Using Acoustic Waves to Modulate Stem Cell Growth and Differentiation

Author(s):  
Jacqueline A. Maynard ◽  
Ahmad S. Arabiyat ◽  
Anna Elefante ◽  
Lucas Shearer ◽  
Eoin King ◽  
...  

During spaceflight, the loss of mechanical loads due to microgravity leads to rapid bone loss, where bone deteriorates at a rate of 1–2% per month, where some astronauts can lose as much as 20% of their skeletal mass in a single expedition [NASA, 2001]. In order to prevent muscle and bone loss, long-term space flight exercise regimes are strictly implemented [Shackleford, 2004]. Current research has demonstrated that mechanical vibrations can help to maintain or improve bone mass [Chan, 2013] and reduce adiposity [Chen, 2015, Sen, 2011] when signals are applied at the appropriate frequency and amplitude. We have developed an acoustic sound chamber that can apply sound waves to stem cells grown in vitro. Characterization of the culture conditions inside the vibration chamber showed considerable variance across the culture plates where an applied acceleration of 0.6g varied at different spots in a 12-well tissue culture plate from as low as 0.47g to 0.78g. We believe the variance is caused by differences in the rigidity of the culture plates that makes the waves transmit inconsistently through the plastic. We hypothesized acoustic waves would induce osteogenic differentiation when applied to stem cells. We utilized pre-osteoblastic stem cells (MC3T3-E1-Subclone 4) to observe the effects of acoustic waves when applied at 0.3g and 0.6g, compared to non-vibrated controls. Cells were vibrated for 30 minutes a day for either 6 days (n = 24/group) or 12 days (n = 12/group). Cellular changes were characterized by assessing well-by-well cell number by a manual cell count and mineral content by Alizarin Red S staining. Differences between groups were determined using One-Way ANOVA with a post hoc test: Student’s t-test. To assess the effects of the variance across the culture plates, correlative analysis was conducted for well-by-well variation using Regression Analysis. Acoustically vibrated wells had 10x more cells after 6 days and showed more mineralization than non-vibrated wells at both 6 and 12 days. Acoustic waves have the ability to increase cell proliferation and can drive stem cell differentiation towards an osteoblastic lineage, this could lead to therapies that prevent bone loss during spaceflight.

2009 ◽  
Vol 1239 ◽  
Author(s):  
Karla Brammer ◽  
Seunghan Oh ◽  
Sungho Jin

AbstractTwo important goals in stem cell research are to control the cell proliferation without differentiation, and also to direct the differentiation into a specific cell lineage when desired. Recent studies indicate that the nanostructures substantially influence the stem cell behavior. It is well known that mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into stromal lineages such as adipocyte, chondrocyte, fibroblast, myocyte, and osteoblast cell types. By examining the cellular behavior of MSCs cultured in vitro on nanostructures, some understanding of the effects that the nanostructures have on the stem cell’s response has been obtained. Here we demonstrate that TiO2 nanotubes produced by anodization on Ti implant surface can regulate human mesenchymal stem cell (hMSC) differentiation towards an osteoblast lineage in the absence of osteogenic inducing factors. Altering the dimensions of nanotubular-shaped titanium oxide surface structures independently allowed either augmented human mesenchymal stem cell (hMSC) adhesion at smaller diameter levels or a specific differentiation of hMSCs into osteoblasts using only the geometric cues. Small (˜30 nm diameter) nanotubes promoted adhesion without noticeable differentiation, while larger (˜70 - 100 nm diameter) nanotubes elicited a dramatic, ˜10 fold stem cell elongation, which induced cytoskeletal stress and selective differentiation into osteoblast-like cells, offering a promising nanotechnology-based route for novel orthopaedics-related hMSC treatments. The fact that a guided and preferential osteogenic differentiation of stem cells can be achieved using substrate nanotopography alone without using potentially toxic, differentiation-inducing chemical agents is significant, which can be useful for future development of novel and enhanced stem cell control and therapeutic implant development.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xudong Wang ◽  
Tongzhou Liang ◽  
Jincheng Qiu ◽  
Xianjian Qiu ◽  
Bo Gao ◽  
...  

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro culture results in loss of MSC stemness. The inflammation that occurs at stem cell transplant sites (such as that resulting from TNF-α) is a contributing factor for stem cell treatment failure. Currently, there is little evidence regarding the protective role of melatonin with regard to the negative effects of TNF-α on the stemness of MSCs. In this study, we report a melatonin-based method to reduce the inflammatory effects on the stemness of bone marrow mesenchymal stem cells (BMMSCs). The results of colony formation assays, Alizarin red staining, western blotting, and reverse transcription-polymerase chain reactions suggest that melatonin can reverse the inflammatory damage caused by TNF-α treatment in the third, seventh, and tenth generations of primary BMMSCs (vs. control and the TNF-α-treated group). Meanwhile, a detailed analysis of the molecular mechanisms showed that the melatonin receptor and YAP signaling pathway are closely related to the role that melatonin plays in negative inflammatory effects against BMMSCs. In addition, in vivo experiments showed that melatonin could reverse the damage caused by TNF-α on bone regeneration by BMMSCs in nude mice. Overall, our results suggest that melatonin can reverse the loss of stemness caused by inflammatory factor TNF-α in BMMSCs. Our results also provide a practical strategy for the application of BMMSCs in tissue engineering and cell therapy.


Author(s):  
Amit Paul ◽  
David Franz ◽  
Sumaira Yahya ◽  
Shan Sun ◽  
Michael Cho

Recent evidence suggests that stem cell differentiation can be regulated by modulation of the cell’s biomechanics. The cytoskeletal structures and arrangements in stem cells undergoing differentiation are dramatically altered, and these alterations vary by lineage. The complexity of events associated with the transformation of these precursor cells leaves many questions unanswered about morphological, structural, proteomic, and functional changes in differentiating stem cells. A thorough understanding of stem cell behavior, both experimentally and computationally, would allow for the development of more effective approaches to the expansion of stem cells in vitro and for the regulation of their commitment to a specific phenotype.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1080-1080 ◽  
Author(s):  
H. Jorgensen ◽  
E. Allan ◽  
N. Jordanides ◽  
A. Hamilton ◽  
J. Mountford ◽  
...  

Abstract AMN107 (Novartis) is a novel Abl tyrosine kinase inhibitor specifically developed to be more selective for BcrAbl. AMN107 also maintains activity against the most common mutations associated with clinical resistance to imatinib mesylate (IM). In preclinical studies in cell lines and animal models, AMN107 was found to have greater potency than IM. By 3H-thymidine proliferation assays, the IC50 for AMN107 in K562 cells was 30 +/− 10nM compared with 600 +/− 60nM for IM. AMN107 and IM reduced K562 output cell number to 25% of input at 50 and 1000nM respectively, at 72h. These data are in keeping with the reported 20-fold increase in potency of AMN107 over IM. In addition, we have tested AMN107 for in vitro activity against primary CD34+Ph+ CML cells during 72h of culture in 5 growth factors. In CML cells (n=5), AMN107 and IM failed to reduce input cell number although the total cell output was restricted to 50% of PBS treated control at 2 +/− 1μM for AMN107 and to 31 +/− 7% of PBS treated control for 5μM IM suggesting the drugs were equipotent. The ability of the drugs to inhibit BcrAbl activity was then measured indirectly via the phosphorylation status of CrkL using a specific antiphospho-CrkL antibody and flow cytometry. Once again AMN107 and IM appeared equipotent in CML cells with 5μM of each compound leading to equal de-phosphorylation of CrkL. We next tested the efficacy of AMN107 as a single agent and in combination with IM against quiescent CML cells using in vitro dye (CFSE) tracking experiments. We evaluated by flow cytometry the proportion of input cells remaining alive, CD34+ and undivided (CFSEmax) or in first division. Compared to PBS treated control, 1.7, 2.5, 3.8 and 4.7-fold increases were found in the proportion of input CD34+ cells recovered in divisions 0 and 1 after 3 days exposure to 0.005, 0.05, 0.5 and 5μM AMN107, respectively. This was less accumulation than observed in the IM (5μM)-treated cells (11.0-fold). The combination of IM and AMN107, each at 5μM, was more effective in terms of total cell kill (54 and 74% fewer total cells remaining than with IM and AMN107 alone, respectively) and resulted in fewer viable cells recovered in divisions 0 and 1 than with either agent alone (for the combination, 1.9-fold on PBS treated recovery). We finally assessed the role of ABCG2 in modulating AMN107’s access to its intracellular BcrAbl target. We have previously shown ABCG2 to be over-expressed on CML stem cells and to interact with IM (Blood (2004); 104: 205a). We hypothesised that AMN107 and IM may co-operate as ABCG2 substrates or inhibitors to increase the intracellular levels of either or both drugs thus amplifying their efficacy against target protein specifically in CML stem cells. In competition assays with a known fluorescent substrate of ABCG2 (ie BODIPY-prazosin, BP), a specific inhibitor of the ABCG2 pump (fumitremorgin C, FTC) and an ABCG2 stably transfected AML cell line (AML6.2), the sample treated with BP plus FTC is taken to have greatest retention (100%). AMN107 inhibited efflux in a dose dependent manner to a maximum of 88% at 5μM, similarly to IM. Thus, AMN107 was equipotent with IM in primary CML stem cells in terms of restricting cell growth, inhibiting BcrAbl activity and interacting with ABCG2. However, AMN107 alone lead to less accumulation of quiescent CML cells in vitro as compared to IM, with the combination even more effective in this regard. The apparent co-operative effect of AMN107 and IM at the stem cell level would be predicted to improve clinical responses if tolerated in patients.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Francesco Da Ros ◽  
Luca Persano ◽  
Dario Bizzotto ◽  
Mariagrazia Michieli ◽  
Paola Braghetta ◽  
...  

Abstract Background Dissection of mechanisms involved in the regulation of bone marrow microenvironment through cell–cell and cell–matrix contacts is essential for the detailed understanding of processes underlying bone marrow activities both under physiological conditions and in hematologic malignancies. Here we describe Emilin-2 as an abundant extracellular matrix component of bone marrow stroma. Methods Immunodetection of Emilin-2 was performed in bone marrow sections of mice from 30 days to 6 months of age. Emilin-2 expression was monitored in vitro in primary and mesenchymal stem cell lines under undifferentiated and adipogenic conditions. Hematopoietic stem cells and progenitors in bone marrow of 3- to 10-month-old wild-type and Emilin-2 null mice were analyzed by flow cytometry. Results Emilin-2 is deposited in bone marrow extracellular matrix in an age-dependent manner, forming a meshwork that extends from compact bone boundaries to the central trabecular regions. Emilin-2 is expressed and secreted by both primary and immortalized bone marrow mesenchymal stem cells, exerting an inhibitory action in adipogenic differentiation. In vivo Emilin-2 deficiency impairs the frequency of hematopoietic stem/progenitor cells in bone marrow during aging. Conclusion Our data provide new insights in the contribution of bone marrow extracellular matrix microenvironment in the regulation of stem cell niches and hematopoietic progenitor differentiation.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 716-716
Author(s):  
Joanne C. Mountford ◽  
Diane Gilmour ◽  
Susan M. Graham ◽  
Niove E. Jordanides ◽  
Siobhan McMillan ◽  
...  

Abstract We have previously described a population of deeply, but reversibly, quiescent stem cells (qSC) found in patients with chronic phase (CP) CML at diagnosis. In vitro studies have proven this population to be highly insensitive to imatinib mesylate (IM; Gleevec, STI571) induced killing, and more worryingly shown that qSC are accumulated after CML CD34+ cells are treated with IM. As it is likely that CML qSC closely resemble normal HSC, we hypothesise that they too may express the stem cell-associated ABCG2 and have therefore examined the expression and function of this drug efflux pump on CML cells. In agreement with other studies we show the interaction between ABCG2 and IM. Using ABCG2 over-expressing cells (AML6.2 and HL60-BCRP) we found that ≥0.5μM IM reduced efflux of the ABCG2 substrate BODIPY-Prazosin by a similar degree as the inhibitor fumitremorgin C (FTC; 10μM). We have now examined expression and function of ABCG2 on primary CML cells taken from patients in chronic phase (CP) and prior to any treatment. Quantitative Taqman analysis of 8 CD34+ enriched (≥90%+) CML samples revealed that the level of expression is 2.46 fold higher than that in normal mobilised CD34+ cells (n=8 CML, n=4 normal). In addition, we undertook microarray analysis of normal or CML CP CD34+ cells fractionated according to cell cycle using Hoechst-Pyronin (G0, G1 and G2/S/M). These analyses (n=3 normal, n=5 CML) show that at all stages of the cycle CML cells express more ABCG2 than normal cells and that G0 CML cells express 2.48 fold more than those in G1 , confirming both the over-expression in CML and relationship to the most primitive subset of cells. Using the antibody BXP21 we found that 8 of 9 samples contain ABCG2+ve cells (5 of 9 ≥60% of cells ABCG2+). We also examined the function of ABCG2 on CML CD34+ cells by performing efflux assays, 4 of 6 showed efflux that was inhibited by 10μM FTC or ≥0.5μM IM, and this efflux capacity correlated with BXP21 staining. We therefore considered whether the combination of IM therapy and ABCG2 inhibition would overcome the accumulation of CML qSCs we have previously reported after treatment with IM. Using CFSE to track cell division we treated CD34+ enriched CML samples with 5μM IM +/− FTC or with 10μM FTC alone for 3 days. In comparison to untreated controls 5μM IM reduced the total number of cells to 31.9±9.2 % and the number of CD34+ cells to 43.2±17.6%. However, the non-cycling qSC significantly increased to 318±75.8% of control. In contrast, the ABCG2 inhibitor FTC did not effect a reduction in total cells (99.5±11.9%) but gave a significant reduction of CD34+ cells (58.6±8.4%; p=0.02) and no accumulation of qSC (104.6±33.8%) when used alone. We saw no cumulative effect when IM and FTC were given concurrently. These data suggest strongly that FTC may be used to deplete CD34+ ‘stem cells’ from CML, as the total cell number is unchanged it is likely that this depletion is by the induction of differentiation. We propose that the expression of ABCG2 may be clinically significant in CP CML and that inhibition of this pump may result in a ‘stem cell targeted therapy’ that could be followed by IM treatment to reduce the tumor load. Such reduction of CML stem cells would result in elimination of minimal residual disease and effect a lasting remission.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4262-4262
Author(s):  
G. Chapman ◽  
J.J. Banks ◽  
L.R. Fanning ◽  
M. Kozik ◽  
M.R. Finney ◽  
...  

Abstract In vitro expansion of UCB using cytokines has been pursued to overcome the limited stem cell content of a single UCB graft. We have previously demonstrated that a feeder layer of huMSC inhibits UCB HSC differentiation during short-term cytokine-driven expansion in vitro. The protein LIF has been shown to inhibit the differentiation of neurosphere stem cells during 3 week culture over a monolayer of murine stromal cells (C. Shih, et al., 2001). We sought to investigate the hypothesis that LIF secreted by bone marrow (BM) derived huMSCs is involved in inhibition of UCB HSC differentiation during short-term cytokine-driven expansion in vitro. BM derived huMSCs (third passage) were cultured at 2x10^6/ml in DMEM supplemented with 10% FBS. Supernatant was collected at 24, 36, 48, and 72 hours and analyzed for LIF secretion levels by ELISA (Quantikine). LIF secreted by huMSC was noted at all four time points, with peak secretion at 48 h (mean 52.1±3.3 pg/ml) (n=3). UCB was obtained according to institutional guidelines after normal full-term deliveries, collected into bags with citrate dextrose (Allegiance), and MNC were separated on a Histopaque-1077 (Sigma) density gradient. UCB CD133+ cells were isolated using AutoMACS magnetic cell sorter (Miltenyi) and surface stained for LIF receptor (LIF-R). Surface expression of LIF-R on gated CD133+ cells was 2.61%. Total LIF-R expression in isolated CD133+ cells was further confirmed by Western blot (n=3) using anti-LIF-R antibody (Chemicon). Isolated UCB CD133+ were plated in 24 well plates at 3.3x10^3/ml and cultured in StemPro™ media supplemented with 10% FBS, L-glutamine, penicillin, streptomycin and amphotericin B (Gibco). UCB CD133+ were culture-expanded for 96h with or without the addition of recombinant human LIF (Chemicon) (10ng/ml) in a combination of cytokines including: IL-3 (20 ng/mL), IL-6 (20 ng/mL), Flt-3L (100 ng/mL) (R&D), SCF (100 ng/mL), G-CSF (20 ng/mL), and EPO (0.1 U/mL) (Amgen Inc.). At 0, 48, and 96 h cell counts were obtained and flow analysis was performed including surface staining for: CD133, CD34, CD38, HLA-DR, CD33, CD71, and CD41B (Becton Dickinson). At 48 hours, higher cell counts in cultures without LIF were noted 6.3x10^4 ± 0.9/ml, compared with cultures with LIF 4.4x10^4 ± 0.8/ml. However, at 96 h cell counts equalized when comparing cultures with or without LIF at 7.510x10^4 ± 0.9/ml, and 7.8x10^4±0.9/ml respectively (n=6). Surface expression of differentiation markers on gated CD133+ cells did not differ when comparing cultures (n=3). In summary, we observed LIF secretion by MSC peaks at 48 h at a concentration 3 logs lower than that previously used to inhibit stem cell differentiation (10 ng/ml). Although LIF-R is expressed on CD133+ HSC, no difference in cell expansion nor surface phenotype of UCB 133+ cells was observed at early time points (96h) during expansion in cytokines with or without the addition of LIF. Taken together, huMSC mediated inhibition of cytokine-driven UCB HSC differentiation is not attributable to LIF secretion alone and may require direct cell contact between UCB CD133 HSC and huMSC. Studies are ongoing to determine whether LIF may augment huMSC-based UCB CD133 expansion.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fanglin Wang ◽  
Xiang Li ◽  
Zhiyuan Li ◽  
Shoushuai Wang ◽  
Jun Fan

The mesenchymal stem cells (MSCs) are known as highly plastic stem cells and can differentiate into specialized tissues such as adipose tissue, osseous tissue, muscle tissue, and nervous tissue. The differentiation of mesenchymal stem cells is very important in regenerative medicine. Their differentiation process is regulated by signaling pathways of epigenetic, transcriptional, and posttranscriptional levels. Circular RNA (circRNA), a class of noncoding RNAs generated from protein-coding genes, plays a pivotal regulatory role in many biological processes. Accumulated studies have demonstrated that several circRNAs participate in the cell differentiation process of mesenchymal stem cells in vitro and in vivo. In the current review, characteristics and functions of circRNAs in stem cell differentiation will be discussed. The mechanism and key role of circRNAs in regulating mesenchymal stem cell differentiation, especially adipogenesis, will be reviewed and discussed. Understanding the roles of these circRNAs will present us with a more comprehensive signal path network of modulating stem cell differentiation and help us discover potential biomarkers and therapeutic targets in clinic.


2017 ◽  
Vol 4 (S) ◽  
pp. 115
Author(s):  
Trung Kien Do ◽  
Nguyen Thi Thanh Nga ◽  
Nguyen Quynh Anh ◽  
Dinh Minh Pham ◽  
Chu Hoang Ha

Fluorescent nanodiamond (FND) indicated that it has excellent biocompatibility and photostability,so it well suited for long-term labeling and tracking of stem cells. There are many reports concerning the factors controlling stem cell differentiation. However, still little knowledge about the biomaterials properties influence stem cell alive, growth and differentiation processing. In this study, we evaluate the effect of fluorescent nanodiamond in in vitro culture and differentiation of ucMSC into hepatocyte-like cell. Mesenchymal stem cells (MSCs) were isolated from the umbilical cord (UC) and CD markers were analyzed by flow cytometry and genes expression. For hepatic differentiation of UC-MSCs, cells were induced with HGF and DMSO treated. FND was supply in the experimental group which 10 g/ml in 4 hours. The FND uptake was detected of fluorescence intensity of FND in cells by flow cytometry and laser scan microscopy. The effect of FND into UCMSCs was not only evaluated by the cell alive and growth assay but also effective differentiation throughout morphology charging or gene expression levels of AFP, ALB, and HNF4 were determined by RT-PCR and real-time PCR. The result showed that the FND was well uptake in UCMSCs. It was no affected into ability of the cell alive and growth. The existence of FNDs does not disturb the functions of UC-MSCs differentiation into hepatocyte-like cell. FND can be utilized for the labeling and tracking of UC-MSCs and hepatocyte-like cell in homing research.


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