Comparison of Cellular Alterations in Fat Cells Harvested With Laser-Assisted Liposuction and Suction-Assisted Liposuction.

PubMed

Yildiz, Kemalettin; Taşli, Pakize Neslihan; Şahin, Fikrettin; Güneren, Ethem

2016-05-01

The aim of the present study was to evaluate the viability and proliferative capacity of adipose-derived stem cells obtained by laser-assisted liposuction (LAL). Fat tissue was obtained from 7 male patients treated surgically for gynecomastia. On one side, harvesting was made before LAL, while it was implemented after LAL on the contralateral side. Viability, cell surface antigens, pluripotency, and apoptosis were assessed and compared in these samples. Cells harvested before and after LAL did not exhibit any significant difference in terms of surface cell markers. Number of viable stem cells was lower initially after exposure to laser, while this difference was reversed at the end of 72 hours. Genetic indicators of cellular differentiation were similar in both groups. Apoptosis indicators were increased remarkably after laser exposure in the first 24 hours, but this increase was absent 72 hours after LAL procedure. The authors' results have promising clinical relevance since mesenchymal stem cells harvested during LAL have maintained appropriate cellular features to be used for autologous fat transfer and fat grafting.

Dynamics of cells function on laser cell-chip system

NASA Astrophysics Data System (ADS)

Kushibiki, Toshihiro; Sano, Tomoko; Ishii, Katsunori; Yoshihashi-Suzuki, Sachiko; Awazu, Kunio

2006-02-01

A new type of cell-cultivation system based on laser processing has been developed for the on-chip cultivation of living cells. We introduce a "laser cell-chip", on which migration of cells, such as stem cells, tumor cells or immunocompetent cells, can be observed. A sheet prepared from epoxy resin was processed by KrF excimer laser (248 nm, 1.6 J/cm2) for preparation of microgrooved surfaces with various groove width, spacing, and depth. A laser cell-chip can make kinetic studies of cell migration depending on the concentration gradient of a chemoattractant. In this study, megakaryocytes were used for the migration on a groove of laser cell-chip by the concentration gradient of the stromal cell derived factor 1 (SDF-1/CXCL12). SDF-1/CXCL12 plays an important and unique role in the regulation of stem/progenitor cell trafficking. A megakaryocyte was migrated on a groove of laser cell-chip depending on the optical concentration gradient of SDF-1/CXCL12. Since SDF-1/CXCL12-induced migration of mature megakaryocyte was known to increase the platelet production in the bone marrow extravascular space, the diagnosis of cell migration on laser cell-chip could provide a new strategy to potentially reconstitute hematopoiesis and avoid life-threatening hemorrhage after myelosuppression or bone marrow failure.

Laser Stimulated Genomic Exchange in Stem Cells. Laser Non-cloning Techniques

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2012-02-01

I propose a novel technique for a pluripotent stem cell generation. Genomic exchange is stimulated by the beat-wave free electron laser, (B-W FEL), frequency matching with the frequencies of the DNAootnotetextJ.D. Watson and F. H. C. Crick, Nature, 171, 737-738 (1953). eigen-oscillations. B-W FEL-1ootnotetextV. Stefan, B.I.Cohen, C. Joshi Science, 243,4890, (Jan 27,1989); Stefan, et al., Bull. APS. 32, No. 9, 1713 (1987); Stefan, APS March-2011, #S1.143; APS- March-2009, #K1.276. scans entire stem cell; B-W FEL-2 probes the chromosomes. The scanning and probing lasers: 300-500nm and 100-300nm, respectively; irradiances: the order-of-10s mW/cm^2 (above the threshold value for a particular gene structure); repetition rate of few-100s Hz. A variety of genetic-matching conditions can be arranged. Genomic glitches, (the cell nucleus transferootnotetextScott Noggle et al. Nature, 478, 70-75 (06 October 2011).), can be hedged by the use of lasers.

The synergistic effect on osteogenic differentiation of human mesenchymal stem cells by diode laser-treated stimulating human umbilical vein endothelial cells

NASA Astrophysics Data System (ADS)

Kao, Chia-Tze; Hsu, Tuan-Ti; Huang, Tsui-Hsien; Wu, Yu-Tin; Chen, Yi-Wen; Shie, Ming-You

2016-02-01

Angiogenesis plays an important role in determining the biostimulation of bone regeneration, in either new bone or blood vessel formation. Human umbilical cord cells (HUVECs) are important effector cells in angiogenesis and are indispensable for osteogenesis and for their heterogeneity and plasticity. However, there are very few studies about the effects of HUVECs on diode laser-stimulated/regulated osteogenesis. In this study, we used diode laser as a model biostimulation to examine the role of HUVECs on laser-stimulated osteogenesis. Several bone formation-related proteins were also significantly up-regulated by the diode laser stimulation, indicating that HUVECs may participate in diode laser-stimulated osteogenesis. Interestingly, when human mesenchymal stem cells (hMSCs) cultured with HUVECs were diode laser-treated, the osteogenesis differentiation of the hMSCs was significantly promoted, indicating the important role of HUVECs in diode laser-enhanced osteogenesis. Adequately activated HUVECs are vital for the success of diode laser-stimulated hard-tissue regeneration. These findings provided valuable insights into the mechanism of diode laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment in periodontal repair.

Laser bioprinting of human induced pluripotent stem cells-the effect of printing and biomaterials on cell survival, pluripotency, and differentiation.

PubMed

Koch, Lothar; Deiwick, Andrea; Franke, Annika; Schwanke, Kristin; Haverich, Axel; Zweigerdt, Robert; Chichkov, Boris

2018-04-25

Research on human induced pluripotent stem cells (hiPSCs) is one of the fastest growing fields in biomedicine. Generated from patient's own somatic cells, hiPSCs can be differentiated towards all functional cell types and returned to the patient without immunological concerns. 3D printing of hiPSCs could enable the generation of functional organs for replacement therapies or realization of organ-on-chip systems for individualized medicine. Printing of living cells was demonstrated with immortalized cell lines, primary cells, and adult stem cells with different printing technologies and biomaterials. However, hiPSCs are more sensitive to handling procedures, in particular, when dissociated into single cells. Both pluripotency and directed differentiation are influenced by numerous environmental factors including culture media, biomaterials, and cell density. Notably, existing literature on the effect of applied biomaterials on pluripotency is rather ambiguous. In this study, laser bioprinting of undifferentiated hiPSCs in combination with different biomaterials was performed and the impact on cells' behavior, pluripotency, and differentiation was investigated. Our findings suggest that hiPSCs are indeed more sensitive to the applied biomaterials, but not to laser printing itself. With appropriate biomaterials, such as the hyaluronic acid based solutions applied in this study, hiPSCs can be successfully laser printed without losing their pluripotency.

Laser-Based Propagation of Human iPS and ES Cells Generates Reproducible Cultures with Enhanced Differentiation Potential

PubMed Central

Hohenstein Elliott, Kristi A.; Peterson, Cory; Soundararajan, Anuradha; Kan, Natalia; Nelson, Brandon; Spiering, Sean; Mercola, Mark; Bright, Gary R.

2012-01-01

Proper maintenance of stem cells is essential for successful utilization of ESCs/iPSCs as tools in developmental and drug discovery studies and in regenerative medicine. Standardization is critical for all future applications of stem cells and necessary to fully understand their potential. This study reports a novel approach for the efficient, consistent expansion of human ESCs and iPSCs using laser sectioning, instead of mechanical devices or enzymes, to divide cultures into defined size clumps for propagation. Laser-mediated propagation maintained the pluripotency, quality, and genetic stability of ESCs/iPSCs and led to enhanced differentiation potential. This approach removes the variability associated with ESC/iPSC propagation, significantly reduces the expertise, labor, and time associated with manual passaging techniques and provides the basis for scalable delivery of standardized ESC/iPSC lines. Adoption of standardized protocols would allow researchers to understand the role of genetics, environment, and/or procedural effects on stem cells and would ensure reproducible production of stem cell cultures for use in clinical/therapeutic applications. PMID:22701128

Femtosecond laser assisted photo-transfection and differentiation of mouse embryonic stem cells

NASA Astrophysics Data System (ADS)

Thobakgale, Lebogang; Manoto, Sello; Ombinda Lemboumba, Satuurnin; Maaza, Malik; Mthunzi-Kufa, Patience

2018-02-01

In tissue engineering research, stem cells have been used as starting material in the synthesis of mammalian cells for the treatment of various cell based diseases. This is done by manipulating the DNA content of the cells to induce a specific effect such as increased proliferation or developing a new cell type through the process of differentiation. Such controlled gene expression of stem cells is achieved by the method of transfection, where exogenous plasmid deoxyribonucleic acid (pDNA) is inserted into a stem cell using chemical, viral or physical methods. In this research, we used femtosecond (fs) laser pulses from a home-build microscope system to perforate the cellular membrane and allow entry of selected pDNA to alter the behaviour of mouse embryonic stem cells (mESCs). In one set of experiments, we induce fluorescence on mESCs using green fluorescence protein plasmid (pGFP) while in other tests; differentiation of mESCs into endoderm cells is performed using Sox-17 plasmid DNA (pSox-17). Primitive endoderm formation was thereafter confirmed using polymerase chain reactions (PCR) and the Sox-17 primer. Cell viability studies using adenosine triphosphate were also conducted. From the data, it was concluded that the photo-transfection method is biocompatible since it was able to induce fluorescence in mESCs. Secondly, it was confirmed that Sox-17 was photo-transfected successfully using 6 μW laser power, 128 fs pulses and 1kHz pulse repetition rate.

Laser-based direct-write techniques for cell printing

PubMed Central

Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

2016-01-01

Fabrication of cellular constructs with spatial control of cell location (±5 μm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. PMID:20814088

Photothermal gold nanoparticle mediated stimulation of cardiomyocyte beating (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kalies, Stefan; Gentemann, Lara; Coffee, Michelle; Zweigerdt, Robert; Heinemann, Dag; Heisterkamp, Alexander

2017-03-01

Photothermal manipulation of cells via heating of gold nanoparticles has proven to be an efficient tool for molecular delivery into cells via cell perforation with short laser pulses. We investigated a potential extension of this technique for cell stimulation of cardiomyocytes using a 532 nm and 850 ps laser system and a surface concentration of 0.5 μg/cm2 of 200 nm gold nanoparticles. The gold nanoparticles were unspecifically attached to the cardiomyocytes after an incubation period of three hours. The laser irradiation leads to a temperature rise directly at the particles of several hundred degrees K which evokes bubble formation and membrane perforation. We examined the effect of laser based photothermal manipulation at different laser powers, with different calcium concentrations, and for a cardiomyocyte-like cell line (HL1 cells), neonatal rat cardiomyocytes and human embryonic stem cell (hESC)-derived cardiomyocytes. Fast calcium oscillations in HL1 cells were observed in the presence and absence of extracellular calcium and most pronounced in the area next to the laser spot after irradiation. Within the laser spot, in particular high laser powers led to a single rise in calcium over a time period of several seconds. These results were confirmed in stem cell-derived cardiomyocytes. In the presence of normal and high calcium concentrations, the spontaneous contraction frequency increased after laser irradiation in neonatal rat cardiomyocytes. Consequently, gold nanoparticle mediated photothermal cell manipulation via pulsed lasers may serve as a potential pacemaker-technique in regenerative approaches, next to optogenetics.

Bioprinting for stem cell research

PubMed Central

Tasoglu, Savas; Demirci, Utkan

2012-01-01

Recently, there has been a growing interest to apply bioprinting techniques to stem cell research. Several bioprinting methods have been developed utilizing acoustics, piezoelectricity, and lasers to deposit living cells onto receiving substrates. Using these technologies, spatially defined gradients of immobilized proteins can be engineered to direct stem cell differentiation into multiple subpopulations of different lineages. Stem cells can also be patterned in a high-throughput manner onto flexible implementation patches for tissue regeneration or onto substrates with the goal of accessing encapsulated stem cell of interest for genomic analysis. Here, we review recent achievements with bioprinting technologies in stem cell research, and identify future challenges and potential applications including tissue engineering and regenerative medicine, wound healing, and genomics. PMID:23260439

Effect of Photobiomodulation on Mesenchymal Stem Cells.

PubMed

Fekrazad, Reza; Asefi, Sohrab; Allahdadi, Mahdi; Kalhori, Katayoun A M

2016-11-01

The purpose of this study was to review available literature about the effect of photobiomodulation (PBM) on mesenchymal stem cells (MSCs). The effects of coherent and noncoherent light sources such as low-level lasers and light-emitting diodes (LEDs) on cells and tissues, known as PBM, form the basis of photomedicine. This treatment technique effects cell function, proliferation, and migration, and plays an important role in tissue regeneration. Stem cells have been found to be helpful elements in tissue regeneration, and the combination of stem cell therapy and laser therapy appears to positively affect treatment results. An electronic search in PubMed was conducted of publications from the previous 12 years. English language articles related to the subject were found using selected key words. The full texts of potentially suitable articles were assessed according to inclusion and exclusion criteria. After evaluation, 30 articles were deemed relevant according to the inclusion criteria. The energy density of the laser was 0.7-9 J/cm 2 . The power used for visible light was 30-110 mW and that used for infrared light was 50-800 mW. Nearly all studies showed that low-level laser therapy had a positive effect on cell proliferation. Similar outcomes were found for LED; however, some studies suggest that the laser alone is not effective, and should be used as an adjunct tool. PBM has positive effects on MSCs. This review concluded that doses of 0.7-4 J/cm 2 and wavelengths of 600-700 nm are appropriate for light therapy. The results were dependent upon different parameters; therefore, optimization of parameters used in light therapy to obtain favorable results is required to provide more accurate comparison.

Labeling of stem cells with monocrystalline iron oxide for tracking and localization by magnetic resonance imaging

PubMed Central

Calzi, Sergio Li; Kent, David L.; Chang, Kyung-Hee; Padgett, Kyle R.; Afzal, Aqeela; Chandra, Saurav B.; Caballero, Sergio; English, Denis; Garlington, Wendy; Hiscott, Paul S.; Sheridan, Carl M.; Grant, Maria B.; Forder, John R.

2013-01-01

Precise localization of exogenously delivered stem cells is critical to our understanding of their reparative response. Our current inability to determine the exact location of small numbers of cells may hinder optimal development of these cells for clinical use. We describe a method using magnetic resonance imaging to track and localize small numbers of stem cells following transplantation. Endothelial progenitor cells (EPC) were labeled with monocrystalline iron oxide nanoparticles (MIONs) which neither adversely altered their viability nor their ability to migrate in vitro and allowed successful detection of limited numbers of these cells in muscle. MION-labeled stem cells were also injected into the vitreous cavity of mice undergoing the model of choroidal neovascularization, laser rupture of Bruch’s membrane. Migration of the MION-labeled cells from the injection site towards the laser burns was visualized by MRI. In conclusion, MION labeling of EPC provides a non-invasive means to define the location of small numbers of these cells. Localization of these cells following injection is critical to their optimization for therapy. PMID:19345699

Human stem cell based corneal tissue mimicking structures using laser-assisted 3D bioprinting and functional bioinks.

PubMed

Sorkio, Anni; Koch, Lothar; Koivusalo, Laura; Deiwick, Andrea; Miettinen, Susanna; Chichkov, Boris; Skottman, Heli

2018-07-01

There is a high demand for developing methods to produce more native-like 3D corneal structures. In the present study, we produced 3D cornea-mimicking tissues using human stem cells and laser-assisted bioprinting (LaBP). Human embryonic stem cell derived limbal epithelial stem cells (hESC-LESC) were used as a cell source for printing epithelium-mimicking structures, whereas human adipose tissue derived stem cells (hASCs) were used for constructing layered stroma-mimicking structures. The development and optimization of functional bioinks was a crucial step towards successful bioprinting of 3D corneal structures. Recombinant human laminin and human sourced collagen I served as the bases for the functional bioinks. We used two previously established LaBP setups based on laser induced forward transfer, with different laser wavelengths and appropriate absorption layers. We bioprinted three types of corneal structures: stratified corneal epithelium using hESC-LESCs, lamellar corneal stroma using alternating acellular layers of bioink and layers with hASCs, and finally structures with both a stromal and epithelial part. The printed constructs were evaluated for their microstructure, cell viability and proliferation, and key protein expression (Ki67, p63α, p40, CK3, CK15, collagen type I, VWF). The 3D printed stromal constructs were also implanted into porcine corneal organ cultures. Both cell types maintained good viability after printing. Laser-printed hESC-LESCs showed epithelial cell morphology, expression of Ki67 proliferation marker and co-expression of corneal progenitor markers p63α and p40. Importantly, the printed hESC-LESCs formed a stratified epithelium with apical expression of CK3 and basal expression of the progenitor markers. The structure of the 3D bioprinted stroma demonstrated that the hASCs had organized horizontally as in the native corneal stroma and showed positive labeling for collagen I. After 7 days in porcine organ cultures, the 3D bioprinted stromal structures attached to the host tissue with signs of hASCs migration from the printed structure. This is the first study to demonstrate the feasibility of 3D LaBP for corneal applications using human stem cells and successful fabrication of layered 3D bioprinted tissues mimicking the structure of the native corneal tissue. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evaluation of phototherapy in the differentiation of mesenchymal stem cells in the tissue repair of rats submitted to a hyperlipidemic diet

NASA Astrophysics Data System (ADS)

Oliveira, C. R. B.; Santos, L. S.; Silva, V. D. U.; Vitória, L. A.; Rodriguez, T. T.; Marques, A. M. C.; Xavier, F. C. A.; Ramalho, L.

2018-04-01

Obese people present a greater risk of developing other systemic diseases and comorbidities such as compromising the tissue repair process. Laser phototherapy can contribute to this repair by improving cellular functions, since stem cells may play an important role in repair due to their pluripotent potential. In this way, the influence of Laser Phototherapy (LP) was evaluated in the tissue repair of rats submitted to a hyperlipid diet through CD49 immunostaining for adipose stem cells. Forty-eight Wistar albinus rats were divided into two experimental groups: Standard Diet (SD) and Hyperlipid Diet (HD) for 20 weeks. After this period, excisional dorsal cutaneous wounds of 1 cm2 were made. The groups were subdivided into control and laser, the laser groups were irradiated (Diode Laser of Gallium and Aluminum Arsenide, λ660nm, 40mW, 6J / cm2) immediately after the surgery and every 48 hours. A group of rats were killed on day 7 and the other group on day 14 and the specimens processed by the immunohistochemical technique. The SD group presented antibodies marked with moderate to intense intensity, whereas in the HD group the weak staining for the time of 14 days prevailed. The irradiation protocol employed had no influence on the CD49 marker when compared to the control and irradiated groups over the same period. According to the methodology used and the results obtained it is concluded that laser light does not influence the recruitment of adipoderivative stem cells for the tissue repair process.

Adipose Derived Stem Cells for Corneal Wound Healing after Laser Induced Corneal Lesions in Mice.

PubMed

Zeppieri, Marco; Salvetat, Maria Letizia; Beltrami, Antonio; Cesselli, Daniela; Russo, Rossella; Alcalde, Ignacio; Merayo-Lloves, Jesús; Brusini, Paolo; Parodi, Pier Camillo

2017-12-05

The aim of our study was to assess the clinical effectiveness of topical adipose derived stem cell (ADSC) treatment in laser induced corneal wounds in mice by comparing epithelial repair, inflammation, and histological analysis between treatment arms. Corneal lesions were performed on both eyes of 40 mice by laser induced photorefractive keratectomy. All eyes were treated with topical azythromycin bid for three days. Mice were divided in three treatment groups ( n = 20), which included: control, stem cells and basic serum; which received topical treatment three times daily for five consecutive days. Biomicroscope assessments and digital imaging were performed by two masked graders at 30, 54, 78, 100, and 172 h to analyze extent of fluorescein positive epithelial defect, corneal inflammation, etc. Immunohistochemical techniques were used in fixed eyes to assess corneal repair markers Ki67, α Smooth Muscle Actin (α-SMA) and E-Cadherin. The fluorescein positive corneal lesion areas were significantly smaller in the stem cells group on days 1 ( p < 0.05), 2 ( p < 0.02) and 3. The stem cell treated group had slightly better and faster re-epithelization than the serum treated group in the initial phases. Comparative histological data showed signs of earlier and better corneal repair in epithelium and stromal layers in stem cell treated eyes, which showed more epithelial layers and enhanced wound healing performance of Ki67, E-Cadherin, and α-SMA. Our study shows the potential clinical and histological advantages in the topical ADSC treatment for corneal lesions in mice.

Adipose Derived Stem Cells for Corneal Wound Healing after Laser Induced Corneal Lesions in Mice

PubMed Central

Salvetat, Maria Letizia; Beltrami, Antonio; Cesselli, Daniela; Russo, Rossella; Merayo-Lloves, Jesús; Brusini, Paolo; Parodi, Pier Camillo

2017-01-01

The aim of our study was to assess the clinical effectiveness of topical adipose derived stem cell (ADSC) treatment in laser induced corneal wounds in mice by comparing epithelial repair, inflammation, and histological analysis between treatment arms. Corneal lesions were performed on both eyes of 40 mice by laser induced photorefractive keratectomy. All eyes were treated with topical azythromycin bid for three days. Mice were divided in three treatment groups (n = 20), which included: control, stem cells and basic serum; which received topical treatment three times daily for five consecutive days. Biomicroscope assessments and digital imaging were performed by two masked graders at 30, 54, 78, 100, and 172 h to analyze extent of fluorescein positive epithelial defect, corneal inflammation, etc. Immunohistochemical techniques were used in fixed eyes to assess corneal repair markers Ki67, α Smooth Muscle Actin (α-SMA) and E-Cadherin. The fluorescein positive corneal lesion areas were significantly smaller in the stem cells group on days 1 (p < 0.05), 2 (p < 0.02) and 3. The stem cell treated group had slightly better and faster re-epithelization than the serum treated group in the initial phases. Comparative histological data showed signs of earlier and better corneal repair in epithelium and stromal layers in stem cell treated eyes, which showed more epithelial layers and enhanced wound healing performance of Ki67, E-Cadherin, and α-SMA. Our study shows the potential clinical and histological advantages in the topical ADSC treatment for corneal lesions in mice. PMID:29206194

Effect of low-level laser irradiation on proliferation and viability of human dental pulp stem cells.

PubMed

Zaccara, Ivana Maria; Ginani, Fernanda; Mota-Filho, Haroldo Gurgel; Henriques, Águida Cristina Gomes; Barboza, Carlos Augusto Galvão

2015-12-01

A positive effect of low-level laser irradiation (LLLI) on the proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). The aim of this study was to identify the lowest energy density able to promote the proliferation of DPSCs and to maintain cell viability. Human DPSCs were isolated from two healthy third molars. In the third passage, the cells were irradiated or not (control) with an InGaAlP diode laser at 0 and 48 h using two different energy densities (0.5 and 1.0 J/cm²). Cell proliferation and viability and mitochondrial activity were evaluated at intervals of 24, 48, 72, and 96 h after the first laser application. Apoptosis- and cell cycle-related events were analyzed by flow cytometry. The group irradiated with an energy density of 1.0 J/cm² exhibited an increase of cell proliferation, with a statistically significant difference (p < 0.05) compared to the control group at 72 and 96 h. No significant changes in cell viability were observed throughout the experiment. The distribution of cells in the cell cycle phases was consistent with proliferating cells in all three groups. We concluded that LLLI, particularly a dose of 1.0 J/cm², contributed to the growth of DPSCs and maintenance of its viability. This fact indicates this therapy to be an important future tool for tissue engineering and regenerative medicine involving stem cells.

Fusion with stem cell makes the hepatocellular carcinoma cells similar to liver tumor-initiating cells.

PubMed

Wang, Ran; Chen, Shuxun; Li, Changxian; Ng, Kevin Tak Pan; Kong, Chi-wing; Cheng, Jinping; Cheng, Shuk Han; Li, Ronald A; Lo, Chung Mau; Man, Kwan; Sun, Dong

2016-02-04

Cell fusion is a fast and highly efficient technique for cells to acquire new properties. The fusion of somatic cells with stem cells can reprogram somatic cells to a pluripotent state. Our research on the fusion of stem cells and cancer cells demonstrates that the fused cells can exhibit stemness and cancer cell-like characteristics. Thus, tumor-initiating cell-like cells are generated. We employed laser-induced single-cell fusion technique to fuse the hepatocellular carcinoma cells and human embryonic stem cells (hESC). Real-time RT-PCR, flow cytometry and in vivo tumorigenicity assay were adopted to identify the gene expression difference. We successfully produced a fused cell line that coalesces the gene expression information of hepatocellular carcinoma cells and stem cells. Experimental results showed that the fused cells expressed cancer and stemness markers as well as exhibited increased resistance to drug treatment and enhanced tumorigenesis. Fusion with stem cells transforms liver cancer cells into tumor initiating-like cells. Results indicate that fusion between cancer cell and stem cell may generate tumor initiating-like cells.

Phototransfection of mouse embryonic stem cells with plasmid DNA using femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Thobakgale, Lebogang; Manoto, Sello Lebohang; Ombinda Lemboumba, Saturnin; Maaza, Malik; Mthunzi-Kufa, Patience

2017-02-01

Cellular manipulation by delivery of molecules into cells has been applied extensively in tissue engineering research for medical applications . The different molecular delivery techniques used range from viral and chemical agents to physical and electrical methods. Although successful in most studies, these techniques have inherent difficulties such as toxicity, unwanted genetic mutations and low reproducibility respectively. Literature recognizes pulsed lasers at femtosecond level to be most efficient in photonic interactions with biological material. As of late, laser pulses have been used for drug and DNA delivery into cells via transient optical perforation of the cellular membrane. Thus in this study, we design and construct an optical system coupled to a femtosecond laser for the purpose of phototransfection or insertion of plasmid DNA (pDNA) into cells using lasers. We used fluorescent green protein (pGFP) to transfect mouse embryonic stem cells as our model. Secondly, we applied fluorescence imaging to view the extent of DNA delivery using this method. We also assessed the biocompatibility of our system by performing molecular assays of the cells post irradiation using adenosine triphosphate (ATP) and lactate dehydrogenase (LDH).

Tumor-stem cells interactions by fluorescence imaging

NASA Astrophysics Data System (ADS)

Meleshina, Aleksandra V.; Cherkasova, Elena I.; Sergeeva, Ekaterina; Turchin, Ilya V.; Kiseleva, Ekaterina V.; Dashinimaev, Erdem B.; Shirmanova, Marina V.; Zagaynova, Elena V.

2013-02-01

Recently, great deal of interest is investigation the function of the stem cells (SC) in tumors. In this study, we studied «recipient-tumor- fluorescent stem cells » system using the methods of in vivo imaging and laser scanning microscopy (LSM). We used adipose-derived adult stem (ADAS) cells of human lentiviral transfected with the gene of fluorescent protein Turbo FP635. ADAS cells were administrated into nude mice with transplanted tumor HeLa Kyoto (human cervical carcinoma) at different stages of tumor growth (0-8 days) intravenously or into tumor. In vivo imaging was performed on the experimental setup for epi - luminescence bioimaging (IAP RAS, Nizhny Novgorod). The results of the imaging showed localization of fluorophore tagged stem cells in the spleen on day 5-9 after injection. The sensitivity of the technique may be improved by spectral separation autofluorescence and fluorescence of stem cells. We compared the results of in vivo imaging and confocal laser scanning microscopy (LSM 510 META, Carl Zeiss, Germany). Internal organs of the animals and tumor tissue were investigated. It was shown that with i.v. injection of ADAS, bright fluorescent structures with spectral characteristics corresponding to TurboFP635 protein are locally accumulated in the marrow, lungs and tumors of animals. These findings indicate that ADAS cells integrate in the animal body with transplanted tumor and can be identified by fluorescence bioimaging techniques in vivo and ex vivo.

Laser-assisted selection and passaging of human pluripotent stem cell colonies.

PubMed

Terstegge, Stefanie; Rath, Barbara H; Laufenberg, Iris; Limbach, Nina; Buchstaller, Andrea; Schütze, Karin; Brüstle, Oliver

2009-09-10

The derivation of somatic cell products from human embryonic stem cells (hESCs) requires a highly standardized production process with sufficient throughput. To date, the most common technique for hESC passaging is the manual dissection of colonies, which is a gentle, but laborious and time-consuming process and is consequently inappropriate for standardized maintenance of hESC. Here, we present a laser-based technique for the contact-free dissection and isolation of living hESCs (laser microdissection and pressure catapulting, LMPC). Following LMPC treatment, 80.6+/-8.7% of the cells remained viable as compared to 88.6+/-1.7% of manually dissected hESCs. Furthermore, there was no significant difference in the expression of pluripotency-associated markers when compared to the control. Flow cytometry revealed that 83.8+/-4.1% of hESCs isolated by LMPC expressed the surface marker Tra-1-60 (control: 83.9+/-3.6%). In vitro differentiation potential of LMPC treated hESCs as determined by embryoid body formation and multi-germlayer formation was not impaired. Moreover, we could not detect any overt karyotype alterations as a result of the LMPC process. Our data demonstrate the feasibility of standardized laser-based passaging of hESC cultures. This technology should facilitate both colony selection and maintenance culture of pluripotent stem cells.

Optical reprogramming with ultrashort femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada; Breunig, Hans G.; Batista, Ana; König, Karsten

2015-03-01

The use of sub-15 femtosecond laser pulses in stem cell research is explored with particular emphasis on the optical reprogramming of somatic cells. The reprogramming of somatic cells into induced pluripotent stem (iPS) cells can be evoked through the ectopic expression of defined transcription factors. Conventional approaches utilize retro/lenti-viruses to deliver genes/transcription factors as well as to facilitate the integration of transcription factors into that of the host genome. However, the use of viruses may result in insertional mutations caused by the random integration of genes and as a result, this may limit the use within clinical applications due to the risk of the formation of cancer. In this study, a new approach is demonstrated in realizing non-viral reprogramming through the use of ultrashort laser pulses, to introduce transcription factors into the cell so as to generate iPS cells.

Wound Healing and Angiogenesis through Combined Use of a Vascularized Tissue Flap and Adipose-Derived Stem Cells in a Rat Hindlimb Irradiated Ischemia Model.

PubMed

Yoshida, Shuhei; Yoshimoto, Hiroshi; Hirano, Akiyoshi; Akita, Sadanori

2016-05-01

Treatment of critical limb ischemia is sometimes difficult because of the patient's condition, and some novel approaches are needed. The hindlimbs of Sprague-Dawley rats, after 20-Gy x-ray irradiation and surgical occlusion, were divided into four groups: with a superficial fascial flap, 5.0 × 10 adipose-derived stromal/stem cells, and both combined. The rats were tested for laser tissue blood flow, immunohistologic blood vessel density, and foot paw punch hole wound healing. Green fluorescent protein-tagged Sprague-Dawley rats were used for further investigation by cell tracking for 2 weeks. Laser tissue blood flow demonstrated a significant increase in the combined treatment of flap and adipose-derived stem cells at both 1 and 2 weeks. There were no significant differences between the treatment groups treated with flaps alone and those treated with adipose-derived stem cells alone. Wound healing was significantly increased following combined treatment at 1 week, and there was no wound by 2 weeks except for the no-flap and no-adipose-derived stem cell group. The number of vessels depicted by von Willebrand factor showed a significant increase in the combined treatment group, at both 1 week and 2 weeks. In the cell tracking group, at 2 weeks, the green fluorescent protein-tagged adipose-derived stem cells were significantly more positive in the no-flap group than in the flap group. Adipose-derived stem cells may be a potent cell source in irradiated and occluded limbs by enhancing tissue blood flow and blood vessel density. Adipose-derived stem cells may play an important role in some difficult ischemic conditions in terms of wound healing.

In vitro mesenchymal stem cell responses on laser-welded NiTi alloy.

PubMed

Chan, C W; Hussain, I; Waugh, D G; Lawrence, J; Man, H C

2013-04-01

The biocompatibility of NiTi after laser welding was studied by examining the in vitro (mesenchymal stem cell) MSC responses at different sets of time varying from early (4 to 12h) to intermediate phases (1 and 4 days) of cell culture. The effects of physical (surface roughness and topography) and chemical (surface Ti/Ni ratio) changes as a consequence of laser welding in different regions (WZ, HAZ, and BM) on the cell morphology and cell coverage were studied. The results in this research indicated that the morphology of MSCs was affected primarily by the topographical factors in the WZ: the well-defined and directional dendritic pattern and the presence of deeper grooves. The morphology of MSCs was not significantly modulated by surface roughness. Despite the possible initial Ni release in the medium during the cell culture, no toxic effect seemed to cause to MSCs as evidenced by the success of adhesion and spreading of the cells onto different regions in the laser weldment. The good biocompatibility of the NiTi laser weldment has been firstly reported in this study. Copyright © 2012 Elsevier B.V. All rights reserved.

Reduction and shaping of graphene-oxide by laser-printing for controlled bone tissue regeneration and bacterial killing

NASA Astrophysics Data System (ADS)

Palmieri, Valentina; Barba, Marta; Di Pietro, Lorena; Gentilini, Silvia; Chiara Braidotti, Maria; Ciancico, Carlotta; Bugli, Francesca; Ciasca, Gabriele; Larciprete, Rosanna; Lattanzi, Wanda; Sanguinetti, Maurizio; De Spirito, Marco; Conti, Claudio; Papi, Massimiliano

2018-01-01

Graphene and graphene oxide (GO) are capable of inducing stem cells differentiation into bone tissue with variable efficacy depending on reductive state of the material. Thus, modulation of osteogenic process and of bone mineral density distribution is theoretically possible by controlling the GO oxidative state. In this study, we laser-printed GO surfaces in order to obtain both a local photo-thermal GO reduction and the formation of nano-wrinkles along precise geometric pattern. Initially, after cells adhered on the surface, stem cells migrated and accumulated on the reduced and wrinkled surface. When the local density of the stem cells on the reduced stripes was high, cells started to proliferate and occupy the oxidized/flat area. The designed surfaces morphology guided stem cell orientation and the reduction accelerated differentiation. Furthermore the reduced sharp nano-wrinkles were able to enhance the GO antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), a common cause of prosthetic joints infections. This strategy can offer a revolution in present and future trends of scaffolds design for regenerative medicine.

CO2 laser increases the regenerative capacity of human adipose-derived stem cells by a mechanism involving the redox state and enhanced secretion of pro-angiogenic molecules.

PubMed

Constantin, Alina; Dumitrescu, Madalina; Mihai Corotchi, Maria Cristina; Jianu, Dana; Simionescu, Maya

2017-01-01

CO 2 laser has a beneficial effect on stem cells by mechanisms that are not clearly elucidated. We hypothesize that the effect of fractional CO 2 laser on human adipose-derived stem cells (ADSC) could be due to changes in redox homeostasis and secretion of factors contributing to cellular proliferation and angiogenic potential. ADSC incubated in medium containing 0.5 or 10 % FBS were exposed to a single irradiation of a 10,600-nm fractional CO 2 laser; non-irradiated ADSC were used as control. Viability/proliferation of ADSC was assessed by MTT assay; the intracellular reactive oxygen species (ROS) levels and the mitochondrial membrane potential (∆Ψ m ) were determined with DCFH-DA and JC-1 fluorescent probes, respectively. Molecules secreted by ADSC in the medium were determined by ELISA assay, and their capacity to support endothelial tube-like formation by the Matrigel assay. The results showed that compared to controls, ADSC kept in low FBS medium and irradiated with CO 2 laser at 9 W exhibited: (a) increased proliferation (∼20 %), (b) transient increase of mitochondrial ROS and the capacity to restore Δψ m after rotenone induced depolarization, and (c) augmented secretion in the conditioned medium of MMP-2 (twofold), MMP-9 (eightfold), VEGF (twofold), and adiponectin (∼50 %) that have the capacity to support angiogenesis of endothelial progenitor cells. In conclusion, the mechanisms underlying the benefic effect of CO 2 laser on ADSC are the activation of the redox pathways which increases cell proliferation and enhances secretion of angiogenic molecules. These results explain, in part, the mechanisms involved in the increased regenerative potential of CO 2 laser-exposed ADSC that could be exploited for clinical applications.

Effect of low-level diode laser on proliferation and osteogenic differentiation of dental pulp stem cells

NASA Astrophysics Data System (ADS)

Tabatabaei, Fahimeh S.; Torshabi, Maryam; Mojahedi Nasab, Masoud; Khosraviani, Keikhosro; Khojasteh, Arash

2015-09-01

This study assessed the effect of low-level laser irradiation (LLLI) on the proliferation and osteogenic differentiation of dental pulp stem cells (DPSCs). DPSCs were exposed to 810 nm laser light (0.1, 0.2, or 0.3 J cm-2) for 7 d (60 s daily). The negative control group (cells in regular medium) and positive control group (cells in osteogenic medium (OM)) were not lased. One group of cells in OM was irradiated with laser operated at 0.2 J cm-2. Cell viability was evaluated at 24 h and one week after the last day of laser irradiation using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Osteogenic differentiation was assessed using real-time reverse transcriptase polymerase chain reaction (RT-PCR) and alizarin Red S staining. Cell proliferation was not affected by laser irradiation at 24 h except in one group (cells in OM exposed to laser at 0.2 J cm-2). However, one week after the last day of laser irradiation, it was significantly increased in groups exposed to laser at 0.1 or 0.2 J cm-2 and decreased in groups containing OM (P  <  0.05). Osteoblast marker expression was observed in groups containing OM. LLLI at 0.2 J cm-2 dramatically enhanced cell differentiation. Laser at 0.3 J cm-2 increased bone sialoprotein (BSP) and decreased alkaline phosphatase (ALP). Mineralized nodules were only observed in groups containing OM. Considering these findings, LLLI may be used as a novel approach for preconditioning of DPSCs in vitro prior to bone tissue engineering.

Laser direct writing of combinatorial libraries of idealized cellular constructs: Biomedical applications

NASA Astrophysics Data System (ADS)

Schiele, Nathan R.; Koppes, Ryan A.; Corr, David T.; Ellison, Karen S.; Thompson, Deanna M.; Ligon, Lee A.; Lippert, Thomas K. M.; Chrisey, Douglas B.

2009-03-01

The ability to control cell placement and to produce idealized cellular constructs is essential for understanding and controlling intercellular processes and ultimately for producing engineered tissue replacements. We have utilized a novel intra-cavity variable aperture excimer laser operated at 193 nm to reproducibly direct write mammalian cells with micrometer resolution to form a combinatorial array of idealized cellular constructs. We deposited patterns of human dermal fibroblasts, mouse myoblasts, rat neural stem cells, human breast cancer cells, and bovine pulmonary artery endothelial cells to study aspects of collagen network formation, breast cancer progression, and neural stem cell proliferation, respectively. Mammalian cells were deposited by matrix assisted pulsed laser evaporation direct write from ribbons comprised of a UV transparent quartz coated with either a thin layer of extracellular matrix or triazene as a dynamic release layer using CAD/CAM control. We demonstrate that through optical imaging and incorporation of a machine vision algorithm, specific cells on the ribbon can be laser deposited in spatial coherence with respect to geometrical arrays and existing cells on the receiving substrate. Having the ability to direct write cells into idealized cellular constructs can help to answer many biomedical questions and advance tissue engineering and cancer research.

Photoactivation of Endogenous Latent Transforming Growth Factor–β1 Directs Dental Stem Cell Differentiation for Regeneration

PubMed Central

Arany, Praveen R.; Cho, Andrew; Hunt, Tristan D.; Sidhu, Gursimran; Shin, Kyungsup; Hahm, Eason; Huang, George X.; Weaver, James; Chen, Aaron Chih-Hao; Padwa, Bonnie L.; Hamblin, Michael R.; Barcellos-Hoff, Mary Helen; Kulkarni, Ashok B.; Mooney, David J.

2014-01-01

Rapid advancements in the field of stem cell biology have led to many current efforts to exploit stem cells as therapeutic agents in regenerative medicine. However, current ex vivo cell manipulations common to most regenerative approaches create a variety of technical and regulatory hurdles to their clinical translation, and even simpler approaches that use exogenous factors to differentiate tissue-resident stem cells carry significant off-target side effects. We show that non-ionizing, low-power laser (LPL) treatment can instead be used as a minimally invasive tool to activate an endogenous latent growth factor complex, transforming growth factor–β1 (TGF-β1), that subsequently differentiates host stem cells to promote tissue regeneration. LPL treatment induced reactive oxygen species (ROS) in a dose-dependent manner, which, in turn, activated latent TGF-β1 (LTGF-β1) via a specific methionine residue (at position 253 on LAP). Laser-activated TGF-β1 was capable of differentiating human dental stem cells in vitro. Further, an in vivo pulp capping model in rat teeth demonstrated significant increase in dentin regeneration after LPL treatment. These in vivo effects were abrogated in TGF-β receptor II (TGF-βRII) conditional knockout (DSPPCreTGF-βRIIfl/fl) mice or when wild-type mice were given a TGF-βRI inhibitor. These findings indicate a pivotal role for TGF-β in mediating LPL-induced dental tissue regeneration. More broadly, this work outlines a mechanistic basis for harnessing resident stem cells with a light-activated endogenous cue for clinical regenerative applications. PMID:24871130

Optical cell cleaning with NIR femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada; Breunig, Hans Georg; Batista, Ana; König, Karsten

2015-03-01

Femtosecond laser microscopes have been used as both micro and nanosurgery tools. The optical knock-out of undesired cells in multiplex cell clusters shall be further reported on in this study. Femtosecond laser-induced cell death is beneficial due to the reduced collateral side effects and therefore can be used to selectively destroy target cells within monolayers, as well as within 3D tissues, all the while preserving cells of interest. This is an important characteristic for the application in stem cell research and cancer treatment. Non-precise damage compromises the viability of neighboring cells by inducing side effects such as stress to the cells surrounding the target due to the changes in the microenvironment, resulting from both the laser and laser-exposed cells. In this study, optimum laser parameters for optical cleaning by isolating single cells and cell colonies are exploited through the use of automated software control. Physiological equilibrium and cellular responses to the laser induced damages are also investigated. Cell death dependence on laser focus, determination and selectivity of intensity/dosage, controllable damage and cell recovery mechanisms are discussed.

Morphological Observations of Mesenchymal Stem Cell Adhesion to a Nanoperiodic-Structured Titanium Surface Patterned Using Femtosecond Laser Processing

NASA Astrophysics Data System (ADS)

Oya, Kei; Aoki, Shun; Shimomura, Kazunori; Sugita, Norihiko; Suzuki, Kenji; Nakamura, Norimasa; Fujie, Hiromichi

2012-12-01

It is known that the adhesive and anisotropic properties of cell-derived biomaterials are affected by micro- or nanoscale structures processed on culture surfaces. In the present study, the femtosecond laser processing technique was used to scan a laser beam at an intensity of approximately the ablation threshold level on a titanium surface for nanoscale processing. Microscopy observation revealed that the processed titanium exhibited a periodic-patterned groove structure at the surface; the width and depth of the groove were 292 ±50 and 99 ±31 nm, respectively, and the periodic pitch of the groove was 501 ±100 nm. Human synovium-derived mesenchymal stem cells were cultured on the surface at a cell density of 3.0×103 cells/cm2 after 4 cell passages. For comparison, the cells were also cultured on a nonprocessed titanium surface under the condition identical to that of the processed surface. Results revealed that the duration for cell attachment to the surface was markedly reduced on the processed titanium as compared with the nonprocessed titanium. Moreover, on the processed titanium, cell extension area significantly increased while cell orientation was aligned along the direction of the periodic grooves. These results suggest that the femtosecond laser processing improves the adhesive and anisotropic properties of cells by producing the nanoperiodic structure on titanium culture surfaces.

Image-guided smart laser system for precision implantation of cells in cartilage

NASA Astrophysics Data System (ADS)

Katta, Nitesh; Rector, John A.; Gardner, Michael R.; McElroy, Austin B.; Choy, Kevin C.; Crosby, Cody; Zoldan, Janet; Milner, Thomas E.

2017-03-01

State-of-the-art treatment for joint diseases like osteoarthritis focus on articular cartilage repair/regeneration by stem cell implantation therapy. However, the technique is limited by a lack of precision in the physician's imaging and cell deposition toolkit. We describe a novel combination of high-resolution, rapid scan-rate optical coherence tomography (OCT) alongside a short-pulsed nanosecond thulium (Tm) laser for precise cell seeding in cartilage. The superior beam quality of thulium lasers and wavelength of operation 1940 nm offers high volumetric tissue removal rates and minimizes the residual thermal footprint. OCT imaging enables targeted micro-well placement, precise cell deposition, and feature contrast. A bench-top system is constructed using a 15 W, 1940 nm, nanosecond-pulsed Tm fiber laser (500 μJ pulse energy, 100 ns pulse duration, 30kHz repetition rate) for removing tissue, and a swept source laser (1310 ± 70 nm, 100 kHz sweep rate) for OCT imaging, forming a combined Tm/OCT system - a "smart laser knife". OCT assists the smart laser knife user in characterizing cartilage to inform micro-well placement. The Tm laser creates micro-wells (2.35 mm diameter length, 1.5 mm width, 300 μm deep) and micro-incisions (1 mm wide, 200 μm deep) while OCT image-guidance assists and demonstrates this precision cutting and cell deposition with real-time feedback. To test micro-well creation and cell deposition protocol, gelatin phantoms are constructed mimicking cartilage optical properties and physiological structure. Cell viability is then assessed to illustrate the efficacy of the hydrogel deposition. Automated OCT feedback is demonstrated for cutting procedures to avoid important surface/subsurface structures. This bench-top smart laser knife system described here offers a new image-guided approach to precise stem cell seeding that can enhance the efficacy of articular cartilage repair.

Fluorescence lifetime imaging of induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada; Batista, Ana; König, Karsten

2014-02-01

The multiphoton FLIM tomograph MPTflex with its flexible scan head, articulated arm, and the tunable femtosecond laser source was employed to study cell monolayers and 3D cell clusters. FLIM was performed with 250 ps temporal resolution and submicron special resolution using time-correlated single photon counting. The autofluorescence based on NAD(P)H and flavins/flavoproteins has been measured in mouse embryonic fibroblasts, induced pluripotent stem cells (iPS cells) originated from mouse embryonic fibroblasts and non-proliferative mouse embryonic fibroblasts.

Low-level laser therapy with helium-neon laser improved viability of osteoporotic bone marrow-derived mesenchymal stem cells from ovariectomy-induced osteoporotic rats

NASA Astrophysics Data System (ADS)

Fallahnezhad, Somaye; Piryaei, Abbas; Tabeie, Faraj; Nazarian, Hamid; Darbandi, Hasan; Amini, Abdoldllah; Mostafavinia, Ataroalsadat; Ghorishi, Seyed Kamran; Jalalifirouzkouhi, Ali; Bayat, Mohammad

2016-09-01

The purpose of this study was to evaluate the influences of helium-neon (He-Ne) and infrared (IR) lasers on the viability and proliferation rate of healthy and ovariectomy-induced osteoporotic (OVX) bone marrow mesenchymal stem cells (BMMSCs) in vitro. MSCs harvested from the BM of healthy and OVX rats were culture expanded. He-Ne and IR lasers were applied three times at energy densities of 0.6, 1.2, and 2.4 J/cm2 for BMMSCs. BMMSCs viability and proliferation rate were evaluated by MTT assay on days 2, 4, 6, 14, and 21. The results showed that healthy BMMSCs responded optimally to 0.6 J/cm2 using an IR laser after three times of laser radiation. Moreover, it was found that OVX-BMMSCs responded optimally to 0.6 J/cm2 with He-Ne laser and one-time laser radiation. It is concluded that the low-level laser therapy (LLLT) effect depends on the physiological state of the BMMSCs, type of the laser, wavelength, and number of laser sessions. The biostimulation efficiency of LLLT also depends on the delivered energy density. LLLT can enhance the viability and proliferation rate of healthy and especially osteoporotic autologous BMMSCs, which could be very useful in regenerative medicine.

Clinical-scale laser-based scanning and processing of live cells: selective photothermal killing of fluorescent tumor targets for autologous stem cell transplantation

NASA Astrophysics Data System (ADS)

Koller, Manfred R.; Hanania, Elie G.; Eisfeld, Timothy; O'Neal, Robert A.; Khovananth, Kevin M.; Palsson, Bernhard O.

2001-04-01

High-dose chemotherapy, followed by autologous hematopoietic stem cell (HSC) transplantation, is widely used for the treatment of cancer. However, contaminating tumor cells within HSC harvests continue to be of major concern since re-infused tumor cells have proven to contribute to disease relapse. Many tumor purging methods have been evaluated, but all leave detectable tumor cells in the transplant and result in significant loss of HSCs. These shortcomings cause engraftment delays and compromise the therapeutic value of purging. A novel approach integrating automated scanning cytometry, image analysis, and selective laser-induced killing of labeled cells within a cell mixture is described here. Non-Hodgkin's lymphoma (NHL) cells were spiked into cell mixtures, and fluorochrome-conjugated antibodies were used to label tumor cells within the mixture. Cells were then allowed to settle on a surface, and as the surface was scanned with a fluorescence excitation source, a laser pulse was fired at every detected tumor cell using high-speed beam steering mirrors. Tumor cells were selectively killed with little effect on adjacent non-target cells, demonstrating the feasibility of this automated cell processing approach. This technology has many potential research and clinical applications, one example of which is tumor cell purging for autologous HSC transplantation.

Concise Review: Bioprinting of Stem Cells for Transplantable Tissue Fabrication.

PubMed

Leberfinger, Ashley N; Ravnic, Dino J; Dhawan, Aman; Ozbolat, Ibrahim T

2017-10-01

Bioprinting is a quickly progressing technology, which holds the potential to generate replacement tissues and organs. Stem cells offer several advantages over differentiated cells for use as starting materials, including the potential for autologous tissue and differentiation into multiple cell lines. The three most commonly used stem cells are embryonic, induced pluripotent, and adult stem cells. Cells are combined with various natural and synthetic materials to form bioinks, which are used to fabricate scaffold-based or scaffold-free constructs. Computer aided design technology is combined with various bioprinting modalities including droplet-, extrusion-, or laser-based bioprinting to create tissue constructs. Each bioink and modality has its own advantages and disadvantages. Various materials and techniques are combined to maximize the benefits. Researchers have been successful in bioprinting cartilage, bone, cardiac, nervous, liver, and vascular tissues. However, a major limitation to clinical translation is building large-scale vascularized constructs. Many challenges must be overcome before this technology is used routinely in a clinical setting. Stem Cells Translational Medicine 2017;6:1940-1948. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Biodegradable Polymers and Stem Cells for Bioprinting.

PubMed

Lei, Meijuan; Wang, Xiaohong

2016-04-29

It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

Laser-assisted nanoceramics reinforced polymer scaffolds for tissue engineering: additional heating and stem cells behavior

NASA Astrophysics Data System (ADS)

Shishkovsky, Igor; Scherbakov, Vladimir; Volchkov, Vladislav; Volova, Larisa

2018-02-01

The conditions of selective laser melting (SLM) of tissue engineering scaffolds affect cell response and must be engineered to support cell adhesion, proliferation, and differentiation. In the present study, the influence of additional heating during SLM process on stem cell viability near biopolymer matrix reinforced by nanoceramics additives was carried out. We used the biocompatible and bioresorbable polymers (polyetheretherketone /PEEK/ and polycaprolactone /PCL/) as a matrix and nano-oxide ceramics - TiO2, Al2O3, ZrO2, FexOy and/or hydroxyapatite as a basis of the additives. The rate of pure PEEK and PCL bio-resorption and in mixtures with nano oxides on the matrix was studied by the method of mass loss on bacteria of hydroxylase and enzyme complex. The stem cellular morphology, proliferative MMSC activity, and adhesion of the 2D and 3D nanocomposite matrices were the subjects of comparison. Medical potential of the SLS/M-fabricated nano-oxide ceramics after additional heating as the basis for tissue engineering scaffolds and cell targeting systems were discussed.

Human mesenchymal stem cell behavior on femtosecond laser-textured Ti-6Al-4V surfaces.

PubMed

Cunha, Alexandre; Zouani, Omar Farouk; Plawinski, Laurent; Botelho do Rego, Ana Maria; Almeida, Amélia; Vilar, Rui; Durrieu, Marie-Christine

2015-01-01

The aim of the present work was to investigate ultrafast laser surface texturing as a surface treatment of Ti-6Al-4V alloy dental and orthopedic implants to improve osteoblastic commitment of human mesenchymal stem cells (hMSCs). Surface texturing was carried out by direct writing with an Yb:KYW chirped-pulse regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. The surface topography and chemical composition were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively. Three types of surface textures with potential interest to improve implant osseointegration can be produced by this method: laser-induced periodic surface structures (LIPSSs); nanopillars (NPs); and microcolumns covered with LIPSSs, forming a bimodal roughness distribution. The potential of the laser treatment in improving hMSC differentiation was assessed by in vitro study of hMSCs spreading, adhesion, elongation and differentiation using epifluorescence microscopy at different times after cell seeding, after specific stainings and immunostainings. Cell area and focal adhesion area were lower on the laser-textured surfaces than on a polished reference surface. Obviously, the laser-textured surfaces have an impact on cell shape. Osteoblastic commitment was observed independently of the surface topography after 2 weeks of cell seeding. When the cells were cultured (after 4 weeks of seeding) in osteogenic medium, LIPSS- and NP- textured surfaces enhanced matrix mineralization and bone-like nodule formation as compared with polished and microcolumn-textured surfaces. The present work shows that surface nanotextures consisting of LIPSSs and NPs can, potentially, improve hMSC differentiation into an osteoblastic lineage.

Early wound healing of laser in situ keratomileusis-like flaps after treatment with human corneal stromal stem cells.

PubMed

Morgan, Siân R; Dooley, Erin P; Kamma-Lorger, Christina; Funderburgh, James L; Funderburgh, Martha L; Meek, Keith M

2016-02-01

To use a well-established organ culture model to investigate the effects of corneal stromal stem cells on the optical and biomechanical properties of corneal wounds after laser in situ keratomileusis (LASIK)-like flap creation. School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom. Experimental study. The LASIK-like flaps were produced in sheep corneas. The flap beds were treated with corneal stromal stem cells and were then replaced and allowed to heal for different periods of up to 3 weeks in organ culture. The optical transmission of the cornea, the force required to detach the flap, and the presence of myofibroblasts near the flap bed were measured. Corneal stromal stem cell-treated flap beds were statistically significantly more transparent after 3 weeks in culture than the untreated controls. At 3 weeks, the mean force necessary to detach the flap was more than twice the force required for the respective control samples. Concurrently, there were 44% activated cells immediately below the flap margin of the controls compared with 29% in the same region of the corneal stromal stem cell-treated flaps. In this system, the presence of corneal stromal stem cells at the wound margin significantly increased the adherence of LASIK-like flaps while maintaining corneal transparency. It is postulated that this is achieved by the deposition of extracellular connective tissue similar to that found in the normal cornea and by the paucity of activated keratocytes (myofibroblasts), which are known to scatter a significant amount of the incident light. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Optical reprogramming of human somatic cells using ultrashort Bessel-shaped near-infrared femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada; Breunig, Hans Georg; Batista, Ana; König, Karsten

2015-11-01

We report a virus-free optical approach to human cell reprogramming into induced pluripotent stem cells with low-power nanoporation using ultrashort Bessel-shaped laser pulses. Picojoule near-infrared sub-20 fs laser pulses at a high 85 MHz repetition frequency are employed to generate transient nanopores in the membrane of dermal fibroblasts for the introduction of four transcription factors to induce the reprogramming process. In contrast to conventional approaches which utilize retro- or lentiviruses to deliver genes or transcription factors into the host genome, the laser method is virus-free; hence, the risk of virus-induced cancer generation limiting clinical application is avoided.

Preconditioning With Low-Level Laser Irradiation Enhances the Therapeutic Potential of Human Adipose-derived Stem Cells in a Mouse Model of Photoaged Skin.

PubMed

Liao, Xuan; Li, Sheng-Hong; Xie, Guang-Hui; Xie, Shan; Xiao, Li-Ling; Song, Jian-Xing; Liu, Hong-Wei

2018-02-19

This study was conducted to explore the therapeutic potential of human adipose-derived stem cells (ADSCs) irradiated with a low-level laser (LLL). Cultured ADSCs were treated with 650-nm GaAlAs laser irradiation at 2, 4 and 8 J cm -2 . Cell proliferation was quantified by MTT assays, cytokine secretion was determined by enzyme-linked immunosorbent assays, and adipogenic differentiation was examined by oil red O staining. Additionally, the expression profiles of putative ADSC surface markers were analyzed by quantitative real-time PCR. In addition, a mouse photoaged skin model was established by UVB irradiation. Effects of GaAlAs laser-treated ADSCs on the thicknesses of the epidermis and dermis were analyzed by hematoxylin and eosin staining. The results showed that GaAlAs laser treatment of cells at a radiant exposure of 4 J cm -2 enhanced ADSC proliferation and adipogenic differentiation and increased secretion of growth factors. Furthermore, GaAlAs laser irradiation upregulated the expression of putative ADSC surface markers. In the mouse model of photoaged skin, ADSCs treated with GaAlAs laser irradiation had markedly decreased the epidermal thickness and increased the dermal thickness of photoaged mouse skin. Our data indicate that LLL irradiation is an effective biostimulator of ADSCs and might enhance the therapeutic potential of ADSCs for clinical use. © 2018 The American Society of Photobiology.

Stem cell recruitment of newly formed host cells via a successful seduction? Filling the gap between neurogenic niche and injured brain site.

PubMed

Tajiri, Naoki; Kaneko, Yuji; Shinozuka, Kazutaka; Ishikawa, Hiroto; Yankee, Ernest; McGrogan, Michael; Case, Casey; Borlongan, Cesar V

2013-01-01

Here, we report that a unique mechanism of action exerted by stem cells in the repair of the traumatically injured brain involves their ability to harness a biobridge between neurogenic niche and injured brain site. This biobridge, visualized immunohistochemically and laser captured, corresponded to an area between the neurogenic subventricular zone and the injured cortex. That the biobridge expressed high levels of extracellular matrix metalloproteinases characterized initially by a stream of transplanted stem cells, but subsequently contained only few to non-detectable grafts and overgrown by newly formed host cells, implicates a novel property of stem cells. The transplanted stem cells manifest themselves as pathways for trafficking the migration of host neurogenic cells, but once this biobridge is formed between the neurogenic site and the injured brain site, the grafted cells disappear and relinquish their task to the host neurogenic cells. Our findings reveal that long-distance migration of host cells from the neurogenic niche to the injured brain site can be achieved through transplanted stem cells serving as biobridges for initiation of endogenous repair mechanisms. This is the first report of a stem cell-paved "biobridge". Indeed, to date the two major schools of discipline in stem cell repair mechanism primarily support the concept of "cell replacement" and bystander effects of "trophic factor secretion". The present novel observations of a stem cell seducing a host cell to engage in brain repair advances basic science concepts on stem cell biology and extracellular matrix, as well as provokes translational research on propagating this stem cell-paved biobridge beyond cell replacement and trophic factor secretion for the treatment of traumatic brain injury and other neurological disorders.

In vitro and in vivo biocompatibility study on laser 3D microstructurable polymers

NASA Astrophysics Data System (ADS)

Malinauskas, Mangirdas; Baltriukiene, Daiva; Kraniauskas, Antanas; Danilevicius, Paulius; Jarasiene, Rasa; Sirmenis, Raimondas; Zukauskas, Albertas; Balciunas, Evaldas; Purlys, Vytautas; Gadonas, Roaldas; Bukelskiene, Virginija; Sirvydis, Vytautas; Piskarskas, Algis

2012-09-01

Films and microstructured scaffolds have been fabricated using direct laser writing out of different polymers: hybrid organic-inorganic ORMOCORE b59, acrylate-based AKRE23, novel organic-inorganic Zr containing hybrid SZ2080, and biodegradable PEG-DA-258. Adult myogenic stem cells were grown on these surfaces in vitro. Their adhesion, growth, and viability test results suggest good potential applicability of the materials in biomedical practice. Pieces of these polymers were implanted in rat's paravertebral back tissue. Histological examination of the implants and surrounding tissue ex vivo after 3 weeks of implantation was conducted and results show the materials to be at least as biocompatible as surgical clips or sutures. The applied direct laser writing technique seems to offer good future prospects in a polymeric 3D scaffold design for artificial tissue engineering with autologous stem cells.

Near infrared laser stimulation of human neural stem cells into neurons on graphene nanomesh semiconductors.

PubMed

Akhavan, Omid; Ghaderi, Elham; Shirazian, Soheil A

2015-02-01

Reduced graphene oxide nanomeshes (rGONMs), as p-type semiconductors with band-gap energy of ∼ 1 eV, were developed and applied in near infrared (NIR) laser stimulation of human neural stem cells (hNSCs) into neurons. The biocompatibility of the rGONMs in growth of hNSCs was found similar to that of the graphene oxide (GO) sheets. Proliferation of the hNSCs on the GONMs was assigned to the excess oxygen functional groups formed on edge defects of the GONMs, resulting in superhydrophilicity of the surface. Under NIR laser stimulation, the graphene layers (especially the rGONMs) exhibited significant cell differentiations, including more elongations of the cells and higher differentiation of neurons than glia. The higher hNSC differentiation on the rGONM than the reduced GO (rGO) was assigned to the stimulation effects of the low-energy photoexcited electrons injected from the rGONM semiconductors into the cells, while the high-energy photoelectrons of the rGO (as a zero band-gap semiconductor) could suppress the cell proliferation and/or even cause cell damages. Using conventional heating of the culture media up to ∼ 43 °C (the temperature typically reached under the laser irradiation), no significant differentiation was observed in dark. This further confirmed the role of photoelectrons in the hNSC differentiation. Copyright © 2014 Elsevier B.V. All rights reserved.

In vitro biological outcome of laser application for modification or processing of titanium dental implants.

PubMed

Hindy, Ahmed; Farahmand, Farzam; Tabatabaei, Fahimeh Sadat

2017-07-01

There are numerous functions for laser in modern implant dentistry including surface treatment, surface coating, and implant manufacturing. As laser application may potentially improve osseointegration of dental implants, we systematically reviewed the literature for in vitro biological responses to laser-modified or processed titanium dental implants. The literature was searched in PubMed, ISI Web, and Scopus, using keywords "titanium dental implants," "laser," "biocompatibility," and their synonyms. After screening the 136 references obtained, 28 articles met the inclusion criteria. We found that Nd:YAG laser was the most commonly used lasers in the treatment or processing of titanium dental implants. Most of the experiments used cell attachment and cell proliferation to investigate bioresponses of the implants. The most commonly used cells in these assays were osteoblast-like cells. Only one study was conducted in stem cells. These in vitro studies reported higher biocompatibility in laser-modified titanium implants. It seems that laser radiation plays a vital role in cell response to dental implants; however, it is necessary to accomplish more studies using different laser types and parameters on various cells to offer a more conclusive result.

Effect of laser treatment on the attachment and viability of mesenchymal stem cell responses on shape memory NiTi alloy.

PubMed

Chan, C W; Hussain, I; Waugh, D G; Lawrence, J; Man, H C

2014-09-01

The objectives of this study were to investigate the effect of laser-induced surface features on the morphology, attachment and viability of mesenchymal stem cells (MSCs) at different periods of time, and to evaluate the biocompatibility of different zones: laser-melted zone (MZ), heat-affected zone (HAZ) and base metal (BM) in laser-treated NiTi alloy. The surface morphology and composition were studied by scanning electron microscope (SEM) and X-ray photoemission spectroscopy (XPS), respectively. The cell morphology was examined by SEM while the cell counting and viability measurements were done by hemocytometer and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. The results indicated that the laser-induced surface features, such as surface roughening, presence of anisotropic dendritic pattern and complete surface Ni oxidation were beneficial to improve the biocompatibility of NiTi as evidenced by the highest cell attachment (4 days of culture) and viability (7 days of culture) found in the MZ. The biocompatibility of the MZ was the best, followed by the BM with the HAZ being the worst. The defective and porous oxide layer as well as the coarse grained structure might attribute to the inferior cell attachment (4 days of culture) and viability (7 days of culture) on the HAZ compared with the BM which has similar surface morphology. Copyright © 2014 Elsevier B.V. All rights reserved.

Stem Cell Physics. Laser Manipulation of Blood Types: Laser-Stripping-Away of Red Blood Cell Surface Antigens

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-03-01

A novel mechanism of importance for the transfusion medicine[2] is proposed. The interaction of ultrashort wavelength multilaser beams with the flowing blood thin films can lead to a conversion of blood types A, B, and AB into O type.[3] The stripping away of antigens is done by the scanning-multiple-lasers of a high repetition rate in the blue-purple frequency domain. The guiding-lasers are in the red-green frequency domain. The laser force, (parametric interaction with the antigen eigen-oscillation),[4] upon the antigen protein molecule must exceed its weight. Supported by Nikola Tesla Labs, La Jolla, CA.

3D printing scaffold coupled with low level light therapy for neural tissue regeneration.

PubMed

Zhu, Wei; George, Jonathan K; Sorger, Volker J; Grace Zhang, Lijie

2017-04-12

3D printing has shown promise for neural regeneration by providing customized nerve scaffolds to structurally support and bridge the defect gap as well as deliver cells or various bioactive substances. Low-level light therapy (LLLT) exhibits positive effects on rehabiliation of degenerative nerves and neural disorders. With this in mind, we postulate that 3D printed neural scaffold coupling with LLLT will generate a new strategy to repair neural degeneration. To achieve this goal, we applied red laser light to stimualte neural stem cells on 3D printed scaffolds and investigated the subsequent cell response with respect to cell proliferation and differentiation. Here we show that cell prolifeartion rate and intracellular reactive oxgen species synthesis were significantly increased after 15 s laser stimulation follwed by 1 d culture. Over culturing time of 14 d in vitro, the laser stimulation promoted neuronal differentiation of neural stem cells, while the glial differentiation was suppressed based on results of both immunocytochemistry studies and real-time quantitative reverse transcription polymerase chain reaction testing. These findings suggest that integration of 3D printing and LLLT might provide a powerful methodology for neural tissue engineering.

Generation and Role of Reactive Oxygen and Nitrogen Species Induced by Plasma, Lasers, Chemical Agents, and Other Systems in Dentistry

PubMed Central

Jha, Nayansi; Ryu, Jae Jun

2017-01-01

The generation of reactive oxygen and nitrogen species (RONS) has been found to occur during inflammatory procedures, during cell ischemia, and in various crucial developmental processes such as cell differentiation and along cell signaling pathways. The most common sources of intracellular RONS are the mitochondrial electron transport system, NADH oxidase, and cytochrome P450. In this review, we analyzed the extracellular and intracellular sources of reactive species, their cell signaling pathways, the mechanisms of action, and their positive and negative effects in the dental field. In dentistry, ROS can be found—in lasers, photosensitizers, bleaching agents, cold plasma, and even resin cements, all of which contribute to the generation and prevalence of ROS. Nonthermal plasma has been used as a source of ROS for biomedical applications and has the potential for use with dental stem cells as well. There are different types of dental stem cells, but their therapeutic use remains largely untapped, with the focus currently on only periodontal ligament stem cells. More research is necessary in this area, including studies about ROS mechanisms with dental cells, along with the utilization of reactive species in redox medicine. Such studies will help to provide successful treatment modalities for various diseases. PMID:29204250

Laser processing of polymer constructs from poly(3-hydroxybutyrate).

PubMed

Volova, T G; Tarasevich, A A; Golubev, A I; Boyandin, A N; Shumilova, A A; Nikolaeva, E D; Shishatskaya, E I

2015-01-01

CO2 laser radiation was used to process poly(3-hydroxybutyrate) constructs - films and 3D pressed plates. Laser processing increased the biocompatibility of unperforated films treated with moderate uniform radiation, as estimated by the number and degree of adhesion of NIH 3T3 mouse fibroblast cells. The biocompatibility of perforated films modified in the pulsed mode did not change significantly. At the same time, pulsed laser processing of the 3D plates produced perforated scaffolds with improved mechanical properties and high biocompatibility with bone marrow-derived multipotent, mesenchymal stem cells, which show great promise for bone regeneration.

Low Reactive Level Laser Therapy for Mesenchymal Stromal Cells Therapies

PubMed Central

Kushibiki, Toshihiro; Hirasawa, Takeshi; Okawa, Shinpei; Ishihara, Miya

2015-01-01

Low reactive level laser therapy (LLLT) is mainly focused on the activation of intracellular or extracellular chromophore and the initiation of cellular signaling by using low power lasers. Over the past forty years, it was realized that the laser therapy had the potential to improve wound healing and reduce pain and inflammation. In recent years, the term LLLT has become widely recognized in the field of regenerative medicine. In this review, we will describe the mechanisms of action of LLLT at a cellular level and introduce the application to mesenchymal stem cells and mesenchymal stromal cells (MSCs) therapies. Finally, our recent research results that LLLT enhanced the MSCs differentiation to osteoblast will also be described. PMID:26273309

Combination of nitric oxide therapy, anti-oxidative therapy, low level laser therapy, plasma rich platelet therapy and stem cell therapy as a novel therapeutic application to manage the pain and treat many clinical conditions

NASA Astrophysics Data System (ADS)

Halasa, Salaheldin; Dickinson, Eva

2014-02-01

From hypertension to diabetes, cancer to HIV, stroke to memory loss and learning disorders to septic shock, male impotence to tuberculosis, there is probably no pathological condition where nitric oxide does not play an important role. Nitric oxide is an analgesic, immune-modulator, vasodilator, anti-apoptotic, growth modulator, angiogenetic, anti-thrombotic, anti-inflammatory and neuro-modulator. Because of the above actions of nitric oxide, many clinical conditions associated with abnormal Nitric oxide (NO) production and bioavailability. Our novel therapeutic approach is to restore the homeostasis of nitric oxide and replace the lost cells by combining nitric oxide therapy, anti-oxidative therapy, low level laser therapy, plasma rich platelet therapy and stem cell therapy.

Modulation of cardiomyocyte activity using pulsed laser irradiated gold nanoparticles

PubMed Central

Gentemann, Lara; Kalies, Stefan; Coffee, Michelle; Meyer, Heiko; Ripken, Tammo; Heisterkamp, Alexander; Zweigerdt, Robert; Heinemann, Dag

2016-01-01

Can photothermal gold nanoparticle mediated laser manipulation be applied to induce cardiac contraction? Based on our previous work, we present a novel concept of cell stimulation. A 532 nm picosecond laser was employed to heat gold nanoparticles on cardiomyocytes. This leads to calcium oscillations in the HL-1 cardiomyocyte cell line. As calcium is connected to the contractility, we aimed to alter the contraction rate of native and stem cell derived cardiomyocytes. A contraction rate increase was particularly observed in calcium containing buffer with neonatal rat cardiomyocytes. Consequently, the study provides conceptual ideas for a light based, nanoparticle mediated stimulation system. PMID:28101410

Adult Human Nasal Mesenchymal-Like Stem Cells Restore Cochlear Spiral Ganglion Neurons After Experimental Lesion

PubMed Central

Bas, Esperanza; Van De Water, Thomas R.; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M.

2014-01-01

A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced pluripotent stem cells that may impede the translation to clinical applications, we sought to utilize an alternative cell source. Here, we show that adult human mesenchymal-like stem cells (MSCs) obtained from nasal tissue can repair spiral ganglion loss in experimentally lesioned cochlear cultures from neonatal rats. Stem cells engraft into gentamicin-lesioned organotypic cultures and orchestrate the restoration of the spiral ganglion neuronal population, involving both direct neuronal differentiation and secondary effects on endogenous cells. As a physiologic assay, nasal MSC-derived cells engrafted into lesioned spiral ganglia demonstrate responses to infrared laser stimulus that are consistent with those typical of excitable cells. The addition of a pharmacologic activator of the canonical Wnt/β-catenin pathway concurrent with stem cell treatment promoted robust neuronal differentiation. The availability of an effective adult autologous cell source for inner ear tissue repair should contribute to efforts to translate cell-based strategies to the clinic. PMID:24172073

The human urothelium consists of multiple clonal units, each maintained by a stem cell.

PubMed

Gaisa, Nadine T; Graham, Trevor A; McDonald, Stuart A C; Cañadillas-Lopez, Sagrario; Poulsom, Richard; Heidenreich, Axel; Jakse, Gerhard; Tadrous, Paul J; Knuechel, Ruth; Wright, Nicholas A

2011-10-01

Little is known about the clonal architecture of human urothelium. It is likely that urothelial stem cells reside within the basal epithelial layer, yet lineage tracing from a single stem cell as a means to show the presence of a urothelial stem cell has never been performed. Here, we identify clonally related cell areas within human bladder mucosa in order to visualize epithelial fields maintained by a single founder/stem cell. Sixteen frozen cystectomy specimens were serially sectioned. Patches of cells deficient for the mitochondrially encoded enzyme cytochrome c oxidase (CCO) were identified using dual-colour enzyme histochemistry. To show that these patches represent clonal proliferations, small CCO-proficient and -deficient areas were individually laser-capture microdissected and the entire mitochondrial genome (mtDNA) in each area was PCR amplified and sequenced to identify mtDNA mutations. Immunohistochemistry was performed for the different cell layers of the urothelium and adjacent mesenchyme. CCO-deficient patches could be observed in normal urothelium of all cystectomy specimens. The two-dimensional length of these negative patches varied from 2-3 cells (about 30 µm) to 4.7 mm. Each cell area within a CCO-deficient patch contained an identical somatic mtDNA mutation, indicating that the patch was a clonal unit. Patches contained all the mature cell differentiation stages present in the urothelium, suggesting the presence of a stem cell. Our results demonstrate that the normal mucosa of human bladder contains stem cell-derived clonal units that actively replenish the urothelium during ageing. The size of the clonal unit attributable to each stem cell was broadly distributed, suggesting replacement of one stem cell clone by another. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Potential of Human Stem Cells for the Study and Treatment of Glaucoma

PubMed Central

Chamling, Xitiz; Sluch, Valentin M.; Zack, Donald J.

2016-01-01

Purpose Currently, the only available and approved treatments for glaucoma are various pharmacologic, laser-based, and surgical procedures that lower IOP. Although these treatments can be effective, they are not always sufficient, and they cannot restore vision that has already been lost. The goal of this review is to briefly assess current developments in the application of stem cell biology to the study and treatment of glaucoma and other forms of optic neuropathy. Methods A combined literature review and summary of the glaucoma-related discussion at the 2015 “Sight Restoration Through Stem Cell Therapy” meeting that was sponsored by the Ocular Research Symposia Foundation (ORSF). Results Ongoing advancements in basic and eye-related developmental biology have enabled researchers to direct murine and human stem cells along specific developmental paths and to differentiate them into a variety of ocular cell types of interest. The most advanced of these efforts involve the differentiation of stem cells into retinal pigment epithelial cells, work that has led to the initiation of several human trials. More related to the glaucoma field, there have been recent advances in developing protocols for differentiation of stem cells into trabecular meshwork and retinal ganglion cells. Additionally, efforts are being made to generate stem cell–derived cells that can be used to secrete neuroprotective factors. Conclusions Advancing stem cell technology provides opportunities to improve our understanding of glaucoma-related biology and develop models for drug development, and offers the possibility of cell-based therapies to restore sight to patients who have already lost vision. PMID:27116666

Adipose-derived stem cells cooperate with fractional carbon dioxide laser in antagonizing photoaging: a potential role of Wnt and β-catenin signaling.

PubMed

Xu, Xiao; Wang, Hong-Yi; Zhang, Yu; Liu, Yang; Li, Yan-Qi; Tao, Kai; Wu, Chu-Tse; Jin, Ji-de; Liu, Xiao-Yan

2014-01-01

It is well established that adipose-derived stem cells (ADSCs) produce and secrete cytokines/growth factors that antagonize UV-induced photoaging of skin. However, the exact molecular basis underlying the anti-photoaging effects exerted by ADSCs is not well understood, and whether ADSCs cooperate with fractional carbon dioxide (CO2) laser to facilitate photoaging skin healing process has not been explored. Here, we investigated the impacts of ADSCs on photoaging in a photoaging animal model, its associated mechanisms, and its functional cooperation with fractional CO2 laser in treatment of photoaging skin. We showed that ADSCs improved dermal thickness and activated the proliferation of dermal fibroblast. We further demonstrated that the combined treatment of ADSCs and fractional CO2 laser, the latter which is often used to resurface skin and treat wrinkles, had more beneficial effects on the photoaging skin compared with each individual treatment. In our prepared HDF photoaging model, flow cytometry showed that, after adipose derived stem cells conditioned medium (ADSC-CM) co-cultured HDF photoaging model, the cell proliferation rate is higher than UVB irradiation induced HDF modeling (p < 0.05). Additionally, the expressions of β-catenin and Wnt3a, which were up-regulated after the transplantation of ADSCs alone or in combination with fractional CO2 laser treatment. And the expression of wnt3a and β-catenin has the positive correlation with photoaging related protein TGF-β2 and COLI. We also verified these protein expressions in tissue level. In addition, after injected SFRP2 into ADSC-CM co-cultured HDF photoaging model, wnt3a inhibitor, compared with un-intervened group, wnt3a, β-catenin protein level significantly decreased. Both ADSCs and fractional CO2 laser improved photoaging skin at least partially via targeting dermal fibroblast activity which was increased in photoaging skin. The combinatorial use of ADSCs and fractional CO2 laser synergistically improved the healing process of photoaging skin. Thus, we provide a strong rationale for a combined use of ADSCs and fractional CO2 laser in treatment of photoaging skin in clinic in the future. Moreover, we provided evidence that the Wnt/β-catenin signaling pathway may contribute to the activation of dermal fibroblast by the transplantation of ADSCs in both vitro and vivo experiment.

Adipose-derived stem cells cooperate with fractional carbon dioxide laser in antagonizing photoaging: a potential role of Wnt and β-catenin signaling

PubMed Central

2014-01-01

Background It is well established that adipose-derived stem cells (ADSCs) produce and secrete cytokines/growth factors that antagonize UV-induced photoaging of skin. However, the exact molecular basis underlying the anti-photoaging effects exerted by ADSCs is not well understood, and whether ADSCs cooperate with fractional carbon dioxide (CO2) laser to facilitate photoaging skin healing process has not been explored. Here, we investigated the impacts of ADSCs on photoaging in a photoaging animal model, its associated mechanisms, and its functional cooperation with fractional CO2 laser in treatment of photoaging skin. Results We showed that ADSCs improved dermal thickness and activated the proliferation of dermal fibroblast. We further demonstrated that the combined treatment of ADSCs and fractional CO2 laser, the latter which is often used to resurface skin and treat wrinkles, had more beneficial effects on the photoaging skin compared with each individual treatment. In our prepared HDF photoaging model, flow cytometry showed that, after adipose derived stem cells conditioned medium (ADSC-CM) co-cultured HDF photoaging model, the cell proliferation rate is higher than UVB irradiation induced HDF modeling (p < 0.05). Additionally, the expressions of β-catenin and Wnt3a, which were up-regulated after the transplantation of ADSCs alone or in combination with fractional CO2 laser treatment. And the expression of wnt3a and β-catenin has the positive correlation with photoaging related protein TGF-β2 and COLI. We also verified these protein expressions in tissue level. In addition, after injected SFRP2 into ADSC-CM co-cultured HDF photoaging model, wnt3a inhibitor, compared with un-intervened group, wnt3a, β-catenin protein level significantly decreased. Conclusion Both ADSCs and fractional CO2 laser improved photoaging skin at least partially via targeting dermal fibroblast activity which was increased in photoaging skin. The combinatorial use of ADSCs and fractional CO2 laser synergistically improved the healing process of photoaging skin. Thus, we provide a strong rationale for a combined use of ADSCs and fractional CO2 laser in treatment of photoaging skin in clinic in the future. Moreover, we provided evidence that the Wnt/β-catenin signaling pathway may contribute to the activation of dermal fibroblast by the transplantation of ADSCs in both vitro and vivo experiment. PMID:24917925

Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration.

PubMed

Bourget, Jean-Michel; Kérourédan, Olivia; Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain; Devillard, Raphaël

2016-01-01

Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro . Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration

PubMed Central

Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain

2016-01-01

Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro. Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors. PMID:27833916

Physicochemical modifications accompanying UV laser induced surface structures on poly(ethylene terephthalate) and their effect on adhesion of mesenchymal cells.

PubMed

Rebollar, Esther; Pérez, Susana; Hernández, Margarita; Domingo, Concepción; Martín, Margarita; Ezquerra, Tiberio A; García-Ruiz, Josefa P; Castillejo, Marta

2014-09-07

This work reports on the formation of different types of structures on the surface of polymer films upon UV laser irradiation. Poly(ethylene terephthalate) was irradiated with nanosecond UV pulses at 193 and 266 nm. The polarization of the laser beam and the irradiation angle of incidence were varied, giving rise to laser induced surface structures with different shapes and periodicities. The irradiated surfaces were topographically characterized by atomic force microscopy and the chemical modifications induced by laser irradiation were inspected via micro-Raman and fluorescence spectroscopies. Contact angle measurements were performed with different liquids, and the results evaluated in terms of surface free energy components. Finally, in order to test the influence of surface properties for a potential application, the modified surfaces were used for mesenchymal stem cell culture assays and the effect of nanostructure and surface chemistry on cell adhesion was evaluated.

Applications of Raman micro-spectroscopy to stem cell technology: label-free molecular discrimination and monitoring cell differentiation.

PubMed

Ghita, Adrian; Pascut, Flavius C; Sottile, Virginie; Denning, Chris; Notingher, Ioan

Stem cell therapy is widely acknowledged as a key medical technology of the 21st century which may provide treatments for many currently incurable diseases. These cells have an enormous potential for cell replacement therapies to cure diseases such as Parkinson's disease, diabetes and cardiovascular disorders, as well as in tissue engineering as a reliable cell source for providing grafts to replace and repair diseased tissues. Nevertheless, the progress in this field has been difficult in part because of lack of techniques that can measure non-invasively the molecular properties of cells. Such repeated measurements can be used to evaluate the culture conditions during differentiation, cell quality and phenotype heterogeneity of stem cell progeny. Raman spectroscopy is an optical technique based on inelastic scattering of laser photons by molecular vibrations of cellular molecules and can be used to provide chemical fingerprints of cells or organelles without fixation, lysis or use of labels and other contrast enhancing chemicals. Because differentiated cells are specialized to perform specific functions, these cells produce specific biochemicals that can be detected by Raman micro-spectroscopy. This mini-review paper describes applications of Raman micro-scpectroscopy to measure moleculare properties of stem cells during differentiation in-vitro. The paper focuses on time- and spatially-resolved Raman spectral measurements that allow repeated investigation of live stem cells in-vitro.

Biodegradable microsphere-mediated cell perforation in microfluidic channel using femtosecond laser

NASA Astrophysics Data System (ADS)

Ishii, Atsuhiro; Ariyasu, Kazumasa; Mitsuhashi, Tatsuki; Heinemann, Dag; Heisterkamp, Alexander; Terakawa, Mitsuhiro

2016-05-01

The use of small particles has expanded the capability of ultrashort pulsed laser optoinjection technology toward simultaneous treatment of multiple cells. The microfluidic platform is one of the attractive systems that has obtained synergy with laser-based technology for cell manipulation, including optoinjection. We have demonstrated the delivery of molecules into suspended-flowing cells in a microfluidic channel by using biodegradable polymer microspheres and a near-infrared femtosecond laser pulse. The use of polylactic-co-glycolic acid microspheres realized not only a higher optoinjection ratio compared to that with polylactic acid microspheres but also avoids optical damage to the microfluidic chip, which is attributable to its higher optical intensity enhancement at the localized spot under a microsphere. Interestingly, optoinjection ratios to nucleus showed a difference for adhered cells and suspended cells. The use of biodegradable polymer microspheres provides high throughput optoinjection; i.e., multiple cells can be treated in a short time, which is promising for various applications in cell analysis, drug delivery, and ex vivo gene transfection to bone marrow cells and stem cells without concerns about residual microspheres.

Photothermal optical coherence tomography for depth-resolved imaging of mesenchymal stem cells via single wall carbon nanotubes

NASA Astrophysics Data System (ADS)

Subhash, Hrebesh M.; Connolly, Emma; Murphy, Mary; Barron, Valerie; Leahy, Martin

2014-03-01

The progress in stem cell research over the past decade holds promise and potential to address many unmet clinical therapeutic needs. Tracking stem cell with modern imaging modalities are critically needed for optimizing stem cell therapy, which offers insight into various underlying biological processes such as cell migration, engraftment, homing, differentiation, and functions etc. In this study we report the feasibility of photothermal optical coherence tomography (PT-OCT) to image human mesenchymal stem cells (hMSCs) labeled with single-walled carbon nanotubes (SWNTs) for in vitro cell tracking in three dimensional scaffolds. PT-OCT is a functional extension of conventional OCT with extended capability of localized detection of absorbing targets from scattering background to provide depth-resolved molecular contrast imaging. A 91 kHz line rate, spectral domain PT-OCT system at 1310nm was developed to detect the photothermal signal generated by 800nm excitation laser. In general, MSCs do not have obvious optical absorption properties and cannot be directly visualized using PT-OCT imaging. However, the optical absorption properties of hMSCs can me modified by labeling with SWNTs. Using this approach, MSC were labeled with SWNT and the cell distribution imaged in a 3D polymer scaffold using PT-OCT.

Multiphoton autofluorescence lifetime imaging of induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Uchugonova, Aisada

2017-06-01

The multiphoton fluorescence lifetime imaging tomograph MPTflex with its flexible 360-deg scan head, articulated arm, and tunable femtosecond laser source was employed to study induced pluripotent stem cell (iPS) cultures. Autofluorescence (AF) lifetime imaging was performed with 250-ps temporal resolution and submicron spatial resolution using time-correlated single-photon counting. The two-photon excited AF was based on the metabolic coenzymes NAD(P)H and flavin adenine dinucleotide/flavoproteins. iPS cells generated from mouse embryonic fibroblasts (MEFs) and cocultured with growth-arrested MEFs as feeder cells have been studied. Significant differences on AF lifetime signatures were identified between iPS and feeder cells as well as between their differentiating counterparts.

Long-Term Effects of Stem Cells on Total-Body Irradiated Mice

NASA Astrophysics Data System (ADS)

Vyalkina, M. V.; Alchinova, I. B.; Yakovenko, E. N.; Medvedeva, Yu S.; Saburina, I. N.; Karganov, M. Yu

2017-01-01

C57Bl/6 mice were exposed to γ-radiation in a sublethal dose of 7.5 Gy. In 3 hours injection 106/mouse of bone marrow multipotent mesenchymal stromal cells stem cells intravenously to experimental group was done. Methods used: body weight measurement, open field behavior, subfraction composition of blood serum (laser correlation spectroscopy, LCS), histological examination of the spleen, liver, and pancreas, count of T and B cells, white blood formula. After 1.5 and 3 months the general trend towards intermediate position of the parameters observed in the experimental between those in intact and irradiated controls attests to partial protective/restorative effects of the injected cells.

Photothermal and photoacoustic processes of laser activated nano-thermolysis of cells

NASA Astrophysics Data System (ADS)

Lapotko, Dmitri; Lukianova, Ekaterina; Mitskevich, Pavel; Smolnikova, Victoria; Potapnev, Michail; Konopleva, Marina; Andreeff, Michael; Oraevsky, Alexander

2007-02-01

Laser Activated Nano-Thermolysis was recently proposed for selective damage of individual target (cancer) cells by pulsed laser induced microbubbles around superheated clusters of optically absorbing nanoparticles (NP). One of the clinical applications of this technology is the elimination of residual tumor cells from human blood and bone marrow. Clinical standards for the safety and efficacy of such procedure require the development and verification of highly selective and controllable mechanisms of cell killing. Our previous experiments showed that laser-induced microbubble is the main damaging factor in the case cell irradiation by short laser pulses above the threshold. Our current aim was to study the cell damage mechanisms and analyze selectivity and efficacy of cell damage as a function of NP parameters, NP-cell interaction conditions, and conditions of bubble generation around NP and NP clusters in cells. Generation of laser-induced bubbles around gold NP with diameters 10-250 nm was studied in Acute Myeloblast Leukemia (AML) cultures, normal stem and model K562 human cells. Short laser pulses (10 ns, 532 nm) were applied to those cells in vitro and the processes in cells were investigated with photothermal, fluorescent and atomic force microscopies and also with fluorescence flow cytometry. We have found that the best selectivity of cell damage is achieved by (1) forming large clusters of optically absorbing NP in target cells and (2) irradiating the cells with single laser pulses with the lowest fluence that can generate microbubble only around large clusters but not around single NP. Laser microbubbles with the lifetime from 20 ns to 2000 ns generated in individual cells caused damage and lysis of the cellular membrane and consequently cell death. Laser microbubbles did not damage normal cells around the damaged target (tumor) cell. Laser irradiation with equal fluence did not cause any damage of cells without accumulated NP clusters.

Retinoblastoma Treatment (PDQ®)—Patient Version

Cancer.gov

Retinoblastoma treatment may include cryosurgery, laser therapy (thermotherapy), chemotherapy, radiation therapy, high-dose chemotherapy with stem cell rescue, and sometimes surgery. Learn more about newly diagnosed and recurrent retinoblastoma in this expert-reviewed summary.

Changing Paradigms in Cranio-Facial Regeneration: Current and New Strategies for the Activation of Endogenous Stem Cells

PubMed Central

Mele, Luigi; Vitiello, Pietro Paolo; Tirino, Virginia; Paino, Francesca; De Rosa, Alfredo; Liccardo, Davide; Papaccio, Gianpaolo; Desiderio, Vincenzo

2016-01-01

Craniofacial area represent a unique district of human body characterized by a very high complexity of tissues, innervation and vascularization, and being deputed to many fundamental function such as eating, speech, expression of emotions, delivery of sensations such as taste, sight, and earing. For this reasons, tissue loss in this area following trauma or for example oncologic resection, have a tremendous impact on patients' quality of life. In the last 20 years regenerative medicine has emerged as one of the most promising approach to solve problem related to trauma, tissue loss, organ failure etc. One of the most powerful tools to be used for tissue regeneration is represented by stem cells, which have been successfully implanted in different tissue/organs with exciting results. Nevertheless, both autologous and allogeneic stem cell transplantation raise many practical and ethical concerns that make this approach very difficult to apply in clinical practice. For this reason different cell free approaches have been developed aiming to the mobilization, recruitment, and activation of endogenous stem cells into the injury site avoiding exogenous cells implant but instead stimulating patients' own stem cells to repair the lesion. To this aim many strategies have been used including functionalized bioscaffold, controlled release of stem cell chemoattractants, growth factors, BMPs, Platelet–Rich-Plasma, and other new strategies such as ultrasound wave and laser are just being proposed. Here we review all the current and new strategies used for activation and mobilization of endogenous stem cells in the regeneration of craniofacial tissue. PMID:26941656

Enhanced photo-transfection efficiency of mammalian cells on graphene coated substrates

NASA Astrophysics Data System (ADS)

Mthunzi, Patience; He, Kuang; Ngcobo, Sandile; Warner, Jamie W.

2014-03-01

Literature reports graphene, an atomic-thick sheet of carbon atoms as one of the promising biocompatible scaffolds that promotes cellular proliferation in human mesenchymal stem cells. On the other hand, different mammalian cell lines including the induced pluripotent stem cells exhibited an accelerated proliferation rate when cultured on graphene or graphene oxide coated substrates. These findings provide strong motivation to explore the full capability of graphene in further pluripotent stem cell research activities as there exists an urgent requirement to preserve their therapeutic potential. This therefore calls for non-invasive procedures for handling stem cells in-vitro. For example, resent literature has shown successful laser light driven transfection in both multipotent and pluripotent stem cells. In order to explore the non-invasive nature of optical transfection alongside biocompatible qualities of graphene, in this work we investigated the impact of optically transfecting mouse embryonic stem (mES) cells plated on graphene coated sample chambers. Using Chinese Hamster Ovary cells (CHO-K1), we further studied the influence of graphene on cell viability as well as cell cytotoxicity through assessing changes in levels of mitochondrial adenosine triphosphate (ATP) activity and the release of cytosolic lactate dehydrogenase (LHD) respectively. Our results showed that compared to those treated on plain glass, CHO-K1 cells optically treated while plated on graphene coated substrates exhibited a higher production of ATP and a milder release of LDH. In addition there was enhanced photo-transfection efficiency in both CHO-K1 and mES cells irradiated on graphene sample chambers.

Multiphoton-generated localized electron plasma for membrane permeability modification in single cells

NASA Astrophysics Data System (ADS)

Merritt, T.; Leblanc, M.; McMillan, J.; Westwood, J.; Khodaparast, G. A.

2014-03-01

Successful incorporation of a specific macromolecule into a single cell would be ideal for characterizing trafficking dynamics through plasmodesmata or for studying intracellular localizations. Here, we demonstrate NIR femtosecond laser-mediated infiltration of a membrane impermeable dextran-conjugated dye into living cells of Arabidopsis thaliana seedling stems. Based on the reactions of fluorescing vacuoles of transgenic cells and artificial cell walls comprised of nanocellulose, laser intensity and exposure time were adjusted to avoid deleterious effects. Using these plant-tailored laser parameters, cells were injected with the fluorophores and long-term dye retention was observed, all while preserving vital cell functions. This method is ideal for studies concerning cell-to-cell interactions and potentially paves the way for introducing transgenes to specific cells. This work was supported by NSF award IOS-0843372 to JHW, with additional support from and U.S. Department of Agriculture Hatch Project no. 135997, and by the Institute of Critical Technology and Applied Sciences (ICTAS) at Virginia Tech.

Biological effects of low-level laser irradiation on umbilical cord mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Chen, Hongli; Wang, Hong; Li, Yingxin; Liu, Weichao; Wang, Chao; Chen, Zhuying

2016-04-01

Low-level laser irradiation (LLLI) can enhance stem cell (SC) activity by increasing migration and proliferation. This study investigated the effects of LLLI on proliferation, enzymatic activity, and growth factor production in human umbilical cord mesenchymal SCs (hUC-MSCs) as well as the underlying mechanisms. hUC-MSCs were assigned to a control group (non-irradiation group) and three LLLI treatment groups (635 nm group, 808 nm group, and 635/808 nm group). Laser power density and energy density of 20 mW/cm2 and 12 J/cm2, respectively, were used for each experiment. The proliferation rate was higher in the 635 nm as compared to the other groups. LLLI at 808 nm did not induce cell proliferation. ROS levels in cells exposed to 635, 808, and 635/808 nm radiation were increased by 52.81%, 26.89%, and 21.15%, respectively, relative to the control group. CAT, tGPx, and SOD activity was increased. LLLI at 808 nm increased the levels of IL-1, IL-6, and NFκB but not VEGF. LLLI improved hUC-MSCs function and increased antioxidant activity. Dual-wavelength LLLI had more potent effects on hUC-MSCs than single-wavelength treatment. LLLI has potential applications in the preconditioning of hUC-MSCs in vitro prior to transplantation, which could improve the regenerative capacity of cells.

Biological effects of low-level laser irradiation on umbilical cord mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Hongli; Wang, Hong; Li, Yingxin, E-mail: yingxinli2005@126.com

2016-04-15

Low-level laser irradiation (LLLI) can enhance stem cell (SC) activity by increasing migration and proliferation. This study investigated the effects of LLLI on proliferation, enzymatic activity, and growth factor production in human umbilical cord mesenchymal SCs (hUC-MSCs) as well as the underlying mechanisms. hUC-MSCs were assigned to a control group (non-irradiation group) and three LLLI treatment groups (635 nm group, 808 nm group, and 635/808 nm group). Laser power density and energy density of 20 mW/cm{sup 2} and 12 J/cm{sup 2}, respectively, were used for each experiment. The proliferation rate was higher in the 635 nm as compared to themore » other groups. LLLI at 808 nm did not induce cell proliferation. ROS levels in cells exposed to 635, 808, and 635/808 nm radiation were increased by 52.81%, 26.89%, and 21.15%, respectively, relative to the control group. CAT, tGPx, and SOD activity was increased. LLLI at 808 nm increased the levels of IL-1, IL-6, and NFκB but not VEGF. LLLI improved hUC-MSCs function and increased antioxidant activity. Dual-wavelength LLLI had more potent effects on hUC-MSCs than single-wavelength treatment. LLLI has potential applications in the preconditioning of hUC-MSCs in vitro prior to transplantation, which could improve the regenerative capacity of cells.« less

Gelatin-based laser direct-write technique for the precise spatial patterning of cells.

PubMed

Schiele, Nathan R; Chrisey, Douglas B; Corr, David T

2011-03-01

Laser direct-writing provides a method to pattern living cells in vitro, to study various cell-cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research.

Low-level laser irradiation induces in vitro proliferation of stem cells from human exfoliated deciduous teeth.

PubMed

Ginani, Fernanda; Soares, Diego Moura; de Oliveira Rocha, Hugo Alexandre; de Souza, Lélia Batista; Barboza, Carlos Augusto Galvão

2018-01-01

The aim of this study was to evaluate the effect of low-level laser irradiation (LLLI) on the proliferation and viability of stem cells from human exfoliated deciduous teeth (SHED). Cells were irradiated or not (control) with an InGaAlP laser diode (660 nm, 30 mW, continuous action mode) using two different energy densities (0.5 J/cm 2 -16 s; 1.0 J/cm 2 -33 s). Irradiation was performed at 0 and 48 h, with the laser probe fixed at a distance of 0.5 cm from the cells. Cell proliferation was analyzed at 0, 24, 48, and 72 h by the Trypan blue exclusion method and MTT assay. Cell cycle and Ki67 expression were analyzed by flow cytometry. Apoptosis-related events were evaluated by expression of annexin V/PI and nuclear morphological changes by staining with DAPI. Differences between groups at each time were analyzed by the Kruskal-Wallis and Mann-Whitney tests, adopting a level of significance of 5% (p < 0.05). The results showed that an energy density of 1.0 J/cm 2 promoted an increase in cell proliferation at 48 and 72 h compared to the control and 0.5 J/cm 2 groups. Cell cycle analysis revealed a predominance of cells in the S and G2/M phases in the irradiated groups. This finding was confirmed by the increased expression of Ki67. Low positive staining for annexin V and PI was observed in all groups, and no nuclear changes were detected, indicating that cell viability was not affected by the energy densities tested. It can be concluded that the LLLI parameters used (660 nm, 30 mW, 1.0 J/cm 2 ) promote the proliferation of SHEDs and the maintenance of cell viability.

Enhancing hair follicle regeneration by nonablative fractional laser: Assessment of irradiation parameters and tissue response.

PubMed

Wu, Yueh-Feng; Wang, Shiou-Han; Wu, Pei-Shan; Fan, Sabrina Mai-Yi; Chiu, Hsien-Yi; Tsai, Tsung-Hua; Lin, Sung-Jan

2015-04-01

Identification of methods to enhance anagen entry can be helpful for alopecia. Recently, nonablative laser has been proposed as a potential treatment for alopecia. However, how the laser parameters affect stem cell activity, hair cycles and the associated side effects have not been well characterized. Here we examine the effects of irradiation parameters of 1,550-nm fractional laser on hair cycles. The dorsal skin of eight-week-old female C57BL/6 mice with hair follicles in synchronized telogen was shaved and irradiated with a 1,550-nm fractional erbium-glass laser (Fraxel RE:STORE (SR1500) Laser System, Solta Medical, U.S.A.) with varied beam energies (5-35 mJ) and beam densities (500-3500 microthermal zones/cm(2) ). The cutaneous changes were evaluated both grossly and histologically. Hair follicle stem cell activity was detected by BrdU incorporation and changes in gene expression were quantified by real-time PCR. Direct thermal injury to hair follicles could be observed early after irradiation, especially at higher beam energy. Anagen induction in the irradiated skin showed an all-or-non change. Anagen induction and ulcer formation were affected by the combination of beam energy and density. The lowest beam energy of 5 mJ failed to promote anagen entry at all beam densities tested. As beam energy increased from 10 mJ to 35 mJ, we found a decreasing trend of beam density that could induce anagen entry within 7-9 days with activation of hair follicle stem cells. Beam density above the pro-regeneration density could lead to ulcers and scarring followed by anagen entry in adjacent skin. Analysis of inflammatory cytokines, including TNF-α, IL-1β, and IL-6, revealed that transient moderate inflammation was associated with anagen induction and intense prolonged inflammation preceded ulcer formation. To avoid side effects of hair follicle injury and scarring, appropriate combination of beam energy and density is required. Parameters outside the therapeutic window can result in either no anagen promotion or ulcer formation. © 2015 Wiley Periodicals, Inc.

Optical Deformability as New Diagnostic Cell Marker

NASA Astrophysics Data System (ADS)

Guck, Jochen; Lincoln, Bryan; Schinkinger, Stefan; Wottawah, Falk; Moore, Samantha; Ananthakrishnan, Revathi; Kas, Josef

2002-03-01

The optical stretcher is a novel laser tool that can deform individual cells in rapid succession. When a cell is trapped between two counterpropagating laser beams the optically induced surface forces stretch the cell along the laser axis. The degree of stretching depends on the optical properties, which determine the forces, as well as the mechanical properties, which govern the response of the cell to the forces. Our results show that different cells can be distinguished based on their optical deformability, which naturally suggests using the optical deformability of cells as a novel cell marker. Many diseases are reflected in an altered cytoskeleton, which leads to a different optical deformability. An important example is the malignant transformation of cells, which is accompanied by a decrease in cytoskeletal integrity and, consequently, cell elasticity. Using optical deformability as cell marker holds the promise of earlier detection and improved diagnosis of cancer. In this context, the optical stretcher can be used as a diagnostic device to detect and sort abnormal cells. Future applications in the study of the normal differentiation of cells from stem cells to mature cells are envisioned.

Hybrid laser technology and doped biomaterials

NASA Astrophysics Data System (ADS)

Jelínek, Miroslav; Zemek, Josef; Remsa, Jan; Mikšovský, Jan; Kocourek, Tomáš; Písařík, Petr; Trávníčková, Martina; Filová, Elena; Bačáková, Lucie

2017-09-01

Hybrid laser-based technologies for deposition of new types of doped thin films are presented. The focus is on arrangements combining pulsed laser deposition (PLD) with magnetron sputtering (MS), and on the setup with two simultaneously running PLD systems (dual PLD). Advantages and disadvantages of both arrangements are discussed. Layers of different dopants concentration were prepared. Experience with deposition of chromium and titanium doped diamond-like carbon (DLC) films for potential coating of bone implants is presented. Properties of the layers prepared by both technologies are compared and discussed. The suitability of the layers for colonization with human bone marrow mesenchymal stem cells and human osteoblast-like cells, were also evaluated under in vitro conditions.

Low-Level Laser Effect on Proliferation, Migration, and Antiapoptosis of Mesenchymal Stem Cells.

PubMed

Yin, Kan; Zhu, Rongjia; Wang, Shihua; Zhao, Robert Chunhua

2017-05-15

Mesenchymal stem cells (MSCs) have been proved to be an important element in cell-based therapy. Photobiomodulation used extremely low-level lasers (LLLs) to affect the behavior of cells. The effect mechanism of LLLs on MSCs from human remained to be discovered. In this study, cell viability was assessed using MTS assays and cell cycle was evaluated by fluorescence-activated cell sorting (FACS). The influence of LLLs on mitochondrial biogenesis (fission or fusion) and function (ATP, reactive oxygen species [ROS], nitric oxide [NO]) was evaluated by transmission electron microscope, FACS, quantitative real time polymerase chain reaction (q-PCR), and immunocytochemistry. Cell migration and cytoskeleton alteration (actin and tubulin) were evaluated using transwell assay, immunocytochemistry, enzyme-linked immunosorbent assay, and western blotting. Cell apoptosis was evaluated using FACS, immunocytochemistry, and western blotting. We investigated that certain influence of LLLs on MSCs in vitro 6 or 24 h after 1 h of LLL irradiation. The mechanism of the effects included proliferation rate increase mediated by increased S phase proportion; mitochondrial biogenesis and function alteration mediated by fusion (Mfn1, Mfn2, and Opa-1) and fission (Fis1, Drp-1, and MTP18)-related proteins, NRF1, TFAM, PGC-1a, and upregulated intracellular ROS and NO concentration; migration acceleration through the ERK1/2 and FAK pathway and upregulation of growth factors such as HGF and PDGF; and resistance to apoptosis with increased Bcl-2 and decreased Bax, or through tunneling nanotube formation between LLL-treated MSCs and 5-fluorouracil-induced apoptotic MSCs. These observations suggested that LLLs enhanced stem cell survival and therapeutic function, which could appear to be an innovative pretreatment in the application of MSCs.

Novel single-cell functional analysis of red blood cells using laser tweezers Raman spectroscopy: application for sickle cell disease.

PubMed

Liu, Rui; Mao, Ziliang; Matthews, Dennis L; Li, Chin-Shang; Chan, James W; Satake, Noriko

2013-07-01

Laser tweezers Raman spectroscopy was used to characterize the oxygenation response of single normal adult, sickle, and cord blood red blood cells (RBCs) to an applied mechanical force. Individual cells were subjected to different forces by varying the laser power of a single-beam optical trap, and the intensities of several oxygenation-specific Raman spectral peaks were monitored to determine the oxygenation state of the cells. For all three cell types, an increase in laser power (or mechanical force) induced a greater deoxygenation of the cell. However, sickle RBCs deoxygenated more readily than normal RBCs when subjected to the same optical forces. Conversely, cord blood RBCs were able to maintain their oxygenation better than normal RBCs. These results suggest that differences in the chemical or mechanical properties of fetal, normal, and sickle cells affect the degree to which applied mechanical forces can deoxygenate the cell. Populations of normal, sickle, and cord RBCs were identified and discriminated based on this mechanochemical phenomenon. This study demonstrates the potential application of laser tweezers Raman spectroscopy as a single-cell, label-free analytical tool to characterize the functional (e.g., mechanical deformability, oxygen binding) properties of normal and diseased RBCs. Copyright © 2013 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

Specificity and Heterogeneity of Terahertz Radiation Effect on Gene Expression in Mouse Mesenchymal Stem Cells

DOE PAGES

Alexandrov, Boian S.; Phipps, M. Lisa; Alexandrov, Ludmil B.; ...

2013-01-31

In this paper, we report that terahertz (THz) irradiation of mouse mesenchymal stem cells (mMSCs) with a single-frequency (SF) 2.52 THz laser or pulsed broadband (centered at 10 THz) source results in irradiation specific heterogenic changes in gene expression. The THz effect depends on irradiation parameters such as the duration and type of THz source, and on the degree of stem cell differentiation. Our microarray survey and RT-PCR experiments demonstrate that prolonged broadband THz irradiation drives mMSCs toward differentiation, while 2-hour irradiation (regardless of THz sources) affects genes transcriptionally active in pluripotent stem cells. The strictly controlled experimental environment indicatesmore » minimal temperature changes and the absence of any discernable response to heat shock and cellular stress genes imply a non-thermal response. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. Finally, we propose that THz radiation has potential for non-contact control of cellular gene expression.« less

In vivo studies of low level laser (light) therapy for traumatic brain injury

NASA Astrophysics Data System (ADS)

Xuan, Weijun; Wu, Qiuhe; Huang, Ying-Ying; Ando, Takahiro; Huang, Liyi; Hamblin, Michael R.

2012-03-01

Low-level laser (or light) therapy (LLLT) is attracting growing interest to treat both stroke and traumatic brain injury (TBI). The fact that near-infrared light can penetrate into the brain allows non-invasive treatment to be carried out with a low likelihood of treatment-related adverse events. It is proposed that red and NIR light is absorbed by chromophores in the mitochondria of cells leading to changes in gene transcription and upregulation of proteins involved in cell survival, antioxidant production, collagen synthesis, reduction of chronic inflammation and cell migration and proliferation. We developed a mouse model of controlled cortical impact (CCI) TBI and examined the effect of 0, 1, 3, and 14 daily 810-nm CW laser treatments in the CCI model as measured by neurological severity score and wire grip and motion test. 1 laser Tx gave a significant improvement while 3 laser Tx was even better. Surprisingly 14 laser Tx was no better than no treatment. Histological studies at necropsy suggested that the neurodegeneration was reduced at 14 days and that the cortical lesion was repaired by BrdU+ve neural progenitor (stem) cells at 28 days. Transcranial laser therapy is a promising treatment for acute (and chronic TBI) and the lack of side-effects and paucity of alternative treatments encourages early clinical trials.

Gelatin-Based Laser Direct-Write Technique for the Precise Spatial Patterning of Cells

PubMed Central

Schiele, Nathan R.; Chrisey, Douglas B.

2011-01-01

Laser direct-writing provides a method to pattern living cells in vitro, to study various cell–cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research. PMID:20849381

The use of fluorescent indoline dyes for side population analysis.

PubMed

Kohara, Hiroshi; Watanabe, Kohei; Shintou, Taichi; Nomoto, Tsuyoshi; Okano, Mie; Shirai, Tomoaki; Miyazaki, Takeshi; Tabata, Yasuhiko

2013-01-01

Dye efflux assay evaluated by flow cytometry is useful for stem cell studies. The side population (SP) cells, characterized by the capacity to efflux Hoechst 33342 dye, have been shown to be enriched for hematopoietic stem cells (HSCs) in bone marrow. In addition, SP cells are isolated from various tissues and cell lines, and are also potential candidates for cancer stem cells. However, ultra violet (UV) light, which is not common for every flow cytometer, is required to excite Hoechst 33342. Here we showed that a fluorescent indoline dye ZMB793 can be excited by 488-nm laser, equipped in almost all the modern flow cytometers, and ZMB793-excluding cells showed SP phenotype. HSCs were exclusively enriched in the ZMB793-excluding cells, while ZMB793 was localized in cytosol of bone marrow lineage cells. The efflux of ZMB793 dye was mediated by ATP binding cassette (ABC) transporter Abcg2. Moreover, staining properties were affected by the side-chain structure of the dyes. These data indicate that the fluorescent dye ZMB793 could be used for the SP cell analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Noninvasive measurement of three-dimensional morphology of adhered animal cells employing phase-shifting laser microscope.

PubMed

Takagi, Mutsumi; Kitabayashi, Takayuki; Ito, Syunsuke; Fujiwara, Masashi; Tokuda, Akio

2007-01-01

Noninvasive measurement of 3-D morphology of adhered animal cells employing a phase-shifting laser microscope (PLM) is investigated, in which the phase shift for each pixel in the view field caused by cell height and the difference in refractive indices between the cells and the medium is determined. By employing saline with different refractive indices instead of a culture medium, the refractive index of the cells, which is necessary for the determination of cell height, is determined under PLM. The observed height of Chinese hamster ovary (CHO) cells cultivated under higher osmolarity is lower than that of the cells cultivated under physiological osmolarity, which is in agreement with previous data observed under an atomic force microscope (AFM). Maximum heights of human bone marrow mesenchymal stem cells and human umbilical cord vein endothelial cells measured under PLM and AFM agree well with each other. The maximum height of nonadherent spherical CHO cells observed under PLM is comparable to the cell diameter measured under a phase contrast inverted microscope. Laser irradiation, which is necessary for the observation under PLM, did not affect 3-D cell morphology. In conclusion, 3-D morphology of adhered animal cells can be noninvasively measured under PLM.

Microfabricated polyester conical microwells for cell culture applications†

PubMed Central

Selimović, Šeila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto

2012-01-01

Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required. PMID:21614380

Proteomic Analysis of Mesenchymal Stem Cells from Normal and Deep Carious Dental Pulp

PubMed Central

Gao, Jie; Yan, Wenjuan; Liu, Ying; Xu, Shuaimei; Wu, Buling

2014-01-01

Dental pulp stem cells (DPSCs), precursor cells of odontoblasts, are ideal seed cells for tooth tissue engineering and regeneration. Our previous study has demonstrated that stem cells exist in dental pulp with deep caries and are called carious dental pulp stem cells (CDPSCs). The results indicated that CDPSCs had a higher proliferative and stronger osteogenic differentiation potential than DPSCs. However, the molecular mechanisms responsible for the biological differences between DPSCs and CDPSCs are poorly understood. The aim of this study was to define the molecular features of DPSCs and CDPSCs by comparing the proteomic profiles using two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) in combination with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Our results revealed that there were 18 protein spots differentially expressed between DPSCs and CDPSCs in a narrow pH range of 4 to 7. These differently expressed proteins are mostly involved in the regulation of cell proliferation, differentiation, cell cytoskeleton and motility. In addition, our results suggested that CDPSCs had a higher expression of antioxidative proteins that might protect CDPSCs from oxidative stress. This study explores some potential proteins responsible for the biological differences between DPSCs and CDPSCs and expands our understanding on the molecular mechanisms of mineralization of DPSCs in the formation of the dentin-pulp complex. PMID:24809979

Fs-laser-induced Ca2+ concentration change during membrane perforation for cell transfection.

PubMed

Baumgart, J; Bintig, W; Ngezahayo, A; Lubatschowski, H; Heisterkamp, A

2010-02-01

Fs-laser based opto-perforation is a gentle method for gene transfer into sensitive cells such as stem cells or primary cells. The high selectivity and the low damage to the cell lead to a high efficiency of transfection. However, there are side effects which induce stress to the cell due to the exchange of intra- and extracellular media as well as the disintegration of the structure of biomolecules resulting from the laser exposure. Moreover, the mechanisms of the optical transfection are still unclear. In this paper, we present our study on calcium (Ca(2+)) homeostasis during cell surgery, especially during laser induced membrane perforation. We show that the manipulation of cells can induce an increase in the cytosolic Ca(2+) concentration. This increase was not observed if the manipulation of the cells was performed in absence of the extracellular calcium indicating the importance of the Ca(2+) uptake. We found, that the uptake of extracellular Ca(2+) strongly depends on the repetition rate and the irradiation time of the laser pulses. The exposure for several seconds to kHz pulses even induces Ca(2+) induced Ca(2+) release. Dependent on the location of perforation, probably in the vicinity of an intracellular Ca(2+) stock, an instantaneous intracellular Ca(2+) release can be induced. Since Ca(2+) could be involved in negative side effect by cell surgery, we propose an application of the optoperforation technique in nominal Ca(2+)-free external solution.

Effect of photobiomodulation on viability and proliferation of stem cells from exfoliated deciduous teeth under different nutritional conditions

NASA Astrophysics Data System (ADS)

Morato de Souza, Letícia; Guilherme Roque Rinco, Ugo; Aparecida Tavares Aguiar, Daniela; Aparecido de Almeida Junior, Luciano; Cosme-Silva, Leopoldo; Marchini Oliveira, Thais; Teixeira Marques, Nádia Carolina; Thiemy Sakai, Vivien

2018-02-01

This study aimed to evaluate the effect of different doses of low-level laser irradiation on the viability and proliferation of stem cells from exfoliated deciduous teeth (SHED) cultured under nutritional deficit (cellular stress) or regular nutritional conditions. SHED underwent irradiation by a red laser between 1.2 and 6.2 J cm-2. Prior to the irradiation, all groups received culture medium (MEMα, Eagle’s minimum essential medium alpha modification) supplemented with 1% of fetal bovine serum (FBS) for 1 h. After the irradiation, cells received MEMα supplemented with 10% of FBS (regular nutrition) or 1% of FBS (nutritional deficit). Cell viability and proliferation were respectively determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and crystal violet assays 6 and 24 h after irradiation (P  <  0.05). At 24 h, SHED under nutritional deficit showed lower viability and proliferation after 1.2 J cm-2 irradiation. All of the irradiated groups revealed significantly higher viability and proliferation in SHED maintained under nutritional deficit than in regular nutritional conditions, except in the 3.7 and 6.2 J cm-2 groups by MTT assay. In the crystal violet assay, SHED irradiated with 1.2 J cm-2 showed no difference between the different nutritional conditions. Decrease of FBS concentration in the culture medium seems to enhance the sensitivity of SHED to the effects of photobiomodulation therapy. Nutritional stress conditions improved cell viability and proliferation of SHED after laser irradiation, except for 1.2 J cm-2.

Intravenously injected human multilineage-differentiating stress-enduring cells selectively engraft into mouse aortic aneurysms and attenuate dilatation by differentiating into multiple cell types.

PubMed

Hosoyama, Katsuhiro; Wakao, Shohei; Kushida, Yoshihiro; Ogura, Fumitaka; Maeda, Kay; Adachi, Osamu; Kawamoto, Shunsuke; Dezawa, Mari; Saiki, Yoshikatsu

2018-06-01

Aortic aneurysms result from the degradation of multiple components represented by endothelial cells, vascular smooth muscle cells, and elastic fibers. Cells that can replenish these components are desirable for cell-based therapy. Intravenously injected multilineage-differentiating stress-enduring (Muse) cells, endogenous nontumorigenic pluripotent-like stem cells, reportedly integrate into the damaged site and repair the tissue through spontaneous differentiation into tissue-compatible cells. We evaluated the therapeutic efficacy of Muse cells in a murine aortic aneurysm model. Human bone marrow Muse cells, isolated as stage-specific embryonic antigen-3 + from bone marrow mesenchymal stem cells, or non-Muse cells (stage-specific embryonic antigen-3 - cells in mesenchymal stem cells), bone marrow mesenchymal stem cells, or vehicle was intravenously injected at day 0, day 7, and 2 weeks (20,000 cells/injection) after inducing aortic aneurysms by periaortic incubation of CaCl 2 and elastase in severe combined immunodeficient mice. At 8 weeks, infusion of human Muse cells attenuated aneurysm dilation, and the aneurysmal size in the Muse group corresponded to approximately 62.5%, 55.6%, and 45.6% in the non-Muse, mesenchymal stem cell, and vehicle groups, respectively. Multiphoton laser confocal microscopy revealed that infused Muse cells migrated into aneurysmal tissue from the adventitial side and penetrated toward the luminal side. Histologic analysis demonstrated robust preservation of elastic fibers and spontaneous differentiation into endothelial cells and vascular smooth muscle cells. After intravenous injection, Muse cells homed and expanded to the aneurysm from the adventitial side. Subsequently, Muse cells differentiated spontaneously into vascular smooth muscle cells and endothelial cells, and elastic fibers were preserved. These Muse cell features together led to substantial attenuation of aneurysmal dilation. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Quantifying migration and polarization of murine mesenchymal stem cells on different bone substitutes by confocal laser scanning microscopy.

PubMed

Roldán, J C; Chang, E; Kelantan, M; Jazayeri, L; Deisinger, U; Detsch, R; Reichert, T E; Gurtner, G C

2010-12-01

Cell migration is preceded by cell polarization. The aim of the present study was to evaluate the impact of the geometry of different bone substitutes on cell morphology and chemical responses in vitro. Cell polarization and migration were monitored temporally by using confocal laser scanning microscopy (CLSM) to follow green fluorescent protein (GFP)±mesenchymal stem cells (MSCs) on anorganic cancellous bovine bone (Bio-Oss(®)), β-tricalcium phosphate (β-TCP) (chronOS(®)) and highly porous calcium phosphate ceramics (Friedrich-Baur-Research-Institute for Biomaterials, Germany). Differentiation GFP±MSCs was observed using pro-angiogenic and pro-osteogenic biomarkers. At the third day of culture polarized vs. non-polarized cellular sub-populations were clearly established. Biomaterials that showed more than 40% of polarized cells at the 3rd day of culture, subsequently showed an enhanced cell migration compared to biomaterials, where non-polarized cells predominated (p<0.003). This trend continued untill the 7th day of culture (p<0.003). The expression of vascular endothelial growth factor was enhanced in biomaterials where cell polarization predominated at the 7th day of culture (p=0.001). This model opens an interesting approach to understand osteoconductivity at a cellular level. MSCs are promising in bone tissue engineering considering the strong angiogenic effect before differentiation occurs. Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Bioactive glass ions as strong enhancers of osteogenic differentiation in human adipose stem cells.

PubMed

Ojansivu, Miina; Vanhatupa, Sari; Björkvik, Leena; Häkkänen, Heikki; Kellomäki, Minna; Autio, Reija; Ihalainen, Janne A; Hupa, Leena; Miettinen, Susanna

2015-07-01

Bioactive glasses are known for their ability to induce osteogenic differentiation of stem cells. To elucidate the mechanism of the osteoinductivity in more detail, we studied whether ionic extracts prepared from a commercial glass S53P4 and from three experimental glasses (2-06, 1-06 and 3-06) are alone sufficient to induce osteogenic differentiation of human adipose stem cells. Cells were cultured using basic medium or osteogenic medium as extract basis. Our results indicate that cells stay viable in all the glass extracts for the whole culturing period, 14 days. At 14 days the mineralization in osteogenic medium extracts was excessive compared to the control. Parallel to the increased mineralization we observed a decrease in the cell amount. Raman and Laser Induced Breakdown Spectroscopy analyses confirmed that the mineral consisted of calcium phosphates. Consistently, the osteogenic medium extracts also increased osteocalcin production and collagen Type-I accumulation in the extracellular matrix at 13 days. Of the four osteogenic medium extracts, 2-06 and 3-06 induced the best responses of osteogenesis. However, regardless of the enhanced mineral formation, alkaline phosphatase activity was not promoted by the extracts. The osteogenic medium extracts could potentially provide a fast and effective way to differentiate human adipose stem cells in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Gap Junction Protein Connexin 43 Serves as a Negative Marker for a Stem Cell-Containing Population of Human Limbal Epithelial Cells

PubMed Central

Chen, Zhuo; Evans, W. Howard; Pflugfelder, Stephen C.; Li, De-Quan

2010-01-01

This study evaluated whether the gap junction protein connexin (Cx) 43 could serve as a negative cell surface marker for human corneal epithelial stem cells. Cx43 expression was evaluated in corneo-limbal tissue and primary limbal epithelial cultures. Immunofluorescent staining and laser scanning confocal microscopy showed that Cx43 was strongly expressed in the corneal and limbal suprabasal epithelial cells, but the basal cells of the limbal epithelium were negative. Cx43 antibody stained mainly large cells but not small cells in primary limbal epithelial cultures. As determined by semiquantitative reverse transcription polymerase chain reaction (PCR) and real-time PCR, Cx43 mRNA was more abundant in the corneal than limbal epithelia, and it was expressed in higher levels in mature limbal epithelial cultures. Using GAP11, a rabbit polyclonal antibody against the Cx32 extracellular loop 2 (151–187), a sequence that is highly homologous in Cx43, the Cx43dim and Cx43bright cells were selected from primary limbal epithelial cultures by fluorescence-activated cell sorting and were evaluated for stem cell properties. These Cx43dim and Cx43bright cells were confirmed by their expression levels of Cx43 protein and mRNA. The Cx43dim cells were found to contain higher percentages of slow-cycling bromodeoxyuridine (BrdU)-label retaining cells and the cells that were positive for stem cell-associated markers p63, ABCG2, and integrin β1 and negative for differentiation markers K3 and involucrin. The Cx43dim cells possessed a greater proliferative potential than Cx43bright cells and nonfractionated cells as evaluated by BrdU incorporation, colony-forming efficiency, and growth capacity. Our findings suggest that human limbal basal cells do not express connexin 43, which could serve as a negative cell surface marker for the stem cell-containing population of human limbal epithelial cells. PMID:16424398

In vitro behavior of human mesenchymal stem cells on poly(N-isopropylacrylamide) based biointerfaces obtained by matrix assisted pulsed laser evaporation

NASA Astrophysics Data System (ADS)

Icriverzi, Madalina; Rusen, Laurentiu; Sima, Livia Elena; Moldovan, Antoniu; Brajnicov, Simona; Bonciu, Anca; Mihailescu, Natalia; Dinescu, Maria; Cimpean, Anisoara; Roseanu, Anca; Dinca, Valentina

2018-05-01

The use of smart coatings with tunable characteristics in bioengineering fields is directly correlated with the surface chemical and topographical properties, the method of preparation, and also with the type of cells implied for the specific application. In this work, a versatile surface modification technique based on the use of lasers (Matrix-Assisted Pulsed Laser Evaporation (MAPLE)) was used to yield poly(N-isopropylacrylamide) (pNIPAM) and its derivatives (amine, azide and amide terminated pNIPAM) functional and termoresponsive thin films. Surface properties of pNIPAM and its derivative films such as morphology, roughness and hydrophobic/hydrophilic character, as well as the thermoresponsive capacity were investigated by atomic force microscopy and contact angle measurements. The chemical characteristics of the pNIPAM based thin films were analysed by Fourier Transform Infrared Spectroscopy (FTIR). The chemical functionality was kept for all the samples obtained by MAPLE and the thermoresponse was demonstrated by the change in the contact angle and thickness values when the temperature was shifted from 37 °C to 24 °C for all the materials tested, with a smaller change for maleimide terminated pNIPAM. Biological assays performed in vitro (fluorescence microscopy and Scanning Electron Microscopy (SEM)) confirmed the conditioning of the early mesenchymal stem cell (MSC) growth by specific chemistry of the coatings. The cell imaging analysis revealed no cytotoxic effect of pNIPAM surfaces irrespective of type of functionalization. An increased proliferation rate of the cells grown on pNIPAM-azide surfaces and a lower cell density on pNIPAM-maleimide surfaces compared to the pNIPAM surfaces was observed, which can direct their use to potential surfaces in regenerative medicine approaches.

Mitigation of Cancer Therapy Side-Effects with Light

NASA Astrophysics Data System (ADS)

Nair, Raj; Bensadoun, René-Jean

2016-10-01

'Light' from low level laser therapy, through a process called photobiomodulation (PBM), has been in existence in supportive care in cancer, in particular in the management of oral mucositis (OM) in patients undergoing chemotherapy, radiation therapy and haematopoietic stem cell transplantation. In this book the authors attempt to portray the current status of the supportive care interventions that are possible with PBM using low level laser therapy (LLLT) in patients undergoing cancer treatment for solid tumours, harmatological malignancies, and head and neck cancers.

Effects of low-level laser therapy on stem cells from human exfoliated deciduous teeth

PubMed Central

FERNANDES, Ana Paula; JUNQUEIRA, Marina de Azevedo; MARQUES, Nádia Carolina Teixeira; MACHADO, Maria Aparecida Andrade Moreira; SANTOS, Carlos Ferreira; OLIVEIRA, Thais Marchini; SAKAI, Vivien Thiemy

2016-01-01

ABSTRACT Low-Level Laser Therapy stimulates the proliferation of a variety of types of cells. However, very little is known about its effect on stem cells from human exfoliated deciduous teeth (SHED). Objective This study aimed to evaluate the influence of different laser therapy energy densities on SHED viability and proliferation. Material and Methods SHED were irradiated according to the groups: I (1.2 J/cm2 - 0.5 mW – 10 s), II (2.5 J/cm2 – 10 mW – 10 s), III (3.7 J/cm2 – 15 mW – 10 s), IV (5.0 J/cm2 – 20 mW – 10 s), V (6.2 J/cm2 – 25 mW – 10 s), and VI (not irradiated – control group). Cell viability was assessed 6 and 24 h after irradiation measuring the mitochondrial activity and using the Crystal Violet assay. Cell proliferation was assessed after 24, 48, and 72 h of irradiation by SRB assay. Results MTT assay demonstrated differences from 6 to 24 hours after irradiation. After 24 h, groups I and IV showed higher absorbance values than those of control group. Crystal Violet assay showed statistically differences in the absorbance rate from 6 to 24 h after irradiation for groups III and VI. At 24 h after irradiation, Group III absorbance rate was greater than that of groups I, II, and IV. Group VI absorbance rate was greater than that of groups I and IV. SRB assay showed that the group I had higher rates than those of groups II, III, V, and VI, at 24 h after irradiation. After 48 h, group I exhibited the greatest cell proliferation rate followed by groups III, V, and VI. After 72 h, group III exhibited the lowest cell proliferation rate than those of groups II, IV, and V. Conclusions The Low-Level Laser Therapy energy densities used in this study did not cause loss of cell viability and stimulated SHED proliferation within the parameters described in this study. PMID:27556203

Comparative effects of chlorhexidine and essential oils containing mouth rinse on stem cells cultured on a titanium surface.

PubMed

Park, Jun-Beom; Lee, Gil; Yun, Byeong Gon; Kim, Chang-Hyen; Ko, Youngkyung

2014-04-01

Chlorhexidine (CHX) and Listerine (LIS), an essential oil compound, are the two commonly used adjunctive agents for mechanical debridement, for reducing the bacterial load in the treatment of peri-implant inflammation. However, antimicrobial agents have been reported to be cytotoxic to the alveolar bone cells and gingival epithelial cells. The present study was performed to examine the effects of antiseptics CHX and LIS, on the morphology and proliferation of stem cells. Stem cells derived from the buccal fat pad were grown on machined titanium discs. Each disc was immersed in CHX or LIS for 30 sec, 1.5 min or 4.5 min. Cell morphology was evaluated with a confocal laser microscope and the viability of the cells was quantitatively analyzed with the cell counting kit-8 (CCK-8). The untreated cells attached to the titanium discs demonstrated well-organized actin cytoskeletons. No marked alterations in the cytoskeletal organization were observed in any of the treated groups. The treatment with CHX and LIS of the titanium discs decreased the viability of the cells grown on the treated discs (P<0.05). The stem cells derived from the buccal fat pad were sensitive to CHX and LIS, and a reduction in cellular viability was observed when these agents were applied to the discs for 30 sec. Further studies are required to determine the optimal application time and concentration of this antimicrobial agent for maximizing the reduction of the bacterial load and minimizing the cytotoxicity to the surrounding cells.

Lithographic microfabrication of biocompatible polymers for tissue engineering and lab-on-a-chip applications

NASA Astrophysics Data System (ADS)

Balciunas, Evaldas; Jonusauskas, Linas; Valuckas, Vytautas; Baltriukiene, Daiva; Bukelskiene, Virginija; Gadonas, Roaldas; Malinauskas, Mangirdas

2012-06-01

In this work, a combination of Direct Laser Writing (DLW), PoliDiMethylSiloxane (PDMS) soft lithography and UV lithography was used to create cm- scale microstructured polymer scaolds for cell culture experiments out of dierent biocompatible materials: novel hybrid organic-inorganic SZ2080, PDMS elastomer, biodegradable PEG- DA-258 and SU-8. Rabbit muscle-derived stem cells were seeded on the fabricated dierent periodicity scaolds to evaluate if the relief surface had any eect on cell proliferation. An array of microlenses was fabricated using DLW out of SZ2080 and replicated in PDMS and PEG-DA-258, showing good potential applicability of the used techniques in many other elds like micro- and nano- uidics, photonics, and MicroElectroMechanical Systems (MEMS). The synergetic employment of three dierent fabrication techniques allowed to produce desired objects with low cost, high throughput and precision as well as use materials that are dicult to process by other means (PDMS and PEG-DA-258). DLW is a relatively slow fabrication method, since the object has to be written point-by-point. By applying PDMS soft lithography, we were enabled to replicate laser-fabricated scaolds for stem cell growth and micro-optical elements for lab-on-a-chip applications with high speed, low cost and good reproducible quality.

Small molecule screening with laser cytometry can be used to identify pro-survival molecules in human embryonic stem cells.

PubMed

Sherman, Sean P; Pyle, April D

2013-01-01

Differentiated cells from human embryonic stem cells (hESCs) provide an unlimited source of cells for use in regenerative medicine. The recent derivation of human induced pluripotent cells (hiPSCs) provides a potential supply of pluripotent cells that avoid immune rejection and could provide patient-tailored therapy. In addition, the use of pluripotent cells for drug screening could enable routine toxicity testing and evaluation of underlying disease mechanisms. However, prior to establishment of patient specific cells for cell therapy it is important to understand the basic regulation of cell fate decisions in hESCs. One critical issue that hinders the use of these cells is the fact that hESCs survive poorly upon dissociation, which limits genetic manipulation because of poor cloning efficiency of individual hESCs, and hampers production of large-scale culture of hESCs. To address the problems associated with poor growth in culture and our lack of understanding of what regulates hESC signaling, we successfully developed a screening platform that allows for large scale screening for small molecules that regulate survival. In this work we developed the first large scale platform for hESC screening using laser scanning cytometry and were able to validate this platform by identifying the pro-survival molecule HA-1077. These small molecules provide targets for both improving our basic understanding of hESC survival as well as a tool to improve our ability to expand and genetically manipulate hESCs for use in regenerative applications.

Analysis of clonal expansions through the normal and premalignant human breast epithelium reveals the presence of luminal stem cells.

PubMed

Cereser, Biancastella; Jansen, Marnix; Austin, Emily; Elia, George; McFarlane, Taneisha; van Deurzen, Carolien Hm; Sieuwerts, Anieta M; Daidone, Maria G; Tadrous, Paul J; Wright, Nicholas A; Jones, Louise; McDonald, Stuart Ac

2018-01-01

It is widely accepted that the cell of origin of breast cancer is the adult mammary epithelial stem cell; however, demonstrating the presence and location of tissue stem cells in the human breast has proved difficult. Furthermore, we do not know the clonal architecture of the normal and premalignant mammary epithelium or its cellular hierarchy. Here, we use deficiency in the mitochondrial enzyme cytochrome c oxidase (CCO), typically caused by somatic mutations in the mitochondrial genome, as a means to perform lineage tracing in the human mammary epithelium. PCR sequencing of laser-capture microdissected cells in combination with immunohistochemistry for markers of lineage differentiation was performed to determine the clonal nature of the mammary epithelium. We have shown that in the normal human breast, clonal expansions (defined here by areas of CCO deficiency) are typically uncommon and of limited size, but can occur at any site within the adult mammary epithelium. The presence of a stem cell population was shown by demonstrating multi-lineage differentiation within CCO-deficient areas. Interestingly, we observed infrequent CCO deficiency that was restricted to luminal cells, suggesting that niche succession, and by inference stem cell location, is located within the luminal layer. CCO-deficient areas appeared large within areas of ductal carcinoma in situ, suggesting that the rate of clonal expansion was altered in the premalignant lesion. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Negatively-chirped laser enables nonlinear excitation and nanoprocessing with sub-20-fs pulses

NASA Astrophysics Data System (ADS)

Uchugonova, A.; Müller, J.; Bückle, R.; Tempea, G.; Isemann, A.; Stingl, A.; König, K.

2008-02-01

It has long been considered that the advantages emerging from employing chirp pre-compensation in nonlinear microscopy were overweighed by the complexity of prism- or grating-based compressors. These concerns were refuted with the advent of dispersive-mirrors-based compressors that are compact, user-friendly and sufficiently accurate to support sub-20-fs pulse delivery. Recent advances in the design of dispersive multilayer mirrors resulted in improved bandwidth (covering now as much as half of the gain bandwidth of Ti:Sapphire) and increased dispersion per bounce (one reflection off a state-of-the-art dispersive mirror pre-compensates the dispersion corresponding to >10mm of glass). The compressor built with these mirrors is sufficiently compact to be integrated in the housing of a sub-12-fs Ti:Sapphire oscillator. A complete scanning nonlinear microscope (FemtOgene, JenLab GmbH) equipped with highly-dispersive, large-NA objectives (Zeiss EC Plan-Neofluoar 40x/1.3, Plan-Neofluar 63x/1,25 Oil) was directly seeded with this negatively chirped laser. The pulse duration was measured at the focus of the objectives by inserting a scanning autocorrelator in the beam path between the laser and the microscope and recording the second order interferometric autocorrelation traces with the detector integrated in the microscope. Pulse durations <20fs were measured with both objectives. The system has been applied for two-photon imaging, transfection and optical manipulation of stem cells. Here we report on the successful transfection of human stem cells by transient optoporation of the cell membrane with a low mean power of < 7 mW and a short μs beam dwell time. Optically transfected cells were able to reproduce. The daughter cell expressed also green fluorescent proteins (GFP) indicating the successful modification of the cellular DNA.

Perivascular Mesenchymal Stem Cells in Sheep: Characterization and Autologous Transplantation in a Model of Articular Cartilage Repair.

PubMed

Hindle, Paul; Baily, James; Khan, Nusrat; Biant, Leela C; Simpson, A Hamish R; Péault, Bruno

2016-11-01

Previous research has indicated that purified perivascular stem cells (PSCs) have increased chondrogenic potential compared to conventional mesenchymal stem cells (MSCs) derived in culture. This study aimed to develop an autologous large animal model for PSC transplantation and to specifically determine if implanted cells are retained in articular cartilage defects. Immunohistochemistry and fluorescence-activated cell sorting were used to ascertain the reactivity of anti-human and anti-ovine antibodies, which were combined and used to identify and isolate pericytes (CD34 - CD45 - CD146 + ) and adventitial cells (CD34 + CD45 - CD146 - ). The purified cells demonstrated osteogenic, adipogenic, and chondrogenic potential in culture. Autologous ovine PSCs (oPSCs) were isolated, cultured, and efficiently transfected using a green fluorescence protein (GFP) encoding lentivirus. The cells were implanted into articular cartilage defects on the medial femoral condyle using hydrogel and collagen membranes. Four weeks following implantation, the condyle was explanted and confocal laser scanning microscopy demonstrated the presence of oPSCs in the defect repaired with the hydrogel. These data suggest the testability in a large animal of native MSC autologous grafting, thus avoiding possible biases associated with xenotransplantation. Such a setting will be used in priority for indications in orthopedics, at first to model articular cartilage repair.

Laser-Sintered Constructs with Bio-inspired Porosity and Surface Micro/Nano-Roughness Enhance Mesenchymal Stem Cell Differentiation and Matrix Mineralization In Vitro.

PubMed

Cheng, Alice; Cohen, David J; Boyan, Barbara D; Schwartz, Zvi

2016-12-01

Direct metal laser sintering can produce porous Ti-6Al-4V orthopedic and dental implants. The process requires reduced resources and time and can provide greater structural control than machine manufacturing. Implants in bone are colonized by mesenchymal stem cells (MSCs), which can differentiate into osteoblasts and contribute to osseointegration. This study examined osteoblast differentiation and matrix mineralization of human MSCs cultured on laser-sintered Ti-6Al-4V constructs with varying porosity and at different time scales. 2D solid disks and low, medium and high porosity (LP, MP, and HP) 3D constructs based on a human trabecular bone template were laser sintered from Ti-6Al-4V powder and further processed to have micro- and nanoscale roughness. hMSCs exhibited greater osteoblastic differentiation and local factor production on all 3D porous constructs compared to 2D surfaces, which was sustained for 9 days without use of exogenous factors. hMSCs cultured for 8 weeks on MP constructs in osteogenic medium (OM), OM supplemented with BMP2 or collagen-coated MP constructs in OM exhibited bone-like extracellular matrix mineralization. Use of bio-inspired porosity for the 3D architecture of additively manufactured Ti-6Al-4V enhanced osteogenic differentiation of hMSCs beyond surface roughness alone. This study suggests that a 3D architecture may enhance the osseointegration of orthopedic and dental implants in vivo.

Generating size-controlled embryoid bodies using laser direct-write.

PubMed

Dias, A D; Unser, A M; Xie, Y; Chrisey, D B; Corr, D T

2014-06-01

Embryonic stem cells (ESCs) have the potential to self-renew and differentiate into any specialized cell type. One common method to differentiate ESCs in vitro is through embryoid bodies (EBs), three-dimensional cellular aggregates that spontaneously self-assemble and generally express markers for the three germ layers, endoderm, ectoderm, and mesoderm. It has been previously shown that both EB size and 2D colony size each influence differentiation. We hypothesized that we could control the size of the EB formed by mouse ESCs (mESCs) by using a cell printing method, laser direct-write (LDW), to control both the size of the initial printed colony and the local cell density in printed colonies. After printing mESCs at various printed colony sizes and printing densities, two-way ANOVAs indicated that the EB diameter was influenced by printing density after three days (p = 0.0002), while there was no effect of the printed colony diameter on the EB diameter at the same timepoint (p = 0.74). There was no significant interaction between these two factors. Tukey's honestly significant difference test showed that high-density colonies formed significantly larger EBs, suggesting that printed mESCs quickly aggregate with nearby cells. Thus, EBs can be engineered to a desired size by controlling printing density, which will influence the design of future differentiation studies. Herein, we highlight the capacity of LDW to control the local cell density and colony size independently, at prescribed spatial locations, potentially leading to better stem cell maintenance and directed differentiation.

Bone-Inspired Spatially Specific Piezoelectricity Induces Bone Regeneration

PubMed Central

Yu, Peng; Ning, Chengyun; Zhang, Yu; Tan, Guoxin; Lin, Zefeng; Liu, Shaoxiang; Wang, Xiaolan; Yang, Haoqi; Li, Kang; Yi, Xin; Zhu, Ye; Mao, Chuanbin

2017-01-01

The extracellular matrix of bone can be pictured as a material made of parallel interspersed domains of fibrous piezoelectric collagenous materials and non-piezoelectric non-collagenous materials. To mimic this feature for enhanced bone regeneration, a material made of two parallel interspersed domains, with higher and lower piezoelectricity, respectively, is constructed to form microscale piezoelectric zones (MPZs). The MPZs are produced using a versatile and effective laser-irradiation technique in which K0.5Na0.5NbO3 (KNN) ceramics are selectively irradiated to achieve microzone phase transitions. The phase structure of the laser-irradiated microzones is changed from a mixture of orthorhombic and tetragonal phases (with higher piezoelectricity) to a tetragonal dominant phase (with lower piezoelectricity). The microzoned piezoelectricity distribution results in spatially specific surface charge distribution, enabling the MPZs to bear bone-like microscale electric cues. Hence, the MPZs induce osteogenic differentiation of stem cells in vitro and bone regeneration in vivo even without being seeded with stem cells. The concept of mimicking the spatially specific piezoelectricity in bone will facilitate future research on the rational design of tissue regenerative materials. PMID:28900517

The effects of femtosecond laser-textured Ti-6Al-4V on wettability and cell response.

PubMed

Raimbault, Ophélie; Benayoun, Stephane; Anselme, Karine; Mauclair, Cyril; Bourgade, Tatiana; Kietzig, Anne-Marie; Girard-Lauriault, Pierre-Luc; Valette, Stephane; Donnet, Christophe

2016-12-01

To study the biological activity effects of femtosecond laser-induced structures on cell behavior, TA6V samples were micro-textured with focused femtosecond laser pulses generating grooves of various dimensions on the micrometer scale (width: 25-75μm; depth: 1-10μm). LIPSS (Laser Induced Periodic Surface Structures) were also generated during the laser irradiation, providing a supplementary structure (sinusoidal form) of hundreds of nanometers at the bottom of the grooves oriented perpendicular (⊥ LIPPS) or parallel (// LIPPS) to the direction of these grooves. C3H10 T1/2 murine mesenchymal stem cells were cultivated on the textured biomaterials. To have a preliminary idea of the spreading of biological media on the substrate, prior to cell culture, contact angle measurement were performed. This showed that the post-irradiation hydrophilicity of the samples can decrease with time according to its storage environment. The multiscale structuration either induced a collaborative or a competitive influence of the LIPSS and grooves on the cells. It has been shown that cells individually and collectively were most sensitive to microscale grooves which were narrower than 25μm and deeper than 5μm with ⊥ LIPPS. In some cases, cells were individually sensitive to the LIPSS but the cell layer organization did not exhibit significant differences in comparison to a non-textured surface. These results showed that cells are more sensitive to the nanoscale structures (LIPSS), unless the microstructures's size is close to the cell size and deeper than 5μm. There, the cells are sensitive to the microscale structures and go on spreading following these structures. Copyright © 2016 Elsevier B.V. All rights reserved.

A Novel Combination of Homeobox Genes Is Expressed in Mesenchymal Chorionic Stem/Stromal Cells in First Trimester and Term Pregnancies

PubMed Central

Liu, Haiying; Murthi, Padma; Qin, Sharon; Kusuma, Gina D.; Borg, Anthony J.; Knöfler, Martin; Haslinger, Peter; Manuelpillai, Ursula; Pertile, Mark D.; Abumaree, Mohamed

2014-01-01

Human chorionic mesenchymal stem/stromal cells (CMSCs) derived from the placenta are similar to adult tissue-derived MSCs. The aim of this study was to investigate the role of these cells in normal placental development. Transcription factors, particularly members of the homeobox gene family, play crucial roles in maintaining stem cell proliferation and lineage specification in embryonic tissues. In adult tissues and organs, stem cells proliferate at low levels in their niche until they receive cues from the microenvironment to differentiate. The homeobox genes that are expressed in the CMSC niche in placental tissues have not been identified. We used the novel strategy of laser capture microdissection to isolate the stromal component of first trimester villi and excluded the cytotrophoblast and syncytiotrophoblast layers that comprise the outer layer of the chorionic villi. Microarray analysis was then used to screen for homeobox genes in the microdissected tissue. Candidate homeobox genes were selected for further RNA analysis. Immunohistochemistry of candidate genes in first trimester placental villous stromal tissue revealed homeobox genes Meis1, myeloid ectropic viral integration site 1 homolog 2 (MEIS2), H2.0-like Drosophila (HLX), transforming growth factor β-induced factor (TGIF), and distal-less homeobox 5 (DLX5) were expressed in the vascular niche where CMSCs have been shown to reside. Expression of MEIS2, HLX, TGIF, and DLX5 was also detected in scattered stromal cells. Real-time polymerase chain reaction and immunocytochemistry verified expression of MEIS2, HLX, TGIF, and DLX5 homeobox genes in first trimester and term CMSCs. These data suggest a combination of regulatory homeobox genes is expressed in CMSCs from early placental development to term, which may be required for stem cell proliferation and differentiation. PMID:24692208

Estimation of Tree Position and STEM Diameter Using Simultaneous Localization and Mapping with Data from a Backpack-Mounted Laser Scanner

NASA Astrophysics Data System (ADS)

Holmgren, J.; Tulldahl, H. M.; Nordlöf, J.; Nyström, M.; Olofsson, K.; Rydell, J.; Willén, E.

2017-10-01

A system was developed for automatic estimations of tree positions and stem diameters. The sensor trajectory was first estimated using a positioning system that consists of a low precision inertial measurement unit supported by image matching with data from a stereo-camera. The initial estimation of the sensor trajectory was then calibrated by adjustments of the sensor pose using the laser scanner data. Special features suitable for forest environments were used to solve the correspondence and matching problems. Tree stem diameters were estimated for stem sections using laser data from individual scanner rotations and were then used for calibration of the sensor pose. A segmentation algorithm was used to associate stem sections to individual tree stems. The stem diameter estimates of all stem sections associated to the same tree stem were then combined for estimation of stem diameter at breast height (DBH). The system was validated on four 20 m radius circular plots and manual measured trees were automatically linked to trees detected in laser data. The DBH could be estimated with a RMSE of 19 mm (6 %) and a bias of 8 mm (3 %). The calibrated sensor trajectory and the combined use of circle fits from individual scanner rotations made it possible to obtain reliable DBH estimates also with a low precision positioning system.

Laser engravings as reason for mechanical failure of titanium-alloyed total hip stems.

PubMed

Kluess, Daniel; Steinhauser, Erwin; Joseph, Micheal; Koch, Ursula; Ellenrieder, Martin; Mittelmeier, Wolfram; Bader, Rainer

2015-07-01

Two revisions of broken β-titanium total hip stems had to be performed in our hospital after 2 and 4 years in situ. Since both fractures were located at the level of a laser engraving, a failure analysis was conducted. Both retrieved hip stems were disinfected and collected in our retrieval database after patient's signed agreement. Each fragment was macroscopically photographed. Fracture surfaces were analyzed using scanning electron microscopy (SEM). Quantification of element content was conducted using energy dispersive X-ray (EDX) analysis. Both stems show fatigue fracture, as displayed by the lines of rest on the fracture surface. The origin of fracture was identified directly at the laser engraving of the company logo at both stems by means of SEM. The EDX analysis showed an oxygen level beneath the laser engraving about twice as high as in the substrate, causing material embrittlement. Laser engravings need to be reduced to a minimum of necessary information, and should be placed at locations with minimum mechanical load. Biomechanical analyses are recommended to identify less loaded areas in implant components to avoid such implant failures.

Deep tissue single cell MSC ablation using a fiber laser source to evaluate therapeutic potential in osteogenesis imperfecta

NASA Astrophysics Data System (ADS)

Tehrani, Kayvan F.; Pendleton, Emily G.; Lin, Charles P.; Mortensen, Luke J.

2016-04-01

Osteogenesis imperfecta (OI) is a currently uncurable disease where a mutation in collagen type I yields brittle bones. One potential therapy is transplantation of mesenchymal stem cells (MSCs), but controlling and enhancing transplanted cell survival has proven challenging. Therefore, we use a 2- photon imaging system to study individual transplanted cells in the living bone marrow. We ablated cells deep in the bone marrow and observed minimal collateral damage to surrounding tissue. Future work will evaluate the local impact of transplanted MSCs on bone deposition in vivo.

Cellular sequestration of cadmium in the hyperaccumulator plant species Sedum alfredii.

PubMed

Tian, Shengke; Lu, Lingli; Labavitch, John; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick

2011-12-01

Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 μg g(-1) were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii.

The use of planarians as in vivo animal model to study laser biomodulation effects

NASA Astrophysics Data System (ADS)

Munin, Egberto; Garcia, Neila Maria Rocha; Braz, Allison Gustavo; de Souza, Sandra Cristina; Alves, Leandro Procópio; Salgado, Miguel Angel Castillo; Pilla, Viviane

2007-02-01

A variety of effects is attributed to the photo stimulation of tissues, such as improved healing of ulcers, analgesic and anti-inflammatory effects, stimulation of the proliferation of cells of different origins and stimulation of bone repair. Some investigations that make qualitative evaluations, like wound healing and evaluation of pain and edema, can be conducted in human subjects. However, deeper investigations on the mechanisms of action of the light stimulus and other quantitative works that requires biopsies or destructive analysis has to be carried out in animal models or in cell cultures. In this work, we propose the use of planarians as a model to study laser-tissue interaction. Contrasting with cell cultures and unicellular organisms, planarians are among the simplest organism having tissue layers, central nerve system, digestive and excretory system that might have been platforms for the evolution of the complex and highly organized tissues and organs found in higher organisms. For the present study, 685 nm laser radiation was employed. Planarians were cut transversally, in a plane posterior to the auricles. The body fragments were left to regenerate and the proliferation dynamics of stem cells was studied by using histological analysis. Maximum cell count was obtained for the laser treated group at the 4 th experimental day. At that experimental time, we also had the largest difference between the irradiated and the non-irradiated control group. We concluded that the studied flatworm could be an interesting animal model for in vivo studies of laser-tissue interactions.

Effects of CO2 Lasers on Dental Pulp Biology in Rats.

PubMed

Ser-Od, Tungalag; Yasumoto, Masafumi; Al-Wahabi, Akram; Nakajima, Kei; Murakami, Satoshi; Matsuzaka, Kenichi; Inoue, Takashi

2016-04-01

The purpose of this study was to investigate the effects of CO2 lasers on the proliferation and differentiation of dental pulp cells, and their latent self-recovery in connection with their stemness using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The first molars from male Sprague-Dawley rats, each weighing ∼150-200 g, were used for this study. The upper first molars were irradiated with a 10,600 nm wavelength CO2 laser under identical parameters (2 W CO2 laser, energy 4J, energy density 203.84 J/cm(2) for 8.8 sec) through the dentin of the occlusal surface. The molars were extracted immediately, or at 1, 3 or 5 days after the laser irradiation. RT-PCR analysis using primers specific for heat shock protein 70 (Hsp70), adenosine triphosphate (ATP)-binding cassette transporter G2 (ABCG2), dentin sialophosphoprotein (DSPP), and dentin matrix protein 1 (DMP1), and immunohistochemistry using antibodies specific for proliferating cell nuclear antigen (PCNA), ABCG2, CD34, and CD44 were performed. RT-PCR analysis revealed that Hsp70 mRNA expression in the immediate group and ABCG2 mRNA expression at day 1 were the highest. DSPP and DMP1 mRNA expression in the laser-irradiated groups increased gradually, reaching its peak on the 5th day of the experiment, although no significant difference found among groups with regard to DMP1 expression. Immunohistochemically, PCNA-positive cells were observed at all times after the laser irradiation; however, they were most evident on day 3. CD44-positive cells were observed strongly on day 1 and day 3, while ABCG2-positive cells were the most evident on day 3. These results demonstrate that CO2 laser irradiation induces degeneration in the pulp tissue, which is then repaired by newly formed odontoblast-like cells.

Latest biomaterials and technology in dentistry.

PubMed

Zandparsa, Roya

2014-01-01

Navigation technology is applied successfully in oral and maxillofacial surgery. Laser beams are used for caries removal. With nanodentistry, it is possible to maintain comprehensive oral health care. Nanorobots induce oral analgesia, desensitize teeth, and manipulate the tissue. They can also be used for preventive, restorative, and curative procedures. Strategies to engineer tissue can be categorized into 3 major classes: conductive, inductive, and cell transplantation approaches. Several populations of cells with stem cell properties have been isolated from different parts of the tooth. Copyright © 2014 Elsevier Inc. All rights reserved.

In vivo morphology of the limbal palisades of vogt correlates with progressive stem cell deficiency in aniridia-related keratopathy.

PubMed

Lagali, Neil; Edén, Ulla; Utheim, Tor Paaske; Chen, Xiangjun; Riise, Ruth; Dellby, Anette; Fagerholm, Per

2013-08-07

To investigate morphologic alterations in the limbal palisades of Vogt in a progressive form of limbal stem cell deficiency. Twenty Norwegian subjects (40 eyes) with congenital aniridia and 9 healthy family members (18 eyes) without aniridia were examined. Clinical grade of aniridia-related keratopathy (ARK) was assessed by slit-lamp biomicroscopy, and tear production and quality, corneal thickness, and sensitivity were additionally measured. The superior and inferior limbal palisades of Vogt and central cornea were examined by laser scanning in vivo confocal microscopy (IVCM). In an aniridia patient with grade 0 ARK, a transparent cornea and normal limbal palisade morphology were found. In grade 1 ARK, 5 of 12 eyes had degraded palisade structures. In the remaining grade 1 eyes and in all 20 eyes with stage 2, 3, and 4 ARK, palisade structures were absent by IVCM. Increasing ARK grade significantly correlated with reduced visual acuity and corneal sensitivity, increased corneal thickness, degree of degradation of superior and inferior palisade structures, reduced peripheral nerves, increased inflammatory cell invasion, and reduced density of basal epithelial cells and central subbasal nerves. Moreover, limbal basal epithelial cell density and central corneal subbasal nerve density were both significantly reduced in aniridia compared to healthy corneas (P = 0.002 and 0.003, respectively). Progression of limbal stem cell deficiency in aniridia correlates with degradation of palisade structures, gradual transformation of epithelial phenotype, onset of inflammation, and a corneal nerve deficit. IVCM can be useful in monitoring early- to late-stage degenerative changes in stem cell-deficient patients.

Multiphoton fluorescence lifetime imaging of metabolic status in mesenchymal stem cell during adipogenic differentiation

NASA Astrophysics Data System (ADS)

Meleshina, A. V.; Dudenkova, V. V.; Shirmanova, M. V.; Bystrova, A. S.; Zagaynova, E. V.

2016-03-01

Non-invasive imaging of cell metabolism is a valuable approach to assess the efficacy of stem cell therapy and understand the tissue development. In this study we analyzed metabolic trajectory of the mesenchymal stem cells (MCSs) during differentiation into adipocytes by measuring fluorescence lifetimes of free and bound forms of the reduced nicotinamide adenine dinucleotide (NAD(P)H) and flavine adenine dinucleotide (FAD). Undifferentiated MSCs and MSCs on the 5, 12, 19, 26 days of differentiation were imaged on a Zeiss 710 microscope with fluorescence lifetime imaging (FLIM) system B&H (Germany). Fluorescence of NAD(P)H and FAD was excited at 750 nm and 900 nm, respectively, by a femtosecond Ti:sapphire laser and detected in a range 455-500 nm and 500-550 nm, correspondingly. We observed the changes in the NAD(P)H and FAD fluorescence lifetimes and their relative contributions in the differentiated adipocytes compare to undifferentiated MSCs. Increase of fluorescence lifetimes of the free and bound forms of NAD(P)H and the contribution of protein-bound NAD(P)H was registered, that can be associated with a metabolic switch from glycolysis to oxidative phosphorylation and/or synthesis of lipids in adipogenically differentiated MSCs. We also found that the contribution of protein-bound FAD decreased during differentiation. After carrying out appropriate biochemical measurements, the observed changes in cellular metabolism can potentially serve to monitor stem cell differentiation by FLIM.

Cell-specific optoporation with near-infrared ultrafast laser and functionalized gold nanoparticles

NASA Astrophysics Data System (ADS)

Bergeron, Eric; Boutopoulos, Christos; Martel, Rosalie; Torres, Alexandre; Rodriguez, Camille; Niskanen, Jukka; Lebrun, Jean-Jacques; Winnik, Françoise M.; Sapieha, Przemyslaw; Meunier, Michel

2015-10-01

Selective targeting of diseased cells can increase therapeutic efficacy and limit off-target adverse effects. We developed a new tool to selectively perforate living cells with functionalized gold nanoparticles (AuNPs) and near-infrared (NIR) femtosecond (fs) laser. The receptor CD44 strongly expressed by cancer stem cells was used as a model for selective targeting. Citrate-capped AuNPs (100 nm in diameter) functionalized with 0.01 orthopyridyl-disulfide-poly(ethylene glycol) (5 kDa)-N-hydroxysuccinimide (OPSS-PEG-NHS) conjugated to monoclonal antibodies per nm2 and 5 μM HS-PEG (5 kDa) were colloidally stable in cell culture medium containing serum proteins. These AuNPs attached mostly as single particles 115 times more to targeted CD44+ MDA-MB-231 and CD44+ ARPE-19 cells than to non-targeted CD44- 661W cells. Optimally functionalized AuNPs enhanced the fs laser (800 nm, 80-100 mJ cm-2 at 250 Hz or 60-80 mJ cm-2 at 500 Hz) to selectively perforate targeted cells without affecting surrounding non-targeted cells in co-culture. This novel highly versatile treatment paradigm can be adapted to target and perforate other cell populations by adapting to desired biomarkers. Since living biological tissues absorb energy very weakly in the NIR range, the developed non-invasive tool may provide a safe, cost-effective clinically relevant approach to ablate pathologically deregulated cells and limit complications associated with surgical interventions.Selective targeting of diseased cells can increase therapeutic efficacy and limit off-target adverse effects. We developed a new tool to selectively perforate living cells with functionalized gold nanoparticles (AuNPs) and near-infrared (NIR) femtosecond (fs) laser. The receptor CD44 strongly expressed by cancer stem cells was used as a model for selective targeting. Citrate-capped AuNPs (100 nm in diameter) functionalized with 0.01 orthopyridyl-disulfide-poly(ethylene glycol) (5 kDa)-N-hydroxysuccinimide (OPSS-PEG-NHS) conjugated to monoclonal antibodies per nm2 and 5 μM HS-PEG (5 kDa) were colloidally stable in cell culture medium containing serum proteins. These AuNPs attached mostly as single particles 115 times more to targeted CD44+ MDA-MB-231 and CD44+ ARPE-19 cells than to non-targeted CD44- 661W cells. Optimally functionalized AuNPs enhanced the fs laser (800 nm, 80-100 mJ cm-2 at 250 Hz or 60-80 mJ cm-2 at 500 Hz) to selectively perforate targeted cells without affecting surrounding non-targeted cells in co-culture. This novel highly versatile treatment paradigm can be adapted to target and perforate other cell populations by adapting to desired biomarkers. Since living biological tissues absorb energy very weakly in the NIR range, the developed non-invasive tool may provide a safe, cost-effective clinically relevant approach to ablate pathologically deregulated cells and limit complications associated with surgical interventions. Electronic supplementary information (ESI) available: Characterization of functionalized gold nanoparticles by UV-visible-NIR spectroscopy and zeta potential measurements; selectivity of cell targeting with functionalized gold nanoparticles by immunofluorescence, flow cytometry and scanning electron microscopy; selective treatment of targeted cells with functionalized gold nanoparticles and ultrafast laser. See DOI: 10.1039/c5nr05650k

Detection and isolation of rare cells by 2-step enrichment high-speed flow cytometry/cell sorting and single cell LEAP laser ablation

NASA Astrophysics Data System (ADS)

Zordan, M. D.; Leary, James F.

2011-02-01

The clonal isolation of rare cells, especially cancer and stem cells, in a population is important to the development of improved medical treatment. We have demonstrated that the Laser-Enabled Analysis and Processing (LEAP, Cyntellect Inc., San Diego, CA) instrument can be used to efficiently produce single cell clones by photoablative dilution. Additionally, we have also shown that cells present at low frequencies can be cloned by photoablative dilution after they are pre-enriched by flow cytometry based cell sorting. Circulating tumor cells were modeled by spiking isolated peripheral blood cells with cells from the lung carcinoma cell line A549. Flow cytometry based cell sorting was used to perform an enrichment sort of A549 cells directly into a 384 well plate. Photoablative dilution was performed with the LEAPTM instrument to remove any contaminating cells, and clonally isolate 1 side population cell per well. We were able to isolate and grow single clones of side population cells using this method at greater than 90% efficiency. We have developed a 2 step method that is able to perform the clonal isolation of rare cells based on a medically relevant functional phenotype.

MicroRNA-193 Pro-Proliferation Effects for Bone Mesenchymal Stem Cells After Low-Level Laser Irradiation Treatment Through Inhibitor of Growth Family, Member 5

PubMed Central

Wang, Jue; Huang, Weicong; Wu, Yihe; Hou, Jianfeng; Nie, Yu; Gu, Haiyong; Li, Jun; Hu, Shengshou

2012-01-01

The enhanced proliferation of mesenchymal stem cells (MSCs) can be helpful for the clinical translation of cell therapy. Low-level laser irradiation (LLLI) has been demonstrated as regulating MSC proliferation. MicroRNAs (miRNAs) are involved in various pathophysiologic processes in stem cells, but the role of miRNAs in the LLLI-based promotion of MSC proliferation remains unclear. We found that the proliferation level and cell cycle-associated genes in MSCs were increased after LLLI treatment in a time-dependent manner. Microarray assays revealed subsets of miRNAs to be differentially regulated, and these dynamic changes were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) after LLLI. miR-193 was the most highly up-regulated miRNA, and the change in it was related with the proliferation level. Gain-loss function experiments demonstrated that miR-193 could regulate the proliferation of MSCs, including human's and rat's, but could not affect the apoptosis and differentiation level. Blockade of miR-193 repressed the MSC proliferation induced by LLLI. By qRT-PCR, we found that miR-193, in particular, regulated cyclin-dependent kinase 2 (CDK2) expression. Bioinformatic analyses and luciferase reporter assays revealed that inhibitor of growth family, member 5 (ING5) could be the best target of miR-193 to functionally regulate proliferation and CDK2 activity, and the mRNA and protein level of ING5 was regulated by miR-193. Furthermore, the ING5 inhibited by small interfering RNA (siRNA) could up-regulate the proliferation of MSCs and the expression of CDK2. Taken together, these results strongly suggest that miR-193 plays a critical part in MSC proliferation in response to LLLI stimulation, which is potentially amenable to therapeutic manipulation for clinical application. PMID:22384930

The Effect of Conditioned Media of Adipose-Derived Stem Cells on Wound Healing after Ablative Fractional Carbon Dioxide Laser Resurfacing

PubMed Central

Zhou, Bing-Rong; Xu, Yang; Guo, Shi-Lei; Xu, Yan; Wang, Ying; Zhu, Fen; Wu, Di; Yin, Zhi-Qiang; Luo, Dan

2013-01-01

Objective. To evaluate the benefits of conditioned medium of Adipose-derived stem cells (ADSC-CM) on wound healing after fractional carbon dioxide laser resurfacing (FxCR) on human skin. Materials and Methods. Nineteen subjects were treated with FxCR on the bilateral inner arms. ADSC-CM was applied on FxCR site of one randomly selected arm. Transepidermal water loss (TEWL), skin color, and gross-elasticity of FxCR site on both arms were measured. Skin samples were taken by biopsy from three subjects 3 weeks after treatment for histopathological manifestations and mRNA expressions of procollagen types I and III, elastin genes were noted. Results. The index of erythema, melanin, and TEWL of the ADSC-CM-treated skin were significantly lower than those of the control side. The mRNA expression of type III procollagen in ADSC-CM-treated group at 3 weeks posttreatment was 2.6 times of that of the control group. Conclusion. Application of allograft ADSC-CM is an effective method for enhancing wound healing after FxCR, by reducing transient adverse effects such as erythema, hyperpigmentation, and increased TEWL. PMID:24381938

Computational prediction of strain-dependent diffusion of transcription factors through the cell nucleus.

PubMed

Nava, Michele M; Fedele, Roberto; Raimondi, Manuela T

2016-08-01

Nuclear spreading plays a crucial role in stem cell fate determination. In previous works, we reported evidence of multipotency maintenance for mesenchymal stromal cells cultured on three-dimensional engineered niche substrates, fabricated via two-photon laser polymerization. We correlated maintenance of multipotency to a more roundish morphology of these cells with respect to those cultured on conventional flat substrates. To interpret these findings, here we present a multiphysics model coupling nuclear strains induced by cell adhesion to passive diffusion across the cell nucleus. Fully three-dimensional reconstructions of cultured cells were developed on the basis of confocal images: in particular, the level of nuclear spreading resulted significantly dependent on the cell localization within the niche architecture. We assumed that the cell diffusivity varies as a function of the local volumetric strain. The model predictions indicate that the higher the level of spreading of the cell, the higher the flux across the nucleus of small solutes such as transcription factors. Our results point toward nuclear spreading as a primary mechanism by which the stem cell translates its shape into a fate decision, i.e., by amplifying the diffusive flow of transcriptional activators into the nucleus.

Synthesis of three-dimensional calcium carbonate nanofibrous structure from eggshell using femtosecond laser ablation

PubMed Central

2011-01-01

Background Natural biomaterials from bone-like minerals derived from avian eggshells have been considered as promising bone substitutes owing to their biodegradability, abundance, and lower price in comparison with synthetic biomaterials. However, cell adhesion to bulk biomaterials is poor and surface modifications are required to improve biomaterial-cell interaction. Three-dimensional (3D) nanostructures are preferred to act as growth support platforms for bone and stem cells. Although there have been several studies on generating nanoparticles from eggshells, no research has been reported on synthesizing 3D nanofibrous structures. Results In this study, we propose a novel technique to synthesize 3D calcium carbonate interwoven nanofibrous platforms from eggshells using high repetition femtosecond laser irradiation. The eggshell waste is value engineered to calcium carbonate nanofibrous layer in a single step under ambient conditions. Our striking results demonstrate that by controlling the laser pulse repetition, nanostructures with different nanofiber density can be achieved. This approach presents an important step towards synthesizing 3D interwoven nanofibrous platforms from natural biomaterials. Conclusion The synthesized 3D nanofibrous structures can promote biomaterial interfacial properties to improve cell-platform surface interaction and develop new functional biomaterials for a variety of biomedical applications. PMID:21251288

Noninvasive in situ evaluation of osteogenic differentiation by time-resolved laser-induced fluorescence spectroscopy.

PubMed

Ashjian, Peter; Elbarbary, Amir; Zuk, Patricia; DeUgarte, Daniel A; Benhaim, Prosper; Marcu, Laura; Hedrick, Marc H

2004-01-01

The clinical implantation of bioengineered tissues requires an in situ nondestructive evaluation of the quality of tissue constructs developed in vitro before transplantation. Time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) is demonstrated here to noninvasively monitor the formation of osteogenic extracellular matrix (ECM) produced by putative stem cells (PLA cells) derived from human adipose tissue. We show that this optical spectroscopy technique can assess the relative expression of collagens (types I, III, IV, and V) within newly forming osteogenic ECM. The results are consistent with those obtained by conventional histochemical techniques (immunofluorescence and Western blot) and demonstrate that TR-LIFS is a potential tool for monitoring the expression of distinct collagen types and the formation of collagen cross-links in intact tissue constructs.

Ultrashort laser pulse cell manipulation using nano- and micro- materials

NASA Astrophysics Data System (ADS)

Schomaker, Markus; Killian, Doreen; Willenbrock, Saskia; Diebold, Eric; Mazur, Eric; Bintig, Willem; Ngezahayo, Anaclet; Nolte, Ingo; Murua Escobar, Hugo; Junghanß, Christian; Lubatschowski, Holger; Heisterkamp, Alexander

2010-08-01

The delivery of extra cellular molecules into cells is essential for cell manipulation. For this purpose genetic materials (DNA/RNA) or proteins have to overcome the impermeable cell membrane. To increase the delivery efficiency and cell viability of common methods different nano- and micro material based approaches were applied. To manipulate the cells, the membrane is in contact with the biocompatible material. Due to a field enhancement of the laser light at the material and the resulting effect the cell membrane gets perforated and extracellular molecules can diffuse into the cytoplasm. Membrane impermeable dyes, fluorescent labelled siRNA, as well as plasmid vectors encoded for GFP expression were used as an indicator for successful perforation or transfection, respectively. Dependent on the used material, perforation efficiencies over 90 % with a cell viability of about 80 % can be achieved. Additionally, we observed similar efficiencies for siRNA transfection. Due to the larger molecule size and the essential transport of the DNA into the nucleus cells are more difficult to transfect with GFP plasmid vectors. Proof of principle experiments show promising and adequate efficiencies by applying micro materials for plasmid vector transfection. For all methods a weakly focused fs laser beam is used to enable a high manipulation throughput for adherent and suspension cells. Furthermore, with these alternative optical manipulation methods it is possible to perforate the membrane of sensitive cell types such as primary and stem cells with a high viability.

Femtosecond laser microstructured Alumina toughened Zirconia: A new strategy to improve osteogenic differentiation of hMSCs

NASA Astrophysics Data System (ADS)

Carvalho, Angela; Cangueiro, Liliana; Oliveira, Vítor; Vilar, Rui; Fernandes, Maria H.; Monteiro, Fernando J.

2018-03-01

The use of topographic patterns has been a continuously growing area of research for tissue engineering and it is widely accepted that the surface topography of biomaterials can influence and modulate the initial biological response. Ultrafast lasers are extremely powerful tools to machine and pattern the surface of a wide range of biomaterials, however, only few work has been performed on ceramics with the intent of biomedical applications, and the biological characterization of these structured materials is scarce. In this work, relevance is given to the biological performance of such materials. A femtosecond laser ablation technique was used to modify Alumina toughened Zirconia (ATZ) surface topography, developing surfaces structured at the micro and nanoscale levels (μATZ), in a controlled and reproducible manner. Materials characterization was performed before and after laser treatment, and both materials were compared in terms of osteogenic response of human bone marrow derived mesenchymal stem cells cultured under basal conditions, expecting that the micro/nanofeatures will improve the biological response of cells. Cells metabolic activity and proliferation increased with the culture time and surface microtopography modulated cells alignment and guided proliferation. The modified surface, displayed significantly higher expression of osteogenic transcription factors and genes and, additionally, the formation of a mineralized extracellular matrix, when compared to the control surface, i.e. unmodified ATZ.

Platelets generated from human embryonic stem cells are functional in vitro and in the microcirculation of living mice

PubMed Central

Lu, Shi-Jiang; Li, Feng; Yin, Hong; Feng, Qiang; Kimbrel, Erin A; Hahm, Eunsil; Thon, Jonathan N; Wang, Wei; Italiano, Joseph E; Cho, Jaehyung; Lanza, Robert

2011-01-01

Platelets play an essential role in hemostasis and atherothrombosis. Owing to their short storage time, there is constant demand for this life-saving blood component. In this study, we report that it is feasible to generate functional megakaryocytes and platelets from human embryonic stem cells (hESCs) on a large scale. Differential-interference contrast and electron microscopy analyses showed that ultrastructural and morphological features of hESC-derived platelets were indistinguishable from those of normal blood platelets. In functional assays, hESC-derived platelets responded to thrombin stimulation, formed microaggregates, and facilitated clot formation/retraction in vitro. Live cell microscopy demonstrated that hESC-platelets formed lamellipodia and filopodia in response to thrombin activation, and tethered to each other as observed in normal blood. Using real-time intravital imaging with high-speed video microscopy, we have also shown that hESC-derived platelets contribute to developing thrombi at sites of laser-induced vascular injury in mice, providing the first evidence for in vivo functionality of hESC-derived platelets. These results represent an important step toward generating an unlimited supply of platelets for transfusion. Since platelets contain no genetic material, they are ideal candidates for early clinical translation involving human pluripotent stem cells. PMID:21221130

Determination of tenogenic differentiation in human mesenchymal stem cells by terahertz waves for measurement of the optical property of cellular suspensions

NASA Astrophysics Data System (ADS)

Morita, Yasuyuki; Azuchi, Kosuke; Ju, Yang; Suzuki, Satoshi; Xu, Baiyao; Yamamoto, Shuhei

2014-06-01

Technology for identifying stem cell-to-tenocyte differentiation that is non-contact and non-destructive in vitro is essential in tissue engineering. It has been found that expression of various RNA and proteins produced by differentiated cells is elevated when human bone marrow mesenchymal stem cells (hBMSCs) differentiate into tenocytes. Also, such biomolecules have absorption bands in the terahertz range. Thus, we attempted to evaluate whether terahertz waves could be used to distinguish hBMSC-to-tenocyte differentiation. Terahertz time-domain spectroscopy (THz-TDS) using femtosecond laser pulses was used for terahertz measurements. HBMSCs differentiated into tenocytes with mechanical stimulation: 10% cyclical uniaxial stretching at 1 Hz for 24 or 48 h. Cellular suspensions before and after differentiation were measured with terahertz waves. Complex refractive index, consisting of a refractive index (real) and an extinction coefficient (imaginary) obtained from the transmitted terahertz signals, was evaluated before and after differentiation at 1.0 THz. As a result, the THz-TDS system enabled discrimination of hBMSC-to-tenocyte differentiation due to the marked contrast in optical parameter before and after differentiation. This is the first report of the potential of a THz-TDS system for the detection of tenogenic differentiation using a non-contact and non-destructive in vitro technique.

Hybrid clone cells derived from human breast epithelial cells and human breast cancer cells exhibit properties of cancer stem/initiating cells.

PubMed

Gauck, Daria; Keil, Silvia; Niggemann, Bernd; Zänker, Kurt S; Dittmar, Thomas

2017-08-02

The biological phenomenon of cell fusion has been associated with cancer progression since it was determined that normal cell × tumor cell fusion-derived hybrid cells could exhibit novel properties, such as enhanced metastatogenic capacity or increased drug resistance, and even as a mechanism that could give rise to cancer stem/initiating cells (CS/ICs). CS/ICs have been proposed as cancer cells that exhibit stem cell properties, including the ability to (re)initiate tumor growth. Five M13HS hybrid clone cells, which originated from spontaneous cell fusion events between M13SV1-EGFP-Neo human breast epithelial cells and HS578T-Hyg human breast cancer cells, and their parental cells were analyzed for expression of stemness and EMT-related marker proteins by Western blot analysis and confocal laser scanning microscopy. The frequency of ALDH1-positive cells was determined by flow cytometry using AldeRed fluorescent dye. Concurrently, the cells' colony forming capabilities as well as the cells' abilities to form mammospheres were investigated. The migratory activity of the cells was analyzed using a 3D collagen matrix migration assay. M13HS hybrid clone cells co-expressed SOX9, SLUG, CK8 and CK14, which were differently expressed in parental cells. A variation in the ALDH1-positive putative stem cell population was observed among the five hybrids ranging from 1.44% (M13HS-7) to 13.68% (M13HS-2). In comparison to the parental cells, all five hybrid clone cells possessed increased but also unique colony formation and mammosphere formation capabilities. M13HS-4 hybrid clone cells exhibited the highest colony formation capacity and second highest mammosphere formation capacity of all hybrids, whereby the mean diameter of the mammospheres was comparable to the parental cells. In contrast, the largest mammospheres originated from the M13HS-2 hybrid clone cells, whereas these cells' mammosphere formation capacity was comparable to the parental breast cancer cells. All M13HS hybrid clones exhibited a mesenchymal phenotype and, with the exception of one hybrid clone, responded to EGF with an increased migratory activity. Fusion of human breast epithelial cells and human breast cancer cells can give rise to hybrid clone cells that possess certain CS/IC properties, suggesting that cell fusion might be a mechanism underlying how tumor cells exhibiting a CS/IC phenotype could originate.

Hydroxyapatite thin films grown by pulsed laser deposition and matrix assisted pulsed laser evaporation: Comparative study

NASA Astrophysics Data System (ADS)

Popescu-Pelin, G.; Sima, F.; Sima, L. E.; Mihailescu, C. N.; Luculescu, C.; Iordache, I.; Socol, M.; Socol, G.; Mihailescu, I. N.

2017-10-01

Pulsed Laser Deposition (PLD) and Matrix Assisted Pulsed Laser Evaporation (MAPLE) techniques were applied for growing hydroxyapatite (HA) thin films on titanium substrates. All experiments were conducted in a reaction chamber using a KrF* excimer laser source (λ = 248 nm, τFWHM ≈ 25 ns). Half of the samples were post-deposition thermally treated at 500 °C in a flux of water vapours in order to restore crystallinity and improve adherence. Coating surface morphologies and topographies specific to the deposition method were evidenced by scanning electron, atomic force microscopy investigations and profilometry. They were shown to depend on deposition technique and also on the post-deposition treatment. Crystalline structure of the coatings evaluated by X-ray diffraction was improved after thermal treatment. Biocompatibility of coatings, cellular adhesion, proliferation and differentiation tests were conducted using human mesenchymal stem cells (MSCs). Results showed that annealed MAPLE deposited HA coatings were supporting MSCs proliferation, while annealed PLD obtained films were stimulating osteogenic differentiation.

Supportive Use of Adipose-Derived Stem Cells in Cell-Assisted Lipotransfer for Localized Scleroderma.

PubMed

Chen, Bo; Wang, Xiaojun; Long, Xiao; Zhang, Mingzi; Huang, Jiuzuo; Yu, Nanze; Xu, Jing

2018-06-01

The authors aimed to analyze factors related to lipotransfer for localized scleroderma, and to explore the feasibility of cell-assisted lipotransfer for localized scleroderma treatment. Abdominal fat samples were taken from six scleroderma patients without corticosteroid therapy, five scleroderma patients with corticosteroid therapy, and 10 normal liposuction patients. Their quantity, morphology, and proliferation ability were measured. Blood flow was measured by laser speckle contrast imaging in localized scleroderma lesions and normal contralateral regions for eight localized scleroderma patients. Bleomycin-induced skin fibrosis nude mice were also used to investigate differences between lipotransfer and cell-assisted lipotransfer. Fat weight was measured, and expression of transforming growth factor (TGF)-β1 and type III collagen in the injected skin was determined by immunohistochemistry. The number of stem cells from scleroderma patients with corticosteroid treatment was significantly reduced. Mean blood perfusion in localized scleroderma lesions was not significantly different than in the contralateral normal regions. In normal nude mice, there were no significant changes in TGF-β1 and type III collagen between the control, lipotransfer, and cell-assisted lipotransfer groups, whereas in bleomycin-induced skin fibrosis nude mice, lipotransfer and cell-assisted lipotransfer reduced TGF-β1 and type III collagen expression. For scleroderma patients, fewer adipose-derived stem cells, because of a history of corticosteroid therapy and a local inflammatory microenvironment, are more important factors, whereas blood supply showed no significant change. Therefore, cell-assisted lipotransfer not only improves the survival rate of transplanted fat but also improves skin texture in bleomycin-induced skin fibrosis nude mice.

Two-layer membranes of calcium phosphate/collagen/PLGA nanofibres: in vitro biomineralisation and osteogenic differentiation of human mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Hild, Nora; Schneider, Oliver D.; Mohn, Dirk; Luechinger, Norman A.; Koehler, Fabian M.; Hofmann, Sandra; Vetsch, Jolanda R.; Thimm, Benjamin W.; Müller, Ralph; Stark, Wendelin J.

2011-02-01

The present study evaluates the in vitro biomedical performance of an electrospun, flexible, anisotropic bilayer with one layer containing a collagen to mineral ratio similar to that in bone. The double membrane consists of a poly(lactide-co-glycolide) (PLGA) layer and an amorphous calcium phosphate (a-CaP)/collagen (Col)/PLGA layer. In vitro biomineralisation and a cell culture study with human mesenchymal stem cells (hMSC) were conducted to characterise such membranes for possible application as biomaterials. Nanofibres with different a-CaP/Col/PLGA compositions were synthesised by electrospinning to mimic the actual composition of bone tissue. Immersion in simulated body fluid and in cell culture medium resulted in the deposition of a hydroxyapatite layer. Incubation of hMSC for 4 weeks allowed for assessment of the proliferation and osteogenic differentiation of the cells on both sides of the double membrane. Confocal laser scanning microscopy was used to observe the proper adhesion of the cells. Calcium and collagen content was proven by Alizarin red S and Sirius red assays. Acute cytotoxic effects of the nanoparticles or the chemicals used in the scaffold preparation could be excluded based on viability assays (alamarBlue and alkaline phosphatase activity). The findings suggest possible application of such double membranes is in treatment of bone defects with complex geometries as wound dressing material.The present study evaluates the in vitro biomedical performance of an electrospun, flexible, anisotropic bilayer with one layer containing a collagen to mineral ratio similar to that in bone. The double membrane consists of a poly(lactide-co-glycolide) (PLGA) layer and an amorphous calcium phosphate (a-CaP)/collagen (Col)/PLGA layer. In vitro biomineralisation and a cell culture study with human mesenchymal stem cells (hMSC) were conducted to characterise such membranes for possible application as biomaterials. Nanofibres with different a-CaP/Col/PLGA compositions were synthesised by electrospinning to mimic the actual composition of bone tissue. Immersion in simulated body fluid and in cell culture medium resulted in the deposition of a hydroxyapatite layer. Incubation of hMSC for 4 weeks allowed for assessment of the proliferation and osteogenic differentiation of the cells on both sides of the double membrane. Confocal laser scanning microscopy was used to observe the proper adhesion of the cells. Calcium and collagen content was proven by Alizarin red S and Sirius red assays. Acute cytotoxic effects of the nanoparticles or the chemicals used in the scaffold preparation could be excluded based on viability assays (alamarBlue and alkaline phosphatase activity). The findings suggest possible application of such double membranes is in treatment of bone defects with complex geometries as wound dressing material. Electronic supplementary information (ESI) available: Additional FT-IR spectra, electron micrographs, XRD patterns, ATR-IR spectra, light microscopy images, confocal laser scanning micrographs, electrospinning parameters and fibre diameters. See DOI: 10.1039/c0nr00615g

Low-level laser (light) therapy (LLLT) on muscle tissue: performance, fatigue and repair benefited by the power of light

PubMed Central

Ferraresi, Cleber; Hamblin, Michael R.; Parizotto, Nivaldo A.

2013-01-01

The use of low level laser (light) therapy (LLLT) has recently expanded to cover areas of medicine that were not previously thought of as the usual applications such as wound healing and inflammatory orthopedic conditions. One of these novel application areas is LLLT for muscle fatigue and muscle injury. Since it is becoming agreed that mitochondria are the principal photoacceptors present inside cells, and it is known that muscle cells are exceptionally rich in mitochondria, this suggests that LLLT should be highly beneficial in muscle injuries. The ability of LLLT to stimulate stem cells and progenitor cells means that muscle satellite cells may respond well to LLLT and help muscle repair. Furthermore the ability of LLLT to reduce inflammation and lessen oxidative stress is also beneficial in cases of muscle fatigue and injury. This review covers the literature relating to LLLT and muscles in both preclinical animal experiments and human clinical studies. Athletes, people with injured muscles, and patients with Duchenne muscular dystrophy may all benefit. PMID:23626925

Care for the Critically Injured Burn Patient Modulation of Burn Scars Through Laser Deliver of Stem Cells

DTIC Science & Technology

2013-10-01

average 1 hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed...dermal remodeling 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a...evaluations made prior to each biopsy. The initial grading system took into account vascularity , pliability, color, contour, texture, and

ABCG2-mediated suppression of chlorin e6 accumulation and photodynamic therapy efficiency in glioblastoma cell lines can be reversed by KO143.

PubMed

Abdel Gaber, Sara A; Müller, Patricia; Zimmermann, Wolfgang; Hüttenberger, Dirk; Wittig, Rainer; Abdel Kader, Mahmoud H; Stepp, Herbert

2018-01-01

Photodynamic therapy (PDT) of malignant brain tumors is a promising adjunct to standard treatment, especially if tumor stem cells thought to be responsible for tumor progression and therapy resistance were also susceptible to this kind of treatment. However, some photosensitizers have been reported to be substrates of ABCG2, one of the membrane transporters mediating resistance to chemotherapy. Here we investigate, whether inhibition of ABCG2 can restore sensitivity to photosensitizer chlorin e6-mediated PDT. Accumulation of chlorin e6 in wild type U87 and doxycycline-inducible U251 glioblastoma cells with or without induction of ABCG2 expression or ABCG2 inhibition by KO143 was analyzed using flow cytometry. In U251 cells, ABCG2 was inducible by doxycycline after stable transfection with a tet-on expression plasmid. Tumor sphere cultivation under low attachment conditions was used to enrich for cells with stem cell-like properties. PDT was done on monolayer cell cultures by irradiation with laser light at 665nm. Elevated levels of ABCG2 in U87 cells grown as tumor spheres or in U251 cells after ABCG2 induction led to a 6-fold lower accumulation of chlorin e6 and the light dose needed to reduce cell viability by 50% (LD50) was 2.5 to 4-fold higher. Both accumulation and PDT response can be restored by KO143, an efficient non-toxic inhibitor of ABCG2. Glioblastoma stem cells might escape phototoxic destruction by ABCG2-mediated reduction of photosensitizer accumulation. Inhibition of ABCG2 during photosensitizer accumulation and irradiation promises to restore full susceptibility of this crucial tumor cell population to photodynamic treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Low level light promotes the proliferation and differentiation of bone marrow derived mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Ahn, Jin-Chul; Rhee, Yun-Hee; Choi, Sun-Hyang; Kim, Dae Yu; Chung, Phil-Sang

2015-03-01

Low-level light irradiation (LLLI) reported to stimulate the proliferation or differentiation of a variety of cell types. However, very little is known about the effect of light therapy on stem cells. The aim of the present study was to evaluate the effect of LLLI on the molecular physiological change of human bone marrow derived stem cells (hBMSC) by wavelength (470, 630, 660, 740 and 850, 50mW). The laser diode was performed with different time interval (0, 7.5, 15, 30J/cm2, 50mW) on hBMSC. To determine the molecular physiological changes of cellular level of hBMSC, the clonogenic assay, ATP assay, reactive oxygen species (ROS) detection, mitochondria membrane potential (MMPΦ) staining and calcium efflux assay were assessed after irradiation. There was a difference between with and without irradiation on hBMSCs. An energy density up to 30 J/cm² improved the cell proliferation in comparison to the control group. Among these irradiated group, 630 and 660nm were significantly increased the cell proliferation. The cellular level of ATP and calcium influx was increased with energy dose-dependent in all LLLI groups. Meanwhile, ROS and MMPΦ were also increased after irradiation except 470nm. It can be concluded that LLLI using infrared light and an energy density up to 30 J/cm² has a positive stimulatory effect on the proliferation or differentiation of hBMSCs. Our results suggest that LLLI may influence to the mitochondrial membrane potential activity through ATP synthesis and increased cell metabolism which leads to cell proliferation and differentiation.

Lasers and intense pulsed light (IPL) association with cancerous lesions.

PubMed

Ash, Caerwyn; Town, Godfrey; Whittall, Rebecca; Tooze, Louise; Phillips, Jaymie

2017-11-01

The development and use of light and lasers for medical and cosmetic procedures has increased exponentially over the past decade. This review article focuses on the incidence of reported cases of skin cancer post laser or IPL treatment. The existing evidence base of over 25 years of laser and IPL use to date has not raised any concerns regarding its long-term safety with only a few anecdotal cases of melanoma post treatment over two decades of use; therefore, there is no evidence to suggest that there is a credible cancer risk. Although laser and IPL technology has not been known to cause skin cancer, this does not mean that laser and IPL therapies are without long-term risks. Light therapies and lasers to treat existing lesions and CO 2 laser resurfacing can be a preventative measure against BCC and SCC tumour formation by removing photo-damaged keratinocytes and encouraged re-epithelisation from stem cells located deeper in the epidermis. A review of the relevant literature has been performed to address the issue of long-term IPL safety, focussing on DNA damage, oxidative stress induction and the impact of adverse events.

Induction of Osteogenic Differentiation of Adipose Derived Stem Cells by Microstructured Nitinol Actuator-Mediated Mechanical Stress

PubMed Central

Strauß, Sarah; Dudziak, Sonja; Hagemann, Ronny; Barcikowski, Stephan; Fliess, Malte; Israelowitz, Meir; Kracht, Dietmar; Kuhbier, Jörn W.; Radtke, Christine; Reimers, Kerstin; Vogt, Peter M.

2012-01-01

The development of large tissue engineered bone remains a challenge in vitro, therefore the use of hybrid-implants might offer a bridge between tissue engineering and dense metal or ceramic implants. Especially the combination of the pseudoelastic implant material Nitinol (NiTi) with adipose derived stem cells (ASCs) opens new opportunities, as ASCs are able to differentiate osteogenically and therefore enhance osseointegration of implants. Due to limited knowledge about the effects of NiTi-structures manufactured by selective laser melting (SLM) on ASCs the study started with an evaluation of cytocompatibility followed by the investigation of the use of SLM-generated 3-dimensional NiTi-structures preseeded with ASCs as osteoimplant model. In this study we could demonstrate for the first time that osteogenic differentiation of ASCs can be induced by implant-mediated mechanical stimulation without support of osteogenic cell culture media. By use of an innovative implant design and synthesis via SLM-technique we achieved high rates of vital cells, proper osteogenic differentiation and mechanically loadable NiTi-scaffolds could be achieved. PMID:23236461

Clonal analysis of human embryonic stem cell differentiation into teratomas.

PubMed

Blum, Barak; Benvenisty, Nissim

2007-08-01

Differentiation of human embryonic stem cells (HESCs) can be studied in vivo through the induction of teratomas in immune-deficient mice. Cells within the teratomas differentiate into all three embryonic germ layers. However, the exact nature of the proliferation and differentiation of HESCs within the teratoma is not fully characterized, and it is not clear whether the differentiation is cell autonomous or affected by neighboring cells. Here, we establish a genetic approach to study the clonality of differentiation in teratomas using a mixture of HESC lines. We first demonstrate, by means of 5-bromo-2'-deoxyuridine incorporation, that cell proliferation occurs throughout the teratoma, and that there are no clusters of undifferentiated-proliferating cells. Using a combination of laser capture microdissection and DNA fingerprinting analysis, we show that different cell lines contribute mutually to the same distinctive tissue structures. Further support for the nonclonal differentiation within the teratoma was achieved by fluorescence in situ hybridization analysis of sex chromosomes. We therefore suggest that in vivo differentiation of HESCs is polyclonal and, thus, may not be cell autonomous, stressing the need for a three-dimensional growth in order to achieve complex differentiation of HESCs. Disclosure of potential conflicts of interest is found at the end of this article.

Phylogeny in Defining Model Plants for Lignocellulosic Ethanol Production: A Comparative Study of Brachypodium distachyon, Wheat, Maize, and Miscanthus x giganteus Leaf and Stem Biomass

PubMed Central

Meineke, Till; Manisseri, Chithra; Voigt, Christian A.

2014-01-01

The production of ethanol from pretreated plant biomass during fermentation is a strategy to mitigate climate change by substituting fossil fuels. However, biomass conversion is mainly limited by the recalcitrant nature of the plant cell wall. To overcome recalcitrance, the optimization of the plant cell wall for subsequent processing is a promising approach. Based on their phylogenetic proximity to existing and emerging energy crops, model plants have been proposed to study bioenergy-related cell wall biochemistry. One example is Brachypodium distachyon, which has been considered as a general model plant for cell wall analysis in grasses. To test whether relative phylogenetic proximity would be sufficient to qualify as a model plant not only for cell wall composition but also for the complete process leading to bioethanol production, we compared the processing of leaf and stem biomass from the C3 grasses B. distachyon and Triticum aestivum (wheat) with the C4 grasses Zea mays (maize) and Miscanthus x giganteus, a perennial energy crop. Lambda scanning with a confocal laser-scanning microscope allowed a rapid qualitative analysis of biomass saccharification. A maximum of 108–117 mg ethanol·g−1 dry biomass was yielded from thermo-chemically and enzymatically pretreated stem biomass of the tested plant species. Principal component analysis revealed that a relatively strong correlation between similarities in lignocellulosic ethanol production and phylogenetic relation was only given for stem and leaf biomass of the two tested C4 grasses. Our results suggest that suitability of B. distachyon as a model plant for biomass conversion of energy crops has to be specifically tested based on applied processing parameters and biomass tissue type. PMID:25133818

Derivation and characterization of novel nonhuman primate embryonic stem cell lines from in vitro-fertilized baboon preimplantation embryos.

PubMed

Chang, Tien-Cheng; Liu, Ya-Guang; Eddy, Carlton A; Jacoby, Ethan S; Binkley, Peter A; Brzyski, Robert G; Schenken, Robert S

2011-06-01

The development of nonhuman primate (NHP) embryonic stem cell (ESC) models holds great promise for cell-mediated treatment of debilitating diseases and to address numerous unanswered questions regarding the therapeutic efficacy of ESCs while supplanting ethical considerations involved with human studies. Here we report successful establishment and characterization of 3 novel baboon (Papio cynocephalus) ESC lines from the inner cell mass of intracytoplasmic sperm injection-derived blastocysts. Embryos were cultured in an improved baboon embryo in vitro culture protocol. The inner cell mass of blastocyst was laser-dissected and plated on mouse embryonic fibroblast feeder cell monolayer in the NHP ESC culture medium. Three cell lines with characteristic ESC morphology have been cultured through an extended period (>14 months), with 2 male cell lines (UT-1 and -2) and 1 female cell line (UT-3) displaying normal baboon karyotypes. Reverse transcription-polymerase chain reaction analysis confirmed that all 3 lines express primate ESC pluripotency markers, including OCT-4, NANOG, SOX-2, TERT, TDGF, LEFTYA, and REX-1. All 3 lines demonstrated positive immunocytochemical staining for OCT-4, stage-specific embryonic antigen-3, stage-specific embryonic antigen-4, TRA-1-60, and TRA-1-81. Baboon ESCs injected into NOD/SCID mice formed teratomas with all 3 germ layers. In addition, embryoid body-like spherical structures were derived and initial outgrowth was observed when embedded into extracellular matrix Matrigel. The ESC lines established in this NHP model have the potential to extend our knowledge in the fields of developmental biology, regenerative medicine, and future applications, including preclinical safety assessment of in vivo stem cell therapy.

Nanoparticles for magnetic biosensing systems

NASA Astrophysics Data System (ADS)

Kurlyandskaya, G. V.; Novoselova, Iu. P.; Schupletsova, V. V.; Andrade, R.; Dunec, N. A.; Litvinova, L. S.; Safronov, A. P.; Yurova, K. A.; Kulesh, N. A.; Dzyuman, A. N.; Khlusov, I. A.

2017-06-01

The further development of magnetic biosensors requires a better understanding of the interaction between living systems and magnetic nanoparticles (MNPs). We describe our experience of fabrication of stable ferrofluids (FF) using electrostatic or steric stabilization of iron oxide MNPs obtained by laser target evaporation. Controlled amounts of FF were used for in vitro experiments with human mesenchymal stem cells. Their morphofunctional responses in the Fe concentration range 2-1000 maximum tolerated dose revealed no cytotoxicity.

Labeling and in vivo visualization of transplanted adipose tissue-derived stem cells with safe cadmium-free aqueous ZnS coating of ZnS-AgInS2 nanoparticles

NASA Astrophysics Data System (ADS)

Ogihara, Yusuke; Yukawa, Hiroshi; Kameyama, Tatsuya; Nishi, Hiroyasu; Onoshima, Daisuke; Ishikawa, Tetsuya; Torimoto, Tsukasa; Baba, Yoshinobu

2017-01-01

The facile synthesis of ZnS-AgInS2 (ZAIS) as cadmium-free QDs and their application, mainly in solar cells, has been reported by our groups. In the present study, we investigated the safety and the usefulness for labeling and in vivo imaging of a newly synthesized aqueous ZnS-coated ZAIS (ZnS-ZAIS) carboxylated nanoparticles (ZZC) to stem cells. ZZC shows the strong fluorescence in aqueous solutions such as PBS and cell culture medium, and a complex of ZZC and octa-arginine (R8) peptides (R8-ZZC) can achieve the highly efficient labeling of adipose tissue-derived stem cells (ASCs). The cytotoxicity of R8-ZZC to ASCs was found to be extremely low in comparison to that of CdSe-based QDs, and R8-ZZC was confirmed to have no influence on the proliferation rate or the differentiation ability of ASCs. Moreover, R8-ZZC was not found to induce the production of major inflammatory cytokines (TNF-α, IFN-γ, IL-12p70, IL-6 and MCP-1) in ASCs. Transplanted R8-ZZC-labeled ASCs could be quantitatively detected in the lungs and liver mainly using an in vivo imaging system. In addition, high-speed multiphoton confocal laser microscopy revealed the presence of aggregates of transplanted ASCs at many sites in the lungs, whereas individual ASCs were found to have accumulated in the liver.

Applying Laser Cutting Techniques through Horology for Teaching Effective STEM in Design and Technology

ERIC Educational Resources Information Center

Jones, Lewis C. R.; Tyrer, John R.; Zanker, Nigel P.

2013-01-01

This paper explores the pedagogy underpinning the use of laser manufacturing methods for the teaching of science, technology, engineering and mathematics (STEM) at key stage 3 design and technology. Clock making (horology) has been a popular project in design and technology (D&T) found in many schools, typically it focuses on aesthetical…

Application of fluoridated hydroxyapatite thin film coatings using KrF pulsed laser deposition.

PubMed

Hashimoto, Yoshiya; Ueda, Mamoru; Kohiga, Yu; Imura, Kazuki; Hontsu, Shigeki

2018-06-08

Fluoridated hydroxyapatite (FHA) was investigated for application as an implant coating for titanium bone substitute materials in dental implants. A KrF pulsed excimer deposition technique was used for film preparation on a titanium plate. The compacts were ablated by laser irradiation at an energy density of 1 J/cm 2 on an area 1×1 mm 2 with the substrate at room temparature. Energydispersive spectrometric analysis of the FHA film revealed peaks of fluorine in addition to calcium and phosphorus. X-ray diffraction revealed the presence of crystalline FHA on the FHA film after a 10 h post annealing treatment at 450°C. The FHA film coating exhibited significant dissolution resistance to sodium phosphate buffer for up to 21 days, and favorable cell attachment of human mesenchymal stem cells compared with HA film. The results of this study suggest that FHA coatings are suitable for real-world implantation applications.

Hydrogels with Spatially and Temporally Controlled Properties to Control Cellular Interactions

NASA Astrophysics Data System (ADS)

Burdick, Jason

2011-03-01

Stem cells (e.g., mesenchymal stem cells, MSCs) respond to many cues from their microenvironment, which may include chemical signals, mechanics, and topography. Importantly, these cues may be incorporated into scaffolding to control stem cell differentiation and optimize their ability to produce tissues in regenerative medicine. Despite the significant amount of work in this area, the materials have been primarily static and uniform. To this end, we have developed a sequential crosslinking process that relies on our ability to crosslinked functional biopolymers (e.g., methacrylated hyaluronic acid, HA) in two steps, namely a Michael-type addition reaction to partially consume reactive groups and then a light-initiated free-radical polymerization to further crosslink the material. With light exposure during the second step comes control over the material in space (via masks and lasers) and time (via intermittent light exposure). We are applying this technique for numerous applications. For example, when the HA hydrogels are crosslinked with MMP degradable peptides with thiol termini during the first step, a material that can be degraded by cells is obtained. However, cell-mediated degradation is obstructed with the introduction of kinetic chains during the second step, leading to spatially controlled cell degradability. Due to the influence of cellular spreading on MSC differentiation, we have controlled cell fates by controlling their spread ability, for instance towards osteoblasts in spread areas and adipocytes when cell remained rounded. We are also using the process of stiffening with time to investigate mechanically induced differentiation, particularly in materials with evolving mechanics. Overall, these advanced HA hydrogels provide us the opportunity to investigate diverse and controlled material properties on MSC interactions.

3D reconstruction of a tree stem using video images and pulse distances

Treesearch

N. E. Clark

2002-01-01

This paper demonstrates how a 3D tree stem model can be reconstructed using video imagery combined with laser pulse distance measurements. Perspective projection is used to place the data collected with the portable video laser-rangefinding device into a real world coordinate system. This hybrid methodology uses a relatively small number of range measurements (compared...

Correlating measured transient temperature rises with damage rate processes in cultured cells

NASA Astrophysics Data System (ADS)

Denton, Michael L.; Tijerina, Amanda J.; Gonzalez, Cherry C.; Gamboa, B. Giovana; Noojin, Gary D.; Ahmed, Elharith M.; Rickman, John M.; Dyer, Phillip H.; Rockwell, Benjamin A.

2017-02-01

Thermal damage rate processes in biological tissues are usually characterized by a kinetics approach. This stems from experimental data that show how the transformation of a specified biological property of cells or biomolecule (plating efficiency for viability, change in birefringence, tensile strength, etc.) is dependent upon both time and temperature. Here, two disparate approaches were used to study thermal damage rate processes in cultured retinal pigment epithelial cells. Laser exposure (photothermal) parameters included 2-μm laser exposure of non-pigmented cells and 532-nm exposures of cells possessing a variety of melanosome particle densities. Photothermal experiments used a mid-IR camera to record temperature histories with spatial resolution of about 8 μm, while fluorescence microscopy of the cell monolayers identified threshold damage at the boundary between live and dead cells. Photothermal exposure durations ranged from 0.05-20 s, and the effects of varying ambient temperature were investigated. Temperature during heat transfer using a water-jacketed cuvette was recorded with a fast microthermister, while damage and viability of the suspended cells were determined as percentages. Exposure durations for the heat transfer experiments ranged from 50- 60 s. Empirically-determined kinetic parameters for the two heating methods were compared with each other, and with values found in the literature.

Placenta Derived Mesenchymal Stem Cells Hosted on RKKP Glass-Ceramic: A Tissue Engineering Strategy for Bone Regenerative Medicine Applications

PubMed Central

Fosca, Marco; De Bonis, Angela; Curcio, Mariangela; Lolli, Maria Grazia; De Stefanis, Adriana; Marchese, Rodolfo; Rau, Julietta V.

2016-01-01

In tissue engineering protocols, the survival of transplanted stem cells is a limiting factor that could be overcome using a cell delivery matrix able to support cell proliferation and differentiation. With this aim, we studied the cell-friendly and biocompatible behavior of RKKP glass-ceramic coated Titanium (Ti) surface seeded with human amniotic mesenchymal stromal cells (hAMSCs) from placenta. The sol-gel synthesis procedure was used to prepare the RKKP glass-ceramic material, which was then deposited onto the Ti surface by Pulsed Laser Deposition method. The cell metabolic activity and proliferation rate, the cytoskeletal actin organization, and the cell cycle phase distribution in hAMSCs seeded on the RKKP coated Ti surface revealed no significant differences when compared to the cells grown on the treated plastic Petri dish. The health of of hAMSCs was also analysed studying the mRNA expressions of MSC key genes and the osteogenic commitment capability using qRT-PCR analysis which resulted in being unchanged in both substrates. In this study, the combination of the hAMSCs' properties together with the bioactive characteristics of RKKP glass-ceramics was investigated and the results obtained indicate its possible use as a new and interesting cell delivery system for bone tissue engineering and regenerative medicine applications. PMID:28078286

Types of Stem Cells

MedlinePlus

... Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

miRNA-regulated cancer stem cells: understanding the property and the role of miRNA in carcinogenesis.

PubMed

Chakraborty, Chiranjib; Chin, Kok-Yong; Das, Srijit

2016-10-01

Over the last few years, microRNAs (miRNA)-controlled cancer stem cells have drawn enormous attention. Cancer stem cells are a small population of tumor cells that possess the stem cell property of self-renewal. Recent data shows that miRNA regulates this small population of stem cells. In the present review, we explained different characteristics of cancer stem cells as well as miRNA regulation of self-renewal and differentiation in cancer stem cells. We also described the migration and tumor formation. Finally, we described the different miRNAs that regulate various types of cancer stem cells, such as prostate cancer stem cells, head and neck cancer stem cells, breast cancer stem cells, colorectal cancer stem cells, lung cancer stem cells, gastric cancer stem cells, pancreatic cancer stem cells, etc. Extensive research is needed in order to employ miRNA-based therapeutics to control cancer stem cell population in various cancers in the future.

What is a stem cell?

PubMed

Slack, Jonathan M W

2018-05-15

The historical roots of the stem cell concept are traced with respect to its usage in embryology and in hematology. The modern consensus definition of stem cells, comprising both pluripotent stem cells in culture and tissue-specific stem cells in vivo, is explained and explored. Methods for identifying stem cells are discussed with respect to cell surface markers, telomerase, label retention and transplantability, and properties of the stem cell niche are explored. The CreER method for identifying stem cells in vivo is explained, as is evidence in favor of a stochastic rather than an obligate asymmetric form of cell division. In conclusion, it is found that stem cells do not possess any unique and specific molecular markers; and stem cell behavior depends on the environment of the cell as well as the stem cell's intrinsic qualities. Furthermore, the stochastic mode of division implies that stem cell behavior is a property of a cell population not of an individual cell. In this sense, stem cells do not exist in isolation but only as a part of multicellular system. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells. © 2018 Wiley Periodicals, Inc.

Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function

PubMed Central

Pankajakshan, Divya; Albuquerque, Maria T.P.; Evans, Joshua D.; Kamocka, Malgorzata M.; Gregory, Richard L.; Bottino, Marco C.

2016-01-01

Introduction Root canal disinfection and the establishment of an intracanal microenvironment conducive to the proliferation/differentiation of stem cells play a significant role in regenerative endodontics. This study was designed to (1) investigate the antimicrobial efficacy of triple antibiotic–containing nanofibers against a dual-species biofilm and (2) evaluate the ability of dental pulp stem cells (DPSCs) to adhere to and proliferate on dentin upon nanofiber exposure. Methods Seven-day-old dual-species biofilm established on dentin specimens was exposed for 3 days to the following: saline (control), antibiotic-free nanofibers (control), and triple antibiotic–containing nanofibers or a saturated triple antibiotic paste (TAP) solution (50 mg/mL in phosphate buffer solution). Bacterial viability was assessed using the LIVE/DEAD assay (Molecular Probes, Inc, Eugene, OR) and confocal laser scanning microscopy. For cyto-compatibility studies, dentin specimens after nanofiber or TAP (1 g/mL in phosphate buffer solution) exposure were evaluated for cell adhesion and spreading by actin-phalloidin staining. DPSC proliferation was assessed on days 1, 3, and 7. Statistics were performed, and significance was set at the 5% level. Results Confocal laser scanning microscopy showed significant bacterial death upon antibiotic-containing nanofiber exposure, differing significantly (P < .05) from antibiotic-free fibers and the control (saline). DPSCs showed enhanced adhesion/spreading on dentin specimens treated with antibiotic-containing nanofibers when compared with its TAP counterparts. The DPSC proliferation rate was similar on days 1 and 3 in antibiotic-free nanofibers, triple antibiotic–containing nanofibers, and TAP-treated dentin. Proliferation was higher (9-fold) on dentin treated with antibiotic-containing nanofibers on day 7 compared with TAP. Conclusions Triple antibiotic–containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin. PMID:27663615

Derivation, characterization and differentiation of a new human embryonic stem cell line from a Chinese hatched blastocyst assisted by a non-contact laser system.

PubMed

Wu, Rongrong; Xu, Chenming; Jin, Fan; Tan, Zhou; Gu, Bin; Chen, Liangbiao; Yao, Xing; Zhang, Ming

2010-08-01

Currently worldwide attention has focused on the derivation of human embryonic stem cells (hESCs) for future therapeutic medicine. However, the majority of existing hESCs are directly or indirectly exposed to non-human materials during their derivation and/or propagation, which greatly restrict their therapeutic potential. Besides the efforts to improve culture systems, the derivation procedure, especially blastocyst manipulation, needs to be optimized. We adopted a non-contact laser-assisted hatching system in combination with sequential culture process to obtain hatched blastocysts as materials for hESC derivation, and derived a hESC line ZJUhES-1 of a Chinese population without exposure to any non-human materials during blastocyst manipulation. ZJUhES-1 satisfies the criteria of pluripotent hESCs: typically morphological characteristics; the expression of alkaline phosphatase, human telomerase reverse transcriptase and multiple hESC-specific markers including SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, OCT-4, Nanog, Rex-1, Sox-2, UTF-1, Connexins 43 and 45, TERF-1 and TERF-2, Glut-1, BCRP-1/ABCG-2, GDF3, LIN28, FGF4, Thy-1, Cripto1/TDGF1, AC133 as well as SMAD1/2/3/5; extended proliferative capacity; maintenance of a stable male karyotype after long-term cultivation; and robust multiple-lineage developmental potentials both in vivo and in vitro. Moreover, ZJUhES-1 has distinct identity revealed from DNA fingerprinting. Our xeno-free blastocyst manipulation procedure may promote the progression toward clinical-grade hESC derivation. © 2010 The Authors. Human Cell © 2010 Japan Human Cell Society.

Multiphoton photochemical crosslinking-based fabrication of protein micropatterns with controllable mechanical properties for single cell traction force measurements

NASA Astrophysics Data System (ADS)

Tong, Ming Hui; Huang, Nan; Zhang, Wei; Zhou, Zhuo Long; Ngan, Alfonso Hing Wan; Du, Yanan; Chan, Barbara Pui

2016-01-01

Engineering 3D microstructures with predetermined properties is critical for stem cell niche studies. We have developed a multiphoton femtosecond laser-based 3D printing platform, which generates complex protein microstructures in minutes. Here, we used the platform to test a series of fabrication and reagent parameters in precisely controlling the mechanical properties of protein micropillars. Atomic force microscopy was utilized to measure the reduced elastic modulus of the micropillars, and transmission electron microscopy was used to visualize the porosity of the structures. The reduced elastic modulus of the micropillars associated positively and linearly with the scanning power. On the other hand, the porosity and pore size of the micropillars associated inversely and linearly with the scanning power and reagent concentrations. While keeping the elastic modulus constant, the stiffness of the micropillars was controlled by varying their height. Subsequently, the single cell traction forces of rabbit chondrocytes, human dermal fibroblasts, human mesenchymal stem cells, and bovine nucleus pulposus cells (bNPCs) were successfully measured by culturing the cells on micropillar arrays of different stiffness. Our results showed that the traction forces of all groups showed positive relationship with stiffness, and that the chondrocytes and bNPCs generated the highest and lowest traction forces, respectively.

In vivo cell tracking and quantification method in adult zebrafish

NASA Astrophysics Data System (ADS)

Zhang, Li; Alt, Clemens; Li, Pulin; White, Richard M.; Zon, Leonard I.; Wei, Xunbin; Lin, Charles P.

2012-03-01

Zebrafish have become a powerful vertebrate model organism for drug discovery, cancer and stem cell research. A recently developed transparent adult zebrafish using double pigmentation mutant, called casper, provide unparalleled imaging power in in vivo longitudinal analysis of biological processes at an anatomic resolution not readily achievable in murine or other systems. In this paper we introduce an optical method for simultaneous visualization and cell quantification, which combines the laser scanning confocal microscopy (LSCM) and the in vivo flow cytometry (IVFC). The system is designed specifically for non-invasive tracking of both stationary and circulating cells in adult zebrafish casper, under physiological conditions in the same fish over time. The confocal imaging part in this system serves the dual purposes of imaging fish tissue microstructure and a 3D navigation tool to locate a suitable vessel for circulating cell counting. The multi-color, multi-channel instrument allows the detection of multiple cell populations or different tissues or organs simultaneously. We demonstrate initial testing of this novel instrument by imaging vasculature and tracking circulating cells in CD41: GFP/Gata1: DsRed transgenic casper fish whose thrombocytes/erythrocytes express the green and red fluorescent proteins. Circulating fluorescent cell incidents were recorded and counted repeatedly over time and in different types of vessels. Great application opportunities in cancer and stem cell researches are discussed.

Evaluation of the Barr & Stroud FP15 and Criterion 400 laser dendrometers for measuring upper stem diameters and heights

Treesearch

Michael S. Williams; Kenneth L. Cormier; Ronald G. Briggs; Donald L. Martinez

1999-01-01

Calibrated Barr & Stroud FP15 and Criterion 400 laser dendrometers were tested for reliability in measuring upper stem diameters and heights under typical field conditions. Data were collected in the Black Hills National Forest, which covers parts of South Dakota and Wyoming in the United States. Mixed effects models were employed to account for differences between...

Transplantation of BDNF-Secreting Mesenchymal Stem Cells Provides Neuroprotection in Chronically Hypertensive Rat Eyes

PubMed Central

Harper, Matthew M.; Grozdanic, Sinisa D.; Blits, Bas; Kuehn, Markus H.; Zamzow, Daniel; Buss, Janice E.; Kardon, Randy H.; Sakaguchi, Donald S.

2011-01-01

Purpose. To evaluate the ability of mesenchymal stem cells (MSCs) engineered to produce and secrete brain-derived neurotrophic factor (BDNF) to protect retinal function and structure after intravitreal transplantation in a rat model of chronic ocular hypertension (COH). Methods. COH was induced by laser cauterization of trabecular meshwork and episcleral veins in rat eyes. COH eyes received an intravitreal transplant of MSCs engineered to express BDNF and green fluorescent protein (BDNF-MSCs) or just GFP (GFP-MSCs). Computerized pupillometry and electroretinography (ERG) were performed to assess optic nerve and retinal function. Quantification of optic nerve damage was performed by counting retinal ganglion cells (RGCs) and evaluating optic nerve cross-sections. Results. After transplantation into COH eyes, BDNF-MSCs preserved significantly more retina and optic nerve function than GFP-MSC–treated eyes when pupil light reflex (PLR) and ERG function were evaluated. PLR analysis showed significantly better function (P = 0.03) in BDNF-MSC–treated eyes (operated/control ratio = 63.00% ± 11.39%) than GFP-MSC–treated eyes (operated/control ratio = 31.81% ± 9.63%) at 42 days after surgery. The BDNF-MSC–transplanted eyes also displayed a greater level of RGC preservation than eyes that received the GFP-MSCs only (RGC cell counts: BDNF-MSC–treated COH eyes, 112.2 ± 19.39 cells/section; GFP-MSC–treated COH eyes, 52.21 ± 11.54 cells/section; P = 0.01). Conclusions. The authors have demonstrated that lentiviral-transduced BDNF-producing MSCs can survive in eyes with chronic hypertension and can provide retina and optic nerve functional and structural protection. Transplantation of BDNF-producing stem cells may be a viable treatment strategy for glaucoma. PMID:21498611

Clinically relevant morphological structures in breast cancer represent transcriptionally distinct tumor cell populations with varied degrees of epithelial-mesenchymal transition and CD44+CD24- stemness

PubMed Central

Denisov, Evgeny V.; Skryabin, Nikolay A.; Gerashchenko, Tatiana S.; Tashireva, Lubov A.; Wilhelm, Jochen; Buldakov, Mikhail A.; Sleptcov, Aleksei A.; Lebedev, Igor N.; Vtorushin, Sergey V.; Zavyalova, Marina V.; Cherdyntseva, Nadezhda V.; Perelmuter, Vladimir M.

2017-01-01

Intratumor morphological heterogeneity in breast cancer is represented by different morphological structures (tubular, alveolar, solid, trabecular, and discrete) and contributes to poor prognosis; however, the mechanisms involved remain unclear. In this study, we performed 3D imaging, laser microdissection-assisted array comparative genomic hybridization and gene expression microarray analysis of different morphological structures and examined their association with the standard immunohistochemistry scorings and CD44+CD24- cancer stem cells. We found that the intratumor morphological heterogeneity is not associated with chromosomal aberrations. By contrast, morphological structures were characterized by specific gene expression profiles and signaling pathways and significantly differed in progesterone receptor and Ki-67 expression. Most importantly, we observed significant differences between structures in the number of expressed genes of the epithelial and mesenchymal phenotypes and the association with cancer invasion pathways. Tubular (tube-shaped) and alveolar (spheroid-shaped) structures were transcriptionally similar and demonstrated co-expression of epithelial and mesenchymal markers. Solid (large shapeless) structures retained epithelial features but demonstrated an increase in mesenchymal traits and collective cell migration hallmarks. Mesenchymal genes and cancer invasion pathways, as well as Ki-67 expression, were enriched in trabecular (one/two rows of tumor cells) and discrete groups (single cells and/or arrangements of 2-5 cells). Surprisingly, the number of CD44+CD24- cells was found to be the lowest in discrete groups and the highest in alveolar and solid structures. Overall, our findings indicate the association of intratumor morphological heterogeneity in breast cancer with the epithelial-mesenchymal transition and CD44+CD24- stemness and the appeal of this heterogeneity as a model for the study of cancer invasion. PMID:28977854

Differential marker expression by cultures rich in mesenchymal stem cells

PubMed Central

2013-01-01

Background Mesenchymal stem cells have properties that make them amenable to therapeutic use. However, the acceptance of mesenchymal stem cells in clinical practice requires standardized techniques for their specific isolation. To date, there are no conclusive marker (s) for the exclusive isolation of mesenchymal stem cells. Our aim was to identify markers differentially expressed between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. We compared and contrasted the phenotype of tissue cultures in which mesenchymal stem cells are rich and rare. By initially assessing mesenchymal stem cell differentiation, we established that bone marrow and breast adipose cultures are rich in mesenchymal stem cells while, in our hands, foreskin fibroblast and olfactory tissue cultures contain rare mesenchymal stem cells. In particular, olfactory tissue cells represent non-stem cell mesenchymal cells. Subsequently, the phenotype of the tissue cultures were thoroughly assessed using immuno-fluorescence, flow-cytometry, proteomics, antibody arrays and qPCR. Results Our analysis revealed that all tissue cultures, regardless of differentiation potential, demonstrated remarkably similar phenotypes. Importantly, it was also observed that common mesenchymal stem cell markers, and fibroblast-associated markers, do not discriminate between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. Examination and comparison of the phenotypes of mesenchymal stem cell and non-stem cell mesenchymal cell cultures revealed three differentially expressed markers – CD24, CD108 and CD40. Conclusion We indicate the importance of establishing differential marker expression between mesenchymal stem cells and non-stem cell mesenchymal cells in order to determine stem cell specific markers. PMID:24304471

Learn About Stem Cells

MedlinePlus

... Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... Home > Learn About Stem Cells > Stem Cell Basics Cells in the human body The human body comprises ...

Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin.

PubMed

Dorn, Isabel; Klich, Katharina; Arauzo-Bravo, Marcos J; Radstaak, Martina; Santourlidis, Simeon; Ghanjati, Foued; Radke, Teja F; Psathaki, Olympia E; Hargus, Gunnar; Kramer, Jan; Einhaus, Martin; Kim, Jeong Beom; Kögler, Gesine; Wernet, Peter; Schöler, Hans R; Schlenke, Peter; Zaehres, Holm

2015-01-01

Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34(+) hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34(+) hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells. Although genome-wide DNA methylation profiling at all promoter regions demonstrates that the epigenetic memory of induced pluripotent stem cells is influenced by the somatic cell type of origin of the stem cells, we found a similar hematopoietic induction potential and erythroid differentiation pattern of induced pluripotent stem cells of different somatic cell origin. All human induced pluripotent stem cell lines showed terminal maturation into normoblasts and enucleated reticulocytes, producing predominantly fetal hemoglobin. Differences were only observed in the growth rate of erythroid cells, which was slightly higher in the induced pluripotent stem cells derived from CD34(+) hematopoietic stem cells. More detailed methylation analysis of the hematopoietic and erythroid promoters identified similar CpG methylation levels in the induced pluripotent stem cell lines derived from CD34(+) cells and those derived from neural stem cells, which confirms their comparable erythroid differentiation potential. Copyright© Ferrata Storti Foundation.

[Progress in stem cells and regenerative medicine].

PubMed

Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

2015-06-01

Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

Application of Graphene Based Nanotechnology in Stem Cells Research.

PubMed

Hu, Shanshan; Zeng, Yongxiang; Yang, Shuying; Qin, Han; Cai, He; Wang, Jian

2015-09-01

The past several years have witnessed significant advances in stem cell therapy, tissue engineering and regenerative medicine. Graphene, with its unique properties such as high electrical conductivity, elasticity and good molecule absorption, have potential for creating the next generation of biomaterials. This review summarizes the interrelationship between graphene and stem cells. The analysis of graphene when applied on mesenchymal stem cells, neural stem cells, induced pluripotent stem cells, embryonic stem cells, periodontal ligament stem cells, human adipose-derived stem cells and cancer stem cells, and how graphene influences cell behavior and differentiation are discussed in details.

Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

NASA Astrophysics Data System (ADS)

Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

2016-03-01

Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

Non-thermal effects of terahertz radiation on gene expression in mouse stem cells

PubMed Central

Alexandrov, Boian S.; Rasmussen, Kim Ø.; Bishop, Alan R.; Usheva, Anny; Alexandrov, Ludmil B.; Chong, Shou; Dagon, Yossi; Booshehri, Layla G.; Mielke, Charles H.; Phipps, M. Lisa; Martinez, Jennifer S.; Chen, Hou-Tong; Rodriguez, George

2011-01-01

Abstract In recent years, terahertz radiation sources are increasingly being exploited in military and civil applications. However, only a few studies have so far been conducted to examine the biological effects associated with terahertz radiation. In this study, we evaluated the cellular response of mesenchymal mouse stem cells exposed to THz radiation. We apply low-power radiation from both a pulsed broad-band (centered at 10 THz) source and from a CW laser (2.52 THz) source. Modeling, empirical characterization, and monitoring techniques were applied to minimize the impact of radiation-induced increases in temperature. qRT-PCR was used to evaluate changes in the transcriptional activity of selected hyperthermic genes. We found that temperature increases were minimal, and that the differential expression of the investigated heat shock proteins (HSP105, HSP90, and CPR) was unaffected, while the expression of certain other genes (Adiponectin, GLUT4, and PPARG) showed clear effects of the THz irradiation after prolonged, broad-band exposure. PMID:21991556

A revisionist history of adult marrow stem cell biology or 'they forgot about the discard'.

PubMed

Quesenberry, P; Goldberg, L

2017-08-01

The adult marrow hematopoietic stem cell biology has largely been based on studies of highly purified stem cells. This is unfortunate because during the stem cell purification the great bulk of stem cells are discarded. These cells are actively proliferating. The final purified stem cell is dormant and not representative of the whole stem cell compartment. Thus, a large number of studies on the cellular characteristics, regulators and molecular details of stem cells have been carried on out of non-represented cells. Niche studies have largely pursued using these purified stem cells and these are largely un-interpretable. Other considerations include the distinction between baseline and transplant stem cells and the modulation of stem cell phenotype by extracellular vesicles, to cite a non-inclusive list. Work needs to proceed on characterizing the true stem cell population.

Perspectives on stem cell therapy for cardiac regeneration. Advances and challenges.

PubMed

Choi, Sung Hyun; Jung, Seok Yun; Kwon, Sang-Mo; Baek, Sang Hong

2012-01-01

Ischemic heart disease (IHD) accelerates cardiomyocyte loss, but the developing stem cell research could be useful for regenerating a variety of tissue cells, including cardiomyocytes. Diverse sources of stem cells for IHD have been reported, including embryonic stem cells, induced pluripotent stem cells, skeletal myoblasts, bone marrow-derived stem cells, mesenchymal stem cells, and cardiac stem cells. However, stem cells have unique advantages and disadvantages for cardiac tissue regeneration, which are important considerations in determining the specific cells for improving cell survival and long-term engraftment after transplantation. Additionally, the dosage and administration method of stem cells need to be standardized to increase stability and efficacy for clinical applications. Accordingly, this review presents a summary of the stem cell therapies that have been studied for cardiac regeneration thus far, and discusses the direction of future cardiac regeneration research for stem cells.

Laser versus traditional techniques in cerebral and brain stem gliomas

NASA Astrophysics Data System (ADS)

Lombard, Gian F.

1996-01-01

In medical literature no significant studies have been published on the effectiveness of laser compared with traditional procedures in two series of cerebral gliomas; for this reason we have studied 220 tumors (200 supratentorial -- 20 brain stem gliomas), 110 operated upon with laser, 100 with conventional techniques. Four surgical protocols have been carried out: (1) traditional techniques; (2) carbon dioxide laser free hand; (3) carbon dioxide laser plus microscope; (4) multiple laser sources plus microscope plus neurosector plus CUSA. Two laser sources have been used alone or in combination (carbon dioxide -- Nd:YAG 1.06 or 1.32). Patients have been monitored for Karnofsky scale before and after operation, 12 - 24 and 36 months later; and for survival rate. Tumors were classified by histological examination, dimensions, vascularization, topography (critical or non critical areas). Results for supratentorial gliomas: survival time is the same in both series (laser and traditional). Post- op morbidity is significantly improved in the laser group (high grade sub-group); long term follow-up shows an improvement of quality of life until 36 months in the low grade sub-group.

Stem Cells

MedlinePlus

Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair ... body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

Care for the Critically Injured Burn Patient Modulation of Burn Scars Through Laser Assisted Delivery of Stem Cells

DTIC Science & Technology

2016-10-01

FL 33186 REPORT DATE: October 2016 TYPE OF REPORT : Annual PREPARED FOR: U.S. Army Medical Research and Materiel Command Fort Detrick...contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so...designated by other documentation. 1 ` REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of

The Role of Integrin α6 (CD49f) in Stem Cells: More than a Conserved Biomarker.

PubMed

Krebsbach, Paul H; Villa-Diaz, Luis G

2017-08-01

Stem cells have the capacity for self-renewal and differentiation into specialized cells that form and repopulated all tissues and organs, from conception to adult life. Depending on their capacity for differentiation, stem cells are classified as totipotent (ie, zygote), pluripotent (ie, embryonic stem cells), multipotent (ie, neuronal stem cells, hematopoietic stem cells, epithelial stem cells, etc.), and unipotent (ie, spermatogonial stem cells). Adult or tissue-specific stem cells reside in specific niches located in, or nearby, their organ or tissue of origin. There, they have microenvironmental support to remain quiescent, to proliferate as undifferentiated cells (self-renewal), and to differentiate into progenitors or terminally differentiated cells that migrate from the niche to perform specialized functions. The presence of proteins at the cell surface is often used to identify, classify, and isolate stem cells. Among the diverse groups of cell surface proteins used for these purposes, integrin α6, also known as CD49f, may be the only biomarker commonly found in more than 30 different populations of stem cells, including some cancer stem cells. This broad expression among stem cell populations indicates that integrin α6 may play an important and conserved role in stem cell biology, which is reaffirmed by recent demonstrations of its role maintaining self-renewal of pluripotent stem cells and breast and glioblastoma cancer stem cells. Therefore, this review intends to highlight and synthesize new findings on the importance of integrin α6 in stem cell biology.

Laser fabrication of porous silicon-based platforms for cell culturing.

PubMed

Peláez, Ramón-J; Afonso, Carmen-N; Vega, Fidel; Recio-Sánchez, Gonzalo; Torres-Costa, Vicente; Manso-Silván, Miguel; García-Ruiz, Josefa-P; Martín-Palma, Raúl-J

2013-11-01

In this study, we explore the selective culturing of human mesenchymal stem cells (hMSCs) on Si-based diffractive platforms. We demonstrate a single-step and flexible method for producing platforms on nanostructured porous silicon (nanoPS) based on the use of single pulses of an excimer laser to expose phase masks. The resulting patterns are typically 1D patterns formed by fringes or 2D patterns formed by circles. They are formed by alternate regions of almost unmodified nanoPS and regions where the nanoPS surface has melted and transformed into Si nanoparticles. The patterns are produced in relatively large areas (a few square millimeters) and can have a wide range of periodicities and aspect ratios. Direct binding, that is, with no previous functionalization of the pattern, alignment, and active polarization of hMSCs are explored. The results show the preferential direct binding of the hMSCs along the transformed regions whenever their width compares with the dimensions of the cells and they escape from patterns for smaller widths suggesting that the selectivity can be tailored through the pattern period. Copyright © 2013 Wiley Periodicals, Inc.

Existence of Normal Limbal Epithelium in Eyes with Clinical Signs of Total Limbal Stem Cell Deficiency

PubMed Central

Codriansky, Andres; Hong, Jiaxu; Xu, Jianjian; Deng, Sophie X.

2016-01-01

Purpose To report the presence of normal limbal epithelium detected by in vivo confocal laser scanning microscopy (IVCM) in three cases of clinically diagnosed total limbal stem cell deficiency (LSCD). Methods This is a retrospective case report consists of three patients who were diagnosed with total LSCD based on clinical exam and/or impression cytology. Clinical data including ocular history, presentation, slit-lamp examination, IVCM and impression cytology were reviewed. Results The etiology was chemical burn in three cases. One patient has two failed penetrating keratoplasty. Another had allogeneic keratolimbal transplantation but the graft failed one year after surgery. The third patient had failed amniotic membrane transplantation. These three patients presented with signs of total LSCD including the absence of normal Vogt palisades, complete superficial vascularization of the peripheral cornea, non-healing epithelial defects, and corneal scarring. Impression cytology was performed in two cases to confirm the presence of goblet cells in two cases. Each patient however still had distinct areas of corneal and/or limbal epithelial cells detected by IVCM. Conclusions Residual normal limbal epithelial cells could be present in eyes with clinical features of total LSCD. IVCM appears to be a more accurate method to evaluate the degree of LSCD. PMID:27362882

Engineering A11 Minibody-Conjugated, Polypeptide-Based Gold Nanoshells for Prostate Stem Cell Antigen (PSCA)-Targeted Photothermal Therapy.

PubMed

Mayle, Kristine M; Dern, Kathryn R; Wong, Vincent K; Chen, Kevin Y; Sung, Shijun; Ding, Ke; Rodriguez, April R; Knowles, Scott; Taylor, Zachary; Zhou, Z Hong; Grundfest, Warren S; Wu, Anna M; Deming, Timothy J; Kamei, Daniel T

2017-02-01

Currently, there is no curative treatment for advanced metastatic prostate cancer, and options, such as chemotherapy, are often nonspecific, harming healthy cells and resulting in severe side effects. Attaching targeting ligands to agents used in anticancer therapies has been shown to improve efficacy and reduce nonspecific toxicity. Furthermore, the use of triggered therapies can enable spatial and temporal control over the treatment. Here, we combined an engineered prostate cancer-specific targeting ligand, the A11 minibody, with a novel photothermal therapy agent, polypeptide-based gold nanoshells, which generate heat in response to near-infrared light. We show that the A11 minibody strongly binds to the prostate stem cell antigen that is overexpressed on the surface of metastatic prostate cancer cells. Compared to nonconjugated gold nanoshells, our A11 minibody-conjugated gold nanoshell exhibited significant laser-induced, localized killing of prostate cancer cells in vitro. In addition, we improved upon a comprehensive heat transfer mathematical model that was previously developed by our laboratory. By relaxing some of the assumptions of our earlier model, we were able to generate more accurate predictions for this particular study. Our experimental and theoretical results demonstrate the potential of our novel minibody-conjugated gold nanoshells for metastatic prostate cancer therapy.

Drosophila's contribution to stem cell research.

PubMed

Singh, Gyanesh

2015-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.

Drosophila's contribution to stem cell research

PubMed Central

Singh, Gyanesh

2016-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila. PMID:26180635

Current overview on dental stem cells applications in regenerative dentistry.

PubMed

Bansal, Ramta; Jain, Aditya

2015-01-01

Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications.

The longest telomeres: a general signature of adult stem cell compartments

PubMed Central

Flores, Ignacio; Canela, Andres; Vera, Elsa; Tejera, Agueda; Cotsarelis, George; Blasco, María A.

2008-01-01

Identification of adult stem cells and their location (niches) is of great relevance for regenerative medicine. However, stem cell niches are still poorly defined in most adult tissues. Here, we show that the longest telomeres are a general feature of adult stem cell compartments. Using confocal telomere quantitative fluorescence in situ hybridization (telomapping), we find gradients of telomere length within tissues, with the longest telomeres mapping to the known stem cell compartments. In mouse hair follicles, we show that cells with the longest telomeres map to the known stem cell compartments, colocalize with stem cell markers, and behave as stem cells upon treatment with mitogenic stimuli. Using K15-EGFP reporter mice, which mark hair follicle stem cells, we show that GFP-positive cells have the longest telomeres. The stem cell compartments in small intestine, testis, cornea, and brain of the mouse are also enriched in cells with the longest telomeres. This constitutes the description of a novel general property of adult stem cell compartments. Finally, we make the novel finding that telomeres shorten with age in different mouse stem cell compartments, which parallels a decline in stem cell functionality, suggesting that telomere loss may contribute to stem cell dysfunction with age. PMID:18283121

Photothermal damage is correlated to the delivery rate of time-integrated temperature

NASA Astrophysics Data System (ADS)

Denton, Michael L.; Noojin, Gary D.; Gamboa, B. Giovanna; Ahmed, Elharith M.; Rockwell, Benjamin A.

2016-03-01

Photothermal damage rate processes in biological tissues are usually characterized by a kinetics approach. This stems from experimental data that show how the transformation of a specified biological property of cells or biomolecule (plating efficiency for viability, change in birefringence, tensile strength, etc.) is dependent upon both time and temperature. However, kinetic methods require determination of kinetic rate constants and knowledge of substrate or product concentrations during the reaction. To better understand photothermal damage processes we have identified temperature histories of cultured retinal cells receiving minimum lethal thermal doses for a variety of laser and culture parameters. These "threshold" temperature histories are of interest because they inherently contain information regarding the fundamental thermal dose requirements for damage in individual cells. We introduce the notion of time-integrated temperature (Tint) as an accumulated thermal dose (ATD) with units of °C s. Damaging photothermal exposure raises the rate of ATD accumulation from that of the ambient (e.g. 37 °C) to one that correlates with cell death (e.g. 52 °C). The degree of rapid increase in ATD (ΔATD) during photothermal exposure depends strongly on the laser exposure duration and the ambient temperature.

Context clues: the importance of stem cell-material interactions

PubMed Central

Murphy, William L.

2014-01-01

Understanding the processes by which stem cells give rise to de novo tissues is an active focus of stem cell biology and bioengineering disciplines. Instructive morphogenic cues surrounding the stem cell during morphogenesis create what is referred to as the stem cell microenvironment. An emerging paradigm in stem cell bioengineering involves “biologically driven assembly,” in which stem cells are encouraged to largely define their own morphogenesis processes. However, even in the case of biologically driven assembly, stem cells do not act alone. The properties of the surrounding microenvironment can be critical regulators of cell fate. Stem cell-material interactions are among the most well-characterized microenvironmental effectors of stem cell fate, and they establish a signaling “context” that can define the mode of influence for morphogenic cues. Here we describe illustrative examples of cell-material interactions that occur during in vitro stem cell studies, with an emphasis on how cell-material interactions create instructive contexts for stem cell differentiation and morphogenesis. PMID:24369691

Cancer stem cells and differentiation therapy.

PubMed

Jin, Xiong; Jin, Xun; Kim, Hyunggee

2017-10-01

Cancer stem cells can generate tumors from only a small number of cells, whereas differentiated cancer cells cannot. The prominent feature of cancer stem cells is its ability to self-renew and differentiate into multiple types of cancer cells. Cancer stem cells have several distinct tumorigenic abilities, including stem cell signal transduction, tumorigenicity, metastasis, and resistance to anticancer drugs, which are regulated by genetic or epigenetic changes. Like normal adult stem cells involved in various developmental processes and tissue homeostasis, cancer stem cells maintain their self-renewal capacity by activating multiple stem cell signaling pathways and inhibiting differentiation signaling pathways during cancer initiation and progression. Recently, many studies have focused on targeting cancer stem cells to eradicate malignancies by regulating stem cell signaling pathways, and products of some of these strategies are in preclinical and clinical trials. In this review, we describe the crucial features of cancer stem cells related to tumor relapse and drug resistance, as well as the new therapeutic strategy to target cancer stem cells named "differentiation therapy."

Clinical trials for stem cell transplantation: when are they needed?

PubMed

Van Pham, Phuc

2016-04-27

In recent years, both stem cell research and the clinical application of these promising cells have increased rapidly. About 1000 clinical trials using stem cells have to date been performed globally. More importantly, more than 10 stem cell-based products have been approved in some countries. With the rapid growth of stem cell applications, some countries have used clinical trials as a tool to diminish the rate of clinical stem cell applications. However, the point at which stem cell clinical trials are essential remains unclear. This commentary discusses when stem cell clinical trials are essential for stem cell transplantation therapies.

Stem cells - biological update and cell therapy progress

PubMed Central

GIRLOVANU, MIHAI; SUSMAN, SERGIU; SORITAU, OLGA; RUS-CIUCA, DAN; MELINCOVICI, CARMEN; CONSTANTIN, ANNE-MARIE; MIHU, CARMEN MIHAELA

2015-01-01

In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods to prevent teratoma formation or the ethical and religious issues regarding especially the embryonic stem cell research. The direct differentiation of stem cells into specialized cells: cardiac myocytes, neural cells, pancreatic islets cells, may represent an option in treating incurable diseases such as: neurodegenerative diseases, type I diabetes, hematologic or cardiac diseases. Nevertheless, stem cell-based therapies, based on stem cell transplantation, remain mainly at the experimental stages and their major limitation is the development of teratoma and cancer after transplantation. The induced pluripotent stem cells (hiPSCs) represent a prime candidate for future cell therapy research because of their significant self-renewal and differentiation potential and the lack of ethical issues. This article presents an overview of the biological advances in the study of stem cells and the current progress made in the field of regenerative medicine. PMID:26609255

Establishment of mouse expanded potential stem cells

PubMed Central

Gao, Xuefei; Antunes, Liliana; Yu, Yong; Zhu, Zhexin; Wang, Juexuan; Kolodziejczyk, Aleksandra A.; Campos, Lia S.; Wang, Cui; Yang, Fengtang; Zhong, Zhen; Fu, Beiyuan; Eckersley-Maslin, Melanie A.; Woods, Michael; Tanaka, Yosuke; Chen, Xi; Wilkinson, Adam C.; Bussell, James; White, Jacqui; Ramirez-Solis, Ramiro; Reik, Wolf; Göttgens, Berthold; Teichmann, Sarah A.; Tam, Patrick P. L.; Nakauchi, Hiromitsu; Zou, Xiangang; Lu, Liming; Liu, Pentao

2018-01-01

Mouse embryonic stem cells derived from the epiblast1 contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and the primitive endoderm2 upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species. PMID:29019987

Imaging of high-angle annular dark-field scanning transmission electron microscopy and observations of GaN-based violet laser diodes.

PubMed

Shiojiri, M; Saijo, H

2006-09-01

The first part of this paper is devoted to physics, to explain high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging and to interpret why HAADF-STEM imaging is incoherent, instructing a strict definition of interference and coherence of electron waves. Next, we present our recent investigations of InGaN/GaN multiple quantum wells and AlGaN/GaN strained-layer superlattice claddings in GaN-based violet laser diodes, which have been performed by HAADF-STEM and high-resolution field-emission gun scanning electron microscopy.

Adult Stem Cell Therapy for Stroke: Challenges and Progress

PubMed Central

Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

2016-01-01

Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell therapies include (a) the limited source of engraftable stem cells, (b) the presence of optimal time window for stem cell therapies, (c) inherited limitation of stem cells in terms of growth, trophic support, and differentiation potential, and (d) possible transplanted cell-mediated adverse effects, such as tumor formation. Here, we discuss recent advances that overcome these hurdles in adult stem cell therapy for stroke. PMID:27733032

A Simple Diffraction Experiment Using Banana Stem as a Natural Grating

ERIC Educational Resources Information Center

Aji, Mahardika Prasetya; Karunawan, Jotti; Chasanah, Widyastuti Rochimatun; Nursuhud, Puji Iman; Wiguna, Pradita Ajeng; Sulhadi

2017-01-01

A simple diffraction experiment was designed using banana stem as natural grating. Coherent beams of lasers with wavelengths of 632.8 nm and 532 nm that pass through banana stem produce periodic diffraction patterns on a screen. The diffraction experiments were able to measure the distances between the slit of the banana stem, i.e. d = (28.76 ±…

Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring.

PubMed

Avci, Pinar; Gupta, Asheesh; Sadasivam, Magesh; Vecchio, Daniela; Pam, Zeev; Pam, Nadav; Hamblin, Michael R

2013-03-01

Low-level laser (light) therapy (LLLT) is a fast-growing technology used to treat a multitude of conditions that require stimulation of healing, relief of pain and inflammation, and restoration of function. Although skin is naturally exposed to light more than any other organ, it still responds well to red and near-infrared wavelengths. The photons are absorbed by mitochondrial chromophores in skin cells. Consequently, electron transport, adenosine triphosphate nitric oxide release, blood flow, reactive oxygen species increase, and diverse signaling pathways are activated. Stem cells can be activated, allowing increased tissue repair and healing. In dermatology, LLLT has beneficial effects on wrinkles, acne scars, hypertrophic scars, and healing of burns. LLLT can reduce UV damage both as a treatment and as a prophylactic measure. In pigmentary disorders such as vitiligo, LLLT can increase pigmentation by stimulating melanocyte proliferation and reduce depigmentation by inhibiting autoimmunity. Inflammatory diseases such as psoriasis and acne can also be managed. The noninvasive nature and almost complete absence of side effects encourage further testing in dermatology.

Two sides of the same coin? Unraveling subtle differences between human embryonic and induced pluripotent stem cells by Raman spectroscopy.

PubMed

Parrotta, Elvira; De Angelis, Maria Teresa; Scalise, Stefania; Candeloro, Patrizio; Santamaria, Gianluca; Paonessa, Mariagrazia; Coluccio, Maria Laura; Perozziello, Gerardo; De Vitis, Stefania; Sgura, Antonella; Coluzzi, Elisa; Mollace, Vincenzo; Di Fabrizio, Enzo Mario; Cuda, Giovanni

2017-11-28

Human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells, hold enormous promise for many biomedical applications, such as regenerative medicine, drug testing, and disease modeling. Although induced pluripotent stem cells resemble embryonic stem cells both morphologically and functionally, the extent to which these cell lines are truly equivalent, from a molecular point of view, remains controversial. Principal component analysis and K-means cluster analysis of collected Raman spectroscopy data were used for a comparative study of the biochemical fingerprint of human induced pluripotent stem cells and human embryonic stem cells. The Raman spectra analysis results were further validated by conventional biological assays. Raman spectra analysis revealed that the major difference between human embryonic stem cells and induced pluripotent stem cells is due to the nucleic acid content, as shown by the strong positive peaks at 785, 1098, 1334, 1371, 1484, and 1575 cm -1 , which is enriched in human induced pluripotent stem cells. Here, we report a nonbiological approach to discriminate human induced pluripotent stem cells from their native embryonic stem cell counterparts.

A family business: stem cell progeny join the niche to regulate homeostasis.

PubMed

Hsu, Ya-Chieh; Fuchs, Elaine

2012-01-23

Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.

A family business: stem cell progeny join the niche to regulate homeostasis

PubMed Central

Hsu, Ya-Chieh; Fuchs, Elaine

2012-01-01

Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems. PMID:22266760

Stem Cell Therapy for Erectile Dysfunction.

PubMed

Matz, Ethan L; Terlecki, Ryan; Zhang, Yuanyuan; Jackson, John; Atala, Anthony

2018-04-06

The prevalence of erectile dysfunction (ED) is substantial and continues to rise. Current therapeutics for ED consist of oral medications, intracavernosal injections, vacuum erection devices, and penile implants. While such options may manage the disease state, none of these modalities, however, restore function. Stem cell therapy has been evaluated for erectile restoration in animal models. These cells have been derived from multiple tissues, have varied potential, and may function via local engraftment or paracrine signaling. Bone marrow-derived stem cells (BMSC) and adipose-derived stem cells (ASC) have both been used in these models with noteworthy effects. Herein, we will review the pathophysiology of ED, animal models, current and novel stem-cell based therapeutics, clinical trials and areas for future research. The relevant literature and contemporary data using keywords, "stem cells and erectile dysfunction" was reviewed. Examination of evidence supporting the association between erectile dysfunction and adipose derived stem cells, bone marrow derived stem cells, placental stem cells, urine stem cells and stem cell therapy respectively. Placental-derived stem cells and urine-derived stem cells possess many similar properties as BMSC and ASC, but the methods of acquisition are favorable. Human clinical trials have already demonstrated successful use of stem cells for improvement of erectile function. The future of stem cell research is constantly being evaluated, although, the evidence suggests a place for stem cells in erectile dysfunction therapeutics. Matz EL, Terlecki R, Zhang Y, et al. Stem Cell Therapy for Erectile Dysfunction. Sex Med Rev 2018;XX:XXX-XXX. Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A new prospect in cancer therapy: targeting cancer stem cells to eradicate cancer.

PubMed

Chen, Li-Sha; Wang, An-Xin; Dong, Bing; Pu, Ke-Feng; Yuan, Li-Hua; Zhu, Yi-Min

2012-12-01

According to the cancer stem cell theory, cancers can be initiated by cancer stem cells. This makes cancer stem cells prime targets for therapeutic intervention. Eradicating cancer stem cells by efficient targeting agents may have the potential to cure cancer. In this review, we summarize recent breakthroughs that have improved our understanding of cancer stem cells, and we discuss the therapeutic strategy of targeting cancer stem cells, a promising future direction for cancer stem cell research.

Adult bone marrow-derived stem cells for organ regeneration and repair.

PubMed

Tögel, Florian; Westenfelder, Christof

2007-12-01

Stem cells have been recognized as a potential tool for the development of innovative therapeutic strategies. There are in general two types of stem cells, embryonic and adult stem cells. While embryonic stem cell therapy has been riddled with problems of allogeneic rejection and ethical concerns, adult stem cells have long been used in the treatment of hematological malignancies. With the recognition of additional, potentially therapeutic characteristics, bone marrow-derived stem cells have become a tool in regenerative medicine. The bone marrow is an ideal source of stem cells because it is easily accessible and harbors two types of stem cells. Hematopoietic stem cells give rise to all blood cell types and have been shown to exhibit plasticity, while multipotent marrow stromal cells are the source of osteocytes, chondrocytes, and fat cells and have been shown to support and generate a large number of different cell types. This review describes the general characteristics of these stem cell populations and their current and potential future applications in regenerative medicine. 2007 Wiley-Liss, Inc

Mechanism and applications of new fluorescent compounds produced by femtosecond laser surgery in biological tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Qu, Jianan Y.; Sun, Qiqi

2017-02-01

The single or multi-photon microscopy based on fluorescent labelling and staining is a sensitive and quantitative method that is widely used in molecular biology and medical research for a variety of experimental, analytical, and quality control applications. However, label-free method is highly desirable in biology and medicine when performing long term live imaging of biological system and obtaining instant tissue examination during surgery procedures. Recently, our group found that femtosecond laser surgery turned a variety of biological tissues and protein samples into highly fluorescent substances. The newly formed fluorescent compounds produced during the laser surgery can be excited via single- and two-photon processes over broad wavelength ranges. We developed a combined confocal and two-photon spectroscopic microscope to characterize the fluorescence from the new compound systematically. The structures of the femtosecond laser treated tissue were studied using Raman spectroscopy and transmission electron microscopy. Our study revealed the mechanisms of the fluorescence emission form the new compound. Furthermore, we demonstrated the applications of the fluorescent compounds for instant evaluation of femtosecond laser microsurgery, study of stem cell responses to muscle injury and neuro-regeneration after spinal cord injury.

Stem cells.

PubMed

Behr, Björn; Ko, Sae Hee; Wong, Victor W; Gurtner, Geoffrey C; Longaker, Michael T

2010-10-01

Stem cells are self-renewing cells capable of differentiating into multiple cell lines and are classified according to their origin and their ability to differentiate. Enormous potential exists in use of stem cells for regenerative medicine. To produce effective stem cell-based treatments for a range of diseases, an improved understanding of stem cell biology and better control over stem cell fate are necessary. In addition, the barriers to clinical translation, such as potential oncologic properties of stem cells, need to be addressed. With renewed government support and continued refinement of current stem cell methodologies, the future of stem cell research is exciting and promises to provide novel reconstructive options for patients and surgeons limited by traditional paradigms.

Some Ethical Concerns About Human Induced Pluripotent Stem Cells.

PubMed

Zheng, Yue Liang

2016-10-01

Human induced pluripotent stem cells can be obtained from somatic cells, and their derivation does not require destruction of embryos, thus avoiding ethical problems arising from the destruction of human embryos. This type of stem cell may provide an important tool for stem cell therapy, but it also results in some ethical concerns. It is likely that abnormal reprogramming occurs in the induction of human induced pluripotent stem cells, and that the stem cells generate tumors in the process of stem cell therapy. Human induced pluripotent stem cells should not be used to clone human beings, to produce human germ cells, nor to make human embryos. Informed consent should be obtained from patients in stem cell therapy.

Potential antitumor therapeutic strategies of human amniotic membrane and amniotic fluid-derived stem cells.

PubMed

Kang, N-H; Hwang, K-A; Kim, S U; Kim, Y-B; Hyun, S-H; Jeung, E-B; Choi, K-C

2012-08-01

As stem cells are capable of self-renewal and can generate differentiated progenies for organ development, they are considered as potential source for regenerative medicine and tissue replacement after injury or disease. Along with this capacity, stem cells have the therapeutic potential for treating human diseases including cancers. According to the origins, stem cells are broadly classified into two types: embryonic stem cells (ESCs) and adult stem cells. In terms of differentiation potential, ESCs are pluripotent and adult stem cells are multipotent. Amnion, which is a membranous sac that contains the fetus and amniotic fluid and functions in protecting the developing embryo during gestation, is another stem cell source. Amnion-derived stem cells are classified as human amniotic membrane-derived epithelial stem cells, human amniotic membrane-derived mesenchymal stem cells and human amniotic fluid-derived stem cells. They are in an intermediate stage between pluripotent ESCs and lineage-restricted adult stem cells, non-tumorigenic, and contribute to low immunogenicity and anti-inflammation. Furthermore, they are easily available and do not cause any controversial issues in their recovery and applications. Not only are amnion-derived stem cells applicable in regenerative medicine, they have anticancer capacity. In non-engineered stem cells transplantation strategies, amnion-derived stem cells effectively target the tumor and suppressed the tumor growth by expressing cytotoxic cytokines. Additionally, they also have a potential as novel delivery vehicles transferring therapeutic genes to the cancer formation sites in gene-directed enzyme/prodrug combination therapy. Owing to their own advantageous properties, amnion-derived stem cells are emerging as a new candidate in anticancer therapy.

In vitro differentiation of primordial germ cells and oocyte-like cells from stem cells.

PubMed

Costa, José J N; Souza, Glaucinete B; Soares, Maria A A; Ribeiro, Regislane P; van den Hurk, Robert; Silva, José R V

2018-02-01

Infertility is the result of failure due to an organic disorder of the reproductive organs, especially their gametes. Recently, much progress has been made on generating germ cells, including oocytes, from various types of stem cells. This review focuses on advances in female germ cell differentiation from different kinds of stem cells, with emphasis on embryonic stem cells, adult stem cells, and induced pluripotent stem cells. The advantages and disadvantages of the derivation of female germ cells from several types of stem cells are also highlighted, as well as the ability of stem cells to generate mature and functional female gametes. This review shows that stem cell therapies have opened new frontiers in medicine, especially in the reproductive area, with the possibility of regenerating fertility.

Reduced hematopoietic stem cell frequency predicts outcome in acute myeloid leukemia.

PubMed

Wang, Wenwen; Stiehl, Thomas; Raffel, Simon; Hoang, Van T; Hoffmann, Isabel; Poisa-Beiro, Laura; Saeed, Borhan R; Blume, Rachel; Manta, Linda; Eckstein, Volker; Bochtler, Tilmann; Wuchter, Patrick; Essers, Marieke; Jauch, Anna; Trumpp, Andreas; Marciniak-Czochra, Anna; Ho, Anthony D; Lutz, Christoph

2017-09-01

In patients with acute myeloid leukemia and low percentages of aldehyde-dehydrogenase-positive cells, non-leukemic hematopoietic stem cells can be separated from leukemic cells. By relating hematopoietic stem cell frequencies to outcome we detected poor overall- and disease-free survival of patients with low hematopoietic stem cell frequencies. Serial analysis of matched diagnostic and follow-up samples further demonstrated that hematopoietic stem cells increased after chemotherapy in patients who achieved durable remissions. However, in patients who eventually relapsed, hematopoietic stem cell numbers decreased dramatically at the time of molecular relapse demonstrating that hematopoietic stem cell levels represent an indirect marker of minimal residual disease, which heralds leukemic relapse. Upon transplantation in immune-deficient mice cases with low percentages of hematopoietic stem cells of our cohort gave rise to leukemic or no engraftment, whereas cases with normal hematopoietic stem cell levels mostly resulted in multi-lineage engraftment. Based on our experimental data, we propose that leukemic stem cells have increased niche affinity in cases with low percentages of hematopoietic stem cells. To validate this hypothesis, we developed new mathematical models describing the dynamics of healthy and leukemic cells under different regulatory scenarios. These models suggest that the mechanism leading to decreases in hematopoietic stem cell frequencies before leukemic relapse must be based on expansion of leukemic stem cells with high niche affinity and the ability to dislodge hematopoietic stem cells. Thus, our data suggest that decreasing numbers of hematopoietic stem cells indicate leukemic stem cell persistence and the emergence of leukemic relapse. Copyright© 2017 Ferrata Storti Foundation.

Constitutive arginine-dependent nitric oxide synthase activity in different organs of pea seedlings during plant development.

PubMed

Corpas, Francisco J; Barroso, Juan B; Carreras, Alfonso; Valderrama, Raquel; Palma, José M; León, Ana M; Sandalio, Luisa M; del Río, Luis A

2006-07-01

Nitric oxide (NO) is an important signalling molecule in different animal and plant physiological processes. Little is known about its biological function in plants and on the enzymatic source or site of NO production during plant development. The endogenous NO production from L-arginine (NO synthase activity) was analyzed in leaves, stems and roots during plant development, using pea seedlings as a model. NOS activity was analyzed using a novel chemiluminescence-based assay which is more sensitive and specific than previous methods used in plant tissues. In parallel, NO accumulation was analyzed by confocal laser scanning microscopy using as fluorescent probes either DAF-2 DA or DAF-FM DA. A strong increase in NOS activity was detected in stems after 11 days growth, coinciding with the maximum stem elongation. The arginine-dependent NOS activity was constitutive and sensitive to aminoguanidine, a well-known irreversible inhibitor of animal NOS, and this NOS activity was differentially modulated depending on the plant organ and seedling developmental stage. In all tissues studied, NO was localized mainly in the vascular tissue (xylem) and epidermal cells and in root hairs. These loci of NO generation and accumulation suggest novel functions for NO in these cell types.

Evaluation of the secretion and release of vascular endothelial growth factor from two-dimensional culture and three-dimensional cell spheroids formed with stem cells and osteoprecursor cells.

PubMed

Lee, Hyunjin; Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2018-05-18

Co-culture has been applied in cell therapy, including stem cells, and has been reported to give enhanced functionality. In this study, stem-cell spheroids were formed in concave micromolds at different ratios of stem cells to osteoprecursor cells, and the amount of secretion of vascular endothelial growth factor (VEGF) was evaluated. Gingiva-derived stem cells and osteoprecursor cells in the amount of 6 × 105 were seeded on a 24-well culture plate or concave micromolds. The ratios of stem cells to osteoprecursor cells included: 0:4 (group 1), 1:3 (group 2), 2:2 (group 3), 3:1 (group 4), and 4:0 (group 5). The morphology of cells in a 2-dimensional culture (groups 1-5) showed a fibroblast-like appearance. The secretion of VEGF increased with the increase in stem cells, and a statistically significant increase was noted in groups 3, 4 and 5 when compared with the media-only group (p < 0.05). Osteoprecursor cells formed spheroids in concave microwells, and no noticeable change in the morphology was noted with the increase in stem cells. Spheroids containing stem cells were positive for the stem-cell markers SSEA-4. The secretion of VEGF from cell spheroids increased with the increase in stem cells. This study showed that cell spheroids formed with stem cells and osteoprecursor cells with different ratios, using microwells, had paracrine effects on the stem cells. The secretion of VEGF increased with the increase in stem cells. This stem-cell spheroid may be applied for tissue-engineering purposes.

The Role of Stem Cells in Aesthetic Surgery: Fact or Fiction?

PubMed Central

McArdle, Adrian; Senarath-Yapa, Kshemendra; Walmsley, Graham G.; Hu, Michael; Atashroo, David A.; Tevlin, Ruth; Zielins, Elizabeth; Gurtner, Geoffrey C.; Wan, Derrick C.; Longaker, Michael T.

2014-01-01

Stem cells are attractive candidates for the development of novel therapies, targeting indications that involve functional restoration of defective tissue. Although most stem cell therapies are new and highly experimental, there are clinics around the world that exploit vulnerable patients with the hope of offering supposed stem cell therapies, many of which operate without credible scientific merit, oversight, or other patient protection. We review the potential, as well as drawbacks, for incorporation of stem cells in cosmetic procedures. A review of FDA-approved indications and ongoing clinical trials with adipose stem cells is provided. Furthermore, a “snapshot” analysis of websites using the search terms “stem cell therapy” or “stem cell treatment” or “stem cell facelift” was performed. Despite the protective net cast by regulatory agencies such as the FDA and professional societies such as the American Society of Plastic Surgeons, we are witnessing worrying advertisements for procedures such as stem cell facelifts, stem cell breast augmentations, and even stem cell vaginal rejuvenation. The marketing and promotion of stem cell procedures in aesthetic surgery is not adequately supported by clinical evidence in the majority of cases. Stem cells offer tremendous potential, but the marketplace is saturated with unsubstantiated and sometimes fraudulent claims that may place patients at risk. With plastic surgeons at the forefront of stem cell-based regenerative medicine, it is critically important that we provide an example of a rigorous approach to research, data collection, and advertising of stem cell therapies. PMID:24732654

Double Knockdown of Prolyyl Hydroxylase and Factor Inhibiting HIF with Non-Viral Minicircle Gene Therapy Enhances Stem Cell Mobilization and Angiogenesis After Myocardial Infarction

PubMed Central

Huang, Mei; Nguyen, Patricia; Jia, Fangjun; Hu, Shijun; Gong, Yongquan; de Almeida, Patricia E.; Wang, Li; Nag, Divya; Kay, Mark A.; Giaccia, Amato J; Robbins, Robert C.; Wu, Joseph C.

2011-01-01

Background Under normoxic conditions, hypoxia inducible factor-1 alpha (HIF-1α) is rapidly degraded by two hydroxylases, prolyl hydroxylase (PHD) and factor inhibiting HIF-1 (FIH). Because HIF-1α mediates the cardioprotective response to ischemic injury, its up-regulation may be an effective therapeutic option for ischemic heart failure. Methods and Results PHD and FIH were cloned from mouse embryonic stem cells. The best candidate short hairpin sequences for inhibiting PHD isoenzyme 2 (shPHD2) and FIH (shFIH) were inserted into novel non-viral minicircle vectors. In vitro studies after cell transfection of mouse C2C12 myoblasts, HL-1 atrial myocytes, and c-kit+ cardiac progenitor cells (CPCs) demonstrated higher expression of angiogenesis factors in the double knockdown group compared to the single knockdown and shScramble control groups. To confirm in vitro data, shRNA minicircle vectors were injected intramyocardially following LAD ligation in adult FVB mice (n=60). Functional studies using magnetic resonance imaging (MRI), echocardiography, and pressure-volume (PV) loops showed greater improvement in cardiac function in the double knockdown group. To assess mechanism(s) of this functional recovery, we performed a cell trafficking experiment, which demonstrated significantly greater recruitment of bone marrow cells to the ischemic myocardium in the double knockdown group. Fluorescence activated cell sorting (FACS) showed significantly higher activation of endogenous c-kit+ cardiac progenitor cells. Immunostaining showed increased neovascularization and decreased apoptosis in areas of injured myocardium. Finally, western blots and laser capture microdissection (LCM) analysis confirmed up-regulation of HIF-1α protein and angiogenesis genes, respectively. Conclusions We demonstrated that HIF-1α up-regulation by double knockdown of PHD and FIH synergistically increases stem cell mobilization and myocardial angiogenesis, leading to improved cardiac function. PMID:21911818

A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis.

PubMed

Lee, Chunghee; Clark, Steven E

2015-01-01

The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified.

A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

PubMed Central

Lee, Chunghee; Clark, Steven E.

2015-01-01

The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

Generation, characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells.

PubMed

Zhang, Zhenzhen; Liu, Jianfang; Liu, Yang; Li, Zheng; Gao, Wei-Qiang; He, Zuping

2013-02-01

Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end-stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end-stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra-hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra-hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. Copyright © 2012 Wiley Periodicals, Inc.

Stem cells in dentistry--part I: stem cell sources.

PubMed

Egusa, Hiroshi; Sonoyama, Wataru; Nishimura, Masahiro; Atsuta, Ikiru; Akiyama, Kentaro

2012-07-01

Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra- and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Plant stem cell niches.

PubMed

Stahl, Yvonne; Simon, Rüdiger

2005-01-01

Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

Stem cells in the Drosophila digestive system.

PubMed

Zeng, Xiankun; Chauhan, Chhavi; Hou, Steven X

2013-01-01

Adult stem cells maintain tissue homeostasis by continuously replenishing damaged, aged and dead cells in any organism. Five types of region and organ-specific multipotent adult stem cells have been identified in the Drosophila digestive system: intestinal stem cells (ISCs) in the posterior midgut; hindgut intestinal stem cells (HISCs) at the midgut/hindgut junction; renal and nephric stem cells (RNSCs) in the Malpighian Tubules; type I gastric stem cells (GaSCs) at foregut/midgut junction; and type II gastric stem cells (GSSCs) at the middle of the midgut. Despite the fact that each type of stem cell is unique to a particular organ, they share common molecular markers and some regulatory signaling pathways. Due to the simpler tissue structure, ease of performing genetic analysis, and availability of abundant mutants, Drosophila serves as an elegant and powerful model system to study complex stem cell biology. The recent discoveries, particularly in the Drosophila ISC system, have greatly advanced our understanding of stem cell self-renewal, differentiation, and the role of stem cells play in tissue homeostasis/regeneration and adaptive tissue growth.

Induced cancer stem cells generated by radiochemotherapy and their therapeutic implications.

PubMed

Chen, Xiewan; Liao, Rongxia; Li, Dezhi; Sun, Jianguo

2017-03-07

Local and distant recurrence of malignant tumors following radio- and/or chemotherapy correlates with poor prognosis of patients. Among the reasons for cancer recurrence, preexisting cancer stem cells (CSCs) are considered the most likely cause due to their properties of self-renewal, pluripotency, plasticity and tumorigenicity. It has been demonstrated that preexisting cancer stem cells derive from normal stem cells and differentiated somatic cells that undergo transformation and dedifferentiation respectively under certain conditions. However, recent studies have revealed that cancer stem cells can also be induced from non-stem cancer cells by radiochemotherapy, constituting the subpopulation of induced cancer stem cells (iCSCs). These findings suggest that radiochemotherapy has the side effect of directly transforming non-stem cancer cells into induced cancer stem cells, possibly contributing to tumor recurrence and metastasis. Therefore, drugs targeting cancer stem cells or preventing dedifferentiation of non-stem cancer cells can be combined with radiochemotherapy to improve its antitumor efficacy. The current review is to investigate the mechanisms by which induced cancer stem cells are generated by radiochemotherapy and hence provide new strategies for cancer treatment.

Stem cells in gastroenterology and hepatology

PubMed Central

Quante, Michael; Wang, Timothy C.

2010-01-01

Cellular and tissue regeneration in the gastrointestinal tract and liver depends on stem cells with properties of longevity, self-renewal and multipotency. Progress in stem cell research and the identification of potential esophageal, gastric, intestinal, colonic, hepatic and pancreatic stem cells provides hope for the use of stem cells in regenerative medicine and treatments for disease. Embryonic stem cells and induced pluripotent stem cells have the potential to give rise to any cell type in the human body, but their therapeutic application remains challenging. The use of adult or tissue-restricted stem cells is emerging as another possible approach for the treatment of gastrointestinal diseases. The same self-renewal properties that allow stem cells to remain immortal and generate any tissue can occasionally make their proliferation difficult to control and make them susceptible to malignant transformation. This Review provides an overview of the different types of stem cell, focusing on tissue-restricted adult stem cells in the fields of gastroenterology and hepatology and summarizing the potential benefits and risks of using stems cells to treat gastroenterological and liver disorders. PMID:19884893

Lower Oncogenic Potential of Human Mesenchymal Stem Cells Derived from Cord Blood Compared to Induced Pluripotent Stem Cells

PubMed Central

Foroutan, T.; Najmi, M.; Kazemi, N.; Hasanlou, M.; Pedram, A.

2015-01-01

Background: In regenerative medicine, use of each of the mesenchymal stem cells derived from bone marrow, cord blood, and adipose tissue, has several cons and pros. Mesenchymal stem cells derived from cord blood have been considered the best source for precursor transplantation. Direct reprogramming of a somatic cell into induced pluripotent stem cells by over-expression of 6 transcription factors Oct4, Sox2, Klf4, lin28, Nanog, and c-Myc has great potential for regenerative medicine, eliminating the ethical issues of embryonic stem cells and the rejection problems of using non-autologous cells. Objective: To compare reprogramming and pluripotent markers OCT4, Sox-2, c-Myc, Klf4, Nanog, and lin28 in mesenchymal stem cells derived from cord blood and induced pluripotent stem cells. Methods: We analyzed the expression level of OCT4, Sox-2, c-Myc, Klf4, Nanog and lin28 genes in human mesenchymal stem cells derived from cord blood and induced pluripotent stem cells by cell culture and RT-PCR. Results: The expression level of pluripotent genes OCT4 and Sox-2, Nanog and lin28 in mesenchymal stem cells derived from cord blood were significantly higher than those in induced pluripotent stem cells. In contrast to OCT-4A and Sox-2, Nanog and lin28, the expression level of oncogenic factors c-Myc and Klf4 were significantly higher in induced pluripotent stem cells than in mesenchymal stem cells derived from cord blood. Conclusion: It could be concluded that mesenchymal stem cells derived from human cord blood have lower oncogenic potential compared to induced pluripotent stem cells. PMID:26306155

Eckol suppresses maintenance of stemness and malignancies in glioma stem-like cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyun, Kyung-Hwan; Yoon, Chang-Hwan; Kim, Rae-Kwon

A subpopulation of cancer cells with stem cell properties is responsible for tumor maintenance and progression, and may contribute to resistance to anticancer treatments. Thus, compounds that target cancer stem-like cells could be usefully applied to destroy cancer. In this study, we investigated the effect of Eckol, a phlorotannin compound, on stemness and malignancies in glioma stem-like cells. To determine whether Eckol targets glioma stem-like cells, we examined whether Eckol treatment could change the expression levels of glioma stem-like cell markers and self-renewal-related proteins as well as the sphere forming ability, and the sensitivity to anticancer treatments. Alterations in themore » malignant properties of sphere-derived cells by Eckol were also investigated by soft-agar colony forming assay, by xenograft assay in nude mice, and by cell invasion assay. Treatment of sphere-forming glioma cells with Eckol effectively decreased the sphere formation as well as the CD133{sup +} cell population. Eckol treatment suppressed expression of the glioma stem-like cell markers and the self-renewal-related proteins without cell death. Moreover, treatment of glioma stem-like cells with Eckol significantly attenuated anchorage-independent growth on soft agar and tumor formation in xenograft mice. Importantly, Eckol treatment effectively reduced the resistance of glioma stem-like cells to ionizing radiation and temozolomide. Treatment of glioma stem-like cells with Eckol markedly blocked both phosphoinositide 3-kinase-Akt and Ras-Raf-1-Erk signaling pathways. These results indicate that the natural phlorotannin Eckol suppresses stemness and malignancies in glioma stem-like cells, and thereby makes glioma stem-like cells more sensitive to anticancer treatments, providing novel therapeutic strategies targeting specifically cancer stem-like cells.« less

Flagellin preconditioning enhances the efficacy of mesenchymal stem cells in an irradiation-induced proctitis model.

PubMed

Linard, Christine; Strup-Perrot, Carine; Lacave-Lapalun, Jean-Victor; Benderitter, Marc

2016-09-01

The success of mesenchymal stem cell transplantation for proctitis depends not only on cell donors but also on host microenvironmental factors, which play a major role in conditioning mesenchymal stem cell immunosuppressive action and repair. This study sought to determine if flagellin, a TLR5 ligand, can enhance the mesenchymal stem cell treatment efficacy in radiation-induced proctitis. With the use of a colorectal model of 27 Gy irradiation in rats, we investigated and compared the effects on immune capacity and remodeling at 28 d after irradiation of the following: 1) systemic mesenchymal stem cell (5 × 10(6)) administration at d 7 after irradiation, 2) administration of flagellin at d 3 and systemic mesenchymal stem cell administration at d 7, and 3) in vitro preconditioning of mesenchymal stem cells with flagellin, 24 h before their administration on d 7. The mucosal CD8(+) T cell population was normalized after treatment with flagellin-preconditioned mesenchymal stem cells or flagellin plus mesenchymal stem cells, whereas mesenchymal stem cells alone did not alter the radiation-induced elevation of CD8(+) T cell frequency. Mesenchymal stem cell treatment returned the irradiation-elevated frequency of CD25(+) cells in the mucosa-to-control levels, whereas both flagellin-preconditioned mesenchymal stem cell and flagellin-plus-mesenchymal stem cell treatment each significantly increased not only CD25(+) cell frequency but also forkhead box p3 and IL-2Rα expression. Specifically, IL-10 was overexpressed after flagellin-preconditioned mesenchymal stem cell treatment. Analysis of collagen expression showed that the collagen type 1/collagen type 3 ratio, an indicator of wound-healing maturation, was low in the irradiated and mesenchymal stem cell-treated groups and returned to the normal level only after the flagellin-preconditioned mesenchymal stem cell treatment. This was associated with a reduction in myofibroblast accumulation. In a proctitis model, flagellin-preconditioned mesenchymal stem cells improved colonic immune capacity and enhanced tissue remodeling. © Society for Leukocyte Biology.

Epidermal stem cells: location, potential and contribution to cancer.

PubMed

Ambler, C A; Määttä, A

2009-01-01

Epidermal stem cells have been classically characterized as slow-cycling, long-lived cells that reside in discrete niches in the skin. Gene expression studies of niche-resident cells have revealed a number of stem cell markers and regulators, including the Wnt/beta-catenin, Notch, p63, c-Myc and Hedgehog pathways. A new study challenges the traditional developmental paradigm of slow-cycling stem cells and rapid-cycling transit amplifying cells in some epidermal regions, and there is mounting evidence to suggest that multi-lineage epidermal progenitors can be isolated from highly proliferative, non-niche regions. Whether there is a unique microenvironment surrounding these progenitors remains to be determined. Interestingly, cancer stem cells derived from epidermal tumours exist independent of the classic skin stem cell niche, yet also have stem cell properties, including multi-lineage differentiation. This review summarizes recent studies identifying the location and regulators of mouse and human epidermal stem cells and highlights the strategies used to identify cancer stem cells, including expression of normal epidermal stem cell markers, expression of cancer stem cell markers identified in other epidermal tumours and characterization of side-population tumour cells.

Photochemical internalisation, a minimally invasive strategy for light-controlled endosomal escape of cancer stem cell-targeting therapeutics.

PubMed

Selbo, Pål Kristian; Bostad, Monica; Olsen, Cathrine Elisabeth; Edwards, Victoria Tudor; Høgset, Anders; Weyergang, Anette; Berg, Kristian

2015-08-01

Despite progress in radio-, chemo- and photodynamic-therapy (PDT) of cancer, treatment resistance still remains a major problem for patients with aggressive tumours. Cancer stem cells (CSCs) or tumour-initiating cells are intrinsically and notoriously resistant to conventional cancer therapies and are proposed to be responsible for the recurrence of tumours after therapy. According to the CSC hypothesis, it is imperative to develop novel anticancer agents or therapeutic strategies that take into account the biology and role of CSCs. The present review outlines our recent study on photochemical internalisation (PCI) using the clinically relevant photosensitiser TPCS2a/Amphinex® as a rational, non-invasive strategy for the light-controlled endosomal escape of CSC-targeting drugs. PCI is an intracellular drug delivery method based on light-induced ROS-generation and a subsequent membrane-disruption of endocytic vesicles, leading to cytosolic release of the entrapped drugs of interest. In different proof-of-concept studies we have demonstrated that PCI of CSC-directed immunotoxins targeting CD133, CD44, CSPG4 and EpCAM is a highly specific and effective strategy for killing cancer cells and CSCs. CSCs overexpressing CD133 are PDT-resistant; however, this is circumvented by PCI of CD133-targeting immunotoxins. In view of the fact that TPCS2a is not a substrate of the efflux pumps ABCG2 and P-glycoprotein (ABCB1), the PCI-method is a promising anti-CSC therapeutic strategy. Due to a laser-controlled exposure, PCI of CSC-targeting drugs will be confined exclusively to the tumour tissue, suggesting that this drug delivery method has the potential to spare distant normal stem cells.

N-glycosylation profile of undifferentiated and adipogenically differentiated human bone marrow mesenchymal stem cells: towards a next generation of stem cell markers.

PubMed

Hamouda, Houda; Ullah, Mujib; Berger, Markus; Sittinger, Michael; Tauber, Rudolf; Ringe, Jochen; Blanchard, Véronique

2013-12-01

Mesenchymal stem cells (MSCs) are multipotent cells that are easy to isolate and expand, develop into several tissues, including fat, migrate to diseased organs, have immunosuppressive properties and secrete regenerative factors. This makes MSCs ideal for regenerative medicine. For application and regulatory purposes, knowledge of (bio)markers characterizing MSCs and their development stages is of paramount importance. The cell surface is coated with glycans that possess lineage-specific nature, which makes glycans to be promising candidate markers. In the context of soft tissue generation, we aimed to identify glycans that could be markers for MSCs and their adipogenically differentiated progeny. MSCs were isolated from human bone marrow, adipogenically stimulated for 15 days and adipogenesis was verified by staining the lipid droplets and quantitative real time polymerase chain reaction of the marker genes peroxisome proliferator-activated receptor gamma (PPARG) and fatty acid binding protein-4 (FABP4). Using matrix-assisted laser desorption-ionization-time of flight mass spectrometry combined with exoglycosidase digestions, we report for the first time the N-glycome of MSCs during adipogenic differentiation. We were able to detect more than 100 different N-glycans, including high-mannose, hybrid, and complex N-glycans, as well as poly-N-acetyllactosamine chains. Adipogenesis was accompanied by an increased amount of biantennary fucosylated structures, decreased amount of fucosylated, afucosylated tri- and tetraantennary structures and increased sialylation. N-glycans H6N5F1 and H7N6F1 were significantly overexpressed in undifferentiated MSCs while H3N4F1 and H5N4F3 were upregulated in adipogenically differentiated MSCs. These glycan structures are promising candidate markers to detect and distinguish MSCs and their adipogenic progeny.

MicroRNAs: key regulators of stem cells.

PubMed

Gangaraju, Vamsi K; Lin, Haifan

2009-02-01

The hallmark of a stem cell is its ability to self-renew and to produce numerous differentiated cells. This unique property is controlled by dynamic interplays between extrinsic signalling, epigenetic, transcriptional and post-transcriptional regulations. Recent research indicates that microRNAs (miRNAs) have an important role in regulating stem cell self-renewal and differentiation by repressing the translation of selected mRNAs in stem cells and differentiating daughter cells. Such a role has been shown in embryonic stem cells, germline stem cells and various somatic tissue stem cells. These findings reveal a new dimension of gene regulation in controlling stem cell fate and behaviour.

[Progress in epidermal stem cells].

PubMed

Wang, Li-Juan; Wang, You-Liang; Yang, Xiao

2010-03-01

Mammalian skin epidermis contains different epidermal stem cell pools which contribute to the homeostasis and repair of skin epithelium. Epidermal stem cells possess two essential features common to all stem cells: self-renewal and differentiation. Disturbing the balance between self-renewal and differentiation of epidermal stem cell often causes tumors or other skin diseases. Epidermal stem cell niches provide a special microenvironment that maintains a balance of stem cell quiescence and activity. This review primarily concentrates on the following points of the epidermal stem cells: the existing evidences, the self-renewal and differentiation, the division pattern, the signal pathways regulating self-renewal and differentiation, and the microenvironment (niche) and macroenvironment maintaining the homeostasis of stem cells.

[Research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration].

PubMed

Liang, Hang; Deng, Xiangyu; Shao, Zengwu

2017-10-01

To summarize the research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration and deduce the therapeutic potential of endogenous repair for intervertebral disc degeneration. The original articles about intervertebral disc endogenous stem cells for intervertebral disc regeneration were extensively reviewed; the reparative potential in vivo and the extraction and identification in vitro of intervertebral disc endogenous stem cells were analyzed; the prospect of endogenous stem cells for intervertebral disc regeneration was predicted. Stem cell niche present in the intervertebral discs, from which stem cells migrate to injured tissues and contribute to tissues regeneration under certain specific microenvironment. Moreover, the migration of stem cells is regulated by chemokines system. Tissue specific progenitor cells have been identified and successfully extracted and isolated. The findings provide the basis for biological therapy of intervertebral disc endogenous stem cells. Intervertebral disc endogenous stem cells play a crucial role in intervertebral disc regeneration. Therapeutic strategy of intervertebral disc endogenous stem cells is proven to be a promising biological approach for intervertebral disc regeneration.

Amnion-derived stem cells: in quest of clinical applications

PubMed Central

2011-01-01

In the promising field of regenerative medicine, human perinatal stem cells are of great interest as potential stem cells with clinical applications. Perinatal stem cells could be isolated from normally discarded human placentae, which are an ideal cell source in terms of availability, the fewer number of ethical concerns, less DNA damage, and so on. Numerous studies have demonstrated that some of the placenta-derived cells possess stem cell characteristics like pluripotent differentiation ability, particularly in amniotic epithelial (AE) cells. Term human amniotic epithelium contains a relatively large number of stem cell marker-positive cells as an adult stem cell source. In this review, we introduce a model theory of why so many AE cells possess stem cell characteristics. We also describe previous work concerning the therapeutic applications and discuss the pluripotency of the AE cells and potential pitfalls for amnion-derived stem cell research. PMID:21596003

The role of stem cells in aesthetic surgery: fact or fiction?

PubMed

McArdle, Adrian; Senarath-Yapa, Kshemendra; Walmsley, Graham G; Hu, Michael; Atashroo, David A; Tevlin, Ruth; Zielins, Elizabeth; Gurtner, Geoffrey C; Wan, Derrick C; Longaker, Michael T

2014-08-01

Stem cells are attractive candidates for the development of novel therapies, targeting indications that involve functional restoration of defective tissue. Although most stem cell therapies are new and highly experimental, there are clinics around the world that exploit vulnerable patients with the hope of offering supposed stem cell therapies, many of which operate without credible scientific merit, oversight, or other patient protection. The authors review the potential and the drawbacks of incorporation of stem cells in cosmetic procedures. A review of U.S. Food and Drug Administration-approved indications and ongoing clinical trials with adipose stem cells is provided. Furthermore, a "snapshot" analysis of Web sites using the search terms "stem cell therapy" or "stem cell treatment" or "stem cell facelift" was performed. Despite the protective net cast by regulatory agencies such as the U.S. Food and Drug Administration and professional societies such as the American Society of Plastic Surgeons, the authors are witnessing worrying advertisements for procedures such as stem cell face lifts, stem cell breast augmentations, and even stem cell vaginal rejuvenation. The marketing and promotion of stem cell procedures in aesthetic surgery is not adequately supported by clinical evidence in the majority of cases. Stem cells offer tremendous potential, but the marketplace is saturated with unsubstantiated and sometimes fraudulent claims that may place patients at risk. With plastic surgeons at the forefront of stem cell-based regenerative medicine, it is critically important that they provide an example of a rigorous approach to research, data collection, and advertising of stem cell therapies.

Polymer microarray technology for stem cell engineering

PubMed Central

Coyle, Robert; Jia, Jia; Mei, Ying

2015-01-01

Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. During the past decade, significant progress has been made in developing soluble factors (e.g., small molecules and growth factors) to direct stem cells into a desired phenotype. However, the current lack of suitable synthetic materials to regulate stem cell activity has limited the realization of the enormous potential of stem cells. This can be attributed to a large number of materials properties (e.g., chemical structures and physical properties of materials) that can affect stem cell fate. This makes it challenging to design biomaterials to direct stem cell behavior. To address this, polymer microarray technology has been developed to rapidly identify materials for a variety of stem cell applications. In this article, we summarize recent developments in polymer array technology and their applications in stem cell engineering. Statement of significance Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. In the last decade, significant progress has been made in developing chemically defined media to direct stem cells into a desired phenotype. However, the current lack of the suitable synthetic materials to regulate stem cell activities has been limiting the realization of the potential of stem cells. This can be attributed to the number of variables in material properties (e.g., chemical structures and physical properties) that can affect stem cells. Polymer microarray technology has shown to be a powerful tool to rapidly identify materials for a variety of stem cell applications. Here we summarize recent developments in polymer array technology and their applications in stem cell engineering. PMID:26497624

Stem cells in kidney regeneration.

PubMed

Yokote, Shinya; Yokoo, Takashi

2012-01-01

Currently many efforts are being made to apply regenerative medicine to kidney diseases using several types of stem/progenitor cells, such as mesenchymal stem cells, renal stem/progenitor cells, embryonic stem cells and induced pluripotent stem cells. Stem cells have the ability to repair injured organs and ameliorate damaged function. The strategy for kidney tissue repair is the recruitment of stem cells and soluble reparative factors to the kidney to elicit tissue repair and the induction of dedifferentiation of resident renal cells. On the other hand, where renal structure is totally disrupted, absolute kidney organ regeneration is needed to rebuild a whole functional kidney. In this review, we describe current advances in stem cell research for kidney tissue repair and de novo organ regeneration.

Stem Cell Sciences plc.

PubMed

Daniels, Sebnem

2006-09-01

Stem Cell Sciences' core objective is to develop safe and effective stem cell-based therapies for currently incurable diseases. In order to achieve this goal, Stem Cell Sciences recognizes the need for multiple technologies and a globally integrated stem cell initiative. The key challenges for the successful application of stem cells in the clinic is the need for a reproducible supply of pure, fully characterized stem cells that have been grown in suitable conditions for use in the clinic.

Stem cell-derived vascular endothelial cells and their potential application in regenerative medicine

USDA-ARS?s Scientific Manuscript database

Although a 'vascular stem cell' population has not been identified or generated, vascular endothelial and mural cells (smooth muscle cells and pericytes) can be derived from currently known pluripotent stem cell sources, including human embryonic stem cells and induced pluripotent stem cells. We rev...

Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

PubMed Central

2013-01-01

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

Stem Cell Basics

MedlinePlus

... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

TOPICAL REVIEW: Stem cells engineering for cell-based therapy

NASA Astrophysics Data System (ADS)

Taupin, Philippe

2007-09-01

Stem cells carry the promise to cure a broad range of diseases and injuries, from diabetes, heart and muscular diseases, to neurological diseases, disorders and injuries. Significant progresses have been made in stem cell research over the past decade; the derivation of embryonic stem cells (ESCs) from human tissues, the development of cloning technology by somatic cell nuclear transfer (SCNT) and the confirmation that neurogenesis occurs in the adult mammalian brain and that neural stem cells (NSCs) reside in the adult central nervous system (CNS), including that of humans. Despite these advances, there may be decades before stem cell research will translate into therapy. Stem cell research is also subject to ethical and political debates, controversies and legislation, which slow its progress. Cell engineering has proven successful in bringing genetic research to therapy. In this review, I will review, in two examples, how investigators are applying cell engineering to stem cell biology to circumvent stem cells' ethical and political constraints and bolster stem cell research and therapy.

From Banking to International Governance: Fostering Innovation in Stem Cell Research

PubMed Central

Isasi, Rosario; Knoppers, Bartha M.

2011-01-01

Stem cell banks are increasingly recognized as an essential resource of biological materials for both basic and translational stem cell research. By providing transnational access to quality controlled and ethically sourced stem cell lines, stem cell banks seek to foster international collaboration and innovation. However, given that national stem cell banks operate under different policy, regulatory and commercial frameworks, the transnational sharing of stem cell materials and data can be complicating. This paper will provide an overview of the most pressing challenges regarding the governance of stem cell banks, and the difficulties in designing regulatory and commercial frameworks that foster stem cell research. Moreover, the paper will shed light on the numerous international initiatives that have arisen to help harmonize and standardize stem cell banking and research processes to overcome such challenges. PMID:21904557

Stem Cells Transplantation in the Treatment of Patients with Liver Failure.

PubMed

Tao, Ya-Chao; Wang, Meng-Lan; Chen, En-Qiang; Tang, Hong

2018-02-23

Liver failure is a life-threatening liver disease encompassing severe acute deterioration of liver function. Emergency liver transplantation is the only curative treatment for liver failure, but is restricted by the severe shortage of organ donors. Stem cell, including embroyonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, hematopoietic stem cells and hepatic progenitor cells, have capacity to proliferate and differentiate and could be used in a variety of liver diseases including hereditary liver diseases, cirrhosis and liver failure. We summarized the basic experimental and clinical advances of stem cell transplantation in liver failure treatment, and also discussed the advantages and disadvantage of different stem cells subtype in this field, aiming to provide a perspective on the stem cell-based therapy for liver failure. Stem cells, especially mesenchymal stem cells (mainly low immunogenicity and paracrine characteristics) and induced pluripotent stem cells (generation of desired cell type from somatic cell), are feasible candidates for cell therapy in the treatment of liver failure, but there are some drawbacks remaining to be resolved, such as low engraftment, cryotpreservation methods and tumorigenesis. Stem cell transplantation is a promising but challenging strategy and paves a new way for curing liver failure. But more efforts need to be made to overcome problems before this new strategy could be safely and effectively applied to humans. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Recent Progress in Stem Cell Modification for Cardiac Regeneration

PubMed Central

Voronina, Natalia; Steinhoff, Gustav

2018-01-01

During the past decades, stem cell-based therapy has acquired a promising role in regenerative medicine. The application of novel cell therapeutics for the treatment of cardiovascular diseases could potentially achieve the ambitious aim of effective cardiac regeneration. Despite the highly positive results from preclinical studies, data from phase I/II clinical trials are inconsistent and the improvement of cardiac remodeling and heart performance was found to be quite limited. The major issues which cardiac stem cell therapy is facing include inefficient cell delivery to the site of injury, accompanied by low cell retention and weak effectiveness of remaining stem cells in tissue regeneration. According to preclinical and clinical studies, various stem cells (adult stem cells, embryonic stem cells, and induced pluripotent stem cells) represent the most promising cell types so far. Beside the selection of the appropriate cell type, researchers have developed several strategies to produce “second-generation” stem cell products with improved regenerative capacity. Genetic and nongenetic modifications, chemical and physical preconditioning, and the application of biomaterials were found to significantly enhance the regenerative capacity of transplanted stem cells. In this review, we will give an overview of the recent developments in stem cell engineering with the goal to facilitate stem cell delivery and to promote their cardiac regenerative activity. PMID:29535769

Eat, breathe, ROS: controlling stem cell fate through metabolism.

PubMed

Kubli, Dieter A; Sussman, Mark A

2017-05-01

Research reveals cardiac regeneration exists at levels previously deemed unattainable. Clinical trials using stem cells demonstrate promising cardiomyogenic and regenerative potential but insufficient contractile recovery. Incomplete understanding of the biology of administered cells likely contributes to inconsistent patient outcomes. Metabolism is a core component of many well-characterized stem cell types, and metabolic changes fundamentally alter stem cell fate from self-renewal to lineage commitment, and vice versa. However, the metabolism of stem cells currently studied for cardiac regeneration remains incompletely understood. Areas covered: Key metabolic features of stem cells are reviewed and unique stem cell metabolic characteristics are discussed. Metabolic changes altering stem cell fate are considered from quiescence and self-renewal to lineage commitment. Key metabolic concepts are applied toward examining cardiac regeneration through stem cell-based approaches, and clinical implications of current cell therapies are evaluated to identify potential areas of improvement. Expert commentary: The metabolism and biology of stem cells used for cardiac therapy remain poorly characterized. A growing appreciation for the fundamental relationship between stem cell functionality and metabolic phenotype is developing. Future studies unraveling links between cardiac stem cell metabolism and regenerative potential may considerably improve treatment strategies and therapeutic outcomes.

Eat, breathe, ROS: controlling stem cell fate through metabolism

PubMed Central

Kubli, Dieter A.; Sussman, Mark A.

2017-01-01

Introduction Research reveals cardiac regeneration exists at levels previously deemed unattainable. Clinical trials using stem cells demonstrate promising cardiomyogenic and regenerative potential but insufficient contractile recovery. Incomplete understanding of the biology of administered cells likely contributes to inconsistent patient outcomes. Metabolism is a core component of many well-characterized stem cell types, and metabolic changes fundamentally alter stem cell fate from self-renewal to lineage commitment, and vice versa. However, the metabolism of stem cells currently studied for cardiac regeneration remains incompletely understood. Areas covered Key metabolic features of stem cells are reviewed and unique stem cell metabolic characteristics are discussed. Metabolic changes altering stem cell fate are considered from quiescence and self-renewal to lineage commitment. Key metabolic concepts are applied toward examining cardiac regeneration through stem cell-based approaches, and clinical implications of current cell therapies are evaluated to identify potential areas of improvement. Expert commentary The metabolism and biology of stem cells used for cardiac therapy remain poorly characterized. A growing appreciation for the fundamental relationship between stem cell functionality and metabolic phenotype is developing. Future studies unraveling links between cardiac stem cell metabolism and regenerative potential may considerably improve treatment strategies and therapeutic outcomes. PMID:28406333

Therapeutic strategies involving uterine stem cells in reproductive medicine.

PubMed

Simoni, Michael; Taylor, Hugh S

2018-06-01

The current review provides an update on recent advances in stem cell biology relevant to female reproduction. Stem cells are undifferentiated cells that often serve as a reservoir of cells to regenerate tissue in settings or injury or cell loss. The endometrium has progenitor stem cells that can replace all of the endometrium during each menstrual cycle. In addition, multipotent endometrial cells replace these progenitor cells when depleted. Recruitment of stem cells from outside of the uterus occurs in setting of increased demand such as ischemia or injury. Bone marrow-derived multipotent stem cells are recruited to the uterus by estrogen or injury-induced expression of the chemokine CXCL12. In the setting of overwhelming injury, especially in the setting of low estrogen levels, there may be insufficient stem cell recruitment to adequately repair the uterus resulting in conditions such as Asherman syndrome or other endometrial defects. In contrast, excessive recruitment of stem cells underlies endometriosis. Enhanced understanding of stem-cell mobilization, recruitment, and engraftment has created the possibility of improved therapy for endometrial defects and endometriosis through enhanced manipulation of stem-cell trafficking. Further, the normal endometrium is a rich source of multipotent stem cells that can be used for numerous applications in regenerative medicine beyond reproduction. A better understanding of reproductive stem-cell biology may allow improved treatment of endometrial disease such as Asherman syndrome and other endometrial receptivity defects. Inhibiting stem-cell mobilization may also be helpful in endometriosis therapy. Finally, endometrial derived multipotent stem cells may play a crucial role in cell therapy for regenerative medicine.

New technology for ultrasensitive detection and isolation of rare cells for clinical diagnostics and therapeutics

NASA Astrophysics Data System (ADS)

Leary, James F.; McLaughlin, Scott R.

1995-04-01

A high-speed, 11-parameter, 6-color fluorescence, laser flow cytometer/cell sorter with a number of special and unique features has been built for ultrasensitive detection and isolation of rare cells for clinical diagnostics and therapeutics. The software for real-time data acquisition and sort control, written as C++ programming language modules with a WindowsTM graphical user interface, runs on a 66-MHz 80486 computer joined by an extended bus to 23 sophisticated multi-layered boards of special data acquisition and sorting electronics. Special features include: high-speed (> 100,000 cells/sec) real-time data classification module (U.S. Patent 5,204,884 (1993)); real-time principal component cell sorting; multi-queue signal-processing system with multiple hardware and software event buffers to reduce instrument dead time, LUT charge-pulse definition, high-resolution `flexible' sorting for optimal yield/purity sort strategies (U.S. Patent 5,199,576); pre-focusing optical wavelength correction for a second laser beam; and two trains of three fluorescence detectors-- each adjustable for spatial separation to interrogate only one of two laser beams, syringe- driven or pressure-driven fluidics, and time-windowed parameters. The system has been built to be both expandable and versatile through the use of LUT's and a modular hardware and software design. The instrument is especially useful at detection and isolation of rare cell subpopulations for which our laboratory is well-known. Cell subpopulations at frequencies as small as 10-7 have been successfully studied with this system. Current applications in clinical diagnostics and therapeutics include detection and isolation of (1) fetal cells from material blood for prenatal diagnosis of birth defects, (2) hematopoietic stem and precursor cells for autologous bone marrow transplantation, (3) metastatic breast cancer cells for molecular characterization, and (4) HIV-infected maternal cells in newborn blood to study mother-to-infant vertical transmission of AIDS.

Gene screening of Wharton's jelly derived stem cells.

PubMed

Mechiche Alami, S; Velard, F; Draux, F; Siu Paredes, F; Josse, J; Lemaire, F; Gangloff, S C; Graesslin, O; Laurent-Maquin, D; Kerdjoudj, H

2014-01-01

Stem cells are the most powerful candidate for the treatment of various diseases. Suitable stem cell source should be harvested with minimal invasive procedure, found in great quantity, and transplanted with no risk of immune response and tumor formation. Fetal derived stem cells have been introduced as an excellent alternative to adult and embryonic stem cells use, but unfortunately, their degree of "stemness" and molecular characterization is still unclear. Several studies have been performed deciphering whether fetal stem cells meet the needs of regenerative medicine. We believe that a transcriptomic screening of Wharton's jelly stem cells will bring insights on cell population features.

In vivo selective cancer-tracking gadolinium eradicator as new-generation photodynamic therapy agent

PubMed Central

Zhang, Tao; Lan, Rongfeng; Chan, Chi-Fai; Law, Ga-Lai; Wong, Wai-Kwok; Wong, Ka-Leung

2014-01-01

In this work, we demonstrate a modality of photodynamic therapy (PDT) through the design of our truly dual-functional—PDT and imaging—gadolinium complex (Gd-N), which can target cancer cells specifically. In the light of our design, the PDT drug can specifically localize on the anionic cell membrane of cancer cells in which its laser-excited photoemission signal can be monitored without triggering the phototoxic generation of reactive oxygen species—singlet oxygen—before due excitation. Comprehensive in vitro and in vivo studies had been conducted for the substantiation of the effectiveness of Gd-N as such a tumor-selective PDT photosensitizer. This treatment modality does initiate a new direction in the development of “precision medicine” in line with stem cell and gene therapies as tools in cancer therapy. PMID:25453097

Stem Cell Banking for Regenerative and Personalized Medicine

PubMed Central

Harris, David T.

2014-01-01

Regenerative medicine, tissue engineering and gene therapy offer the opportunity to treat and cure many of today’s intractable afflictions. These approaches to personalized medicine often utilize stem cells to accomplish these goals. However, stem cells can be negatively affected by donor variables such as age and health status at the time of collection, compromising their efficacy. Stem cell banking offers the opportunity to cryogenically preserve stem cells at their most potent state for later use in these applications. Practical stem cell sources include bone marrow, umbilical cord blood and tissue, and adipose tissue. Each of these sources contains stem cells that can be obtained from most individuals, without too much difficulty and in an economical fashion. This review will discuss the advantages and disadvantages of each stem cell source, factors to be considered when contemplating banking each stem cell source, the methodology required to bank each stem cell source, and finally, current and future clinical uses of each stem cell source. PMID:28548060

Nine Things to Know About Stem Cell Treatments

MedlinePlus

... Toggle Nav Nine Things To Know About Stem Cell Treatments Home > Stem Cells and Medicine > Nine Things ... About Stem Cell Treatments Many clinics offering stem cell treatments make claims that are not supported by ...

Effects of low-level laser therapy on stem cells from human exfoliated deciduous teeth.

PubMed

Fernandes, Ana Paula; Junqueira, Marina de Azevedo; Marques, Nádia Carolina Teixeira; Machado, Maria Aparecida Andrade Moreira; Santos, Carlos Ferreira; Oliveira, Thais Marchini; Sakai, Vivien Thiemy

2016-01-01

This study aimed to evaluate the influence of different laser therapy energy densities on SHED viability and proliferation. SHED were irradiated according to the groups: I (1.2 J/cm2 - 0.5 mW - 10 s), II (2.5 J/cm2 - 10 mW - 10 s), III (3.7 J/cm2 - 15 mW - 10 s), IV (5.0 J/cm2 - 20 mW - 10 s), V (6.2 J/cm2 - 25 mW - 10 s), and VI (not irradiated - control group). Cell viability was assessed 6 and 24 h after irradiation measuring the mitochondrial activity and using the Crystal Violet assay. Cell proliferation was assessed after 24, 48, and 72 h of irradiation by SRB assay. MTT assay demonstrated differences from 6 to 24 hours after irradiation. After 24 h, groups I and IV showed higher absorbance values than those of control group. Crystal Violet assay showed statistically differences in the absorbance rate from 6 to 24 h after irradiation for groups III and VI. At 24 h after irradiation, Group III absorbance rate was greater than that of groups I, II, and IV. Group VI absorbance rate was greater than that of groups I and IV. SRB assay showed that the group I had higher rates than those of groups II, III, V, and VI, at 24 h after irradiation. After 48 h, group I exhibited the greatest cell proliferation rate followed by groups III, V, and VI. After 72 h, group III exhibited the lowest cell proliferation rate than those of groups II, IV, and V. The Low-Level Laser Therapy energy densities used in this study did not cause loss of cell viability and stimulated SHED proliferation within the parameters described in this study.

Cancer (stem) cell differentiation: An inherent or acquired property?

PubMed

Mohr, Marieke; Zänker, Kurt S; Dittmar, Thomas

2015-12-01

There is a growing list of data indicating that cancer (stem) cells could functionally adapt foreign tissue features, such as endothelial-like cells or neuroendocrine cells, express lineage markers or could differentiate into various lineages in response to appropriate differentiation criteria. The finding that cancer (stem) cells may possess some kind of differentiation capacity poses the question whether this might be an inherent or acquired property. Cancer stem cells share stem cell characteristics and may thus possess an inherent differentiation capacity enabling the cells to respond to various differentiation stimuli. Considering the plasticity of cancer (stem) cells, even non-tumorigenic (and putatively non-differentiable) tumor cells could give rise to tumorigenic tumor stem cells, exhibiting stem cell characteristics including an inherent differentiation capacity. On the contrary, cancer (stem) cells may have acquired differentiation capacity as a consequence of a previous cell fusion event with cell types exhibiting differentiation potential and being fusogenic, such as macrophages or stem cells. Of pivotal interest in a tumor context are macrophages, which chiefly foster the chronically inflamed tumor microenvironment. Because chronically inflamed tissue is a well-known trigger for cell fusion and both macrophages and stem cells are highly fusogenic we conclude that cell fusion events between these cell types and cancer (stem) cells should frequently occur, thereby giving rise to hybrid cells exhibiting not only novel properties, like an enhanced metastatogenic phenotype, but also parental characteristics, such as differentiation capacity. Conceivably, the combination of both properties might be advantageous for metastasizing cancer (stem) cells to adapt better and faster to a foreign organ tissue environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sox10+ adult stem cells contribute to biomaterial encapsulation and microvascularization

PubMed Central

Wang, Dong; Wang, Aijun; Wu, Fan; Qiu, Xuefeng; Li, Ye; Chu, Julia; Huang, Wen-Chin; Xu, Kang; Gong, Xiaohua; Li, Song

2017-01-01

Implanted biomaterials and biomedical devices generally induce foreign body reaction and end up with encapsulation by a dense avascular fibrous layer enriched in extracellular matrix. Fibroblasts/myofibroblasts are thought to be the major cell type involved in encapsulation, but it is unclear whether and how stem cells contribute to this process. Here we show, for the first time, that Sox10+ adult stem cells contribute to both encapsulation and microvessel formation. Sox10+ adult stem cells were found sparsely in the stroma of subcutaneous loose connective tissues. Upon subcutaneous biomaterial implantation, Sox10+ stem cells were activated and recruited to the biomaterial scaffold, and differentiated into fibroblasts and then myofibroblasts. This differentiation process from Sox10+ stem cells to myofibroblasts could be recapitulated in vitro. On the other hand, Sox10+ stem cells could differentiate into perivascular cells to stabilize newly formed microvessels. Sox10+ stem cells and endothelial cells in three-dimensional co-culture self-assembled into microvessels, and platelet-derived growth factor had chemotactic effect on Sox10+ stem cells. Transplanted Sox10+ stem cells differentiated into smooth muscle cells to stabilize functional microvessels. These findings demonstrate the critical role of adult stem cells in tissue remodeling and unravel the complexity of stem cell fate determination. PMID:28071739

Tumor suppressors Sav/Scrib and oncogene Ras regulate stem cell transformation in adult Drosophila Malpighian Tubules

PubMed Central

Zeng, Xiankun; Singh, Shree Ram; Hou, David; Hou, Steven X.

2012-01-01

An increasing body of evidence suggests that tumors might originate from a few transformed cells that share many properties with normal stem cells. However, it remains unclear how normal stem cells are transformed into cancer stem cells. Here, we demonstrated that mutations causing the loss of tumor suppressor Sav or Scrib or activation of the oncogene Ras transform normal stem cells into cancer stem cells through a multistep process in the adult Drosophila Malpighian Tubules (MTs). In wild-type MTs, each stem cell generates one self-renewing and one differentiating daughter cell. However, in flies with loss-of-function sav or scrib or gain-of-function Ras mutations, both daughter cells grew and behaved like stem cells, leading to the formation of tumors in MTs. Ras functioned downstream of Sav and Scrib in regulating the stem cell transformation. The Ras-transformed stem cells exhibited many of the hallmarks of cancer, such as increased proliferation, reduced cell death, and failure to differentiate. We further demonstrated that several signal transduction pathways (including MEK/MAPK, RhoA, PKA, and TOR) mediate Rasṕ function in the stem cell transformation. Therefore, we have identified a molecular mechanism that regulates stem cell transformation, and this finding may lead to strategies for preventing tumor formation in certain organs. PMID:20432470

The king is dead, long live the king: entering a new era of stem cell research and clinical development.

PubMed

Ichim, Thomas; Riordan, Neil H; Stroncek, David F

2011-12-20

In mid November the biopharma industry was shocked by the announcement from Geron that they were ending work on embryonic stem cell research and therapy. For more than 10 years the public image of all stem cell research has been equated with embryonic stem cells. Unfortunately, a fundamentally important medical and financial fact was being ignored: embryonic stem cell therapy is extremely immature. In parallel to efforts in embryonic stem cell research and development, scientists and physicians in the field of adult stem cells realized that the natural role of adult stem cells in the body is to promote healing and to act like endogenous "repair cells" and, as a result, numerous companies have entered the field of adult stem cell therapy with the goal of expanding numbers of adult stem cells for administration to patients with various conditions. In contrast to embryonic stem cells, which are extremely expensive and potentially dangerous, adult cell cells are inexpensive and have an excellent safety record when used in humans. Many studies are now showing that adult stem cells are practical, patient-applicable, therapeutics that are very close to being available for incorporation into the practice of medicine. These events signal the entrance of the field of stem cells into a new era: an era where hype and misinformation no longer triumph over economic and medical realities.

Control of stem cell fate by engineering their micro and nanoenvironment

PubMed Central

Griffin, Michelle F; Butler, Peter E; Seifalian, Alexander M; Kalaskar, Deepak M

2015-01-01

Stem cells are capable of long-term self-renewal and differentiation into specialised cell types, making them an ideal candidate for a cell source for regenerative medicine. The control of stem cell fate has become a major area of interest in the field of regenerative medicine and therapeutic intervention. Conventional methods of chemically inducing stem cells into specific lineages is being challenged by the advances in biomaterial technology, with evidence highlighting that material properties are capable of driving stem cell fate. Materials are being designed to mimic the clues stem cells receive in their in vivo stem cell niche including topographical and chemical instructions. Nanotopographical clues that mimic the extracellular matrix (ECM) in vivo have shown to regulate stem cell differentiation. The delivery of ECM components on biomaterials in the form of short peptides sequences has also proved successful in directing stem cell lineage. Growth factors responsible for controlling stem cell fate in vivo have also been delivered via biomaterials to provide clues to determine stem cell differentiation. An alternative approach to guide stem cells fate is to provide genetic clues including delivering DNA plasmids and small interfering RNAs via scaffolds. This review, aims to provide an overview of the topographical, chemical and molecular clues that biomaterials can provide to guide stem cell fate. The promising features and challenges of such approaches will be highlighted, to provide directions for future advancements in this exciting area of stem cell translation for regenerative medicine. PMID:25621104

The Neurovascular Properties of Dental Stem Cells and Their Importance in Dental Tissue Engineering

PubMed Central

Ratajczak, Jessica; Bronckaers, Annelies; Dillen, Yörg; Gervois, Pascal; Vangansewinkel, Tim; Driesen, Ronald B.; Wolfs, Esther; Lambrichts, Ivo

2016-01-01

Within the field of tissue engineering, natural tissues are reconstructed by combining growth factors, stem cells, and different biomaterials to serve as a scaffold for novel tissue growth. As adequate vascularization and innervation are essential components for the viability of regenerated tissues, there is a high need for easily accessible stem cells that are capable of supporting these functions. Within the human tooth and its surrounding tissues, different stem cell populations can be distinguished, such as dental pulp stem cells, stem cells from human deciduous teeth, stem cells from the apical papilla, dental follicle stem cells, and periodontal ligament stem cells. Given their straightforward and relatively easy isolation from extracted third molars, dental stem cells (DSCs) have become an attractive source of mesenchymal-like stem cells. Over the past decade, there have been numerous studies supporting the angiogenic, neuroprotective, and neurotrophic effects of the DSC secretome. Together with their ability to differentiate into endothelial cells and neural cell types, this makes DSCs suitable candidates for dental tissue engineering and nerve injury repair. PMID:27688777

Multipotent Stem Cell and Reproduction.

PubMed

Khanlarkhani, Neda; Baazm, Maryam; Mohammadzadeh, Farzaneh; Najafi, Atefeh; Mehdinejadiani, Shayesteh; Sobhani, Aligholi

Stem cells are self-renewing and undifferentiated cell types that can be differentiate into functional cells. Stem cells can be classified into two main types based on their source of origin: Embryonic and Adult stem cells. Stem cells also classified based on the range of differentiation potentials into Totipotent, Pluripotent, Multipotent, and Unipotent. Multipotent stem cells have the ability to differentiate into all cell types within one particular lineage. There are plentiful advantages and usages for multipotent stem cells. Multipotent Stem cells act as a significant key in procedure of development, tissue repair, and protection. The accessibility and adaptability of these amazing cells create them a great therapeutic choice for different part of medical approaches, and it becomes interesting topic in the scientific researches to found obvious method for the most advantageous use of MSC-based therapies. Recent studies in the field of stem cell biology have provided new perspectives and opportunities for the treatment of infertility disorders.

Strategies to improve homing of mesenchymal stem cells for greater efficacy in stem cell therapy.

PubMed

Naderi-Meshkin, Hojjat; Bahrami, Ahmad Reza; Bidkhori, Hamid Reza; Mirahmadi, Mahdi; Ahmadiankia, Naghmeh

2015-01-01

Stem/progenitor cell-based therapeutic approach in clinical practice has been an elusive dream in medical sciences, and improvement of stem cell homing is one of major challenges in cell therapy programs. Stem/progenitor cells have a homing response to injured tissues/organs, mediated by interactions of chemokine receptors expressed on the cells and chemokines secreted by the injured tissue. For improvement of directed homing of the cells, many techniques have been developed either to engineer stem/progenitor cells with higher amount of chemokine receptors (stem cell-based strategies) or to modulate the target tissues to release higher level of the corresponding chemokines (target tissue-based strategies). This review discusses both of these strategies involved in the improvement of stem cell homing focusing on mesenchymal stem cells as most frequent studied model in cellular therapies. © 2014 International Federation for Cell Biology.

College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning

ERIC Educational Resources Information Center

Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

2010-01-01

In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before…

Stem cell biobanks.

PubMed

Bardelli, Silvana

2010-04-01

Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

PubMed

Cornelison, Ddw; Perdiguero, Eusebio

2017-01-01

Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

Redox regulation of plant stem cell fate.

PubMed

Zeng, Jian; Dong, Zhicheng; Wu, Haijun; Tian, Zhaoxia; Zhao, Zhong

2017-10-02

Despite the importance of stem cells in plant and animal development, the common mechanisms of stem cell maintenance in both systems have remained elusive. Recently, the importance of hydrogen peroxide (H 2 O 2 ) signaling in priming stem cell differentiation has been extensively studied in animals. Here, we show that different forms of reactive oxygen species (ROS) have antagonistic roles in plant stem cell regulation, which were established by distinct spatiotemporal patterns of ROS-metabolizing enzymes. The superoxide anion (O2·-) is markedly enriched in stem cells to activate WUSCHEL and maintain stemness, whereas H 2 O 2 is more abundant in the differentiating peripheral zone to promote stem cell differentiation. Moreover, H 2 O 2 negatively regulates O2·- biosynthesis in stem cells, and increasing H 2 O 2 levels or scavenging O2·- leads to the termination of stem cells. Our results provide a mechanistic framework for ROS-mediated control of plant stem cell fate and demonstrate that the balance between O2·- and H 2 O 2 is key to stem cell maintenance and differentiation. © 2017 The Authors.

Ocular Stem Cell Research from Basic Science to Clinical Application: A Report from Zhongshan Ophthalmic Center Ocular Stem Cell Symposium

PubMed Central

Ouyang, Hong; Goldberg, Jeffrey L.; Chen, Shuyi; Li, Wei; Xu, Guo-Tong; Li, Wei; Zhang, Kang; Nussenblatt, Robert B.; Liu, Yizhi; Xie, Ting; Chan, Chi-Chao; Zack, Donald J.

2016-01-01

Stem cells hold promise for treating a wide variety of diseases, including degenerative disorders of the eye. The eye is an ideal organ for stem cell therapy because of its relative immunological privilege, surgical accessibility, and its being a self-contained system. The eye also has many potential target diseases amenable to stem cell-based treatment, such as corneal limbal stem cell deficiency, glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa (RP). Among them, AMD and glaucoma are the two most common diseases, affecting over 200 million people worldwide. Recent results on the clinical trial of retinal pigment epithelial (RPE) cells from human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) in treating dry AMD and Stargardt’s disease in the US, Japan, England, and China have generated great excitement and hope. This marks the beginning of the ocular stem cell therapy era. The recent Zhongshan Ophthalmic Center Ocular Stem Cell Symposium discussed the potential applications of various stem cell types in stem cell-based therapies, drug discoveries and tissue engineering for treating ocular diseases. PMID:27102165

Fast and Robust STEM Reconstruction in Complex Environments Using Terrestrial Laser Scanning

NASA Astrophysics Data System (ADS)

Wang, D.; Hollaus, M.; Puttonen, E.; Pfeifer, N.

2016-06-01

Terrestrial Laser Scanning (TLS) is an effective tool in forest research and management. However, accurate estimation of tree parameters still remains challenging in complex forests. In this paper, we present a novel algorithm for stem modeling in complex environments. This method does not require accurate delineation of stem points from the original point cloud. The stem reconstruction features a self-adaptive cylinder growing scheme. This algorithm is tested for a landslide region in the federal state of Vorarlberg, Austria. The algorithm results are compared with field reference data, which show that our algorithm is able to accurately retrieve the diameter at breast height (DBH) with a root mean square error (RMSE) of ~1.9 cm. This algorithm is further facilitated by applying an advanced sampling technique. Different sampling rates are applied and tested. It is found that a sampling rate of 7.5% is already able to retain the stem fitting quality and simultaneously reduce the computation time significantly by ~88%.

StemTextSearch: Stem cell gene database with evidence from abstracts.

PubMed

Chen, Chou-Cheng; Ho, Chung-Liang

2017-05-01

Previous studies have used many methods to find biomarkers in stem cells, including text mining, experimental data and image storage. However, no text-mining methods have yet been developed which can identify whether a gene plays a positive or negative role in stem cells. StemTextSearch identifies the role of a gene in stem cells by using a text-mining method to find combinations of gene regulation, stem-cell regulation and cell processes in the same sentences of biomedical abstracts. The dataset includes 5797 genes, with 1534 genes having positive roles in stem cells, 1335 genes having negative roles, 1654 genes with both positive and negative roles, and 1274 with an uncertain role. The precision of gene role in StemTextSearch is 0.66, and the recall is 0.78. StemTextSearch is a web-based engine with queries that specify (i) gene, (ii) category of stem cell, (iii) gene role, (iv) gene regulation, (v) cell process, (vi) stem-cell regulation, and (vii) species. StemTextSearch is available through http://bio.yungyun.com.tw/StemTextSearch.aspx. Copyright © 2017. Published by Elsevier Inc.

Application of Stem Cell Technology in Dental Regenerative Medicine.

PubMed

Feng, Ruoxue; Lengner, Chistopher

2013-07-01

In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.

The UK Stem Cell Bank: a UK government-funded, international resource center for stem cell research.

PubMed

Stacey, Glyn; Hunt, Charles J

2006-01-01

The UK Stem Cell Bank is a UK Research Council-funded initiative that aims to provide ethically sourced and quality controlled stocks of cells for researchers and also establish seed stocks of cell lines for clinical trials. Whilst the Bank is prohibited from carrying out basic stem cell research (to avoid conflicts of interest) it is working to improve stem cell banking procedures including cryopreservation, characterization and quality control. The Bank also supports training activities and has provided the hub for the International Stem Cell Initiative, which includes 17 expert stem cell centers aiming to characterize a large number of human embryonic stem cell lines in a standardized way to improve our understanding of the characteristics of these cells.

Methods for Stem Cell Production and Therapy

NASA Technical Reports Server (NTRS)

Valluri, Jagan V. (Inventor); Claudio, Pier Paolo (Inventor)

2015-01-01

The present invention relates to methods for rapidly expanding a stem cell population with or without culture supplements in simulated microgravity conditions. The present invention relates to methods for rapidly increasing the life span of stem cell populations without culture supplements in simulated microgravity conditions. The present invention also relates to methods for increasing the sensitivity of cancer stem cells to chemotherapeutic agents by culturing the cancer stem cells under microgravity conditions and in the presence of omega-3 fatty acids. The methods of the present invention can also be used to proliferate cancer cells by culturing them in the presence of omega-3 fatty acids. The present invention also relates to methods for testing the sensitivity of cancer cells and cancer stem cells to chemotherapeutic agents by culturing the cancer cells and cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce tissue for use in transplantation by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors to promote differentiation of cancer stem cells under microgravity conditions.

Dental pulp stem cells in regenerative dentistry.

PubMed

Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

2011-01-01

Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

Translating stem cell therapies: the role of companion animals in regenerative medicine

PubMed Central

Volk, Susan W.; Theoret, Christine

2013-01-01

Veterinarians and veterinary medicine have been integral to the development of stem cell therapies. The contributions of large animal experimental models to the development and refinement of modern hematopoietic stem cell transplantation were noted nearly five decades ago. More recent advances in adult stem cell/regenerative cell therapies continue to expand knowledge of the basic biology and clinical applications of stem cells. A relatively liberal legal and ethical regulation of stem cell research in veterinary medicine has facilitated the development and in some instances clinical translation of a variety of cell-based therapies involving hematopoietic (HSC) and mesenchymal stem cells (MSC) as well as other adult regenerative cells and recently embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC). In fact, many of the pioneering developments in these fields of stem cell research have been achieved through collaborations of veterinary and human scientists. This review aims to provide an overview of the contribution of large animal veterinary models in advancing stem cell therapies for both human and clinical veterinary applications. Moreover, in the context of the “One Health Initiative”, the role veterinary patients may play in the future evolution of stem cell therapies for both human and animal patients will be explored. PMID:23627495

Wnt6 maintains anterior escort cells as an integral component of the germline stem cell niche

PubMed Central

2018-01-01

ABSTRACT Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. In Drosophila ovaries, germline stem cells depend on cap cells for self-renewing signals and physical attachment. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are absolutely required for germline stem cell maintenance. When escort cells die from impaired Wnt signaling or hid expression, the loss of anterior escort cells causes loss of germline stem cells. Anterior escort cells function as an integral niche component by promoting DE-cadherin anchorage and by transiently expressing the Dpp ligand to promote full-strength BMP signaling in germline stem cells. Anterior escort cells are maintained by Wnt6 ligands produced by cap cells; without Wnt6 signaling, anterior escort cells die leaving vacancies in the niche, leading to loss of germline stem cells. Our data identify anterior escort cells as constituents of the germline stem cell niche, maintained by a cap cell-produced Wnt6 survival signal. PMID:29361569

Wnt6 maintains anterior escort cells as an integral component of the germline stem cell niche.

PubMed

Wang, Xiaoxi; Page-McCaw, Andrea

2018-02-07

Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. In Drosophila ovaries, germline stem cells depend on cap cells for self-renewing signals and physical attachment. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are absolutely required for germline stem cell maintenance. When escort cells die from impaired Wnt signaling or hid expression, the loss of anterior escort cells causes loss of germline stem cells. Anterior escort cells function as an integral niche component by promoting DE-cadherin anchorage and by transiently expressing the Dpp ligand to promote full-strength BMP signaling in germline stem cells. Anterior escort cells are maintained by Wnt6 ligands produced by cap cells; without Wnt6 signaling, anterior escort cells die leaving vacancies in the niche, leading to loss of germline stem cells. Our data identify anterior escort cells as constituents of the germline stem cell niche, maintained by a cap cell-produced Wnt6 survival signal. © 2018. Published by The Company of Biologists Ltd.

21st Nantes Actualités Transplantation: "When Stem Cells Meet Immunology".

PubMed

Anegon, Ignacio; Nguyen, Tuan Huy

2017-01-01

"When Stem Cells Meet Immunology" has been the topic of the 21st annual "Nantes Actualités en Transplantation" meeting (June 9-10, 2016, Nantes, France). This meeting brought together pioneers and leading experts in the fields of stem cells, biomaterials and immunoregulation. Presentations covered multipotent (mesenchymal and hematopoietic) and pluripotent stem cells (embryonic and induced) for regenerative medicine of incurable diseases, immunotherapy and blood transfusions. An additional focus had been immune rejections and responses of allogeneic or autologous stem cells. Conversely, stem cells are also able to directly modulate the immune response through the production of immunoregulatory molecules. Moreover, stem cells may also provide an unlimited source of immune cells (DCs, NK cells, B cells, and T cells) that can operate as "super" immune cells, for example, through genetic engineering with chimeric antigen receptors.This meeting report puts presentations into an overall context highlighting new potential biomarkers for potency prediction of mesenchymal stem cell-derived and pluripotent stem cell-derived multicellular organoids. Finally, we propose future directions arising from the flourishing encounter of stem cell and immune biology.

Differential sensitivity of Glioma stem cells to Aurora kinase A inhibitors: implications for stem cell mitosis and centrosome dynamics.

PubMed

Mannino, Mariella; Gomez-Roman, Natividad; Hochegger, Helfrid; Chalmers, Anthony J

2014-07-01

Glioma stem-cell-like cells are considered to be responsible for treatment resistance and tumour recurrence following chemo-radiation in glioblastoma patients, but specific targets by which to kill the cancer stem cell population remain elusive. A characteristic feature of stem cells is their ability to undergo both symmetric and asymmetric cell divisions. In this study we have analysed specific features of glioma stem cell mitosis. We found that glioma stem cells appear to be highly prone to undergo aberrant cell division and polyploidization. Moreover, we discovered a pronounced change in the dynamic of mitotic centrosome maturation in these cells. Accordingly, glioma stem cell survival appeared to be strongly dependent on Aurora A activity. Unlike differentiated cells, glioma stem cells responded to moderate Aurora A inhibition with spindle defects, polyploidization and a dramatic increase in cellular senescence, and were selectively sensitive to Aurora A and Plk1 inhibitor treatment. Our study proposes inhibition of centrosomal kinases as a novel strategy to selectively target glioma stem cells. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of aging on stem cells

PubMed Central

Ahmed, Abu Shufian Ishtiaq; Sheng, Matilda HC; Wasnik, Samiksha; Baylink, David J; Lau, Kin-Hing William

2017-01-01

Pluripotent stem cells have the remarkable self-renewal ability and are capable of differentiating into multiple diverse cells. There is increasing evidence that the aging process can have adverse effects on stem cells. As stem cells age, their renewal ability deteriorates and their ability to differentiate into the various cell types is altered. Accordingly, it is suggested aging-induced deterioration of stem cell functions may play a key role in the pathophysiology of the various aging-associated disorders. Understanding the role of the aging process in deterioration of stem cell function is crucial, not only in understanding the pathophysiology of aging-associated disorders, but also in future development of novel effective stem cell-based therapies to treat aging-associated diseases. This review article first focuses on the basis of the various aging disease-related stem cell dysfunction. It then addresses the several concepts on the potential mechanism that causes aging-related stem cell dysfunction. It also briefly discusses the current potential therapies under development for aging-associated stem cell defects. PMID:28261550

Engineering Stem Cells for Biomedical Applications

PubMed Central

Yin, Perry T.; Han, Edward

2018-01-01

Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer. PMID:25772134

Therapeutic potential of dental stem cells

PubMed Central

Chalisserry, Elna Paul; Nam, Seung Yun; Park, Sang Hyug; Anil, Sukumaran

2017-01-01

Stem cell biology has become an important field in regenerative medicine and tissue engineering therapy since the discovery and characterization of mesenchymal stem cells. Stem cell populations have also been isolated from human dental tissues, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla, dental follicle progenitor cells, and periodontal ligament stem cells. Dental stem cells are relatively easily obtainable and exhibit high plasticity and multipotential capabilities. The dental stem cells represent a gold standard for neural-crest-derived bone reconstruction in humans and can be used for the repair of body defects in low-risk autologous therapeutic strategies. The bioengineering technologies developed for tooth regeneration will make substantial contributions to understand the developmental process and will encourage future organ replacement by regenerative therapies in a wide variety of organs such as the liver, kidney, and heart. The concept of developing tooth banking and preservation of dental stem cells is promising. Further research in the area has the potential to herald a new dawn in effective treatment of notoriously difficult diseases which could prove highly beneficial to mankind in the long run. PMID:28616151

Single-cell sequencing in stem cell biology.

PubMed

Wen, Lu; Tang, Fuchou

2016-04-15

Cell-to-cell variation and heterogeneity are fundamental and intrinsic characteristics of stem cell populations, but these differences are masked when bulk cells are used for omic analysis. Single-cell sequencing technologies serve as powerful tools to dissect cellular heterogeneity comprehensively and to identify distinct phenotypic cell types, even within a 'homogeneous' stem cell population. These technologies, including single-cell genome, epigenome, and transcriptome sequencing technologies, have been developing rapidly in recent years. The application of these methods to different types of stem cells, including pluripotent stem cells and tissue-specific stem cells, has led to exciting new findings in the stem cell field. In this review, we discuss the recent progress as well as future perspectives in the methodologies and applications of single-cell omic sequencing technologies.

The Implications of the Cancer Stem Cell Hypothesis for Neuro-Oncology and Neurology.

PubMed

Rich, Jeremy N

2008-05-01

The cancer stem cell hypothesis posits that cancers contain a subset of neoplastic cells that propagate and maintain tumors through sustained self-renewal and potent tumorigenecity. Recent excitement has been generated by a number of reports that have demonstrated the existence of cancer stem cells in several types of brain tumors. Brain cancer stem cells - also called tumor initiating cells or tumor propagating cells - share features with normal neural stem cells but do not necessarily originate from stem cells. Although most cancers have only a small fraction of cancer stem cells, these tumor cells have been shown in laboratory studies to contribute to therapeutic resistance, formation of new blood vessels to supply the tumor, and tumor spread. As malignant brain tumors rank among the deadliest of all neurologic diseases, the identification of new cellular targets may have profound implications in neuro-oncology. Novel drugs that target stem cell pathways active in brain tumors have been efficacious against cancer stem cells suggesting that anti-cancer stem cell therapies may advance brain tumor therapy. The cancer stem cell hypothesis may have several implications for other neurologic diseases as caution must be exercised in activating stem cell maintenance pathways in cellular therapies for neurodegenerative diseases. The ability for a small fraction of cells to determine the overall course of a disease may also inform new paradigms of disease that may translate into improved patient outcomes.

Can bone marrow differentiate into renal cells?

PubMed

Imai, Enyu; Ito, Takahito

2002-10-01

A considerable plasticity of adult stem cells has been confirmed in a wide variety of tissues. In particular, the pluripotency of bone marrow-derived stem cells may influence the regeneration of injured tissues and may provide novel avenues in regenerative medicine. Bone marrow contains at least hematopoietic and mesenchymal stem cells, and both can differentiate into a wide range of differentiated cells. Side population (SP) cells, which are originally defined in bone marrow cells by high efflux of DNA-binding dye, seem to be a new class of multipotent stem cells. Irrespective of the approach used to obtain stem cells, the fates of marrow-derived cells following bone marrow transplantation can be traced by labeling donor cells with green fluorescence protein or by identifying donor Y chromosome in female recipients. So far, bone marrow-derived cells have been reported to differentiate into renal cells, including mesangial cells, endothelial cells, podocytes, and tubular cells in the kidney, although controversy exists. Further studies are required to address this issue. Cell therapy will be promising when we learn to control stem cells such as bone marrow-derived stem cells, embryonic stem cells, and resident stem cells in the kidney. Identification of factors that support stem cells or promote their differentiation should provide a relevant step towards cell therapy.

[The emerging technology of tissue engineering : Focus on stem cell niche].

PubMed

Schlötzer-Schrehardt, U; Freudenberg, U; Kruse, F E

2017-04-01

Limbal stem cells reside in a highly specialized complex microenvironment that is known as the stem cell niche, an anatomically protected region at the bottom of the Palisades of Vogt, where the stem cells are located and where their quiescence, proliferation and differentiation are maintained in balance. Besides the epithelial stem and progenitor cell clusters, the limbal niche comprises several types of supporting niche cells and a specific extracellular matrix mediating biochemical and biophysical signals. Stem cell-based tissue engineering aims to mimic the native stem cell niche and to present appropriate microenvironmental cues in a controlled and reproducible fashion in order to maintain stem cell function within the graft. Current therapeutic approaches for ex vivo expansion of limbal stem cells only take advantage of surrogate niches. However, new insights into the molecular composition of the limbal niche and innovative biosynthetic scaffolds have stimulated novel strategies for niche-driven stem cell cultivation. Promising experimental approaches include collagen-based organotypic coculture systems of limbal epithelial stem cells with their niche cells and biomimetic hydrogel platforms prefunctionalized with appropriate biomolecular and biophysical signals. Future translation of these novel regenerative strategies into clinical application is expected to improve long-term outcomes of limbal stem cell transplantation for ocular surface reconstruction.

Combination cell therapy with mesenchymal stem cells and neural stem cells for brain stroke in rats.

PubMed

Hosseini, Seyed Mojtaba; Farahmandnia, Mohammad; Razi, Zahra; Delavari, Somayeh; Shakibajahromi, Benafsheh; Sarvestani, Fatemeh Sabet; Kazemi, Sepehr; Semsar, Maryam

2015-05-01

Brain stroke is the second most important events that lead to disability and morbidity these days. Although, stroke is important, there is no treatment for curing this problem. Nowadays, cell therapy has opened a new window for treating central nervous system disease. In some previous studies the Mesenchymal stem cells and neural stem cells. In this study, we have designed an experiment to assess the combination cell therapy (Mesenchymal and Neural stem cells) effects on brain stroke. The Mesenchymal stem cells were isolated from adult rat bone marrow and the neural stem cells were isolated from ganglion eminence of rat embryo 14 days. The Mesenchymal stem cells were injected 1 day after middle cerebral artery occlusion (MCAO) and the neural stem cells transplanted 7 day after MCAO. After 28 days, the neurological outcomes and brain lesion volumes were evaluated. Also, the activity of Caspase 3 was assessed in different groups. The group which received combination cell therapy had better neurological examination and less brain lesion. Also the combination cell therapy group had the least Caspase 3 activity among the groups. The combination cell therapy is more effective than Mesenchymal stem cell therapy and neural stem cell therapy separately in treating the brain stroke in rats.

Application of Stem Cells in Oral Disease Therapy: Progresses and Perspectives

PubMed Central

Yang, Bo; Qiu, Yi; Zhou, Niu; Ouyang, Hong; Ding, Junjun; Cheng, Bin; Sun, Jianbo

2017-01-01

Stem cells are undifferentiated and pluripotent cells that can differentiate into specialized cells with a more specific function. Stem cell therapies become preferred methods for the treatment of multiple diseases. Oral and maxillofacial defect is one kind of the diseases that could be most possibly cured by stem cell therapies. Here we discussed oral diseases, oral adult stem cells, iPS cells, and the progresses/challenges/perspectives of application of stem cells for oral disease treatment. PMID:28421002

Diploid, but not haploid, human embryonic stem cells can be derived from microsurgically repaired tripronuclear human zygotes

PubMed Central

Fan, Yong; Li, Rong; Huang, Jin; Yu, Yang; Qiao, Jie

2013-01-01

Human embryonic stem cells have shown tremendous potential in regenerative medicine, and the recent progress in haploid embryonic stem cells provides new insights for future applications of embryonic stem cells. Disruption of normal fertilized embryos remains controversial; thus, the development of a new source for human embryonic stem cells is important for their usefulness. Here, we investigated the feasibility of haploid and diploid embryo reconstruction and embryonic stem cell derivation using microsurgically repaired tripronuclear human zygotes. Diploid and haploid zygotes were successfully reconstructed, but a large proportion of them still had a tripolar spindle assembly. The reconstructed embryos developed to the blastocyst stage, although the loss of chromosomes was observed in these zygotes. Finally, triploid and diploid human embryonic stem cells were derived from tripronuclear and reconstructed zygotes (from which only one pronucleus was removed), but haploid human embryonic stem cells were not successfully derived from the reconstructed zygotes when two pronuclei were removed. Both triploid and diploid human embryonic stem cells showed the general characteristics of human embryonic stem cells. These results indicate that the lower embryo quality resulting from abnormal spindle assembly contributed to the failure of the haploid embryonic stem cell derivation. However, the successful derivation of diploid embryonic stem cells demonstrated that microsurgical tripronuclear zygotes are an alternative source of human embryonic stem cells. In the future, improving spindle assembly will facilitate the application of triploid zygotes to the field of haploid embryonic stem cells. PMID:23255130

Nano scaffolds and stem cell therapy in liver tissue engineering

NASA Astrophysics Data System (ADS)

Montaser, Laila M.; Fawzy, Sherin M.

2015-08-01

Tissue engineering and regenerative medicine have been constantly developing of late due to the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Although stem cells hold great potential for the treatment of many injuries and degenerative diseases, several obstacles must be overcome before their therapeutic application can be realized. These include the development of advanced techniques to understand and control functions of micro environmental signals and novel methods to track and guide transplanted stem cells. A major complication encountered with stem cell therapies has been the failure of injected cells to engraft to target tissues. The application of nanotechnology to stem cell biology would be able to address those challenges. Combinations of stem cell therapy and nanotechnology in tissue engineering and regenerative medicine have achieved significant advances. These combinations allow nanotechnology to engineer scaffolds with various features to control stem cell fate decisions. Fabrication of Nano fiber cell scaffolds onto which stem cells can adhere and spread, forming a niche-like microenvironment which can guide stem cells to proceed to heal damaged tissues. In this paper, current and emergent approach based on stem cells in the field of liver tissue engineering is presented for specific application. The combination of stem cells and tissue engineering opens new perspectives in tissue regeneration for stem cell therapy because of the potential to control stem cell behavior with the physical and chemical characteristics of the engineered scaffold environment.

Stem-Cell-Based Tumorigenesis in Adult Drosophila.

PubMed

Hou, S X; Singh, S R

2017-01-01

Recent studies suggest that a small subset of cells within a tumor, the so-called cancer stem cells (CSCs), are responsible for tumor propagation, relapse, and the eventual death of most cancer patients. CSCs may derive from a few tumor-initiating cells, which are either transformed normal stem cells or reprogrammed differentiated cells after acquiring initial cancer-causing mutations. CSCs and normal stem cells share some properties, but CSCs differ from normal stem cells in their tumorigenic ability. Notably, CSCs are usually resistant to chemo- and radiation therapies. Despite the apparent roles of CSCs in human cancers, the biology underlying their behaviors remains poorly understood. Over the past few years, studies in Drosophila have significantly contributed to this new frontier of cancer research. Here, we first review how stem-cell tumors are initiated and propagated in Drosophila, through niche appropriation in the posterior midgut and through stem-cell competition for niche occupancy in the testis. We then discuss the differences between normal and tumorigenic stem cells, revealed by studying Ras V12 -transformed stem-cell tumors in the Drosophila kidney. Finally, we review the biology behind therapy resistance, which has been elucidated through studies of stem-cell resistance and sensitivity to death inducers using female germline stem cells and intestinal stem cells of the posterior midgut. We expect that screens using adult Drosophila neoplastic stem-cell tumor models will be valuable for identifying novel and effective compounds for treating human cancers. © 2017 Elsevier Inc. All rights reserved.

Challenging tumour immunological techniques that help to track cancer stem cells in malignant melanomas and other solid tumours.

PubMed

Kotlan, Beatrix; Plotar, Vanda; Eles, Klara; Horvath, Szabolcs; Balatoni, Timea; Csuka, Orsolya; Újhelyi, Mihaly; Sávolt, Ákos; Szollar, Andras; Vamosi-Nagy, Istvan; Toth, Laszlo; Farkas, Emil; Toth, Jozsef; Kasler, Miklos; Liszkay, Gabriella

2018-03-01

The arsenal of questions and answers about the minor cancer initiating cancer stem cell (CSC) population put responsible for cancer invasiveness and metastases, has left with an unsolved puzzle. Specific aims of a complex project were partly focused on revealing new biomarkers of cancer. We designed and set up novel techniques to facilitate the detection of cancerous cells. As a novel approach, we investigated B cells infiltrating breast carcinomas and melanomas (TIL-B) in terms of their tumour antigen binding potential. By developing the TIL-B phage display technology we provide here a new technology for the specific detection of highly tumour-associated antigens. Single chain Fv (scFv) antibody fragment phage ELISA, immunofluorescence (IF) FACS analysis, chamber slide technique with IF confocal laser microscopy and immunohistochemistry (IHC) in paraffin-embedded tissue sections were set up and standardized. We showed strong tumour-associated disialylated glycosphingolipid expression levels on various cancer cells using scFv antibody fragments, generated previously by uniquely invasive breast carcinoma TIL-B phage display library technology. We report herein a novel strategy to obtain antibody fragments of human origin that recognise tumour-associated ganglioside antigens. Our investigations have the power to detect privileged molecules in cancer progression, invasiveness, and metastases. The technical achievements of this study are being harnessed for early diagnostics and effective cancer therapeutics.

Stem cells with potential to generate insulin producing cells in man.

PubMed

Zulewski, Henryk

2006-10-14

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Stem cells with potential to generate insulin-producing cells in man.

PubMed

Zulewski, Henryk

2007-03-02

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Mechanical forces direct stem cell behaviour in development and regeneration

PubMed Central

Vining, Kyle H.; Mooney, David J.

2018-01-01

Stem cells and their local microenvironment, or niche, communicate through mechanical, cues to regulate cell fate and cell behaviour, and to guide developmental processes. During embryonic development, mechanical forces are involved in patterning and organogenesis. The physical environment of pluripotent stem cells regulates their differentiation and self-renewal. Mechanical and physical cues are also important in adult tissues, where adult stem cells require physical interactions with the extracellular matrix to maintain their potency. In vitro, synthetic models of the stem cell niche can be used to precisely control and manipulate the biophysical and biochemical properties of the stem cell microenvironment and examine how the mode and magnitude of mechanical cues, such as matrix stiffness or applied forces, direct stem cell differentiation and function. Fundamental insights on the mechanobiology of stem cells also inform the design of artificial niches to support stem cells for regenerative therapies. PMID:29115301

Recent Advances towards the Clinical Application of Stem Cells for Retinal Regeneration

PubMed Central

Becker, Silke; Jayaram, Hari; Limb, G. Astrid

2012-01-01

Retinal degenerative diseases constitute a major cause of irreversible blindness in the world. Stem cell-based therapies offer hope for these patients at risk of or suffering from blindness due to the deterioration of the neural retina. Various sources of stem cells are currently being investigated, ranging from human embryonic stem cells to adult-derived induced pluripotent stem cells as well as human Müller stem cells, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. This review aims to summarize the latest advances in the development of stem cell strategies for the replacement of retinal neurons and their supportive cells, the retinal pigment epithelium (RPE) affected by retinal degenerative conditions. Particular emphasis will be given to the advances in stem cell transplantation and the challenges associated with their translation into clinical practice. PMID:24710533

Stem-Cell Therapy Advances in China.

PubMed

Hu, Lei; Zhao, Bin; Wang, Songlin

2018-02-01

Stem-cell therapy is a promising method for treating patients with a wide range of diseases and injuries. Increasing government funding of scientific research has promoted rapid developments in stem-cell research in China, as evidenced by the substantial increase in the number and quality of publications in the past 5 years. Multiple high-quality studies have been performed in China that concern cell reprogramming, stem-cell homeostasis, gene modifications, and immunomodulation. The number of translation studies, including basic and preclinical investigations, has also increased. Around 100 stem-cell banks have been established in China, 10 stem-cell drugs are currently in the approval process, and >400 stem cell-based clinical trials are currently registered in China. With continued state funding, advanced biotechnical support, and the development of regulatory standards for the clinical application of stem cells, further innovations are expected that will lead to a boom in stem-cell therapies. This review highlights recent achievements in stem-cell research in China and discusses future prospects.

New insights into mechanisms of stem cell daughter fate determination in regenerative tissues.

PubMed

Sada, Aiko; Tumbar, Tudorita

2013-01-01

Stem cells can self-renew and differentiate over extended periods of time. Understanding how stem cells acquire their fates is a central question in stem cell biology. Early work in Drosophila germ line and neuroblast showed that fate choice is achieved by strict asymmetric divisions that can generate each time one stem and one differentiated cell. More recent work suggests that during homeostasis, some stem cells can divide symmetrically to generate two differentiated cells or two identical stem cells to compensate for stem cell loss that occurred by direct differentiation or apoptosis. The interplay of all these factors ensures constant tissue regeneration and the maintenance of stem cell pool size. This interplay can be modeled as a population-deterministic dynamics that, at least in some systems, may be described as stochastic behavior. Here, we overview recent progress made on the characterization of stem cell dynamics in regenerative tissues. Copyright © 2013 Elsevier Inc. All rights reserved.

Automated matching of multiple terrestrial laser scans for stem mapping without the use of artificial references

NASA Astrophysics Data System (ADS)

Liu, Jingbin; Liang, Xinlian; Hyyppä, Juha; Yu, Xiaowei; Lehtomäki, Matti; Pyörälä, Jiri; Zhu, Lingli; Wang, Yunsheng; Chen, Ruizhi

2017-04-01

Terrestrial laser scanning has been widely used to analyze the 3D structure of a forest in detail and to generate data at the level of a reference plot for forest inventories without destructive measurements. Multi-scan terrestrial laser scanning is more commonly applied to collect plot-level data so that all of the stems can be detected and analyzed. However, it is necessary to match the point clouds of multiple scans to yield a point cloud with automated processing. Mismatches between datasets will lead to errors during the processing of multi-scan data. Classic registration methods based on flat surfaces cannot be directly applied in forest environments; therefore, artificial reference objects have conventionally been used to assist with scan matching. The use of artificial references requires additional labor and expertise, as well as greatly increasing the cost. In this study, we present an automated processing method for plot-level stem mapping that matches multiple scans without artificial references. In contrast to previous studies, the registration method developed in this study exploits the natural geometric characteristics among a set of tree stems in a plot and combines the point clouds of multiple scans into a unified coordinate system. Integrating multiple scans improves the overall performance of stem mapping in terms of the correctness of tree detection, as well as the bias and the root-mean-square errors of forest attributes such as diameter at breast height and tree height. In addition, the automated processing method makes stem mapping more reliable and consistent among plots, reduces the costs associated with plot-based stem mapping, and enhances the efficiency.

Selection of Phage Display Peptides Targeting Human Pluripotent Stem Cell-Derived Progenitor Cell Lines.

PubMed

Bignone, Paola A; Krupa, Rachel A; West, Michael D; Larocca, David

2016-01-01

The ability of human pluripotent stem cells (hPS) to both self-renew and differentiate into virtually any cell type makes them a promising source of cells for cell-based regenerative therapies. However, stem cell identity, purity, and scalability remain formidable challenges that need to be overcome for translation of pluripotent stem cell research into clinical applications. Directed differentiation from hPS cells is inefficient and residual contamination with pluripotent cells that have the potential to form tumors remains problematic. The derivation of scalable (self-renewing) embryonic progenitor stem cell lines offers a solution because they are well defined and clonally pure. Clonally pure progenitor stem cell lines also provide a means for identifying cell surface targeting reagents that are useful for identification, tracking, and repeated derivation of the corresponding progenitor stem cell types from additional hPS cell sources. Such stem cell targeting reagents can then be applied to the manufacture of genetically diverse banks of human embryonic progenitor cell lines for drug screening, disease modeling, and cell therapy. Here we present methods to identify human embryonic progenitor stem cell targeting peptides by selection of phage display libraries on clonal embryonic progenitor cell lines and demonstrate their use for targeting quantum dots (Qdots) for stem cell labeling.

Extinction models for cancer stem cell therapy

PubMed Central

Sehl, Mary; Zhou, Hua; Sinsheimer, Janet S.; Lange, Kenneth L.

2012-01-01

Cells with stem cell-like properties are now viewed as initiating and sustaining many cancers. This suggests that cancer can be cured by driving these cancer stem cells to extinction. The problem with this strategy is that ordinary stem cells are apt to be killed in the process. This paper sets bounds on the killing differential (difference between death rates of cancer stem cells and normal stem cells) that must exist for the survival of an adequate number of normal stem cells. Our main tools are birth–death Markov chains in continuous time. In this framework, we investigate the extinction times of cancer stem cells and normal stem cells. Application of extreme value theory from mathematical statistics yields an accurate asymptotic distribution and corresponding moments for both extinction times. We compare these distributions for the two cell populations as a function of the killing rates. Perhaps a more telling comparison involves the number of normal stem cells NH at the extinction time of the cancer stem cells. Conditioning on the asymptotic time to extinction of the cancer stem cells allows us to calculate the asymptotic mean and variance of NH. The full distribution of NH can be retrieved by the finite Fourier transform and, in some parameter regimes, by an eigenfunction expansion. Finally, we discuss the impact of quiescence (the resting state) on stem cell dynamics. Quiescence can act as a sanctuary for cancer stem cells and imperils the proposed therapy. We approach the complication of quiescence via multitype branching process models and stochastic simulation. Improvements to the τ-leaping method of stochastic simulation make it a versatile tool in this context. We conclude that the proposed therapy must target quiescent cancer stem cells as well as actively dividing cancer stem cells. The current cancer models demonstrate the virtue of attacking the same quantitative questions from a variety of modeling, mathematical, and computational perspectives. PMID:22001354

Extinction models for cancer stem cell therapy.

PubMed

Sehl, Mary; Zhou, Hua; Sinsheimer, Janet S; Lange, Kenneth L

2011-12-01

Cells with stem cell-like properties are now viewed as initiating and sustaining many cancers. This suggests that cancer can be cured by driving these cancer stem cells to extinction. The problem with this strategy is that ordinary stem cells are apt to be killed in the process. This paper sets bounds on the killing differential (difference between death rates of cancer stem cells and normal stem cells) that must exist for the survival of an adequate number of normal stem cells. Our main tools are birth-death Markov chains in continuous time. In this framework, we investigate the extinction times of cancer stem cells and normal stem cells. Application of extreme value theory from mathematical statistics yields an accurate asymptotic distribution and corresponding moments for both extinction times. We compare these distributions for the two cell populations as a function of the killing rates. Perhaps a more telling comparison involves the number of normal stem cells NH at the extinction time of the cancer stem cells. Conditioning on the asymptotic time to extinction of the cancer stem cells allows us to calculate the asymptotic mean and variance of NH. The full distribution of NH can be retrieved by the finite Fourier transform and, in some parameter regimes, by an eigenfunction expansion. Finally, we discuss the impact of quiescence (the resting state) on stem cell dynamics. Quiescence can act as a sanctuary for cancer stem cells and imperils the proposed therapy. We approach the complication of quiescence via multitype branching process models and stochastic simulation. Improvements to the τ-leaping method of stochastic simulation make it a versatile tool in this context. We conclude that the proposed therapy must target quiescent cancer stem cells as well as actively dividing cancer stem cells. The current cancer models demonstrate the virtue of attacking the same quantitative questions from a variety of modeling, mathematical, and computational perspectives. Copyright © 2011 Elsevier Inc. All rights reserved.

Aging and stem cell therapy: AMPK as an applicable pharmacological target for rejuvenation of aged stem cells and achieving higher efficacy in stem cell therapy.

PubMed

Khorraminejad-Shirazi, Mohammadhossein; Farahmandnia, Mohammad; Kardeh, Bahareh; Estedlal, Alireza; Kardeh, Sina; Monabati, Ahmad

2017-10-19

In recent years, tissue regeneration has become a promising field for developing stem cell-based transplantation therapies for human patients. Adult stem cells are affected by the same aging mechanisms that involve somatic cells. One of the mechanisms involved in cellular aging is hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and disruption of 5' adenosine monophosphate-activated protein kinase (AMPK). Aging of stem cells results in their impaired regenerative capacity and depletion of stem cell pools in adult tissue, which results in lower efficacy of stem cell therapy. By utilizing an effective therapeutic intervention for aged stem cells, stem cell therapy can become more promising for future application. mTORC1 inhibition is a practical approach to preserve the stem cell pool. In this article, we review the dynamic interaction between sirtuin (silent mating type information regulation 2 homolog) 1, AMPK, and mTORC1. We propose that using AMPK activators such as 5-aminoimidazole-4-carboxamide ribonucleotide, A769662, metformin, and oxidized nicotinamide adenine dinucleotide (NAD + ) are practical ways to be employed for achieving better optimized results in stem cell-based transplantation therapies. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

Stemness of spermatogonial stem cells encapsulated in alginate hydrogel during cryopreservation.

PubMed

Pirnia, A; Parivar, K; Hemadi, M; Yaghmaei, P; Gholami, M

2017-06-01

This study investigated the effect of spermatogonial stem cell encapsulated in alginate hydrogel during cryopreservation, as cells were protected against damage during cryopreservation within the hydrogel. Spermatogonial stem cells were isolated from the testes of Balb/c mice pups (6 days old), purified in laminin-coated dishes and CD90.1 microbeads, encapsulated in alginate hydrogel and then cryopreserved. After thawing, cell viability and Spermatogonial stem cell (SSC) colony diameter were evaluated. After RNA was isolated and cDNA was synthesised, the expression of stemness genes was considered using RT real-time PCR. Finally, spermatogonial stem cells labelled with BrdU were transplanted to busulfan azoospermic mouse models. Lin28a and Sall4 genes were significantly upregulated after cryopreservation in alginate hydrogel. However, cell viability was significantly decreased. The diameter of colonies consisting of spermatogonial stem cells freeze-thawed in alginate microbeads showed no significant difference with fresh spermatogonial stem cells and the control group. The injection of freeze-thawed spermatogonial stem cells encapsulated in alginate hydrogel resulted in spermatogenesis recovery. Alginate mimics the extracellular matrices (ECM) for spermatogonial stem cells; therefore, it can support stemness potential during the cell cryopreservation process and restart spermatogenesis after transplantation. © 2016 Blackwell Verlag GmbH.

Normal and cancer mammary stem cells evade interferon-induced constraint through the miR-199a-LCOR Axis

PubMed Central

Celià-Terrassa, Toni; Liu, Daniel; Choudhury, Abrar; Hang, Xiang; Wei, Yong; Zamalloa, Jose; Alfaro-Aco, Raymundo; Chakrabarti, Rumela; Jiang, Yi-Zhou; Koh, Bong Ihn; Smith, Heath; DeCoste, Christina; Li, Jun-Jing; Shao, Zhi-Ming; Kang, Yibin

2017-01-01

Tumor-initiating cells (TICs), or cancer stem cells (CSC), possess stem cell-like properties observed in normal adult tissue stem cells. Normal and cancerous stem cells may therefore share regulatory mechanisms for maintaining self-renewing capacity and resisting differentiation elicited by cell-intrinsic or microenvironmental cues. Here, we show that miR-199a promotes stem cell properties in mammary stem cells (MaSCs) and breast CSCs by directly repressing nuclear receptor corepressor LCOR, which primes interferon (IFN) responses. Elevated miR-199a expression in stem cell-enriched populations protects normal and malignant stem-like cells from differentiation and senescence induced by IFNs that are produced by epithelial and immune cells in the mammary gland. Importantly, the miR-199a-LCOR-IFN axis is activated in poorly differentiated ER− breast tumors, functionally promotes tumor initiation and metastasis, and is associated with poor clinical outcome. Our study therefore reveals a common mechanism shared by normal and malignant stem cells to protect them from suppressive immune cytokine signaling. PMID:28530657

The Role of Epithelial-Mesenchymal Transition in the Formation of Normal and Neoplastic Mammary Epithelial Stem Cells

DTIC Science & Technology

2011-09-01

separating stem cell and non- stem cell populations of normal and breast cancer cells and identified EMT transcription factors most likely involved in... stem cell biology. Preliminary results directly demonstrate that transient induction of EMT increases the number of mammary epithelial stem cells...EMT and entrance into a stem - cell state. The outcome of these experiments holds important implications for the mechanisms controlling the formation of

Role of the Stem Cell Niche in Hormone-Induced Tumorigenesis in Fetal Mouse Mammary Epithelium

DTIC Science & Technology

2005-08-01

responsive, self renewing and pluripotent. A structure specialized to contain and regulate stem cell activity has been structurally and molecularly...described in Drosophila and some mammalian tissues. The structure, the stem cell niche, functions to 1) shield the stem cell from the burden of incoming...directing stem cell renewal and maturation, 3) prevent stem cells from wandering through the tissue and producing new cells inappropriately, 4) prevent

Alpha-fetoprotein, stem cells and cancer: how study of the production of alpha-fetoprotein during chemical hepatocarcinogenesis led to reaffirmation of the stem cell theory of cancer.

PubMed

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein during development, in response to liver injury and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas. When the cellular changes in these processes were compared to that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue-determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as normal tissues: stem cells, transit-amplifying cells and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, antiangiogenesis and differentiation therapy) are directed against the cancer transit-amplifying cells. When these therapies are discontinued, the cancer reforms from the cancer stem cells. Therapy directed toward interruption of the cell signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of regrowth of the cancer. Copyright 2008 S. Karger AG, Basel.

ALPHA-FETOPROTEIN (AFP), STEM CELLS, AND CANCER: HOW STUDY OF THE PRODUCTION OF AFP DURING CHEMICAL HEPATOCARCINOGENESIS LED TO REAFFIRMATION OF THE STEM CELL THEORY OF CANCER

PubMed Central

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein (AFP) during development, in response to liver injury, and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas (HCC). When the cellular changes in these processes were compared that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as do normal tissues: stem cells, transit-amplifying cells, and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, anti-angiogenesis and differentiation therapy) are directed against the cancer transit amplifying cells. When these therapies are discontinued, the cancer re-forms from the cancer stem cells. Therapy directed toward interruption of the cell-signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of re-growth of the cancer. PMID:18612221

A Comparative Transcriptomic Analysis Reveals Conserved Features of Stem Cell Pluripotency in Planarians and Mammals

PubMed Central

Labbé, Roselyne M.; Irimia, Manuel; Currie, Ko W.; Lin, Alexander; Zhu, Shu Jun; Brown, David D.R.; Ross, Eric J.; Voisin, Veronique; Bader, Gary D.; Blencowe, Benjamin J.; Pearson, Bret J.

2014-01-01

Many long-lived species of animals require the function of adult stem cells throughout their lives. However, the transcriptomes of stem cells in invertebrates and vertebrates have not been compared, and consequently, ancestral regulatory circuits that control stem cell populations remain poorly defined. In this study, we have used data from high-throughput RNA sequencing to compare the transcriptomes of pluripotent adult stem cells from planarians with the transcriptomes of human and mouse pluripotent embryonic stem cells. From a stringently defined set of 4,432 orthologs shared between planarians, mice and humans, we identified 123 conserved genes that are ≥5-fold differentially expressed in stem cells from all three species. Guided by this gene set, we used RNAi screening in adult planarians to discover novel stem cell regulators, which we found to affect the stem cell-associated functions of tissue homeostasis, regeneration, and stem cell maintenance. Examples of genes that disrupted these processes included the orthologs of TBL3, PSD12, TTC27, and RACK1. From these analyses, we concluded that by comparing stem cell transcriptomes from diverse species, it is possible to uncover conserved factors that function in stem cell biology. These results provide insights into which genes comprised the ancestral circuitry underlying the control of stem cell self-renewal and pluripotency. PMID:22696458

Investigating the mincing method for isolation of adipose-derived stem cells from pregnant women fat.

PubMed

Li, Yuan-Sheng; Chen, Pao-Jen; Wu, Li-Wei; Chou, Pei-Wen; Sun, Li-Yi; Chiou, Tzyy-Wen

2018-02-01

The success of stem cell application in regenerative medicine, usually require a stable source of stem or progenitor cells. Fat tissue represents a good source of stem cells because it is rich in stem cells and there are fewer ethical issues related to the use of such stem cells, unlike embryonic stem cells. Therefore, there has been increased interest in adipose-derived stem cells (ADSCs) for tissue engineering applications. Here, we aim to provide an easy processing method for isolating adult stem cells from human adipose tissue harvested from the subcutaneous fat of the abdominal wall during gynecologic surgery. We used a homogenizer to mince fat and compared the results with those obtained from the traditional cut method involving a sterile scalpel and forceps. Our results showed that our method provides another stable and quality source of stem cells that could be used in cases with a large quantity of fat. Furthermore, we found that pregnancy adipose-derived stem cells (P-ADSCs) could be maintained in vitro for extended periods with a stable population doubling and low senescence levels. P-ADSCs could also differentiate in vitro into adipogenic, osteogenic, chondrogenic, and insulin-producing cells in the presence of lineage-specific induction factors. In conclusion, like human lipoaspirates, adipose tissues obtained from pregnant women contain multipotent cells with better proliferation and showed great promise for use in both stem cell banking studies as well as in stem cell therapy.

Gremlin 1 Identifies a Skeletal Stem Cell with Bone, Cartilage, and Reticular Stromal Potential

PubMed Central

Worthley, Daniel L.; Churchill, Michael; Compton, Jocelyn T.; Tailor, Yagnesh; Rao, Meenakshi; Si, Yiling; Levin, Daniel; Schwartz, Matthew G.; Uygur, Aysu; Hayakawa, Yoku; Gross, Stefanie; Renz, Bernhard W.; Setlik, Wanda; Martinez, Ashley N.; Chen, Xiaowei; Nizami, Saqib; Lee, Heon Goo; Kang, H. Paco; Caldwell, Jon-Michael; Asfaha, Samuel; Westphalen, C. Benedikt; Graham, Trevor; Jin, Guangchun; Nagar, Karan; Wang, Hongshan; Kheirbek, Mazen A.; Kolhe, Alka; Carpenter, Jared; Glaire, Mark; Nair, Abhinav; Renders, Simon; Manieri, Nicholas; Muthupalani, Sureshkumar; Fox, James G.; Reichert, Maximilian; Giraud, Andrew S.; Schwabe, Robert F.; Pradere, Jean-Phillipe; Walton, Katherine; Prakash, Ajay; Gumucio, Deborah; Rustgi, Anil K.; Stappenbeck, Thaddeus S.; Friedman, Richard A.; Gershon, Michael D.; Sims, Peter; Grikscheit, Tracy; Lee, Francis Y.; Karsenty, Gerard; Mukherjee, Siddhartha; Wang, Timothy C.

2014-01-01

The stem cells that maintain and repair the postnatal skeleton remain undefined. One model suggests that perisinusoidal mesenchymal stem cells (MSCs) give rise to osteoblasts, chondrocytes, marrow stromal cells, and adipocytes, although the existence of these cells has not been proven through fate-mapping experiments. We demonstrate here that expression of the bone morphogenetic protein (BMP) antagonist gremlin 1 defines a population of osteochondroreticular (OCR) stem cells in the bone marrow. OCR stem cells self-renew and generate osteoblasts, chondrocytes, and reticular marrow stromal cells, but not adipocytes. OCR stem cells are concentrated within the metaphysis of long bones not in the perisinusoidal space and are needed for bone development, bone remodeling, and fracture repair. Grem1 expression also identifies intestinal reticular stem cells (iRSCs) that are cells of origin for the periepithelial intestinal mesenchymal sheath. Grem1 expression identifies distinct connective tissue stem cells in both the bone (OCR stem cells) and the intestine (iRSCs). PMID:25594183

Biochemistry of epidermal stem cells.

PubMed

Eckert, Richard L; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A; Vemuri, Mohan C; Boucher, Shayne E; Bickenbach, Jackie R; Kerr, Candace

2013-02-01

The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Basics and applications of stem cells in the pancreas.

PubMed

Sekine, Keisuke; Taniguchi, Hideki

2012-11-01

Enormous efforts have been made to establish pancreatic stem/progenitor cells as a source for regenerative medicine for the treatment of diabetes mellitus. In recent years, it has been recognized that the self-renewal of beta cells is the dominant process involved in postnatal beta-cell regeneration and expansion. Nevertheless, several in-vitro studies have suggested that ductal or as yet unidentified cells are candidates for pancreatic stem/progenitor cells that can differentiate into multilineage cells, including insulin(+) cells. The question remains as to whether beta cells are generated postnatally from stem/progenitor cells other than pre-existing beta cells. Furthermore, mutated pancreatic stem cells are considered to be prospective candidates for cancer stem cells or tumor-initiating cells. This review highlights recent progress in pancreatic stem/progenitor cell research.

Ablation of proliferating neural stem cells during early life is sufficient to reduce adult hippocampal neurogenesis.

PubMed

Youssef, Mary; Krish, Varsha S; Kirshenbaum, Greer S; Atsak, Piray; Lass, Tamara J; Lieberman, Sophie R; Leonardo, E David; Dranovsky, Alex

2018-05-09

Environmental exposures during early life, but not during adolescence or adulthood, lead to persistent reductions in neurogenesis in the adult hippocampal dentate gyrus (DG). The mechanisms by which early life exposures lead to long-term deficits in neurogenesis remain unclear. Here, we investigated whether targeted ablation of dividing neural stem cells during early life is sufficient to produce long-term decreases in DG neurogenesis. Having previously found that the stem cell lineage is resistant to long-term effects of transient ablation of dividing stem cells during adolescence or adulthood (Kirshenbaum et al., 2014), we used a similar pharmacogenetic approach to target dividing neural stem cells for elimination during early life periods sensitive to environmental insults. We then assessed the Nestin stem cell lineage in adulthood. We found that the adult neural stem cell reservoir was depleted following ablation during the first postnatal week, when stem cells were highly proliferative, but not during the third postnatal week, when stem cells were more quiescent. Remarkably, ablating proliferating stem cells during either the first or third postnatal week led to reduced adult neurogenesis out of proportion to the changes in the stem cell pool, indicating a disruption of the stem cell function or niche following stem cell ablation in early life. These results highlight the first three postnatal weeks as a series of sensitive periods during which elimination of dividing stem cells leads to lasting alterations in adult DG neurogenesis and stem cell function. These findings contribute to our understanding of the relationship between DG development and adult neurogenesis, as well as suggest a possible mechanism by which early life experiences may lead to lasting deficits in adult hippocampal neurogenesis. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

State performance in pluripotent and adult stem cell research, 2009-2016.

PubMed

Surani, Sana H; Levine, Aaron D

2018-04-01

To examine how the geographic distribution of pluripotent and adult stem cell research publications within the USA differs from other areas of biomedical research. Publication count data for pluripotent stem cell research, adult stem cell research and a comparison group representative of biomedical research more broadly were collected and analyzed for each US state from 2009 to 2016. The distribution of pluripotent stem cell research differed from the other fields with overperformance in pluripotent stem cell research observed in California, as well as Wisconsin, Massachusetts, Maryland and Connecticut. Our analysis suggests that permissive state stem cell policy may be one of the several factors contributing to strong state performance in pluripotent stem cell research.

Stem cell clinics online: the direct-to-consumer portrayal of stem cell medicine.

PubMed

Lau, Darren; Ogbogu, Ubaka; Taylor, Benjamin; Stafinski, Tania; Menon, Devidas; Caulfield, Timothy

2008-12-04

Despite the immature state of stem cell medicine, patients are seeking and accessing putative stem cell therapies in an "early market" in which direct-to-consumer advertising via the internet likely plays an important role. We analyzed stem cell clinic websites and appraised the relevant published clinical evidence of stem cell therapies to address three questions about the direct-to-consumer portrayal of stem cell medicine in this early market: What sorts of therapies are being offered? How are they portrayed? Is there clinical evidence to support the use of these therapies? We found that the portrayal of stem cell medicine on provider websites is optimistic and unsubstantiated by peer-reviewed literature.

Effects of Telomerase and Telomere Length on Epidermal Stem Cell Behavior

NASA Astrophysics Data System (ADS)

Flores, Ignacio; Cayuela, María L.; Blasco, María A.

2005-08-01

A key process in organ homeostasis is the mobilization of stem cells out of their niches. We show through analysis of mouse models that telomere length, as well as the catalytic component of telomerase, Tert, are critical determinants in the mobilization of epidermal stem cells. Telomere shortening inhibited mobilization of stem cells out of their niche, impaired hair growth, and resulted in suppression of stem cell proliferative capacity in vitro. In contrast, Tert overexpression in the absence of changes in telomere length promoted stem cell mobilization, hair growth, and stem cell proliferation in vitro. The effects of telomeres and telomerase on stem cell biology anticipate their role in cancer and aging.

Prospects for neural stem cell-based therapies for neurological diseases.

PubMed

Imitola, Jaime

2007-10-01

Neural stem and progenitor cells have great potential for the treatment of neurological disorders. However, many obstacles remain to translate this field to the patient's bedside, including rationales for using neural stem cells in individual neurological disorders; the challenges of neural stem cell biology; and the caveats of current strategies of isolation and culturing neural precursors. Addressing these challenges is critical for the translation of neural stem cell biology to the clinic. Recent work using neural stem cells has yielded novel biologic concepts such as the importance of the reciprocal interaction between neural stem cells and the neurodegenerative environment. The prospect of using transplants of neural stem cells and progenitors to treat neurological diseases requires a better understanding of the molecular mechanisms of both neural stem cell behavior in experimental models and the intrinsic repair capacity of the injured brain.

Impact of genomic damage and ageing on stem cell function

PubMed Central

Behrens, Axel; van Deursen, Jan M.; Rudolph, K. Lenhard; Schumacher, Björn

2014-01-01

Impairment of stem cell function contributes to the progressive deterioration of tissue maintenance and repair with ageing. Evidence is mounting that age-dependent accumulation of DNA damage in both stem cells and cells that comprise the stem cell microenvironment are partly responsible for stem cell dysfunction with ageing. Here, we review the impact of the various types of DNA damage that accumulate with ageing on stem cell functionality, as well as the development of cancer. We discuss DNA-damage-induced cell intrinsic and extrinsic alterations that influence these processes, and review recent advances in understanding systemic adjustments to DNA damage and how they affect stem cells. PMID:24576896

Lgr proteins in epithelial stem cell biology.

PubMed

Barker, Nick; Tan, Shawna; Clevers, Hans

2013-06-01

The ultimate success of global efforts to exploit adult stem cells for regenerative medicine will depend heavily on the availability of robust, highly selective stem cell surface markers that facilitate the isolation of stem cells from human tissues. Any subsequent expansion or manipulation of isolated stem cells will also require an intimate knowledge of the mechanisms that regulate these cells, to ensure maintenance of their regenerative capacities and to minimize the risk of introducing undesirable growth traits that could pose health risks for patients. A subclass of leucine-rich repeat-containing G-protein-coupled receptor (Lgr) proteins has recently gained prominence as adult stem cell markers with crucial roles in maintaining stem cell functions. Here, we discuss the major impact that their discovery has had on our understanding of adult stem cell biology in various self-renewing tissues and in accelerating progress towards the development of effective stem cell therapies.

Nanotechnology in the regulation of stem cell behavior

NASA Astrophysics Data System (ADS)

Wu, King-Chuen; Tseng, Ching-Li; Wu, Chi-Chang; Kao, Feng-Chen; Tu, Yuan-Kun; So, Edmund C.; Wang, Yang-Kao

2013-10-01

Stem cells are known for their potential to repair damaged tissues. The adhesion, growth and differentiation of stem cells are likely controlled by the surrounding microenvironment which contains both chemical and physical cues. Physical cues in the microenvironment, for example, nanotopography, were shown to play important roles in stem cell fate decisions. Thus, controlling stem cell behavior by nanoscale topography has become an important issue in stem cell biology. Nanotechnology has emerged as a new exciting field and research from this field has greatly advanced. Nanotechnology allows the manipulation of sophisticated surfaces/scaffolds which can mimic the cellular environment for regulating cellular behaviors. Thus, we summarize recent studies on nanotechnology with applications to stem cell biology, including the regulation of stem cell adhesion, growth, differentiation, tracking and imaging. Understanding the interactions of nanomaterials with stem cells may provide the knowledge to apply to cell-scaffold combinations in tissue engineering and regenerative medicine.

A novel platelet lysate hydrogel for endothelial cell and mesenchymal stem cell-directed neovascularization.

PubMed

Robinson, Scott T; Douglas, Alison M; Chadid, Tatiana; Kuo, Katie; Rajabalan, Ajai; Li, Haiyan; Copland, Ian B; Barker, Thomas H; Galipeau, Jacques; Brewster, Luke P

2016-05-01

Mesenchymal stem cells (MSC) hold promise in promoting vascular regeneration of ischemic tissue in conditions like critical limb ischemia of the leg. However, this approach has been limited in part by poor cell retention and survival after delivery. New biomaterials offer an opportunity to localize cells to the desired tissue after delivery, but also to improve cell survival after delivery. Here we characterize the mechanical and microstructural properties of a novel hydrogel composed of pooled human platelet lysate (PL) and test its ability to promote MSC angiogenic activity using clinically relevant in vitro and in vivo models. This PL hydrogel had comparable storage and loss modulus and behaved as a viscoelastic solid similar to fibrin hydrogels despite having 1/4-1/10th the fibrin content of standard fibrin gels. Additionally, PL hydrogels enabled sustained release of endogenous PDGF-BB for up to 20days and were resistant to protease degradation. PL hydrogel stimulated pro-angiogenic activity by promoting human MSC growth and invasion in a 3D environment, and enhancing endothelial cell sprouting alone and in co-culture with MSCs. When delivered in vivo, the combination of PL and human MSCs improved local tissue perfusion after 8days compared to controls when assessed with laser Doppler perfusion imaging in a murine model of hind limb ischemia. These results support the use of a PL hydrogel as a scaffold for MSC delivery to promote vascular regeneration. Innovative strategies for improved retention and viability of mesenchymal stem cells (MSCs) are needed for cellular therapies. Human platelet lysate is a potent serum supplement that improves the expansion of MSCs. Here we characterize our novel PL hydrogel's desirable structural and biologic properties for human MSCs and endothelial cells. PL hydrogel can localize cells for retention in the desired tissue, improves cell viability, and augments MSCs' angiogenic activity. As a result of these unique traits, PL hydrogel is ideally suited to serve as a cell delivery vehicle for MSCs injected into ischemic tissues to promote vascular regeneration, as demonstrated here in a murine model of hindlimb ischemia. Published by Elsevier Ltd.

Characterization of Amniotic Stem Cells

PubMed Central

Koike, Chika; Zhou, Kaixuan; Takeda, Yuji; Fathy, Moustafa; Okabe, Motonori; Yoshida, Toshiko; Nakamura, Yukio; Kato, Yukio

2014-01-01

Abstract The amnion membrane is developed from embryo-derived cells, and amniotic cells have been shown to exhibit multidifferentiation potential. These cells represent a desirable source for stem cells for a variety of reasons. However, to date very few molecular analyses of amnion-derived cells have been reported, and efficient markers for isolating the stem cells remain unclear. This paper assesses the characterization of amnion-derived cells as stem cells by examining stemness marker expressions for amnion-derived epithelial cells and mesenchymal cells by flow cytometry, immunocytochemistry, and quantitative PCR. Flow cytometry revealed that amnion epithelial cells expressed CD133, CD 271, and TRA-1-60, whereas mecenchymal cells expressed CD44, CD73, CD90, and CD105. Immunohistochemistry showed that both cells expressed the stemness markers Oct3/4, Sox2, Klf4, and SSEA4. Stemness genes' expression in amnion epithelial cells, mesenchymal cells, fibroblast, bone marrow–derived mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) was compared by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Amnion-derived epithelial cells and mesenchymal cells expressed Oct3/4, Nanog, and Klf4 more than bone marrow–derived MSCs. The sorted TRA1-60–positive cells expressed Oct3/4, Nanog, and Klf4 more than unsorted cells or TRA1-60–negative cells. TRA1-60 can be a marker for isolating amnion epithelial stem cells. PMID:25068631

Electroporation of the Testis

NASA Astrophysics Data System (ADS)

Yomogida, Kentaro

The mature mammalian testis is a marvelous organ that produces numerous sperm cells during its reproductive phase. This biologically significant process consists of three steps: stem cell self-renewal and differentiation, meiosis and genetic recombination, and haploid cell morphogenesis into sperm (Russell et al., 1990). The first step provides a good model for investigating the molecular mechanism of stem cell regulation. Currently, the mechanism underlying sperm cell production is a very exciting topic in regenerative medicine (Lensch et al. 2007; Okita et al., 2007). The spermatogonial stem cell system has several advantages, including the easy histological identification of stem cells (Russell et al., 1990), a clear relationship between stem cells and the supporting Sertoli cells, which provide a stem cell niche (Tadokoro et al., 2002; Yomogida et al., 2003), and a transplantation assay for stem cell activity (Oatley & Brinster, 2006). Although germline stem (GS) cells derived from the gonocytes in newborn testis constitute a suitable in vitro system for investigating the properties of spermatogonial stem cells (Kanatsu-Shinohara et al., 2003, 2004), studies using living mammalian testes continue to provide information regarding the roles of the stem cell niche. In vivo electroporation of the supporting cells in the testis will expand our ability to study it.

Current applications of human pluripotent stem cells: possibilities and challenges.

PubMed

Ho, Pai-Jiun; Yen, Men-Luh; Yet, Shaw-Fang; Yen, B Linju

2012-01-01

Stem cells are self-renewable cells with the differentiation capacity to develop into somatic cells with biological functions. This ability to sustain a renewable source of multi- and/or pluripotential differentiation has brought new hope to the field of regenerative medicine in terms of cell therapy and tissue engineering. Moreover, stem cells are invaluable tools as in vitro models for studying diverse fields, from basic scientific questions such as developmental processes and lineage commitment, to practical application including drug screening and testing. The stem cells with widest differentiation potential are pluripotent stem cells (PSCs), which are rare cells with the ability to generate somatic cells from all three germ layers. PSCs are considered the most optimal choice for therapeutic potential of stem cells, bringing new impetus to the field of regenerative medicine. In this article, we discuss the therapeutic potential of human PSCs (hPSCs) including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), reviewing the current preclinical and clinical data using these stem cells. We describe the classification of different sources of hPSCs, ongoing research, and currently encountered clinical obstacles of these novel and versatile human stem cells.

Monolayered mesenchymal stem cells repair scarred myocardium after myocardial infarction.

PubMed

Miyahara, Yoshinori; Nagaya, Noritoshi; Kataoka, Masaharu; Yanagawa, Bobby; Tanaka, Koichi; Hao, Hiroyuki; Ishino, Kozo; Ishida, Hideyuki; Shimizu, Tatsuya; Kangawa, Kenji; Sano, Shunji; Okano, Teruo; Kitamura, Soichiro; Mori, Hidezo

2006-04-01

Mesenchymal stem cells are multipotent cells that can differentiate into cardiomyocytes and vascular endothelial cells. Here we show, using cell sheet technology, that monolayered mesenchymal stem cells have multipotent and self-propagating properties after transplantation into infarcted rat hearts. We cultured adipose tissue-derived mesenchymal stem cells characterized by flow cytometry using temperature-responsive culture dishes. Four weeks after coronary ligation, we transplanted the monolayered mesenchymal stem cells onto the scarred myocardium. After transplantation, the engrafted sheet gradually grew to form a thick stratum that included newly formed vessels, undifferentiated cells and few cardiomyocytes. The mesenchymal stem cell sheet also acted through paracrine pathways to trigger angiogenesis. Unlike a fibroblast cell sheet, the monolayered mesenchymal stem cells reversed wall thinning in the scar area and improved cardiac function in rats with myocardial infarction. Thus, transplantation of monolayered mesenchymal stem cells may be a new therapeutic strategy for cardiac tissue regeneration.

Genetic and epigenetic instability of stem cells.

PubMed

Rajamani, Karthyayani; Li, Yuan-Sheng; Hsieh, Dean-Kuo; Lin, Shinn-Zong; Harn, Horng-Jyh; Chiou, Tzyy-Wen

2014-01-01

Recently, research on stem cells has been receiving an increasing amount of attention, both for its advantages and disadvantages. Genetic and epigenetic instabilities among stem cells have been a recurring obstacle to progress in regenerative medicine using stem cells. Various reports have stated that these instabilities can transform stem cells when transferred in vivo and thus have the potential to develop tumors. Previous research has shown that various extrinsic and intrinsic factors can contribute to the stability of stem cells. The extrinsic factors include growth supplements, growth factors, oxygen tension, passage technique, and cryopreservation. Controlling these factors based on previous reports may assist researchers in developing strategies for the production and clinical application of "safe" stem cells. On the other hand, the intrinsic factors can be unpredictable and uncontrollable; therefore, to ensure the successful use of stem cells in regenerative medicine, it is imperative to develop and implement appropriate strategies and technique for culturing stem cells and to confirm the genetic and epigenetic safety of these stem cells before employing them in clinical trials.

Dipeptide species regulate p38MAPK–Smad3 signalling to maintain chronic myelogenous leukaemia stem cells

PubMed Central

Naka, Kazuhito; Jomen, Yoshie; Ishihara, Kaori; Kim, Junil; Ishimoto, Takahiro; Bae, Eun-Jin; Mohney, Robert P.; Stirdivant, Steven M.; Oshima, Hiroko; Oshima, Masanobu; Kim, Dong-Wook; Nakauchi, Hiromitsu; Takihara, Yoshihiro; Kato, Yukio; Ooshima, Akira; Kim, Seong-Jin

2015-01-01

Understanding the specific survival of the rare chronic myelogenous leukaemia (CML) stem cell population could provide a target for therapeutics aimed at eradicating these cells. However, little is known about how survival signalling is regulated in CML stem cells. In this study, we survey global metabolic differences between murine normal haematopoietic stem cells (HSCs) and CML stem cells using metabolomics techniques. Strikingly, we show that CML stem cells accumulate significantly higher levels of certain dipeptide species than normal HSCs. Once internalized, these dipeptide species activate amino-acid signalling via a pathway involving p38MAPK and the stemness transcription factor Smad3, which promotes CML stem cell maintenance. Importantly, pharmacological inhibition of dipeptide uptake inhibits CML stem cell activity in vivo. Our results demonstrate that dipeptide species support CML stem cell maintenance by activating p38MAPK–Smad3 signalling in vivo, and thus point towards a potential therapeutic target for CML treatment. PMID:26289811

Microencapsulated VEGF gene-modified umbilical cord mesenchymal stromal cells promote the vascularization of tissue-engineered dermis: an experimental study.

PubMed

Han, Yanfu; Tao, Ran; Han, Yanqing; Sun, Tianjun; Chai, Jiake; Xu, Guang; Liu, Jing

2014-02-01

Tissue-engineered dermis (TED) is thought to be the best treatment for skin defect wounds; however, lack of vascular structures in these products can cause slow vascularization or even transplant failure. We assessed the therapeutic potential of microencapsulated human umbilical cord mesenchymal stromal cells (hUCMSCs) expressing vascular endothelial growth factor (VEGF) in vascularization of TED. hUCMSCs were isolated by means of enzymatic digestion and identified by means of testing biological characteristics. hUCMSCs were induced to differentiate into dermal fibroblasts in conditioned induction media. Collagen-chitosan laser drilling acellular dermal matrix (ADM) composite scaffold was prepared by means of the freeze dehydration and dehydrothermal cross-linking method. hUCMSC-derived fibroblasts were implanted on composite scaffolds to construct TED. TED with microencapsulated VEGF gene-modified hUCMSCs was then transplanted into skin defect wounds in pigs. The angiogenesis of TED at 1 week and status of wound healing at 3 weeks were observed. The collagen-chitosan laser ADM composite has a uniform microporous structure. This composite has been used to grow hUCMSC-derived fibroblasts in vitro and to successfully construct stem cell-derived TED. Microencapsulated VEGF gene-modified hUCMSCs were prepared with the use of a sodium alginate-barium chloride one-step encapsulation technology. Seven days after the transplantation of the stem cell-derived TED and microencapsulated VEGF gene-modified hUCMSCs into the skin defect wounds on the backs of miniature pigs, the VEGF expression increased and the TED had a higher degree of vascularization. Re-epithelialization of the wound was completed after 3 weeks. Microencapsulated VEGF gene-modified hUCMSCs can effectively improve the vascularization of TED and consequently the quality of wound healing. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function.

PubMed

Pankajakshan, Divya; Albuquerque, Maria T P; Evans, Joshua D; Kamocka, Malgorzata M; Gregory, Richard L; Bottino, Marco C

2016-10-01

Root canal disinfection and the establishment of an intracanal microenvironment conducive to the proliferation/differentiation of stem cells play a significant role in regenerative endodontics. This study was designed to (1) investigate the antimicrobial efficacy of triple antibiotic-containing nanofibers against a dual-species biofilm and (2) evaluate the ability of dental pulp stem cells (DPSCs) to adhere to and proliferate on dentin upon nanofiber exposure. Seven-day-old dual-species biofilm established on dentin specimens was exposed for 3 days to the following: saline (control), antibiotic-free nanofibers (control), and triple antibiotic-containing nanofibers or a saturated triple antibiotic paste (TAP) solution (50 mg/mL in phosphate buffer solution). Bacterial viability was assessed using the LIVE/DEAD assay (Molecular Probes, Inc, Eugene, OR) and confocal laser scanning microscopy. For cytocompatibility studies, dentin specimens after nanofiber or TAP (1 g/mL in phosphate buffer solution) exposure were evaluated for cell adhesion and spreading by actin-phalloidin staining. DPSC proliferation was assessed on days 1, 3, and 7. Statistics were performed, and significance was set at the 5% level. Confocal laser scanning microscopy showed significant bacterial death upon antibiotic-containing nanofiber exposure, differing significantly (P < .05) from antibiotic-free fibers and the control (saline). DPSCs showed enhanced adhesion/spreading on dentin specimens treated with antibiotic-containing nanofibers when compared with its TAP counterparts. The DPSC proliferation rate was similar on days 1 and 3 in antibiotic-free nanofibers, triple antibiotic-containing nanofibers, and TAP-treated dentin. Proliferation was higher (9-fold) on dentin treated with antibiotic-containing nanofibers on day 7 compared with TAP. Triple antibiotic-containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Engineering Stem Cells for Biomedical Applications.

PubMed

Yin, Perry T; Han, Edward; Lee, Ki-Bum

2016-01-07

Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Applications of rigid and flexible GRIN-endoscopes

NASA Astrophysics Data System (ADS)

Schenkl, Selma; Ehlers, Alexander; Riemann, Iris; Messerschmidt, Bernhard; Bückle, Rainer; König, Karsten

2007-02-01

Multiphoton autofluorescence imaging became an important technique for minimal invasive examination of cells in biological tissue. Rigid and flexible endoscopes based on gradient index lenses (GRIN-lenses) extend this minimalinvasive technique to deep lying cell layers, inner body and specimens, difficult to access. In the rigid endoscope, a GRIN-lens overcomes the limited depth range, given by the working distance of the microscope objective. The focus of the conventional laser scanning tomography is reproduced tens of millimeters in the specimen under study by the GRIN-lens (diameter 1.8 and 3 μm). We will present images of fluorescent beads, proteins cells and skin tissue, as well as first in vivo measurements on human skin. The autofluorescence signal stems from the endogenous fluorophore elastin and SHG from collagen. The flexible endoscope dispenses completely the need of a microscope next to the specimen of interest. The excitation laser pulses is delivered via a well-characterized photonic crystal fiber and subsequently focused by a newly designed GRIN-lens system. The fluorescence, also transferred by a fiber is detected by a PMT detector. We will show the excellent imaging qualities of a newly developed GRIN-lens system with high-resolution images of proteins, cells and plant tissue and give an out-look on multiphoton endoscopy.

Modeling TSC and LAM Using Patient Derived Induced Pluripotent Stem Cells

DTIC Science & Technology

2016-10-01

lentiviral knockdown, and CRISPR /Cas9 genome editing in embryonic stem cells (ESCs). We have characterized the iPSCs extensively and found that they display...induced pluripotent stem cells (iPSCs) embryonic stem cells (ESCs) reprogramming CRISPR /Cas9 genome editing neural stem cells (NSCs) neural crest... CRISPR /cas9 in two additional human pluripotent stem cell lines (WA07 (H7) – female cell line registry #0061; and a control male iPSC lines generated

Biochemistry of epidermal stem cells☆

PubMed Central

Eckert, Richard L.; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A.; Vemuri, Mohan C.; Boucher, Shayne E.; Bickenbach, Jackie R.; Kerr, Candace

2014-01-01

Background The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. Scope of review A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. Major conclusions An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. General significance Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. PMID:22820019

Cryopreservation of Human Stem Cells for Clinical Application: A Review

PubMed Central

Hunt, Charles J.

2011-01-01

Summary Stem cells have been used in a clinical setting for many years. Haematopoietic stem cells have been used for the treatment of both haematological and non-haematological disease; while more recently mesenchymal stem cells derived from bone marrow have been the subject of both laboratory and early clinical studies. Whilst these cells show both multipotency and expansion potential, they nonetheless do not form stable cell lines in culture which is likely to limit the breadth of their application in the field of regenerative medicine. Human embryonic stem cells are pluripotent cells, capable of forming stable cell lines which retain the capacity to differentiate into cells from all three germ layers. This makes them of special significance in both regenerative medicine and toxicology. Induced pluripotent stem (iPS) cells may also provide a similar breadth of utility without some of the confounding ethical issues surrounding embryonic stem cells. An essential pre-requisite to the commercial and clinical application of stem cells are suitable cryopreservation protocols for long-term storage. Whilst effective methods for cryopreservation and storage have been developed for haematopoietic and mesenchymal stem cells, embryonic cells and iPS cells have proved more refractory. This paper reviews the current state of cryopreservation as it pertains to stem cells and in particular the embryonic and iPS cell. PMID:21566712

Cryopreservation of Human Stem Cells for Clinical Application: A Review.

PubMed

Hunt, Charles J

2011-01-01

SUMMARY: Stem cells have been used in a clinical setting for many years. Haematopoietic stem cells have been used for the treatment of both haematological and non-haematological disease; while more recently mesenchymal stem cells derived from bone marrow have been the subject of both laboratory and early clinical studies. Whilst these cells show both multipotency and expansion potential, they nonetheless do not form stable cell lines in culture which is likely to limit the breadth of their application in the field of regenerative medicine. Human embryonic stem cells are pluripotent cells, capable of forming stable cell lines which retain the capacity to differentiate into cells from all three germ layers. This makes them of special significance in both regenerative medicine and toxicology. Induced pluripotent stem (iPS) cells may also provide a similar breadth of utility without some of the confounding ethical issues surrounding embryonic stem cells. An essential pre-requisite to the commercial and clinical application of stem cells are suitable cryopreservation protocols for long-term storage. Whilst effective methods for cryopreservation and storage have been developed for haematopoietic and mesenchymal stem cells, embryonic cells and iPS cells have proved more refractory. This paper reviews the current state of cryopreservation as it pertains to stem cells and in particular the embryonic and iPS cell.

YAP/TAZ enhance mammalian embryonic neural stem cell characteristics in a Tead-dependent manner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Dasol; Byun, Sung-Hyun; Park, Soojeong

Mammalian brain development is regulated by multiple signaling pathways controlling cell proliferation, migration and differentiation. Here we show that YAP/TAZ enhance embryonic neural stem cell characteristics in a cell autonomous fashion using diverse experimental approaches. Introduction of retroviral vectors expressing YAP or TAZ into the mouse embryonic brain induced cell localization in the ventricular zone (VZ), which is the embryonic neural stem cell niche. This change in cell distribution in the cortical layer is due to the increased stemness of infected cells; YAP-expressing cells were colabeled with Sox2, a neural stem cell marker, and YAP/TAZ increased the frequency and sizemore » of neurospheres, indicating enhanced self-renewal- and proliferative ability of neural stem cells. These effects appear to be TEA domain family transcription factor (Tead)–dependent; a Tead binding-defective YAP mutant lost the ability to promote neural stem cell characteristics. Consistently, in utero gene transfer of a constitutively active form of Tead2 (Tead2-VP16) recapitulated all the features of YAP/TAZ overexpression, and dominant negative Tead2-EnR resulted in marked cell exit from the VZ toward outer cortical layers. Taken together, these results indicate that the Tead-dependent YAP/TAZ signaling pathway plays important roles in neural stem cell maintenance by enhancing stemness of neural stem cells during mammalian brain development. - Highlights: • Roles of YAP and Tead in vivo during mammalian brain development are clarified. • Expression of YAP promotes embryonic neural stem cell characteristics in vivo in a cell autonomous fashion. • Enhancement of neural stem cell characteristics by YAP depends on Tead. • Transcriptionally active form of Tead alone can recapitulate the effects of YAP. • Transcriptionally repressive form of Tead severely reduces stem cell characteristics.« less

Recent progress in stem cell differentiation directed by material and mechanical cues.

PubMed

Lin, Xunxun; Shi, Yuan; Cao, Yilin; Liu, Wei

2016-02-02

Stem cells play essential roles in tissue regeneration in vivo via specific lineage differentiation induced by environmental factors. In the past, biochemical signals were the focus of induced stem cell differentiation. As reported by Engler et al (2006 Cell 126 677-89), biophysical signal mediated stem cell differentiation could also serve as an important inducer. With the advancement of material science, it becomes a possible strategy to generate active biophysical signals for directing stem cell fate through specially designed material microstructures. In the past five years, significant progress has been made in this field, and these designed biophysical signals include material elasticity/rigidity, micropatterned structure, extracellular matrix (ECM) coated materials, material transmitted extracellular mechanical force etc. A large number of investigations involved material directed differentiation of mesenchymal stem cells, neural stem/progenitor cells, adipose derived stem cells, hematopoietic stem/progenitor cells, embryonic stem cells and other cells. Hydrogel based materials were commonly used to create varied mechanical properties via modifying the ratio of different components, crosslinking levels, matrix concentration and conjugation with other components. Among them, polyacrylamide (PAM) and polydimethylsiloxane (PDMS) hydrogels remained the major types of material. Specially designed micropatterning was not only able to create a unique topographical surface to control cell shape, alignment, cell-cell and cell-matrix contact for basic stem cell biology study, but also could be integrated with 3D bioprinting to generate micropattered 3D structure and thus to induce stem cell based tissue regeneration. ECM coating on a specific topographical structure was capable of inducing even more specific and potent stem cell differentiation along with soluble factors and mechanical force. The article overviews the progress of the past five years in this particular field.

Engineering Hydrogel Microenvironments to Recapitulate the Stem Cell Niche.

PubMed

Madl, Christopher M; Heilshorn, Sarah C

2018-06-04

Stem cells are a powerful resource for many applications including regenerative medicine, patient-specific disease modeling, and toxicology screening. However, eliciting the desired behavior from stem cells, such as expansion in a naïve state or differentiation into a particular mature lineage, remains challenging. Drawing inspiration from the native stem cell niche, hydrogel platforms have been developed to regulate stem cell fate by controlling microenvironmental parameters including matrix mechanics, degradability, cell-adhesive ligand presentation, local microstructure, and cell-cell interactions. We survey techniques for modulating hydrogel properties and review the effects of microenvironmental parameters on maintaining stemness and controlling differentiation for a variety of stem cell types. Looking forward, we envision future hydrogel designs spanning a spectrum of complexity, ranging from simple, fully defined materials for industrial expansion of stem cells to complex, biomimetic systems for organotypic cell culture models.

Incorporation of Biomaterials in Multicellular Aggregates Modulates Pluripotent Stem Cell Differentiation

PubMed Central

Bratt-Leal, Andrés M.; Carpenedo, Richard L.; Ungrin, Mark; Zandstra, Peter W.; McDevitt, Todd C.

2010-01-01

Biomaterials are increasingly being used to engineer the biochemical and biophysical properties of the extracellular stem cell microenvironment in order to tailor niche characteristics and direct cell phenotype. To date, stem cell-biomaterial interactions have largely been studied by introducing stem cells into artificial environments, such as 2D cell culture on biomaterial surfaces, encapsulation of cell suspensions within hydrogel materials, or cell seeding on 3D polymeric scaffolds. In this study, microparticles fabricated from different materials, such as agarose, PLGA and gelatin, were stably integrated, in a dose-dependent manner, within aggregates of pluripotent stem cells (PSCs) prior to differentiation as a means to directly examine stem cell-biomaterial interactions in 3D. Interestingly, the presence of the materials within the stem cell aggregates differentially modulated the gene and protein expression patterns of several differentiation markers without adversely affecting cell viability. Microparticle incorporation within 3D stem cell aggregates can control the spatial presentation of extracellular environmental cues (i.e. soluble factors, extracellular matrix and intercellular adhesion molecules) as a means to direct the differentiation of stem cells for tissue engineering and regenerative medicine applications. In addition, these results suggest that the physical presence of microparticles within stem cell aggregates does not compromise PSC differentiation, but in fact the choice of biomaterials can impact the propensity of stem cells to adopt particular differentiated cell phenotypes. PMID:20864164

Markers for the identification of tendon-derived stem cells in vitro and tendon stem cells in situ - update and future development.

PubMed

Lui, Pauline Po Yee

2015-06-02

The efficacy of tendon-derived stem cells (TDSCs) for the promotion of tendon and tendon-bone junction repair has been reported in animal studies. Modulation of the tendon stem cell niche in vivo has also been reported to influence tendon structure. There is a need to have specific and reliable markers that can define TDSCs in vitro and tendon stem cells in situ for several reasons: to understand the basic biology of TDSCs and their subpopulations in vitro; to understand the identity, niches and functions of tendon/progenitor stem cells in vivo; to meet the governmental regulatory requirements for quality of TDSCs when translating the exciting preclinical findings into clinical trial/practice; and to develop new treatment strategies for mobilizing endogenous stem/progenitor cells in tendon. TDSCs were reported to express the common mesenchymal stem cell (MSC) markers and some embryonic stem cell (ESC) markers, and there were attempts to use these markers to label tendon stem cells in situ. Are these stem cell markers useful for the identification of TDSCs in vitro and tracking of tendon stem cells in situ? This review aims to discuss the values of the panel of MSC, ESC and tendon-related markers for the identification of TDSCs in vitro. Important factors influencing marker expression by TDSCs are discussed. The usefulness and limitations of the panel of MSC, ESC and tendon-related markers for tracking stem cells in tendon, especially tendon stem cells, in situ are then reviewed. Future research directions are proposed.

Haematopoietic stem and progenitor cells from human pluripotent stem cells

PubMed Central

Sugimura, Ryohichi; Jha, Deepak Kumar; Han, Areum; Soria-Valles, Clara; da Rocha, Edroaldo Lummertz; Lu, Yi-Fen; Goettel, Jeremy A.; Serrao, Erik; Rowe, R. Grant; Malleshaiah, Mohan; Wong, Irene; Sousa, Patricia; Zhu, Ted N.; Ditadi, Andrea; Keller, Gordon; Engelman, Alan N.; Snapper, Scott B.; Doulatov, Sergei; Daley, George Q.

2018-01-01

A variety of tissue lineages can be differentiated from pluripotent stem cells by mimicking embryonic development through stepwise exposure to morphogens, or by conversion of one differentiated cell type into another by enforced expression of master transcription factors. Here, to yield functional human haematopoietic stem cells, we perform morphogen-directed differentiation of human pluripotent stem cells into haemogenic endothelium followed by screening of 26 candidate haematopoietic stem-cell-specifying transcription factors for their capacity to promote multi-lineage haematopoietic engraftment in mouse hosts. We recover seven transcription factors (ERG, HOXA5, HOXA9, HOXA10, LCOR, RUNX1 and SPI1) that are sufficient to convert haemogenic endothelium into haematopoietic stem and progenitor cells that engraft myeloid, B and T cells in primary and secondary mouse recipients. Our combined approach of morphogen-driven differentiation and transcription-factor-mediated cell fate conversion produces haematopoietic stem and progenitor cells from pluripotent stem cells and holds promise for modelling haematopoietic disease in humanized mice and for therapeutic strategies in genetic blood disorders. PMID:28514439

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure.

PubMed

Yun, Hongmin; Zhou, Yi; Wills, Andrew; Du, Yiqin

2016-06-01

Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration.

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure

PubMed Central

Yun, Hongmin; Zhou, Yi; Wills, Andrew

2016-01-01

Abstract Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration. PMID:27183473

New perspectives in human stem cell therapeutic research.

PubMed

Trounson, Alan

2009-06-11

Human stem cells are in evaluation in clinical stem cell trials, primarily as autologous bone marrow studies, autologous and allogenic mesenchymal stem cell trials, and some allogenic neural stem cell transplantation projects. Safety and efficacy are being addressed for a number of disease state applications. There is considerable data supporting safety of bone marrow and mesenchymal stem cell transplants but the efficacy data are variable and of mixed benefit. Mechanisms of action of many of these cells are unknown and this raises the concern of unpredictable results in the future. Nevertheless there is considerable optimism that immune suppression and anti-inflammatory properties of mesenchymal stem cells will be of benefit for many conditions such as graft versus host disease, solid organ transplants and pulmonary fibrosis. Where bone marrow and mesenchymal stem cells are being studied for heart disease, stroke and other neurodegenerative disorders, again progress is mixed and mostly without significant benefit. However, correction of multiple sclerosis, at least in the short term is encouraging. Clinical trials on the use of embryonic stem cell derivatives for spinal injury and macular degeneration are beginning and a raft of other clinical trials can be expected soon, for example, the use of neural stem cells for killing inoperable glioma and embryonic stem cells for regenerating beta islet cells for diabetes. The change in attitude to embryonic stem cell research with the incoming Obama administration heralds a new co-operative environment for study and evaluation of stem cell therapies. The Californian stem cell initiative (California Institute for Regenerative Medicine) has engendered global collaboration for this new medicine that will now also be supported by the US Federal Government. The active participation of governments, academia, biotechnology, pharmaceutical companies, and private investment is a powerful consortium for advances in health.

Invincible, but not invisible: imaging approaches toward in vivo detection of cancer stem cells.

PubMed

Hart, Lori S; El-Deiry, Wafik S

2008-06-10

With evidence emerging in support of a cancer stem-cell model of carcinogenesis, it is of paramount importance to identify and image these elusive cells in their natural environment. The cancer stem-cell hypothesis has the potential to explain unresolved questions of tumorigenesis, tumor heterogeneity, chemotherapeutic and radiation resistance, and even the metastatic phenotype. Intravital imaging of cancer stem cells could be of great value for determining prognosis, as well as monitoring therapeutic efficacy and influencing therapeutic protocols. Cancer stem cells represent a rare population of cells, as low as 0.1% of cells within a human tumor, and the phenotype of isolated cancer stem cells is easily altered when placed under in vitro conditions. This represents a challenge in studying cancer stem cells without manipulation or extraction from their natural environment. Advanced imaging techniques allow for the in vivo observation of physiological events at cellular resolution. Cancer stem-cell studies must take advantage of such technology to promote a better understanding of the cancer stem-cell model in relation to tumor growth and metastasis, as well as to potentially improve on the principles by which cancers are treated. This review examines the opportunities for in vivo imaging of putative cancer stem cells with regard to currently accepted cancer stem-cell characteristics and advanced imaging technologies.

Neural stem cell-based treatment for neurodegenerative diseases.

PubMed

Kim, Seung U; Lee, Hong J; Kim, Yun B

2013-10-01

Human neurodegenerative diseases such as Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD) are caused by a loss of neurons and glia in the brain or spinal cord. Neurons and glial cells have successfully been generated from stem cells such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs) and neural stem cells (NSCs), and stem cell-based cell therapies for neurodegenerative diseases have been developed. A recent advance in generation of a new class of pluripotent stem cells, induced pluripotent stem cells (iPSCs), derived from patients' own skin fibroblasts, opens doors for a totally new field of personalized medicine. Transplantation of NSCs, neurons or glia generated from stem cells in animal models of neurodegenerative diseases, including PD, HD, ALS and AD, demonstrates clinical improvement and also life extension of these animals. Additional therapeutic benefits in these animals can be provided by stem cell-mediated gene transfer of therapeutic genes such as neurotrophic factors and enzymes. Although further research is still needed, cell and gene therapy based on stem cells, particularly using neurons and glia derived from iPSCs, ESCs or NSCs, will become a routine treatment for patients suffering from neurodegenerative diseases and also stroke and spinal cord injury. © 2013 Japanese Society of Neuropathology.

Constitutive Proteasomal Degradation of TWIST-1 in Epithelial Ovarian Cancer Stem Cells Impacts Differentiation and Metastatic Potential

PubMed Central

Yin, Gang; Alvero, Ayesha B.; Craveiro, Vinicius; Holmberg, Jennie C.; Fu, Han-Hsuan; Montagna, Michele K.; Yang, Yang; Chefetz-Menaker, Ilana; Nuti, Sudhakar; Rossi, Michael; Silasi, Dan-Arin; Rutherford, Thomas; Mor, Gil

2013-01-01

Epithelial-mesenchymal transition (EMT) is a critical process for embryogenesis but is abnormally activated during cancer metastasis and recurrence. This process enables epithelial cancer cells to acquire mobility and traits associated with stemness. It is unknown whether epithelial stem cells or epithelial cancer stem cells are able to undergo EMT, and what molecular mechanism regulates this process in these specific cell types. We found that Epithelial Ovarian Cancer Stem cells (EOC stem cells) are the source of metastatic progenitor cells through a differentiation process involving EMT and Mesenchymal-Epithelial Transition (MET). We demonstrate both in vivo and in vitro the differentiation of EOC stem cells into mesenchymal spheroid-forming cells (MSFCs) and their capacity to initiate an active carcinomatosis. Furthermore, we demonstrate that human EOC stem cells injected i.p in mice are able to form ovarian tumors, suggesting that the EOC stem cells have the ability to “home” to the ovaries and establish tumors. Most interestingly, we found that TWIST1 is constitutively degraded in EOC stem cells, and that the acquisition of TWIST1 requires additional signals that will trigger the differentiation process. These findings are relevant for understanding the differentiation and metastasis process in EOC stem cells. PMID:22349827

Hepatic differentiation of pluripotent stem cells.

PubMed

Loya, Komal; Eggenschwiler, Reto; Ko, Kinarm; Sgodda, Malte; André, Francoise; Bleidissel, Martina; Schöler, Hans R; Cantz, Tobias

2009-10-01

In regenerative medicine pluripotent stem cells are considered to be a valuable self-renewing source for therapeutic cell transplantations, given that a functional organ-specific phenotype can be acquired by in vitro differentiation protocols. Furthermore, derivatives of pluripotent stem cells that mimic fetal progenitor stages could serve as an important tool to analyze organ development with in vitro approaches. Because of ethical issues regarding the generation of human embryonic stem (ES) cells, other sources for pluripotent stem cells are intensively studied. Like in less developed vertebrates, pluripotent stem cells can be generated from the female germline even in mammals, via parthenogenetic activation of oocytes. Recently, testis-derived pluripotent stem cells were derived from the male germline. Therefore, we compared two different hepatic differentiation approaches and analyzed the generation of definitive endoderm progenitor cells and their further maturation into a hepatic phenotype using murine parthenogenetic ES cells, germline-derived pluripotent stem cells, and ES cells. Applying quantitative RT-PCR, both germline-derived pluripotent cell lines show similar differentiation capabilities as normal murine ES cells and can be considered an alternative source for pluripotent stem cells in regenerative medicine.

An overview on ethical considerations in stem cell research in Iran and ethical recommendations: A review.

PubMed

Farajkhoda, Tahmineh

2017-02-01

Conducting research on the stem cell lines might bring some worthy good to public. Human Stem Cells (hSCs) research has provided opportunities for scientific progresses and new therapies, but some complex ethical matters should be noticed to ensure that stem cell research is carried out in an ethically appropriate manner. The aim of this review article is to discuss the importance of stem cell research, code of ethics for stem cell research in Iran and ethical recommendation. Generation of stem cells for research from human embryo or adult stem cells, saving, maintenance and using of them are the main ethical, legal and jurisprudence concerns in Iran. Concerns regarding human reproduction or human cloning, breach of human dignity, genetic manipulation and probability of tumorogenisity are observed in adult/somatic stem cells. Destruction of embryo to generate stem cell is an important matter in Iran. In this regards, obtaining stem cell from donated frozen embryos through infertility treatment that would be discarded is an acceptable solution in Iran for generation of embryo for research. Ethical, legal, and jurisprudence strategies for using adult/somatic stem cells are determination of ownership of stem cells, trade prohibition of human body, supervision on bio banks and information of Oversight Committee on Stem Cell Research. Recommendations to handle ethical issues for conducting stem cell research are well-designed studies, compliance codes of ethics in biomedical research (specifically codes of ethics on stem cell research, codes of ethics on clinical trials studies and codes of ethics on animals studies), appropriate collaboration with ethics committees and respecting of rights of participants (including both of human and animal rights) in research. In addition, there is a necessity for extending global networks of bioethics for strengthening communications within organizations at both the regional and international level, strengthening legislation systems, designing and establishing convenient collaborative educational courses at different levels.

An overview on ethical considerations in stem cell research in Iran and ethical recommendations: A review

PubMed Central

Farajkhoda, Tahmineh

2017-01-01

Conducting research on the stem cell lines might bring some worthy good to public. Human Stem Cells (hSCs) research has provided opportunities for scientific progresses and new therapies, but some complex ethical matters should be noticed to ensure that stem cell research is carried out in an ethically appropriate manner. The aim of this review article is to discuss the importance of stem cell research, code of ethics for stem cell research in Iran and ethical recommendation. Generation of stem cells for research from human embryo or adult stem cells, saving, maintenance and using of them are the main ethical, legal and jurisprudence concerns in Iran. Concerns regarding human reproduction or human cloning, breach of human dignity, genetic manipulation and probability of tumorogenisity are observed in adult/somatic stem cells. Destruction of embryo to generate stem cell is an important matter in Iran. In this regards, obtaining stem cell from donated frozen embryos through infertility treatment that would be discarded is an acceptable solution in Iran for generation of embryo for research. Ethical, legal, and jurisprudence strategies for using adult/somatic stem cells are determination of ownership of stem cells, trade prohibition of human body, supervision on bio banks and information of Oversight Committee on Stem Cell Research. Recommendations to handle ethical issues for conducting stem cell research are well-designed studies, compliance codes of ethics in biomedical research (specifically codes of ethics on stem cell research, codes of ethics on clinical trials studies and codes of ethics on animals studies), appropriate collaboration with ethics committees and respecting of rights of participants (including both of human and animal rights) in research. In addition, there is a necessity for extending global networks of bioethics for strengthening communications within organizations at both the regional and international level, strengthening legislation systems, designing and establishing convenient collaborative educational courses at different levels. PMID:28462397

Effect of Dedifferentiation on Time to Mutation Acquisition in Stem Cell-Driven Cancers

PubMed Central

Jilkine, Alexandra; Gutenkunst, Ryan N.

2014-01-01

Accumulating evidence suggests that many tumors have a hierarchical organization, with the bulk of the tumor composed of relatively differentiated short-lived progenitor cells that are maintained by a small population of undifferentiated long-lived cancer stem cells. It is unclear, however, whether cancer stem cells originate from normal stem cells or from dedifferentiated progenitor cells. To address this, we mathematically modeled the effect of dedifferentiation on carcinogenesis. We considered a hybrid stochastic-deterministic model of mutation accumulation in both stem cells and progenitors, including dedifferentiation of progenitor cells to a stem cell-like state. We performed exact computer simulations of the emergence of tumor subpopulations with two mutations, and we derived semi-analytical estimates for the waiting time distribution to fixation. Our results suggest that dedifferentiation may play an important role in carcinogenesis, depending on how stem cell homeostasis is maintained. If the stem cell population size is held strictly constant (due to all divisions being asymmetric), we found that dedifferentiation acts like a positive selective force in the stem cell population and thus speeds carcinogenesis. If the stem cell population size is allowed to vary stochastically with density-dependent reproduction rates (allowing both symmetric and asymmetric divisions), we found that dedifferentiation beyond a critical threshold leads to exponential growth of the stem cell population. Thus, dedifferentiation may play a crucial role, the common modeling assumption of constant stem cell population size may not be adequate, and further progress in understanding carcinogenesis demands a more detailed mechanistic understanding of stem cell homeostasis. PMID:24603301

PGE2 /EP4 Signaling Controls the Transfer of the Mammary Stem Cell State by Lipid Rafts in Extracellular Vesicles.

PubMed

Lin, Meng-Chieh; Chen, Shih-Yin; Tsai, Ho-Min; He, Pei-Lin; Lin, Yen-Chun; Herschman, Harvey; Li, Hua-Jung

2017-02-01

Prostaglandin E 2 (PGE 2 )-initiated signaling contributes to stem cell homeostasis and regeneration. However, it is unclear how PGE 2 signaling controls cell stemness. This study identifies a previously unknown mechanism by which PGE 2 /prostaglandin E receptor 4 (EP 4 ) signaling regulates multiple signaling pathways (e.g., PI3K/Akt signaling, TGFβ signaling, Wnt signaling, EGFR signaling) which maintain the basal mammary stem cell phenotype. A shift of basal mammary epithelial stem cells (MaSCs) from a mesenchymal/stem cell state to a non-basal-MaSC state occurs in response to prostaglandin E receptor 4 (EP 4 ) antagonism. EP 4 antagonists elicit release of signaling components, by controlling their trafficking into extracellular vesicles/exosomes in a lipid raft/caveolae-dependent manner. Consequently, EP 4 antagonism indirectly inactivates, through induced extracellular vesicle/exosome release, pathways required for mammary epithelial stem cell homeostasis, e.g. canonical/noncanonical Wnt, TGFβ and PI3K/Akt pathways. EP 4 antagonism causes signaling receptors and signaling components to shift from non-lipid raft fractions to lipid raft fractions, and to then be released in EP 4 antagonist-induced extracellular vesicles/exosomes, resulting in the loss of the stem cell state by mammary epithelial stem cells. In contrast, luminal mammary epithelial cells can acquire basal stem cell properties following ingestion of EP 4 antagonist-induced stem cell extracellular vesicles/exosomes, and can then form mammary glands. These findings demonstrate that PGE 2 /EP 4 signaling controls homeostasis of mammary epithelial stem cells through regulating extracellular vesicle/exosome release. Reprogramming of mammary epithelial cells can result from EP 4 -mediated stem cell property transfer by extracellular vesicles/exosomes containing caveolae-associated proteins, between mammary basal and luminal epithelial cells. Stem Cells 2017;35:425-444. © 2016 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

The Drosophila ovarian and testis stem cell niches: similar somatic stem cells and signals.

PubMed

Decotto, Eva; Spradling, Allan C

2005-10-01

The stem cell niches at the apex of Drosophila ovaries and testes have been viewed as distinct in two major respects. While both contain germline stem cells, the testis niche also contains "cyst progenitor" stem cells, which divide to produce somatic cells that encase developing germ cells. Moreover, while both niches utilize BMP signaling, the testis niche requires a key JAK/STAT signal. We now show, by lineage marking, that the ovarian niche also contains a second type of stem cell. These "escort stem cells" morphologically resemble testis cyst progenitor cells and their daughters encase developing cysts before undergoing apoptosis at the time of follicle formation. In addition, we show that JAK/STAT signaling also plays a critical role in ovarian niche function, and acts within escort cells. These observations reveal striking similarities in the stem cell niches of male and female gonads, and suggest that they are largely governed by common mechanisms.

Fatigue fracture of a proximally modular, distally tapered fluted implant with diaphyseal fixation.

PubMed

Buttaro, Martín A; Mayor, Michael B; Van Citters, Douglas; Piccaluga, Francisco

2007-08-01

We report and analyze the causes of a fracture in a proximally modular, distally tapered fluted MP stem in a 48-year-old woman (168 cm, 67 kg) with severe proximal bone deficiency. Evidence of fatigue failure with striations initiated laterally was observed in the laser etching of the tensile aspect of the prosthesis. However, metallurgical analysis suggested that laser engraving did not alter the microstructure of the stem. Stress due to the absence of proximal femoral bone support may have been sufficiently high to put this particular stem at risk for fatigue fracture. This important complication should be addressed when choosing this therapeutic option in cases with substantial proximal femoral bone loss. Strut allograft support should be recommended in such cases.

Proteomic analysis of laser-captured paraffin-embedded tissues: a molecular portrait of head and neck cancer progression.

PubMed

Patel, Vyomesh; Hood, Brian L; Molinolo, Alfredo A; Lee, Norman H; Conrads, Thomas P; Braisted, John C; Krizman, David B; Veenstra, Timothy D; Gutkind, J Silvio

2008-02-15

Squamous cell carcinoma of the head and neck (HNSCC), the sixth most prevalent cancer among men worldwide, is associated with poor prognosis, which has improved only marginally over the past three decades. A proteomic analysis of HNSCC lesions may help identify novel molecular targets for the early detection, prevention, and treatment of HNSCC. Laser capture microdissection was combined with recently developed techniques for protein extraction from formalin-fixed paraffin-embedded (FFPE) tissues and a novel proteomics platform. Approximately 20,000 cells procured from FFPE tissue sections of normal oral epithelium and well, moderately, and poorly differentiated HNSCC were processed for mass spectrometry and bioinformatic analysis. A large number of proteins expressed in normal oral epithelium and HNSCC, including cytokeratins, intermediate filaments, differentiation markers, and proteins involved in stem cell maintenance, signal transduction, migration, cell cycle regulation, growth and angiogenesis, matrix degradation, and proteins with tumor suppressive and oncogenic potential, were readily detected. Of interest, the relative expression of many of these molecules followed a distinct pattern in normal squamous epithelia and well, moderately, and poorly differentiated HNSCC tumor tissues. Representative proteins were further validated using immunohistochemical studies in HNSCC tissue sections and tissue microarrays. The ability to combine laser capture microdissection and in-depth proteomic analysis of FFPE tissues provided a wealth of information regarding the nature of the proteins expressed in normal squamous epithelium and during HNSCC progression, which may allow the development of novel biomarkers of diagnostic and prognostic value and the identification of novel targets for therapeutic intervention in HNSCC.

Placenta-an alternative source of stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matikainen, Tiina; Laine, Jarmo

2005-09-01

The two most promising practical applications of human stem cells are cellular replacement therapies in human disease and toxicological screening of candidate drug molecules. Both require a source of human stem cells that can be isolated, purified, expanded in number and differentiated into the cell type of choice in a controlled manner. Currently, uses of both embryonic and adult stem cells are investigated. While embryonic stem cells are pluripotent and can differentiate into any specialised cell type, their use requires establishment of embryonic stem cell lines using the inner cell mass of an early pre-implantation embryo. As the blastocyst ismore » destroyed during the process, ethical issues need to be carefully considered. The use of embryonic stem cells is also limited by the difficulties in growing large numbers of the cells without inducing spontaneous differentiation, and the problems in controlling directed differentiation of the cells. The use of adult stem cells, typically derived from bone marrow, but also from other tissues, is ethically non-controversial but their differentiation potential is more limited than that of the embryonic stem cells. Since human cord blood, umbilical cord, placenta and amnion are normally discarded at birth, they provide an easily accessible alternative source of stem cells. We review the potential and current status of the use of adult stem cells derived from the placenta or umbilical cord in therapeutic and toxicological applications.« less

Pluripotent stem cells and reprogrammed cells in farm animals.

PubMed

Nowak-Imialek, Monika; Kues, Wilfried; Carnwath, Joseph W; Niemann, Heiner

2011-08-01

Pluripotent cells are unique because of their ability to differentiate into the cell lineages forming the entire organism. True pluripotent stem cells with germ line contribution have been reported for mice and rats. Human pluripotent cells share numerous features of pluripotentiality, but confirmation of their in vivo capacity for germ line contribution is impossible due to ethical and legal restrictions. Progress toward derivation of embryonic stem cells from domestic species has been made, but the derived cells were not able to produce germ line chimeras and thus are termed embryonic stem-like cells. However, domestic animals, in particular the domestic pig (Sus scrofa), are excellent large animals models, in which the clinical potential of stem cell therapies can be studied. Reprogramming technologies for somatic cells, including somatic cell nuclear transfer, cell fusion, in vitro culture in the presence of cell extracts, in vitro conversion of adult unipotent spermatogonial stem cells into germ line derived pluripotent stem cells, and transduction with reprogramming factors have been developed with the goal of obtaining pluripotent, germ line competent stem cells from domestic animals. This review summarizes the present state of the art in the derivation and maintenance of pluripotent stem cells in domestic animals.

Information on Stem Cell Research

MedlinePlus

... of stem cells share similar properties there are differences as well. For example, ES cells and iPS cells are able to differentiate into any type of cell, whereas adult stem cells are more restricted in their potential. The promise of all stem cells for use ...

The Development of Stem Cell-Based Treatment for Liver Failure.

PubMed

Zhu, Tiantian; Li, Yuwen; Guo, Yusheng; Zhu, Chuanlong

2017-01-01

Liver failure is a devastating clinical syndrome with a persistently mortality rate despite advanced care. Orthotopic liver transplantation protected patients from hepatic failure. Yet, limitations including postoperative complications, high costs, and shortages of donor organs defect its application. The development of stem cell therapy complements the deficiencies of liver transplantation, due to the inherent ability of stem cells to proliferate and differentiate. Understand the source of stem cells, as well as the advantages and disadvantages of stem cell therapy. Based on published papers, we discussed the cell sources and therapeutic effect of stem cells. We also summarized the pros and cons, as well as optimization of stem cell-based treatment. Finally outlook future prospects of stem cell therapy. Stem cells may be harvested from a variety of human tissues, and then used to promote the convalescence of hepatocellular function. The emergence of the co-cultured system, tissueengineered technology and genetic modfication has further enhanced the functionality of stem cells. However, the tumorigenicity, the low survival rate and the scarcity of long-term treatment effect are obstacles for the further development of stem cell therapy. In this review, we highlight current research findings and present the future prospects in the area of stem cell-based treatment for liver failure. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

76 FR 11491 - Advisory Council on Blood Stem Cell Transplantation; Request for Nominations for Voting Members

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

... Council on Blood Stem Cell Transplantation; Request for Nominations for Voting Members AGENCY: Health... on Blood Stem Cell Transplantation. The Advisory Council on Blood Stem Cell Transplantation was...: Nominations should be submitted to the Executive Secretary, Advisory Council on Blood Stem Cell...

3 CFR - Guidelines for Human Stem Cell Research

Code of Federal Regulations, 2010 CFR

2010-01-01

... 3 The President 1 2010-01-01 2010-01-01 false Guidelines for Human Stem Cell Research Presidential Documents Other Presidential Documents Memorandum of July 30, 2009 Guidelines for Human Stem Cell Research..., scientifically worthy human stem cell research, including human embryonic stem cell research, to the extent...

Aging, metabolism and stem cells: Spotlight on muscle stem cells.

PubMed

García-Prat, Laura; Muñoz-Cánoves, Pura

2017-04-15

All tissues and organs undergo a progressive regenerative decline as they age. This decline has been mainly attributed to loss of stem cell number and/or function, and both stem cell-intrinsic changes and alterations in local niches and/or systemic environment over time are known to contribute to the stem cell aging phenotype. Advancing in the molecular understanding of the deterioration of stem cell cells with aging is key for targeting the specific causes of tissue regenerative dysfunction at advanced stages of life. Here, we revise exciting recent findings on why stem cells age and the consequences on tissue regeneration, with a special focus on regeneration of skeletal muscle. We also highlight newly identified common molecular pathways affecting diverse types of aging stem cells, such as altered proteostasis, metabolism, or senescence entry, and discuss the questions raised by these findings. Finally, we comment on emerging stem cell rejuvenation strategies, principally emanating from studies on muscle stem cells, which will surely burst tissue regeneration research for future benefit of the increasing human aging population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In vitro spatially organizing the differentiation in individual multicellular stem cell aggregates.

PubMed

Qi, Hao; Huang, Guoyou; Han, Yu Long; Lin, Wang; Li, Xiujun; Wang, Shuqi; Lu, Tian Jian; Xu, Feng

2016-01-01

With significant potential as a robust source to produce specific somatic cells for regenerative medicine, stem cells have attracted increasing attention from both academia and government. In vivo, stem cell differentiation is a process under complicated regulations to precisely build tissue with unique spatial structures. Since multicellular spheroidal aggregates of stem cells, commonly called as embryoid bodies (EBs), are considered to be capable of recapitulating the events in early stage of embryonic development, a variety of methods have been developed to form EBs in vitro for studying differentiation of embryonic stem cells. The regulation of stem cell differentiation is crucial in directing stem cells to build tissue with the correct spatial architecture for specific functions. However, stem cells within the three-dimensional multicellular aggregates undergo differentiation in a less unpredictable and spatially controlled manner in vitro than in vivo. Recently, various microengineering technologies have been developed to manipulate stem cells in vitro in a spatially controlled manner. Herein, we take the spotlight on these technologies and researches that bring us the new potential for manipulation of stem cells for specific purposes.

Stem cells in nephrology: present status and future.

PubMed

Watorek, Ewa; Klinger, Marian

2006-01-01

Stem cell biology is currently developing rapidly because of the potential therapeutic utility of stem cells. The ability to acquire any desired phenotype raises hope for regenerative therapies. Manipulation of these cells is a potentially valuable tool; however, the mechanisms of stem cell differentiation and plasticity are currently beyond our control. In the field of nephrology, the presence of adult kidney stem cells has been debated. Renal adult stem cells may be descendants of some early kidney progenitors, or may be derived from bone marrow. Evidence of a hematopoietic stem-cell contribution to renal repair encourages the possibility of bone marrow or stem cell transplantation as a means of treating autoimmune glomerulopathies. The transplantation of fetal kidney tissue containing renal progenitors, which then develop into functional nephrons, is a step towards renal regeneration. According to recent reports, the development of functional nephrons from human mesenchymal stem cells in rodent whole-embryo culture is possible. Establishing in vitro self organs from autologous stem cells would be a promising therapeutic solution in light of the shortage of allogenic organs and the unresolved problem of chronic allograft rejection.

Socializing with the neighbors: stem cells and their niche.

PubMed

Fuchs, Elaine; Tumbar, Tudorita; Guasch, Geraldine

2004-03-19

The potential of stem cells in regenerative medicine relies upon removing them from their natural habitat, propagating them in culture, and placing them into a foreign tissue environment. To do so, it is essential to understand how stem cells interact with their microenvironment, the so-called stem cell niche, to establish and maintain their properties. In this review, we examine adult stem cell niches and their impact on stem cell biology.

Stem Cells News Update: A Personal Perspective

PubMed Central

Wong, SC

2013-01-01

This article is a follow-up to a previous Commentary published in 2011. It updates some of the events mentioned in that Commentary and continues with more interesting and exciting news on stem cell research and the emerging field of Regenerative Medicine. Some of the news includes: 1) the 2012 Nobel Prize for Medicine awarded to John B. Gurdon and Shinya Yamanaka; 2) the cloning of human embryonic stem cells; 3) the continued search for truly pluripotent adult stem cells via in vitro and in vivo protocols; 4) the breakthrough in organ replacements; 5) the global stem cell race; 6) the global stem cell cryo-preservation business; 7) the worldwide stem cell donor registries, and 8) the issue of government regulation on stem cell therapy. PMID:24778557

Stem cells news update: a personal perspective.

PubMed

Wong, Sc

2013-12-01

This article is a follow-up to a previous Commentary published in 2011. It updates some of the events mentioned in that Commentary and continues with more interesting and exciting news on stem cell research and the emerging field of Regenerative Medicine. Some of the news includes: 1) the 2012 Nobel Prize for Medicine awarded to John B. Gurdon and Shinya Yamanaka; 2) the cloning of human embryonic stem cells; 3) the continued search for truly pluripotent adult stem cells via in vitro and in vivo protocols; 4) the breakthrough in organ replacements; 5) the global stem cell race; 6) the global stem cell cryo-preservation business; 7) the worldwide stem cell donor registries, and 8) the issue of government regulation on stem cell therapy.

Platelet-rich plasma derived growth factors contribute to stem cell differentiation in musculoskeletal regeneration

NASA Astrophysics Data System (ADS)

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-10-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of platelet-rich plasma derived growth factors with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Elements of the niche for adult stem cell expansion

PubMed Central

Redondo, Patricia A; Pavlou, Marina; Loizidou, Marilena; Cheema, Umber

2017-01-01

Adult stem cells are crucial for tissue homeostasis. These cells reside within exclusive locations in tissues, termed niches, which protect adult stem cell fidelity and regulate their many functions through biophysical-, biochemical- and cellular-mediated mechanisms. There is a growing understanding of how these mechanisms and their components contribute towards maintaining stem cell quiescence, self-renewal, expansion and differentiation patterns. In vitro expansion of adult stem cells is a powerful tool for understanding stem cell biology, and for tissue engineering and regenerative medicine applications. However, it is technically challenging, since adult stem cell removal from their native microenvironment has negative repercussions on their sustainability. In this review, we overview specific elements of the biomimetic niche and how recreating such elements can help in vitro propagation of adult stem cells. PMID:28890779

Platelet-Rich Plasma Derived Growth Factors Contribute to Stem Cell Differentiation in Musculoskeletal Regeneration.

PubMed

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-01-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of PRP derived GFs with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Elements of the niche for adult stem cell expansion.

PubMed

Redondo, Patricia A; Pavlou, Marina; Loizidou, Marilena; Cheema, Umber

2017-01-01

Adult stem cells are crucial for tissue homeostasis. These cells reside within exclusive locations in tissues, termed niches, which protect adult stem cell fidelity and regulate their many functions through biophysical-, biochemical- and cellular-mediated mechanisms. There is a growing understanding of how these mechanisms and their components contribute towards maintaining stem cell quiescence, self-renewal, expansion and differentiation patterns. In vitro expansion of adult stem cells is a powerful tool for understanding stem cell biology, and for tissue engineering and regenerative medicine applications. However, it is technically challenging, since adult stem cell removal from their native microenvironment has negative repercussions on their sustainability. In this review, we overview specific elements of the biomimetic niche and how recreating such elements can help in vitro propagation of adult stem cells.

Stem cell maintenance by manipulating signaling pathways: past, current and future

PubMed Central

Chen, Xi; Ye, Shoudong; Ying, Qi-Long

2015-01-01

Pluripotent stem cells only exist in a narrow window during early embryonic development, whereas multipotent stem cells are abundant throughout embryonic development and are retainedin various adult tissues and organs. While pluripotent stem cell lines have been established from several species, including mouse, rat, and human, it is still challenging to establish stable multipotent stem cell lines from embryonic or adult tissues. Based on current knowledge, we anticipate that by manipulating extrinsic and intrinsic signaling pathways, most if not all types of stem cells can be maintained in a long-term culture. In this article, we summarize current culture conditions established for the long-term maintenance of authentic pluripotent and multipotent stem cells and the signaling pathways involved. We also discuss the general principles of stem cell maintenance and propose several strategies on the establishment of novel stem cell lines through manipulation of signaling pathways. [BMB Reports 2015; 48(12): 668-676] PMID:26497581

Stem cells and female reproduction.

PubMed

Du, Hongling; Taylor, Hugh S

2009-02-01

Several recent findings in stem cell biology have resulted in new opportunities for the treatment of reproductive disease. Endometrial regeneration can be driven by bone marrow derived stem cells. This finding has potential implications for the treatment of uterine disorders. It also supports a new theory for the etiology of endometriosis. The ovaries have been shown to contain stem cells that form oocytes in adults and can be cultured in vitro to develop mature oocytes. Stem cells from the fetus have been demonstrated to lead to microchimerism in the mother and implicated in several maternal diseases. Additionally the placenta may be another source of hematopoietic stem cell. Finally endometrial derived stem cells have been demonstrated to differentiate into non-reproductive tissues. While we are just beginning to understand stem cells and many key questions remain, the potential advantages of stem cells in reproductive biology and medicine are apparent.

The potential of nanofibers in tissue engineering and stem cell therapy.

PubMed

Gholizadeh-Ghaleh Aziz, Shiva; Gholizadeh-Ghaleh Aziz, Sara; Akbarzadeh, Abolfazl

2016-08-01

Electrospinning is a technique in which materials in solution are shaped into continuous nano- and micro-sized fibers. Combining stem cells with biomaterial scaffolds and nanofibers affords a favorable approach for bone tissue engineering, stem cell growth and transfer, ocular surface reconstruction, and treatment of congenital corneal diseases. This review seeks to describe the current examples of the use of scaffolds in stem cell therapy. Stem cells are classified as adult or embryonic stem (ES) cells, and the advantages and drawbacks of each group are detailed. The nanofibers and scaffolds are further classified in Tables I and II , which describe specific examples from the literature. Finally, the current applications of biomaterial scaffolds containing stem cells for tissue engineering applications are presented. Overall, this review seeks to give an overview of the biomaterials available for use in combination with stem cells, and the application of nanofibers in stem cell therapy.

The stem cell patent landscape as relevant to cancer vaccines.

PubMed

Wang, Shyh-Jen

2011-10-01

Cancer vaccine targeting cancer stem cells is proposed to serve as a potent immunotherapy. Thus, it would be useful to examine the main trends in stem cell patenting activity as a guide for those seeking to develop such cancer vaccines. We found that a substantial number of stem cell patents were granted up to the end of 2010, including ~2000 issued in the US. Many of these have been filed since 2001, including 7,551 applications in the US. Stem cell development, as evidenced by the numbers of PubMed articles, has matured steadily in recent years. However, the other metrics, such as the number of patent applications, the technology-science linkage and the number of patent assignees, have been stagnant. Moreover, the ownership of stem cell patents is still quiet fragmented across multiple organizations, and the number of stem cell patent assignees from the business sector has not increased significantly. Academic and nonprofit institutions not only account for a large share of stem cell patents but also apply for patents continually. Based on this analysis, the strength of stem cell resources seems to remain stagnant in recent years due to the ban on government funding of embryonic stem cell research. Furthermore, the patent prosecution or technical barriers in the field of stem cells would be another main reason that the number of US-issued stem cell patents for each application have been in gradual decline since 2000. Therefore, we consider stem cell technology to still be under development.

Fraudsters operate and officialdom turns a blind eye: a proposal for controlling stem cell therapy in China.

PubMed

Jiang, Li; Dong, Bing He

2016-09-01

Stem cell tourism-the flow of patients from home countries to destination countries to obtain stem cell treatment-is a growing business in China. Many concerns have been raised regarding fraudsters that operate unsafe stem cell therapies and an officialdom that turns a blind eye to the questionable technology. The Chinese regulatory approach to stem cell research is based on Guidelines and Administrative Measures, rather than legislation, and may have no binding force on certain institutions, such as military hospitals. There is no liability and traceability system and no visible set of penalties for non-compliance in the stem cell legal framework. In addition to the lack of safety and efficacy systems in the regulations, no specific expert authority has been established to monitor stem cell therapy to date. Recognizing the global nature of stem cell tourism, this article argues that resolving stem cell tourism issues may require not only the Chinese government but also an international mechanism for transparency and ethical oversight. A stringent set of international regulations that govern stem cell therapies can encourage China to improve stem cell regulation and enforcement to fulfill its obligations. Through an international consensus, a minimum standard for clinical stem cell research and a central enforcement system will be provided. As a result, rogue clinics that conduct unauthorized stem cell therapies can be penalized, and countries that are reluctant to implement the reconciled regulations should be sanctioned.

Epigenetic Control of Stem Cell Potential During Homeostasis, Aging, and Disease

PubMed Central

Beerman, Isabel; Rossi, Derrick J.

2015-01-01

Stem cell decline is an important cellular driver of aging-associated pathophysiology in multiple tissues. Epigenetic regulation is central to establishing and maintaining stem cell function, and emerging evidence indicates that epigenetic dysregulation contributes to the altered potential of stem cells during aging. Unlike terminally differentiated cells, the impact of epigenetic dysregulation in stem cells is propagated beyond self; alterations can be heritably transmitted to differentiated progeny, in addition to being perpetuated and amplified within the stem cell pool through self-renewal divisions. This review focuses on recent studies examining epigenetic regulation of tissue-specific stem cells in homeostasis, aging, and aging-related disease. PMID:26046761

Attitude of A Sample of Iranian Researchers toward The Future of Stem Cell Research.

PubMed

Lotfipanah, Mahdi; Azadeh, Fereydoon; Totonchi, Mehdi; Omani-Samani, Reza

2018-10-01

Stem cells that have unlimited proliferation potential as well as differentiation potency are considered to be a promising future treatment method for incurable diseases. The aim of the present study is to evaluate the future trend of stem cell researches from researchers' viewpoints. This was a cross-sectional descriptive study on researchers involved in stem cell research at Royan Institute. We designed a questionnaire using a qualitative study based on expert opinion and a literature review. Content validity was performed using three rounds of the Delphi method with experts. Face validity was undertaken by a Persian literature expert and a graphics designer. The questionnaire was distributed among 150 researchers involved in stem cell studies in Royan Institute biology laboratories. We collected 138 completed questionnaires. The mean age of participants was 31.13 ± 5.8 years; most (60.9%) were females. Participants (76.1%) considered the budget to be the most important issue in stem cell research, 79.7% needed financial support from the government, and 77.5% felt that charities could contribute substantially to stem cell research. A total of 90.6% of participants stated that stem cells should lead to commercial usage which could support future researches (86.2%). The aim of stem cell research was stipulated as increasing health status of the society according to 92.8% of the participants. At present, among cell types, importance was attached to cord blood and adult stem cells. Researchers emphasized the importance of mesenchymal stem cells (MSCs) rather than hematopoietic stem cells (HSCs, 57.73%). The prime priorities were given to cancer so that stem cell research could be directed to sphere stem cell research whereas the least preference was given to skin research. Regenerative medicine is considered the future of stem cell research with emphasis on application of these cells, especially in cancer treatment. Copyright© by Royan Institute. All rights reserved.

Translating stem cell research: challenges at the research frontier.

PubMed

Magnus, David

2010-01-01

This paper will address the translation of basic stem cell research into clinical research. While "stem cell" trials are sometimes used to describe established practices of bone marrow transplantation or transplantation of primary cells derived from bone marrow, for the purposes of this paper, I am primarily focusing on stem cell trials which are far less established, including use of hESC derived stem cells. The central ethical challenges in stem cell clinical trials arise in frontier research, not in standard, well-established areas of research.

Murine hepatocellular carcinoma derived stem cells reveal epithelial-to-mesenchymal plasticity.

PubMed

Jayachandran, Aparna; Shrestha, Ritu; Dhungel, Bijay; Huang, I-Tao; Vasconcelos, Marianna Yumi Kawashima; Morrison, Brian J; Ramlogan-Steel, Charmaine A; Steel, Jason C

2017-09-26

To establish a model to enrich and characterize stem-like cells from murine normal liver and hepatocellular carcinoma (HCC) cell lines and to further investigate stem-like cell association with epithelial-to-mesenchymal transition (EMT). In this study, we utilized a stem cell conditioned serum-free medium to enrich stem-like cells from mouse HCC and normal liver cell lines, Hepa 1-6 and AML12, respectively. We isolated the 3-dimensional spheres and assessed their stemness characteristics by evaluating the RNA levels of stemness genes and a cell surface stem cell marker by quantitative reverse transcriptase-PCR (qRT-PCR). Next, we examined the relationship between stem cells and EMT using qRT-PCR. Three-dimensional spheres were enriched by culturing murine HCC and normal hepatocyte cell lines in stem cell conditioned serum-free medium supplemented with epidermal growth factor, basic fibroblast growth factor and heparin sulfate. The 3-dimensional spheres had enhanced stemness markers such as Klf4 and Bmi1 and hepatic cancer stem cell (CSC) marker Cd44 compared to parental cells grown as adherent cultures. We report that epithelial markers E-cadherin and ZO-1 were downregulated, while mesenchymal markers Vimentin and Fibronectin were upregulated in 3-dimensional spheres. The 3-dimensional spheres also exhibited changes in expression of Snai , Zeb and Twist family of EMT transcription factors. Our novel method successfully enriched stem-like cells which possessed an EMT phenotype. The isolation and characterization of murine hepatic CSCs could establish a precise target for the development of more effective therapies for HCC.

Wnt/β-Catenin Signaling Determines the Vasculogenic Fate of Postnatal Mesenchymal Stem Cells.

PubMed

Zhang, Zhaocheng; Nör, Felipe; Oh, Min; Cucco, Carolina; Shi, Songtao; Nör, Jacques E

2016-06-01

Vasculogenesis is the process of de novo blood vessel formation observed primarily during embryonic development. Emerging evidence suggest that postnatal mesenchymal stem cells are capable of recapitulating vasculogenesis when these cells are engaged in tissue regeneration. However, the mechanisms underlining the vasculogenic differentiation of mesenchymal stem cells remain unclear. Here, we used stem cells from human permanent teeth (dental pulp stem cells [DPSC]) or deciduous teeth (stem cells from human exfoliated deciduous teeth [SHED]) as models of postnatal primary human mesenchymal stem cells to understand mechanisms regulating their vasculogenic fate. GFP-tagged mesenchymal stem cells seeded in human tooth slice/scaffolds and transplanted into immunodeficient mice differentiate into human blood vessels that anastomize with the mouse vasculature. In vitro, vascular endothelial growth factor (VEGF) induced the vasculogenic differentiation of DPSC and SHED via potent activation of Wnt/β-catenin signaling. Further, activation of Wnt signaling is sufficient to induce the vasculogenic differentiation of postnatal mesenchymal stem cells, while Wnt inhibition blocked this process. Notably, β-catenin-silenced DPSC no longer differentiate into endothelial cells in vitro, and showed impaired vasculogenesis in vivo. Collectively, these data demonstrate that VEGF signaling through the canonical Wnt/β-catenin pathway defines the vasculogenic fate of postnatal mesenchymal stem cells. Stem Cells 2016;34:1576-1587. © 2016 AlphaMed Press.

MiR-7 inhibited peripheral nerve injury repair by affecting neural stem cells migration and proliferation through cdc42.

PubMed

Zhou, Nan; Hao, Shuang; Huang, Zongqiang; Wang, Weiwei; Yan, Penghui; Zhou, Wei; Zhu, Qihang; Liu, Xiaokang

2018-01-01

Objective Neural stem cells play an important role in the recovery and regeneration of peripheral nerve injury, and the microRNA-7 (miR-7) regulates differentiation of neural stem cells. This study aimed to explore the role of miR-7 in neural stem cells homing and proliferation and its influence on peripheral nerve injury repair. Methods The mice model of peripheral nerve injury was created by segmental sciatic nerve defect (sciatic nerve injury), and neural stem cells treatment was performed with a gelatin hydrogel conduit containing neural stem cells inserted into the sciatic nerve injury mice. The Sciatic Function Index was used to quantify sciatic nerve functional recovery in the mice. The messenger RNA and protein expression were detected by reverse transcription polymerase chain reaction and Western blot, respectively. Luciferase reporter assay was used to confirm the binding between miR-7 and the 3'UTR of cell division cycle protein 42 (cdc42). The neural stem cells migration and proliferation were analyzed by transwell assay and a Cell-LightTM EdU DNA Cell Proliferation kit, respectively. Results Neural stem cells treatment significantly promoted nerve repair in sciatic nerve injury mice. MiR-7 expression was decreased in sciatic nerve injury mice with neural stem cells treatment, and miR-7 mimic transfected into neural stem cells suppressed migration and proliferation, while miR-7 inhibitor promoted migration and proliferation. The expression level and effect of cdc42 on neural stem cells migration and proliferation were opposite to miR-7, and the luciferase reporter assay proved that cdc42 was a target of miR-7. Using co-transfection into neural stem cells, we found pcDNA3.1-cdc42 and si-cdc42 could reverse respectively the role of miR-7 mimic and miR-7 inhibitor on neural stem cells migration and proliferation. In addition, miR-7 mimic-transfected neural stem cells could abolish the protective role of neural stem cells on peripheral nerve injury. Conclusion MiR-7 inhibited peripheral nerve injury repair by affecting neural stem cells migration and proliferation through cdc42.

International Society for Stem Cell Research

MedlinePlus

... cell and regenerative medicine community. More stem cell research Take a closer look Recent Blogs View All ... nonprofit organization & the voice of the stem cell research community The International Society for Stem Cell Research ( ...

Stem cell regenerative potential combined with nanotechnology and tissue engineering for myocardial regeneration.

PubMed

Calin, Manuela; Stan, Daniela; Simion, Viorel

2013-07-01

The stem cell-based therapy for post-infarction myocardial regeneration has been introduced more than a decade ago, but the functional improvement obtained is limited due to the poor retention and short survival rate of transplanted cells into the damaged myocardium. More recently, the emerging nanotechnology concepts for advanced diagnostics and therapy provide promising opportunities of using stem cells for myocardial regeneration. In this paper will be provided an overview of the use of nanotechnology approaches in stem cell research for: 1) cell labeling to track the distribution of stem cells after transplantation, 2) nanoparticle-mediated gene delivery to stem cells to promote their homing, engraftment, survival and differentiation in the ischemic myocardium and 3) obtaining of bio-inspired materials to provide suitable myocardial scaffolds for delivery of stem cells or stem cell-derived factors.

Advances in Bone Marrow Stem Cell Therapy for Retinal Dysfunction

PubMed Central

Park, Susanna S.; Moisseiev, Elad; Bauer, Gerhard; Anderson, Johnathon D.; Grant, Maria B.; Zam, Azhar; Zawadzki, Robert J.; Werner, John S.; Nolta, Jan A.

2016-01-01

The most common cause of untreatable vision loss is dysfunction of the retina. Conditions, such as age-related macular degeneration, diabetic retinopathy and glaucoma remain leading causes of untreatable blindness worldwide. Various stem cell approaches are being explored for treatment of retinal regeneration. The rationale for using bone marrow stem cells to treat retinal dysfunction is based on preclinical evidence showing that bone marrow stem cells can rescue degenerating and ischemic retina. These stem cells have primarily paracrine trophic effects although some cells can directly incorporate into damaged tissue. Since the paracrine trophic effects can have regenerative effects on multiple cells in the retina, the use of this cell therapy is not limited to a particular retinal condition. Autologous bone marrow-derived stem cells are being explored in early clinical trials as therapy for various retinal conditions. These bone marrow stem cells include mesenchymal stem cells, mononuclear cells and CD34+ cells. Autologous therapy requires no systemic immunosuppression or donor matching. Intravitreal delivery of CD34+ cells and mononuclear cells appears to be tolerated and is being explored since some of these cells can home into the damaged retina after intravitreal administration. The safety of intravitreal delivery of mesenchymal stem cells has not been well established. This review provides an update of the current evidence in support of the use of bone marrow stem cells as treatment for retinal dysfunction. The potential limitations and complications of using certain forms of bone marrow stem cells as therapy are discussed. Future directions of research include methods to optimize the therapeutic potential of these stem cells, non-cellular alternatives using extracellular vesicles, and in vivo high-resolution retinal imaging to detect cellular changes in the retina following cell therapy. PMID:27784628

Light-controlled endosomal escape of the novel CD133-targeting immunotoxin AC133-saporin by photochemical internalization - A minimally invasive cancer stem cell-targeting strategy.

PubMed

Bostad, Monica; Olsen, Cathrine Elisabeth; Peng, Qian; Berg, Kristian; Høgset, Anders; Selbo, Pål Kristian

2015-05-28

The cancer stem cell (CSC) marker CD133 is an attractive target to improve antitumor therapy. We have used photochemical internalization (PCI) for the endosomal escape of the novel CD133-targeting immunotoxin AC133-saporin (PCIAC133-saporin). PCI employs an endocytic vesicle-localizing photosensitizer, which generates reactive oxygen species upon light-activation causing a rupture of the vesicle membranes and endosomal escape of entrapped drugs. Here we show that AC133-saporin co-localizes with the PCI-photosensitizer TPCS2a, which upon light exposure induces cytosolic release of AC133-saporin. PCI of picomolar levels of AC133-saporin in colorectal adenocarcinoma WiDr cells blocked cell proliferation and induced 100% inhibition of cell viability and colony forming ability at the highest light doses, whereas no cytotoxicity was obtained in the absence of light. Efficient PCI-based CD133-targeting was in addition demonstrated in the stem-cell-like, triple negative breast cancer cell line MDA-MB-231 and in the aggressive malignant melanoma cell line FEMX-1, whereas no enhanced targeting was obtained in the CD133-negative breast cancer cell line MCF-7. PCIAC133-saporin induced mainly necrosis and a minimal apoptotic response based on assessing cleavage of caspase-3 and PARP, and the TUNEL assay. PCIAC133-saporin resulted in S phase arrest and reduced LC3-II conversion compared to control treatments. Notably, co-treatment with Bafilomycin A1 and PCIAC133-saporin blocked LC3-II conversion, indicating a termination of the autophagic flux in WiDr cells. For the first time, we demonstrate laser-controlled targeting of CD133 in vivo. After only one systemic injection of AC133-saporin and TPCS2a, a strong anti-tumor response was observed after PCIAC133-saporin. The present PCI-based endosomal escape technology represents a minimally invasive strategy for spatio-temporal, light-controlled targeting of CD133+ cells in localized primary tumors or metastasis. Copyright © 2015 Elsevier B.V. All rights reserved.

Role of stem cell derived exosomes in tumor biology.

PubMed

Sharma, Aman

2018-03-15

Exosomes are nano-scale messengers loaded with bio-molecular cargo of RNA, DNA, and Proteins. As a master regulator of cellular signaling, stem cell (both normal, and cancer stem cells) secreted exosome orchestrate various autocrine and paracrine functions which alter tumor micro-environment, growth and progression. Exosomes secreted by one of the two important stem cell phenotypes in cancers a) Mesenchymal stem cells, and b) Cancer stem cells not only promote cancerous growth but also impart therapy resistance in cancer cells. In tumors, normal or mesenchymal stem cell (MSCs) derived exosomes (MSC-exo) modulate tumor hallmarks by delivering unique miRNA species to neighboring cells and help in tumor progression. Apart from regulating tumor cell fate, MSC-exo are also capable of inducing physiological processes, for example, angiogenesis, metastasis and so forth. Similarly, cancer stem cells (CSCs) derived exosomes (CSC-exo) contain stemness-specific proteins, self-renewal promoting regulatory miRNAs, and survival factors. CSC-exo specific cargo maintains tumor heterogeneity and alters tumor progression. In this review we critically discuss the importance of stem cell specific exosomes in tumor cell signaling pathways with their role in tumor biology. © 2017 UICC.

Stochasticity and Spatial Interaction Govern Stem Cell Differentiation Dynamics

NASA Astrophysics Data System (ADS)

Smith, Quinton; Stukalin, Evgeny; Kusuma, Sravanti; Gerecht, Sharon; Sun, Sean X.

2015-07-01

Stem cell differentiation underlies many fundamental processes such as development, tissue growth and regeneration, as well as disease progression. Understanding how stem cell differentiation is controlled in mixed cell populations is an important step in developing quantitative models of cell population dynamics. Here we focus on quantifying the role of cell-cell interactions in determining stem cell fate. Toward this, we monitor stem cell differentiation in adherent cultures on micropatterns and collect statistical cell fate data. Results show high cell fate variability and a bimodal probability distribution of stem cell fraction on small (80-140 μm diameter) micropatterns. On larger (225-500 μm diameter) micropatterns, the variability is also high but the distribution of the stem cell fraction becomes unimodal. Using a stochastic model, we analyze the differentiation dynamics and quantitatively determine the differentiation probability as a function of stem cell fraction. Results indicate that stem cells can interact and sense cellular composition in their immediate neighborhood and adjust their differentiation probability accordingly. Blocking epithelial cadherin (E-cadherin) can diminish this cell-cell contact mediated sensing. For larger micropatterns, cell motility adds a spatial dimension to the picture. Taken together, we find stochasticity and cell-cell interactions are important factors in determining cell fate in mixed cell populations.

NANOS2 acts downstream of glial cell line-derived neurotrophic factor signaling to suppress differentiation of spermatogonial stem cells.

PubMed

Sada, Aiko; Hasegawa, Kazuteru; Pin, Pui Han; Saga, Yumiko

2012-02-01

Stem cells are maintained by both stem cell-extrinsic niche signals and stem cell-intrinsic factors. During murine spermatogenesis, glial cell line-derived neurotrophic factor (GDNF) signal emanated from Sertoli cells and germ cell-intrinsic factor NANOS2 represent key regulators for the maintenance of spermatogonial stem cells. However, it remains unclear how these factors intersect in stem cells to control their cellular state. Here, we show that GDNF signaling is essential to maintain NANOS2 expression, and overexpression of Nanos2 can alleviate the stem cell loss phenotype caused by the depletion of Gfra1, a receptor for GDNF. By using an inducible Cre-loxP system, we show that NANOS2 expression is downregulated upon the conditional knockout (cKO) of Gfra1, while ectopic expression of Nanos2 in GFRA1-negative spermatogonia does not induce de novo GFRA1 expression. Furthermore, overexpression of Nanos2 in the Gfra1-cKO testes prevents precocious differentiation of the Gfra1-knockout stem cells and partially rescues the stem cell loss phenotypes of Gfra1-deficient mice, indicating that the stem cell differentiation can be suppressed by NANOS2 even in the absence of GDNF signaling. Taken together, we suggest that NANOS2 acts downstream of GDNF signaling to maintain undifferentiated state of spermatogonial stem cells. Copyright © 2011 AlphaMed Press.

Isolation and functional interrogation of adult human prostate epithelial stem cells at single cell resolution.

PubMed

Hu, Wen-Yang; Hu, Dan-Ping; Xie, Lishi; Li, Ye; Majumdar, Shyama; Nonn, Larisa; Hu, Hong; Shioda, Toshi; Prins, Gail S

2017-08-01

Using primary cultures of normal human prostate epithelial cells, we developed a novel prostasphere-based, label-retention assay that permits identification and isolation of stem cells at a single cell level. Their bona fide stem cell nature was corroborated using in vitro and in vivo regenerative assays and documentation of symmetric/asymmetric division. Robust WNT10B and KRT13 levels without E-cadherin or KRT14 staining distinguished individual stem cells from daughter progenitors in spheroids. Following FACS to isolate label-retaining stem cells from label-free progenitors, RNA-seq identified unique gene signatures for the separate populations which may serve as useful biomarkers. Knockdown of KRT13 or PRAC1 reduced sphere formation and symmetric self-renewal highlighting their role in stem cell maintenance. Pathways analysis identified ribosome biogenesis and membrane estrogen-receptor signaling enriched in stem cells with NF-ĸB signaling enriched in progenitors; activities that were biologically confirmed. Further, bioassays identified heightened autophagy flux and reduced metabolism in stem cells relative to progenitors. These approaches similarly identified stem-like cells from prostate cancer specimens and prostate, breast and colon cancer cell lines suggesting wide applicability. Together, the present studies isolate and identify unique characteristics of normal human prostate stem cells and uncover processes that maintain stem cell homeostasis in the prostate gland. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Materials as stem cell regulators

PubMed Central

Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

2014-01-01

The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine. PMID:24845994

Stem cells in genetically-engineered mouse models of prostate cancer

PubMed Central

Shibata, Maho; Shen, Michael M.

2015-01-01

The cancer stem cell model proposes that tumors have a hierarchical organization in which tumorigenic cells give rise to non-tumorigenic cells, with only a subset of stem-like cells able to propagate the tumor. In the case of prostate cancer, recent analyses of genetically engineered mouse (GEM) models have provided evidence supporting the existence of cancer stem cells in vivo. These studies suggest that cancer stem cells capable of tumor propagation exist at various stages of tumor progression from prostatic intraepithelial neoplasia (PIN) to advanced metastatic and castration-resistant disease. However, studies of stem cells in prostate cancer have been limited by available approaches for evaluating their functional properties in cell culture and transplantation assays. Given the role of the tumor microenvironment and the putative cancer stem cell niche, future studies using GEM models to analyze cancer stem cells in their native tissue microenvironment are likely to be highly informative. PMID:26341780

The evolution of chicken stem cell culture methods.

PubMed

Farzaneh, M; Attari, F; Mozdziak, P E; Khoshnam, S E

2017-12-01

1. The avian embryo is an excellent model for studying embryology and the production of pharmaceutical proteins in transgenic chickens. Furthermore, chicken stem cells have the potential for proliferation and differentiation and emerged as an attractive tool for various cell-based technologies. 2. The objective of these studies is the derivation and culture of these stem cells is the production of transgenic birds for recombinant biomaterials and vaccine manufacture, drug and cytotoxicity testing, as well as to gain insight into basic science, including cell tracking. 3. Despite similarities among the established chicken stem cell lines, fundamental differences have been reported between their culture conditions and applications. Recent conventional protocols used for expansion and culture of chicken stem cells mostly depend on feeder cells, serum-containing media and static culture. 4. Utilising chicken stem cells for generation of cell-based transgenic birds and a variety of vaccines requires large-scale cell production. However, scaling up the conventional adherent chicken stem cells is challenging and labour intensive. Development of a suspension cell culture process for chicken embryonic stem cells (cESCs), chicken primordial germ cells (PGCs) and chicken induced pluripotent stem cells (ciPSCs) will be an important advance for increasing the growth kinetics of these cells. 6. This review describes various approaches and suggestions to achieve optimal cell growth for defined chicken stem cells cultures and use in future manufacturing applications.

Blue light potentiates neurogenesis induced by retinoic acid-loaded responsive nanoparticles.

PubMed

Santos, Tiago; Ferreira, Raquel; Quartin, Emanuel; Boto, Carlos; Saraiva, Cláudia; Bragança, José; Peça, João; Rodrigues, Cecília; Ferreira, Lino; Bernardino, Liliana

2017-09-01

Neurogenic niches constitute a powerful endogenous source of new neurons that can be used for brain repair strategies. Neuronal differentiation of these cells can be regulated by molecules such as retinoic acid (RA) or by mild levels of reactive oxygen species (ROS) that are also known to upregulate RA receptor alpha (RARα) levels. Data showed that neural stem cells from the subventricular zone (SVZ) exposed to blue light (405nm laser) transiently induced NADPH oxidase-dependent ROS, resulting in β-catenin activation and neuronal differentiation, and increased RARα levels. Additionally, the same blue light stimulation was capable of triggering the release of RA from light-responsive nanoparticles (LR-NP). The synergy between blue light and LR-NP led to amplified neurogenesis both in vitro and in vivo, while offering a temporal and spatial control of RA release. In conclusion, this combinatory treatment offers great advantages to potentiate neuronal differentiation, and provides an innovative and efficient application for brain regenerative therapies. Controlling the differentiation of stem cells would support the development of promising brain regenerative therapies. Blue light transiently increased reactive oxygen species, resulting in neuronal differentiation and increased retinoic acid receptor (RARα) levels. Additionally, the same blue light stimulation was capable of triggering the release of RA from light-responsive nanoparticles (LR-NP). The synergy between blue light and LR-NP led to amplified neurogenesis, while offering a temporal and spatial control of RA release. In this sense, our approach relying on the modulation of endogenous stem cells for the generation of new neurons may support the development of novel clinical therapies. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Development of hematopoietic stem and progenitor cells from human pluripotent stem cells.

PubMed

Chen, Tong; Wang, Fen; Wu, Mengyao; Wang, Zack Z

2015-07-01

Human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), provide a new cell source for regenerative medicine, disease modeling, drug discovery, and preclinical toxicity screening. Understanding of the onset and the sequential process of hematopoietic cells from differentiated hPSCs will enable the achievement of personalized medicine and provide an in vitro platform for studying of human hematopoietic development and disease. During embryogenesis, hemogenic endothelial cells, a specified subset of endothelial cells in embryonic endothelium, are the primary source of multipotent hematopoietic stem cells. In this review, we discuss current status in the generation of multipotent hematopoietic stem and progenitor cells from hPSCs via hemogenic endothelial cells. We also review the achievements in direct reprogramming from non-hematopoietic cells to hematopoietic stem and progenitor cells. Further characterization of hematopoietic differentiation in hPSCs will improve our understanding of blood development and expedite the development of hPSC-derived blood products for therapeutic purpose. © 2015 Wiley Periodicals, Inc.

Therapeutic microparticles functionalized with biomimetic cardiac stem cell membranes and secretome

PubMed Central

Tang, Junnan; Shen, Deliang; Caranasos, Thomas George; Wang, Zegen; Vandergriff, Adam C.; Allen, Tyler A.; Hensley, Michael Taylor; Dinh, Phuong-Uyen; Cores, Jhon; Li, Tao-Sheng; Zhang, Jinying; Kan, Quancheng; Cheng, Ke

2017-01-01

Stem cell therapy represents a promising strategy in regenerative medicine. However, cells need to be carefully preserved and processed before usage. In addition, cell transplantation carries immunogenicity and/or tumourigenicity risks. Mounting lines of evidence indicate that stem cells exert their beneficial effects mainly through secretion (of regenerative factors) and membrane-based cell–cell interaction with the injured cells. Here, we fabricate a synthetic cell-mimicking microparticle (CMMP) that recapitulates stem cell functions in tissue repair. CMMPs carry similar secreted proteins and membranes as genuine cardiac stem cells do. In a mouse model of myocardial infarction, injection of CMMPs leads to the preservation of viable myocardium and augmentation of cardiac functions similar to cardiac stem cell therapy. CMMPs (derived from human cells) do not stimulate T-cell infiltration in immuno-competent mice. In conclusion, CMMPs act as ‘synthetic stem cells’ which mimic the paracrine and biointerfacing activities of natural stem cells in therapeutic cardiac regeneration. PMID:28045024

Stem cell plasticity enables hair regeneration following Lgr5+ cell loss.

PubMed

Hoeck, Joerg D; Biehs, Brian; Kurtova, Antonina V; Kljavin, Noelyn M; de Sousa E Melo, Felipe; Alicke, Bruno; Koeppen, Hartmut; Modrusan, Zora; Piskol, Robert; de Sauvage, Frederic J

2017-06-01

Under injury conditions, dedicated stem cell populations govern tissue regeneration. However, the molecular mechanisms that induce stem cell regeneration and enable plasticity are poorly understood. Here, we investigate stem cell recovery in the context of the hair follicle to understand how two molecularly distinct stem cell populations are integrated. Utilizing diphtheria-toxin-mediated cell ablation of Lgr5 + (leucine-rich repeat-containing G-protein-coupled receptor 5) stem cells, we show that killing of Lgr5 + cells in mice abrogates hair regeneration but this is reversible. During recovery, CD34 + (CD34 antigen) stem cells activate inflammatory response programs and start dividing. Pharmacological attenuation of inflammation inhibits CD34 + cell proliferation. Subsequently, the Wnt pathway controls the recovery of Lgr5 + cells and inhibition of Wnt signalling prevents Lgr5 + cell and hair germ recovery. Thus, our study uncovers a compensatory relationship between two stem cell populations and the underlying molecular mechanisms that enable hair follicle regeneration.

SILAC proteomics of planarians identifies Ncoa5 as a conserved component of pluripotent stem cells.

PubMed

Böser, Alexander; Drexler, Hannes C A; Reuter, Hanna; Schmitz, Henning; Wu, Guangming; Schöler, Hans R; Gentile, Luca; Bartscherer, Kerstin

2013-11-27

Planarian regeneration depends on the presence of pluripotent stem cells in the adult. We developed an in vivo stable isotope labeling by amino acids in cell culture (SILAC) protocol in planarians to identify proteins that are enriched in planarian stem cells. Through a comparison of SILAC proteomes of normal and stem cell-depleted planarians and of a stem cell-enriched population of sorted cells, we identified hundreds of stem cell proteins. One of these is an ortholog of nuclear receptor coactivator-5 (Ncoa5/CIA), which is known to regulate estrogen-receptor-mediated transcription in human cells. We show that Ncoa5 is essential for the maintenance of the pluripotent stem cell population in planarians and that a putative mouse ortholog is expressed in pluripotent cells of the embryo. Our study thus identifies a conserved component of pluripotent stem cells, demonstrating that planarians, in particular, when combined with in vivo SILAC, are a powerful model in stem cell research. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Stem cells in reproductive medicine: ready for the patient?

PubMed

Vassena, R; Eguizabal, C; Heindryckx, B; Sermon, K; Simon, C; van Pelt, A M M; Veiga, A; Zambelli, F

2015-09-01

Are there effective and clinically validated stem cell-based therapies for reproductive diseases? At the moment, clinically validated stem cell treatments for reproductive diseases and alterations are not available. Research in stem cells and regenerative medicine is growing in scope, and its translation to the clinic is heralded by the recent initiation of controlled clinical trials with pluripotent derived cells. Unfortunately, stem cell 'treatments' are currently offered to patients outside of the controlled framework of scientifically sound research and regulated clinical trials. Both physicians and patients in reproductive medicine are often unsure about stem cells therapeutic options. An international working group was assembled to review critically the available scientific literature in both the human species and animal models. This review includes work published in English until December 2014, and available through Pubmed. A few areas of research in stem cell and reproductive medicine were identified: in vitro gamete production, endometrial regeneration, erectile dysfunction amelioration, vaginal reconstruction. The stem cells studied range from pluripotent (embryonic stem cells and induced pluripotent stem cells) to monopotent stem cells, such as spermatogonial stem cells or mesenchymal stem cells. The vast majority of studies have been carried out in animal models, with data that are preliminary at best. This review was not conducted in a systematic fashion, and reports in publications not indexed in Pubmed were not analyzed. A much broader clinical knowledge will have to be acquired before translation to the clinic of stem cell therapies in reproductive medicine; patients and physicians should be wary of unfounded claims of improvement of existing medical conditions; at the moment, effective stem cell treatment for reproductive diseases and alterations is not available. None. NA. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Telocytes and putative stem cells in the lungs: electron microscopy, electron tomography and laser scanning microscopy.

PubMed

Popescu, Laurentiu M; Gherghiceanu, Mihaela; Suciu, Laura C; Manole, Catalin G; Hinescu, Mihail E

2011-09-01

This study describes a novel type of interstitial (stromal) cell - telocytes (TCs) - in the human and mouse respiratory tree (terminal and respiratory bronchioles, as well as alveolar ducts). TCs have recently been described in pleura, epicardium, myocardium, endocardium, intestine, uterus, pancreas, mammary gland, etc. (see www.telocytes.com ). TCs are cells with specific prolongations called telopodes (Tp), frequently two to three per cell. Tp are very long prolongations (tens up to hundreds of μm) built of alternating thin segments known as podomers (≤ 200 nm, below the resolving power of light microscope) and dilated segments called podoms, which accommodate mitochondria, rough endoplasmic reticulum and caveolae. Tp ramify dichotomously, making a 3-dimensional network with complex homo- and heterocellular junctions. Confocal microscopy reveals that TCs are c-kit- and CD34-positive. Tp release shed vesicles or exosomes, sending macromolecular signals to neighboring cells and eventually modifying their transcriptional activity. At bronchoalveolar junctions, TCs have been observed in close association with putative stem cells (SCs) in the subepithelial stroma. SCs are recognized by their ultrastructure and Sca-1 positivity. Tp surround SCs, forming complex TC-SC niches (TC-SCNs). Electron tomography allows the identification of bridging nanostructures, which connect Tp with SCs. In conclusion, this study shows the presence of TCs in lungs and identifies a TC-SC tandem in subepithelial niches of the bronchiolar tree. In TC-SCNs, the synergy of TCs and SCs may be based on nanocontacts and shed vesicles.

I.V. infusion of brain-derived neurotrophic factor gene-modified human mesenchymal stem cells protects against injury in a cerebral ischemia model in adult rat.

PubMed

Nomura, T; Honmou, O; Harada, K; Houkin, K; Hamada, H; Kocsis, J D

2005-01-01

I.V. delivery of mesenchymal stem cells prepared from adult bone marrow reduces infarction size and ameliorates functional deficits in rat cerebral ischemia models. Administration of the brain-derived neurotrophic factor to the infarction site has also been demonstrated to be neuroprotective. To test the hypothesis that brain-derived neurotrophic factor contributes to the therapeutic benefits of mesenchymal stem cell delivery, we compared the efficacy of systemic delivery of human mesenchymal stem cells and human mesenchymal stem cells transfected with a fiber-mutant F/RGD adenovirus vector with a brain-derived neurotrophic factor gene (brain-derived neurotrophic factor-human mesenchymal stem cells). A permanent middle cerebral artery occlusion was induced by intraluminal vascular occlusion with a microfilament. Human mesenchymal stem cells and brain-derived neurotrophic factor-human mesenchymal stem cells were i.v. injected into the rats 6 h after middle cerebral artery occlusion. Lesion size was assessed at 6 h, 1, 3 and 7 days using MR imaging, and histological methods. Functional outcome was assessed using the treadmill stress test. Both human mesenchymal stem cells and brain-derived neurotrophic factor-human mesenchymal stem cells reduced lesion volume and elicited functional improvement compared with the control sham group, but the effect was greater in the brain-derived neurotrophic factor-human mesenchymal stem cell group. ELISA analysis of the infarcted hemisphere revealed an increase in brain-derived neurotrophic factor in the human mesenchymal stem cell groups, but a greater increase in the brain-derived neurotrophic factor-human mesenchymal stem cell group. These data support the hypothesis that brain-derived neurotrophic factor contributes to neuroprotection in cerebral ischemia and cellular delivery of brain-derived neurotrophic factor can be achieved by i.v. delivery of human mesenchymal stem cells.

Distinct roles of neuroepithelial-like and radial glia-like progenitor cells in cerebellar regeneration.

PubMed

Kaslin, Jan; Kroehne, Volker; Ganz, Julia; Hans, Stefan; Brand, Michael

2017-04-15

Zebrafish can regenerate after brain injury, and the regenerative process is driven by resident stem cells. Stem cells are heterogeneous in the vertebrate brain, but the significance of having heterogeneous stem cells in regeneration is not understood. Limited availability of specific stem cells might impair the regeneration of particular cell lineages. We studied regeneration of the adult zebrafish cerebellum, which contains two major stem and progenitor cell types: ventricular zone and neuroepithelial cells. Using conditional lineage tracing we demonstrate that cerebellar regeneration depends on the availability of specific stem cells. Radial glia-like cells are thought to be the predominant stem cell type in homeostasis and after injury. However, we find that radial glia-like cells play a minor role in adult cerebellar neurogenesis and in recovery after injury. Instead, we find that neuroepithelial cells are the predominant stem cell type supporting cerebellar regeneration after injury. Zebrafish are able to regenerate many, but not all, cell types in the cerebellum, which emphasizes the need to understand the contribution of different adult neural stem and progenitor cell subtypes in the vertebrate central nervous system. © 2017. Published by The Company of Biologists Ltd.

Role of the Stem Cell Niche in Hormone-induced Tumorigenesis in Fetal Mouse Mammary Epithelium

DTIC Science & Technology

2006-08-01

Develop an immunohistochemical method for identifying stem cells and stem cell niches, and to use this to determine if in utero estrogenic...overstimulation causes changes in the number of stem cells or their niches. To extend the power of ex vivo stem cell isolation and enumeration by providing a...marginal success due primarily to 1) most antibodies previously reputed to be stem cell specific turned out to be present in differentiated mammary

Wnt and BMP Signaling Crosstalk in Regulating Dental Stem Cells: Implications in Dental Tissue Engineering

PubMed Central

Zhang, Fugui; Song, Jinglin; Zhang, Hongmei; Huang, Enyi; Song, Dongzhe; Tollemar, Viktor; Wang, Jing; Wang, Jinhua; Mohammed, Maryam; Wei, Qiang; Fan, Jiaming; Liao, Junyi; Zou, Yulong; Liu, Feng; Hu, Xue; Qu, Xiangyang; Chen, Liqun; Yu, Xinyi; Luu, Hue H.; Lee, Michael J.; He, Tong-Chuan; Ji, Ping

2016-01-01

Tooth is a complex hard tissue organ and consists of multiple cell types that are regulated by important signaling pathways such as Wnt and BMP signaling. Serious injuries and/or loss of tooth or periodontal tissues may significantly impact aesthetic appearance, essential oral functions and the quality of life. Regenerative dentistry holds great promise in treating oral/dental disorders. The past decade has witnessed a rapid expansion of our understanding of the biological features of dental stem cells, along with the signaling mechanisms governing stem cell self-renewal and differentiation. In this review, we first summarize the biological characteristics of seven types of dental stem cells, including dental pulp stem cells, stem cells from apical papilla, stem cells from human exfoliated deciduous teeth, dental follicle precursor cells, periodontal ligament stem cells, alveolar bone-derived mesenchymal stem cells (MSCs), and MSCs from gingiva. We then focus on how these stem cells are regulated by bone morphogenetic protein (BMP) and/or Wnt signaling by examining the interplays between these pathways. Lastly, we analyze the current status of dental tissue engineering strategies that utilize oral/dental stem cells by harnessing the interplays between BMP and Wnt pathways. We also highlight the challenges that must be addressed before the dental stem cells may reach any clinical applications. Thus, we can expect to witness significant progresses to be made in regenerative dentistry in the coming decade. PMID:28491933

Extracellular Matrix as a Regulator of Epidermal Stem Cell Fate.

PubMed

Chermnykh, Elina; Kalabusheva, Ekaterina; Vorotelyak, Ekaterina

2018-03-27

Epidermal stem cells reside within the specific anatomic location, called niche, which is a microenvironment that interacts with stem cells to regulate their fate. Regulation of many important processes, including maintenance of stem cell quiescence, self-renewal, and homeostasis, as well as the regulation of division and differentiation, are common functions of the stem cell niche. As it was shown in multiple studies, extracellular matrix (ECM) contributes a lot to stem cell niches in various tissues, including that of skin. In epidermis, ECM is represented, primarily, by a highly specialized ECM structure, basement membrane (BM), which separates the epidermal and dermal compartments. Epidermal stem cells contact with BM, but when they lose the contact and migrate to the overlying layers, they undergo terminal differentiation. When considering all of these factors, ECM is of fundamental importance in regulating epidermal stem cells maintenance, proper mobilization, and differentiation. Here, we summarize the remarkable progress that has recently been made in the research of ECM role in regulating epidermal stem cell fate, paying special attention to the hair follicle stem cell niche. We show that the destruction of ECM components impairs epidermal stem cell morphogenesis and homeostasis. A deep understanding of ECM molecular structure as well as the development of in vitro system for stem cell maintaining by ECM proteins may bring us to developing new approaches for regenerative medicine.

Knowledge and Attitude about Stem Cells and Their Application in Medicine among Nursing Students in Universiti Sains Malaysia, Malaysia

PubMed Central

LYE, Jee Leng; SOON, Lean Keng; WAN AHMAD, Wan Amir Nizam; TAN, Suat Cheng

2015-01-01

Background: Stem cell research has been extensively explored worldwide to enhance human health in medical setting. Nevertheless, there is currently no full understanding of the stem cell knowledge and attitude levels among student nurses in Malaysia. This study aimed to assess the level of stem cell knowledge, attitude toward stem cell application in medicine, and its association with years of education, among Universiti Sains Malaysia (USM) undergraduate nursing students. Methods: A cross-sectional study (n = 88) was conducted using self-administered questionnaire consisted of demographic information, stem cells knowledge and attitude statements. Data was analysed using Statistical Package Social Software 20.0. Results: The majority of participants (92%) had moderate knowledge score about stem cells. Many students (33%) worried that stem cell application might cause a harm to humanity yet had a positive (76.1%) attitude towards its therapeutic potential (45.5%). Poor correlation between knowledge and attitude (r = 0.08) indicated that acceptance towards stem cell is not solely based on the knowledge level but also on other factors including religion and culture. Conclusion: Therefore, this study suggests that various educational programs on stem cell should be implemented considering the religion, cultural, social, and behavioural determinants in the population to improve stem cell knowledge and encourage a more positive attitude towards stem cells in medicine among these nursing students. PMID:26715905

Knowledge and Attitude about Stem Cells and Their Application in Medicine among Nursing Students in Universiti Sains Malaysia, Malaysia.

PubMed

Lye, Jee Leng; Soon, Lean Keng; Wan Ahmad, Wan Amir Nizam; Tan, Suat Cheng

2015-01-01

Stem cell research has been extensively explored worldwide to enhance human health in medical setting. Nevertheless, there is currently no full understanding of the stem cell knowledge and attitude levels among student nurses in Malaysia. This study aimed to assess the level of stem cell knowledge, attitude toward stem cell application in medicine, and its association with years of education, among Universiti Sains Malaysia (USM) undergraduate nursing students. A cross-sectional study (n = 88) was conducted using self-administered questionnaire consisted of demographic information, stem cells knowledge and attitude statements. Data was analysed using Statistical Package Social Software 20.0. The majority of participants (92%) had moderate knowledge score about stem cells. Many students (33%) worried that stem cell application might cause a harm to humanity yet had a positive (76.1%) attitude towards its therapeutic potential (45.5%). Poor correlation between knowledge and attitude (r = 0.08) indicated that acceptance towards stem cell is not solely based on the knowledge level but also on other factors including religion and culture. Therefore, this study suggests that various educational programs on stem cell should be implemented considering the religion, cultural, social, and behavioural determinants in the population to improve stem cell knowledge and encourage a more positive attitude towards stem cells in medicine among these nursing students.

Stem cell motility enables a density-dependent rate of fate commitment during scaled resizing of adult organs

NASA Astrophysics Data System (ADS)

Du, Xinxin; O'Brien, Lucy; Riedel-Kruse, Ingmar

Many adult organs grow or shrink to accommodate fluctuating levels of physiological demand. Specifically, the intestine of the fruit fly (the midgut) expands four-fold in the number of mature cells and, proportionally, the number of stem cells when the fly eats. However, the cellular behaviors that give rise to this stem scaling are not well-understood. Here we present a biophysical model of the adult fly midgut. A set of differential equations can recapitulate the physiological kinetics of cells during midgut growth and shrinkage as long as the rate of stem cell fate commitment depends on the stem cell number density in the tissue. To elucidate the source of this dependence, we model the tissue in a 2D simulation with soft spheres, where stem cells choose fate commitment through Delta-Notch pathway interactions with other stem cells, a known process in fly midguts. We find that as long as stem cells exhibit a large enough amplitude of random motion through the tissue (`stem cell motility'), and explore a large enough `territory' in their lifetime, stem cell scaling can occur. These model observations are confirmed through in vivo live-imaging, where we indeed see that stem cells are motile in the fly midgut.

Ethics and Policy Issues for Stem Cell Research and Pulmonary Medicine

PubMed Central

Lowenthal, Justin

2015-01-01

Stem cell research and related initiatives in regenerative medicine, cell-based therapy, and tissue engineering have generated considerable scientific and public interest. Researchers are applying stem cell technologies to chest medicine in a variety of ways: using stem cells as models for drug discovery, testing stem cell-based therapies for conditions as diverse as COPD and cystic fibrosis, and producing functional lung and tracheal tissue for physiologic modeling and potential transplantation. Although significant scientific obstacles remain, it is likely that stem cell-based regenerative medicine will have a significant clinical impact in chest medicine. However, stem cell research has also generated substantial controversy, posing a variety of ethical and regulatory challenges for research and clinical practice. Some of the most prominent ethical questions related to the use of stem cell technologies in chest medicine include (1) implications for donors, (2) scientific prerequisites for clinical testing and use, (3) stem cell tourism, (4) innovation and clinical use of emerging stem cell-based interventions, (5) responsible translation of stem cell-based therapies to clinical use, and (6) appropriate and equitable access to emerging therapies. Having a sense of these issues should help to put emerging scientific advances into appropriate context and to ensure the responsible clinical translation of promising therapeutics. PMID:25732448

A Survey of Italian Physicians' Opinion about Stem Cells Research: What Doctors Prefer and What the Law Requires

PubMed Central

Frati, Paola; Pacchiarotti, Arianna; D'Errico, Stefano

2014-01-01

To evaluate the Italian physicians' knowledge/information level about the therapeutic potential of stem cells, the research choice between embryonic and cordonal stem cells, and the preference between autologous and heterologous storage of cordonal stem cells, we performed a national survey. The questionnaire—distributed to 3361 physicians—involved physicians of different religious orientations and of different medical specialities. Most of the physicians involved (67%) were Catholics, and the majority were gynaecologists and paediatricians (43%) who are mainly in charge to inform future mothers about the possibility of cordonal stem cells conservation. The majority of the physicians interviewed do not have specific knowledge about stem cells (59%), most of them having only generic information (92%). The largest part of physicians prefer to use umbilical cord blood cells rather than embryonic stem cells. Nevertheless, a large percentage of physicians were in favour of embryo research, especially when embryos are supernumerary (44% versus 34%). Eighty-seven % of the physicians interviewed proved to have a general knowledge about stem cells and believe in their therapeutic potential. They prefer research on cordonal stem cells rather than on embryo stem cells. Although they are in favour of heterologous stem cells donation, they still prefer cryopreservation for personal use. PMID:24877099

Ethics and policy issues for stem cell research and pulmonary medicine.

PubMed

Lowenthal, Justin; Sugarman, Jeremy

2015-03-01

Stem cell research and related initiatives in regenerative medicine, cell-based therapy, and tissue engineering have generated considerable scientific and public interest. Researchers are applying stem cell technologies to chest medicine in a variety of ways: using stem cells as models for drug discovery, testing stem cell-based therapies for conditions as diverse as COPD and cystic fibrosis, and producing functional lung and tracheal tissue for physiologic modeling and potential transplantation. Although significant scientific obstacles remain, it is likely that stem cell-based regenerative medicine will have a significant clinical impact in chest medicine. However, stem cell research has also generated substantial controversy, posing a variety of ethical and regulatory challenges for research and clinical practice. Some of the most prominent ethical questions related to the use of stem cell technologies in chest medicine include (1) implications for donors, (2) scientific prerequisites for clinical testing and use, (3) stem cell tourism, (4) innovation and clinical use of emerging stem cell-based interventions, (5) responsible translation of stem cell-based therapies to clinical use, and (6) appropriate and equitable access to emerging therapies. Having a sense of these issues should help to put emerging scientific advances into appropriate context and to ensure the responsible clinical translation of promising therapeutics.

Propagation of human spermatogonial stem cells in vitro.

PubMed

Sadri-Ardekani, Hooman; Mizrak, Sefika C; van Daalen, Saskia K M; Korver, Cindy M; Roepers-Gajadien, Hermien L; Koruji, Morteza; Hovingh, Suzanne; de Reijke, Theo M; de la Rosette, Jean J M C H; van der Veen, Fulco; de Rooij, Dirk G; Repping, Sjoerd; van Pelt, Ans M M

2009-11-18

Young boys treated with high-dose chemotherapy are often confronted with infertility once they reach adulthood. Cryopreserving testicular tissue before chemotherapy and autotransplantation of spermatogonial stem cells at a later stage could theoretically allow for restoration of fertility. To establish in vitro propagation of human spermatogonial stem cells from small testicular biopsies to obtain an adequate number of cells for successful transplantation. Study performed from April 2007 to July 2009 using testis material donated by 6 adult men who underwent orchidectomy as part of prostate cancer treatment. Testicular cells were isolated and cultured in supplemented StemPro medium; germline stem cell clusters that arose were subcultured on human placental laminin-coated dishes in the same medium. Presence of spermatogonia was determined by reverse transcriptase polymerase chain reaction and immunofluorescence for spermatogonial markers. To test for the presence of functional spermatogonial stem cells in culture, xenotransplantation to testes of immunodeficient mice was performed, and migrated human spermatogonial stem cells after transplantation were detected by COT-1 fluorescence in situ hybridization. The number of colonized spermatogonial stem cells transplanted at early and later points during culture were counted to determine propagation. Propagation of spermatogonial stem cells over time. Testicular cells could be cultured and propagated up to 15 weeks. Germline stem cell clusters arose in the testicular cell cultures from all 6 men and could be subcultured and propagated up to 28 weeks. Expression of spermatogonial markers on both the RNA and protein level was maintained throughout the entire culture period. In 4 of 6 men, xenotransplantation to mice demonstrated the presence of functional spermatogonial stem cells, even after prolonged in vitro culture. Spermatogonial stem cell numbers increased 53-fold within 19 days in the testicular cell culture and increased 18,450-fold within 64 days in the germline stem cell subculture. Long-term culture and propagation of human spermatogonial stem cells in vitro is achievable.

Stem cell technology for drug discovery and development.

PubMed

Hook, Lilian A

2012-04-01

Stem cells have enormous potential to revolutionise the drug discovery process at all stages, from target identification through to toxicology studies. Their ability to generate physiologically relevant cells in limitless supply makes them an attractive alternative to currently used recombinant cell lines or primary cells. However, realisation of the full potential of stem cells is currently hampered by the difficulty in routinely directing stem cell differentiation to reproducibly and cost effectively generate pure populations of specific cell types. In this article we discuss how stem cells have already been used in the drug discovery process and how novel technologies, particularly in relation to stem cell differentiation, can be applied to attain widespread adoption of stem cell technology by the pharmaceutical industry. Copyright © 2011 Elsevier Ltd. All rights reserved.

College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning

NASA Astrophysics Data System (ADS)

Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

2010-04-01

In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before and after instruction. Two goals of the instruction were to: (1) help students construct accurate scientific ideas, and (2) enhance their reasoning about socioscientific issues. The course structure included interactive lectures, case discussions, hands-on activities, and independent projects. Overall, students' understandings of stem cells, stem cell research, and cloning increased from pre-test to post-test. For example, on the post-test, students gained knowledge concerning the age of an organism related to the type of stem cell it possesses. However, we found that some incorrect ideas that were evident on the pre-test persisted after instruction. For example, before and after instruction several students maintained the idea that stem cells can currently be used to produce organs.

Advances and Prospects in Stem Cells for Cartilage Regeneration

PubMed Central

Wang, Mingjie; Yuan, Zhiguo; Ma, Ning; Hao, Chunxiang; Guo, Weimin; Zou, Gengyi; Zhang, Yu; Chen, Mingxue; Gao, Shuang; Wang, Aiyuan; Wang, Yu; Sui, Xiang; Xu, Wenjing; Lu, Shibi

2017-01-01

The histological features of cartilage call attention to the fact that cartilage has a little capacity to repair itself owing to the lack of a blood supply, nerves, or lymphangion. Stem cells have emerged as a promising option in the field of cartilage tissue engineering and regenerative medicine and could lead to cartilage repair. Much research has examined cartilage regeneration utilizing stem cells. However, both the potential and the limitations of this procedure remain controversial. This review presents a summary of emerging trends with regard to using stem cells in cartilage tissue engineering and regenerative medicine. In particular, it focuses on the characterization of cartilage stem cells, the chondrogenic differentiation of stem cells, and the various strategies and approaches involving stem cells that have been used in cartilage repair and clinical studies. Based on the research into chondrocyte and stem cell technologies, this review discusses the damage and repair of cartilage and the clinical application of stem cells, with a view to increasing our systematic understanding of the application of stem cells in cartilage regeneration; additionally, several advanced strategies for cartilage repair are discussed. PMID:28246531

Stem Cell-Derived Exosome in Cardiovascular Diseases: Macro Roles of Micro Particles.

PubMed

Yuan, Ye; Du, Weijie; Liu, Jiaqi; Ma, Wenya; Zhang, Lai; Du, Zhimin; Cai, Benzhi

2018-01-01

The stem cell-based therapy has emerged as the promising therapeutic strategies for cardiovascular diseases (CVDs). Recently, increasing evidence suggest stem cell-derived active exosomes are important communicators among cells in the heart via delivering specific substances to the adjacent/distant target cells. These exosomes and their contents such as certain proteins, miRNAs and lncRNAs exhibit huge beneficial effects on preventing heart damage and promoting cardiac repair. More importantly, stem cell-derived exosomes are more effective and safer than stem cell transplantation. Therefore, administration of stem cell-derived exosomes will expectantly be an alternative stem cell-based therapy for the treatment of CVDs. Furthermore, modification of stem cell-derived exosomes or artificial synthesis of exosomes will be the new therapeutic tools for CVDs in the future. In addition, stem cell-derived exosomes also have been implicated in the diagnosis and prognosis of CVDs. In this review, we summarize the current advances of stem cell-derived exosome-based treatment and prognosis for CVDs, including their potential benefits, underlying mechanisms and limitations, which will provide novel insights of exosomes as a new tool in clinical therapeutic translation in the future.

Stem cells and reproduction.

PubMed

Du, Hongling; Taylor, Hugh S

2010-06-01

To review the latest developments in reproductive tract stem cell biology. In 2004, two studies indicated that ovaries contain stem cells which form oocytes in adults and that can be cultured in vitro into mature oocytes. A live birth after orthotopic transplantation of cryopreserved ovarian tissue in a woman whose ovaries were damaged by chemotherapy demonstrates the clinical potential of these cells. In the same year, another study provided novel evidence of endometrial regeneration by stem cells in women who received bone marrow transplants. This finding has potential for the use in treatment of uterine disorders. It also supports a new theory for the cause of endometriosis, which may have its origin in ectopic transdifferentiation of stem cells. Several recent studies have demonstrated that fetal cells enter the maternal circulation and generate microchimerism in the mother. The uterus is a dynamic organ permeable to fetal stem cells, capable of transdifferentiation and an end organ in which bone marrow stem cells may differentiate. Finally stem cell transformation can be an underlying cause of ovarian cancer. Whereas we are just beginning to understand stem cells, the potential implications of stem cells to reproductive biology and medicine are apparent.

Biliary tract cancer stem cells - translational options and challenges

PubMed Central

Mayr, Christian; Ocker, Matthias; Ritter, Markus; Pichler, Martin; Neureiter, Daniel; Kiesslich, Tobias

2017-01-01

Management of biliary tract cancer remains challenging. Tumors show high recurrence rates and therapeutic resistance, leading to dismal prognosis and short survival. The cancer stem cell model states that a tumor is a heterogeneous conglomerate of cells, in which a certain subpopulation of cells - the cancer stem cells - possesses stem cell properties. Cancer stem cells have high clinical relevance due to their potential contributions to development, progression and aggressiveness as well as recurrence and metastasis of malignant tumors. Consequently, reliable identification of as well as pharmacological intervention with cancer stem cells is an intensively investigated and promising research field. The involvement of cancer stem cells in biliary tract cancer is likely as a number of studies demonstrated their existence and the obvious clinical relevance of several established cancer stem cell markers in biliary tract cancer models and tissues. In the present article, we review and discuss the currently available literature addressing the role of putative cancer stem cells in biliary tract cancer as well as the connection between known contributors of biliary tract tumorigenesis such as oncogenic signaling pathways, micro-RNAs and the tumor microenvironment with cancer stem cells. PMID:28465631

Ultraviolet Radiation-Induced Skin Aging: The Role of DNA Damage and Oxidative Stress in Epidermal Stem Cell Damage Mediated Skin Aging

PubMed Central

Panich, Uraiwan; Sittithumcharee, Gunya; Rathviboon, Natwarath

2016-01-01

Skin is the largest human organ. Skin continually reconstructs itself to ensure its viability, integrity, and ability to provide protection for the body. Some areas of skin are continuously exposed to a variety of environmental stressors that can inflict direct and indirect damage to skin cell DNA. Skin homeostasis is maintained by mesenchymal stem cells in inner layer dermis and epidermal stem cells (ESCs) in the outer layer epidermis. Reduction of skin stem cell number and function has been linked to impaired skin homeostasis (e.g., skin premature aging and skin cancers). Skin stem cells, with self-renewal capability and multipotency, are frequently affected by environment. Ultraviolet radiation (UVR), a major cause of stem cell DNA damage, can contribute to depletion of stem cells (ESCs and mesenchymal stem cells) and damage of stem cell niche, eventually leading to photoinduced skin aging. In this review, we discuss the role of UV-induced DNA damage and oxidative stress in the skin stem cell aging in order to gain insights into the pathogenesis and develop a way to reduce photoaging of skin cells. PMID:27148370

Identification of Metastatic Tumor Stem Cell

DTIC Science & Technology

2010-09-01

addition to a tumor stem cell , an existence of a metastatic stem cell is predicted. Despite the critical importance of the concept, this idea has not been...isolating stem cell population from a unique set of breast tumor cell lines and by examining their metastatic behavior in an animal model. The overall...will (i) isolate stem - cell population from non-metastatic and metastatic cells of a pair of syngenic breast tumor cell lines, and test their metastatic

Roles of neural stem cells in the repair of peripheral nerve injury.

PubMed

Wang, Chong; Lu, Chang-Feng; Peng, Jiang; Hu, Cheng-Dong; Wang, Yu

2017-12-01

Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.

Day-night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis.

PubMed

Tulina, Natalia M; Chen, Wen-Feng; Chen, Jung Hsuan; Sowcik, Mallory; Sehgal, Amita

2014-02-25

Adult stem cells maintain tissue integrity and function by renewing cellular content of the organism through regulated mitotic divisions. Previous studies showed that stem cell activity is affected by local, systemic, and environmental cues. Here, we explore a role of environmental day-night cycles in modulating cell cycle progression in populations of adult stem cells. Using a classic stem cell system, the Drosophila spermatogonial stem cell niche, we reveal daily rhythms in division frequencies of germ-line and somatic stem cells that act cooperatively to produce male gametes. We also examine whether behavioral sleep-wake cycles, which are driven by the environmental day-night cycles, regulate stem cell function. We find that flies lacking the sleep-promoting factor Sleepless, which maintains normal sleep in Drosophila, have increased germ-line stem cell (GSC) division rates, and this effect is mediated, in part, through a GABAergic signaling pathway. We suggest that alterations in sleep can influence the daily dynamics of GSC divisions.

IL-17B activated mesenchymal stem cells enhance proliferation and migration of gastric cancer cells.

PubMed

Bie, Qingli; Zhang, Bin; Sun, Caixia; Ji, Xiaoyun; Barnie, Prince Amoah; Qi, Chen; Peng, Jingjing; Zhang, Danyi; Zheng, Dong; Su, Zhaoliang; Wang, Shengjun; Xu, Huaxi

2017-03-21

Mesenchymal stem cells are important cells in tumor microenvironment. We have previously demonstrated that IL-17B/IL-17RB signal promoted progression of gastric cancer. In this study, we further explored the effect of IL-17B on mesenchymal stem cells in tumor microenvironment and its impact on the tumor progression. The results showed that IL-17B induced the expression of stemness-related genes Nanog, Sox2, and Oct4 in mesenchymal stem cells and enhanced its tumor-promoting effect. The supernatant from cultured mesenchymal stem cells after treating with exogenous rIL-17B promoted the proliferation and migration of MGC-803, therefor suggesting that rIL-17B might promote mesenchymal stem cells to produce soluble factors. In addition, rIL-17B also activated the NF-κΒ, STAT3, β-catenin pathway in mesenchymal stem cells. Our data revealed a new mechanism that IL-17B enhanced the progression of gastric cancer by activating mesenchymal stem cells.

A Phenotype-Based RNAi Screening for Ras-ERK/MAPK Signaling-Associated Stem Cell Regulators in C. elegans.

PubMed

Lee, Myon-Hee; Yoon, Dong Suk

2017-01-01

Stem cells have the ability to self-renew and to generate differentiated cell types. A regulatory network that controls this balance is critical for stem cell homeostasis and normal animal development. Particularly, Ras-ERK/MAPK signaling pathway is critical for stem cell self-renewal and differentiation in mammals, including humans. Aberrant regulation of Ras-ERK/MAPK signaling pathway results in either stem cell or overproliferation. Therefore, the identification of Ras-ERK/MAPK signaling pathway-associated regulators is critical to understand the mechanism of stem cell (possibly cancer stem cell) control. In this report, using the nematode C. elegans mutants, we developed a methodology for a phenotype-based RNAi screening that identifies stem cell regulator genes associated with Ras-ERK/MAPK signaling within the context of a whole organism. Importantly, this phenotype-based RNAi screening can be applied for other stem cell-associated signaling pathways such as Wnt/β-catenin and Notch using the C. elegans.

Adipose-derived mesenchymal stem cells and regenerative medicine.

PubMed

Konno, Masamitsu; Hamabe, Atsushi; Hasegawa, Shinichiro; Ogawa, Hisataka; Fukusumi, Takahito; Nishikawa, Shimpei; Ohta, Katsuya; Kano, Yoshihiro; Ozaki, Miyuki; Noguchi, Yuko; Sakai, Daisuke; Kudoh, Toshihiro; Kawamoto, Koichi; Eguchi, Hidetoshi; Satoh, Taroh; Tanemura, Masahiro; Nagano, Hiroaki; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

2013-04-01

Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow-derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

A dual role of p21 in stem cell aging.

PubMed

Ju, Zhenyu; Choudhury, Aaheli Roy; Rudolph, K Lenhard

2007-04-01

A decline in adult stem cell function occurs during aging, likely contributing to the decline in organ homeostasis and regeneration with age. An emerging field in aging research is to analyze molecular pathways limiting adult stem cell function in response to macromolecular damage accumulation during aging. Current data suggest that the p21 cell cycle inhibitor has a dual role in stem cell aging: On one hand, p21 protects adult stem cells from acute genotoxic stress by preventing inappropriate cycling of acutely damaged stem cells. On the other hand, p21 activation impairs stem cell function and survival of aging telomere dysfunctional mice indicating that p21 checkpoint function is disadvantageous in the context of chronic and persistent damage, which accumulates during aging. This article focuses on these dual roles of p21 in aging stem cells.

Stem Cell Pathology.

PubMed

Fu, Dah-Jiun; Miller, Andrew D; Southard, Teresa L; Flesken-Nikitin, Andrea; Ellenson, Lora H; Nikitin, Alexander Yu

2018-01-24

Rapid advances in stem cell biology and regenerative medicine have opened new opportunities for better understanding disease pathogenesis and the development of new diagnostic, prognostic, and treatment approaches. Many stem cell niches are well defined anatomically, thereby allowing their routine pathological evaluation during disease initiation and progression. Evaluation of the consequences of genetic manipulations in stem cells and investigation of the roles of stem cells in regenerative medicine and pathogenesis of various diseases such as cancer require significant expertise in pathology for accurate interpretation of novel findings. Therefore, there is an urgent need for developing stem cell pathology as a discipline to facilitate stem cell research and regenerative medicine. This review provides examples of anatomically defined niches suitable for evaluation by diagnostic pathologists, describes neoplastic lesions associated with them, and discusses further directions of stem cell pathology.

The clinical use of regenerative therapy in COPD

PubMed Central

Lipsi, Roberto; Rogliani, Paola; Calzetta, Luigino; Segreti, Andrea; Cazzola, Mario

2014-01-01

Regenerative or stem cell therapy is an emerging field of treatment based on stimulation of endogenous resident stem cells or administration of exogenous stem cells to treat diseases or injury and to replace malfunctioning or damaged tissues. Current evidence suggests that in the lung, these cells may participate in tissue homeostasis and regeneration after injury. Animal and human studies have demonstrated that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for the activation of endogenous stem/progenitor cells may be a potent next-generation therapy for chronic obstructive pulmonary disease. The use of bone marrow-derived stem cells could allow repairing and regenerate the damaged tissue present in chronic obstructive pulmonary disease by means of their engraftment into the lung. Another approach could be the stimulation of resident stem cells by means of humoral factors or photobiostimulation. PMID:25548520

Plant stem cell niches.

PubMed

Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

2012-01-01

Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

Induction of muscle stem cell quiescence by the secreted niche factor Oncostatin M.

PubMed

Sampath, Srinath C; Sampath, Srihari C; Ho, Andrew T V; Corbel, Stéphane Y; Millstone, Joshua D; Lamb, John; Walker, John; Kinzel, Bernd; Schmedt, Christian; Blau, Helen M

2018-04-18

The balance between stem cell quiescence and proliferation in skeletal muscle is tightly controlled, but perturbed in a variety of disease states. Despite progress in identifying activators of stem cell proliferation, the niche factor(s) responsible for quiescence induction remain unclear. Here we report an in vivo imaging-based screen which identifies Oncostatin M (OSM), a member of the interleukin-6 family of cytokines, as a potent inducer of muscle stem cell (MuSC, satellite cell) quiescence. OSM is produced by muscle fibers, induces reversible MuSC cell cycle exit, and maintains stem cell regenerative capacity as judged by serial transplantation. Conditional OSM receptor deletion in satellite cells leads to stem cell depletion and impaired regeneration following injury. These results identify Oncostatin M as a secreted niche factor responsible for quiescence induction, and for the first time establish a direct connection between induction of quiescence, stemness, and transplantation potential in solid organ stem cells.

Nuclear Mechanics and Stem Cell Differentiation.

PubMed

Mao, Xinjian; Gavara, Nuria; Song, Guanbin

2015-12-01

Stem cells are characterized by their self-renewal and multi-lineage differentiation potential. Stem cell differentiation is a prerequisite for the application of stem cells in regenerative medicine and clinical therapy. In addition to chemical stimulation, mechanical cues play a significant role in regulating stem cell differentiation. The integrity of mechanical sensors is necessary for the ability of cells to respond to mechanical signals. The nucleus, the largest and stiffest cellular organelle, interacts with the cytoskeleton as a key mediator of cell mechanics. Nuclear mechanics are involved in the complicated interactions of lamins, chromatin and nucleoskeleton-related proteins. Thus, stem cell differentiation is intimately associated with nuclear mechanics due to its indispensable role in mechanotransduction and mechanical response. This paper reviews several main contributions of nuclear mechanics, highlights the hallmarks of the nuclear mechanics of stem cells, and provides insight into the relationship between nuclear mechanics and stem cell differentiation, which may guide clinical applications in the future.

Parthenogenesis-derived Multipotent Stem Cells Adapted for Tissue Engineering Applications

PubMed Central

Koh, Chester J.; Delo, Dawn M.; Lee, Jang Won; Siddiqui, M. Minhaj; Lanza, Robert P.; Soker, Shay; Yoo, James J.; Atala, Anthony

2009-01-01

Embryonic stem cells are envisioned as a viable source of pluripotent cells for use in regenerative medicine applications when donor tissue is not available. However, most current harvest techniques for embryonic stem cells require the destruction of embryos, which has led to significant political and ethical limitations on their usage. Parthenogenesis, the process by which an egg can develop into an embryo in the absence of sperm, may be a potential source of embryonic stem cells that may avoid some of the political and ethical concerns surrounding embryonic stem cells. Here we provide the technical aspects of embryonic stem cell isolation and expansion from the parthenogenetic activation of oocytes. These cells were characterized for their stem-cell properties. In addition, these cells were induced to differentiate to the myogenic, osteogenic, adipogenic, and endothelial lineages, and were able to form muscle-like and bony-like tissue in vivo. Furthermore, parthenogenetic stem cells were able to integrate into injured muscle tissue. Together, these results demonstrate that parthenogenetic stem cells can be successfully isolated and utilized for various tissue engineering applications. PMID:18799133

The human stem cell hierarchy is defined by a functional dependence on Mcl-1 for self-renewal capacity.

PubMed

Campbell, Clinton J V; Lee, Jung Bok; Levadoux-Martin, Marilyne; Wynder, Tracy; Xenocostas, Anargyros; Leber, Brian; Bhatia, Mickie

2010-09-02

The molecular basis for the unique proliferative and self-renewal properties that hierarchically distinguish human stem cells from progenitors and terminally differentiated cells remains largely unknown. We report a role for the Bcl-2 family member myeloid cell leukemia-1 (Mcl-1) as an indispensable regulator of self-renewal in human stem cells and show that a functional dependence on Mcl-1 defines the human stem cell hierarchy. In vivo pharmacologic targeting of the Bcl-2 family members in human hematopoietic stem cells (HSCs) and human leukemic stem cells reduced stem cell regenerative and self-renewal function. Subsequent protein expression studies showed that, among the Bcl-2 family members, only Mcl-1 was up-regulated exclusively in the human HSC fraction on in vivo regeneration of hematopoiesis. Short hairpin RNA-knockdown of Mcl-1 in human cord blood cells did not affect survival in the HSC or hematopoietic progenitor cell fractions in vitro but specifically reduced the in vivo self-renewal function of human HSCs. Moreover, knockdown of Mcl-1 in ontogenetically primitive human pluripotent stem cells resulted in almost complete ablation of stem cell self-renewal function. Our findings show that Mcl-1 is an essential regulator of stem cell self-renewal in humans and therefore represents an axis for therapeutic interventions.

Fake news portrayals of stem cells and stem cell research.

PubMed

Marcon, Alessandro R; Murdoch, Blake; Caulfield, Timothy

2017-10-01

This study examines how stem cells and stem cell research are portrayed on websites deemed to be purveyors of distorted and dubious information. Content analysis was conducted on 224 articles from 2015 to 2016, compiled by searching with the keywords 'stem cell(s)' on a list of websites flagged for containing either 'fake' or 'junk science' news. Articles contained various exaggerated positive and negative claims about stem cells and stem cell science, health and science related conspiracy theories, and statements promoting fear and mistrust of conventional medicine. Findings demonstrate the existence of organized misinformation networks, which may lead the public away from accurate information and facilitate a polarization of public discourse.

Skin appendage-derived stem cells: cell biology and potential for wound repair.

PubMed

Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

2016-01-01

Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

Paracrine Engineering of Human Explant-Derived Cardiac Stem Cells to Over-Express Stromal-Cell Derived Factor 1α Enhances Myocardial Repair.

PubMed

Tilokee, Everad L; Latham, Nicholas; Jackson, Robyn; Mayfield, Audrey E; Ye, Bin; Mount, Seth; Lam, Buu-Khanh; Suuronen, Erik J; Ruel, Marc; Stewart, Duncan J; Davis, Darryl R

2016-07-01

First generation cardiac stem cell products provide indirect cardiac repair but variably produce key cardioprotective cytokines, such as stromal-cell derived factor 1α, which opens the prospect of maximizing up-front paracrine-mediated repair. The mesenchymal subpopulation within explant derived human cardiac stem cells underwent lentiviral mediated gene transfer of stromal-cell derived factor 1α. Unlike previous unsuccessful attempts to increase efficacy by boosting the paracrine signature of cardiac stem cells, cytokine profiling revealed that stromal-cell derived factor 1α over-expression prevented lv-mediated "loss of cytokines" through autocrine stimulation of CXCR4+ cardiac stem cells. Stromal-cell derived factor 1α enhanced angiogenesis and stem cell recruitment while priming cardiac stem cells to readily adopt a cardiac identity. As compared to injection with unmodified cardiac stem cells, transplant of stromal-cell derived factor 1α enhanced cells into immunodeficient mice improved myocardial function and angiogenesis while reducing scarring. Increases in myocardial stromal-cell derived factor 1α content paralleled reductions in myocyte apoptosis but did not influence long-term engraftment or the fate of transplanted cells. Transplantation of stromal-cell derived factor 1α transduced cardiac stem cells increased the generation of new myocytes, recruitment of bone marrow cells, new myocyte/vessel formation and the salvage of reversibly damaged myocardium to enhance cardiac repair after experimental infarction. Stem Cells 2016;34:1826-1835. © 2016 AlphaMed Press.

Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring

PubMed Central

Avci, Pinar; Gupta, Asheesh; Sadasivam, Magesh; Vecchio, Daniela; Pam, Zeev; Pam, Nadav; Hamblin, Michael R

2013-01-01

Low-level laser (light) therapy (LLLT) is a fast-growing technology used to treat a multitude of conditions that require stimulation of healing, relief of pain and inflammation, and restoration of function. Although the skin is the organ that is naturally exposed to light more than any other organ, it still responds well to red and near-infrared wavelengths. The photons are absorbed by mitochondrial chromophores in skin cells. Consequently electron transport, adenosine triphosphate (ATP) nitric oxide release, blood flow, reactive oxygen species increase and diverse signaling pathways get activated. Stem cells can be activated allowing increased tissue repair and healing. In dermatology, LLLT has beneficial effects on wrinkles, acne scars, hypertrophic scars, and healing of burns. LLLT can reduce UV damage both as a treatment and as a prophylaxis. In pigmentary disorders such as vitiligo, LLLT can increase pigmentation by stimulating melanocyte proliferation and reduce depigmentation by inhibiting autoimmunity. Inflammatory diseases such as psoriasis and acne can also benefit. The non-invasive nature and almost complete absence of side-effects encourages further testing in dermatology. PMID:24049929

Basic Science and Clinical Application of Stem Cells in Veterinary Medicine

NASA Astrophysics Data System (ADS)

Ribitsch, I.; Burk, J.; Delling, U.; Geißler, C.; Gittel, C.; Jülke, H.; Brehm, W.

Stem cells play an important role in veterinary medicine in different ways. Currently several stem cell therapies for animal patients are being developed and some, like the treatment of equine tendinopathies with mesenchymal stem cells (MSCs), have already successfully entered the market. Moreover, animal models are widely used to study the properties and potential of stem cells for possible future applications in human medicine. Therefore, in the young and emerging field of stem cell research, human and veterinary medicine are intrinsically tied to one another. Many of the pioneering innovations in the field of stem cell research are achieved by cooperating teams of human and veterinary medical scientists.

CD34+ Testicular Stromal Cells Support Long-Term Expansion of Embryonic and Adult Stem and Progenitor Cells

PubMed Central

Kim, Jiyeon; Seandel, Marco; Falciatori, Ilaria; Wen, Duancheng; Rafii, Shahin

2010-01-01

Stem cells reside in specialized microenvironments created by supporting stromal cells that orchestrate self-renewal and lineage-specific differentiation. However, the precise identity of the cellular and molecular pathways that support self-renewal of stem cells is not known. For example, long-term culture of prototypical stem cells, such as adult spermatogonial stem and progenitor cells (SPCs), in vitro has been impeded by the lack of an optimal stromal cell line that initiates and sustains proliferation of these cells. Indeed, current methods, including the use of mouse embryonic fibroblasts (MEFs), have not been efficient and have generally led to inconsistent results. Here, we report the establishment of a novel CD34-positive cell line, referred to as JK1, derived from mouse testicular stromal cells that not only facilitated long-term SPC culture but also allowed faithful generation of SPCs and multipotent stem cells. SPCs generated on JK1 maintained key features of germ line stem cells, including expression of PLZF, DAZL, and GCNA. Furthermore, these feeders also promoted the long-term cultivation of other types of primitive cells including multi-potent adult spermatogonial-derived stem cells, pluripotent murine embryonic stem cells, and embryonic germ cells derived from primordial germ cells. Stem cells could be passaged serially and still maintained expression of characteristic markers such as OCT4 and NANOG in vitro, as well as the ability to generate all three germ layers in vivo. These results indicate that the JK1 cell line is capable of promoting long-term culture of primitive cells. As such, this cell line allows for identification of stromal-derived factors that support long-term proliferation of various types of stem cells and constitutes a convenient alternative to other types of feeder layers. PMID:18669907

Personalizing Stem Cell Research and Therapy: The Arduous Road Ahead or Missed Opportunity?

PubMed Central

Patel, S.A.; King, C.C.; Lim, P.K.; Habiba, U.; Dave, M.; Porecha, R.; Rameshwar, P.

2010-01-01

The euphoria of stem cell therapy has diminished, allowing scientists, clinicians and the general public to seriously re-examine how and what types of stem cells would effectively repair damaged tissue, prevent further tissue damage and/or replace lost cells. Importantly, there is a growing recognition that there are substantial person-to-person differences in the outcome of stem cell therapy. Even though the small molecule pharmaceuticals have long remained a primary focus of the personalized medicine research, individualized or targeted use of stem cells to suit a particular individual could help forecast potential failures of the therapy or identify, early on, the individuals who might benefit from stem cell interventions. This would however demand collaboration among several specialties such as pharmacology, immunology, genomics and transplantation medicine. Such transdisciplinary work could also inform how best to achieve efficient and predictable stem cell migration to sites of tissue damage, thereby facilitating tissue repair. This paper discusses the possibility of polarizing immune responses to rationalize and individualize therapy with stem cell interventions, since generalized “one-size-fits-all” therapy is difficult to achieve in the face of the diverse complexities posed by stem cell biology. We also present the challenges to stem cell delivery in the context of the host related factors. Although we focus on the mesenchymal stem cells in this paper, the overarching rationale can be extrapolated to other types of stem cells as well. Hence, the broader purpose of this paper is to initiate a dialogue within the personalized medicine community by expanding the scope of inquiry in the field from pharmaceuticals to stem cells and related cell-based health interventions. PMID:20563265

Genetics of Gonadal Stem Cell Renewal

PubMed Central

Greenspan, Leah Joy; de Cuevas, Margaret

2015-01-01

Stem cells are necessary for the maintenance of many adult tissues. Signals within the stem cell microenvironment, or niche, regulate the self-renewal and differentiation capability of these cells. Misregulation of these signals through mutation or damage can lead to overgrowth or depletion of different stem cell pools. In this review, we focus on the Drosophila testis and ovary, both of which contain well-defined niches, as well as the mouse testis, which has become a more approachable stem cell system with recent technical advances. We discuss the signals that regulate gonadal stem cells in their niches, how these signals mediate self-renewal and differentiation under homeostatic conditions, and how stress, whether from mutations or damage, can cause changes in cell fate and drive stem cell competition. PMID:26355592

Multifaceted Roles of Connexin 43 in Stem Cell Niches.

PubMed

Genet, Nafiisha; Bhatt, Neha; Bourdieu, Antonin; Hirschi, Karen K

2018-01-01

Considerable progress has been made in the field of stem cell research; nonetheless, the use of stem cells for regenerative medicine therapies, for either endogenous tissue repair or cellular grafts post injury, remains a challenge. To better understand how to maintain stem cell potential in vivo and promote differentiation ex vivo, it is fundamentally important to elucidate the interactions between stem cells and their surrounding partners within their distinct niches. Among the vast array of proteins depicted as mediators for cell-to-cell interactions, connexin-comprised gap junctions play pivotal roles in the regulation of stem cell fate both in vivo and in vitro. This review summarizes and illustrates the current knowledge regarding the multifaceted roles of Cx43, specifically, in various stem cell niches.

Cell of Origin and Cancer Stem Cell Phenotype in Medulloblastomas

DTIC Science & Technology

2015-07-01

dominant role over some oncogene function.In addition, we recently reported that cancer stem cells (CSCs)- stem cell like cells in tumors that have stem ... cell properties and tumor initiating ability- retain epigenetic memories of their cells of origin (Chow et al., 2014). We showed that CSCs derived from

Detection of Ultra-Rare Mitochondrial Mutations in Breast Stem Cells by Duplex Sequencing.

PubMed

Ahn, Eun Hyun; Hirohata, Kensen; Kohrn, Brendan F; Fox, Edward J; Chang, Chia-Cheng; Loeb, Lawrence A

2015-01-01

Long-lived adult stem cells could accumulate non-repaired DNA damage or mutations that increase the risk of tumor formation. To date, studies on mutations in stem cells have concentrated on clonal (homoplasmic) mutations and have not focused on rarely occurring stochastic mutations that may accumulate during stem cell dormancy. A major challenge in investigating these rare mutations is that conventional next generation sequencing (NGS) methods have high error rates. We have established a new method termed Duplex Sequencing (DS), which detects mutations with unprecedented accuracy. We present a comprehensive analysis of mitochondrial DNA mutations in human breast normal stem cells and non-stem cells using DS. The vast majority of mutations occur at low frequency and are not detectable by NGS. The most prevalent point mutation types are the C>T/G>A and A>G/T>C transitions. The mutations exhibit a strand bias with higher prevalence of G>A, T>C, and A>C mutations on the light strand of the mitochondrial genome. The overall rare mutation frequency is significantly lower in stem cells than in the corresponding non-stem cells. We have identified common and unique non-homoplasmic mutations between non-stem and stem cells that include new mutations which have not been reported previously. Four mutations found within the MT-ND5 gene (m.12684G>A, m.12705C>T, m.13095T>C, m.13105A>G) are present in all groups of stem and non-stem cells. Two mutations (m.8567T>C, m.10547C>G) are found only in non-stem cells. This first genome-wide analysis of mitochondrial DNA mutations may aid in characterizing human breast normal epithelial cells and serve as a reference for cancer stem cell mutation profiles.

Mesenchymal Stem Cells From Bone Marrow, Adipose Tissue, and Lung Tissue Differentially Mitigate Lung and Distal Organ Damage in Experimental Acute Respiratory Distress Syndrome.

PubMed

Silva, Johnatas D; Lopes-Pacheco, Miquéias; Paz, Ana H R; Cruz, Fernanda F; Melo, Elga B; de Oliveira, Milena V; Xisto, Débora G; Capelozzi, Vera L; Morales, Marcelo M; Pelosi, Paolo; Cirne-Lima, Elizabeth; Rocco, Patricia R M

2018-02-01

Mesenchymal stem cells-based therapies have shown promising effects in experimental acute respiratory distress syndrome. Different mesenchymal stem cells sources may result in diverse effects in respiratory diseases; however, there is no information regarding the best source of mesenchymal stem cells to treat pulmonary acute respiratory distress syndrome. We tested the hypothesis that mesenchymal stem cells derived from bone marrow, adipose tissue, and lung tissue would lead to different beneficial effects on lung and distal organ damage in experimental pulmonary acute respiratory distress syndrome. Animal study and primary cell culture. Laboratory investigation. Seventy-five Wistar rats. Wistar rats received saline (control) or Escherichia coli lipopolysaccharide (acute respiratory distress syndrome) intratracheally. On day 2, acute respiratory distress syndrome animals were further randomized to receive saline or bone marrow, adipose tissue, or lung tissue mesenchymal stem cells (1 × 10 cells) IV. Lung mechanics, histology, and protein levels of inflammatory mediators and growth factors were analyzed 5 days after mesenchymal stem cells administration. RAW 264.7 cells (a macrophage cell line) were incubated with lipopolysaccharide followed by coculture or not with bone marrow, adipose tissue, and lung tissue mesenchymal stem cells (10 cells/mL medium). Regardless of mesenchymal stem cells source, cells administration improved lung function and reduced alveolar collapse, tissue cellularity, collagen, and elastic fiber content in lung tissue, as well as decreased apoptotic cell counts in liver. Bone marrow and adipose tissue mesenchymal stem cells administration also reduced levels of tumor necrosis factor-α, interleukin-1β, keratinocyte-derived chemokine, transforming growth factor-β, and vascular endothelial growth factor, as well as apoptotic cell counts in lung and kidney, while increasing expression of keratinocyte growth factor in lung tissue. Additionally, mesenchymal stem cells differently modulated the secretion of biomarkers by macrophages depending on their source. Mesenchymal stem cells from different sources led to variable responses in lungs and distal organs. Bone marrow and adipose tissue mesenchymal stem cells yielded greater beneficial effects than lung tissue mesenchymal stem cells. These findings may be regarded as promising in clinical trials.

The Role of Tumor Associated Macrophage in Recurrent Growth of Tumor Stem Cell

DTIC Science & Technology

2011-09-01

recent cancer stem cell (CSC) theory, recurrent tumor must arise from a dormant tumor stem cell whose re-growth is triggered by shifting of...microenvironment. This project aims at clarifying the roles of TAM in recurrent growth of dormant stem cell in breast cancer. We hypothesize that the balance of...dormancy and recurrence is determined by the ability of the tumor stem cells to recruit TAM which in turn promotes self-renewal of the stem cell . We

3D modeling of cancer stem cell niche

PubMed Central

He, Jun; Xiong, Li; Li, Qinglong; Lin, Liangwu; Miao, Xiongying; Yan, Shichao; Hong, Zhangyong; Yang, Leping; Wen, Yu; Deng, Xiyun

2018-01-01

Cancer stem cells reside in a distinct microenvironment called niche. The reciprocal interactions between cancer stem cells and niche contribute to the maintenance and enrichment of cancer stem cells. In order to simulate the interactions between cancer stem cells and niche, three-dimensional models have been developed. These in vitro culture systems recapitulate the spatial dimension, cellular heterogeneity, and the molecular networks of the tumor microenvironment and show great promise in elucidating the pathophysiology of cancer stem cells and designing more clinically relavant treatment modalites. PMID:29416698

Stem cells for the treatment of neurodegenerative diseases

PubMed Central

2010-01-01

Stem cells offer an enormous pool of resources for the understanding of the human body. One proposed use of stem cells has been as an autologous therapy. The use of stem cells for neurodegenerative diseases has become of interest. Clinical applications of stem cells for Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and multiple sclerosis will increase in the coming years, and although great care will need to be taken when moving forward with prospective treatments, the application of stem cells is highly promising. PMID:21144012

Stem Cell-based Tissue Engineering Approaches for Musculoskeletal Regeneration

PubMed Central

Brown, Patrick T.; Handorf, Andrew M.; Jeon, Won Bae; Li, Wan-Ju

2014-01-01

The field of regenerative medicine and tissue engineering is an ever evolving field that holds promise in treating numerous musculoskeletal diseases and injuries. An important impetus in the development of the field was the discovery and implementation of stem cells. The utilization of mesenchymal stem cells, and later embryonic and induced pluripotent stem cells, opens new arenas for tissue engineering and presents the potential of developing stem cell-based therapies for disease treatment. Multipotent and pluripotent stem cells can produce various lineage tissues, and allow for derivation of a tissue that may be comprised of multiple cell types. As the field grows, the combination of biomaterial scaffolds and bioreactors provides methods to create an environment for stem cells that better represent their microenvironment for new tissue formation. As technologies for the fabrication of biomaterial scaffolds advance, the ability of scaffolds to modulate stem cell behavior advances as well. The composition of scaffolds could be of natural or synthetic materials and could be tailored to enhance cell self-renewal and/or direct cell fates. In addition to biomaterial scaffolds, studies of tissue development and cellular microenvironments have determined other factors, such as growth factors and oxygen tension, that are crucial to the regulation of stem cell activity. The overarching goal of stem cell-based tissue engineering research is to precisely control differentiation of stem cells in culture. In this article, we review current developments in tissue engineering, focusing on several stem cell sources, induction factors including growth factors, oxygen tension, biomaterials, and mechanical stimulation, and the internal and external regulatory mechanisms that govern proliferation and differentiation. PMID:23432679

Stem Cells for Skeletal Muscle Tissue Engineering.

PubMed

Pantelic, Molly N; Larkin, Lisa M

2018-04-19

Volumetric muscle loss (VML) is a debilitating condition wherein muscle loss overwhelms the body's normal physiological repair mechanism. VML is particularly common among military service members who have sustained war injuries. Because of the high social and medical cost associated with VML and suboptimal current surgical treatments, there is great interest in developing better VML therapies. Skeletal muscle tissue engineering (SMTE) is a promising alternative to traditional VML surgical treatments that use autogenic tissue grafts, and rather uses isolated stem cells with myogenic potential to generate de novo skeletal muscle tissues to treat VML. Satellite cells are the native precursors to skeletal muscle tissue, and are thus the most commonly studied starting source for SMTE. However, satellite cells are difficult to isolate and purify, and it is presently unknown whether they would be a practical source in clinical SMTE applications. Alternative myogenic stem cells, including adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, perivascular stem cells, umbilical cord mesenchymal stem cells, induced pluripotent stem cells, and embryonic stem cells, each have myogenic potential and have been identified as possible starting sources for SMTE, although they have yet to be studied in detail for this purpose. These alternative stem cell varieties offer unique advantages and disadvantages that are worth exploring further to advance the SMTE field toward highly functional, safe, and practical VML treatments. The following review summarizes the current state of satellite cell-based SMTE, details the properties and practical advantages of alternative myogenic stem cells, and offers guidance to tissue engineers on how alternative myogenic stem cells can be incorporated into SMTE research.

Ocular stem cells: a status update!

PubMed Central

2014-01-01

Stem cells are unspecialized cells that have been a major focus of the field of regenerative medicine, opening new frontiers and regarded as the future of medicine. The ophthalmology branch of the medical sciences was the first to directly benefit from stem cells for regenerative treatment. The success stories of regenerative medicine in ophthalmology can be attributed to its accessibility, ease of follow-up and the eye being an immune-privileged organ. Cell-based therapies using stem cells from the ciliary body, iris and sclera are still in animal experimental stages but show potential for replacing degenerated photoreceptors. Limbal, corneal and conjunctival stem cells are still limited for use only for surface reconstruction, although they might have potential beyond this. Iris pigment epithelial, ciliary body epithelial and choroidal epithelial stem cells in laboratory studies have shown some promise for retinal or neural tissue replacement. Trabecular meshwork, orbital and sclera stem cells have properties identical to cells of mesenchymal origin but their potential has yet to be experimentally determined and validated. Retinal and retinal pigment epithelium stem cells remain the most sought out stem cells for curing retinal degenerative disorders, although treatments using them have resulted in variable outcomes. The functional aspects of the therapeutic application of lenticular stem cells are not known and need further attention. Recently, embryonic stem cell-derived retinal pigment epithelium has been used for treating patients with Stargardts disease and age-related macular degeneration. Overall, the different stem cells residing in different components of the eye have shown some success in clinical and animal studies in the field of regenerative medicine. PMID:25158127

Maintenance of sweat glands by stem cells located in the acral epithelium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohe, Shuichi; Department of Dermatology, Kansai Medical University, Osaka 573-1010; Tanaka, Toshihiro

The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexalmore » epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes. - Highlights: • The acral epithelium have two types of stem cells. • Lgr6-positive cells are rapid-cycling, short-term stem cells. • Bmi1-positive cells are slow-cycling stem cells that act as reserver stem cells. • Lgr5 may be a useful sweat gland marker in mice.« less

Challenges and Opportunities to Harnessing the (Hematopoietic) Stem Cell Niche

PubMed Central

Choi, Ji Sun; Harley, Brendan A. C.

2016-01-01

In our body, stem cells reside in a microenvironment termed the niche. While the exact composition and therefore the level of complexity of a stem cell niche can vary significantly tissue-to-tissue, the stem cell niche microenvironment is dynamic, typically containing spatial and temporal variations in both cellular, extracellular matrix, and biomolecular components. This complex flow of secreted or bound biomolecules, cytokines, extracellular matrix components, and cellular constituents all contribute to the regulation of stem cell fate specification events, making engineering approaches at the nano- and micro-scale of particular interest for creating an artificial niche environment in vitro. Recent advances in fabrication approaches have enabled biomedical researchers to capture and recreate the complexity of stem cell niche microenvironments in vitro. Such engineered platforms show promise as a means to enhance our understanding of the mechanisms underlying niche-mediated stem cell regulation as well as offer opportunities to precisely control stem cell expansion and differentiation events for clinical applications. While these principles generally apply to all adult stem cells and niches, in this review, we focus on recent developments in engineering synthetic niche microenvironments for one of the best-characterized stem cell populations, hematopoietic stem cells (HSC). Specifically, we highlight recent advances in platforms designed to facilitate the extrinsic control of HSC fate decisions. PMID:27134819

[Morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates].

PubMed

Isaeva, V V; Akhmadieva, A V; Aleksandriova, Ia N; Shukaliuk, A I

2009-01-01

Published and original data indicating evolutionary conservation of the morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates are reviewed. Stem cells were studied in representatives of five animal types: archeocytes in sponge Oscarella malakhovi (Porifera), large interstitial cells in colonial hydroid Obelia longissima (Cnidaria), neoblasts in an asexual race of planarian Girardia tigrina (Platyhelmintes), stem cells in colonial rhizocephalans Peltogasterella gracilis, Polyascus polygenea, and Thylacoplethus isaevae (Arthropoda), and colonial ascidian Botryllus tuberatus (Chordata). Stem cells in animals of such diverse taxa feature the presence of germinal granules, are positive for proliferating cell nuclear antigen, demonstrate alkaline phosphatase activity (at marker of embryonic stem cells and primary germ cells in vertebrates), and rhizocephalan stem cells express the vasa-like gene (such genes are expressed in germline cells of different metazoans). The self-renewing pool of stem cells is the cellular basis of the reproductive strategy including sexual and asexual reproduction.

The neural stem cell fate determinant TLX promotes tumorigenesis and genesis of cells resembling glioma stem cells.

PubMed

Park, Hyo-Jung; Kim, Jun-Kyum; Jeon, Hye-Min; Oh, Se-Yeong; Kim, Sung-Hak; Nam, Do-Hyun; Kim, Hyunggee

2010-11-01

A growing body of evidence indicates that deregulation of stem cell fate determinants is a hallmark of many types of malignancies. The neural stem cell fate determinant TLX plays a pivotal role in neurogenesis in the adult brain by maintaining neural stem cells. Here, we report a tumorigenic role of TLX in brain tumor initiation and progression. Increased TLX expression was observed in a number of glioma cells and glioma stem cells, and correlated with poor survival of patients with gliomas. Ectopic expression of TLX in the U87MG glioma cell line and Ink4a/Arf-deficient mouse astrocytes (Ink4a/Arf(-/-) astrocytes) induced cell proliferation with a concomitant increase in cyclin D expression, and accelerated foci formation in soft agar and tumor formation in in vivo transplantation assays. Furthermore, overexpression of TLX in Ink4a/Arf(-/-) astrocytes inhibited cell migration and invasion and promoted neurosphere formation and Nestin expression, which are hallmark characteristics of glioma stem cells, under stem cell culture conditions. Our results indicate that TLX is involved in glioma stem cell genesis and represents a potential therapeutic target for this type of malignancy.

First steps to define murine amniotic fluid stem cell microenvironment.

PubMed

Bertin, E; Piccoli, M; Franzin, C; Spiro, G; Donà, S; Dedja, A; Schiavi, F; Taschin, E; Bonaldo, P; Braghetta, P; De Coppi, P; Pozzobon, M

2016-11-15

Stem cell niche refers to the microenvironment where stem cells reside in living organisms. Several elements define the niche and regulate stem cell characteristics, such as stromal support cells, gap junctions, soluble factors, extracellular matrix proteins, blood vessels and neural inputs. In the last years, different studies demonstrated the presence of cKit + cells in human and murine amniotic fluid, which have been defined as amniotic fluid stem (AFS) cells. Firstly, we characterized the murine cKit + cells present both in the amniotic fluid and in the amnion. Secondly, to analyze the AFS cell microenvironment, we injected murine YFP + embryonic stem cells (ESC) into the amniotic fluid of E13.5 wild type embryos. Four days after transplantation we found that YFP + sorted cells maintained the expression of pluripotency markers and that ESC adherent to the amnion were more similar to original ESC in respect to those isolated from the amniotic fluid. Moreover, cytokines evaluation and oxygen concentration analysis revealed in this microenvironment the presence of factors that are considered key regulators in stem cell niches. This is the first indication that AFS cells reside in a microenvironment that possess specific characteristics able to maintain stemness of resident and exogenous stem cells.

Identification and isolation of adult liver stem/progenitor cells.

PubMed

Tanaka, Minoru; Miyajima, Atsushi

2012-01-01

Hepatoblasts are considered to be liver stem/progenitor cells in the fetus because they propagate and differentiate into two types of liver epithelial cells, hepatocytes and cholangiocytes. In adults, oval cells that emerge in severely injured liver are considered facultative hepatic stem/progenitor cells. However, the nature of oval cells has remained unclear for long time due to the lack of a method to isolate them. It has also been unclear whether liver stem/progenitor cells exist in normal adult liver. Recently, we and others have successfully identified oval cells and adult liver stem/progenitor cells. Here, we describe the identification and isolation of mouse liver stem/progenitor cells by utilizing antibodies against specific cell surface marker molecules.

Evaluation of the maintenance of stemness, viability, and differentiation potential of gingiva-derived stem-cell spheroids.

PubMed

Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2017-05-01

Gingiva-derived stem cells have been applied for tissue-engineering purposes and may be considered a favorable source of mesenchymal stem cells as harvesting stem cells from the mandible or maxilla may be performed with ease under local anesthesia. The present study was performed to fabricate stem-cell spheroids using concave microwells and to evaluate the maintenance of stemness, viability, and differentiation potential. Gingiva-derived stem cells were isolated, and the stem cells of 4×10 5 (group A) or 8×10 5 (group B) cells were seeded into polydimethylsiloxane-based, concave micromolds with 600 µm diameters. The morphology of the microspheres and the change of the diameters of the spheroids were evaluated. The viability of spheroids was qualitatively analyzed via Live/Dead kit assay. A cell viability analysis was performed on days 1, 3, 6, and 12 with Cell Counting Kit-8. The maintenance of stemness was evaluated with immunocytochemical staining using SSEA-4, TRA-1-60(R) (positive markers), and SSEA-1 (negative marker). Osteogenic, adipogenic, and chondrogenic differentiation potential was evaluated by incubating spheroids in osteogenic, adipogenic and chondrogenic induction medium, respectively. The gingiva-derived stem cells formed spheroids in the concave microwells. The diameters of the spheroids were larger in group A than in group B. The majority of cells in the spheroids emitted green fluorescence, indicating the presence of live cells at day 6. At day 12, the majority of cells in the spheroids emitted green fluorescence, and a small portion of red fluorescence was also noted, which indicated the presence of dead cells. The spheroids were positive for the stem-cell markers SSEA-4 and TRA-1-60(R) and were negative for SSEA-1, suggesting that these spheroids primarily contained undifferentiated human stem cells. Osteogenic, adipogenic, and chondrogenic differentiation was more evident with an increase of incubation time: Mineralized extracellular deposits were observed following Alizarin Red S staining at days 14 and 21; oil globules were increased at day 18 when compared with day 6; and Alcian blue staining was more evident at day 18 when compared with day 6. Within the limits of this study, stem-cell spheroids from gingival cells maintained the stemness, viability, and differentiation potential during the experimental periods. This method may be applied for a promising strategy for stem-cell therapy.

Evaluation of the osteogenic differentiation of gingiva-derived stem cells grown on culture plates or in stem cell spheroids: Comparison of two- and three-dimensional cultures.

PubMed

Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2017-09-01

Three-dimensional cell culture systems provide a convenient in vitro model for the study of complex cell-cell and cell-matrix interactions in the absence of exogenous substrates. The current study aimed to evaluate the osteogenic differentiation potential of gingiva-derived stem cells cultured in two-dimensional or three-dimensional systems. To the best of our knowledge, the present study is the first to compare the growth of gingiva-derived stem cells in monolayer culture to a three-dimensional culture system with microwells. For three-dimensional culture, gingiva-derived stem cells were isolated and seeded into polydimethylsiloxane-based concave micromolds. Alkaline phosphatase activity and alizarin red S staining assays were then performed to evaluate osteogenesis and the degree of mineralization, respectively. Stem cell spheroids had a significantly increased level of alkaline phosphatase activity and mineralization compared with cells from the two-dimensional culture. In addition, an increase in mineralized deposits was observed with an increase in the loading cell number. The results of present study indicate that gingiva-derived stem cell spheroids exhibit an increased osteogenic potential compared with stem cells from two-dimensional culture. This highlights the potential of three-dimensional culture systems using gingiva-derived stem cells for regenerative medicine applications requiring stem cells with osteogenic potential.

[Embryonic stem cells and therapeutic cloning].

PubMed

Sunde, A; Eftedal, I

2001-08-30

Increased interest in the therapeutic use of human stem cells has emerged following significant progress in ongoing research. The cloning of a sheep, the isolation of human embryonic stem cells, and the discovery that adult stem cells may be reprogrammed taken together give substance to hopes that novel principles of treatment may be developed for a variety of serious conditions. Embryonic stem cells are derived from pre-embryos at the blastocyst stage and may give rise to all bodily tissues and cells. Animal models have demonstrated that embryonic stem cells when transplanted into adult hosts may differentiate and develop into cells and tissues applicable for treatment of a variety of conditions, including Parkinson's disease, multiple sclerosis, spinal injuries, cardiac stroke and cancer. Transplanted embryonic stem cells are exposed to immune reactions similar to those acting on organ transplants, hence immunosuppression of the recipient is generally required. It is, however, possible to obtain embryonic stem cells that are genetically identical to the patient's own cells by means of therapeutic cloning techniques. The nucleus from a somatic cell is transferred into an egg after removal of the egg's own genetic material. Under specific condition the egg will use genetic information from the somatic cell in organising the formation of a blastocyst which in turn generates embryonic stem cells. These cells have a genetic composition identical to that of the patient and are suitable for stem cell therapy.

Development of bioengineering system for stem cell proliferation

NASA Astrophysics Data System (ADS)

Park, H. S.; Shah, R.; Shah, C.

2016-08-01

From last decades, intensive research in the field of stem cells proliferation had been promoted due to the unique property of stem cells to self-renew themselves into multiples and has potential to replicate into an organ or tissues and so it's highly demanding though challenging. Bioreactor, a mechanical device, works as a womb for stem cell proliferation by providing nutritious environment for the proper growth of stem cells. Various factors affecting stem cells growth are the bioreactor mechanism, feeding of continuous nutrients, healthy environment, etc., but it always remains a challenge for controlling biological parameters. The present paper unveils the design of mechanical device commonly known as bioreactor in tissues engineering and biotech field, use for proliferation of stem cells and imparts the proper growing condition for stem cells. This high functional bioreactor provides automation mixing of cell culture and stem cells. This design operates in conjunction with mechanism of reciprocating motion. Compare to commercial bioreactors, this proposed design is more convenient, easy to operate and less maintenance is required as bioreactor culture bag is made of polyethylene which is single use purpose. Development of this bioengineering system will be beneficial for better growth and expansion of stem cell

Stem Cell Therapy in Bladder Dysfunction: Where Are We? And Where Do We Have to Go?

PubMed Central

Lee, Sang-Rae; Song, Yun Seob; Lee, Hong Jun

2013-01-01

To date, stem cell therapy for the bladder has been conducted mainly on an experimental basis in the areas of bladder dysfunction. The therapeutic efficacy of stem cells was originally thought to be derived from their ability to differentiate into various cell types. Studies about stem cell therapy for bladder dysfunction have been limited to an experimental basis and have been less focused than bladder regeneration. Bladder dysfunction was listed in MESH as “urinary bladder neck obstruction”, “urinary bladder, overactive”, and “urinary bladder, neurogenic”. Using those keywords, several articles were searched and studied. The bladder dysfunction model includes bladder outlet obstruction, cryoinjured, diabetes, ischemia, and spinal cord injury. Adipose derived stem cells (ADSCs), bone marrow stem cells (BMSCs), and skeletal muscle derived stem cells (SkMSCs) are used for transplantation to treat bladder dysfunction. The main mechanisms of stem cells to reconstitute or restore bladder dysfunction are migration, differentiation, and paracrine effects. The aim of this study is to review the stem cell therapy for bladder dysfunction and to provide the status of stem cell therapy for bladder dysfunction. PMID:24151627

Mesenchymal stem cells induce dermal fibroblast responses to injury

PubMed Central

Smith, Andria N.; Willis, Elise; Chan, Vincent T.; Muffley, Lara A.; Isik, F. Frank; Gibran, Nicole S.; Hocking, Anne M.

2009-01-01

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury. PMID:19666021

Application of stem cells in targeted therapy of breast cancer: a systematic review.

PubMed

Madjd, Zahra; Gheytanchi, Elmira; Erfani, Elham; Asadi-Lari, Mohsen

2013-01-01

The aim of this systematic review was to investigate whether stem cells could be effectively applied in targeted therapy of breast cancer. A systematic literature search was performed for original articles published from January 2007 until May 2012. Nine studies met the inclusion criteria for phase I or II clinical trials, of which three used stem cells as vehicles, two trials used autologous hematopoetic stem cells and in four trials cancer stem cells were targeted. Mesenchymal stem cells (MSCs) were applied as cellular vehicles to transfer therapeutic agents. Cell therapy with MSC can successfully target resistant cancers. Cancer stem cells were selectively targeted via a proteasome-dependent suicide gene leading to tumor regression. Wnt/β-catenin signaling pathway has been also evidenced to be an attractive CSC-target. This systematic review focused on two different concepts of stem cells and breast cancer marking a turning point in the trials that applied stem cells as cellular vehicles for targeted delivery therapy as well as CSC-targeted therapies. Applying stem cells as targeted therapy could be an effective therapeutic approach for treatment of breast cancer in the clinic and in therapeutic marketing; however this needs to be confirmed with further clinical investigations.

Applications of stem cell biology to oculoplastic surgery.

PubMed

Daniel, Michael G; Wu, Albert Y

2016-09-01

The review examines the utility of stem cell biology in ophthalmology and oculoplastic surgery. The applicability of stem cell biology varies across a range of different subfields within ophthalmology and oculoplastic surgery. Resident stem cells have been identified in the lacrimal gland, corneal limbus, orbital fat, and muscles of the eye, and can potentially be applied for in-vitro cell and organ cultures with the intent of disease modeling and transplants. The discovery of adipocyte-derived stem cells offered a potentially powerful tool for a variety of oculoplastic applications, such as wound healing, skin rejuvenation, and burn therapeutics. Several groups are currently identifying new uses for stem cells in oculoplastic surgery. The need for stem cell treatment spans a wide array of subfields within ophthalmology, ranging from reconstruction of the eyelid to the generation of artificial lacrimal glands and oncological therapeutics. The advent of induced pluripotent stem cells opened the realm of regenerative medicine, making the modeling of patient-specific diseases a possibility. The identification and characterization of endogenous stem cell populations in the eye makes it possible to obtain specific tissues through induced pluripotent stem cells differentiation, permitting their use in transplants for oculoplastic surgery.

[Bioethical challenges of stem cell tourism].

PubMed

Ventura-Juncá, Patricio; Erices, Alejandro; Santos, Manuel J

2013-08-01

Stem cells have drawn extraordinary attention from scientists and the general public due to their potential to generate effective therapies for incurable diseases. At the same time, the production of embryonic stem cells involves a serious ethical issue concerning the destruction of human embryos. Although adult stem cells and induced pluripotential cells do not pose this ethical objection, there are other bioethical challenges common to all types of stem cells related particularly to the clinical use of stem cells. Their clinical use should be based on clinical trials, and in special situations, medical innovation, both of which have particular ethical dimensions. The media has raised unfounded expectations in patients and the public about the real clinical benefits of stem cells. At the same time, the number of unregulated clinics is increasing around the world, making direct offers through Internet of unproven stem cell therapies that attract desperate patients that have not found solutions in standard medicine. This is what is called stem cells tourism. This article reviews this situation, its consequences and the need for international cooperation to establish effective regulations to prevent the exploitation of patients and to endanger the prestige of legitimate stem cell research.

[Breakthrough in research on pluripotent stem cells and their application in medicine].

PubMed

Valdimarsdóttir, Guðrún; Richter, Anne

2015-12-01

Embryonic stem cells are, as the name indicates, isolated from embryos. They are pluripotent cells which can be maintained undifferentiated or induced to differentiate into any cell type of the body. In 1998 the first isolation of human embryonic stem cells was successful and they became an interesting source for stem cell regenerative medicine. Only 8 years later pluripotent stem cells were generated by reprogramming somatic cells into induced pluripotent stem cells (iPSCs). This was a revolution in the way people thought of cell commitment during development. Since then, a lot of research has been done in understanding the molecular biology of pluripotent stem cells. iPSCs can be generated from somatic cells of a patient and therefore have the same genome. Hence, iPSCs have great potential application in medicine, as they can be utilized in disease modelling, drug screening and cell replacement therapy.

Cell motion predicts human epidermal stemness

PubMed Central

Toki, Fujio; Tate, Sota; Imai, Matome; Matsushita, Natsuki; Shiraishi, Ken; Sayama, Koji; Toki, Hiroshi; Higashiyama, Shigeki

2015-01-01

Image-based identification of cultured stem cells and noninvasive evaluation of their proliferative capacity advance cell therapy and stem cell research. Here we demonstrate that human keratinocyte stem cells can be identified in situ by analyzing cell motion during their cultivation. Modeling experiments suggested that the clonal type of cultured human clonogenic keratinocytes can be efficiently determined by analysis of early cell movement. Image analysis experiments demonstrated that keratinocyte stem cells indeed display a unique rotational movement that can be identified as early as the two-cell stage colony. We also demonstrate that α6 integrin is required for both rotational and collective cell motion. Our experiments provide, for the first time, strong evidence that cell motion and epidermal stemness are linked. We conclude that early identification of human keratinocyte stem cells by image analysis of cell movement is a valid parameter for quality control of cultured keratinocytes for transplantation. PMID:25897083

Limbal Stem Cell Deficiency and Treatment with Stem Cell Transplantation.

PubMed

Barut Selver, Özlem; Yağcı, Ayşe; Eğrilmez, Sait; Gürdal, Mehmet; Palamar, Melis; Çavuşoğlu, Türker; Ateş, Utku; Veral, Ali; Güven, Çağrı; Wolosin, Jose Mario

2017-10-01

The cornea is the outermost tissue of the eye and it must be transparent for the maintenance of good visual function. The superficial epithelium of the cornea, which is renewed continuously by corneal stem cells, plays a critical role in the permanence of this transparency. These stem cells are localized at the cornea-conjunctival transition zone, referred to as the limbus. When this zone is affected/destroyed, limbal stem cell deficiency ensues. Loss of limbal stem cell function allows colonization of the corneal surface by conjunctival epithelium. Over 6 million people worldwide are affected by corneal blindness, and limbal stem cell deficiency is one of the main causes. Fortunately, it is becoming possible to recover vision by autologous transplantation of limbal cells obtained from the contralateral eye in unilateral cases. Due to the potential risks to the donor eye, only a small amount of tissue can be obtained, in which only 1-2% of the limbal epithelial cells are actually limbal stem cells. Vigorous attempts are being made to expand limbal stem cells in culture to preserve or even enrich the stem cell population. Ex vivo expanded limbal stem cell treatment in limbal stem cell deficiency was first reported in 1997. In the 20 years since, various protocols have been developed for the cultivation of limbal epithelial cells. It is still not clear which method promotes effective stem cell viability and this remains a subject of ongoing research. The most preferred technique for limbal cell culture is the explant culture model. In this approach, a small donor eye limbal biopsy is placed as an explant onto a biocompatible substrate (preferably human amniotic membrane) for expansion. The outgrowth (cultivated limbal epithelial cells) is then surgically transferred to the recipient eye. Due to changing regulations concerning cell-based therapy, the implementation of cultivated limbal epithelial transplantation in accordance with Good Laboratory Practice using xenobiotic-free systems is becoming widely accepted both in Turkey and worldwide.

"Mouse Clone Model" for evaluating the immunogenicity and tumorigenicity of pluripotent stem cells.

PubMed

Zhang, Gang; Zhang, Yi

2015-12-18

To investigate the immune-rejection and tumor-formation potentials of induced pluripotent stem cells and other stem cells, we devised a model-designated the "Mouse Clone Model"-which combined the theory of somatic animal cloning, tetraploid complementation, and induced pluripotent stem cells to demonstrate the applicability of stem cells for transplantation therapy.

Elucidating the identity and behavior of spermatogenic stem cells in the mouse testis.

PubMed

Yoshida, Shosei

2012-09-01

Spermatogenesis in mice and other mammalians is supported by a robust stem cell system. Stem cells maintain themselves and continue to produce progeny that will differentiate into sperm over a long period. The pioneering studies conducted from the 1950s to the 1970s, which were based largely on extensive morphological analyses, have established the fundamentals of mammalian spermatogenesis and its stem cells. The prevailing so-called A(single) (A(s)) model, which was originally established in 1971, proposes that singly isolated A(s) spermatogonia are in fact the stem cells. In 1994, the first functional stem cell assay was established based on the formation of repopulating colonies after transplantation in germ cell-depleted host testes, which substantially accelerated the understanding of spermatogenic stem cells. However, because testicular tissues are dissociated into single-cell suspension before transplantation, it was impossible to evaluate the A(s) and other classical models solely by this technique. From 2007 onwards, functional assessment of stem cells without destroying the tissue architecture has become feasible by means of pulse-labeling and live-imaging strategies. Results obtained from these experiments have been challenging the classical thought of stem cells, in which stem cells are a limited number of specialized cells undergoing asymmetric division to produce one self-renewing and one differentiating daughter cells. In contrast, the emerging data suggest that an extended and heterogeneous population of cells exhibiting different degrees of self-renewing and differentiating probabilities forms a reversible, flexible, and stochastic stem cell system as a population. These features may lead to establishment of a more universal principle on stem cells that is shared by other systems.

Quality Assurance in Stem Cell Banking: Emphasis on Embryonic and Induced Pluripotent Stem Cell Banking.

PubMed

Kallur, Therése; Blomberg, Pontus; Stenfelt, Sonya; Tryggvason, Kristian; Hovatta, Outi

2017-01-01

For quality assurance (QA) in stem cell banking, a planned system is needed to ensure that the banked products, stem cells, meet the standards required for research, clinical use, and commercial biotechnological applications. QA is process oriented, avoids, or minimizes unacceptable product defects, and particularly encompasses the management and operational systems of the bank, as well as the ethical and legal frameworks. Quality control (QC ) is product oriented and therefore ensures the stem cells of a bank are what they are expected to be. Testing is for controlling, not assuring, product quality, and is therefore a part of QC , not QA. Like QA, QC is essential for banking cells for quality research and translational application (Schwartz et al., Lancet 379:713-720, 2012). Human embryonic stem cells (hESCs), as cells derived from donated supernumerary embryos from in vitro fertilization (IVF) therapy, are different from other stem cell types in resulting from an embryo that has had two donors . This imposes important ethical and legal constraints on the utility of the cells, which, together with quite specific culture conditions, require special attention in the QA system. Importantly, although the origin and derivation of induced pluripotent stem cells (iPSCs ) differ from that of hESCs, many of the principles of QA for hESC banking are applicable to iPSC banking (Stacey et al., Cell Stem Cell 13:385-388, 2013). Furthermore, despite differences between the legal and regulatory frameworks for hESC and iPSC banking between different countries, the requirements for QA are being harmonized (Stacey et al., Cell Stem Cell 13:385-388, 2013; International Stem Cell Banking Initiative, Stem Cell Rev 5:301-314, 2009).

A natural stem cell therapy? How novel findings and biotechnology clarify the ethics of stem cell research

PubMed Central

Patel, P

2006-01-01

The natural replacement of damaged cells by stem cells occurs actively and often in adult tissues, especially rapidly dividing cells such as blood cells. An exciting case in Boston, however, posits a kind of natural stem cell therapy provided to a mother by her fetus—long after the fetus is born. Because there is a profound lack of medical intervention, this therapy seems natural enough and is unlikely to be morally suspect. Nevertheless, we feel morally uncertain when we consider giving this type of therapy to patients who would not naturally receive it. Much has been written about the ethics of stem cell research and therapy; this paper will focus on how recent advances in biotechnology and biological understandings of development narrow the debate. Here, the author briefly reviews current stem cell research practices, revisits the natural stem cell therapy case for moral evaluation, and ultimately demonstrates the importance of permissible stem cell research and therapy, even absent an agreement about the definition of when embryonic life begins. Although one promising technology, blighted ovum utilisation, uses fertilised but developmentally bankrupt eggs, it is argued that utilisation of unfertilised eggs to derive totipotent stem cells obviates the moral debate over when life begins. There are two existing technologies that fulfil this criterion: somatic cell nuclear transfer and parthenogenic stem cell derivation. Although these technologies are far from therapeutic, concerns over the morality of embryonic stem cell derivation should not hinder their advancement. PMID:16574879

[Cell therapy for Parkinson's disease: III. Neonatal, fetal and embryonic stem cell-based applications].

PubMed

Anisimov, S V

2009-01-01

Motor dysfunctions in Parkinson's disease are believed to be primarily due to the degeneration of dopaminergic neurons located in the substantia nigra pars compacta. Numerous cell replacement therapy approaches have been developed and tested, including these based on donor cell transplantation (embryonic and adult tissue-derived), adult mesenchymal stem cells (hMSCs)-, neural stem cells (hNSCs)- and finally human embryonic stem cells (hESCs)-based. Despite the progress achieved, numerous difficulties prevent wider practical application of stem cell-based therapy approaches for the treatment of Parkinson's disease. Among the latter, ethical, safety and technical issues stand out. Current series of reviews (Cell therapy for Parkinson's disease: I. Embryonic and adult donor tissue-based applications; II. Adult stem cell-based applications; III. Neonatal, fetal and embryonic stem cell-based applications; IV. Risks and future trends) aims providing a balanced and updated view on various issues associated with cell types (including stem cells) in regards to their potential in the treatment of Parkinson's disease. Essential features of the individual cell subtypes, principles of available cell handling protocols, transplantation, and safety issues are discussed extensively.

Research progress on the proliferation and differentiation of

NASA Astrophysics Data System (ADS)

An, A.; Tan, B.

Space environments such as microgravity magnetic field radiation and heavy metal ions affects the development and functions of human and mammalian cells To study these influences and the corresponding metabolisms is in favour of knowing about the development and differentiation process of organism cells In recent years researches on the differentiation of stem cells induced in vitro provide a new pathway for the repair of tissue lesion and therapy of human diseases Stem cells are potential in capable of differentiating into different functional cells But there has no reliable methods to induce the stem cells differentiating forward specific cells and to gain enough cells for transplantation which limited their application on clinical therapy It has been indicated that microgravity influenced embryonic development hematopoietic and mesenchymal stem cells and so on Hematopoietic stem cell migration and its differentiation were affected by microgravity The specific differentiation of hematopoietic stem cells was inhibited under microgravity The expression of proteins regulating cell cycle period also changed Mesenchymal stem cells provide a source of cells for the repair of musculoskeletal tissue in ground experiment While under microgravity the proliferation and differentiation of mesenchymal stem cells were influenced along with the differentiated cells function changed Furthermore in the differentiation process of stem cells under microgravity the mechanism of signal transport was also affected and the specific differentiation

Epithelial-mesenchymal transition transcription factors control pluripotent adult stem cell migration in vivo in planarians

PubMed Central

Abnave, Prasad; Aboukhatwa, Ellen; Kosaka, Nobuyoshi; Thompson, James; Hill, Mark A.

2017-01-01

Migration of stem cells underpins the physiology of metazoan animals. For tissues to be maintained, stem cells and their progeny must migrate and differentiate in the correct positions. This need is even more acute after tissue damage by wounding or pathogenic infection. Inappropriate migration also underpins metastasis. Despite this, few mechanistic studies address stem cell migration during repair or homeostasis in adult tissues. Here, we present a shielded X-ray irradiation assay that allows us to follow stem cell migration in planarians. We demonstrate the use of this system to study the molecular control of stem cell migration and show that snail-1, snail-2 and zeb-1 EMT transcription factor homologs are necessary for cell migration to wound sites and for the establishment of migratory cell morphology. We also observed that stem cells undergo homeostatic migration to anterior regions that lack local stem cells, in the absence of injury, maintaining tissue homeostasis. This requires the polarity determinant notum. Our work establishes planarians as a suitable model for further in-depth study of the processes controlling stem cell migration in vivo. PMID:28893948

Prostate Cancer Stem Cells: Viewing Signaling Cascades at a Finer Resolution.

PubMed

Lin, Xiukun; Farooqi, Ammad Ahmad; Qureshi, Muhammad Zahid; Romero, Mirna Azalea; Tabassum, Sobia; Ismail, Muhammad

2016-06-01

It is becoming characteristically more understandable that within tumor cells, there lies a sub-population of tumor cells with "stem cell" like properties and remarkable ability of self-renewal. Many features of these self-renewing cells are comparable with normal stem cells and are termed as "cancer stem cells". Accumulating experimentally verified data has started to scratch the surface of spatio-temporally dysregulated intracellular signaling cascades in the biology of prostate cancer stem cells. We partition this multicomponent review into how different signaling cascades operate in cancer stem cells and how bioactive ingredients isolated from natural sources may modulate signaling network.

A planarian p53 homolog regulates proliferation and self-renewal in adult stem cell lineages.

PubMed

Pearson, Bret J; Sánchez Alvarado, Alejandro

2010-01-01

The functions of adult stem cells and tumor suppressor genes are known to intersect. However, when and how tumor suppressors function in the lineages produced by adult stem cells is unknown. With a large population of stem cells that can be manipulated and studied in vivo, the freshwater planarian is an ideal system with which to investigate these questions. Here, we focus on the tumor suppressor p53, homologs of which have no known role in stem cell biology in any invertebrate examined thus far. Planaria have a single p53 family member, Smed-p53, which is predominantly expressed in newly made stem cell progeny. When Smed-p53 is targeted by RNAi, the stem cell population increases at the expense of progeny, resulting in hyper-proliferation. However, ultimately the stem cell population fails to self-renew. Our results suggest that prior to the vertebrates, an ancestral p53-like molecule already had functions in stem cell proliferation control and self-renewal.

Safe genetic modification of cardiac stem cells using a site-specific integration technique.

PubMed

Lan, Feng; Liu, Junwei; Narsinh, Kazim H; Hu, Shijun; Han, Leng; Lee, Andrew S; Karow, Marisa; Nguyen, Patricia K; Nag, Divya; Calos, Michele P; Robbins, Robert C; Wu, Joseph C

2012-09-11

Human cardiac progenitor cells (hCPCs) are a promising cell source for regenerative repair after myocardial infarction. Exploitation of their full therapeutic potential may require stable genetic modification of the cells ex vivo. Safe genetic engineering of stem cells, using facile methods for site-specific integration of transgenes into known genomic contexts, would significantly enhance the overall safety and efficacy of cellular therapy in a variety of clinical contexts. We used the phiC31 site-specific recombinase to achieve targeted integration of a triple fusion reporter gene into a known chromosomal context in hCPCs and human endothelial cells. Stable expression of the reporter gene from its unique chromosomal integration site resulted in no discernible genomic instability or adverse changes in cell phenotype. Namely, phiC31-modified hCPCs were unchanged in their differentiation propensity, cellular proliferative rate, and global gene expression profile when compared with unaltered control hCPCs. Expression of the triple fusion reporter gene enabled multimodal assessment of cell fate in vitro and in vivo using fluorescence microscopy, bioluminescence imaging, and positron emission tomography. Intramyocardial transplantation of genetically modified hCPCs resulted in significant improvement in myocardial function 2 weeks after cell delivery, as assessed by echocardiography (P=0.002) and MRI (P=0.001). We also demonstrated the feasibility and therapeutic efficacy of genetically modifying differentiated human endothelial cells, which enhanced hind limb perfusion (P<0.05 at day 7 and 14 after transplantation) on laser Doppler imaging. The phiC31 integrase genomic modification system is a safe, efficient tool to enable site-specific integration of reporter transgenes in progenitor and differentiated cell types.

Generation of male differentiated germ cells from various types of stem cells.

PubMed

Hou, Jingmei; Yang, Shi; Yang, Hao; Liu, Yang; Liu, Yun; Hai, Yanan; Chen, Zheng; Guo, Ying; Gong, Yuehua; Gao, Wei-Qiang; Li, Zheng; He, Zuping

2014-06-01

Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10-15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells 'especially functional spermatids' is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients. © 2014 Society for Reproduction and Fertility.

Spatial Light Modulators with Arbitrary Quantum Well Profiles

DTIC Science & Technology

1991-01-14

vertical cavity surface emitting lasers ( VCSEL ) is also...aDlications stemming from the research effort. An application of the MBE compositional grading technique to vertical cavity surface emitting lasers was described in section 2e. G. Other statements ... cavity surface emitting laser ( VCSEL ). This uses compositionally graded Bragg reflectors to reduce the electrical resistance of the mirrors

Integrating physiological regulation with stem cell and tissue homeostasis

PubMed Central

Nakada, Daisuke; Levi, Boaz P.; Morrison, Sean J.

2015-01-01

Summary Stem cells are uniquely able to self-renew, to undergo multilineage differentiation, and to persist throughout life in a number of tissues. Stem cells are regulated by a combination of shared and tissue-specific mechanisms and are distinguished from restricted progenitors by differences in transcriptional and epigenetic regulation. Emerging evidence suggests that other aspects of cellular physiology, including mitosis, signal transduction, and metabolic regulation also differ between stem cells and their progeny. These differences may allow stem cells to be regulated independently of differentiated cells in response to circadian rhythms, changes in metabolism, diet, exercise, mating, aging, infection, and disease. This allows stem cells to sustain homeostasis or to remodel relevant tissues in response to physiological change. Stem cells are therefore not only regulated by short-range signals that maintain homeostasis within their tissue of origin, but also by long-range signals that integrate stem cell function with systemic physiology. PMID:21609826

mTOR plays critical roles in pancreatic cancer stem cells through specific and stemness-related functions

NASA Astrophysics Data System (ADS)

Matsubara, Shyuichiro; Ding, Qiang; Miyazaki, Yumi; Kuwahata, Taisaku; Tsukasa, Koichiro; Takao, Sonshin

2013-11-01

Pancreatic cancer is characterized by near-universal mutations in KRAS. The mammalian target of rapamycin (mTOR), which functions downstream of RAS, has divergent effects on stem cells. In the present study, we investigated the significance of the mTOR pathway in maintaining the properties of pancreatic cancer stem cells. The mTOR inhibitor, rapamycin, reduced the viability of CD133+ pancreatic cancer cells and sphere formation which is an index of self-renewal of stem-like cells, indicating that the mTOR pathway functions to maintain cancer stem-like cells. Further, rapamycin had different effects on CD133+ cells compared to cyclopamine which is an inhibitor of the Hedgehog pathway. Thus, the mTOR pathway has a distinct role although both pathways maintain pancreatic cancer stem cells. Therefore, mTOR might be a promising target to eliminate pancreatic cancer stem cells.

Effects of enamel matrix derivative on the proliferation and osteogenic differentiation of human gingival mesenchymal stem cells

PubMed Central

2014-01-01

Introduction Gingiva-derived mesenchymal stem cells (GMSCs) have recently been harvested and applied for rebuilding lost periodontal tissue. Enamel matrix derivative (EMD) has been used for periodontal regeneration and the formation of new cementum with inserting collagen fibers; however, alveolar bone formation is minimal. Recently, EMD has been shown to enhance the proliferation and mineralization of human bone marrow mesenchymal stem cells. Because the gingival flap is the major component to cover the surgical wound, the effects of EMD on the proliferation and mineralization of GMSCs were evaluated in the present study. Methods After single cell suspension, the GMSCs were isolated from the connective tissues of human gingiva. The colony forming unit assay of the isolated GMSCs was measured. The expression of stem cell markers was examined by flow cytometry. The cellular telomerase activity was identified by polymerase chain reaction (PCR). The osteogenic, adipogenic and neural differentiations of the GMSCs were further examined. The cell proliferation was determined by MTS assay, while the expression of mRNA and protein for mineralization (including core binding factor alpha, cbfα-1; alkaline phosphatase, ALP; and osteocalcin, OC; ameloblastin, AMBN) were analyzed by real time-PCR, enzyme activity and confocal laser scanning microscopy. Results The cell colonies could be easily identified and the colony forming rates and the telomerase activities increased after passaging. The GMSCs expressed high levels of surface markers for CD73, CD90, and CD105, but showed low expression of STRO-1. Osteogenic, adipogenic and neural differentiations were successfully induced. The proliferation of GMSCs was increased after EMD treatment. ALP mRNA was significantly augmented by treating with EMD for 3 hours, whereas AMBN mRNA was significantly increased at 6 hours after EMD treatment. The gene expression of OC was enhanced at the dose of 100 μg/ml EMD at day 3. Increased protein expression for cbfα-1 at day 3, for ALP at day 5 and 7, and for OC at week 4 after the EMD treatments were observed. Conclusions Human GMSCs could be successfully isolated and identified. EMD treatments not only induced the proliferation of GMSCs but also enhanced their osteogenic differentiation after induction. PMID:24739572

Leech segmental repeats develop normally in the absence of signals from either anterior or posterior segments

NASA Technical Reports Server (NTRS)

Seaver, E. C.; Shankland, M.

2000-01-01

We have investigated whether the development of segmental repeats is autonomous in the embryo of the leech Helobdella robusta. The segmental tissues of the germinal band arise from progeny of five stem cells called teloblasts. Asymmetric divisions of the teloblasts form chains of segment founder cells (called primary blast cells) that divide in a stereotypical manner to produce differentiated descendants. Using two distinct techniques, we have looked for potential interactions between neighboring blast cell clones along the anterior-posterior axis. In one technique, we prevented the birth of primary blast cells by injection of DNase I into the teloblast, thereby depriving the last blast cell produced before the ablation of its normal posterior neighbors. We also ablated single blast cells with a laser microbeam, which allowed us to assess potential signals acting on either more anterior or more posterior primary blast cell clones. Our results suggest that interactions along the anterior-posterior axis between neighboring primary blast cell clones are not required for development of normal segmental organization within the blast cell clone. We also examined the possibility that blast cells receive redundant signals from both anterior and posterior neighboring clones and that either is sufficient for normal development. Using double blast cell laser ablations to isolate a primary blast cell clone by removal of both its anterior and its posterior neighbor, we found that the isolated clone still develops normally. These results reveal that the fundamental segmental repeat in the leech embryo, the primary blast cell clone, can develop normally in the apparent absence of signals from adjacent repeats along the anterior-posterior axis.

Analysis for apoptosis and necrosis on adipocytes, stromal vascular fraction, and adipose-derived stem cells in human lipoaspirates after liposuction.

PubMed

Wang, Wei Z; Fang, Xin-Hua; Williams, Shelley J; Stephenson, Linda L; Baynosa, Richard C; Wong, Nancy; Khiabani, Kayvan T; Zamboni, William A

2013-01-01

Adipose-derived stem cells have become the most studied adult stem cells. The authors examined the apoptosis and necrosis rates for adipocyte, stromal vascular fraction, and adipose-derived stem cells in fresh human lipoaspirates. Human lipoaspirate (n = 8) was harvested using a standard liposuction technique. Stromal vascular fraction cells were separated from adipocytes and cultured to obtain purified adipose-derived stem cells. A panel of stem cell markers was used to identify the surface phenotypes of cultured adipose-derived stem cells. Three distinct stem cell subpopulations (CD90/CD45, CD105/CD45, and CD34/CD31) were selected from the stromal vascular fraction. Apoptosis and necrosis were determined by annexin V/propidium iodide assay and analyzed by flow cytometry. The cultured adipose-derived stem cells demonstrated long-term proliferation and differentiation evidenced by cell doubling time and positive staining with oil red O and alkaline phosphatase. Isolated from lipoaspirates, adipocytes exhibited 19.7 ± 3.7 percent apoptosis and 1.1 ± 0.3 percent necrosis; stromal vascular fraction cells revealed 22.0 ± 6.3 percent of apoptosis and 11.2 ± 1.9 percent of necrosis; stromal vascular fraction cells had a higher rate of necrosis than adipocytes (p < 0.05). Among the stromal vascular fraction cells, 51.1 ± 3.7 percent expressed CD90/CD45, 7.5 ± 1.0 percent expressed CD105/CD45, and 26.4 ± 3.8 percent expressed CD34/CD31. CD34/CD31 adipose-derived stem cells had lower rates of apoptosis and necrosis compared with CD105/CD45 adipose-derived stem cells (p < 0.05). Adipose-derived stem cells had a higher rate of apoptosis and necrosis than adipocytes. However, the extent of apoptosis and necrosis was significantly different among adipose-derived stem cell subpopulations.

Genome editing: a robust technology for human stem cells.

PubMed

Chandrasekaran, Arun Pandian; Song, Minjung; Ramakrishna, Suresh

2017-09-01

Human pluripotent stem cells comprise induced pluripotent and embryonic stem cells, which have tremendous potential for biological and therapeutic applications. The development of efficient technologies for the targeted genome alteration of stem cells in disease models is a prerequisite for utilizing stem cells to their full potential. Genome editing of stem cells is possible with the help of synthetic nucleases that facilitate site-specific modification of a gene of interest. Recent advances in genome editing techniques have improved the efficiency and speed of the development of stem cells for human disease models. Zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system are powerful tools for editing DNA at specific loci. Here, we discuss recent technological advances in genome editing with site-specific nucleases in human stem cells.

Engineering Approaches Toward Deconstructing and Controlling the Stem Cell Environment

PubMed Central

Edalat, Faramarz; Bae, Hojae; Manoucheri, Sam; Cha, Jae Min; Khademhosseini, Ali

2012-01-01

Stem cell-based therapeutics have become a vital component in tissue engineering and regenerative medicine. The microenvironment within which stem cells reside, i.e. the niche, plays a crucial role in regulating stem cell self-renewal and differentiation. However, current biological techniques lack the means to recapitulate the complexity of this microenvironment. Nano- and microengineered materials offer innovative methods to: (1) deconstruct the stem cell niche to understand the effects of individual elements; (2) construct complex tissue-like structures resembling the niche to better predict and control cellular processes; and (3) transplant stem cells or activate endogenous stem cell populations for regeneration of aged or diseased tissues. Here, we highlight some of the latest advances in this field and discuss future applications and directions of the use of nano- and microtechnologies for stem cell engineering. PMID:22101755

Engineering approaches toward deconstructing and controlling the stem cell environment.

PubMed

Edalat, Faramarz; Bae, Hojae; Manoucheri, Sam; Cha, Jae Min; Khademhosseini, Ali

2012-06-01

Stem cell-based therapeutics have become a vital component in tissue engineering and regenerative medicine. The microenvironment within which stem cells reside, i.e., the niche, plays a crucial role in regulating stem cell self-renewal and differentiation. However, current biological techniques lack the means to recapitulate the complexity of this microenvironment. Nano- and microengineered materials offer innovative methods to (1) deconstruct the stem cell niche to understand the effects of individual elements; (2) construct complex tissue-like structures resembling the niche to better predict and control cellular processes; and (3) transplant stem cells or activate endogenous stem cell populations for regeneration of aged or diseased tissues. In this article, we highlight some of the latest advances in this field and discuss future applications and directions of the use of nano- and microtechnologies for stem cell engineering.

Stem cells: science, policy, and ethics

PubMed Central

Fischbach, Gerald D.; Fischbach, Ruth L.

2004-01-01

Human embryonic stem cells offer the promise of a new regenerative medicine in which damaged adult cells can be replaced with new cells. Research is needed to determine the most viable stem cell lines and reliable ways to promote the differentiation of pluripotent stem cells into specific cell types (neurons, muscle cells, etc.). To create new cell lines, it is necessary to destroy preimplantation blastocysts. This has led to an intense debate that threatens to limit embryonic stem cell research. The profound ethical issues raised call for informed, dispassionate debate. PMID:15545983