scholarly journals Material microenvironmental properties couple to induce distinct transcriptional programs in mammalian stem cells

2018 ◽  
Vol 115 (36) ◽  
pp. E8368-E8377 ◽  
Author(s):  
Max Darnell ◽  
Alison O’Neil ◽  
Angelo Mao ◽  
Luo Gu ◽  
Lee L. Rubin ◽  
...  

Variations in a multitude of material microenvironmental properties have been observed across tissues in vivo, and these have profound effects on cell phenotype. Phenomenological experiments have suggested that certain of these features of the physical microenvironment, such as stiffness, could sensitize cells to other features; meanwhile, mechanistic studies have detailed a number of biophysical mechanisms for this sensing. However, the broad molecular consequences of these potentially complex and nonlinear interactions bridging from biophysical sensing to phenotype have not been systematically characterized, limiting the overall understanding and rational deployment of these biophysical cues. Here, we explore these interactions by employing a 3D cell culture system that allows for the independent control of culture substrate stiffness, stress relaxation, and adhesion ligand density to systematically explore the transcriptional programs affected by distinct combinations of biophysical parameters using RNA-seq. In mouse mesenchymal stem cells and human cortical neuron progenitors, we find dramatic coupling among these substrate properties, and that the relative contribution of each property to changes in gene expression varies with cell type. Motivated by the bioinformatic analysis, the stiffness of hydrogels encapsulating mouse mesenchymal stem cells was found to regulate the secretion of a wide range of cytokines, and to accordingly influence hematopoietic stem cell differentiation in a Transwell coculture model. These results give insights into how biophysical features are integrated by cells across distinct tissues and offer strategies to synthetic biologists and bioengineers for designing responses to a cell’s biophysical environment.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2351-2351
Author(s):  
Chiemi Nishida ◽  
Kaori Sato-Kusubata ◽  
Yoshihiko Tashiro ◽  
Ismael Gritli ◽  
Aki Sato ◽  
...  

Abstract Abstract 2351 Stem cells reside in a physical niche. The organization of cellular niches has been shown to play a key role in regulating normal stem cell differentiation, stem cell maintenance and regeneration. Various stem cell niches have been shown to be hypoxic, thereby maintaining the stem cell phenotype of e.g. hematopoietic stem cells (HSCs) or cancer stem cells. The bone marrow (BM) niche is a rich reservoir of tissue-specific pluripotent HSCs. Proteases such as matrix metalloproteinases (MMPs) have been implicated in cell movement, partly due to their proteolytic function, and they have been linked to cellular processes such as cell proliferation and differentiation. The proteolytic function of Membrane-type 1 MMP (MT1-MMP/MMP-14) is essential for angiogenesis, arthritis and tumour growth. Recently, it has been reported that MT1-MMP is highly expressed in HSCs and stromal/niche cells. However the clear function of MT1-MMP in hematopoiesis is not well understood. To reveal the functional consequences of MT1-MMP deficiency for post-natal hematopoiesis in vivo, we have taken advantage of MT1-MMP−/− mice to demonstrate that MT1-MMP deficiency leads to impaired steady state hematopoiesis of all hematopoietic cell lineages. In a search for factors whose deficiency could cause this hematopoietic phenotype, we found not only reduced protein release, but also reduced transcription of the following growth factors/chemokines in MT1-MMP−/− mice: erythropoietin (Epo), stromal cell-derived factor-1 (SDF-1a/CXCL12), interleukin-7 (IL-7) and Kit ligand (KitL, also known as stem cell factor). All of these factors, except for Epo, are typical stromal cell-derived factors. To ensure that impaired gene transcription in vivo was not due to a lower number of stromal cells in vivo, we demonstrated that MT1-MMP knockdown in stromal cells in vitro also reduced transcription of the stromal cell derived factors SDF-1a/CXCL12, IL-7 and KitL. In contrast, overexpression of MT1-MMP in stromal cells enhanced gene transcription of these factors. All genes, whose transcription was altered in vitro and in vivo due to MT1-MMP deficiency, had one thing in common: their gene transcription is regulated by the hypoxia inducible factor-1 (HIF-1) pathway. Further mechanistic studies revealed that MT1-MMP activates the HIF-1 pathway via factor inhibiting HIF-1 (FIH-1) within niche cells, thereby inducing the transcription of HIF-responsive genes, which induce terminal hematopoietic differentiation. Thus, MT1-MMP in niche cells regulates postnatal hematopoiesis by modulating hematopoietic HIF-dependent niche factors that are critical for terminal differentiation and migration. Disclosures: No relevant conflicts of interest to declare.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Hyun Sook Hong ◽  
Suna Kim ◽  
Youngsook Son

Bone marrow stem cells, especially, endothelial precursor cells (EPC), mesenchymal stem cells (MSC) or hematopoietic stem cell (HSC) are expected as reparative cells for the repair of a variety of tissue damages such as stroke and myocardial infarction, even though their role in the repair is not demonstrated. This report was investigated to find a role of Substance-p (SP) as a reparative agent in the tissue repair requiring EPC and MSC. In order to examine EPC (EPC SP ) and MSC (MSC SP ) mobilized by SP, we injected SP intravenously for consecutive 2 days and saline was injected as a vehicle. At 3 post injection, peripheral blood (PB) was collected.To get mesenchymal stem cells or endothelial progenitor cells, MNCs were incubated in MSCGM or EGM-2 respectively for 10 days. Functional characteristics of the EPC SP were proven by the capacity to form endothelial tubule network in the matrigel in vitro and in the matrigel plug assay in vivo. In contrast, MSC SP did not form a tube-like structure but formed a pellet-structure on matrigel. However, when both cells were premixed before the matrigel assay, much longer and branched tubular network was formed, in which a-SMA expressing MSC SP were decorating outside of the endothelial tube, especially enriched at the bifurcating point. MSC SP may contribute and reinforce elaborate vascular network formation in vivo by working as pericyte-like cells. Thus, the EPC SP and MSC SP were labeled with PKH green and PKH red respectively and their tubular network was examined. Well organized tubular network was formed, which was covered by PKH green labeled cells and was decorated in a punctate pattern by PKH red labeled cells. In order to investigate the role of EPC SP and MSC SP specifically in vivo, rabbit EPC SP and MSC SP were transplanted to full thickness skin wound. The vessel of EPC SP -transplanted groups was UEA-lectin+, which was not covered with a-SMA+ pericytes but EPC SP + MSC SP -transplanted groups showed, in part, a-SMA+ pericyte-encircled UEA-lectin+ vessels. This proved the specific role of MSC SP as pericytes. From these data, we have postulated that the collaboration of MSC and EPC is essential for normal vessel structure and furthermore, accelerated wound healing as ischemia diseases, which can be stimulated through by SP injection.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4193-4193
Author(s):  
Anna C. Berardi ◽  
Pamela Manieri ◽  
Elisa Ciraci ◽  
Roberto Tribuzi ◽  
Ilaria Di Girolamo ◽  
...  

Abstract A key mechanism responsible for processing of peptide-MHC class II complexes in mature Dendritic Cells (DCs) is the generalized activation of lysosomal function. Mechanisms underlie these developmental changes are controversial. Thus, it is unclear whether immature DCs can present self antigens, and which are the checkpoints that regulate antigen presentation in immature and mature DCs. Here we generated in-vitro human DCs from peripheral blood CD34+ hematopoietic stem cells (HSCs), by adding to the medium culture Flt-3, GM-CSF, IL-4, and TNF-a (cytokine cocktail, CC) at 37°C for 14 days, and analysed the lysosomal glycohydrolases production and function. Lysosomal enzymes, b-N-Acetyl-Hexosaminidase, a-Mannosidase, b-Galactosidase and b-Glucoronidase are highly increased in a wide range in DCs (14 days of culture) with respect to the CD34+HSCs. All the glycohydrolases activities measured at 3 and 7 days in-vitro culture, were similar and four times more than CD34+HSCs (day 0) respectively. Interestingly, no activities increase were observed, even when SCF, an early acting cytokine, promoting cellular proliferation, were added to the CC medium, indicating that this phenomenon is independent from the proliferation process. Moreover, LPS treatment, to induce DCs maturation, slightly enhance the specific activities of all enzymes that we tested as respect to the untreated cells. and support the evidence that the lysosomal glycohydrolases activation is up-stream to DCs maturation process. Furthermore, for the first time, this date indicated that lysosomal glycohydrolases are regulated during the stem cell differentiation process. Understanding the key mechanism leading this phenomenon is critical for therapeutic application in immunologic or neoplastic disease.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
John Michel ◽  
Matthew Penna ◽  
Juan Kochen ◽  
Herman Cheung

Modern day tissue engineering and cellular therapies have gravitated toward using stem cells with scaffolds as a dynamic modality to aid in differentiation and tissue regeneration. Mesenchymal stem cells (MSCs) are one of the most studied stem cells used in combination with scaffolds. These cells differentiate along the osteogenic lineage when seeded on hydroxyapatite containing scaffolds and can be used as a therapeutic option to regenerate various tissues. In recent years, the combination of hydroxyapatite and natural or synthetic polymers has been studied extensively. Due to the interest in these scaffolds, this review will cover the wide range of hydroxyapatite containing scaffolds used with MSCs forin vitroandin vivoexperiments. Further, in order to maintain a progressive scope of the field this review article will only focus on literature utilizing adult human derived MSCs (hMSCs) published in the last three years.


2020 ◽  
Author(s):  
Yanan Kong ◽  
Liuhanghang Cheng ◽  
Min Xuan ◽  
Hao Ding ◽  
Biao Cheng

Abstract Background Hematopoietic stem cells(HSCs) and mesenchymal stem cells(MSCs) can participate in wound healing. However, very few studies had shown HSCs and MSCs could arrive to the wound and differentiate into tissues. In this study, we intend to investigate the role of bone marrow HSCs and MSCs in wound healing. Methods We first removed the bone marrow of mice by irradiation. Furthermore, we injected different colours of fluorescent HSCs and MSCs into the tail vein of irradiated mice to reconstruct bone marrow function. We prepared wound models on the back of these mice. In vivo imaging and immunohistochemical staining were used to track the expression of fluorescent protein. Results HSCs and MSCs have been isolated and cultured. HSCs expressed expressed Sca1, not lineage, CD34 or CD48. MSCs expressed expressed CD29 and CD44,not CD34 or CD45. HSCs labeled with green fluorescent protein reached the wound and co-expressed with desmin and α-SMA. MSCs didn’t stay on the wound. Conclusions The results show HSCs in the bone marrow of mice can directly participate in wound healing and differentiate into pericytes and myofibroblasts.


Author(s):  
Juan Gao ◽  
Shuaibing Hou ◽  
Shengnan Yuan ◽  
Yuxia Wang ◽  
Yanan Gao ◽  
...  

Myeloid cells have been identified as hematopoietic stem cell (HSC)-regulating cells. However, the mechanisms by which myeloid cells regulate the function of HSCs are not fully defined. Our previous study indicated that the HSCs are over-expanded in Vav1-Cre;Rheb1fl/fl mice. Here, using in vivo and in vitro models, we found that Rheb1-deficient neutrophils remodeled the bone marrow environment and induced expansion of HSCs in vivo. Further studies showed that loss of Rheb1 impaired neutrophils’ ability to secrete IL-6, led mesenchymal stem cells (MSCs) to produce more SCF, and promote HSC proliferation. We further found that IL-6 suppressed SCF mRNA expression in human MSCs. Interesting, the high level of IL-6 was also related with poor survival of chronic myeloid leukemia (CML) patients, and higher expression of IL-6 in CML cells is associated with the lower expression of SCF in MSCs in patients. Our studies suggested that blocking IL-6 signaling pathway might stimulate MSCs to secrete more SCF, and to support hematopoietic stem/progenitor cells proliferation.


Author(s):  
Álvaro Sierra-Sánchez ◽  
Trinidad Montero-Vilchez ◽  
María I. Quiñones-Vico ◽  
Manuel Sanchez-Diaz ◽  
Salvador Arias-Santiago

Skin disease may be related with immunological disorders, external aggressions, or genetic conditions. Injuries or cutaneous diseases such as wounds, burns, psoriasis, and scleroderma among others are common pathologies in dermatology, and in some cases, conventional treatments are ineffective. In recent years, advanced therapies using human mesenchymal stem cells (hMSCs) from different sources has emerged as a promising strategy for the treatment of many pathologies. Due to their properties; regenerative, immunomodulatory and differentiation capacities, they could be applied for the treatment of cutaneous diseases. In this review, a total of thirteen types of hMSCs used as advanced therapy have been analyzed, considering the last 5 years (2015–2020). The most investigated types were those isolated from umbilical cord blood (hUCB-MSCs), adipose tissue (hAT-MSCs) and bone marrow (hBM-MSCs). The most studied diseases were wounds and ulcers, burns and psoriasis. At preclinical level, in vivo studies with mice and rats were the main animal models used, and a wide range of types of hMSCs were used. Clinical studies analyzed revealed that cell therapy by intravenous administration was the advanced therapy preferred except in the case of wounds and burns where tissue engineering was also reported. Although in most of the clinical trials reviewed results have not been posted yet, safety was high and only local slight adverse events (mild nausea or abdominal pain) were reported. In terms of effectiveness, it was difficult to compare the results due to the different doses administered and variables measured, but in general, percentage of wound’s size reduction was higher than 80% in wounds, Psoriasis Area and Severity Index and Severity Scoring for Atopic Dermatitis were significantly reduced, for scleroderma, parameters such as Modified Rodnan skin score (MRSC) or European Scleroderma Study Group activity index reported an improvement of the disease and for hypertrophic scars, Vancouver Scar Scale (VSS) score was decreased after applying these therapies. On balance, hMSCs used for the treatment of cutaneous diseases is a promising strategy, however, the different experimental designs and endpoints stablished in each study, makes necessary more research to find the best way to treat each patient and disease.


2021 ◽  
Vol 11 (5) ◽  
pp. 193-195
Author(s):  
Kaiser Jay Aziz-Andersen

CRISPR gene editing is a genetic engineering technique applied in clinical applications in which the genomes of living organisms may be modified. It is based on the principles of the CRISPR-Cas9 antiviral defense system. It is based on delivering the Cas9 nuclease complexed with a synthetic guide RNA into a living organism cell and that organisms’s genome can be “cut” and –“paste” at a desired location, allowing existing genes to be modified for desired outcome (i.e., CRISPR for Precision Medicine). CRISPR gene editing harnesses the natural defense mechanisms of some bacteria to cut human DNA strands. Then the DNA strand either heals itself or injects a new piece of DNA to mend the gap. Studies have been reported in Lung Cancer diagnosis and treatments. CRISPR-based engineering techniques have been developed for T Cells and Stem cells applications (i.e. Gene Corrections in Hematopoietic Stem Cells for the Treatment of Blood and Immune System Diseases). Even though earlier CRISPR methodologies were used for performing simple DNA edits, recent applications include the ability to delete genes or insert genes, and edit regulatory regions in a wide range of cell types. The role of CRISPR in human therapeutics is currently focused on utilizing CRISPR techniques to perform either in vivo editing of human cells–everything from the head, eye all the way to neurons and liver cells--or performing ex vivo therapies. The FDA’s new genomic CRISPR technology based products approval process begins with review and evaluation of preclinical studies in order to establish and characterize the proposed product’s safety profile. New genomic products must be shown to be safe and effective for the FDA approval process. The sponsor of the new genomic product must show that the product is safe and effective in human subjects.1


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5805-5805
Author(s):  
Lukun Zhou ◽  
Shuang Liu ◽  
Chuanyi M. Lu ◽  
Jianfeng Yao ◽  
Yuyan Shen ◽  
...  

Abstract Liver injury associated with veno-occlusive disease and graft-versus-host disease (GVHD) is a frequent and severe complication of hematopoietic stem cell transplantation, and remains an important cause of transplant-related mortality. Bone marrow derived mesenchymal stem cells (MSCs) have been evaluated for the prevention and treatment of refractory GVHD. However, poor cell viability has limited the therapeutic capacity of mesenchymal stromal cell therapy in vivo. In this study, we genetically engineered C57BL/6 mouse bone marrow MSCs using ex vivo retroviral transduction to overexpress Akt1, a serine threonine kinase and pro-survival signal protein, and tested the hypothesis that Akt1-expressing MSCs (Akt1-MSCs) are more resistant to apoptosis and can ameliorate acute liver injury induced by concanavalin A (ConA) in BALB/c mice. Cell proliferation and apoptosis analyses showed that, under both regular culture and high concentration IFN-γ (100 ng/mL) stimulation conditions, Akt1-GFP-MSCs had proliferation and survival (anti-apoptotic) advantages with down-regulated apoptosis pathways, compared to control GFP-MSCs. Twenty-four hours after receiving lethal dose of ConA (40 mg/kg, intravenous) (N=10 each group), no mouse survived, with or without 1x106 Akt1-MSCs or GFP-MSCs administration (intravenous); however, 3 and 1 survived in the 5×106 Akt1-MSCs group and 5×106 GFP-MSCs groups, respectively. In subsequent sub-lethal dose ConA (20 mg/kg) experiments, compared to GFP-MSCs, mice received Akt1-MSCs administration had significantly lower serum AST, ALT, TNF-α and IFN-γ levels and less histopathological abnormalities. In addition, Akt1-MSCs treated mice had significantly higher serum concentrations of IL-10, vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). In vivo imaging showed that, hepatic fluorescence signal in sub-lethal ConA+Akt1-MSCs group was significantly stronger than ConA+GFP-MSCs group on day 0, and persisted up to 14 days, whereas the signal in ConA+GFP-MSCs, Akt1-MSCs and GFP-MSCs groups was negligible on both day 7 and day 14. Thus, bone marrow derived MSCs genetically enhanced with Akt1 had survival advantage in vitro and in vivo, and have the potential to be a potent therapy for prevention and amelioration of GVHD-associated liver impairment. Further translational pre-clinical studies are ongoing to further determine the efficacy, dosage and timing of administration of Akt1-MSCs in animal models. Disclosures No relevant conflicts of interest to declare.


2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Lukun Zhou ◽  
Shuang Liu ◽  
Zhao Wang ◽  
Jianfeng Yao ◽  
Wenbin Cao ◽  
...  

Abstract Background Liver injury associated with acute graft-versus-host disease (aGVHD) is a frequent and severe complication of hematopoietic stem cell transplantation and remains a major cause of transplant-related mortality. Bone marrow-derived mesenchymal stem cells (BM-MSCs) has been proposed as a potential therapeutic approach for aGVHD. However, the therapeutic effects are not always achieved. In this study, we genetically engineered C57BL/6 mouse BM-MSCs with AKT1 gene and tested whether AKT1-MSCs was superior to control MSCs (Null-MSCs) for cell therapy of liver aGVHD. Results In vitro apoptosis analyses showed that, under both routine culture condition and high concentration interferon-γ (IFN-γ) (100ng/mL) stimulation condition, AKT1-MSCs had a survival (anti-apoptotic) advantage compared to Null-MSCs. In vivo imaging showed that AKT1-MSCs had better homing capacity and longer persistence in injured liver compared to Null-MSCs. Most importantly, AKT1-MSCs demonstrated an enhanced immunomodulatory function by releasing more immunosuppressive cytokines, such as IL-10. Adoptive transfer of AKT1-MSCs mitigated the histopathological abnormalities of concanavalin A(ConA)-induced liver injury along with significantly lowered serum levels of ALT and AST. The attenuation of liver injury correlated with the decrease of TNF-α and IFN-γ both in liver tissue and in the serum. Conclusions In summary, BM-MSCs genetically modified with AKT1 has a survival advantage and an enhanced immunomodulatory function both in vitro and in vivo and thus demonstrates the therapeutic potential for prevention and amelioration of liver GVHD and other immunity-associated liver injuries.


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