Stem cells and development最新文献

Immunotherapy utilizes immune cells to target cancer and improves treatment outcomes with few side effects. Despite the effectiveness of immunotherapy, the limited availability of monocytes, which are essential for the differentiation of antigen-presenting cells, remains a major challenge. In this study, we developed a technique for inducing monocytes from hematopoietic stem and progenitor cells by using a serum-free (SF) medium supplemented with optimal concentrations of serum substitutes and cytokines. Three key serum substitutes, namely lipids, ascorbic acid, and β-glycerophosphate, were identified through factorial design screening, with their concentrations optimized through steepest ascent path analysis. Iscove's modified Dulbecco's medium was identified as the optimal basal medium. Long-term culturing confirmed the successful induction of CD14⁺CD16⁺ and CD14⁺CD16^- monocytes. Functional assays validated the efficacy of this technique with comparable gene expression, cytokine secretion, phagocytosis ability, and T-cell stimulating ability between SF and serum-containing cultures. Under SF conditions, high expression levels of CD16 were detected, indicating the broad range of potential applications of CD16⁺ monocytes. Overall, this technique represents a feasible SF alternative for monocyte generation, with potential benefits for immunotherapy.

Ninety-nine percent of alpha-synuclein (α-syn) in the human body is distributed in erythrocytes. However, the role that α-syn plays in erythropoiesis remains unclear. To determine the effect of α-syn on erythroid differentiation, the erythroid cells, derived from human CD34+ progenitors in the umbilical cord, were cultured in a system composed of a series of cytokines and harvested after 6 days. Our work showed α-syn inhibition-promoted erythropoiesis as characterized by altered activity of surface markers of erythroid development such as CD49d, CD36, and CD71; and different methylation status of GDP-D-mannose dehydratase, aldolase fructose-bisphosphate A, and sorbitol dehydrogenase, key enzymes involved in fructose and mannose metabolism. Reduced adenosine triphosphate and elevated lactic acid also suggested a shift in cellular metabolism from mitochondrial respiration to glycolysis. Our study revealed a previously unknown role for α-syn as a methylation regulator that alters the activity of key enzymes of the fructose and mannose metabolism, thus contributing to erythropoiesis.

Autologous hematopoietic stem cell transplantation is used to restore bone marrow function after high-dose chemotherapy. For apheresis, granulocyte colony-stimulating factor (G-CSF) is standard of care, but obtaining sufficient stem cells can be challenging. Other mobilization agents include plerixafor and PEGylated G-CSF (PEG-G-CSF). While efficacy of these is established in adults, limited data for their use in pediatric patients are available. Here, we compare Good versus Poor Mobilizers and study success of different mobilization regimens in regard to CD34⁺cell-collection, -quality, -phenotype and hematologic reconstitution in pediatric patients. In this multi-center retrospective study, we analyzed data of 278 patients with solid tumors and lymphoma, mobilized with either G-CSF (n = 224), PEG-G-CSF (n = 34), or G-CSF/PEG-G-CSF with additional plerixafor (n = 20). In Poor Mobilizers (13.7% of all patients), addition of plerixafor to G-CSF augmented CD34⁺cell collection, without adverse effects on hematologic reconstitution and CD34⁺cell quality. PEG-G-CSF-aided mobilization was successful as first-line treatment in two-thirds of patients and did not impair hematological reconstitution, compared to G-CSF-only. Within the Poor Mobilizer group, G-CSF+plerixafor increased primitive (CD45RA^-CD38^-CD90⁺CD49f⁺) and CXCR4-expressing CD34⁺cells in apheresis products compared to G-CSF-only, without exceeding levels of Good Mobilizers. No plerixafor-related increase in tumor cells was observed in apheresis products. In conclusion, our comprehensive study supports the use of plerixafor and furthermore demonstrates the potential of patient-friendly PEG-G-CSF for mobilization of pediatric patients.

In adults, the limbal stem cells (LSC) reside in the limbal region of the eye, at the junction of the cornea and the sclera where they renew the outer epithelial layer of the cornea assuring transparency. LSC deficiencies (LSCD) due to disease or injury account for one of the major causes of blindness. Among current treatments for LSCD, cornea transparency can be restored by providing new LSC to the damaged eye and induced pluripotent stem cells (iPSC) holds great promise as a new advanced cell source. A synthetic mRNA-based protocol to produce human iPSC from bone marrow mesenchymal stem cells has been defined. The results demonstrate a standardizable method that can be easily adaptable for clinical-grade production standards, produce high-purity LSC-like cells in a relatively rapid timeframe of 12 days, and can be successfully seeded on amniotic membrane or a biodegradable fibrin gel for transplantation. In vivo data demonstrated it is feasible to transplant the iPSC-LSC fibrin patch. In conclusion, an efficient method has been developed to produce patient-specific LSC and seed them on a scaffold fibrin gel for future treatment of LSC-deficiency disease.

Fasting regimens have shown profound impact on pro-longevity and tissue regeneration in diverse species. Physiological events can induce a regenerative response in adult stem cells. However, little is known about signaling and activation of adult stem cells which are modulated by fasting. This study analyzed the presence of hematopoietic stem/progenitor cells (HSPCs) and their circulation in the peripheral blood (PB) of healthy male adults practicing Ramadan fasting. Ten healthy male volunteers were enrolled in this prospective observational study. PB samples were collected twice daily on days 0, 10, 20, and 30 of Ramadan fasting (RF). Populations of stem cells and serum soluble factors were analyzed by flow cytometry. As a response to RF, we report an increase in the average absolute count of circulating of HSPCs, defined as LIN^-CD45^- and LIN^-CD45⁺ cell subsets expressing the stem markers, CD34 and CD133. Changes in the number of HSPCs subsets reflected changes in the peripheral concentration of chemoattractant soluble factors during fasting. A chemotaxis assay showed a migratory property of HSPCs towards plasma, collected at D30 of fasting that contained a higher concentration of SCF and G-CSF. The relationship between RF and an increase in the number of circulating HSPCs in part, describes a regenerative response to the physiological changes during fasting and may open opportunities to define the role of dietary intervention in the stem cell therapy.

Current treatments for retinal degenerative diseases are limited and cell replacement therapies, in tandem with a supportive biomaterial scaffold, serve as a promising emerging option. However, the development and in vitro testing of these therapies require large quantities of human retinal progenitor cells (RPCs) to thoroughly assess the impact of material properties, culture conditions, and surgical parameters on cell survival and fate to refine and optimize this approach. Although induced pluripotent stem cells (iPSCs) are an ideal cell source for human RPC derivation, large-scale production is resource-intensive and requires specialized expertise. In this study, our objective was to address this barrier by creating conditional, Tet-On SV40-T immortalized RPCs derived from human iPSCs. In our approach, we employ the Tet-On system to conditionally immortalize RPCs by inducing a SV40 large T (SV40-T) antigen, a gene known to influence cell cycle regulation and differentiation. We transduced human iPSCs with the Tet-On SV40-T system and analyzed their proliferation and RPC differentiation capabilities in the presence and absence of doxycycline (a tetracycline class of antibiotics). Our results revealed that while SV40-T immortalization increased cell proliferation, it adversely impacted the expression of crucial RPC markers (PAX6, SOX2, CHX10), leading to a significant loss of RPC identity and multipotency. This de-differentiation was irreversible, even after removing doxycycline, indicating permanent alterations in differentiation potential. Overall, this study highlights the challenges associated with generating and maintaining an immortal human RPC cell line, particularly with respect to balancing proliferation and differentiation. Our findings prompt further research into optimizing conditional immortalization techniques, culture conditions, and proliferation timing to maintain the integrity and functional characteristics of RPCs. Such advancements are crucial for reducing labor and costs associated with in vitro testing of therapeutics as we work toward the development of improved stem cell-based interventions for retinal disease.

The quality of organoid models can be assessed by single-cell-RNA-sequencing (scRNA-seq) but often only bulk transcriptome data is available. Here we present a pipeline for the analysis of scRNA-seq data and subsequent "deconvolution," which is a method for estimating cell type fractions in bulk transcriptome data based on expression profiles and cell types found in scRNA-seq data derived from biopsies. We applied this pipeline on bulk iPSC-derived kidney and brain organoid transcriptome data to identify cell types employing two scRNA-seq kidney datasets and one brain dataset. Relevant cells present in kidney (e.g., proximal tubules, distal convoluted tubules, and podocytes) and brain (e.g., neurons, astrocytes, oligodendrocytes, and microglia) with obligatory endothelial and immune-related cells were identified. We anticipate that this pipeline will also enable estimation of cell type fractions in organoids of other tissues.

This review explores the potential of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) in cartilage regeneration and osteoarthritis treatment. It covers key factors influencing chondrogenesis, including growth factors, cytokines, and hypoxia, focusing on precise timing. The effectiveness of three-dimensional cultures and scaffold-based strategies in chondrogenic differentiation is discussed. Specific biomaterials such as chitosan and hyaluronic acid are highlighted for tissue engineering. The document reviews clinical applications, incorporating evidence from animal research and early trials and molecular and histological assessments of chondrogenic differentiation processes. It addresses challenges and strategies for optimizing MSC-derived chondrocyte therapy, emphasizing the immunomodulatory properties of these cells. The review concludes as a comprehensive road map for future research and clinical applications in regenerative medicine.

Radiation therapy (RT) is a typical treatment for head and neck cancers. However, prolonged irradiation of the esophagus can cause esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. The objective of this study was to determine whether myogenic gene-transfected mesenchymal stem cells (MSCs) could ameliorate damage to esophageal muscles in a mouse model of radiation-induced esophageal fibrosis. We cloned esophageal myogenic genes (MyoD, MyoG, and Myf6) using plasmid DNA. Afterward, myogenic genes were transfected into Human Mesenchymal Stem Cells (hMSCs) using electroporation. Gene transfer efficiency, stemness, and myogenic gene profile were examined using flow cytometry, quantitative polymerase chain reaction, and RNA sequencing. In vivo efficacy of gene-transfected hMSCs was demonstrated through histological and gene expression analyses using a radiation-induced esophageal fibrosis animal model. We have confirmed that the gene transfer efficiency was high (∼75%). Pluripotency levels in gene-transfected MSCs were significantly decreased compared with those in the control (vector). Particularly, myogenesis-related genes such as OAS2, OAS3, and HSPA1A were overexpressed in the group transfected with three genes. At 4 weeks after injection, it was found that thickness collagen layer and esophageal muscle in MSCs transfected with all three genes were significantly reduced compared to those in the saline group. Muscularis mucosa was observed prominently in the gene combination group. Moreover, expression levels of myogenin, Myf6, calponin, and SM22α known to be specific markers of esophageal muscles tended to increase in the group transfected with three genes. Therefore, using gene-transfected MSCs has the potential as a promising therapy against radiation-induced esophageal fibrosis.