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Research Containing: Cell Proliferation

Change in skin physiological parameters in space–report on and results of the first study on man

by on 9 June 2015in Technology Development & Demonstration No comment

Astronauts often show skin reactions in space. Systematic tests, e.g. with noninvasive skin physiological test methods, have not yet been done. In an interdisciplinary cooperation, a test series with skin physiological measurements was carried out before, during and after a long-term mission in the International Space Station. The hydration of the stratum corneum (Corneometer), transepidermal water loss (Tewameter), and the surface structure of the skin (SkinVisiometer) were measured. In order to record cutaneous states, the suction elasticity was measured (Cutometer), and an ultrasound measurement with 20 MHz (DermaScan) was also made. In addition, one measuring field of the two inner forearms was treated with a skin care emulsion. There were indications of a delayed epidermal proliferation of the cells, which would correspond to the clinical symptoms. Hydration and TEWL values are improved by respective skin care. On the cutaneous level, the elasticity measurements and the ultrasound picture showed results which correspond to a significant loss of elasticity of the skin. Further examinations are necessary to validate these preliminary results.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/18663342

A biaxial rotating bioreactor for the culture of fetal mesenchymal stem cells for bone tissue engineering

by on 9 June 2015in Biology & Biotechnology No comment

The generation of effective tissue engineered bone grafts requires efficient exchange of nutrients and mechanical stimulus. Bioreactors provide a manner in which this can be achieved. We have recently developed a biaxial rotating bioreactor with efficient fluidics through in-silico modeling. Here we investigated its performance for generation of highly osteogenic bone graft using polycaprolactone-tricalcium phosphate (PCL-TCP) scaffolds seeded with human fetal mesenchymal stem cell (hfMSC). hfMSC scaffolds were cultured in either bioreactor or static cultures, with assessment of cellular viability, proliferation and osteogenic differentiation it) vitro and also after transplantation into immunodeficient mice. Compared to static culture, bioreactor-cultured hfMSC scaffolds reached cellular confluence earlier (day 7 vs. day 28), with greater cellularity (2x, p < 0.01), and maintained high cellular viability in the core, which was 2000 Inn from the surface. In addition, bioreactor culture was associated with greater osteogenic induction, ALP expression (1.5x P < 0.01), calcium deposition (5.5x, p < 0.001) and bony nodule formation on SEM, and in-vivo ectopic bone formation in immunodeficient mice (3.2x, p < 0.001) compared with static-cultured scaffolds. The use of biaxial bioreactor here allowed the maintenance of cellular viability beyond the limits of conventional diffusion, with increased proliferation and osteogenic differentiation both in vitro and in vivo, suggesting its utility for bone tissue engineering applications. (C) 2009 Elsevier Ltd. All rights reserved.

Related URLs:
<Go to ISI>://WOS:000264953900005

Regulation of adult human mesenchymal stem cells into osteogenic and chondrogenic lineages by different bioreactor systems

by on 9 June 2015in Biology & Biotechnology No comment

The aim of this study was to examine the feasibility of expanding and regulating mesenchymal stem cells (MSCs) from isolated adult human bone marrow mononuclear cells, seeded on gelatin-hyaluronic acid biomatrices, and then to quantitatively compare the gene expression in three different culture systems. Individual and interactive effects of model system parameters on construct structure, function, and molecular properties were evaluated. The results showed that these adult human MSCs even at old age not only expressed primitive mesenchymal cell markers but also maintained a high level of colony-forming efficiency and were capable of differentiating into osteoblasts, chondrocytes, and adipocytes upon appropriate inductions. After 21 days of culture, we found that the osteoblastic and chondrocytic lineage gene expression were earlier and higher expressed in spinner flask bioreactor culture group when compared with the static culture and rotating wall vessel reactor culture. The osteogenic lineage proteins type I collagen, alkaline phosphatase, and osteocalcin were strongly stained in histological sections of spinner flask bioreactor culture, whereas these were less detected in the other two groups, especially in rotating wall vessel reactor culture. As for the markers associated with the chondrogenic lineage differentiation proteins, type II collagen was apparently expressed in spinner flask culture group, while the expression of proteoglycans (aggreacan, decorin) in three culture conditions took the lead of each other. We conclude that the spinner flask bioreactor with appropriate induction medium reported in this study may be used to rapidly expand adult MSCs and is likely to possess better induction results toward osteoblastic and chondrocytic lineages. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 88A: 935-946, 2009

Related URLs:
<Go to ISI>://WOS:000263383700011

Effects of simulated microgravity on embryonic stem cells

by on 9 June 2015in Biology & Biotechnology No comment

There have been many studies on the biological effects of simulated microgravity (SMG) on differentiated cells or adult stem cells. However, there has been no systematic study on the effects of SMG on embryonic stem (ES) cells. In this study, we investigated various effects (including cell proliferation, cell cycle distribution, cell differentiation, cell adhesion, apoptosis, genomic integrity and DNA damage repair) of SMG on mouse embryonic stem (mES) cells. Mouse ES cells cultured under SMG condition had a significantly reduced total cell number compared with cells cultured under 1 g gravity (1G) condition. However, there was no significant difference in cell cycle distribution between SMG and 1G culture conditions, indicating that cell proliferation was not impaired significantly by SMG and was not a major factor contributing to the total cell number reduction. In contrast, a lower adhesion rate cultured under SMG condition contributed to the lower cell number in SMG. Our results also revealed that SMG alone could not induce DNA damage in mES cells while it could affect the repair of radiation-induced DNA lesions of mES cells. Taken together, mES cells were sensitive to SMG and the major alterations in cellular events were cell number expansion, adhesion rate decrease, increased apoptosis and delayed DNA repair progression, which are distinct from the responses of other types of cells to SMG.

Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed10&AN=2011698685
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:10.1371%2Fjournal.pone.0029214&issn=1932-6203&isbn=&volume=6&issue=12&spage=e29214&pages=&date=2011&title=PLoS+ONE&atitle=Effects+of+simulated+microgravity+on+embryonic+stem+cells&aulast=Wang&pid=%3Cauthor%3EWang+Y.%3C%2Fauthor%3E&%3CAN%3E2011698685%3C%2FAN%3E

Change in skin physiological parameters in space–report on and results of the first study on man

by on 9 June 2015in Biology & Biotechnology No comment

Astronauts often show skin reactions in space. Systematic tests, e.g. with noninvasive skin physiological test methods, have not yet been done. In an interdisciplinary cooperation, a test series with skin physiological measurements was carried out before, during and after a long-term mission in the International Space Station. The hydration of the stratum corneum (Corneometer), transepidermal water loss (Tewameter), and the surface structure of the skin (SkinVisiometer) were measured. In order to record cutaneous states, the suction elasticity was measured (Cutometer), and an ultrasound measurement with 20 MHz (DermaScan) was also made. In addition, one measuring field of the two inner forearms was treated with a skin care emulsion. There were indications of a delayed epidermal proliferation of the cells, which would correspond to the clinical symptoms. Hydration and TEWL values are improved by respective skin care. On the cutaneous level, the elasticity measurements and the ultrasound picture showed results which correspond to a significant loss of elasticity of the skin. Further examinations are necessary to validate these preliminary results.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/18663342

Effect of dynamic 3-D culture on proliferation, distribution, and osteogenic differentiation of human mesenchymal stem cells

by on 9 June 2015in Biology & Biotechnology No comment

Ex vivo engineering of autologous bone tissue as an alternative to bone grafting is a major clinical need. In the present study, we evaluated the effect of 3-D dynamic spinner flask culture on the proliferation, distribution, and differentiation of human mesenchymal stem cells (MSCs). Immortalized human MSCs were cultured on porous 75:25 PLGA scaffolds for Lip to 3 weeks. Dynamically cultured cell/scaffold constructs demonstrated a 20% increase in DNA content (21 days), enhanced ALP specific activity (7 days and 21 days), a more than tenfold higher Ca(2+) content (21 days), and significantly increased transcript levels of early osteogenesis markers (e.g., COL1A1, BMP2, RUNX-2) as compared with static culture. Despite the formation of a dense superficial cell layer, markedly increased cell ingrowth was observed by fluorescence microscopy on day 21. Furthermore, increased extracellular matrix deposition was visualized by scanning electron microscopy after I and 3 weeks of dynamic culture. The observed increased ingrowth and osteogenic differentiation of 3-D dynamically cultured human MSCs can be explained by generation of fluid shear stress and enhanced mass transport to the interior of the scaffold mimicking the native microenvironment of bone cells. This study provides evidence for the effectiveness of dynamic Culture of human MSCs during the initial phase of ex vivo osteogenesis. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 96-107, 2009

Related URLs:
<Go to ISI>://WOS:000263981300009

Simultaneous expansion and harvest of hematopoietic stem cells and mesenchymal stem cells derived from umbilical cord blood

by on 9 June 2015in Biology & Biotechnology No comment

The simultaneous expansion and harvest of hematopoietic stem cells and mesenchymal stem cells derived from umbilical cord blood were carried out using bioreactors. The co-culture of umbilical cord blood (UCB)-derived hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) was performed within spinner flasks and a rotating wall vessel (RWV) bioreactor using glass-coated styrene copolymer (GCSC) microcarriers. The medium used was composed of serum-free IMDM containing a cocktail of SCF 15 ng center dot mL(-1), FL 5 ng center dot mL(-1), TPO 6 ng center dot mL(-1), IL-3 15 ng center dot mL(-1), G-CSF 1 ng center dot mL(-1) and GM-CSF 5 ng center dot mL(-1). Accessory stromal cells derived from normal allogeneic adipose tissue were encapsulated in alginate-chitosan (AC) beads and used as feeding cells. The quality of the harvested UCB-HSCs and MSCs was assessed by immunophenotype analysis, methylcellulose colony and multi-lineage differentiation assays. After 12 days of culture, the fold-expansion of total cell numbers, colony-forming units (CFU-C), CD34(+)/CD45(+)/CD105(-) (HSCs) cells and CD34(-)/CD45(-)/CD105(+) (MSCs) cells using the RWV bioreactor were (3.7 +/- A 0.3)- , (5.1 +/- A 1.2)- , (5.2 +/- A 0.4)- , and (13.9 +/- A 1.2)-fold respectively, significantly better than those obtained using spinner flasks. Moreover, UCB-HSCs and UCB-MSCs could be easily separated by gravity sedimentation after the co-culture period as only UCB-MSCs adhered on to the microcarriers. Simultaneously, we found that the fibroblast-like cells growing on the surface of the GCSC microcarriers could be induced and differentiated towards the osteoblastic, chondrocytic and adipocytic lineages. Phenotypically, these cells were very similarly to the MSCs derived from bone marrow positively expressing the MSCs-related markers CD13, CD44, CD73 and CD105, while negatively expressing the HSCs-related markers CD34, CD45 and HLA-DR. It was thus demonstrated that the simultaneous expansion and harvest of UCB-HSCs and UCB-MSCs is possible to be accomplished using a feasible bioreactor culture system such as the RWV bioreactor with the support of GCSC microcarriers.

Related URLs:
<Go to ISI>://WOS:000284600400014

Properties of mechano-transduction via simulated microgravity and its effects on intracellular trafficking of VEGFR's

by on 9 June 2015in Biology & Biotechnology No comment

This study emphasizes the dynamical properties of mechanical loading via simulated microgravity, its effect on acute myeloid leukemia proliferation and hematopoietic stem cell (HSPC) growth and its implications in the area of tissue regeneration. Data presented illustrates that mechanical transduction changes the expression of humoral factors by facilitating paracrine/autocrine signalling, therefore modulating intracellular trafficking of tyrosine kinase receptors. Understanding mechano-transduction in the context of cell and tissue morphogenesis is the major focus of this study. The effects of external physiological stresses, such as blood flow, on several cellular subtypes seem to produce very intricate cellular responses. It is well accepted that mechanical loading plays an intrinsic and extrinsic influence on cell survival. This study shows how microgravity effects hematopoietic stem cells, and human leukemic cell proliferation and expression of its receptors that control cell survival, such as the tyrosine kinase vascular endothelial growth factor receptor-1, receptor-2 and receptor-3.

Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed10&AN=2012656922
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:&issn=1949-2553&isbn=&volume=3&issue=4&spage=426&pages=426-434&date=2012&title=Oncotarget&atitle=Properties+of+mechano-transduction+via+simulated+microgravity+and+its+effects+on+intracellular+trafficking+of+VEGFR%27s&aulast=Puca&pid=%3Cauthor%3EPuca+A.%3C%2Fauthor%3E&%3CAN%3E2012656922%3C%2FAN%3E

Activation of Nervous System Development Genes in Bone Marrow Derived Mesenchymal Stem Cells Following Spaceflight Exposure

by on 9 June 2015in Biology & Biotechnology No comment

Stalled cell division in precursor bone cells and reduced osteoblast function are considered responsible for the microgravity-induced bone loss observed during spaceflight. However, underlying molecular mechanisms remain unraveled. Having overcome technological difficulties associated with flying cells in a space mission, we present the first report on the behavior of the potentially osteogenic murine bone marrow stromal cells (BMSC) in a 3D culture system, flown inside the KUBIK aboard space mission ISS 12S (Soyuz TMA-8+Increment 13) from March 30 to April 8, 2006 (experiment "Stroma-2''). Flight 1g control cultures were performed in a centrifuge located within the payload. Ground controls were maintained on Earth in another KUBIK payload and in Petri dishes. Half of the cultures were stimulated with osteo-inductive medium. Differences in total RNA extracted suggested that cell proliferation was inhibited in flight samples. Affymetrix technology revealed that 1,599 genes changed expression after spaceflight exposure. A decreased expression of cell-cycle genes confirmed the inhibition of cell proliferation in space. Unexpectedly, most of the modulated expression was found in genes related to various processes of neural development, neuron morphogenesis, transmission of nerve impulse and synapse, raising the question on the lineage restriction in BMSC. J. Cell. Biochem. 111: 442-452, 2010. (C) 2010 Wiley-Liss, Inc.

Related URLs:
<Go to ISI>://WOS:000282482400020

The effect of gravitational force on limbal stem cell growth

by on 9 June 2015in Biology & Biotechnology No comment

Aim To evaluate the effect of gravity on corneal epithelial cell migration in vitro. Methods Fourteen donor peripheral corneoscleral rims were used. Twenty explants were chosen of which 10 were placed vertically and 10 were placed horizontally during culture. Analyses were performed to investigate the effect of gravity on epithelial growth by measuring the extent of epithelial cell growth above and below the horizontal meridian and counting the total number of cells using a haemocytometer. Results There was no statistically significant difference in cell growth between the explants that were placed horizontally and vertically. However, in the vertical explant group the cells grew preferentially towards the 6 o'clock direction, possibly as a result of gravity. Conclusions Gravitational forces may influence cell migration in vitro. This could be of significance in the planning of limbal transplantation, because a superior graft may be more likely to succeed than a gravitationally challenged inferior graft.

Related URLs:
<Go to ISI>://WOS:000305579000023