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

MicroRNAs in islet immunobiology and transplantation.

PubMed

Pileggi, Antonello; Klein, Dagmar; Fotino, Carmen; Bravo-Egaña, Valia; Rosero, Samuel; Doni, Marco; Podetta, Michele; Ricordi, Camillo; Molano, R Damaris; Pastori, Ricardo L

2013-12-01

The ultimate goal of diabetes therapy is the restoration of physiologic metabolic control. For type 1 diabetes, research efforts are focused on the prevention or early intervention to halt the autoimmune process and preserve β cell function. Replacement of pancreatic β cells via islet transplantation reestablishes physiologic β cell function in patients with diabetes. Emerging research shows that microRNAs (miRNAs), noncoding small RNA molecules produced by a newly discovered class of genes, negatively regulate gene expression. MiRNAs recognize and bind to partially complementary sequences of target messenger RNA (mRNA), regulating mRNA translation and affecting gene expression. Correlation between miRNA signatures and genome-wide RNA expression allows identification of multiple miRNA-mRNA pairs in biological processes. Because miRNAs target functionally related genes, they represent an exciting and indispensable approach for biomarkers and drug discovery. We are studying the role of miRNA in the context of islet immunobiology. Our research aims at understanding the mechanisms underlying pancreatic β cell loss and developing clinically relevant approaches for preservation and restoration of β cell function to treat insulin-dependent diabetes. Herein, we discuss some of our recent efforts related to the study of miRNA in islet inflammation and islet engraftment. Our working hypothesis is that modulation of the expression of specific microRNAs in the transplant microenvironment will be of assistance in enhancing islet engraftment and promoting long-term function.

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.

Terrestrial Microgravity Model and Threshold Gravity Simulation sing Magnetic Levitation

NASA Technical Reports Server (NTRS)

Ramachandran, N.

2005-01-01

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successiblly simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

Yeast for virus research

PubMed Central

Zhao, Richard Yuqi

2017-01-01

Budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are two popular model organisms for virus research. They are natural hosts for viruses as they carry their own indigenous viruses. Both yeasts have been used for studies of plant, animal and human viruses. Many positive sense (+) RNA viruses and some DNA viruses replicate with various levels in yeasts, thus allowing study of those viral activities during viral life cycle. Yeasts are single cell eukaryotic organisms. Hence, many of the fundamental cellular functions such as cell cycle regulation or programed cell death are highly conserved from yeasts to higher eukaryotes. Therefore, they are particularly suited to study the impact of those viral activities on related cellular activities during virus-host interactions. Yeasts present many unique advantages in virus research over high eukaryotes. Yeast cells are easy to maintain in the laboratory with relative short doubling time. They are non-biohazardous, genetically amendable with small genomes that permit genome-wide analysis of virologic and cellular functions. In this review, similarities and differences of these two yeasts are described. Studies of virologic activities such as viral translation, viral replication and genome-wide study of virus-cell interactions in yeasts are highlighted. Impacts of viral proteins on basic cellular functions such as cell cycle regulation and programed cell death are discussed. Potential applications of using yeasts as hosts to carry out functional analysis of small viral genome and to develop high throughput drug screening platform for the discovery of antiviral drugs are presented. PMID:29082230

Enhanced Heme Function and Mitochondrial Respiration Promote the Progression of Lung Cancer Cells

PubMed Central

Alam, Md Maksudul; Shah, Ajit; Cao, Thai M.; Sullivan, Laura A.; Brekken, Rolf; Zhang, Li

2013-01-01

Lung cancer is the leading cause of cancer-related mortality, and about 85% of the cases are non-small-cell lung cancer (NSCLC). Importantly, recent advance in cancer research suggests that altering cancer cell bioenergetics can provide an effective way to target such advanced cancer cells that have acquired mutations in multiple cellular regulators. This study aims to identify bioenergetic alterations in lung cancer cells by directly measuring and comparing key metabolic activities in a pair of cell lines representing normal and NSCLC cells developed from the same patient. We found that the rates of oxygen consumption and heme biosynthesis were intensified in NSCLC cells. Additionally, the NSCLC cells exhibited substantially increased levels in an array of proteins promoting heme synthesis, uptake and function. These proteins include the rate-limiting heme biosynthetic enzyme ALAS, transporter proteins HRG1 and HCP1 that are involved in heme uptake, and various types of oxygen-utilizing hemoproteins such as cytoglobin and cytochromes. Several types of human tumor xenografts also displayed increased levels of such proteins. Furthermore, we found that lowering heme biosynthesis and uptake, like lowering mitochondrial respiration, effectively reduced oxygen consumption, cancer cell proliferation, migration and colony formation. In contrast, lowering heme degradation does not have an effect on lung cancer cells. These results show that increased heme flux and function are a key feature of NSCLC cells. Further, increased generation and supply of heme and oxygen-utilizing hemoproteins in cancer cells will lead to intensified oxygen consumption and cellular energy production by mitochondrial respiration, which would fuel cancer cell proliferation and progression. The results show that inhibiting heme and respiratory function can effectively arrest the progression of lung cancer cells. Hence, understanding heme function can positively impact on research in lung cancer biology and therapeutics. PMID:23704904

[Correlation between four properties of traditional Chinese medicine and function of reversing multidrug resistance of tumor cells].

PubMed

Tang, Tao; Liao, Zheng-Gen; Dong, Wei; Zhang, Jing; Zhao, Guo-Wei; Guan, Xue-Jing; Liang, Xin-Li

2017-02-01

To study the correlation of four properties of traditional Chinese medicine and the function of reversing multidrug resistance (MDR) of tumor cells, with 580 herbs in Chinese Pharmacopoeia 2015 version as the research objects. CNKI, CBA, Wanfang, VIP, and PubMed were searched to screen the documents related to the reversal of MDR for collection, summarizing and analysis. The results of the research showed that a total of 114 species Chinese herbs had been reported to be associated with reversal of MDR in tumor cells. Among 15 Chinese herbs with heat nature, 7 herbs had the function of reversing MDR in tumor cells, accounting for 46.7%. Among the 48 herbs with cool nature, 12 herbs had the function of reversing MDR, accounting for 25%. Among the 211 herbs with cold nature, 46 herbs had the function of reversing MDR, accounting for 21.8%. Among the 179 herbs with warm nature, 34 herbs had the function of reversing MDR, accounting for 19%. Among the 127 herbs with neutral nature, 15 herbs had the function of reversing MDR, accounting for 11.8%. Through the analysis on the relationship between four properties of 114 kinds of traditional Chinese medicines and reversing multidrug resistance of tumor cells, this paper speculated that there was a certain correlation between four properties of traditional Chinese medicine and the function of reversing multidrug resistance of tumor cells. Copyright© by the Chinese Pharmaceutical Association.

Toward Optimal Cryopreservation and Storage for Achievement of High Cell Recovery and Maintenance of Cell Viability and T Cell Functionality.

PubMed

Angel, Stephanie; von Briesen, Hagen; Oh, Young-Joo; Baller, Marko K; Zimmermann, Heiko; Germann, Anja

2016-12-01

Cryopreservation of biological materials such as cells, tissues, and organs is a prevailing topic of high importance. It is employed not only in many research fields but also in the clinical area. Cryopreservation is of great importance for reproductive medicine and clinical studies, as well as for the development of vaccines. Peripheral blood mononuclear cells (PBMCs) are commonly used in vaccine research where comparable and reliable results between different research institutions and laboratories are of high importance. Whereas freezing and thawing processes are well studied, controlled, and standardized, storage conditions are often disregarded. To close this gap, we investigated the influence of suboptimal storage conditions during low-temperature storage on PBMC viability, recovery, and T cell functionality. For this purpose, PBMCs were isolated and exposed with help of a robotic system in a low-temperature environment from 0 up to 350 temperature fluctuation cycles in steps of 50 cycles to simulate storage conditions in large biorepositories with sample storage, removal, and sorting functions. After the simulation, the viability, recovery, and T cell functionality were analyzed to determine the number of temperature rises, which ultimately lead to significant cell damage. All studied parameters decreased with increasing number of temperature cycles. Sometimes after as little as only 50 temperature cycles, a significant effect was observed. These results are very important for all fields in which cell cryopreservation is employed, particularly for clinical and multicenter studies wherein the comparability and reproducibility of results play a crucial role. To obtain reliable results and to maintain the quality of the cells, not only the freezing and thawing processes but also the storage conditions should be controlled and standardized, and any deviations should be documented.

Nanotechnology & human stem cells: Applications in cardiogenesis and neurogenesis

NASA Astrophysics Data System (ADS)

Tomov, Martin L.

Human stem cell research holds an unprecedented promise to revolutionize the way we approach medicine and healthcare in general, moving us from a position of mostly addressing the symptoms to a state where treatments can focus on removing the underlying causes of a condition. Stem cell research can shed light into normal developmental pathways, as we are beginning to replicate them in a petri dish and can also be used to model diseases and abnormal conditions. Direct applications can range from finding cures for single or multigene diseases to demonstrating that we can replace these genes with a normal copy. We can even begin to model lifelong conditions such as aging by iPSC technology by relying on fetal, young, adult, and centenarian populations to provide insights into the process. We have also begun to understand the microenvironment in which specific cell populations reside. Being able to replicate the chemical, physical mechanical, and spatial needs of those cells, research groups are successfully generating full organs using cadaver scaffolds of heart and kidney, and there is promising research to reach the same success with other organs, such as the liver, and pancreas. Advances in those areas open an enormous potential to study organs, organoids, organ valves, tubes or other functional elements such as beating cardiomyocytes in vitro. There is also the need to evaluate the whole genome of induced and differentiated cells, with its myriad of interacting pathways. Bioinformatics can help our understanding of embryogenesis, organ differentiation and function. It can also help optimize our stem cell and bio-scaffold tools to advance closer to functional organs and tissues. Such a combination approach will also include pluripotency evaluation and multi-lineage differentiation, as well as platforms that may assist in cell therapies: 3D structures, micro-ribbons, directed patterning to name a few. There is now a clearer path forward with stem cell research than was ever before possible. My research has made fundamental contributions to the stem cell field by detailed analysis of uniformly generated 3D stem cell intermediates that are embryoid bodies. I have also contributed to the derivation of the first fully characterized ethnically diverse induced pluripotent stem cells from minority populations (ED-iPSCs), and advances in generating functional beating cardiomyocytes in vitro to aid cardiomyoplasty therapies. My work has also explored scaffolds for directing neural cell assembly or encouraging self-assembly for applications in CNS neurodegeneration, addiction, and spinal cord injury. These contributions to the field are outlined in my Specific Aims below and detailed in the chapters of my thesis.

Peripheral Glial Cells in the Development of Diabetic Neuropathy.

PubMed

Gonçalves, Nádia Pereira; Vægter, Christian Bjerggaard; Pallesen, Lone Tjener

2018-01-01

The global prevalence of diabetes is rapidly increasing, affecting more than half a billion individuals within the next few years. As diabetes negatively affects several physiological systems, this dramatic increase represents not only impaired quality of life on the individual level but also a huge socioeconomic challenge. One of the physiological consequences affecting up to half of diabetic patients is the progressive deterioration of the peripheral nervous system, resulting in spontaneous pain and eventually loss of sensory function, motor weakness, and organ dysfunctions. Despite intense research on the consequences of hyperglycemia on nerve functions, the biological mechanisms underlying diabetic neuropathy are still largely unknown, and treatment options lacking. Research has mainly focused directly on the neuronal component, presumably from the perspective that this is the functional signal-transmitting unit of the nerve. However, it is noteworthy that each single peripheral sensory neuron is intimately associated with numerous glial cells; the neuronal soma is completely enclosed by satellite glial cells and the length of the longest axons covered by at least 1,000 Schwann cells. The glial cells are vital for the neuron, but very little is still known about these cells in general and especially how they respond to diabetes in terms of altered neuronal support. We will discuss current knowledge of peripheral glial cells and argue that increased research in these cells is imperative for a better understanding of the mechanisms underlying diabetic neuropathy.

Peripheral Glial Cells in the Development of Diabetic Neuropathy

PubMed Central

Gonçalves, Nádia Pereira; Vægter, Christian Bjerggaard; Pallesen, Lone Tjener

2018-01-01

The global prevalence of diabetes is rapidly increasing, affecting more than half a billion individuals within the next few years. As diabetes negatively affects several physiological systems, this dramatic increase represents not only impaired quality of life on the individual level but also a huge socioeconomic challenge. One of the physiological consequences affecting up to half of diabetic patients is the progressive deterioration of the peripheral nervous system, resulting in spontaneous pain and eventually loss of sensory function, motor weakness, and organ dysfunctions. Despite intense research on the consequences of hyperglycemia on nerve functions, the biological mechanisms underlying diabetic neuropathy are still largely unknown, and treatment options lacking. Research has mainly focused directly on the neuronal component, presumably from the perspective that this is the functional signal-transmitting unit of the nerve. However, it is noteworthy that each single peripheral sensory neuron is intimately associated with numerous glial cells; the neuronal soma is completely enclosed by satellite glial cells and the length of the longest axons covered by at least 1,000 Schwann cells. The glial cells are vital for the neuron, but very little is still known about these cells in general and especially how they respond to diabetes in terms of altered neuronal support. We will discuss current knowledge of peripheral glial cells and argue that increased research in these cells is imperative for a better understanding of the mechanisms underlying diabetic neuropathy. PMID:29770116

2011 Plant Lipids: Structure, Metabolism, & Function Gordon Research Conference

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

Christopher Benning

2011-02-04

This is the second Gordon Research Conference on 'Plant Lipids: Structure, Metabolism & Function'. It covers current topics in lipid structure, metabolism and function in eukaryotic photosynthetic organisms including seed plants, algae, mosses and ferns. Work in photosynthetic bacteria is considered as well as it serves the understanding of specific aspects of lipid metabolism in plants. Breakthroughs are discussed in research on plant lipids as diverse as glycerolipids, sphingolipids, lipids of the cell surface, isoprenoids, fatty acids and their derivatives. The program covers nine concepts at the forefront of research under which afore mentioned plant lipid classes are discussed. Themore » goal is to integrate areas such as lipid signaling, basic lipid metabolism, membrane function, lipid analysis, and lipid engineering to achieve a high level of stimulating interaction among diverse researchers with interests in plant lipids. One Emphasis is on the dynamics and regulation of lipid metabolism during plant cell development and in response to environmental factors.« less

Quantitative and Functional Requirements for Bioluminescent Cancer Models.

PubMed

Feys, Lynn; Descamps, Benedicte; Vanhove, Christian; Vermeulen, Stefan; Vandesompele, J O; Vanderheyden, Katrien; Messens, Kathy; Bracke, Marc; De Wever, Olivier

2016-01-01

Bioluminescent cancer models are widely used but detailed quantification of the luciferase signal and functional comparison with a non-transfected control cell line are generally lacking. In the present study, we provide quantitative and functional tests for luciferase-transfected cells. We quantified the luciferase expression in BLM and HCT8/E11 transfected cancer cells, and examined the effect of long-term luciferin exposure. The present study also investigated functional differences between parental and transfected cancer cells. Our results showed that quantification of different single-cell-derived populations are superior with droplet digital polymerase chain reaction. Quantification of luciferase protein level and luciferase bioluminescent activity is only useful when there is a significant difference in copy number. Continuous exposure of cell cultures to luciferin leads to inhibitory effects on mitochondrial activity, cell growth and bioluminescence. These inhibitory effects correlate with luciferase copy number. Cell culture and mouse xenograft assays showed no significant functional differences between luciferase-transfected and parental cells. Luciferase-transfected cells should be validated by quantitative and functional assays before starting large-scale experiments. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The Cell's Sophisticated Army to Defend Against Assaults on DNAThe Cell's Sophisticated Army to Defend Against Assaults on DNA | Center for Cancer Research

Cancer.gov

The maintenance of genome integrity and function is essen-tial for the survival of cells and organisms. Any damage to our genetic material must be immediately sensed and repaired to preserve a cell’s func-tional integrity. Cells are constantly faced with the challenge of protecting their DNA from assaults by damaging chemicals and ultraviolet light. DNA damage that escapes

Terrestrial Microgravity Model and Threshold Gravity Simulation using Magnetic Levitation

NASA Technical Reports Server (NTRS)

Ramachandran, N.

2005-01-01

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars. The paper will discuss experiments md modeling work to date in support of this project.

Threshold Gravity Determination and Artificial Gravity Studies Using Magnetic Levitation

NASA Technical Reports Server (NTRS)

Ramachandran, N.; Leslie, F.

2005-01-01

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required (magnitude and duration)? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for a variable gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

TLR4 plays a crucial role in MSC-induced inhibition of NK cell function

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

Lu, Ying; Liu, Jin; Liu, Yang

2015-08-21

Mesenchymal stem cells (MSC) are a kind of stromal cell within the tumor microenvironment. In our research, MSC derived from acute myeloid leukemia patients' bone marrow (AML-MSC) and lung cancer tissues (LC-MSC) as well as normal bone marrow-derived MSC (BM-MSC) cultured in conditioned medium of HeLa cells were found to have higher expressions of Toll-like receptor (TLR4) mRNA compared with BM-MSC. The sorted TLR4-positive MSC (TLR4+ MSC) differed in cytokine (interleukin-6, interleukin-8, and monocyte chemoattractant protein-1) secretion from those of unsorted MSC. MSC was reported to inhibit natural killer (NK) cell proliferation and function. In this research, we confirmed thatmore » TLR4+ MSC aggravate this suppression. Furthermore, when TLR4 in the sorted cells were stimulated by LPS or following blocked by antibody, the suppression on NK cell proliferation and cytotoxicity were more intensive or recovered respectively. Compared to unsorted MSC, NKG2D receptor expression on NK cells were also inhibited by TLR4+ MSC. These findings suggest that activation of TLR4 pathway is important for TLR4+ MSC and MSC to obstruct anti-tumor immunity by inhibiting NK cell function, which may provide a potential stroma-targeted tumor therapy. - Highlights: • TLR4+ MSC inhibit NK cell proliferation in vivo and in vitro. • TLR4+ MSC inhibit NKG2D expression on NK cells and NK cell cytotoxicity. • The distinguished cytokine expression of TLR4+ MSC may contribute to the inhibition on NK cell function.« less

Recent developments of the in situ wet cell technology for transmission electron microscopies.

PubMed

Chen, Xin; Li, Chang; Cao, Hongling

2015-03-21

In situ wet cells for transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) allow studying structures and processes in a liquid environment with high temporal and spatial resolutions, and have been attracting increasing research interests in many fields. In this review, we highlight the structural and functional developments of the wet cells for TEM and STEM. One of the key features of the wet cells is the sealing technique used to isolate the liquid sample from the TEM/STEM vacuum environments, thus the existing in situ wet cells are grouped by different sealing methods. In this study, the advantages and shortcomings of each type of in situ wet cells are discussed, the functional developments of different wet cells are presented, and the future trends of the wet cell technology are addressed. It is suggested that in the future the in situ wet cell TEM/STEM technology will have an increasing impact on frontier nanoscale research.

Functional Human Podocytes Generated in Organoids from Amniotic Fluid Stem Cells

PubMed Central

Benedetti, Valentina; Novelli, Rubina; Abbate, Mauro; Rizzo, Paola; Conti, Sara; Tomasoni, Susanna; Corna, Daniela; Pozzobon, Michela; Cavallotti, Daniela; Yokoo, Takashi; Morigi, Marina; Benigni, Ariela; Remuzzi, Giuseppe

2016-01-01

Generating kidney organoids using human stem cells could offer promising prospects for research and therapeutic purposes. However, no cell-based strategy has generated nephrons displaying an intact three-dimensional epithelial filtering barrier. Here, we generated organoids using murine embryonic kidney cells, and documented that these tissues recapitulated the complex three-dimensional filtering structure of glomerular slits in vivo and accomplished selective glomerular filtration and tubular reabsorption. Exploiting this technology, we mixed human amniotic fluid stem cells with mouse embryonic kidney cells to establish three-dimensional chimeric organoids that engrafted in vivo and grew to form vascularized glomeruli and tubular structures. Human cells contributed to the formation of glomerular structures, differentiated into podocytes with slit diaphragms, and internalized exogenously infused BSA, thus attaining in vivo degrees of specialization and function unprecedented for donor stem cells. In conclusion, human amniotic fluid stem cell chimeric organoids may offer new paths for studying renal development and human podocyte disease, and for facilitating drug discovery and translational research. PMID:26516208

Thyroid cell lines in research on goitrogenesis.

PubMed

Gerber, H; Peter, H J; Asmis, L; Studer, H

1991-12-01

Thyroid cell lines have contributed a lot to the understanding of goitrogenesis. The cell lines mostly used in thyroid research are briefly discussed, namely the rat thyroid cell lines FRTL and FRTL-5, the porcine thyroid cell lines PORTHOS and ARTHOS, The sheep thyroid cell lines OVNIS 5H and 6H, the cat thyroid cell lines PETCAT 1 to 4 and ROMCAT, and the human thyroid cell lines FTC-133 and HTh 74. Chinese hamster ovary (CHO) cells and COS-7 cells, stably transfected with TSH receptor cDNA and expressing a functional TSH receptor, are discussed as examples for non-thyroidal cells, transfected with thyroid genes.

MODULATION OF RAT LEYDIG CELL STEROIDOGENIC FUNCTION BY DI(2-ETHYLHEXYL)PHTHALATE

EPA Science Inventory

Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate.

Akingbemi BT, Youker RT, Sottas CM, Ge R, Katz E, Klinefelter GR, Zirkin BR, Hardy MP.

Center for Biomedical Research, Population Council, New York, New York 10021, USA. benson@popcbr...

Ex-vivo imaging of excised tissue using vital dyes and confocal microscopy

PubMed Central

Johnson, Simon; Rabinovitch, Peter

2012-01-01

Vital dyes routinely used for staining cultured cells can also be used to stain and image live tissue slices ex-vivo. Staining tissue with vital dyes allows researchers to collect structural and functional data simultaneously and can be used for qualitative or quantitative fluorescent image collection. The protocols presented here are useful for structural and functional analysis of viable properties of cells in intact tissue slices, allowing for the collection of data in a structurally relevant environment. With these protocols, vital dyes can be applied as a research tool to disease processes and properties of tissue not amenable to cell culture based studies. PMID:22752953

Applications of CRISPR Genome Engineering in Cell Biology.

PubMed

Wang, Fangyuan; Qi, Lei S

2016-11-01

Recent advances in genome engineering are starting a revolution in biological research and translational applications. The clustered regularly interspaced short palindromic repeats (CRISPR)-associated RNA-guided endonuclease CRISPR associated protein 9 (Cas9) and its variants enable diverse manipulations of genome function. In this review, we describe the development of Cas9 tools for a variety of applications in cell biology research, including the study of functional genomics, the creation of transgenic animal models, and genomic imaging. Novel genome engineering methods offer a new avenue to understand the causality between the genome and phenotype, thus promising a fuller understanding of cell biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Liver-resident NK cells and their potential functions.

PubMed

Peng, Hui; Sun, Rui

2017-09-18

Natural killer (NK) cells represent a heterogeneous population of innate lymphocytes with phenotypically and functionally distinct subsets. In particular, recent studies have identified a unique subset of NK cells residing within the liver that are maintained as tissue-resident cells, confer antigen-specific memory responses and exhibit different phenotypical and developmental characteristics compared with conventional NK (cNK) cells. These findings have encouraged researchers to uncover tissue-resident NK cells at other sites, and detailed analyses have revealed that these tissue-resident NK cells share many similarities with liver-resident NK cells and tissue-resident memory T cells. Here, we present a brief historical perspective on the discovery of liver-resident NK cells and discuss their relationship to cNK cells and other emerging NK cell subsets and their potential functions.Cellular &Molecular Immunology advance online publication, 18 September 2017; doi:10.1038/cmi.2017.72.

Reference earth orbital research and applications investigations (blue book). Volume 8: Life sciences

NASA Technical Reports Server (NTRS)

1971-01-01

The functional program element for the life sciences facilities to operate aboard manned space stations is presented. The life sciences investigations will consist of the following subjects: (1) medical research, (2) vertebrate research, (3) plant research, (4) cells and tissue research, (5) invertebrate research, (6) life support and protection, and (7) man-system integration. The equipment required to provide the desired functional capability for the research facilities is defined. The goals and objectives of each research facility are described.

Importance of being Nernst: Synaptic activity and functional relevance in stem cell-derived neurons

PubMed Central

Bradford, Aaron B; McNutt, Patrick M

2015-01-01

Functional synaptogenesis and network emergence are signature endpoints of neurogenesis. These behaviors provide higher-order confirmation that biochemical and cellular processes necessary for neurotransmitter release, post-synaptic detection and network propagation of neuronal activity have been properly expressed and coordinated among cells. The development of synaptic neurotransmission can therefore be considered a defining property of neurons. Although dissociated primary neuron cultures readily form functioning synapses and network behaviors in vitro, continuously cultured neurogenic cell lines have historically failed to meet these criteria. Therefore, in vitro-derived neuron models that develop synaptic transmission are critically needed for a wide array of studies, including molecular neuroscience, developmental neurogenesis, disease research and neurotoxicology. Over the last decade, neurons derived from various stem cell lines have shown varying ability to develop into functionally mature neurons. In this review, we will discuss the neurogenic potential of various stem cells populations, addressing strengths and weaknesses of each, with particular attention to the emergence of functional behaviors. We will propose methods to functionally characterize new stem cell-derived neuron (SCN) platforms to improve their reliability as physiological relevant models. Finally, we will review how synaptically active SCNs can be applied to accelerate research in a variety of areas. Ultimately, emphasizing the critical importance of synaptic activity and network responses as a marker of neuronal maturation is anticipated to result in in vitro findings that better translate to efficacious clinical treatments. PMID:26240679

Hybrid cell adhesive material for instant dielectrophoretic cell trapping and long-term cell function assessment.

PubMed

Reyes, Darwin R; Hong, Jennifer S; Elliott, John T; Gaitan, Michael

2011-08-16

Dielectrophoresis (DEP) for cell manipulation has focused, for the most part, on approaches for separation/enrichment of cells of interest. Advancements in cell positioning and immobilization onto substrates for cell culture, either as single cells or as cell aggregates, has benefited from the intensified research efforts in DEP (electrokinetic) manipulation. However, there has yet to be a DEP approach that provides the conditions for cell manipulation while promoting cell function processes such as cell differentiation. Here we present the first demonstration of a system that combines DEP with a hybrid cell adhesive material (hCAM) to allow for cell entrapment and cell function, as demonstrated by cell differentiation into neuronlike cells (NLCs). The hCAM, comprised of polyelectrolytes and fibronectin, was engineered to function as an instantaneous cell adhesive surface after DEP manipulation and to support long-term cell function (cell proliferation, induction, and differentiation). Pluripotent P19 mouse embryonal carcinoma cells flowing within a microchannel were attracted to the DEP electrode surface and remained adhered onto the hCAM coating under a fluid flow field after the DEP forces were removed. Cells remained viable after DEP manipulation for up to 8 d, during which time the P19 cells were induced to differentiate into NLCs. This approach could have further applications in areas such as cell-cell communication, three-dimensional cell aggregates to create cell microenvironments, and cell cocultures.

[Mitochondria inheritance in yeast saccharomyces cerevisiae].

PubMed

Fizikova, A Iu

2011-01-01

The review is devoted to the main mechanisms of mitochondria inheritance in yeast Saccharonmyces cerevisiae. The genetic mechanisms of functionally active mitochondria inheritance in eukaryotic cells is one of the most relevant in modem researches. A great number of genetic diseases are associated with mitochondria dysfunction. Plasticity of eukaryotic cell metabolism according to the environmental changes is ensured by adequate mitochondria functioning by means of ATP synthesis coordination, reactive oxygen species accumulation, apoptosis regulation and is an important factor of cell adaptation to stress. Mitochondria participation in important for cell vitality processes masters the presence of accurate mechanisms of mitochondria functions regulation according to environment fluctuations. The mechanisms of mitochondria division and distribution are highly conserved. Baker yeast S. cerevisiae is an ideal model object for mitochondria researches due to energetic metabolism lability, ability to switch over respiration to fermentation, and petite-positive phenotype. Correction of metabolism according to the environmental changes is necessary for cell vitality. The influence of respiratory, carbon, amino acid and phosphate metabolism on mitochondria functions was shown. As far as the mechanisms that stabilize functions of mitochondria and mtDNA are highly conserve, we can project yeast regularities on higher eukaryotes systems. This makes it possible to approximate understanding the etiology and pathogenesis of a great number of human diseases.

Cell-Biomaterial Mechanical Interaction in the Framework of Tissue Engineering: Insights, Computational Modeling and Perspectives

PubMed Central

Sanz-Herrera, Jose A.; Reina-Romo, Esther

2011-01-01

Tissue engineering is an emerging field of research which combines the use of cell-seeded biomaterials both in vitro and/or in vivo with the aim of promoting new tissue formation or regeneration. In this context, how cells colonize and interact with the biomaterial is critical in order to get a functional tissue engineering product. Cell-biomaterial interaction is referred to here as the phenomenon involved in adherent cells attachment to the biomaterial surface, and their related cell functions such as growth, differentiation, migration or apoptosis. This process is inherently complex in nature involving many physico-chemical events which take place at different scales ranging from molecular to cell body (organelle) levels. Moreover, it has been demonstrated that the mechanical environment at the cell-biomaterial location may play an important role in the subsequent cell function, which remains to be elucidated. In this paper, the state-of-the-art research in the physics and mechanics of cell-biomaterial interaction is reviewed with an emphasis on focal adhesions. The paper is focused on the different models developed at different scales available to simulate certain features of cell-biomaterial interaction. A proper understanding of cell-biomaterial interaction, as well as the development of predictive models in this sense, may add some light in tissue engineering and regenerative medicine fields. PMID:22174660

N-3 fatty acids and membrane microdomains: from model membranes to lymphocyte function.

PubMed

Shaikh, Saame Raza; Teague, Heather

2012-12-01

This article summarizes the author's research on fish oil derived n-3 fatty acids, plasma membrane organization and B cell function. We first cover basic model membrane studies that investigated how docosahexaenoic acid (DHA) targeted the organization of sphingolipid-cholesterol enriched lipid microdomains. A key finding here was that DHA had a relatively poor affinity for cholesterol. This work led to a model that predicted DHA acyl chains in cells would manipulate lipid-protein microdomain organization and thereby function. We then review how the predictions of the model were tested with B cells in vitro followed by experiments using mice fed fish oil. These studies reveal a highly complex picture on how n-3 fatty acids target lipid-protein organization and B cell function. Key findings are as follows: (1) n-3 fatty acids target not just the plasma membrane but also endomembrane organization; (2) DHA, but not eicosapentaenoic acid (EPA), disrupts microdomain spatial distribution (i.e. clustering), (3) DHA alters protein lateral organization and (4) changes in membrane organization are accompanied by functional effects on both innate and adaptive B cell function. Altogether, the research over the past 10 years has led to an evolution of the original model on how DHA reorganizes membrane microdomains. The work raises the intriguing possibility of testing the model at the human level to target health and disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mkit: A Cell Migration Assay Based on Microfluidic Device and Smartphone

PubMed Central

Yang, Ke; Wu, Jiandong; Peretz-Soroka, Hagit; Zhu, Ling; Li, Zhigang; Sang, Yaoshuo; Hipolito, Jolly; Zhang, Michael; Santos, Susy; Hillier, Craig; de Faria, Ricardo Lobato; Liu, Yong; Lin, Francis

2017-01-01

Mobile sensing based on the integration of microfluidic device and smartphone, so-called MS2 technology, has enabled many applications over recent years, and continues to stimulate growing interest in both research communities and industries. In particular, it has been envisioned that MS2 technology can be developed for various cell functional assays to enable basic research and clinical applications. Toward this direction, in this paper, we describe the development of a MS2-based cell functional assay for testing cell migration (the Mkit). The system is constructed as an integrated test kit, which includes microfluidic chips, a smartphone-based imaging platform, the phone apps for image capturing and data analysis, and a set of reagent and accessories for performing the cell migration assay. We demonstrated that the Mkit can effectively measure purified neutrophil and cancer cell chemotaxis. Furthermore, neutrophil chemotaxis can be tested from a drop of whole blood using the Mkit with red blood cell (RBC) lysis. The effects of chemoattractant dose and gradient profile on neutrophil chemotaxis were also tested using the Mkit. In addition to research applications, we demonstrated the effective use of the Mkit for on-site test at the hospital and for testing clinical samples from chronic obstructive pulmonary disease patient. Thus, this developed Mkit provides an easy and integrated experimental platform for cell migration related research and potential medical diagnostic applications. PMID:28772229

Strategies for regeneration of heart muscle.

PubMed

Guyette, Jacques P; Cohen, Ira S; Gaudette, Glenn R

2010-01-01

Regenerative medicine has emerged to the forefront of cardiac research, marrying discoveries in both basic science and engineering to develop viable therapeutic approaches for treating the diseased heart. Signifi cant advancements in gene therapy, stem cell biology, and cardiomyoplasty provide new optimism for regenerating damaged myocardium. Exciting new strategies for endogenous and exogenous regeneration have been proposed. However, questions remain as to whether these approaches can provide enough new myocyte mass to sufficiently restore mechanical function to the heart. In this article, we consider the mechanisms of endogenous cardiomyocyte regeneration and exogenous cell differentiation (with respect to myoblasts, stem cells, and induced pluripotent cells being researched for cell therapies). We begin by reviewing some of the cues that are being harnessed in strategies of gene/cell therapy for regenerating myocardium. We also consider some of the technical challenges that remain in determining new myocyte generation, tracking delivered cells in vivo, and correlating new myocyte contractility with cardiac function. Strategies for regenerating the heart are being realized as both animal and clinical trials suggest that these new approaches provide short-term improvement of cardiac function. However, a more complete understanding of the underlying mechanisms and applications is necessary to sustain longer-term therapeutic success.

Which bank? A guardian model for regulation of embryonic stem cell research in Australia.

PubMed

McLennan, A

2007-08-01

In late 2005 the Legislation Review: Prohibition of Human Cloning Act 2002 (Cth) and the Research Involving Human Embryos Act 2002 (Cth) recommended the establishment of an Australian stem cell bank. This article aims to address a lack of discussion of issues surrounding stem cell banking by suggesting possible answers to the questions of whether Australia should establish a stem cell bank and what its underlying philosophy and functions should be. Answers are developed through an analysis of regulatory, scientific and intellectual property issues relating to embryonic stem cell research in the United Kingdom, United States and Australia. This includes a detailed analysis of the United Kingdom Stem Cell Bank. It is argued that a "guardian" model stem cell bank should be established in Australia. This bank would aim to promote the maximum public benefit from human embryonic stem cell research by providing careful regulatory oversight and addressing ethical issues, while also facilitating research by addressing practical scientific concerns and intellectual property issues.

Overviews of Emerging Research Techniques in Hearing, Bioacoustics, and Biomechanics: Proceedings of the 1981 Meeting

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

Not Available

These proceedings of the 1981 annual meeting of the Committee on Hearing, Bioacoustics, and Biomechanics cover topics of emerging research in several areas of interest to the Committee. Topics covered include: hair cell function; transduction process of hair cells; speech synthesis; machine recognition of words; neuromagnetic analysis of sensory systems; tinnitus; tactile communication of speech; and biodynamic research at the Air Force Aerospace Medical Research Laboratory.

Each cell counts: Hematopoiesis and immunity research in the era of single cell genomics.

PubMed

Jaitin, Diego Adhemar; Keren-Shaul, Hadas; Elefant, Naama; Amit, Ido

2015-02-01

Hematopoiesis and immunity are mediated through complex interactions between multiple cell types and states. This complexity is currently addressed following a reductionist approach of characterizing cell types by a small number of cell surface molecular features and gross functions. While the introduction of global transcriptional profiling technologies enabled a more comprehensive view, heterogeneity within sampled populations remained unaddressed, obscuring the true picture of hematopoiesis and immune system function. A critical mass of technological advances in molecular biology and genomics has enabled genome-wide measurements of single cells - the fundamental unit of immunity. These new advances are expected to boost detection of less frequent cell types and fuzzy intermediate cell states, greatly expanding the resolution of current available classifications. This new era of single-cell genomics in immunology research holds great promise for further understanding of the mechanisms and circuits regulating hematopoiesis and immunity in both health and disease. In the near future, the accuracy of single-cell genomics will ultimately enable precise diagnostics and treatment of multiple hematopoietic and immune related diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Highlights of the advances in basic immunology in 2011.

PubMed

Liu, Juan; Liu, Shuxun; Cao, Xuetao

2012-05-01

In this review, we summarize the major fundamental advances in immunological research reported in 2011. The highlights focus on the improved understanding of key questions in basic immunology, including the initiation and activation of innate responses as well as mechanisms for the development and function of various T-cell subsets. The research includes the identification of novel cytosolic RNA and DNA sensors as well as the identification of the novel regulators of the Toll-like receptor (TLR) and retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway. Moreover, remarkable advances have been made in the developmental and functional properties of innate lymphoid cells (ILCs). Helper T cells and regulatory T (Treg) cells play indispensable roles in orchestrating adaptive immunity. There have been exciting discoveries regarding the regulatory mechanisms of the development of distinct T-cell subsets, particularly Th17 cells and Treg cells. The emerging roles of microRNAs (miRNAs) in T cell immunity are discussed, as is the recent identification of a novel T-cell subset referred to as follicular regulatory T (TFR) cells.

Highlights of the advances in basic immunology in 2011

PubMed Central

Liu, Juan; Liu, Shuxun; Cao, Xuetao

2012-01-01

In this review, we summarize the major fundamental advances in immunological research reported in 2011. The highlights focus on the improved understanding of key questions in basic immunology, including the initiation and activation of innate responses as well as mechanisms for the development and function of various T-cell subsets. The research includes the identification of novel cytosolic RNA and DNA sensors as well as the identification of the novel regulators of the Toll-like receptor (TLR) and retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway. Moreover, remarkable advances have been made in the developmental and functional properties of innate lymphoid cells (ILCs). Helper T cells and regulatory T (Treg) cells play indispensable roles in orchestrating adaptive immunity. There have been exciting discoveries regarding the regulatory mechanisms of the development of distinct T-cell subsets, particularly Th17 cells and Treg cells. The emerging roles of microRNAs (miRNAs) in T cell immunity are discussed, as is the recent identification of a novel T-cell subset referred to as follicular regulatory T (TFR) cells. PMID:22522654

Role of nanotopography in the development of tissue engineered 3D organs and tissues using mesenchymal stem cells.

PubMed

Salmasi, Shima; Kalaskar, Deepak M; Yoon, Wai-Weng; Blunn, Gordon W; Seifalian, Alexander M

2015-03-26

Recent regenerative medicine and tissue engineering strategies (using cells, scaffolds, medical devices and gene therapy) have led to fascinating progress of translation of basic research towards clinical applications. In the past decade, great deal of research has focused on developing various three dimensional (3D) organs, such as bone, skin, liver, kidney and ear, using such strategies in order to replace or regenerate damaged organs for the purpose of maintaining or restoring organs' functions that may have been lost due to aging, accident or disease. The surface properties of a material or a device are key aspects in determining the success of the implant in biomedicine, as the majority of biological reactions in human body occur on surfaces or interfaces. Furthermore, it has been established in the literature that cell adhesion and proliferation are, to a great extent, influenced by the micro- and nano-surface characteristics of biomaterials and devices. In addition, it has been shown that the functions of stem cells, mesenchymal stem cells in particular, could be regulated through physical interaction with specific nanotopographical cues. Therefore, guided stem cell proliferation, differentiation and function are of great importance in the regeneration of 3D tissues and organs using tissue engineering strategies. This review will provide an update on the impact of nanotopography on mesenchymal stem cells for the purpose of developing laboratory-based 3D organs and tissues, as well as the most recent research and case studies on this topic.

Extracellular hemoglobin: the case of a friend turned foe

PubMed Central

Quaye, Isaac K.

2015-01-01

Hemoglobin (Hb) is a highly conserved molecule present in all life forms and functionally tied to the complexity of aerobic organisms on earth in utilizing oxygen from the atmosphere and delivering to cells and tissues. This primary function sustains the energy requirements of cells and maintains cellular homeostasis. Decades of intensive research has presented a paradigm shift that shows how the molecule also functions to facilitate smooth oxygen delivery through the cardiovascular system for cellular bioenergetic homeostasis and signaling for cell function and defense. These roles are particularly highlighted in the binding of Hb to gaseous molecules carbon dioxide (CO2), nitric oxide (NO) and carbon monoxide (CO), while also serving indirectly or directly as sources of these signaling molecules. The functional activities impacted by Hb outside of bioenergetics homeostasis, include fertilization, signaling functions, modulation of inflammatory responses for defense and cell viability. These activities are efficiently executed while Hb is sequestered safely within the confines of the red blood cell (rbc). Outside of rbc confines, Hb disaggregates and becomes a danger molecule to cell survival. In these perpectives, Hb function is broadly dichotomous, either a friend in its natural environment providing and facilitating the means for cell function or foe when dislocated from its habitat under stress or pathological condition disrupting cell function. The review presents insights into how this dichotomy in function manifests. PMID:25941490

Study characterizes long non-coding RNA’s response to DNA damage in colon cancer cells | Center for Cancer Research

Cancer.gov

Researchers led by Ashish Lal, Ph.D., Investigator in the Genetics Branch, have shown that when the DNA in human colon cancer cells is damaged, a long non-coding RNA (lncRNA) regulates the expression of genes that halt growth, which allows the cells to repair the damage and promote survival. Their findings suggest an important pro-survival function of a lncRNA in cancer cells.  Read more...

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.

Multimodal Light Microscopy Approaches to Reveal Structural and Functional Properties of Promyelocytic Leukemia Nuclear Bodies.

PubMed

Hoischen, Christian; Monajembashi, Shamci; Weisshart, Klaus; Hemmerich, Peter

2018-01-01

The promyelocytic leukemia ( pml ) gene product PML is a tumor suppressor localized mainly in the nucleus of mammalian cells. In the cell nucleus, PML seeds the formation of macromolecular multiprotein complexes, known as PML nuclear bodies (PML NBs). While PML NBs have been implicated in many cellular functions including cell cycle regulation, survival and apoptosis their role as signaling hubs along major genome maintenance pathways emerged more clearly. However, despite extensive research over the past decades, the precise biochemical function of PML in these pathways is still elusive. It remains a big challenge to unify all the different previously suggested cellular functions of PML NBs into one mechanistic model. With the advent of genetically encoded fluorescent proteins it became possible to trace protein function in living specimens. In parallel, a variety of fluorescence fluctuation microscopy (FFM) approaches have been developed which allow precise determination of the biophysical and interaction properties of cellular factors at the single molecule level in living cells. In this report, we summarize the current knowledge on PML nuclear bodies and describe several fluorescence imaging, manipulation, FFM, and super-resolution techniques suitable to analyze PML body assembly and function. These include fluorescence redistribution after photobleaching, fluorescence resonance energy transfer, fluorescence correlation spectroscopy, raster image correlation spectroscopy, ultraviolet laser microbeam-induced DNA damage, erythrocyte-mediated force application, and super-resolution microscopy approaches. Since most if not all of the microscopic equipment to perform these techniques may be available in an institutional or nearby facility, we hope to encourage more researches to exploit sophisticated imaging tools for their research in cancer biology.

Electrical research on solar cells and photovoltaic materials

NASA Technical Reports Server (NTRS)

Orehotsky, J.

1985-01-01

A systematic study of the properties of various polymer pottant materials and of the electrochemical corrosion mechanisms in solar cell materials is required for advancing the technology of terrestrial photovoltaic modules. The items of specific concern in this sponsored research activity involve: (1) kinetics of plasticizer loss in PVB, (2) kinetics of water absorption and desorption in PVB, (3) kinetics of water absorption and desorption in EVA, (4) the electrical properties at PVB as a function of temperature and humidity, (5) the electrical properties of EVA as a function of temperature and humidity, (6) solar cell corrosion characteristics, (7) water absorption effects in PVB and EVA, and (8) ion implantation and radiation effects in PVB and EVA.

In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine.

PubMed

Pi, Jiang; Jin, Hua; Yang, Fen; Chen, Zheng W; Cai, Jiye

2014-11-07

The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In this review, we attempt to summarize the characteristics of these advanced techniques for use in the in situ single molecule imaging of cell membranes. We believe that this work will help to promote the technological and methodological developments of super-resolution techniques for the single molecule imaging of cell membranes and help researchers better understand which technique is most suitable for their future exploring of membrane biomolecules; ultimately promoting further developments in cell biology, immunology and medicine.

In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine

NASA Astrophysics Data System (ADS)

Pi, Jiang; Jin, Hua; Yang, Fen; Chen, Zheng W.; Cai, Jiye

2014-10-01

The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In this review, we attempt to summarize the characteristics of these advanced techniques for use in the in situ single molecule imaging of cell membranes. We believe that this work will help to promote the technological and methodological developments of super-resolution techniques for the single molecule imaging of cell membranes and help researchers better understand which technique is most suitable for their future exploring of membrane biomolecules; ultimately promoting further developments in cell biology, immunology and medicine.

Applications of carbon nanotubes in stem cell research.

PubMed

Ramón-Azcón, Javier; Ahadian, Samad; Obregón, Raquel; Shiku, Hitoshi; Ramalingam, Murugan; Matsue, Tomokazu

2014-10-01

Stem cells are a key element in tissue engineering and regenerative medicine. However, they require a suitable microenvironment to grow and regenerate. Carbon nanotubes (CNTs) have attracted much attention as promising materials for stem cell research due to their extraordinary properties, such as their extracellular matrix-like structure, high mechanical strength, optical properties, and high electrical conductivity. Of particular interest is the use of CNTs as biomimetic substrates to control the differentiation of stem cells. CNTs have also been combined with commonly used scaffolds to fabricate functional scaffolds to direct stem cell fate. CNTs can also be used for stem cell labeling due to their high optical absorbance in the near-infrared regime. In this paper, we review and discuss the applications of CNTs in stem cell research along with CNT toxicity issues.

Avian macrophage: effector functions in health and disease.

PubMed

Qureshi, M A; Heggen, C L; Hussain, I

2000-01-01

Monocytes-macrophages, cells belonging to the mononuclear phagocytic system, are considered as the first line of immunological defense. Being mobile scavenger cells, macrophages participate in innate immunity by serving as phagocytic cells. These cells arise in the bone marrow and subsequently enter the blood circulation as blood monocytes. Upon migration to various tissues, monocytes mature and differentiate into tissue macrophages. Macrophages then initiate the 'acquired' immune response in their capacity as antigen processing and presenting cells. While responding to their tissue microenvironment or exogenous antigenic challenge, macrophages may secrete several immunoregulatory cytokines or metabolites. Being the first line of immunological defense, macrophages therefore represent an important step during interaction with infectious agents. The outcome of the macrophage-pathogen interaction depends upon several factors including the stage of macrophage activation, the nature of the infectious agent, the level of genetic control on macrophage function as well as environmental and nutritional factors that may modulate macrophage activation and functions. Research in avian macrophages has lagged behind that in mammals. This has been largely due to the lack of harvestable resident macrophages from the chicken peritoneal cavity. However, the development of elicitation protocols to harvest inflammatory abdominal macrophages and the availability of transformed chicken macrophage cell lines, has enabled researchers to address several questions related to chicken macrophage biology and function in health and disease. In this manuscript the basic profiles of several macrophage effector functions are described. In addition, the interaction of macrophages with various pathogens as well as the effect of genetic and environmental factors on macrophage functional modulation is described.

Systematic computation with functional gene-sets among leukemic and hematopoietic stem cells reveals a favorable prognostic signature for acute myeloid leukemia.

PubMed

Yang, Xinan Holly; Li, Meiyi; Wang, Bin; Zhu, Wanqi; Desgardin, Aurelie; Onel, Kenan; de Jong, Jill; Chen, Jianjun; Chen, Luonan; Cunningham, John M

2015-03-24

Genes that regulate stem cell function are suspected to exert adverse effects on prognosis in malignancy. However, diverse cancer stem cell signatures are difficult for physicians to interpret and apply clinically. To connect the transcriptome and stem cell biology, with potential clinical applications, we propose a novel computational "gene-to-function, snapshot-to-dynamics, and biology-to-clinic" framework to uncover core functional gene-sets signatures. This framework incorporates three function-centric gene-set analysis strategies: a meta-analysis of both microarray and RNA-seq data, novel dynamic network mechanism (DNM) identification, and a personalized prognostic indicator analysis. This work uses complex disease acute myeloid leukemia (AML) as a research platform. We introduced an adjustable "soft threshold" to a functional gene-set algorithm and found that two different analysis methods identified distinct gene-set signatures from the same samples. We identified a 30-gene cluster that characterizes leukemic stem cell (LSC)-depleted cells and a 25-gene cluster that characterizes LSC-enriched cells in parallel; both mark favorable-prognosis in AML. Genes within each signature significantly share common biological processes and/or molecular functions (empirical p = 6e-5 and 0.03 respectively). The 25-gene signature reflects the abnormal development of stem cells in AML, such as AURKA over-expression. We subsequently determined that the clinical relevance of both signatures is independent of known clinical risk classifications in 214 patients with cytogenetically normal AML. We successfully validated the prognosis of both signatures in two independent cohorts of 91 and 242 patients respectively (log-rank p < 0.0015 and 0.05; empirical p < 0.015 and 0.08). The proposed algorithms and computational framework will harness systems biology research because they efficiently translate gene-sets (rather than single genes) into biological discoveries about AML and other complex diseases.

CRISPR/Cas9 in Stem Cell Research: Current Application and Future Perspective.

PubMed

Patmanathan, Sathya Narayanan; Gnanasegaran, Nareshwaran; Lim, Moon Nian; Husaini, Roslina; Fakiruddin, Kamal Shaik; Zakaria, Zubaidah

2018-06-12

The clustered regularly interspaced short palindromic repeats-associated protein 9 or CRISPR/Cas9 system is one of the hottest topics discussed lately due to its robustness and effectiveness in genome editing. The technology has been widely used in life science research including microbial, plant, animal, and human cell studies. Combined with the pluripotency of stem cells, the technology represents a powerful tool to generate various cell types for disease modeling, drug screening, toxicology, and targeted therapies. Generally, the CRISPR/Cas9 system has been applied in genetic modification of pluripotent or multipotent stem cells, after which the cells are differentiated into specific cell types and used for functional analysis or even clinical transplantation. Recent advancement in CRISPR/Cas9 technology has widened the scope of stem cell research and its therapeutic application. This review provides an overview of the current application and the prospect of CRISPR/Cas9 technology, particularly in stem cell research and therapy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Using Yeast to Determine the Functional Consequences of Mutations in the Human p53 Tumor Suppressor Gene: An Introductory Course-Based Undergraduate Research Experience in Molecular and Cell Biology

ERIC Educational Resources Information Center

Hekmat-Scafe, Daria S.; Brownell, Sara E.; Seawell, Patricia Chandler; Malladi, Shyamala; Imam, Jamie F. Conklin; Singla, Veena; Bradon, Nicole; Cyert, Martha S.; Stearns, Tim

2017-01-01

The opportunity to engage in scientific research is an important, but often neglected, component of undergraduate training in biology. We describe the curriculum for an innovative, course-based undergraduate research experience (CURE) appropriate for a large, introductory cell and molecular biology laboratory class that leverages students' high…

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.

Mkit: A cell migration assay based on microfluidic device and smartphone.

PubMed

Yang, Ke; Wu, Jiandong; Peretz-Soroka, Hagit; Zhu, Ling; Li, Zhigang; Sang, Yaoshuo; Hipolito, Jolly; Zhang, Michael; Santos, Susy; Hillier, Craig; de Faria, Ricardo Lobato; Liu, Yong; Lin, Francis

2018-01-15

Mobile sensing based on the integration of microfluidic device and smartphone, so-called MS 2 technology, has enabled many applications over recent years, and continues to stimulate growing interest in both research communities and industries. In particular, it has been envisioned that MS 2 technology can be developed for various cell functional assays to enable basic research and clinical applications. Toward this direction, in this paper, we describe the development of a MS 2 -based cell functional assay for testing cell migration (the M kit ). The system is constructed as an integrated test kit, which includes microfluidic chips, a smartphone-based imaging platform, the phone apps for image capturing and data analysis, and a set of reagent and accessories for performing the cell migration assay. We demonstrated that the M kit can effectively measure purified neutrophil and cancer cell chemotaxis. Furthermore, neutrophil chemotaxis can be tested from a drop of whole blood using the M kit with red blood cell (RBC) lysis. The effects of chemoattractant dose and gradient profile on neutrophil chemotaxis were also tested using the M kit . In addition to research applications, we demonstrated the effective use of the M kit for on-site test at the hospital and for testing clinical samples from chronic obstructive pulmonary disease patient. Thus, this developed M kit provides an easy and integrated experimental platform for cell migration related research and potential medical diagnostic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic capture of polydopamine-encapsulated Hela cells for the analysis of cell surface proteins.

PubMed

Liu, Yiying; Yan, Guoquan; Gao, Mingxia; Zhang, Xiangmin

2018-02-10

A novel method to characterize cell surface proteins and complexes has been developed. Polydopamine (PDA)-encapsulated Hela cells were prepared for plasma membrane proteome research. Since the PDA protection, the encapsulated cells could be maintained for more than two weeks. Amino groups functionalized magnetic nanoparticles were also used for cell capture by the reaction with the PDA coatings. Plasma membrane fragments were isolated and enriched with assistance of an external magnetic field after disruption of the coated cells by ultrasonic treatment. Plasma membrane proteins (PMPs) and complexes were well preserved on the fragments and identified by shot-gun proteomic analytical strategy. 385 PMPs and 1411 non-PMPs were identified using the method. 85.2% of these PMPs were lipid-raft associated proteins. Ingenuity Pathway Analysis was employed for bio-information extraction from the identified proteins. It was found that 653 non-PMPs had interactions with 140 PMPs. Among them, epidermal growth factor receptor and its complexes, and a series of important pathways including STAT3 pathway were observed. All these results demonstrated that the new approach is of great importance in applying to the research of physiological function and mechanism of the plasma membrane proteins. This work developed a novel strategy for the proteomic analysis of cell surface proteins. According to the results, 73.3% of total identified proteins were lipid-raft associated proteins, which imply that the proposed method is of great potential in the identification of lipid-raft associated proteins. In addition, a series of protein-protein interactions and pathways related to Hela cells were pointed out. All these results demonstrated that our proposed approach is of great importance and could well be applied to the physiological function and mechanism research of plasma membrane proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

Combination of low-energy shock-wave therapy and bone marrow mesenchymal stem cell transplantation to improve the erectile function of diabetic rats

PubMed Central

Shan, Hai-Tao; Zhang, Hai-Bo; Chen, Wen-Tao; Chen, Feng-Zhi; Wang, Tao; Luo, Jin-Tai; Yue, Min; Lin, Ji-Hong; Wei, An-Yang

2017-01-01

Stem cell transplantation and low-energy shock-wave therapy (LESWT) have emerged as potential and effective treatment protocols for diabetic erectile dysfunction. During the tracking of transplanted stem cells in diabetic erectile dysfunction models, the number of visible stem cells was rather low and decreased quickly. LESWT could recruit endogenous stem cells to the cavernous body and improve the microenvironment in diabetic cavernous tissue. Thus, we deduced that LESWT might benefit transplanted stem cell survival and improve the effects of stem cell transplantation. In this research, 42 streptozotocin-induced diabetic rats were randomized into four groups: the diabetic group (n = 6), the LESWT group (n = 6), the bone marrow-derived mesenchymal stem cell (BMSC) transplantation group (n = 15), and the combination of LESWT and BMSC transplantation group (n = 15). One and three days after BMSC transplantation, three rats were randomly chosen to observe the survival numbers of BMSCs in the cavernous body. Four weeks after BMSC transplantation, the following parameters were assessed: the surviving number of transplanted BMSCs in the cavernous tissue, erectile function, real-time polymerase chain reaction, and penile immunohistochemical assessment. Our research found that LESWT favored the survival of transplanted BMSCs in the cavernous body, which might be related to increased stromal cell-derived factor-1 expression and the enhancement of angiogenesis in the diabetic cavernous tissue. The combination of LESWT and BMSC transplantation could improve the erectile function of diabetic erectile function rats more effectively than LESWT or BMSC transplantation performed alone. PMID:27427555

Combination of low-energy shock-wave therapy and bone marrow mesenchymal stem cell transplantation to improve the erectile function of diabetic rats.

PubMed

Shan, Hai-Tao; Zhang, Hai-Bo; Chen, Wen-Tao; Chen, Feng-Zhi; Wang, Tao; Luo, Jin-Tai; Yue, Min; Lin, Ji-Hong; Wei, An-Yang

2017-01-01

Stem cell transplantation and low-energy shock-wave therapy (LESWT) have emerged as potential and effective treatment protocols for diabetic erectile dysfunction. During the tracking of transplanted stem cells in diabetic erectile dysfunction models, the number of visible stem cells was rather low and decreased quickly. LESWT could recruit endogenous stem cells to the cavernous body and improve the microenvironment in diabetic cavernous tissue. Thus, we deduced that LESWT might benefit transplanted stem cell survival and improve the effects of stem cell transplantation. In this research, 42 streptozotocin-induced diabetic rats were randomized into four groups: the diabetic group (n = 6), the LESWT group (n = 6), the bone marrow-derived mesenchymal stem cell (BMSC) transplantation group (n = 15), and the combination of LESWT and BMSC transplantation group (n = 15). One and three days after BMSC transplantation, three rats were randomly chosen to observe the survival numbers of BMSCs in the cavernous body. Four weeks after BMSC transplantation, the following parameters were assessed: the surviving number of transplanted BMSCs in the cavernous tissue, erectile function, real-time polymerase chain reaction, and penile immunohistochemical assessment. Our research found that LESWT favored the survival of transplanted BMSCs in the cavernous body, which might be related to increased stromal cell-derived factor-1 expression and the enhancement of angiogenesis in the diabetic cavernous tissue. The combination of LESWT and BMSC transplantation could improve the erectile function of diabetic erectile function rats more effectively than LESWT or BMSC transplantation performed alone.

What we can learn from a tadpole about ciliopathies and airway diseases: Using systems biology in Xenopus to study cilia and mucociliary epithelia.

PubMed

Walentek, Peter; Quigley, Ian K

2017-01-01

Over the past years, the Xenopus embryo has emerged as an incredibly useful model organism for studying the formation and function of cilia and ciliated epithelia in vivo. This has led to a variety of findings elucidating the molecular mechanisms of ciliated cell specification, basal body biogenesis, cilia assembly, and ciliary motility. These findings also revealed the deep functional conservation of signaling, transcriptional, post-transcriptional, and protein networks employed in the formation and function of vertebrate ciliated cells. Therefore, Xenopus research can contribute crucial insights not only into developmental and cell biology, but also into the molecular mechanisms underlying cilia related diseases (ciliopathies) as well as diseases affecting the ciliated epithelium of the respiratory tract in humans (e.g., chronic lung diseases). Additionally, systems biology approaches including transcriptomics, genomics, and proteomics have been rapidly adapted for use in Xenopus, and broaden the applications for current and future translational biomedical research. This review aims to present the advantages of using Xenopus for cilia research, highlight some of the evolutionarily conserved key concepts and mechanisms of ciliated cell biology that were elucidated using the Xenopus model, and describe the potential for Xenopus research to address unresolved questions regarding the molecular mechanisms of ciliopathies and airway diseases. © 2017 Wiley Periodicals, Inc.

Translational Cellular Research on the International Space Station

NASA Technical Reports Server (NTRS)

Love, John; Cooley, Vic

2016-01-01

The emerging field of Translational Research aims to coalesce interdisciplinary findings from basic science for biomedical applications. To complement spaceflight research using human subjects, translational studies can be designed to address aspects of space-related human health risks and help develop countermeasures to prevent or mitigate them, with therapeutical benefits for analogous conditions experienced on Earth. Translational research with cells and model organisms is being conducted onboard the International Space Station (ISS) in connection with various human systems impacted by spaceflight, such as the cardiovascular, musculoskeletal, and immune systems. Examples of recent cell-based translational investigations on the ISS include the following. The JAXA investigation Cell Mechanosensing seeks to identify gravity sensors in skeletal muscle cells to develop muscle atrophy countermeasures by analyzing tension fluctuations in the plasma membrane, which changes the expression of key proteins and genes. Earth applications of this study include therapeutic approaches for some forms of muscular dystrophy, which appear to parallel aspects of muscle wasting in space. Spheroids is an ESA investigation examining the system of endothelial cells lining the inner surface of all blood vessels in terms of vessel formation, cellular proliferation, and programmed cell death, because injury to the endothelium has been implicated as underpinning various cardiovascular and musculoskeletal problems arising during spaceflight. Since endothelial cells are involved in the functional integrity of the vascular wall, this research has applications to Earth diseases such as atherosclerosis, diabetes, and hypertension. The goal of the T-Cell Activation in Aging NASA investigation is to understand human immune system depression in microgravity by identifying gene expression patterns of candidate molecular regulators, which will provide further insight into factors that may play a critical role in immune function loss during aging. In addition, Omics investigations with cells have synergistic applications ranging from the evaluation of pharmacological countermeasures to drug discovery. Thus, cell-based translational research onboard the ISS is bidirectionally bridging cutting-edge cellular and molecular approaches with space bioastronautics and human health methodologies on Earth.

[Establishment of human embryonic stem cell lines and their therapeutic application].

PubMed

Suemori, Hirofumi

2004-03-01

Embryonic stem (ES) cell lines are pluripotent stem cell lines that can be propagated indefinitely in culture, retaining their potency to differentiate into every type of cell and tissue in the body. ES cell lines were first established from mouse blastocysts, and have been used for research in developmental biology. ES cells have been proven to be very valuable in the genetic modification of the mouse, especially in producing knockout mice. Since establishment of human ES cell lines was reported, their use in cell replacement therapies has been enthusiastically expected. There have been reports of the differentiation of several useful cell types from human ES cell lines, and clinical use of functional tissues and cells from human ES cells is anticipated. In Japan, there have also been many demands for the use of human ES cells in basic and pre-clinical research. We obtained governmental permission to establish human ES cell lines in April 2002 and started research using donated frozen embryos in January 2003. We successfully established three ES cell line from three blastocysts. These cell lines will be distributed at cost to researchers who have governmental permission to use human ES cells.

The Fragile X Syndrome: From Molecular Genetics to Neurobiology

ERIC Educational Resources Information Center

Willemsen, Rob; Oostra, Ben A.; Bassell, Gary J.; Dictenberg, Jason

2004-01-01

Since the identification of the FMR1 gene basic research has been focused on the molecular characterization of the FMR1 gene product, the fragile X mental retardation protein (FMRP). Recent developments in fragile X research have provided new insights and knowledge about the physiological function of FMRP in the cell and the nerve cell in…

Challenges of primate embryonic stem cell research.

PubMed

Bavister, Barry D; Wolf, Don P; Brenner, Carol A

2005-01-01

Embryonic stem (ES) cells hold great promise for treating degenerative diseases, including diabetes, Parkinson's, Alzheimer's, neural degeneration, and cardiomyopathies. This research is controversial to some because producing ES cells requires destroying embryos, which generally means human embryos. However, some of the surplus human embryos available from in vitro fertilization (IVF) clinics may have a high rate of genetic errors and therefore would be unsuitable for ES cell research. Although gross chromosome errors can readily be detected in ES cells, other anomalies such as mitochondrial DNA defects may have gone unrecognized. An insurmountable problem is that there are no human ES cells derived from in vivo-produced embryos to provide normal comparative data. In contrast, some monkey ES cell lines have been produced using in vivo-generated, normal embryos obtained from fertile animals; these can represent a "gold standard" for primate ES cells. In this review, we argue a need for strong research programs using rhesus monkey ES cells, conducted in parallel with studies on human ES and adult stem cells, to derive the maximum information about the biology of normal stem cells and to produce technical protocols for their directed differentiation into safe and functional replacement cells, tissues, and organs. In contrast, ES cell research using only human cell lines is likely to be incomplete, which could hinder research progress, and delay or diminish the effective application of ES cell technology to the treatment of human diseases.

Seventeen-Year Journey Working With a Master.

PubMed

Zhu, Jinfang

2018-01-01

It had been a great honor for me to work with the late Dr. William E. Paul for 17 years in the Laboratory of Immunology (LI) from 1998 until his passing in 2015. He was such a master in the immunology field. Under his outstanding guidance, my research has been focusing on transcriptional regulation of T helper (Th) cell differentiation, especially, on the role of a master transcription factor GATA3 during Th2 cell differentiation. Just as enormous scientific contributions of Dr. Paul (we all call him Bill) to the immunology community are far beyond his serving as the Chief of the LI, GATA3 also plays important roles in different lymphocytes at various developmental stages besides its critical functions in Th2 cells. In this special review dedicated to the memory of Bill, I will summarize the research that I have carried out in Bill's lab working on GATA3 in the context of related studies by other groups in the field of T cell differentiation and innate lymphoid cell (ILC) development. These include the essential role of GATA3 in regulating Th2/ILC2 differentiation/development and their functions, the critical role of GATA3 during the development of T cells and innate lymphoid cells, and dynamic and quantitative expression of GATA3 in controlling lymphocyte homeostasis and functions.

Sperm quality assays: How good are they? The horse perspective.

PubMed

Love, Charles C

2018-04-22

Sperm quality assays have increased in number in the last 10 years. Most of these assays are flow cytometry based in application and are modified from assays that have been developed to measure somatic cell function. The goal of any sperm quality assay should be to advance the clinicians/researchers understanding of sperm cell function and the relationship to fertility. While these assays appear to measure somatic cell-like functions in sperm there tends to be little understanding how the results of these assays relate to fertility. Copyright © 2018. Published by Elsevier B.V.

The skeleton in the closet: actin cytoskeletal remodeling in β-cell function.

PubMed

Arous, Caroline; Halban, Philippe A

2015-10-01

Over the last few decades, biomedical research has considered not only the function of single cells but also the importance of the physical environment within a whole tissue, including cell-cell and cell-extracellular matrix interactions. Cytoskeleton organization and focal adhesions are crucial sensors for cells that enable them to rapidly communicate with the physical extracellular environment in response to extracellular stimuli, ensuring proper function and adaptation. The involvement of the microtubular-microfilamentous cytoskeleton in secretion mechanisms was proposed almost 50 years ago, since when the evolution of ever more sensitive and sophisticated methods in microscopy and in cell and molecular biology have led us to become aware of the importance of cytoskeleton remodeling for cell shape regulation and its crucial link with signaling pathways leading to β-cell function. Emerging evidence suggests that dysfunction of cytoskeletal components or extracellular matrix modification influences a number of disorders through potential actin cytoskeleton disruption that could be involved in the initiation of multiple cellular functions. Perturbation of β-cell actin cytoskeleton remodeling could arise secondarily to islet inflammation and fibrosis, possibly accounting in part for impaired β-cell function in type 2 diabetes. This review focuses on the role of actin remodeling in insulin secretion mechanisms and its close relationship with focal adhesions and myosin II. Copyright © 2015 the American Physiological Society.

Single-Cell Sequencing Technologies for Cardiac Stem Cell Studies.

PubMed

Liu, Tiantian; Wu, Hongjin; Wu, Shixiu; Wang, Charles

2017-11-01

Today with the rapid advancements in stem cell studies and the promising potential of using stem cells in clinical therapy, there is an increasing demand for in-depth comprehensive analysis on individual cell transcriptome and epigenome, as they play critical roles in a number of cell functions such as cell differentiation, growth, and reprogramming. The development of single-cell sequencing technologies has helped in revealing some exciting new perspectives in stem cells and regenerative medicine research. Among the various potential applications, single-cell analysis for cardiac stem cells (CSCs) holds tremendous promises in understanding the mechanisms of heart development and regeneration, which might light up the path toward cell therapy for cardiovascular diseases. This review briefly highlights the recent progresses in single-cell sequencing analysis technologies and their applications in CSC research.

Phycocyanin: A Potential Drug for Cancer Treatment

PubMed Central

Jiang, Liangqian; Wang, Yujuan; Yin, Qifeng; Liu, Guoxiang; Liu, Huihui; Huang, Yajing; Li, Bing

2017-01-01

Phycocyanin isolated from marine organisms has the characteristics of high efficiency and low toxicity, and it can be used as a functional food. It has been reported that phycocyanin has anti-oxidative function, anti-inflammatory activity, anti-cancer function, immune enhancement function, liver and kidney protection pharmacological effects. Thus, phycocyanin has an important development and utilization as a potential drug, and phycocyanin has become a new hot spot in the field of drug research. So far, there are more and more studies have shown that phycocyanin has the anti-cancer effect, which can block the proliferation of cancer cells and kill cancer cells. Phycocyanin exerts anti-cancer activity by blocking tumor cell cell cycle, inducing tumor cell apoptosis and autophagy, thereby phycocyanin can serve as a promising anti-cancer agent. This review discusses the therapeutic use of phycocyanin and focuses on the latest advances of phycocyanin as a promising anti-cancer drug. PMID:29151925

Dual function of MG53 in membrane repair and insulin signaling

PubMed Central

Tan, Tao; Ko, Young-Gyu; Ma, Jianjie

2016-01-01

MG53 is a member of the TRIM-family protein that acts as a key component of the cell membrane repair machinery. MG53 is also an E3-ligase that ubiquinates insulin receptor substrate-1 and controls insulin signaling in skeletal muscle cells. Since its discovery in 2009, research efforts have been devoted to translate this basic discovery into clinical applications in human degenerative and metabolic diseases. This review article highlights the dual function of MG53 in cell membrane repair and insulin signaling, the mechanism that underlies the control of MG53 function, and the therapeutic value of targeting MG53 function in regenerative medicine. [BMB Reports 2016; 49(8): 414-423] PMID:27174502

Kinesin and Dynein Mechanics: Measurement Methods and Research Applications.

PubMed

Abraham, Zachary; Hawley, Emma; Hayosh, Daniel; Webster-Wood, Victoria A; Akkus, Ozan

2018-02-01

Motor proteins play critical roles in the normal function of cells and proper development of organisms. Among motor proteins, failings in the normal function of two types of proteins, kinesin and dynein, have been shown to lead many pathologies, including neurodegenerative diseases and cancers. As such, it is critical to researchers to understand the underlying mechanics and behaviors of these proteins, not only to shed light on how failures may lead to disease, but also to guide research toward novel treatment and nano-engineering solutions. To this end, many experimental techniques have been developed to measure the force and motility capabilities of these proteins. This review will (a) discuss such techniques, specifically microscopy, atomic force microscopy (AFM), optical trapping, and magnetic tweezers, and (b) the resulting nanomechanical properties of motor protein functions such as stalling force, velocity, and dependence on adenosine triphosophate (ATP) concentrations will be comparatively discussed. Additionally, this review will highlight the clinical importance of these proteins. Furthermore, as the understanding of the structure and function of motor proteins improves, novel applications are emerging in the field. Specifically, researchers have begun to modify the structure of existing proteins, thereby engineering novel elements to alter and improve native motor protein function, or even allow the motor proteins to perform entirely new tasks as parts of nanomachines. Kinesin and dynein are vital elements for the proper function of cells. While many exciting experiments have shed light on their function, mechanics, and applications, additional research is needed to completely understand their behavior.

Study characterizes long non-coding RNA’s response to DNA damage in colon cancer cells | Center for Cancer Research

Cancer.gov

Researchers led by Ashish Lal, Ph.D., Investigator in the Genetics Branch, have shown that when the DNA in human colon cancer cells is damaged, a long non-coding RNA (lncRNA) regulates the expression of genes that halt growth, which allows the cells to repair the damage and promote survival. Their findings suggest an important pro-survival function of a lncRNA in cancer

Riding the Waves: How Our Cells Send Signals | Center for Cancer Research

Cancer.gov

The ability of cells to perceive and respond to their environment is critical in order to maintain basic cellular functions such as development, tissue repair, and response to stress. This process happens through a complex system of communication, called cell signaling, which governs basic cellular activities and coordinates cell actions. Errors in cell signaling have been

Multimodal Light Microscopy Approaches to Reveal Structural and Functional Properties of Promyelocytic Leukemia Nuclear Bodies

PubMed Central

Hoischen, Christian; Monajembashi, Shamci; Weisshart, Klaus; Hemmerich, Peter

2018-01-01

The promyelocytic leukemia (pml) gene product PML is a tumor suppressor localized mainly in the nucleus of mammalian cells. In the cell nucleus, PML seeds the formation of macromolecular multiprotein complexes, known as PML nuclear bodies (PML NBs). While PML NBs have been implicated in many cellular functions including cell cycle regulation, survival and apoptosis their role as signaling hubs along major genome maintenance pathways emerged more clearly. However, despite extensive research over the past decades, the precise biochemical function of PML in these pathways is still elusive. It remains a big challenge to unify all the different previously suggested cellular functions of PML NBs into one mechanistic model. With the advent of genetically encoded fluorescent proteins it became possible to trace protein function in living specimens. In parallel, a variety of fluorescence fluctuation microscopy (FFM) approaches have been developed which allow precise determination of the biophysical and interaction properties of cellular factors at the single molecule level in living cells. In this report, we summarize the current knowledge on PML nuclear bodies and describe several fluorescence imaging, manipulation, FFM, and super-resolution techniques suitable to analyze PML body assembly and function. These include fluorescence redistribution after photobleaching, fluorescence resonance energy transfer, fluorescence correlation spectroscopy, raster image correlation spectroscopy, ultraviolet laser microbeam-induced DNA damage, erythrocyte-mediated force application, and super-resolution microscopy approaches. Since most if not all of the microscopic equipment to perform these techniques may be available in an institutional or nearby facility, we hope to encourage more researches to exploit sophisticated imaging tools for their research in cancer biology. PMID:29888200

Tailored immune responses: novel effector helper T cell subsets in protective immunity.

PubMed

Kara, Ervin E; Comerford, Iain; Fenix, Kevin A; Bastow, Cameron R; Gregor, Carly E; McKenzie, Duncan R; McColl, Shaun R

2014-02-01

Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H)1/T(H)2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

Printing of Three-Dimensional Tissue Analogs for Regenerative Medicine

PubMed Central

Lee, Vivian K.; Dai, Guohao

2016-01-01

3-D cell printing, which can accurately deposit cells, biomaterial scaffolds and growth factors in precisely defined spatial patterns to form biomimetic tissue structures, has emerged as a powerful enabling technology to create live tissue and organ structures for drug discovery and tissue engineering applications. Unlike traditional 3-D printing that uses metals, plastics and polymers as the printing materials, cell printing has to be compatible with living cells and biological matrix. It is also required that the printing process preserves the biological functions of the cells and extracellular matrix, and to mimic the cell-matrix architectures and mechanical properties of the native tissues. Therefore, there are significant challenges in order to translate the technologies of traditional 3-D printing to cell printing, and ultimately achieve functional outcomes in the printed tissues. So it is essential to develop new technologies specially designed for cell printing and in-depth basic research in the bioprinted tissues, such as developing novel biomaterials specifically for cell printing applications, understanding the complex cell-matrix remodeling for the desired mechanical properties and functional outcomes, establishing proper vascular perfusion in bioprinted tissues, etc. In recent years, many exciting research progresses have been made in the 3-D cell printing technology and its application in engineering live tissue constructs. This review paper summarized the current development in 3-D cell printing technologies; focus on the outcomes of the live printed tissues and their potential applications in drug discovery and regenerative medicine. Current challenges and limitations are highlighted, and future directions of 3-D cell printing technology are also discussed. PMID:27066784

Adult neural stem cells: The promise of the future

PubMed Central

Taupin, Philippe

2007-01-01

Stem cells are self-renewing undifferentiated cells that give rise to multiple types of specialized cells of the body. In the adult, stem cells are multipotents and contribute to homeostasis of the tissues and regeneration after injury. Until recently, it was believed that the adult brain was devoid of stem cells, hence unable to make new neurons and regenerate. With the recent evidences that neurogenesis occurs in the adult brain and neural stem cells (NSCs) reside in the adult central nervous system (CNS), the adult brain has the potential to regenerate and may be amenable to repair. The function(s) of NSCs in the adult CNS remains the source of intense research and debates. The promise of the future of adult NSCs is to redefine the functioning and physiopathology of the CNS, as well as to treat a broad range of CNS diseases and injuries. PMID:19300610

NK cell subsets in autoimmune diseases.

PubMed

Zhang, Cai; Tian, Zhigang

2017-09-01

Natural killer (NK) cells are lymphocytes of the innate immune system. They not only exert cell-mediated cytotoxicity against tumor cells or infected cells, but also play regulatory role through promoting or suppressing functions of other immune cells by secretion of cytokines and chemokines. However, overactivation or dysfunction of NK cells may be associated with pathogenesis of some diseases. NK cells are found to act as a two edged weapon and play opposite roles with both regulatory and inducer activity in autoimmune diseases. Though the precise mechanisms for the opposite effects of NK cells has not been fully elucidated, the importance of NK cells in autoimmune diseases might be associated with different NK cell subsets, different tissue microenvironment and different stages of corresponding diseases. The local tissue microenvironment, unique cellular interactions and different stages of corresponding diseases shape the properties and function of NK cells. In this review, we focus on recent research on the features and function of different NK cell subsets, particularly tissue-resident NK cells in different tissues, and their potential role in autoimmune diseases. Copyright © 2017. Published by Elsevier Ltd.

Lentiviral transduction of rat Sertoli cells as a means to modify gene expression

PubMed Central

Nicholls, Peter K.; Stanton, Peter G.; Rainczuk, Katarzyna E.; Qian, Hongwei; Gregorevic, Paul; Harrison, Craig A.

2012-01-01

Primary cell culture is an established and widely used technique to study Sertoli cell function in vitro. However, the relative difficulty of stably overexpressing or knocking down genes in Sertoli cell culture has limited progress in the field. In this technical report, we present a method to transduce 20 dpp rat Sertoli cell cultures with VSV-G pseudotyped lentiviral based vectors at a high rate (~80%), with stable reporter gene expression. Although high transgene expression is desirable, it was noted that at transduction rates > 60% inter-Sertoli cell tight junction integrity and, hence, Sertoli cell function, were transiently compromised. We envisage that this optimized procedure has the potential to stimulate Sertoli cell research, and motivate the use of Sertoli cells in various cell therapy applications. PMID:23248769

Mammalian skin cell biology: at the interface between laboratory and clinic.

PubMed

Watt, Fiona M

2014-11-21

Mammalian skin research represents the convergence of three complementary disciplines: cell biology, mouse genetics, and dermatology. The skin provides a paradigm for current research in cell adhesion, inflammation, and tissue stem cells. Here, I discuss recent insights into the cell biology of skin. Single-cell analysis has revealed that human epidermal stem cells are heterogeneous and differentiate in response to multiple extrinsic signals. Live-cell imaging, optogenetics, and cell ablation experiments show skin cells to be remarkably dynamic. High-throughput, genome-wide approaches have yielded unprecedented insights into the circuitry that controls epidermal stem cell fate. Last, integrative biological analysis of human skin disorders has revealed unexpected functions for elements of the skin that were previously considered purely structural. Copyright © 2014, American Association for the Advancement of Science.

Lidocaine Stimulates the Function of Natural Killer Cells in Different Experimental Settings.

PubMed

Cata, Juan P; Ramirez, Maria F; Velasquez, Jose F; Di, A I; Popat, Keyuri U; Gottumukkala, Vijaya; Black, Dahlia M; Lewis, Valerae O; Vauthey, Jean N

2017-09-01

One of the functions of natural killer (NK) cells is to eliminate cancer cells. The cytolytic activity of NK cells is tightly regulated by inhibitory and activation receptors located in the surface membrane. Lidocaine stimulates the function of NK cells at clinically relevant concentrations. It remains unknown whether this effect of lidocaine has an impact on the expression of surface receptors of NK cells, can uniformly stimulate across different cancer cell lines, and enhances the function of cells obtained during oncological surgery. NK cells from healthy donors and 43 patients who had undergone surgery for cancer were isolated. The function of NK cells was measured by lactate dehydrogenase release assay. NK cells were incubated with clinically relevant concentrations of lidocaine. By flow cytometry, we determined the impact of lidocaine on the expression of galactosylgalactosylxylosylprotein3-beta-glucuronosytranferase 1, marker of cell maturation (CD57), killer cell lectin like receptor A, inhibitory (NKG2A) receptors and killer cell lectin like receptor D, activation (NKG2D) receptors of NK cells. Differences in expression at p<0.05 were considered statistically significant. Lidocaine increased the expression of NKG2D receptors and stimulated the function of NK cells against ovarian, pancreatic and ovarian cancer cell lines. Lidocaine also increased the cytolytic activity of NK cells from patients who underwent oncological surgery, except for those who had orthopedic procedures. Lidocaine showed an important stimulatory activity on NK cells. Our findings suggest that lidocaine might be used perioperatively to minimize the impact of surgery on NK cells. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Tissue constructs: platforms for basic research and drug discovery.

PubMed

Elson, Elliot L; Genin, Guy M

2016-02-06

The functions, form and mechanical properties of cells are inextricably linked to their extracellular environment. Cells from solid tissues change fundamentally when, isolated from this environment, they are cultured on rigid two-dimensional substrata. These changes limit the significance of mechanical measurements on cells in two-dimensional culture and motivate the development of constructs with cells embedded in three-dimensional matrices that mimic the natural tissue. While measurements of cell mechanics are difficult in natural tissues, they have proven effective in engineered tissue constructs, especially constructs that emphasize specific cell types and their functions, e.g. engineered heart tissues. Tissue constructs developed as models of disease also have been useful as platforms for drug discovery. Underlying the use of tissue constructs as platforms for basic research and drug discovery is integration of multiscale biomaterials measurement and computational modelling to dissect the distinguishable mechanical responses separately of cells and extracellular matrix from measurements on tissue constructs and to quantify the effects of drug treatment on these responses. These methods and their application are the main subjects of this review.

Tissue constructs: platforms for basic research and drug discovery

PubMed Central

Elson, Elliot L.; Genin, Guy M.

2016-01-01

The functions, form and mechanical properties of cells are inextricably linked to their extracellular environment. Cells from solid tissues change fundamentally when, isolated from this environment, they are cultured on rigid two-dimensional substrata. These changes limit the significance of mechanical measurements on cells in two-dimensional culture and motivate the development of constructs with cells embedded in three-dimensional matrices that mimic the natural tissue. While measurements of cell mechanics are difficult in natural tissues, they have proven effective in engineered tissue constructs, especially constructs that emphasize specific cell types and their functions, e.g. engineered heart tissues. Tissue constructs developed as models of disease also have been useful as platforms for drug discovery. Underlying the use of tissue constructs as platforms for basic research and drug discovery is integration of multiscale biomaterials measurement and computational modelling to dissect the distinguishable mechanical responses separately of cells and extracellular matrix from measurements on tissue constructs and to quantify the effects of drug treatment on these responses. These methods and their application are the main subjects of this review. PMID:26855763

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

EPConDB: a web resource for gene expression related to pancreatic development, beta-cell function and diabetes.

PubMed

Mazzarelli, Joan M; Brestelli, John; Gorski, Regina K; Liu, Junmin; Manduchi, Elisabetta; Pinney, Deborah F; Schug, Jonathan; White, Peter; Kaestner, Klaus H; Stoeckert, Christian J

2007-01-01

EPConDB (http://www.cbil.upenn.edu/EPConDB) is a public web site that supports research in diabetes, pancreatic development and beta-cell function by providing information about genes expressed in cells of the pancreas. EPConDB displays expression profiles for individual genes and information about transcripts, promoter elements and transcription factor binding sites. Gene expression results are obtained from studies examining tissue expression, pancreatic development and growth, differentiation of insulin-producing cells, islet or beta-cell injury, and genetic models of impaired beta-cell function. The expression datasets are derived using different microarray platforms, including the BCBC PancChips and Affymetrix gene expression arrays. Other datasets include semi-quantitative RT-PCR and MPSS expression studies. For selected microarray studies, lists of differentially expressed genes, derived from PaGE analysis, are displayed on the site. EPConDB provides database queries and tools to examine the relationship between a gene, its transcriptional regulation, protein function and expression in pancreatic tissues.

An introduction to the molecular basics of aryl hydrocarbon receptor biology.

PubMed

Abel, Josef; Haarmann-Stemmann, Thomas

2010-11-01

Depending on their chemical structure and properties, environmental chemicals and other xenobiotics that enter the cell can affect cellular function by either nonselective binding to cellular macromolecules or by interference with cellular receptors, which would initiate a more defined cell biological response. One of these intracellular chemosensor molecules is the aryl hydrocarbon receptor (AhR), a transcription factor of the bHLH/PAS family that is known to mediate the biochemical and toxic effects of dioxins, polyaromatic hydrocarbons and related compounds. Numerous investigations have revealed that the AhR is not only a master regulator of drug metabolism activated by anthropogenic chemicals, but is also triggered by natural and endogenous ligands and can influence cell biological endpoints such as growth and differentiation. Cutting-edge research has identified new intriguing functions of the AhR, such as during proteasomal degradation of steroid hormone receptors, the cellular UVB stress response and the differentiation of certain T-cell subsets. In this review we provide both a survey of the fundamental basics of AhR biology and an insight into new functional aspects of AhR signaling to further stimulate research on this intriguing transcription factor at the interface between toxicology, cell biology and immunology.

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

Microfluidic cell culture systems for drug research.

PubMed

Wu, Min-Hsien; Huang, Song-Bin; Lee, Gwo-Bin

2010-04-21

In pharmaceutical research, an adequate cell-based assay scheme to efficiently screen and to validate potential drug candidates in the initial stage of drug discovery is crucial. In order to better predict the clinical response to drug compounds, a cell culture model that is faithful to in vivo behavior is required. With the recent advances in microfluidic technology, the utilization of a microfluidic-based cell culture has several advantages, making it a promising alternative to the conventional cell culture methods. This review starts with a comprehensive discussion on the general process for drug discovery and development, the role of cell culture in drug research, and the characteristics of the cell culture formats commonly used in current microfluidic-based, cell-culture practices. Due to the significant differences in several physical phenomena between microscale and macroscale devices, microfluidic technology provides unique functionality, which is not previously possible by using traditional techniques. In a subsequent section, the niches for using microfluidic-based cell culture systems for drug research are discussed. Moreover, some critical issues such as cell immobilization, medium pumping or gradient generation in microfluidic-based, cell-culture systems are also reviewed. Finally, some practical applications of microfluidic-based, cell-culture systems in drug research particularly those pertaining to drug toxicity testing and those with a high-throughput capability are highlighted.

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.

Protective effects of a natural product, curcumin, against amyloid β induced mitochondrial and synaptic toxicities in Alzheimer's disease.

PubMed

Reddy, P Hemachandra; Manczak, Maria; Yin, Xiangling; Grady, Mary Catharine; Mitchell, Andrew; Kandimalla, Ramesh; Kuruva, Chandra Sekhar

2016-12-01

The purpose of our study was to investigate the protective effects of a natural product-'curcumin'- in Alzheimer's disease (AD)-like neurons. Although much research has been done in AD, very little has been reported on the effects of curcumin on mitochondrial biogenesis, dynamics, function and synaptic activities. Therefore, the present study investigated the protective effects against amyloid β (Aβ) induced mitochondrial and synaptic toxicities. Using human neuroblastoma (SHSY5Y) cells, curcumin and Aβ, we studied the protective effects of curcumin against Aβ. Further, we also studied preventive (curcumin+Aβ) and intervention (Aβ+curcumin) effects of curcumin against Aβ in SHSY5Y cells. Using real time RT-PCR, immunoblotting and immunofluorescence analysis, we measured mRNA and protein levels of mitochondrial dynamics, mitochondrial biogenesis and synaptic genes. We also assessed mitochondrial function by measuring hydrogen peroxide, lipid peroxidation, cytochrome oxidase activity and mitochondrial ATP. Cell viability was studied using the MTT assay. Aβ was found to impair mitochondrial dynamics, reduce mitochondrial biogenesis and decrease synaptic activity and mitochondrial function. In contrast, curcumin enhanced mitochondrial fusion activity and reduced fission machinery, and increased biogenesis and synaptic proteins. Mitochondrial function and cell viability were elevated in curcumin treated cells. Interestingly, curcumin pre- and post-treated cells incubated with Aβ showed reduced mitochondrial dysfunction, and maintained cell viability and mitochondrial dynamics, mitochondrial biogenesis and synaptic activity. Further, the protective effects of curcumin were stronger in pretreated SHSY5Y cells than in post-treated cells, indicating that curcumin works better in prevention than treatment in AD-like neurons. Our findings suggest that curcumin is a promising drug molecule to treat AD patients. Copyright © 2016 American Federation for Medical Research.

CAVEOLINS AND LUNG FUNCTION

PubMed Central

Maniatis, Nikolaos A.; Chernaya, Olga; Shinin, Vasily; Minshall, Richard D.

2012-01-01

The primary function of the mammalian lung is to facilitate diffusion of oxygen to venous blood and to ventilate carbon dioxide produced by catabolic reactions within cells. However, it is also responsible for a variety of other important functions, including host defense and production of vasoactive agents to regulate not only systemic blood pressure, but also water, electrolyte and acid-base balance. Caveolin-1 is highly expressed in the majority of cell types in the lung, including epithelial, endothelial, smooth muscle, connective tissue cells, and alveolar macrophages. Deletion of caveolin-1 in these cells results in major functional aberrations, suggesting that caveolin-1 may be crucial to lung homeostasis and development. Furthermore, generation of mutant mice that under-express caveolin-1 results in severe functional distortion with phenotypes covering practically the entire spectrum of known lung diseases, including pulmonary hypertension, fibrosis, increased endothelial permeability, and immune defects. In this Chapter, we outline the current state of knowledge regarding caveolin-1-dependent regulation of pulmonary cell functions and discuss recent research findings on the role of caveolin-1 in various pulmonary disease states, including obstructive and fibrotic pulmonary vascular and inflammatory diseases. PMID:22411320

Goblet Cells of the Conjunctiva: A Review of Recent Findings

PubMed Central

Gipson, Ilene K

2016-01-01

Goblet cells within the conjunctival epithelium are specialized cells that secrete mucins onto the surface of the eye. Recent research has demonstrated new characteristics of the cells, including factors influencing their differentiation, their gene products and their functions at the ocular surface. The following review summarizes the newly discovered aspects of the role of Spdef, a member of the Ets transcription factor family in conjunctival goblet cell differentiation, the newly discovered goblet cell products including claudin2, the Wnt inhibitor Frzb, and the transmembrane mucin Muc16. The current concepts of conjunctival goblet cell function, including debris removal and immune surveillance are reviewed, as are changes in the goblet cell population in ocular surface diseases. Major remaining questions regarding conjunctival cell biology are discussed. PMID:27091323

Blocking Glycolytic Metabolism Increases Memory T Cells and Antitumor Function | Center for Cancer Research

Cancer.gov

CD8+ T cells are a major component of the cellular immune response, which is necessary to control a variety of bacterial and viral infections. CD8+ T cells also play a major role in the cell-mediated antitumor immune response. After encountering antigen, naïve CD8+ T cells undergo an extensive period of proliferation and expansion, and differentiate into effector cells and

Functionalized Nanostructures with Application in Regenerative Medicine

PubMed Central

Perán, Macarena; García, María A.; López-Ruiz, Elena; Bustamante, Milán; Jiménez, Gema; Madeddu, Roberto; Marchal, Juan A.

2012-01-01

In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application. PMID:22489186

Phosphoinositide function in cytokinesis.

PubMed

Brill, Julie A; Wong, Raymond; Wilde, Andrew

2011-11-22

In systems as diverse as yeast, slime mold and animal cells, the levels and distribution of phosphatidylinositol phosphates (PIPs) must be strictly regulated for successful cell cleavage. The precise mechanism by which PIPs function in this process remains unknown. Recent experiments are beginning to shed light on the cellular pathways in which PIPs make key contributions during cytokinesis. In particular, PIPs promote proper actin cytoskeletal organization and direct membrane trafficking in dividing cells. Future research will uncover temporal and spatial regulation of the different PIPs, thus elucidating their role in cytoskeletal and membrane events that drive cell cleavage. Copyright © 2011 Elsevier Ltd. All rights reserved.

Plant and algal cell walls: diversity and functionality

PubMed Central

Popper, Zoë A.; Ralet, Marie-Christine; Domozych, David S.

2014-01-01

Background Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore, wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes (plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. Scope The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every aspect of plant and algal physiology that will present many of the major challenges in future cell wall research. PMID:25453142

Plant and algal cell walls: diversity and functionality.

PubMed

Popper, Zoë A; Ralet, Marie-Christine; Domozych, David S

2014-10-01

Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore,wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes ( plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every aspect of plant and algal physiology that will present many of the major challenges in future cell wall research.

Somatostatin-Positive Gamma-Aminobutyric Acid Interneuron Deficits in Depression: Cortical Microcircuit and Therapeutic Perspectives.

PubMed

Fee, Corey; Banasr, Mounira; Sibille, Etienne

2017-10-15

The functional integration of external and internal signals forms the basis of information processing and is essential for higher cognitive functions. This occurs in finely tuned cortical microcircuits whose functions are balanced at the cellular level by excitatory glutamatergic pyramidal neurons and inhibitory gamma-aminobutyric acidergic (GABAergic) interneurons. The balance of excitation and inhibition, from cellular processes to neural network activity, is characteristically disrupted in multiple neuropsychiatric disorders, including major depressive disorder (MDD), bipolar disorder, anxiety disorders, and schizophrenia. Specifically, nearly 3 decades of research demonstrate a role for reduced inhibitory GABA level and function across disorders. In MDD, recent evidence from human postmortem and animal studies suggests a selective vulnerability of GABAergic interneurons that coexpress the neuropeptide somatostatin (SST). Advances in cell type-specific molecular genetics have now helped to elucidate several important roles for SST interneurons in cortical processing (regulation of pyramidal cell excitatory input) and behavioral control (mood and cognition). Here, we review evidence for altered inhibitory function arising from GABAergic deficits across disorders and specifically in MDD. We then focus on properties of the cortical microcircuit, where SST-positive GABAergic interneuron deficits may disrupt functioning in several ways. Finally, we discuss the putative origins of SST cell deficits, as informed by recent research, and implications for therapeutic approaches. We conclude that deficits in SST interneurons represent a contributing cellular pathology and therefore a promising target for normalizing altered inhibitory function in MDD and other disorders with reduced SST cell and GABA functions. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

ROS is Required for Alternatively Activated Macrophage Differentiation | Center for Cancer Research

Cancer.gov

Macrophages are key regulators in host inflammatory responses. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are responsible for inducing macrophage differentiation from monocytes. GM-CSF or M-CSF-differentiated macrophages can be further differentiated, or polarized, to more specialized cells. Classically activated, or M1, macrophages have immune-stimulatory properties and cytotoxic function against tumor cells. Alternatively activated, or M2, macrophages have low cytotoxic function but high tissue-remodeling activity. There are also M2-like cells called tumor-associated macrophages (TAMs) that are responsible for many tumor-promoting activities. Blocking the function of TAMs inhibits tumorigenesis.

Cell and region specificity of Aryl hydrocarbon Receptor (AhR) system in the testis and the epididymis.

PubMed

Wajda, A; Łapczuk, J; Grabowska, M; Pius-Sadowska, E; Słojewski, M; Laszczynska, M; Urasinska, E; Machalinski, B; Drozdzik, M

2017-04-01

Aryl hydrocarbon receptor (AhR) plays multiple important functions in adaptive responses. Exposure to AhR ligands may produce an altered metabolic activity controlled by the AhR pathways, and consequently affect drug/toxin responses, hormonal status and cellular homeostasis. This research revealed species-, cell- and region-specific pattern of the AhR system expression in the rat and human testis and epididymis, complementing the existing knowledge, especially within the epididymal segments. The study showed that AhR level in the rat and human epididymis is higher than in the testis. The downregulation of AhR expression after TCDD treatment was revealed in the spermatogenic cells at different stages and the epididymal epithelial cells, but not in the Sertoli and Leydig cells. Hence, this basic research provides information about the AhR function in the testis and epididymis, which may provide an insight into deleterious effects of drugs, hormones and environmental pollutants on male fertility. Copyright © 2017 Elsevier Inc. All rights reserved.

GIANT 2.0: genome-scale integrated analysis of gene networks in tissues.

PubMed

Wong, Aaron K; Krishnan, Arjun; Troyanskaya, Olga G

2018-05-25

GIANT2 (Genome-wide Integrated Analysis of gene Networks in Tissues) is an interactive web server that enables biomedical researchers to analyze their proteins and pathways of interest and generate hypotheses in the context of genome-scale functional maps of human tissues. The precise actions of genes are frequently dependent on their tissue context, yet direct assay of tissue-specific protein function and interactions remains infeasible in many normal human tissues and cell-types. With GIANT2, researchers can explore predicted tissue-specific functional roles of genes and reveal changes in those roles across tissues, all through interactive multi-network visualizations and analyses. Additionally, the NetWAS approach available through the server uses tissue-specific/cell-type networks predicted by GIANT2 to re-prioritize statistical associations from GWAS studies and identify disease-associated genes. GIANT2 predicts tissue-specific interactions by integrating diverse functional genomics data from now over 61 400 experiments for 283 diverse tissues and cell-types. GIANT2 does not require any registration or installation and is freely available for use at http://giant-v2.princeton.edu.

The evolving roles of memory immune cells in transplantation

PubMed Central

Chen, Wenhao; Ghobrial, Rafik M.; Li, Xian C.

2015-01-01

Memory cells are the products of immune responses but also exert significant impact on subsequent immunity and immune tolerance, thus placing them in a unique position in transplant research. Memory cells are heterogeneous, including not only memory T cells but also memory B cells and innate memory cells. Memory cells are a critical component of protective immunity against invading pathogens, especially in immunosuppressed patients, but they also mediate graft loss and tolerance resistance. Recent studies suggest that some memory cells unexpectedly act as regulatory cells, promoting rather than hindering transplant survival. This functional diversity makes therapeutic targeting of memory cells a challenging task in transplantation. In this article we highlight recent advances in our understanding of memory cells, focusing on diversity of memory cells and mechanisms involved in their induction and functions. We also provide a broad overview on the challenges and opportunities in targeting memory cells in the induction of transplant tolerance. PMID:26102615

Bioartificial liver devices: Perspectives on the state of the art.

PubMed

Ding, Yi-Tao; Shi, Xiao-Lei

2011-03-01

Acute liver failure remains a significant cause of morbidity and mortality. Bioartificial liver (BAL) devices have been in development for more than 20 years. Such devices aim to temporarily take over the metabolic and excretory functions of the liver until the patients' own liver has recovered or a donor liver becomes available for transplant. The important issues include the choice of cell materials and the design of the bioreactor. Ideal BAL cell materials should be of good viability and functionality, easy to access, and exclude immunoreactive and tumorigenic cell materials. Unfortunately, the current cells in use in BAL do not meet these requirements. One of the challenges in BAL development is the improvement of current materials; another key point concerning cell materials is the coculture of different cells. The bioreactor is an important component of BAL, because it determines the viability and function of the hepatocytes within it. From the perspective of bioengineering, a successful and clinically effective bioreactor should mimic the structure of the liver and provide an in vivo-like microenvironment for the growth of hepatocytes, thereby maintaining the cells' viability and function to the maximum extent. One future trend in the development of the bioreactor is to improve the oxygen supply system. Another direction for future research on bioreactors is the application of biomedical materials. In conclusion, BAL is, in principle, an important therapeutic strategy for patients with acute liver failure, and may also be a bridge to liver transplantation. It requires further research and development, however, before it can enter clinical practice.

O-GlcNAc: a novel regulator of immunometabolism.

PubMed

Machacek, Miranda; Slawson, Chad; Fields, Patrick E

2018-06-01

The rapidly expanding field of immunometabolism focuses on how metabolism controls the function of immune cells. CD4 + T cells are essential for the adaptive immune response leading to the eradication of specific pathogens. However, when T cells are inappropriately over-active, they can drive autoimmunity, allergic disease, and chronic inflammation. The mechanisms by which metabolic changes influence function in CD4 + T cells are not fully understood. The post-translational protein modification, O-GlcNAc (O-linked β-N-acetylglucosamine), dynamically cycles on and off of intracellular proteins as cells respond to their environment and flux through metabolic pathways changes. As the rate of O-GlcNAc cycling fluctuates, protein function, stability, and/or localization can be affected. Thus, O-GlcNAc is critically poised at the nexus of cellular metabolism and function. This review highlights the intra- and extracellular metabolic factors that influence CD4 + T cell activation and differentiation and how O-GlcNAc regulates these processes. We also propose areas of future research that may illuminate O-GlcNAc's role in the plasticity and pathogenicity of CD4 + T cells and uncover new potential therapeutic targets.

Cell chips as new tools for cell biology--results, perspectives and opportunities.

PubMed

Primiceri, Elisabetta; Chiriacò, Maria Serena; Rinaldi, Ross; Maruccio, Giuseppe

2013-10-07

Cell culture technologies were initially developed as research tools for studying cell functions, but nowadays they are essential for the biotechnology industry, with rapidly expanding applications requiring more and more advancements with respect to traditional tools. Miniaturization and integration of sensors and microfluidic components with cell culture techniques open the way to the development of cellomics as a new field of research targeting innovative analytic platforms for high-throughput studies. This approach enables advanced cell studies under controllable conditions by providing inexpensive, easy-to-operate devices. Thanks to their numerous advantages cell-chips have become a hotspot in biosensors and bioelectronics fields and have been applied to very different fields. In this review exemplary applications will be discussed, for cell counting and detection, cytotoxicity assays, migration assays and stem cell studies.

A T-Cell Receptor Breaks the Rules | Center for Cancer Research

Cancer.gov

Most mature T cells function immunologically when a T-cell receptor (TCR) located on the cell surface encounters and engages its ligand, a major histocompatability complex (MHC), which displays a specific part of a target protein called an antigen. This antigen-presenting complex is assembled from one of the dozen or so MHC molecules that every person inherits from their

Tissue Architecture and Microenvironment Sustain Hormone Signaling | Center for Cancer Research

Cancer.gov

Cells interact with their environments in part through protein receptors embedded in the cell membrane. Activation of a receptor by external signaling molecules sets off a complex chain of events within the cell that can result in alterations in protein structure and function and/or changes in gene expression. Proper integration of these signals is crucial for normal cell

Nanobiotechnology: Cell Membrane-Based Delivery Systems.

PubMed

Zhang, Pengfei; Liu, Gang; Chen, Xiaoyuan

2017-04-01

The increasingly rapid pace of research in the field of bioinspired drug delivery systems is revealing the promise of cell membrane-based nanovesicles for biomedical applications. Those cell membrane-based nanoparticles combine the natural functionalities of cell plasma membranes and the bioengineering flexibility of synthetic nanomaterials, and such versatility provides a means of designing exciting new drug formulations for personalized treatment in future nanomedicine.

Bench to bedside molecular functional imaging in translational cancer medicine: to image or to imagine?

PubMed

Mahajan, A; Goh, V; Basu, S; Vaish, R; Weeks, A J; Thakur, M H; Cook, G J

2015-10-01

Ongoing research on malignant and normal cell biology has substantially enhanced the understanding of the biology of cancer and carcinogenesis. This has led to the development of methods to image the evolution of cancer, target specific biological molecules, and study the anti-tumour effects of novel therapeutic agents. At the same time, there has been a paradigm shift in the field of oncological imaging from purely structural or functional imaging to combined multimodal structure-function approaches that enable the assessment of malignancy from all aspects (including molecular and functional level) in a single examination. The evolving molecular functional imaging using specific molecular targets (especially with combined positron-emission tomography [PET] computed tomography [CT] using 2- [(18)F]-fluoro-2-deoxy-D-glucose [FDG] and other novel PET tracers) has great potential in translational research, giving specific quantitative information with regard to tumour activity, and has been of pivotal importance in diagnoses and therapy tailoring. Furthermore, molecular functional imaging has taken a key place in the present era of translational cancer research, producing an important tool to study and evolve newer receptor-targeted therapies, gene therapies, and in cancer stem cell research, which could form the basis to translate these agents into clinical practice, popularly termed "theranostics". Targeted molecular imaging needs to be developed in close association with biotechnology, information technology, and basic translational scientists for its best utility. This article reviews the current role of molecular functional imaging as one of the main pillars of translational research. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Purinergic signalling in bone

PubMed Central

Rumney, Robin M. H.; Wang, Ning; Agrawal, Ankita; Gartland, Alison

2012-01-01

Purinergic signaling in bone was first proposed in the early 1990s with the observation that extracellular ATP could modulate events crucial to the normal functioning of bone cells. Since then the expression of nearly all the P2Y and P2X receptors by osteoblasts and osteoclasts has been reported, mediating multiple processes including cell proliferation, differentiation, function, and death. This review will highlight the most recent developments in the field of purinergic signaling in bone, with a special emphasis on recent work resulting from the European Framework 7 funded collaboration ATPBone, as well as Arthritis Research UK and Bone Research Society supported projects. PMID:23049524

Evaluation of cell viability and functionality in vessel-like bioprintable cell-laden tubular channels.

PubMed

Yu, Yin; Zhang, Yahui; Martin, James A; Ozbolat, Ibrahim T

2013-09-01

Organ printing is a novel concept recently introduced in developing artificial three-dimensional organs to bridge the gap between transplantation needs and organ shortage. One of the major challenges is inclusion of blood-vessellike channels between layers to support cell viability, postprinting functionality in terms of nutrient transport, and waste removal. In this research, we developed a novel and effective method to print tubular channels encapsulating cells in alginate to mimic the natural vascular system. An experimental investigation into the influence on cartilage progenitor cell (CPCs) survival, and the function of printing parameters during and after the printing process were presented. CPC functionality was evaluated by checking tissue-specific genetic marker expression and extracellular matrix production. Our results demonstrated the capability of direct fabrication of cell-laden tubular channels by our newly designed coaxial nozzle assembly and revealed that the bioprinting process could induce quantifiable cell death due to changes in dispensing pressure, coaxial nozzle geometry, and biomaterial concentration. Cells were able to recover during incubation, as well as to undergo differentiation with high-level cartilage-associated gene expression. These findings may not only help optimize our system but also can be applied to biomanufacturing of 3D functional cellular tissue engineering constructs for various organ systems.

The human Piwi protein Hiwi2 associates with tRNA-derived piRNAs in somatic cells.

PubMed

Keam, Simon P; Young, Paul E; McCorkindale, Alexandra L; Dang, Thurston H Y; Clancy, Jennifer L; Humphreys, David T; Preiss, Thomas; Hutvagner, Gyorgy; Martin, David I K; Cropley, Jennifer E; Suter, Catherine M

2014-08-01

The Piwi-piRNA pathway is active in animal germ cells where its functions are required for germ cell maintenance and gamete differentiation. Piwi proteins and piRNAs have been detected outside germline tissue in multiple phyla, but activity of the pathway in mammalian somatic cells has been little explored. In particular, Piwi expression has been observed in cancer cells, but nothing is known about the piRNA partners or the function of the system in these cells. We have surveyed the expression of the three human Piwi genes, Hiwi, Hili and Hiwi2, in multiple normal tissues and cancer cell lines. We find that Hiwi2 is ubiquitously expressed; in cancer cells the protein is largely restricted to the cytoplasm and is associated with translating ribosomes. Immunoprecipitation of Hiwi2 from MDAMB231 cancer cells enriches for piRNAs that are predominantly derived from processed tRNAs and expressed genes, species which can also be found in adult human testis. Our studies indicate that a Piwi-piRNA pathway is present in human somatic cells, with an uncharacterised function linked to translation. Taking this evidence together with evidence from primitive organisms, we propose that this somatic function of the pathway predates the germline functions of the pathway in modern animals. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Regulation of Mitochondria Function by TRAF3 in B Lymphocytes and B Cell Malignancies

DTIC Science & Technology

2015-10-01

1, 2014. 2. Chair, Block Symposia of Innate Immune Responses in Monocytes/Macrophages, Dendritic Cells , and Myeloid Cells , the Annual Meeting of...Xie P. TRAF3-mediated regulation of innate immunity and inflammation. Research Forum, Department of Cell Biology and Neuroscience, Rutgers...TRAF3: a regulator of innate immunity and inflammation. Department of Cell & Molecular Physiology, University of Loyola, Chicago, IL. Aug. 27, 2014 9

Chimeric PD-1:28 Receptor Upgrades Low-Avidity T cells and Restores Effector Function of Tumor-Infiltrating Lymphocytes for Adoptive Cell Therapy.

PubMed

Schlenker, Ramona; Olguín-Contreras, Luis Felipe; Leisegang, Matthias; Schnappinger, Julia; Disovic, Anja; Rühland, Svenja; Nelson, Peter J; Leonhardt, Heinrich; Harz, Hartmann; Wilde, Susanne; Schendel, Dolores J; Uckert, Wolfgang; Willimsky, Gerald; Noessner, Elfriede

2017-07-01

Inherent intermediate- to low-affinity T-cell receptors (TCR) that develop during the natural course of immune responses may not allow sufficient activation for tumor elimination, making the majority of T cells suboptimal for adoptive T-cell therapy (ATT). TCR affinity enhancement has been implemented to provide stronger T-cell activity but carries the risk of creating undesired cross-reactivity leading to potential serious adverse effects in clinical application. We demonstrate here that engineering of low-avidity T cells recognizing a naturally processed and presented tumor-associated antigen with a chimeric PD-1:28 receptor increases effector function to levels seen with high-avidity T cells of identical specificity. Upgrading the function of low-avidity T cells without changing the TCR affinity will allow a large arsenal of low-avidity T cells previously thought to be therapeutically inefficient to be considered for ATT. PD-1:28 engineering reinstated Th1 function in tumor-infiltrating lymphocytes that had been functionally disabled in the human renal cell carcinoma environment without unleashing undesired Th2 cytokines or IL10. Involved mechanisms may be correlated to restoration of ERK and AKT signaling pathways. In mouse tumor models of ATT, PD-1:28 engineering enabled low-avidity T cells to proliferate stronger and prevented PD-L1 upregulation and Th2 polarization in the tumor milieu. Engineered T cells combined with checkpoint blockade secreted significantly more IFNγ compared with T cells without PD-1:28, suggesting a beneficial combination with checkpoint blockade therapy or other therapeutic strategies. Altogether, the supportive effects of PD-1:28 engineering on T-cell function make it an attractive tool for ATT. Cancer Res; 77(13); 3577-90. ©2017 AACR . ©2017 American Association for Cancer Research.

Technical aspects and recommendations for single-cell qPCR.

PubMed

Ståhlberg, Anders; Kubista, Mikael

2018-02-01

Single cells are basic physiological and biological units that can function individually as well as in groups in tissues and organs. It is central to identify, characterize and profile single cells at molecular level to be able to distinguish different kinds, to understand their functions and determine how they interact with each other. During the last decade several technologies for single-cell profiling have been developed and used in various applications, revealing many novel findings. Quantitative PCR (qPCR) is one of the most developed methods for single-cell profiling that can be used to interrogate several analytes, including DNA, RNA and protein. Single-cell qPCR has the potential to become routine methodology but the technique is still challenging, as it involves several experimental steps and few molecules are handled. Here, we discuss technical aspects and provide recommendation for single-cell qPCR analysis. The workflow includes experimental design, sample preparation, single-cell collection, direct lysis, reverse transcription, preamplification, qPCR and data analysis. Detailed reporting and sharing of experimental details and data will promote further development and make validation studies possible. Efforts aiming to standardize single-cell qPCR open up means to move single-cell analysis from specialized research settings to standard research laboratories. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cancer Cytokines and the Relevance of 3D Cultures for Studying Those Implicated in Human Cancers.

PubMed

Maddaly, Ravi; Subramaniyan, Aishwarya; Balasubramanian, Harini

2017-09-01

Cancers are complex conditions and involve several factors for oncogenesis and progression. Of the various factors influencing the physiology of cancers, cytokines are known to play significant roles as mediators of functions. Intricate cytokine networks have been identified in cancers and interest in cytokines associated with cancers has been gaining ground. Of late, some of these cytokines are even identified as potential targets for cancer therapy apart from a few others such as IL-6 being identified as markers for disease prognosis. Of the major contributors to cancer research, cancer cell lines occupy the top slot as the most widely used material in vitro. In vitro cell cultures have seen significant evolution by the introduction of 3-dimensional (3D) culture systems. 3D cell cultures are now widely accepted as excellent material for cancer research which surpass the traditional monolayer cultures. Cancer research has benefited from 3D cell cultures for understanding the various hallmarks of cancers. However, the potential of these culture systems are still unexploited for cancer cytokine research compared to the other aspects of cancers such as gene expression changes, drug-induced toxicity, morphology, angiogenesis, and invasion. Considering the importance of cancer cytokines, 3D cell cultures can be better utilized in understanding their roles and functions. Some of the possibilities where 3D cell cultures can contribute to cancer cytokine research arise from the distinct morphology of the tumor spheroids, the extracellular matrix (ECM), and the spontaneous occurrence of nutrient and oxygen gradients. Also, the 3D culture models enable one to co-culture different types of cells as a simulation of in vivo conditions, enhancing their utility to study cancer cytokines. We review here the cancer associated cytokines and the contributions of 3D cancer cell cultures for studying cancer cytokines. J. Cell. Biochem. 118: 2544-2558, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

[Cell-derived microparticles unveil their fibrinolytic and proteolytic function].

PubMed

Doeuvre, Loïc; Angles-Cano, Eduardo

2009-01-01

Cell-derived microparticles (MP) are membrane microvesicles, 0.1-1 microm in size, shed by cells following activation or during apoptosis in a variety of pathological conditions. MPs released by blood cells or by vascular endothelial cells display molecular signatures that allow their identification and functional characterization. In addition, they provide tissue factor (TF) and a procoagulant phospholipid surface. Therefore, at present, the most strongly established applied research on MPs is their procoagulant activity as a determinant of thrombotic risk in various clinical conditions. Previous studies have indicated that MPs derived from malignant cells express matrix metalloproteinases, urokinase and its receptor (uPA/uPAR) that, in the presence of plasminogen, may act in concert to degrade extracellular matrix proteins. Recently, it was shown that MPs from TNFa-stimulated endothelial cells served as a surface for interaction with plasminogen and its conversion into plasmin by the uPA/uPAR system expressed at their surface. This capacity of MPs to promote plasmin generation confers them a new profibrinolytic and proteolytic function that may be of relevance in fibrinolysis, cell migration, angiogenesis, dissemination of malignant cells, cell detachment and apoptosis.

[Recent research advance on bone marrow microenvironment-mediated leukemia drug resistant mechanism].

PubMed

Fu, Bing; Ling, Yan-Juan

2011-06-01

The bone marrow microenvironment consists of bone marrow stromal cells, osteoblasts and osteoclasts which facilities the survival, differentiation and proliferation of hematopoietic cells through secreting soluble factors and extracellular matrix proteins that mediate these functions. This environment not only supports the growth of normal and malignant hematopoietic cells, but also protects them against the damage from chemotherapeutic agents through the secretion of soluble cytokines, cell adhesion, up-regulation of resistant genes and changes of cell cycle. In this review, the research advances on drug-resistance mechanisms mediated by bone marrow microenvironment are summarized briefly, including soluble factors mediating drug resistance, intercellular adhesion inducing drug resistance, up-regulation of some drug resistance genes, regulation in metabolism of leukemic cells, changes in cell cycles of tumor cells and so on.

The Functional Architecture of the Retina.

ERIC Educational Resources Information Center

Masland, Richard H.

1986-01-01

Examines research related to the retina's coding of visual input with emphasis on the organization of two kinds of ganglion cell receptive fields. Reviews current techniques for examining the shapes and arrangement in the retina of entire populations of nerve cells. (ML)

Location, morphology and function of nephrocytes in termites.

PubMed

Costa-Leonardo, Ana Maria; Janei, Vanelize; Laranjo, Lara Teixeira; Haifig, Ives

2015-07-01

Insect nephrocytes are cells bathed in hemolymph and considered to have an excretory function. These cells have ambiguous nomenclature and are understudied in termites. This study is the first report on the occurrence, morphology and function of nephrocytes in different termite castes. Cytological characteristics in specific developmental stages and castes enable physiological functions to be inferred. Perforate diaphragms indicate a role in filtration, while the extensive peripheral invaginations of the cell membrane suggest active endocytosis. A sequence of morphologies in putative digestive vacuoles infers a lysosomal system and the occurrence of phosphatases suggests a function involving detoxification of substances sequestered from hemolymph. Pericardical nephrocytes took up the dye trypan blue injected in live termites, suggesting their activity connected to the filtration of the hemolymph. Additionally, histochemical tests showed the existence of stored proteins in their cytoplasm. These cells present a well-developed Golgi apparatus and abundant rough endoplasmic reticulum, consistent with protein synthesis. This study highlights the importance of nephrocytes in Isoptera and opens perspectives for further research of these cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

[CD4 + CD25 + regulatory T cells and their importance to human illnesses].

PubMed

Kelsen, Jens; Hvas, Christian Lodberg; Agnholt, Jørgen; Dahlerup, Jens F

2006-01-03

Regulatory T cells ensure a balanced immune response that is competent both to fight pathogens, at the same time, to recognize self-antigens and commensals as harmless. Regulatory mechanisms are essential in preventing autoimmune disorders but may also facilitate the progression of malignant diseases and the establishment of latent infections via suppression of the host immune response. Regulatory T cells arise in the thymus, and regulatory T cell function can be induced in the periphery, so-called infectious tolerance. An absolute or relative defect in regulatory T cell function may contribute to the development of autoimmune disorders such as rheumatoid arthritis, type 1 diabetes mellitus, multiple sclerosis and chronic inflammatory bowel disease. Regulatory T cell therapy is a tempting strategy for reestablishing the immune balance and thus preventing or reversing these disorders. Reestablishment of the immune balance may be accomplished by adoptive transfer of ex vivo-propagated regulatory T cells or by induction of regulatory functions locally in the organs, although such strategies are in their infancy in human research.

Robust and Highly-Efficient Differentiation of Functional Monocytic Cells from Human Pluripotent Stem Cells under Serum- and Feeder Cell-Free Conditions

PubMed Central

Yanagimachi, Masakatsu D.; Niwa, Akira; Tanaka, Takayuki; Honda-Ozaki, Fumiko; Nishimoto, Seiko; Murata, Yuuki; Yasumi, Takahiro; Ito, Jun; Tomida, Shota; Oshima, Koichi; Asaka, Isao; Goto, Hiroaki; Heike, Toshio; Nakahata, Tatsutoshi; Saito, Megumu K.

2013-01-01

Monocytic lineage cells (monocytes, macrophages and dendritic cells) play important roles in immune responses and are involved in various pathological conditions. The development of monocytic cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is of particular interest because it provides an unlimited cell source for clinical application and basic research on disease pathology. Although the methods for monocytic cell differentiation from ESCs/iPSCs using embryonic body or feeder co-culture systems have already been established, these methods depend on the use of xenogeneic materials and, therefore, have a relatively poor-reproducibility. Here, we established a robust and highly-efficient method to differentiate functional monocytic cells from ESCs/iPSCs under serum- and feeder cell-free conditions. This method produced 1.3×106±0.3×106 floating monocytes from approximately 30 clusters of ESCs/iPSCs 5–6 times per course of differentiation. Such monocytes could be differentiated into functional macrophages and dendritic cells. This method should be useful for regenerative medicine, disease-specific iPSC studies and drug discovery. PMID:23573196

[Formula: see text]Executive functioning and health-related quality of life in pediatric sickle cell disease.

PubMed

Allen, Taryn M; Anderson, Lindsay M; Rothman, Jennifer A; Bonner, Melanie J

2017-11-01

Research consistently indicates that children with sickle cell disease (SCD) face multiple risk factors for neurocognitive impairment. Despite this, no empirical research to date has examined the impact of neurocognitive functioning on quality of life for this pediatric group. Thus, the current study aims to examine the relationship between executive functioning and quality of life in a sample of children with SCD and further explore psychosocial and family/caregiver resources as moderators of this relationship. A total of 45 children with SCD aged 8 to 16 years and their caregivers completed measures of quality of life, behavioral ratings of executive functioning, and psychosocial functioning. Hierarchical linear regression models were utilized to determine the impact of executive functioning on quality of life and further test the interaction effects of proposed moderating variables. Controlling for age, pain, and socioeconomic status (SES), executive functioning was found to significantly predict child- and parent-reported quality of life among youth with SCD. Psychosocial resources of the primary caregiver or family was not found to moderate the relationship between executive functioning and quality of life. These results provide the first empirical evidence that lower executive skills negatively predict quality of life for children with SCD, supporting clinical and research efforts which aim to establish efficacious interventions that target cognitive decrements within this pediatric population.

How the study of Listeria monocytogenes has led to new concepts in biology.

PubMed

Rolhion, Nathalie; Cossart, Pascale

2017-06-01

The opportunistic intracellular bacterial pathogen Listeria monocytogenes has in 30 years emerged as an exceptional bacterial model system in infection biology. Research on this bacterium has provided considerable insight into how pathogenic bacteria adapt to mammalian hosts, invade eukaryotic cells, move intracellularly, interfere with host cell functions and disseminate within tissues. It also contributed to unveil features of normal host cell pathways and unsuspected functions of previously known cellular proteins. This review provides an updated overview of our knowledge on this pathogen. In many examples, findings on L. monocytogenes provided the basis for new concepts in bacterial regulation, cell biology and infection processes.

Material Cues as Potent Regulators of Epigenetics and Stem Cell Function.

PubMed

Crowder, Spencer W; Leonardo, Vincent; Whittaker, Thomas; Papathanasiou, Peter; Stevens, Molly M

2016-01-07

Biophysical signals act as potent regulators of stem cell function, lineage commitment, and epigenetic status. In recent years, synthetic biomaterials have been used to study a wide range of outside-in signaling events, and it is now well appreciated that material cues modulate the epigenome. Here, we review the role of extracellular signals in guiding stem cell behavior via epigenetic regulation, and we stress the role of physicochemical material properties as an often-overlooked modulator of intracellular signaling. We also highlight promising new research tools for ongoing interrogation of the stem cell-material interface. Copyright © 2016 Elsevier Inc. All rights reserved.

Immune regulation by CD40-CD40-l interactions - 2; Y2K update.

PubMed

van Kooten, C

2000-11-01

CD40 is a cell surface receptor, which belongs to the TNF-R family, and which was first identified and functionally characterized on B lymphocytes. However, in recent years it has become clear that CD40 is expressed much broader, including expression on monocytes, dendritic cells, endothelial cells and epithelial cells. Therefore it is now thought that CD40 plays a more general role in immune regulation. The present paper reviews recent developments in this field of research, with main emphasis on CD40 signal transduction and on in vivo functions of CD40/CD40-L interactions.

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve uncontrolled growth.

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve

The Function of Neuroendocrine Cells in Prostate Cancer

DTIC Science & Technology

2015-06-20

Comprehensive Cancer Center and 4Broad Center for Regenerative Medicine and Stem Cell Biology, David Geffen School of Medicine at UCLA, 10833 Le Conte... Regenerative Medicine and Stem Cell Research, UCLA David Geffen School of Medicine , Los Angeles, California. 2Department of Urology, The First...progress in prostate cancer. Soochou University Annual Translational Medicine Meeting, Suzhou, China, November 2013 21. Prostate Cancer Stem Cells

Renal cell carcinoma: new insights and challenges for a clinician scientist.

PubMed

Shingarev, Roman; Jaimes, Edgar A

2017-08-01

There is a growing recognition of the complex interplay between renal cell cancer (RCC), kidney function, mechanical reduction of nephron mass, and systemic agents targeting the cancer. Earlier detection of RCC and rising life expectancy of cancer survivors places a greater emphasis on preservation of renal function after cancer resection and during systemic therapy. Unique adverse effects associated with RCC drugs not only help reveal cancer pathophysiology but also expand our knowledge of normal cell signaling and metabolism. In this review, we outline our current understanding of RCC biology and treatment, their bidirectional relationship with kidney function, and unmet research needs in this field. Copyright © 2017 the American Physiological Society.

Simulation and experimental research on micro-channel for detecting cell status in bio-artificial liver.

PubMed

Wu, Changzhe; Cao, Yue; Huo, Xiaolin; Li, Ming

2015-01-01

Bioartificial liver support system (BALSS) based on culturing hepatocytes is an important research field for the treatment of acute liver failure. It is necessary to monitor the state of liver cell functions during the treatment of BALSS in order to guide clinical treatment. To design a micro-channel chip to achieve flash mixing for timely detection of liver cell status in bioreactors and improving liver cells growth environment to ensure the efficacy of the bio-artificial liver support system. Alanine aminotransferase (ALT) and Urea are chosen as detection indicators to reflect the degree of liver cell injury and the detoxification function. A diamond tandem structure micro-channel is designed and optimized to achieve the efficient mixing of serum and ALT or Urea reagent. The simulation and experimental results show that the diamond tandem structure micro-channel can significantly improve the mixing efficiency and meet the online detecting requirements. The easily controllable diamond tandem structure micro-channel combines the advantages of active and passive mixer and can effectively mix the serum and ALT or Urea reagent. It lays the foundation for online monitoring of liver cells and will help to improve the viability of liver cell in the bioreactor.

Genipin-crosslinked microcarriers mediating hepatocellular aggregates formation and functionalities.

PubMed

Lau, Ting Ting; Wang, Chunming; Png, Sze Wei; Su, Kai; Wang, Dong-An

2011-01-01

In engineered regenerative medicine, various types of scaffolds have been customized to pursue the optimal environment for different types of therapeutic cells. In liver therapeutic research, hepatocytes require attachment to solid anchors for survival and proliferation before they could grow into cellular aggregates with enhanced functionalities. Among the various biomaterials scaffolds and vehicles, microspherical cell carriers are suited to these requirements. Individual spheres may provide two-dimensional (2D) cell-affinitive surfaces for cell adhesion and spreading; whereas multiple microcarriers may form three-dimensional (3D) matrices with inter-spherical space for cell expansion and multicellular aggregation. In this study, we culture human liver carcinoma cell line (HepG2) cells on genipin-crosslinked gelatin microspheres of two different sizes. Results suggest that both microcarriers support cell adhesion, proliferation, and spontaneous formation of hepatocellular aggregates, among which the spheres with bigger size (200-300 μm) seem more favorable than the smaller ones in terms of aggregate formation and liver specific functionalities. These findings suggest that the genipin-crosslinked microcarrier is a competent vehicle for liver cell delivery. Copyright © 2010 Wiley Periodicals, Inc.

Microfabricated biocapsules for the immunoisolation of pancreatic islets of Langerhans

NASA Astrophysics Data System (ADS)

Desai, Tejal Ashwin

1998-08-01

A silicon-based microfabricated biocapsule was developed and evaluated for use in the immunoisolation of transplanted cells, specifically pancreatic islets of Langerhans for the treatment of Type I diabetes. The transplantation of cells with specific functions is a promising therapy for a wide variety of pathologies including diabetes, Parkinson's, and hemophilia. Such transplanted cells, however, are sensitive to both cellular and humoral immune rejection as well as damage by autoimmune activity, without chronic immunosuppression. The research presented in this dissertation investigated whether microfabricated silicon-based biocapsules, with uniform membrane pore sizes in the tens of nanometer range, could provide an immunoprotective environment for pancreatic islets and other insulin-secreting cell lines, while maintaining cell viability and functionality. By utilizing fabrication techniques commonly employed in the microelectronics industry (MEMS), membranes were fabricated with precisely controlled and uniform pore sizes, allowing the optimization of biocapsule membrane parameters for the encapsulation of specific hormone-secreting cell types. The biocapsule-forming process employed bulk micromachining to define cell-containing chambers within single crystalline silicon wafers. These chambers interface with the surrounding biological environment through polycrystalline silicon filter membranes, which were surface micromachined to present a high density of uniform pores to allow sufficient permeability to oxygen, glucose, and insulin. Both in vitro and in vivo experiments established the biocompatibility of the microfabricated biocapsule, and demonstrated that encapsulated cells could live and function normally in terms of insulin-secretion within microfabricated environments for extended periods of time. This novel research shows the potential of using microfabricated biocapsules for the encapsulation of several different cell xenografts. The semipermeability of microfabricated biocapsules, their biocompatibility, along with their thermal and chemical stability, may provide an improved encapsulation device for the immunoisolation of cell xenografts in hormone-replacement and cell-based therapies.

Doxycycline Impairs Mitochondrial Function and Protects Human Glioma Cells from Hypoxia-Induced Cell Death: Implications of Using Tet-Inducible Systems.

PubMed

Luger, Anna-Luisa; Sauer, Benedikt; Lorenz, Nadja I; Engel, Anna L; Braun, Yannick; Voss, Martin; Harter, Patrick N; Steinbach, Joachim P; Ronellenfitsch, Michael W

2018-05-17

Inducible gene expression is an important tool in molecular biology research to study protein function. Most frequently, the antibiotic doxycycline is used for regulation of so-called tetracycline (Tet)-inducible systems. In contrast to stable gene overexpression, these systems allow investigation of acute and reversible effects of cellular protein induction. Recent reports have already called for caution when using Tet-inducible systems as the employed antibiotics can disturb mitochondrial function and alter cellular metabolism by interfering with mitochondrial translation. Reprogramming of energy metabolism has lately been recognized as an important emerging hallmark of cancer and is a central focus of cancer research. Therefore, the scope of this study was to systematically analyze dose-dependent metabolic effects of doxycycline on a panel of glioma cell lines with concomitant monitoring of gene expression from Tet-inducible systems. We report that doxycycline doses commonly used with inducible expression systems (0.01⁻1 µg/mL) substantially alter cellular metabolism: Mitochondrial protein synthesis was inhibited accompanied by reduced oxygen and increased glucose consumption. Furthermore, doxycycline protected human glioma cells from hypoxia-induced cell death. An impairment of cell growth was only detectable with higher doxycycline doses (10 µg/mL). Our findings describe settings where doxycycline exerts effects on eukaryotic cellular metabolism, limiting the employment of Tet-inducible systems.

To Be or Not to Be: Controlling Cellular Suicide | Center for Cancer Research

Cancer.gov

When a cell is damaged and can no longer function properly, a complex series of molecular steps is triggered that allows it to die in a controlled manner. This cellular suicide is called programmed cell death, or apoptosis.

Maintenance of Epithelial Stem Cells by Cbl Proteins

DTIC Science & Technology

2013-09-01

our research findings during the entire grant period (Sept. 2010 – Aug. 2013). 1. Analysis of Cbl functions in progenitor-type mammary epithelial...catenin pathway, but further investigation is required to establish this. 2. Analysis of Cbl functions in vivo using gene mutant mouse models We...Nandwani N, Gu H, Band V, Band H. Rapidly fatal myeloproliferative disorders in mice with deletion of Casitas B-cell lymphoma (Cbl) and Cbl-b in

Biology Education Research Trends in Turkey

ERIC Educational Resources Information Center

Gul, Seyda; Sozbilir, Mustafa

2015-01-01

This paper reports on a content analysis of 633 biology education research [BER] papers published by Turkish science educators in national and international journals. The findings indicate that more research has been undertaken in environment and ecology, the cell and animal form and functions. In addition learning, teaching and attitudes were in…

Advances in Monitoring Cell-Based Therapies with Magnetic Resonance Imaging: Future Perspectives

PubMed Central

Ngen, Ethel J.; Artemov, Dmitri

2017-01-01

Cell-based therapies are currently being developed for applications in both regenerative medicine and in oncology. Preclinical, translational, and clinical research on cell-based therapies will benefit tremendously from novel imaging approaches that enable the effective monitoring of the delivery, survival, migration, biodistribution, and integration of transplanted cells. Magnetic resonance imaging (MRI) offers several advantages over other imaging modalities for elucidating the fate of transplanted cells both preclinically and clinically. These advantages include the ability to image transplanted cells longitudinally at high spatial resolution without exposure to ionizing radiation, and the possibility to co-register anatomical structures with molecular processes and functional changes. However, since cellular MRI is still in its infancy, it currently faces a number of challenges, which provide avenues for future research and development. In this review, we describe the basic principle of cell-tracking with MRI; explain the different approaches currently used to monitor cell-based therapies; describe currently available MRI contrast generation mechanisms and strategies for monitoring transplanted cells; discuss some of the challenges in tracking transplanted cells; and suggest future research directions. PMID:28106829

Synthetic biology in mammalian cells: Next generation research tools and therapeutics

PubMed Central

Lienert, Florian; Lohmueller, Jason J; Garg, Abhishek; Silver, Pamela A

2014-01-01

Recent progress in DNA manipulation and gene circuit engineering has greatly improved our ability to programme and probe mammalian cell behaviour. These advances have led to a new generation of synthetic biology research tools and potential therapeutic applications. Programmable DNA-binding domains and RNA regulators are leading to unprecedented control of gene expression and elucidation of gene function. Rebuilding complex biological circuits such as T cell receptor signalling in isolation from their natural context has deepened our understanding of network motifs and signalling pathways. Synthetic biology is also leading to innovative therapeutic interventions based on cell-based therapies, protein drugs, vaccines and gene therapies. PMID:24434884

Assessment of Safety and Functional Efficacy of Stem Cell-Based Therapeutic Approaches Using Retinal Degenerative Animal Models

PubMed Central

Lin, Tai-Chi; Zhu, Danhong; Hinton, David R.; Clegg, Dennis O.; Humayun, Mark S.

2017-01-01

Dysfunction and death of retinal pigment epithelium (RPE) and or photoreceptors can lead to irreversible vision loss. The eye represents an ideal microenvironment for stem cell-based therapy. It is considered an “immune privileged” site, and the number of cells needed for therapy is relatively low for the area of focused vision (macula). Further, surgical placement of stem cell-derived grafts (RPE, retinal progenitors, and photoreceptor precursors) into the vitreous cavity or subretinal space has been well established. For preclinical tests, assessments of stem cell-derived graft survival and functionality are conducted in animal models by various noninvasive approaches and imaging modalities. In vivo experiments conducted in animal models based on replacing photoreceptors and/or RPE cells have shown survival and functionality of the transplanted cells, rescue of the host retina, and improvement of visual function. Based on the positive results obtained from these animal experiments, human clinical trials are being initiated. Despite such progress in stem cell research, ethical, regulatory, safety, and technical difficulties still remain a challenge for the transformation of this technique into a standard clinical approach. In this review, the current status of preclinical safety and efficacy studies for retinal cell replacement therapies conducted in animal models will be discussed. PMID:28928775

Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity

PubMed Central

Eisenstein, Sarah A.; Gredysa, Danuta M.; Antenor–Dorsey, Jo Ann; Green, Leonard; Arbeláez, Ana Maria; Koller, Jonathan M.; Black, Kevin J.; Perlmutter, Joel S.; Moerlein, Stephen M.; Hershey, Tamara

2015-01-01

Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30) and non-obese (n = 20; body mass index<30) adults were assessed for percent body fat with dual-energy X-ray absorptiometry and for β-cell function using disposition index. Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methyl)benperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting). Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting). In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans. PMID:26192187

Insulin, Central Dopamine D2 Receptors, and Monetary Reward Discounting in Obesity.

PubMed

Eisenstein, Sarah A; Gredysa, Danuta M; Antenor-Dorsey, Jo Ann; Green, Leonard; Arbeláez, Ana Maria; Koller, Jonathan M; Black, Kevin J; Perlmutter, Joel S; Moerlein, Stephen M; Hershey, Tamara

2015-01-01

Animal research finds that insulin regulates dopamine signaling and reward behavior, but similar research in humans is lacking. We investigated whether individual differences in body mass index, percent body fat, pancreatic β-cell function, and dopamine D2 receptor binding were related to reward discounting in obese and non-obese adult men and women. Obese (n = 27; body mass index>30) and non-obese (n = 20; body mass index<30) adults were assessed for percent body fat with dual-energy X-ray absorptiometry and for β-cell function using disposition index. Choice of larger, but delayed or less certain, monetary rewards relative to immediate, certain smaller monetary rewards was measured using delayed and probabilistic reward discounting tasks. Positron emission tomography using a non-displaceable D2-specific radioligand, [11C](N-methyl)benperidol quantified striatal D2 receptor binding. Groups differed in body mass index, percent body fat, and disposition index, but not in striatal D2 receptor specific binding or reward discounting. Higher percent body fat in non-obese women related to preference for a smaller, certain reward over a larger, less likely one (greater probabilistic discounting). Lower β-cell function in the total sample and lower insulin sensitivity in obese related to stronger preference for an immediate and smaller monetary reward over delayed receipt of a larger one (greater delay discounting). In obese adults, higher striatal D2 receptor binding related to greater delay discounting. Interestingly, striatal D2 receptor binding was not significantly related to body mass index, percent body fat, or β-cell function in either group. Our findings indicate that individual differences in percent body fat, β-cell function, and striatal D2 receptor binding may each contribute to altered reward discounting behavior in non-obese and obese individuals. These results raise interesting questions about whether and how striatal D2 receptor binding and metabolic factors, including β-cell function, interact to affect reward discounting in humans.

Supporting Biomaterials for Articular Cartilage Repair

PubMed Central

Duarte Campos, Daniela Filipa; Drescher, Wolf; Rath, Björn; Tingart, Markus

2012-01-01

Orthopedic surgeons and researchers worldwide are continuously faced with the challenge of regenerating articular cartilage defects. However, until now, it has not been possible to completely mimic the biological and biochemical properties of articular cartilage using current research and development approaches. In this review, biomaterials previously used for articular cartilage repair research are addressed. Furthermore, a brief discussion of the state of the art of current cell printing procedures mimicking native cartilage is offered in light of their use as future alternatives for cartilage tissue engineering. Inkjet cell printing, controlled deposition cell printing tools, and laser cell printing are cutting-edge techniques in this context. The development of mimetic hydrogels with specific biological properties relevant to articular cartilage native tissue will support the development of improved, functional, and novel engineered tissue for clinical application. PMID:26069634

Stem cells: sources and applications.

PubMed

Vats, A; Tolley, N S; Polak, J M; Buttery, L D K

2002-08-01

Tissue engineering is a multidisciplinary area of research aimed at regeneration of tissues and restoration of function of organs through implantation of cells/tissues grown outside the body, or stimulating cells to grow into implanted matrix. In this short review, some of the most recent developments in the use of stem cells for tissue repair and regeneration will be discussed. There is no doubt that stem cells derived from adult and embryonic sources hold great therapeutic potential but it is clear that there is still much research required before their use is commonplace. There is much debate over adult versus embryonic stem cells and whether both are required. It is probably too early to disregard one or other of these cell sources. With regard to embryonic stem cells, the major concern relates to the ethics of their creation and the proposed practice of therapeutic cloning.

Phosphoinositide kinases and the synthesis of polyphosphoinositides in higher plant cells

NASA Technical Reports Server (NTRS)

Drobak, B. K.; Dewey, R. E.; Boss, W. F.; Davies, E. (Principal Investigator)

1999-01-01

Phosphoinositides are a family of inositol-containing phospholipids which are present in all eukaryotic cells. Although in most cells these lipids, with the exception of phosphatidylinositol, constitute only a very minor proportion of total cellular lipids, they have received immense attention by researchers in the past 15-20 years. This is due to the discovery that these lipids, rather than just having structural functions, play key roles in a wide range of important cellular processes. Much less is known about the plant phosphoinositides than about their mammalian counterparts. However, it has been established that a functional phosphoinositide system exists in plant cells and it is becoming increasingly clear that inositol-containing lipids are likely to play many important roles throughout the life of a plant. It is not our intention to give an exhaustive overview of all aspects of the field, but rather we focus on the phosphoinositide kinases responsible for the synthesis of all phosphorylated forms of phosphatidylinositol. Also, we mention some of the aspects of current phosphoinositide research which, in our opinion, are most likely to provide a suitable starting point for further research into the role of phosphoinositides in plants.

Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant1[C][W

PubMed Central

Hudik, Elodie; Yoshioka, Yasushi; Domenichini, Séverine; Bourge, Mickaël; Soubigout-Taconnat, Ludivine; Mazubert, Christelle; Yi, Dalong; Bujaldon, Sandrine; Hayashi, Hiroyuki; De Veylder, Lieven; Bergounioux, Catherine; Benhamed, Moussa; Raynaud, Cécile

2014-01-01

The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants. PMID:25037213

The SLIT/ROBO pathway: a regulator of cell function with implications for the reproductive system

PubMed Central

Dickinson, Rachel E; Duncan, W Colin

2010-01-01

The secreted SLIT glycoproteins and their Roundabout (ROBO) receptors were originally identified as important axon guidance molecules. They function as a repulsive cue with an evolutionarily conserved role in preventing axons from migrating to inappropriate locations during the assembly of the nervous system. In addition the SLIT-ROBO interaction is involved in the regulation of cell migration, cell death and angiogenesis and, as such, has a pivotal role during the development of other tissues such as the lung, kidney, liver and breast. The cellular functions that the SLIT/ROBO pathway controls during tissue morphogenesis are processes that are dysregulated during cancer development. Therefore inactivation of certain SLITs and ROBOs is associated with advanced tumour formation and progression in disparate tissues. Recent research has indicated that the SLIT/ROBO pathway could also have important functions in the reproductive system. The fetal ovary expresses most members of the SLIT and ROBO families. The SLITs and ROBOs also appear to be regulated by steroid hormones and regulate physiological cell functions in adult reproductive tissues such as the ovary and endometrium. Furthermore several SLITs and ROBOs are aberrantly expressed during the development of ovarian, endometrial, cervical and prostate cancer. This review will examine the roles this pathway could have in the development, physiology and pathology of the reproductive system and highlight areas for future research that could further dissect the influence of the SLIT/ROBO pathway in reproduction. PMID:20100881

The SLIT-ROBO pathway: a regulator of cell function with implications for the reproductive system.

PubMed

Dickinson, Rachel E; Duncan, W Colin

2010-04-01

The secreted SLIT glycoproteins and their Roundabout (ROBO) receptors were originally identified as important axon guidance molecules. They function as a repulsive cue with an evolutionarily conserved role in preventing axons from migrating to inappropriate locations during the assembly of the nervous system. In addition the SLIT-ROBO interaction is involved in the regulation of cell migration, cell death and angiogenesis and, as such, has a pivotal role during the development of other tissues such as the lung, kidney, liver and breast. The cellular functions that the SLIT/ROBO pathway controls during tissue morphogenesis are processes that are dysregulated during cancer development. Therefore inactivation of certain SLITs and ROBOs is associated with advanced tumour formation and progression in disparate tissues. Recent research has indicated that the SLIT/ROBO pathway could also have important functions in the reproductive system. The fetal ovary expresses most members of the SLIT and ROBO families. The SLITs and ROBOs also appear to be regulated by steroid hormones and regulate physiological cell functions in adult reproductive tissues such as the ovary and endometrium. Furthermore several SLITs and ROBOs are aberrantly expressed during the development of ovarian, endometrial, cervical and prostate cancer. This review will examine the roles this pathway could have in the development, physiology and pathology of the reproductive system and highlight areas for future research that could further dissect the influence of the SLIT/ROBO pathway in reproduction.

The Sertoli cell: one hundred fifty years of beauty and plasticity

PubMed Central

França, L. R.; Hess, R. A.; Dufour, J. M.; Hofmann, M. C.; Griswold, M. D.

2017-01-01

SUMMARY It has been one and a half centuries since Enrico Sertoli published the seminal discovery of the testicular ‘nurse cell’, not only a key cell in the testis, but indeed one of the most amazing cells in the vertebrate body. In this review, we begin by examining the three phases of morphological research that have occurred in the study of Sertoli cells, because microscopic anatomy was essentially the only scientific discipline available for about the first 75 years after the discovery. Biochemistry and molecular biology then changed all of biological sciences, including our understanding of the functions of Sertoli cells. Immunology and stem cell biology were not even topics of science in 1865, but they have now become major issues in our appreciation of Sertoli cell’s role in spermatogenesis. We end with the universal importance and plasticity of function by comparing Sertoli cells in fish, amphibians, and mammals. In these various classes of vertebrates, Sertoli cells have quite different modes of proliferation and epithelial maintenance, cystic vs. tubular formation, yet accomplish essentially the same function but in strikingly different ways. PMID:26846984

RNAi Technique in Stem Cell Research: Current Status and Future Perspectives.

PubMed

Zou, Gang-Ming

2017-01-01

RNAi is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double-strand RNA molecules. In the 18 years since the initial report, RNAi has now been demonstrated to function in mammalian cells to alter gene expression and has been used as a means for genetic discovery as well as a possible strategy for genetic correction and genetic therapy in cancer and other disease. The aim of this review is to provide a general overview of how RNAi suppresses gene expression and to examine some published RNAi approaches that have resulted in changes in stem cell function and suggest the possible clinical relevance of this work in cancer therapy through targeting cancer stem cells.

EGF-like peptide-enhanced cell motility in Dictyostelium functions independently of the cAMP-mediated pathway and requires active Ca2+/calmodulin signaling.

PubMed

Huber, Robert; O'Day, Danton H

2011-04-01

Current knowledge suggests that cell movement in the eukaryotic slime mold Dictyostelium discoideum is mediated by different signaling pathways involving a number of redundant components. Our previous research has identified a specific motility-enhancing function for epidermal growth factor-like (EGFL) repeats in Dictyostelium, specifically for the EGFL repeats of cyrA, a matricellular, calmodulin (CaM)-binding protein in Dictyostelium. Using mutants of cAMP signaling (carA(-), carC(-), gpaB(-), gpbA(-)), the endogenous calcium (Ca(2+)) release inhibitor TMB-8, the CaM antagonist W-7, and a radial motility bioassay, we show that DdEGFL1, a synthetic peptide whose sequence is obtained from the first EGFL repeat of cyrA, functions independently of the cAMP-mediated signaling pathways to enhance cell motility through a mechanism involving Ca(2+) signaling, CaM, and RasG. We show that DdEGFL1 increases the amounts of polymeric myosin II heavy chain and actin in the cytoskeleton by 24.1±10.7% and 25.9±2.1% respectively and demonstrate a link between Ca(2+)/CaM signaling and cytoskeletal dynamics. Finally, our findings suggest that carA and carC mediate a brake mechanism during chemotaxis since DdEGFL1 enhanced the movement of carA(-)/carC(-) cells by 844±136% compared to only 106±6% for parental DH1 cells. Based on our data, this signaling pathway also appears to involve the G-protein β subunit, RasC, RasGEFA, and protein kinase B. Together, our research provides insight into the functionality of EGFL repeats in Dictyostelium and the signaling pathways regulating cell movement in this model organism. It also identifies several mechanistic components of DdEGFL1-enhanced cell movement, which may ultimately provide a model system for understanding EGFL repeat function in higher organisms. Copyright © 2010 Elsevier Inc. All rights reserved.

Bone culture research

NASA Technical Reports Server (NTRS)

Partridge, Nicola C.

1993-01-01

The experiments described are aimed at exploring PTH regulation of production of collagenase and protein inhibitors of collagenase (tissue inhibitors of metalloproteases, TIMP-1 and -2) by osteoblast-like osteosarcoma cells under conditions of weightlessness. The results of this work will contribute to information as to whether a microgravity environment alters the functions and responsiveness of the osteoblast. The objectives of the Bone Culture Research (BCR) experiment are: to observe the effects of microgravity on the morphology, rate of proliferation, and behavior of the osteoblastic cells, UMR 106-01; to determine whether microgravy affects the hormonal sensitivity of osteroblastic cells; and to measure the secretion of collagenase and its inhibitors into the medium under conditions of microgravity. The methods employed will consist of the following: the osteoblast-like cells, UMR-106-01, will be cultured in four NASDA cell culture chambers; two chambers will be subjected to microgravity on SL-J; two chambers will remain on the ground at KSC as ground controls but subjected to an identical set of culture conditions as on the shuttle; media will be changed four times; twice the cells will receive the hormone parathyroid hormone-related protein (PTHrP) and media collected; cells will be photographed under conditions of microgravity; and media and photographs will be analyzed upon return to determine whether functions of the cells changed.

Genetic Tools for Self-Organizing Culture of Mouse Embryonic Stem Cells via Small Regulatory RNA-Mediated Technologies, CRISPR/Cas9, and Inducible RNAi.

PubMed

Takata, Nozomu; Sakakura, Eriko; Sakuma, Tetsushi; Yamamoto, Takashi

2017-01-01

Approaches to investigate gene functions in experimental biology are becoming more diverse and reliable. Furthermore, several kinds of tissues and organs that possess their original identities can be generated in petri dishes from stem cells including embryonic, adult and induced pluripotent stem cells. Researchers now have several choices of experimental methods and their combinations to analyze gene functions in various biological systems. Here, as an example we describe one of the better protocols, which combines three-dimensional embryonic stem cell culture with small regulatory RNA-mediated technologies, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), and inducible RNA interference (RNAi). This protocol allows investigation of genes of interest to better understand gene functions in target tissues (or organs) during in vitro development.

Engineering Concepts in Stem Cell Research.

PubMed

Narayanan, Karthikeyan; Mishra, Sachin; Singh, Satnam; Pei, Ming; Gulyas, Balazs; Padmanabhan, Parasuraman

2017-12-01

The field of regenerative medicine integrates advancements made in stem cells, molecular biology, engineering, and clinical methodologies. Stem cells serve as a fundamental ingredient for therapeutic application in regenerative medicine. Apart from stem cells, engineering concepts have equally contributed to the success of stem cell based applications in improving human health. The purpose of various engineering methodologies is to develop regenerative and preventive medicine to combat various diseases and deformities. Explosion of stem cell discoveries and their implementation in clinical setting warrants new engineering concepts and new biomaterials. Biomaterials, microfluidics, and nanotechnology are the major engineering concepts used for the implementation of stem cells in regenerative medicine. Many of these engineering technologies target the specific niche of the cell for better functional capability. Controlling the niche is the key for various developmental activities leading to organogenesis and tissue homeostasis. Biomimetic understanding not only helped to improve the design of the matrices or scaffolds by incorporating suitable biological and physical components, but also ultimately aided adoption of designs that helped these materials/devices have better function. Adoption of engineering concepts in stem cell research improved overall achievement, however, several important issues such as long-term effects with respect to systems biology needs to be addressed. Here, in this review the authors will highlight some interesting breakthroughs in stem cell biology that use engineering methodologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical compaction directly modulates the dynamics of bile canaliculi formation.

PubMed

Wang, Yan; Toh, Yi-Chin; Li, Qiushi; Nugraha, Bramasta; Zheng, Baixue; Lu, Thong Beng; Gao, Yi; Ng, Mary Mah Lee; Yu, Hanry

2013-02-01

Homeostatic pressure-driven compaction is a ubiquitous mechanical force in multicellular organisms and is proposed to be important in the maintenance of multicellular tissue integrity and function. Previous cell-free biochemical models have demonstrated that there are cross-talks between compaction forces and tissue structural functions, such as cell-cell adhesion. However, its involvement in physiological tissue function has yet to be directly demonstrated. Here, we use the bile canaliculus (BC) as a physiological example of a multicellular functional structure in the liver, and employ a novel 3D microfluidic hepatocyte culture system to provide an unprecedented opportunity to experimentally modulate the compaction states of primary hepatocyte aggregates in a 3D physiological-mimicking environment. Mechanical compaction alters the physical attributes of the hepatocyte aggregates, including cell shape, cell packing density and cell-cell contact area, but does not impair the hepatocytes' remodeling and functional capabilities. Characterization of structural and functional polarity shows that BC formation in compact hepatocyte aggregates is accelerated to as early as 12 hours post-seeding; whereas non-compact control requires 48 hours for functional BC formation. Further dynamic immunofluorescence imaging and gene expression profiling reveal that compaction accelerated BC formation is accompanied by changes in actin cytoskeleton remodeling dynamics and transcriptional levels of hepatic nuclear factor 4α and Annexin A2. Our report not only provides a novel strategy of modeling BC formation for in vitro hepatology research, but also shows a first instance that homeostatic pressure-driven compaction force is directly coupled to the higher-order multicellular functions.

Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells.

PubMed

Koehler, Karl R; Nie, Jing; Longworth-Mills, Emma; Liu, Xiao-Ping; Lee, Jiyoon; Holt, Jeffrey R; Hashino, Eri

2017-06-01

The derivation of human inner ear tissue from pluripotent stem cells would enable in vitro screening of drug candidates for the treatment of hearing and balance dysfunction and may provide a source of cells for cell-based therapies of the inner ear. Here we report a method for differentiating human pluripotent stem cells to inner ear organoids that harbor functional hair cells. Using a three-dimensional culture system, we modulate TGF, BMP, FGF, and WNT signaling to generate multiple otic-vesicle-like structures from a single stem-cell aggregate. Over 2 months, the vesicles develop into inner ear organoids with sensory epithelia that are innervated by sensory neurons. Additionally, using CRISPR-Cas9, we generate an ATOH1-2A-eGFP cell line to detect hair cell induction and demonstrate that derived hair cells exhibit electrophysiological properties similar to those of native sensory hair cells. Our culture system should facilitate the study of human inner ear development and research on therapies for diseases of the inner ear.

Integrative Technologies and Knowledge Gatekeepers: Bridging the Gap between Epistemic Communities in the Case of Stem Cell Science

ERIC Educational Resources Information Center

Wink, Rudiger

2008-01-01

The article analyses the role of gatekeepers between regional and disciplinary innovation systems in stem cell research as a case of integrative technologies. Which kind of gatekeepers is needed and which function can be fulfilled, differs along the knowledge value chain. Empirical results are used to explain the rationality of stem cell policies…

Cell-cell recognition and social networking in bacteria

PubMed Central

Troselj, Vera; Cao, Pengbo; Wall, Daniel

2018-01-01

SUMMARY The ability to recognize self and to recognize partnering cells allows microorganisms to build social networks that perform functions beyond the capabilities of the individual. In bacteria, recognition typically involves genetic determinants that provide cell surface receptors or diffusible signaling chemicals to identify proximal cells at the molecular level that can participate in cooperative processes. Social networks also rely on discriminating mechanisms to exclude competing cells from joining and exploiting their groups. In addition to their appropriate genotypes, cell-cell recognition also requires compatible phenotypes, which vary according to environmental cues or exposures as well as stochastic processes that leads to heterogeneity and potential disharmony in the population. Understanding how bacteria identify their social partners and how they synchronize their behaviors to conduct multicellular functions is an expanding field of research. Here we review recent progress in the field and contrast the various strategies used in recognition and behavioral networking. PMID:29194914

Steady state peripheral blood provides cells with functional and metabolic characteristics of real hematopoietic stem cells.

PubMed

Bourdieu, Antonin; Avalon, Maryse; Lapostolle, Véronique; Ismail, Sadek; Mombled, Margaux; Debeissat, Christelle; Guérinet, Marianne; Duchez, Pascale; Chevaleyre, Jean; Vlaski-Lafarge, Marija; Villacreces, Arnaud; Praloran, Vincent; Ivanovic, Zoran; Brunet de la Grange, Philippe

2018-01-01

Hematopoietic stem cells (HSCs), which are located in the bone marrow, also circulate in cord and peripheral blood. Despite high availability, HSCs from steady state peripheral blood (SSPB) are little known and not used for research or cell therapy. We thus aimed to characterize and select HSCs from SSPB by a direct approach with a view to delineating their main functional and metabolic properties and the mechanisms responsible for their maintenance. We chose to work on Side Population (SP) cells which are highly enriched in HSCs in mouse, human bone marrow, and cord blood. However, no SP cells from SSBP have as yet been characterized. Here we showed that SP cells from SSPB exhibited a higher proliferative capacity and generated more clonogenic progenitors than non-SP cells in vitro. Furthermore, xenotransplantation studies on immunodeficient mice demonstrated that SP cells are up to 45 times more enriched in cells with engraftment capacity than non-SP cells. From a cell regulation point of view, we showed that SP activity depended on O 2 concentrations close to those found in HSC niches, an effect which is dependent on both hypoxia-induced factors HIF-1α and HIF-2α. Moreover SP cells displayed a reduced mitochondrial mass and, in particular, a lower mitochondrial activity compared to non-SP cells, while they exhibited a similar level of glucose incorporation. These results provided evidence that SP cells from SSPB displayed properties of very primitive cells and HSC, thus rendering them an interesting model for research and cell therapy. © 2017 Wiley Periodicals, Inc.

Bioengineering and Stem Cell Technology in the Treatment of Congenital Heart Disease

PubMed Central

Bosman, Alexis; Edel, Michael J.; Blue, Gillian; Dilley, Rodney J.; Harvey, Richard P.; Winlaw, David S.

2015-01-01

Congenital heart disease places a significant burden on the individual, family and community despite significant advances in our understanding of aetiology and treatment. Early research in ischaemic heart disease has paved the way for stem cell technology and bioengineering, which promises to improve both structural and functional aspects of disease. Stem cell therapy has demonstrated significant improvements in cardiac function in adults with ischaemic heart disease. This finding, together with promising case studies in the paediatric setting, demonstrates the potential for this treatment in congenital heart disease. Furthermore, induced pluripotent stems cell technology, provides a unique opportunity to address aetiological, as well as therapeutic, aspects of disease. PMID:26239354

Dietary Nutrients and Bioactive Substances Modulate Heat Shock Protein (HSP) Expression: A Review.

PubMed

Moura, Carolina Soares; Lollo, Pablo Christiano Barboza; Morato, Priscila Neder; Amaya-Farfan, Jaime

2018-05-28

Interest in the heat shock proteins (HSPs), as a natural physiological toolkit of living organisms, has ranged from their chaperone function in nascent proteins to the remedial role following cell stress. As part of the defence system, HSPs guarantee cell tolerance against a variety of stressors, including exercise, oxidative stress, hyper and hypothermia, hyper and hypoxia and improper diets. For the past couple of decades, research on functional foods has revealed a number of substances likely to trigger cell protection through mechanisms that involve the induction of HSP expression. This review will summarize the occurrence of the most easily inducible HSPs and describe the effects of dietary proteins, peptides, amino acids, probiotics, high-fat diets and other food-derived substances reported to induce HSP response in animals and humans studies. Future research may clarify the mechanisms and explore the usefulness of this natural alternative of defense and the modulating mechanism of each substance.

Mesenchymal stem-cell potential in cartilage repair: an update

PubMed Central

Mazor, M; Lespessailles, E; Coursier, R; Daniellou, R; Best, T M; Toumi, H

2014-01-01

Articular cartilage damage and subsequent degeneration are a frequent occurrence in synovial joints. Treatment of these lesions is a challenge because this tissue is incapable of quality repair and/or regeneration to its native state. Non-operative treatments endeavour to control symptoms and include anti-inflammatory medications, viscosupplementation, bracing, orthotics and activity modification. Classical surgical techniques for articular cartilage lesions are frequently insufficient in restoring normal anatomy and function and in many cases, it has not been possible to achieve the desired results. Consequently, researchers and clinicians are focusing on alternative methods for cartilage preservation and repair. Recently, cell-based therapy has become a key focus of tissue engineering research to achieve functional replacement of articular cartilage. The present manuscript is a brief review of stem cells and their potential in the treatment of early OA (i.e. articular cartilage pathology) and recent progress in the field. PMID:25353372

The emergence of ECM mechanics and cytoskeletal tension as important regulators of cell function.

PubMed

Peyton, Shelly R; Ghajar, Cyrus M; Khatiwala, Chirag B; Putnam, Andrew J

2007-01-01

The ability to harvest and maintain viable cells from mammalian tissues represented a critical advance in biomedical research, enabling individual cells to be cultured and studied in molecular detail. However, in these traditional cultures, cells are grown on rigid glass or polystyrene substrates, the mechanical properties of which often do not match those of the in vivo tissue from which the cells were originally derived. This mechanical mismatch likely contributes to abrupt changes in cellular phenotype. In fact, it has been proposed that mechanical changes in the cellular microenvironment may alone be responsible for driving specific cellular behaviors. Recent multidisciplinary efforts from basic scientists and engineers have begun to address this hypothesis more explicitly by probing the effects of ECM mechanics on cell and tissue function. Understanding the consequences of such mechanical changes is physiologically relevant in the context of a number of tissues in which altered mechanics may either correlate with or play an important role in the onset of pathology. Examples include changes in the compliance of blood vessels associated with atherosclerosis and intimal hyperplasia, as well as changes in the mechanical properties of developing tumors. Compelling evidence from 2-D in vitro model systems has shown that substrate mechanical properties induce changes in cell shape, migration, proliferation, and differentiation, but it remains to be seen whether or not these same effects translate to 3-D systems or in vivo. Furthermore, the molecular "mechanotransduction" mechanisms by which cells respond to changes in ECM mechanics remain unclear. Here, we provide some historical context for this emerging area of research, and discuss recent evidence that regulation of cytoskeletal tension by changes in ECM mechanics (either directly or indirectly) may provide a critical switch that controls cell function.

Nuclear transport in Entamoeba histolytica: knowledge gap and therapeutic potential.

PubMed

Gwairgi, Marina A; Ghildyal, Reena

2018-03-22

Entamoeba histolytica is the protozoan parasite that causes human amoebiasis. It is one of the leading parasitic disease burdens in tropical regions and developing countries, with spread to developed countries through migrants from and travellers to endemic regions. Understanding E. histolytica's invasion mechanisms requires an understanding of how it interacts with external cell components and how it engulfs and kills cells (phagocytosis). Recent research suggests that optimal phagocytosis requires signalling events from the cell surface to the nucleus via the cytoplasm, and the induction of several factors that are transported to the plasma membrane. Current research in other protozoans suggests the presence of proteins with nuclear localization signals, nuclear export signals and Ran proteins; however, there is limited literature on their functionality and their functional similarity to higher eukaryotes. Based on learnings from the development of antivirals, nuclear transport elements in E. histolytica may present viable, specific, therapeutic targets. In this review, we aim to summarize our limited knowledge of the eukaryotic nuclear transport mechanisms that are conserved and may function in E. histolytica.

Electron-Ion Dynamics with Time-Dependent Density Functional Theory: Towards Predictive Solar Cell Modeling: Final Technical Report

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

Maitra, Neepa

2016-07-14

This project investigates the accuracy of currently-used functionals in time-dependent density functional theory, which is today routinely used to predict and design materials and computationally model processes in solar energy conversion. The rigorously-based electron-ion dynamics method developed here sheds light on traditional methods and overcomes challenges those methods have. The fundamental research undertaken here is important for building reliable and practical methods for materials discovery. The ultimate goal is to use these tools for the computational design of new materials for solar cell devices of high efficiency.

Effects of Rosiglitazone, Glyburide, and Metformin on β-Cell Function and Insulin Sensitivity in ADOPT

PubMed Central

Kahn, Steven E.; Lachin, John M.; Zinman, Bernard; Haffner, Steven M.; Aftring, R. Paul; Paul, Gitanjali; Kravitz, Barbara G.; Herman, William H.; Viberti, Giancarlo; Holman, Rury R.

2011-01-01

OBJECTIVE ADOPT (A Diabetes Outcome Progression Trial) demonstrated that initial monotherapy with rosiglitazone provided superior durability of glycemic control compared with metformin and glyburide in patients with recently diagnosed type 2 diabetes. Herein, we examine measures of β-cell function and insulin sensitivity from an oral glucose tolerance test (OGTT) over a 4-year period among the three treatments. RESEARCH DESIGN AND METHODS Recently diagnosed, drug-naïve patients with type 2 diabetes (4,360 total) were treated for a median of 4.0 years with rosiglitazone, metformin, or glyburide and were examined with periodic metabolic testing using an OGTT. RESULTS Measures of β-cell function and insulin sensitivity from an OGTT showed more favorable changes over time with rosiglitazone versus metformin or glyburide. Persistent improvements were seen in those who completed 4 years of monotherapy and marked deterioration of β-cell function in those who failed to maintain adequate glucose control with initial monotherapy. CONCLUSIONS The favorable combined changes in β-cell function and insulin sensitivity over time with rosiglitazone appear to be responsible for its superior glycemic durability over metformin and glyburide as initial monotherapy in type 2 diabetes. PMID:21415383

Functional selectivity of G-protein-coupled receptors: from recombinant systems to native human cells.

PubMed

Seifert, Roland

2013-10-01

In the mid 1990s, it was assumed that a two-state model, postulating an inactive (R) state and an active (R*) state provides the molecular basis for GPCR activation. However, it became clear that this model could not accommodate many experimental observations. Accordingly, the two-state model was superseded by a multi-state model according to which any given ligand stabilizes a unique receptor conformation with distinct capabilities of activating down-stream G-proteins and β-arrestin. Much of this research was conducted with the β2-adrenoceptor in recombinant systems. At the molecular level, there is now no doubt anymore that ligand-specific receptor conformations, also referred to as functional selectivity, exist. This concept holds great potential for drug discovery in terms of developing drugs with higher selectivity for specific cells and/or cell functions and fewer side effects. A major challenge is the analysis for functional selectivity in native cells. Here, I discuss our current knowledge on functional selectivity of three representative GPCRs, the β2-adrenoceptor and the histamine H2- and H4-receptors, in recombinant systems and native human cells. Studies with human neutrophils and eosinophils support the concept of functional selectivity. A major strategy for the analysis of functional selectivity in native cells is to generate complete concentration/response curves with a large set of structurally diverse ligands for multiple parameters. Next, correlations of potencies and efficacies are analyzed, and deviations of the correlations from linearity are indicative for functional selectivity. Additionally, pharmacological inhibitors are used to dissect cell functions from each other. Copyright © 2013 Elsevier Inc. All rights reserved.

Characterization of the human oncogene SCL/TAL1 interrupting locus (Stil) mediated Sonic hedgehog (Shh) signaling transduction in proliferating mammalian dopaminergic neurons

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

Sun, Lei; Department of Physiology, Nankai University School of Medicine, Tianjin 300071; Carr, Aprell L.

2014-07-11

Highlights: • Stil is a human oncogene that is conserved in vertebrate species. • Stil functions in the Shh pathway in mammalian cells. • The expression of Stil is required for mammalian dopaminergic cell proliferation. - Abstract: The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in all vertebrate species. In humans, the expression of Stil is involved in cancer cell survival, apoptosis and proliferation. In this research, we investigated the roles of Stil expression in cell proliferation of mammalian dopaminergic (DA) PC12 cells. Stil functions through the Sonic hedgehog (Shh) signal transduction pathway. Co-immunoprecipitation tests revealed that STILmore » interacts with Shh downstream components, which include SUFU and GLI1. By examining the expression of Stil, Gli1, CyclinD2 (cell-cycle marker) and PCNA (proliferating cell nuclear antigen), we found that up-regulation of Stil expression (transfection with overexpression plasmids) increased Shh signaling transduction and PC12 cell proliferation, whereas down-regulation of Stil expression (by shRNA) inhibited Shh signaling transduction, and thereby decreased PC12 cell proliferation. Transient transfection of PC12 cells with Stil knockdown or overexpression plasmids did not affect PC12 cell neural differentiation, further indicating the specific roles of Stil in cell proliferation. The results from this research suggest that Stil may serve as a bio-marker for neurological diseases involved in DA neurons, such as Parkinson’s disease.« less

Engineering Human Neural Tissue by 3D Bioprinting.

PubMed

Gu, Qi; Tomaskovic-Crook, Eva; Wallace, Gordon G; Crook, Jeremy M

2018-01-01

Bioprinting provides an opportunity to produce three-dimensional (3D) tissues for biomedical research and translational drug discovery, toxicology, and tissue replacement. Here we describe a method for fabricating human neural tissue by 3D printing human neural stem cells with a bioink, and subsequent gelation of the bioink for cell encapsulation, support, and differentiation to functional neurons and supporting neuroglia. The bioink uniquely comprises the polysaccharides alginate, water-soluble carboxymethyl-chitosan, and agarose. Importantly, the method could be adapted to fabricate neural and nonneural tissues from other cell types, with the potential to be applied for both research and clinical product development.

Joint diseases: from connexins to gap junctions.

PubMed

Donahue, Henry J; Qu, Roy W; Genetos, Damian C

2017-12-19

Connexons form the basis of hemichannels and gap junctions. They are composed of six tetraspan proteins called connexins. Connexons can function as individual hemichannels, releasing cytosolic factors (such as ATP) into the pericellular environment. Alternatively, two hemichannel connexons from neighbouring cells can come together to form gap junctions, membrane-spanning channels that facilitate cell-cell communication by enabling signalling molecules of approximately 1 kDa to pass from one cell to an adjacent cell. Connexins are expressed in joint tissues including bone, cartilage, skeletal muscle and the synovium. Indicative of their importance as gap junction components, connexins are also known as gap junction proteins, but individual connexin proteins are gaining recognition for their channel-independent roles, which include scaffolding and signalling functions. Considerable evidence indicates that connexons contribute to the function of bone and muscle, but less is known about the function of connexons in other joint tissues. However, the implication that connexins and gap junctional channels might be involved in joint disease, including age-related bone loss, osteoarthritis and rheumatoid arthritis, emphasizes the need for further research into these areas and highlights the therapeutic potential of connexins.

Making a big thing of a small cell--recent advances in single cell analysis.

PubMed

Galler, Kerstin; Bräutigam, Katharina; Große, Christina; Popp, Jürgen; Neugebauer, Ute

2014-03-21

Single cell analysis is an emerging field requiring a high level interdisciplinary collaboration to provide detailed insights into the complex organisation, function and heterogeneity of life. This review is addressed to life science researchers as well as researchers developing novel technologies. It covers all aspects of the characterisation of single cells (with a special focus on mammalian cells) from morphology to genetics and different omics-techniques to physiological, mechanical and electrical methods. In recent years, tremendous advances have been achieved in all fields of single cell analysis: (1) improved spatial and temporal resolution of imaging techniques to enable the tracking of single molecule dynamics within single cells; (2) increased throughput to reveal unexpected heterogeneity between different individual cells raising the question what characterizes a cell type and what is just natural biological variation; and (3) emerging multimodal approaches trying to bring together information from complementary techniques paving the way for a deeper understanding of the complexity of biological processes. This review also covers the first successful translations of single cell analysis methods to diagnostic applications in the field of tumour research (especially circulating tumour cells), regenerative medicine, drug discovery and immunology.

Metabolic functions of AMPK: aspects of structure and of natural mutations in the regulatory gamma subunits.

PubMed

Moffat, Cynthia; Harper, Mary Ellen

2010-10-01

AMP-activated protein kinase, AMPK, is widely accepted as the master regulator of energy levels within the cell. Responding quickly to changing energy demands, AMPK works to restore levels of ATP during times of cellular stress by promoting ATP producing catabolic pathways and inhibiting ATP consuming anabolic ones. As a heterotrimeric protein complex, AMPK's subunits each act in unique and crucial ways to control AMPK function and its localization within the cell. Research in the last decade has identified and begun to characterize the impact of naturally occurring mutations in the gamma regulatory subunits. Mutations in the γ2 subunit have implications for cardiac function and disease, while the R225W mutation in the γ3 subunit have implications for skeletal muscle fuel metabolism and resistance to fatigue. Research focused on structure-function aspects of AMPK regulatory subunits will lead to a better understanding of the roles of AMPK in health and disease.

Mitochondria and Endothelial Function

PubMed Central

Kluge, Matthew A.; Fetterman, Jessica L.; Vita, Joseph A.

2013-01-01

In contrast to their role in other cell types with higher energy demands, mitochondria in endothelial cells primarily function in signaling cellular responses to environmental cues. This article provides an overview of key aspects of mitochondrial biology in endothelial cells, including subcellular location, biogenesis, dynamics, autophagy, ROS production and signaling, calcium homeostasis, regulated cell death, and heme biosynthesis. In each section, we introduce key concepts and then review studies showing the importance of that mechanism to endothelial control of vasomotor tone, angiogenesis, and inflammatory activation. We particularly highlight the small number of clinical and translational studies that have investigated each mechanism in human subjects. Finally, we review interventions that target different aspects of mitochondrial function and their effects on endothelial function. The ultimate goal of such research is the identification of new approaches for therapy. The reviewed studies make it clear that mitochondria are important in endothelial physiology and pathophysiology. A great deal of work will be needed, however, before mitochondria-directed therapies are available for the prevention and treatment of cardiovascular disease. PMID:23580773

Primary cilia proteins: ciliary and extraciliary sites and functions.

PubMed

Hua, Kiet; Ferland, Russell J

2018-05-01

Primary cilia are immotile organelles known for their roles in development and cell signaling. Defects in primary cilia result in a range of disorders named ciliopathies. Because this organelle can be found singularly on almost all cell types, its importance extends to most organ systems. As such, elucidating the importance of the primary cilium has attracted researchers from all biological disciplines. As the primary cilia field expands, caution is warranted in attributing biological defects solely to the function of this organelle, since many of these "ciliary" proteins are found at other sites in cells and likely have non-ciliary functions. Indeed, many, if not all, cilia proteins have locations and functions outside the primary cilium. Extraciliary functions are known to include cell cycle regulation, cytoskeletal regulation, and trafficking. Cilia proteins have been observed in the nucleus, at the Golgi apparatus, and even in immune synapses of T cells (interestingly, a non-ciliated cell). Given the abundance of extraciliary sites and functions, it can be difficult to definitively attribute an observed phenotype solely to defective cilia rather than to some defective extraciliary function or a combination of both. Thus, extraciliary sites and functions of cilia proteins need to be considered, as well as experimentally determined. Through such consideration, we will understand the true role of the primary cilium in disease as compared to other cellular processes' influences in mediating disease (or through a combination of both). Here, we review a compilation of known extraciliary sites and functions of "cilia" proteins as a means to demonstrate the potential non-ciliary roles for these proteins.

The establishment and characterization of immortal hepatocyte cell lines from a mouse liver injury model.

PubMed

Risal, Prabodh; Cho, Baik Hwan; Sylvester, Karl G; Kim, Jae-Chun; Kim, Hyoung Tae; Jeong, Yeon Jun

2011-09-01

Hepatocytes are an important research tool used for numerous applications. However, a short life span and a limited capacity to replicate in vitro limit the usefulness of primary hepatocyte cultures. We have hypothesized that in vivo priming of hepatocyte could make them more susceptible to growth factors in the medium for continuous proliferation in vitro. Here, a novel approach used to establish hepatocyte cell lines that included hepatocyte priming in vivo prior to culture with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet was attempted. The cell line grew in a monolayer while maintaining a granular cytoplasm and a round nucleus. Electron microscopy displayed hepatocyte-like features including mitochondria, glycogen granules, and the presence of bile canaliculi. This cell line expressed many mature hepatocyte-specific genes including albumin, alpha1-antitrypsin, glucose 6-phosphatase, and tyrosine aminotransferase. Functional characteristic of hepatocytes like the ability to store glycogen, lipid, and synthesis of urea is well demonstrated by this cell line. These cells demonstrated anchorage dependent growth properties in soft agar and did not form tumors after transplantation into nude mice. This cell line can be sustained in culture for more than 100 passages (>1.5 years) without undergoing noticeable morphological changes or transformation. This novel method resulted in the establishment of an immortal, non-transformed hepatocyte cell line with functional characteristics that may aid research of cell metabolism, toxicology, and hepatocyte transplantation.

Engineered fusokine GIFT4 licenses the ability of B cells to trigger a tumoricidal T-cell response.

PubMed

Deng, Jiusheng; Yuan, Shala; Pennati, Andrea; Murphy, Jordan; Wu, Jian Hui; Lawson, David; Galipeau, Jacques

2014-08-01

Engineered chimeric cytokines can generate gain-of-function activity in immune cells. Here, we report potent antitumor activity for a novel fusion cytokine generated by N-terminal coupling of GM-CSF to IL4, generating a fusokine termed GIFT4. B cells treated with GIFT4 clustered GM-CSF and IL4 receptors on the cell surface and displayed a pan-STAT hyperphosphorylation associated with acquisition of a distinct phenotype and function described to date. In C57BL/6J mice, administration of GIFT4 expanded endogenous B cells and suppressed the growth of B16F0 melanoma cells. Furthermore, B16F0 melanoma cells engineered to secrete GIFT4 were rejected immunologically in a B-cell-dependent manner. This effect was abolished when GIFT4-expressing B16F0 cells were implanted in B-cell-deficient mice, confirming a B-cell-dependent antitumor effect. Human GIFT4-licensed B cells primed cytotoxic T cells and specifically killed melanoma cells in vitro and in vivo. Taken together, our results demonstrated that GIFT4 could mediate expansion of B cells with potent antigen-specific effector function. GIFT4 may offer a novel immunotherapeutic tool and define a previously unrecognized potential for B cells in melanoma immunotherapy. ©2014 American Association for Cancer Research.

Analyzing structure-function relationships of artificial and cancer-associated PARP1 variants by reconstituting TALEN-generated HeLa PARP1 knock-out cells.

PubMed

Rank, Lisa; Veith, Sebastian; Gwosch, Eva C; Demgenski, Janine; Ganz, Magdalena; Jongmans, Marjolijn C; Vogel, Christopher; Fischbach, Arthur; Buerger, Stefanie; Fischer, Jan M F; Zubel, Tabea; Stier, Anna; Renner, Christina; Schmalz, Michael; Beneke, Sascha; Groettrup, Marcus; Kuiper, Roland P; Bürkle, Alexander; Ferrando-May, Elisa; Mangerich, Aswin

2016-12-01

Genotoxic stress activates PARP1, resulting in the post-translational modification of proteins with poly(ADP-ribose) (PAR). We genetically deleted PARP1 in one of the most widely used human cell systems, i.e. HeLa cells, via TALEN-mediated gene targeting. After comprehensive characterization of these cells during genotoxic stress, we analyzed structure-function relationships of PARP1 by reconstituting PARP1 KO cells with a series of PARP1 variants. Firstly, we verified that the PARP1\\E988K mutant exhibits mono-ADP-ribosylation activity and we demonstrate that the PARP1\\L713F mutant is constitutively active in cells. Secondly, both mutants exhibit distinct recruitment kinetics to sites of laser-induced DNA damage, which can potentially be attributed to non-covalent PARP1-PAR interaction via several PAR binding motifs. Thirdly, both mutants had distinct functional consequences in cellular patho-physiology, i.e. PARP1\\L713F expression triggered apoptosis, whereas PARP1\\E988K reconstitution caused a DNA-damage-induced G2 arrest. Importantly, both effects could be rescued by PARP inhibitor treatment, indicating distinct cellular consequences of constitutive PARylation and mono(ADP-ribosyl)ation. Finally, we demonstrate that the cancer-associated PARP1 SNP variant (V762A) as well as a newly identified inherited PARP1 mutation (F304L\\V762A) present in a patient with pediatric colorectal carcinoma exhibit altered biochemical and cellular properties, thereby potentially supporting human carcinogenesis. Together, we establish a novel cellular model for PARylation research, by revealing strong structure-function relationships of natural and artificial PARP1 variants. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Claudin-4 Overexpression in Epithelial Ovarian Cancer Is Associated with Hypomethylation and Is a Potential Target for Modulation of Tight Junction Barrier Function Using a C-Terminal Fragment of Clostridium perfringens Enterotoxin1

PubMed Central

Litkouhi, Babak; Kwong, Joseph; Lo, Chun-Min; Smedley, James G; McClane, Bruce A; Aponte, Margarita; Gao, Zhijian; Sarno, Jennifer L; Hinners, Jennifer; Welch, William R; Berkowitz, Ross S; Mok, Samuel C; Garner, Elizabeth I O

2007-01-01

Background Claudin-4, a tight junction (TJ) protein and receptor for the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE), is overexpressed in epithelial ovarian cancer (EOC). Previous research suggests DNA methylation is a mechanism for claudin-4 overexpression in cancer and that C-CPE acts as an absorption-enhancing agent in claudin-4-expressing cells. We sought to correlate claudin-4 overexpression in EOC with clinical outcomes and TJ barrier function, investigate DNA methylation as a mechanism for overexpression, and evaluate the effect of C-CPE on the TJ. Methods Claudin-4 expression in EOC was quantified and correlated with clinical outcomes. Claudin-4 methylation status was determined, and claudin-4-negative cell lines were treated with a demethylating agent. Electric cell-substrate impedance sensing was used to calculate junctional (paracellular) resistance (Rb) in EOC cells after claudin-4 silencing and after C-CPE treatment. Results Claudin-4 overexpression in EOC does not correlate with survival or other clinical endpoints and is associated with hypomethylation. Claudin-4 overexpression correlates with Rb and C-CPE treatment of EOC cells significantly decreased Rb in a dose- and claudin-4-dependent noncytotoxic manner. Conclusions C-CPE treatment of EOC cells leads to altered TJ function. Further research is needed to determine the potential clinical applications of C-CPE in EOC drug delivery strategies. PMID:17460774

Nanotechnology in stem cells research: advances and applications.

PubMed

Deb, Kaushik Dilip; Griffith, May; Muinck, Ebo De; Rafat, Mehrdad

2012-01-01

Human beings suffer from a myriad of disorders caused by biochemical or biophysical alteration of physiological systems leading to organ failure. For a number of these conditions, stem cells and their enormous reparative potential may be the last hope for restoring function to these failing organ or tissue systems. To harness the potential of stem cells for biotherapeutic applications, we need to work at the size scale of molecules and processes that govern stem cells fate. Nanotechnology provides us with such capacity. Therefore, effective amalgamation of nanotechnology and stem cells - medical nanoscience or nanomedicine - offers immense benefits to the human race. The aim of this paper is to discuss the role and importance of nanotechnology in stem cell research by focusing on several important areas such as stem cell visualization and imaging, genetic modifications and reprogramming by gene delivery systems, creating stem cell niche, and similar therapeutic applications.

Hematopoietic cell transplantation and HIV cure: where we are and what next?

PubMed

Zou, Shimian; Glynn, Simone; Kuritzkes, Daniel; Shah, Monica; Cook, Nakela; Berliner, Nancy

2013-10-31

The report of the so-called Berlin patient cured of HIV with hematopoietic stem cell transplantation and a few other studies raised tremendous hope, excitement, and curiosity in the field. The National Heart, Lung and Blood Institute of the National Institutes of Health convened a Working Group to address emerging heart, lung, and blood research priorities related to HIV infection. Hematopoietic cells could contribute to HIV cure through allogeneic or autologous transplantation of naturally occurring or engineered cells with anti-HIV moieties. Protection of central memory T cells from HIV infection could be a critical determinant of achieving a functional cure. HIV cure can only be achieved if the virus is eradicated from reservoirs in resting T cells and possibly other hematopoietic cells. The Working Group recommended multidisciplinary efforts leveraging HIV and cell therapy expertise to answer the critical need to support research toward an HIV cure.

[The implementation of computer model in research of dynamics of proliferation of cells of thyroid gland follicle].

PubMed

Abduvaliev, A A; Gil'dieva, M S; Khidirov, B N; Saĭdalieva, M; Khasanov, A A; Musaeva, Sh N; Saatov, T S

2012-04-01

The article deals with the results of computational experiments in research of dynamics of proliferation of cells of thyroid gland follicle in normal condition and in the case of malignant neoplasm. The model studies demonstrated that the chronic increase of parameter of proliferation of cells of thyroid gland follicle results in abnormal behavior of numbers of cell cenosis of thyroid gland follicle. The stationary state interrupts, the auto-oscillations occur with transition to irregular oscillations with unpredictable cell proliferation and further to the "black hole" effect. It is demonstrated that the present medical biologic experimental data and theory propositions concerning the structural functional organization of thyroid gland on cell level permit to develop mathematical models for quantitative analysis of numbers of cell cenosis of thyroid gland follicle in normal conditions. The technique of modeling of regulative mechanisms of living systems and equations of cell cenosis regulations was used

Defining the phenotype of young healthy nucleus pulposus cells: recommendations of the Spine Research Interest Group at the 2014 annual ORS meeting.

PubMed

Risbud, Makarand V; Schoepflin, Zachary R; Mwale, Fackson; Kandel, Rita A; Grad, Sibylle; Iatridis, James C; Sakai, Daisuke; Hoyland, Judith A

2015-03-01

Low back pain is a major physical and socioeconomic problem. Degeneration of the intervertebral disc and especially that of nucleus pulposus (NP) has been linked to low back pain. In spite of much research focusing on the NP, consensus among the research community is lacking in defining the NP cell phenotype. A consensus agreement will allow easier distinguishing of NP cells from annulus fibrosus (AF) cells and endplate chondrocytes, a better gauge of therapeutic success, and a better guidance of tissue-engineering-based regenerative strategies that attempt to replace lost NP tissue. Most importantly, a clear definition will further the understanding of physiology and function of NP cells, ultimately driving development of novel cell-based therapeutic modalities. The Spine Research Interest Group at the 2014 Annual ORS Meeting in New Orleans convened with the task of compiling a working definition of the NP cell phenotype with hope that a consensus statement will propel disc research forward into the future. Based on evaluation of recent studies describing characteristic NP markers and their physiologic relevance, we make the recommendation of the following healthy NP phenotypic markers: stabilized expression of HIF-1α, GLUT-1, aggrecan/collagen II ratio >20, Shh, Brachyury, KRT18/19, CA12, and CD24. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Possible roles of platelet-derived microparticles in atherosclerosis.

PubMed

Wang, Zhi-Ting; Wang, Zi; Hu, Yan-Wei

2016-05-01

Platelets and platelet-derived microparticles (PMPs) play important roles in cardiovascular diseases, especially atherosclerosis. Continued research has revealed that PMPs have numerous functions in atherosclerosis, not only in thrombosis formation, but also by induction of inflammation. PMPs also induce formation of foam cells. Recent evidence strongly indicates a significant role of PMPs in atherosclerosis. Here, current research on the function of PMPs in atherosclerosis is reviewed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Accurate and reproducible functional maps in 127 human cell types via 2D genome segmentation

PubMed Central

Hardison, Ross C.

2017-01-01

Abstract The Roadmap Epigenomics Consortium has published whole-genome functional annotation maps in 127 human cell types by integrating data from studies of multiple epigenetic marks. These maps have been widely used for studying gene regulation in cell type-specific contexts and predicting the functional impact of DNA mutations on disease. Here, we present a new map of functional elements produced by applying a method called IDEAS on the same data. The method has several unique advantages and outperforms existing methods, including that used by the Roadmap Epigenomics Consortium. Using five categories of independent experimental datasets, we compared the IDEAS and Roadmap Epigenomics maps. While the overall concordance between the two maps is high, the maps differ substantially in the prediction details and in their consistency of annotation of a given genomic position across cell types. The annotation from IDEAS is uniformly more accurate than the Roadmap Epigenomics annotation and the improvement is substantial based on several criteria. We further introduce a pipeline that improves the reproducibility of functional annotation maps. Thus, we provide a high-quality map of candidate functional regions across 127 human cell types and compare the quality of different annotation methods in order to facilitate biomedical research in epigenomics. PMID:28973456

Differential and functional interactions emphasize the multiple roles of polyamines in plants

USDA-ARS?s Scientific Manuscript database

Biogenic amines putrescine, spermidine and spermine are ubiquitous in nature and have interested researchers because they are essential for cell division and viability, and due to a large body of their pharmacological effects on growth and development in most living cells. The genes and enzymes invo...

Temperature fluctuations during deep temperature cryopreservation reduce PBMC recovery, viability and T-cell function.

PubMed

Germann, Anja; Oh, Young-Joo; Schmidt, Tomm; Schön, Uwe; Zimmermann, Heiko; von Briesen, Hagen

2013-10-01

The ability to analyze cryopreserved peripheral blood mononuclear cell (PBMC) from biobanks for antigen-specific immunity is necessary to evaluate response to immune-based therapies. To ensure comparable assay results, collaborative research in multicenter trials needs reliable and reproducible cryopreservation that maintains cell viability and functionality. A standardized cryopreservation procedure is comprised of not only sample collection, preparation and freezing but also low temperature storage in liquid nitrogen without any temperature fluctuations, to avoid cell damage. Therefore, we have developed a storage approach to minimize suboptimal storage conditions in order to maximize cell viability, recovery and T-cell functionality. We compared the influence of repeated temperature fluctuations on cell health from sample storage, sample sorting and removal in comparison to sample storage without temperature rises. We found that cyclical temperature shifts during low temperature storage reduce cell viability, recovery and immune response against specific-antigens. We showed that samples handled under a protective hood system, to avoid or minimize such repeated temperature rises, have comparable cell viability and cell recovery rates to samples stored without any temperature fluctuations. Also T-cell functionality could be considerably increased with the use of the protective hood system compared to sample handling without such a protection system. This data suggests that the impact of temperature fluctuation on cell integrity should be carefully considered in future clinical vaccine trials and consideration should be given to optimal sample storage conditions. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Mammalian Synthetic Biology: Engineering Biological Systems.

PubMed

Black, Joshua B; Perez-Pinera, Pablo; Gersbach, Charles A

2017-06-21

The programming of new functions into mammalian cells has tremendous application in research and medicine. Continued improvements in the capacity to sequence and synthesize DNA have rapidly increased our understanding of mechanisms of gene function and regulation on a genome-wide scale and have expanded the set of genetic components available for programming cell biology. The invention of new research tools, including targetable DNA-binding systems such as CRISPR/Cas9 and sensor-actuator devices that can recognize and respond to diverse chemical, mechanical, and optical inputs, has enabled precise control of complex cellular behaviors at unprecedented spatial and temporal resolution. These tools have been critical for the expansion of synthetic biology techniques from prokaryotic and lower eukaryotic hosts to mammalian systems. Recent progress in the development of genome and epigenome editing tools and in the engineering of designer cells with programmable genetic circuits is expanding approaches to prevent, diagnose, and treat disease and to establish personalized theranostic strategies for next-generation medicines. This review summarizes the development of these enabling technologies and their application to transforming mammalian synthetic biology into a distinct field in research and medicine.

Novel in vivo techniques to visualize kidney anatomy and function.

PubMed

Peti-Peterdi, János; Kidokoro, Kengo; Riquier-Brison, Anne

2015-07-01

Intravital imaging using multiphoton microscopy (MPM) has become an increasingly popular and widely used experimental technique in kidney research over the past few years. MPM allows deep optical sectioning of the intact, living kidney tissue with submicron resolution, which is unparalleled among intravital imaging approaches. MPM has solved a long-standing critical technical barrier in renal research to study several complex and inaccessible cell types and anatomical structures in vivo in their native environment. Comprehensive and quantitative kidney structure and function MPM studies helped our better understanding of the cellular and molecular mechanisms of the healthy and diseased kidney. This review summarizes recent in vivo MPM studies with a focus on the glomerulus and the filtration barrier, although select, glomerulus-related renal vascular and tubular functions are also mentioned. The latest applications of serial MPM of the same glomerulus in vivo, in the intact kidney over several days, during the progression of glomerular disease are discussed. This visual approach, in combination with genetically encoded fluorescent markers of cell lineage, has helped track the fate and function (e.g., cell calcium changes) of single podocytes during the development of glomerular pathologies, and provided visual proof for the highly dynamic, rather than static, nature of the glomerular environment. Future intravital imaging applications have the promise to further push the limits of optical microscopy, and to advance our understanding of the mechanisms of kidney injury. Also, MPM will help to study new mechanisms of tissue repair and regeneration, a cutting-edge area of kidney research.

Human neural stem cell-derived cultures in three-dimensional substrates form spontaneously functional neuronal networks.

PubMed

Smith, Imogen; Silveirinha, Vasco; Stein, Jason L; de la Torre-Ubieta, Luis; Farrimond, Jonathan A; Williamson, Elizabeth M; Whalley, Benjamin J

2017-04-01

Differentiated human neural stem cells were cultured in an inert three-dimensional (3D) scaffold and, unlike two-dimensional (2D) but otherwise comparable monolayer cultures, formed spontaneously active, functional neuronal networks that responded reproducibly and predictably to conventional pharmacological treatments to reveal functional, glutamatergic synapses. Immunocytochemical and electron microscopy analysis revealed a neuronal and glial population, where markers of neuronal maturity were observed in the former. Oligonucleotide microarray analysis revealed substantial differences in gene expression conferred by culturing in a 3D vs a 2D environment. Notable and numerous differences were seen in genes coding for neuronal function, the extracellular matrix and cytoskeleton. In addition to producing functional networks, differentiated human neural stem cells grown in inert scaffolds offer several significant advantages over conventional 2D monolayers. These advantages include cost savings and improved physiological relevance, which make them better suited for use in the pharmacological and toxicological assays required for development of stem cell-based treatments and the reduction of animal use in medical research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

microRNAs in the regulation of dendritic cell functions in inflammation and atherosclerosis.

PubMed

Busch, Martin; Zernecke, Alma

2012-08-01

Atherosclerosis has been established as a chronic inflammatory disease of the vessel wall. Among the mononuclear cell types recruited to the lesions, specialized dendritic cells (DCs) have gained increasing attention, and their secretory products and interactions shape the progression of atherosclerotic plaques. The regulation of DC functions by microRNAs (miRNAs) may thus be of primary importance in disease. We here systematically summarize the biogenesis and functions of miRNAs and provide an overview of miRNAs in DCs, their targets, and potential implications for atherosclerosis, with a particular focus on the best characterized miRNAs in DCs, namely, miR-155 and miR-146. MiRNA functions in DCs range from regulation of lipid uptake to cytokine production and T cell responses with a complex picture emerging, in which miRNAs cooperate or antagonize DC behavior, thereby promoting or counterbalancing inflammatory responses. As miRNAs regulate key functions of DCs known to control atherosclerotic vascular disease, their potential as a therapeutic target holds promise and should be attended to in future research.

The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration

PubMed Central

Makris, Eleftherios A.; Hadidi, Pasha; Athanasiou, Kyriacos A.

2011-01-01

Extensive scientific investigations in recent decades have established the anatomical, biomechanical, and functional importance that the meniscus holds within the knee joint. As a vital part of the joint, it acts to prevent the deterioration and degeneration of articular cartilage, and the onset and development of osteoarthritis. For this reason, research into meniscus repair has been the recipient of particular interest from the orthopedic and bioengineering communities. Current repair techniques are only effective in treating lesions located in the peripheral vascularized region of the meniscus. Healing lesions found in the inner avascular region, which functions under a highly demanding mechanical environment, is considered to be a significant challenge. An adequate treatment approach has yet to be established, though many attempts have been undertaken. The current primary method for treatment is partial meniscectomy, which commonly results in the progressive development of osteoarthritis. This drawback has shifted research interest towards the fields of biomaterials and bioengineering, where it is hoped that meniscal deterioration can be tackled with the help of tissue engineering. So far, different approaches and strategies have contributed to the in vitro generation of meniscus constructs, which are capable of restoring meniscal lesions to some extent, both functionally as well as anatomically. The selection of the appropriate cell source (autologous, allogeneic, or xenogeneic cells, or stem cells) is undoubtedly regarded as key to successful meniscal tissue engineering. Furthermore, a large variation of scaffolds for tissue engineering have been proposed and produced in experimental and clinical studies, although a few problems with these (e.g., byproducts of degradation, stress shielding) have shifted research interest towards new strategies (e.g., scaffoldless approaches, self-assembly). A large number of different chemical (e.g., TGF-β1, C-ABC) and mechanical stimuli (e.g., direct compression, hydrostatic pressure) have also been investigated, both in terms of encouraging functional tissue formation, as well as in differentiating stem cells. Even though the problems accompanying meniscus tissue engineering research are considerable, we are undoubtedly in the dawn of a new era, whereby recent advances in biology, engineering, and medicine are leading to the successful treatment of meniscal lesions. PMID:21764438

Mesenchymal stromal cell-mediated neuroprotection and functional preservation of retinal ganglion cells in a rodent model of glaucoma.

PubMed

Mead, Ben; Hill, Lisa J; Blanch, Richard J; Ward, Kelly; Logan, Ann; Berry, Martin; Leadbeater, Wendy; Scheven, Ben A

2016-04-01

Glaucoma is a leading cause of irreversible blindness involving loss of retinal ganglion cells (RGC). Mesenchymal stromal cells (MSC) have shown promise as a paracrine-mediated therapy for compromised neurons. It is, however, unknown whether dental pulp stem cells (DPSC) are effective as a cellular therapy in glaucoma and how their hypothesized influence compares with other more widely researched MSC sources. The present study aimed to compare the efficacy of adipose-derived stem cells, bone marrow-derived MSC (BMSC) and DPSC in preventing the loss of RGC and visual function when transplanted into the vitreous of glaucomatous rodent eyes. Thirty-five days after raised intraocular pressure (IOP) and intravitreal stem cell transplantation, Brn3a(+) RGC numbers, retinal nerve fibre layer thickness (RNFL) and RGC function were evaluated by immunohistochemistry, optical coherence tomography and electroretinography, respectively. Control glaucomatous eyes that were sham-treated with heat-killed DPSC had a significant loss of RGC numbers, RNFL thickness and function compared with intact eyes. BMSC and, to a greater extent, DPSC provided significant protection from RGC loss and RNFL thinning and preserved RGC function. The study supports the use of DPSC as a neuroprotective cellular therapy in retinal degenerative disease such as glaucoma. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Epigenetics: the language of the cell?

PubMed

Huang, Biao; Jiang, Cizhong; Zhang, Rongxin

2014-02-01

Epigenetics is one of the most rapidly developing fields of biological research. Breakthroughs in several technologies have enabled the possibility of genome-wide epigenetic research, for example the mapping of human genome-wide DNA methylation. In addition, with the development of various high-throughput and high-resolution sequencing technologies, a large number of functional noncoding RNAs have been identified. Massive studies indicated that these functional ncRNA also play an important role in epigenetics. In this review, we gain inspiration from the recent proposal of the ceRNAs hypothesis. This hypothesis proposes that miRNAs act as a language of communication. Accordingly, we further deduce that all of epigenetics may functionally acquire such a unique language characteristic. In summary, various epigenetic markers may not only participate in regulating cellular processes, but they may also act as the intracellular 'language' of communication and are involved in extensive information exchanges within cell.

Analyzing cell fate control by cytokines through continuous single cell biochemistry.

PubMed

Rieger, Michael A; Schroeder, Timm

2009-10-01

Cytokines are important regulators of cell fates with high clinical and commercial relevance. However, despite decades of intense academic and industrial research, it proved surprisingly difficult to describe the biological functions of cytokines in a precise and comprehensive manner. The exact analysis of cytokine biology is complicated by the fact that individual cytokines control many different cell fates and activate a multitude of intracellular signaling pathways. Moreover, although activating different molecular programs, different cytokines can be redundant in their biological effects. In addition, cytokines with different biological effects can activate overlapping signaling pathways. This prospect article will outline the necessity of continuous single cell biochemistry to unravel the biological functions of molecular cytokine signaling. It focuses on potentials and limitations of recent technical developments in fluorescent time-lapse imaging and single cell tracking allowing constant long-term observation of molecules and behavior of single cells. (c) 2009 Wiley-Liss, Inc.

Actin Engine in Immunological Synapse

PubMed Central

Piragyte, Indre

2012-01-01

T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse. PMID:22916042

Tissuelike 3D Assemblies of Human Broncho-Epithelial Cells

NASA Technical Reports Server (NTRS)

Goodwin, Thomas J.

2010-01-01

Three-dimensional (3D) tissuelike assemblies (TLAs) of human broncho-epithelial (HBE) cells have been developed for use in in vitro research on infection of humans by respiratory viruses. The 2D monolayer HBE cell cultures heretofore used in such research lack the complex cell structures and interactions characteristic of in vivo tissues and, consequently, do not adequately emulate the infection dynamics of in-vivo microbial adhesion and invasion. In contrast, the 3D HBE TLAs are characterized by more-realistic reproductions of the geometrical and functional complexity, differentiation of cells, cell-to-cell interactions, and cell-to-matrix interactions characteristic of human respiratory epithelia. Hence, the 3D HBE TLAs are expected to make it possible to perform at least some of the research in vitro under more-realistic conditions, without need to infect human subjects. The TLAs are grown on collagen-coated cyclodextran microbeads under controlled conditions in a nutrient liquid in the simulated microgravitational environment of a bioreactor of the rotating- wall-vessel type. Primary human mesenchymal bronchial-tracheal cells are used as a foundation matrix, while adult human bronchial epithelial immortalized cells are used as the overlying component. The beads become coated with cells, and cells on adjacent beads coalesce into 3D masses. The resulting TLAs have been found to share significant characteristics with in vivo human respiratory epithelia including polarization, tight junctions, desmosomes, and microvilli. The differentiation of the cells in these TLAs into tissues functionally similar to in vivo tissues is confirmed by the presence of compounds, including villin, keratins, and specific lung epithelium marker compounds, and by the production of tissue mucin. In a series of initial infection tests, TLA cultures were inoculated with human respiratory syncytial viruses and parainfluenza type 3 viruses. Infection was confirmed by photomicrographs that showed signs of damage by viruses and virus titers (see figure) that indicated large increases in the populations of viruses during the days following inoculation.

Purpose-driven biomaterials research in liver-tissue engineering.

PubMed

Ananthanarayanan, Abhishek; Narmada, Balakrishnan Chakrapani; Mo, Xuejun; McMillian, Michael; Yu, Hanry

2011-03-01

Bottom-up engineering of microscale tissue ("microtissue") constructs to recapitulate partially the complex structure-function relationships of liver parenchyma has been realized through the development of sophisticated biomaterial scaffolds, liver-cell sources, and in vitro culture techniques. With regard to in vivo applications, the long-lived stem/progenitor cell constructs can improve cell engraftment, whereas the short-lived, but highly functional hepatocyte constructs stimulate host liver regeneration. With regard to in vitro applications, microtissue constructs are being adapted or custom-engineered into cell-based assays for testing acute, chronic and idiosyncratic toxicities of drugs or pathogens. Systems-level methods and computational models that represent quantitative relationships between biomaterial scaffolds, cells and microtissue constructs will further enable their rational design for optimal integration into specific biomedical applications. Copyright © 2010 Elsevier Ltd. All rights reserved.

Modeling human development in 3D culture.

PubMed

Ader, Marius; Tanaka, Elly M

2014-12-01

Recently human embryonic stem cell research has taken on a new dimension - the third dimension. Capitalizing on increasing knowledge on directing pluripotent cells along different lineages, combined with ECM supported three-dimensional culture conditions, it has become possible to generate highly organized tissues of the central nervous system, gut, liver and kidney. Each system has been used to study different aspects of organogenesis and function including physical forces underlying optic cup morphogenesis, the function of disease related genes in progenitor cell control, as well as interaction of the generated tissues with host tissue upon transplantation. Pluripotent stem cell derived organoids represent powerful systems for the study of how cells self-organize to generate tissues with a given shape, pattern and form. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cytocompatibility of polyethylene grafted with triethylenetetramine functionalized carbon nanoparticles

NASA Astrophysics Data System (ADS)

Žáková, Pavlína; Slepičková Kasálková, Nikola; Slepička, Petr; Kolská, Zdeňka; Karpíšková, Jana; Stibor, Ivan; Švorčík, Václav

2017-11-01

Various carbon nanostructures are widely researched as scaffolds for tissue engineering. We evaluated the surface properties and cell-substrate interactions of carbon nanoparticles functionalized with triethylenetetramine (CNPs) grafted polymer film. Two forms of polyethylene (HDPE, LDPE) were treated in an inert argon plasma discharge and, subsequently, grafted with CNPs. The surface properties were studied using multiple methods, including Raman spectroscopy, goniometry, atomic force microscopy, X-ray photoelectron spectroscopy and electrokinetic analysis. Cell-substrate interactions were determined in vitro by studying adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs) from the aorta of a rat. Cell-substrate interactions on pristine and modified substrates were compared to standard tissue culture polystyrene. Our results show that CNPs affect surface morphology and wettability and therefore adhesion, proliferation and viability of cultured muscle cells.

The Cell's Sophisticated Army to Defend Against Assaults on DNAThe Cell's Sophisticated Army to Defend Against Assaults on DNA | Center for Cancer Research

Cancer.gov

The maintenance of genome integrity and function is essen-tial for the survival of cells and organisms. Any damage to our genetic material must be immediately sensed and repaired to preserve a cell’s func-tional integrity. Cells are constantly faced with the challenge of protecting their DNA from assaults by damaging chemicals and ultraviolet light. DNA damage that escapes repair can lead to a variety of genetic disorders and diseases, particularly cancer. To avoid this catastrophe, the cell employs an army of DNA repair factors that “rush to the scene” and initiate a cascade of events to repair the damage. Exactly how different repair factors sense DNA damage and orchestrate their concert-ed response is not well understood.

Bone Tissue Engineering: Recent Advances and Challenges

PubMed Central

Amini, Ami R.; Laurencin, Cato T.; Nukavarapu, Syam P.

2013-01-01

The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field. PMID:23339648

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Genetics of Cancer Susceptibility Section in the Mouse Cancer Genetics Program at NCI is seeking a highly motivated postdoctoral researcher to identify novel genetic interactors of BRCA2 using CRISPR-based genetic screen in mouse embryonic stem cells and perform functional studies in mouse models.

Synthetic Spores Give Insight into the Real Thing and Reveal Functional Applications | Center for Cancer Research

Cancer.gov

Spores from bacteria, such as Bacillus subtilis, are produced to allow the bacterium’s genetic material to survive harsh environments. When the bacterium senses nutrient depletion, it divides asymmetrically into a forespore and a mother cell. The mother cell engulfs the forespore, and coat proteins synthesized by the mother cell localize to the surface of the forespore. The

From embryonic stem cells to functioning germ cells: science, clinical and ethical perspectives.

PubMed

Kiatpongsan, Sorapop

2007-10-01

Embryonic stem cells have been well recognized as cells having a versatile potential to differentiate into all types of cells in the body including germ cells. There are many research studies focusing on the differentiation processes and protocols to derive various types of somatic cells from embryonic stem cells. However, germ cells have unique differentiation process and developmental pathway compared with somatic cells. Consequently, they will require different differentiation protocols and special culture techniques. More understanding and established in vitro systems for gametogenesis will greatly contribute to further progression of knowledge and technology in germ cell biology, reproductive biology and reproductive medicine. Moreover if oocytes can be efficiently produced in vitro, this will play an important role on progression in nuclear transfer and nuclear reprogramming technology. The present article will provide concise review on past important discoveries, current ongoing studies and future views of this challenging research area. An ethical perspective has also been proposed to give comprehensive summary and viewpoint for future clinical application.

Single cell biology beyond the era of antibodies: relevance, challenges, and promises in biomedical research.

PubMed

Abraham, Parvin; Maliekal, Tessy Thomas

2017-04-01

Research of the past two decades has proved the relevance of single cell biology in basic research and translational medicine. Successful detection and isolation of specific subsets is the key to understand their functional heterogeneity. Antibodies are conventionally used for this purpose, but their relevance in certain contexts is limited. In this review, we discuss some of these contexts, posing bottle neck for different fields of biology including biomedical research. With the advancement of chemistry, several methods have been introduced to overcome these problems. Even though microfluidics and microraft array are newer techniques exploited for single cell biology, fluorescence-activated cell sorting (FACS) remains the gold standard technique for isolation of cells for many biomedical applications, like stem cell therapy. Here, we present a comprehensive and comparative account of some of the probes that are useful in FACS. Further, we illustrate how these techniques could be applied in biomedical research. It is postulated that intracellular molecular markers like nucleostemin (GNL3), alkaline phosphatase (ALPL) and HIRA can be used for improving the outcome of cardiac as well as bone regeneration. Another field that could utilize intracellular markers is diagnostics, and we propose the use of specific peptide nucleic acid probes (PNPs) against certain miRNAs for cancer surgical margin prediction. The newer techniques for single cell biology, based on intracellular molecules, will immensely enhance the repertoire of possible markers for the isolation of cell types useful in biomedical research.

Japanese photovoltaic power generation for space application

NASA Technical Reports Server (NTRS)

Saga, T.; Kiyota, Y.; Matsutani, T.; Suzuki, A.; Kawasaki, O.; Hisamatsu, T.; Matsuda, S.

1996-01-01

This paper describes Japanese activities on mainly silicon solar cell research development and applications. The high efficiency thin silicon solar cells and the same kinds of solar cells with integrated bypass function (IBF cells) were developed and qualified for space applications. The most efficient cells (NRS/LBSF cells) showed average 18% at AMO and 28 C conditions. After electron irradiation, NRS/BSF cells showed higher efficiency than NRS/LBSF cells. The IBF cells do not suffer high reverse voltage and can survive from shadowing. The designs and characteristics of these solar cells are presented. In the last section, our future plan for the solar cell calibration is presented.

Comprehensive analysis of alternative splicing and functionality in neuronal differentiation of P19 cells.

PubMed

Suzuki, Hitoshi; Osaki, Ken; Sano, Kaori; Alam, A H M Khurshid; Nakamura, Yuichiro; Ishigaki, Yasuhito; Kawahara, Kozo; Tsukahara, Toshifumi

2011-02-18

Alternative splicing, which produces multiple mRNAs from a single gene, occurs in most human genes and contributes to protein diversity. Many alternative isoforms are expressed in a spatio-temporal manner, and function in diverse processes, including in the neural system. The purpose of the present study was to comprehensively investigate neural-splicing using P19 cells. GeneChip Exon Array analysis was performed using total RNAs purified from cells during neuronal cell differentiation. To efficiently and readily extract the alternative exon candidates, 9 filtering conditions were prepared, yielding 262 candidate exons (236 genes). Semiquantitative RT-PCR results in 30 randomly selected candidates suggested that 87% of the candidates were differentially alternatively spliced in neuronal cells compared to undifferentiated cells. Gene ontology and pathway analyses suggested that many of the candidate genes were associated with neural events. Together with 66 genes whose functions in neural cells or organs were reported previously, 47 candidate genes were found to be linked to 189 events in the gene-level profile of neural differentiation. By text-mining for the alternative isoform, distinct functions of the isoforms of 9 candidate genes indicated by the result of Exon Array were confirmed. Alternative exons were successfully extracted. Results from the informatics analyses suggested that neural events were primarily governed by genes whose expression was increased and whose transcripts were differentially alternatively spliced in the neuronal cells. In addition to known functions in neural cells or organs, the uninvestigated alternative splicing events of 11 genes among 47 candidate genes suggested that cell cycle events are also potentially important. These genes may help researchers to differentiate the roles of alternative splicing in cell differentiation and cell proliferation.

Concise Review: Stem Cell Interventions for People With Cerebral Palsy: Systematic Review With Meta-Analysis.

PubMed

Novak, Iona; Walker, Karen; Hunt, Rod W; Wallace, Euan M; Fahey, Michael; Badawi, Nadia

2016-08-01

: Evidence for stem cells as a potential intervention for cerebral palsy is emerging. Our objective was to determine the efficacy and safety of stem cells for improving motor and cognitive function of people with cerebral palsy. Searches were conducted in October 2015 in CENTRAL, EMBASE, MEDLINE, and Cochrane Libraries. Randomized controlled trials and controlled clinical trials of stem cells for cerebral palsy were included. Two authors independently decided upon included trials, extracted data, quality, and risk of bias. The primary outcome was gross motor function. Secondary outcomes were cognitive function and adverse events (AEs). Effects were expressed as standardized mean differences (SMD) with 95% confidence intervals (CI), using a random-effects model. Five trials comprising 328 participants met inclusion criteria. Four cell types were studied: olfactory ensheathing, neural, neural progenitors, and allogeneic umbilical cord blood (UCBs). Transplantation procedures differed from central nervous system neurosurgical transplantation to intravenous/arterial infusion. Participants were followed short-term for only 6 months. Evidence of variable quality indicated a small statistically significant intervention effect from stem cells on gross motor skills (SMD 1.27; 95% CI 0.22, 2.33), with UCBs most effective. There were insufficient and heterogeneous data to compare cognitive effects. Serious AEs were rare (n = 4/135 [3%] stem cells; n = 3/139 [2%] controls). Stem cells appeared to induce short-term improvements in motor skills. Different types of stem cell interventions were compared, meaning the data were heterogeneous and are a study limitation. Further randomized controlled trials are warranted, using rigorous methodologies. Stem cells are emerging as a scientifically plausible treatment and possible cure for cerebral palsy, but are not yet proven. The lack of valid animal models has significantly hampered the scope of clinical trials. Despite the state of current treatment evidence, parents remain optimistic about the potential improvements from stem cell intervention and feel compelled to exhaust all therapeutic options, including stem cell tourism. Receiving unproven therapies from unvalidated sources is potentially dangerous. Thus it is essential that researchers and clinicians stay up to date. A systematic review and meta-analysis summarizing and aggregating current research data may provide more conclusive evidence to inform treatment decision making and help direct future research. ©AlphaMed Press.

Concise Review: Stem Cell Interventions for People With Cerebral Palsy: Systematic Review With Meta-Analysis

PubMed Central

Walker, Karen; Hunt, Rod W.; Wallace, Euan M.; Fahey, Michael; Badawi, Nadia

2016-01-01

Evidence for stem cells as a potential intervention for cerebral palsy is emerging. Our objective was to determine the efficacy and safety of stem cells for improving motor and cognitive function of people with cerebral palsy. Searches were conducted in October 2015 in CENTRAL, EMBASE, MEDLINE, and Cochrane Libraries. Randomized controlled trials and controlled clinical trials of stem cells for cerebral palsy were included. Two authors independently decided upon included trials, extracted data, quality, and risk of bias. The primary outcome was gross motor function. Secondary outcomes were cognitive function and adverse events (AEs). Effects were expressed as standardized mean differences (SMD) with 95% confidence intervals (CI), using a random-effects model. Five trials comprising 328 participants met inclusion criteria. Four cell types were studied: olfactory ensheathing, neural, neural progenitors, and allogeneic umbilical cord blood (UCBs). Transplantation procedures differed from central nervous system neurosurgical transplantation to intravenous/arterial infusion. Participants were followed short-term for only 6 months. Evidence of variable quality indicated a small statistically significant intervention effect from stem cells on gross motor skills (SMD 1.27; 95% CI 0.22, 2.33), with UCBs most effective. There were insufficient and heterogeneous data to compare cognitive effects. Serious AEs were rare (n = 4/135 [3%] stem cells; n = 3/139 [2%] controls). Stem cells appeared to induce short-term improvements in motor skills. Different types of stem cell interventions were compared, meaning the data were heterogeneous and are a study limitation. Further randomized controlled trials are warranted, using rigorous methodologies. Significance Stem cells are emerging as a scientifically plausible treatment and possible cure for cerebral palsy, but are not yet proven. The lack of valid animal models has significantly hampered the scope of clinical trials. Despite the state of current treatment evidence, parents remain optimistic about the potential improvements from stem cell intervention and feel compelled to exhaust all therapeutic options, including stem cell tourism. Receiving unproven therapies from unvalidated sources is potentially dangerous. Thus it is essential that researchers and clinicians stay up to date. A systematic review and meta-analysis summarizing and aggregating current research data may provide more conclusive evidence to inform treatment decision making and help direct future research. PMID:27245364

Safety hazards associated with the charging of lithium/sulfur dioxide cells

NASA Technical Reports Server (NTRS)

Frank, H.; Halpert, G.; Lawson, D. D.; Barnes, J. A.; Bis, R. F.

1986-01-01

A continuing research program to assess the responses of spirally wound, lithium/sulfur dioxide cells to charging as functions of charging current, temperature, and cell condition prior to charging is described. Partially discharged cells that are charged at currents greater than one ampere explode with the time to explosion inversely proportional to the charging current. Cells charged at currents of less than one ampere may fail in one of several modes. The data allows an empirical prediction of when certain cells will fail given a constant charging current.

Organ engineering--combining stem cells, biomaterials, and bioreactors to produce bioengineered organs for transplantation.

PubMed

Murphy, Sean Vincent; Atala, Anthony

2013-03-01

Often the only treatment available for patients suffering from diseased and injured organs is whole organ transplant. However, there is a severe shortage of donor organs for transplantation. The goal of organ engineering is to construct biological substitutes that will restore and maintain normal function in diseased and injured tissues. Recent progress in stem cell biology, biomaterials, and processes such as organ decellularization and electrospinning has resulted in the generation of bioengineered blood vessels, heart valves, livers, kidneys, bladders, and airways. Future advances that may have a significant impact for the field include safe methods to reprogram a patient's own cells to directly differentiate into functional replacement cell types. The subsequent combination of these cells with natural, synthetic and/or decellularized organ materials to generate functional tissue substitutes is a real possibility. This essay reviews the current progress, developments, and challenges facing researchers in their goal to create replacement tissues and organs for patients. Copyright © 2013 WILEY Periodicals, Inc.

Emerging Role and Characterization of Immunometabolism: Relevance to HIV Pathogenesis, Serious Non-AIDS Events, and a Cure.

PubMed

Palmer, Clovis S; Henstridge, Darren C; Yu, Di; Singh, Amit; Balderson, Brad; Duette, Gabriel; Cherry, Catherine L; Anzinger, Joshua J; Ostrowski, Matias; Crowe, Suzanne M

2016-06-01

Immune cells cycle between a resting and an activated state. Their metabolism is tightly linked to their activation status and, consequently, functions. Ag recognition induces T lymphocyte activation and proliferation and acquisition of effector functions that require and depend on cellular metabolic reprogramming. Likewise, recognition of pathogen-associated molecular patterns by monocytes and macrophages induces changes in cellular metabolism. As obligate intracellular parasites, viruses manipulate the metabolism of infected cells to meet their structural and functional requirements. For example, HIV-induced changes in immune cell metabolism and redox state are associated with CD4(+) T cell depletion, immune activation, and inflammation. In this review, we highlight how HIV modifies immunometabolism with potential implications for cure research and pathogenesis of comorbidities observed in HIV-infected patients, including those with virologic suppression. In addition, we highlight recently described key methods that can be applied to study the metabolic dysregulation of immune cells in disease states. Copyright © 2016 by The American Association of Immunologists, Inc.

Nrf2: bane or blessing in cancer?

PubMed

Xiang, MingJun; Namani, Akhileshwar; Wu, ShiJun; Wang, XiaoLi

2014-08-01

The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor-E2-related factor 2 (Nrf2)-antioxidant response element pathway serves a major function in endogenous cytoprotection in normal cells. Nrf2 is a transcription factor that mainly regulates the expression of a wide array of genes that produce the antioxidants and other proteins responsible for the detoxification of xenobiotics and reactive oxygen species. Nrf2 mediates the chemoprevention of cancer in normal cells. Growing body of evidence suggests that Nrf2 is not only involved in the chemoprevention of normal cells but also promotes the growth of cancer cells. However, the mechanism underlying the function of Nrf2 in oncogenesis and tumor protection in cancer cells remains unclear and thus requires further study. This review aims to rationalize the existing functions of Nrf2 in chemoprevention and tumorigenesis, as well as the somatic mutations of Nrf2 and Keap1 in cancer and Nrf2 cross talk with miRNAs. This review also discusses the future challenges in Nrf2 research.

Gold Functionalized Mesoporous Silica Nanoparticle Mediated Protein and DNA Codelivery to Plant Cells Via the Biolistic Method

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

Martin-Ortigosa, Susana; Valenstein, Justin S.; Lin, Victor S.-Y.

2012-09-11

The synthesis and characterization of a gold nanoparticle functionalized mesoporous silica nanoparticle (Au-MSN) platform for codelivery of proteins and plasmid DNA to plant tissues using a biolistic particle delivery system is reported. The in vitro uptake and release profiles of fluorescently labeled bovine serum albumin (BSA) and enhanced green fluorescent protein (eGFP) are investigated. As a proof-of-concept demonstration, Au-MSN with large average pore diameters (10 nm) are shown to deliver and subsequently release proteins and plasmid DNA to the same cell after passing through the plant cell wall upon bombardment. Release of fluorescent eGFP indicates the delivery of active, non-denaturedmore » proteins to plant cells. This advance represents the first example of biolistic-mediated codelivery of proteins and plasmid DNA to plant cells via gold-functionalized MSN and provides a powerful tool for both fundamental and applied research of plant sciences.« less

[Technologies for hair reconstruction and their applicability for pharmaceutical research].

PubMed

Matsuzaki, Takashi

2008-01-01

Hair follicles are the organs that produce hair shafts. They periodically regenerate throughout the life of the organisms, which is called the hair cycle. To develop new drugs to treat hair disorders and diseases, reproducible and high throughput assays or screening methods have been required to estimate the efficacy of various factors on hair follicle function. Although organ culture of hair follicles is one of the useful ways to carry out such research, it is not suitable for manipulating the genes or cells present in hair follicles. Patch assay is a method used to reconstruct hair follicles from enzymatically dissociated skin cells and has many advantages compared to the conventional Chamber method. Using the Patch method, transferring genes into follicular cells becomes easier than ever before. Chimeric follicles could be produced with dissociated cells by modifying the combination of cells or by simply merging cells of different origins. These applications certainly help the progress of hair research. However, we recently found that some functions of dermal papillae and follicular epithelia change during the growing phase (anagen) of the hair cycle. Dermal papillae produce different factors in early anagen and mid anagen. The signals from dermal papillae in early anagen could produce hair bulbs with clonogenic epithelial precursors but not with dormant epithelial precursors. On the other hand, the signals from dermal papillae in mid anagen strongly promote hair formation with dormant epithelial precursors. Therefore, more attention should be given to the hair cycle stages when using organ culture of hair follicles and conducting reconstruction experiments with follicularly derived cells.

Checkpoints to the Brain: Directing Myeloid Cell Migration to the Central Nervous System

PubMed Central

Harrison-Brown, Meredith; Liu, Guo-Jun; Banati, Richard

2016-01-01

Myeloid cells are a unique subset of leukocytes with a diverse array of functions within the central nervous system during health and disease. Advances in understanding of the unique properties of these cells have inspired interest in their use as delivery vehicles for therapeutic genes, proteins, and drugs, or as “assistants” in the clean-up of aggregated proteins and other molecules when existing drainage systems are no longer adequate. The trafficking of myeloid cells from the periphery to the central nervous system is subject to complex cellular and molecular controls with several ‘checkpoints’ from the blood to their destination in the brain parenchyma. As important components of the neurovascular unit, the functional state changes associated with lineage heterogeneity of myeloid cells are increasingly recognized as important for disease progression. In this review, we discuss some of the cellular elements associated with formation and function of the neurovascular unit, and present an update on the impact of myeloid cells on central nervous system (CNS) diseases in the laboratory and the clinic. We then discuss emerging strategies for harnessing the potential of site-directed myeloid cell homing to the CNS, and identify promising avenues for future research, with particular emphasis on the importance of untangling the functional heterogeneity within existing myeloid subsets. PMID:27918464

Multi-walled carbon nanotubes and metallic nanoparticles and their application in biomedicine.

PubMed

Rojas-Chapana, Jose A; Giersig, Michael

2006-02-01

Interdisciplinary research has become a matter of paramount importance for novel applications of nanomaterials in biology and medicine. As such, many disciplines-physics, chemistry, microbiology, cell biology, and material science-all contribute to the design, synthesis and fabrication of functional and biocompatible devices at the nanometer scale. Since the most areas of cell biology and biomedicine deal with functional entities such as DNA and proteins, mimicry of these structures and function in the nanosize range offers exciting opportunities for the development of biosensors, biochips, and bioplatforms. In this report we highlight the potential benefits and challenges that arise in the manufacture of biocompatible nanoparticles and nano-networks that can be coupled with biological objects. Among the challenges facing us are those concerned with making the necessary advances in enabling affordability, innovation, and quality of manufactured nanodevices for rapid progress in the emerging field of bio-nanotechnology. The convergence of nanotechnology and biomedicine makes nanoscale research highly promising for new discoveries that can cost-effectively accelerate progress in moving from basic research to practical prototypes and products.

A Probabilistic Cell Tracking Algorithm

NASA Astrophysics Data System (ADS)

Steinacker, Reinhold; Mayer, Dieter; Leiding, Tina; Lexer, Annemarie; Umdasch, Sarah

2013-04-01

The research described below was carried out during the EU-Project Lolight - development of a low cost, novel and accurate lightning mapping and thunderstorm (supercell) tracking system. The Project aims to develop a small-scale tracking method to determine and nowcast characteristic trajectories and velocities of convective cells and cell complexes. The results of the algorithm will provide a higher accuracy than current locating systems distributed on a coarse scale. Input data for the developed algorithm are two temporally separated lightning density fields. Additionally a Monte Carlo method minimizing a cost function is utilizied which leads to a probabilistic forecast for the movement of thunderstorm cells. In the first step the correlation coefficients between the first and the second density field are computed. Hence, the first field is shifted by all shifting vectors which are physically allowed. The maximum length of each vector is determined by the maximum possible speed of thunderstorm cells and the difference in time for both density fields. To eliminate ambiguities in determination of directions and velocities, the so called Random Walker of the Monte Carlo process is used. Using this method a grid point is selected at random. Moreover, one vector out of all predefined shifting vectors is suggested - also at random but with a probability that is related to the correlation coefficient. If this exchange of shifting vectors reduces the cost function, the new direction and velocity are accepted. Otherwise it is discarded. This process is repeated until the change of cost functions falls below a defined threshold. The Monte Carlo run gives information about the percentage of accepted shifting vectors for all grid points. In the course of the forecast, amplifications of cell density are permitted. For this purpose, intensity changes between the investigated areas of both density fields are taken into account. Knowing the direction and speed of thunderstorm cells is important for nowcasting. Therefore, the presented method is based on IC discharges which account for most lightning discharges and occur minutes before the first CG discharge. The cell tracking algorithm will be used as part of the integrated LoLight system. The research leading to these results has received funding from the European Union's Seventh Framework Programme managed by REA-Research Executive Agency http://ec.europa.eu/research/rea ([FP7/2007-2013] [FP7/2007-2011]) under grant agreement n° [262200].

Extracellular matrix functionalized microcavities to control hematopoietic stem and progenitor cell fate.

PubMed

Kurth, Ina; Franke, Katja; Pompe, Tilo; Bornhäuser, Martin; Werner, Carsten

2011-06-14

Polymeric microcavities functionalized with extracellular matrix components were used as an experimental in vitro model to investigate principles of hematopoietic stem and progenitor cell (HSPC) fate control. Using human CD133+ HSPC we could demonstrate distinct differences in HSPC cycling and differentiation dependence on the adhesion ligand specificity (i.e., heparin, collagen I) and cytokine levels. The presented microcavity platform provides a powerful in vitro approach to explore the role of exogenous cues in HSPC fate decisions and can therefore be instrumental to progress in stem cell biology and translational research toward new therapies. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular Interactions of High Energy Fuels and Jet Fuels with Oncogenic Viruses and Endogenous Viruses.

DTIC Science & Technology

1981-10-01

Function of depressed immunologic reactivity during carcinogenesis, 3. Nati. Cancer Inst., 31, 791, 1963. 13. Tarr, M.3., Olsen, R.G., Hoover, E.A...cell line, RDII4/RD. This cell line was obtained from the biological carcinogenesis program of Frederick Cancer Research Center. After discussion with...Sandra West of the Frederick Cancer Research Center, a procedure was developed and is now routinely used to produce and isolate the RD14 virus. The RD14

The Emerging Role of Epigenetics in Inflammation and Immunometabolism.

PubMed

Raghuraman, Sukanya; Donkin, Ida; Versteyhe, Soetkin; Barrès, Romain; Simar, David

2016-11-01

Recent research developments have shed light on the risk factors contributing to metabolic complications, implicating both genetic and environmental factors, potentially integrated by epigenetic mechanisms. Distinct epigenetic changes in immune cells are frequently observed in obesity and type 2 diabetes mellitus, and these are associated with alterations in the phenotype, function, and trafficking patterns of these cells. The first step in the development of effective therapeutic strategies is the identification of distinct epigenetic signatures associated with metabolic disorders. In this review we provide an overview of the epigenetic mechanisms influencing immune cell phenotype and function, summarize current knowledge about epigenetic changes affecting immune functions in the context of metabolic diseases, and discuss the therapeutic options currently available to counteract epigenetically driven metabolic complications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rat Bone Marrow-Derived Schwann-Like Cells Differentiated by the Optimal Inducers Combination on Microfluidic Chip and Their Functional Performance

PubMed Central

Lv, Decheng

2012-01-01

Numerous researches demonstrated the possibility of derivation of Schwann-like (SC-like) cells in vitro from bone marrow stromal cells (BMSCs). However, the concentration of the induce factors were different in those studies, especially for the critical factors forskolin (FSK) and β-heregulin (HRG). Here, we used a new and useful method to build an integrated microfluidic chip for rapid analyses of the optimal combination between the induce factors FSK and HRG. The microfluidic device was mainly composed of an upstream concentration gradient generator (CGG) and a downstream cell culture module. Rat BMSCs were cultured in the cell chambers for 11 days at the different concentrations of induce factors generated by CGG. The result of immunofluorescence staining on-chip showed that the group of 4.00 µM FSK and 250.00 ng/ml HRG presented an optimal effect to promote the derivation of SC-like cells. Moreover, the optimal SC-like cells obtained on-chip were further tested using DRG co-culture and ELISA to detect their functional performance. Our findings demonstrate that SC-like cells could be obtained with high efficiency and functional performance in the optimal inducers combination. PMID:22880114

Rat bone marrow-derived Schwann-like cells differentiated by the optimal inducers combination on microfluidic chip and their functional performance.

PubMed

Tian, Xiliang; Wang, Shouyu; Zhang, Zhen; Lv, Decheng

2012-01-01

Numerous researches demonstrated the possibility of derivation of Schwann-like (SC-like) cells in vitro from bone marrow stromal cells (BMSCs). However, the concentration of the induce factors were different in those studies, especially for the critical factors forskolin (FSK) and β-heregulin (HRG). Here, we used a new and useful method to build an integrated microfluidic chip for rapid analyses of the optimal combination between the induce factors FSK and HRG. The microfluidic device was mainly composed of an upstream concentration gradient generator (CGG) and a downstream cell culture module. Rat BMSCs were cultured in the cell chambers for 11 days at the different concentrations of induce factors generated by CGG. The result of immunofluorescence staining on-chip showed that the group of 4.00 µM FSK and 250.00 ng/ml HRG presented an optimal effect to promote the derivation of SC-like cells. Moreover, the optimal SC-like cells obtained on-chip were further tested using DRG co-culture and ELISA to detect their functional performance. Our findings demonstrate that SC-like cells could be obtained with high efficiency and functional performance in the optimal inducers combination.

Unique cell culture systems for ground based research

NASA Technical Reports Server (NTRS)

Lewis, Marian L.

1990-01-01

The horizontally rotating fluid-filled, membrane oxygenated bioreactors developed at NASA Johnson for spacecraft applications provide a powerful tool for ground-based research. Three-dimensional aggregates formed by cells cultured on microcarrier beads are useful for study of cell-cell interactions and tissue development. By comparing electron micrographs of plant seedlings germinated during Shuttle flight 61-C and in an earth-based rotating bioreactor it is shown that some effects of microgravity are mimicked. Bioreactors used in the UAH Bioreactor Laboratory will make it possible to determine some of the effects of altered gravity at the cellular level. Bioreactors can be valuable for performing critical, preliminary-to-spaceflight experiments as well as medical investigations such as in vitro tumor cell growth and chemotherapeutic drug response; the enrichment of stem cells from bone marrow; and the effect of altered gravity on bone and muscle cell growth and function and immune response depression.

A Review of the Cell to Graphene-Based Nanomaterial Interface

NASA Astrophysics Data System (ADS)

Darbandi, Arash; Gottardo, Erik; Huff, Joshua; Stroscio, Michael; Shokuhfar, Tolou

2018-04-01

The area of cellular interactions of nanomaterials is an important research interest. The sensitivity of cells toward their extracellular matrix allows researchers to create microenvironments for guided stem cell differentiation. Among nanomaterials, graphene, often called the "wonder material," and its derivatives are at the forefront of such endeavors. Graphene's carbon backbone, paired with its biocompatibility and ease of functionalization, has been used as an enhanced method of controlled cell proliferation. Graphene's honeycomb nature allows for compatibility with polymers and biological material for the creation of nanocomposite scaffolds that help differentiation into cell types that have otherwise been proven difficult. Such materials and their role in guiding cell growth can aid the construction of tissue grafts where shortages and patient compatibility create a low success rate. This review will bring together novel studies and techniques used to understand and optimizes graphene's role in cell growth mechanisms.

Three-Dimensional Cell Culture Models for Infectious Disease and Drug Development

NASA Technical Reports Server (NTRS)

Nickerson, Cheryl A.; Honer zu Bentrup, Kerstin; Ott, C. Mark

2005-01-01

Three-dimensional (3-D) cell cultures hold enormous potential to advance our understanding of infectious disease and to effectively translate basic cellular research into clinical applications. Using novel NASA bioreactor technology, the rotating wall vessel (RWV), we have engineered physiologically relevant 3-D human tissue culture models for infectious disease studies. The design of the RWV is based on the understanding that organs and tissues function in a 3-D environment, and that this 3-D architecture is critical for the differentiated form and function of tissues in vivo. The RWV provides large numbers of cells which are amenable to a wide variety of experimental manipulations and provides an easy, reproducible, and cost-effective approach to enhance differentiated features of cell culture models.

Digital Microfluidics for Manipulation and Analysis of a Single Cell.

PubMed

He, Jie-Long; Chen, An-Te; Lee, Jyong-Huei; Fan, Shih-Kang

2015-09-15

The basic structural and functional unit of a living organism is a single cell. To understand the variability and to improve the biomedical requirement of a single cell, its analysis has become a key technique in biological and biomedical research. With a physical boundary of microchannels and microstructures, single cells are efficiently captured and analyzed, whereas electric forces sort and position single cells. Various microfluidic techniques have been exploited to manipulate single cells through hydrodynamic and electric forces. Digital microfluidics (DMF), the manipulation of individual droplets holding minute reagents and cells of interest by electric forces, has received more attention recently. Because of ease of fabrication, compactness and prospective automation, DMF has become a powerful approach for biological application. We review recent developments of various microfluidic chips for analysis of a single cell and for efficient genetic screening. In addition, perspectives to develop analysis of single cells based on DMF and emerging functionality with high throughput are discussed.

Digital Microfluidics for Manipulation and Analysis of a Single Cell

PubMed Central

He, Jie-Long; Chen, An-Te; Lee, Jyong-Huei; Fan, Shih-Kang

2015-01-01

The basic structural and functional unit of a living organism is a single cell. To understand the variability and to improve the biomedical requirement of a single cell, its analysis has become a key technique in biological and biomedical research. With a physical boundary of microchannels and microstructures, single cells are efficiently captured and analyzed, whereas electric forces sort and position single cells. Various microfluidic techniques have been exploited to manipulate single cells through hydrodynamic and electric forces. Digital microfluidics (DMF), the manipulation of individual droplets holding minute reagents and cells of interest by electric forces, has received more attention recently. Because of ease of fabrication, compactness and prospective automation, DMF has become a powerful approach for biological application. We review recent developments of various microfluidic chips for analysis of a single cell and for efficient genetic screening. In addition, perspectives to develop analysis of single cells based on DMF and emerging functionality with high throughput are discussed. PMID:26389890

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.

The role of mast cells in oral squamous cell carcinoma

PubMed Central

Gudiseva, Swetha; Chitturi, Raviteja; Anumula, Vamsikrishna; Poosarla, Chandrashekar; Baddam, Venkat Ramana Reddy

2017-01-01

The mast cells are initial effective lineage in both humoral and adaptive immunity. They are ubiquitous in skin, mucosa, and in function. They contain biologically essential and dynamic mediators in healthy and harmful conditions of tissue. Mast cell malfunctioning could be attributed to various chronic allergic diseases. Considerately, emerging evidence of mast cell involvement in various cancers shows them to have both positive and negative roles in tumour growth. It mostly indulges in tumour progression and metastasis via angiogenesis, extracellular matrix degradation, and mitogenic activity in the tumour microenvironment. The current paper reviewed research papers on mast cells in oral squamous cell carcinoma through the PubMed database from 1980 to the present date. The present paper is an attempt to summarise the research reports on the role of mast cells in oral squamous cell carcinoma. Further to this note, this paper also outlines the role of mast cells in normal physiological processes and tumour biology. PMID:28435394

Immunomodulatory Effect of Mesenchymal Stem Cells on B Cells

PubMed Central

Franquesa, Marcella; Hoogduijn, M. J.; Bestard, O.; Grinyó, J. M.

2012-01-01

The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches. Mesenchymal stem cells (MSC) are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field. PMID:22833744

Will stem cell therapies be safe and effective for treating spinal cord injuries?

PubMed Central

Thomas, Katharine E.; Moon, Lawrence D. F.

2017-01-01

Introduction A large number of different cells including embryonic and adult stem cells have been transplanted into animal models of spinal cord injury, and in many cases these procedures have resulted in modest sensorimotor benefits. In October 2010 the world’s first clinical trial using human embryonic stem cells began, using stem cells converted into oligodendrocyte precursor cells. Sources of data In this review we examine some of the publically-available pre-clinical evidence that some of these cell types improve outcome in animal models of spinal cord injury. Much evidence is not available for public scrutiny, however, being private commercial property of various stem cell companies. Areas of agreement Transplantation of many different types of stem and progenitor cell enhances spontaneous recovery of function when transplanted acutely after spinal cord injury in animal models. Areas of disagreement The common mechanism(s) whereby the generic procedure of cellular transplantation enhances recovery of function are not well understood, although a range of possibilities are usually cited (including preservation of tissue, remyelination, axon sprouting, glial cell replacement). Only in exceptional cases has it been shown that functional recovery depends causally on the survival and differentiation of the transplanted cells. There is no agreement about the optimal cell type for transplantation: candidate stem cells have not yet been compared with each other or with other cell types (e.g., autologous Schwann cells) in a single study. Areas timely for developing research Transplantation of cells into animals with a long lifespan is important to determine whether or not tumours will eventually form. It will also be important to determine whether long-term survival of cells is required for functional recovery, and if so, how many are optimal. PMID:21586446

Non-linear optical measurements using a scanned, Bessel beam

NASA Astrophysics Data System (ADS)

Collier, Bradley B.; Awasthi, Samir; Lieu, Deborah K.; Chan, James W.

2015-03-01

Oftentimes cells are removed from the body for disease diagnosis or cellular research. This typically requires fluorescent labeling followed by sorting with a flow cytometer; however, possible disruption of cellular function or even cell death due to the presence of the label can occur. This may be acceptable for ex vivo applications, but as cells are more frequently moving from the lab to the body, label-free methods of cell sorting are needed to eliminate these issues. This is especially true of the growing field of stem cell research where specialized cells are needed for treatments. Because differentiation processes are not completely efficient, cells must be sorted to eliminate any unwanted cells (i.e. un-differentiated or differentiated into an unwanted cell type). In order to perform label-free measurements, non-linear optics (NLO) have been increasingly utilized for single cell analysis because of their ability to not disrupt cellular function. An optical system was developed for the measurement of NLO in a microfluidic channel similar to a flow cytometer. In order to improve the excitation efficiency of NLO, a scanned Bessel beam was utilized to create a light-sheet across the channel. The system was tested by monitoring twophoton fluorescence from polystyrene microbeads of different sizes. Fluorescence intensity obtained from light-sheet measurements were significantly greater than measurements made using a static Gaussian beam. In addition, the increase in intensity from larger sized beads was more evident for the light-sheet system.

Organ reconstruction: Dream or reality for the future.

PubMed

Stoltz, J-F; Zhang, L; Ye, J S; De Isla, N

2017-01-01

The relevance of research on reconstructed organs is justified by the lack of organs available for transplant and the growing needs for the ageing population. The development of a reconstructed organ involves two parallel complementary steps: de-cellularization of the organ with the need to maintain the structural integrity of the extracellular matrix and vascular network and re-cellularization of the scaffold with stem cells or resident cells.Whole organ engineering for liver, heart, lung or kidneys, is particularly difficult because of the structural complexity of organs and heterogeneity of cells. Rodent, porcine and rhesus monkey organs have been de-cellularized to obtain a scaffold with preserved extracellular matrix and vascular network. As concern the cells for re-cellularization, embryonic, foetal, adult, progenitor stem cells and also iPS have been proposed.Heart construction could be an alternative option for the treatment of cardiac insufficiency. It is based on the use of an extra-cellular matrix coming from an animal's heart and seeded with cells likely to reconstruct a normal cardiac function. Though de-cellularization techniques now seem controlled, the issues posed by the selection of cells capable of generating the various components of cardiac tissue are not settled yet. In addition, the recolonisation of the matrix does not only depend on the phenotype of cells that are used, but it is also impacted by the nature of biochemical signals emitted.Recent researches have shown that it is possible to use decellularized whole liver treated by detergents as scaffold, which keeps the entire network of blood vessels and the integrated extracellular matrix (ECM). Beside of decellularized whole organ scaffold seeding cells selected to repopulate a decellularized liver scaffold are critical for the function of the bioengineered liver. At present, potential cell sources are hepatocyte, and mesenchymal stem cells.Pulmonary regeneration using engineering approaches is complex. In fact, several types of local progenitor cells that contribute to cell repair have been described at different levels of the respiratory tract. Moving towards the alveoles, one finds bronchioalveolar stem cells as well as epithelial cells and pneumocytes. A promising option to increase the donor organ pool is to use allogeneic or xenogeneic decellularized lungs as a scaffold to engineer functional lung tissue ex vivo.The kidney is certainly one of the most difficult organs to reconstruct due to its complex nature and the heterogeneous nature of the cells. There is relatively little research on auto-construction, and experiments have been performed on rats, pigs and monkeys.Nevertheless, before these therapeutic approaches can be applied in clinical practice, many researches are necessary to understand and in particular the behaviour of cells on the decellularized organs as well as the mechanisms of their interaction with the microenvironment. Current knowledges allow optimism for the future but definitive answers can only be given after long term animal studies and controlled clinical studies.

Human cells and cell cultures: availability, authentication and future prospects.

PubMed

Hay, R J

1996-09-01

The availability of well characterized, viable human cells, tissues and cell lines along with pertinent data on the specific patient donors is a prerequisite for much current transplantation and biomedical research. In the USA, institutional and multi-center networks have been established for provision of primary human cells and tissues to qualified clinicians and research scientists. Monetary support derives from government, university, institutional and fee sources. Problems involved include concern for the rights and privacy of tissue donors, cultural reservations relating to tissue provision, the need for safe and expeditious transport, short term survival and limited supply, adequate correlation of patient data with samples provided, presence of infectious viruses and microorganisms, as well as state or government regulations regarding national or international shipping. The use of human cell lines with continuous or even somewhat limited doubling potentials overcomes many of the above difficulties. National cell banks have been established to provide reference lines for use by multiple investigators. Use of such cell lines assures improved research comparability both geographically and with time. Authentication procedures are critically important for all of these programs. Verification of tissue types and conditions is required through histological, biochemical and immunological assays. Tests for microbial and viral contaminants must be applied. In addition to such procedures utilized for tissues, with cell lines the banking agency must also verify species and where possible identity, properties and functions. The literature is replete with descriptions documenting incorrect identifications and infections of proliferating cell strains used for research. The availability of viable tissue through local sources and distribution agencies in the USA is becoming more commonplace even including full family participation and collection of related, detailed histories. Increased support for this developmental activity is needed, coupled with provision of blood and normal cells and cell lines from family members in many disease categories. Modern techniques, new and improved culture ware, serum-free media, reagents such as growth, adherence and transfer factors will permit isolation, propagation and wide spread distribution not only of human tumor cells but also normal and functional human cells of most renewing and expanding tissue types. Hybridization and immortalization techniques are enhancing this capability such that virtually all human cell types should be available for short or longer-term propagation and study in the foreseeable future.

Functional hepatocyte clusters on bioactive blend silk matrices towards generating bioartificial liver constructs.

PubMed

Janani, G; Nandi, Samit K; Mandal, Biman B

2018-02-01

The creation of in vitro functional hepatic tissue simulating micro-environmental niche of native liver is a keen area of research due to its demand in bioartificial liver (BAL) and cell-based tissue engineering. Here, we investigated the potential of novel blend (BA) silk scaffold fabricated by blending mulberry (Bombyx mori, BM) silk fibroin with cell adhesion motif (RGD) rich non-mulberry (Antheraea assamensis, AA) silk fibroin, in generating a functional liver construct. Three-dimensional (3D) porous silk scaffolds (BM, AA and BA) were physico-chemically characterized and functionally evaluated using human hepatocarcinoma cells (HepG2) and primary neonatal rat hepatocytes. The growth and distribution of hepatocytes within the scaffolds were tracked by FESEM, alamar blue proliferation assay and live/dead staining. Hemocompatible BA scaffolds supported the formation of high density hepatocyte clusters, facilitating cell-matrix and cell-cell interactions. Blend scaffolds evinced enhanced liver-specific functions of cultured hepatocytes in terms of albumin synthesis, urea synthesis and cytochrome P450 enzyme activity over 21 days. Subcutaneous implantation of scaffolds demonstrated minimal macrophage infiltration in blend scaffolds. These findings substantiate that the integral property of blend (BA) scaffold offers a befitting environment by influencing spheroidal growth of hepatocytes with enhanced biological activity. Collectively, the present study provides a new 3D bio-matrix niche for growing functional liver cells that would have future prospects in BAL as well as regenerative medicine. An end stage liver disease called cirrhosis perturbs the self-healing ability and physiological functions of liver. Due to the scarcity of healthy donors, a functional in vitro hepatic construct retaining the liver-specific functions is in great demand for its prospects in bioartificial liver (BAL) and cell-based tissue engineering. Physicochemical attributes of a matrix influence the behavior of cultured hepatocytes in terms of attachment, morphology and functionality. Mulberry and non-mulberry silk fibroin presents unique amino acid sequence with difference in hydrophobicity and crystallinity. Considering this, the present study focuses on the development of a suitable three-dimensional (3D) bioactive matrix incorporating both mulberry silk fibroin and cell adhesion motif (RGD) rich non-mulberry silk fibroin. Porous silk blend scaffolds facilitated the formation of hepatocyte clusters with enhanced liver-specific functions emphasizing both cell-cell and cell-matrix interactions. Hemocompatibility and integral property of blend scaffolds offers a biological niche for seeding functional liver cells that would have future prospects in biohybrid devices. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Cell Membrane Coating Nanotechnology.

PubMed

Fang, Ronnie H; Kroll, Ashley V; Gao, Weiwei; Zhang, Liangfang

2018-06-01

Nanoparticle-based therapeutic, prevention, and detection modalities have the potential to greatly impact how diseases are diagnosed and managed in the clinic. With the wide range of nanomaterials available, the rational design of nanocarriers on an application-specific basis has become increasingly commonplace. Here, a comprehensive overview is provided on an emerging platform: cell-membrane-coating nanotechnology. As a fundamental unit of biology, cells carry out a wide range of functions, including the remarkable ability to interface and interact with their surrounding environment. Instead of attempting to replicate such functions via synthetic techniques, researchers are now directly leveraging naturally derived cell membranes as a means of bestowing nanoparticles with enhanced biointerfacing capabilities. This top-down technique is facile, highly generalizable, and has the potential to greatly augment existing nanocarriers. Further, the introduction of a natural membrane substrate onto nanoparticles surfaces has enabled additional applications beyond those traditionally associated with nanomedicine. Despite its relative youth, there exists an impressive body of literature on cell membrane coating, which is covered here in detail. Overall, there is still significant room for development, as researchers continue to refine existing workflows while finding new and exciting applications that can take advantage of this developing technology. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lidocaine/monoethylglycinexylidide test, galactose elimination test, and sorbitol elimination test for metabolic assessment of liver cell bioreactors.

PubMed

Gerlach, Jörg C; Brayfield, Candace; Puhl, Gero; Borneman, Reiner; Müller, Christian; Schmelzer, Eva; Zeilinger, Katrin

2010-06-01

Various metabolic tests were compared for the performance characterization of a liver cell bioreactor as a routine function assessment of cultures in a standby for patient application in clinical studies. Everyday quality assessment (QA) is essential to ensure a continuous level of cellular functional capacity in the development of hepatic progenitor cell expansion systems providing cells for regenerative medicine research; it is also of interest to meet safety requirements in bioartificial extracorporeal liver support systems under clinical evaluation. Quality criteria for the description of bioreactor cultures were developed using primary porcine liver cells as a model. Porcine liver cells isolated by collagenase perfusion with an average of 3 x 10(9) primary cells were used in 39 bioreactors for culture periods up to 33 days. Measurements of monoethylglycinexylidide synthesis and elimination of lidocaine, galactose elimination, and sorbitol elimination proved to be useful for routine QA of primary liver cell cultures. We demonstrate two methods for dispensing test substances, bolus administration and continuous, steady-state administration. Bolus test data were grouped in Standard, Therapy, Infection/Contamination, and Cell-free control groups. Statistical analyses show significant differences among all groups for every test substance. Post hoc comparisons indicated significant differences between Standard and Cell-free groups for all elimination parameters. For continuous tests, results were categorized according to number of culture days and time-dependent changes were analyzed. Continuous administration enables a better view of culture health and the time dependency of cellular function, whereas bolus administration is more flexible. Both procedures can be used to define cell function. Assessment of cellular function and bioreactor quality can contribute significantly to the quality of experimental or clinical studies in the field of hepatic bioreactor development.

The Mutation-Associated Neoantigen Functional Expansion of Specific T cells (MANAFEST) assay: a sensitive platform for monitoring antitumor immunity.

PubMed

Danilova, Ludmila; Anagnostou, Valsamo; Caushi, Justina X; Sidhom, John-William; Guo, Haidan; Chan, Hok Yee; Suri, Prerna; Tam, Ada J; Zhang, Jiajia; El Asmar, Margueritta; Marrone, Kristen A; Naidoo, Jarushka; Brahmer, Julie R; Forde, Patrick M; Baras, Alexander S; Cope, Leslie; Velculescu, Victor E; Pardoll, Drew; Housseau, Franck; Smith, Kellie N

2018-06-12

Mutation-associated neoantigens (MANAs) are a target of antitumor T-cell immunity. Sensitive, simple, and standardized assays are needed to assess the repertoire of functional MANA-specific T cells in oncology. Assays analyzing in vitro cytokine production such as ELISpot and intracellular cytokine staining (ICS) have been useful but have limited sensitivity in assessing tumor-specific T-cell responses and do not analyze antigen-specific T-cell repertoires. The FEST (Functional Expansion of Specific T cells) assay described herein integrates TCR sequencing of short-term, peptide-stimulated cultures with a bioinformatic platform to identify antigen-specific clonotypic amplifications. This assay can be adapted for all types of antigens, including mutation associated neoantigens (MANAs) via tumor exome-guided prediction of MANAs. Following in vitro identification by the MANAFEST assay, the MANA-specific CDR3 sequence can be used as a molecular barcode to detect and monitor the dynamics of these clonotypes in blood, tumor, and normal tissue of patients receiving immunotherapy. MANAFEST is compatible with high-throughput routine clinical and lab practices. Copyright ©2018, American Association for Cancer Research.

Efficient delivery of RNA interference oligonucleotides to polarized airway epithelia in vitro

PubMed Central

Ramachandran, Shyam; Krishnamurthy, Sateesh; Jacobi, Ashley M.; Wohlford-Lenane, Christine; Behlke, Mark A.; Davidson, Beverly L.

2013-01-01

Polarized and pseudostratified primary airway epithelia present barriers that significantly reduce their transfection efficiency and the efficacy of RNA interference oligonucleotides. This creates an impediment in studies of the airway epithelium, diminishing the utility of loss-of-function as a research tool. Here we outline methods to introduce RNAi oligonucleotides into primary human and porcine airway epithelia grown at an air-liquid interface and difficult-to-transfect transformed epithelial cell lines grown on plastic. At the time of plating, we reverse transfect small-interfering RNA (siRNA), Dicer-substrate siRNA, or microRNA oligonucleotides into cells by use of lipid or peptide transfection reagents. Using this approach we achieve significant knockdown in vitro of hypoxanthine-guanine phosphoribosyltransferase, IL-8, and CFTR expression at the mRNA and protein levels in 1–3 days. We also attain significant reduction of secreted IL-8 in polarized primary pig airway epithelia 3 days posttransfection and inhibition of CFTR-mediated Cl− conductance in polarized air-liquid interface cultures of human airway epithelia 2 wk posttransfection. These results highlight an efficient means to deliver RNA interference reagents to airway epithelial cells and achieve significant knockdown of target gene expression and function. The ability to reliably conduct loss-of-function assays in polarized primary airway epithelia offers benefits to research in studies of epithelial cell homeostasis, candidate gene function, gene-based therapeutics, microRNA biology, and targeting the replication of respiratory viruses. PMID:23624792

Flow Cytometry Technician | Center for Cancer Research

Cancer.gov

PROGRAM DESCRIPTION The Basic Science Program (BSP) pursues independent, multidisciplinary research in basic and applied molecular biology, immunology, retrovirology, cancer biology, and human genetics. Research efforts and support are an integral part of the Center for Cancer Research (CCR) at the Frederick National Laboratory for Cancer Research (FNLCR). KEY ROLES/RESPONSIBILITIES The Flow Cytometry Core (Flow Core) of the Cancer and Inflammation Program (CIP) is a service core which supports the research efforts of the CCR by providing expertise in the field of flow cytometry (using analyzers and sorters) with the goal of gaining a more thorough understanding of the biology of cancer and cancer cells. The Flow Core provides service to 12-15 CIP laboratories and more than 22 non-CIP laboratories. Flow core staff provide technical advice on the experimental design of applications, which include immunological phenotyping, cell function assays, and cell cycle analysis. Work is performed per customer requirements, and no independent research is involved. The Flow Cytometry Technician will be responsible for: Monitor performance of and maintain high dimensional flow cytometer analyzers and cell sorters Operate high dimensional flow cytometer analyzers and cell sorters Monitoring lab supply levels and order lab supplies, perform various record keeping responsibilities Assist in the training of scientific end users on the use of flow cytometry in their research, as well as how to operate and troubleshoot the bench-top analyzer instruments Experience with sterile technique and tissue culture

Exosome-Mediated Genetic Information Transfer, a Missing Piece of Osteoblast-Osteoclast Communication Puzzle.

PubMed

Yin, Pengbin; Lv, Houchen; Li, Yi; Deng, Yuan; Zhang, Licheng; Tang, Peifu

2017-01-01

The skeletal system functions and maintains itself based on communication between cells of diverse origins, especially between osteoblasts (OBs) and osteoclasts (OCs), accounting for bone formation and resorption, respectively. Previously, protein-level information exchange has been the research focus, and this has been discussed in detail. The regulative effects of microRNAs (miRNAs) on OB and OC ignite the question as to whether genetic information could be transferred between bone cells. Exosomes, extracellular membrane vesicles 30-100 nm in diameter, have recently been demonstrated to transfer functional proteins, mRNAs, and miRNAs, and serve as mediators of intercellular communication. By reviewing the distinguishing features of exosomes, a hypothesis was formulated and evaluated in this article that exosome-mediated genetic information transfer may represent a novel strategy for OB-OC communication. The exosomes may coordinately regulate these two cells under certain physiological conditions by transferring genetic information. Further research in exosome-shuttered miRNAs in OB-OC communication may add a missing piece to the bone cells communication "puzzle."

Structural characteristics of surface-functionalized nitrogen-doped diamond-like carbon films and effective adjustment to cell attachment

NASA Astrophysics Data System (ADS)

Liu, Ai-Ping; Liu, Min; Yu, Jian-Can; Qian, Guo-Dong; Tang, Wei-Hua

2015-05-01

Nitrogen-doped diamond-like carbon (DLC:N) films prepared by the filtered cathodic vacuum arc technology are functionalized with various chemical molecules including dopamine (DA), 3-Aminobenzeneboronic acid (APBA), and adenosine triphosphate (ATP), and the impacts of surface functionalities on the surface morphologies, compositions, microstructures, and cell compatibility of the DLC:N films are systematically investigated. We demonstrate that the surface groups of DLC:N have a significant effect on the surface and structural properties of the film. The activity of PC12 cells depends on the particular type of surface functional groups of DLC:N films regardless of surface roughness and wettability. Our research offers a novel way for designing functionalized carbon films as tailorable substrates for biosensors and biomedical engineering applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51272237, 51272231, and 51010002) and the China Postdoctoral Science Foundation (Grant Nos. 2012M520063, 2013T60587, and Bsh1201016).

Regulatory T-cells in autoimmune diseases: challenges, controversies and--yet--unanswered questions.

PubMed

Grant, Charlotte R; Liberal, Rodrigo; Mieli-Vergani, Giorgina; Vergani, Diego; Longhi, Maria Serena

2015-02-01

Regulatory T cells (Tregs) are central to the maintenance of self-tolerance and tissue homeostasis. Markers commonly used to define human Tregs in the research setting include high expression of CD25, FOXP3 positivity and low expression/negativity for CD127. Many other markers have been proposed, but none unequivocally identifies bona fide Tregs. Tregs are equipped with an array of mechanisms of suppression, including the modulation of antigen presenting cell maturation and function, the killing of target cells, the disruption of metabolic pathways and the production of anti-inflammatory cytokines. Treg impairment has been reported in a number of human autoimmune conditions and includes Treg numerical and functional defects and conversion into effector cells in response to inflammation. In addition to intrinsic Treg impairment, resistance of effector T cells to Treg control has been described. Discrepancies in the literature are common, reflecting differences in the choice of study participants and the technical challenges associated with investigating this cell population. Studies differ in terms of the methodology used to define and isolate putative regulatory cells and to assess their suppressive function. In this review we outline studies describing Treg frequency and suppressive function in systemic and organ specific autoimmune diseases, with a specific focus on the challenges faced when investigating Tregs in these conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterisation of cell functions and receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME).

PubMed

Hardcastle, Sharni Lee; Brenu, Ekua Weba; Johnston, Samantha; Nguyen, Thao; Huth, Teilah; Wong, Naomi; Ramos, Sandra; Staines, Donald; Marshall-Gradisnik, Sonya

2015-06-02

Abnormal immune function is often an underlying component of illness pathophysiology and symptom presentation. Functional and phenotypic immune-related alterations may play a role in the obscure pathomechanism of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). The objective of this study was to investigate the functional ability of innate and adaptive immune cells in moderate and severe CFS/ME patients. The 1994 Fukuda criteria for CFS/ME were used to define CFS/ME patients. CFS/ME participants were grouped based on illness severity with 15 moderately affected (moderate) and 12 severely affected (severe) CFS/ME patients who were age and sex matched with 18 healthy controls. Flow cytometric protocols were used for immunological analysis of dendritic cells, monocytes and neutrophil function as well as measures of lytic proteins and T, natural killer (NK) and B cell receptors. CFS/ME patients exhibited alterations in NK receptors and adhesion markers and receptors on CD4(+)T and CD8(+)T cells. Moderate CFS/ME patients had increased CD8(+) CD45RA effector memory T cells, SLAM expression on NK cells, KIR2DL5(+) on CD4(+)T cells and BTLA4(+) on CD4(+)T central memory cells. Moderate CFS/ME patients also had reduced CD8(+)T central memory LFA-1, total CD8(+)T KLRG1, naïve CD4(+)T KLRG1 and CD56(dim)CD16(-) NK cell CD2(+) and CD18(+)CD2(+). Severe CFS/ME patients had increased CD18(+)CD11c(-) in the CD56(dim)CD16(-) NK cell phenotype and reduced NKp46 in CD56(bright)CD16(dim) NK cells. This research accentuated the presence of immunological abnormalities in CFS/ME and highlighted the importance of assessing functional parameters of both innate and adaptive immune systems in the illness.

How cancer cells dictate their microenvironment: present roles of extracellular vesicles.

PubMed

Naito, Yutaka; Yoshioka, Yusuke; Yamamoto, Yusuke; Ochiya, Takahiro

2017-02-01

Intercellular communication plays an important role in cancer initiation and progression through secretory molecules, including growth factors and cytokines. Recent advances have revealed that small membrane vesicles, termed extracellular vesicles (EVs), served as a regulatory agent in the intercellular communication of cancer. EVs enable the transfer of functional molecules, including proteins, mRNA and microRNAs (miRNAs), into recipient cells. Cancer cells utilize EVs to dictate the unique phenotype of surrounding cells, thereby promoting cancer progression. Against such "education" by cancer cells, non-tumoral cells suppress cancer initiation and progression via EVs. Therefore, researchers consider EVs to be important cues to clarify the molecular mechanisms of cancer biology. Understanding the functions of EVs in cancer progression is an important aspect of cancer biology that has not been previously elucidated. In this review, we summarize experimental data that indicate the pivotal roles of EVs in cancer progression.

The potential role of adult stem cells in the management of the rheumatic diseases

PubMed Central

Franceschetti, Tiziana; De Bari, Cosimo

2017-01-01

Adult stem cells are considered as appealing therapeutic candidates for inflammatory and degenerative musculoskeletal diseases. A large body of preclinical research has contributed to describing their immune-modulating properties and regenerative potential. Additionally, increasing evidence suggests that stem cell differentiation and function are disrupted in the pathogenesis of rheumatic diseases. Clinical studies have been limited, for the most part, to the application of adult stem cell-based treatments on small numbers of patients or as a ‘salvage’ therapy in life-threatening disease cases. Nevertheless, these preliminary studies indicate that adult stem cells are promising tools for the long-term treatment of rheumatic diseases. This review highlights recent knowledge acquired in the fields of hematopoietic and mesenchymal stem cell therapy for the management of systemic sclerosis (SSc), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and osteoarthritis (OA) and the potential mechanisms mediating their function. PMID:28717403

MicroRNAs – Important Molecules in Lung Cancer Research

PubMed Central

Leidinger, Petra; Keller, Andreas; Meese, Eckart

2011-01-01

MicroRNAs (miRNA) are important regulators of gene expression. They are involved in many physiological processes ensuring the cellular homeostasis of human cells. Alterations of the miRNA expression have increasingly been associated with pathophysiologic changes of cancer cells making miRNAs currently to one of the most analyzed molecules in cancer research. Here, we provide an overview of miRNAs in lung cancer. Specifically, we address biological functions of miRNAs in lung cancer cells, miRNA signatures generated from tumor tissue and from patients’ body fluids, the potential of miRNAs as diagnostic and prognostic biomarker for lung cancer, and its role as therapeutic target. PMID:22303398

On-chip Magnetic Separation and Cell Encapsulation in Droplets

NASA Astrophysics Data System (ADS)

Chen, A.; Byvank, T.; Bharde, A.; Miller, B. L.; Chalmers, J. J.; Sooryakumar, R.; Chang, W.-J.; Bashir, R.

2012-02-01

The demand for high-throughput single cell assays is gaining importance because of the heterogeneity of many cell suspensions, even after significant initial sorting. These suspensions may display cell-to-cell variability at the gene expression level that could impact single cell functional genomics, cancer, stem-cell research and drug screening. The on-chip monitoring of individual cells in an isolated environment could prevent cross-contamination, provide high recovery yield and ability to study biological traits at a single cell level These advantages of on-chip biological experiments contrast to conventional methods, which require bulk samples that provide only averaged information on cell metabolism. We report on a device that integrates microfluidic technology with a magnetic tweezers array to combine the functionality of separation and encapsulation of objects such as immunomagnetically labeled cells or magnetic beads into pico-liter droplets on the same chip. The ability to control the separation throughput that is independent of the hydrodynamic droplet generation rate allows the encapsulation efficiency to be optimized. The device can potentially be integrated with on-chip labeling and/or bio-detection to become a powerful single-cell analysis device.

Isoforms, structures, and functions of versatile spectraplakin MACF1.

PubMed

Hu, Lifang; Su, Peihong; Li, Runzhi; Yin, Chong; Zhang, Yan; Shang, Peng; Yang, Tuanmin; Qian, Airong

2016-01-01

Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others.

From microgravity to osmotic conditions: mechanical integration of plant cells in response to stress

NASA Astrophysics Data System (ADS)

Wojtaszek, Przemyslaw; Kasprowicz, Anna; Michalak, Michal; Janczara, Renata; Volkmann, Dieter; Baluska, Frantisek

Chemical reactions and interactions between molecules are commonly thought of as being at the basis of Life. Research of recent years, however, is more and more evidently indicating that physical forces are profoundly affecting the functioning of life at all levels of its organiza-tion. To detect and to respond to such forces, plant cells need to be integrated mechanically. Cell walls are the outermost functional zone of plant cells. They surround the individual cells, and also form a part of the apoplast. In cell suspensions, cell walls are embedded in the cul-ture medium which can be considered as a superapoplast. Through physical and chemical interactions they provide a basis for the structural and functional cell wall-plasma membrane-cytoskeleton (WMC) continuum spanning the whole cell. Here, the working of WMC contin-uum, and the participation of signalling molecules, like NO, would be presented in the context of plant responses to stress. In addition, the effects of the changing composition of WMC continuum will be considered, with particular attention paid to the modifications of the WMC components. Plant cells are normally adapted to changing osmotic conditions, resulting from variable wa-ter availability. The appearance of the osmotic stress activates adaptory mechanisms. If the strength of osmotic stress grows relatively slowly over longer period of time, the cells are able to adapt to conditions that are lethal to non-adapted cells. During stepwise adaptation of tobacco BY-2 suspension cells to the presence of various osmotically active agents, cells diverged into independent, osmoticum type-specific lines. In response to ionic agents (NaCl, KCl), the adhe-sive properties were increased and randomly dividing cells formed clumps, while cells adapted to nonionic osmotica (mannitol, sorbitol, PEG) revealed ordered pattern of precisely positioned cell divisions, resulting in the formation of long cell files. Changes in the growth patterns were accompanied by the alterations in the composition of wall proteins and polysaccharides. With respect to the cytoskeleton, in cells exposed to short-term osmotic stress significant rearrange-ments were observed. Surprisingly, the analyses of microfilaments and microtubules in adapted and in non-adapted, normal BY-2 cells, revealed no significant changes. It seems that upon prolonged exposure to osmotic stress conditions selective and adaptive alterations in wall com-position were occurring. Walls of cells grown in the presence of ionic agents were homogenous, while longitudinal walls and cross-walls in cells adapted to nonionic agents were significantly different. This might affect the anchorage of the cytoskeleton in the walls and modify the func-tioning of the whole WMC continuum. In this way, cell's mechanical balance restoration will be ensured and, in consequence, cells will be able to resist osmotic pressure and divide under severe stress conditions. In plants, cross-walls within cell files of axial organs exhibit specific properties that allow them to act as domains of contact and intense intercellular communica-tion, and the sites of the anchorage of cytoskeleton. As a further consequence, also cell-to-cell interactions would be affected. MM and RJ are students of biotechnology at Adam Mickiewicz University. The data coming from the authors' lab come from research supported by the DAAD scholarship to AK, and Alexander von Humboldt Research Fellowship and Polish Ministry of Science and Higher Edu-cation grants PBZ-KBN-110/P04/2004, N N303 294434, N N301 164435, and N N303 360735 to PW.

[Advances in the research of effects of glutamine on immune function of burn patients].

PubMed

Liu, Y H; Guo, P F; Chen, G Y; Bo, Y C; Ma, Y; Cui, Z J

2018-04-20

Glutamine is the most abundant amino acid found in plasma and cells. It is the preferred fuel for enterocytes in the small intestine, macrophages, and lymphocytes. After serious burn, increased requirement of glutamine by the gastrointestinal tract, kidney and lymphocytes, and relatively insufficient self synthesis likely contribute to the rapid decline of glutamine in circulation and cells. Glutamine supplementation can not only protect intestinal mucosa, maintain normal intestinal barrier function, reduce bacterial translocation, and enhance the intestinal immune function, but also increase the number of lymphocytes, enhance the phagocytic function of macrophage, promote the synthesis of immunoglobulin, and reduce the body's inflammatory response, so as to enhance the immune function. Therefore, glutamine supplementation can improve and enhance the immune function, reduce complications and promote the prognosis of severely burned patients.

Combining Induced Pluripotent Stem Cells and Genome Editing Technologies for Clinical Applications.

PubMed

Chang, Chia-Yu; Ting, Hsiao-Chien; Su, Hong-Lin; Jeng, Jing-Ren

2018-01-01

In this review, we introduce current developments in induced pluripotent stem cells (iPSCs), site-specific nuclease (SSN)-mediated genome editing tools, and the combined application of these two novel technologies in biomedical research and therapeutic trials. The sustainable pluripotent property of iPSCs in vitro not only provides unlimited cell sources for basic research but also benefits precision medicines for human diseases. In addition, rapidly evolving SSN tools efficiently tailor genetic manipulations for exploring gene functions and can be utilized to correct genetic defects of congenital diseases in the near future. Combining iPSC and SSN technologies will create new reliable human disease models with isogenic backgrounds in vitro and provide new solutions for cell replacement and precise therapies.

From Never Born Proteins to Minimal Living Cells: two projects in synthetic biology.

PubMed

Luisi, Pier Luigi; Chiarabelli, Cristiano; Stano, Pasquale

2006-12-01

The Never Born Proteins (NBPs) and the Minimal Cell projects are two currently developed research lines belonging to the field of synthetic biology. The first deals with the investigation of structural and functional properties of de novo proteins with random sequences, selected and isolated using phage display methods. The minimal cell is the simplest cellular construct which displays living properties, such as self-maintenance, self-reproduction and evolvability. The semi-synthetic approach to minimal cells involves the use of extant genes and proteins in order to build a supramolecular construct based on lipid vesicles. Results and outlooks on these two research lines are shortly discussed, mainly focusing on their relevance to the origin of life studies.

Spermatogonial stem cell transplantation and male infertility: Current status and future directions.

PubMed

Forbes, Connor M; Flannigan, Ryan; Schlegel, Peter N

2018-03-01

To summarise the current state of research into spermatogonial stem cell (SSC) therapies with a focus on future directions, as SSCs show promise as a source for preserving or initiating fertility in otherwise infertile men. We performed a search for publications addressing spermatogonial stem cell transplantation in the treatment of male infertility. The search engines PubMed and Google Scholar were used from 1990 to 2017. Search terms were relevant for spermatogonial stem cell therapies. Titles of publications were screened for relevance; abstracts were read, if related and full papers were reviewed for directly pertinent original research. In all, 58 papers were found to be relevant to this review, and were included in appropriate subheadings. This review discusses the various techniques that SSCs are being investigated to treat forms of male infertility. Evidence does not yet support clinical application of SSCs in humans. However, significant progress in the in vitro and in vivo development of SSCs, including differentiation into functional germ cells, gives reason for cautious optimism for future research.

Regulatory B cells in human inflammatory and autoimmune diseases: from mouse models to clinical research.

PubMed

Miyagaki, Tomomitsu; Fujimoto, Manabu; Sato, Shinichi

2015-10-01

B cells have been generally considered to be positive regulators of immune responses because of their ability to produce antigen-specific antibodies and to activate T cells through antigen presentation. Impairment of B cell development and function may cause inflammatory and autoimmune diseases. Recently, specific B cell subsets that can negatively regulate immune responses have been described in mouse models of a wide variety of inflammatory and autoimmune diseases. The concept of those B cells, termed regulatory B cells, is now recognized as important in the murine immune system. Among several regulatory B cell subsets, IL-10-producing regulatory B cells are the most widely investigated. On the basis of discoveries from studies of such mice, human regulatory B cells that produce IL-10 in most cases are becoming an active area of research. There have been emerging data suggesting the importance of human regulatory B cells in various diseases. Revealing the immune regulation mechanisms of human regulatory B cells in human inflammatory and autoimmune diseases could lead to the development of novel B cell targeted therapies. This review highlights the current knowledge on regulatory B cells, mainly IL-10-producing regulatory B cells, in animal models of inflammatory and autoimmune diseases and in clinical research using human samples. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cross-talk between T Cells and Hematopoietic Stem Cells during Adoptive Cellular Therapy for Malignant Glioma.

PubMed

Wildes, Tyler J; Grippin, Adam; Dyson, Kyle A; Wummer, Brandon M; Damiani, David J; Abraham, Rebecca S; Flores, Catherine T; Mitchell, Duane A

2018-04-30

Purpose: Adoptive T-cell immunotherapy (ACT) has emerged as a viable therapeutic for peripheral and central nervous system (CNS) tumors. In peripheral cancers, optimal efficacy of ACT is reliant on dendritic cells (DCs) in the tumor microenvironment. However, the CNS is largely devoid of resident migratory DCs to function as antigen-presenting cells during immunotherapy. Herein, we demonstrate that cellular interactions between adoptively transferred tumor-reactive T cells and bone marrow-derived hematopoietic stem and progenitor cells (HSPCs) lead to the generation of potent intratumoral DCs within the CNS compartment. Experimental Design: We evaluated HSPC differentiation during ACT in vivo in glioma-bearing hosts and HSPC proliferation and differentiation in vitro using a T-cell coculture system. We utilized FACS, ELISAs, and gene expression profiling to study the phenotype and function of HSPC-derived cells ex vivo and in vivo. To demonstrate the impact of HSPC differentiation and function on antitumor efficacy, we performed survival experiments. Results: Transfer of HSPCs with concomitant ACT led to the production of activated CD86 + CD11c + MHCII + cells consistent with DC phenotype and function within the brain tumor microenvironment. These intratumoral DCs largely supplanted abundant host myeloid-derived suppressor cells. We determined that during ACT, HSPC-derived cells in gliomas rely on T-cell-released IFNγ to differentiate into DCs, activate T cells, and reject intracranial tumors. Conclusions: Our data support the use of HSPCs as a novel cellular therapy. Although DC vaccines induce robust immune responses in the periphery, our data demonstrate that HSPC transfer uniquely generates intratumoral DCs that potentiate T-cell responses and promote glioma rejection in situ Clin Cancer Res; 1-12. ©2018 AACR. ©2018 American Association for Cancer Research.

Tissue Architecture and Microenvironment Sustain Hormone Signaling | Center for Cancer Research

Cancer.gov

Cells interact with their environments in part through protein receptors embedded in the cell membrane. Activation of a receptor by external signaling molecules sets off a complex chain of events within the cell that can result in alterations in protein structure and function and/or changes in gene expression. Proper integration of these signals is crucial for normal cell growth and development. A more complete understanding of these normal processes will help elucidate how aberrant signaling results in diseases such as cancer.  

Novel Functions of NF-kappaB2/p52 in Androgen Receptor Signaling in CRPC

DTIC Science & Technology

2015-09-01

cells . Endocr Relat Cancer 17:241–253 59. Taguchi Y, Yamamoto M, Yamate T et al (1998) Interleukin- 6-type cytokines stimulate mesenchymal progenitor... stem cells ”. Thus, it is conceivable that the benign prostate gland exhibits high expression of Lin28 in the basal cell layer. It is interesting to...Epithelial- Mesenchymal Transition in Lung Cancer Cell Lines. Cancer Research, 2010. 70(18): p. 7137-7147. 10. Kumar, M.S., et al., Impaired microRNA

Research and Development Strategies for the Current and Future Medical Treatment of Radiation Casualties

DTIC Science & Technology

2014-09-01

M.B. Grace et al., “ 5-AED Enhances Survival of Irradiated Mice in a G-CSF-dependent Manner, Stimulates Innate Immune Cell Function, Reduces Radiation...exposure to a low IR dose, such as that incurred in a routine medical x-ray, cells can often recover utilizing their innate DNA repair pathways. A small...differentiate. In differentiation, HP stem cells become either myeloid or lymphoid progenitors. Once the cells have differentiated, they cannot de

Culture on electrospun polyurethane scaffolds decreases atrial natriuretic peptide expression by cardiomyocytes in vitro.

PubMed

Rockwood, Danielle N; Akins, Robert E; Parrag, Ian C; Woodhouse, Kimberly A; Rabolt, John F

2008-12-01

The function of the mammalian heart depends on the functional alignment of cardiomyocytes, and controlling cell alignment is an important consideration in biomaterial design for cardiac tissue engineering and research. The physical cues that guide functional cell alignment in vitro and the impact of substrate-imposed alignment on cell phenotype, however, are only partially understood. In this report, primary cardiac ventricular cells were grown on electrospun, biodegradable polyurethane (ES-PU) with either aligned or unaligned microfibers. ES-PU scaffolds supported high-density cultures and cell subpopulations remained intact over two weeks in culture. ES-PU cultures contained electrically-coupled cardiomyocytes with connexin-43 localized to points of cell:cell contact. Multi-cellular organization correlated with microfiber orientation and aligned materials yielded highly oriented cardiomyocyte groupings. Atrial natriuretic peptide, a molecular marker that shows decreasing expression during ventricular cell maturation, was significantly lower in cultures grown on ES-PU scaffolds than in those grown on tissue culture polystyrene. Cells grown on aligned ES-PU had significantly lower steady state levels of ANP and constitutively released less ANP over time indicating that scaffold-imposed cell organization resulted in a shift in cell phenotype to a more mature state. We conclude that the physical organization of microfibers in ES-PU scaffolds impacts both multi-cellular architecture and cardiac cell phenotype in vitro.

Mitochondrial DNA 3243A>G heteroplasmy is associated with changes in cytoskeletal protein expression and cell mechanics.

PubMed

Kandel, Judith; Picard, Martin; Wallace, Douglas C; Eckmann, David M

2017-06-01

Mitochondrial and mechanical alterations in cells have both been shown to be hallmarks of human disease. However, little research has endeavoured to establish connections between these two essential features of cells in both functional and dysfunctional situations. In this work, we hypothesized that a specific genetic alteration in mitochondrial function known to cause human disease would trigger changes in cell mechanics. Using a previously characterized set of mitochondrial cybrid cell lines, we examined the relationship between heteroplasmy for the mitochondrial DNA (mtDNA) 3243A>G mutation, the cell cytoskeleton, and resulting cellular mechanical properties. We found that cells with increasing mitochondrial dysfunction markedly differed from one another in gene expression and protein production of various co-regulated cytoskeletal elements. The intracellular positioning and organization of actin also differed across cell lines. To explore the relationship between these changes and cell mechanics, we then measured cellular mechanical properties using atomic force microscopy and found that cell stiffness correlated with gene expression data for known determinants of cell mechanics, γ-actin, α-actinin and filamin A. This work points towards a mechanism linking mitochondrial genetics to single-cell mechanical properties. The transcriptional and structural regulation of cytoskeletal components by mitochondrial function may explain why energetic and mechanical alterations often coexist in clinical conditions. © 2017 The Author(s).

Advances in using MRI probes and sensors for in vivo cell tracking as applied to regenerative medicine

PubMed Central

Srivastava, Amit K.; Kadayakkara, Deepak K.; Bar-Shir, Amnon; Gilad, Assaf A.; McMahon, Michael T.; Bulte, Jeff W. M.

2015-01-01

The field of molecular and cellular imaging allows molecules and cells to be visualized in vivo non-invasively. It has uses not only as a research tool but in clinical settings as well, for example in monitoring cell-based regenerative therapies, in which cells are transplanted to replace degenerating or damaged tissues, or to restore a physiological function. The success of such cell-based therapies depends on several critical issues, including the route and accuracy of cell transplantation, the fate of cells after transplantation, and the interaction of engrafted cells with the host microenvironment. To assess these issues, it is necessary to monitor transplanted cells non-invasively in real-time. Magnetic resonance imaging (MRI) is a tool uniquely suited to this task, given its ability to image deep inside tissue with high temporal resolution and sensitivity. Extraordinary efforts have recently been made to improve cellular MRI as applied to regenerative medicine, by developing more advanced contrast agents for use as probes and sensors. These advances enable the non-invasive monitoring of cell fate and, more recently, that of the different cellular functions of living cells, such as their enzymatic activity and gene expression, as well as their time point of cell death. We present here a review of recent advancements in the development of these probes and sensors, and of their functioning, applications and limitations. PMID:26035841

Lamprey immune protein-1 (LIP-1) from Lampetra japonica induces cell cycle arrest and cell death in HeLa cells.

PubMed

Chi, Xiaoyuan; Su, Peng; Bi, Dan; Tai, Zhao; Li, Yingying; Pang, Yue; Li, Qingwei

2018-04-01

The lamprey (Lampetra japonica), a representative of the jawless vertebrates, is the oldest extant species in the world. LIP-1, which has a jacalin-like domain and an aerolysin pore-forming domain, has previously been identified in Lampetra japonica. However, the structure and function of the LIP-1 protein have not been described. In this study, the LIP-1 gene was overexpressed in HeLa cells and H293T cells. The results showed that the overexpression of LIP-1 in HeLa cells significantly elevated LDH release (P < 0.05), phosphatidylserine exposure and ROS accumulation. The overexpression of LIP-1 also had remarkable effects on the organelles in HeLa cells, while it had no effect on H293T cell organelles. Array data indicated that overexpression of LIP-1 primarily upregulated P53 signaling pathways in HeLa cells. Cell cycle assay results confirmed that LIP-1 caused arrest in the G 2 /M phase of the cell cycle in HeLa cells. In summary, our findings provide insights into the function and characterization of LIP-1 genes in vertebrates and establish the foundation for further research into the biological function of LIP-1. Our observations suggest that this lamprey protein has the potential for use in new applications in the medical field. Copyright © 2018. Published by Elsevier Ltd.

[Research advance on role of Coxsackie and adenovirus receptor (CAR) in tumor progression].

PubMed

Fan, Liang-Sheng; Chen, Gang; Ma, Ding

2009-03-01

Coxsackie and adenovirus receptor (CAR) is originally identified as the cellular receptor of 2-and 5-type adenoviruses. Many researches have suggested that CAR can affect the growth, adhesive ability and cytoskeleton of tumor cells, and has complicated functions in metastasis and invasion of tumors. Moreover, the expression of CAR has close relationship with tumor prognosis and cytoreduction mediated by adenoviruses. CAR has become a new hotspot in the research on mechanism of tumor progression and gene therapy. Our review focuses on the structure and function of CAR and its role in mediating occurrence and progression of tumor.

Long-term Culture and Cloning of Primary Human Bronchial Basal Cells that Maintain Multipotent Differentiation Capacity and CFTR Channel Function.

PubMed

Peters-Hall, Jennifer Ruth; Coquelin, Melissa L; Torres, Michael J; LaRanger, Ryan; Alabi, Busola Ruth; Sho, Sei; Calva-Moreno, Jose Francisco; Thomas, Philip J; Shay, Jerry William

2018-05-03

While primary cystic fibrosis (CF) and non-CF human bronchial epithelial basal cells (HBECs) accurately represent in vivo phenotypes, one barrier to their wider use has been a limited ability to clone and expand cells in sufficient numbers to produce rare genotypes using genome editing tools. Recently, conditional reprogramming of cells (CRC) with a ROCK inhibitor and culture on an irradiated fibroblast feeder layer resulted in extension of the lifespan of HBECs, but differentiation capacity and CF transmembrane conductance regulator (CFTR) function decreased as a function of passage. This report details modifications to the standard HBEC CRC protocol (Mod CRC), including the use of bronchial epithelial growth medium instead of F-medium and 2% oxygen instead of 21% oxygen, that extend HBEC lifespan while preserving multipotent differentiation capacity and CFTR function. Critically, Mod CRC conditions support clonal growth of primary HBECs from a single cell and the resulting clonal HBEC population maintains multipotent differentiation capacity, including CFTR function, permitting gene editing of these cells. As a proof of concept, CRISPR/Cas9 genome editing and cloning was used to introduce insertions/deletions in CFTR exon 11. Mod CRC conditions overcome many barriers to the expanded use of HBECs for basic research and drug screens. Importantly, Mod CRC conditions support the creation of isogenic cell lines in which CFTR is mutant or wild-type in the same genetic background with no history of CF to enable determination of the primary defects of mutant CFTR.

Microengineering of cellular interactions.

PubMed

Folch, A; Toner, M

2000-01-01

Tissue function is modulated by an intricate architecture of cells and biomolecules on a micrometer scale. Until now, in vitro cellular interactions were mainly studied by random seeding over homogeneous substrates. Although this strategy has led to important discoveries, it is clearly a nonoptimal analog of the in vivo scenario. With the incorporation--and adaptation--of microfabrication technology into biology, it is now possible to design surfaces that reproduce some of the aspects of that architecture. This article reviews past research on the engineering of cell-substrate, cell-cell, and cell-medium interactions on the micrometer scale.

A single cell penetration system by ultrasonic driving

NASA Astrophysics Data System (ADS)

Zhou, Zhaoying; Xiao, Mingfei; Yang, Xing; Wu, Ting

2008-12-01

The researches of single cell's control and operation are the hotspots in whole world. Among the various technologies, the transmission of ectogenic genetic materials between cell membrane is very significant. Imitating the Chinese traditional acupuncture therapy, a new ultrasonic resonance driving method, is imported to drive a cell's penetration probe. A set of the single cell penetration system was established to perform this function. This system includes four subsystems: driving part, micromanipulation part, observation and measurement part, and actuation part. Some fish egg experiments indicate that this system is workable and effective.

Concepts and practices used to develop functional PLGA-based nanoparticulate systems.

PubMed

Sah, Hongkee; Thoma, Laura A; Desu, Hari R; Sah, Edel; Wood, George C

2013-01-01

The functionality of bare polylactide-co-glycolide (PLGA) nanoparticles is limited to drug depot or drug solubilization in their hard cores. They have inherent weaknesses as a drug-delivery system. For instance, when administered intravenously, the nanoparticles undergo rapid clearance from systemic circulation before reaching the site of action. Furthermore, plain PLGA nanoparticles cannot distinguish between different cell types. Recent research shows that surface functionalization of nanoparticles and development of new nanoparticulate dosage forms help overcome these delivery challenges and improve in vivo performance. Immense research efforts have propelled the development of diverse functional PLGA-based nanoparticulate delivery systems. Representative examples include PEGylated micelles/nanoparticles (PEG, polyethylene glycol), polyplexes, polymersomes, core-shell-type lipid-PLGA hybrids, cell-PLGA hybrids, receptor-specific ligand-PLGA conjugates, and theranostics. Each PLGA-based nanoparticulate dosage form has specific features that distinguish it from other nanoparticulate systems. This review focuses on fundamental concepts and practices that are used in the development of various functional nanoparticulate dosage forms. We describe how the attributes of these functional nanoparticulate forms might contribute to achievement of desired therapeutic effects that are not attainable using conventional therapies. Functional PLGA-based nanoparticulate systems are expected to deliver chemotherapeutic, diagnostic, and imaging agents in a highly selective and effective manner.

Concepts and practices used to develop functional PLGA-based nanoparticulate systems

PubMed Central

Sah, Hongkee; Thoma, Laura A; Desu, Hari R; Sah, Edel; Wood, George C

2013-01-01

The functionality of bare polylactide-co-glycolide (PLGA) nanoparticles is limited to drug depot or drug solubilization in their hard cores. They have inherent weaknesses as a drug-delivery system. For instance, when administered intravenously, the nanoparticles undergo rapid clearance from systemic circulation before reaching the site of action. Furthermore, plain PLGA nanoparticles cannot distinguish between different cell types. Recent research shows that surface functionalization of nanoparticles and development of new nanoparticulate dosage forms help overcome these delivery challenges and improve in vivo performance. Immense research efforts have propelled the development of diverse functional PLGA-based nanoparticulate delivery systems. Representative examples include PEGylated micelles/nanoparticles (PEG, polyethylene glycol), polyplexes, polymersomes, core-shell–type lipid-PLGA hybrids, cell-PLGA hybrids, receptor-specific ligand-PLGA conjugates, and theranostics. Each PLGA-based nanoparticulate dosage form has specific features that distinguish it from other nanoparticulate systems. This review focuses on fundamental concepts and practices that are used in the development of various functional nanoparticulate dosage forms. We describe how the attributes of these functional nanoparticulate forms might contribute to achievement of desired therapeutic effects that are not attainable using conventional therapies. Functional PLGA-based nanoparticulate systems are expected to deliver chemotherapeutic, diagnostic, and imaging agents in a highly selective and effective manner. PMID:23459088

Functionally Diverse NK-Like T Cells Are Effectors and Predictors of Successful Aging

PubMed Central

Michel, Joshua J.; Griffin, Patricia; Vallejo, Abbe N.

2016-01-01

The fundamental challenge of aging and long-term survivorship is maintenance of functional independence and compression of morbidity despite a life history of disease. Inasmuch as immunity is a determinant of individual health and fitness, unraveling novel mechanisms of immune homeostasis in late life is of paramount interest. Comparative studies of young and old persons have documented age-related atrophy of the thymus, the contraction of diversity of the T cell receptor (TCR) repertoire, and the intrinsic inefficiency of classical TCR signaling in aged T cells. However, the elderly have highly heterogeneous health phenotypes. Studies of defined populations of persons aged 75 and older have led to the recognition of successful aging, a distinct physiologic construct characterized by high physical and cognitive functioning without measurable disability. Significantly, successful agers have a unique T cell repertoire; namely, the dominance of highly oligoclonal αβT cells expressing a diverse array of receptors normally expressed by NK cells. Despite their properties of cell senescence, these unusual NK-like T cells are functionally active effectors that do not require engagement of their clonotypic TCR. Thus, NK-like T cells represent a beneficial remodeling of the immune repertoire with advancing age, consistent with the concept of immune plasticity. Significantly, certain subsets are predictors of physical/cognitive performance among older adults. Further understanding of the roles of these NK-like T cells to host defense, and how they integrate with other physiologic domains of function are new frontiers for investigation in Aging Biology. Such pursuits will require a research paradigm shift from the usual young-versus-old comparison to the analysis of defined elderly populations. These endeavors may also pave way to age-appropriate, group-targeted immune interventions for the growing elderly population. PMID:27933066

Functionally Diverse NK-Like T Cells Are Effectors and Predictors of Successful Aging.

PubMed

Michel, Joshua J; Griffin, Patricia; Vallejo, Abbe N

2016-01-01

The fundamental challenge of aging and long-term survivorship is maintenance of functional independence and compression of morbidity despite a life history of disease. Inasmuch as immunity is a determinant of individual health and fitness, unraveling novel mechanisms of immune homeostasis in late life is of paramount interest. Comparative studies of young and old persons have documented age-related atrophy of the thymus, the contraction of diversity of the T cell receptor (TCR) repertoire, and the intrinsic inefficiency of classical TCR signaling in aged T cells. However, the elderly have highly heterogeneous health phenotypes. Studies of defined populations of persons aged 75 and older have led to the recognition of successful aging, a distinct physiologic construct characterized by high physical and cognitive functioning without measurable disability. Significantly, successful agers have a unique T cell repertoire; namely, the dominance of highly oligoclonal αβT cells expressing a diverse array of receptors normally expressed by NK cells. Despite their properties of cell senescence, these unusual NK-like T cells are functionally active effectors that do not require engagement of their clonotypic TCR. Thus, NK-like T cells represent a beneficial remodeling of the immune repertoire with advancing age, consistent with the concept of immune plasticity. Significantly, certain subsets are predictors of physical/cognitive performance among older adults. Further understanding of the roles of these NK-like T cells to host defense, and how they integrate with other physiologic domains of function are new frontiers for investigation in Aging Biology. Such pursuits will require a research paradigm shift from the usual young-versus-old comparison to the analysis of defined elderly populations. These endeavors may also pave way to age-appropriate, group-targeted immune interventions for the growing elderly population.

IL-10+ regulatory B cells are enriched in cord blood and may protect against cGVHD after cord blood transplantation.

PubMed

Sarvaria, Anushruti; Basar, Rafet; Mehta, Rohtesh S; Shaim, Hila; Muftuoglu, Muharrem; Khoder, Ahmad; Sekine, Takuye; Gokdemir, Elif; Kondo, Kayo; Marin, David; Daher, May; Alousi, Amin M; Alsuliman, Abdullah; Liu, Enli; Oran, Betul; Olson, Amanda; Jones, Roy B; Popat, Uday; Hosing, Chitra; Champlin, Richard; Shpall, Elizabeth J; Rezvani, Katayoun

2016-09-08

Cord blood (CB) offers a number of advantages over other sources of hematopoietic stem cells, including a lower rate of chronic graft-versus-host disease (cGVHD) in the presence of increased HLA disparity. Recent research in experimental models of autoimmunity and in patients with autoimmune or alloimmune disorders has identified a functional group of interleukin-10 (IL-10)-producing regulatory B cells (Bregs) that negatively regulate T-cell immune responses. At present, however, there is no consensus on the phenotypic signature of Bregs, and their prevalence and functional characteristics in CB remain unclear. Here, we demonstrate that CB contains an abundance of B cells with immunoregulatory function. Bregs were identified in both the naive and transitional B-cell compartments and suppressed T-cell proliferation and effector function through IL-10 production as well as cell-to-cell contact involving CTLA-4. We further show that the suppressive capacity of CB-derived Bregs can be potentiated through CD40L signaling, suggesting that inflammatory environments may induce their function. Finally, there was robust recovery of IL-10-producing Bregs in patients after CB transplantation, to higher frequencies and absolute numbers than seen in the peripheral blood of healthy donors or in patients before transplant. The reconstituting Bregs showed strong in vitro suppressive activity against allogeneic CD4(+) T cells, but were deficient in patients with cGVHD. Together, these findings identify a rich source of Bregs and suggest a protective role for CB-derived Bregs against cGVHD development in CB recipients. This advance could propel the development of Breg-based strategies to prevent or ameliorate this posttransplant complication. © 2016 by The American Society of Hematology.

A new fluorescent dye accumulation assay for parallel measurements of the ABCG2, ABCB1 and ABCC1 multidrug transporter functions.

PubMed

Szabó, Edit; Türk, Dóra; Telbisz, Ágnes; Kucsma, Nóra; Horváth, Tamás; Szakács, Gergely; Homolya, László; Sarkadi, Balázs; Várady, György

2018-01-01

ABC multidrug transporters are key players in cancer multidrug resistance and in general xenobiotic elimination, thus their functional assays provide important tools for research and diagnostic applications. In this study we have examined the potential interactions of three key human ABC multidrug transporters with PhenGreen diacetate (PGD), a cell permeable fluorescent metal ion indicator. The non-fluorescent, hydrophobic PGD rapidly enters the cells and, after cleavage by cellular esterases, in the absence of quenching metal ions, PhenGreen (PG) becomes highly fluorescent. We found that in cells expressing functional ABCG2, ABCB1, or ABCC1 transporters, cellular PG fluorescence is strongly reduced. This fluorescence signal in the presence of specific transporter inhibitors is increased to the fluorescence levels in the control cells. Thus the PG accumulation assay is a new, unique tool for the parallel determination of the function of the ABCG2, ABCB1, and ABCC1 multidrug transporters. Since PG has very low cellular toxicity, the PG accumulation assay also allows the selection, separation and culturing of selected cell populations expressing either of these transporters.

Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

NASA Astrophysics Data System (ADS)

Carrière, Marie; Gouget, Barbara; Gallien, Jean-Paul; Avoscan, Laure; Gobin, Renée; Verbavatz, Jean-Marc; Khodja, Hicham

2005-04-01

The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM).

Production of Functional Glucagon-Secreting α-Cells From Human Embryonic Stem Cells

PubMed Central

Rezania, Alireza; Riedel, Michael J.; Wideman, Rhonda D.; Karanu, Francis; Ao, Ziliang; Warnock, Garth L.; Kieffer, Timothy J.

2011-01-01

OBJECTIVE Differentiation of human embryonic stem (hES) cells to fully developed cell types holds great therapeutic promise. Despite significant progress, the conversion of hES cells to stable, fully differentiated endocrine cells that exhibit physiologically regulated hormone secretion has not yet been achieved. Here we describe an efficient differentiation protocol for the in vitro conversion of hES cells to functional glucagon-producing α- cells. RESEARCH DESIGN AND METHODS Using a combination of small molecule screening and empirical testing, we developed a six-stage differentiation protocol for creating functional α-cells. An extensive in vitro and in vivo characterization of the differentiated cells was performed. RESULTS A high rate of synaptophysin expression (>75%) and robust expression of glucagon and the α-cell transcription factor ARX was achieved. After a transient polyhormonal state in which cells coexpress glucagon and insulin, maturation in vitro or in vivo resulted in depletion of insulin and other β-cell markers with concomitant enrichment of α-cell markers. After transplantation, these cells secreted fully processed, biologically active glucagon in response to physiologic stimuli including prolonged fasting and amino acid challenge. Moreover, glucagon release from transplanted cells was sufficient to reduce demand for pancreatic glucagon, resulting in a significant decrease in pancreatic α-cell mass. CONCLUSIONS These results indicate that fully differentiated pancreatic endocrine cells can be created via stepwise differentiation of hES cells. These cells may serve as a useful screening tool for the identification of compounds that modulate glucagon secretion as well as those that promote the transdifferentiation of α-cells to β-cells. PMID:20971966

New MSC: MSCs as pericytes are Sentinels and gatekeepers.

PubMed

Caplan, Arnold I

2017-06-01

Human Mesenchymal Stem Cells, hMSCs, were first named over 25 years ago with the "stem cell" nomenclature derived from the fact that we and others could cause these cells to differentiate into a number of different mesodermal phenotypes in cell culture. The capacity to form skeletal tissue in vitro encouraged the use of hMSCs for the fabrication of tissue engineered skeletal repair tissue with subsequent transplantation to in vivo sites. With the current realization that MSCs are derived from perivascular cells, pericytes, and the immunomodulatory and trophic capabilities of MSCs in both in vitro and in vivo test systems, a complete re-evaluation of the role and functions of MSCs in the body was required. Additionally, the skeleton is a preferred organ for cancer dissemination from various tumor malignancies. To date, most efforts to understand skeletal metastasis have focused on the invasive and digestive capability of disseminated tumor cells (DTCs). The contribution of the target organ-specific microvascular structure influencing extravasation is less well understood. Current targeted cancer therapies are designed to alter not only biological functions in DTCs, but also components of the tumor stroma/microenvironment such as blood vessels. We now have a comprehensive image of the critical role of the host vasculature as an instructive niche for DTCs. The focus of this manuscript is to present the current information about MSC function in situ and to emphasize how these new observations provide insight into understanding the role of the pericyte/MSC in skeletal activities including our new hypothesis for how these cells act as a gatekeeper for metastasis of melanoma into bone. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1151-1159, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

VirtualLeaf: an open-source framework for cell-based modeling of plant tissue growth and development.

PubMed

Merks, Roeland M H; Guravage, Michael; Inzé, Dirk; Beemster, Gerrit T S

2011-02-01

Plant organs, including leaves and roots, develop by means of a multilevel cross talk between gene regulation, patterned cell division and cell expansion, and tissue mechanics. The multilevel regulatory mechanisms complicate classic molecular genetics or functional genomics approaches to biological development, because these methodologies implicitly assume a direct relation between genes and traits at the level of the whole plant or organ. Instead, understanding gene function requires insight into the roles of gene products in regulatory networks, the conditions of gene expression, etc. This interplay is impossible to understand intuitively. Mathematical and computer modeling allows researchers to design new hypotheses and produce experimentally testable insights. However, the required mathematics and programming experience makes modeling poorly accessible to experimental biologists. Problem-solving environments provide biologically intuitive in silico objects ("cells", "regulation networks") required for setting up a simulation and present those to the user in terms of familiar, biological terminology. Here, we introduce the cell-based computer modeling framework VirtualLeaf for plant tissue morphogenesis. The current version defines a set of biologically intuitive C++ objects, including cells, cell walls, and diffusing and reacting chemicals, that provide useful abstractions for building biological simulations of developmental processes. We present a step-by-step introduction to building models with VirtualLeaf, providing basic example models of leaf venation and meristem development. VirtualLeaf-based models provide a means for plant researchers to analyze the function of developmental genes in the context of the biophysics of growth and patterning. VirtualLeaf is an ongoing open-source software project (http://virtualleaf.googlecode.com) that runs on Windows, Mac, and Linux.

Outlines on nanotechnologies applied to bladder tissue engineering.

PubMed

Alberti, C

2012-01-01

Tissue engineering technologies are more and more expanding as consequence of recent developments in the field of biomaterial science and nanotechnology research. An important issue in designing scaffold materials is that of recreating the ECM (extra-cellular matrix) functional features - particularly ECM-derived complex molecule signalling - to mimic its capability of directing cell-growth and neotissue morphogenesis. In this way the nanotechnology may offer intriguing chances, biomaterial nanoscale-based scaffold geometry behaving as nanomechanotransducer complex interacting with different cell nanosize proteins, especially with those of cell surface mechanoreceptors. To fabricate 3D-scaffold complex architectures, endowed with controlled geometry and functional properties, bottom-up approaches, based on molecular self-assembling of small building polymer units, are used, sometimes functionalizing them by incorporation of bioactive peptide sequences such as RDG (arginine - glycine - aspartic acid, a cell-integrin binding domain of fibronectin), whereas the top-down approaches are useful to fabricate micro/nanoscale structures, such as a microvasculature within an existing complex bioarchitecture. Synthetic polymer-based nanofibers, produced by electrospinning process, may be used to create fibrous scaffolds that can facilitate, given their nanostructured geometry and surface roughness, cell adhesion and growth. Also bladder tissue engineering may benefit by nanotechnology advances to achieve a better reliability of the bladder engineered tissue. Particularly, bladder smooth muscle cell adhesion to nanostructured polymeric surfaces is significantly enhanced in comparison with that to conventional biomaterials. Moreover nanostructured surfaces of bladder engineered tissue show a decreased calcium stone production. In a bladder tumor animal model, the dispersion of carbon nanofibers in a polymeric scaffold-based tissue engineered replacement neobladder, appears to inhibit a carcinogenic relapse in bladder prosthetic material. Facing the future, a full success of bladder tissue engineering will mainly depend on the progress of both biomaterial nanotechnologies and stem cell biology research.

The SGBS cell strain as a model for the in vitro study of obesity and cancer.

PubMed

Allott, Emma H; Oliver, Elizabeth; Lysaght, Joanne; Gray, Steven G; Reynolds, John V; Roche, Helen M; Pidgeon, Graham P

2012-10-01

The murine adipocyte cell line 3T3-L1 is well characterised and used widely, while the human pre-adipocyte cell strain, Simpson-Golabi-Behmel Syndrome (SGBS), requires validation for use in human studies. Obesity is currently estimated to account for up to 41 % of the worldwide cancer burden. A human in vitro model system is required to elucidate the molecular mechanisms for this poorly understood association. This work investigates the relevance of the SGBS cell strain for obesity and cancer research in humans. Pre-adipocyte 3T3-L1 and SGBS were differentiated according to standard protocols. Morphology was assessed by Oil Red O staining. Adipocyte-specific gene expression was measured by qPCR and biochemical function was assessed by glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity. Differential gene expression in oesophageal adenocarcinoma cell line OE33 following co-culture with SGBS or primary omental human adipocytes was investigated using Human Cancer Profiler qPCR arrays. During the process of differentiation, SGBS expressed higher levels of adipocyte-specific transcripts and fully differentiated SGBS expressed more similar morphology, transcript levels and biochemical function to primary omental adipocytes, relative to 3T3-L1. Co-culture with SGBS or primary omental adipocytes induced differential expression of genes involved in adhesion (ITGB3), angiogenesis (IGF1, TEK, TNF, VEGFA), apoptosis (GZMA, TERT) and invasion and metastasis (MMP9, TIMP3) in OE33 tumour cells. Comparable adipocyte-specific gene expression, biochemical function and a shared induced gene signature in co-cultured OE33 cells indicate that SGBS is a relevant in vitro model for obesity and cancer research in humans.

Regenerative medicine for the respiratory system: distant future or tomorrow's treatment?

PubMed

Brouwer, Katrien M; Hoogenkamp, Henk R; Daamen, Willeke F; van Kuppevelt, Toin H

2013-03-01

Regenerative medicine (RM) is a new field of biomedical science that focuses on the regeneration of tissues and organs and the restoration of organ function. Although regeneration of organ systems such as bone, cartilage, and heart has attracted intense scientific research over recent decades, RM research regarding the respiratory system, including the trachea, the lung proper, and the diaphragm, has lagged behind. However, the last 5 years have witnessed novel approaches and initial clinical applications of tissue-engineered constructs to restore organ structure and function. In this regard, this article briefly addresses the basics of RM and introduces the key elements necessary for tissue regeneration, including (stem) cells, biomaterials, and extracellular matrices. In addition, the current status of the (clinical) application of RM to the respiratory system is discussed, and bottlenecks and recent approaches are identified. For the trachea, several initial clinical studies have been reported and have used various combinations of cells and scaffolds. Although promising, the methods used in these studies require optimization and standardization. For the lung proper, only (stem) cell-based approaches have been probed clinically, but it is becoming apparent that combinations of cells and scaffolds are required to successfully restore the lung's architecture and function. In the case of the diaphragm, clinical applications have focused on the use of decellularized scaffolds, but novel scaffolds, with or without cells, are clearly needed for true regeneration of diaphragmatic tissue. We conclude that respiratory treatment with RM will not be realized tomorrow, but its future looks promising.

A Lifetime's Adventure in Extracellular K+ Regulation: The Scottish Connection.

PubMed

Brown, Angus M

2017-09-01

In a career that has spanned 45 years and shows no signs of slowing down, Dr Bruce Ransom has devoted considerable time and energy to studying regulation of interstitial K + . When Bruce commenced his studies in 1969 virtually nothing was known of the functions of glial cells, but Bruce's research contributed to the physiological assignation of function to mammalian astrocytes, namely interstitial K + buffering. The experiments that I describe in this review concern the response of the membrane potential (Em) of in vivo cat cortical astrocytes to changes in [K + ] o , an experimental manoeuvre that was achieved in two different ways. The first involved recording the Em of an astrocyte while the initial aCSF was switched to one with different K + , whereas in the second series of experiments the cortex was stimulated and the response of the astrocyte Em to the K + released from neighbouring neurons was recorded. The astrocytes responded in a qualitatively predictable manner, but quantitatively the changes were not as predicted by the Nernst equation. Elevations in interstitial K + are not sustained and K + returns to baseline rapidly due to the buffering capacity of astrocytes, a phenomenon studied by Bruce, and his son Chris, published 27 years after Bruce's initial publications. Thus, a lifetime spent investigating K + buffering has seen enormous advances in glial research, from the time cells were identified as 'presumed' glial cells or 'silent cells', to the present day, where glial cells are recognised as contributing to every important physiological brain function.

Macrophage Phenotype and Function in Different Stages of Atherosclerosis

PubMed Central

Tabas, Ira; Bornfeldt, Karin E.

2016-01-01

The remarkable plasticity and plethora of biological functions performed by macrophages have enticed scientists to study these cells in relation to atherosclerosis for more than 50 years, and major discoveries continue to be made today. It is now understood that macrophages play important roles in all stages of atherosclerosis, from initiation of lesions and lesion expansion, to necrosis leading to rupture and the clinical manifestations of atherosclerosis, to resolution and regression of atherosclerotic lesions. Lesional macrophages are derived primarily from blood monocytes, although recent research has shown that lesional macrophage-like cells can also be derived from smooth muscle cells. Lesional macrophages take on different phenotypes depending on their environment and which intracellular signaling pathways are activated. Rather than a few distinct populations of macrophages, the phenotype of the lesional macrophage is more complex and likely changes during the different phases of atherosclerosis and with the extent of lipid and cholesterol loading, activation by a plethora of receptors, and metabolic state of the cells. These different phenotypes allow the macrophage to engulf lipids, dead cells, and other substances perceived as danger signals; efflux cholesterol to HDL; proliferate and migrate; undergo apoptosis and death; and secrete a large number of inflammatory and pro-resolving molecules. This review article, part of the Compendium on Atherosclerosis, discusses recent advances in our understanding of lesional macrophage phenotype and function in different stages of atherosclerosis. With the increasing understanding of the roles of lesional macrophages, new research areas and treatment strategies are beginning to emerge. PMID:26892964

Cancer Stem Cells (CSCs) and Mechanisms of Their Regulation: Implications for Cancer Therapy

PubMed Central

Bao, Bin; Ahmad, Aamir; Azmi, Asfar S.; Ali, Shadan; Sarkar, Fazlul H.

2013-01-01

The identification of small subpopulations of cancer stem cells (CSCs) from blood mononuclear cells in human acute myeloid leukemia (AML) in 1997 was the landmark observation for recognizing the potential role of CSCs in tumor aggressiveness. Two critical properties contribute to the functional role of CSCs in the establishment and recurrence of cancerous tumors: their self-renewal capacity and their potential to differentiate into unlimited heterogeneous populations of cancer cells. These findings suggest that CSCs may represent novel therapeutic targets for the treatment and/or prevention of tumor progression as they appear to be involved in cell migration, invasion, metastasis, and treatment resistance, all of which lead to poor clinical outcomes. The identification of CSC-specific markers, the isolation and characterization of CSCs from malignant tissues, and targeting strategies for the destruction of CSCs provides a novel opportunity for cancer research. Described in this overview is the potential implication of several common CSC markers in the identification of CSC subpopulation restricted to common malignant diseases e.g., leukemia, breast, prostate, pancreatic and lung cancers. The role of microRNAs (miRNAs) in the regulation of CSC function is also discussed, as are several methods commonly used in CSC research. The potential role of the anti-diabetic drug metformin that has been shown to have effects on CSCs, and known function as an anti-tumor agent, provides an example of this new class of chemotherapeutics. PMID:23744710

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Neural Development Section (NDS) headed by Dr. Lino Tessarollo has an open postdoctoral fellow position. The candidate should have a background in neurobiology and basic expertise in molecular biology, cell biology, immunoistochemistry and biochemistry.  Experience in confocal analysis is desired. The NDS study the biology of neurotrophin and Trk receptors function by using both in vitro and in vivo approaches. Our group makes extensive use of engineered mouse models and cell culture models. The current research emphasis is on understanding the molecular mechanisms by which activated trk receptor function. Specifically, we are dissecting the molecular mechanism responsible for modulating Trk receptors activity, including their interaction with specific scaffold proteins and proteins leading to de-activation of Trk signaling. Moreover, we are attempting to identify new signaling pathways activated by truncated Trk receptors.

Virtual Global Transplant Laboratory Standard Operating Procedures for Blood Collection, PBMC Isolation, and Storage.

PubMed

Higdon, Lauren E; Lee, Karim; Tang, Qizhi; Maltzman, Jonathan S

2016-09-01

Research on human immune responses frequently involves the use of peripheral blood mononuclear cells (PBMC) immediately, or at significantly delayed timepoints, after collection. This requires PBMC isolation from whole blood and cryopreservation for some applications. It is important to standardize protocols for blood collection, PBMC isolation, cryopreservation, and thawing that maximize survival and functionality of PBMC at the time of analysis. This resource includes detailed protocols describing blood collection tubes, isolation of PBMC using a density gradient, cryopreservation of PBMC, and thawing of cells as well as preparation for functional assays. For each protocol, we include important considerations, such as timing, storage temperatures, and freezing rate. In addition, we provide alternatives so that researchers can make informed decisions in determining the optimal protocol for their application.

Association of social-environmental factors with cognitive function in children with sickle cell disease.

PubMed

Yarboi, Janet; Compas, Bruce E; Brody, Gene H; White, Desiree; Rees Patterson, Jenny; Ziara, Kristen; King, Allison

2017-04-01

The aim of this study was to examine the relationship between cognitive function in pediatric sickle cell disease (SCD) patients and mothers' reports of social-environmental stress, depressive symptoms, and parenting. A total of 65 children with SCD completed comprehensive neuropsychological testing to assess several domains of cognitive functioning, including general intellectual ability, academic achievement, and executive function. Mothers reported on demographics, social-environmental stress, depressive symptoms, and parenting. As predicted, children with SCD significantly underperformed relative to normative data on measures of cognitive function. Associations between maternal social-environmental stress, maternal depressive symptoms, and parenting were mixed. The results show partial support for the hypothesis that greater stress and depressive symptoms and less positive parenting are associated with poorer cognitive function in children with SCD. Linear regression analyses showed that maternal financial stress was the strongest predictor across all domains of cognitive function. The findings replicate and extend past research, reaffirming that children with SCD are at risk for cognitive impairment across multiple domains. Additionally, social-environmental stress, particularly financial strain, is linked to mothers' depressive symptoms and parenting behaviors as well as children's cognitive function. Future studies using direct observations of parenting behaviors are needed. These findings, along with recent research on parenting interventions, may inform the development of concrete, teachable parenting and coping skills to improve cognitive functioning in children with SCD.

Surface-Micromachined Microfiltration Membranes for Efficient Isolation and Functional Immunophenotyping of Subpopulations of Immune Cells

PubMed Central

Oh, Boram; Lam, Raymond H. W.; Fan, Rong; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

2015-01-01

An accurate measurement of the immune status in patients with immune system disorders is critical in evaluating the stage of diseases and tailoring drug treatments. The functional cellular immunity test is a promising method to establish the diagnosis of immune dysfunctions. The conventional functional cellular immunity test involves measurements of the capacity of peripheral blood mononuclear cells to produce pro-inflammatory cytokines when stimulated ex vivo. However, this “bulk” assay measures the overall reactivity of a population of lymphocytes and monocytes, making it difficult to pinpoint the phenotype or real identity of the reactive immune cells involved. In this research, we develop a large surface micromachined polydimethylsiloxane (PDMS) microfiltration membrane (PMM) with high porosity, which is integrated in a microfluidic microfiltration platform. Using the PMM with functionalized microbeads conjugated with antibodies against specific cell surface proteins, we demonstrated rapid, efficient and high-throughput on-chip isolation, enrichment, and stimulation of subpopulations of immune cells from blood specimens. Furthermore, the PMM-integrated microfiltration platform, coupled with a no-wash homogeneous chemiluminescence assay (“AlphaLISA”), enables us to demonstrate rapid and sensitive on-chip immunophenotyping assays for subpopulations of immune cells isolated directly from minute quantities of blood samples. PMID:23335389

Microfluidics as a functional tool for cell mechanics.

PubMed

Vanapalli, Siva A; Duits, Michel H G; Mugele, Frieder

2009-01-05

Living cells are a fascinating demonstration of nature's most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax-thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remodeling of the cytoskeleton. To understand this intricate coupling between mechanical properties, mechanical function and force-induced biochemical signaling requires tools that are capable of both controlling and manipulating the cell microenvironment and measuring the resulting mechanical response. In this review, the power of microfluidics as a functional tool for research in cell mechanics is highlighted. In particular, current literature is discussed to show that microfluidics powered by soft lithographic techniques offers the following capabilities that are of significance for understanding the mechanical behavior of cells: (i) Microfluidics enables the creation of in vitro models of physiological environments in which cell mechanics can be probed. (ii) Microfluidics is an excellent means to deliver physical cues that affect cell mechanics, such as cell shape, fluid flow, substrate topography, and stiffness. (iii) Microfluidics can also expose cells to chemical cues, such as growth factors and drugs, which alter their mechanical behavior. Moreover, these chemical cues can be delivered either at the whole cell or subcellular level. (iv) Microfluidic devices offer the possibility of measuring the intrinsic mechanical properties of cells in a high throughput fashion. (v) Finally, microfluidic methods provide exquisite control over drop size, generation, and manipulation. As a result, droplets are being increasingly used to control the physicochemical environment of cells and as biomimetic analogs of living cells. These powerful attributes of microfluidics should further stimulate novel means of investigating the link between physicochemical cues and the biomechanical response of cells. Insights from such studies will have implications in areas such as drug delivery, medicine, tissue engineering, and biomedical diagnostics.

Controlled cell morphology and liver-specific function of engineered primary hepatocytes by fibroblast layer cell densities.

PubMed

Sakai, Yusuke; Koike, Makiko; Kawahara, Daisuke; Hasegawa, Hideko; Murai, Tomomi; Yamanouchi, Kosho; Soyama, Akihiko; Hidaka, Masaaki; Takatsuki, Mitsuhisa; Fujita, Fumihiko; Kuroki, Tamotsu; Eguchi, Susumu

2018-03-05

Engineered primary hepatocytes, including co-cultured hepatocyte sheets, are an attractive to basic scientific and clinical researchers because they maintain liver-specific functions, have reconstructed cell polarity, and have high transplantation efficiency. However, co-culture conditions regarding engineered primary hepatocytes were suboptimal in promoting these advantages. Here we report that the hepatocyte morphology and liver-specific function levels are controlled by the normal human diploid fibroblast (TIG-118 cell) layer cell density. Primary rat hepatocytes were plated onto TIG-118 cells, previously plated 3 days before at 1.04, 5.21, and 26.1×10 3  cells/cm 2 . Hepatocytes plated onto lower TIG-118 cell densities expanded better during the early culture period. The hepatocytes gathered as colonies and only exhibited small adhesion areas because of the pushing force from proliferating TIG-118 cells. The smaller areas of each hepatocyte result in the development of bile canaliculi. The highest density of TIG-118 cells downregulated albumin synthesis activity of hepatocytes. The hepatocytes may have undergone apoptosis associated with high TGF-β1 concentration and necrosis due to a lack of oxygen. These occurrences were supported by apoptotic chromatin condensation and high expression of both proteins HIF-1a and HIF-1b. Three types of engineered hepatocyte/fibroblast sheets comprising different TIG-118 cell densities were harvested after 4 days of hepatocyte culture and showed a complete cell sheet format without any holes. Hepatocyte morphology and liver-specific function levels are controlled by TIG-118 cell density, which helps to design better engineered hepatocytes for future applications such as in vitro cell-based assays and transplantable hepatocyte tissues. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Thymic function in the regulation of T cells, and molecular mechanisms underlying the modulation of cytokines and stress signaling (Review).

PubMed

Yan, Fenggen; Mo, Xiumei; Liu, Junfeng; Ye, Siqi; Zeng, Xing; Chen, Dacan

2017-11-01

The thymus is critical in establishing and maintaining the appropriate microenvironment for promoting the development and selection of T cells. The function and structure of the thymus gland has been extensively studied, particularly as the thymus serves an important physiological role in the lymphatic system. Numerous studies have investigated the morphological features of thymic involution. Recently, research attention has increasingly been focused on thymic proteins as targets for drug intervention. Omics approaches have yielded novel insights into the thymus and possible drug targets. The present review addresses the signaling and transcriptional functions of the thymus, including the molecular mechanisms underlying the regulatory functions of T cells and their role in the immune system. In addition, the levels of cytokines secreted in the thymus have a significant effect on thymic functions, including thymocyte migration and development, thymic atrophy and thymic recovery. Furthermore, the regulation and molecular mechanisms of stress‑mediated thymic atrophy and involution were investigated, with particular emphasis on thymic function as a potential target for drug development and discovery using proteomics.

Proteolytic Systems in Milk: Perspectives on the Evolutionary Function within the Mammary Gland and the Infant

PubMed Central

Dallas, David C.; Murray, Niamh M.; Gan, Junai

2015-01-01

Milk contains elements of numerous proteolytic systems (zymogens, active proteases, protease inhibitors and protease activators) produced in part from blood, in part by mammary epithelial cells and in part by immune cell secretion. Researchers have examined milk proteases for decades, as they can cause major defects in milk quality and cheese production. Most previous research has examined these proteases with the aim to eliminate or control their actions. However, our recent peptidomics research demonstrates that these milk proteases produce specific peptides in healthy milk and continue to function within the infant’s gastrointestinal tract. These findings suggest that milk proteases have an evolutionary function in aiding the infant’s digestion or releasing functional peptides. In other words, the mother provides the infant with not only dietary proteins but also the means to digest them. However, proteolysis in the milk is controlled by a balance of protease inhibitors and protease activators so that only a small portion of milk proteins are digested within the mammary gland. This regulation presents a question: If proteolysis is beneficial to the infant, what benefits are gained by preventing complete proteolysis through the presence of protease inhibitors? In addition to summarizing what is known about milk proteolytic systems, we explore possible evolutionary explanations for this proteolytic balance. PMID:26179272

Tissue engineering and cell-based therapy toward integrated strategy with artificial organs.

PubMed

Gojo, Satoshi; Toyoda, Masashi; Umezawa, Akihiro

2011-09-01

Research in order that artificial organs can supplement or completely replace the functions of impaired or damaged tissues and internal organs has been underway for many years. The recent clinical development of implantable left ventricular assist devices has revolutionized the treatment of patients with heart failure. The emerging field of regenerative medicine, which uses human cells and tissues to regenerate internal organs, is now advancing from basic and clinical research to clinical application. In this review, we focus on the novel biomaterials, i.e., fusion protein, and approaches such as three-dimensional and whole-organ tissue engineering. We also compare induced pluripotent stem cells, directly reprogrammed cardiomyocytes, and somatic stem cells for cell source of future cell-based therapy. Integrated strategy of artificial organ and tissue engineering/regenerative medicine should give rise to a new era of medical treatment to organ failure.

Microgravity

NASA Image and Video Library

1998-01-01

Cells from kidneys lose some of their special features in conventional culture but form spheres replete with specialized cell microvilli (hair) and synthesize hormones that may be clinically useful. Ground-based research studies have demonstrated that both normal and neoplastic cells and tissues recreate many of the characteristics in the NASA bioreactor that they display in vivo. Proximal kidney tubule cells that normally have rich apically oriented microvilli with intercellular clefts in the kidney do not form any of these structures in conventional two-dimensional monolayer culture. However, when normal proximal renal tubule cells are cultured in three-dimensions in the bioreactor, both the microvilli and the intercellular clefts form. This is important because, when the morphology is recreated, the function is more likely also to be rejuvenated. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

Tissue grown in NASA Bioreactor

NASA Technical Reports Server (NTRS)

1998-01-01

Cells from kidneys lose some of their special features in conventional culture but form spheres replete with specialized cell microvilli (hair) and synthesize hormones that may be clinically useful. Ground-based research studies have demonstrated that both normal and neoplastic cells and tissues recreate many of the characteristics in the NASA bioreactor that they display in vivo. Proximal kidney tubule cells that normally have rich apically oriented microvilli with intercellular clefts in the kidney do not form any of these structures in conventional two-dimensional monolayer culture. However, when normal proximal renal tubule cells are cultured in three-dimensions in the bioreactor, both the microvilli and the intercellular clefts form. This is important because, when the morphology is recreated, the function is more likely also to be rejuvenated. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

Translational findings from cardiovascular stem cell research.

PubMed

Mazhari, Ramesh; Hare, Joshua M

2012-01-01

The possibility of using stem cells to regenerate damaged myocardium has been actively investigated since the late 1990s. Consistent with the traditional view that the heart is a "postmitotic" organ that possesses minimal capacity for self-repair, much of the preclinical and clinical work has focused exclusively on introducing stem cells into the heart, with the hope of differentiation of these cells into functioning cardiomyocytes. This approach is ongoing and retains promise but to date has yielded inconsistent successes. More recently, it has become widely appreciated that the heart possesses endogenous repair mechanisms that, if adequately stimulated, might regenerate damaged cardiac tissue from in situ cardiac stem cells. Accordingly, much recent work has focused on engaging and enhancing endogenous cardiac repair mechanisms. This article reviews the literature on stem cell-based myocardial regeneration, placing emphasis on the mutually enriching interaction between basic and clinical research. Copyright © 2012 Elsevier Inc. All rights reserved.

Blood cell interactions and segregation in flow.

PubMed

Munn, Lance L; Dupin, Michael M

2008-04-01

For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall.

Nanoparticle mediated ablation of breast cancer cells using a nanosecond pulsed electric field

NASA Astrophysics Data System (ADS)

Burford, Christopher

In the past, both nanomaterials and various heating modalities have been researched as means for treating cancers. However, many of the current methodologies have the flaws of inconsistent tumor ablation and significant destruction of healthy cells. Based on research performed using constant radiofrequency electric fields and metallic nanoparticles (where cell necrosis is induced by the heating of these nanoparticles) we have developed a modality that simlarly uses functionalized metallic nanoparticles, specific for the T47D breast cancer cell line, and nanosecond pulsed electric fields as the hyperthermic inducer. Using both iron oxide and gold nanoparticles the results of our pilot studies indicated that up to 90% of the cancer cells were ablated given the optimal treatment parameters. These quantities of ablated cells were achieved using a cumulative exposure time 6 orders of magnitude less than most in vitro radiofrequency electric field studies.

Encapsulated Optically Responsive Cell Systems: Toward Smart Implants in Biomedicine.

PubMed

Boss, Christophe; Bouche, Nicolas; De Marchi, Umberto

2018-04-01

Managing increasingly prevalent chronic diseases will require close continuous monitoring of patients. Cell-based biosensors may be used for implantable diagnostic systems to monitor health status. Cells are indeed natural sensors in the body. Functional cellular systems can be maintained in the body for long-term implantation using cell encapsulation technology. By taking advantage of recent progress in miniaturized optoelectronic systems, the genetic engineering of optically responsive cells may be combined with cell encapsulation to generate smart implantable cell-based sensing systems. In biomedical research, cell-based biosensors may be used to study cell signaling, therapeutic effects, and dosing of bioactive molecules in preclinical models. Today, a wide variety of genetically encoded fluorescent sensors have been developed for real-time imaging of living cells. Here, recent developments in genetically encoded sensors, cell encapsulation, and ultrasmall optical systems are highlighted. The integration of these components in a new generation of biosensors is creating innovative smart in vivo cell-based systems, bringing novel perspectives for biomedical research and ultimately allowing unique health monitoring applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interplay between cancer cell cycle and metabolism: Challenges, targets and therapeutic opportunities.

PubMed

Roy, Debmalya; Sheng, Gao Ying; Herve, Semukunzi; Carvalho, Evandro; Mahanty, Arpan; Yuan, Shengtao; Sun, Li

2017-05-01

A growing interest has emerged in the field of studying the cross-talk between cancer cell cycle and metabolism. In this review, we aimed to present how metabolism and cell cycle are correlated and how cancer cells get energy to drive cell cycle. Cell proliferation and cell death largely depend on the metabolic activity of the cell. Cell cycle proteins, e.g. cyclin D, cyclin dependent kinase (CDK), some pro-apoptotic and anti-apoptotic proteins, and P53 have been shown to be regulated by metabolic crosstalk. Dysregulation of this cross-talk between metabolism and cell cycle leads to degenerative disorder(s) and cancer. It is not fully understood the actual reason of aberration between metabolism and cell cycle, but it is a hallmark of cancer research. Herein, we discussed the role of some regulatory molecules relative of cell cycle and metabolism and highlight how they control the function of each other. We also pointed out, current therapeutic opportunities and some additional crucial therapeutic targets on these fields that could be a breakthrough in cancer research. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Intracellular delivery of nanomaterials for sub-cellular imaging and tracking of biomolecules

NASA Astrophysics Data System (ADS)

Medepalli, Krishna Kiran

Nanomaterials have many intriguing applications in biology and medicine. Unique properties such as enhanced electrical properties, increased chemical reactivity and resistance to degradation, novel optical properties and comparable size to that of biological systems have led to their use in various biomedical applications. The most important applications of nanomaterials for medicine are in drug delivery and imaging. This research focuses on utilizing the biocompatibility of single walled Carbon nanotubes (SWCNTs) and optical properties colloidal quantum dots (QDs) for cellular drug delivery and imaging of biomolecules. The first part of this research deals with single walled carbon nanotubes which are excellent candidates for targeted drug delivery applications due their unique structural and functional properties. However, prior to their use in therapeutics, their biocompatibility needs to be thoroughly investigated. The objectives of this research were to establish the biocompatibility of SWCNTs and demonstrate their use as drug delivery carriers into cells. Blood, a living tissue, is chosen as the biological system as it contains various cells which can potentially interact with SWCNTs during the delivery mechanism. The interactions of these cells in the blood (specifically white blood cells or leukocytes) with the SWCNTs provide vital information regarding the immune response of the host to the nanotubes. This research investigates the immune response of white blood cells due to SWCNTs via (a) direct interaction---presence of nanotubes in the blood and, (b) indirect interaction---presentation of nanotubes by antigen-presenting-cells to white blood cells. These two interactions recreate the innate and adaptive immune responses occurring in the body to any foreign substance. SWCNTs are functionalized with single stranded DNA (ss-DNA), which serves as a dispersant of nanotubes as well as a backbone for further attachment of other biomolecules of interest. Confocal microscopy and flow cytometric studies are performed to characterize the interactions. Results from this acute immune response study demonstrate the biocompatibility of SWCNTs in whole blood and also confirm the cellular delivery of single stranded DNA. The second part of the research is on colloidal quantum dots (QDs): nanometer sized semiconductor crystals typically between 1 nm to 20 nm in diameter. In addition to being size comparable with many biological systems, and having large surface area for multiple biomolecules attachment, they possess high resistance to chemical and photo degradation, tunable emission based on size and composition which makes them excellent candidates for cellular delivery and imaging. The main objectives of this research was to demonstrate the use of QDs for cellular imaging as well as targeted biomolecule delivery by conjugating the QDs with an antibody to a functional protein and delivery into live cells. Conventional techniques deliver QDs as aggregates, however, a major challenge in the use of QDs for cellular imaging and biomolecule delivery is achieving freely dispersed QDs inside the cells. In this research, a new technique to deliver monodispersed QDs inside live cells was developed. The approach combines osmosis driven fluid transport into cells achieved by creating hypotonic environment and reversible permeabilization using low concentrations of cell permeabilization agents like Saponin. The results confirm that highly efficient endocytosis-free intracellular delivery of QDs can be accomplished using this method. Confocal microscopy is used to image the QDs inside the cells and flow cytometry is used for quantifying the fluorescence. To demonstrate targeted delivery, QDs are conjugated to the antibody of a protein: the nuclear transcriptional factor, NFkB (Nuclear Factor kappa-light chain-enhancer of activated B cells) using EDC/sulfo NHS chemistry methods. NFkB is a family of proteins with 5 different subunits and is involved in a variety of biological processes such as immune and inflammatory responses and cellular developmental processes. In unstimulated cells, NFkB is inactive in cytoplasm and translocates to the nucleus upon stimulation using bacterial products, viruses, radiation, and the like. QDs fluorescence could be used to monitor NFKB activity over extended periods of time in live cells.

Adducin in tumorigenesis and metastasis.

PubMed

Luo, Cong; Shen, Jiayu

2017-07-18

Adducin is a membrane-skeletal protein localized at spectrin-actin junctions, involving in the formation of the network of cytoskeleton, cellular signal transduction, ionic transportation, cell motility and cell proliferation. While previous researches focused mainly on the relationship between adducin and hypertension, there are few studies focusing on the role of adducin in tumor. Previous studies showed that adducin played a role in the evolution and progression of neoplasm. This review makes a brief summary on the structure, function and mechanism of adducin and how adducin functions in tumorigenesis and metastasis.

Neuropilins: expression and roles in the epithelium

PubMed Central

Wild, Jonathan R L; Staton, Carolyn A; Chapple, Keith; Corfe, Bernard M

2012-01-01

Summary Initially found expressed in neuronal and then later in endothelial cells, it is well established that the transmembrane glycoproteins neuropilin-1 (NRP1) and neuropilin-2 (NRP2) play essential roles in axonal growth and guidance and in physiological and pathological angiogenesis. Neuropilin expression and function in epithelial cells has received little attention when compared with neuronal and endothelial cells. Overexpression of NRPs is shown to enhance growth, correlate with invasion and is associated with poor prognosis in various tumour types, especially those of epithelial origin. The contribution of NRP and its ligands to tumour growth and metastasis has spurred a strong interest in NRPs as novel chemotherapy drug targets. Given NRP’s role as a multifunctional co-receptor with an ability to bind with disparate ligand families, this has sparked new areas of research implicating NRPs in diverse biological functions. Here, we review the growing body of research demonstrating NRP expression and role in the normal and neoplastic epithelium. PMID:22414290

Cerebellum-from J. E. Purkyně up to Contemporary Research.

PubMed

Vožeh, František

2017-06-01

Jan. Evangelista Purkyně, the most famous among Czech physiologists, was the first who identified and described the largest nerve cells in the cerebellum. The most distinguished researchers of the nervous system then recommended naming these neurons Purkinje cells in his honor. Through experiments by Purkinje and his followers, the function of the cerebellum was properly attributed to the precision of motor movements and skills. This traditional concept was valid until early 1990s, when it was readjusted and replenished with new and important findings. It was discovered that the cerebellar cortex contains more neurons than the cerebral cortex and shortly thereafter was gradually revealed that such enormous numbers of neural cells are not without impact on brain functions. It was shown that the cerebellum, in addition to its traditional role, also participates in higher nervous activity. These new findings were obtained thanks to the introduction of modern methods of examination into the clinical praxis, and experimental procedures using animal models of cerebellar disorders described in this work.

[Biofabrication: new approaches for tissue regeneration].

PubMed

Horch, Raymund E; Weigand, Annika; Wajant, Harald; Groll, Jürgen; Boccaccini, Aldo R; Arkudas, Andreas

2018-04-01

The advent of Tissue Engineering (TE) in the early 1990ies was fostered by the increasing need for functional tissue and organ replacement. Classical TE was based on the combination of carrier matrices, cells and growth factors to reconstitute lost or damaged tissue and organs. Despite considerable results in vitro and in experimental settings the lack of early vascularization has hampered its translation into daily clinical practice so far. A new field of research, called "biofabrication" utilizing latest 3D printing technologies aims at hierarchically and spatially incorporating different cells, biomaterials and molecules into a matrix to alleviate a directed maturation of artificial tissue. A literature research of the relevant publications regarding biofabrication and bioprinting was performed using the PubMed data base. Relevant papers were selected and evaluated with secondary analysis of specific citations on the bioprinting techniques. 180 relevant papers containing the key words were identified and evaluated. Basic principles into the developing field of bioprinting technology could be discerned. Key elements comprise the high-throughput assembly of cells and the fabrication of complex and functional hierarchically organized tissue constructs. Five relevant technological principles for bioprinting were identified, such as stereolithography, extrusion-based printing, laser-assisted printing, inkjet-based printing and nano-bioprinting. The different technical methods of 3D printing were found to be associated with various positive but also negative effects on cells and proteins during the printing process. Research efforts in this field obviously aim towards the development of optimizing the so called bioinks and the printing technologies. This review details the evolution of the classical methods of TE in Regenerative Medicine into the evolving field of biofabrication by bioprinting. The advantages of 3D bioprinting over traditional tissue engineering techniques are based on the assembling of cells, biomaterials and biomolecules in a spatially controlled manner to reproduce native tissue macro-, micro- and nanoarchitectures, that can be utilized not only to potentially produce functional replacement tissues or organs but also to serve as new models for basic research. Mimicking the stromal microenvironment of tumor cells to study the process of tumor formation and progression, metastasis, angiogenesis and modulation of the associated processes is one of these applications under research. To this end a close collaboration of specialists from the fields of engineering, biomaterial science, cell biology and reconstructive microsurgery will be necessary to develop future strategies that can overcome current limitations of tissue generation. © Georg Thieme Verlag KG Stuttgart · New York.

Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

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

Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca; Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca; Tan, Bo, E-mail: tanbo@ryerson.ca

2015-09-10

Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approachmore » to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel cancer cells while favoring the adhesion of normal cells. - Highlights: • Si platforms with cytophobic/philic patterns were developed to program cell growth. • Both nanotopography and chemistry contributed to the cytophobic property. • Cytophobic zones efficiently repel and drive HeLa cells to migrate to adhesive sites. • The approach enables cell patterning, directionality, channelling, and trapping. • This approach paves the way for developing anti-cancer platforms.« less

With Gottlieb beyond Gottlieb: The Role of Epigenetics in Psychobiological Development

ERIC Educational Resources Information Center

Lux, Vanessa

2013-01-01

The emerging field of molecular epigenetics studies relatively stable changes in genetic activity that are not due to changes in the DNA sequence. Initial research results indicate a functional role for epigenetic mechanisms in neuron development and neuronal cell function. However, concepts that integrate these findings in an overall theory of…

First person - Pawel Leznicki.

PubMed

2018-05-16

First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Pawel Leznicki is the first author on 'Expansion of DUB functionality generated by alternative isoforms - USP35, a case study', published in Journal of Cell Science. Pawel conducted the research in this article while in Yogesh Kulathu's lab at the University of Dundee, UK. He is now a research associate in the lab of Stephen High at the University of Manchester, UK, investigating protein biogenesis processes and their quality control. © 2018. Published by The Company of Biologists Ltd.

Keeping It All Going-Complement Meets Metabolism.

PubMed

Kolev, Martin; Kemper, Claudia

2017-01-01

The complement system is an evolutionary old and crucial component of innate immunity, which is key to the detection and removal of invading pathogens. It was initially discovered as a liver-derived sentinel system circulating in serum, the lymph, and interstitial fluids that mediate the opsonization and lytic killing of bacteria, fungi, and viruses and the initiation of the general inflammatory responses. Although work performed specifically in the last five decades identified complement also as a critical instructor of adaptive immunity-indicating that complement's function is likely broader than initially anticipated-the dominant opinion among researchers and clinicians was that the key complement functions were in principle defined. However, there is now a growing realization that complement activity goes well beyond "classic" immune functions and that this system is also required for normal (neuronal) development and activity and general cell and tissue integrity and homeostasis. Furthermore, the recent discovery that complement activation is not confined to the extracellular space but occurs within cells led to the surprising understanding that complement is involved in the regulation of basic processes of the cell, particularly those of metabolic nature-mostly via novel crosstalks between complement and intracellular sensor, and effector, pathways that had been overlooked because of their spatial separation. These paradigm shifts in the field led to a renaissance in complement research and provide new platforms to now better understand the molecular pathways underlying the wide-reaching effects of complement functions in immunity and beyond. In this review, we will cover the current knowledge about complement's emerging relationship with the cellular metabolism machinery with a focus on the functional differences between serum-circulating versus intracellularly active complement during normal cell survival and induction of effector functions. We will also discuss how taking a closer look into the evolution of key complement components not only made the functional connection between complement and metabolism rather "predictable" but how it may also give clues for the discovery of additional roles for complement in basic cellular processes.

The cell cycle.

PubMed

Singh, N; Lim, R B; Sawyer, M A

2000-07-01

The cell cycle and the cell cycle control system are the engines that drive life. They allow for the processes of cell renewal and the growth of organisms, under controlled conditions. The control system is essential for the monitoring of normal cell growth and replication of genetic material and to ensure that normal, functional daughter cells are produced at completion of each cell cycle. Although certain clinical applications exist which take advantage of the events of the cell cycle, our understanding of its mechanisms and how to manipulate them is infantile. The next decades will continue to see the effort of many researchers focused upon unlocking the mysteries of the cell cycle and the cell cycle control system.

Differentiation and Transplantation of Human Embryonic Stem Cell-Derived Hepatocytes

PubMed Central

Basma, Hesham; Soto-Gutiérrez, Alejandro; Yannam, Govardhana Rao; Liu, Liping; Ito, Ryotaro; Yamamoto, Toshiyuki; Ellis, Ewa; Carson, Steven D.; Sato, Shintaro; Chen, Yong; Muirhead, David; Navarro-Álvarez, Nalu; Wong, Ron; Roy-Chowdhury, Jayanta; Platt, Jeffrey L.; Mercer, David F.; Miller, John D.; Strom, Stephen C.; Kobayashi, Noaya; Fox, Ira J.

2009-01-01

Background & Aims The ability to obtain unlimited numbers of human hepatocytes would improve development of cell-based therapies for liver diseases, facilitate the study of liver biology and improve the early stages of drug discovery. Embryonic stem cells are pluripotent, can potentially differentiate into any cell type and could therefore be developed as a source of human hepatocytes. Methods To generate human hepatocytes, human embryonic stem cells were differentiated by sequential culture in fibroblast growth factor 2 and human Activin-A, hepatocyte growth factor, and dexamethasone. Functional hepatocytes were isolated by sorting for surface asialoglycoprotein receptor expression. Characterization was performed by real-time PCR, imunohistochemistry, immunoblot, functional assays and transplantation. Results Embryonic stem cell-derived hepatocytes expressed liver-specific genes but not genes representing other lineages, secreted functional human liver-specific proteins similar to those of primary human hepatocytes and demonstrated human hepatocyte cytochrome P450 metabolic activity. Serum from rodents given injections of embryonic stem cell-derived hepatocytes contained significant amounts of human albumin and alpha-1-antitrypsin. Colonies of cytokeratin-18 and human albumin-expressing cells were present in the livers of recipient animals. Conclusion Human embryonic stem cells can be differentiated into cells with many characteristics of primary human hepatocytes. Hepatocyte-like cells can be enriched and recovered based on asialoglycoprotein receptor expression and could potentially be used in drug discovery research and developed as therapeutics. PMID:19026649

Analytic considerations and axiomatic approaches to the concept cell death and cell survival functions in biology and cancer treatment.

PubMed

Gkigkitzis, Ioannis; Haranas, Ioannis; Austerlitz, Carlos

2015-01-01

This study contains a discussion on the connection between current mathematical and biological modeling systems in response to the main research need for the development of a new mathematical theory for study of cell survival after medical treatment and cell biological behavior in general. This is a discussion of suggested future research directions and relations with interdisciplinary science. In an effort to establish the foundations for a possible framework that may be adopted to study and analyze the process of cell survival during treatment, we investigate the organic connection among an axiomatic system foundation, a predator-prey rate equation, and information theoretic signal processing. A new set theoretic approach is also introduced through the definition of cell survival units or cell survival units indicating the use of "proper classes" according to the Zermelo-Fraenkel set theory and the axiom of choice, as the mathematics appropriate for the development of biological theory of cell survival.

Analysis of Average Telomere Length in Human Telomeric Protein Knockout Cells Generated by CRISPR/Cas9.

PubMed

Xu, Jun; Songyang, Zhou; Liu, Dan; Kim, Hyeung

2017-01-01

Telomeres play an important role in ensuring the integrity of the genome. Telomere shortening can lead to loss of genetic information and trigger DNA damage responses. Cultured mammalian cells have served as critical model systems for studying the function of telomere binding proteins and telomerase. Tremendous heterogeneity can be observed both between species and within a single cell population. Recent advances in genome editing (such as the development of the CRISPR/Cas9 platform) have further enabled researchers to carry out loss-of-function analysis of how disrupting key players in telomere maintenance affects telomere length regulation. Here we describe the steps to be carried out in order to analyze the average length of telomeres in CRISPR-engineered human knockout (KO) cells (TRF analysis).

Angiogenesis Research to Improve Therapies for Vascular Leak Syndromes, Intra-Abdominal Adhesions, and Arterial Injuries

DTIC Science & Technology

2007-02-01

characterization of functional human microvessels in immunodeficient mice. Lab Invest. 2001;81:453-463. 14. Rafii S, Lyden D. Therapeutic stem and progenitor cell... Rafii S, Wu MH, et al. Evidence for circulating bone marrow-derived endothelial cells. Blood. 1998;92:362-367. 32. Hristov M, Erl W, Weber PC

Anthocyanin-rich acai (Euterpe oleracea mart.) fruit pulp fractions attenuate inflammatory stress signaling in mouse brain BV-2 microglial cells

USDA-ARS?s Scientific Manuscript database

Age-related increases in oxidative stress and inflammation are associated with loss of cognitive and motor functions. Previous research has shown that supplementation with berry fruits can modulate signaling in primary hippocampal neurons or BV-2 mouse microglial cells. Because of the high polypheno...

The Function of Neuroendocrine Cells in Prostate Cancer

DTIC Science & Technology

2012-04-01

high profile article describing the technology developed by our group (Goldstein et al. Nat Protoc. 2011; 6:656-67). We explored the utility of...UGSM cells and transplanted in vivo into immune-deficient mice. We utilize an activated form of AKT (myristoylated rendering it membrane-bound) which... utilized for research can vary greatly. The second possibility is that the SV40 T-antigen is toxic to naïve benign primary human prostate cells when

Label-Free Optofluidic Nanobiosensor Enables Real-Time Analysis of Single-Cell Cytokine Secretion.

PubMed

Li, Xiaokang; Soler, Maria; Szydzik, Crispin; Khoshmanesh, Khashayar; Schmidt, Julien; Coukos, George; Mitchell, Arnan; Altug, Hatice

2018-06-01

Single-cell analysis of cytokine secretion is essential to understand the heterogeneity of cellular functionalities and develop novel therapies for multiple diseases. Unraveling the dynamic secretion process at single-cell resolution reveals the real-time functional status of individual cells. Fluorescent and colorimetric-based methodologies require tedious molecular labeling that brings inevitable interferences with cell integrity and compromises the temporal resolution. An innovative label-free optofluidic nanoplasmonic biosensor is introduced for single-cell analysis in real time. The nanobiosensor incorporates a novel design of a multifunctional microfluidic system with small volume microchamber and regulation channels for reliable monitoring of cytokine secretion from individual cells for hours. Different interleukin-2 secretion profiles are detected and distinguished from single lymphoma cells. The sensor configuration combined with optical spectroscopic imaging further allows us to determine the spatial single-cell secretion fingerprints in real time. This new biosensor system is anticipated to be a powerful tool to characterize single-cell signaling for basic and clinical research. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Natural Killer Cells Promote Fetal Development through the Secretion of Growth-Promoting Factors.

PubMed

Fu, Binqing; Zhou, Yonggang; Ni, Xiang; Tong, Xianhong; Xu, Xiuxiu; Dong, Zhongjun; Sun, Rui; Tian, Zhigang; Wei, Haiming

2017-12-19

Natural killer (NK) cells are present in large populations at the maternal-fetal interface during early pregnancy. However, the role of NK cells in fetal growth is unclear. Here, we have identified a CD49a + Eomes + subset of NK cells that secreted growth-promoting factors (GPFs), including pleiotrophin and osteoglycin, in both humans and mice. The crosstalk between HLA-G and ILT2 served as a stimulus for GPF-secreting function of this NK cell subset. Decreases in this GPF-secreting NK cell subset impaired fetal development, resulting in fetal growth restriction. The transcription factor Nfil3, but not T-bet, affected the function and the number of this decidual NK cell subset. Adoptive transfer of induced CD49a + Eomes + NK cells reversed impaired fetal growth and rebuilt an appropriate local microenvironment. These findings reveal properties of NK cells in promoting fetal growth. In addition, this research proposes approaches for therapeutic administration of NK cells in order to reverse restricted nourishments within the uterine microenvironment during early pregnancy. Copyright © 2017 Elsevier Inc. All rights reserved.

The effects of cryopreservation on the expression of canine regulatory T-cell markers.

PubMed

Tarpataki, Noemi; Wawrzyniak, Marcin; Akdis, Cezmi A; Rückert, Beate; Meli, Marina L; Fischer, Nina M; Favrot, Claude; Rostaher, Ana

2017-08-01

Regulatory T (Treg) cells have been described as key regulators in various immunological processes and are of growing interest in veterinary allergy. Cryopreservation of immune cells is performed routinely in human basic science research and in clinical studies. As such, it allows batch testing of collected samples at a single time point, resulting in a significant reduction in sample variability. Data which describe the effects of cryopreservation on Treg cell frequency and functionality in the canine species are important to inform future research. The purpose of this study was to establish a robust freeze/thaw procedure and flow cytometric staining protocol for canine Treg cells, and to compare the frequencies of different canine Treg cell phenotypes before and after cryopreservation. Nine privately owned dogs. Peripheral blood mononuclear cells were isolated and Treg cells stained and analysed by flow cytometry, before and after three months of cryopreservation. The recovery percentages and the corresponding correlations (fresh versus cryopreserved) for CD4 + CD25 + , CD4 + FOXP3 + and CD4 + CD25 + FOXP3 + cell populations were calculated. A high recovery rate of 97.2 (r = 0.94, P < 0.0001), 93.9 (r = 0.77, P < 0.01) and 101.7% (r = 0.99, P < 0.0001) for CD4 + CD25 + , CD4 + FOXP3 + and CD4 + CD25 + FOXP3 + cell populations, respectively, was observed. This study demonstrates an optimized protocol for freezing, thawing and quantifying canine Treg cells. These results indicate that cryopreservation does not substantially affect the expression of surface and intracellular markers of canine Treg cells; however, additional studies will be necessary to assess whether functionality of the cells is also maintained. © 2017 ESVD and ACVD.

The functional basis of adaptive evolution in chemostats.

PubMed

Gresham, David; Hong, Jungeui

2015-01-01

Two of the central problems in biology are determining the molecular basis of adaptive evolution and understanding how cells regulate their growth. The chemostat is a device for culturing cells that provides great utility in tackling both of these problems: it enables precise control of the selective pressure under which organisms evolve and it facilitates experimental control of cell growth rate. The aim of this review is to synthesize results from studies of the functional basis of adaptive evolution in long-term chemostat selections using Escherichia coli and Saccharomyces cerevisiae. We describe the principle of the chemostat, provide a summary of studies of experimental evolution in chemostats, and use these studies to assess our current understanding of selection in the chemostat. Functional studies of adaptive evolution in chemostats provide a unique means of interrogating the genetic networks that control cell growth, which complements functional genomic approaches and quantitative trait loci (QTL) mapping in natural populations. An integrated approach to the study of adaptive evolution that accounts for both molecular function and evolutionary processes is critical to advancing our understanding of evolution. By renewing efforts to integrate these two research programs, experimental evolution in chemostats is ideally suited to extending the functional synthesis to the study of genetic networks. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Influence of Zero-Shear on Yeast Development

NASA Technical Reports Server (NTRS)

McGinnis, Michael R.

1997-01-01

The objective of the research was to begin evaluating the effect of zero-shear on the development of the cell wall of Saccharomyces cerevisiae employing the High Aspect Rotating-Wall Vessel (HARV) NASA bioreactor. This particular yeast has enormous potential for research as a model eukaryotic system on the International Space Station, as well as the production of food stuffs' at the future lunar colony. Because the cell wall is the barrier between the cell and the environment, its form and function as influenced by microgravity is of great importance. Morphologic studies revealed that the circularity and total area of the individual yeast cells were essentially the same in both the control and test HARV's. The growth rates were also essentially the same. In zero-shear, the yeast grew in clumps consisting of rudimentary pseudohyphae in contrast to solitary budding cells in the control. Based upon mechanical and sonic shear applied to the yeast cells, those grown in zero-shear had stronger cell walls and septa. This suggests that there are structural differences, most likely related to the chitin skeleton of the cell wall. From this research further NASA support was obtained to continue the work. Investigations will deal with gene expression and ultrastructure. These will lead to a clearer assessment of the value of S. cerevisiae eukaryotic as a model for space station research.

Space Flight Immunodeficiency

NASA Technical Reports Server (NTRS)

Shearer, William T.

1999-01-01

The National Aeronautics and Space Administration (NASA) has had sufficient concern for the well-being of astronauts traveling in space to create the National Space Biomedical Research Institute (NSBRI), which is investigating several areas of biomedical research including those of immunology. As part of the Immunology, Infection, and Hematology Team, the co-investigators of the Space Flight Immunodeficiency Project began their research projects on April 1, 1998 and are now just into the second year of work. Two areas of research have been targeted: 1) specific immune (especially antibody) responses and 2) non-specific inflammation and adhesion. More precise knowledge of these two areas of research will help elucidate the potential harmful effects of space travel on the immune system, possibly sufficient to create a secondary state of immunodeficiency in astronauts. The results of these experiments are likely to lead to the delineation of functional alterations in antigen presentation, specific immune memory, cytokine regulation of immune responses, cell to cell interactions, and cell to endothelium interactions.

Carbon Nanotube Based Devices for Intracellular Analysis

NASA Astrophysics Data System (ADS)

Singhal, Riju Mohan

Scientific investigations on individual cells have gained increasing attention in recent years as efforts are being made to understand cellular functioning in complex processes, such as cell division during embryonic development, and owing to realization of heterogeneity amongst a population of a single cell type (for instance, certain individual cancer cells being immune to chemotherapy). Therefore devices enabling electrochemical detection, spectroscopy, optical observations, and separation techniques, along with cell piercing and fluid transfer capabilities at the intra-cellular level, are required. Glass pipettes have conventionally been used for single cell interrogation, however their poor mechanical properties and an intrusive conical geometry have led to limited precision and frequent cell damage or death, justifying research efforts to develop novel, non-intrusive cell probes. Carbon nanotubes (CNTs) are known for their superior physical properties and tunable chemical structure. They possess a high aspect ratio and offer minimally invasive thin carbon walls and tubular geometry. Moreover, possibility of chemical functionalization of CNTs enables multi-functional probes. In this dissertation, novel nanofluidic instruments that have nanostructured carbon tips will be presented along with techniques that utilize the exceptional physical properties of carbon nanotubes, to take miniature biomedical instrumentation to the next level. New methods for fabricating the probes were rigorously developed and their operation was extensively studied. The devices were mechanically robust and were used to inject liquids to a single cell, detect electrochemical signals and enable surface enhanced Raman spectroscopy (SERS) while inducing minimal harm to the cell. Particular attention was focused on the CVD process-which was used to deposit carbon, fluid flow through the nanotubes, and separation of chemical species (atto-liter chromatography) at the nanometer scale that would potentially lead to the highly sought after "selective component extraction" and analysis from a single cell. These multi-functional devices therefore provide a picture of the physiological state of a living cell and function as endoscopes for single cell analysis.

Vaccinia Virus: A Tool for Research and Vaccine Development

NASA Astrophysics Data System (ADS)

Moss, Bernard

1991-06-01

Vaccinia virus is no longer needed for smallpox immunization, but now serves as a useful vector for expressing genes within the cytoplasm of eukaryotic cells. As a research tool, recombinant vaccinia viruses are used to synthesize biologically active proteins and analyze structure-function relations, determine the targets of humoral- and cell-mediated immunity, and investigate the immune responses needed for protection against specific infectious diseases. When more data on safety and efficacy are available, recombinant vaccinia and related poxviruses may be candidates for live vaccines and for cancer immunotherapy.

Expression of HLA Class II Molecules in Humanized NOD.Rag1KO.IL2RgcKO Mice is Critical for Development and Function of Human T and B Cells

DTIC Science & Technology

2011-05-17

HSC-infused DRAG and control mice were immunized with 1 flocculation unit of TT vaccine ( Sanofi Pasteur) by the intramuscular route, and the titers... Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America, 2 Department...human vaccines prior to clinical trials. However, current humanized mouse models show sub-optimal human T cell reconstitution and limited ability to

Graphene-based materials for energy conversion.

PubMed

Sahoo, Nanda Gopal; Pan, Yongzheng; Li, Lin; Chan, Siew Hwa

2012-08-08

With the depletion of conventional energy sources, the demand for renewable energy and energy-efficient devices continues to grow. As a novel 2D nanomaterial, graphene attracts considerable research interest due to its unique properties and is a promising material for applications in energy conversion and storage devices. Recently, the fabrication of fuel cells and solar cells using graphene for various functional parts has been studied extensively. This research news summarizes and compares the advancements that have been made and are in progress in the utilization of graphene-based materials for energy conversion.

High performance hybrid functional Petri net simulations of biological pathway models on CUDA.

PubMed

Chalkidis, Georgios; Nagasaki, Masao; Miyano, Satoru

2011-01-01

Hybrid functional Petri nets are a wide-spread tool for representing and simulating biological models. Due to their potential of providing virtual drug testing environments, biological simulations have a growing impact on pharmaceutical research. Continuous research advancements in biology and medicine lead to exponentially increasing simulation times, thus raising the demand for performance accelerations by efficient and inexpensive parallel computation solutions. Recent developments in the field of general-purpose computation on graphics processing units (GPGPU) enabled the scientific community to port a variety of compute intensive algorithms onto the graphics processing unit (GPU). This work presents the first scheme for mapping biological hybrid functional Petri net models, which can handle both discrete and continuous entities, onto compute unified device architecture (CUDA) enabled GPUs. GPU accelerated simulations are observed to run up to 18 times faster than sequential implementations. Simulating the cell boundary formation by Delta-Notch signaling on a CUDA enabled GPU results in a speedup of approximately 7x for a model containing 1,600 cells.

Roles of exosomes in the normal and diseased eye.

PubMed

Klingeborn, Mikael; Dismuke, W Michael; Bowes Rickman, Catherine; Stamer, W Daniel

2017-07-01

Exosomes are nanometer-sized vesicles that are released by cells in a controlled fashion and mediate a plethora of extra- and intercellular activities. Some key functions of exosomes include cell-cell communication, immune modulation, extracellular matrix turnover, stem cell division/differentiation, neovascularization and cellular waste removal. While much is known about their role in cancer, exosome function in the many specialized tissues of the eye is just beginning to undergo rigorous study. Here we review current knowledge of exosome function in the visual system in the context of larger bodies of data from other fields, in both health and disease. Additionally, we discuss recent advances in the exosome field including use of exosomes as a therapeutic vehicle, exosomes as a source of biomarkers for disease, plus current standards for isolation and validation of exosome populations. Finally, we use this foundational information about exosomes in the eye as a platform to identify areas of opportunity for future research studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Liver cell therapy and tissue engineering for transplantation.

PubMed

Vacanti, Joseph P; Kulig, Katherine M

2014-06-01

Liver transplantation remains the only definitive treatment for liver failure and is available to only a tiny fraction of patients with end-stage liver diseases. Major limitations for the procedure include donor organ shortage, high cost, high level of required expertise, and long-term consequences of immune suppression. Alternative cell-based liver therapies could potentially greatly expand the number of patients provided with effective treatment. Investigative research into augmenting or replacing liver function extends into three general strategies. Bioartificial livers (BALs) are extracorporeal devices that utilize cartridges of primary hepatocytes or cell lines to process patient plasma. Injection of liver cell suspensions aims to foster organ regeneration or provide a missing metabolic function arising from a genetic defect. Tissue engineering recreates the organ in vitro for subsequent implantation to augment or replace patient liver function. Translational models and clinical trials have highlighted both the immense challenges involved and some striking examples of success. Copyright © 2014. Published by Elsevier Inc.

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

A postdoctoral position is available in Dr. Efsun Arda’s Developmental Genomics Group within the Laboratory of Receptor Biology and Gene Expression Branch at the National Cancer Institute (NCI), National Institutes of Health (NIH). Our research is focused on understanding the regulatory networks that govern pancreas cell identity and function in the context of diabetes and

Isoforms, structures, and functions of versatile spectraplakin MACF1

PubMed Central

Hu, Lifang; Su, Peihong; Li, Runzhi; Yin, Chong; Zhang, Yan; Shang, Peng; Yang, Tuanmin; Qian, Airong

2016-01-01

Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others. [BMB Reports 2016; 49(1): 37-44] PMID:26521939

Bat-mouse bone marrow chimera: a novel animal model for dissecting the uniqueness of the bat immune system.

PubMed

Yong, Kylie Su Mei; Ng, Justin Han Jia; Her, Zhisheng; Hey, Ying Ying; Tan, Sue Yee; Tan, Wilson Wei Sheng; Irac, Sergio Erdal; Liu, Min; Chan, Xue Ying; Gunawan, Merry; Foo, Randy Jee Hiang; Low, Dolyce Hong Wen; Mendenhall, Ian Hewitt; Chionh, Yok Teng; Dutertre, Charles-Antoine; Chen, Qingfeng; Wang, Lin-Fa

2018-03-16

Bats are an important animal model with long lifespans, low incidences of tumorigenesis and an ability to asymptomatically harbour pathogens. Currently, in vivo studies of bats are hampered due to their low reproduction rates. To overcome this, we transplanted bat cells from bone marrow (BM) and spleen into an immunodeficient mouse strain NOD-scid IL-2R -/- (NSG), and have successfully established stable, long-term reconstitution of bat immune cells in mice (bat-mice). Immune functionality of our bat-mouse model was demonstrated through generation of antigen-specific antibody response by bat cells following immunization. Post-engraftment of total bat BM cells and splenocytes, bat immune cells survived, expanded and repopulated the mouse without any observable clinical abnormalities. Utilizing bat's remarkable immunological functions, this novel model has a potential to be transformed into a powerful platform for basic and translational research.

Elucidation of monocyte/macrophage dynamics and function by intravital imaging

PubMed Central

Rua, Rejane; McGavern, Dorian B.

2015-01-01

Monocytes and macrophages are a diverse population of innate immune cells that play a critical role in homeostasis and inflammation. These cells are surveillant by nature and closely monitor the vasculature and surrounding tissue during states of health and disease. Given their abundance and strategic positioning throughout the body, myeloid cells are among the first responders to any inflammatory challenge and are active participants in most immune-mediated diseases. Recent studies have shed new light on myeloid cell dynamics and function by use of an imaging technique referred to as intravital microscopy (IVM). This powerful approach allows researchers to gain real-time insights into monocytes and macrophages performing homeostatic and inflammatory tasks in living tissues. In this review, we will present a contemporary synopsis of how intravital microscopy has revolutionized our understanding of myeloid cell contributions to vascular maintenance, microbial defense, autoimmunity, tumorigenesis, and acute/chronic inflammatory diseases. PMID:26162402

Regulation of cellular function via electromagnetic field frequency and extracellular environment: A theoretical- experimental approach

NASA Astrophysics Data System (ADS)

Taghian, Toloo; Sheikh, Abdul; Narmoneva, Daria; Kogan, Andrei

2015-03-01

Application of external electric field (EF) as a non-pharmacological, non-invasive tool to control cell function is of great therapeutic interest. We developed a theoretical-experimental approach to investigate the biophysical mechanisms of EF interaction with cells in electrode-free physiologically-relevant configuration. Our numerical results demonstrated that EF frequency is the major parameter to control cell response to EF. Non-oscillating or low-frequency EF leads to charge accumulation on the cell surface membrane that may mediate membrane initiated cell responses. In contrast, high-frequency EF penetrates the cell membrane and reaches cell cytoplasm, where it may directly activate intracellular responses. The theoretical predictions were confirmed in our experimental studies of the effects of applied EF on vascular cell function. Results show that non-oscillating EF increases vascular endothelial growth factor (VEGF) expression while field polarity controls cell adhesion rate. High-frequency, but not low frequency, EF provides differential regulation of cytoplasmic focal adhesion kinase and VEGF expression depending on the substrate, with increased expression in cells cultured on RGD-rich synthetic hydrogels, and decreased expression for matrigel culture. The authors acknowledge the financial support from the NSF (DMR-1206784 & DMR-0804199 to AK); the NIH (1R21 DK078814-01A1 to DN) and the University of Cincinnati (Interdisciplinary Faculty Research Support Grant to DN and AK).

Isolation, Characterization, and Establishment of Spontaneously Immortalized Cell Line HRPE-2S With Stem Cell Properties.

PubMed

Shams Najafabadi, Hoda; Soheili, Zahra-Soheila; Samiei, Shahram; Ahmadieh, Hamid; Ranaei Pirmardan, Ehsan; Masoumi, Maryam

2017-10-01

The retinal pigment epithelium is a monolayer of highly specialized pigmented cells located between the neural retina and the Bruch's membrane of the choroid. RPE cells play a crucial role in the maintenance and function of the underlying photoreceptors. This study introduces a spontaneously arising human retinal pigment epithelial cell line, HRPE-2S, which was isolated from primary RPE cell culture of 2 days old male donor. We characterized morphology and functional properties of the new cell line. The immortalized cell line was maintained in culture for more than 70 passages and 240 divisions. The average doubling time of the cells was approximately 22 h and got freezed at 26th passage. The cell line expressed RPE-specific markers RPE65 and cell junction protein ZO1 as an epithelial cell marker. It also expressed CHX10, PAX6, Nestin, SOX2 as stem and retinal progenitor cell markers. Ki67 as a marker of cell proliferation was expressed in all HRPE-2S cells. It represented typical epithelial cobblestone morphology and did not phenotypically change through several passages. Stem cell-like aggregations (neurospheres) were observed in SEM microscopy. The cells represented high mitotic index. They could be viable under hypoxic conditions and serum deprivation. According to functional studies, the cell line exhibited stem cell-like behaviors with particular emphasis on its self-renewal capacity. LDH isoenzymes expression pattern confirmed the same cellular source for both of the HRPE-2S cells and primary RPE cells. Characteristics of HRPE-2S cells promise it as an in vitro model for RPE stem cell-based researches. J. Cell. Physiol. 232: 2626-2640, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

High accuracy indirect optical manipulation of live cells with functionalized microtools

NASA Astrophysics Data System (ADS)

Vizsnyiczai, Gaszton; Aekbote, Badri L.; Buzás, András.; Grexa, István.; Ormos, Pál.; Kelemen, Lóránd

2016-09-01

Optical micro manipulation of live cells has been extensively used to study a wide range of cellular phenomena with relevance in basic research or in diagnostics. The approaches span from manipulation of many cells for high throughput measurement or sorting, to more elaborated studies of intracellular events on trapped single cells when coupled with modern imaging techniques. In case of direct cell trapping the damaging effects of light-cell interaction must be minimized, for instance with the choice of proper laser wavelength. Microbeads have already been used for trapping cells indirectly thereby reducing the irradiation damage and increasing trapping efficiency with their high refractive index contrast. We show here that such intermediate objects can be tailor-made for indirect cell trapping to further increase cell-to-focal spot distance while maintaining their free and fast maneuverability. Carefully designed structures were produced with two-photon polymerization with shapes optimized for effective manipulation and cell attachment. Functionalization of the microstructures is also presented that enables cell attachment to them within a few seconds with strength much higher that the optical forces. Fast cell actuation in 6 degrees of freedom is demonstrated with the outlook to possible applications in cell imaging.

Mechanical Stimulation of Adipose-Derived Stem Cells for Functional Tissue Engineering of the Musculoskeletal System via Cyclic Hydrostatic Pressure, Simulated Microgravity, and Cyclic Tensile Strain.

PubMed

Nordberg, Rachel C; Bodle, Josie C; Loboa, Elizabeth G

2018-01-01

It is critical that human adipose stem cell (hASC) tissue-engineering therapies possess appropriate mechanical properties in order to restore function of the load bearing tissues of the musculoskeletal system. In an effort to elucidate the hASC response to mechanical stimulation and develop mechanically robust tissue engineered constructs, recent research has utilized a variety of mechanical loading paradigms including cyclic tensile strain, cyclic hydrostatic pressure, and mechanical unloading in simulated microgravity. This chapter describes methods for applying these mechanical stimuli to hASC to direct differentiation for functional tissue engineering of the musculoskeletal system.

Proteomic and cellular localisation studies suggest non-tight junction cytoplasmic and nuclear roles for occludin in astrocytes.

PubMed

Morgan, Sarah V; Garwood, Claire J; Jennings, Luke; Simpson, Julie E; Castelli, Lydia M; Heath, Paul R; Mihaylov, Simeon R; Vaquéz-Villaseñor, Irina; Minshull, Thomas C; Ince, Paul G; Dickman, Mark J; Hautbergue, Guillaume M; Wharton, Stephen B

2018-05-08

Occludin is a component of tight junctions, which are essential structural components of the blood-brain barrier. However, occludin is expressed in cells without tight junctions, implying additional functions. We determined the expression and localisation of occludin in astrocytes in cell culture and in human brain tissue, and sought novel binding partners using a proteomic approach. Expression was investigated by immunocytochemistry and immunoblotting in the 1321N1 astrocytoma cell line and ScienCell human primary astrocytes, and by immunohistochemistry in human autopsy brain tissue. Recombinant N- and C-terminal occludin was used to pull-down proteins from 1321N1 cell lysates and protein-binding partners identified by mass spectrometry analysis. Occludin was expressed in both the cytoplasm and nucleus of astrocytes in vitro and in vivo. Mass spectrometry identified binding to nuclear and cytoplasmic proteins, particularly those related to RNA metabolism and nuclear function. Occludin is expressed in several subcellular compartments of brain cell-types that do not form tight junctions and the expression patterns in cell culture reflect those in human brain tissue, indicating they are suitable model systems. Proteomic analysis suggests that occludin has novel functions in neuroepithelial cells that are unrelated to tight junction formation. Further research will establish the roles of these functions in both cellular physiology and in disease states. © 2018 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Olfactory epithelium: Cells, clinical disorders, and insights from an adult stem cell niche

PubMed Central

Choi, Rhea

2018-01-01

Disorders causing a loss of the sense of smell remain a therapeutic challenge. Basic research has, however, greatly expanded our knowledge of the organization and function of the olfactory system. This review describes advances in our understanding of the cellular components of the peripheral olfactory system, specifically the olfactory epithelium in the nose. The article discusses recent findings regarding the mechanisms involved in regeneration and cellular renewal from basal stem cells in the adult olfactory epithelium, considering the strategies involved in embryonic olfactory development and insights from research on other stem cell niches. In the context of clinical conditions causing anosmia, the current view of adult olfactory neurogenesis, tissue homeostasis, and failures in these processes is considered, along with current and future treatment strategies. Level of Evidence NA PMID:29492466

Establishment of functional acinar-like cultures from human salivary glands.

PubMed

Jang, S I; Ong, H L; Gallo, A; Liu, X; Illei, G; Alevizos, I

2015-02-01

Disorders of human salivary glands resulting from therapeutic radiation treatment for head and neck cancers or from the autoimmune disease Sjögren syndrome (SS) frequently result in the reduction or complete loss of saliva secretion. Such irreversible dysfunction of the salivary glands is due to the impairment of acinar cells, the major glandular cells of protein, salt secretion, and fluid movement. Availability of primary epithelial cells from human salivary gland tissue is critical for studying the underlying mechanisms of these irreversible disorders. We applied 2 culture system techniques on human minor salivary gland epithelial cells (phmSG) and optimized the growth conditions to achieve the maintenance of phmSG in an acinar-like phenotype. These phmSG cells exhibited progenitor cell markers (keratin 5 and nanog) as well as acinar-specific markers-namely, α-amylase, cystatin C, TMEM16A, and NKCC1. Importantly, with an increase of the calcium concentration in the growth medium, these phmSG cells were further promoted to acinar-like cells in vitro, as indicated by an increase in AQP5 expression. In addition, these phmSG cells also demonstrated functional calcium mobilization, formation of epithelial monolayer with high transepithelial electrical resistance (TER), and polarized secretion of α-amylase secretion after β-adrenergic receptor stimulation. Taken together, suitable growth conditions have been established to isolate and support culture of acinar-like cells from the human salivary gland. These primary epithelial cells can be useful for study of molecular mechanisms involved in regulating the function of acinar cells and in the loss of salivary gland function in patients. © International & American Associations for Dental Research 2014.

Cell-Type-Specific Predictive Network Yields Novel Insights into Mouse Embryonic Stem Cell Self-Renewal and Cell Fate

PubMed Central

Dowell, Karen G.; Simons, Allen K.; Wang, Zack Z.; Yun, Kyuson; Hibbs, Matthew A.

2013-01-01

Self-renewal, the ability of a stem cell to divide repeatedly while maintaining an undifferentiated state, is a defining characteristic of all stem cells. Here, we clarify the molecular foundations of mouse embryonic stem cell (mESC) self-renewal by applying a proven Bayesian network machine learning approach to integrate high-throughput data for protein function discovery. By focusing on a single stem-cell system, at a specific developmental stage, within the context of well-defined biological processes known to be active in that cell type, we produce a consensus predictive network that reflects biological reality more closely than those made by prior efforts using more generalized, context-independent methods. In addition, we show how machine learning efforts may be misled if the tissue specific role of mammalian proteins is not defined in the training set and circumscribed in the evidential data. For this study, we assembled an extensive compendium of mESC data: ∼2.2 million data points, collected from 60 different studies, under 992 conditions. We then integrated these data into a consensus mESC functional relationship network focused on biological processes associated with embryonic stem cell self-renewal and cell fate determination. Computational evaluations, literature validation, and analyses of predicted functional linkages show that our results are highly accurate and biologically relevant. Our mESC network predicts many novel players involved in self-renewal and serves as the foundation for future pluripotent stem cell studies. This network can be used by stem cell researchers (at http://StemSight.org) to explore hypotheses about gene function in the context of self-renewal and to prioritize genes of interest for experimental validation. PMID:23468881

Limitations of Using Microsoft Excel Version 2016 (MS Excel 2016) for Statistical Analysis for Medical Research.

PubMed

Tanavalee, Chotetawan; Luksanapruksa, Panya; Singhatanadgige, Weerasak

2016-06-01

Microsoft Excel (MS Excel) is a commonly used program for data collection and statistical analysis in biomedical research. However, this program has many limitations, including fewer functions that can be used for analysis and a limited number of total cells compared with dedicated statistical programs. MS Excel cannot complete analyses with blank cells, and cells must be selected manually for analysis. In addition, it requires multiple steps of data transformation and formulas to plot survival analysis graphs, among others. The Megastat add-on program, which will be supported by MS Excel 2016 soon, would eliminate some limitations of using statistic formulas within MS Excel.

Engineering self-assembled bioreactors from protein microcompartments

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

Savage, David

2016-10-12

The goals of this research are to understand how organisms such as bacteria segregate certain metabolic processes inside of specific structures, or “microcompartments,” in the cell and apply this knowledge to develop novel engineered microcompartments for use in nanotechnology and metabolic engineering. For example, in some bacteria, self-assembling protein microcompartments called carboxysomes encapsulate the enzymes involved in carbon fixation, enabling the cell to utilize carbon dioxide more effectively than if the enzymes were free in the cell. The proposed research will determine how structures such as carboxysomes assemble and function in bacteria and develop a means for creating novel, syntheticmore » microcompartments for optimizing production of specific energy-rich compounds.« less

Synthetic Virology: Engineering Viruses for Gene Delivery

PubMed Central

Guenther, Caitlin M.; Kuypers, Brianna E.; Lam, Michael T.; Robinson, Tawana M.; Zhao, Julia; Suh, Junghae

2014-01-01

The success of gene therapy relies heavily on the performance of vectors that can effectively deliver transgenes to desired cell populations. As viruses have evolved to deliver genetic material into cells, a prolific area of research has emerged over the last several decades to leverage the innate properties of viruses as well as to engineer new features into them. Specifically, the field of synthetic virology aims to capitalize on knowledge accrued from fundamental virology research in order to design functionally enhanced gene delivery vectors. The enhanced viral vectors, or “bionic” viruses, feature engineered components, or “parts”, that are natural (intrinsic to viruses or from other organisms) and synthetic (such as man-made polymers or inorganic nanoparticles). Various design strategies – rational, combinatorial, and pseudo-rational – have been pursued to create the hybrid viruses. The gene delivery vectors of the future will likely criss-cross the boundaries between natural and synthetic domains to harness the unique strengths afforded by the various functional parts that can be grafted onto virus capsids. Such research endeavours will further expand and enable enhanced control over the functional capacity of these nanoscale devices for biomedicine. PMID:25195922

Synthetic virology: engineering viruses for gene delivery.

PubMed

Guenther, Caitlin M; Kuypers, Brianna E; Lam, Michael T; Robinson, Tawana M; Zhao, Julia; Suh, Junghae

2014-01-01

The success of gene therapy relies heavily on the performance of vectors that can effectively deliver transgenes to desired cell populations. As viruses have evolved to deliver genetic material into cells, a prolific area of research has emerged over the last several decades to leverage the innate properties of viruses as well as to engineer new features into them. Specifically, the field of synthetic virology aims to capitalize on knowledge accrued from fundamental virology research in order to design functionally enhanced gene delivery vectors. The enhanced viral vectors, or 'bionic' viruses, feature engineered components, or 'parts', that are natural (intrinsic to viruses or from other organisms) and synthetic (such as man-made polymers or inorganic nanoparticles). Various design strategies--rational, combinatorial, and pseudo-rational--have been pursued to create the hybrid viruses. The gene delivery vectors of the future will likely criss-cross the boundaries between natural and synthetic domains to harness the unique strengths afforded by the various functional parts that can be grafted onto virus capsids. Such research endeavors will further expand and enable enhanced control over the functional capacity of these nanoscale devices for biomedicine. © 2014 Wiley Periodicals, Inc.

What are the origins and relevance of spontaneous bladder contractions? ICI-RS 2017.

PubMed

Drake, Marcus J; Fry, Christopher H; Hashitani, Hikaru; Kirschner-Hermanns, Ruth; Rahnama'i, Mohammad S; Speich, John E; Tomoe, Hikaru; Kanai, Anthony J; McCloskey, Karen D

2018-01-23

Storage phase bladder activity is a counter-intuitive observation of spontaneous contractions. They are potentially an intrinsic feature of the smooth muscle, but interstitial cells in the mucosa and the detrusor itself, as well as other muscular elements in the mucosa may substantially influence them. They are identified in several models explaining lower urinary tract dysfunction. A consensus meeting at the International Consultation on Incontinence Research Society (ICI-RS) 2017 congress considered the origins and relevance of spontaneous bladder contractions by debating which cell type(s) modulate bladder spontaneous activity, whether the methodologies are sufficiently robust, and implications for healthy and abnormal lower urinary tract function. The identified research priorities reflect a wide range of unknown aspects. Cellular contributions to spontaneous contractions in detrusor smooth muscle are still uncertain. Accordingly, insight into the cellular physiology of the bladder wall, particularly smooth muscle cells, interstitial cells, and urothelium, remains important. Upstream influences, such as innervation, endocrine, and paracrine factors, are particularly important. The cellular interactions represent the key understanding to derive the integrative physiology of organ function, notably the nature of signalling between mucosa and detrusor layers. Indeed, it is still not clear to what extent spontaneous contractions generated in isolated preparations mirror their normal and pathological counterparts in the intact bladder. Improved models of how spontaneous contractions influence pressure generation and sensory nerve function are also needed. Deriving approaches to robust evaluation of spontaneous contractions and their influences for experimental and clinical use could yield considerable progress in functional urology. © 2018 Wiley Periodicals, Inc.

Platelet Function Tests

MedlinePlus

... Time and International Normalized Ratio (PT/INR) PSEN1 Quantitative Immunoglobulins Red Blood Cell (RBC) Antibody Identification Red ... 100 – FAQ. Florida Hospital Cancer Institute, Clinical and Research Laboratories [On-line information]. Available online at http:// ...

Enhanced Imaging of Specific Cell-Surface Glycosylation Based on Multi-FRET.

PubMed

Yuan, Baoyin; Chen, Yuanyuan; Sun, Yuqiong; Guo, Qiuping; Huang, Jin; Liu, Jianbo; Meng, Xiangxian; Yang, Xiaohai; Wen, Xiaohong; Li, Zenghui; Li, Lie; Wang, Kemin

2018-05-15

Cell-surface glycosylation contains abundant biological information that reflects cell physiological state, and it is of great value to image cell-surface glycosylation to elucidate its functions. Here we present a hybridization chain reaction (HCR)-based multifluorescence resonance energy transfer (multi-FRET) method for specific imaging of cell-surface glycosylation. By installing donors through metabolic glycan labeling and acceptors through aptamer-tethered nanoassemblies on the same glycoconjugate, intramolecular multi-FRET occurs due to near donor-acceptor distance. Benefiting from amplified effect and spatial flexibility of the HCR nanoassemblies, enhanced multi-FRET imaging of specific cell-surface glycosylation can be obtained. With this HCR-based multi-FRET method, we achieved obvious contrast in imaging of protein-specific GalNAcylation on 7211 cell surfaces. In addition, we demonstrated the general applicability of this method by visualizing the protein-specific sialylation on CEM cell surfaces. Furthermore, the expression changes of CEM cell-surface protein-specific sialylation under drug treatment was accurately monitored. This developed imaging method may provide a powerful tool in researching glycosylation functions, discovering biomarkers, and screening drugs.

Guiding osteogenesis of mesenchymal stem cells using carbon-based nanomaterials

NASA Astrophysics Data System (ADS)

Kang, Ee-Seul; Kim, Da-Seul; Suhito, Intan Rosalina; Choo, Sung-Sik; Kim, Seung-Jae; Song, Inbeom; Kim, Tae-Hyung

2017-01-01

In the field of regenerative medicine, stem cells are highly promising due to their innate ability to generate multiple types of cells that could replace/repair damaged parts of human organs and tissues. It has been reported that both in vitro and in vivo function/survival of stem cells could significantly be improved by utilizing functional materials such as biodegradable polymers, metal composites, nanopatterns and nanohybrid particles. Of various biocompatible materials available for use in stem cell-based therapy and research, carbon-based materials—including fullerenes graphene/graphene oxide and carbon nanotubes—have been found to possess unique physicochemical characteristics that contribute to the effective guidance of stem cell differentiation into specific lineages. In this review, we discuss a number of previous reports that investigated the use of carbon-based materials to control stem cell behavior, with a particular focus on their immense potential to guide the osteogenesis of mesenchymal stem cells (MSCs). We hope that this review will provide information on the full potential of using various carbon-based materials in stem cell-mediated regenerative therapy, particularly for bone regeneration and repair.

Label-free screening of niche-to-niche variation in satellite stem cells using functionalized pores

NASA Astrophysics Data System (ADS)

Chapman, Matthew R.; Balakrishnan, Karthik; Conboy, Michael J.; Mohanty, Swomitra; Jabart, Eric; Huang, Haiyan; Hack, James; Conboy, Irina M.; Sohn, Lydia L.

2012-02-01

Combinations of surface markers are currently used to identify muscle satellite cells. Using pores functionalized with specific antibodies and measuring the transit time of cells passing through these pores, we discovered remarkable heterogeneity in the expression of these markers in muscle (satellite) stem cells that reside in different single myofibers. Microniche-specific variation in stem cells of the same organ has not been previously described, as bulk analysis does not discriminate between separate myofibers or even separate hind-leg muscle groups. We found a significant population of Sca-1+ satellite cells that form myotubes, thereby demonstrating the myogenic potential of Sca-1+ cells, which are currently excluded in bulk sorting. Finally, using our label-free pore screening technique, we have been able to quantify directly surface expression of Notch1 without activation of the Notch pathway. We show for the first time Notch1-expression heterogeneity in unactivated satellite cells. The discovery of fiber-to-fiber variations prompts new research into the reasons for such diversity in muscle stem cells.

Meeting report: a hard look at the state of enamel research

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

Klein, Ophir D.; Duverger, Olivier; Shaw, Wendy

Enamel is a principal component of the dentition, and defects in this hard tissue are associated with a wide variety of diseases. To assess the state of the field of enamel research, the National Institute of Dental and Craniofacial Research (NIDCR) convened the “Encouraging Novel Amelogenesis Models and Ex vivo cell Lines (ENAMEL) Development” workshop at its Bethesda headquarters on 23 June 2017. Enamel formation involves complex developmental stages and cellular differentiation mechanisms that are summarized in Figure 1. The meeting, which was organized by Jason Wan from NIDCR, had three sessions: model organisms, stem cells/cell lines, and tissues/ 3Dmore » cell culture/organoids. In attendance were investigators interested in enamel from a broad range of disciplines as well as NIDCR leadership and staff. The meeting brought together developmental biologists, cell biologists, human geneticists, materials scientists, and clinical researchers from across the United States to discuss recent progress and future challenges in our understanding of the formation and function of enamel. Lively discussions took place throughout the day, and this meeting report highlights some of the major findings and ideas that emerged during the workshop.« less

Resolved and open issues in chromaffin cell development.

PubMed

Unsicker, Klaus; Huber, Katrin; Schober, Andreas; Kalcheim, Chaya

2013-01-01

Ten years of research within the DFG-funded Collaborative Research Grant SFB 488 at the University of Heidelberg have added many new facets to our understanding of chromaffin cell development. Glucocorticoid signaling is no longer the key for understanding the determination of the chromaffin phenotype, yet a novel role has been attributed to glucocorticoids: they are essential for the postnatal maintenance of adrenal and extra-adrenal chromaffin cells. Transcription factors, as, e.g. MASH1 and Phox2B, have similar, but also distinct functions in chromaffin and sympathetic neuronal development, and BMP-4 not only induces sympathoadrenal (SA) cells at the dorsal aorta and within the adrenal gland, but also promotes chromaffin cell maturation. Chromaffin cells and sympathetic neurons share a common progenitor in the dorsal neural tube (NT) in vivo, as revealed by single cell electroporations into the dorsal NT. Thus, specification of chromaffin cells is likely to occur after cell emigration either during migration or close to colonization of the target regions. Mechanisms underlying the specification of chromaffin cells vs. sympathetic neurons are currently being explored. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Wound Models for Periodontal and Bone Regeneration: the role of biological research

PubMed Central

Sculean, Anton; Chapple, Iain L.C.; Giannobile, William V.

2015-01-01

The ultimate goal of periodontal therapy remains the complete regeneration of those periodontal tissues lost to the destructive inflammatory-immune response, or to trauma, with tissues that possess the same structure and function, and to reestablish and sustain a heath promoting biofilm from one characterised by dysbiosis. This volume discusses the multiple facets of a transition during the late 1960’s to the present day, towards regenerative therapies founded upon a clearer understanding of the biophysiology of normal structure and function, rather than empiricism. This introductory manuscript provides an overview on the requirements of appropriate in-vitro laboratory models (e.g. cell culture), of pre-clinical (i.e. animal) models and human studies for periodontal wound and bone repair. Laboratory studies may provide valuable fundamental insights into basic mechanisms involved in wound repair and regeneration, but also suffer from a uni-dimensional and simplistic approach that does not account for the complexities of the in vivo situation, where multiple cell types and interactions all contribute to definitive outcomes. Therefore, such laboratory studies require validatory research employing preclinical models specifically designed to demonstrate proof-of-concept efficacy, preliminary safety and adaptation to human disease scenarios. Small animal models provide the most economic and logistically feasible preliminary approaches, but outcomes do not necessarily translate to larger animal or human models. The advantages and limitations of all periodontal regeneration models need to be carefully considered when planning investigations to ensure that the optimal design is adopted to answer the specific research question posed. Future challenges lie in the areas of stem cell research, scaffold designs, cell delivery and choice of growth factors, along with research to ensure appropriate gingival coverage in order to prevent gingival recession during the healing phase. PMID:25867976

Upregulation of the long non-coding RNA SNHG1 predicts poor prognosis, promotes cell proliferation and invasion, and reduces apoptosis in glioma.

PubMed

Wang, Qiang; Li, Qing; Zhou, Peng; Deng, Danni; Xue, Lian; Shao, Naiyuan; Peng, Ya; Zhi, Feng

2017-07-01

Long non-coding RNAs (lncRNAs), which are non-coding RNAs with a length above 200 nucleotides, have emerged as novel and important gene expression modulators in carcinogenesis. Recent evidence indicates that the lncRNA small nucleolar RNA host gene 1 (SNHG1) functions as an oncogene in several types of human cancers. However, its function in the development of glioma remains unknown. The aim of this research was to investigate the clinical aspects and biological mechanisms of SNHG1 in glioma. SNHG1 expression was measured in glioma tissues and cell lines by quantitative real-time PCR (qRT-PCR). The association between SNHG1 expression in tissues and clinicopathological characteristics and prognosis in glioma patients was also explored. Gain-of-function and loss-of-function studies using SNHG1 cDNA and siRNA, respectively, were used to investigate the role of SNHG1 in cell proliferation, invasion and apoptosis in glioma. SNHG1 was highly expressed in glioma tissues, and its upregulation was closely related to old age. Kaplan-Meier analysis showed that high expression of SNHG1 was significantly associated with poor overall survival (OS). Functionally, ectopic expression of SNHG1 enhanced cell proliferation and cell invasion and reduced cell apoptosis in vitro, while SNHG1 knockdown reversed these effects. Taken together, our findings indicate that SNHG1 functions as an oncogene in glioma and may serve as a novel therapeutic target in future treatments. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Applications of slow positrons to cancer research: Search for selectivity of positron annihilation to skin cancer

NASA Astrophysics Data System (ADS)

Jean, Y. C.; Li, Ying; Liu, Gaung; Chen, Hongmin; Zhang, Junjie; Gadzia, Joseph E.

2006-02-01

Slow positrons and positron annihilation spectroscopy (PAS) have been applied to medical research in searching for positron annihilation selectivity to cancer cells. We report the results of positron lifetime and Doppler broadening energy spectroscopies in human skin samples with and without cancer as a function of positron incident energy (up to 8 μm depth) and found that the positronium annihilates at a significantly lower rate and forms at a lower probability in the samples having either basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) than in the normal skin. The significant selectivity of positron annihilation to skin cancer may open a new research area of developing positron annihilation spectroscopy as a novel medical tool to detect cancer formation externally and non-invasively at the early stages.

Lessons from single-cell transcriptome analysis of oxygen-sensing cells.

PubMed

Zhou, Ting; Matsunami, Hiroaki

2018-05-01

The advent of single-cell RNA-sequencing (RNA-Seq) technology has enabled transcriptome profiling of individual cells. Comprehensive gene expression analysis at the single-cell level has proven to be effective in characterizing the most fundamental aspects of cellular function and identity. This unbiased approach is revolutionary for small and/or heterogeneous tissues like oxygen-sensing cells in identifying key molecules. Here, we review the major methods of current single-cell RNA-Seq technology. We discuss how this technology has advanced the understanding of oxygen-sensing glomus cells in the carotid body and helped uncover novel oxygen-sensing cells and mechanisms in the mice olfactory system. We conclude by providing our perspective on future single-cell RNA-Seq research directed at oxygen-sensing cells.

The ubiquitin proteasome system in glia and its role in neurodegenerative diseases

PubMed Central

Jansen, Anne H. P.; Reits, Eric A. J.; Hol, Elly M.

2014-01-01

The ubiquitin proteasome system (UPS) is crucial for intracellular protein homeostasis and for degradation of aberrant and damaged proteins. The accumulation of ubiquitinated proteins is a hallmark of many neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer’s, Parkinson’s, and Huntington’s disease, leading to the hypothesis that proteasomal impairment is contributing to these diseases. So far, most research related to the UPS in neurodegenerative diseases has been focused on neurons, while glial cells have been largely disregarded in this respect. However, glial cells are essential for proper neuronal function and adopt a reactive phenotype in neurodegenerative diseases, thereby contributing to an inflammatory response. This process is called reactive gliosis, which in turn affects UPS function in glial cells. In many neurodegenerative diseases, mostly neurons show accumulation and aggregation of ubiquitinated proteins, suggesting that glial cells may be better equipped to maintain proper protein homeostasis. During an inflammatory reaction, the immunoproteasome is induced in glia, which may contribute to a more efficient degradation of disease-related proteins. Here we review the role of the UPS in glial cells in various neurodegenerative diseases, and we discuss how studying glial cell function might provide essential information in unraveling mechanisms of neurodegenerative diseases. PMID:25152710

Regulation of Innate Lymphoid Cells by Aryl Hydrocarbon Receptor

PubMed Central

Li, Shiyang; Bostick, John W.; Zhou, Liang

2018-01-01

With striking similarity to their adaptive T helper cell counterparts, innate lymphoid cells (ILCs) represent an emerging family of cell types that express signature transcription factors, including T-bet+ Eomes+ natural killer cells, T-bet+ Eomes− group 1 ILCs, GATA3+ group 2 ILCs, RORγt+ group 3 ILCs, and newly identified Id3+ regulatory ILC. ILCs are abundantly present in barrier tissues of the host (e.g., the lung, gut, and skin) at the interface of host–environment interactions. Active research has been conducted to elucidate molecular mechanisms underlying the development and function of ILCs. The aryl hydrocarbon receptor (Ahr) is a ligand-dependent transcription factor, best known to mediate the effects of xenobiotic environmental toxins and endogenous microbial and dietary metabolites. Here, we review recent progresses regarding Ahr function in ILCs. We focus on the Ahr-mediated cross talk between ILCs and other immune/non-immune cells in host tissues especially in the gut. We discuss the molecular mechanisms of the action of Ahr expression and activity in regulation of ILCs in immunity and inflammation, and the interaction between Ahr and other pathways/transcription factors in ILC development and function with their implication in disease. PMID:29354125

Assessing Estrogen-Induced Proliferative Response in an Endometrial Cancer Cell Line Using a Universally Applicable Methodological Guide.

PubMed

Parkes, Christina; Kamal, Areege; Valentijn, Anthony J; Alnafakh, Rafah; Gross, Stephane R; Barraclough, Roger; Moss, Diana; Kirwan, John; Hapangama, Dharani K

2018-01-01

Translational endometrial cancer (EC) research benefits from an in vitro experimental approach using EC cell lines. We demonstrated the steps that are required to examine estrogen-induced proliferative response, a simple yet important research question pertinent to EC, and devised a pragmatic methodological workflow for using EC cell lines in experimental models. Comprehensive review of all commercially available EC cell lines was carried out, and Ishikawa cell line was selected to study the estrogen responsiveness with HEC1A, RL95-2, and MFE280 cell lines as comparators where appropriate, examining relevant differential molecular (steroid receptors) and functional (phenotype, anchorage-independent growth, hormone responsiveness, migration, invasion, and chemosensitivity) characteristics in 2-dimensional and 3-dimensional cultures in vitro using immunocytochemistry, immunofluorescence, quantitative polymerase chain reaction, and Western blotting. In vivo tumor, formation, and chemosensitivity were also assessed in a chick chorioallantoic membrane model. Short tandem repeat analysis authenticated the purchased cell lines, whereas gifted cells deviated significantly from the published profile. We demonstrate the importance of prior assessment of the suitability of each cell line for the chosen in vitro experimental technique. Prior establishment of baseline, nonenriched conditions was required to induce a proliferative response to estrogen. The chorioallantoic membrane model was a suitable in vivo multicellular animal model for EC for producing rapid and reproducible data. We have developed a methodological guide for EC researchers when using endometrial cell lines to answer important translational research questions (exemplified by estrogen-responsive cell proliferation) to facilitate robust data, while saving time and resources.

Neural Mechanisms Linking Mild Traumatic Brain Injury and Anxiety States in an Animal Model

DTIC Science & Technology

2011-09-01

cells in each region were determined. In separate groups of rats, the effects of mTBI on anxiety-like behaviors, motor function, nociception, and...granule cells in the dentate gyrus rapidly extend axons into the hippocampal CA3 region following experimental brain injury. J Neurotrauma 22 :978-988...Furthermore, this research suggests that heightened fear and anxiety states following mild TBI may result from alterations to cell death and neuronal

The Drosophila T-box transcription factor Midline functions within the Notch–Delta signaling pathway to specify sensory organ precursor cell fates and regulates cell survival within the eye imaginal disc

PubMed Central

Das, Sudeshna; Chen, Q. Brent; Saucier, Joseph D.; Drescher, Brandon; Zong, Yan; Morgan, Sarah; Forstall, John; Meriwether, Andrew; Toranzo, Randy; Leal, Sandra M.

2014-01-01

We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch–Delta signaling pathway essential for specifying the fates of sensory organ precursor cells. This complements an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in diverse neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch–Delta signaling hierarchy and is essential for maintaining cell viability within by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. PMID:23962751

[Advance in research on regulatory mechanism and functions of neutral sphingomyelinse 2].

PubMed

Zhang, Lan; Guo, Jun

2013-10-01

Neutral sphingomyelinase 2 (nSMase2), which located mainly on the plasma membrane, hydrolyzes sphingomyelin into ceramide and plays an important role in the physiological and pathological regulation of cell apoptosis, cell growth arrest, and inflammation. nSMase2 is also involved in the development of Alzheimer's disease and the bone growth.Under neutral pH and the presence of Ca(2+), Mg(2+), and Mn(+), the activity of nSMase2 is induced by oxidative stress through phosphorylation. Furthermore, the induced interaction of anionic phospholipids and the signaling molecules like receptor for activated C-kinase 1/embryonic ectodermal development with nSMase2 are also crucial mechanisms of protein activation. In the review, recent research advances in the structure and function of nSMase2 and its underlying mechanisms are summarized.

Recent advances in CD8+ regulatory T cell research

PubMed Central

Yu, Yating; Ma, Xinbo; Gong, Rufei; Zhu, Jianmeng; Wei, Lihua; Yao, Jinguang

2018-01-01

Various subgroups of CD8+ T lymphocytes do not only demonstrate cytotoxic effects, but also serve important regulatory roles in the body's immune response. In particular, CD8+ regulatory T cells (CD8+ Tregs), which possess important immunosuppressive functions, are able to effectively block the overreacting immune response and maintain the body's immune homeostasis. In recent years, studies have identified a small set of special CD8+ Tregs that can recognize major histocompatibility complex class Ib molecules, more specifically Qa-1 in mice and HLA-E in humans, and target the self-reactive CD4+ T ce lls. These findings have generated broad implications in the scientific community and attracted general interest to CD8+ Tregs. The present study reviews the recent research progress on CD8+ Tregs, including their origin, functional classification, molecular markers and underlying mechanisms of action.

Stem Cell Niche, the Microenvironment and Immunological Crosstalk

PubMed Central

Sujata, Law; Chaudhuri, S

2008-01-01

The concept of stem cells, their physiological existence, the intricate anatomical localization, the known and the unknown functions, and their exclusive utility for the purpose of regenerative medicine, are all now encompassed within an emergent question, ‘how compatible these cells are immunologically?' Indeed, the medical aspects of stem cells are dependent on a large number of queries based on the basic properties of the cells. It has greatly been emphasized to probe into the basic research on stem cells before any successful therapeutic attempts are made. One of the intricate aspects of the adult stem cells is its immunological behavior in relation to the microenvironmental associates, the stromal cells in the presence of a suitable target. PMID:18445340

Stem cell niche, the microenvironment and immunological crosstalk.

PubMed

Sujata, Law; Chaudhuri, S

2008-04-01

The concept of stem cells, their physiological existence, the intricate anatomical localization, the known and the unknown functions, and their exclusive utility for the purpose of regenerative medicine, are all now encompassed within an emergent question, 'how compatible these cells are immunologically?' Indeed, the medical aspects of stem cells are dependent on a large number of queries based on the basic properties of the cells. It has greatly been emphasized to probe into the basic research on stem cells before any successful therapeutic attempts are made. One of the intricate aspects of the adult stem cells is its immunological behavior in relation to the microenvironmental associates, the stromal cells in the presence of a suitable target.

Ultrastructural analysis of testicular tissue and sperm by transmission and scanning electron microscopy.

PubMed

Chemes, Hector E

2013-01-01

Transmission electron microscopy (TEM) studies have provided the basis for an in-depth understanding of the cell biology and normal functioning of the testis and male gametes and have opened the way to characterize the functional role played by specific organelles in spermatogenesis and sperm function. The development of the scanning electron microscope (SEM) extended these boundaries to the recognition of cell and organ surface features and the architectural array of cells and tissues. The merging of immunocytochemical and histochemical approaches with electron microscopy has completed a series of technical improvements that integrate structural and functional features to provide a broad understanding of cell biology in health and disease. With these advances the detailed study of the intricate structural and molecular organization as well as the chemical composition of cellular organelles is now possible. Immunocytochemistry is used to identify proteins or other components and localize them in specific cells or organelles with high specificity and sensitivity, and histochemistry can be used to understand their function (i.e., enzyme activity). When these techniques are used in conjunction with electron microscopy their resolving power is further increased to subcellular levels. In the present chapter we will describe in detail various ultrastructural techniques that are now available for basic or translational research in reproductive biology and reproductive medicine. These include TEM, ultrastructural immunocytochemistry, ultrastructural histochemistry, and SEM.

Stretchable living materials and devices with hydrogel–elastomer hybrids hosting programmed cells

PubMed Central

Liu, Xinyue; Tang, Tzu-Chieh; Tham, Eléonore; Yuk, Hyunwoo; Lin, Shaoting; Lu, Timothy K.; Zhao, Xuanhe

2017-01-01

Living systems, such as bacteria, yeasts, and mammalian cells, can be genetically programmed with synthetic circuits that execute sensing, computing, memory, and response functions. Integrating these functional living components into materials and devices will provide powerful tools for scientific research and enable new technological applications. However, it has been a grand challenge to maintain the viability, functionality, and safety of living components in freestanding materials and devices, which frequently undergo deformations during applications. Here, we report the design of a set of living materials and devices based on stretchable, robust, and biocompatible hydrogel–elastomer hybrids that host various types of genetically engineered bacterial cells. The hydrogel provides sustainable supplies of water and nutrients, and the elastomer is air-permeable, maintaining long-term viability and functionality of the encapsulated cells. Communication between different bacterial strains and with the environment is achieved via diffusion of molecules in the hydrogel. The high stretchability and robustness of the hydrogel–elastomer hybrids prevent leakage of cells from the living materials and devices, even under large deformations. We show functions and applications of stretchable living sensors that are responsive to multiple chemicals in a variety of form factors, including skin patches and gloves-based sensors. We further develop a quantitative model that couples transportation of signaling molecules and cellular response to aid the design of future living materials and devices. PMID:28202725

An overview—Functional nanomaterials for lithium rechargeable batteries, supercapacitors, hydrogen storage, and fuel cells

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

Liu, Hua Kun, E-mail: hua@uow.edu.au

2013-12-15

Graphical abstract: Nanomaterials play important role in lithium ion batteries, supercapacitors, hydrogen storage and fuel cells. - Highlights: • Nanomaterials play important role for lithium rechargeable batteries. • Nanostructured materials increase the capacitance of supercapacitors. • Nanostructure improves the hydrogenation/dehydrogenation of hydrogen storage materials. • Nanomaterials enhance the electrocatalytic activity of the catalysts in fuel cells. - Abstract: There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithiummore » ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on the synthesis, characterization, and applications of functional nanomaterials, including nanoparticles, nanotubes, nanowires, nanoporous materials, and nanocomposites. The emphases are placed on advanced nanotechnology, design, and control of the composition, morphology, nanostructure, and functionality of the nanomaterials, and on the subsequent applications of these materials to areas including lithium ion batteries, supercapacitors, hydrogen storage, and fuel cells.« less

Carbon nanotubes as multifunctional biological transporters and near-infrared agents for selective cancer cell destruction

NASA Astrophysics Data System (ADS)

Nadine Wong Shi Kam,; O'Connell, Michael; Wisdom, Jeffrey A.; Dai, Hongjie

2005-08-01

Biological systems are known to be highly transparent to 700- to 1,100-nm near-infrared (NIR) light. It is shown here that the strong optical absorbance of single-walled carbon nanotubes (SWNTs) in this special spectral window, an intrinsic property of SWNTs, can be used for optical stimulation of nanotubes inside living cells to afford multifunctional nanotube biological transporters. For oligonucleotides transported inside living cells by nanotubes, the oligos can translocate into cell nucleus upon endosomal rupture triggered by NIR laser pulses. Continuous NIR radiation can cause cell death because of excessive local heating of SWNT in vitro. Selective cancer cell destruction can be achieved by functionalization of SWNT with a folate moiety, selective internalization of SWNTs inside cells labeled with folate receptor tumor markers, and NIR-triggered cell death, without harming receptor-free normal cells. Thus, the transporting capabilities of carbon nanotubes combined with suitable functionalization chemistry and their intrinsic optical properties can lead to new classes of novel nanomaterials for drug delivery and cancer therapy. Author contributions: N.W.S.K., M.O., and H.D. designed research; N.W.S.K., M.O., and J.A.W. performed research; N.W.S.K., M.O., and H.D. analyzed data; and N.W.S.K. and H.D. wrote the paper.This paper was submitted directly (Track II) to the PNAS office.Abbreviations: NIR, near-infrared; SWNT, single-walled carbon nanotube; AFM, atomic force microscopy; PL, phospholipid; PEG, polyethylene glycol; FA, folic acid; FR, folate receptor.

Stem Cell Therapies for Treating Diabetes: Progress and Remaining Challenges.

PubMed

Sneddon, Julie B; Tang, Qizhi; Stock, Peter; Bluestone, Jeffrey A; Roy, Shuvo; Desai, Tejal; Hebrok, Matthias

2018-06-01

Restoration of insulin independence and normoglycemia has been the overarching goal in diabetes research and therapy. While whole-organ and islet transplantation have become gold-standard procedures in achieving glucose control in diabetic patients, the profound lack of suitable donor tissues severely hampers the broad application of these therapies. Here, we describe current efforts aimed at generating a sustainable source of functional human stem cell-derived insulin-producing islet cells for cell transplantation and present state-of-the-art efforts to protect such cells via immune modulation and encapsulation strategies. Copyright © 2018. Published by Elsevier Inc.

The gammaTuRC Nanomachine Mechanism and Future Applications

NASA Astrophysics Data System (ADS)

Riehlman, Timothy D.

The complexity and precision of the eukaryotic cell's cytoskeletal network is unrivaled by any man-made systems, perfected by billions of years of evolution, mastering elegant processes of self-assembly, error correction, and self-repair. Understanding the capabilities of these networks will have important and far reaching applications in human medicine by aiding our understanding of developmental processes, cellular division, and disease mechanisms, and through biomimicry will provide insights for biosynthetic manufacturing at the nanoscale and across scales. My research utilizes cross species techniques from Human to the model organism of Fission Yeast to investigate the structure and mechanisms of the g-tubulin ring complex (gTuRC). The gTuRC is a highly conserved eukaryotic multiprotein complex serving as a microtubule organizing center (MTOC) responsible for microtubule nucleation through templating, regulation of dynamics, and establishment of microtubule polarity. Microtubules are 25 nm diameter dynamic flexible polymers of a/b-tubulin heterodimers that function as scaffolds, force generators, distributors, and intracellular highways. The microtubule cytoskeleton is essential for numerous fundamental cellular processes such as mitotic division of chromosomes and cell division, organelle distribution within the cell, cell signaling, and cell shape. This incredible diversity in functions is made possible in part due to molecular motor Kinesin-like proteins (Klps), which allow expansion into more specialized neural, immune, and ciliated cell functions. Combined, the MTOC, microtubules, and Klps represent ideal microtubule cytoskeleton protein (MCP) modular components for in vitro biomimicry towards generation of adaptable patterned networks for human designed applications. My research investigates the hypothesis that a mechanistic understanding of conserved MTOC gTuRC mechanisms will help us understand dynamic cellular nanomachines and their ability to self-assemble complex structures for applications in biomedicine and new roles in biomimetic nanotechnologies.

Mechanics of the Nucleus

PubMed Central

Lammerding, Jan

2015-01-01

The nucleus is the distinguishing feature of eukaryotic cells. Until recently, it was often considered simply as a unique compartment containing the genetic information of the cell and associated machinery, without much attention to its structure and mechanical properties. This article provides compelling examples that illustrate how specific nuclear structures are associated with important cellular functions, and how defects in nuclear mechanics can cause a multitude of human diseases. During differentiation, embryonic stem cells modify their nuclear envelope composition and chromatin structure, resulting in stiffer nuclei that reflect decreased transcriptional plasticity. In contrast, neutrophils have evolved characteristic lobulated nuclei that increase their physical plasticity, enabling passage through narrow tissue spaces in their response to inflammation. Research on diverse cell types further demonstrates how induced nuclear deformations during cellular compression or stretch can modulate cellular function. Pathological examples of disturbed nuclear mechanics include the many diseases caused by mutations in the nuclear envelope proteins lamin A/C and associated proteins, as well as cancer cells that are often characterized by abnormal nuclear morphology. In this article, we will focus on determining the functional relationship between nuclear mechanics and cellular (dys-)function, describing the molecular changes associated with physiological and pathological examples, the resulting defects in nuclear mechanics, and the effects on cellular function. New insights into the close relationship between nuclear mechanics and cellular organization and function will yield a better understanding of normal biology and will offer new clues into therapeutic approaches to the various diseases associated with defective nuclear mechanics. PMID:23737203

AP1 Keeps Chromatin Poised for Action | Center for Cancer Research

Cancer.gov

The human genome harbors gene-encoding DNA, the blueprint for building proteins that regulate cellular function. Embedded across the genome, in non-coding regions, are DNA elements to which regulatory factors bind. The interaction of regulatory factors with DNA at these sites modifies gene expression to modulate cell activity. In cells, DNA exists in a complex with proteins

Sirt1 Protects Stressed Adult Hematopoietic Stem Cells | Center for Cancer Research

Cancer.gov

The immune system relies on a stable pool of hematopoietic stem and progenitor cells (HSPCs) to respond properly to injury or stress. Maintaining genomic integrity and appropriate gene expression is essential for HSPC homeostasis, and dysregulation can result in myeloproliferative disorders or loss of immune function. Sirt1 is a histone deacetylase that can protect embryonic

International Narcotic Research Conference (14th) Held at Garmisch-Partenkirchen, West Germany on 27 June-1 July 1983.

DTIC Science & Technology

1984-06-01

recep- tors at leas" in NG-108-15 cells. When cells were treated with chloroquine which intarfeceswith lyzosoimai enzyme function by changing the pil...but not by its quaternary analogue . Further, when the peripheral component of morphine’s net effect on feeding is blocked by co-administration of

News and views in Histochemistry and Cell Biology.

PubMed

Asan, Esther; Drenckhahn, Detlev

2004-12-01

Advances in histochemical methodology and ingenious applications of novel and improved methods continue to confirm the standing of morphological means and approaches in research efforts, and contribute significantly to increasing our knowledge about structures and functions in all areas of the life sciences from cell biology to pathology. Reports published during recent months documenting this progress are summarized in the present review.

Stopping Liver Cancer's Rogue COP | Center for Cancer Research

Cancer.gov

Liver cancer is the fourth most common cancer type and the third leading cause of cancer death worldwide. Many liver tumors are actually metastases, tumors seeded in the liver by cancer cells from another organ, but hepatocellular carcinomas (HCCs), the most common liver tumors, are a heterogeneous family of cancers that arise in hepatocytes, the functional cells of the liver.

Solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation: piece by piece.

PubMed

Lundy, David J; Lee, Desy S; Hsieh, Patrick C H

2017-03-01

There is a growing need for in vitro models which can serve as platforms for drug screening and basic research. Human adult cardiomyocytes cannot be readily obtained or cultured, and so pluripotent stem cell-derived cardiomyocytes appear to be an attractive option. Unfortunately, these cells are structurally and functionally immature-more comparable to foetal cardiomyocytes than adult. A recent study by Ruan et al ., provides new insights into accelerating the maturation process and takes us a step closer to solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation.

Preliminary Performance of Lithium-ion Cell Designs for Ares I Upper Stage Applications

NASA Technical Reports Server (NTRS)

Miller, Thomas B.; Reid, Concha M.; Kussmaul, Michael T.

2011-01-01

NASA's Ares I Crew Launch Vehicle (CLV) baselined lithium-ion technology for the Upper Stage (US). Under this effort, the NASA Glenn Research Center investigated three different aerospace lithium-ion cell suppliers to assess the performance of the various lithium-ion cell designs under acceptance and characterization testing. This paper describes the overall testing approaches associated with lithium-ion cells, their ampere-hour capacity as a function of temperature and discharge rates, as well as their performance limitations for use on the Ares I US vehicle.

Bach2 Promotes Regulatory T-cell Development by Limiting Effector Differentiation | Center for Cancer Research

Cancer.gov

A number of allergic and autoimmune disorders, such as Crohn’s disease, asthma, type I diabetes and multiple sclerosis, are associated with polymorphisms in a gene encoding the transcription factor, BACH2. Despite this, the mechanism Bach2 uses to prevent immune-mediated diseases was not known. To function appropriately, the immune system relies on a delicate balance between immune-stimulating and immune-regulating cells. When immune-stimulating cells become too active, or immune-regulating cells become ineffective, autoimmune and allergic diseases can ensue.

Intramedullary spindle cell hemangioma: case report.

PubMed

Nasser, Rani; Ashayeri, Kimberly; Legatt, Alan D; Houten, John K

2016-09-01

The authors describe the case of a 48-year-old man found to have the first reported intramedullary spinal cord spindle cell hemangioma. Previous research indicates that spindle cell hemangiomas are rarely found in the spine. Only 3 previous cases exist, all in the intradural, extramedullary space. In the present case, gross-total resection of the tumor was possible with no loss of function from baseline. This report presents the successful resection of the first reported intramedullary spindle cell hemangioma and reports 4-month follow-up, demonstrating the biological behavior of this rare tumor.

Molecular targeting of growth factor receptor-bound 2 (Grb2) as an anti-cancer strategy.

PubMed

Dharmawardana, Pathirage G; Peruzzi, Benedetta; Giubellino, Alessio; Burke, Terrence R; Bottaro, Donald P

2006-01-01

Growth factor receptor-bound 2 (Grb2) is a ubiquitously expressed adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway. As such, it has been implicated in the oncogenesis of several important human malignancies. In addition to this function, research over the last decade has revealed other fundamental roles for Grb2 in cell motility and angiogenesis--processes that also contribute to tumor growth, invasiveness and metastasis. This functional profile makes Grb2 a high priority target for anti-cancer drug development. Knowledge of Grb2 protein structure, its component Src homology domains and their respective structure-function relationships has facilitated the rapid development of sophisticated drug candidates that can penetrate cells, bind Grb2 with high affinity and potently antagonize Grb2 signaling. These novel compounds offer considerable promise in our growing arsenal of rationally designed anti-cancer therapeutics.

The biology, function and clinical implications of exosomes in lung cancer.

PubMed

Zhou, Li; Lv, Tangfeng; Zhang, Qun; Zhu, Qingqing; Zhan, Ping; Zhu, Suhua; Zhang, Jianya; Song, Yong

2017-10-28

Exosomes are 30-100 nm small membrane vesicles of endocytic origin that are secreted by all types of cells, and can also be found in various body fluids. Increasing evidence implicates that exosomes confer stability and can deliver their cargos such as proteins and nucleic acids to specific cell types, which subsequently serve as important messengers and carriers in lung carcinogenesis. Here, we describe the biogenesis and components of exosomes mainly in lung cancer, we summarize their function in lung carcinogenesis (epithelial mesenchymal transition, oncogenic cell transformation, angiogenesis, metastasis and immune response in tumor microenvironment), and importantly we focus on the clinical potential of exosomes as biomarkers and therapeutics in lung cancer. In addition, we also discuss current challenges that might impede the clinical use of exosomes. Further studies on the functional roles of exosomes in lung cancer requires thorough research. Copyright © 2017 Elsevier B.V. All rights reserved.

[Research Progress on Metabolic Regulatory Mechanisms of Hematopoietic Stem Cells -Review].

PubMed

Zhang, Ya-Wen; Cheng, Hui; Cheng, Tao

2018-06-01

Hematopoietic stem cells (HSC) are a class of stem cells with self-renewal and multipotent differentiation into a variety of blood cells and are most thoroughly studied, maturely applied in the clinic adult stem cell. Function of HSC is closely associated with metabolic regulation. The metabolic state mainly maintains HSC living in hypoxic bone marrow microenvironment depending on glycolysis for energy metabolism, and keeping low reactive oxygen species (ROS) level. Proteins like Hif-1, FoxO3, ATM, PTPMT1 protect HSC from ROS injury, maintaining HSC in hypoxic state. In addition, glucose metabolism-related enzymes, glutamine, fatty acid oxidation, purine and amino acid metabolism also play important roles in metabolic regulation of HSC. In this review the research progress on metabolism regnlation mechanisms of HSC is summurized, focusing on the mechanisms releted with oxydation metabolism regulation, carbohydrate metabolism level, purine metabolism and aminoacide metabolism.

Inhibitory Effects of Leptin on Pancreatic α-Cell Function

PubMed Central

Tudurí, Eva; Marroquí, Laura; Soriano, Sergi; Ropero, Ana B.; Batista, Thiago M.; Piquer, Sandra; López-Boado, Miguel A.; Carneiro, Everardo M.; Gomis, Ramón; Nadal, Angel; Quesada, Ivan

2009-01-01

OBJECTIVE Leptin released from adipocytes plays a key role in the control of food intake, energy balance, and glucose homeostasis. In addition to its central action, leptin directly affects pancreatic β-cells, inhibiting insulin secretion, and, thus, modulating glucose homeostasis. However, despite the importance of glucagon secretion in glucose homeostasis, the role of leptin in α-cell function has not been studied in detail. In the present study, we have investigated this functional interaction. RESEARCH DESIGN AND METHODS The presence of leptin receptors (ObR) was demonstrated by RT-PCR analysis, Western blot, and immunocytochemistry. Electrical activity was analyzed by patch-clamp and Ca2+ signals by confocal microscopy. Exocytosis and glucagon secretion were assessed using fluorescence methods and radioimmunoassay, respectively. RESULTS The expression of several ObR isoforms (a–e) was detected in glucagon-secreting αTC1-9 cells. ObRb, the main isoform involved in leptin signaling, was identified at the protein level in αTC1-9 cells as well as in mouse and human α-cells. The application of leptin (6.25 nmol/l) hyperpolarized the α-cell membrane potential, suppressing the electrical activity induced by 0.5 mmol/l glucose. Additionally, leptin inhibited Ca2+ signaling in αTC1-9 cells and in mouse and human α-cells within intact islets. A similar result occurred with 0.625 nmol/l leptin. These effects were accompanied by a decrease in glucagon secretion from mouse islets and were counteracted by the phosphatidylinositol 3-kinase inhibitor, wortmannin, suggesting the involvement of this pathway in leptin action. CONCLUSIONS These results demonstrate that leptin inhibits α-cell function, and, thus, these cells are involved in the adipoinsular communication. PMID:19401420

CD155T/TIGIT Signaling Regulates CD8+ T-cell Metabolism and Promotes Tumor Progression in Human Gastric Cancer.

PubMed

He, Weiling; Zhang, Hui; Han, Fei; Chen, Xinlin; Lin, Run; Wang, Wei; Qiu, Haibo; Zhuang, Zhenhong; Liao, Qi; Zhang, Weijing; Cai, Qinbo; Cui, Yongmei; Jiang, Wenting; Wang, Han; Ke, Zunfu

2017-11-15

The T-cell surface molecule TIGIT is an immune checkpoint molecule that inhibits T-cell responses, but its roles in cancer are little understood. In this study, we evaluated the role TIGIT checkpoint plays in the development and progression of gastric cancer. We show that the percentage of CD8 T cells that are TIGIT + was increased in gastric cancer patients compared with healthy individuals. These cells showed functional exhaustion with impaired activation, proliferation, cytokine production, and metabolism, all of which were rescued by glucose. In addition, gastric cancer tissue and cell lines expressed CD155, which bound TIGIT receptors and inactivated CD8 T cells. In a T cell-gastric cancer cell coculture system, gastric cancer cells deprived CD8 T cells of glucose and impaired CD8 T-cell effector functions; these effects were neutralized by the additional glucose or by TIGIT blockade. In gastric cancer tumor cells, CD155 silencing increased T-cell metabolism and IFNγ production, whereas CD155 overexpression inhibited T-cell metabolism and IFNγ production; this inhibition was neutralized by TIGIT blockade. Targeting CD155/TIGIT enhanced CD8 T-cell reaction and improved survival in tumor-bearing mice. Combined targeting of TIGIT and PD-1 further enhanced CD8 T-cell activation and improved survival in tumor-bearing mice. Our results suggest that gastric cancer cells inhibit CD8 T-cell metabolism through CD155/TIGIT signaling, which inhibits CD8 T-cell effector functions, resulting in hyporesponsive antitumor immunity. These findings support the candidacy of CD155/TIGIT as a potential therapeutic target in gastric cancer. Cancer Res; 77(22); 6375-88. ©2017 AACR . ©2017 American Association for Cancer Research.

Recent progresses in biomedical applications of aptamer-functionalized systems.

PubMed

Ding, Fei; Gao, Yangguang; He, Xianran

2017-09-15

Aptamers, known as "chemical antibodies" are screened via a combinational technology of systematic evolution of ligands by exponential enrichment (SELEX). Due to their specific targeting ability, high binding affinity, low immunogenicity and easy modification, aptamer-functionalized systems have been extensively applied in various fields and exhibit favorable results. However, there is still a long way for them to be commercialized, and few aptamer-functionalized systems have yet successfully entered clinical and industrial use. Thus, it is necessary to overview the recent research progresses of aptamer-functionalized systems for the researchers to improve or design novel and better aptamer-functionalized systems. In this review, we first introduce the recent progresses of aptamer-functionalized systems' applications in biosensing, targeted drug delivery, gene therapy and cancer cell imaging, followed by a discussion of the challenges faced with extensive applications of aptamer-functionalized systems and speculation of the future prospects of them. Copyright © 2017 Elsevier Ltd. All rights reserved.

The flavivirus capsid protein: Structure, function and perspectives towards drug design.

PubMed

Oliveira, Edson R A; Mohana-Borges, Ronaldo; de Alencastro, Ricardo B; Horta, Bruno A C

2017-01-02

Flaviviruses, such as dengue and zika viruses, are etiologic agents transmitted to humans mainly by arthropods and are of great epidemiological interest. The flavivirus capsid protein is a structural element required for the viral nucleocapsid assembly that presents the classical function of sheltering the viral genome. After decades of research, many reports have shown its different functionalities and influence over cell normal functioning. The subcellular distribution of this protein, which involves accumulation around lipid droplets and nuclear localization, also corroborates with its multi-functional characteristic. As flavivirus diseases are still in need of global control and in view of the possible key functionalities that the capsid protein promotes over flavivirus biology, novel considerations arise towards anti-flavivirus drug research. This review covers the main aspects concerning structural and functional features of the flavivirus C protein, ultimately, highlighting prospects in drug discovery based on this viral target. Copyright © 2016 Elsevier B.V. All rights reserved.

Human skin dendritic cells in health and disease.

PubMed

Haniffa, Muzlifah; Gunawan, Merry; Jardine, Laura

2015-02-01

Dendritic cells (DCs) are specialized antigen presenting cells abundant in peripheral tissues such as skin where they function as immune sentinels. Skin DCs migrate to draining lymph node where they interact with naïve T cells to induce immune responses to microorganisms, vaccines, tumours and self-antigens. In this review, we present the key historical developments and recent advances in human skin DC research. We also integrate the current understanding on the origin and functional specializations of DC subsets in healthy skin with findings in inflammatory skin diseases focusing on psoriasis and atopic eczema. A comprehensive understanding of the dynamic changes in DC subsets in health and disease will form a strong foundation to facilitate the clinical translation of DC-based therapeutic and vaccination strategies. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Type 1 Diabetes and NKT Cells: A Report on the 3rd International Workshop on NKT Cells and CD1-Mediated Antigen Presentation, September 2004, Heron Island, QLD, Australia

PubMed Central

Fletcher, Julie M.; Jordan, Margaret A.; Baxter, Alan G.

2004-01-01

NKT cells play a major role in regulating the vigor and character of a broad range of immune responses. Defects in NKT cell numbers and function have been associated with type 1 diabetes, especially in the NOD mouse model. The 3rd International Workshop on NKT Cells and CD1-Mediated Antigen Presentation provided an opportunity for researchers in the field of NKT cell biology to discuss their latest results, many of which have direct relevance to understanding the etiology and pathogenesis of diabetes. PMID:17491677

Adult mesenchymal stem cells and cell-based tissue engineering

PubMed Central

Tuan, Rocky S; Boland, Genevieve; Tuli, Richard

2003-01-01

The identification of multipotential mesenchymal stem cells (MSCs) derived from adult human tissues, including bone marrow stroma and a number of connective tissues, has provided exciting prospects for cell-based tissue engineering and regeneration. This review focuses on the biology of MSCs, including their differentiation potentials in vitro and in vivo, and the application of MSCs in tissue engineering. Our current understanding of MSCs lags behind that of other stem cell types, such as hematopoietic stem cells. Future research should aim to define the cellular and molecular fingerprints of MSCs and elucidate their endogenous role(s) in normal and abnormal tissue functions. PMID:12716446

Emerging Mitochondrial Therapeutic Targets in Optic Neuropathies.

PubMed

Lopez Sanchez, M I G; Crowston, J G; Mackey, D A; Trounce, I A

2016-09-01

Optic neuropathies are an important cause of blindness worldwide. The study of the most common inherited mitochondrial optic neuropathies, Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) has highlighted a fundamental role for mitochondrial function in the survival of the affected neuron-the retinal ganglion cell. A picture is now emerging that links mitochondrial dysfunction to optic nerve disease and other neurodegenerative processes. Insights gained from the peculiar susceptibility of retinal ganglion cells to mitochondrial dysfunction are likely to inform therapeutic development for glaucoma and other common neurodegenerative diseases of aging. Despite it being a fast-evolving field of research, a lack of access to human ocular tissues and limited animal models of mitochondrial disease have prevented direct retinal ganglion cell experimentation and delayed the development of efficient therapeutic strategies to prevent vision loss. Currently, there are no approved treatments for mitochondrial disease, including optic neuropathies caused by primary or secondary mitochondrial dysfunction. Recent advances in eye research have provided important insights into the molecular mechanisms that mediate pathogenesis, and new therapeutic strategies including gene correction approaches are currently being investigated. Here, we review the general principles of mitochondrial biology relevant to retinal ganglion cell function and provide an overview of the major optic neuropathies with mitochondrial involvement, LHON and ADOA, whilst highlighting the emerging link between mitochondrial dysfunction and glaucoma. The pharmacological strategies currently being trialed to improve mitochondrial dysfunction in these optic neuropathies are discussed in addition to emerging therapeutic approaches to preserve retinal ganglion cell function. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of psycho-behavioral interventions on immune functioning in cancer patients: a systematic review.

PubMed

Tong, Guixian; Geng, Qingqing; Cheng, Jing; Chai, Jing; Xia, Yi; Feng, Rui; Zhang, Lu; Wang, Debin

2014-01-01

This study aimed at summarizing evidence about effects of psycho-behavioral interventions (PBIs) on immune responses among cancer patients and analyzing quality of published studies so as to inform future researches. Literature retrieval utilized both highly inclusive algorithms searching randomized controlled studies published in English and Chinese and manual searching of eligible studies from references of relevant review papers. Two researchers examined the articles selected separately and extracted the information using a pre-designed form for soliciting data about the trials (e.g., sample size, disease status, intervention, immune responses) and quality ratings of the studies. Both narrative descriptions and meta-analysis (via Review manager 5) were used synthesizing the effects of PBIs on immune responses among cancer patients and state of art of the researches in this area. Seventy-six RCTs met inclusion criteria. PBIs implemented were divided into three major categories including psychological state adjustment, physical activity and dietary modification. Immune indicators measured included CD4+ cells, CD8+ cells, CD4/CDC8+ ratio, CD3+ cells, NK cell activity, etc. Effects of PBIs on immune responses documented in individual papers were mixed and pooled analysis of CD4+ cells, CD4+/CD8+ ratio, CD3+ cells, NKCA, IgG, IgM and IL-2 showed modest effects. However, there were huge discrepancies in intervention effects between studies published in English and Chinese and the results should be interpreted with caution. Besides, most studies suffer from some quality flaws concerning blinding, randomization procedures, compliance, attrition and intention-to-treat analyses, etc. Although there are considerable evidences of PBI effects on some immune indicators, the effect sizes are modest and it is still premature to conclude whether PBIs have effects on immune functions among cancer patients. There is a clear need for much more rigorous efforts in this area and future researches should pay particular attention to intervention dose and focus, sample size and comparable immune measures.

Single-Walled Carbon Nanotubes in Solar Cells.

PubMed

Jeon, Il; Matsuo, Yutaka; Maruyama, Shigeo

2018-01-22

Photovoltaics, more generally known as solar cells, are made from semiconducting materials that convert light into electricity. Solar cells have received much attention in recent years due to their promise as clean and efficient light-harvesting devices. Single-walled carbon nanotubes (SWNTs) could play a crucial role in these devices and have been the subject of much research, which continues to this day. SWNTs are known to outperform multi-walled carbon nanotubes (MWNTs) at low densities, because of the difference in their optical transmittance for the same current density, which is the most important parameter in comparing SWNTs and MWNTs. SWNT films show semiconducting features, which make SWNTs function as active or charge-transporting materials. This chapter, consisting of two sections, focuses on the use of SWNTs in solar cells. In the first section, we discuss SWNTs as a light harvester and charge transporter in the photoactive layer, which are reviewed chronologically to show the history of the research progress. In the second section, we discuss SWNTs as a transparent conductive layer outside of the photoactive layer, which is relatively more actively researched. This section introduces SWNT applications in silicon solar cells, organic solar cells, and perovskite solar cells each, from their prototypes to recent results. As we go along, the science and prospects of the application of solar cells will be discussed.

Tissue matrix arrays for high throughput screening and systems analysis of cell function

PubMed Central

Beachley, Vince Z.; Wolf, Matthew T.; Sadtler, Kaitlyn; Manda, Srikanth S.; Jacobs, Heather; Blatchley, Michael; Bader, Joel S.; Pandey, Akhilesh; Pardoll, Drew; Elisseeff, Jennifer H.

2015-01-01

Cell and protein arrays have demonstrated remarkable utility in the high-throughput evaluation of biological responses; however, they lack the complexity of native tissue and organs. Here, we describe tissue extracellular matrix (ECM) arrays for screening biological outputs and systems analysis. We spotted processed tissue ECM particles as two-dimensional arrays or incorporated them with cells to generate three-dimensional cell-matrix microtissue arrays. We then investigated the response of human stem, cancer, and immune cells to tissue ECM arrays originating from 11 different tissues, and validated the 2D and 3D arrays as representative of the in vivo microenvironment through quantitative analysis of tissue-specific cellular responses, including matrix production, adhesion and proliferation, and morphological changes following culture. The biological outputs correlated with tissue proteomics, and network analysis identified several proteins linked to cell function. Our methodology enables broad screening of ECMs to connect tissue-specific composition with biological activity, providing a new resource for biomaterials research and translation. PMID:26480475

Lipid Cell Biology: A Focus on Lipids in Cell Division.

PubMed

Storck, Elisabeth M; Özbalci, Cagakan; Eggert, Ulrike S

2018-06-20

Cells depend on hugely diverse lipidomes for many functions. The actions and structural integrity of the plasma membrane and most organelles also critically depend on membranes and their lipid components. Despite the biological importance of lipids, our understanding of lipid engagement, especially the roles of lipid hydrophobic alkyl side chains, in key cellular processes is still developing. Emerging research has begun to dissect the importance of lipids in intricate events such as cell division. This review discusses how these structurally diverse biomolecules are spatially and temporally regulated during cell division, with a focus on cytokinesis. We analyze how lipids facilitate changes in cellular morphology during division and how they participate in key signaling events. We identify which cytokinesis proteins are associated with membranes, suggesting lipid interactions. More broadly, we highlight key unaddressed questions in lipid cell biology and techniques, including mass spectrometry, advanced imaging, and chemical biology, which will help us gain insights into the functional roles of lipids.

Oufti: An integrated software package for high-accuracy, high-throughput quantitative microscopy analysis

PubMed Central

Paintdakhi, Ahmad; Parry, Bradley; Campos, Manuel; Irnov, Irnov; Elf, Johan; Surovtsev, Ivan; Jacobs-Wagner, Christine

2016-01-01

Summary With the realization that bacteria display phenotypic variability among cells and exhibit complex subcellular organization critical for cellular function and behavior, microscopy has re-emerged as a primary tool in bacterial research during the last decade. However, the bottleneck in today’s single-cell studies is quantitative image analysis of cells and fluorescent signals. Here, we address current limitations through the development of Oufti, a stand-alone, open-source software package for automated measurements of microbial cells and fluorescence signals from microscopy images. Oufti provides computational solutions for tracking touching cells in confluent samples, handles various cell morphologies, offers algorithms for quantitative analysis of both diffraction and non-diffraction-limited fluorescence signals, and is scalable for high-throughput analysis of massive datasets, all with subpixel precision. All functionalities are integrated in a single package. The graphical user interface, which includes interactive modules for segmentation, image analysis, and post-processing analysis, makes the software broadly accessible to users irrespective of their computational skills. PMID:26538279

Dissecting mitochondrial apoptosis pathways by gain-of-function cell culture screens.

PubMed

Grimm, Stefan

2013-05-01

While more primitive organism such as Caenorhabditis elegans and Drosophila melanogaster feature a limited, and by now probably mostly known, array of basic cell death factors, the mammalian cell is replete with additional regulators of the cell's demise. This abundance of apoptosis mediators has made it imperative to set up a systematic inventory of mammalian cell death genes. Genetic screens in this biological system have recently uncovered the rich diversity of cell death signalling and have in particular highlighted mitochondria as an organelle loaded with apoptosis regulators. Many of the screens that have addressed this utilised the novel technique of RNA interference but some also looked at gain-of-functions with transfected cDNAs. Here we give an overview of the rationale for the latter approach, present the genes discovered by this strategy and in particular describe the involvement of mitochondria and their signalling pathways defined by those genes. Copyright © 2012 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

Neural stem cells and neuro/gliogenesis in the central nervous system: understanding the structural and functional plasticity of the developing, mature, and diseased brain.

PubMed

Yamaguchi, Masahiro; Seki, Tatsunori; Imayoshi, Itaru; Tamamaki, Nobuaki; Hayashi, Yoshitaka; Tatebayashi, Yoshitaka; Hitoshi, Seiji

2016-05-01

Neurons and glia in the central nervous system (CNS) originate from neural stem cells (NSCs). Knowledge of the mechanisms of neuro/gliogenesis from NSCs is fundamental to our understanding of how complex brain architecture and function develop. NSCs are present not only in the developing brain but also in the mature brain in adults. Adult neurogenesis likely provides remarkable plasticity to the mature brain. In addition, recent progress in basic research in mental disorders suggests an etiological link with impaired neuro/gliogenesis in particular brain regions. Here, we review the recent progress and discuss future directions in stem cell and neuro/gliogenesis biology by introducing several topics presented at a joint meeting of the Japanese Association of Anatomists and the Physiological Society of Japan in 2015. Collectively, these topics indicated that neuro/gliogenesis from NSCs is a common event occurring in many brain regions at various ages in animals. Given that significant structural and functional changes in cells and neural networks are accompanied by neuro/gliogenesis from NSCs and the integration of newly generated cells into the network, stem cell and neuro/gliogenesis biology provides a good platform from which to develop an integrated understanding of the structural and functional plasticity that underlies the development of the CNS, its remodeling in adulthood, and the recovery from diseases that affect it.

Mitochondria: more than just a powerhouse.

PubMed

McBride, Heidi M; Neuspiel, Margaret; Wasiak, Sylwia

2006-07-25

Pioneering biochemical studies have long forged the concept that the mitochondria are the 'energy powerhouse of the cell'. These studies, combined with the unique evolutionary origin of the mitochondria, led the way to decades of research focusing on the organelle as an essential, yet independent, functional component of the cell. Recently, however, our conceptual view of this isolated organelle has been profoundly altered with the discovery that mitochondria function within an integrated reticulum that is continually remodeled by both fusion and fission events. The identification of a number of proteins that regulate these activities is beginning to provide mechanistic details of mitochondrial membrane remodeling. However, the broader question remains regarding the underlying purpose of mitochondrial dynamics and the translation of these morphological transitions into altered functional output. One hypothesis has been that mitochondrial respiration and metabolism may be spatially and temporally regulated by the architecture and positioning of the organelle. Recent evidence supports and expands this idea by demonstrating that mitochondria are an integral part of multiple cell signaling cascades. Interestingly, proteins such as GTPases, kinases and phosphatases are involved in bi-directional communication between the mitochondrial reticulum and the rest of the cell. These proteins link mitochondrial function and dynamics to the regulation of metabolism, cell-cycle control, development, antiviral responses and cell death. In this review we will highlight the emerging evidence that provides molecular definition to mitochondria as a central platform in the execution of diverse cellular events.

Monitoring stem cells in phase contrast imaging

NASA Astrophysics Data System (ADS)

Lam, K. P.; Dempsey, K. P.; Collins, D. J.; Richardson, J. B.

2016-04-01

Understanding the mechanisms behind the proliferation of Mesenchymal Stem cells (MSCs) can offer a greater insight into the behaviour of these cells throughout their life cycles. Traditional methods of determining the rate of MSC differentiation rely on population based studies over an extended time period. However, such methods can be inadequate as they are unable to track cells as they interact; for example, in autologous cell therapies for osteoarthritis, the development of biological assays that could predict in vivo functional activity and biological action are particularly challenging. Here further research is required to determine non-histochemical biomarkers which provide correlations between cell survival and predictive functional outcome. This paper proposes using a (previously developed) advanced texture-based analysis algorithm to facilitate in vitro cells tracking using time-lapsed microscopy. The technique was adopted to monitor stem cells in the context of unlabelled, phase contrast imaging, with the goal of examining the cell to cell interactions in both monoculture and co-culture systems. The results obtained are analysed using established exploratory procedures developed for time series data and compared with the typical fluorescent-based approach of cell labelling. A review of the progress and the lessons learned are also presented.

The miR-290-295 cluster as multi-faceted players in mouse embryonic stem cells.

PubMed

Yuan, Kai; Ai, Wen-Bing; Wan, Lin-Yan; Tan, Xiao; Wu, Jiang-Feng

2017-01-01

Increasing evidence indicates that embryonic stem cell specific microRNAs (miRNAs) play an essential role in the early development of embryo. Among them, the miR-290-295 cluster is the most highly expressed in the mouse embryonic stem cells and involved in various biological processes. In this paper, we reviewed the research progress of the function of the miR-290-295 cluster in embryonic stem cells. The miR-290-295 cluster is involved in regulating embryonic stem cell pluripotency maintenance, self-renewal, and reprogramming somatic cells to an embryonic stem cell-like state. Moreover, the miR-290-295 cluster has a latent pro-survival function in embryonic stem cells and involved in tumourigenesis and senescence with a great significance. Elucidating the interaction between the miR-290-295 cluster and other modes of gene regulation will provide us new ideas on the biology of pluripotent stem cells. In the near future, the broad prospects of the miRNA cluster will be shown in the stem cell field, such as altering cell identities with high efficiency through the transient introduction of tissue-specific miRNA cluster.

Cell adhesion molecules in context

PubMed Central

2011-01-01

Cell adhesion molecules (CAMs) are now known to mediate much more than adhesion between cells and between cells and the extracellular matrix. Work by many researchers has illuminated their roles in modulating activation of molecules such as receptor tyrosine kinases, with subsequent effects on cell survival, migration and process extension. CAMs are also known to serve as substrates for proteases that can create diffusible fragments capable of signaling independently from the CAM. The diversity of interactions is further modulated by membrane rafts, which can co-localize or separate potential signaling partners to affect the likelihood of a given signaling pathway being activated. Given the ever-growing number of known CAMs and the fact that their heterophilic binding in cis or in trans can affect their interactions with other molecules, including membrane-bound receptors, one would predict a wide range of effects attributable to a particular CAM in a particular cell at a particular stage of development. The function(s) of a given CAM must therefore be considered in the context of the history of the cell expressing it and the repertoire of molecules expressed both by that cell and its neighbors. PMID:20948304

Natural Killer Cell Function and Dysfunction in Hepatitis C Virus Infection

PubMed Central

Holder, Kayla A.; Russell, Rodney S.; Grant, Michael D.

2014-01-01

Viruses must continually adapt against dynamic innate and adaptive responses of the host immune system to establish chronic infection. Only a small minority (~20%) of those exposed to hepatitis C virus (HCV) spontaneously clear infection, leaving approximately 200 million people worldwide chronically infected with HCV. A number of recent research studies suggest that establishment and maintenance of chronic HCV infection involve natural killer (NK) cell dysfunction. This relationship is illustrated in vitro by disruption of typical NK cell responses including both cell-mediated cytotoxicity and cytokine production. Expression of a number of activating NK cell receptors in vivo is also affected in chronic HCV infection. Thus, direct in vivo and in vitro evidence of compromised NK function in chronic HCV infection in conjunction with significant epidemiological associations between the outcome of HCV infection and certain combinations of NK cell regulatory receptor and class I human histocompatibility linked antigen (HLA) genotypes indicate that NK cells are important in the immune response against HCV infection. In this review, we highlight evidence suggesting that selective impairment of NK cell activity is related to establishment of chronic HCV infection. PMID:25057504

A difunctional squarylium indocyanine dye distinguishes dead cells through diverse staining of the cell nuclei/membranes.

PubMed

Li, Jie; Guo, Kunru; Shen, Jie; Yang, Wantai; Yin, Meizhen

2014-04-09

Functionalized fluorescent dyes have attracted great interest for the specific staining of subcellular organelles in multicellular organisms. A novel nanometer-sized water-soluble multi-functional squarylium indocyanine dye (D1) that contains four primary amines is synthesized. The dye exhibits good photostability, non-toxicity and biocompatibility. Isothermal titration calorimetry demonstrates that an affinity between D1 and DNA is higher than that between D1 and analogue of phospholipids. Analysis of circular dichroism spectra indicates that D1 targets to the DNA minor groove and aggregates to a helix. Because of the distinct affinity between the dye and subcellular organelles, the dye exhibits difunctional abilities to label the cell nuclei in fixed cells/tissue and the cell membranes in live cells/tissue. By combination of the two staining capabilities, the dye is further explored as a specific marker to distinguish apoptotic cells in live cells/tissue. The research opens a new way to design novel multifunctional dyes for life science applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Supportive development of functional tissues for biomedical research using the MINUSHEET® perfusion system

PubMed Central

2012-01-01

Functional tissues generated under in vitro conditions are urgently needed in biomedical research. However, the engineering of tissues is rather difficult, since their development is influenced by numerous parameters. In consequence, a versatile culture system was developed to respond the unmet needs. Optimal adhesion for cells in this system is reached by the selection of individual biomaterials. To protect cells during handling and culture, the biomaterial is mounted onto a MINUSHEET® tissue carrier. While adherence of cells takes place in the static environment of a 24 well culture plate, generation of tissues is accomplished in one of several available perfusion culture containers. In the basic version a continuous flow of always fresh culture medium is provided to the developing tissue. In a gradient perfusion culture container epithelia are exposed to different fluids at the luminal and basal sides. Another special container with a transparent lid and base enables microscopic visualization of ongoing tissue development. A further container exhibits a flexible silicone lid to apply force onto the developing tissue thereby mimicking mechanical load that is required for developing connective and muscular tissue. Finally, stem/progenitor cells are kept at the interface of an artificial polyester interstitium within a perfusion culture container offering for example an optimal environment for the spatial development of renal tubules. The system presented here was evaluated by various research groups. As a result a variety of publications including most interesting applications were published. In the present paper these data were reviewed and analyzed. All of the results point out that the cell biological profile of engineered tissues can be strongly improved, when the introduced perfusion culture technique is applied in combination with specific biomaterials supporting primary adhesion of cells. PMID:23369669

'The Right Time and the Right Place': An Interview with Jacques Miller.

PubMed

Anderson, Warwick

2016-01-01

Professor Jacques F.P. Miller spoke about his career in immunology with Warwick Anderson on 3 February 2014. Born in Nice, France, Miller attended high school and medical school in Sydney, Australia. As a Ph.D. student and postgraduate researcher in London, Miller discovered the immunological function of the thymus gland. Spending the rest of his career at the Walter and Eliza Hall Institute for Medical Research in Melbourne, Miller conducted pioneering research in lymphocyte population dynamics and the mechanisms of the human immune response. With Graham Mitchell, he demonstrated that mammalian lymphocytes can be divided into what became known as T cells and B cells, which interact to produce antibodies.

[Research advances in breastfeeding].

PubMed

Liu, Xi-Hong

2016-10-01

Human breast milk is the most natural and ideal food for the baby. Breastfeeding provides benefits for maternal and child health, child immune function, growth and development, and society. The operation of human milk bank and the use of donor human milk undoubtedly provides a new way of nutrition support for the preterm infants without their own mother's milk and a new kind of treatment for other diseases. Present research on the composition of breast milk focuses on the variety and quantity of proteins, bioactive substances, probiotics and cell population.Future research may focus on the bioactive substances, the mechanism of regulation and effect of cell population, the application of probiotics and the clinical application of donor human milk.

[P21-activated kinases and their role in the nervous system].

PubMed

Qin, Yuan; Ding, Yue-Min; Xia, Qiang

2012-12-25

P21-activated kinases (PAK) participate in a variety of important cellular activities, such as cytoskeleton remodeling, cell migration, cell cycle regulation, and apoptosis or survival. PAK also has an important impact on brain development, neuronal differentiation, and regulation of synaptic plasticity in the nervous system. PAK abnormalities result in diseases including cancer, Parkinson's disease (PD), Alzheimer's disease (AD) and neural retardation. Therefore, it is of vital physiological significance to investigate the neuronal function of PAK. In this paper we review the advancement of research on the neuronal biological function and the underlying mechanisms of PAK.

Aquaporins in Cardiovascular System.

PubMed

Tie, Lu; Wang, Di; Shi, Yundi; Li, Xuejun

2017-01-01

Recent studies have shown that some aquaporins (AQPs ), including AQP1, AQP4, AQP7 and AQP9, are expressed in endothelial cells, vascular smooth muscle cells and heart of cardiovascular system. These AQPs are involved in the cardiovascular function and in pathological process of related diseases, such as cerebral ischemia , congestion heart failure , hypertension and angiogenesis. Therefore, it is important to understand the accurate association between AQPs and cardiovascular system, which may provide novel approaches to prevent and treat related diseases. Here we will discuss the expression and physiological function of AQPs in cardiovascular system and summarize recent researches on AQPs related cardiovascular diseases.

Designer nanoparticle: nanobiotechnology tool for cell biology

NASA Astrophysics Data System (ADS)

Thimiri Govinda Raj, Deepak B.; Khan, Niamat Ali

2016-09-01

This article discusses the use of nanotechnology for subcellular compartment isolation and its application towards subcellular omics. This technology review significantly contributes to our understanding on use of nanotechnology for subcellular systems biology. Here we elaborate nanobiotechnology approach of using superparamagnetic nanoparticles (SPMNPs) optimized with different surface coatings for subcellular organelle isolation. Using pulse-chase approach, we review that SPMNPs interacted differently with the cell depending on its surface functionalization. The article focuses on the use of functionalized-SPMNPs as a nanobiotechnology tool to isolate high quality (both purity and yield) plasma membranes and endosomes or lysosomes. Such nanobiotechnology tool can be applied in generating subcellular compartment inventories. As a future perspective, this strategy could be applied in areas such as immunology, cancer and stem cell research.

Research Advances in Resistance to Platinum-based Chemotherapy in Lung Cancer.

PubMed

Zhang, Yajuan; Chang, De; Zhang, Jianpeng

2017-02-20

Platinum-based chemotherapy is the the cornerstone of treatment of many cancers. Combinations of platinum drugs with other agents are still the mainstream therapies for non-small cell lung cancer,showing significant effectiveness in an early phase. Along with the treatment,the tumor cells can become resistant to chemotherapy drugs,which affect the efficacy and prognosis. The mechanisms of drug resistance are complicated,including abnormal expressions of membrane proteins,enhanced DNA repair functions,abnormal regulation mechanisms of apoptosis,and enhanced cellular detoxification function. In this article we summarize some of the main mechanisms of platinum resistance in lung cancer cells,with an attempt to identify new potential target analogues or inhibitors and improve the efficacies of the combined use of platinum-based drugs.

Moving Toward the Light: Using New Technology to Answer Old Questions

PubMed Central

LUCITTI, JENNIFER L.; DICKINSON, MARY E.

2006-01-01

Fluorescence microscopy has become a principle methodology in the field of developmental biology. Recent technological advances have led to the design of high-speed and high-resolution confocal and multiphoton microscopes that enable researchers to obtain three- and four-dimensional information in living cells and whole embryos. Paralleling this progress, the development of stable and bright vital fluorescent probes has revolutionized the ability to track individual cells in vitro and in vivo and to visualize intercellular and subcellular molecular interactions in real time. Combining imaging modalities and labeling techniques that are increasingly unobtrusive to cell and whole animal function, our understanding of how proteins interact, tissues take form, and organs synchronize to create a functioning animal is reaching a whole new level. PMID:16690954

Designer nanoparticle: nanobiotechnology tool for cell biology.

PubMed

Thimiri Govinda Raj, Deepak B; Khan, Niamat Ali

2016-01-01

This article discusses the use of nanotechnology for subcellular compartment isolation and its application towards subcellular omics. This technology review significantly contributes to our understanding on use of nanotechnology for subcellular systems biology. Here we elaborate nanobiotechnology approach of using superparamagnetic nanoparticles (SPMNPs) optimized with different surface coatings for subcellular organelle isolation. Using pulse-chase approach, we review that SPMNPs interacted differently with the cell depending on its surface functionalization. The article focuses on the use of functionalized-SPMNPs as a nanobiotechnology tool to isolate high quality (both purity and yield) plasma membranes and endosomes or lysosomes. Such nanobiotechnology tool can be applied in generating subcellular compartment inventories. As a future perspective, this strategy could be applied in areas such as immunology, cancer and stem cell research.

Mesenchymal Stem/Progenitor Cells Derived from Articular Cartilage, Synovial Membrane and Synovial Fluid for Cartilage Regeneration: Current Status and Future Perspectives.

PubMed

Huang, Yi-Zhou; Xie, Hui-Qi; Silini, Antonietta; Parolini, Ornella; Zhang, Yi; Deng, Li; Huang, Yong-Can

2017-10-01

Large articular cartilage defects remain an immense challenge in the field of regenerative medicine because of their poor intrinsic repair capacity. Currently, the available medical interventions can relieve clinical symptoms to some extent, but fail to repair the cartilaginous injuries with authentic hyaline cartilage. There has been a surge of interest in developing cell-based therapies, focused particularly on the use of mesenchymal stem/progenitor cells with or without scaffolds. Mesenchymal stem/progenitor cells are promising graft cells for tissue regeneration, but the most suitable source of cells for cartilage repair remains controversial. The tissue origin of mesenchymal stem/progenitor cells notably influences the biological properties and therapeutic potential. It is well known that mesenchymal stem/progenitor cells derived from synovial joint tissues exhibit superior chondrogenic ability compared with those derived from non-joint tissues; thus, these cell populations are considered ideal sources for cartilage regeneration. In addition to the progress in research and promising preclinical results, many important research questions must be answered before widespread success in cartilage regeneration is achieved. This review outlines the biology of stem/progenitor cells derived from the articular cartilage, the synovial membrane, and the synovial fluid, including their tissue distribution, function and biological characteristics. Furthermore, preclinical and clinical trials focusing on their applications for cartilage regeneration are summarized, and future research perspectives are discussed.

Rotating microgravity-bioreactor cultivation enhances the hepatic differentiation of mouse embryonic stem cells on biodegradable polymer scaffolds.

PubMed

Wang, Yingjie; Zhang, Yunping; Zhang, Shichang; Peng, Guangyong; Liu, Tao; Li, Yangxin; Xiang, Dedong; Wassler, Michael J; Shelat, Harnath S; Geng, Yongjian

2012-11-01

Embryonic stem (ES) cells are pluripotent cells that are capable of differentiating all the somatic cell lineages, including those in the liver tissue. We describe the generation of functional hepatic-like cells from mouse ES (mES) cells using a biodegradable polymer scaffold and a rotating bioreactor that allows simulated microgravity. Cells derived from ES cells cultured in the three-dimensional (3D) culture system with exogenous growth factors and hormones can differentiate into hepatic-like cells with morphologic characteristics of typical mature hepatocytes. Reverse-transcription polymerase chain-reaction testing, Western blot testing, immunostaining, and flow cytometric analysis show that these cells express hepatic-specific genes and proteins during differentiation. Differentiated cells on scaffolds further exhibit morphologic traits and biomarkers characteristic of liver cells, including albumin production, cytochrome P450 activity, and low-density lipoprotein uptake. When these stem cell-bearing scaffolds are transplanted into severe combined immunodeficient mice, the 3D constructs remained viable, undergoing further differentiation and maturation of hepatic-like cells in vivo. In conclusion, the growth and differentiation of ES cells in a biodegradable polymer scaffold and a rotating microgravity bioreactor can yield functional and organizational hepatocytes useful for research involving bioartificial liver and engineered liver tissue.

Tunneling Nanotubes: Intimate Communication between Myeloid Cells.

PubMed

Dupont, Maeva; Souriant, Shanti; Lugo-Villarino, Geanncarlo; Maridonneau-Parini, Isabelle; Vérollet, Christel

2018-01-01

Tunneling nanotubes (TNT) are dynamic connections between cells, which represent a novel route for cell-to-cell communication. A growing body of evidence points TNT towards a role for intercellular exchanges of signals, molecules, organelles, and pathogens, involving them in a diverse array of functions. TNT form among several cell types, including neuronal cells, epithelial cells, and almost all immune cells. In myeloid cells (e.g., macrophages, dendritic cells, and osteoclasts), intercellular communication via TNT contributes to their differentiation and immune functions. Importantly, TNT enable myeloid cells to communicate with a targeted neighboring or distant cell, as well as with other cell types, therefore creating a complex variety of cellular exchanges. TNT also contribute to pathogen spread as they serve as "corridors" from a cell to another. Herein, we addressed the complexity of the definition and in vitro characterization of TNT in innate immune cells, the different processes involved in their formation, and their relevance in vivo . We also assess our current understanding of how TNT participate in immune surveillance and the spread of pathogens, with a particular interest for HIV-1. Overall, despite recent progress in this growing research field, we highlight that further investigation is needed to better unveil the role of TNT in both physiological and pathological conditions.

Rapamycin Monotherapy in Patients With Type 1 Diabetes Modifies CD4+CD25+FOXP3+ Regulatory T-Cells

PubMed Central

Monti, Paolo; Scirpoli, Miriam; Maffi, Paola; Piemonti, Lorenzo; Secchi, Antonio; Bonifacio, Ezio; Roncarolo, Maria-Grazia; Battaglia, Manuela

2008-01-01

OBJECTIVE—Rapamycin is an immunosuppressive drug currently used to prevent graft rejection in humans, which is considered permissive for tolerance induction. Rapamycin allows expansion of both murine and human naturally occurring CD4+CD25+FOXP3+ T regulatory cells (nTregs), which are pivotal for the induction and maintenance of peripheral tolerance. Preclinical murine models have shown that rapamycin enhances nTreg proliferation and regulatory function also in vivo. Objective of this study was to assess whether rapamycin has in vivo effects on human nTregs. RESEARCH DESIGN AND METHODS—nTreg numbers and function were examined in a unique set of patients with type 1 diabetes who underwent rapamycin monotherapy before islet transplantation. RESULTS—We found that rapamycin monotherapy did not alter the frequency and functional features, namely proliferation and cytokine production, of circulating nTregs. However, nTregs isolated from type 1 diabetic patients under rapamycin treatment had an increased capability to suppress proliferation of CD4+CD25− effector T-cells compared with that before treatment. CONCLUSIONS—These findings demonstrate that rapamycin directly affects human nTreg function in vivo, which consists of refitting their suppressive activity, whereas it does not directly change effector T-cell function. PMID:18559659

Functional imaging of microdomains in cell membranes.

PubMed

Duggan, James; Jamal, Ghadir; Tilley, Mark; Davis, Ben; McKenzie, Graeme; Vere, Kelly; Somekh, Michael G; O'Shea, Paul; Harris, Helen

2008-10-01

The presence of microdomains or rafts within cell membranes is a topic of intense study and debate. The role of these structures in cell physiology, however, is also not yet fully understood with many outstanding problems. This problem is partly based on the small size of raft structures that presents significant problems to their in vivo study, i.e., within live cell membranes. But the structure and dynamics as well as the factors that control the assembly and disassembly of rafts are also of major interest. In this review we outline some of the problems that the study of rafts in cell membranes present as well as describing some views of what are considered the generalised functions of membrane rafts. We point to the possibility that there may be several different 'types' of membrane raft in cell membranes and consider the factors that affect raft assembly and disassembly, particularly, as some researchers suggest that the lifetimes of rafts in cell membranes may be sub-second. We attempt to review some of the methods that offer the ability to interrogate rafts directly as well as describing factors that appear to affect their functionality. The former include both near-field and far-field optical approaches as well as scanning probe techniques. Some of the advantages and disadvantages of these techniques are outlined. Finally, we describe our own views of raft functionality and properties, particularly, concerning the membrane dipole potential, and describe briefly some of the imaging strategies we have developed for their study.

Discovery of the cell-penetrating function of A2 domain derived from LTA subunit of Escherichia coli heat-labile enterotoxin.

PubMed

Liu, Di; Guo, Hua; Zheng, Wenyun; Zhang, Na; Wang, Tianwen; Wang, Ping; Ma, Xingyuan

2016-06-01

Heat-labile enterotoxin (LT) is a protein toxin produced by enterotoxigenic Escherichia coli (ETEC). As a bacterial toxin, LT holotoxin can enter intestinal epithelial cells and cause diarrhea. In addition, LT is also a powerful mucosal adjuvant capable of enhancing the strong immune responses to co-administered antigens. However, the LT immunological mechanism is still not clear in some aspects, especially with the respect to how the LTA subunit functions alone. Here, we discovered that the A2 domain of LTA could carry a fluorescent protein into cells, whose function is similar to a cell-penetrating peptide. The transmembrane-transporting ability of the A2 domain is non-specific in its cell-penetrating function, which was shown through testing with different cell types. Moreover, the LTA2 fusion protein penetrated a fluorescently labeled cell membrane that identified LTA2 internalization through membrane transport pathways, and showed it finally localized in the endoplasmic reticulum. Furthermore, low-temperature stress and pharmacological agent treatments showed that the LTA2 internalization route is a temperature-dependent process involving the clathrin-mediated endocytosis and the macropinocytosis pathways. These results could explain the internalization of the LTA subunit alone without the LTB pentamer, contributing to a better understanding of LTA working as a mucosal adjuvant; they also suggest that the A2 domain could be used as a novel transport vehicle for research and treatment of disease.

Noncoding Effects of Circular RNA CCDC66 Promote Colon Cancer Growth and Metastasis.

PubMed

Hsiao, Kuei-Yang; Lin, Ya-Chi; Gupta, Sachin Kumar; Chang, Ning; Yen, Laising; Sun, H Sunny; Tsai, Shaw-Jenq

2017-05-01

Circular RNA (circRNA) is a class of noncoding RNA whose functions remain mostly unknown. Recent studies indicate circRNA may be involved in disease pathogenesis, but direct evidence is scarce. Here, we characterize the functional role of a novel circRNA, circCCDC66, in colorectal cancer. RNA-Seq data from matched normal and tumor colon tissue samples identified numerous circRNAs specifically elevated in cancer cells, several of which were verified by quantitative RT-PCR. CircCCDC66 expression was elevated in polyps and colon cancer and was associated with poor prognosis. Gain-of-function and loss-of-function studies in colorectal cancer cell lines demonstrated that circCCDC66 controlled multiple pathological processes, including cell proliferation, migration, invasion, and anchorage-independent growth. In-depth characterization revealed that circCCDC66 exerts its function via regulation of a subset of oncogenes, and knockdown of circCCDC66 inhibited tumor growth and cancer invasion in xenograft and orthotopic mouse models, respectively. Taken together, these findings highlight a novel oncogenic function of circRNA in cancer progression and metastasis. Cancer Res; 77(9); 2339-50. ©2017 AACR . ©2017 American Association for Cancer Research.

The structure and function of cell membranes studied by atomic force microscopy.

PubMed

Shi, Yan; Cai, Mingjun; Zhou, Lulu; Wang, Hongda

2018-01-01

The cell membrane, involved in almost all communications of cells and surrounding matrix, is one of the most complicated components of cells. Lack of suitable methods for the detection of cell membranes in vivo has sparked debates on the biochemical composition and structure of cell membranes over half a century. The development of single molecule techniques, such as AFM, SMFS, and TREC, provides a versatile platform for imaging and manipulating cell membranes in biological relevant environments. Here, we discuss the latest developments in AFM and the progress made in cell membrane research. In particular, we highlight novel structure models and dynamic processes, including the mechanical properties of the cell membranes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of the functional role of CSLD proteins in plant cell wall deposition

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

Nielsen, Erik Etlar

The overall goal of this research proposal was to characterize the molecular machinery responsible for polarized secretion of cell wall components in Arabidopsis thaliana. We have used the polarized expansion that occurs during root hair cell growth to identify membrane trafficking pathways involved in polarized secretion of cell wall components to the expanding tips of these cells, and we have recently shown that CSLD3 is preferentially targeted to the apical plasma membranes in root hair cells, where it plays essential roles during cell wall deposition in these cells. The specific aims of the project are designed to answer the followingmore » objective: Identification of the cell wall polysaccharide class that CSLD proteins synthesize.« less

Engineering mesenchymal stem cells for regenerative medicine and drug delivery.

PubMed

Park, Ji Sun; Suryaprakash, Smruthi; Lao, Yeh-Hsing; Leong, Kam W

2015-08-01

Researchers have applied mesenchymal stem cells (MSC) to a variety of therapeutic scenarios by harnessing their multipotent, regenerative, and immunosuppressive properties with tropisms toward inflamed, hypoxic, and cancerous sites. Although MSC-based therapies have been shown to be safe and effective to a certain degree, the efficacy remains low in most cases when MSC are applied alone. To enhance their therapeutic efficacy, researchers have equipped MSC with targeted delivery functions using genetic engineering, therapeutic agent incorporation, and cell surface modification. MSC can be genetically modified virally or non-virally to overexpress therapeutic proteins that complement their innate properties. MSC can also be primed with non-peptidic drugs or magnetic nanoparticles for enhanced efficacy and externally regulated targeting, respectively. Furthermore, MSC can be functionalized with targeting moieties to augment their homing toward therapeutic sites using enzymatic modification, chemical conjugation, or non-covalent interactions. These engineering techniques are still works in progress, requiring optimization to improve the therapeutic efficacy and targeting effectiveness while minimizing any loss of MSC function. In this review, we will highlight the advanced techniques of engineering MSC, describe their promise and the challenges of translation into clinical settings, and suggest future perspectives on realizing their full potential for MSC-based therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Construction of human induced pluripotent stem cell-derived oriented bone matrix microstructure by using in vitro engineered anisotropic culture model.

PubMed

Ozasa, Ryosuke; Matsugaki, Aira; Isobe, Yoshihiro; Saku, Taro; Yun, Hui-Suk; Nakano, Takayoshi

2018-02-01

Bone tissue has anisotropic microstructure based on collagen/biological apatite orientation, which plays essential roles in the mechanical and biological functions of bone. However, obtaining an appropriate anisotropic microstructure during the bone regeneration process remains a great challenging. A powerful strategy for the control of both differentiation and structural development of newly-formed bone is required in bone tissue engineering, in order to realize functional bone tissue regeneration. In this study, we developed a novel anisotropic culture model by combining human induced pluripotent stem cells (hiPSCs) and artificially-controlled oriented collagen scaffold. The oriented collagen scaffold allowed hiPSCs-derived osteoblast alignment and further construction of anisotropic bone matrix which mimics the bone tissue microstructure. To the best of our knowledge, this is the first report showing the construction of bone mimetic anisotropic bone matrix microstructure from hiPSCs. Moreover, we demonstrated for the first time that the hiPSCs-derived osteoblasts possess a high level of intact functionality to regulate cell alignment. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 360-369, 2018. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

Functionalized gold nanorods for molecular optoacoustic imaging

NASA Astrophysics Data System (ADS)

Eghtedari, Mohammad; Oraevsky, Alexander; Conjusteau, Andre; Copland, John A.; Kotov, Nicholas A.; Motamedi, Massoud

2007-02-01

The development of gold nanoparticles for molecular optoacoustic imaging is a very promising area of research and development. Enhancement of optoacoustic imaging for molecular detection of tumors requires the engineering of nanoparticles with geometrical and molecular features that can enhance selective targeting of malignant cells while optimizing the sensitivity of optoacoustic detection. In this article, cylindrical gold nanoparticles (i.e. gold nanorods) were fabricated with a plasmon resonance frequency in the near infra-red region of the spectrum, where deep irradiation of tissue is possible using an Alexandrite laser. Gold nanorods (Au-NRs) were functionalized by covalent attachment of Poly(ethylene glycol) to enhance their biocompatibility. These particles were further functionalized with the aim of targeting breast cancer cells using monoclonal antibodies that binds to Her2/neu receptors, which are over expressed on the surface of breast cancer cells. A custom Laser Optoacoustic Imaging System (LOIS) was designed and employed to image nanoparticle-targeted cancer cells in a phantom and PEGylated Au-NRs that were injected subcutaneously into a nude mouse. The results of our experiments show that functionalized Au-NRs with a plasmon resonance frequency at near infra-red region of the spectrum can be detected and imaged in vivo using laser optoacoustic imaging system.

Conserved form and function of the germinal epithelium through 500 million years of vertebrate evolution.

PubMed

Grier, Harry J; Uribe, Mari Carmen; Lo Nostro, Fabiana L; Mims, Steven D; Parenti, Lynne R

2016-08-01

The germinal epithelium, i.e., the site of germ cell production in males and females, has maintained a constant form and function throughout 500 million years of vertebrate evolution. The distinguishing characteristic of germinal epithelia among all vertebrates, males, and females, is the presence of germ cells among somatic epithelial cells. The somatic epithelial cells, Sertoli cells in males or follicle (granulosa) cells in females, encompass and isolate germ cells. Morphology of all vertebrate germinal epithelia conforms to the standard definition of an epithelium: epithelial cells are interconnected, border a body surface or lumen, are avascular and are supported by a basement membrane. Variation in morphology of gonads, which develop from the germinal epithelium, is correlated with the evolution of reproductive modes. In hagfishes, lampreys, and elasmobranchs, the germinal epithelia of males produce spermatocysts. A major rearrangement of testis morphology diagnoses osteichthyans: the spermatocysts are arranged in tubules or lobules. In protogynous (female to male) sex reversal in teleost fishes, female germinal epithelial cells (prefollicle cells) and oogonia transform into the first male somatic cells (Sertoli cells) and spermatogonia in the developing testis lobules. This common origin of cell types from the germinal epithelium in fishes with protogynous sex reversal supports the homology of Sertoli cells and follicle cells. Spermatogenesis in amphibians develops within spermatocysts in testis lobules. In amniotes vertebrates, the testis is composed of seminiferous tubules wherein spermatogenesis occurs radially. Emerging research indicates that some mammals do not have lifetime determinate fecundity. The fact emerged that germinal epithelia occur in the gonads of all vertebrates examined herein of both sexes and has the same form and function across all vertebrate taxa. Continued study of the form and function of the germinal epithelium in vertebrates will increasingly clarify our understanding of vertebrate reproduction. J. Morphol. 277:1014-1044, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Fueling dreams of grandeur: Fuel cell research and development and the pursuit of the technological panacea, 1940--2005

NASA Astrophysics Data System (ADS)

Eisler, Matthew Nicholas

The record of fuel cell research and development is one of the great enigmas in the history of science and technology. For years, this electrochemical power source, which combines hydrogen and oxygen to produce electricity and waste water, excited the imaginations of researchers in many countries. Because fuel cells directly convert chemical into electrical energy, people have long believed them exempt from the so-called Carnot cycle limitation on heat engines, which dictates that such devices must operate at less than 100 per cent efficiency owing to the randomization of energy as heat. Fuel cells have thus struck some scientists and engineers as the "magic bullet" of energy technologies. This dissertation explores why people have not been able to develop a cheap, durable commercial fuel cell despite more than 50 years of concerted effort since the end of Second World War. I argue this is so mainly because expectations have always been higher than the knowledge base. I investigate fuel cell research and development communities as central nodes of expectation generation. They have functioned as a nexus where the physical realities of fuel cell technology meet external factors, those political, economic and cultural pressures that create a "need" for a "miracle" power source. The unique economic exigencies of these communities have shaped distinct material practices that have done much to inform popular ideas of the capabilities of fuel cell technology. After the Second World War, the fuel cell was relatively unknown in industrial and governmental science and technology circles. Researchers in most leading industrialized countries, above all the United States, sought to raise the technology's profile through dramatic demonstrations in reductive circumstances, employing notional fuel cells using pure hydrogen and oxygen. Researchers paid less attention to cost and durability, concentrating on increasing power output, a criterion that could be met relatively easily in controlled conditions. While such demonstrations typically led to short-term investments in further research, they also generated expectations for long-lived and affordable fuel cells using hydrocarbons. However, developing commercial fuel cell technology was an expensive and arduous process, one that few sponsors were willing to support for long in the absence of rapid progress. Despite this mixed record, the fuel cell has become a powerful symbol of technological perfection that continues to inspire further research and dreams of energy plenitude.

Immune repertoire: A potential biomarker and therapeutic for hepatocellular carcinoma.

PubMed

Han, Yingxin; Li, Hongmei; Guan, Yanfang; Huang, Jian

2016-09-01

The immune repertoire (IR) refers to the sum of B cells and T cells with functional diversity in the circulatory system of one individual at any given time. Immune cells, which reside within microenvironments and are responsible for protecting the human body, include T cells, B cells, macrophages, and dendritic cells. These dedicated immune cells have a characteristic structure and function. T and B cells are the main lymphocytes and are responsible for cellular immunity and humoral immunity, respectively. The T cell receptor (TCR) and B cell receptor (BCR) are composed of multiple peptide chains with antigen specificity. The amino acid composition and sequence order are more diverse in the complementarity-determining regions (including CDR1, CDR2 and CDR3) of each peptide chain, allowing a vast library of TCRs and BCRs. IR research is becoming increasingly focused on the study of CDR3 diversity. Deep profiling of CDR3s using high-throughput sequencing is a powerful approach for elucidating the composition and distribution of the CDR3s in a given sample, with in-depth information at the sequence level. Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. To identify novel biomarkers for diagnosis and drug targets for therapeutic interventions, several groups attempted to describe immune repertoire characteristics of the liver in the physiological environment or/and pathological conditions. This paper reviews the recent progress in IR research on human diseases, including hepatocellular carcinoma, attempting to depict the relationships between hepatocellular carcinogenesis and the IR, and discusses the possibility of IR as a potential biomarker and therapeutic for hepatocellular carcinoma. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Integration of Genomic, Biologic, and Chemical Approaches to Target p53 Loss and Gain-of-Function in Triple Negative Breast Cancer

DTIC Science & Technology

2014-09-01

in this renewal: p53 triple negative breast cancer subtypes gene expression somatic cell genetics CRISPR /Cas 3. OVERALL PROJECT SUMMARY...to the efficacy of the synthetic lethality screen. In addition, we have optimized the use of CRISPR /Cas, a novel somatic cell recombination...completing this stage of the research within the upcoming Year 2 of the award period. Figure 1. CRISPR /Cas-mediated in vitro somatic cell

Poppers: large cancer increase and immune suppression in animal tests.

PubMed

James, J S

1999-04-16

A study on mice injected with cancer cells and then exposed to isobutyl nitrite (poppers) revealed that inhalant-treated mice developed tumors more readily and rapidly than control mice. The control mice were also injected with cancer cells, but only breathed air. Related studies found that poppers suppress certain immune functions involved in killing tumor cells. These studies suggest that further research of persons with HIV/AIDS who use poppers is needed to determine if they are at a high risk for developing malignancies.

Relaxation dynamics of light-induced photon emission by mammalian cells and nuclei

NASA Astrophysics Data System (ADS)

Van Wijk, R.; Van Aken, J. M.; Laerdal, H. E.; Souren, J. E. M.

1995-12-01

Photon emission from mammalian cells has been the subject of study for many years. Throughout the history of this field of research the question of a functional biological role of the low intensity emission has been repeatedly raised. The discussion concerns the possible participation of biophotons in intra- and intercellular communication. In this paper we consider the significance of the studies on light-induced photon emission of isolated mammalian cells. Furthermore we report on the source of this light-induced photon emission.

Generation of a new Gateway-compatible inducible lentiviral vector platform allowing easy derivation of co-transduced cells.

PubMed

De Groote, Philippe; Grootjans, Sasker; Lippens, Saskia; Eichperger, Chantal; Leurs, Kirsten; Kahr, Irene; Tanghe, Giel; Bruggeman, Inge; De Schamphelaire, Wouter; Urwyler, Corinne; Vandenabeele, Peter; Haustraete, Jurgen; Declercq, Wim

2016-01-01

In contrast to most common gene delivery techniques, lentiviral vectors allow targeting of almost any mammalian cell type, even non-dividing cells, and they stably integrate in the genome. Therefore, these vectors are a very powerful tool for biomedical research. Here we report the generation of a versatile new set of 22 lentiviral vectors with broad applicability in multiple research areas. In contrast to previous systems, our platform provides a choice between constitutive and/or conditional expression and six different C-terminal fusions. Furthermore, two compatible selection markers enable the easy derivation of stable cell lines co-expressing differently tagged transgenes in a constitutive or inducible manner. We show that all of the vector features are functional and that they contribute to transgene overexpression in proof-of-principle experiments.

Pathways over Time: Functional Genomics Research in an Introductory Laboratory Course.

PubMed

Reeves, Todd D; Warner, Douglas M; Ludlow, Larry H; O'Connor, Clare M

2018-01-01

National reports have called for the introduction of research experiences throughout the undergraduate curriculum, but practical implementation at many institutions faces challenges associated with sustainability, cost, and large student populations. We describe a novel course-based undergraduate research experience (CURE) that introduces introductory-level students to research in functional genomics in a 3-credit, multisection laboratory class. In the Pathways over Time class project, students study the functional conservation of the methionine biosynthetic pathway between divergent yeast species. Over the five semesters described in this study, students ( N = 793) showed statistically significant and sizable growth in content knowledge ( d = 1.85) and in self-reported research methods skills ( d = 0.65), experimental design, oral and written communication, database use, and collaboration. Statistical analyses indicated that content knowledge growth was larger for underrepresented minority students and that growth in content knowledge, but not research skills, varied by course section. Our findings add to the growing body of evidence that CUREs can support the scientific development of large numbers of students with diverse characteristics. The Pathways over Time project is designed to be sustainable and readily adapted to other institutional settings. © 2018 T. D. Reeves et al. CBE—Life Sciences Education © 2018 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

“Multi-Omics” Analyses of the Development and Function of Natural Killer Cells

PubMed Central

Zhou, Yonggang; Xu, Xiuxiu; Tian, Zhigang; Wei, Haiming

2017-01-01

For over four decades, our understanding of natural killer (NK) cells has evolved from the original description of cluster of differentiation (CD)56+CD3− to establishing NK cells as an important subset of innate lymphocytes in the host’s surveillance against viral infections and malignancy. The progress of research on the fundamental properties and therapeutic prospects for translational medicine using NK cells excites immunologists and clinicians. Over the past decade, numerous advances in “-omics”-scale methods and new technological approaches have addressed many essential questions in the biology of NK cells. We now have further understanding of the overall molecular mechanisms of action that determine the development, function, plasticity, diversity, and immune reactivity of NK cells. These findings are summarized here, and our view on how to study NK cells using “multi-omics” is highlighted. We also describe “-omics” analyses of the relationships between NK cells and viral infection, tumorigenesis, and autoimmune diseases. Ultimately, a deeper and more comprehensive understanding of NK cells in multiple conditions will provide more effective strategies to manipulate NK cells for the treatment of human disease. PMID:28928751

Role of the glucocorticoid-induced TNFR-related protein (GITR)-GITR ligand pathway in innate and adaptive immunity.

PubMed

Azuma, Miyuki

2010-01-01

Glucocorticoid-induced TNF receptor-related protein (GITR) is expressed in regulatory T cells at high levels, but is also inducible in conventional effector T cells after activation. Initial studies using an agonistic anti- GITR mAb mislead this line of research with respect to the contribution of GITR stimulation on the function of regulatory T cells. In fact, GITR acts as a costimulatory receptor for both effector and regulatory T cells by enhancing effector and regulatory functions, respectively. Unlike other costimulatory ligands, GITR ligand (GITRL) expression on mature myeloid dendritic cells (DCs) is extremely limited and the GITR-GITRL pathway does not contribute markedly to direct interactions with T cells and antigen-presenting cells in the secondary lymphoid tissues. Rather, GITRL is constitutively expressed on parenchymal tissue cells and interacts with GITR expressed on tissue-infiltrating macrophages and DCs, or effector and regulatory T cells. Interactions with GITR and GITRL at local inflammatory sites induce site-specific production of cytokines and chemokines, resulting in control activation of tissue-infiltrating effector or regulatory cells and their migration. This review summarizes recent reports on the GITR-GITRL pathway, which controls both innate and adaptive immune responses.

Dynamics and functions of CD4⁺CD25 (high) regulatory T lymphocytes in Chinese rhesus macaques during the early stage of infection with SIVmac239.

PubMed

Li, Shao-You; Xia, Hou-Jun; Dai, Zheng-Xi; Zhang, Gao-Hong; Fan, Bo; Li, Ming-Hua; Wang, Rui-Rui; Zheng, Yong-Tang

2012-05-01

CD4(+)CD25(high) regulatory T cells (Treg), which are a specialized subset of T cells, play an important role in the prevention of autoimmune diseases, maintenance of immune system homeostasis and tolerance to self-antigens. Chinese rhesus macaques (CRMs) are widely used in preclinical research on potential therapeutic drugs, vaccines and mechanisms of human diseases. However, the basic immunological characterization of Treg cells of CRMs has not been well established. To characterize Treg cells, peripheral blood of 43 adult CRMs was analyzed for CD4+ T lymphocytes by flow cytometry. It was found that Treg cells ranged from 1.52% to 11.1% of CD4+ T cells, and the average value was 5.7%. With our SIV-infected CRM model, through further studies, it was found that Treg cells in peripheral blood increased both in relative and absolute quantities. Moreover, Treg cells maintained their functions by suppressing Th1 cytokine secretion of their target cells. The results show that Treg cells might render cellular immunity against SIV viruses dysfunctional during the early stage after infection.

Off to the Organelles - Killing Cancer Cells with Targeted Gold Nanoparticles

PubMed Central

Kodiha, Mohamed; Wang, Yi Meng; Hutter, Eliza; Maysinger, Dusica; Stochaj, Ursula

2015-01-01

Gold nanoparticles (AuNPs) are excellent tools for cancer cell imaging and basic research. However, they have yet to reach their full potential in the clinic. At present, we are only beginning to understand the molecular mechanisms that underlie the biological effects of AuNPs, including the structural and functional changes of cancer cells. This knowledge is critical for two aspects of nanomedicine. First, it will define the AuNP-induced events at the subcellular and molecular level, thereby possibly identifying new targets for cancer treatment. Second, it could provide new strategies to improve AuNP-dependent cancer diagnosis and treatment. Our review summarizes the impact of AuNPs on selected subcellular organelles that are relevant to cancer therapy. We focus on the nucleus, its subcompartments, and mitochondria, because they are intimately linked to cancer cell survival, growth, proliferation and death. While non-targeted AuNPs can damage tumor cells, concentrating AuNPs in particular subcellular locations will likely improve tumor cell killing. Thus, it will increase cancer cell damage by photothermal ablation, mechanical injury or localized drug delivery. This concept is promising, but AuNPs have to overcome multiple hurdles to perform these tasks. AuNP size, morphology and surface modification are critical parameters for their delivery to organelles. Recent strategies explored all of these variables, and surface functionalization has become crucial to concentrate AuNPs in subcellular compartments. Here, we highlight the use of AuNPs to damage cancer cells and their organelles. We discuss current limitations of AuNP-based cancer research and conclude with future directions for AuNP-dependent cancer treatment. PMID:25699096

p53 as Batman: using a movie plot to understand control of the cell cycle.

PubMed

Gadi, Nikhita; Foley, Sage E; Nowey, Mark; Plopper, George E

2013-04-16

This Teaching Resource provides and describes a two-part classroom exercise to help students understand control of the cell cycle, with a focus on the transcription factor p53, the E3 ubiquitin ligase Mdm2, the Mdm2 inhibitor ARF, the kinases ATM and ATR, the kinase Chk2, and the cell cycle inhibitor p21(Cip1). Students use characters and scenes from the movie The Dark Knight to represent elements of the cell cycle control machinery, then they apply these characters and scenes to translate a primary research article on p53 function into a new movie scene in the "Batman universe." This exercise is appropriate for college-level courses in cell biology and cancer biology and requires students to have a background in introductory cell biology. Explicit learning outcomes and associated assessment methods are provided, as well as slides, student assignments, the primary research article, and an instructor's guide for the exercise.

Automated live cell screening system based on a 24-well-microplate with integrated micro fluidics.

PubMed

Lob, V; Geisler, T; Brischwein, M; Uhl, R; Wolf, B

2007-11-01

In research, pharmacologic drug-screening and medical diagnostics, the trend towards the utilization of functional assays using living cells is persisting. Research groups working with living cells are confronted with the problem, that common endpoint measurement methods are not able to map dynamic changes. With consideration of time as a further dimension, the dynamic and networked molecular processes of cells in culture can be monitored. These processes can be investigated by measuring several extracellular parameters. This paper describes a high-content system that provides real-time monitoring data of cell parameters (metabolic and morphological alterations), e.g., upon treatment with drug compounds. Accessible are acidification rates, the oxygen consumption and changes in adhesion forces within 24 cell cultures in parallel. Addressing the rising interest in biomedical and pharmacological high-content screening assays, a concept has been developed, which integrates multi-parametric sensor readout, automated imaging and probe handling into a single embedded platform. A life-maintenance system keeps important environmental parameters (gas, humidity, sterility, temperature) constant.

Blood Cell Interactions and Segregation in Flow

PubMed Central

Munn, Lance L.; Dupin, Michael M.

2009-01-01

For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall. PMID:18188702

Sensorimotor Functional and Structural Networks after Intracerebral Stem Cell Grafts in the Ischemic Mouse Brain.

PubMed

Green, Claudia; Minassian, Anuka; Vogel, Stefanie; Diedenhofen, Michael; Beyrau, Andreas; Wiedermann, Dirk; Hoehn, Mathias

2018-02-14

Past investigations on stem cell-mediated recovery after stroke have limited their focus on the extent and morphological development of the ischemic lesion itself over time or on the integration capacity of the stem cell graft ex vivo However, an assessment of the long-term functional and structural improvement in vivo is essential to reliably quantify the regenerative capacity of cell implantation after stroke. We induced ischemic stroke in nude mice and implanted human neural stem cells (H9 derived) into the ipsilateral cortex in the acute phase. Functional and structural connectivity changes of the sensorimotor network were noninvasively monitored using magnetic resonance imaging for 3 months after stem cell implantation. A sharp decrease of the functional sensorimotor network extended even to the contralateral hemisphere, persisting for the whole 12 weeks of observation. In mice with stem cell implantation, functional networks were stabilized early on, pointing to a paracrine effect as an early supportive mechanism of the graft. This stabilization required the persistent vitality of the stem cells, monitored by bioluminescence imaging. Thus, we also observed deterioration of the early network stabilization upon vitality loss of the graft after a few weeks. Structural connectivity analysis showed fiber-density increases between the cortex and white matter regions occurring predominantly on the ischemic hemisphere. These fiber-density changes were nearly the same for both study groups. This motivated us to hypothesize that the stem cells can influence, via early paracrine effect, the functional networks, while observed structural changes are mainly stimulated by the ischemic event. SIGNIFICANCE STATEMENT In recent years, research on strokes has made a shift away from a focus on immediate ischemic effects and towards an emphasis on the long-range effects of the lesion on the whole brain. Outcome improvements in stem cell therapies also require the understanding of their influence on the whole-brain networks. Here, we have longitudinally and noninvasively monitored the structural and functional network alterations in the mouse model of focal cerebral ischemia. Structural changes of fiber-density increases are stimulated in the endogenous tissue without further modulation by the stem cells, while functional networks are stabilized by the stem cells via a paracrine effect. These results will help decipher the underlying networks of brain plasticity in response to cerebral lesions and offer clues to unravelling the mystery of how stem cells mediate regeneration. Copyright © 2018 the authors 0270-6474/18/381648-14$15.00/0.

Therapeutic Targeting the Diverse Immunologic Functions Expressed by Hepatic NKT cells

PubMed Central

Duwaerts, Caroline C.; Gregory, Stephen H.

2011-01-01

Introduction NKT cells comprise approximately 30% of the hepatic lymphoid population in mice (~50% in humans). Most mouse hepatic NKT cells [invariant (i)NKT cells] express T cell receptors, composed of invariant Vα14Jα18 chains. Unlike conventional T cells, iNKT cells recognize glycolipid molecules presented in association with MHC class Ib (CD1d) molecules. Purportedly, iNKT cells serve a key function in a wide range of immunological events; the precise nature of this function is often unclear. Indeed, the consequences of hepatic iNKT cell activation can be beneficial or detrimental. α-Galactosylceramide, the prototypic glycolipid recognized by the iNKT cell receptor, stimulates the rapid production of both interferon-γ and interleukin-4. The reciprocal suppression exhibited by these cytokines limits the potential therapeutic value of α-galactosylceramide. An extensive research effort is ongoing to develop α-galactosylceramide analogs that modulate iNKT cell activity and selectively promote interferon-γ or interleukin-4. Areas covered This review provides a broad overview of hepatic iNKT cells and their purported role in liver disease. Efforts to develop therapeutic agents that promote their beneficial contributions are detailed. Expert Opinion While a growing body of literature documents the differential effects of α-GalCer analogs on IFN-γ and IL-4 production, the effects of these analogs on other iNKT cell activities, e.g., cytolysis and the production of other cytokines, remain to be determined. Similarly, an exhaustive examination of the effects of these analogs on inflammation and liver injury in animal models remains prior to considering their utility in clinical trials. PMID:21564001

Novel effector phenotype of Tim-3+ regulatory T cells leads to enhanced suppressive function in head and neck cancer patients.

PubMed

Liu, Zhuqing; McMichael, Elizabeth L; Shayan, Gulidanna; Li, Jing; Chen, Kevin; Srivastava, Raghvendra M; Kane, Lawrence P; Lu, Binfeng; Ferris, Robert L

2018-04-30

Regulatory T (Treg) cells are important suppressive cells among tumor infiltrating lymphocytes (TIL). Treg express the well-known immune checkpoint receptor PD-1, which is reported to mark "exhausted" Treg with lower suppressive function. T cell immunoglobulin mucin (Tim)-3, a negative regulator of Th1 immunity, is expressed by a sizeable fraction of TIL Tregs, but the functional status of Tim-3+ Tregs remains unclear. CD4+CTLA-4+CD25high Treg were sorted from freshly excised head and neck squamous cell carcinoma (HNSCC) TIL based on Tim-3 expression. Functional and phenotypic features of these Tim-3+ and Tim-3- TIL Tregs were tested by in vitro suppression assays and multi-color flow cytometry. Gene expression profiling and NanoString analysis of Tim-3+ TIL Treg were performed. A murine HNSCC tumor model was used to test the effect of anti-PD-1 immunotherapy on Tim-3+ Treg.  Results: Despite high PD-1 expression, Tim-3+ TIL Treg displayed a greater capacity to inhibit naïve T cell proliferation than Tim-3- Treg. Tim-3+ Treg from human HNSCC TIL also displayed an effector-like phenotype, with more robust expression of CTLA-4, PD-1, CD39 and IFN-γ receptor. Exogenous IFN-γ treatment could partially reverse the suppressive function of Tim-3+ TIL Treg. Anti-PD-1 immunotherapy downregulated Tim-3 expression on Tregs isolated from murine HNSCC tumors, and this treatment reversed the suppressive function of HNSCC TIL Tregs. Tim-3+ Treg are functionally and phenotypically distinct in HNSCC TIL, and are highly effective at inhibiting T cell proliferation despite high PD-1 expression.  IFN-γ induced by anti-PD-1 immunotherapy may be beneficial by reversing Tim-3+ Treg suppression. Copyright ©2018, American Association for Cancer Research.

Deciphering the Epigenetic Code in Embryonic and Dental Pulp Stem Cells

PubMed Central

Bayarsaihan, Dashzeveg

2016-01-01

A close cooperation between chromatin states, transcriptional modulation, and epigenetic modifications is required for establishing appropriate regulatory circuits underlying self-renewal and differentiation of adult and embryonic stem cells. A growing body of research has established that the epigenome topology provides a structural framework for engaging genes in the non-random chromosomal interactions to orchestrate complex processes such as cell-matrix interactions, cell adhesion and cell migration during lineage commitment. Over the past few years, the functional dissection of the epigenetic landscape has become increasingly important for understanding gene expression dynamics in stem cells naturally found in most tissues. Adult stem cells of the human dental pulp hold great promise for tissue engineering, particularly in the skeletal and tooth regenerative medicine. It is therefore likely that progress towards pulp regeneration will have a substantial impact on the clinical research. This review summarizes the current state of knowledge regarding epigenetic cues that have evolved to regulate the pluripotent differentiation potential of embryonic stem cells and the lineage determination of developing dental pulp progenitors. PMID:28018144

SH-SY5Y human neuroblastoma cell line: in vitro cell model of dopaminergic neurons in Parkinson's disease.

PubMed

Xie, Hong-rong; Hu, Lin-sen; Li, Guo-yi

2010-04-20

To evaluate the human neuroblastoma SH-SY5Y cell line as an in vitro model of dopaminergic (DAergic) neurons for Parkinson's disease (PD) research and to determine the effect of differentiation on this cell model. The data of this review were selected from the original reports and reviews related to SH-SY5Y cells published in Chinese and foreign journals (Pubmed 1973 to 2009). After searching the literature, 60 articles were selected to address this review. The SH-SY5Y cell line has become a popular cell model for PD research because this cell line posses many characteristics of DAergic neurons. For example, these cells express tyrosine hydroxylase and dopamine-beta-hydroxylase, as well as the dopamine transporter. Moreover, this cell line can be differentiated into a functionally mature neuronal phenotype in the presence of various agents. Upon differentiation, SH-SY5Y cells stop proliferating and a constant cell number is subsequently maintained. However, different differentiating agents induce different neuronal phenotypes and biochemical changes. For example, retinoic acid induces differentiation toward a cholinergic neuronal phenotype and increases the susceptibility of SH-SY5Y cells to neurotoxins and neuroprotective agents, whereas treatment with retinoic acid followed by phorbol ester 12-O-tetradecanoylphorbol-13-acetate results in a DAergic neuronal phenotype and decreases the susceptibility of cells to neurotoxins and neuroprotective agents. Some differentiating agents also alter kinetics of 1-methyl-4-phenyl-pyridinium (MPP(+)) uptake, making SH-SY5Y cells more similar to primary mesencephalic neurons. Differentiated and undifferentiated SH-SY5Y cells have been widely used as a cell model of DAergic neurons for PD research. Some differentiating agents afford SH-SY5Y cells with more potential for studying neurotoxicity and neuroprotection and are thus more relevant to experimental PD research.

A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

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

Brückner, Sandra, E-mail: sandra.brueckner@medizin.uni-leipzig.de; Tautenhahn, Hans-Michael, E-mail: hans-michael.tautenhahn@medizin.uni-leipzig.de; TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103

Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention inmore » the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte differentiation of porcine adipose tissue-derived MSC was shown for the first time yielding hepatocyte-like cells with specific functions similar in bone marrow and subcutaneous adipose tissue-derived MSC. That makes them good pre-clinical candidates for supportive approaches after liver resection in the pig. - Highlights: • First time to show hepatocytic differentiation of porcine adipose tissue-derived MSC. • Hepatocytic-differentiated MSC display metabolic qualities of primary hepatocytes. • Metabolic potency varies between differentiated MSC from different tissues. • MSC are good candidates for pre-clinical evaluation of stem cell-based therapies.« less

Skeletal myoblasts for heart regeneration and repair: state of the art and perspectives on the mechanisms for functional cardiac benefits.

PubMed

Formigli, L; Zecchi-Orlandini, S; Meacci, E; Bani, D

2010-01-01

Until recently, skeletal myoblasts (SkMBs) have been the most widely used cells in basic research and clinical trials of cell based therapy for cardiac repair and regeneration. Although SkMB engraftment into the post-infarcted heart has been consistently found to improve cardiac contractile function, the underlying therapeutic mechanisms remain still a matter of controversy and debate. This is basically because SkMBs do not attain a cardiac-like phenotype once homed into the diseased heart nor they form a contractile tissue functionally coupled with the surrounding viable myocardium. This issue of concern has generated the idea that the cardiotropic action of SkMBs may depend on the release of paracrine factors. However, the paracrine hypothesis still remains ill-defined, particularly concerning the identification of the whole spectrum of cell-derived soluble factors and details on their cardiac effects. In this context, the possibility to genetically engineering SkMBs to potentate their paracrine attitudes appears particularly attractive and is actually raising great expectation. Aim of the present review is not to cover all the aspects of cell-based therapy with SkMBs, as this has been the object of previous exhaustive reviews in this field. Rather, we focused on novel aspects underlying the interactions between SkMBs and the host cardiac tissues which may be relevant for directing the future basic and applied research on SkMB transplantation for post ischemic cardiac dysfunction.

Organizing human functioning and rehabilitation research into distinct scientific fields. Part I: Developing a comprehensive structure from the cell to society.

PubMed

Stucki, Gerold; Grimby, Gunnar

2007-05-01

There is a need to organize rehabilitation and related research into distinct scientific fields in order to overcome the current limitations of rehabilitation research. Based on the general distinction in basic, applied and professional sciences applicable to research in general, and the rehabilitation relevant distinction between the comprehensive perspective based on WHO's integrative model of human functioning (ICF) and the partial perspective focusing on the biomedical aspects of functioning, it is possible to identify 5 distinct scientific fields of human functioning and rehabilitation research. These are the emerging human functioning sciences and integrative rehabilitation sciences from the comprehensive perspective, the established biosciences and biomedical rehabilitation sciences and engineering from the partial perspective, and the professional rehabilitation sciences at the cutting edge of research and practice. The human functioning sciences aim to understand human functioning and to identify targets for comprehensive interventions, with the goal of contributing to the minimization of the experience of disability in the population. The biosciences in rehabilitation aim to explain body injury and repair and to identify targets for biomedical interventions. The integrative rehabilitation sciences design and study comprehensive assessments and interventions that integrate biomedical, personal factor and environmental approaches suited to optimize people's performance. The biomedical rehabilitation sciences and engineering study diagnostic measures and interventions suitable to minimize impairment, including symptom control, and to optimize people's capacity. The professional rehabilitation sciences study how to provide best care with the goal of enabling people with health conditions experiencing or likely to experience disability to achieve and maintain optimal functioning in interaction with the environment. The organization of human functioning and rehabilitation research into the 5 distinct scientific fields facilitates the development of academic training programs and career building as well as the development of research structures dedicated to human functioning and rehabilitation research.

Alteration of Lymphocyte Phenotype and Function in Sickle Cell Anemia: Implications for Vaccine Responses

PubMed Central

Balandya, Emmanuel; Reynolds, Teri; Obaro, Stephen; Makani, Julie

2016-01-01

Individuals with sickle cell anemia (SCA) have increased susceptibility to infections, secondary to impairment of immune function. Besides the described dysfunction in innate immunity, including impaired opsonization and phagocytosis of bacteria, evidence of dysfunction of T and B lymphocytes in SCA has also been reported. This includes reduction in the proportion of circulating CD4+ and CD8+ T cells, reduction of CD4+ helper : CD8+ suppressor T cell ratio, aberrant activation and dysfunction of regulatory T cells (Treg), skewing of CD4+ T cells towards Th2 response and loss of IgM-secreting CD27+IgMhighIgDlow memory B cells. These changes occur on the background of immune activation characterized by predominance of memory CD4+ T cell phenotypes, increased Th17 signaling and elevated levels of C-reactive protein and pro-inflammatory cytokines IL-6 and TNF-α, which may affect the immunogenicity and protective efficacy of vaccines available to prevent infections in SCA. Thus, in order to optimize the use of vaccines in SCA, a thorough understanding of T and B lymphocyte functions and vaccine reactivity among individuals with SCA is needed. Studies should be encouraged of different SCA populations, including sub-Saharan Africa where the burden of SCA is highest. This article summarizes our current understanding of lymphocyte biology in SCA, and highlights areas that warrant future research. PMID:27237467

Electrophysiological properties of neurons derived from human stem cells and iNeurons in vitro.

PubMed

Halliwell, Robert F

2017-06-01

Functional studies of neurons have traditionally used nervous system tissues from a variety of non-human vertebrate and invertebrate species, even when the focus of much of this research has been directed at understanding human brain function. Over the last decade, the identification and isolation of human stem cells from embryonic, tissue (or adult) and induced pluripotent stem cells (iPSCs) has revolutionized the availability of human neurons for experimental studies in vitro. In addition, the direct conversion of terminally differentiated fibroblasts into Induced neurons (iN) has generated great excitement because of the likely value of such human stem cell derived neurons (hSCNs) and iN cells in drug discovery, neuropharmacology, neurotoxicology and regenerative medicine. This review addresses the current state of our knowledge of functional receptors and ion channels expressed in neurons derived from human stem cells and iNeurons and identifies gaps and questions that might be investigated in future studies; it focusses almost exclusively on what is known about the electrophysiological properties of neurons derived from human stem cells and iN cells in vitro with an emphasis on voltage and ligand gated ion channels, since these mediate synaptic signalling in the nervous system and they are at the heart of neuropharmacology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Visualizing High-Efficiency HIV Transfer | Center for Cancer Research

Cancer.gov

The Human Immunodeficiency Virus (HIV), the causative agent of Acquired Immunodeficiency Syndrome (AIDS), infects and eventually kills CD4 receptor-expressing T cells, which are critical for proper immune system function. The gp120 protein on the surface of HIV particles is known to bind CD4 and a co-receptor, either CCR5 or CXCR4, leading to fusion of the virus and T cell

HDAC Inhibitors Target Replication Forks to Take a Stab at Cancer | Center for Cancer Research

Cancer.gov

The stability and function of many proteins within the cell can be altered with the addition or removal of certain chemical groups, including acetyl groups. Therefore, the enzymes that regulate these modifications have an important impact on the cell. One class of such enzymes—histone deacetylases, or HDACs—has been implicated in cancer and has become a target for cancer

Effects of Radiation on Proteasome Function in Prostate Cancer Cells

DTIC Science & Technology

2012-02-01

California Breast Cancer Research Program Innovative Development and Exploratory Award (IDEA) Competitive Renewal Modulation of...Weissman IL. Establishment of a normal hemato- poietic and leukemia stem cell hierarchy. Cold Spring Harb Symp Quant Biol 2008;73:439–449. 9 Trott KR...existence of CSCs in solid cancer has been advocated by radiobiologists for decades [Withers et al., 1988; Trott , 1994]. However, until recently this

Sexy again: the renaissance of neutrophils in psoriasis.

PubMed

Schön, Michael P; Broekaert, Sigrid M C; Erpenbeck, Luise

2017-04-01

Notwithstanding their prominent presence in psoriatic skin, the functional role of neutrophilic granulocytes still remains somewhat enigmatic. Sparked by exciting scientific discoveries regarding neutrophil functions within the last years, the interest in these short-lived cells of the innate immune system has been boosted recently. While it had been known for some time that neutrophils produce and respond to a number of inflammatory mediators, recent research has linked neutrophils with the pathogenic functions of IL-17, possibly in conjunction with the formation of NETs (neutrophil extracellular traps). Antipsoriatic therapies exert their effects, at least in part, through interference with neutrophils. Neutrophils also appear to connect psoriasis with comorbid diseases. However, directly tampering with neutrophil functions is not trivial as evinced by the failure of therapeutic approaches targeting redundantly regulated cellular communication networks. It has also become apparent that neutrophils link important pathogenic functions of the innate and the adaptive immune system and that they are intricately involved in regulatory networks underlying the pathophysiology of psoriasis. In order to advocate intensified research into the role of this interesting cell population, we here highlight some features of neutrophils and put them into perspective with our current view of the pathophysiology of psoriasis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Engineering of microscale three-dimensional pancreatic islet models in vitro and their biomedical applications.

PubMed

Gao, Bin; Wang, Lin; Han, Shuang; Pingguan-Murphy, Belinda; Zhang, Xiaohui; Xu, Feng

2016-08-01

Diabetes now is the most common chronic disease in the world inducing heavy burden for the people's health. Based on this, diabetes research such as islet function has become a hot topic in medical institutes of the world. Today, in medical institutes, the conventional experiment platform in vitro is monolayer cell culture. However, with the development of micro- and nano-technologies, several microengineering methods have been developed to fabricate three-dimensional (3D) islet models in vitro which can better mimic the islet of pancreases in vivo. These in vitro islet models have shown better cell function than monolayer cells, indicating their great potential as better experimental platforms to elucidate islet behaviors under both physiological and pathological conditions, such as the molecular mechanisms of diabetes and clinical islet transplantation. In this review, we present the state-of-the-art advances in the microengineering methods for fabricating microscale islet models in vitro. We hope this will help researchers to better understand the progress in the engineering 3D islet models and their biomedical applications such as drug screening and islet transplantation.

Congenital hypoplasia of the cerebellum: developmental causes and behavioral consequences

PubMed Central

Basson, M. Albert; Wingate, Richard J.

2013-01-01

Over the last 60 years, the spotlight of research has periodically returned to the cerebellum as new techniques and insights have emerged. Because of its simple homogeneous structure, limited diversity of cell types and characteristic behavioral pathologies, the cerebellum is a natural home for studies of cell specification, patterning, and neuronal migration. However, recent evidence has extended the traditional range of perceived cerebellar function to include modulation of cognitive processes and implicated cerebellar hypoplasia and Purkinje neuron hypo-cellularity with autistic spectrum disorder. In the light of this emerging frontier, we review the key stages and genetic mechanisms behind cerebellum development. In particular, we discuss the role of the midbrain hindbrain isthmic organizer in the development of the cerebellar vermis and the specification and differentiation of Purkinje cells and granule neurons. These developmental processes are then considered in relation to recent insights into selected human developmental cerebellar defects: Joubert syndrome, Dandy–Walker malformation, and pontocerebellar hypoplasia. Finally, we review current research that opens up the possibility of using the mouse as a genetic model to study the role of the cerebellum in cognitive function. PMID:24027500

Type 1 Diabetes TrialNet--an international collaborative clinical trials network.

PubMed

Skyler, Jay S; Greenbaum, Carla J; Lachin, John M; Leschek, Ellen; Rafkin-Mervis, Lisa; Savage, Peter; Spain, Lisa

2008-12-01

Type 1 Diabetes TrialNet is an international consortium of clinical research centers aimed at the prevention or delay of type 1 diabetes (T1D). The fundamental goal of TrialNet is to counter the T1D disease process by immune modulation and/or enhancement of beta cell proliferation and regeneration. To achieve this goal, TrialNet researchers are working to better understand the natural history of the disease, to identify persons at risk, and to clinically evaluate novel therapies that balance potential risks and benefits. The particular focus is on studies of preventive measures. In addition, TrialNet evaluates therapies in individuals with newly diagnosed T1D with preserved beta cell function to help determine the risk/benefit profile and gain an initial assessment of potential efficacy in preservation of beta cell function, so that promising agents can be studied in prevention trials. In addition, TrialNet evaluates methodologies that enhance the conduct of its clinical trials, which includes tests of outcome assessment methodology, the evaluation of surrogate markers, and mechanistic studies laying the foundation for future clinical trials.

Subversion of plant cellular functions by bacterial type-III effectors: beyond suppression of immunity.

PubMed

Macho, Alberto P

2016-04-01

Most bacterial plant pathogens employ a type-III secretion system to inject type-III effector (T3E) proteins directly inside plant cells. These T3Es manipulate host cellular processes in order to create a permissive niche for bacterial proliferation, allowing development of the disease. An important role of T3Es in plant pathogenic bacteria is the suppression of plant immune responses. However, in recent years, research has uncovered T3E functions different from direct immune suppression, including the modulation of plant hormone signaling, metabolism or organelle function. This insight article discusses T3E functions other than suppression of immunity, which may contribute to the modulation of plant cells in order to promote bacterial survival, nutrient release, and bacterial replication and dissemination. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

A bio-inspired design of live cell biosensors

NASA Astrophysics Data System (ADS)

Marcek Chorvatova, A.; Teplicky, T.; Pavlinska, Z.; Kronekova, Z.; Trelova, D.; Razga, F.; Nemethova, V.; Uhelska, L.; Lacik, I.; Chorvat, D.

2018-02-01

The last decade has witnessed a rapid growth of nanoscale-oriented biosensors that becomes one of the most promising and rapidly growing areas of modern research. Despite significant advancements in conception of such biosensors, most are based at evaluation of molecular, or protein interactions. It is however becoming increasingly evident that functionality of a living system does not reside in genome or in individual proteins, as no real biological functionality is expressed at these levels. Instead, to comprehend the true functioning of a biological system, it is essential to understand the integrative physiological behavior of the complex molecular interactions in their natural environment and precise spatio-temporal topology. In this contribution we therefore present a new concept for creation of biosensors, bio-inspired from true functioning of living cells, while monitoring their endogenous fluorescence, or autofluorescence.

Naturally Engineered Maturation of Cardiomyocytes

PubMed Central

Scuderi, Gaetano J.; Butcher, Jonathan

2017-01-01

Ischemic heart disease remains one of the most prominent causes of mortalities worldwide with heart transplantation being the gold-standard treatment option. However, due to the major limitations associated with heart transplants, such as an inadequate supply and heart rejection, there remains a significant clinical need for a viable cardiac regenerative therapy to restore native myocardial function. Over the course of the previous several decades, researchers have made prominent advances in the field of cardiac regeneration with the creation of in vitro human pluripotent stem cell-derived cardiomyocyte tissue engineered constructs. However, these engineered constructs exhibit a functionally immature, disorganized, fetal-like phenotype that is not equivalent physiologically to native adult cardiac tissue. Due to this major limitation, many recent studies have investigated approaches to improve pluripotent stem cell-derived cardiomyocyte maturation to close this large functionality gap between engineered and native cardiac tissue. This review integrates the natural developmental mechanisms of cardiomyocyte structural and functional maturation. The variety of ways researchers have attempted to improve cardiomyocyte maturation in vitro by mimicking natural development, known as natural engineering, is readily discussed. The main focus of this review involves the synergistic role of electrical and mechanical stimulation, extracellular matrix interactions, and non-cardiomyocyte interactions in facilitating cardiomyocyte maturation. Overall, even with these current natural engineering approaches, pluripotent stem cell-derived cardiomyocytes within three-dimensional engineered heart tissue still remain mostly within the early to late fetal stages of cardiomyocyte maturity. Therefore, although the end goal is to achieve adult phenotypic maturity, more emphasis must be placed on elucidating how the in vivo fetal microenvironment drives cardiomyocyte maturation. This information can then be utilized to develop natural engineering approaches that can emulate this fetal microenvironment and thus make prominent progress in pluripotent stem cell-derived maturity toward a more clinically relevant model for cardiac regeneration. PMID:28529939

Mechanisms of T-Cell Immunosuppression by Mesenchymal Stromal Cells: What Do We Know So Far?

PubMed Central

Haddad, Rodrigo; Saldanha-Araujo, Felipe

2014-01-01

Mesenchymal stromal cells (MSCs) are multipotent cells, which can give rise to several cell types including osteoblasts, adipocytes, and chondroblasts. These cells can be found in a variety of adult and fetal tissues, such as bone marrow, adipose tissue, cord blood, and placenta. In recent years, the biological properties of MSCs have attracted the attention of researchers worldwide due to their potential application for treating a series of clinical situations. Among these properties, special attention should be given to the immunoregulatory potential of those cells. MSCs are able to act on all cells of the immune system, which includes the capacity to inhibit the proliferation and function of T-cells. This feature renders them natural candidates to treat several diseases in which cellular immune response is exacerbated. In this review, we outline the main mechanisms by which MSCs immunosuppress T-cell response, focusing on cell-cell contact, secretion of soluble factors, and regulatory T-cell generation. The influence of surface markers in the immunosuppression process and features of MSCs isolated from different sources are also discussed. Finally, the influences of toll-like receptors and cytokines on the inflammatory microenvironment are highlighted regarding the activation of MSCs to exert their immunoregulatory function. PMID:25025040

Integrated Micro/nanoengineered Functional Biomaterials for Cell Mechanics and Mechanobiology: A Materials Perspective

PubMed Central

Shao, Yue

2014-01-01

The rapid development of micro/nanoengineered functional biomaterials in the last two decades has empowered materials scientists and bioengineers to precisely control different aspects of the in vitro cell microenvironment. Following a philosophy of reductionism, many studies using synthetic functional biomaterials have revealed instructive roles of individual extracellular biophysical and biochemical cues in regulating cellular behaviors. Development of integrated micro/nanoengineered functional biomaterials to study complex and emergent biological phenomena has also thrived rapidly in recent years, revealing adaptive and integrated cellular behaviors closely relevant to human physiological and pathological conditions. Working at the interface between materials science and engineering, biology, and medicine, we are now at the beginning of a great exploration using micro/nanoengineered functional biomaterials for both fundamental biology study and clinical and biomedical applications such as regenerative medicine and drug screening. In this review, we present an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions and highlight them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. We also discuss the recent exciting trend where micro/nanoengineered biomaterials are integrated into miniaturized biological and biomimetic systems for dynamic multiparametric microenvironmental control of emergent and integrated cellular behaviors. The impact of integrated micro/nanoengineered functional biomaterials for future in vitro studies of regenerative medicine, cell biology, as well as human development and disease models are discussed. PMID:24339188

Concise Review: Fluorescent Reporters in Human Pluripotent Stem Cells: Contributions to Cardiac Differentiation and Their Applications in Cardiac Disease and Toxicity.

PubMed

Den Hartogh, Sabine C; Passier, Robert

2016-01-01

In the last decade, since the first report of induced pluripotent stem cells, the stem cell field has made remarkable progress in the differentiation to specialized cell-types of various tissues and organs, including the heart. Cardiac lineage- and tissue-specific human pluripotent stem cell (hPSC) reporter lines have been valuable for the identification, selection, and expansion of cardiac progenitor cells and their derivatives, and for our current understanding of the underlying molecular mechanisms. In order to further advance the use of hPSCs in the fields of regenerative medicine, disease modeling, and preclinical drug development in cardiovascular research, it is crucial to identify functionally distinct cardiac subtypes and to study their biological signaling events and functional aspects in healthy and diseased conditions. In this review, we discuss the various strategies that have been followed to generate and study fluorescent reporter lines in hPSCs and provide insights how these reporter lines contribute to a better understanding and improvement of cell-based therapies and preclinical drug and toxicity screenings in the cardiac field. © AlphaMed Press.

Scanning electrochemical microscopy based evaluation of influence of pH on bioelectrochemical activity of yeast cells - Saccharomyces cerevisiae.

PubMed

Ramanavicius, A; Morkvenaite-Vilkonciene, I; Kisieliute, A; Petroniene, J; Ramanaviciene, A

2017-01-01

In this research scanning electrochemical microscopy was applied for the investigation of immobilized yeast Saccharomyces cerevisiae cells. Two redox mediators based system was applied in order to increase the efficiency of charge transfer from yeast cells. 9,10-phenanthrenequinone (PQ) was applied as a lipophilic redox mediator, which has the ability to cross the cell's membrane; another redox mediator was ferricyanide, which acted as a hydrophylic electron acceptor able to transfer electrons from the PQ to the working electrode of SECM. Hill's function was applied to determine the optimal pH for this described SECM-based system. The influence of pH on cell viability could be well described by Hill's function. It was determined that at pH 6.5 the PQ has a minimal toxic influence on yeast cells, and the kinetics of metabolic processes in cells as well as electron transfer rate achieved in consecutive action of both redox mediators were appropriate to achieve optimal current signals. Copyright © 2016 Elsevier B.V. All rights reserved.

Dissecting Immune Circuits by Linking CRISPR-Pooled Screens with Single-Cell RNA-Seq.

PubMed

Jaitin, Diego Adhemar; Weiner, Assaf; Yofe, Ido; Lara-Astiaso, David; Keren-Shaul, Hadas; David, Eyal; Salame, Tomer Meir; Tanay, Amos; van Oudenaarden, Alexander; Amit, Ido

2016-12-15

In multicellular organisms, dedicated regulatory circuits control cell type diversity and responses. The crosstalk and redundancies within these circuits and substantial cellular heterogeneity pose a major research challenge. Here, we present CRISP-seq, an integrated method for massively parallel single-cell RNA sequencing (RNA-seq) and clustered regularly interspaced short palindromic repeats (CRISPR)-pooled screens. We show that profiling the genomic perturbation and transcriptome in the same cell enables us to simultaneously elucidate the function of multiple factors and their interactions. We applied CRISP-seq to probe regulatory circuits of innate immunity. By sampling tens of thousands of perturbed cells in vitro and in mice, we identified interactions and redundancies between developmental and signaling-dependent factors. These include opposing effects of Cebpb and Irf8 in regulating the monocyte/macrophage versus dendritic cell lineages and differential functions for Rela and Stat1/2 in monocyte versus dendritic cell responses to pathogens. This study establishes CRISP-seq as a broadly applicable, comprehensive, and unbiased approach for elucidating mammalian regulatory circuits. Copyright © 2016 Elsevier Inc. All rights reserved.

Kidney regeneration by xeno-embryonic nephrogenesis.

PubMed

Yokoo, Takashi; Fukui, Akira; Matsumoto, Kei; Kawamura, Tetsuya

2008-03-01

Establishment of a functional whole kidney de novo has not received much attention because of the formidable challenges and the slow pace of advances in this field of research. This situation has changed recently with publication of data revealing the catastrophic nature of Medicaid costs for dialysis-related diseases. An innovative approach is needed in our search for therapies for kidney diseases and to provide a substitute for dialysis as soon as possible. Regenerative medicine offers great hope for realizing this goal. We established a system by which human mesenchymal stem cells can differentiate into a functional renal unit using a program of nephrogenesis in a developing xeno-embryo. In this article, recent research in the field of developing whole kidneys is reviewed, and possible therapeutic applications for kidney diseases are proposed in combination with our knowledge of the emerging field of kidney stem cell biology.

Massage Therapy Research Review

PubMed Central

Field, Tiffany

2017-01-01

Moderate pressure massage has contributed to many positive effects including increased weight gain in preterm infants, reduced pain in different syndromes including fibromyalgia and rheumatoid arthritis, enhanced attentiveness, reduced depression and enhanced immune function (increased natural killer cells and natural killer cell activity). Surprisingly, these recent studies have not been reviewed, highlighting the need for the current review. When moderate and light pressure massage have been compared in laboratory studies, moderate pressure massage reduced depression, anxiety and heart rate, and it altered EEG patterns, as in a relaxation response. Moderate pressure massage has also led to increased vagal activity and decreased cortisol levels. Functional magnetic resonance imaging data have suggested that moderate pressure massage was represented in several brain regions including the amygdala, the hypothalamus and the anterior cingulate cortex, all areas involved in stress and emotion regulation. Further research is needed to identify underlying neurophysiological and biochemical mechanisms associated with moderate pressure massage. PMID:25172313

Research on B Cell Algorithm for Learning to Rank Method Based on Parallel Strategy.

PubMed

Tian, Yuling; Zhang, Hongxian

2016-01-01

For the purposes of information retrieval, users must find highly relevant documents from within a system (and often a quite large one comprised of many individual documents) based on input query. Ranking the documents according to their relevance within the system to meet user needs is a challenging endeavor, and a hot research topic-there already exist several rank-learning methods based on machine learning techniques which can generate ranking functions automatically. This paper proposes a parallel B cell algorithm, RankBCA, for rank learning which utilizes a clonal selection mechanism based on biological immunity. The novel algorithm is compared with traditional rank-learning algorithms through experimentation and shown to outperform the others in respect to accuracy, learning time, and convergence rate; taken together, the experimental results show that the proposed algorithm indeed effectively and rapidly identifies optimal ranking functions.

Research on B Cell Algorithm for Learning to Rank Method Based on Parallel Strategy

PubMed Central

Tian, Yuling; Zhang, Hongxian

2016-01-01

For the purposes of information retrieval, users must find highly relevant documents from within a system (and often a quite large one comprised of many individual documents) based on input query. Ranking the documents according to their relevance within the system to meet user needs is a challenging endeavor, and a hot research topic–there already exist several rank-learning methods based on machine learning techniques which can generate ranking functions automatically. This paper proposes a parallel B cell algorithm, RankBCA, for rank learning which utilizes a clonal selection mechanism based on biological immunity. The novel algorithm is compared with traditional rank-learning algorithms through experimentation and shown to outperform the others in respect to accuracy, learning time, and convergence rate; taken together, the experimental results show that the proposed algorithm indeed effectively and rapidly identifies optimal ranking functions. PMID:27487242

Massage therapy research review.

PubMed

Field, Tiffany

2014-11-01

Moderate pressure massage has contributed to many positive effects including increased weight gain in preterm infants, reduced pain in different syndromes including fibromyalgia and rheumatoid arthritis, enhanced attentiveness, reduced depression and enhanced immune function (increased natural killer cells and natural killer cell activity).Surprisingly, these recent studies have not been reviewed, highlighting the need for the current review. When moderate and light pressure massage have been compared in laboratory studies, moderate pressure massage reduced depression, anxiety and heart rate, and it altered EEG patterns, as in a relaxation response. Moderate pressure massage has also led to increased vagal activity and decreased cortisol levels. Functional magnetic resonance imaging data have suggested that moderate pressure massage was represented in several brain regions including the amygdala, the hypothalamus and the anterior cingulate cortex, all areas involved in stress and emotion regulation. Further research is needed to identify underlying neurophysiological and biochemical mechanisms associated with moderate pressure massage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production and Functional Characterization of Murine Osteoclasts Differentiated from ER-Hoxb8-Immortalized Myeloid Progenitor Cells.

PubMed

Zach, Frank; Mueller, Alexandra; Gessner, André

2015-01-01

In vitro differentiation into functional osteoclasts is routinely achieved by incubation of embryonic stem cells, induced pluripotent stem cells, or primary as well as cryopreserved spleen and bone marrow-derived cells with soluble receptor activator of nuclear factor kappa-B ligand and macrophage colony-stimulating factor. Additionally, osteoclasts can be derived from co-cultures with osteoblasts or by direct administration of soluble receptor activator of nuclear factor kappa-B ligand to RAW 264.7 macrophage lineage cells. However, despite their benefits for osteoclast-associated research, these different methods have several drawbacks with respect to differentiation yields, time and animal consumption, storage life of progenitor cells or the limited potential for genetic manipulation of osteoclast precursors. In the present study, we therefore established a novel protocol for the differentiation of osteoclasts from murine ER-Hoxb8-immortalized myeloid stem cells. We isolated and immortalized bone marrow cells from wild type and genetically manipulated mouse lines, optimized protocols for osteoclast differentiation and compared these cells to osteoclasts derived from conventional sources. In vitro generated ER-Hoxb8 osteoclasts displayed typical osteoclast characteristics such as multi-nucleation, tartrate-resistant acid phosphatase staining of supernatants and cells, F-actin ring formation and bone resorption activity. Furthermore, the osteoclast differentiation time course was traced on a gene expression level. Increased expression of osteoclast-specific genes and decreased expression of stem cell marker genes during differentiation of osteoclasts from ER-Hoxb8-immortalized myeloid progenitor cells were detected by gene array and confirmed by semi-quantitative and quantitative RT-PCR approaches. In summary, we established a novel method for the quantitative production of murine bona fide osteoclasts from ER-Hoxb8 stem cells generated from wild type or genetically manipulated mouse lines. These cells represent a standardized and theoretically unlimited source for osteoclast-associated research projects.

The Drosophila T-box transcription factor Midline functions within the Notch-Delta signaling pathway to specify sensory organ precursor cell fates and regulates cell survival within the eye imaginal disc.

PubMed

Das, Sudeshna; Chen, Q Brent; Saucier, Joseph D; Drescher, Brandon; Zong, Yan; Morgan, Sarah; Forstall, John; Meriwether, Andrew; Toranzo, Randy; Leal, Sandra M

2013-01-01

We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch-Delta signaling pathway essential for specifying the fates of sensory organ precursor (SOP) cells. These findings complement an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in unique neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch-Delta signaling hierarchy and is essential for maintaining cell viability by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Tumor Associated Mesenchymal Stromal Cells Show Higher Immunosuppressive and Angiogenic Properties Compared to Adipose Derived MSCs.

PubMed

Langroudi, Ladan; Hassan, Zuhair Muhammad; Soleimani, Masoud; Hashemi, Seyed Mahmoud

2015-12-01

Differentiation, migratory properties and availability of Mesenchymal Stromal Cells (MSC) have become an important part of biomedical research. However, the functional heterogeneity of cells derived from different tissues has hampered providing definitive phenotypic markers for these cells. To characterize and compare the phenotype and cytokines of adipose derived MSCs (AD-MSCs) and tumoral-MSCs (T-MSCs) isolated from mammary tumors of BALB/c mice. Immunophenotyping and in vitro differentiation tests were used for MSC characterization. Cytokine and enzyme profiles were assessed using ELISA and Real-time PCR, respectively. T-MSCs expressed significantly higher levels of HLA-DR (p=0.04). Higher levels of PGE2 and COX-2 enzyme were also observed in T-MSCs (p=0.07 and p=0.00, respectively). Additionally, T-MSCs expressed higher levels of iNOS and MMP9 (p=0.01 and p=0.01, respectively). T-MSCs were also able to induce higher levels of proliferation and migration of HUVEC endothelial cells in wound scratch assay compared to AD-MSCs (p=0.015). Functional differences showed by the surface markers of MSCs, cytokine and enzyme production indicate the effect of different microenvironments on MSCs phenotype and function.

Three-dimensional hydrogel cell culture systems for modeling neural tissue

NASA Astrophysics Data System (ADS)

Frampton, John

Two-dimensional (2-D) neural cell culture systems have served as physiological models for understanding the cellular and molecular events that underlie responses to physical and chemical stimuli, control sensory and motor function, and lead to the development of neurological diseases. However, the development of three-dimensional (3-D) cell culture systems will be essential for the advancement of experimental research in a variety of fields including tissue engineering, chemical transport and delivery, cell growth, and cell-cell communication. In 3-D cell culture, cells are provided with an environment similar to tissue, in which they are surrounded on all sides by other cells, structural molecules and adhesion ligands. Cells grown in 3-D culture systems display morphologies and functions more similar to those observed in vivo, and can be cultured in such a way as to recapitulate the structural organization and biological properties of tissue. This thesis describes a hydrogel-based culture system, capable of supporting the growth and function of several neural cell types in 3-D. Alginate hydrogels were characterized in terms of their biomechanical and biochemical properties and were functionalized by covalent attachment of whole proteins and peptide epitopes. Methods were developed for rapid cross-linking of alginate hydrogels, thus permitting the incorporation of cells into 3-D scaffolds without adversely affecting cell viability or function. A variety of neural cell types were tested including astrocytes, microglia, and neurons. Cells remained viable and functional for longer than two weeks in culture and displayed process outgrowth in 3-D. Cell constructs were created that varied in cell density, type and organization, providing experimental flexibility for studying cell interactions and behavior. In one set of experiments, 3-D glial-endothelial cell co-cultures were used to model blood-brain barrier (BBB) structure and function. This co-culture system was designed for use as a tool to predict the transport and processing that occurs prior to drug uptake in the central nervous system (CNS), and to predict BBB permeability. Electrochemical techniques and immunohistochemistry were used to validate this model and provide detailed information about cellular organization and function. Electrochemical impedance spectroscopy (EIS) provided evidence that endothelial cells cultured in the presence of astrocytes formed tight junctions capable of occluding the flow of electrical current. In a second series of experiments, a microglia-astrocyte co-culture system was developed to assess the effects of glial cells on electrode impedance recorded from neural prosthetic devices in vitro. Impedance measurements were compared with confocal images to determine the effects of glial cell density and cell type on electrode performance. The results indicate that EIS data can be used to model components of the reactive cell responses in brain tissue, and that impedance measurements recorded in vitro can be compared to measurements recorded in vivo. Taken together, these results demonstrate that alginate hydrogels can be used for the creation of 3-D neural cell scaffolds, and that such cell scaffolds can be used to model a variety of three-dimensional neural tissues in vitro, that cannot be studied in 2-D cultures.

Nano-biomedical approaches of cancer therapy using carbon based and magnetic nanomaterials

NASA Astrophysics Data System (ADS)

Karmakar, Alokita

Since the inception of nanoparticles, they have affected almost each and every field of modern science and technology both in terms of research and application. Due to its subcellular level size and ease of modification for biological and medical purposes, nanoparticles have contributed greatly in various field of biomedical reaserch including cancer research. In this dissertation, emphasis has been given on an important area of research of a multi-modal anticancer therapeutic approach using carbon-based and magnetic inorganic nanoparticles. Ethylenediamine functionalized single wall carbon nanotubes (SWNTs) have been used to deliver a functional copy of p53 gene in a plasmid construct, to human breast cancer cell line MCF-7, in order to restore the activity of p53 protein, which in this case is extremely short-lived. The attachment of the plasmid on the SWNTs was determined by atomic force microscopy. The nanutobe has successfully delivered the plasmid into the MCF-7 cell which follows the expression of the p53 protein into the cell as evidenced by the expression of Green fluorescence protein which was tagged to p53 plasmid. Upon expression, the functional activity of the p53 protein was found to be significantly restored as after 72 hours of incubation ~40% of cancer cells were apoptotic. Apoptosis was further determined by caspase assay. In chapter 3, we have used SWNTs to accomplish the targeted delivery by functionalizing it with human epidermal growth factor (EGF). As EGF receptor is over expressed in many of the cancer cells, it is possible to deliver any chemotherapeutic agents selectively to those cancer cells. We used EGF conjugated to SWNTs for targeted delivery to PANC-1 cells. Results indicate EGF-functionalized SWNTs accumulate more into PANC-1 cells compared to only SWNTs only. Upon targeting, Raman spectroscopy and ELIZA assay were used to determine the association and dissociation pattern of the targeted SWCNTs. 2D-Raman mapping was used to show the higher accumulation EGF targeted SWCNTs to PANC-1 cells. In chapter 4, we have explored the multimodality of nanotechnology by using EGF-functionalized iron cored, carbon shelled (FeC) magnetic nanoprticle that can generate heat when exposed to radiofrequency (RF). This process called hyperthermia, which is an effective way to kill different cancer cells as cancer cells are most susceptible to heat increase beyond a threshold level compared to normal cells. By targeting the nanoparticles this process was made more efficient by selectively populating magnetic nanoparticles specifically in cancer cells only. Two different cells line, MCF-7 and PANC-1 were incubated with the magnetic nanopartilces for 24 hours followed by exposure to the RF (350KHz, 5kW) for 10 min. EB/AO and flow-cytometry were used to determine the apoptotic and necrotic cells. EGF targeted FeC was superior in apoptosis induction in both cell lines, while the untargeted nanoparticles showed little effect. The MCF-7 cells were more vulnerable to the targeted FeC nanoparticles compared to PANC-1 cells. Caspase-8 and caspase-3 assays were done to provide the involvement of these two capsizes in two different cell lines. To enhance the therapeutic efficiency of anticancer drug, two FDA approved anticancer drugs doxorubicin and erlotinib were loaded on FeC nanoparticles (Chapter 5). The loading capacity was determined by UV-Vis spectroscopy. MTT assay was also used to determine the loaded and unloaded forms of drug. RF treatment was used to generate hyperthermia and which also helps in releasing the drug from nanoparticles. Flow-cytomertic detection of apoptosis showed above 90% cells died after combined hyperthermia and doxorubicin treatment. Graphene is a 2D carbon nanoparticle that has been proven to be an excellent carrier of chemotherapeutic drugs. In chapter 6, -COOH functionalized graphene (FG) was used to deliver a potent but extremely hydrophobic and water insoluble drug, parthenolide (PTL), to PANC-1 cells. WST-1 assay showed significant lowering of the IC50 value when PTL was delivered with FG compared to PLT alone. Results also indicate, Graphene mediated delivery of PTL increased intracellular reactive oxygen species (ROS) leading to disruption of mitochondrial membrane potential (MMP) and finally apoptosis. JC-1 assay was used to determine the MMP disruption. Flow-cytometry and caspase assay and fluorescence measurement were done to verify the apoptotic process. (Abstract shortened by UMI.)

Adaptive non-linear control for cancer therapy through a Fokker-Planck observer.

PubMed

Shakeri, Ehsan; Latif-Shabgahi, Gholamreza; Esmaeili Abharian, Amir

2018-04-01

In recent years, many efforts have been made to present optimal strategies for cancer therapy through the mathematical modelling of tumour-cell population dynamics and optimal control theory. In many cases, therapy effect is included in the drift term of the stochastic Gompertz model. By fitting the model with empirical data, the parameters of therapy function are estimated. The reported research works have not presented any algorithm to determine the optimal parameters of therapy function. In this study, a logarithmic therapy function is entered in the drift term of the Gompertz model. Using the proposed control algorithm, the therapy function parameters are predicted and adaptively adjusted. To control the growth of tumour-cell population, its moments must be manipulated. This study employs the probability density function (PDF) control approach because of its ability to control all the process moments. A Fokker-Planck-based non-linear stochastic observer will be used to determine the PDF of the process. A cost function based on the difference between a predefined desired PDF and PDF of tumour-cell population is defined. Using the proposed algorithm, the therapy function parameters are adjusted in such a manner that the cost function is minimised. The existence of an optimal therapy function is also proved. The numerical results are finally given to demonstrate the effectiveness of the proposed method.

FY09 Final Report for LDRD Project: Understanding Viral Quasispecies Evolution through Computation and Experiment

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

Zhou, C

2009-11-12

In FY09 they will (1) complete the implementation, verification, calibration, and sensitivity and scalability analysis of the in-cell virus replication model; (2) complete the design of the cell culture (cell-to-cell infection) model; (3) continue the research, design, and development of their bioinformatics tools: the Web-based structure-alignment-based sequence variability tool and the functional annotation of the genome database; (4) collaborate with the University of California at San Francisco on areas of common interest; and (5) submit journal articles that describe the in-cell model with simulations and the bioinformatics approaches to evaluation of genome variability and fitness.

An early history of T cell-mediated cytotoxicity.

PubMed

Golstein, Pierre; Griffiths, Gillian M

2018-04-16

After 60 years of intense fundamental research into T cell-mediated cytotoxicity, we have gained a detailed knowledge of the cells involved, specific recognition mechanisms and post-recognition perforin-granzyme-based and FAS-based molecular mechanisms. What could not be anticipated at the outset was how discovery of the mechanisms regulating the activation and function of cytotoxic T cells would lead to new developments in cancer immunotherapy. Given the profound recent interest in therapeutic manipulation of cytotoxic T cell responses, it is an opportune time to look back on the early history of the field. This Timeline describes how the early findings occurred and eventually led to current therapeutic applications.

In Vivo Reprogramming for CNS Repair: Regenerating Neurons from Endogenous Glial Cells

PubMed Central

Li, Hedong; Chen, Gong

2017-01-01

Neuroregeneration in the central nervous system (CNS) has proven to be difficult despite decades of research. The old dogma that CNS neurons cannot be regenerated in the adult mammalian brain has been overturned; however, endogenous adult neurogenesis appears to be insufficient for brain repair. Stem cell therapy once held promise for generating large quantities of neurons in the CNS, but immunorejection and long-term functional integration remain major hurdles. In this perspective, we discuss the use of in vivo reprogramming as an emerging technology to regenerate functional neurons from endogenous glial cells inside the brain and spinal cord. Besides the CNS, in vivo reprogramming has been demonstrated successfully in the pancreas, heart and liver, and may be adopted in other organs. Although challenges remain for translating this technology into clinical therapies, we anticipate that in vivo reprogramming may revolutionize regenerative medicine by using a patient’s own internal cells for tissue repair. PMID:27537482

Doxorubicin Action on Mitochondria: Relevance to Osteosarcoma Therapy?

PubMed

Armstrong, Jo; Dass, Crispin R

2018-01-01

The mitochondria may very well determine the final commitment of the cell to death, particularly in times of energy stress. Cancer chemotherapeutics such as the anthracycline doxorubicin perturb mitochondrial structure and function in tumour cells, as evidenced in osteosarcoma, for which doxorubicin is used clinically as frontline therapy. This same mechanism of cell inhibition is also pertinent to doxorubicin's primary cause of side-effects, that to the cardiac tissue, culminating in such dire events as congestive heart failure. Reactive oxygen species are partly to blame for this effect on the mitochondria, which impact the electron transport chain. As this review highlights that, there is much more to be learnt about the mitochondria and how it is affected by such effective but toxic drugs as doxorubicin. Such information will aid researchers who search for cancer treatment able to preserve mitochondrial number and function in normal cells. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Direct Reprogramming—The Future of Cardiac Regeneration?

PubMed Central

Doppler, Stefanie A.; Deutsch, Marcus-André; Lange, Rüdiger; Krane, Markus

2015-01-01

Today, the only available curative therapy for end stage congestive heart failure (CHF) is heart transplantation. This therapeutic option is strongly limited by declining numbers of available donor hearts and by restricted long-term performance of the transplanted graft. The disastrous prognosis for CHF with its restricted therapeutic options has led scientists to develop different concepts of alternative regenerative treatment strategies including stem cell transplantation or stimulating cell proliferation of different cardiac cell types in situ. However, first clinical trials with overall inconsistent results were not encouraging, particularly in terms of functional outcome. Among other approaches, very promising ongoing pre-clinical research focuses on direct lineage conversion of scar fibroblasts into functional myocardium, termed “direct reprogramming” or “transdifferentiation.” This review seeks to summarize strategies for direct cardiac reprogramming including the application of different sets of transcription factors, microRNAs, and small molecules for an efficient generation of cardiomyogenic cells for regenerative purposes. PMID:26230692

Development and Function of the Drosophila Tracheal System.

PubMed

Hayashi, Shigeo; Kondo, Takefumi

2018-06-01

The tracheal system of insects is a network of epithelial tubules that functions as a respiratory organ to supply oxygen to various target organs. Target-derived signaling inputs regulate stereotyped modes of cell specification, branching morphogenesis, and collective cell migration in the embryonic stage. In the postembryonic stages, the same set of signaling pathways controls highly plastic regulation of size increase and pattern elaboration during larval stages, and cell proliferation and reprograming during metamorphosis. Tracheal tube morphogenesis is also regulated by physicochemical interaction of the cell and apical extracellular matrix to regulate optimal geometry suitable for air flow. The trachea system senses both the external oxygen level and the metabolic activity of internal organs, and helps organismal adaptation to changes in environmental oxygen level. Cellular and molecular mechanisms underlying the high plasticity of tracheal development and physiology uncovered through research on Drosophila are discussed. Copyright © 2018 by the Genetics Society of America.