Stem Cells International最新文献

The scientific field concerned with the study of regeneration has developed rapidly in recent years. Stem cell therapy is a highly promising therapeutic modality for repairing tissue defects; however, several limitations exist, such as cytotoxicity, potential immune rejection, and ethical issues. Exosomes secreted by stem cells are cell-specific secreted vesicles that play a regulatory role in many biological functions in the human body; they not only have a series of functional roles of stem cells and exert the expected therapeutic effects, but they can also overcome the mass limitations of stem cells and are thus considered in the research as an alternative treatment strategy for stem cells. Since dental stem cell-derived exosomes (DSC-Exos) are easy to acquire and present modulating effects in several fields, including neurovascular regeneration and craniofacial soft and hard tissue regeneration processes, they are served as an emerging cell-free therapeutic strategy in various systematic diseases. There is a growing body of research on various types of DSC-Exos; however, they lack systematic elaboration and tabular summarization. Therefore, this review presents the isolation, characterization, and phenotypes of DSC-Exos and focuses on their current status of functions and mechanisms, as well as the multiple challenges prior to clinical applications.

Objectives: To explore the efficacy and the mechanism of the umbilical cord-derived cells combined with cyclosporine A (CsA) in treating aplastic anemia (AA) in mice.

Methods: Immune-mediated AA model mice were treated with CsA + UC mesenchymal stem cells (UC-MSC), CsA + umbilical cord blood regulatory T cells (UCB-T_reg), UC-MSC, UCB-T_reg, CsA alone, or blank control, respectively (n = 9 mice/group). CsA and the cell infusion was administered on d0. Routine peripheral blood testing was performed once weekly; bone marrow colony culture, bone marrow cell flow cytometry, peripheral blood T cell subsets, and serum inflammatory cytokines tests were performed on d14. Transcriptome sequencing was performed for cells from CsA + UC-MSC, CsA + UCB-T_reg, and CsA groups to detect the possible related genes. Gene function cluster and signal pathway enrichment analysis were also performed.

Results: Blank control mice died due to pancytopenia within 21 days, whereas mice in other groups survived for >28 days. On d14, the CsA + UC-MSC and CsA + UCB-T_reg groups had higher white blood cell (WBC) counts than the other groups (p < 0.05), along with higher burst-forming unit (BFU) and colony-forming unit-granulocyte, macrophage (CFU-GM) counts (p < 0.01). The CsA + UC-MSC group had the highest BFU count (p < 0.01). The CsA + UC-MSC and CsA + UCB-T_reg groups exhibited the highest bone marrow CD34⁺ cell proportion (9.68% ± 1.35% and 8.17% ± 0.53%, respectively; p < 0.01). Tumor necrosis factor (TNF)-α and interleukin (IL)-2 levels in the CsA + UC-MSC group (p < 0.05) and TNF-α, interleukin-2, and interferon (INF)-γ levels in the CsA + UC-T_reg group (p < 0.01) were lower than those in the CsA group. Compared with CsA treatment, CsA + UC-MSC significantly downregulated the histone methylation pathway (p < 0.05), whereas CsA + UCB-T_reg significantly upregulated energy metabolism processes (p < 0.05). Treatment with CsA + UC-MSC upregulated superoxide dismutase activity compared with CsA + UCB-T_reg treatment.

Conclusions: Adding UC-MSC or UCB-T_reg to CsA markedly enhanced the reconstruction of hematopoiesis in AA mice, with UC-MSC eliciting greater efficiency than UCB-T_reg. Accordingly, the addition of these cells could further improve immune abnormalities.

Gastric cancer (GC) is the fourth leading cause of cancer-related death, associated with late diagnosis and treatment resistance. Currently, screening tests for GC are not cost-effective or have low accuracy. Previously, we described an extended phenotype of gastric cancer stem cells (GCSCs; CD24⁺CD44⁺CD54⁺EpCAM⁺) that is associated with metastasis and tumor stage in GC patients. The goal of the current research is to evaluate the presence of these GCSCs in the peripheral blood of GC patients and healthy volunteers. A total of 73 blood samples were collected from 32 GC patients and 41 healthy volunteers. After peripheral blood mononuclear cell (PBMC) extraction, multiparametric flow cytometry was performed looking for GCSCs. Using clustering data through artificial intelligence (AI), we defined high/low levels of circulating GCSCs (cGCSCs) and proceeded to evaluate its association with clinical and prognostic variables. Finally, a diagnostic test analysis was performed evaluating patients and healthy volunteers. We found that cGCSCs are present in most GC patients with a mean concentration of 0.48%. The AI clustering showed two groups with different cGCSC levels and clinical characteristics. Through statistical analysis, we confirmed the association between cGCSC levels and lymph node metastasis, distant metastasis, and overall survival. The diagnostic test analysis showed sensibility, specificity, and area under the curve (AUC) of 83%, 95%, and 0.911, respectively. Our results suggest that the assessment of cGCSCs CD24⁺CD44⁺CD54⁺EpCAM⁺ could be a potential noninvasive test, with prognostic value, as well as highly sensitive and specific for screening or diagnosis of GC; however, a larger scale study will be necessary to confirm this.

Currently, a series of licensing strategies has been investigated to enhance the functional properties of mesenchymal stem cells (MSCs). Licensing with IFN-γ is one of the most investigated strategies for enhancing the immunosuppressive potential of such cells. However, it is not yet known whether this licensing strategy could interfere with the ability of MSCs to control bacterial growth, which may be relevant considering their clinical potential. In this study, we compared the antimicrobial potential of IFN-γ-licensed and unlicensed MSCs by exposing them to Pseudomonas aeruginosa and its quorum-sensing inducer molecule OdDHL. Our data show that-when challenged with OdDHL-IFN-γ-licensed and unlicensed MSCs present increased levels of the antimicrobial HAMP transcript, but that only IFN-γ-licensed MSCs undergo modulation of CASP1 and BCL2, entering apoptosis. Furthermore, we demonstrate that only IFN-γ-licensed MSCs show modulation in genes involved in apoptosis and tend to undergo cell death when cultured with P. aeruginosa. As a consequence, IFN-γ-licensed MSCs showed lower capacity to control bacterial growth, compared to unlicensed MSCs. Taken together, our observations reveal an increased susceptibility to apoptosis of IFN-γ-licensed MSCs, which compromises their potential to control the bacterial growth in vitro. These findings are relevant to the field of cell therapy, considering the potential applicability of MSCs.

The ovary is an important organ for women to maintain reproductive and endocrine functions. Ovarian aging can lead to female reproductive aging, which is a key factor causing rapid aging of the female body. Umbilical cord-derived MSCs (UC-MSCs) play a therapeutic role in various degenerative diseases. Dehydroepiandrosterone (DHEA) is widely used in the treatment of reversing oocyte quality. However, it is unclear whether UC-MSCs combined with DHEA supplementation can improve ovarian senescence in naturally aging mice. To address this question, we studied the influence of the combination of human UC-MSCs (hUC-MSCs) and DHEA on ovarian morphology and function in naturally aging mice. The results showed a significant augmentation in the number of primary follicles, as well as a significant upregulation of estradiol (E2), follicle-stimulating hormone (FSH), and anti-Mullerian hormone (AMH) hormone levels, and a significant increase in survival rate in naturally aging mice treated by hUC-MSCs and DHEA. Moreover, the combination of hUC-MSCs and DHEA significantly reduced the reactive oxygen species (ROS) level and downregulated the expression levels of proinflammatory factors IL-6, IL-18, and TNF-α. Furthermore, the PI3K/AKT/mTOR pathway was inhibited. Conclusively, the combination therapy of hUC-MSC + DHEA contributed to restore ovarian function in aging mice and extend their lifespan by restoring hormone levels and inhibiting inflammatory factors.

[This corrects the article DOI: 10.1155/2021/2347506.].

Background: Using a toxin-induced lethal acute liver failure (ALF) monkey model, we have recently shown that early peripheral infusion of human umbilical cord mesenchymal stem cells (hUC-MSCs) can alleviate liver damage and improve animal survival by suppressing the activation of circulating monocytes and the subsequent cytokine storm. Here, we explored whether the administration of hUC-MSCs could still improve ALF when the cytokine storm is fully developed.

Method: We treated ALF monkeys with peripheral delivery of hUC-MSCs at 48 hr after toxin challenge. Liver indices, histology, imaging, and animal survival were recorded and analyzed.

Results: In our cohort study, we conducted and demonstrated that the infusion of hUC-MSCs significantly improved liver histology, effectively controlled inflammatory cytokine storms, and increased survival rates. Additionally, the administration of a higher dose of hUC-MSCs (2 × 10⁷/monkey) yielded superior outcomes compared to a lower dose (1 × 10⁷/monkey).

Conclusion: Treatment of hUC-MSCs can significantly improve the pathological and survival outcomes of ALF even when the cytokine storm has been fully developed, indicating a promising clinical solution for ALF.

Patients with focal segmental glomerulosclerosis (FSGS) who are refractory to drug treatment may present progressive loss of kidney function, leading to chronic kidney disease stage 5 under dialysis treatment. The safety of systemic administration of bone marrow-derived mononuclear cells (BMDMCs) has been shown in different preclinical models of kidney diseases. However, to date, no study has evaluated the safety and biodistribution of BMDMCs after infusion in renal arteries in patients with FSGS. We used a prospective, non-randomized, single-center longitudinal design to investigate this approach. Five patients with refractory FSGS and an estimated glomerular filtration rate (eGFR) between 20 and 40 ml/min/1.73 m² underwent bone marrow aspiration and received an arterial infusion of autologous BMDMCs (5 × 10⁷) for each kidney. In addition, BMDMCs labeled with technetium-99m (^99mTc-BMDMCs) were used to assess the biodistribution by scintigraphy. All patients completed the 270-day follow-up protocol with no serious adverse events. A transient increase in creatinine was observed after the cell therapy, with improvement on day 30. ^99mTc-BMDMCs were detected in both kidneys and counts were higher after 2 hr compared with 24 hr. The arterial infusion of BMDMCs in both kidneys of patients with FSGS was considered safe with stable eGFR at the end of follow-up. This trial is registered with NCT02693366.

Gastric cancer stem cells (GCSCs) originate from both gastric adult stem cells and bone marrow cells and are conspicuously present within the histological milieu of gastric cancer tissue. GCSCs play pivotal and multifaceted roles in the initiation, progression, and recurrence of gastric cancer. Hence, the characterization of GCSCs not only facilitates precise target identification for prospective therapeutic interventions in gastric cancer but also has significant implications for targeted therapy and the prognosis of gastric cancer. The prevailing techniques for GCSC purification involve their isolation using surface-specific cell markers, such as those identified by flow cytometry and immunomagnetic bead sorting techniques. In addition, in vitro culture and side-population cell sorting are integral methods in this context. This review discusses the surface biomarkers, isolation techniques, and identification methods of GCSCs, as well as their role in the treatment of gastric cancer.