Current Stem Cell Research & Therapy - Volume 18, Issue 8, 2023

Graft-versus-host disease (GvHD), including the acute and chronic types (aGvHD, cGvHD), arise as the dominating secondary disease in patients with unsatisfying consequences of allogeneic hematopoietic stem cell transplantation (HSCT). Approximately half of GvHD patients were steroid-resistant, with a two-year overall survival rate lower than 20%. Worse still, there are no standardized criteria for an optimal second-line therapy for steroid-resistant aGVHD patients. Notably, pioneering investigators have highlighted the ameliorative or therapeutic effects of human umbilical cord-derived mesenchymal stem/stromal cells (hUC-MSCs) upon GvHD largely attributed to their unique hematopoietic-supporting and immunomodulatory properties. Of note, quality control (QC) is the prerequisite to assure the safety and quality of hUC-MSCs before investigational new drug (IND) applications and large-scale clinical applications. Herein, we summarize the state-of-the-art updates upon IND-associated QC and clinical trials of hUC-MSCs during allogeneic HSCT in China. Meanwhile, the supervisory policy and medical ethics of current licensed MSC products for GvHD administration and the concomitant opportunities and challenges have also been discussed.

Biomaterials are developed to aid a variety of regenerative medicine strategies, such as providing a framework for cell adhesion and proliferation or serving as carriers of bioactive factors, while stem cells are increasingly implanted in biomaterial scaffolds to improve therapeutic efficacy. Advanced biomaterials like metals, synthetic polymers, and ceramics are used in bone regeneration technology. The ultimate goal of biomaterial-directed SC (stem cells) culture is to replicate the physical and biochemical characteristics of the physiological SC niche. The primary structural component of tumour ECM (extracellular matrix) is collagen. Cancer initiation, EMT (epithelial-mesenchymal transition), drug resistance, and CSC (cancer stem cells) self-renewal have all been linked to collagen subtypes. The enhancement of liver CSCs has already been investigated using collagen I-based platforms. Alginate and chitosan are two naturally occurring polymers with biological macromolecules that are similar. Biomaterial-based therapies, on the whole, offer incredible versatility and tailorability in the fight against the disease. They could also be used as tissue-engineered scaffolds for immune cell replenishment, potentially making them a key weapon in the next generation of therapeutic approaches.

Mesenchymal stem cells (MSCs) are getting attention in the field of cancer immunotherapy. The main effects of MSCs on tumors are homing and regulation of inflammatory and immune responses. Indeed, cancer immunotherapy has become a promising treatment and MSCs play a potential role in regulating the efficacy of immunotherapy. In addition, MSCs are an ideal carrier for immunomodulatory protein transmission. As such MSCs combined with immunotherapy drugs could act synergistically against tumors, throwing a great impact on cancer therapy. And MSCs may have potential in the treatment of cytokine storm or cytokine release syndrome (CRS). It is assumed that MSCs can form chimeric antigen receptor MSCs (CAR-MSCs). Whether CAR-MSCs can provide a new idea of cancer immunotherapy is unknown. It is a prime time to review the latest progress of MSCs in cancer immunotherapy, in order to clarify to fully understand the role of MSCs in cancer therapy in clinical practice.

Stem cells are known for their extraordinary properties, mainly their potency, self-renewal, and clonality. In recent years, we have witnessed notable advancements in the field of cell therapy. Due to its remarkable properties and versatility, this cutting-edge therapy has now become a potentially promising cure for many diseases. Stem cell-based therapies have been utilized to treat various dermatological conditions, for instance, autoimmune skin disorders, atopic dermatitis, skin aging, wound healing, scar treatment, and many others. This article aims to serve as an overview of cell-based therapy's current application in dermatology field.

Different types of stem cells have remarkable characteristics such as high proliferation rate, multi/pluripotency, self-renewal, and broad differentiation that can effectively treat diseases, cancers, and damage. Despite abundant therapeutic applications of stem cells in medical science, numerous risks threaten stem cell transplantation. Tumor development, immune response, cellular senescence, dosage effects, and administration timing are critical risks that should be considered in stem cell therapy. Hence, an investigation of possible risks is required before utilizing stem cell-based medicinal products in the clinical phase and human trials. This review aims to survey the literature and perspectives on the advantages and risks associated with pluripotent and multipotent stem cells.

Hepatic disease is one of the most common causes of death worldwide and has become a global health problem. Liver transplantation is the only effective treatment strategy for patients with hepatic function failure, but the insufficient number of donated healthy livers is the main obstacle limiting this process. To alleviate the demand for donor's livers, alternative approaches are being actively explored using liver tissue engineering principles. Liver tissue engineering consists of three elements, including seeding cells, extracellular matrix, and bioreactors. Among them, seeding cell is the most key factor. In this regard, hepatocyte-based tissue engineering can overcome the above shortages for tissue repair and regeneration in hepatic disorders. Primary human hepatocytes in liver regenerative medicine are the most preferred seeding cells, although limited access to a sufficient number of functional hepatocytes are a major issue due to the difficulties in long-term function maintenance of hepatocyte as well as the lack of availability of healthy donors. Hepatocyte-like cells (HLCs), derived from various stem cells, including non-liver-derived stem cells and liver-derived stem cells, as well as trans-differentiation of other cell types, may provide adequate cell sources and could replace primary human hepatocytes as seeding cells. However, it is still a great difficulty that HLCs generated by stem cell differentiation meet the quality required for clinical therapy. Furthermore, none of the standardized protocols to generate high-quality HLCs is available. Whether primary hepatocytes or HLCs are from various sources, preventing the functional deterioration of hepatocytes or generating fully functional hepatocytes is also a big challenge, respectively. In addition, the adoptions of three-dimensional co-culture systems and some small-molecule compounds contribute to maintaining the hepatic functionality of primary hepatocytes and enhancing the liver-specific functions of HLCs. In short, hepatocyte-based liver regenerative medicine is an attractive alternative strategy for liver diseases, notwithstanding some challenges still exist from bench to bedside. This review summarizes the current status, issues, and challenges in availability, functionality, and safety, as well as quality control of seeding hepatocytes with regard to liver tissue engineering in regenerative medicine for the treatment of liver disorders.

Background: Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in polyvinyl chloride products which is widely utilized. Previously we found, DEHP reduced the viability and proliferation ability of bone marrow mesenchymal stem cells (BMSCs). Objective: In the present study, the mechanism of DEHP toxicity was investigated. Methods: Rat BMSCs were cultured up to 3^rd passage and their viability was determined after treatment with 100 and 500 μM of DEHP for 24 and 48 hours. The levels of sodium, potassium, and calcium as well as induction of apoptosis were investigated. Using flow cytometry, cell cycle analysis was performed and the expression of genes involved in the cell cycle was evaluated using reverse transcriptase-PCR. Data were analyzed and p < 0.05 was taken as the level of significance. Results: Although the viability and electrolyte level of BMSCs were not affected with 100 μM of DEHP, this environmental pollution induced caspase-dependent apoptosis in a concentration-dependent manner. In both of the concentrations, DEHP arrests the cell cycle at the G0/G1 phase, and the expression of Cdk2 and Cdk4 was significantly reduced whereas an over-expression of P53 was observed. However, the expression of the raf1 gene remained unchanged. Conclusion: DEHP induces caspase-dependent apoptosis in BMSCs and arrests the cell cycle due to the reduction of Cdk2 and Cdk4 expression via over-expression of P53.

Aim: The study aims to investigate the immunomodulatory effect of Amniotic fluid stem (AFS) cells to Th2-skewed allergic rhinitis (AR) on T-lymphocyte proliferation, viability, activation and cytokine production. Background: AFS cells can suppress peripheral blood mononuclear cells (PBMCs) proliferation and display immunomodulatory properties, but AFS cells' immunoregulation on AR has not been defined. Methods: Human AFS cells were derived from magnetic cell sorting and co-cultured with PBMCs from AR patients stimulated by phytohemagglutinin (PHA). The AFS cells-associated suppressive proliferation was analyzed using CellTrace™ Violet assay; the T lymphocytes proliferation, viability, activation and the Foxp3⁺ Treg cells were determined by flow cytometry; cytokine levels were measured using an enzyme- linked immunosorbent assay. Results: We determined that AFS cells significantly inhibited PHA-induced CD3⁺ T lymphocyte proliferation at the ratio higher than 1:50 (AFS cells: PBMCs) (P<0.05); AFS cells obviously increased the T lymphocytes viability (P<0.01), inhibited the apoptosis of T lymphocytes (P<0.001), compared to PBMCs alone; AFS cells suppressed CD3⁺CD25⁺ T lymphocytes activated by PHA (P<0.05); AFS cells significantly promote Treg cells expansion in house dust mite (HDM)-stimulated PBMCs from AR patients (P<0.05). Compared with HDM-stimulated PBMCs, AFS cell co-culture predominantly decreased IL-4 level (P<0.05), but increased IFN-γ and IL-10 levels (P<0.01). Conclusion: AFS cells modulate the T-cells' immune imbalance towards Th2 suppression in AR, which can be used as a new cell banking for allergic airway diseases.

Background: Bone tissue engineering, as a relatively new approach, has focused on combining biodegradable scaffolds, cells, and biologically active molecules for the recovery of different damaged tissues, such as bone defects. Polyurethane (PU), as a synthetic polymer, benefits from a porous structure which impersonates bone's natural environment. However, PU lacks osteoinduction activities. Cobalt nanoparticles (CoNPs) stimulate angiogenesis and biomineralization, which greatly favors osteogenesis. Methods: Here, we designed a novel scaffold based on PU and combined it with CoNPs for bone regeneration applications. The composition and structure of PU-CoNPs nanocomposite were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). MTT and AO data showed biocompatibility and enhanced viability and proliferation of fibroblasts on PU-CoNPs scaffold. Ascorbic acid-2-phosphate, β-glycerophosphate, and dexamethasone-induced osteogenesis for 14 days. Results: The alkaline phosphatase test asserts the increased mineralization of hADSCs cultured on PUCoNPs compared to pure PU scaffold. Further, the results disclosed an elevated osteogenic differentiation at the level of genes and proteins using immunocytochemical analysis (ICC) and quantitative real-time PCR (qPCR). Conclusion: These findings provide an evidence that PU-CoNPs nanocomposite might be a promising candidate for bone repair applications.

Background: Colorectal cancer (CRC) is the third most common cancer worldwide. Recently, mesenchymal stem cells (MSCs) have been considered a suitable cell therapy option for cancer due to their high migration rate to the tumor site. Objectives: The study aimed to compare the effects of human umbilical cord blood derived-MSC (UCMSC) and human Wharton’s Jelly derived-MSC (WJ-MSC) on the HT-29 cell line. Methods: UC-MSC was obtained by Ficoll-Paque density gradient and WJ-MSC by explant method. The characterizations of MSCs and apoptosis assays were performed by flow cytometry, and caspase-3 protein levels were measured by ELISA. Results: After 72 hours of HT-29 cancer cells incubation, it was indicated that WJ-MSC was more effective at 1:5 and 1:10 ratios. Similar results were found for caspase-3 by ELISA. Moreover, WJ-MSC (1:5, p < 0.006; 1:10, p < 0.007) was found to be more effective at both doses compared to UC-MSC. Conclusion: In this study, we used two different MSC sources at two different ratios to evaluate the apoptotic effect of MSC in vitro on HT-29 CRC cells. As a result, WJ-MSC indicated a more apoptotic effect on HT-29 cells compared to CB-MSC. We anticipated that this preliminary in vitro study would be extended in future in vitro/in vivo studies. Moreover, investigating the behavior of MSC in colorectal tumor microenvironment will be beneficial for the stem cell therapy approach.

Background: Bone marrow mesenchymal stem cells (BMSCs) are pluripotent cells with the ability to differentiate into adipocytes, chondrocytes, and osteoblasts. BMSCs are widely used in regenerative medicine and cartilage tissue engineering. Role of lncRNA LRRC75A-AS1 (leucine-rich repeat containing 75A antisense RNA 1) in the chondrogenic differentiation of BMSCs was investigated in this study. Methods: BMSCs were isolated from rat bone marrow and then identified using flow cytometry. Alcian blue staining was used to detect chondrogenic differentiation. The effect of LRRC75A-AS1 on chondrogenic differentiation was assessed by western blot. The downstream target of LRRC75A-AS1 was determined by dual luciferase activity assay. Results: BMSCs were identified with positive CD29 and CD44 staining and negative staining of CD34 and CD45. LRRC75A-AS1 was decreased during the chondrogenic differentiation of BMSCs. Silencing of LRRC75A-AS1 increased collagen II (COL II), aggrecan and SOX9 and promoted chondrogenic differentiation. However, over-expression of LRRC75A-AS1 inhibited chondrogenic differentiation. miR- 140-3p was increased during chondrogenic differentiation and interacted with LRRC75A-AS1. miR-140- 3p bind to wnt3a, and inhibition of miR-140-3p up-regulated wnt3a and nuclear β-catenin expression. Wnt3a and nuclear β-catenin were decreased during chondrogenic differentiation. Inhibition of miR-140- 3p attenuated LRRC75A-AS1 deficiency-induced up-regulation of COL II, aggrecan and SOX9. Conclusion: LRRC75A-AS1 suppressed chondrogenic differentiation of BMSCs through down-regulation of miR-140-3p and up-regulation of the wnt/β-catenin pathway.

Objective: The Achilles tendon is the most frequently injured tendon in the human body, despite being the strongest. Many conventional treatments including medication, surgical interventions, and physical therapy are available, however, the desired results are often not achieved. Stromal vascular fraction (SVF) and bone marrow concentrate (BMC) are two additional cellular treatment options. The purpose of this study is to evaluate the effect of SVF and BMC, used as a combination, for the treatment of Achilles tendon injuries. Methods: Five male New Zealand rabbits were used for each of the 6 study groups. A 3-mm of SVF and BMC were injected on the Achilles tendons at certain ratios. The histological results were classified by the Movin grading system for tendon healing. The collagen type-I and type-III structures in the tendons were examined by immunohistochemical evaluation. The expressions of tendon-specific genes were also examined by using the RT-PCR method to analyze tendon healing. Results: Histological and immunohistochemical evaluation indicated that tendons receiving the SVF and BMAC mixture performed better than control and individual groups (p < 0.05). Moreover, RT-PCR evaluation showed that mixture-receiving groups were the closest similar to the uninjured group (p < 0.05). Conclusion: The combined use of BMC and SVF improved Achilles tendon healing when compared to the individual use of each mixture.

Background: Due to its effective osteogenic ability, BMP9 is a promising candidate for bone regeneration medicine. Whereas, BMP9 can also induce adipogenesis simultaneously. LCN2 is a cytokine associated with osteogenesis and adipogenesis. Reducing the adipogenic potential may be a feasible measure to enhance the osteogenic capability of BMP9. Objective: The objective of the study was to explore the role of LCN2 in regulating the BMP9-initialized osteogenic and adipogenic differentiation in mouse embryonic fibroblasts (MEFs), and clarify the possible underlying mechanism. Methods: Histochemical stain, western blot, real-time PCR, laser confocal, immunoprecipitation, cranial defect repair, and fetal limb culture assays were used to evaluate the effects of LCN2 on BMP9-induced osteogenic and adipogenic differentiation, as well as Wnt/β-catenin signaling. Results: LCN2 was down-regulated by BMP9. The BMP9-induced osteogenic markers were inhibited by LCN2 overexpression, but the adipogenic markers were increased; LCN2 knockdown exhibited opposite effects. Similar results were found in bone defect repair and fetal limb culture tests. The level of β-catenin nucleus translocation was found to be reduced by LCN2 overexpression, but increased by LCN2 knockdown. The inhibitory effect of LCN2 overexpression on the osteogenic capability of BMP9 was reversed by β-catenin overexpression; whereas, the effect of LCN2 knockdown on promoting BMP9 osteogenic potential was almost eliminated by β-catenin knockdown. LCN2 could bind with LRP6 specifically, and the inhibitory effect of LCN2 on the osteogenic potential of BMP9 could not be enhanced by LRP6 knockdown. Conclusion: LCN2 inhibits the BMP9-induced osteogenic differentiation but promotes its adipogenic potential in MEFs, which may be partially mediated by reducing Wnt/β-catenin signaling via binding with LRP6.

Aim: The aim of this study was to identify the biological characteristics and potential roles of endometrial progenitor cells in the pathogenesis of endometriosis. Background: It is generally believed that progenitor cells in human endometrium are responsible for rapid endometrial regeneration. However, the biological characteristics and potential roles of the paired eutopic and ectopic endometrial progenitor cells in endometriosis remain unclear. Objective: This study intends to isolate the epithelial progenitor (EP) cells and endometrial mesenchymal stem cells (eMSCs) from the eutopic and ectopic endometria from endometriosis patients, further to reveal their features and functions respectively. Methods: The distributions of EP cells and eMSCs and the expression of steroid hormone receptors in the endometrium and endometriotic tissues were assessed by immunohistochemistry. EP cells and eMSCs were sorted from paired eutopic and ectopic endometria with epithelial cell adhesion molecule (EpCAM) magnetic beads. The clonogenicity, cell viability after being treated with estradiol and progesterone, and cell markers expression were evaluated with colony forming on Matrigel, CCK-8 and immunofluorescence staining, respectively. The differentially expressed genes (DEGs) were further identified with RNA sequencing. Results: SSEA-1- and PDGFRβ-positive cells were distributed in the epithelial and stromal layers. The ERβ staining was much more intense in endometriotic tissues, but PR expression was almost absent. The ectopic EP cells exhibit strong clonogenicity and ERβ expression but weak PR expression, leading to progesterone resistance. There are 12604 and 13242 DEGs revealed by RNA sequencing between eutopic and ectopic EP cells or eMSCs. GO and KEGG analyses revealed that the functions and pathways of DEGs enriched in cellular energy metabolism and regulation of the immune response, respectively. Additionally, ERβ targets were mainly enriched in ectopic EP cells. Conclusion: Both EP cells and eMSCs may engage in ectopic lesion formation in endometriosis by modifying the metabolic mode and immune tolerance. These data not only help to understand the molecular mechanism of endometriosis but also could potentially contribute to the discovery of therapeutic targets for endometriosis.