STEM CELLS最新文献

Introduction: Mesenchymal stromal cells (MSCs) can modulate immune responses and suppress inflammation in autoimmune diseases. Although their safety has been established in clinical trials, the efficacy of MSCs is inconsistent due to variability in potency among different preparations and limited specificity in targeting mechanisms driving autoimmune diseases.

Methods: We utilized High-Dimensional Design of Experiments methodology to identify factor combinations that modulate gene expression by MSCs to mitigate inflammation. This led to a novel MSC-based cell therapy, HXB-319. Its anti-inflammatory properties were validated in vitro by flow cytometry, RT-PCR, and mass spectrophotometry. To evaluate in vivo efficacy, we treated a diffuse alveolar hemorrhage (DAH) mouse model (C57Bl/6). Seven days post-DAH induction with pristane, mice received either MSCs or HXB-319 (2X106 cells, IP). On day 14, peritoneal lavage fluid (PLF) and lung tissue were collected for flow cytometry, histopathological examination and mRNA.

Results: HXB-319 increased gene expression levels of anti-inflammatory, angiogenic and anti-fibrotic factors (e.g. TSG-6, VEGF and HGF). KEGG pathway analysis confirmed significant activation of relevant anti-inflammatory, angiogenic, and anti-fibrotic proteins, corroborating RT-PCR results.In the DAH model, HXB-319 significantly reduced lung inflammation and alveolar hemorrhage compared to MSC treated and untreated DAH mice. HXB-319 treatment also significantly decreased neutrophils, plasmacytoid dendritic cells and RORγT cells, and increased FoxP3+ cells in PLF, and reversed alterations in mRNA encoding IL-6, IL-10 and TSG-6 in lung tissue compared to DAH mice.

Conclusion: HXB-319 effectively controls inflammation and prevents tissue damage in pristane induced DAH, highlighting its therapeutic potential for autoimmune inflammatory diseases.

Insulin-producing pancreatic β-like cells derived from human pluripotent stem cells (PSCs) are anticipated as a novel cell source for cell replacement therapy for diabetes patients. Here, we describe the identification of small molecule compounds that promote the differentiation of the PSCs into insulin-producing cells by high throughput screening with a chemical library composed of 55,000 compounds. The initial hit compound K-1 and one derivative K-3 increased the proportion of PSC-derived insulin-positive endocrine cells and their glucose-stimulated insulin secretory (GSIS) functions. K-3 preferentially acts on stage 3 pancreatic progenitor cells and increases the population expressing high levels of PDX1. As a result, the ratios of the PSC-derived PDX1 / NKX6.1 double-positive endocrine progenitor and INS / NKX6.1 double-positive mono-hormonal endocrine cells were increased. K-3 enhances the expression of functional pancreatic β cell markers and affects biological processes concerning organ development. K-3 also increased the yield of endocrine cells at the end of stage 5. The novel compound is a beneficial new tool for efficiently generating PSC-derived insulin-producing cells with high functionality and differentiation efficiency.

Neural stem cells (NSCs) are found along the neuraxis of the developing and mature central nervous system. They are found in defined niches that have been shown to regulate NSC behaviour in a regionally distinct manner. Specifically, previous research has shown that myelin basic protein (MBP), when presented in the spinal cord niche, inhibits NSC proliferation and oligodendrogenesis. Herein, we investigate the cell-based mechanism(s) underlying this spinal-cord niche derived MBP-mediated inhibition. We used reporter mice to sort for subpopulations of cells and found that spinal cord niche derived microglia release a soluble factor in response to MBP that is responsible for NSC inhibition. Microglia, but not other niche cells, release soluble CD40/TNFRSF5 (sCD40) in the presence of MBP which may indirectly reduce activation of transmembrane CD40/TNFRSF5 receptor on both spinal cord and brain NSCs. This is consistent with sCD40 binding to CD40 ligand (CD40L) thereby preventing CD40 receptor binding on NSCs and inhibiting NSC proliferation. The identification of the cell-based mechanism that regulates NSC behaviour in response to MBP, which is dysregulated in injury/disease, provides insight into a potential target for strategies to enhance neural repair through endogenous stem cell activation.

In the central nervous system, cell-to-cell interaction is essential for brain plasticity and repair, and its alteration is critically involved in the development of neurodegenerative diseases. Neural stem cells are a plentiful source of biological signals promoting neuroplasticity and the maintenance of cognitive functions. Extracellular vesicles (EVs) represent an additional strategy for cells to release signals in the surrounding cellular environment or to exchange information among both neighboring and distant cells. In the last years, rising attention has been devoted to the ability of stem cell (SC)-derived EVs to counteract inflammatory and degenerative brain disorders taking advantage of their immunomodulatory capacities and regenerative potential. Here, we review the role of adult neurogenesis impairment in the cognitive decline associated with neurodegenerative diseases and describe the beneficial effects of SC-derived EVs on brain plasticity and repair also discussing the advantages of SC-derived EV administration versus SC transplantation in the treatment of neurodegenerative disorders.

Bone marrow (BM) mesenchymal stromal cells (MSCs) are important regulators of hematopoietic stem and progenitor cells (HSPCs). When transformed to a dysplastic phenotype, MSCs contribute to hematopoietic diseases such as myelodysplastic syndromes (MDS), but it remains unclear if there are specific properties in MDS-MSCs that contribute to the disease course. To understand this, we investigated MDS-MSCs from fast (MDSfast) vs slow (MDSslow) progressing disease groups and discovered differences between these groups. MDSfast-MSCs secrete more inflammatory factors, support myeloid-skewed differentiation of HSPCs, and importantly, show poorer response to hypomethylation as a key differentiator in GSEA analysis. When exposed to long-term in vivo stimulation with primary MDSfast-MSCs-based scaffolds, healthy donor (HD) HSPCs show elevated NF-κB expression, similar to leukemic HSPCs in MDS. Those "MDSfast-MSCs-primed" HD-HSPCs continue to show enhanced engraftment rates in secondary MDS-MSC-based scaffolds, providing evidence for the microenvironmental selection pressures in MDS towards leukemic HSPCs. Together, our data point towards a degree of co-development between MSCs and HSPCs during the progression of MDS, where changes in MDS-MSCs take place mainly at the transcriptomic and functional levels. These unique differences in MDS-MSCs can be utilized to improve disease prognostication and implement targeted therapy for unmet clinical needs.

Peripheral arterial disease (PAD) is associated with lower-extremity muscle wasting. Hallmark features of PAD-associated skeletal muscle pathology include loss of skeletal muscle mass, reduced strength and physical performance, increased inflammation, fibrosis, and adipocyte infiltration. At the molecular level, skeletal muscle ischemia has also been associated with gene and microRNA (miRNA) dysregulation. Mesenchymal stromal cells (MSCs) have been shown to enhance muscle regeneration and improve muscle function in various skeletal muscle injuries. This study aimed to evaluate the effects of intramuscularly delivered human umbilical cord-derived MSCs (hUC-MSCs) on skeletal muscle ischemia. Herein, we report an hUC-MSC-mediated amelioration of ischemia-induced skeletal muscle atrophy and function via enhancement of myofiber regeneration, reduction of tissue inflammation, adipocyte accumulation, and tissue fibrosis. These changes were observed in the absence of cell-mediated enhancement of blood flow recovery as measured by laser Doppler imaging. Furthermore, reduced tissue fibrosis in the hUC-MSC-treated group was associated with upregulation of miR-1, miR-133a, and miR-29b and downregulation of targeted pro-fibrotic genes such as Col1a1 and Fn1. Our results support the use of hUC-MSCs as a novel approach to reduce fibrosis and promote skeletal muscle regeneration after ischemic injury in patients with PAD.

Prior evidence indicates that the erythroid cellular response to glucocorticoids (GC) has developmental specificity, namely, that developmentally more advanced cells that are undergoing or have undergone fetal to adult globin switching are more responsive to GC-induced expansion. To investigate the molecular underpinnings of this, we focused on the major developmental globin regulator BCL11A. We compared: (1) levels of expression and nuclear content of BCL11A in adult erythroid cells upon GC stimulation; (2) response to GC of CD34+ cells from patients with BCL11A microdeletions and reduced BCL11A expression, and; (3) response to GC of 2 cellular models (HUDEP-2 and adult CD34+ cells) before and after reduction of BCL11A expression by shRNA. We observed that: (1) GC-expanded erythroid cells from a large cohort of blood donors displayed amplified expression and nuclear accumulation of BCL11A; (2) CD34 + cells from BCL11A microdeletion patients generated fewer erythroid cells when cultured with GC compared to their parents, while the erythroid expansion of the patients was similar to that of their parents in cultures without GC, and; (3) adult CD34+ cells and HUDEP-2 cells with shRNA-depleted expression of BCL11A exhibit reduced expansion in response to GC. In addition, RNA-seq profiling of shRNA-BCL11A CD34+ cells cultured with and without GC was similar (very few differentially expressed genes), while GC-specific responses (differential expression of GILZ and of numerous additional genes) were observed only in control cells with unperturbed BCL11A expression. These data indicate that BCL11A is an important participant in certain aspects of the stress pathway sustained by GC.

CRISPR-Cas9 editing triggers activation of the TP53-p21 pathway, but the impacts of different editing components and delivery methods have not been fully explored. In this study, we introduce a p21-mNeonGreen reporter iPSC line to monitor TP53-p21 pathway activation. This reporter enables dynamic tracking of p21 expression via flow cytometry, revealing a strong correlation between p21 expression and indel frequencies, and highlighting its utility in guide RNA screening. Our findings show that p21 activation is significantly more pronounced with double-stranded oligodeoxynucleotides (ODNs) or adeno-associated viral vectors (AAVs) compared to their single-stranded counterparts. Lentiviral vectors (LVs) and integrase-defective lentiviral vectors induce notably lower p21 expression than AAVs, suggesting their suitability for gene therapy in sensitive cells such as hematopoietic stem cells or immune cells. Additionally, specific viral promoters like SFFV significantly amplify p21 activation, emphasizing the critical role of promoter selection in vector development. Thus, the p21-mNeonGreen reporter iPSC line is a valuable tool for assessing the potential adverse effects of gene editing methodologies and vectors. Highlights Established a p21-mNeonGreen reporter iPSC line to track activation of the TP53-p21 pathway. Found a direct correlation between p21-mNeonGreen expression and indel frequencies, aiding in gRNA screening. Showed that LVs are preferable over AAVs for certain cells due to lower p21 activation, with viral promoter choice impacting p21 response.