Current Stem Cell Research & Therapy - Current Issue

Stem cells play a therapeutic role in many diseases by virtue of their strong self-renewal and differentiation abilities, especially in the treatment of autoimmune diseases. At present, the mechanism of the stem cell treatment of autoimmune diseases mainly relies on their immune regulation ability, regulating the number and function of auxiliary cells, anti-inflammatory factors and proinflammatory factors in patients to reduce inflammation. On the other hand, the stem cell- derived secretory body has weak immunogenicity and low molecular weight, can target the site of injury, and can extend the length of its active time in the patient after combining it with the composite material. Therefore, the role of secretory bodies in the stem cell treatment of autoimmune diseases is increasingly important.

Stem cells hold great promise as novel and encouraging therapeutic tools in the treatment of degenerative disorders due to their differentiation potential while maintaining the capability to self-renewal and their unlimited ability to divide and regenerate tissue. A variety of different types of stem cells can be used in cell therapy. Among these, mesenchymal stem cell (MSC) therapy has gradually established itself as a novel method for treating damaged tissues that need restoration and renewal. Male infertility is an important health challenge affecting approximately 8-12% of people around the world. This abnormality can be caused by primary, congenital, acquired, or idiopathic reasons. Men with no sperm in their semen have a condition called azoospermia, caused by non-obstructive (NOA) causes and post-testicular obstructive causes. Accumulating evidence has shown that various types of MSCs can differentiate into germ cells and improve spermatogenesis in the seminiferous tubules of animal models. In addition, recent studies in animal models have exhibited that extracellular vesicles derived from MSCs can stimulate the progression of spermatogenesis and germ cell regeneration in the recipient testes. In spite of the fact that various improvements have been made in the treatment of azoospermia disorder in animal models by MSC or their extracellular vesicles, no clinical trials have been carried out to test their therapeutic effect on the NOA. In this review, we summarize the potential of MSC transplantation for treating infertility caused by NOA.

Introduction: Mesenchymal stem cells (MSCs) have been widely studied because of their established anti-inflammatory properties. During chronic salpingitis (CS), infiltrated macrophages have vital roles in inflammation and tissue remodeling. Methods: We employed the type of MSCs, human umbilical cord (huc) MSCs in an experimental CS model and therapeutic efficacy was assessed. hucMSCs exerted this therapeutic effect by regulating macrophage function. To verify the regulatory effects of hucMSCs on the macrophage, macrophage line RAW264.7 markers were analyzed under LPS stimulation with or without co-culturing with hucMSCs for 12h and 24h. In addition, flow cytometry analysis was applied to reveal the interaction of co-culture. For animal studies, CS was induced by the MoPn strain Chlamydia trachomatis (CT), hucMSCs were intravaginally injected in the CS, and we analyzed the infiltrated macrophage by immunofluorescence. Results: We found the markers IL-10 was markedly increased and IL-1β, caspase-1 was notably downregulated after co-culturing with hucMSCs by RT-PCR. hucMSCs promote macrophage line RAW264.7 apoptosis. We also found that hucMSCs treatment can alleviate CS by decreasing the mRNA expression of IL-1β, caspase-1 and MCP-1 in the tubal tissue by RT-PCR and decreasing the protein expression of IL-1β, caspase-1 and TGF-β by western blotting. Conclusion: These results suggest that macrophage function may be related to the immune-modulating characteristics of hucMSCs that contribute to CS.

Background: Transplantation of pancreatic β-cells generated from human induced pluripotent stem cells (hiPSCs) has great potential as a root treatment for type 1 diabetes. However, their current level of efficiency to differentiate into β-cells is still not at par for clinical use. Previous research has shown that differentiation efficiency varies among human embryonic stem cells and mouse-induced pluripotent stem cell lines. Therefore, selecting a suitable cell line for efficient induction into desired tissues and organs is crucial. Methods: In this study, we have evaluated the efficiency of 15 hiPSC lines available for clinical use to differentiate into pancreatic β-cells. Results: Our investigation has revealed induction efficiency to differ among the hiPSC lines, even when derived from the same donor. Among the hiPSC lines tested, the 16A01 cell line exhibited the highest Insulin expression and low Glucagon expression, suggesting that this cell line is suitable for differentiation into β-cells. Conclusion: Our study has demonstrated the importance of selecting a suitable hiPSC line for effective differentiation into β-cells.

Introduction: Bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) may function as novel candidates for treating diabetic wounds due to their ability to promote angiogenesis. Materials and Methods: This study investigated the effects of BMSC-exos on the growth and metastasis of human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG). The exosomes were separated from BMSCs and identified. The cell phenotype was detected by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and 5-ethynyl-2’-deoxyuridine, wound healing, and transwell assays, while the number of tubes was measured via tube formation assay. Result: The RNA and protein expression levels were studied using reverse transcription-quantitative polymerase chain reaction and western blotting, whereas integration of microRNA-99b-5p (miR-99b-5p) with THAP domain containing 2 (THAP2) was confirmed via dual-luciferase reporter and RNA pull-down assays. Results of transmission electron microscopy, nanoparticle tracking analysis, and laser scanning confocal microscopy revealed that exosomes were successfully separated from BMSCs and endocytosed into the cytoplasm by HUVECs. Similarly, BMSC-exos were found to promote the growth of HG-treated HUVECs, while their growth was inhibited by suppressing miR-99b-5p. THAP2 was found to bind to miR-99b-5p, where THAP2 inhibition reversed the miR-99b-5p-induced effects on cell growth, migration, and tube numbers. Conclusion: In conclusion, miR-99b-5p in BMSC-exo protects HUVECs by negatively regulating THAP2 expression.

Objective: In recent times, it has been recognized that mesenchymal stem cells (MSCs) possess the capability to address osteoarthritis (OA). The objective of this research was to examine the impact of injecting human adipose-derived stem cells (hADSCs) into a novel rabbit osteoarthritis model with dual damage. Methods: The OA model was established surgically first by medial collateral ligament and anterior cruciate ligament transection and medial meniscectomy, then by articular cartilage full-thickness defect. Enhanced Green Fluorescence Protein expressing lentivirus FG12 was used to label hADSCs, which were then injected into the knee joints. Every single rabbit was sacrificed after 4 and 8 weeks following the surgical procedure. Macroscopic examination, immunohistochemistry staining, magnetic resonance imaging, qRT-PCR, and ELISA analysis were utilized for the assessments. Results: After 4 and 8 weeks, the injection of hADSCs resulted in reduced cartilage loss, minimal fissures and cracks, and a decrease in the volume of joint effusion and cartilage defect as measured by MRI. Moreover, the application of ELISA and qRT-PCR techniques revealed that the administration of hADSCs resulted in an elevation in the IGF-1 concentration. Conclusions: Based on our findings, it can be inferred that the transplantation of hADSCs facilitates the healing of articular cartilage in the osteoarthritis model of rabbits with double damage. The upregulated IGF-1 may play a crucial part in the process of cartilage repair using hADSCs. The use of hADSC transplantation could potentially be appropriate for clinical implementation in managing osteoarthritis.

Background: The effectiveness of fucoxanthin (Fx) in liver diseases has been reported due to its anti-inflammatory and antifibrotic effects. Mesenchymal stem cells (MSCs)-based therapy has also been proposed as a promising strategy for liver fibrosis treatment. Recent studies have shown that the co-administration of MSCs and drugs demonstrates a pronounced effect on liver fibrosis. Aim: This study aimed to determine the therapeutic potential of placenta-derived MSCs (PD-MSCs) in combination with Fx to treat liver fibrosis and evaluate their impact on the main links of liver fibrosis pathogenesis. Methods: After PD-MSCs isolation and identification, outbred ICR/CD1 mice were divided into five groups: Control group, CCl4group (CCl4), Fx group (CCl4+Fx), PD-MSCs group (CCl4+MSCs) and cotreatment group (CCl4+MSCs+Fx). Biochemical histopathological investigations were performed. Semiquantitative analysis of the alpha-smooth muscle actin (α-SMA+), matrix metalloproteinases (MMP-9+, MMP-13+), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1+) areas, and the number of positive cells in them were studied by immunohistochemical staining. Transforming growth factor-beta (TGF-β), hepatic growth factor (HGF), procollagen-1 (COL1α1) in liver homogenate and proinflammatory cytokines in blood serum were determined using an enzyme immunoassay. Results: Compared to the single treatment with PD-MSCs or Fx, their combined administration significantly reduced liver enzyme activity, the severity of liver fibrosis, the proinflammatory cytokine levels, TGF-β level, α-SMA+, TIMP-1+ areas and the number of positive cells in them, and increased HGF level, MMP-13+, and MMP-9+ areas. Conclusion: Fx enhanced the therapeutic potential of PD-MSCs in CCl4-induced liver fibrosis, but more investigations are necessary to understand the mutual impact of PD-MSCs and Fx.

Background: Retinal aging is one of the common public health problems caused by population aging and has become an important cause of acquired vision loss in adults. The aim of this study was to determine the role of human umbilical cord mesenchymal stem cells (hUCMSCs) in delaying retinal ganglion cell (RGC) aging and part of the network of molecular mechanisms involved. Methods: A retinal ganglion cell senescence model was established in vitro and treated with UCMSC. Successful establishment of the senescence system was demonstrated using β- galactosidase staining. The ameliorative effect of MSC on senescence was demonstrated using CCK8 cell viability and Annexin V-PI apoptosis staining. The relevant targets of RGC, MSC, and senescence were mainly obtained by searching the GeneCards database. The protein interaction network among the relevant targets was constructed using the String database and Cytoscape, and 10 key target genes were calculated based on the MCC algorithm, based on which Gene ontologies (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were performed. Changes in relevant target genes were detected using real-time fluorescence quantitative PCR and the mechanism of action of UCMSC was determined by RNA interference. Results: β-galactosidase staining showed that UCMSC significantly reduced the positive results of RGC. The retinal aging process was alleviated. The bioinformatics screen yielded 201 shared genes. 10 key genes were selected by the MCC algorithm, including vascular endothelial growth factor A (VEGFA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), albumin (ALB), interleukin- 6 (IL6), tumor necrosis factor (TNF), tumor protein P53 (TP53), insulin (INS), matrix metalloproteinase 9 (MMP9), epidermal growth factor (EGF), interleukin-1β (IL1B), and enrichment to related transferase activity and kinase activity regulated biological processes involved in oxidative stress and inflammation related pathways. In addition, PCR results showed that all the above molecules were altered in expression after UCMSC involvement. Conclusion: This experiment demonstrated the role of UCMSC in delaying retinal ganglion cell senescence and further elucidated that UCMSC may be associated with the activation of VEGFA, TP53, ALB, GAPDH, IL6, IL1B, MMP9 genes and the inhibition of INS, EGF, and TNF in delaying retinal senescence.

Introduction: Toll-like receptor 4 (TLR4) is a receptor that traditionally plays an important role in immunomodulation (regulation of the immune system) and the initiation of proinflammatory responses. TLR4 is used in the body to recognize molecular patterns of pathogens or damaged cells from outside. However, in recent years, it has also become clear that TLR4 can affect the immune system and the function of stem cells, especially mesenchymal stem cells. Therefore, understanding how TLR4 signaling works at the cellular and molecular level and using this knowledge in regenerative medicine could be potentially useful, especially in the treatment of adipose- derived mesenchymal stem cells (ADMSCs). How these cells can use TLR4 signaling when used to increase their regenerative potential and repair tissues is an area of research. Aims: This study aims to elucidate the multifaceted role of TLR4-mediated signaling in ADMSCs. Methods: Employing a comprehensive set of assays, including MTT for cell viability, flow cytometry for surface marker expression, and gene expression analysis, we demonstrate that TLR4 activation significantly modulates key aspects of ADMSC biology. Specifically, TLR4 signaling was found to regulate ADMSCs proliferation, surface marker expression, and regenerative capacity in a dose- and time-dependent manner. Furthermore, TLR4 activation conferred cytoprotective effects against Doxorubicin (DOX)-induced cellular apoptosis. Results: These findings suggest that TLR4 signaling could be used to enhance the regenerative abilities of ADMSCs and enable ADMSC-based therapies to be used more effectively for tissue engineering and therapeutic purposes. Conclusion: However, it is important to note that research in this area needs more details and clinical studies.

Background: MSCs are a part of the tumor microenvironment, which secrete cytokines and chemokines. They can affect metastasis and the growth of tumors. metastamiRs are newly recognized regulatory elements of the metastasis pathway which are involved in epithelial-to-mesenchymal transition (EMT). Objective: In the present study, we aimed to assess the expression profile of metastamiRs in the context of MSCs in correlation with their invasion and migration power. Methods: Tumor-isolated BC-MSCs and normal human mammary epithelial cells (HMECs) along with MCF-7, MDA-MB231, and MCF-10A cells were prepared and confirmed for their identity. The cells were assessed for CD44+CD24¯ percentage, Oct-4, and Survivin expression. GEO, KEGG, and TCGA databases were investigated to detect differential miR-expressions. Real- time PCR for 13 miRs was performed using LNA primers. Ultimately, Transwell-Matrigel assays as used to assess the level of migration and invasion. Results: Our results indicated that some oncomiRs like miR-10b were upregulated in BC-MSCs, while the levels of miR-373 and miR-520c were similar to the MCF-10A. Generally, miR-200 family members were on lower levels compared to the other miR-suppressor (miR-146a, 146b, and 335). miR-31 and 193b were up-regulated in MCF-10A. The most invasiveness was observed in the MDA-MB231 cell line. Conclusion: We have demonstrated that the miR-expression levels of BC-MSCs are somewhat in between MCF-7 and MDA-MB231 miR-expression levels. This could be the logic behind the moderate level of invasion in BC-MSCs. Therefore, miR-therapy approaches such as miR-mimic or antagomiRs could be used for BC-MSCs in clinical cancer therapy.