSCs in new therapeutic strategies should be cautious under the malignant conditions.

Human umbilical cord mesenchymal stem cells promote carcinoma growth and lymph node metastasis when co-injected with esophageal carcinoma cells in nude mice

BACKGROUND

Human umbilical cord blood derived-mesenchymal stem cells (hUCMSCs) offer an attractive alternative to bone marrow-derived MSCs (BMMSCs) for cell-based therapy as it is a less invasive source of biological material. However, limited studies have been conducted with hUCMSCs as compared to BMMSCs. The present study was conducted to evaluate the effects of hUCMSCs in esophageal carcinoma (EC).

METHODS

hUCMSCs together with EC cells were transplanted subcutaneously into BALB/c nude mice to observe the effects of hUCMSCs on tumor establishment. hUCMSCs injected through the caudal vein to the mice with pre-established EC to observe the effects of hUCMSCs on tumor outgrowth. In order to elucidate the underlying mechanisms, we also performed in vitro experiments including directly co-culture, transwell assay, proliferation assay and western blotting analysis.

RESULTS

hUCMSCs promoted EC formation in nude mice. In the in vivo model of pre-established EC, intravenously injected hUCMSCs potently promoted tumor growth. When in vitro co-cultured with hUCMSCs, EC cells proliferation increased. After co-cultured with hUCMSCs through transwell system, EC cells showed increased proliferation. Through transwell assay, we also observed that EC cells recruited MSCs, and MSCs promoted EC cells migration and invasion. Western blotting data showed that the expressions of proliferation related proteins Bcl-2, survivin and metastasis related proteins MMP-2 and MMP-9 were up-regulated in the EC cells transwell co-cultured with hUCMSCs.

CONCLUSIONS

Our results indicated that hUCMSCs could favor tumor growth in vivo and in vitro. Thus, the exploitation of hUCMSCs in new therapeutic strategies should be cautious under the malignant conditions.

Identification of appropriate reference genes for human mesenchymal stem cell analysis by quantitative real-time PCR

Normalization to a reference gene is the method of choice for quantitative reverse transcription-PCR (RT-qPCR) analysis. The stability of reference genes is critical for accurate experimental results and conclusions. We have evaluated the expression stability of eight commonly used reference genes found in four different human mesenchymal stem cells (MSC). Using geNorm, NormFinder and BestKeeper algorithms, we show that beta-2-microglobulin and peptidyl-prolylisomerase A were the optimal reference genes for normalizing RT-qPCR data obtained from MSC, whereas the TATA box binding protein was not suitable due to its extensive variability in expression. Our findings emphasize the significance of validating reference genes for qPCR analyses. We offer a short list of reference genes to use for normalization and recommend some commercially-available software programs as a rapid approach to validate reference genes. We also demonstrate that the two reference genes, β-actin and glyceraldehyde-3-phosphate dehydrogenase, are frequently used are not always successful in many cases.

Umbilical cord mesenchymal stem cells: the new gold standard for mesenchymal stem cell-based therapies?

Due to their self-renewal capacity, multilineage differentiation potential, paracrine effects, and immunosuppressive properties, mesenchymal stromal cells (MSCs) are an attractive and promising tool for regenerative medicine. MSCs can be isolated from various tissues but despite their common immunophenotypic characteristics and functional properties, source-dependent differences in MSCs properties have recently emerged and lead to different clinical applications. Considered for a long time as a medical waste, umbilical cord appears these days as a promising source of MSCs. Several reports have shown that umbilical cord-derived MSCs are more primitive, proliferative, and immunosuppressive than their adult counterparts. In this review, we aim at synthesizing the differences between umbilical cord MSCs and MSCs from other sources (bone marrow, adipose tissue, periodontal ligament, dental pulp,…) with regard to their proliferation capacity, proteic and transcriptomic profiles, and their secretome involved in their regenerative, homing, and immunomodulatory capacities. Although umbilical cord MSCs are until now not particularly used as an MSC source in clinical practice, accumulating evidence shows that they may have a therapeutic advantage to treat several diseases, especially autoimmune and neurodegenerative diseases.