STEM CELLS最新文献

The human hand is traumatized more frequently than any other bodily part. Trauma and pathological processes (eg, rheumatoid arthritis, osteoarthritis) commonly implicate the finger joints and specifically damage also the layer of articular cartilage. Endeavors are now being made to surgically repair such cartilage lesions biologically using tissue-engineering approaches that draw on donor cells and/or donor tissues. The tendon sheaths, particularly their inner layers, that is, the peritendineum, surround the numerous tendons in the hand. The peritendineum is composed of mesenchymal tissue. We hypothesize that this tissue harbors pluripotent mesenchymal stem cells and thus could be used for cartilage repair, irrespective of the donor's age. Using a bovine model (young calves vs adult cows), the pluripotentiality of the peritendineal stem cells, namely, their osteogenicity, chondrogenicity, and adipogenicity, was investigated by implementing conventional techniques. Subsequently, the chondrogenic potential of the peritendineal tissue itself was analyzed. Its differentiation into cartilage was induced by the application of specific growth factors (members of the TGF-β-superfamily). The characteristics of the tissue formed were evaluated structurally (immuno) histochemically, histomorphometrically, and biochemically (gene expression and protein level). Our data confirm that the bovine peritendineum contains stem cells whose pluripotentiality is independent of donor age. This tissue could also be induced to differentiate into cartilage, likewise, irrespective of the donor's age. Preliminary investigations with adult human peritendineal biopsy material derived from the hand's peritendineal flexor tendon sheaths revealed that this tissue can also be induced to differentiate into cartilage.

Bone marrow (BM) mesenchymal stromal cells (MSCs) are important regulators of hematopoietic stem and progenitor cells (HSPCs). When transformed into 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 toward leukemic HSPCs. Together, our data point toward 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.

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 patients with diabetes. 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.

The large majority of Alzheimer's disease (AD) cases are sporadic with unknown genetic causes. In contrast, only a small percentage of AD cases are familial, with known genetic causes. Paradoxically, there are only few validated mouse models of sporadic AD but many of familial AD. Senescence accelerated mouse-prone 8 (SAMP8) mice are a model of accelerated aging with features of sporadic AD. They exhibit a more complete suite of human AD-relevant pathologies than most familial models. SAMP8 brains are characterized by inflammation, glial activation, b-amyloid deposits, and hyperphosphorylated Tau. The excess amyloid deposits congregate around blood vessels leading to vascular impairment and leaky BBBs in these mice. SAMP8 mice also exhibit neuronal cell death, a feature not typically seen in models of familial AD. Additionally, adult hippocampal neurogenesis is decreased in SAMP8 mice and correspondingly, they have reduced cognitive ability. In line with this, hippocampal LTP is significantly compromised in SAMP8 mice. No model is perfect and SAMP8 mice are limited by the lack of clarity about their genomic differences from control Senescence Accelerated Mouse-Resistant 1 (SAMR1) mice although their transcriptomics changes are being revealed. To further complicate matters, multiple substrains of SAMP8 mice have emerged over the years, sometimes making comparisons of studies difficult. Despite these challenges, we argue that SAMP8 mice can be useful for studying AD-relevant symptoms and propose important experiments to strengthen this already useful model.

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 (eg, 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, 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 pristine-induced DAH, highlighting its therapeutic potential for autoimmune inflammatory diseases.

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 behavior 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 behavior 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.

Gut microbiota plays an important role in regulating brain function and adult neurogenesis. Although probiotics have recently been reported as effective against certain psychiatric disorders, the underlying mechanisms remain unclear. In particular, the combination of 3 probiotic strains, Bacillus subtilis TO-A, Enterococcus faecium T-110, and Clostridium butyricum TO-A, hereafter referred to as ProB3, has been reported to potentially alleviate psychiatric symptoms in patients with schizophrenia. Herein, we show that ProB3 promotes adult neurogenesis in mice and restores its dysregulation in germ-free (GF) mice. ProB3 colonization in GF mice enhanced the proliferation of adult neural stem cells compared to specific-pathogen-free and GF mice. Furthermore, ProB3 colonization was sufficient to ameliorate the arrest of newborn neuron maturation and the diminution of quiescent neural stem cells in GF mice. ProB3 colonization in mice increased the levels of several metabolites in the blood, including theanine and 3-hydroxybutyrate, and imidazole peptides, including anserine, which promoted proliferation, neurogenesis, and maturation of newborn neurons in cultured human fetus neural stem cells, as well as mouse adult hippocampal neural stem cells. Collectively, these results indicate that the essential role of the gut microbiota in adult hippocampal neurogenesis can be effectively complemented by the intake of a specific 3-strain probiotic, ProB3, providing novel insights into the brain-gut axis.

iPSCs can serve as a renewable source of a consistent edited cell product, overcoming limitations of primary cells. While feeder-free generation of clinical grade iPSC-derived CD8 T cells has been achieved, differentiation of iPSC-derived CD4sp and regulatory T cells requires mouse stromal cells in an artificial thymic organoid. Here we report a serum- and feeder-free differentiation process suitable for large-scale production. Using an optimized concentration of PMA/Ionomycin, we generated iPSC-CD4sp T cells at high efficiency and converted them to Tregs using TGFβ and ATRA. Using genetic engineering, we demonstrated high, non-viral, targeted integration of an HLA-A2 CAR in iPSCs. iPSC-Tregs +/- HLA-A2-targeted CAR phenotypically, transcriptionally and functionally resemble primary Tregs and suppress T cell proliferation in vitro. Our work is the first to demonstrate an iPSC-based platform amenable to manufacturing CD4 T cells to complement iPSC-CD8 oncology products and functional iPSC-Tregs to deliver Treg cell therapies at scale.

Neural stem cells (NSCs) have great potentials in the application of neurodegenerative disease therapy, drug screening, and disease modeling. However, current approaches for induced NSCs (iNSCs) generation from somatic cells are still slow and inefficient. Here we establish a rapid and efficient method of iNSCs generation from human and mouse fibroblasts by single microRNAs (miR-302a). These iNSCs exhibited morphological, molecular and functional properties resembling those of adult human and mouse NSCs, and human iNSCs can be expanded for more than 20 passages in vitro. Furthermore, miR-302a alone was demonstrated to be sufficient to reprogram both human and mouse fibroblasts into iNSCs. Our results showed that direct conversion of autologous fibroblasts with miR-302a into iNSCs, which provides a rapid and efficient strategy to generate iNSCs for both basic research and clinical applications.

Myocardial infarction can lead to the loss of billions of cardiomyocytes, and while cell-based therapies are an option, immature nature of in vitro-generated human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) is a roadblock to their development. Existing iPSC differentiation protocols don't go beyond producing fetal iCMs. Recently, adult extracellular matrix (ECM) was shown to retain tissue memory and have some success driving tissue-specific differentiation in unspecified cells in various organ systems. Therefore, we focused on investigating the effect of adult human heart-derived ECM on iPSC cardiac differentiation and subsequent maturation. By preconditioning iPSCs with ECM, we tested whether creating cardiac environments around iPSCs would drive iPSCs toward cardiac fate and which ECM components might be involved. We report novel high- and low- abundance proteomes of young, adult, and aged human hearts, with relative abundances to total proteins and each other. We found that adult ECM had extracellular galactin-1, fibronectin, fibrillins, and perlecan (HSPG2) which are implicated in normal heart development. We also showed preconditioning iPSCs with adult cardiac ECM resulted in enhanced cardiac differentiation, yielding iCMs with higher functional maturity, more developed mitochondrial network and coverage, enhanced metabolic maturity, and shift towards more energetic profile. These findings demonstrate the potential use of cardiac ECM in iCM maturation and as a promising strategy for developing iCM-based therapies, disease modeling, and drug screening studies. Upon manipulating ECM, we concluded that the beneficial effects observed were not solely due to the ECM proteins, which might be related to the decorative units attached.